1
2/*
3 * Copyright (c) 2001-2002 Packet Design, LLC.
4 * All rights reserved.
5 *
6 * Subject to the following obligations and disclaimer of warranty,
7 * use and redistribution of this software, in source or object code
8 * forms, with or without modifications are expressly permitted by
9 * Packet Design; provided, however, that:
10 *
11 * (i) Any and all reproductions of the source or object code
12 * must include the copyright notice above and the following
13 * disclaimer of warranties; and
14 * (ii) No rights are granted, in any manner or form, to use
15 * Packet Design trademarks, including the mark "PACKET DESIGN"
16 * on advertising, endorsements, or otherwise except as such
17 * appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
22 * THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
23 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
24 * OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
25 * OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
26 * OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
27 * RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE
28 * LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
29 * OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
31 * DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
32 * USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
35 * THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
36 * THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * Author: Archie Cobbs <archie@freebsd.org>
39 *
| 1
2/*
3 * Copyright (c) 2001-2002 Packet Design, LLC.
4 * All rights reserved.
5 *
6 * Subject to the following obligations and disclaimer of warranty,
7 * use and redistribution of this software, in source or object code
8 * forms, with or without modifications are expressly permitted by
9 * Packet Design; provided, however, that:
10 *
11 * (i) Any and all reproductions of the source or object code
12 * must include the copyright notice above and the following
13 * disclaimer of warranties; and
14 * (ii) No rights are granted, in any manner or form, to use
15 * Packet Design trademarks, including the mark "PACKET DESIGN"
16 * on advertising, endorsements, or otherwise except as such
17 * appears in the above copyright notice or in the software.
18 *
19 * THIS SOFTWARE IS BEING PROVIDED BY PACKET DESIGN "AS IS", AND
20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, PACKET DESIGN MAKES NO
21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING
22 * THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED
23 * WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE,
24 * OR NON-INFRINGEMENT. PACKET DESIGN DOES NOT WARRANT, GUARANTEE,
25 * OR MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS
26 * OF THE USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY,
27 * RELIABILITY OR OTHERWISE. IN NO EVENT SHALL PACKET DESIGN BE
28 * LIABLE FOR ANY DAMAGES RESULTING FROM OR ARISING OUT OF ANY USE
29 * OF THIS SOFTWARE, INCLUDING WITHOUT LIMITATION, ANY DIRECT,
30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, PUNITIVE, OR CONSEQUENTIAL
31 * DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, LOSS OF
32 * USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY THEORY OF
33 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
35 * THE USE OF THIS SOFTWARE, EVEN IF PACKET DESIGN IS ADVISED OF
36 * THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * Author: Archie Cobbs <archie@freebsd.org>
39 *
|
40 * $FreeBSD: head/sys/netgraph/ng_l2tp.c 102244 2002-08-22 00:30:03Z archie $
| 40 * $FreeBSD: head/sys/netgraph/ng_l2tp.c 108107 2002-12-19 22:58:27Z bmilekic $
|
41 */
42
43/*
44 * L2TP netgraph node type.
45 *
46 * This node type implements the lower layer of the
47 * L2TP protocol as specified in RFC 2661.
48 */
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/kernel.h>
53#include <sys/time.h>
54#include <sys/conf.h>
55#include <sys/mbuf.h>
56#include <sys/malloc.h>
57#include <sys/errno.h>
| 41 */
42
43/*
44 * L2TP netgraph node type.
45 *
46 * This node type implements the lower layer of the
47 * L2TP protocol as specified in RFC 2661.
48 */
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/kernel.h>
53#include <sys/time.h>
54#include <sys/conf.h>
55#include <sys/mbuf.h>
56#include <sys/malloc.h>
57#include <sys/errno.h>
|
| 58#include <sys/libkern.h>
|
58
59#include <netgraph/ng_message.h>
60#include <netgraph/netgraph.h>
61#include <netgraph/ng_parse.h>
62#include <netgraph/ng_l2tp.h>
63
64#ifdef NG_SEPARATE_MALLOC
65MALLOC_DEFINE(M_NETGRAPH_L2TP, "netgraph_l2tp", "netgraph l2tp node");
66#else
67#define M_NETGRAPH_L2TP M_NETGRAPH
68#endif
69
70/* L2TP header format (first 2 bytes only) */
71#define L2TP_HDR_CTRL 0x8000 /* control packet */
72#define L2TP_HDR_LEN 0x4000 /* has length field */
73#define L2TP_HDR_SEQ 0x0800 /* has ns, nr fields */
74#define L2TP_HDR_OFF 0x0200 /* has offset field */
75#define L2TP_HDR_PRIO 0x0100 /* give priority */
76#define L2TP_HDR_VERS_MASK 0x000f /* version field mask */
77#define L2TP_HDR_VERSION 0x0002 /* version field */
78
79/* Bits that must be zero or one in first two bytes of header */
80#define L2TP_CTRL_0BITS 0x030d /* ctrl: must be 0 */
81#define L2TP_CTRL_1BITS 0xc802 /* ctrl: must be 1 */
82#define L2TP_DATA_0BITS 0x800d /* data: must be 0 */
83#define L2TP_DATA_1BITS 0x0002 /* data: must be 1 */
84
85/* Standard xmit ctrl and data header bits */
86#define L2TP_CTRL_HDR (L2TP_HDR_CTRL | L2TP_HDR_LEN \
87 | L2TP_HDR_SEQ | L2TP_HDR_VERSION)
88#define L2TP_DATA_HDR (L2TP_HDR_VERSION) /* optional: len, seq */
89
90/* Some hard coded values */
91#define L2TP_MAX_XWIN 16 /* my max xmit window */
92#define L2TP_MAX_REXMIT 5 /* default max rexmit */
93#define L2TP_MAX_REXMIT_TO 30 /* default rexmit to */
94#define L2TP_DELAYED_ACK ((hz + 19) / 20) /* delayed ack: 50 ms */
95
96/* Default data sequence number configuration for new sessions */
97#define L2TP_CONTROL_DSEQ 1 /* we are the lns */
98#define L2TP_ENABLE_DSEQ 1 /* enable data seq # */
99
100/* Compare sequence numbers using circular math */
101#define L2TP_SEQ_DIFF(x, y) ((int)((int16_t)(x) - (int16_t)(y)))
102
103/*
104 * Sequence number state
105 *
106 * Invariants:
107 * - If cwnd < ssth, we're doing slow start, otherwise congestion avoidance
108 * - The number of unacknowledged xmit packets is (ns - rack) <= seq->wmax
109 * - The first (ns - rack) mbuf's in xwin[] array are copies of these
110 * unacknowledged packets; the remainder of xwin[] consists first of
111 * zero or more further untransmitted packets in the transmit queue
112 * - We try to keep the peer's receive window as full as possible.
113 * Therefore, (i < cwnd && xwin[i] != NULL) implies (ns - rack) > i.
114 * - rack_timer is running iff (ns - rack) > 0 (unack'd xmit'd pkts)
115 * - If xack != nr, there are unacknowledged recv packet(s) (delayed ack)
116 * - xack_timer is running iff xack != nr (unack'd rec'd pkts)
117 */
118struct l2tp_seq {
119 u_int16_t ns; /* next xmit seq we send */
120 u_int16_t nr; /* next recv seq we expect */
121 u_int16_t rack; /* last 'nr' we rec'd */
122 u_int16_t xack; /* last 'nr' we sent */
123 u_int16_t wmax; /* peer's max recv window */
124 u_int16_t cwnd; /* current congestion window */
125 u_int16_t ssth; /* slow start threshold */
126 u_int16_t acks; /* # consecutive acks rec'd */
127 u_int16_t rexmits; /* # retransmits sent */
128 u_int16_t max_rexmits; /* max # retransmits sent */
129 u_int16_t max_rexmit_to; /* max retransmit timeout */
130 struct callout rack_timer; /* retransmit timer */
131 struct callout xack_timer; /* delayed ack timer */
132 u_char rack_timer_running; /* xmit timer running */
133 u_char xack_timer_running; /* ack timer running */
134 struct mbuf *xwin[L2TP_MAX_XWIN]; /* transmit window */
135};
136
137/* Node private data */
138struct ng_l2tp_private {
139 node_p node; /* back pointer to node */
140 hook_p ctrl; /* hook to upper layers */
141 hook_p lower; /* hook to lower layers */
142 struct ng_l2tp_config conf; /* node configuration */
143 struct ng_l2tp_stats stats; /* node statistics */
144 struct l2tp_seq seq; /* ctrl sequence number state */
145 ng_ID_t ftarget; /* failure message target */
146};
147typedef struct ng_l2tp_private *priv_p;
148
149/* Hook private data (data session hooks only) */
150struct ng_l2tp_hook_private {
151 struct ng_l2tp_sess_config conf; /* hook/session config */
152 u_int16_t ns; /* data ns sequence number */
153 u_int16_t nr; /* data nr sequence number */
154};
155typedef struct ng_l2tp_hook_private *hookpriv_p;
156
157/* Netgraph node methods */
158static ng_constructor_t ng_l2tp_constructor;
159static ng_rcvmsg_t ng_l2tp_rcvmsg;
160static ng_shutdown_t ng_l2tp_shutdown;
161static ng_newhook_t ng_l2tp_newhook;
162static ng_rcvdata_t ng_l2tp_rcvdata;
163static ng_disconnect_t ng_l2tp_disconnect;
164
165/* Internal functions */
166static int ng_l2tp_recv_lower(node_p node, item_p item);
167static int ng_l2tp_recv_ctrl(node_p node, item_p item);
168static int ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv);
169
170static int ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns);
171
172static void ng_l2tp_seq_init(priv_p priv);
173static int ng_l2tp_seq_adjust(priv_p priv,
174 const struct ng_l2tp_config *conf);
175static void ng_l2tp_seq_reset(priv_p priv);
176static void ng_l2tp_seq_failure(priv_p priv);
177static void ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr);
178static int ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns);
179static void ng_l2tp_seq_xack_timeout(void *arg);
180static void ng_l2tp_seq_rack_timeout(void *arg);
181
182static ng_fn_eachhook ng_l2tp_find_session;
183static ng_fn_eachhook ng_l2tp_reset_session;
184
185#ifdef INVARIANTS
186static void ng_l2tp_seq_check(struct l2tp_seq *seq);
187#endif
188
189/* Parse type for struct ng_l2tp_config */
190static const struct ng_parse_struct_field
191 ng_l2tp_config_type_fields[] = NG_L2TP_CONFIG_TYPE_INFO;
192static const struct ng_parse_type ng_l2tp_config_type = {
193 &ng_parse_struct_type,
194 &ng_l2tp_config_type_fields,
195};
196
197/* Parse type for struct ng_l2tp_sess_config */
198static const struct ng_parse_struct_field
199 ng_l2tp_sess_config_type_fields[] = NG_L2TP_SESS_CONFIG_TYPE_INFO;
200static const struct ng_parse_type ng_l2tp_sess_config_type = {
201 &ng_parse_struct_type,
202 &ng_l2tp_sess_config_type_fields,
203};
204
205/* Parse type for struct ng_l2tp_stats */
206static const struct ng_parse_struct_field
207 ng_l2tp_stats_type_fields[] = NG_L2TP_STATS_TYPE_INFO;
208static const struct ng_parse_type ng_pptp_stats_type = {
209 &ng_parse_struct_type,
210 &ng_l2tp_stats_type_fields
211};
212
213/* List of commands and how to convert arguments to/from ASCII */
214static const struct ng_cmdlist ng_l2tp_cmdlist[] = {
215 {
216 NGM_L2TP_COOKIE,
217 NGM_L2TP_SET_CONFIG,
218 "setconfig",
219 &ng_l2tp_config_type,
220 NULL
221 },
222 {
223 NGM_L2TP_COOKIE,
224 NGM_L2TP_GET_CONFIG,
225 "getconfig",
226 NULL,
227 &ng_l2tp_config_type
228 },
229 {
230 NGM_L2TP_COOKIE,
231 NGM_L2TP_SET_SESS_CONFIG,
232 "setsessconfig",
233 &ng_l2tp_sess_config_type,
234 NULL
235 },
236 {
237 NGM_L2TP_COOKIE,
238 NGM_L2TP_GET_SESS_CONFIG,
239 "getsessconfig",
240 &ng_parse_hint16_type,
241 &ng_l2tp_sess_config_type
242 },
243 {
244 NGM_L2TP_COOKIE,
245 NGM_L2TP_GET_STATS,
246 "getstats",
247 NULL,
248 &ng_pptp_stats_type
249 },
250 {
251 NGM_L2TP_COOKIE,
252 NGM_L2TP_CLR_STATS,
253 "clrstats",
254 NULL,
255 NULL
256 },
257 {
258 NGM_L2TP_COOKIE,
259 NGM_L2TP_GETCLR_STATS,
260 "getclrstats",
261 NULL,
262 &ng_pptp_stats_type
263 },
264 {
265 NGM_L2TP_COOKIE,
266 NGM_L2TP_ACK_FAILURE,
267 "ackfailure",
268 NULL,
269 NULL
270 },
271 { 0 }
272};
273
274/* Node type descriptor */
275static struct ng_type ng_l2tp_typestruct = {
276 NG_ABI_VERSION,
277 NG_L2TP_NODE_TYPE,
278 NULL,
279 ng_l2tp_constructor,
280 ng_l2tp_rcvmsg,
281 ng_l2tp_shutdown,
282 ng_l2tp_newhook,
283 NULL,
284 NULL,
285 ng_l2tp_rcvdata,
286 ng_l2tp_disconnect,
287 ng_l2tp_cmdlist
288};
289NETGRAPH_INIT(l2tp, &ng_l2tp_typestruct);
290
291/* Sequence number state sanity checking */
292#ifdef INVARIANTS
293#define L2TP_SEQ_CHECK(seq) ng_l2tp_seq_check(seq)
294#else
295#define L2TP_SEQ_CHECK(x) do { } while (0)
296#endif
297
| 59
60#include <netgraph/ng_message.h>
61#include <netgraph/netgraph.h>
62#include <netgraph/ng_parse.h>
63#include <netgraph/ng_l2tp.h>
64
65#ifdef NG_SEPARATE_MALLOC
66MALLOC_DEFINE(M_NETGRAPH_L2TP, "netgraph_l2tp", "netgraph l2tp node");
67#else
68#define M_NETGRAPH_L2TP M_NETGRAPH
69#endif
70
71/* L2TP header format (first 2 bytes only) */
72#define L2TP_HDR_CTRL 0x8000 /* control packet */
73#define L2TP_HDR_LEN 0x4000 /* has length field */
74#define L2TP_HDR_SEQ 0x0800 /* has ns, nr fields */
75#define L2TP_HDR_OFF 0x0200 /* has offset field */
76#define L2TP_HDR_PRIO 0x0100 /* give priority */
77#define L2TP_HDR_VERS_MASK 0x000f /* version field mask */
78#define L2TP_HDR_VERSION 0x0002 /* version field */
79
80/* Bits that must be zero or one in first two bytes of header */
81#define L2TP_CTRL_0BITS 0x030d /* ctrl: must be 0 */
82#define L2TP_CTRL_1BITS 0xc802 /* ctrl: must be 1 */
83#define L2TP_DATA_0BITS 0x800d /* data: must be 0 */
84#define L2TP_DATA_1BITS 0x0002 /* data: must be 1 */
85
86/* Standard xmit ctrl and data header bits */
87#define L2TP_CTRL_HDR (L2TP_HDR_CTRL | L2TP_HDR_LEN \
88 | L2TP_HDR_SEQ | L2TP_HDR_VERSION)
89#define L2TP_DATA_HDR (L2TP_HDR_VERSION) /* optional: len, seq */
90
91/* Some hard coded values */
92#define L2TP_MAX_XWIN 16 /* my max xmit window */
93#define L2TP_MAX_REXMIT 5 /* default max rexmit */
94#define L2TP_MAX_REXMIT_TO 30 /* default rexmit to */
95#define L2TP_DELAYED_ACK ((hz + 19) / 20) /* delayed ack: 50 ms */
96
97/* Default data sequence number configuration for new sessions */
98#define L2TP_CONTROL_DSEQ 1 /* we are the lns */
99#define L2TP_ENABLE_DSEQ 1 /* enable data seq # */
100
101/* Compare sequence numbers using circular math */
102#define L2TP_SEQ_DIFF(x, y) ((int)((int16_t)(x) - (int16_t)(y)))
103
104/*
105 * Sequence number state
106 *
107 * Invariants:
108 * - If cwnd < ssth, we're doing slow start, otherwise congestion avoidance
109 * - The number of unacknowledged xmit packets is (ns - rack) <= seq->wmax
110 * - The first (ns - rack) mbuf's in xwin[] array are copies of these
111 * unacknowledged packets; the remainder of xwin[] consists first of
112 * zero or more further untransmitted packets in the transmit queue
113 * - We try to keep the peer's receive window as full as possible.
114 * Therefore, (i < cwnd && xwin[i] != NULL) implies (ns - rack) > i.
115 * - rack_timer is running iff (ns - rack) > 0 (unack'd xmit'd pkts)
116 * - If xack != nr, there are unacknowledged recv packet(s) (delayed ack)
117 * - xack_timer is running iff xack != nr (unack'd rec'd pkts)
118 */
119struct l2tp_seq {
120 u_int16_t ns; /* next xmit seq we send */
121 u_int16_t nr; /* next recv seq we expect */
122 u_int16_t rack; /* last 'nr' we rec'd */
123 u_int16_t xack; /* last 'nr' we sent */
124 u_int16_t wmax; /* peer's max recv window */
125 u_int16_t cwnd; /* current congestion window */
126 u_int16_t ssth; /* slow start threshold */
127 u_int16_t acks; /* # consecutive acks rec'd */
128 u_int16_t rexmits; /* # retransmits sent */
129 u_int16_t max_rexmits; /* max # retransmits sent */
130 u_int16_t max_rexmit_to; /* max retransmit timeout */
131 struct callout rack_timer; /* retransmit timer */
132 struct callout xack_timer; /* delayed ack timer */
133 u_char rack_timer_running; /* xmit timer running */
134 u_char xack_timer_running; /* ack timer running */
135 struct mbuf *xwin[L2TP_MAX_XWIN]; /* transmit window */
136};
137
138/* Node private data */
139struct ng_l2tp_private {
140 node_p node; /* back pointer to node */
141 hook_p ctrl; /* hook to upper layers */
142 hook_p lower; /* hook to lower layers */
143 struct ng_l2tp_config conf; /* node configuration */
144 struct ng_l2tp_stats stats; /* node statistics */
145 struct l2tp_seq seq; /* ctrl sequence number state */
146 ng_ID_t ftarget; /* failure message target */
147};
148typedef struct ng_l2tp_private *priv_p;
149
150/* Hook private data (data session hooks only) */
151struct ng_l2tp_hook_private {
152 struct ng_l2tp_sess_config conf; /* hook/session config */
153 u_int16_t ns; /* data ns sequence number */
154 u_int16_t nr; /* data nr sequence number */
155};
156typedef struct ng_l2tp_hook_private *hookpriv_p;
157
158/* Netgraph node methods */
159static ng_constructor_t ng_l2tp_constructor;
160static ng_rcvmsg_t ng_l2tp_rcvmsg;
161static ng_shutdown_t ng_l2tp_shutdown;
162static ng_newhook_t ng_l2tp_newhook;
163static ng_rcvdata_t ng_l2tp_rcvdata;
164static ng_disconnect_t ng_l2tp_disconnect;
165
166/* Internal functions */
167static int ng_l2tp_recv_lower(node_p node, item_p item);
168static int ng_l2tp_recv_ctrl(node_p node, item_p item);
169static int ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv);
170
171static int ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns);
172
173static void ng_l2tp_seq_init(priv_p priv);
174static int ng_l2tp_seq_adjust(priv_p priv,
175 const struct ng_l2tp_config *conf);
176static void ng_l2tp_seq_reset(priv_p priv);
177static void ng_l2tp_seq_failure(priv_p priv);
178static void ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr);
179static int ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns);
180static void ng_l2tp_seq_xack_timeout(void *arg);
181static void ng_l2tp_seq_rack_timeout(void *arg);
182
183static ng_fn_eachhook ng_l2tp_find_session;
184static ng_fn_eachhook ng_l2tp_reset_session;
185
186#ifdef INVARIANTS
187static void ng_l2tp_seq_check(struct l2tp_seq *seq);
188#endif
189
190/* Parse type for struct ng_l2tp_config */
191static const struct ng_parse_struct_field
192 ng_l2tp_config_type_fields[] = NG_L2TP_CONFIG_TYPE_INFO;
193static const struct ng_parse_type ng_l2tp_config_type = {
194 &ng_parse_struct_type,
195 &ng_l2tp_config_type_fields,
196};
197
198/* Parse type for struct ng_l2tp_sess_config */
199static const struct ng_parse_struct_field
200 ng_l2tp_sess_config_type_fields[] = NG_L2TP_SESS_CONFIG_TYPE_INFO;
201static const struct ng_parse_type ng_l2tp_sess_config_type = {
202 &ng_parse_struct_type,
203 &ng_l2tp_sess_config_type_fields,
204};
205
206/* Parse type for struct ng_l2tp_stats */
207static const struct ng_parse_struct_field
208 ng_l2tp_stats_type_fields[] = NG_L2TP_STATS_TYPE_INFO;
209static const struct ng_parse_type ng_pptp_stats_type = {
210 &ng_parse_struct_type,
211 &ng_l2tp_stats_type_fields
212};
213
214/* List of commands and how to convert arguments to/from ASCII */
215static const struct ng_cmdlist ng_l2tp_cmdlist[] = {
216 {
217 NGM_L2TP_COOKIE,
218 NGM_L2TP_SET_CONFIG,
219 "setconfig",
220 &ng_l2tp_config_type,
221 NULL
222 },
223 {
224 NGM_L2TP_COOKIE,
225 NGM_L2TP_GET_CONFIG,
226 "getconfig",
227 NULL,
228 &ng_l2tp_config_type
229 },
230 {
231 NGM_L2TP_COOKIE,
232 NGM_L2TP_SET_SESS_CONFIG,
233 "setsessconfig",
234 &ng_l2tp_sess_config_type,
235 NULL
236 },
237 {
238 NGM_L2TP_COOKIE,
239 NGM_L2TP_GET_SESS_CONFIG,
240 "getsessconfig",
241 &ng_parse_hint16_type,
242 &ng_l2tp_sess_config_type
243 },
244 {
245 NGM_L2TP_COOKIE,
246 NGM_L2TP_GET_STATS,
247 "getstats",
248 NULL,
249 &ng_pptp_stats_type
250 },
251 {
252 NGM_L2TP_COOKIE,
253 NGM_L2TP_CLR_STATS,
254 "clrstats",
255 NULL,
256 NULL
257 },
258 {
259 NGM_L2TP_COOKIE,
260 NGM_L2TP_GETCLR_STATS,
261 "getclrstats",
262 NULL,
263 &ng_pptp_stats_type
264 },
265 {
266 NGM_L2TP_COOKIE,
267 NGM_L2TP_ACK_FAILURE,
268 "ackfailure",
269 NULL,
270 NULL
271 },
272 { 0 }
273};
274
275/* Node type descriptor */
276static struct ng_type ng_l2tp_typestruct = {
277 NG_ABI_VERSION,
278 NG_L2TP_NODE_TYPE,
279 NULL,
280 ng_l2tp_constructor,
281 ng_l2tp_rcvmsg,
282 ng_l2tp_shutdown,
283 ng_l2tp_newhook,
284 NULL,
285 NULL,
286 ng_l2tp_rcvdata,
287 ng_l2tp_disconnect,
288 ng_l2tp_cmdlist
289};
290NETGRAPH_INIT(l2tp, &ng_l2tp_typestruct);
291
292/* Sequence number state sanity checking */
293#ifdef INVARIANTS
294#define L2TP_SEQ_CHECK(seq) ng_l2tp_seq_check(seq)
295#else
296#define L2TP_SEQ_CHECK(x) do { } while (0)
297#endif
298
|
298/* mem*() macros */
| 299/* memmove macro */
|
299#define memmove(d, s, l) ovbcopy(s, d, l)
| 300#define memmove(d, s, l) ovbcopy(s, d, l)
|
300#define memset(d, z, l) bzero(d, l) /* XXX */
| |
301
302/* Whether to use m_copypacket() or m_dup() */
303#define L2TP_COPY_MBUF m_copypacket
304
305/************************************************************************
306 NETGRAPH NODE STUFF
307************************************************************************/
308
309/*
310 * Node type constructor
311 */
312static int
313ng_l2tp_constructor(node_p node)
314{
315 priv_p priv;
316
317 /* Allocate private structure */
318 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
319 if (priv == NULL)
320 return (ENOMEM);
321 NG_NODE_SET_PRIVATE(node, priv);
322 priv->node = node;
323
324 /* Apply a semi-reasonable default configuration */
325 priv->conf.peer_win = 1;
326 priv->conf.rexmit_max = L2TP_MAX_REXMIT;
327 priv->conf.rexmit_max_to = L2TP_MAX_REXMIT_TO;
328
329 /* Initialize sequence number state */
330 ng_l2tp_seq_init(priv);
331
332 /* Done */
333 return (0);
334}
335
336/*
337 * Give our OK for a hook to be added.
338 */
339static int
340ng_l2tp_newhook(node_p node, hook_p hook, const char *name)
341{
342 const priv_p priv = NG_NODE_PRIVATE(node);
343
344 /* Check hook name */
345 if (strcmp(name, NG_L2TP_HOOK_CTRL) == 0) {
346 if (priv->ctrl != NULL)
347 return (EISCONN);
348 priv->ctrl = hook;
349 } else if (strcmp(name, NG_L2TP_HOOK_LOWER) == 0) {
350 if (priv->lower != NULL)
351 return (EISCONN);
352 priv->lower = hook;
353 } else {
354 static const char hexdig[16] = "0123456789abcdef";
355 u_int16_t session_id;
356 hookpriv_p hpriv;
357 const char *hex;
358 int i;
359 int j;
360
361 /* Parse hook name to get session ID */
362 if (strncmp(name, NG_L2TP_HOOK_SESSION_P,
363 sizeof(NG_L2TP_HOOK_SESSION_P) - 1) != 0)
364 return (EINVAL);
365 hex = name + sizeof(NG_L2TP_HOOK_SESSION_P) - 1;
366 for (session_id = i = 0; i < 4; i++) {
367 for (j = 0; j < 16 && hex[i] != hexdig[j]; j++);
368 if (j == 16)
369 return (EINVAL);
370 session_id = (session_id << 4) | j;
371 }
372 if (hex[i] != '\0')
373 return (EINVAL);
374
375 /* Create hook private structure */
376 MALLOC(hpriv, hookpriv_p,
377 sizeof(*hpriv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
378 if (hpriv == NULL)
379 return (ENOMEM);
380 hpriv->conf.session_id = htons(session_id);
381 hpriv->conf.control_dseq = L2TP_CONTROL_DSEQ;
382 hpriv->conf.enable_dseq = L2TP_ENABLE_DSEQ;
383 NG_HOOK_SET_PRIVATE(hook, hpriv);
384 }
385
386 /* Done */
387 return (0);
388}
389
390/*
391 * Receive a control message.
392 */
393static int
394ng_l2tp_rcvmsg(node_p node, item_p item, hook_p lasthook)
395{
396 const priv_p priv = NG_NODE_PRIVATE(node);
397 struct ng_mesg *resp = NULL;
398 struct ng_mesg *msg;
399 int error = 0;
400
401 NGI_GET_MSG(item, msg);
402 switch (msg->header.typecookie) {
403 case NGM_L2TP_COOKIE:
404 switch (msg->header.cmd) {
405 case NGM_L2TP_SET_CONFIG:
406 {
407 struct ng_l2tp_config *const conf =
408 (struct ng_l2tp_config *)msg->data;
409
410 /* Check for invalid or illegal config */
411 if (msg->header.arglen != sizeof(*conf)) {
412 error = EINVAL;
413 break;
414 }
415 conf->enabled = !!conf->enabled;
416 conf->match_id = !!conf->match_id;
417 conf->tunnel_id = htons(conf->tunnel_id);
418 conf->peer_id = htons(conf->peer_id);
419 if (priv->conf.enabled
420 && ((priv->conf.tunnel_id != 0
421 && conf->tunnel_id != priv->conf.tunnel_id)
422 || ((priv->conf.peer_id != 0
423 && conf->peer_id != priv->conf.peer_id)))) {
424 error = EBUSY;
425 break;
426 }
427
428 /* Save calling node as failure target */
429 priv->ftarget = NGI_RETADDR(item);
430
431 /* Adjust sequence number state */
432 if ((error = ng_l2tp_seq_adjust(priv, conf)) != 0)
433 break;
434
435 /* Update node's config */
436 priv->conf = *conf;
437 break;
438 }
439 case NGM_L2TP_GET_CONFIG:
440 {
441 struct ng_l2tp_config *conf;
442
443 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
444 if (resp == NULL) {
445 error = ENOMEM;
446 break;
447 }
448 conf = (struct ng_l2tp_config *)resp->data;
449 *conf = priv->conf;
450
451 /* Put ID's in host order */
452 conf->tunnel_id = ntohs(conf->tunnel_id);
453 conf->peer_id = ntohs(conf->peer_id);
454 break;
455 }
456 case NGM_L2TP_SET_SESS_CONFIG:
457 {
458 struct ng_l2tp_sess_config *const conf =
459 (struct ng_l2tp_sess_config *)msg->data;
460 hookpriv_p hpriv;
461 hook_p hook;
462
463 /* Check for invalid or illegal config */
464 if (msg->header.arglen != sizeof(*conf)) {
465 error = EINVAL;
466 break;
467 }
468
469 /* Put ID's in network order */
470 conf->session_id = htons(conf->session_id);
471 conf->peer_id = htons(conf->peer_id);
472
473 /* Find matching hook */
474 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
475 (void *)(uintptr_t)conf->session_id, hook);
476 if (hook == NULL) {
477 error = ENOENT;
478 break;
479 }
480 hpriv = NG_HOOK_PRIVATE(hook);
481
482 /* Update hook's config */
483 hpriv->conf = *conf;
484 break;
485 }
486 case NGM_L2TP_GET_SESS_CONFIG:
487 {
488 struct ng_l2tp_sess_config *conf;
489 u_int16_t session_id;
490 hookpriv_p hpriv;
491 hook_p hook;
492
493 /* Get session ID */
494 if (msg->header.arglen != sizeof(session_id)) {
495 error = EINVAL;
496 break;
497 }
498 memcpy(&session_id, msg->data, 2);
499 session_id = htons(session_id);
500
501 /* Find matching hook */
502 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
503 (void *)(uintptr_t)session_id, hook);
504 if (hook == NULL) {
505 error = ENOENT;
506 break;
507 }
508 hpriv = NG_HOOK_PRIVATE(hook);
509
510 /* Send response */
511 NG_MKRESPONSE(resp, msg, sizeof(hpriv->conf), M_NOWAIT);
512 if (resp == NULL) {
513 error = ENOMEM;
514 break;
515 }
516 conf = (struct ng_l2tp_sess_config *)resp->data;
517 *conf = hpriv->conf;
518
519 /* Put ID's in host order */
520 conf->session_id = ntohs(conf->session_id);
521 conf->peer_id = ntohs(conf->peer_id);
522 break;
523 }
524 case NGM_L2TP_GET_STATS:
525 case NGM_L2TP_CLR_STATS:
526 case NGM_L2TP_GETCLR_STATS:
527 {
528 if (msg->header.cmd != NGM_L2TP_CLR_STATS) {
529 NG_MKRESPONSE(resp, msg,
530 sizeof(priv->stats), M_NOWAIT);
531 if (resp == NULL) {
532 error = ENOMEM;
533 break;
534 }
535 memcpy(resp->data,
536 &priv->stats, sizeof(priv->stats));
537 }
538 if (msg->header.cmd != NGM_L2TP_GET_STATS)
539 memset(&priv->stats, 0, sizeof(priv->stats));
540 break;
541 }
542 default:
543 error = EINVAL;
544 break;
545 }
546 break;
547 default:
548 error = EINVAL;
549 break;
550 }
551
552 /* Done */
553 NG_RESPOND_MSG(error, node, item, resp);
554 NG_FREE_MSG(msg);
555 return (error);
556}
557
558/*
559 * Receive incoming data on a hook.
560 */
561static int
562ng_l2tp_rcvdata(hook_p hook, item_p item)
563{
564 const node_p node = NG_HOOK_NODE(hook);
565 const priv_p priv = NG_NODE_PRIVATE(node);
566 int error;
567
568 /* Sanity check */
569 L2TP_SEQ_CHECK(&priv->seq);
570
571 /* If not configured, reject */
572 if (!priv->conf.enabled) {
573 NG_FREE_ITEM(item);
574 return (ENXIO);
575 }
576
577 /* Handle incoming frame from below */
578 if (hook == priv->lower) {
579 error = ng_l2tp_recv_lower(node, item);
580 goto done;
581 }
582
583 /* Handle outgoing control frame */
584 if (hook == priv->ctrl) {
585 error = ng_l2tp_recv_ctrl(node, item);
586 goto done;
587 }
588
589 /* Handle outgoing data frame */
590 error = ng_l2tp_recv_data(node, item, NG_HOOK_PRIVATE(hook));
591
592done:
593 /* Done */
594 L2TP_SEQ_CHECK(&priv->seq);
595 return (error);
596}
597
598/*
599 * Destroy node
600 */
601static int
602ng_l2tp_shutdown(node_p node)
603{
604 const priv_p priv = NG_NODE_PRIVATE(node);
605 struct l2tp_seq *const seq = &priv->seq;
606
607 /* Sanity check */
608 L2TP_SEQ_CHECK(seq);
609
610 /* Reset sequence number state */
611 ng_l2tp_seq_reset(priv);
612
613 /* Free private data if neither timer is running */
614 if (!seq->rack_timer_running && !seq->xack_timer_running) {
615 FREE(priv, M_NETGRAPH_L2TP);
616 NG_NODE_SET_PRIVATE(node, NULL);
617 }
618
619 /* Unref node */
620 NG_NODE_UNREF(node);
621 return (0);
622}
623
624/*
625 * Hook disconnection
626 */
627static int
628ng_l2tp_disconnect(hook_p hook)
629{
630 const node_p node = NG_HOOK_NODE(hook);
631 const priv_p priv = NG_NODE_PRIVATE(node);
632
633 /* Zero out hook pointer */
634 if (hook == priv->ctrl)
635 priv->ctrl = NULL;
636 else if (hook == priv->lower)
637 priv->lower = NULL;
638 else {
639 FREE(NG_HOOK_PRIVATE(hook), M_NETGRAPH_L2TP);
640 NG_HOOK_SET_PRIVATE(hook, NULL);
641 }
642
643 /* Go away if no longer connected to anything */
644 if (NG_NODE_NUMHOOKS(node) == 0 && NG_NODE_IS_VALID(node))
645 ng_rmnode_self(node);
646 return (0);
647}
648
649/*************************************************************************
650 INTERNAL FUNCTIONS
651*************************************************************************/
652
653/*
654 * Find the hook with a given session ID.
655 */
656static int
657ng_l2tp_find_session(hook_p hook, void *arg)
658{
659 const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
660 const u_int16_t sid = (u_int16_t)(uintptr_t)arg;
661
662 if (hpriv == NULL || hpriv->conf.session_id != sid)
663 return (-1);
664 return (0);
665}
666
667/*
668 * Reset a hook's session state.
669 */
670static int
671ng_l2tp_reset_session(hook_p hook, void *arg)
672{
673 const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
674
675 if (hpriv != NULL) {
676 hpriv->conf.control_dseq = 0;
677 hpriv->conf.enable_dseq = 0;
678 hpriv->nr = 0;
679 hpriv->ns = 0;
680 }
681 return (-1);
682}
683
684/*
685 * Handle an incoming frame from below.
686 */
687static int
688ng_l2tp_recv_lower(node_p node, item_p item)
689{
690 static const u_int16_t req_bits[2][2] = {
691 { L2TP_DATA_0BITS, L2TP_DATA_1BITS },
692 { L2TP_CTRL_0BITS, L2TP_CTRL_1BITS },
693 };
694 const priv_p priv = NG_NODE_PRIVATE(node);
695 hookpriv_p hpriv = NULL;
696 hook_p hook = NULL;
697 u_int16_t ids[2];
698 struct mbuf *m;
699 u_int16_t hdr;
700 u_int16_t ns;
701 u_int16_t nr;
702 int is_ctrl;
703 int error;
704 int len;
705
706 /* Grab mbuf */
707 NGI_GET_M(item, m);
708
709 /* Update stats */
710 priv->stats.recvPackets++;
711 priv->stats.recvOctets += m->m_pkthdr.len;
712
713 /* Get initial header */
714 if (m->m_pkthdr.len < 6) {
715 priv->stats.recvRunts++;
716 NG_FREE_ITEM(item);
717 NG_FREE_M(m);
718 return (EINVAL);
719 }
720 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
721 priv->stats.memoryFailures++;
722 NG_FREE_ITEM(item);
723 return (EINVAL);
724 }
725 hdr = ntohs(*mtod(m, u_int16_t *));
726 m_adj(m, 2);
727
728 /* Check required header bits and minimum length */
729 is_ctrl = (hdr & L2TP_HDR_CTRL) != 0;
730 if ((hdr & req_bits[is_ctrl][0]) != 0
731 || (~hdr & req_bits[is_ctrl][1]) != 0) {
732 priv->stats.recvInvalid++;
733 NG_FREE_ITEM(item);
734 NG_FREE_M(m);
735 return (EINVAL);
736 }
737 if (m->m_pkthdr.len < 4 /* tunnel, session id */
738 + (2 * ((hdr & L2TP_HDR_LEN) != 0)) /* length field */
739 + (4 * ((hdr & L2TP_HDR_SEQ) != 0)) /* seq # fields */
740 + (2 * ((hdr & L2TP_HDR_OFF) != 0))) { /* offset field */
741 priv->stats.recvRunts++;
742 NG_FREE_ITEM(item);
743 NG_FREE_M(m);
744 return (EINVAL);
745 }
746
747 /* Get and validate length field if present */
748 if ((hdr & L2TP_HDR_LEN) != 0) {
749 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
750 priv->stats.memoryFailures++;
751 NG_FREE_ITEM(item);
752 return (EINVAL);
753 }
754 len = (u_int16_t)ntohs(*mtod(m, u_int16_t *)) - 4;
755 m_adj(m, 2);
756 if (len < 0 || len > m->m_pkthdr.len) {
757 priv->stats.recvInvalid++;
758 NG_FREE_ITEM(item);
759 NG_FREE_M(m);
760 return (EINVAL);
761 }
762 if (len < m->m_pkthdr.len) /* trim extra bytes */
763 m_adj(m, -(m->m_pkthdr.len - len));
764 }
765
766 /* Get tunnel ID and session ID */
767 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
768 priv->stats.memoryFailures++;
769 NG_FREE_ITEM(item);
770 return (EINVAL);
771 }
772 memcpy(ids, mtod(m, u_int16_t *), 4);
773 m_adj(m, 4);
774
775 /* Check tunnel ID */
776 if (ids[0] != priv->conf.tunnel_id
777 && (priv->conf.match_id || ids[0] != 0)) {
778 priv->stats.recvWrongTunnel++;
779 NG_FREE_ITEM(item);
780 NG_FREE_M(m);
781 return (EADDRNOTAVAIL);
782 }
783
784 /* Check session ID (for data packets only) */
785 if ((hdr & L2TP_HDR_CTRL) == 0) {
786 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
787 (void *)(uintptr_t)ids[1], hook);
788 if (hook == NULL) {
789 priv->stats.recvUnknownSID++;
790 NG_FREE_ITEM(item);
791 NG_FREE_M(m);
792 return (ENOTCONN);
793 }
794 hpriv = NG_HOOK_PRIVATE(hook);
795 }
796
797 /* Get Ns, Nr fields if present */
798 if ((hdr & L2TP_HDR_SEQ) != 0) {
799 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
800 priv->stats.memoryFailures++;
801 NG_FREE_ITEM(item);
802 return (EINVAL);
803 }
804 memcpy(&ns, &mtod(m, u_int16_t *)[0], 2);
805 ns = ntohs(ns);
806 memcpy(&nr, &mtod(m, u_int16_t *)[1], 2);
807 nr = ntohs(nr);
808 m_adj(m, 4);
809 }
810
811 /* Strip offset padding if present */
812 if ((hdr & L2TP_HDR_OFF) != 0) {
813 u_int16_t offset;
814
815 /* Get length of offset padding */
816 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
817 priv->stats.memoryFailures++;
818 NG_FREE_ITEM(item);
819 return (EINVAL);
820 }
821 memcpy(&offset, mtod(m, u_int16_t *), 2);
822 offset = ntohs(offset);
823
824 /* Trim offset padding */
825 if (offset <= 2 || offset > m->m_pkthdr.len) {
826 priv->stats.recvInvalid++;
827 NG_FREE_ITEM(item);
828 NG_FREE_M(m);
829 return (EINVAL);
830 }
831 m_adj(m, offset);
832 }
833
834 /* Handle control packets */
835 if ((hdr & L2TP_HDR_CTRL) != 0) {
836
837 /* Handle receive ack sequence number Nr */
838 ng_l2tp_seq_recv_nr(priv, nr);
839
840 /* Discard ZLB packets */
841 if (m->m_pkthdr.len == 0) {
842 priv->stats.recvZLBs++;
843 NG_FREE_ITEM(item);
844 NG_FREE_M(m);
845 return (0);
846 }
847
848 /*
849 * Prepend session ID to packet here: we don't want to accept
850 * the send sequence number Ns if we have to drop the packet
851 * later because of a memory error, because then the upper
852 * layer would never get the packet.
853 */
854 M_PREPEND(m, 2, M_DONTWAIT);
855 if (m == NULL) {
856 priv->stats.memoryFailures++;
857 NG_FREE_ITEM(item);
858 return (ENOBUFS);
859 }
860 memcpy(mtod(m, u_int16_t *), &ids[1], 2);
861
862 /* Now handle send sequence number */
863 if (ng_l2tp_seq_recv_ns(priv, ns) == -1) {
864 NG_FREE_ITEM(item);
865 NG_FREE_M(m);
866 return (0);
867 }
868
869 /* Deliver packet to upper layers */
870 NG_FWD_NEW_DATA(error, item, priv->ctrl, m);
871 return (error);
872 }
873
874 /* Follow peer's lead in data sequencing, if configured to do so */
875 if (!hpriv->conf.control_dseq)
876 hpriv->conf.enable_dseq = ((hdr & L2TP_HDR_SEQ) != 0);
877
878 /* Handle data sequence numbers if present and enabled */
879 if ((hdr & L2TP_HDR_SEQ) != 0) {
880 if (hpriv->conf.enable_dseq
881 && L2TP_SEQ_DIFF(ns, hpriv->nr) < 0) {
882 NG_FREE_ITEM(item); /* duplicate or out of order */
883 NG_FREE_M(m);
884 priv->stats.recvDataDrops++;
885 return (0);
886 }
887 hpriv->nr = ns + 1;
888 }
889
890 /* Drop empty data packets */
891 if (m->m_pkthdr.len == 0) {
892 NG_FREE_ITEM(item);
893 NG_FREE_M(m);
894 return (0);
895 }
896
897 /* Deliver data */
898 NG_FWD_NEW_DATA(error, item, hook, m);
899 return (error);
900}
901
902/*
903 * Handle an outgoing control frame.
904 */
905static int
906ng_l2tp_recv_ctrl(node_p node, item_p item)
907{
908 const priv_p priv = NG_NODE_PRIVATE(node);
909 struct l2tp_seq *const seq = &priv->seq;
910 struct mbuf *m;
911 int i;
912
913 /* Grab mbuf and discard other stuff XXX */
914 NGI_GET_M(item, m);
915 NG_FREE_ITEM(item);
916
917 /* Packet should have session ID prepended */
918 if (m->m_pkthdr.len < 2) {
919 priv->stats.xmitInvalid++;
920 m_freem(m);
921 return (EINVAL);
922 }
923
924 /* Check max length */
925 if (m->m_pkthdr.len >= 0x10000 - 14) {
926 priv->stats.xmitTooBig++;
927 m_freem(m);
928 return (EOVERFLOW);
929 }
930
931 /* Find next empty slot in transmit queue */
932 for (i = 0; i < L2TP_MAX_XWIN && seq->xwin[i] != NULL; i++);
933 if (i == L2TP_MAX_XWIN) {
934 priv->stats.xmitDrops++;
935 m_freem(m);
936 return (ENOBUFS);
937 }
938 seq->xwin[i] = m;
939
940 /* Sanity check receive ack timer state */
941 KASSERT((i == 0) ^ seq->rack_timer_running,
942 ("%s: xwin %d full but rack timer %srunning",
943 __FUNCTION__, i, seq->rack_timer_running ? "" : "not "));
944
945 /* If peer's receive window is already full, nothing else to do */
946 if (i >= seq->cwnd)
947 return (0);
948
949 /* Start retransmit timer if not already running */
950 if (!seq->rack_timer_running) {
951 callout_reset(&seq->rack_timer,
952 hz, ng_l2tp_seq_rack_timeout, node);
953 seq->rack_timer_running = 1;
954 NG_NODE_REF(node);
955 }
956
957 /* Copy packet */
| 301
302/* Whether to use m_copypacket() or m_dup() */
303#define L2TP_COPY_MBUF m_copypacket
304
305/************************************************************************
306 NETGRAPH NODE STUFF
307************************************************************************/
308
309/*
310 * Node type constructor
311 */
312static int
313ng_l2tp_constructor(node_p node)
314{
315 priv_p priv;
316
317 /* Allocate private structure */
318 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
319 if (priv == NULL)
320 return (ENOMEM);
321 NG_NODE_SET_PRIVATE(node, priv);
322 priv->node = node;
323
324 /* Apply a semi-reasonable default configuration */
325 priv->conf.peer_win = 1;
326 priv->conf.rexmit_max = L2TP_MAX_REXMIT;
327 priv->conf.rexmit_max_to = L2TP_MAX_REXMIT_TO;
328
329 /* Initialize sequence number state */
330 ng_l2tp_seq_init(priv);
331
332 /* Done */
333 return (0);
334}
335
336/*
337 * Give our OK for a hook to be added.
338 */
339static int
340ng_l2tp_newhook(node_p node, hook_p hook, const char *name)
341{
342 const priv_p priv = NG_NODE_PRIVATE(node);
343
344 /* Check hook name */
345 if (strcmp(name, NG_L2TP_HOOK_CTRL) == 0) {
346 if (priv->ctrl != NULL)
347 return (EISCONN);
348 priv->ctrl = hook;
349 } else if (strcmp(name, NG_L2TP_HOOK_LOWER) == 0) {
350 if (priv->lower != NULL)
351 return (EISCONN);
352 priv->lower = hook;
353 } else {
354 static const char hexdig[16] = "0123456789abcdef";
355 u_int16_t session_id;
356 hookpriv_p hpriv;
357 const char *hex;
358 int i;
359 int j;
360
361 /* Parse hook name to get session ID */
362 if (strncmp(name, NG_L2TP_HOOK_SESSION_P,
363 sizeof(NG_L2TP_HOOK_SESSION_P) - 1) != 0)
364 return (EINVAL);
365 hex = name + sizeof(NG_L2TP_HOOK_SESSION_P) - 1;
366 for (session_id = i = 0; i < 4; i++) {
367 for (j = 0; j < 16 && hex[i] != hexdig[j]; j++);
368 if (j == 16)
369 return (EINVAL);
370 session_id = (session_id << 4) | j;
371 }
372 if (hex[i] != '\0')
373 return (EINVAL);
374
375 /* Create hook private structure */
376 MALLOC(hpriv, hookpriv_p,
377 sizeof(*hpriv), M_NETGRAPH_L2TP, M_NOWAIT | M_ZERO);
378 if (hpriv == NULL)
379 return (ENOMEM);
380 hpriv->conf.session_id = htons(session_id);
381 hpriv->conf.control_dseq = L2TP_CONTROL_DSEQ;
382 hpriv->conf.enable_dseq = L2TP_ENABLE_DSEQ;
383 NG_HOOK_SET_PRIVATE(hook, hpriv);
384 }
385
386 /* Done */
387 return (0);
388}
389
390/*
391 * Receive a control message.
392 */
393static int
394ng_l2tp_rcvmsg(node_p node, item_p item, hook_p lasthook)
395{
396 const priv_p priv = NG_NODE_PRIVATE(node);
397 struct ng_mesg *resp = NULL;
398 struct ng_mesg *msg;
399 int error = 0;
400
401 NGI_GET_MSG(item, msg);
402 switch (msg->header.typecookie) {
403 case NGM_L2TP_COOKIE:
404 switch (msg->header.cmd) {
405 case NGM_L2TP_SET_CONFIG:
406 {
407 struct ng_l2tp_config *const conf =
408 (struct ng_l2tp_config *)msg->data;
409
410 /* Check for invalid or illegal config */
411 if (msg->header.arglen != sizeof(*conf)) {
412 error = EINVAL;
413 break;
414 }
415 conf->enabled = !!conf->enabled;
416 conf->match_id = !!conf->match_id;
417 conf->tunnel_id = htons(conf->tunnel_id);
418 conf->peer_id = htons(conf->peer_id);
419 if (priv->conf.enabled
420 && ((priv->conf.tunnel_id != 0
421 && conf->tunnel_id != priv->conf.tunnel_id)
422 || ((priv->conf.peer_id != 0
423 && conf->peer_id != priv->conf.peer_id)))) {
424 error = EBUSY;
425 break;
426 }
427
428 /* Save calling node as failure target */
429 priv->ftarget = NGI_RETADDR(item);
430
431 /* Adjust sequence number state */
432 if ((error = ng_l2tp_seq_adjust(priv, conf)) != 0)
433 break;
434
435 /* Update node's config */
436 priv->conf = *conf;
437 break;
438 }
439 case NGM_L2TP_GET_CONFIG:
440 {
441 struct ng_l2tp_config *conf;
442
443 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
444 if (resp == NULL) {
445 error = ENOMEM;
446 break;
447 }
448 conf = (struct ng_l2tp_config *)resp->data;
449 *conf = priv->conf;
450
451 /* Put ID's in host order */
452 conf->tunnel_id = ntohs(conf->tunnel_id);
453 conf->peer_id = ntohs(conf->peer_id);
454 break;
455 }
456 case NGM_L2TP_SET_SESS_CONFIG:
457 {
458 struct ng_l2tp_sess_config *const conf =
459 (struct ng_l2tp_sess_config *)msg->data;
460 hookpriv_p hpriv;
461 hook_p hook;
462
463 /* Check for invalid or illegal config */
464 if (msg->header.arglen != sizeof(*conf)) {
465 error = EINVAL;
466 break;
467 }
468
469 /* Put ID's in network order */
470 conf->session_id = htons(conf->session_id);
471 conf->peer_id = htons(conf->peer_id);
472
473 /* Find matching hook */
474 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
475 (void *)(uintptr_t)conf->session_id, hook);
476 if (hook == NULL) {
477 error = ENOENT;
478 break;
479 }
480 hpriv = NG_HOOK_PRIVATE(hook);
481
482 /* Update hook's config */
483 hpriv->conf = *conf;
484 break;
485 }
486 case NGM_L2TP_GET_SESS_CONFIG:
487 {
488 struct ng_l2tp_sess_config *conf;
489 u_int16_t session_id;
490 hookpriv_p hpriv;
491 hook_p hook;
492
493 /* Get session ID */
494 if (msg->header.arglen != sizeof(session_id)) {
495 error = EINVAL;
496 break;
497 }
498 memcpy(&session_id, msg->data, 2);
499 session_id = htons(session_id);
500
501 /* Find matching hook */
502 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
503 (void *)(uintptr_t)session_id, hook);
504 if (hook == NULL) {
505 error = ENOENT;
506 break;
507 }
508 hpriv = NG_HOOK_PRIVATE(hook);
509
510 /* Send response */
511 NG_MKRESPONSE(resp, msg, sizeof(hpriv->conf), M_NOWAIT);
512 if (resp == NULL) {
513 error = ENOMEM;
514 break;
515 }
516 conf = (struct ng_l2tp_sess_config *)resp->data;
517 *conf = hpriv->conf;
518
519 /* Put ID's in host order */
520 conf->session_id = ntohs(conf->session_id);
521 conf->peer_id = ntohs(conf->peer_id);
522 break;
523 }
524 case NGM_L2TP_GET_STATS:
525 case NGM_L2TP_CLR_STATS:
526 case NGM_L2TP_GETCLR_STATS:
527 {
528 if (msg->header.cmd != NGM_L2TP_CLR_STATS) {
529 NG_MKRESPONSE(resp, msg,
530 sizeof(priv->stats), M_NOWAIT);
531 if (resp == NULL) {
532 error = ENOMEM;
533 break;
534 }
535 memcpy(resp->data,
536 &priv->stats, sizeof(priv->stats));
537 }
538 if (msg->header.cmd != NGM_L2TP_GET_STATS)
539 memset(&priv->stats, 0, sizeof(priv->stats));
540 break;
541 }
542 default:
543 error = EINVAL;
544 break;
545 }
546 break;
547 default:
548 error = EINVAL;
549 break;
550 }
551
552 /* Done */
553 NG_RESPOND_MSG(error, node, item, resp);
554 NG_FREE_MSG(msg);
555 return (error);
556}
557
558/*
559 * Receive incoming data on a hook.
560 */
561static int
562ng_l2tp_rcvdata(hook_p hook, item_p item)
563{
564 const node_p node = NG_HOOK_NODE(hook);
565 const priv_p priv = NG_NODE_PRIVATE(node);
566 int error;
567
568 /* Sanity check */
569 L2TP_SEQ_CHECK(&priv->seq);
570
571 /* If not configured, reject */
572 if (!priv->conf.enabled) {
573 NG_FREE_ITEM(item);
574 return (ENXIO);
575 }
576
577 /* Handle incoming frame from below */
578 if (hook == priv->lower) {
579 error = ng_l2tp_recv_lower(node, item);
580 goto done;
581 }
582
583 /* Handle outgoing control frame */
584 if (hook == priv->ctrl) {
585 error = ng_l2tp_recv_ctrl(node, item);
586 goto done;
587 }
588
589 /* Handle outgoing data frame */
590 error = ng_l2tp_recv_data(node, item, NG_HOOK_PRIVATE(hook));
591
592done:
593 /* Done */
594 L2TP_SEQ_CHECK(&priv->seq);
595 return (error);
596}
597
598/*
599 * Destroy node
600 */
601static int
602ng_l2tp_shutdown(node_p node)
603{
604 const priv_p priv = NG_NODE_PRIVATE(node);
605 struct l2tp_seq *const seq = &priv->seq;
606
607 /* Sanity check */
608 L2TP_SEQ_CHECK(seq);
609
610 /* Reset sequence number state */
611 ng_l2tp_seq_reset(priv);
612
613 /* Free private data if neither timer is running */
614 if (!seq->rack_timer_running && !seq->xack_timer_running) {
615 FREE(priv, M_NETGRAPH_L2TP);
616 NG_NODE_SET_PRIVATE(node, NULL);
617 }
618
619 /* Unref node */
620 NG_NODE_UNREF(node);
621 return (0);
622}
623
624/*
625 * Hook disconnection
626 */
627static int
628ng_l2tp_disconnect(hook_p hook)
629{
630 const node_p node = NG_HOOK_NODE(hook);
631 const priv_p priv = NG_NODE_PRIVATE(node);
632
633 /* Zero out hook pointer */
634 if (hook == priv->ctrl)
635 priv->ctrl = NULL;
636 else if (hook == priv->lower)
637 priv->lower = NULL;
638 else {
639 FREE(NG_HOOK_PRIVATE(hook), M_NETGRAPH_L2TP);
640 NG_HOOK_SET_PRIVATE(hook, NULL);
641 }
642
643 /* Go away if no longer connected to anything */
644 if (NG_NODE_NUMHOOKS(node) == 0 && NG_NODE_IS_VALID(node))
645 ng_rmnode_self(node);
646 return (0);
647}
648
649/*************************************************************************
650 INTERNAL FUNCTIONS
651*************************************************************************/
652
653/*
654 * Find the hook with a given session ID.
655 */
656static int
657ng_l2tp_find_session(hook_p hook, void *arg)
658{
659 const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
660 const u_int16_t sid = (u_int16_t)(uintptr_t)arg;
661
662 if (hpriv == NULL || hpriv->conf.session_id != sid)
663 return (-1);
664 return (0);
665}
666
667/*
668 * Reset a hook's session state.
669 */
670static int
671ng_l2tp_reset_session(hook_p hook, void *arg)
672{
673 const hookpriv_p hpriv = NG_HOOK_PRIVATE(hook);
674
675 if (hpriv != NULL) {
676 hpriv->conf.control_dseq = 0;
677 hpriv->conf.enable_dseq = 0;
678 hpriv->nr = 0;
679 hpriv->ns = 0;
680 }
681 return (-1);
682}
683
684/*
685 * Handle an incoming frame from below.
686 */
687static int
688ng_l2tp_recv_lower(node_p node, item_p item)
689{
690 static const u_int16_t req_bits[2][2] = {
691 { L2TP_DATA_0BITS, L2TP_DATA_1BITS },
692 { L2TP_CTRL_0BITS, L2TP_CTRL_1BITS },
693 };
694 const priv_p priv = NG_NODE_PRIVATE(node);
695 hookpriv_p hpriv = NULL;
696 hook_p hook = NULL;
697 u_int16_t ids[2];
698 struct mbuf *m;
699 u_int16_t hdr;
700 u_int16_t ns;
701 u_int16_t nr;
702 int is_ctrl;
703 int error;
704 int len;
705
706 /* Grab mbuf */
707 NGI_GET_M(item, m);
708
709 /* Update stats */
710 priv->stats.recvPackets++;
711 priv->stats.recvOctets += m->m_pkthdr.len;
712
713 /* Get initial header */
714 if (m->m_pkthdr.len < 6) {
715 priv->stats.recvRunts++;
716 NG_FREE_ITEM(item);
717 NG_FREE_M(m);
718 return (EINVAL);
719 }
720 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
721 priv->stats.memoryFailures++;
722 NG_FREE_ITEM(item);
723 return (EINVAL);
724 }
725 hdr = ntohs(*mtod(m, u_int16_t *));
726 m_adj(m, 2);
727
728 /* Check required header bits and minimum length */
729 is_ctrl = (hdr & L2TP_HDR_CTRL) != 0;
730 if ((hdr & req_bits[is_ctrl][0]) != 0
731 || (~hdr & req_bits[is_ctrl][1]) != 0) {
732 priv->stats.recvInvalid++;
733 NG_FREE_ITEM(item);
734 NG_FREE_M(m);
735 return (EINVAL);
736 }
737 if (m->m_pkthdr.len < 4 /* tunnel, session id */
738 + (2 * ((hdr & L2TP_HDR_LEN) != 0)) /* length field */
739 + (4 * ((hdr & L2TP_HDR_SEQ) != 0)) /* seq # fields */
740 + (2 * ((hdr & L2TP_HDR_OFF) != 0))) { /* offset field */
741 priv->stats.recvRunts++;
742 NG_FREE_ITEM(item);
743 NG_FREE_M(m);
744 return (EINVAL);
745 }
746
747 /* Get and validate length field if present */
748 if ((hdr & L2TP_HDR_LEN) != 0) {
749 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
750 priv->stats.memoryFailures++;
751 NG_FREE_ITEM(item);
752 return (EINVAL);
753 }
754 len = (u_int16_t)ntohs(*mtod(m, u_int16_t *)) - 4;
755 m_adj(m, 2);
756 if (len < 0 || len > m->m_pkthdr.len) {
757 priv->stats.recvInvalid++;
758 NG_FREE_ITEM(item);
759 NG_FREE_M(m);
760 return (EINVAL);
761 }
762 if (len < m->m_pkthdr.len) /* trim extra bytes */
763 m_adj(m, -(m->m_pkthdr.len - len));
764 }
765
766 /* Get tunnel ID and session ID */
767 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
768 priv->stats.memoryFailures++;
769 NG_FREE_ITEM(item);
770 return (EINVAL);
771 }
772 memcpy(ids, mtod(m, u_int16_t *), 4);
773 m_adj(m, 4);
774
775 /* Check tunnel ID */
776 if (ids[0] != priv->conf.tunnel_id
777 && (priv->conf.match_id || ids[0] != 0)) {
778 priv->stats.recvWrongTunnel++;
779 NG_FREE_ITEM(item);
780 NG_FREE_M(m);
781 return (EADDRNOTAVAIL);
782 }
783
784 /* Check session ID (for data packets only) */
785 if ((hdr & L2TP_HDR_CTRL) == 0) {
786 NG_NODE_FOREACH_HOOK(node, ng_l2tp_find_session,
787 (void *)(uintptr_t)ids[1], hook);
788 if (hook == NULL) {
789 priv->stats.recvUnknownSID++;
790 NG_FREE_ITEM(item);
791 NG_FREE_M(m);
792 return (ENOTCONN);
793 }
794 hpriv = NG_HOOK_PRIVATE(hook);
795 }
796
797 /* Get Ns, Nr fields if present */
798 if ((hdr & L2TP_HDR_SEQ) != 0) {
799 if (m->m_len < 4 && (m = m_pullup(m, 4)) == NULL) {
800 priv->stats.memoryFailures++;
801 NG_FREE_ITEM(item);
802 return (EINVAL);
803 }
804 memcpy(&ns, &mtod(m, u_int16_t *)[0], 2);
805 ns = ntohs(ns);
806 memcpy(&nr, &mtod(m, u_int16_t *)[1], 2);
807 nr = ntohs(nr);
808 m_adj(m, 4);
809 }
810
811 /* Strip offset padding if present */
812 if ((hdr & L2TP_HDR_OFF) != 0) {
813 u_int16_t offset;
814
815 /* Get length of offset padding */
816 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
817 priv->stats.memoryFailures++;
818 NG_FREE_ITEM(item);
819 return (EINVAL);
820 }
821 memcpy(&offset, mtod(m, u_int16_t *), 2);
822 offset = ntohs(offset);
823
824 /* Trim offset padding */
825 if (offset <= 2 || offset > m->m_pkthdr.len) {
826 priv->stats.recvInvalid++;
827 NG_FREE_ITEM(item);
828 NG_FREE_M(m);
829 return (EINVAL);
830 }
831 m_adj(m, offset);
832 }
833
834 /* Handle control packets */
835 if ((hdr & L2TP_HDR_CTRL) != 0) {
836
837 /* Handle receive ack sequence number Nr */
838 ng_l2tp_seq_recv_nr(priv, nr);
839
840 /* Discard ZLB packets */
841 if (m->m_pkthdr.len == 0) {
842 priv->stats.recvZLBs++;
843 NG_FREE_ITEM(item);
844 NG_FREE_M(m);
845 return (0);
846 }
847
848 /*
849 * Prepend session ID to packet here: we don't want to accept
850 * the send sequence number Ns if we have to drop the packet
851 * later because of a memory error, because then the upper
852 * layer would never get the packet.
853 */
854 M_PREPEND(m, 2, M_DONTWAIT);
855 if (m == NULL) {
856 priv->stats.memoryFailures++;
857 NG_FREE_ITEM(item);
858 return (ENOBUFS);
859 }
860 memcpy(mtod(m, u_int16_t *), &ids[1], 2);
861
862 /* Now handle send sequence number */
863 if (ng_l2tp_seq_recv_ns(priv, ns) == -1) {
864 NG_FREE_ITEM(item);
865 NG_FREE_M(m);
866 return (0);
867 }
868
869 /* Deliver packet to upper layers */
870 NG_FWD_NEW_DATA(error, item, priv->ctrl, m);
871 return (error);
872 }
873
874 /* Follow peer's lead in data sequencing, if configured to do so */
875 if (!hpriv->conf.control_dseq)
876 hpriv->conf.enable_dseq = ((hdr & L2TP_HDR_SEQ) != 0);
877
878 /* Handle data sequence numbers if present and enabled */
879 if ((hdr & L2TP_HDR_SEQ) != 0) {
880 if (hpriv->conf.enable_dseq
881 && L2TP_SEQ_DIFF(ns, hpriv->nr) < 0) {
882 NG_FREE_ITEM(item); /* duplicate or out of order */
883 NG_FREE_M(m);
884 priv->stats.recvDataDrops++;
885 return (0);
886 }
887 hpriv->nr = ns + 1;
888 }
889
890 /* Drop empty data packets */
891 if (m->m_pkthdr.len == 0) {
892 NG_FREE_ITEM(item);
893 NG_FREE_M(m);
894 return (0);
895 }
896
897 /* Deliver data */
898 NG_FWD_NEW_DATA(error, item, hook, m);
899 return (error);
900}
901
902/*
903 * Handle an outgoing control frame.
904 */
905static int
906ng_l2tp_recv_ctrl(node_p node, item_p item)
907{
908 const priv_p priv = NG_NODE_PRIVATE(node);
909 struct l2tp_seq *const seq = &priv->seq;
910 struct mbuf *m;
911 int i;
912
913 /* Grab mbuf and discard other stuff XXX */
914 NGI_GET_M(item, m);
915 NG_FREE_ITEM(item);
916
917 /* Packet should have session ID prepended */
918 if (m->m_pkthdr.len < 2) {
919 priv->stats.xmitInvalid++;
920 m_freem(m);
921 return (EINVAL);
922 }
923
924 /* Check max length */
925 if (m->m_pkthdr.len >= 0x10000 - 14) {
926 priv->stats.xmitTooBig++;
927 m_freem(m);
928 return (EOVERFLOW);
929 }
930
931 /* Find next empty slot in transmit queue */
932 for (i = 0; i < L2TP_MAX_XWIN && seq->xwin[i] != NULL; i++);
933 if (i == L2TP_MAX_XWIN) {
934 priv->stats.xmitDrops++;
935 m_freem(m);
936 return (ENOBUFS);
937 }
938 seq->xwin[i] = m;
939
940 /* Sanity check receive ack timer state */
941 KASSERT((i == 0) ^ seq->rack_timer_running,
942 ("%s: xwin %d full but rack timer %srunning",
943 __FUNCTION__, i, seq->rack_timer_running ? "" : "not "));
944
945 /* If peer's receive window is already full, nothing else to do */
946 if (i >= seq->cwnd)
947 return (0);
948
949 /* Start retransmit timer if not already running */
950 if (!seq->rack_timer_running) {
951 callout_reset(&seq->rack_timer,
952 hz, ng_l2tp_seq_rack_timeout, node);
953 seq->rack_timer_running = 1;
954 NG_NODE_REF(node);
955 }
956
957 /* Copy packet */
|
958 if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_NOWAIT)) == NULL) {
| 958 if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_DONTWAIT)) == NULL) {
|
959 priv->stats.memoryFailures++;
960 return (ENOBUFS);
961 }
962
963 /* Send packet and increment xmit sequence number */
964 return (ng_l2tp_xmit_ctrl(priv, m, seq->ns++));
965}
966
967/*
968 * Handle an outgoing data frame.
969 */
970static int
971ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv)
972{
973 const priv_p priv = NG_NODE_PRIVATE(node);
974 struct mbuf *m;
975 u_int16_t hdr;
976 int error;
977 int i = 1;
978
979 /* Get mbuf */
980 NGI_GET_M(item, m);
981
982 /* Check max length */
983 if (m->m_pkthdr.len >= 0x10000 - 12) {
984 priv->stats.xmitDataTooBig++;
985 NG_FREE_ITEM(item);
986 NG_FREE_M(m);
987 return (EOVERFLOW);
988 }
989
990 /* Prepend L2TP header */
991 M_PREPEND(m, 6
992 + (2 * (hpriv->conf.include_length != 0))
993 + (4 * (hpriv->conf.enable_dseq != 0)),
994 M_DONTWAIT);
995 if (m == NULL) {
996 priv->stats.memoryFailures++;
997 NG_FREE_ITEM(item);
998 return (ENOBUFS);
999 }
1000 hdr = L2TP_DATA_HDR;
1001 if (hpriv->conf.include_length) {
1002 hdr |= L2TP_HDR_LEN;
1003 mtod(m, u_int16_t *)[i++] = htons(m->m_pkthdr.len);
1004 }
1005 mtod(m, u_int16_t *)[i++] = priv->conf.peer_id;
1006 mtod(m, u_int16_t *)[i++] = hpriv->conf.peer_id;
1007 if (hpriv->conf.enable_dseq) {
1008 hdr |= L2TP_HDR_SEQ;
1009 mtod(m, u_int16_t *)[i++] = htons(hpriv->ns);
1010 mtod(m, u_int16_t *)[i++] = htons(hpriv->nr);
1011 hpriv->ns++;
1012 }
1013 mtod(m, u_int16_t *)[0] = htons(hdr);
1014
1015 /* Send packet */
1016 NG_FWD_NEW_DATA(error, item, priv->lower, m);
1017 return (error);
1018}
1019
1020/*
1021 * Send a message to our controlling node that we've failed.
1022 */
1023static void
1024ng_l2tp_seq_failure(priv_p priv)
1025{
1026 struct ng_mesg *msg;
1027 int error;
1028
1029 NG_MKMESSAGE(msg, NGM_L2TP_COOKIE, NGM_L2TP_ACK_FAILURE, 0, M_NOWAIT);
1030 if (msg == NULL)
1031 return;
1032 NG_SEND_MSG_ID(error, priv->node, msg, priv->ftarget, 0);
1033}
1034
1035/************************************************************************
1036 SEQUENCE NUMBER HANDLING
1037************************************************************************/
1038
1039/*
1040 * Initialize sequence number state.
1041 */
1042static void
1043ng_l2tp_seq_init(priv_p priv)
1044{
1045 struct l2tp_seq *const seq = &priv->seq;
1046
1047 KASSERT(priv->conf.peer_win >= 1,
1048 ("%s: peer_win is zero", __FUNCTION__));
1049 memset(seq, 0, sizeof(*seq));
1050 seq->cwnd = 1;
1051 seq->wmax = priv->conf.peer_win;
1052 if (seq->wmax > L2TP_MAX_XWIN)
1053 seq->wmax = L2TP_MAX_XWIN;
1054 seq->ssth = seq->wmax;
1055 seq->max_rexmits = priv->conf.rexmit_max;
1056 seq->max_rexmit_to = priv->conf.rexmit_max_to;
1057 callout_init(&seq->rack_timer, 0);
1058 callout_init(&seq->xack_timer, 0);
1059 L2TP_SEQ_CHECK(seq);
1060}
1061
1062/*
1063 * Adjust sequence number state accordingly after reconfiguration.
1064 */
1065static int
1066ng_l2tp_seq_adjust(priv_p priv, const struct ng_l2tp_config *conf)
1067{
1068 struct l2tp_seq *const seq = &priv->seq;
1069 u_int16_t new_wmax;
1070
1071 /* If disabling node, reset state sequence number */
1072 if (!conf->enabled) {
1073 ng_l2tp_seq_reset(priv);
1074 return (0);
1075 }
1076
1077 /* Adjust peer's max recv window; it can only increase */
1078 new_wmax = conf->peer_win;
1079 if (new_wmax > L2TP_MAX_XWIN)
1080 new_wmax = L2TP_MAX_XWIN;
1081 if (new_wmax == 0)
1082 return (EINVAL);
1083 if (new_wmax < seq->wmax)
1084 return (EBUSY);
1085 seq->wmax = new_wmax;
1086
1087 /* Update retransmit parameters */
1088 seq->max_rexmits = conf->rexmit_max;
1089 seq->max_rexmit_to = conf->rexmit_max_to;
1090
1091 /* Done */
1092 return (0);
1093}
1094
1095/*
1096 * Reset sequence number state.
1097 */
1098static void
1099ng_l2tp_seq_reset(priv_p priv)
1100{
1101 struct l2tp_seq *const seq = &priv->seq;
1102 hook_p hook;
1103 int i;
1104
1105 /* Sanity check */
1106 L2TP_SEQ_CHECK(seq);
1107
1108 /* Stop timers */
1109 if (seq->rack_timer_running && callout_stop(&seq->rack_timer) == 1) {
1110 seq->rack_timer_running = 0;
1111 NG_NODE_UNREF(priv->node);
1112 }
1113 if (seq->xack_timer_running && callout_stop(&seq->xack_timer) == 1) {
1114 seq->xack_timer_running = 0;
1115 NG_NODE_UNREF(priv->node);
1116 }
1117
1118 /* Free retransmit queue */
1119 for (i = 0; i < L2TP_MAX_XWIN; i++) {
1120 if (seq->xwin[i] == NULL)
1121 break;
1122 m_freem(seq->xwin[i]);
1123 }
1124
1125 /* Reset session hooks' sequence number states */
1126 NG_NODE_FOREACH_HOOK(priv->node, ng_l2tp_reset_session, NULL, hook);
1127
1128 /* Reset node's sequence number state */
1129 memset(seq, 0, sizeof(*seq));
1130 seq->cwnd = 1;
1131 seq->wmax = L2TP_MAX_XWIN;
1132 seq->ssth = seq->wmax;
1133
1134 /* Done */
1135 L2TP_SEQ_CHECK(seq);
1136}
1137
1138/*
1139 * Handle receipt of an acknowledgement value (Nr) from peer.
1140 */
1141static void
1142ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr)
1143{
1144 struct l2tp_seq *const seq = &priv->seq;
1145 struct mbuf *m;
1146 int nack;
1147 int i;
1148
1149 /* Verify peer's ACK is in range */
1150 if ((nack = L2TP_SEQ_DIFF(nr, seq->rack)) <= 0)
1151 return; /* duplicate ack */
1152 if (L2TP_SEQ_DIFF(nr, seq->ns) > 0) {
1153 priv->stats.recvBadAcks++; /* ack for packet not sent */
1154 return;
1155 }
1156 KASSERT(nack <= L2TP_MAX_XWIN,
1157 ("%s: nack=%d > %d", __FUNCTION__, nack, L2TP_MAX_XWIN));
1158
1159 /* Update receive ack stats */
1160 seq->rack = nr;
1161 seq->rexmits = 0;
1162
1163 /* Free acknowledged packets and shift up packets in the xmit queue */
1164 for (i = 0; i < nack; i++)
1165 m_freem(seq->xwin[i]);
1166 memmove(seq->xwin, seq->xwin + nack,
1167 (L2TP_MAX_XWIN - nack) * sizeof(*seq->xwin));
1168 memset(seq->xwin + (L2TP_MAX_XWIN - nack), 0,
1169 nack * sizeof(*seq->xwin));
1170
1171 /*
1172 * Do slow-start/congestion avoidance windowing algorithm described
1173 * in RFC 2661, Appendix A. Here we handle a multiple ACK as if each
1174 * ACK had arrived separately.
1175 */
1176 if (seq->cwnd < seq->wmax) {
1177
1178 /* Handle slow start phase */
1179 if (seq->cwnd < seq->ssth) {
1180 seq->cwnd += nack;
1181 nack = 0;
1182 if (seq->cwnd > seq->ssth) { /* into cg.av. phase */
1183 nack = seq->cwnd - seq->ssth;
1184 seq->cwnd = seq->ssth;
1185 }
1186 }
1187
1188 /* Handle congestion avoidance phase */
1189 if (seq->cwnd >= seq->ssth) {
1190 seq->acks += nack;
1191 while (seq->acks >= seq->cwnd) {
1192 seq->acks -= seq->cwnd;
1193 if (seq->cwnd < seq->wmax)
1194 seq->cwnd++;
1195 }
1196 }
1197 }
1198
1199 /* Stop xmit timer */
1200 if (seq->rack_timer_running && callout_stop(&seq->rack_timer) == 1) {
1201 seq->rack_timer_running = 0;
1202 NG_NODE_UNREF(priv->node);
1203 }
1204
1205 /* If transmit queue is empty, we're done for now */
1206 if (seq->xwin[0] == NULL)
1207 return;
1208
1209 /* Start restransmit timer again */
1210 callout_reset(&seq->rack_timer,
1211 hz, ng_l2tp_seq_rack_timeout, priv->node);
1212 seq->rack_timer_running = 1;
1213 NG_NODE_REF(priv->node);
1214
1215 /*
1216 * Send more packets, trying to keep peer's receive window full.
1217 * If there is a memory error, pretend packet was sent, as it
1218 * will get retransmitted later anyway.
1219 */
1220 while ((i = L2TP_SEQ_DIFF(seq->ns, seq->rack)) < seq->cwnd
1221 && seq->xwin[i] != NULL) {
| 959 priv->stats.memoryFailures++;
960 return (ENOBUFS);
961 }
962
963 /* Send packet and increment xmit sequence number */
964 return (ng_l2tp_xmit_ctrl(priv, m, seq->ns++));
965}
966
967/*
968 * Handle an outgoing data frame.
969 */
970static int
971ng_l2tp_recv_data(node_p node, item_p item, hookpriv_p hpriv)
972{
973 const priv_p priv = NG_NODE_PRIVATE(node);
974 struct mbuf *m;
975 u_int16_t hdr;
976 int error;
977 int i = 1;
978
979 /* Get mbuf */
980 NGI_GET_M(item, m);
981
982 /* Check max length */
983 if (m->m_pkthdr.len >= 0x10000 - 12) {
984 priv->stats.xmitDataTooBig++;
985 NG_FREE_ITEM(item);
986 NG_FREE_M(m);
987 return (EOVERFLOW);
988 }
989
990 /* Prepend L2TP header */
991 M_PREPEND(m, 6
992 + (2 * (hpriv->conf.include_length != 0))
993 + (4 * (hpriv->conf.enable_dseq != 0)),
994 M_DONTWAIT);
995 if (m == NULL) {
996 priv->stats.memoryFailures++;
997 NG_FREE_ITEM(item);
998 return (ENOBUFS);
999 }
1000 hdr = L2TP_DATA_HDR;
1001 if (hpriv->conf.include_length) {
1002 hdr |= L2TP_HDR_LEN;
1003 mtod(m, u_int16_t *)[i++] = htons(m->m_pkthdr.len);
1004 }
1005 mtod(m, u_int16_t *)[i++] = priv->conf.peer_id;
1006 mtod(m, u_int16_t *)[i++] = hpriv->conf.peer_id;
1007 if (hpriv->conf.enable_dseq) {
1008 hdr |= L2TP_HDR_SEQ;
1009 mtod(m, u_int16_t *)[i++] = htons(hpriv->ns);
1010 mtod(m, u_int16_t *)[i++] = htons(hpriv->nr);
1011 hpriv->ns++;
1012 }
1013 mtod(m, u_int16_t *)[0] = htons(hdr);
1014
1015 /* Send packet */
1016 NG_FWD_NEW_DATA(error, item, priv->lower, m);
1017 return (error);
1018}
1019
1020/*
1021 * Send a message to our controlling node that we've failed.
1022 */
1023static void
1024ng_l2tp_seq_failure(priv_p priv)
1025{
1026 struct ng_mesg *msg;
1027 int error;
1028
1029 NG_MKMESSAGE(msg, NGM_L2TP_COOKIE, NGM_L2TP_ACK_FAILURE, 0, M_NOWAIT);
1030 if (msg == NULL)
1031 return;
1032 NG_SEND_MSG_ID(error, priv->node, msg, priv->ftarget, 0);
1033}
1034
1035/************************************************************************
1036 SEQUENCE NUMBER HANDLING
1037************************************************************************/
1038
1039/*
1040 * Initialize sequence number state.
1041 */
1042static void
1043ng_l2tp_seq_init(priv_p priv)
1044{
1045 struct l2tp_seq *const seq = &priv->seq;
1046
1047 KASSERT(priv->conf.peer_win >= 1,
1048 ("%s: peer_win is zero", __FUNCTION__));
1049 memset(seq, 0, sizeof(*seq));
1050 seq->cwnd = 1;
1051 seq->wmax = priv->conf.peer_win;
1052 if (seq->wmax > L2TP_MAX_XWIN)
1053 seq->wmax = L2TP_MAX_XWIN;
1054 seq->ssth = seq->wmax;
1055 seq->max_rexmits = priv->conf.rexmit_max;
1056 seq->max_rexmit_to = priv->conf.rexmit_max_to;
1057 callout_init(&seq->rack_timer, 0);
1058 callout_init(&seq->xack_timer, 0);
1059 L2TP_SEQ_CHECK(seq);
1060}
1061
1062/*
1063 * Adjust sequence number state accordingly after reconfiguration.
1064 */
1065static int
1066ng_l2tp_seq_adjust(priv_p priv, const struct ng_l2tp_config *conf)
1067{
1068 struct l2tp_seq *const seq = &priv->seq;
1069 u_int16_t new_wmax;
1070
1071 /* If disabling node, reset state sequence number */
1072 if (!conf->enabled) {
1073 ng_l2tp_seq_reset(priv);
1074 return (0);
1075 }
1076
1077 /* Adjust peer's max recv window; it can only increase */
1078 new_wmax = conf->peer_win;
1079 if (new_wmax > L2TP_MAX_XWIN)
1080 new_wmax = L2TP_MAX_XWIN;
1081 if (new_wmax == 0)
1082 return (EINVAL);
1083 if (new_wmax < seq->wmax)
1084 return (EBUSY);
1085 seq->wmax = new_wmax;
1086
1087 /* Update retransmit parameters */
1088 seq->max_rexmits = conf->rexmit_max;
1089 seq->max_rexmit_to = conf->rexmit_max_to;
1090
1091 /* Done */
1092 return (0);
1093}
1094
1095/*
1096 * Reset sequence number state.
1097 */
1098static void
1099ng_l2tp_seq_reset(priv_p priv)
1100{
1101 struct l2tp_seq *const seq = &priv->seq;
1102 hook_p hook;
1103 int i;
1104
1105 /* Sanity check */
1106 L2TP_SEQ_CHECK(seq);
1107
1108 /* Stop timers */
1109 if (seq->rack_timer_running && callout_stop(&seq->rack_timer) == 1) {
1110 seq->rack_timer_running = 0;
1111 NG_NODE_UNREF(priv->node);
1112 }
1113 if (seq->xack_timer_running && callout_stop(&seq->xack_timer) == 1) {
1114 seq->xack_timer_running = 0;
1115 NG_NODE_UNREF(priv->node);
1116 }
1117
1118 /* Free retransmit queue */
1119 for (i = 0; i < L2TP_MAX_XWIN; i++) {
1120 if (seq->xwin[i] == NULL)
1121 break;
1122 m_freem(seq->xwin[i]);
1123 }
1124
1125 /* Reset session hooks' sequence number states */
1126 NG_NODE_FOREACH_HOOK(priv->node, ng_l2tp_reset_session, NULL, hook);
1127
1128 /* Reset node's sequence number state */
1129 memset(seq, 0, sizeof(*seq));
1130 seq->cwnd = 1;
1131 seq->wmax = L2TP_MAX_XWIN;
1132 seq->ssth = seq->wmax;
1133
1134 /* Done */
1135 L2TP_SEQ_CHECK(seq);
1136}
1137
1138/*
1139 * Handle receipt of an acknowledgement value (Nr) from peer.
1140 */
1141static void
1142ng_l2tp_seq_recv_nr(priv_p priv, u_int16_t nr)
1143{
1144 struct l2tp_seq *const seq = &priv->seq;
1145 struct mbuf *m;
1146 int nack;
1147 int i;
1148
1149 /* Verify peer's ACK is in range */
1150 if ((nack = L2TP_SEQ_DIFF(nr, seq->rack)) <= 0)
1151 return; /* duplicate ack */
1152 if (L2TP_SEQ_DIFF(nr, seq->ns) > 0) {
1153 priv->stats.recvBadAcks++; /* ack for packet not sent */
1154 return;
1155 }
1156 KASSERT(nack <= L2TP_MAX_XWIN,
1157 ("%s: nack=%d > %d", __FUNCTION__, nack, L2TP_MAX_XWIN));
1158
1159 /* Update receive ack stats */
1160 seq->rack = nr;
1161 seq->rexmits = 0;
1162
1163 /* Free acknowledged packets and shift up packets in the xmit queue */
1164 for (i = 0; i < nack; i++)
1165 m_freem(seq->xwin[i]);
1166 memmove(seq->xwin, seq->xwin + nack,
1167 (L2TP_MAX_XWIN - nack) * sizeof(*seq->xwin));
1168 memset(seq->xwin + (L2TP_MAX_XWIN - nack), 0,
1169 nack * sizeof(*seq->xwin));
1170
1171 /*
1172 * Do slow-start/congestion avoidance windowing algorithm described
1173 * in RFC 2661, Appendix A. Here we handle a multiple ACK as if each
1174 * ACK had arrived separately.
1175 */
1176 if (seq->cwnd < seq->wmax) {
1177
1178 /* Handle slow start phase */
1179 if (seq->cwnd < seq->ssth) {
1180 seq->cwnd += nack;
1181 nack = 0;
1182 if (seq->cwnd > seq->ssth) { /* into cg.av. phase */
1183 nack = seq->cwnd - seq->ssth;
1184 seq->cwnd = seq->ssth;
1185 }
1186 }
1187
1188 /* Handle congestion avoidance phase */
1189 if (seq->cwnd >= seq->ssth) {
1190 seq->acks += nack;
1191 while (seq->acks >= seq->cwnd) {
1192 seq->acks -= seq->cwnd;
1193 if (seq->cwnd < seq->wmax)
1194 seq->cwnd++;
1195 }
1196 }
1197 }
1198
1199 /* Stop xmit timer */
1200 if (seq->rack_timer_running && callout_stop(&seq->rack_timer) == 1) {
1201 seq->rack_timer_running = 0;
1202 NG_NODE_UNREF(priv->node);
1203 }
1204
1205 /* If transmit queue is empty, we're done for now */
1206 if (seq->xwin[0] == NULL)
1207 return;
1208
1209 /* Start restransmit timer again */
1210 callout_reset(&seq->rack_timer,
1211 hz, ng_l2tp_seq_rack_timeout, priv->node);
1212 seq->rack_timer_running = 1;
1213 NG_NODE_REF(priv->node);
1214
1215 /*
1216 * Send more packets, trying to keep peer's receive window full.
1217 * If there is a memory error, pretend packet was sent, as it
1218 * will get retransmitted later anyway.
1219 */
1220 while ((i = L2TP_SEQ_DIFF(seq->ns, seq->rack)) < seq->cwnd
1221 && seq->xwin[i] != NULL) {
|
1222 if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_NOWAIT)) == NULL)
| 1222 if ((m = L2TP_COPY_MBUF(seq->xwin[i], M_DONTWAIT)) == NULL)
|
1223 priv->stats.memoryFailures++;
1224 else
1225 ng_l2tp_xmit_ctrl(priv, m, seq->ns);
1226 seq->ns++;
1227 }
1228}
1229
1230/*
1231 * Handle receipt of a sequence number value (Ns) from peer.
1232 * We make no attempt to re-order out of order packets.
1233 *
1234 * This function should only be called for non-ZLB packets.
1235 *
1236 * Returns:
1237 * 0 Accept packet
1238 * -1 Drop packet
1239 */
1240static int
1241ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns)
1242{
1243 struct l2tp_seq *const seq = &priv->seq;
1244
1245 /* If not what we expect, drop packet and send an immediate ZLB ack */
1246 if (ns != seq->nr) {
1247 if (L2TP_SEQ_DIFF(ns, seq->nr) < 0)
1248 priv->stats.recvDuplicates++;
1249 else
1250 priv->stats.recvOutOfOrder++;
1251 ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
1252 return (-1);
1253 }
1254
1255 /* Update recv sequence number */
1256 seq->nr++;
1257
1258 /* Start receive ack timer, if not already running */
1259 if (!seq->xack_timer_running) {
1260 callout_reset(&seq->xack_timer,
1261 L2TP_DELAYED_ACK, ng_l2tp_seq_xack_timeout, priv->node);
1262 seq->xack_timer_running = 1;
1263 NG_NODE_REF(priv->node);
1264 }
1265
1266 /* Accept packet */
1267 return (0);
1268}
1269
1270/*
1271 * Handle an ack timeout. We have an outstanding ack that we
1272 * were hoping to piggy-back, but haven't, so send a ZLB.
1273 */
1274static void
1275ng_l2tp_seq_xack_timeout(void *arg)
1276{
1277 const node_p node = arg;
1278 const priv_p priv = NG_NODE_PRIVATE(node);
1279 struct l2tp_seq *const seq = &priv->seq;
1280 int s;
1281
1282 /* Check if node is going away */
1283 s = splnet();
1284 if (NG_NODE_NOT_VALID(node)) {
1285 seq->xack_timer_running = 0;
1286 if (!seq->rack_timer_running) {
1287 FREE(priv, M_NETGRAPH_L2TP);
1288 NG_NODE_SET_PRIVATE(node, NULL);
1289 }
1290 NG_NODE_UNREF(node);
1291 splx(s);
1292 return;
1293 }
1294
1295 /* Sanity check */
1296 L2TP_SEQ_CHECK(seq);
1297
1298 /* If ack is still outstanding, send a ZLB */
1299 if (seq->xack != seq->nr)
1300 ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
1301
1302 /* Done */
1303 seq->xack_timer_running = 0;
1304 NG_NODE_UNREF(node);
1305 L2TP_SEQ_CHECK(seq);
1306 splx(s);
1307}
1308
1309/*
1310 * Handle a transmit timeout. The peer has failed to respond
1311 * with an ack for our packet, so retransmit it.
1312 */
1313static void
1314ng_l2tp_seq_rack_timeout(void *arg)
1315{
1316 const node_p node = arg;
1317 const priv_p priv = NG_NODE_PRIVATE(node);
1318 struct l2tp_seq *const seq = &priv->seq;
1319 struct mbuf *m;
1320 u_int delay;
1321 int s;
1322
1323 /* Check if node is going away */
1324 s = splnet();
1325 if (NG_NODE_NOT_VALID(node)) {
1326 seq->rack_timer_running = 0;
1327 if (!seq->xack_timer_running) {
1328 FREE(priv, M_NETGRAPH_L2TP);
1329 NG_NODE_SET_PRIVATE(node, NULL);
1330 }
1331 NG_NODE_UNREF(node);
1332 splx(s);
1333 return;
1334 }
1335
1336 /* Sanity check */
1337 L2TP_SEQ_CHECK(seq);
1338
1339 /* Make sure peer's ack is still outstanding before doing anything */
1340 if (seq->rack == seq->ns) {
1341 seq->rack_timer_running = 0;
1342 NG_NODE_UNREF(node);
1343 goto done;
1344 }
1345 priv->stats.xmitRetransmits++;
1346
1347 /* Have we reached the retransmit limit? If so, notify owner. */
1348 if (seq->rexmits++ >= seq->max_rexmits)
1349 ng_l2tp_seq_failure(priv);
1350
1351 /* Restart timer, this time with an increased delay */
1352 delay = (seq->rexmits > 12) ? (1 << 12) : (1 << seq->rexmits);
1353 if (delay > seq->max_rexmit_to)
1354 delay = seq->max_rexmit_to;
1355 callout_reset(&seq->rack_timer,
1356 hz * delay, ng_l2tp_seq_rack_timeout, node);
1357
1358 /* Do slow-start/congestion algorithm windowing algorithm */
1359 seq->ssth = (seq->cwnd + 1) / 2;
1360 seq->cwnd = 1;
1361 seq->acks = 0;
1362
1363 /* Retransmit oldest unack'd packet */
| 1223 priv->stats.memoryFailures++;
1224 else
1225 ng_l2tp_xmit_ctrl(priv, m, seq->ns);
1226 seq->ns++;
1227 }
1228}
1229
1230/*
1231 * Handle receipt of a sequence number value (Ns) from peer.
1232 * We make no attempt to re-order out of order packets.
1233 *
1234 * This function should only be called for non-ZLB packets.
1235 *
1236 * Returns:
1237 * 0 Accept packet
1238 * -1 Drop packet
1239 */
1240static int
1241ng_l2tp_seq_recv_ns(priv_p priv, u_int16_t ns)
1242{
1243 struct l2tp_seq *const seq = &priv->seq;
1244
1245 /* If not what we expect, drop packet and send an immediate ZLB ack */
1246 if (ns != seq->nr) {
1247 if (L2TP_SEQ_DIFF(ns, seq->nr) < 0)
1248 priv->stats.recvDuplicates++;
1249 else
1250 priv->stats.recvOutOfOrder++;
1251 ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
1252 return (-1);
1253 }
1254
1255 /* Update recv sequence number */
1256 seq->nr++;
1257
1258 /* Start receive ack timer, if not already running */
1259 if (!seq->xack_timer_running) {
1260 callout_reset(&seq->xack_timer,
1261 L2TP_DELAYED_ACK, ng_l2tp_seq_xack_timeout, priv->node);
1262 seq->xack_timer_running = 1;
1263 NG_NODE_REF(priv->node);
1264 }
1265
1266 /* Accept packet */
1267 return (0);
1268}
1269
1270/*
1271 * Handle an ack timeout. We have an outstanding ack that we
1272 * were hoping to piggy-back, but haven't, so send a ZLB.
1273 */
1274static void
1275ng_l2tp_seq_xack_timeout(void *arg)
1276{
1277 const node_p node = arg;
1278 const priv_p priv = NG_NODE_PRIVATE(node);
1279 struct l2tp_seq *const seq = &priv->seq;
1280 int s;
1281
1282 /* Check if node is going away */
1283 s = splnet();
1284 if (NG_NODE_NOT_VALID(node)) {
1285 seq->xack_timer_running = 0;
1286 if (!seq->rack_timer_running) {
1287 FREE(priv, M_NETGRAPH_L2TP);
1288 NG_NODE_SET_PRIVATE(node, NULL);
1289 }
1290 NG_NODE_UNREF(node);
1291 splx(s);
1292 return;
1293 }
1294
1295 /* Sanity check */
1296 L2TP_SEQ_CHECK(seq);
1297
1298 /* If ack is still outstanding, send a ZLB */
1299 if (seq->xack != seq->nr)
1300 ng_l2tp_xmit_ctrl(priv, NULL, seq->ns);
1301
1302 /* Done */
1303 seq->xack_timer_running = 0;
1304 NG_NODE_UNREF(node);
1305 L2TP_SEQ_CHECK(seq);
1306 splx(s);
1307}
1308
1309/*
1310 * Handle a transmit timeout. The peer has failed to respond
1311 * with an ack for our packet, so retransmit it.
1312 */
1313static void
1314ng_l2tp_seq_rack_timeout(void *arg)
1315{
1316 const node_p node = arg;
1317 const priv_p priv = NG_NODE_PRIVATE(node);
1318 struct l2tp_seq *const seq = &priv->seq;
1319 struct mbuf *m;
1320 u_int delay;
1321 int s;
1322
1323 /* Check if node is going away */
1324 s = splnet();
1325 if (NG_NODE_NOT_VALID(node)) {
1326 seq->rack_timer_running = 0;
1327 if (!seq->xack_timer_running) {
1328 FREE(priv, M_NETGRAPH_L2TP);
1329 NG_NODE_SET_PRIVATE(node, NULL);
1330 }
1331 NG_NODE_UNREF(node);
1332 splx(s);
1333 return;
1334 }
1335
1336 /* Sanity check */
1337 L2TP_SEQ_CHECK(seq);
1338
1339 /* Make sure peer's ack is still outstanding before doing anything */
1340 if (seq->rack == seq->ns) {
1341 seq->rack_timer_running = 0;
1342 NG_NODE_UNREF(node);
1343 goto done;
1344 }
1345 priv->stats.xmitRetransmits++;
1346
1347 /* Have we reached the retransmit limit? If so, notify owner. */
1348 if (seq->rexmits++ >= seq->max_rexmits)
1349 ng_l2tp_seq_failure(priv);
1350
1351 /* Restart timer, this time with an increased delay */
1352 delay = (seq->rexmits > 12) ? (1 << 12) : (1 << seq->rexmits);
1353 if (delay > seq->max_rexmit_to)
1354 delay = seq->max_rexmit_to;
1355 callout_reset(&seq->rack_timer,
1356 hz * delay, ng_l2tp_seq_rack_timeout, node);
1357
1358 /* Do slow-start/congestion algorithm windowing algorithm */
1359 seq->ssth = (seq->cwnd + 1) / 2;
1360 seq->cwnd = 1;
1361 seq->acks = 0;
1362
1363 /* Retransmit oldest unack'd packet */
|
1364 if ((m = L2TP_COPY_MBUF(seq->xwin[0], M_NOWAIT)) == NULL)
| 1364 if ((m = L2TP_COPY_MBUF(seq->xwin[0], M_DONTWAIT)) == NULL)
|
1365 priv->stats.memoryFailures++;
1366 else
1367 ng_l2tp_xmit_ctrl(priv, m, seq->rack);
1368
1369done:
1370 /* Done */
1371 L2TP_SEQ_CHECK(seq);
1372 splx(s);
1373}
1374
1375/*
1376 * Transmit a control stream packet, payload optional.
1377 * The transmit sequence number is not incremented.
1378 */
1379static int
1380ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns)
1381{
1382 struct l2tp_seq *const seq = &priv->seq;
1383 u_int16_t session_id = 0;
1384 meta_p meta = NULL;
1385 int error;
1386
1387 /* If no mbuf passed, send an empty packet (ZLB) */
1388 if (m == NULL) {
1389
1390 /* Create a new mbuf for ZLB packet */
1391 MGETHDR(m, M_DONTWAIT, MT_DATA);
1392 if (m == NULL) {
1393 priv->stats.memoryFailures++;
1394 return (ENOBUFS);
1395 }
1396 m->m_len = m->m_pkthdr.len = 12;
1397 m->m_pkthdr.rcvif = NULL;
1398 priv->stats.xmitZLBs++;
1399 } else {
1400
1401 /* Strip off session ID */
1402 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
1403 priv->stats.memoryFailures++;
1404 return (ENOBUFS);
1405 }
1406 memcpy(&session_id, mtod(m, u_int16_t *), 2);
1407 m_adj(m, 2);
1408
1409 /* Make room for L2TP header */
1410 M_PREPEND(m, 12, M_DONTWAIT);
1411 if (m == NULL) {
1412 priv->stats.memoryFailures++;
1413 return (ENOBUFS);
1414 }
1415 }
1416
1417 /* Fill in L2TP header */
1418 mtod(m, u_int16_t *)[0] = htons(L2TP_CTRL_HDR);
1419 mtod(m, u_int16_t *)[1] = htons(m->m_pkthdr.len);
1420 mtod(m, u_int16_t *)[2] = priv->conf.peer_id;
1421 mtod(m, u_int16_t *)[3] = session_id;
1422 mtod(m, u_int16_t *)[4] = htons(ns);
1423 mtod(m, u_int16_t *)[5] = htons(seq->nr);
1424
1425 /* Update sequence number info and stats */
1426 priv->stats.xmitPackets++;
1427 priv->stats.xmitOctets += m->m_pkthdr.len;
1428
1429 /* Stop ack timer: we're sending an ack with this packet */
1430 if (seq->xack_timer_running && callout_stop(&seq->xack_timer) == 1) {
1431 seq->xack_timer_running = 0;
1432 NG_NODE_UNREF(priv->node);
1433 }
1434 seq->xack = seq->nr;
1435
1436 /* Send packet */
1437 NG_SEND_DATA(error, priv->lower, m, meta);
1438 return (error);
1439}
1440
1441#ifdef INVARIANTS
1442/*
1443 * Sanity check sequence number state.
1444 */
1445static void
1446ng_l2tp_seq_check(struct l2tp_seq *seq)
1447{
1448 const int self_unack = L2TP_SEQ_DIFF(seq->nr, seq->xack);
1449 const int peer_unack = L2TP_SEQ_DIFF(seq->ns, seq->rack);
1450 int i;
1451
1452#define CHECK(p) KASSERT((p), ("%s: not: %s", __FUNCTION__, #p))
1453
1454 CHECK(seq->wmax <= L2TP_MAX_XWIN);
1455 CHECK(seq->cwnd >= 1);
1456 CHECK(seq->cwnd <= seq->wmax);
1457 CHECK(seq->ssth >= 1);
1458 CHECK(seq->ssth <= seq->wmax);
1459 if (seq->cwnd < seq->ssth)
1460 CHECK(seq->acks == 0);
1461 else
1462 CHECK(seq->acks <= seq->cwnd);
1463 CHECK(self_unack >= 0);
1464 CHECK(peer_unack >= 0);
1465 CHECK(peer_unack <= seq->wmax);
1466 CHECK((self_unack == 0) ^ seq->xack_timer_running);
1467 CHECK((peer_unack == 0) ^ seq->rack_timer_running);
1468 CHECK(seq->rack_timer_running || !callout_pending(&seq->rack_timer));
1469 CHECK(seq->xack_timer_running || !callout_pending(&seq->xack_timer));
1470 for (i = 0; i < peer_unack; i++)
1471 CHECK(seq->xwin[i] != NULL);
1472 for ( ; i < seq->cwnd; i++) /* verify peer's recv window full */
1473 CHECK(seq->xwin[i] == NULL);
1474
1475#undef CHECK
1476}
1477#endif /* INVARIANTS */
1478
1479
| 1365 priv->stats.memoryFailures++;
1366 else
1367 ng_l2tp_xmit_ctrl(priv, m, seq->rack);
1368
1369done:
1370 /* Done */
1371 L2TP_SEQ_CHECK(seq);
1372 splx(s);
1373}
1374
1375/*
1376 * Transmit a control stream packet, payload optional.
1377 * The transmit sequence number is not incremented.
1378 */
1379static int
1380ng_l2tp_xmit_ctrl(priv_p priv, struct mbuf *m, u_int16_t ns)
1381{
1382 struct l2tp_seq *const seq = &priv->seq;
1383 u_int16_t session_id = 0;
1384 meta_p meta = NULL;
1385 int error;
1386
1387 /* If no mbuf passed, send an empty packet (ZLB) */
1388 if (m == NULL) {
1389
1390 /* Create a new mbuf for ZLB packet */
1391 MGETHDR(m, M_DONTWAIT, MT_DATA);
1392 if (m == NULL) {
1393 priv->stats.memoryFailures++;
1394 return (ENOBUFS);
1395 }
1396 m->m_len = m->m_pkthdr.len = 12;
1397 m->m_pkthdr.rcvif = NULL;
1398 priv->stats.xmitZLBs++;
1399 } else {
1400
1401 /* Strip off session ID */
1402 if (m->m_len < 2 && (m = m_pullup(m, 2)) == NULL) {
1403 priv->stats.memoryFailures++;
1404 return (ENOBUFS);
1405 }
1406 memcpy(&session_id, mtod(m, u_int16_t *), 2);
1407 m_adj(m, 2);
1408
1409 /* Make room for L2TP header */
1410 M_PREPEND(m, 12, M_DONTWAIT);
1411 if (m == NULL) {
1412 priv->stats.memoryFailures++;
1413 return (ENOBUFS);
1414 }
1415 }
1416
1417 /* Fill in L2TP header */
1418 mtod(m, u_int16_t *)[0] = htons(L2TP_CTRL_HDR);
1419 mtod(m, u_int16_t *)[1] = htons(m->m_pkthdr.len);
1420 mtod(m, u_int16_t *)[2] = priv->conf.peer_id;
1421 mtod(m, u_int16_t *)[3] = session_id;
1422 mtod(m, u_int16_t *)[4] = htons(ns);
1423 mtod(m, u_int16_t *)[5] = htons(seq->nr);
1424
1425 /* Update sequence number info and stats */
1426 priv->stats.xmitPackets++;
1427 priv->stats.xmitOctets += m->m_pkthdr.len;
1428
1429 /* Stop ack timer: we're sending an ack with this packet */
1430 if (seq->xack_timer_running && callout_stop(&seq->xack_timer) == 1) {
1431 seq->xack_timer_running = 0;
1432 NG_NODE_UNREF(priv->node);
1433 }
1434 seq->xack = seq->nr;
1435
1436 /* Send packet */
1437 NG_SEND_DATA(error, priv->lower, m, meta);
1438 return (error);
1439}
1440
1441#ifdef INVARIANTS
1442/*
1443 * Sanity check sequence number state.
1444 */
1445static void
1446ng_l2tp_seq_check(struct l2tp_seq *seq)
1447{
1448 const int self_unack = L2TP_SEQ_DIFF(seq->nr, seq->xack);
1449 const int peer_unack = L2TP_SEQ_DIFF(seq->ns, seq->rack);
1450 int i;
1451
1452#define CHECK(p) KASSERT((p), ("%s: not: %s", __FUNCTION__, #p))
1453
1454 CHECK(seq->wmax <= L2TP_MAX_XWIN);
1455 CHECK(seq->cwnd >= 1);
1456 CHECK(seq->cwnd <= seq->wmax);
1457 CHECK(seq->ssth >= 1);
1458 CHECK(seq->ssth <= seq->wmax);
1459 if (seq->cwnd < seq->ssth)
1460 CHECK(seq->acks == 0);
1461 else
1462 CHECK(seq->acks <= seq->cwnd);
1463 CHECK(self_unack >= 0);
1464 CHECK(peer_unack >= 0);
1465 CHECK(peer_unack <= seq->wmax);
1466 CHECK((self_unack == 0) ^ seq->xack_timer_running);
1467 CHECK((peer_unack == 0) ^ seq->rack_timer_running);
1468 CHECK(seq->rack_timer_running || !callout_pending(&seq->rack_timer));
1469 CHECK(seq->xack_timer_running || !callout_pending(&seq->xack_timer));
1470 for (i = 0; i < peer_unack; i++)
1471 CHECK(seq->xwin[i] != NULL);
1472 for ( ; i < seq->cwnd; i++) /* verify peer's recv window full */
1473 CHECK(seq->xwin[i] == NULL);
1474
1475#undef CHECK
1476}
1477#endif /* INVARIANTS */
1478
1479
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