1/*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
30 */
31
32#include <sys/cdefs.h>
| 1/*-
2 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95
30 */
31
32#include <sys/cdefs.h>
|
33__FBSDID("$FreeBSD: head/sys/netinet/tcp_subr.c 215392 2010-11-16 08:30:39Z lstewart $");
| 33__FBSDID("$FreeBSD: head/sys/netinet/tcp_subr.c 215701 2010-11-22 19:32:54Z dim $");
|
34
35#include "opt_compat.h"
36#include "opt_inet.h"
37#include "opt_inet6.h"
38#include "opt_ipsec.h"
39#include "opt_tcpdebug.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/callout.h>
44#include <sys/kernel.h>
45#include <sys/sysctl.h>
46#include <sys/jail.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#ifdef INET6
50#include <sys/domain.h>
51#endif
52#include <sys/priv.h>
53#include <sys/proc.h>
54#include <sys/socket.h>
55#include <sys/socketvar.h>
56#include <sys/protosw.h>
57#include <sys/random.h>
58
59#include <vm/uma.h>
60
61#include <net/route.h>
62#include <net/if.h>
63#include <net/vnet.h>
64
65#include <netinet/cc.h>
66#include <netinet/in.h>
67#include <netinet/in_systm.h>
68#include <netinet/ip.h>
69#ifdef INET6
70#include <netinet/ip6.h>
71#endif
72#include <netinet/in_pcb.h>
73#ifdef INET6
74#include <netinet6/in6_pcb.h>
75#endif
76#include <netinet/in_var.h>
77#include <netinet/ip_var.h>
78#ifdef INET6
79#include <netinet6/ip6_var.h>
80#include <netinet6/scope6_var.h>
81#include <netinet6/nd6.h>
82#endif
83#include <netinet/ip_icmp.h>
84#include <netinet/tcp_fsm.h>
85#include <netinet/tcp_seq.h>
86#include <netinet/tcp_timer.h>
87#include <netinet/tcp_var.h>
88#include <netinet/tcp_syncache.h>
89#include <netinet/tcp_offload.h>
90#ifdef INET6
91#include <netinet6/tcp6_var.h>
92#endif
93#include <netinet/tcpip.h>
94#ifdef TCPDEBUG
95#include <netinet/tcp_debug.h>
96#endif
97#include <netinet6/ip6protosw.h>
98
99#ifdef IPSEC
100#include <netipsec/ipsec.h>
101#include <netipsec/xform.h>
102#ifdef INET6
103#include <netipsec/ipsec6.h>
104#endif
105#include <netipsec/key.h>
106#include <sys/syslog.h>
107#endif /*IPSEC*/
108
109#include <machine/in_cksum.h>
110#include <sys/md5.h>
111
112#include <security/mac/mac_framework.h>
113
114VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
115#ifdef INET6
116VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
117#endif
118
119static int
120sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
121{
122 int error, new;
123
124 new = V_tcp_mssdflt;
125 error = sysctl_handle_int(oidp, &new, 0, req);
126 if (error == 0 && req->newptr) {
127 if (new < TCP_MINMSS)
128 error = EINVAL;
129 else
130 V_tcp_mssdflt = new;
131 }
132 return (error);
133}
134
135SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
136 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
137 &sysctl_net_inet_tcp_mss_check, "I",
138 "Default TCP Maximum Segment Size");
139
140#ifdef INET6
141static int
142sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
143{
144 int error, new;
145
146 new = V_tcp_v6mssdflt;
147 error = sysctl_handle_int(oidp, &new, 0, req);
148 if (error == 0 && req->newptr) {
149 if (new < TCP_MINMSS)
150 error = EINVAL;
151 else
152 V_tcp_v6mssdflt = new;
153 }
154 return (error);
155}
156
157SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
158 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
159 &sysctl_net_inet_tcp_mss_v6_check, "I",
160 "Default TCP Maximum Segment Size for IPv6");
161#endif
162
163/*
164 * Minimum MSS we accept and use. This prevents DoS attacks where
165 * we are forced to a ridiculous low MSS like 20 and send hundreds
166 * of packets instead of one. The effect scales with the available
167 * bandwidth and quickly saturates the CPU and network interface
168 * with packet generation and sending. Set to zero to disable MINMSS
169 * checking. This setting prevents us from sending too small packets.
170 */
171VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
172SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
173 &VNET_NAME(tcp_minmss), 0,
174 "Minmum TCP Maximum Segment Size");
175
176VNET_DEFINE(int, tcp_do_rfc1323) = 1;
177SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
178 &VNET_NAME(tcp_do_rfc1323), 0,
179 "Enable rfc1323 (high performance TCP) extensions");
180
181static int tcp_log_debug = 0;
182SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
183 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
184
185static int tcp_tcbhashsize = 0;
186SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
187 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
188
189static int do_tcpdrain = 1;
190SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
191 "Enable tcp_drain routine for extra help when low on mbufs");
192
193SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
194 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
195
| 34
35#include "opt_compat.h"
36#include "opt_inet.h"
37#include "opt_inet6.h"
38#include "opt_ipsec.h"
39#include "opt_tcpdebug.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/callout.h>
44#include <sys/kernel.h>
45#include <sys/sysctl.h>
46#include <sys/jail.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#ifdef INET6
50#include <sys/domain.h>
51#endif
52#include <sys/priv.h>
53#include <sys/proc.h>
54#include <sys/socket.h>
55#include <sys/socketvar.h>
56#include <sys/protosw.h>
57#include <sys/random.h>
58
59#include <vm/uma.h>
60
61#include <net/route.h>
62#include <net/if.h>
63#include <net/vnet.h>
64
65#include <netinet/cc.h>
66#include <netinet/in.h>
67#include <netinet/in_systm.h>
68#include <netinet/ip.h>
69#ifdef INET6
70#include <netinet/ip6.h>
71#endif
72#include <netinet/in_pcb.h>
73#ifdef INET6
74#include <netinet6/in6_pcb.h>
75#endif
76#include <netinet/in_var.h>
77#include <netinet/ip_var.h>
78#ifdef INET6
79#include <netinet6/ip6_var.h>
80#include <netinet6/scope6_var.h>
81#include <netinet6/nd6.h>
82#endif
83#include <netinet/ip_icmp.h>
84#include <netinet/tcp_fsm.h>
85#include <netinet/tcp_seq.h>
86#include <netinet/tcp_timer.h>
87#include <netinet/tcp_var.h>
88#include <netinet/tcp_syncache.h>
89#include <netinet/tcp_offload.h>
90#ifdef INET6
91#include <netinet6/tcp6_var.h>
92#endif
93#include <netinet/tcpip.h>
94#ifdef TCPDEBUG
95#include <netinet/tcp_debug.h>
96#endif
97#include <netinet6/ip6protosw.h>
98
99#ifdef IPSEC
100#include <netipsec/ipsec.h>
101#include <netipsec/xform.h>
102#ifdef INET6
103#include <netipsec/ipsec6.h>
104#endif
105#include <netipsec/key.h>
106#include <sys/syslog.h>
107#endif /*IPSEC*/
108
109#include <machine/in_cksum.h>
110#include <sys/md5.h>
111
112#include <security/mac/mac_framework.h>
113
114VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
115#ifdef INET6
116VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
117#endif
118
119static int
120sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
121{
122 int error, new;
123
124 new = V_tcp_mssdflt;
125 error = sysctl_handle_int(oidp, &new, 0, req);
126 if (error == 0 && req->newptr) {
127 if (new < TCP_MINMSS)
128 error = EINVAL;
129 else
130 V_tcp_mssdflt = new;
131 }
132 return (error);
133}
134
135SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
136 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
137 &sysctl_net_inet_tcp_mss_check, "I",
138 "Default TCP Maximum Segment Size");
139
140#ifdef INET6
141static int
142sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
143{
144 int error, new;
145
146 new = V_tcp_v6mssdflt;
147 error = sysctl_handle_int(oidp, &new, 0, req);
148 if (error == 0 && req->newptr) {
149 if (new < TCP_MINMSS)
150 error = EINVAL;
151 else
152 V_tcp_v6mssdflt = new;
153 }
154 return (error);
155}
156
157SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
158 CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
159 &sysctl_net_inet_tcp_mss_v6_check, "I",
160 "Default TCP Maximum Segment Size for IPv6");
161#endif
162
163/*
164 * Minimum MSS we accept and use. This prevents DoS attacks where
165 * we are forced to a ridiculous low MSS like 20 and send hundreds
166 * of packets instead of one. The effect scales with the available
167 * bandwidth and quickly saturates the CPU and network interface
168 * with packet generation and sending. Set to zero to disable MINMSS
169 * checking. This setting prevents us from sending too small packets.
170 */
171VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
172SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
173 &VNET_NAME(tcp_minmss), 0,
174 "Minmum TCP Maximum Segment Size");
175
176VNET_DEFINE(int, tcp_do_rfc1323) = 1;
177SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
178 &VNET_NAME(tcp_do_rfc1323), 0,
179 "Enable rfc1323 (high performance TCP) extensions");
180
181static int tcp_log_debug = 0;
182SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
183 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
184
185static int tcp_tcbhashsize = 0;
186SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
187 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
188
189static int do_tcpdrain = 1;
190SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
191 "Enable tcp_drain routine for extra help when low on mbufs");
192
193SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
194 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
195
|
196STATIC_VNET_DEFINE(int, icmp_may_rst) = 1;
| 196static VNET_DEFINE(int, icmp_may_rst) = 1;
|
197#define V_icmp_may_rst VNET(icmp_may_rst)
198SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
199 &VNET_NAME(icmp_may_rst), 0,
200 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
201
| 197#define V_icmp_may_rst VNET(icmp_may_rst)
198SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
199 &VNET_NAME(icmp_may_rst), 0,
200 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
201
|
202STATIC_VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
| 202static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
|
203#define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
204SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
205 &VNET_NAME(tcp_isn_reseed_interval), 0,
206 "Seconds between reseeding of ISN secret");
207
208#ifdef TCP_SORECEIVE_STREAM
209static int tcp_soreceive_stream = 0;
210SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
211 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
212#endif
213
214VNET_DEFINE(uma_zone_t, sack_hole_zone);
215#define V_sack_hole_zone VNET(sack_hole_zone)
216
217static struct inpcb *tcp_notify(struct inpcb *, int);
218static void tcp_isn_tick(void *);
219static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
220 void *ip4hdr, const void *ip6hdr);
221
222/*
223 * Target size of TCP PCB hash tables. Must be a power of two.
224 *
225 * Note that this can be overridden by the kernel environment
226 * variable net.inet.tcp.tcbhashsize
227 */
228#ifndef TCBHASHSIZE
229#define TCBHASHSIZE 512
230#endif
231
232/*
233 * XXX
234 * Callouts should be moved into struct tcp directly. They are currently
235 * separate because the tcpcb structure is exported to userland for sysctl
236 * parsing purposes, which do not know about callouts.
237 */
238struct tcpcb_mem {
239 struct tcpcb tcb;
240 struct tcp_timer tt;
241 struct cc_var ccv;
242};
243
| 203#define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
204SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
205 &VNET_NAME(tcp_isn_reseed_interval), 0,
206 "Seconds between reseeding of ISN secret");
207
208#ifdef TCP_SORECEIVE_STREAM
209static int tcp_soreceive_stream = 0;
210SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
211 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
212#endif
213
214VNET_DEFINE(uma_zone_t, sack_hole_zone);
215#define V_sack_hole_zone VNET(sack_hole_zone)
216
217static struct inpcb *tcp_notify(struct inpcb *, int);
218static void tcp_isn_tick(void *);
219static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
220 void *ip4hdr, const void *ip6hdr);
221
222/*
223 * Target size of TCP PCB hash tables. Must be a power of two.
224 *
225 * Note that this can be overridden by the kernel environment
226 * variable net.inet.tcp.tcbhashsize
227 */
228#ifndef TCBHASHSIZE
229#define TCBHASHSIZE 512
230#endif
231
232/*
233 * XXX
234 * Callouts should be moved into struct tcp directly. They are currently
235 * separate because the tcpcb structure is exported to userland for sysctl
236 * parsing purposes, which do not know about callouts.
237 */
238struct tcpcb_mem {
239 struct tcpcb tcb;
240 struct tcp_timer tt;
241 struct cc_var ccv;
242};
243
|
244STATIC_VNET_DEFINE(uma_zone_t, tcpcb_zone);
| 244static VNET_DEFINE(uma_zone_t, tcpcb_zone);
|
245#define V_tcpcb_zone VNET(tcpcb_zone)
246
247MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
248struct callout isn_callout;
249static struct mtx isn_mtx;
250
251#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
252#define ISN_LOCK() mtx_lock(&isn_mtx)
253#define ISN_UNLOCK() mtx_unlock(&isn_mtx)
254
255/*
256 * TCP initialization.
257 */
258static void
259tcp_zone_change(void *tag)
260{
261
262 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
263 uma_zone_set_max(V_tcpcb_zone, maxsockets);
264 tcp_tw_zone_change();
265}
266
267static int
268tcp_inpcb_init(void *mem, int size, int flags)
269{
270 struct inpcb *inp = mem;
271
272 INP_LOCK_INIT(inp, "inp", "tcpinp");
273 return (0);
274}
275
276void
277tcp_init(void)
278{
279 int hashsize;
280
281 hashsize = TCBHASHSIZE;
282 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
283 if (!powerof2(hashsize)) {
284 printf("WARNING: TCB hash size not a power of 2\n");
285 hashsize = 512; /* safe default */
286 }
287 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
288 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE);
289
290 /*
291 * These have to be type stable for the benefit of the timers.
292 */
293 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
294 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
295 uma_zone_set_max(V_tcpcb_zone, maxsockets);
296
297 tcp_tw_init();
298 syncache_init();
299 tcp_hc_init();
300 tcp_reass_init();
301
302 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
303 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
304 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
305
306 /* Skip initialization of globals for non-default instances. */
307 if (!IS_DEFAULT_VNET(curvnet))
308 return;
309
310 /* XXX virtualize those bellow? */
311 tcp_delacktime = TCPTV_DELACK;
312 tcp_keepinit = TCPTV_KEEP_INIT;
313 tcp_keepidle = TCPTV_KEEP_IDLE;
314 tcp_keepintvl = TCPTV_KEEPINTVL;
315 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
316 tcp_msl = TCPTV_MSL;
317 tcp_rexmit_min = TCPTV_MIN;
318 if (tcp_rexmit_min < 1)
319 tcp_rexmit_min = 1;
320 tcp_rexmit_slop = TCPTV_CPU_VAR;
321 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
322 tcp_tcbhashsize = hashsize;
323
324#ifdef TCP_SORECEIVE_STREAM
325 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
326 if (tcp_soreceive_stream) {
327 tcp_usrreqs.pru_soreceive = soreceive_stream;
328 tcp6_usrreqs.pru_soreceive = soreceive_stream;
329 }
330#endif
331
332#ifdef INET6
333#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
334#else /* INET6 */
335#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
336#endif /* INET6 */
337 if (max_protohdr < TCP_MINPROTOHDR)
338 max_protohdr = TCP_MINPROTOHDR;
339 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
340 panic("tcp_init");
341#undef TCP_MINPROTOHDR
342
343 ISN_LOCK_INIT();
344 callout_init(&isn_callout, CALLOUT_MPSAFE);
345 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL);
346 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
347 SHUTDOWN_PRI_DEFAULT);
348 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
349 EVENTHANDLER_PRI_ANY);
350}
351
352#ifdef VIMAGE
353void
354tcp_destroy(void)
355{
356
357 tcp_reass_destroy();
358 tcp_hc_destroy();
359 syncache_destroy();
360 tcp_tw_destroy();
361 in_pcbinfo_destroy(&V_tcbinfo);
362 uma_zdestroy(V_sack_hole_zone);
363 uma_zdestroy(V_tcpcb_zone);
364}
365#endif
366
367void
368tcp_fini(void *xtp)
369{
370
371 callout_stop(&isn_callout);
372}
373
374/*
375 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
376 * tcp_template used to store this data in mbufs, but we now recopy it out
377 * of the tcpcb each time to conserve mbufs.
378 */
379void
380tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
381{
382 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
383
384 INP_WLOCK_ASSERT(inp);
385
386#ifdef INET6
387 if ((inp->inp_vflag & INP_IPV6) != 0) {
388 struct ip6_hdr *ip6;
389
390 ip6 = (struct ip6_hdr *)ip_ptr;
391 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
392 (inp->inp_flow & IPV6_FLOWINFO_MASK);
393 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
394 (IPV6_VERSION & IPV6_VERSION_MASK);
395 ip6->ip6_nxt = IPPROTO_TCP;
396 ip6->ip6_plen = htons(sizeof(struct tcphdr));
397 ip6->ip6_src = inp->in6p_laddr;
398 ip6->ip6_dst = inp->in6p_faddr;
399 } else
400#endif
401 {
402 struct ip *ip;
403
404 ip = (struct ip *)ip_ptr;
405 ip->ip_v = IPVERSION;
406 ip->ip_hl = 5;
407 ip->ip_tos = inp->inp_ip_tos;
408 ip->ip_len = 0;
409 ip->ip_id = 0;
410 ip->ip_off = 0;
411 ip->ip_ttl = inp->inp_ip_ttl;
412 ip->ip_sum = 0;
413 ip->ip_p = IPPROTO_TCP;
414 ip->ip_src = inp->inp_laddr;
415 ip->ip_dst = inp->inp_faddr;
416 }
417 th->th_sport = inp->inp_lport;
418 th->th_dport = inp->inp_fport;
419 th->th_seq = 0;
420 th->th_ack = 0;
421 th->th_x2 = 0;
422 th->th_off = 5;
423 th->th_flags = 0;
424 th->th_win = 0;
425 th->th_urp = 0;
426 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
427}
428
429/*
430 * Create template to be used to send tcp packets on a connection.
431 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
432 * use for this function is in keepalives, which use tcp_respond.
433 */
434struct tcptemp *
435tcpip_maketemplate(struct inpcb *inp)
436{
437 struct tcptemp *t;
438
439 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
440 if (t == NULL)
441 return (NULL);
442 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
443 return (t);
444}
445
446/*
447 * Send a single message to the TCP at address specified by
448 * the given TCP/IP header. If m == NULL, then we make a copy
449 * of the tcpiphdr at ti and send directly to the addressed host.
450 * This is used to force keep alive messages out using the TCP
451 * template for a connection. If flags are given then we send
452 * a message back to the TCP which originated the * segment ti,
453 * and discard the mbuf containing it and any other attached mbufs.
454 *
455 * In any case the ack and sequence number of the transmitted
456 * segment are as specified by the parameters.
457 *
458 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
459 */
460void
461tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
462 tcp_seq ack, tcp_seq seq, int flags)
463{
464 int tlen;
465 int win = 0;
466 struct ip *ip;
467 struct tcphdr *nth;
468#ifdef INET6
469 struct ip6_hdr *ip6;
470 int isipv6;
471#endif /* INET6 */
472 int ipflags = 0;
473 struct inpcb *inp;
474
475 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
476
477#ifdef INET6
478 isipv6 = ((struct ip *)ipgen)->ip_v == 6;
479 ip6 = ipgen;
480#endif /* INET6 */
481 ip = ipgen;
482
483 if (tp != NULL) {
484 inp = tp->t_inpcb;
485 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
486 INP_WLOCK_ASSERT(inp);
487 } else
488 inp = NULL;
489
490 if (tp != NULL) {
491 if (!(flags & TH_RST)) {
492 win = sbspace(&inp->inp_socket->so_rcv);
493 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
494 win = (long)TCP_MAXWIN << tp->rcv_scale;
495 }
496 }
497 if (m == NULL) {
498 m = m_gethdr(M_DONTWAIT, MT_DATA);
499 if (m == NULL)
500 return;
501 tlen = 0;
502 m->m_data += max_linkhdr;
503#ifdef INET6
504 if (isipv6) {
505 bcopy((caddr_t)ip6, mtod(m, caddr_t),
506 sizeof(struct ip6_hdr));
507 ip6 = mtod(m, struct ip6_hdr *);
508 nth = (struct tcphdr *)(ip6 + 1);
509 } else
510#endif /* INET6 */
511 {
512 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
513 ip = mtod(m, struct ip *);
514 nth = (struct tcphdr *)(ip + 1);
515 }
516 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
517 flags = TH_ACK;
518 } else {
519 /*
520 * reuse the mbuf.
521 * XXX MRT We inherrit the FIB, which is lucky.
522 */
523 m_freem(m->m_next);
524 m->m_next = NULL;
525 m->m_data = (caddr_t)ipgen;
526 /* m_len is set later */
527 tlen = 0;
528#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
529#ifdef INET6
530 if (isipv6) {
531 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
532 nth = (struct tcphdr *)(ip6 + 1);
533 } else
534#endif /* INET6 */
535 {
536 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
537 nth = (struct tcphdr *)(ip + 1);
538 }
539 if (th != nth) {
540 /*
541 * this is usually a case when an extension header
542 * exists between the IPv6 header and the
543 * TCP header.
544 */
545 nth->th_sport = th->th_sport;
546 nth->th_dport = th->th_dport;
547 }
548 xchg(nth->th_dport, nth->th_sport, uint16_t);
549#undef xchg
550 }
551#ifdef INET6
552 if (isipv6) {
553 ip6->ip6_flow = 0;
554 ip6->ip6_vfc = IPV6_VERSION;
555 ip6->ip6_nxt = IPPROTO_TCP;
556 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) +
557 tlen));
558 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
559 } else
560#endif
561 {
562 tlen += sizeof (struct tcpiphdr);
563 ip->ip_len = tlen;
564 ip->ip_ttl = V_ip_defttl;
565 if (V_path_mtu_discovery)
566 ip->ip_off |= IP_DF;
567 }
568 m->m_len = tlen;
569 m->m_pkthdr.len = tlen;
570 m->m_pkthdr.rcvif = NULL;
571#ifdef MAC
572 if (inp != NULL) {
573 /*
574 * Packet is associated with a socket, so allow the
575 * label of the response to reflect the socket label.
576 */
577 INP_WLOCK_ASSERT(inp);
578 mac_inpcb_create_mbuf(inp, m);
579 } else {
580 /*
581 * Packet is not associated with a socket, so possibly
582 * update the label in place.
583 */
584 mac_netinet_tcp_reply(m);
585 }
586#endif
587 nth->th_seq = htonl(seq);
588 nth->th_ack = htonl(ack);
589 nth->th_x2 = 0;
590 nth->th_off = sizeof (struct tcphdr) >> 2;
591 nth->th_flags = flags;
592 if (tp != NULL)
593 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
594 else
595 nth->th_win = htons((u_short)win);
596 nth->th_urp = 0;
597#ifdef INET6
598 if (isipv6) {
599 nth->th_sum = 0;
600 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
601 sizeof(struct ip6_hdr),
602 tlen - sizeof(struct ip6_hdr));
603 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
604 NULL, NULL);
605 } else
606#endif /* INET6 */
607 {
608 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
609 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
610 m->m_pkthdr.csum_flags = CSUM_TCP;
611 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
612 }
613#ifdef TCPDEBUG
614 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
615 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
616#endif
617#ifdef INET6
618 if (isipv6)
619 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
620 else
621#endif /* INET6 */
622 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
623}
624
625/*
626 * Create a new TCP control block, making an
627 * empty reassembly queue and hooking it to the argument
628 * protocol control block. The `inp' parameter must have
629 * come from the zone allocator set up in tcp_init().
630 */
631struct tcpcb *
632tcp_newtcpcb(struct inpcb *inp)
633{
634 struct tcpcb_mem *tm;
635 struct tcpcb *tp;
636#ifdef INET6
637 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
638#endif /* INET6 */
639
640 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
641 if (tm == NULL)
642 return (NULL);
643 tp = &tm->tcb;
644
645 /* Initialise cc_var struct for this tcpcb. */
646 tp->ccv = &tm->ccv;
647 tp->ccv->type = IPPROTO_TCP;
648 tp->ccv->ccvc.tcp = tp;
649
650 /*
651 * Use the current system default CC algorithm.
652 */
653 CC_LIST_RLOCK();
654 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
655 CC_ALGO(tp) = CC_DEFAULT();
656 CC_LIST_RUNLOCK();
657
658 if (CC_ALGO(tp)->cb_init != NULL)
659 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
660 uma_zfree(V_tcpcb_zone, tm);
661 return (NULL);
662 }
663
664#ifdef VIMAGE
665 tp->t_vnet = inp->inp_vnet;
666#endif
667 tp->t_timers = &tm->tt;
668 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
669 tp->t_maxseg = tp->t_maxopd =
670#ifdef INET6
671 isipv6 ? V_tcp_v6mssdflt :
672#endif /* INET6 */
673 V_tcp_mssdflt;
674
675 /* Set up our timeouts. */
676 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
677 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
678 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
679 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
680 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
681
682 if (V_tcp_do_rfc1323)
683 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
684 if (V_tcp_do_sack)
685 tp->t_flags |= TF_SACK_PERMIT;
686 TAILQ_INIT(&tp->snd_holes);
687 tp->t_inpcb = inp; /* XXX */
688 /*
689 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
690 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
691 * reasonable initial retransmit time.
692 */
693 tp->t_srtt = TCPTV_SRTTBASE;
694 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
695 tp->t_rttmin = tcp_rexmit_min;
696 tp->t_rxtcur = TCPTV_RTOBASE;
697 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
698 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
699 tp->t_rcvtime = ticks;
700 /*
701 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
702 * because the socket may be bound to an IPv6 wildcard address,
703 * which may match an IPv4-mapped IPv6 address.
704 */
705 inp->inp_ip_ttl = V_ip_defttl;
706 inp->inp_ppcb = tp;
707 return (tp); /* XXX */
708}
709
710/*
711 * Switch the congestion control algorithm back to NewReno for any active
712 * control blocks using an algorithm which is about to go away.
713 * This ensures the CC framework can allow the unload to proceed without leaving
714 * any dangling pointers which would trigger a panic.
715 * Returning non-zero would inform the CC framework that something went wrong
716 * and it would be unsafe to allow the unload to proceed. However, there is no
717 * way for this to occur with this implementation so we always return zero.
718 */
719int
720tcp_ccalgounload(struct cc_algo *unload_algo)
721{
722 struct cc_algo *tmpalgo;
723 struct inpcb *inp;
724 struct tcpcb *tp;
725 VNET_ITERATOR_DECL(vnet_iter);
726
727 /*
728 * Check all active control blocks across all network stacks and change
729 * any that are using "unload_algo" back to NewReno. If "unload_algo"
730 * requires cleanup code to be run, call it.
731 */
732 VNET_LIST_RLOCK();
733 VNET_FOREACH(vnet_iter) {
734 CURVNET_SET(vnet_iter);
735 INP_INFO_RLOCK(&V_tcbinfo);
736 /*
737 * New connections already part way through being initialised
738 * with the CC algo we're removing will not race with this code
739 * because the INP_INFO_WLOCK is held during initialisation. We
740 * therefore don't enter the loop below until the connection
741 * list has stabilised.
742 */
743 LIST_FOREACH(inp, &V_tcb, inp_list) {
744 INP_WLOCK(inp);
745 /* Important to skip tcptw structs. */
746 if (!(inp->inp_flags & INP_TIMEWAIT) &&
747 (tp = intotcpcb(inp)) != NULL) {
748 /*
749 * By holding INP_WLOCK here, we are assured
750 * that the connection is not currently
751 * executing inside the CC module's functions
752 * i.e. it is safe to make the switch back to
753 * NewReno.
754 */
755 if (CC_ALGO(tp) == unload_algo) {
756 tmpalgo = CC_ALGO(tp);
757 /* NewReno does not require any init. */
758 CC_ALGO(tp) = &newreno_cc_algo;
759 if (tmpalgo->cb_destroy != NULL)
760 tmpalgo->cb_destroy(tp->ccv);
761 }
762 }
763 INP_WUNLOCK(inp);
764 }
765 INP_INFO_RUNLOCK(&V_tcbinfo);
766 CURVNET_RESTORE();
767 }
768 VNET_LIST_RUNLOCK();
769
770 return (0);
771}
772
773/*
774 * Drop a TCP connection, reporting
775 * the specified error. If connection is synchronized,
776 * then send a RST to peer.
777 */
778struct tcpcb *
779tcp_drop(struct tcpcb *tp, int errno)
780{
781 struct socket *so = tp->t_inpcb->inp_socket;
782
783 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
784 INP_WLOCK_ASSERT(tp->t_inpcb);
785
786 if (TCPS_HAVERCVDSYN(tp->t_state)) {
787 tp->t_state = TCPS_CLOSED;
788 (void) tcp_output_reset(tp);
789 TCPSTAT_INC(tcps_drops);
790 } else
791 TCPSTAT_INC(tcps_conndrops);
792 if (errno == ETIMEDOUT && tp->t_softerror)
793 errno = tp->t_softerror;
794 so->so_error = errno;
795 return (tcp_close(tp));
796}
797
798void
799tcp_discardcb(struct tcpcb *tp)
800{
801 struct inpcb *inp = tp->t_inpcb;
802 struct socket *so = inp->inp_socket;
803#ifdef INET6
804 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
805#endif /* INET6 */
806
807 INP_WLOCK_ASSERT(inp);
808
809 /*
810 * Make sure that all of our timers are stopped before we delete the
811 * PCB.
812 *
813 * XXXRW: Really, we would like to use callout_drain() here in order
814 * to avoid races experienced in tcp_timer.c where a timer is already
815 * executing at this point. However, we can't, both because we're
816 * running in a context where we can't sleep, and also because we
817 * hold locks required by the timers. What we instead need to do is
818 * test to see if callout_drain() is required, and if so, defer some
819 * portion of the remainder of tcp_discardcb() to an asynchronous
820 * context that can callout_drain() and then continue. Some care
821 * will be required to ensure that no further processing takes place
822 * on the tcpcb, even though it hasn't been freed (a flag?).
823 */
824 callout_stop(&tp->t_timers->tt_rexmt);
825 callout_stop(&tp->t_timers->tt_persist);
826 callout_stop(&tp->t_timers->tt_keep);
827 callout_stop(&tp->t_timers->tt_2msl);
828 callout_stop(&tp->t_timers->tt_delack);
829
830 /*
831 * If we got enough samples through the srtt filter,
832 * save the rtt and rttvar in the routing entry.
833 * 'Enough' is arbitrarily defined as 4 rtt samples.
834 * 4 samples is enough for the srtt filter to converge
835 * to within enough % of the correct value; fewer samples
836 * and we could save a bogus rtt. The danger is not high
837 * as tcp quickly recovers from everything.
838 * XXX: Works very well but needs some more statistics!
839 */
840 if (tp->t_rttupdated >= 4) {
841 struct hc_metrics_lite metrics;
842 u_long ssthresh;
843
844 bzero(&metrics, sizeof(metrics));
845 /*
846 * Update the ssthresh always when the conditions below
847 * are satisfied. This gives us better new start value
848 * for the congestion avoidance for new connections.
849 * ssthresh is only set if packet loss occured on a session.
850 *
851 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
852 * being torn down. Ideally this code would not use 'so'.
853 */
854 ssthresh = tp->snd_ssthresh;
855 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
856 /*
857 * convert the limit from user data bytes to
858 * packets then to packet data bytes.
859 */
860 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
861 if (ssthresh < 2)
862 ssthresh = 2;
863 ssthresh *= (u_long)(tp->t_maxseg +
864#ifdef INET6
865 (isipv6 ? sizeof (struct ip6_hdr) +
866 sizeof (struct tcphdr) :
867#endif
868 sizeof (struct tcpiphdr)
869#ifdef INET6
870 )
871#endif
872 );
873 } else
874 ssthresh = 0;
875 metrics.rmx_ssthresh = ssthresh;
876
877 metrics.rmx_rtt = tp->t_srtt;
878 metrics.rmx_rttvar = tp->t_rttvar;
879 metrics.rmx_cwnd = tp->snd_cwnd;
880 metrics.rmx_sendpipe = 0;
881 metrics.rmx_recvpipe = 0;
882
883 tcp_hc_update(&inp->inp_inc, &metrics);
884 }
885
886 /* free the reassembly queue, if any */
887 tcp_reass_flush(tp);
888 /* Disconnect offload device, if any. */
889 tcp_offload_detach(tp);
890
891 tcp_free_sackholes(tp);
892
893 /* Allow the CC algorithm to clean up after itself. */
894 if (CC_ALGO(tp)->cb_destroy != NULL)
895 CC_ALGO(tp)->cb_destroy(tp->ccv);
896
897 CC_ALGO(tp) = NULL;
898 inp->inp_ppcb = NULL;
899 tp->t_inpcb = NULL;
900 uma_zfree(V_tcpcb_zone, tp);
901}
902
903/*
904 * Attempt to close a TCP control block, marking it as dropped, and freeing
905 * the socket if we hold the only reference.
906 */
907struct tcpcb *
908tcp_close(struct tcpcb *tp)
909{
910 struct inpcb *inp = tp->t_inpcb;
911 struct socket *so;
912
913 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
914 INP_WLOCK_ASSERT(inp);
915
916 /* Notify any offload devices of listener close */
917 if (tp->t_state == TCPS_LISTEN)
918 tcp_offload_listen_close(tp);
919 in_pcbdrop(inp);
920 TCPSTAT_INC(tcps_closed);
921 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
922 so = inp->inp_socket;
923 soisdisconnected(so);
924 if (inp->inp_flags & INP_SOCKREF) {
925 KASSERT(so->so_state & SS_PROTOREF,
926 ("tcp_close: !SS_PROTOREF"));
927 inp->inp_flags &= ~INP_SOCKREF;
928 INP_WUNLOCK(inp);
929 ACCEPT_LOCK();
930 SOCK_LOCK(so);
931 so->so_state &= ~SS_PROTOREF;
932 sofree(so);
933 return (NULL);
934 }
935 return (tp);
936}
937
938void
939tcp_drain(void)
940{
941 VNET_ITERATOR_DECL(vnet_iter);
942
943 if (!do_tcpdrain)
944 return;
945
946 VNET_LIST_RLOCK_NOSLEEP();
947 VNET_FOREACH(vnet_iter) {
948 CURVNET_SET(vnet_iter);
949 struct inpcb *inpb;
950 struct tcpcb *tcpb;
951
952 /*
953 * Walk the tcpbs, if existing, and flush the reassembly queue,
954 * if there is one...
955 * XXX: The "Net/3" implementation doesn't imply that the TCP
956 * reassembly queue should be flushed, but in a situation
957 * where we're really low on mbufs, this is potentially
958 * usefull.
959 */
960 INP_INFO_RLOCK(&V_tcbinfo);
961 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
962 if (inpb->inp_flags & INP_TIMEWAIT)
963 continue;
964 INP_WLOCK(inpb);
965 if ((tcpb = intotcpcb(inpb)) != NULL) {
966 tcp_reass_flush(tcpb);
967 tcp_clean_sackreport(tcpb);
968 }
969 INP_WUNLOCK(inpb);
970 }
971 INP_INFO_RUNLOCK(&V_tcbinfo);
972 CURVNET_RESTORE();
973 }
974 VNET_LIST_RUNLOCK_NOSLEEP();
975}
976
977/*
978 * Notify a tcp user of an asynchronous error;
979 * store error as soft error, but wake up user
980 * (for now, won't do anything until can select for soft error).
981 *
982 * Do not wake up user since there currently is no mechanism for
983 * reporting soft errors (yet - a kqueue filter may be added).
984 */
985static struct inpcb *
986tcp_notify(struct inpcb *inp, int error)
987{
988 struct tcpcb *tp;
989
990 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
991 INP_WLOCK_ASSERT(inp);
992
993 if ((inp->inp_flags & INP_TIMEWAIT) ||
994 (inp->inp_flags & INP_DROPPED))
995 return (inp);
996
997 tp = intotcpcb(inp);
998 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
999
1000 /*
1001 * Ignore some errors if we are hooked up.
1002 * If connection hasn't completed, has retransmitted several times,
1003 * and receives a second error, give up now. This is better
1004 * than waiting a long time to establish a connection that
1005 * can never complete.
1006 */
1007 if (tp->t_state == TCPS_ESTABLISHED &&
1008 (error == EHOSTUNREACH || error == ENETUNREACH ||
1009 error == EHOSTDOWN)) {
1010 return (inp);
1011 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1012 tp->t_softerror) {
1013 tp = tcp_drop(tp, error);
1014 if (tp != NULL)
1015 return (inp);
1016 else
1017 return (NULL);
1018 } else {
1019 tp->t_softerror = error;
1020 return (inp);
1021 }
1022#if 0
1023 wakeup( &so->so_timeo);
1024 sorwakeup(so);
1025 sowwakeup(so);
1026#endif
1027}
1028
1029static int
1030tcp_pcblist(SYSCTL_HANDLER_ARGS)
1031{
1032 int error, i, m, n, pcb_count;
1033 struct inpcb *inp, **inp_list;
1034 inp_gen_t gencnt;
1035 struct xinpgen xig;
1036
1037 /*
1038 * The process of preparing the TCB list is too time-consuming and
1039 * resource-intensive to repeat twice on every request.
1040 */
1041 if (req->oldptr == NULL) {
1042 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1043 n += imax(n / 8, 10);
1044 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1045 return (0);
1046 }
1047
1048 if (req->newptr != NULL)
1049 return (EPERM);
1050
1051 /*
1052 * OK, now we're committed to doing something.
1053 */
1054 INP_INFO_RLOCK(&V_tcbinfo);
1055 gencnt = V_tcbinfo.ipi_gencnt;
1056 n = V_tcbinfo.ipi_count;
1057 INP_INFO_RUNLOCK(&V_tcbinfo);
1058
1059 m = syncache_pcbcount();
1060
1061 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1062 + (n + m) * sizeof(struct xtcpcb));
1063 if (error != 0)
1064 return (error);
1065
1066 xig.xig_len = sizeof xig;
1067 xig.xig_count = n + m;
1068 xig.xig_gen = gencnt;
1069 xig.xig_sogen = so_gencnt;
1070 error = SYSCTL_OUT(req, &xig, sizeof xig);
1071 if (error)
1072 return (error);
1073
1074 error = syncache_pcblist(req, m, &pcb_count);
1075 if (error)
1076 return (error);
1077
1078 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1079 if (inp_list == NULL)
1080 return (ENOMEM);
1081
1082 INP_INFO_RLOCK(&V_tcbinfo);
1083 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1084 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1085 INP_WLOCK(inp);
1086 if (inp->inp_gencnt <= gencnt) {
1087 /*
1088 * XXX: This use of cr_cansee(), introduced with
1089 * TCP state changes, is not quite right, but for
1090 * now, better than nothing.
1091 */
1092 if (inp->inp_flags & INP_TIMEWAIT) {
1093 if (intotw(inp) != NULL)
1094 error = cr_cansee(req->td->td_ucred,
1095 intotw(inp)->tw_cred);
1096 else
1097 error = EINVAL; /* Skip this inp. */
1098 } else
1099 error = cr_canseeinpcb(req->td->td_ucred, inp);
1100 if (error == 0) {
1101 in_pcbref(inp);
1102 inp_list[i++] = inp;
1103 }
1104 }
1105 INP_WUNLOCK(inp);
1106 }
1107 INP_INFO_RUNLOCK(&V_tcbinfo);
1108 n = i;
1109
1110 error = 0;
1111 for (i = 0; i < n; i++) {
1112 inp = inp_list[i];
1113 INP_RLOCK(inp);
1114 if (inp->inp_gencnt <= gencnt) {
1115 struct xtcpcb xt;
1116 void *inp_ppcb;
1117
1118 bzero(&xt, sizeof(xt));
1119 xt.xt_len = sizeof xt;
1120 /* XXX should avoid extra copy */
1121 bcopy(inp, &xt.xt_inp, sizeof *inp);
1122 inp_ppcb = inp->inp_ppcb;
1123 if (inp_ppcb == NULL)
1124 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1125 else if (inp->inp_flags & INP_TIMEWAIT) {
1126 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1127 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1128 } else {
1129 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1130 if (xt.xt_tp.t_timers)
1131 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1132 }
1133 if (inp->inp_socket != NULL)
1134 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1135 else {
1136 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1137 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1138 }
1139 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1140 INP_RUNLOCK(inp);
1141 error = SYSCTL_OUT(req, &xt, sizeof xt);
1142 } else
1143 INP_RUNLOCK(inp);
1144 }
1145 INP_INFO_WLOCK(&V_tcbinfo);
1146 for (i = 0; i < n; i++) {
1147 inp = inp_list[i];
1148 INP_WLOCK(inp);
1149 if (!in_pcbrele(inp))
1150 INP_WUNLOCK(inp);
1151 }
1152 INP_INFO_WUNLOCK(&V_tcbinfo);
1153
1154 if (!error) {
1155 /*
1156 * Give the user an updated idea of our state.
1157 * If the generation differs from what we told
1158 * her before, she knows that something happened
1159 * while we were processing this request, and it
1160 * might be necessary to retry.
1161 */
1162 INP_INFO_RLOCK(&V_tcbinfo);
1163 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1164 xig.xig_sogen = so_gencnt;
1165 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1166 INP_INFO_RUNLOCK(&V_tcbinfo);
1167 error = SYSCTL_OUT(req, &xig, sizeof xig);
1168 }
1169 free(inp_list, M_TEMP);
1170 return (error);
1171}
1172
1173SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1174 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1175
1176static int
1177tcp_getcred(SYSCTL_HANDLER_ARGS)
1178{
1179 struct xucred xuc;
1180 struct sockaddr_in addrs[2];
1181 struct inpcb *inp;
1182 int error;
1183
1184 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1185 if (error)
1186 return (error);
1187 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1188 if (error)
1189 return (error);
1190 INP_INFO_RLOCK(&V_tcbinfo);
1191 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr,
1192 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1193 if (inp != NULL) {
1194 INP_RLOCK(inp);
1195 INP_INFO_RUNLOCK(&V_tcbinfo);
1196 if (inp->inp_socket == NULL)
1197 error = ENOENT;
1198 if (error == 0)
1199 error = cr_canseeinpcb(req->td->td_ucred, inp);
1200 if (error == 0)
1201 cru2x(inp->inp_cred, &xuc);
1202 INP_RUNLOCK(inp);
1203 } else {
1204 INP_INFO_RUNLOCK(&V_tcbinfo);
1205 error = ENOENT;
1206 }
1207 if (error == 0)
1208 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1209 return (error);
1210}
1211
1212SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1213 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1214 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1215
1216#ifdef INET6
1217static int
1218tcp6_getcred(SYSCTL_HANDLER_ARGS)
1219{
1220 struct xucred xuc;
1221 struct sockaddr_in6 addrs[2];
1222 struct inpcb *inp;
1223 int error, mapped = 0;
1224
1225 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1226 if (error)
1227 return (error);
1228 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1229 if (error)
1230 return (error);
1231 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1232 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1233 return (error);
1234 }
1235 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1236 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1237 mapped = 1;
1238 else
1239 return (EINVAL);
1240 }
1241
1242 INP_INFO_RLOCK(&V_tcbinfo);
1243 if (mapped == 1)
1244 inp = in_pcblookup_hash(&V_tcbinfo,
1245 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1246 addrs[1].sin6_port,
1247 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1248 addrs[0].sin6_port,
1249 0, NULL);
1250 else
1251 inp = in6_pcblookup_hash(&V_tcbinfo,
1252 &addrs[1].sin6_addr, addrs[1].sin6_port,
1253 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL);
1254 if (inp != NULL) {
1255 INP_RLOCK(inp);
1256 INP_INFO_RUNLOCK(&V_tcbinfo);
1257 if (inp->inp_socket == NULL)
1258 error = ENOENT;
1259 if (error == 0)
1260 error = cr_canseeinpcb(req->td->td_ucred, inp);
1261 if (error == 0)
1262 cru2x(inp->inp_cred, &xuc);
1263 INP_RUNLOCK(inp);
1264 } else {
1265 INP_INFO_RUNLOCK(&V_tcbinfo);
1266 error = ENOENT;
1267 }
1268 if (error == 0)
1269 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1270 return (error);
1271}
1272
1273SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1274 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1275 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1276#endif
1277
1278
1279void
1280tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1281{
1282 struct ip *ip = vip;
1283 struct tcphdr *th;
1284 struct in_addr faddr;
1285 struct inpcb *inp;
1286 struct tcpcb *tp;
1287 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1288 struct icmp *icp;
1289 struct in_conninfo inc;
1290 tcp_seq icmp_tcp_seq;
1291 int mtu;
1292
1293 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1294 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1295 return;
1296
1297 if (cmd == PRC_MSGSIZE)
1298 notify = tcp_mtudisc;
1299 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1300 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1301 notify = tcp_drop_syn_sent;
1302 /*
1303 * Redirects don't need to be handled up here.
1304 */
1305 else if (PRC_IS_REDIRECT(cmd))
1306 return;
1307 /*
1308 * Source quench is depreciated.
1309 */
1310 else if (cmd == PRC_QUENCH)
1311 return;
1312 /*
1313 * Hostdead is ugly because it goes linearly through all PCBs.
1314 * XXX: We never get this from ICMP, otherwise it makes an
1315 * excellent DoS attack on machines with many connections.
1316 */
1317 else if (cmd == PRC_HOSTDEAD)
1318 ip = NULL;
1319 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1320 return;
1321 if (ip != NULL) {
1322 icp = (struct icmp *)((caddr_t)ip
1323 - offsetof(struct icmp, icmp_ip));
1324 th = (struct tcphdr *)((caddr_t)ip
1325 + (ip->ip_hl << 2));
1326 INP_INFO_WLOCK(&V_tcbinfo);
1327 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport,
1328 ip->ip_src, th->th_sport, 0, NULL);
1329 if (inp != NULL) {
1330 INP_WLOCK(inp);
1331 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1332 !(inp->inp_flags & INP_DROPPED) &&
1333 !(inp->inp_socket == NULL)) {
1334 icmp_tcp_seq = htonl(th->th_seq);
1335 tp = intotcpcb(inp);
1336 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1337 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1338 if (cmd == PRC_MSGSIZE) {
1339 /*
1340 * MTU discovery:
1341 * If we got a needfrag set the MTU
1342 * in the route to the suggested new
1343 * value (if given) and then notify.
1344 */
1345 bzero(&inc, sizeof(inc));
1346 inc.inc_faddr = faddr;
1347 inc.inc_fibnum =
1348 inp->inp_inc.inc_fibnum;
1349
1350 mtu = ntohs(icp->icmp_nextmtu);
1351 /*
1352 * If no alternative MTU was
1353 * proposed, try the next smaller
1354 * one. ip->ip_len has already
1355 * been swapped in icmp_input().
1356 */
1357 if (!mtu)
1358 mtu = ip_next_mtu(ip->ip_len,
1359 1);
1360 if (mtu < V_tcp_minmss
1361 + sizeof(struct tcpiphdr))
1362 mtu = V_tcp_minmss
1363 + sizeof(struct tcpiphdr);
1364 /*
1365 * Only cache the the MTU if it
1366 * is smaller than the interface
1367 * or route MTU. tcp_mtudisc()
1368 * will do right thing by itself.
1369 */
1370 if (mtu <= tcp_maxmtu(&inc, NULL))
1371 tcp_hc_updatemtu(&inc, mtu);
1372 }
1373
1374 inp = (*notify)(inp, inetctlerrmap[cmd]);
1375 }
1376 }
1377 if (inp != NULL)
1378 INP_WUNLOCK(inp);
1379 } else {
1380 bzero(&inc, sizeof(inc));
1381 inc.inc_fport = th->th_dport;
1382 inc.inc_lport = th->th_sport;
1383 inc.inc_faddr = faddr;
1384 inc.inc_laddr = ip->ip_src;
1385 syncache_unreach(&inc, th);
1386 }
1387 INP_INFO_WUNLOCK(&V_tcbinfo);
1388 } else
1389 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1390}
1391
1392#ifdef INET6
1393void
1394tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1395{
1396 struct tcphdr th;
1397 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1398 struct ip6_hdr *ip6;
1399 struct mbuf *m;
1400 struct ip6ctlparam *ip6cp = NULL;
1401 const struct sockaddr_in6 *sa6_src = NULL;
1402 int off;
1403 struct tcp_portonly {
1404 u_int16_t th_sport;
1405 u_int16_t th_dport;
1406 } *thp;
1407
1408 if (sa->sa_family != AF_INET6 ||
1409 sa->sa_len != sizeof(struct sockaddr_in6))
1410 return;
1411
1412 if (cmd == PRC_MSGSIZE)
1413 notify = tcp_mtudisc;
1414 else if (!PRC_IS_REDIRECT(cmd) &&
1415 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1416 return;
1417 /* Source quench is depreciated. */
1418 else if (cmd == PRC_QUENCH)
1419 return;
1420
1421 /* if the parameter is from icmp6, decode it. */
1422 if (d != NULL) {
1423 ip6cp = (struct ip6ctlparam *)d;
1424 m = ip6cp->ip6c_m;
1425 ip6 = ip6cp->ip6c_ip6;
1426 off = ip6cp->ip6c_off;
1427 sa6_src = ip6cp->ip6c_src;
1428 } else {
1429 m = NULL;
1430 ip6 = NULL;
1431 off = 0; /* fool gcc */
1432 sa6_src = &sa6_any;
1433 }
1434
1435 if (ip6 != NULL) {
1436 struct in_conninfo inc;
1437 /*
1438 * XXX: We assume that when IPV6 is non NULL,
1439 * M and OFF are valid.
1440 */
1441
1442 /* check if we can safely examine src and dst ports */
1443 if (m->m_pkthdr.len < off + sizeof(*thp))
1444 return;
1445
1446 bzero(&th, sizeof(th));
1447 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1448
1449 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1450 (struct sockaddr *)ip6cp->ip6c_src,
1451 th.th_sport, cmd, NULL, notify);
1452
1453 bzero(&inc, sizeof(inc));
1454 inc.inc_fport = th.th_dport;
1455 inc.inc_lport = th.th_sport;
1456 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1457 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1458 inc.inc_flags |= INC_ISIPV6;
1459 INP_INFO_WLOCK(&V_tcbinfo);
1460 syncache_unreach(&inc, &th);
1461 INP_INFO_WUNLOCK(&V_tcbinfo);
1462 } else
1463 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1464 0, cmd, NULL, notify);
1465}
1466#endif /* INET6 */
1467
1468
1469/*
1470 * Following is where TCP initial sequence number generation occurs.
1471 *
1472 * There are two places where we must use initial sequence numbers:
1473 * 1. In SYN-ACK packets.
1474 * 2. In SYN packets.
1475 *
1476 * All ISNs for SYN-ACK packets are generated by the syncache. See
1477 * tcp_syncache.c for details.
1478 *
1479 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1480 * depends on this property. In addition, these ISNs should be
1481 * unguessable so as to prevent connection hijacking. To satisfy
1482 * the requirements of this situation, the algorithm outlined in
1483 * RFC 1948 is used, with only small modifications.
1484 *
1485 * Implementation details:
1486 *
1487 * Time is based off the system timer, and is corrected so that it
1488 * increases by one megabyte per second. This allows for proper
1489 * recycling on high speed LANs while still leaving over an hour
1490 * before rollover.
1491 *
1492 * As reading the *exact* system time is too expensive to be done
1493 * whenever setting up a TCP connection, we increment the time
1494 * offset in two ways. First, a small random positive increment
1495 * is added to isn_offset for each connection that is set up.
1496 * Second, the function tcp_isn_tick fires once per clock tick
1497 * and increments isn_offset as necessary so that sequence numbers
1498 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1499 * random positive increments serve only to ensure that the same
1500 * exact sequence number is never sent out twice (as could otherwise
1501 * happen when a port is recycled in less than the system tick
1502 * interval.)
1503 *
1504 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1505 * between seeding of isn_secret. This is normally set to zero,
1506 * as reseeding should not be necessary.
1507 *
1508 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1509 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1510 * general, this means holding an exclusive (write) lock.
1511 */
1512
1513#define ISN_BYTES_PER_SECOND 1048576
1514#define ISN_STATIC_INCREMENT 4096
1515#define ISN_RANDOM_INCREMENT (4096 - 1)
1516
| 245#define V_tcpcb_zone VNET(tcpcb_zone)
246
247MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
248struct callout isn_callout;
249static struct mtx isn_mtx;
250
251#define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
252#define ISN_LOCK() mtx_lock(&isn_mtx)
253#define ISN_UNLOCK() mtx_unlock(&isn_mtx)
254
255/*
256 * TCP initialization.
257 */
258static void
259tcp_zone_change(void *tag)
260{
261
262 uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
263 uma_zone_set_max(V_tcpcb_zone, maxsockets);
264 tcp_tw_zone_change();
265}
266
267static int
268tcp_inpcb_init(void *mem, int size, int flags)
269{
270 struct inpcb *inp = mem;
271
272 INP_LOCK_INIT(inp, "inp", "tcpinp");
273 return (0);
274}
275
276void
277tcp_init(void)
278{
279 int hashsize;
280
281 hashsize = TCBHASHSIZE;
282 TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
283 if (!powerof2(hashsize)) {
284 printf("WARNING: TCB hash size not a power of 2\n");
285 hashsize = 512; /* safe default */
286 }
287 in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
288 "tcp_inpcb", tcp_inpcb_init, NULL, UMA_ZONE_NOFREE);
289
290 /*
291 * These have to be type stable for the benefit of the timers.
292 */
293 V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
294 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
295 uma_zone_set_max(V_tcpcb_zone, maxsockets);
296
297 tcp_tw_init();
298 syncache_init();
299 tcp_hc_init();
300 tcp_reass_init();
301
302 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
303 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
304 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
305
306 /* Skip initialization of globals for non-default instances. */
307 if (!IS_DEFAULT_VNET(curvnet))
308 return;
309
310 /* XXX virtualize those bellow? */
311 tcp_delacktime = TCPTV_DELACK;
312 tcp_keepinit = TCPTV_KEEP_INIT;
313 tcp_keepidle = TCPTV_KEEP_IDLE;
314 tcp_keepintvl = TCPTV_KEEPINTVL;
315 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
316 tcp_msl = TCPTV_MSL;
317 tcp_rexmit_min = TCPTV_MIN;
318 if (tcp_rexmit_min < 1)
319 tcp_rexmit_min = 1;
320 tcp_rexmit_slop = TCPTV_CPU_VAR;
321 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
322 tcp_tcbhashsize = hashsize;
323
324#ifdef TCP_SORECEIVE_STREAM
325 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
326 if (tcp_soreceive_stream) {
327 tcp_usrreqs.pru_soreceive = soreceive_stream;
328 tcp6_usrreqs.pru_soreceive = soreceive_stream;
329 }
330#endif
331
332#ifdef INET6
333#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
334#else /* INET6 */
335#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
336#endif /* INET6 */
337 if (max_protohdr < TCP_MINPROTOHDR)
338 max_protohdr = TCP_MINPROTOHDR;
339 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
340 panic("tcp_init");
341#undef TCP_MINPROTOHDR
342
343 ISN_LOCK_INIT();
344 callout_init(&isn_callout, CALLOUT_MPSAFE);
345 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL);
346 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
347 SHUTDOWN_PRI_DEFAULT);
348 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
349 EVENTHANDLER_PRI_ANY);
350}
351
352#ifdef VIMAGE
353void
354tcp_destroy(void)
355{
356
357 tcp_reass_destroy();
358 tcp_hc_destroy();
359 syncache_destroy();
360 tcp_tw_destroy();
361 in_pcbinfo_destroy(&V_tcbinfo);
362 uma_zdestroy(V_sack_hole_zone);
363 uma_zdestroy(V_tcpcb_zone);
364}
365#endif
366
367void
368tcp_fini(void *xtp)
369{
370
371 callout_stop(&isn_callout);
372}
373
374/*
375 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
376 * tcp_template used to store this data in mbufs, but we now recopy it out
377 * of the tcpcb each time to conserve mbufs.
378 */
379void
380tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
381{
382 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
383
384 INP_WLOCK_ASSERT(inp);
385
386#ifdef INET6
387 if ((inp->inp_vflag & INP_IPV6) != 0) {
388 struct ip6_hdr *ip6;
389
390 ip6 = (struct ip6_hdr *)ip_ptr;
391 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
392 (inp->inp_flow & IPV6_FLOWINFO_MASK);
393 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
394 (IPV6_VERSION & IPV6_VERSION_MASK);
395 ip6->ip6_nxt = IPPROTO_TCP;
396 ip6->ip6_plen = htons(sizeof(struct tcphdr));
397 ip6->ip6_src = inp->in6p_laddr;
398 ip6->ip6_dst = inp->in6p_faddr;
399 } else
400#endif
401 {
402 struct ip *ip;
403
404 ip = (struct ip *)ip_ptr;
405 ip->ip_v = IPVERSION;
406 ip->ip_hl = 5;
407 ip->ip_tos = inp->inp_ip_tos;
408 ip->ip_len = 0;
409 ip->ip_id = 0;
410 ip->ip_off = 0;
411 ip->ip_ttl = inp->inp_ip_ttl;
412 ip->ip_sum = 0;
413 ip->ip_p = IPPROTO_TCP;
414 ip->ip_src = inp->inp_laddr;
415 ip->ip_dst = inp->inp_faddr;
416 }
417 th->th_sport = inp->inp_lport;
418 th->th_dport = inp->inp_fport;
419 th->th_seq = 0;
420 th->th_ack = 0;
421 th->th_x2 = 0;
422 th->th_off = 5;
423 th->th_flags = 0;
424 th->th_win = 0;
425 th->th_urp = 0;
426 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
427}
428
429/*
430 * Create template to be used to send tcp packets on a connection.
431 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
432 * use for this function is in keepalives, which use tcp_respond.
433 */
434struct tcptemp *
435tcpip_maketemplate(struct inpcb *inp)
436{
437 struct tcptemp *t;
438
439 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
440 if (t == NULL)
441 return (NULL);
442 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
443 return (t);
444}
445
446/*
447 * Send a single message to the TCP at address specified by
448 * the given TCP/IP header. If m == NULL, then we make a copy
449 * of the tcpiphdr at ti and send directly to the addressed host.
450 * This is used to force keep alive messages out using the TCP
451 * template for a connection. If flags are given then we send
452 * a message back to the TCP which originated the * segment ti,
453 * and discard the mbuf containing it and any other attached mbufs.
454 *
455 * In any case the ack and sequence number of the transmitted
456 * segment are as specified by the parameters.
457 *
458 * NOTE: If m != NULL, then ti must point to *inside* the mbuf.
459 */
460void
461tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
462 tcp_seq ack, tcp_seq seq, int flags)
463{
464 int tlen;
465 int win = 0;
466 struct ip *ip;
467 struct tcphdr *nth;
468#ifdef INET6
469 struct ip6_hdr *ip6;
470 int isipv6;
471#endif /* INET6 */
472 int ipflags = 0;
473 struct inpcb *inp;
474
475 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
476
477#ifdef INET6
478 isipv6 = ((struct ip *)ipgen)->ip_v == 6;
479 ip6 = ipgen;
480#endif /* INET6 */
481 ip = ipgen;
482
483 if (tp != NULL) {
484 inp = tp->t_inpcb;
485 KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
486 INP_WLOCK_ASSERT(inp);
487 } else
488 inp = NULL;
489
490 if (tp != NULL) {
491 if (!(flags & TH_RST)) {
492 win = sbspace(&inp->inp_socket->so_rcv);
493 if (win > (long)TCP_MAXWIN << tp->rcv_scale)
494 win = (long)TCP_MAXWIN << tp->rcv_scale;
495 }
496 }
497 if (m == NULL) {
498 m = m_gethdr(M_DONTWAIT, MT_DATA);
499 if (m == NULL)
500 return;
501 tlen = 0;
502 m->m_data += max_linkhdr;
503#ifdef INET6
504 if (isipv6) {
505 bcopy((caddr_t)ip6, mtod(m, caddr_t),
506 sizeof(struct ip6_hdr));
507 ip6 = mtod(m, struct ip6_hdr *);
508 nth = (struct tcphdr *)(ip6 + 1);
509 } else
510#endif /* INET6 */
511 {
512 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
513 ip = mtod(m, struct ip *);
514 nth = (struct tcphdr *)(ip + 1);
515 }
516 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
517 flags = TH_ACK;
518 } else {
519 /*
520 * reuse the mbuf.
521 * XXX MRT We inherrit the FIB, which is lucky.
522 */
523 m_freem(m->m_next);
524 m->m_next = NULL;
525 m->m_data = (caddr_t)ipgen;
526 /* m_len is set later */
527 tlen = 0;
528#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
529#ifdef INET6
530 if (isipv6) {
531 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
532 nth = (struct tcphdr *)(ip6 + 1);
533 } else
534#endif /* INET6 */
535 {
536 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
537 nth = (struct tcphdr *)(ip + 1);
538 }
539 if (th != nth) {
540 /*
541 * this is usually a case when an extension header
542 * exists between the IPv6 header and the
543 * TCP header.
544 */
545 nth->th_sport = th->th_sport;
546 nth->th_dport = th->th_dport;
547 }
548 xchg(nth->th_dport, nth->th_sport, uint16_t);
549#undef xchg
550 }
551#ifdef INET6
552 if (isipv6) {
553 ip6->ip6_flow = 0;
554 ip6->ip6_vfc = IPV6_VERSION;
555 ip6->ip6_nxt = IPPROTO_TCP;
556 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) +
557 tlen));
558 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
559 } else
560#endif
561 {
562 tlen += sizeof (struct tcpiphdr);
563 ip->ip_len = tlen;
564 ip->ip_ttl = V_ip_defttl;
565 if (V_path_mtu_discovery)
566 ip->ip_off |= IP_DF;
567 }
568 m->m_len = tlen;
569 m->m_pkthdr.len = tlen;
570 m->m_pkthdr.rcvif = NULL;
571#ifdef MAC
572 if (inp != NULL) {
573 /*
574 * Packet is associated with a socket, so allow the
575 * label of the response to reflect the socket label.
576 */
577 INP_WLOCK_ASSERT(inp);
578 mac_inpcb_create_mbuf(inp, m);
579 } else {
580 /*
581 * Packet is not associated with a socket, so possibly
582 * update the label in place.
583 */
584 mac_netinet_tcp_reply(m);
585 }
586#endif
587 nth->th_seq = htonl(seq);
588 nth->th_ack = htonl(ack);
589 nth->th_x2 = 0;
590 nth->th_off = sizeof (struct tcphdr) >> 2;
591 nth->th_flags = flags;
592 if (tp != NULL)
593 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
594 else
595 nth->th_win = htons((u_short)win);
596 nth->th_urp = 0;
597#ifdef INET6
598 if (isipv6) {
599 nth->th_sum = 0;
600 nth->th_sum = in6_cksum(m, IPPROTO_TCP,
601 sizeof(struct ip6_hdr),
602 tlen - sizeof(struct ip6_hdr));
603 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
604 NULL, NULL);
605 } else
606#endif /* INET6 */
607 {
608 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
609 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
610 m->m_pkthdr.csum_flags = CSUM_TCP;
611 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
612 }
613#ifdef TCPDEBUG
614 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
615 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
616#endif
617#ifdef INET6
618 if (isipv6)
619 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
620 else
621#endif /* INET6 */
622 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
623}
624
625/*
626 * Create a new TCP control block, making an
627 * empty reassembly queue and hooking it to the argument
628 * protocol control block. The `inp' parameter must have
629 * come from the zone allocator set up in tcp_init().
630 */
631struct tcpcb *
632tcp_newtcpcb(struct inpcb *inp)
633{
634 struct tcpcb_mem *tm;
635 struct tcpcb *tp;
636#ifdef INET6
637 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
638#endif /* INET6 */
639
640 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
641 if (tm == NULL)
642 return (NULL);
643 tp = &tm->tcb;
644
645 /* Initialise cc_var struct for this tcpcb. */
646 tp->ccv = &tm->ccv;
647 tp->ccv->type = IPPROTO_TCP;
648 tp->ccv->ccvc.tcp = tp;
649
650 /*
651 * Use the current system default CC algorithm.
652 */
653 CC_LIST_RLOCK();
654 KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
655 CC_ALGO(tp) = CC_DEFAULT();
656 CC_LIST_RUNLOCK();
657
658 if (CC_ALGO(tp)->cb_init != NULL)
659 if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
660 uma_zfree(V_tcpcb_zone, tm);
661 return (NULL);
662 }
663
664#ifdef VIMAGE
665 tp->t_vnet = inp->inp_vnet;
666#endif
667 tp->t_timers = &tm->tt;
668 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
669 tp->t_maxseg = tp->t_maxopd =
670#ifdef INET6
671 isipv6 ? V_tcp_v6mssdflt :
672#endif /* INET6 */
673 V_tcp_mssdflt;
674
675 /* Set up our timeouts. */
676 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE);
677 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE);
678 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE);
679 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE);
680 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE);
681
682 if (V_tcp_do_rfc1323)
683 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
684 if (V_tcp_do_sack)
685 tp->t_flags |= TF_SACK_PERMIT;
686 TAILQ_INIT(&tp->snd_holes);
687 tp->t_inpcb = inp; /* XXX */
688 /*
689 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
690 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
691 * reasonable initial retransmit time.
692 */
693 tp->t_srtt = TCPTV_SRTTBASE;
694 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
695 tp->t_rttmin = tcp_rexmit_min;
696 tp->t_rxtcur = TCPTV_RTOBASE;
697 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
698 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
699 tp->t_rcvtime = ticks;
700 /*
701 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
702 * because the socket may be bound to an IPv6 wildcard address,
703 * which may match an IPv4-mapped IPv6 address.
704 */
705 inp->inp_ip_ttl = V_ip_defttl;
706 inp->inp_ppcb = tp;
707 return (tp); /* XXX */
708}
709
710/*
711 * Switch the congestion control algorithm back to NewReno for any active
712 * control blocks using an algorithm which is about to go away.
713 * This ensures the CC framework can allow the unload to proceed without leaving
714 * any dangling pointers which would trigger a panic.
715 * Returning non-zero would inform the CC framework that something went wrong
716 * and it would be unsafe to allow the unload to proceed. However, there is no
717 * way for this to occur with this implementation so we always return zero.
718 */
719int
720tcp_ccalgounload(struct cc_algo *unload_algo)
721{
722 struct cc_algo *tmpalgo;
723 struct inpcb *inp;
724 struct tcpcb *tp;
725 VNET_ITERATOR_DECL(vnet_iter);
726
727 /*
728 * Check all active control blocks across all network stacks and change
729 * any that are using "unload_algo" back to NewReno. If "unload_algo"
730 * requires cleanup code to be run, call it.
731 */
732 VNET_LIST_RLOCK();
733 VNET_FOREACH(vnet_iter) {
734 CURVNET_SET(vnet_iter);
735 INP_INFO_RLOCK(&V_tcbinfo);
736 /*
737 * New connections already part way through being initialised
738 * with the CC algo we're removing will not race with this code
739 * because the INP_INFO_WLOCK is held during initialisation. We
740 * therefore don't enter the loop below until the connection
741 * list has stabilised.
742 */
743 LIST_FOREACH(inp, &V_tcb, inp_list) {
744 INP_WLOCK(inp);
745 /* Important to skip tcptw structs. */
746 if (!(inp->inp_flags & INP_TIMEWAIT) &&
747 (tp = intotcpcb(inp)) != NULL) {
748 /*
749 * By holding INP_WLOCK here, we are assured
750 * that the connection is not currently
751 * executing inside the CC module's functions
752 * i.e. it is safe to make the switch back to
753 * NewReno.
754 */
755 if (CC_ALGO(tp) == unload_algo) {
756 tmpalgo = CC_ALGO(tp);
757 /* NewReno does not require any init. */
758 CC_ALGO(tp) = &newreno_cc_algo;
759 if (tmpalgo->cb_destroy != NULL)
760 tmpalgo->cb_destroy(tp->ccv);
761 }
762 }
763 INP_WUNLOCK(inp);
764 }
765 INP_INFO_RUNLOCK(&V_tcbinfo);
766 CURVNET_RESTORE();
767 }
768 VNET_LIST_RUNLOCK();
769
770 return (0);
771}
772
773/*
774 * Drop a TCP connection, reporting
775 * the specified error. If connection is synchronized,
776 * then send a RST to peer.
777 */
778struct tcpcb *
779tcp_drop(struct tcpcb *tp, int errno)
780{
781 struct socket *so = tp->t_inpcb->inp_socket;
782
783 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
784 INP_WLOCK_ASSERT(tp->t_inpcb);
785
786 if (TCPS_HAVERCVDSYN(tp->t_state)) {
787 tp->t_state = TCPS_CLOSED;
788 (void) tcp_output_reset(tp);
789 TCPSTAT_INC(tcps_drops);
790 } else
791 TCPSTAT_INC(tcps_conndrops);
792 if (errno == ETIMEDOUT && tp->t_softerror)
793 errno = tp->t_softerror;
794 so->so_error = errno;
795 return (tcp_close(tp));
796}
797
798void
799tcp_discardcb(struct tcpcb *tp)
800{
801 struct inpcb *inp = tp->t_inpcb;
802 struct socket *so = inp->inp_socket;
803#ifdef INET6
804 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
805#endif /* INET6 */
806
807 INP_WLOCK_ASSERT(inp);
808
809 /*
810 * Make sure that all of our timers are stopped before we delete the
811 * PCB.
812 *
813 * XXXRW: Really, we would like to use callout_drain() here in order
814 * to avoid races experienced in tcp_timer.c where a timer is already
815 * executing at this point. However, we can't, both because we're
816 * running in a context where we can't sleep, and also because we
817 * hold locks required by the timers. What we instead need to do is
818 * test to see if callout_drain() is required, and if so, defer some
819 * portion of the remainder of tcp_discardcb() to an asynchronous
820 * context that can callout_drain() and then continue. Some care
821 * will be required to ensure that no further processing takes place
822 * on the tcpcb, even though it hasn't been freed (a flag?).
823 */
824 callout_stop(&tp->t_timers->tt_rexmt);
825 callout_stop(&tp->t_timers->tt_persist);
826 callout_stop(&tp->t_timers->tt_keep);
827 callout_stop(&tp->t_timers->tt_2msl);
828 callout_stop(&tp->t_timers->tt_delack);
829
830 /*
831 * If we got enough samples through the srtt filter,
832 * save the rtt and rttvar in the routing entry.
833 * 'Enough' is arbitrarily defined as 4 rtt samples.
834 * 4 samples is enough for the srtt filter to converge
835 * to within enough % of the correct value; fewer samples
836 * and we could save a bogus rtt. The danger is not high
837 * as tcp quickly recovers from everything.
838 * XXX: Works very well but needs some more statistics!
839 */
840 if (tp->t_rttupdated >= 4) {
841 struct hc_metrics_lite metrics;
842 u_long ssthresh;
843
844 bzero(&metrics, sizeof(metrics));
845 /*
846 * Update the ssthresh always when the conditions below
847 * are satisfied. This gives us better new start value
848 * for the congestion avoidance for new connections.
849 * ssthresh is only set if packet loss occured on a session.
850 *
851 * XXXRW: 'so' may be NULL here, and/or socket buffer may be
852 * being torn down. Ideally this code would not use 'so'.
853 */
854 ssthresh = tp->snd_ssthresh;
855 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
856 /*
857 * convert the limit from user data bytes to
858 * packets then to packet data bytes.
859 */
860 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
861 if (ssthresh < 2)
862 ssthresh = 2;
863 ssthresh *= (u_long)(tp->t_maxseg +
864#ifdef INET6
865 (isipv6 ? sizeof (struct ip6_hdr) +
866 sizeof (struct tcphdr) :
867#endif
868 sizeof (struct tcpiphdr)
869#ifdef INET6
870 )
871#endif
872 );
873 } else
874 ssthresh = 0;
875 metrics.rmx_ssthresh = ssthresh;
876
877 metrics.rmx_rtt = tp->t_srtt;
878 metrics.rmx_rttvar = tp->t_rttvar;
879 metrics.rmx_cwnd = tp->snd_cwnd;
880 metrics.rmx_sendpipe = 0;
881 metrics.rmx_recvpipe = 0;
882
883 tcp_hc_update(&inp->inp_inc, &metrics);
884 }
885
886 /* free the reassembly queue, if any */
887 tcp_reass_flush(tp);
888 /* Disconnect offload device, if any. */
889 tcp_offload_detach(tp);
890
891 tcp_free_sackholes(tp);
892
893 /* Allow the CC algorithm to clean up after itself. */
894 if (CC_ALGO(tp)->cb_destroy != NULL)
895 CC_ALGO(tp)->cb_destroy(tp->ccv);
896
897 CC_ALGO(tp) = NULL;
898 inp->inp_ppcb = NULL;
899 tp->t_inpcb = NULL;
900 uma_zfree(V_tcpcb_zone, tp);
901}
902
903/*
904 * Attempt to close a TCP control block, marking it as dropped, and freeing
905 * the socket if we hold the only reference.
906 */
907struct tcpcb *
908tcp_close(struct tcpcb *tp)
909{
910 struct inpcb *inp = tp->t_inpcb;
911 struct socket *so;
912
913 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
914 INP_WLOCK_ASSERT(inp);
915
916 /* Notify any offload devices of listener close */
917 if (tp->t_state == TCPS_LISTEN)
918 tcp_offload_listen_close(tp);
919 in_pcbdrop(inp);
920 TCPSTAT_INC(tcps_closed);
921 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
922 so = inp->inp_socket;
923 soisdisconnected(so);
924 if (inp->inp_flags & INP_SOCKREF) {
925 KASSERT(so->so_state & SS_PROTOREF,
926 ("tcp_close: !SS_PROTOREF"));
927 inp->inp_flags &= ~INP_SOCKREF;
928 INP_WUNLOCK(inp);
929 ACCEPT_LOCK();
930 SOCK_LOCK(so);
931 so->so_state &= ~SS_PROTOREF;
932 sofree(so);
933 return (NULL);
934 }
935 return (tp);
936}
937
938void
939tcp_drain(void)
940{
941 VNET_ITERATOR_DECL(vnet_iter);
942
943 if (!do_tcpdrain)
944 return;
945
946 VNET_LIST_RLOCK_NOSLEEP();
947 VNET_FOREACH(vnet_iter) {
948 CURVNET_SET(vnet_iter);
949 struct inpcb *inpb;
950 struct tcpcb *tcpb;
951
952 /*
953 * Walk the tcpbs, if existing, and flush the reassembly queue,
954 * if there is one...
955 * XXX: The "Net/3" implementation doesn't imply that the TCP
956 * reassembly queue should be flushed, but in a situation
957 * where we're really low on mbufs, this is potentially
958 * usefull.
959 */
960 INP_INFO_RLOCK(&V_tcbinfo);
961 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
962 if (inpb->inp_flags & INP_TIMEWAIT)
963 continue;
964 INP_WLOCK(inpb);
965 if ((tcpb = intotcpcb(inpb)) != NULL) {
966 tcp_reass_flush(tcpb);
967 tcp_clean_sackreport(tcpb);
968 }
969 INP_WUNLOCK(inpb);
970 }
971 INP_INFO_RUNLOCK(&V_tcbinfo);
972 CURVNET_RESTORE();
973 }
974 VNET_LIST_RUNLOCK_NOSLEEP();
975}
976
977/*
978 * Notify a tcp user of an asynchronous error;
979 * store error as soft error, but wake up user
980 * (for now, won't do anything until can select for soft error).
981 *
982 * Do not wake up user since there currently is no mechanism for
983 * reporting soft errors (yet - a kqueue filter may be added).
984 */
985static struct inpcb *
986tcp_notify(struct inpcb *inp, int error)
987{
988 struct tcpcb *tp;
989
990 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
991 INP_WLOCK_ASSERT(inp);
992
993 if ((inp->inp_flags & INP_TIMEWAIT) ||
994 (inp->inp_flags & INP_DROPPED))
995 return (inp);
996
997 tp = intotcpcb(inp);
998 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
999
1000 /*
1001 * Ignore some errors if we are hooked up.
1002 * If connection hasn't completed, has retransmitted several times,
1003 * and receives a second error, give up now. This is better
1004 * than waiting a long time to establish a connection that
1005 * can never complete.
1006 */
1007 if (tp->t_state == TCPS_ESTABLISHED &&
1008 (error == EHOSTUNREACH || error == ENETUNREACH ||
1009 error == EHOSTDOWN)) {
1010 return (inp);
1011 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
1012 tp->t_softerror) {
1013 tp = tcp_drop(tp, error);
1014 if (tp != NULL)
1015 return (inp);
1016 else
1017 return (NULL);
1018 } else {
1019 tp->t_softerror = error;
1020 return (inp);
1021 }
1022#if 0
1023 wakeup( &so->so_timeo);
1024 sorwakeup(so);
1025 sowwakeup(so);
1026#endif
1027}
1028
1029static int
1030tcp_pcblist(SYSCTL_HANDLER_ARGS)
1031{
1032 int error, i, m, n, pcb_count;
1033 struct inpcb *inp, **inp_list;
1034 inp_gen_t gencnt;
1035 struct xinpgen xig;
1036
1037 /*
1038 * The process of preparing the TCB list is too time-consuming and
1039 * resource-intensive to repeat twice on every request.
1040 */
1041 if (req->oldptr == NULL) {
1042 n = V_tcbinfo.ipi_count + syncache_pcbcount();
1043 n += imax(n / 8, 10);
1044 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
1045 return (0);
1046 }
1047
1048 if (req->newptr != NULL)
1049 return (EPERM);
1050
1051 /*
1052 * OK, now we're committed to doing something.
1053 */
1054 INP_INFO_RLOCK(&V_tcbinfo);
1055 gencnt = V_tcbinfo.ipi_gencnt;
1056 n = V_tcbinfo.ipi_count;
1057 INP_INFO_RUNLOCK(&V_tcbinfo);
1058
1059 m = syncache_pcbcount();
1060
1061 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
1062 + (n + m) * sizeof(struct xtcpcb));
1063 if (error != 0)
1064 return (error);
1065
1066 xig.xig_len = sizeof xig;
1067 xig.xig_count = n + m;
1068 xig.xig_gen = gencnt;
1069 xig.xig_sogen = so_gencnt;
1070 error = SYSCTL_OUT(req, &xig, sizeof xig);
1071 if (error)
1072 return (error);
1073
1074 error = syncache_pcblist(req, m, &pcb_count);
1075 if (error)
1076 return (error);
1077
1078 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
1079 if (inp_list == NULL)
1080 return (ENOMEM);
1081
1082 INP_INFO_RLOCK(&V_tcbinfo);
1083 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
1084 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
1085 INP_WLOCK(inp);
1086 if (inp->inp_gencnt <= gencnt) {
1087 /*
1088 * XXX: This use of cr_cansee(), introduced with
1089 * TCP state changes, is not quite right, but for
1090 * now, better than nothing.
1091 */
1092 if (inp->inp_flags & INP_TIMEWAIT) {
1093 if (intotw(inp) != NULL)
1094 error = cr_cansee(req->td->td_ucred,
1095 intotw(inp)->tw_cred);
1096 else
1097 error = EINVAL; /* Skip this inp. */
1098 } else
1099 error = cr_canseeinpcb(req->td->td_ucred, inp);
1100 if (error == 0) {
1101 in_pcbref(inp);
1102 inp_list[i++] = inp;
1103 }
1104 }
1105 INP_WUNLOCK(inp);
1106 }
1107 INP_INFO_RUNLOCK(&V_tcbinfo);
1108 n = i;
1109
1110 error = 0;
1111 for (i = 0; i < n; i++) {
1112 inp = inp_list[i];
1113 INP_RLOCK(inp);
1114 if (inp->inp_gencnt <= gencnt) {
1115 struct xtcpcb xt;
1116 void *inp_ppcb;
1117
1118 bzero(&xt, sizeof(xt));
1119 xt.xt_len = sizeof xt;
1120 /* XXX should avoid extra copy */
1121 bcopy(inp, &xt.xt_inp, sizeof *inp);
1122 inp_ppcb = inp->inp_ppcb;
1123 if (inp_ppcb == NULL)
1124 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1125 else if (inp->inp_flags & INP_TIMEWAIT) {
1126 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
1127 xt.xt_tp.t_state = TCPS_TIME_WAIT;
1128 } else {
1129 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
1130 if (xt.xt_tp.t_timers)
1131 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
1132 }
1133 if (inp->inp_socket != NULL)
1134 sotoxsocket(inp->inp_socket, &xt.xt_socket);
1135 else {
1136 bzero(&xt.xt_socket, sizeof xt.xt_socket);
1137 xt.xt_socket.xso_protocol = IPPROTO_TCP;
1138 }
1139 xt.xt_inp.inp_gencnt = inp->inp_gencnt;
1140 INP_RUNLOCK(inp);
1141 error = SYSCTL_OUT(req, &xt, sizeof xt);
1142 } else
1143 INP_RUNLOCK(inp);
1144 }
1145 INP_INFO_WLOCK(&V_tcbinfo);
1146 for (i = 0; i < n; i++) {
1147 inp = inp_list[i];
1148 INP_WLOCK(inp);
1149 if (!in_pcbrele(inp))
1150 INP_WUNLOCK(inp);
1151 }
1152 INP_INFO_WUNLOCK(&V_tcbinfo);
1153
1154 if (!error) {
1155 /*
1156 * Give the user an updated idea of our state.
1157 * If the generation differs from what we told
1158 * her before, she knows that something happened
1159 * while we were processing this request, and it
1160 * might be necessary to retry.
1161 */
1162 INP_INFO_RLOCK(&V_tcbinfo);
1163 xig.xig_gen = V_tcbinfo.ipi_gencnt;
1164 xig.xig_sogen = so_gencnt;
1165 xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
1166 INP_INFO_RUNLOCK(&V_tcbinfo);
1167 error = SYSCTL_OUT(req, &xig, sizeof xig);
1168 }
1169 free(inp_list, M_TEMP);
1170 return (error);
1171}
1172
1173SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
1174 tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
1175
1176static int
1177tcp_getcred(SYSCTL_HANDLER_ARGS)
1178{
1179 struct xucred xuc;
1180 struct sockaddr_in addrs[2];
1181 struct inpcb *inp;
1182 int error;
1183
1184 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1185 if (error)
1186 return (error);
1187 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1188 if (error)
1189 return (error);
1190 INP_INFO_RLOCK(&V_tcbinfo);
1191 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr,
1192 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
1193 if (inp != NULL) {
1194 INP_RLOCK(inp);
1195 INP_INFO_RUNLOCK(&V_tcbinfo);
1196 if (inp->inp_socket == NULL)
1197 error = ENOENT;
1198 if (error == 0)
1199 error = cr_canseeinpcb(req->td->td_ucred, inp);
1200 if (error == 0)
1201 cru2x(inp->inp_cred, &xuc);
1202 INP_RUNLOCK(inp);
1203 } else {
1204 INP_INFO_RUNLOCK(&V_tcbinfo);
1205 error = ENOENT;
1206 }
1207 if (error == 0)
1208 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1209 return (error);
1210}
1211
1212SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
1213 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1214 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
1215
1216#ifdef INET6
1217static int
1218tcp6_getcred(SYSCTL_HANDLER_ARGS)
1219{
1220 struct xucred xuc;
1221 struct sockaddr_in6 addrs[2];
1222 struct inpcb *inp;
1223 int error, mapped = 0;
1224
1225 error = priv_check(req->td, PRIV_NETINET_GETCRED);
1226 if (error)
1227 return (error);
1228 error = SYSCTL_IN(req, addrs, sizeof(addrs));
1229 if (error)
1230 return (error);
1231 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
1232 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
1233 return (error);
1234 }
1235 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
1236 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
1237 mapped = 1;
1238 else
1239 return (EINVAL);
1240 }
1241
1242 INP_INFO_RLOCK(&V_tcbinfo);
1243 if (mapped == 1)
1244 inp = in_pcblookup_hash(&V_tcbinfo,
1245 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
1246 addrs[1].sin6_port,
1247 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
1248 addrs[0].sin6_port,
1249 0, NULL);
1250 else
1251 inp = in6_pcblookup_hash(&V_tcbinfo,
1252 &addrs[1].sin6_addr, addrs[1].sin6_port,
1253 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL);
1254 if (inp != NULL) {
1255 INP_RLOCK(inp);
1256 INP_INFO_RUNLOCK(&V_tcbinfo);
1257 if (inp->inp_socket == NULL)
1258 error = ENOENT;
1259 if (error == 0)
1260 error = cr_canseeinpcb(req->td->td_ucred, inp);
1261 if (error == 0)
1262 cru2x(inp->inp_cred, &xuc);
1263 INP_RUNLOCK(inp);
1264 } else {
1265 INP_INFO_RUNLOCK(&V_tcbinfo);
1266 error = ENOENT;
1267 }
1268 if (error == 0)
1269 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
1270 return (error);
1271}
1272
1273SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
1274 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
1275 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
1276#endif
1277
1278
1279void
1280tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
1281{
1282 struct ip *ip = vip;
1283 struct tcphdr *th;
1284 struct in_addr faddr;
1285 struct inpcb *inp;
1286 struct tcpcb *tp;
1287 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1288 struct icmp *icp;
1289 struct in_conninfo inc;
1290 tcp_seq icmp_tcp_seq;
1291 int mtu;
1292
1293 faddr = ((struct sockaddr_in *)sa)->sin_addr;
1294 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
1295 return;
1296
1297 if (cmd == PRC_MSGSIZE)
1298 notify = tcp_mtudisc;
1299 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
1300 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
1301 notify = tcp_drop_syn_sent;
1302 /*
1303 * Redirects don't need to be handled up here.
1304 */
1305 else if (PRC_IS_REDIRECT(cmd))
1306 return;
1307 /*
1308 * Source quench is depreciated.
1309 */
1310 else if (cmd == PRC_QUENCH)
1311 return;
1312 /*
1313 * Hostdead is ugly because it goes linearly through all PCBs.
1314 * XXX: We never get this from ICMP, otherwise it makes an
1315 * excellent DoS attack on machines with many connections.
1316 */
1317 else if (cmd == PRC_HOSTDEAD)
1318 ip = NULL;
1319 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
1320 return;
1321 if (ip != NULL) {
1322 icp = (struct icmp *)((caddr_t)ip
1323 - offsetof(struct icmp, icmp_ip));
1324 th = (struct tcphdr *)((caddr_t)ip
1325 + (ip->ip_hl << 2));
1326 INP_INFO_WLOCK(&V_tcbinfo);
1327 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport,
1328 ip->ip_src, th->th_sport, 0, NULL);
1329 if (inp != NULL) {
1330 INP_WLOCK(inp);
1331 if (!(inp->inp_flags & INP_TIMEWAIT) &&
1332 !(inp->inp_flags & INP_DROPPED) &&
1333 !(inp->inp_socket == NULL)) {
1334 icmp_tcp_seq = htonl(th->th_seq);
1335 tp = intotcpcb(inp);
1336 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) &&
1337 SEQ_LT(icmp_tcp_seq, tp->snd_max)) {
1338 if (cmd == PRC_MSGSIZE) {
1339 /*
1340 * MTU discovery:
1341 * If we got a needfrag set the MTU
1342 * in the route to the suggested new
1343 * value (if given) and then notify.
1344 */
1345 bzero(&inc, sizeof(inc));
1346 inc.inc_faddr = faddr;
1347 inc.inc_fibnum =
1348 inp->inp_inc.inc_fibnum;
1349
1350 mtu = ntohs(icp->icmp_nextmtu);
1351 /*
1352 * If no alternative MTU was
1353 * proposed, try the next smaller
1354 * one. ip->ip_len has already
1355 * been swapped in icmp_input().
1356 */
1357 if (!mtu)
1358 mtu = ip_next_mtu(ip->ip_len,
1359 1);
1360 if (mtu < V_tcp_minmss
1361 + sizeof(struct tcpiphdr))
1362 mtu = V_tcp_minmss
1363 + sizeof(struct tcpiphdr);
1364 /*
1365 * Only cache the the MTU if it
1366 * is smaller than the interface
1367 * or route MTU. tcp_mtudisc()
1368 * will do right thing by itself.
1369 */
1370 if (mtu <= tcp_maxmtu(&inc, NULL))
1371 tcp_hc_updatemtu(&inc, mtu);
1372 }
1373
1374 inp = (*notify)(inp, inetctlerrmap[cmd]);
1375 }
1376 }
1377 if (inp != NULL)
1378 INP_WUNLOCK(inp);
1379 } else {
1380 bzero(&inc, sizeof(inc));
1381 inc.inc_fport = th->th_dport;
1382 inc.inc_lport = th->th_sport;
1383 inc.inc_faddr = faddr;
1384 inc.inc_laddr = ip->ip_src;
1385 syncache_unreach(&inc, th);
1386 }
1387 INP_INFO_WUNLOCK(&V_tcbinfo);
1388 } else
1389 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
1390}
1391
1392#ifdef INET6
1393void
1394tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d)
1395{
1396 struct tcphdr th;
1397 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
1398 struct ip6_hdr *ip6;
1399 struct mbuf *m;
1400 struct ip6ctlparam *ip6cp = NULL;
1401 const struct sockaddr_in6 *sa6_src = NULL;
1402 int off;
1403 struct tcp_portonly {
1404 u_int16_t th_sport;
1405 u_int16_t th_dport;
1406 } *thp;
1407
1408 if (sa->sa_family != AF_INET6 ||
1409 sa->sa_len != sizeof(struct sockaddr_in6))
1410 return;
1411
1412 if (cmd == PRC_MSGSIZE)
1413 notify = tcp_mtudisc;
1414 else if (!PRC_IS_REDIRECT(cmd) &&
1415 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
1416 return;
1417 /* Source quench is depreciated. */
1418 else if (cmd == PRC_QUENCH)
1419 return;
1420
1421 /* if the parameter is from icmp6, decode it. */
1422 if (d != NULL) {
1423 ip6cp = (struct ip6ctlparam *)d;
1424 m = ip6cp->ip6c_m;
1425 ip6 = ip6cp->ip6c_ip6;
1426 off = ip6cp->ip6c_off;
1427 sa6_src = ip6cp->ip6c_src;
1428 } else {
1429 m = NULL;
1430 ip6 = NULL;
1431 off = 0; /* fool gcc */
1432 sa6_src = &sa6_any;
1433 }
1434
1435 if (ip6 != NULL) {
1436 struct in_conninfo inc;
1437 /*
1438 * XXX: We assume that when IPV6 is non NULL,
1439 * M and OFF are valid.
1440 */
1441
1442 /* check if we can safely examine src and dst ports */
1443 if (m->m_pkthdr.len < off + sizeof(*thp))
1444 return;
1445
1446 bzero(&th, sizeof(th));
1447 m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
1448
1449 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
1450 (struct sockaddr *)ip6cp->ip6c_src,
1451 th.th_sport, cmd, NULL, notify);
1452
1453 bzero(&inc, sizeof(inc));
1454 inc.inc_fport = th.th_dport;
1455 inc.inc_lport = th.th_sport;
1456 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
1457 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
1458 inc.inc_flags |= INC_ISIPV6;
1459 INP_INFO_WLOCK(&V_tcbinfo);
1460 syncache_unreach(&inc, &th);
1461 INP_INFO_WUNLOCK(&V_tcbinfo);
1462 } else
1463 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src,
1464 0, cmd, NULL, notify);
1465}
1466#endif /* INET6 */
1467
1468
1469/*
1470 * Following is where TCP initial sequence number generation occurs.
1471 *
1472 * There are two places where we must use initial sequence numbers:
1473 * 1. In SYN-ACK packets.
1474 * 2. In SYN packets.
1475 *
1476 * All ISNs for SYN-ACK packets are generated by the syncache. See
1477 * tcp_syncache.c for details.
1478 *
1479 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
1480 * depends on this property. In addition, these ISNs should be
1481 * unguessable so as to prevent connection hijacking. To satisfy
1482 * the requirements of this situation, the algorithm outlined in
1483 * RFC 1948 is used, with only small modifications.
1484 *
1485 * Implementation details:
1486 *
1487 * Time is based off the system timer, and is corrected so that it
1488 * increases by one megabyte per second. This allows for proper
1489 * recycling on high speed LANs while still leaving over an hour
1490 * before rollover.
1491 *
1492 * As reading the *exact* system time is too expensive to be done
1493 * whenever setting up a TCP connection, we increment the time
1494 * offset in two ways. First, a small random positive increment
1495 * is added to isn_offset for each connection that is set up.
1496 * Second, the function tcp_isn_tick fires once per clock tick
1497 * and increments isn_offset as necessary so that sequence numbers
1498 * are incremented at approximately ISN_BYTES_PER_SECOND. The
1499 * random positive increments serve only to ensure that the same
1500 * exact sequence number is never sent out twice (as could otherwise
1501 * happen when a port is recycled in less than the system tick
1502 * interval.)
1503 *
1504 * net.inet.tcp.isn_reseed_interval controls the number of seconds
1505 * between seeding of isn_secret. This is normally set to zero,
1506 * as reseeding should not be necessary.
1507 *
1508 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
1509 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
1510 * general, this means holding an exclusive (write) lock.
1511 */
1512
1513#define ISN_BYTES_PER_SECOND 1048576
1514#define ISN_STATIC_INCREMENT 4096
1515#define ISN_RANDOM_INCREMENT (4096 - 1)
1516
|
1517STATIC_VNET_DEFINE(u_char, isn_secret[32]);
1518STATIC_VNET_DEFINE(int, isn_last_reseed);
1519STATIC_VNET_DEFINE(u_int32_t, isn_offset);
1520STATIC_VNET_DEFINE(u_int32_t, isn_offset_old);
| 1517static VNET_DEFINE(u_char, isn_secret[32]);
1518static VNET_DEFINE(int, isn_last_reseed);
1519static VNET_DEFINE(u_int32_t, isn_offset);
1520static VNET_DEFINE(u_int32_t, isn_offset_old);
|
1521
1522#define V_isn_secret VNET(isn_secret)
1523#define V_isn_last_reseed VNET(isn_last_reseed)
1524#define V_isn_offset VNET(isn_offset)
1525#define V_isn_offset_old VNET(isn_offset_old)
1526
1527tcp_seq
1528tcp_new_isn(struct tcpcb *tp)
1529{
1530 MD5_CTX isn_ctx;
1531 u_int32_t md5_buffer[4];
1532 tcp_seq new_isn;
1533
1534 INP_WLOCK_ASSERT(tp->t_inpcb);
1535
1536 ISN_LOCK();
1537 /* Seed if this is the first use, reseed if requested. */
1538 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1539 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1540 < (u_int)ticks))) {
1541 read_random(&V_isn_secret, sizeof(V_isn_secret));
1542 V_isn_last_reseed = ticks;
1543 }
1544
1545 /* Compute the md5 hash and return the ISN. */
1546 MD5Init(&isn_ctx);
1547 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1548 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1549#ifdef INET6
1550 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1551 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1552 sizeof(struct in6_addr));
1553 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1554 sizeof(struct in6_addr));
1555 } else
1556#endif
1557 {
1558 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1559 sizeof(struct in_addr));
1560 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1561 sizeof(struct in_addr));
1562 }
1563 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1564 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1565 new_isn = (tcp_seq) md5_buffer[0];
1566 V_isn_offset += ISN_STATIC_INCREMENT +
1567 (arc4random() & ISN_RANDOM_INCREMENT);
1568 new_isn += V_isn_offset;
1569 ISN_UNLOCK();
1570 return (new_isn);
1571}
1572
1573/*
1574 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary
1575 * to keep time flowing at a relatively constant rate. If the random
1576 * increments have already pushed us past the projected offset, do nothing.
1577 */
1578static void
1579tcp_isn_tick(void *xtp)
1580{
1581 VNET_ITERATOR_DECL(vnet_iter);
1582 u_int32_t projected_offset;
1583
1584 VNET_LIST_RLOCK_NOSLEEP();
1585 ISN_LOCK();
1586 VNET_FOREACH(vnet_iter) {
1587 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */
1588 projected_offset =
1589 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100;
1590
1591 if (SEQ_GT(projected_offset, V_isn_offset))
1592 V_isn_offset = projected_offset;
1593
1594 V_isn_offset_old = V_isn_offset;
1595 CURVNET_RESTORE();
1596 }
1597 ISN_UNLOCK();
1598 VNET_LIST_RUNLOCK_NOSLEEP();
1599 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL);
1600}
1601
1602/*
1603 * When a specific ICMP unreachable message is received and the
1604 * connection state is SYN-SENT, drop the connection. This behavior
1605 * is controlled by the icmp_may_rst sysctl.
1606 */
1607struct inpcb *
1608tcp_drop_syn_sent(struct inpcb *inp, int errno)
1609{
1610 struct tcpcb *tp;
1611
1612 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1613 INP_WLOCK_ASSERT(inp);
1614
1615 if ((inp->inp_flags & INP_TIMEWAIT) ||
1616 (inp->inp_flags & INP_DROPPED))
1617 return (inp);
1618
1619 tp = intotcpcb(inp);
1620 if (tp->t_state != TCPS_SYN_SENT)
1621 return (inp);
1622
1623 tp = tcp_drop(tp, errno);
1624 if (tp != NULL)
1625 return (inp);
1626 else
1627 return (NULL);
1628}
1629
1630/*
1631 * When `need fragmentation' ICMP is received, update our idea of the MSS
1632 * based on the new value in the route. Also nudge TCP to send something,
1633 * since we know the packet we just sent was dropped.
1634 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1635 */
1636struct inpcb *
1637tcp_mtudisc(struct inpcb *inp, int errno)
1638{
1639 struct tcpcb *tp;
1640 struct socket *so;
1641
1642 INP_WLOCK_ASSERT(inp);
1643 if ((inp->inp_flags & INP_TIMEWAIT) ||
1644 (inp->inp_flags & INP_DROPPED))
1645 return (inp);
1646
1647 tp = intotcpcb(inp);
1648 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1649
1650 tcp_mss_update(tp, -1, NULL, NULL);
1651
1652 so = inp->inp_socket;
1653 SOCKBUF_LOCK(&so->so_snd);
1654 /* If the mss is larger than the socket buffer, decrease the mss. */
1655 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1656 tp->t_maxseg = so->so_snd.sb_hiwat;
1657 SOCKBUF_UNLOCK(&so->so_snd);
1658
1659 TCPSTAT_INC(tcps_mturesent);
1660 tp->t_rtttime = 0;
1661 tp->snd_nxt = tp->snd_una;
1662 tcp_free_sackholes(tp);
1663 tp->snd_recover = tp->snd_max;
1664 if (tp->t_flags & TF_SACK_PERMIT)
1665 EXIT_FASTRECOVERY(tp->t_flags);
1666 tcp_output_send(tp);
1667 return (inp);
1668}
1669
1670/*
1671 * Look-up the routing entry to the peer of this inpcb. If no route
1672 * is found and it cannot be allocated, then return 0. This routine
1673 * is called by TCP routines that access the rmx structure and by
1674 * tcp_mss_update to get the peer/interface MTU.
1675 */
1676u_long
1677tcp_maxmtu(struct in_conninfo *inc, int *flags)
1678{
1679 struct route sro;
1680 struct sockaddr_in *dst;
1681 struct ifnet *ifp;
1682 u_long maxmtu = 0;
1683
1684 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1685
1686 bzero(&sro, sizeof(sro));
1687 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1688 dst = (struct sockaddr_in *)&sro.ro_dst;
1689 dst->sin_family = AF_INET;
1690 dst->sin_len = sizeof(*dst);
1691 dst->sin_addr = inc->inc_faddr;
1692 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1693 }
1694 if (sro.ro_rt != NULL) {
1695 ifp = sro.ro_rt->rt_ifp;
1696 if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
1697 maxmtu = ifp->if_mtu;
1698 else
1699 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
1700
1701 /* Report additional interface capabilities. */
1702 if (flags != NULL) {
1703 if (ifp->if_capenable & IFCAP_TSO4 &&
1704 ifp->if_hwassist & CSUM_TSO)
1705 *flags |= CSUM_TSO;
1706 }
1707 RTFREE(sro.ro_rt);
1708 }
1709 return (maxmtu);
1710}
1711
1712#ifdef INET6
1713u_long
1714tcp_maxmtu6(struct in_conninfo *inc, int *flags)
1715{
1716 struct route_in6 sro6;
1717 struct ifnet *ifp;
1718 u_long maxmtu = 0;
1719
1720 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1721
1722 bzero(&sro6, sizeof(sro6));
1723 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1724 sro6.ro_dst.sin6_family = AF_INET6;
1725 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1726 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1727 rtalloc_ign((struct route *)&sro6, 0);
1728 }
1729 if (sro6.ro_rt != NULL) {
1730 ifp = sro6.ro_rt->rt_ifp;
1731 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
1732 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1733 else
1734 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
1735 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1736
1737 /* Report additional interface capabilities. */
1738 if (flags != NULL) {
1739 if (ifp->if_capenable & IFCAP_TSO6 &&
1740 ifp->if_hwassist & CSUM_TSO)
1741 *flags |= CSUM_TSO;
1742 }
1743 RTFREE(sro6.ro_rt);
1744 }
1745
1746 return (maxmtu);
1747}
1748#endif /* INET6 */
1749
1750#ifdef IPSEC
1751/* compute ESP/AH header size for TCP, including outer IP header. */
1752size_t
1753ipsec_hdrsiz_tcp(struct tcpcb *tp)
1754{
1755 struct inpcb *inp;
1756 struct mbuf *m;
1757 size_t hdrsiz;
1758 struct ip *ip;
1759#ifdef INET6
1760 struct ip6_hdr *ip6;
1761#endif
1762 struct tcphdr *th;
1763
1764 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1765 return (0);
1766 MGETHDR(m, M_DONTWAIT, MT_DATA);
1767 if (!m)
1768 return (0);
1769
1770#ifdef INET6
1771 if ((inp->inp_vflag & INP_IPV6) != 0) {
1772 ip6 = mtod(m, struct ip6_hdr *);
1773 th = (struct tcphdr *)(ip6 + 1);
1774 m->m_pkthdr.len = m->m_len =
1775 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1776 tcpip_fillheaders(inp, ip6, th);
1777 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1778 } else
1779#endif /* INET6 */
1780 {
1781 ip = mtod(m, struct ip *);
1782 th = (struct tcphdr *)(ip + 1);
1783 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1784 tcpip_fillheaders(inp, ip, th);
1785 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1786 }
1787
1788 m_free(m);
1789 return (hdrsiz);
1790}
1791#endif /* IPSEC */
1792
1793#ifdef TCP_SIGNATURE
1794/*
1795 * Callback function invoked by m_apply() to digest TCP segment data
1796 * contained within an mbuf chain.
1797 */
1798static int
1799tcp_signature_apply(void *fstate, void *data, u_int len)
1800{
1801
1802 MD5Update(fstate, (u_char *)data, len);
1803 return (0);
1804}
1805
1806/*
1807 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1808 *
1809 * Parameters:
1810 * m pointer to head of mbuf chain
1811 * _unused
1812 * len length of TCP segment data, excluding options
1813 * optlen length of TCP segment options
1814 * buf pointer to storage for computed MD5 digest
1815 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1816 *
1817 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1818 * When called from tcp_input(), we can be sure that th_sum has been
1819 * zeroed out and verified already.
1820 *
1821 * Return 0 if successful, otherwise return -1.
1822 *
1823 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1824 * search with the destination IP address, and a 'magic SPI' to be
1825 * determined by the application. This is hardcoded elsewhere to 1179
1826 * right now. Another branch of this code exists which uses the SPD to
1827 * specify per-application flows but it is unstable.
1828 */
1829int
1830tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1831 u_char *buf, u_int direction)
1832{
1833 union sockaddr_union dst;
1834 struct ippseudo ippseudo;
1835 MD5_CTX ctx;
1836 int doff;
1837 struct ip *ip;
1838 struct ipovly *ipovly;
1839 struct secasvar *sav;
1840 struct tcphdr *th;
1841#ifdef INET6
1842 struct ip6_hdr *ip6;
1843 struct in6_addr in6;
1844 char ip6buf[INET6_ADDRSTRLEN];
1845 uint32_t plen;
1846 uint16_t nhdr;
1847#endif
1848 u_short savecsum;
1849
1850 KASSERT(m != NULL, ("NULL mbuf chain"));
1851 KASSERT(buf != NULL, ("NULL signature pointer"));
1852
1853 /* Extract the destination from the IP header in the mbuf. */
1854 bzero(&dst, sizeof(union sockaddr_union));
1855 ip = mtod(m, struct ip *);
1856#ifdef INET6
1857 ip6 = NULL; /* Make the compiler happy. */
1858#endif
1859 switch (ip->ip_v) {
1860 case IPVERSION:
1861 dst.sa.sa_len = sizeof(struct sockaddr_in);
1862 dst.sa.sa_family = AF_INET;
1863 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1864 ip->ip_src : ip->ip_dst;
1865 break;
1866#ifdef INET6
1867 case (IPV6_VERSION >> 4):
1868 ip6 = mtod(m, struct ip6_hdr *);
1869 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1870 dst.sa.sa_family = AF_INET6;
1871 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1872 ip6->ip6_src : ip6->ip6_dst;
1873 break;
1874#endif
1875 default:
1876 return (EINVAL);
1877 /* NOTREACHED */
1878 break;
1879 }
1880
1881 /* Look up an SADB entry which matches the address of the peer. */
1882 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1883 if (sav == NULL) {
1884 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
1885 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
1886#ifdef INET6
1887 (ip->ip_v == (IPV6_VERSION >> 4)) ?
1888 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
1889#endif
1890 "(unsupported)"));
1891 return (EINVAL);
1892 }
1893
1894 MD5Init(&ctx);
1895 /*
1896 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
1897 *
1898 * XXX The ippseudo header MUST be digested in network byte order,
1899 * or else we'll fail the regression test. Assume all fields we've
1900 * been doing arithmetic on have been in host byte order.
1901 * XXX One cannot depend on ipovly->ih_len here. When called from
1902 * tcp_output(), the underlying ip_len member has not yet been set.
1903 */
1904 switch (ip->ip_v) {
1905 case IPVERSION:
1906 ipovly = (struct ipovly *)ip;
1907 ippseudo.ippseudo_src = ipovly->ih_src;
1908 ippseudo.ippseudo_dst = ipovly->ih_dst;
1909 ippseudo.ippseudo_pad = 0;
1910 ippseudo.ippseudo_p = IPPROTO_TCP;
1911 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
1912 optlen);
1913 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
1914
1915 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
1916 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
1917 break;
1918#ifdef INET6
1919 /*
1920 * RFC 2385, 2.0 Proposal
1921 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
1922 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
1923 * extended next header value (to form 32 bits), and 32-bit segment
1924 * length.
1925 * Note: Upper-Layer Packet Length comes before Next Header.
1926 */
1927 case (IPV6_VERSION >> 4):
1928 in6 = ip6->ip6_src;
1929 in6_clearscope(&in6);
1930 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1931 in6 = ip6->ip6_dst;
1932 in6_clearscope(&in6);
1933 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1934 plen = htonl(len + sizeof(struct tcphdr) + optlen);
1935 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
1936 nhdr = 0;
1937 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1938 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1939 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1940 nhdr = IPPROTO_TCP;
1941 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1942
1943 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
1944 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
1945 break;
1946#endif
1947 default:
1948 return (EINVAL);
1949 /* NOTREACHED */
1950 break;
1951 }
1952
1953
1954 /*
1955 * Step 2: Update MD5 hash with TCP header, excluding options.
1956 * The TCP checksum must be set to zero.
1957 */
1958 savecsum = th->th_sum;
1959 th->th_sum = 0;
1960 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
1961 th->th_sum = savecsum;
1962
1963 /*
1964 * Step 3: Update MD5 hash with TCP segment data.
1965 * Use m_apply() to avoid an early m_pullup().
1966 */
1967 if (len > 0)
1968 m_apply(m, doff, len, tcp_signature_apply, &ctx);
1969
1970 /*
1971 * Step 4: Update MD5 hash with shared secret.
1972 */
1973 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
1974 MD5Final(buf, &ctx);
1975
1976 key_sa_recordxfer(sav, m);
1977 KEY_FREESAV(&sav);
1978 return (0);
1979}
1980#endif /* TCP_SIGNATURE */
1981
1982static int
1983sysctl_drop(SYSCTL_HANDLER_ARGS)
1984{
1985 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
1986 struct sockaddr_storage addrs[2];
1987 struct inpcb *inp;
1988 struct tcpcb *tp;
1989 struct tcptw *tw;
1990 struct sockaddr_in *fin, *lin;
1991#ifdef INET6
1992 struct sockaddr_in6 *fin6, *lin6;
1993#endif
1994 int error;
1995
1996 inp = NULL;
1997 fin = lin = NULL;
1998#ifdef INET6
1999 fin6 = lin6 = NULL;
2000#endif
2001 error = 0;
2002
2003 if (req->oldptr != NULL || req->oldlen != 0)
2004 return (EINVAL);
2005 if (req->newptr == NULL)
2006 return (EPERM);
2007 if (req->newlen < sizeof(addrs))
2008 return (ENOMEM);
2009 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2010 if (error)
2011 return (error);
2012
2013 switch (addrs[0].ss_family) {
2014#ifdef INET6
2015 case AF_INET6:
2016 fin6 = (struct sockaddr_in6 *)&addrs[0];
2017 lin6 = (struct sockaddr_in6 *)&addrs[1];
2018 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2019 lin6->sin6_len != sizeof(struct sockaddr_in6))
2020 return (EINVAL);
2021 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2022 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2023 return (EINVAL);
2024 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2025 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2026 fin = (struct sockaddr_in *)&addrs[0];
2027 lin = (struct sockaddr_in *)&addrs[1];
2028 break;
2029 }
2030 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2031 if (error)
2032 return (error);
2033 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2034 if (error)
2035 return (error);
2036 break;
2037#endif
2038 case AF_INET:
2039 fin = (struct sockaddr_in *)&addrs[0];
2040 lin = (struct sockaddr_in *)&addrs[1];
2041 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2042 lin->sin_len != sizeof(struct sockaddr_in))
2043 return (EINVAL);
2044 break;
2045 default:
2046 return (EINVAL);
2047 }
2048 INP_INFO_WLOCK(&V_tcbinfo);
2049 switch (addrs[0].ss_family) {
2050#ifdef INET6
2051 case AF_INET6:
2052 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr,
2053 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0,
2054 NULL);
2055 break;
2056#endif
2057 case AF_INET:
2058 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr,
2059 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL);
2060 break;
2061 }
2062 if (inp != NULL) {
2063 INP_WLOCK(inp);
2064 if (inp->inp_flags & INP_TIMEWAIT) {
2065 /*
2066 * XXXRW: There currently exists a state where an
2067 * inpcb is present, but its timewait state has been
2068 * discarded. For now, don't allow dropping of this
2069 * type of inpcb.
2070 */
2071 tw = intotw(inp);
2072 if (tw != NULL)
2073 tcp_twclose(tw, 0);
2074 else
2075 INP_WUNLOCK(inp);
2076 } else if (!(inp->inp_flags & INP_DROPPED) &&
2077 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2078 tp = intotcpcb(inp);
2079 tp = tcp_drop(tp, ECONNABORTED);
2080 if (tp != NULL)
2081 INP_WUNLOCK(inp);
2082 } else
2083 INP_WUNLOCK(inp);
2084 } else
2085 error = ESRCH;
2086 INP_INFO_WUNLOCK(&V_tcbinfo);
2087 return (error);
2088}
2089
2090SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2091 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2092 0, sysctl_drop, "", "Drop TCP connection");
2093
2094/*
2095 * Generate a standardized TCP log line for use throughout the
2096 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2097 * allow use in the interrupt context.
2098 *
2099 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2100 * NB: The function may return NULL if memory allocation failed.
2101 *
2102 * Due to header inclusion and ordering limitations the struct ip
2103 * and ip6_hdr pointers have to be passed as void pointers.
2104 */
2105char *
2106tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2107 const void *ip6hdr)
2108{
2109
2110 /* Is logging enabled? */
2111 if (tcp_log_in_vain == 0)
2112 return (NULL);
2113
2114 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2115}
2116
2117char *
2118tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2119 const void *ip6hdr)
2120{
2121
2122 /* Is logging enabled? */
2123 if (tcp_log_debug == 0)
2124 return (NULL);
2125
2126 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2127}
2128
2129static char *
2130tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2131 const void *ip6hdr)
2132{
2133 char *s, *sp;
2134 size_t size;
2135 struct ip *ip;
2136#ifdef INET6
2137 const struct ip6_hdr *ip6;
2138
2139 ip6 = (const struct ip6_hdr *)ip6hdr;
2140#endif /* INET6 */
2141 ip = (struct ip *)ip4hdr;
2142
2143 /*
2144 * The log line looks like this:
2145 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2146 */
2147 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2148 sizeof(PRINT_TH_FLAGS) + 1 +
2149#ifdef INET6
2150 2 * INET6_ADDRSTRLEN;
2151#else
2152 2 * INET_ADDRSTRLEN;
2153#endif /* INET6 */
2154
2155 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2156 if (s == NULL)
2157 return (NULL);
2158
2159 strcat(s, "TCP: [");
2160 sp = s + strlen(s);
2161
2162 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2163 inet_ntoa_r(inc->inc_faddr, sp);
2164 sp = s + strlen(s);
2165 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2166 sp = s + strlen(s);
2167 inet_ntoa_r(inc->inc_laddr, sp);
2168 sp = s + strlen(s);
2169 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2170#ifdef INET6
2171 } else if (inc) {
2172 ip6_sprintf(sp, &inc->inc6_faddr);
2173 sp = s + strlen(s);
2174 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2175 sp = s + strlen(s);
2176 ip6_sprintf(sp, &inc->inc6_laddr);
2177 sp = s + strlen(s);
2178 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2179 } else if (ip6 && th) {
2180 ip6_sprintf(sp, &ip6->ip6_src);
2181 sp = s + strlen(s);
2182 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2183 sp = s + strlen(s);
2184 ip6_sprintf(sp, &ip6->ip6_dst);
2185 sp = s + strlen(s);
2186 sprintf(sp, "]:%i", ntohs(th->th_dport));
2187#endif /* INET6 */
2188 } else if (ip && th) {
2189 inet_ntoa_r(ip->ip_src, sp);
2190 sp = s + strlen(s);
2191 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2192 sp = s + strlen(s);
2193 inet_ntoa_r(ip->ip_dst, sp);
2194 sp = s + strlen(s);
2195 sprintf(sp, "]:%i", ntohs(th->th_dport));
2196 } else {
2197 free(s, M_TCPLOG);
2198 return (NULL);
2199 }
2200 sp = s + strlen(s);
2201 if (th)
2202 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2203 if (*(s + size - 1) != '\0')
2204 panic("%s: string too long", __func__);
2205 return (s);
2206}
| 1521
1522#define V_isn_secret VNET(isn_secret)
1523#define V_isn_last_reseed VNET(isn_last_reseed)
1524#define V_isn_offset VNET(isn_offset)
1525#define V_isn_offset_old VNET(isn_offset_old)
1526
1527tcp_seq
1528tcp_new_isn(struct tcpcb *tp)
1529{
1530 MD5_CTX isn_ctx;
1531 u_int32_t md5_buffer[4];
1532 tcp_seq new_isn;
1533
1534 INP_WLOCK_ASSERT(tp->t_inpcb);
1535
1536 ISN_LOCK();
1537 /* Seed if this is the first use, reseed if requested. */
1538 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
1539 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
1540 < (u_int)ticks))) {
1541 read_random(&V_isn_secret, sizeof(V_isn_secret));
1542 V_isn_last_reseed = ticks;
1543 }
1544
1545 /* Compute the md5 hash and return the ISN. */
1546 MD5Init(&isn_ctx);
1547 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
1548 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
1549#ifdef INET6
1550 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
1551 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
1552 sizeof(struct in6_addr));
1553 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
1554 sizeof(struct in6_addr));
1555 } else
1556#endif
1557 {
1558 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
1559 sizeof(struct in_addr));
1560 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
1561 sizeof(struct in_addr));
1562 }
1563 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
1564 MD5Final((u_char *) &md5_buffer, &isn_ctx);
1565 new_isn = (tcp_seq) md5_buffer[0];
1566 V_isn_offset += ISN_STATIC_INCREMENT +
1567 (arc4random() & ISN_RANDOM_INCREMENT);
1568 new_isn += V_isn_offset;
1569 ISN_UNLOCK();
1570 return (new_isn);
1571}
1572
1573/*
1574 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary
1575 * to keep time flowing at a relatively constant rate. If the random
1576 * increments have already pushed us past the projected offset, do nothing.
1577 */
1578static void
1579tcp_isn_tick(void *xtp)
1580{
1581 VNET_ITERATOR_DECL(vnet_iter);
1582 u_int32_t projected_offset;
1583
1584 VNET_LIST_RLOCK_NOSLEEP();
1585 ISN_LOCK();
1586 VNET_FOREACH(vnet_iter) {
1587 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */
1588 projected_offset =
1589 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100;
1590
1591 if (SEQ_GT(projected_offset, V_isn_offset))
1592 V_isn_offset = projected_offset;
1593
1594 V_isn_offset_old = V_isn_offset;
1595 CURVNET_RESTORE();
1596 }
1597 ISN_UNLOCK();
1598 VNET_LIST_RUNLOCK_NOSLEEP();
1599 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL);
1600}
1601
1602/*
1603 * When a specific ICMP unreachable message is received and the
1604 * connection state is SYN-SENT, drop the connection. This behavior
1605 * is controlled by the icmp_may_rst sysctl.
1606 */
1607struct inpcb *
1608tcp_drop_syn_sent(struct inpcb *inp, int errno)
1609{
1610 struct tcpcb *tp;
1611
1612 INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
1613 INP_WLOCK_ASSERT(inp);
1614
1615 if ((inp->inp_flags & INP_TIMEWAIT) ||
1616 (inp->inp_flags & INP_DROPPED))
1617 return (inp);
1618
1619 tp = intotcpcb(inp);
1620 if (tp->t_state != TCPS_SYN_SENT)
1621 return (inp);
1622
1623 tp = tcp_drop(tp, errno);
1624 if (tp != NULL)
1625 return (inp);
1626 else
1627 return (NULL);
1628}
1629
1630/*
1631 * When `need fragmentation' ICMP is received, update our idea of the MSS
1632 * based on the new value in the route. Also nudge TCP to send something,
1633 * since we know the packet we just sent was dropped.
1634 * This duplicates some code in the tcp_mss() function in tcp_input.c.
1635 */
1636struct inpcb *
1637tcp_mtudisc(struct inpcb *inp, int errno)
1638{
1639 struct tcpcb *tp;
1640 struct socket *so;
1641
1642 INP_WLOCK_ASSERT(inp);
1643 if ((inp->inp_flags & INP_TIMEWAIT) ||
1644 (inp->inp_flags & INP_DROPPED))
1645 return (inp);
1646
1647 tp = intotcpcb(inp);
1648 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
1649
1650 tcp_mss_update(tp, -1, NULL, NULL);
1651
1652 so = inp->inp_socket;
1653 SOCKBUF_LOCK(&so->so_snd);
1654 /* If the mss is larger than the socket buffer, decrease the mss. */
1655 if (so->so_snd.sb_hiwat < tp->t_maxseg)
1656 tp->t_maxseg = so->so_snd.sb_hiwat;
1657 SOCKBUF_UNLOCK(&so->so_snd);
1658
1659 TCPSTAT_INC(tcps_mturesent);
1660 tp->t_rtttime = 0;
1661 tp->snd_nxt = tp->snd_una;
1662 tcp_free_sackholes(tp);
1663 tp->snd_recover = tp->snd_max;
1664 if (tp->t_flags & TF_SACK_PERMIT)
1665 EXIT_FASTRECOVERY(tp->t_flags);
1666 tcp_output_send(tp);
1667 return (inp);
1668}
1669
1670/*
1671 * Look-up the routing entry to the peer of this inpcb. If no route
1672 * is found and it cannot be allocated, then return 0. This routine
1673 * is called by TCP routines that access the rmx structure and by
1674 * tcp_mss_update to get the peer/interface MTU.
1675 */
1676u_long
1677tcp_maxmtu(struct in_conninfo *inc, int *flags)
1678{
1679 struct route sro;
1680 struct sockaddr_in *dst;
1681 struct ifnet *ifp;
1682 u_long maxmtu = 0;
1683
1684 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
1685
1686 bzero(&sro, sizeof(sro));
1687 if (inc->inc_faddr.s_addr != INADDR_ANY) {
1688 dst = (struct sockaddr_in *)&sro.ro_dst;
1689 dst->sin_family = AF_INET;
1690 dst->sin_len = sizeof(*dst);
1691 dst->sin_addr = inc->inc_faddr;
1692 in_rtalloc_ign(&sro, 0, inc->inc_fibnum);
1693 }
1694 if (sro.ro_rt != NULL) {
1695 ifp = sro.ro_rt->rt_ifp;
1696 if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
1697 maxmtu = ifp->if_mtu;
1698 else
1699 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
1700
1701 /* Report additional interface capabilities. */
1702 if (flags != NULL) {
1703 if (ifp->if_capenable & IFCAP_TSO4 &&
1704 ifp->if_hwassist & CSUM_TSO)
1705 *flags |= CSUM_TSO;
1706 }
1707 RTFREE(sro.ro_rt);
1708 }
1709 return (maxmtu);
1710}
1711
1712#ifdef INET6
1713u_long
1714tcp_maxmtu6(struct in_conninfo *inc, int *flags)
1715{
1716 struct route_in6 sro6;
1717 struct ifnet *ifp;
1718 u_long maxmtu = 0;
1719
1720 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
1721
1722 bzero(&sro6, sizeof(sro6));
1723 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
1724 sro6.ro_dst.sin6_family = AF_INET6;
1725 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6);
1726 sro6.ro_dst.sin6_addr = inc->inc6_faddr;
1727 rtalloc_ign((struct route *)&sro6, 0);
1728 }
1729 if (sro6.ro_rt != NULL) {
1730 ifp = sro6.ro_rt->rt_ifp;
1731 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
1732 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
1733 else
1734 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
1735 IN6_LINKMTU(sro6.ro_rt->rt_ifp));
1736
1737 /* Report additional interface capabilities. */
1738 if (flags != NULL) {
1739 if (ifp->if_capenable & IFCAP_TSO6 &&
1740 ifp->if_hwassist & CSUM_TSO)
1741 *flags |= CSUM_TSO;
1742 }
1743 RTFREE(sro6.ro_rt);
1744 }
1745
1746 return (maxmtu);
1747}
1748#endif /* INET6 */
1749
1750#ifdef IPSEC
1751/* compute ESP/AH header size for TCP, including outer IP header. */
1752size_t
1753ipsec_hdrsiz_tcp(struct tcpcb *tp)
1754{
1755 struct inpcb *inp;
1756 struct mbuf *m;
1757 size_t hdrsiz;
1758 struct ip *ip;
1759#ifdef INET6
1760 struct ip6_hdr *ip6;
1761#endif
1762 struct tcphdr *th;
1763
1764 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
1765 return (0);
1766 MGETHDR(m, M_DONTWAIT, MT_DATA);
1767 if (!m)
1768 return (0);
1769
1770#ifdef INET6
1771 if ((inp->inp_vflag & INP_IPV6) != 0) {
1772 ip6 = mtod(m, struct ip6_hdr *);
1773 th = (struct tcphdr *)(ip6 + 1);
1774 m->m_pkthdr.len = m->m_len =
1775 sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
1776 tcpip_fillheaders(inp, ip6, th);
1777 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1778 } else
1779#endif /* INET6 */
1780 {
1781 ip = mtod(m, struct ip *);
1782 th = (struct tcphdr *)(ip + 1);
1783 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
1784 tcpip_fillheaders(inp, ip, th);
1785 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
1786 }
1787
1788 m_free(m);
1789 return (hdrsiz);
1790}
1791#endif /* IPSEC */
1792
1793#ifdef TCP_SIGNATURE
1794/*
1795 * Callback function invoked by m_apply() to digest TCP segment data
1796 * contained within an mbuf chain.
1797 */
1798static int
1799tcp_signature_apply(void *fstate, void *data, u_int len)
1800{
1801
1802 MD5Update(fstate, (u_char *)data, len);
1803 return (0);
1804}
1805
1806/*
1807 * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
1808 *
1809 * Parameters:
1810 * m pointer to head of mbuf chain
1811 * _unused
1812 * len length of TCP segment data, excluding options
1813 * optlen length of TCP segment options
1814 * buf pointer to storage for computed MD5 digest
1815 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
1816 *
1817 * We do this over ip, tcphdr, segment data, and the key in the SADB.
1818 * When called from tcp_input(), we can be sure that th_sum has been
1819 * zeroed out and verified already.
1820 *
1821 * Return 0 if successful, otherwise return -1.
1822 *
1823 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a
1824 * search with the destination IP address, and a 'magic SPI' to be
1825 * determined by the application. This is hardcoded elsewhere to 1179
1826 * right now. Another branch of this code exists which uses the SPD to
1827 * specify per-application flows but it is unstable.
1828 */
1829int
1830tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
1831 u_char *buf, u_int direction)
1832{
1833 union sockaddr_union dst;
1834 struct ippseudo ippseudo;
1835 MD5_CTX ctx;
1836 int doff;
1837 struct ip *ip;
1838 struct ipovly *ipovly;
1839 struct secasvar *sav;
1840 struct tcphdr *th;
1841#ifdef INET6
1842 struct ip6_hdr *ip6;
1843 struct in6_addr in6;
1844 char ip6buf[INET6_ADDRSTRLEN];
1845 uint32_t plen;
1846 uint16_t nhdr;
1847#endif
1848 u_short savecsum;
1849
1850 KASSERT(m != NULL, ("NULL mbuf chain"));
1851 KASSERT(buf != NULL, ("NULL signature pointer"));
1852
1853 /* Extract the destination from the IP header in the mbuf. */
1854 bzero(&dst, sizeof(union sockaddr_union));
1855 ip = mtod(m, struct ip *);
1856#ifdef INET6
1857 ip6 = NULL; /* Make the compiler happy. */
1858#endif
1859 switch (ip->ip_v) {
1860 case IPVERSION:
1861 dst.sa.sa_len = sizeof(struct sockaddr_in);
1862 dst.sa.sa_family = AF_INET;
1863 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
1864 ip->ip_src : ip->ip_dst;
1865 break;
1866#ifdef INET6
1867 case (IPV6_VERSION >> 4):
1868 ip6 = mtod(m, struct ip6_hdr *);
1869 dst.sa.sa_len = sizeof(struct sockaddr_in6);
1870 dst.sa.sa_family = AF_INET6;
1871 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
1872 ip6->ip6_src : ip6->ip6_dst;
1873 break;
1874#endif
1875 default:
1876 return (EINVAL);
1877 /* NOTREACHED */
1878 break;
1879 }
1880
1881 /* Look up an SADB entry which matches the address of the peer. */
1882 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
1883 if (sav == NULL) {
1884 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
1885 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
1886#ifdef INET6
1887 (ip->ip_v == (IPV6_VERSION >> 4)) ?
1888 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
1889#endif
1890 "(unsupported)"));
1891 return (EINVAL);
1892 }
1893
1894 MD5Init(&ctx);
1895 /*
1896 * Step 1: Update MD5 hash with IP(v6) pseudo-header.
1897 *
1898 * XXX The ippseudo header MUST be digested in network byte order,
1899 * or else we'll fail the regression test. Assume all fields we've
1900 * been doing arithmetic on have been in host byte order.
1901 * XXX One cannot depend on ipovly->ih_len here. When called from
1902 * tcp_output(), the underlying ip_len member has not yet been set.
1903 */
1904 switch (ip->ip_v) {
1905 case IPVERSION:
1906 ipovly = (struct ipovly *)ip;
1907 ippseudo.ippseudo_src = ipovly->ih_src;
1908 ippseudo.ippseudo_dst = ipovly->ih_dst;
1909 ippseudo.ippseudo_pad = 0;
1910 ippseudo.ippseudo_p = IPPROTO_TCP;
1911 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) +
1912 optlen);
1913 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo));
1914
1915 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip));
1916 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen;
1917 break;
1918#ifdef INET6
1919 /*
1920 * RFC 2385, 2.0 Proposal
1921 * For IPv6, the pseudo-header is as described in RFC 2460, namely the
1922 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero-
1923 * extended next header value (to form 32 bits), and 32-bit segment
1924 * length.
1925 * Note: Upper-Layer Packet Length comes before Next Header.
1926 */
1927 case (IPV6_VERSION >> 4):
1928 in6 = ip6->ip6_src;
1929 in6_clearscope(&in6);
1930 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1931 in6 = ip6->ip6_dst;
1932 in6_clearscope(&in6);
1933 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr));
1934 plen = htonl(len + sizeof(struct tcphdr) + optlen);
1935 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t));
1936 nhdr = 0;
1937 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1938 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1939 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1940 nhdr = IPPROTO_TCP;
1941 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t));
1942
1943 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr));
1944 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen;
1945 break;
1946#endif
1947 default:
1948 return (EINVAL);
1949 /* NOTREACHED */
1950 break;
1951 }
1952
1953
1954 /*
1955 * Step 2: Update MD5 hash with TCP header, excluding options.
1956 * The TCP checksum must be set to zero.
1957 */
1958 savecsum = th->th_sum;
1959 th->th_sum = 0;
1960 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr));
1961 th->th_sum = savecsum;
1962
1963 /*
1964 * Step 3: Update MD5 hash with TCP segment data.
1965 * Use m_apply() to avoid an early m_pullup().
1966 */
1967 if (len > 0)
1968 m_apply(m, doff, len, tcp_signature_apply, &ctx);
1969
1970 /*
1971 * Step 4: Update MD5 hash with shared secret.
1972 */
1973 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
1974 MD5Final(buf, &ctx);
1975
1976 key_sa_recordxfer(sav, m);
1977 KEY_FREESAV(&sav);
1978 return (0);
1979}
1980#endif /* TCP_SIGNATURE */
1981
1982static int
1983sysctl_drop(SYSCTL_HANDLER_ARGS)
1984{
1985 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
1986 struct sockaddr_storage addrs[2];
1987 struct inpcb *inp;
1988 struct tcpcb *tp;
1989 struct tcptw *tw;
1990 struct sockaddr_in *fin, *lin;
1991#ifdef INET6
1992 struct sockaddr_in6 *fin6, *lin6;
1993#endif
1994 int error;
1995
1996 inp = NULL;
1997 fin = lin = NULL;
1998#ifdef INET6
1999 fin6 = lin6 = NULL;
2000#endif
2001 error = 0;
2002
2003 if (req->oldptr != NULL || req->oldlen != 0)
2004 return (EINVAL);
2005 if (req->newptr == NULL)
2006 return (EPERM);
2007 if (req->newlen < sizeof(addrs))
2008 return (ENOMEM);
2009 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
2010 if (error)
2011 return (error);
2012
2013 switch (addrs[0].ss_family) {
2014#ifdef INET6
2015 case AF_INET6:
2016 fin6 = (struct sockaddr_in6 *)&addrs[0];
2017 lin6 = (struct sockaddr_in6 *)&addrs[1];
2018 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
2019 lin6->sin6_len != sizeof(struct sockaddr_in6))
2020 return (EINVAL);
2021 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
2022 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
2023 return (EINVAL);
2024 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
2025 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
2026 fin = (struct sockaddr_in *)&addrs[0];
2027 lin = (struct sockaddr_in *)&addrs[1];
2028 break;
2029 }
2030 error = sa6_embedscope(fin6, V_ip6_use_defzone);
2031 if (error)
2032 return (error);
2033 error = sa6_embedscope(lin6, V_ip6_use_defzone);
2034 if (error)
2035 return (error);
2036 break;
2037#endif
2038 case AF_INET:
2039 fin = (struct sockaddr_in *)&addrs[0];
2040 lin = (struct sockaddr_in *)&addrs[1];
2041 if (fin->sin_len != sizeof(struct sockaddr_in) ||
2042 lin->sin_len != sizeof(struct sockaddr_in))
2043 return (EINVAL);
2044 break;
2045 default:
2046 return (EINVAL);
2047 }
2048 INP_INFO_WLOCK(&V_tcbinfo);
2049 switch (addrs[0].ss_family) {
2050#ifdef INET6
2051 case AF_INET6:
2052 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr,
2053 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0,
2054 NULL);
2055 break;
2056#endif
2057 case AF_INET:
2058 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr,
2059 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL);
2060 break;
2061 }
2062 if (inp != NULL) {
2063 INP_WLOCK(inp);
2064 if (inp->inp_flags & INP_TIMEWAIT) {
2065 /*
2066 * XXXRW: There currently exists a state where an
2067 * inpcb is present, but its timewait state has been
2068 * discarded. For now, don't allow dropping of this
2069 * type of inpcb.
2070 */
2071 tw = intotw(inp);
2072 if (tw != NULL)
2073 tcp_twclose(tw, 0);
2074 else
2075 INP_WUNLOCK(inp);
2076 } else if (!(inp->inp_flags & INP_DROPPED) &&
2077 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
2078 tp = intotcpcb(inp);
2079 tp = tcp_drop(tp, ECONNABORTED);
2080 if (tp != NULL)
2081 INP_WUNLOCK(inp);
2082 } else
2083 INP_WUNLOCK(inp);
2084 } else
2085 error = ESRCH;
2086 INP_INFO_WUNLOCK(&V_tcbinfo);
2087 return (error);
2088}
2089
2090SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
2091 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
2092 0, sysctl_drop, "", "Drop TCP connection");
2093
2094/*
2095 * Generate a standardized TCP log line for use throughout the
2096 * tcp subsystem. Memory allocation is done with M_NOWAIT to
2097 * allow use in the interrupt context.
2098 *
2099 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
2100 * NB: The function may return NULL if memory allocation failed.
2101 *
2102 * Due to header inclusion and ordering limitations the struct ip
2103 * and ip6_hdr pointers have to be passed as void pointers.
2104 */
2105char *
2106tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2107 const void *ip6hdr)
2108{
2109
2110 /* Is logging enabled? */
2111 if (tcp_log_in_vain == 0)
2112 return (NULL);
2113
2114 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2115}
2116
2117char *
2118tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2119 const void *ip6hdr)
2120{
2121
2122 /* Is logging enabled? */
2123 if (tcp_log_debug == 0)
2124 return (NULL);
2125
2126 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
2127}
2128
2129static char *
2130tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2131 const void *ip6hdr)
2132{
2133 char *s, *sp;
2134 size_t size;
2135 struct ip *ip;
2136#ifdef INET6
2137 const struct ip6_hdr *ip6;
2138
2139 ip6 = (const struct ip6_hdr *)ip6hdr;
2140#endif /* INET6 */
2141 ip = (struct ip *)ip4hdr;
2142
2143 /*
2144 * The log line looks like this:
2145 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
2146 */
2147 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
2148 sizeof(PRINT_TH_FLAGS) + 1 +
2149#ifdef INET6
2150 2 * INET6_ADDRSTRLEN;
2151#else
2152 2 * INET_ADDRSTRLEN;
2153#endif /* INET6 */
2154
2155 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
2156 if (s == NULL)
2157 return (NULL);
2158
2159 strcat(s, "TCP: [");
2160 sp = s + strlen(s);
2161
2162 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
2163 inet_ntoa_r(inc->inc_faddr, sp);
2164 sp = s + strlen(s);
2165 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2166 sp = s + strlen(s);
2167 inet_ntoa_r(inc->inc_laddr, sp);
2168 sp = s + strlen(s);
2169 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2170#ifdef INET6
2171 } else if (inc) {
2172 ip6_sprintf(sp, &inc->inc6_faddr);
2173 sp = s + strlen(s);
2174 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
2175 sp = s + strlen(s);
2176 ip6_sprintf(sp, &inc->inc6_laddr);
2177 sp = s + strlen(s);
2178 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
2179 } else if (ip6 && th) {
2180 ip6_sprintf(sp, &ip6->ip6_src);
2181 sp = s + strlen(s);
2182 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2183 sp = s + strlen(s);
2184 ip6_sprintf(sp, &ip6->ip6_dst);
2185 sp = s + strlen(s);
2186 sprintf(sp, "]:%i", ntohs(th->th_dport));
2187#endif /* INET6 */
2188 } else if (ip && th) {
2189 inet_ntoa_r(ip->ip_src, sp);
2190 sp = s + strlen(s);
2191 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
2192 sp = s + strlen(s);
2193 inet_ntoa_r(ip->ip_dst, sp);
2194 sp = s + strlen(s);
2195 sprintf(sp, "]:%i", ntohs(th->th_dport));
2196 } else {
2197 free(s, M_TCPLOG);
2198 return (NULL);
2199 }
2200 sp = s + strlen(s);
2201 if (th)
2202 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS);
2203 if (*(s + size - 1) != '\0')
2204 panic("%s: string too long", __func__);
2205 return (s);
2206}
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