tcp_debug.c revision 169350
1/*-
2 * Copyright (c) 1982, 1986, 1993
3 *	The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 4. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 *	@(#)tcp_debug.c	8.1 (Berkeley) 6/10/93
31 * $FreeBSD: head/sys/netinet/tcp_debug.c 169350 2007-05-07 14:05:23Z rwatson $
32 */
33
34#include "opt_inet.h"
35#include "opt_inet6.h"
36#include "opt_tcpdebug.h"
37
38#ifndef INET
39#error The option TCPDEBUG requires option INET.
40#endif
41
42#ifdef TCPDEBUG
43/* load symbolic names */
44#define PRUREQUESTS
45#define TCPSTATES
46#define	TCPTIMERS
47#define	TANAMES
48#endif
49
50#include <sys/param.h>
51#include <sys/systm.h>
52#include <sys/kernel.h>
53#include <sys/lock.h>
54#include <sys/mbuf.h>
55#include <sys/mutex.h>
56#include <sys/protosw.h>
57#include <sys/socket.h>
58
59#include <netinet/in.h>
60#include <netinet/in_systm.h>
61#include <netinet/ip.h>
62#ifdef INET6
63#include <netinet/ip6.h>
64#endif
65#include <netinet/ip_var.h>
66#include <netinet/tcp.h>
67#include <netinet/tcp_fsm.h>
68#include <netinet/tcp_timer.h>
69#include <netinet/tcp_var.h>
70#include <netinet/tcpip.h>
71#include <netinet/tcp_debug.h>
72
73#ifdef TCPDEBUG
74static int		tcpconsdebug = 0;
75#endif
76
77/*
78 * Global ring buffer of TCP debugging state.  Each entry captures a snapshot
79 * of TCP connection state at any given moment.  tcp_debx addresses at the
80 * next available slot.  There is no explicit export of this data structure;
81 * it will be read via /dev/kmem by debugging tools.
82 */
83static struct tcp_debug	tcp_debug[TCP_NDEBUG];
84static int		tcp_debx;
85
86/*
87 * All global state is protected by tcp_debug_mtx; tcp_trace() is split into
88 * two parts, one of which saves connection and other state into the global
89 * array (locked by tcp_debug_mtx).
90 */
91struct mtx		tcp_debug_mtx;
92MTX_SYSINIT(tcp_debug_mtx, &tcp_debug_mtx, "tcp_debug_mtx", MTX_DEF);
93
94/*
95 * Save TCP state at a given moment; optionally, both tcpcb and TCP packet
96 * header state will be saved.
97 */
98void
99tcp_trace(short act, short ostate, struct tcpcb *tp, void *ipgen,
100    struct tcphdr *th, int req)
101{
102#ifdef INET6
103	int isipv6;
104#endif /* INET6 */
105	tcp_seq seq, ack;
106	int len, flags;
107	struct tcp_debug *td;
108
109	mtx_lock(&tcp_debug_mtx);
110	td = &tcp_debug[tcp_debx++];
111	if (tcp_debx == TCP_NDEBUG)
112		tcp_debx = 0;
113	bzero(td, sizeof(*td));
114#ifdef INET6
115	isipv6 = (ipgen != NULL && ((struct ip *)ipgen)->ip_v == 6) ? 1 : 0;
116#endif /* INET6 */
117	td->td_family =
118#ifdef INET6
119	    (isipv6 != 0) ? AF_INET6 :
120#endif
121	    AF_INET;
122	td->td_time = iptime();
123	td->td_act = act;
124	td->td_ostate = ostate;
125	td->td_tcb = (caddr_t)tp;
126	if (tp != NULL)
127		td->td_cb = *tp;
128	if (ipgen != NULL) {
129		switch (td->td_family) {
130		case AF_INET:
131			bcopy(ipgen, &td->td_ti.ti_i, sizeof(td->td_ti.ti_i));
132			break;
133#ifdef INET6
134		case AF_INET6:
135			bcopy(ipgen, td->td_ip6buf, sizeof(td->td_ip6buf));
136			break;
137#endif
138		}
139	}
140	if (th != NULL) {
141		switch (td->td_family) {
142		case AF_INET:
143			td->td_ti.ti_t = *th;
144			break;
145#ifdef INET6
146		case AF_INET6:
147			td->td_ti6.th = *th;
148			break;
149#endif
150		}
151	}
152	td->td_req = req;
153	mtx_unlock(&tcp_debug_mtx);
154#ifdef TCPDEBUG
155	if (tcpconsdebug == 0)
156		return;
157	if (tp != NULL)
158		printf("%p %s:", tp, tcpstates[ostate]);
159	else
160		printf("???????? ");
161	printf("%s ", tanames[act]);
162	switch (act) {
163	case TA_INPUT:
164	case TA_OUTPUT:
165	case TA_DROP:
166		if (ipgen == NULL || th == NULL)
167			break;
168		seq = th->th_seq;
169		ack = th->th_ack;
170		len =
171#ifdef INET6
172		    isipv6 ? ((struct ip6_hdr *)ipgen)->ip6_plen :
173#endif
174		    ((struct ip *)ipgen)->ip_len;
175		if (act == TA_OUTPUT) {
176			seq = ntohl(seq);
177			ack = ntohl(ack);
178			len = ntohs((u_short)len);
179		}
180		if (act == TA_OUTPUT)
181			len -= sizeof (struct tcphdr);
182		if (len)
183			printf("[%x..%x)", seq, seq+len);
184		else
185			printf("%x", seq);
186		printf("@%x, urp=%x", ack, th->th_urp);
187		flags = th->th_flags;
188		if (flags) {
189			char *cp = "<";
190#define pf(f) {					\
191	if (th->th_flags & TH_##f) {		\
192		printf("%s%s", cp, #f);		\
193		cp = ",";			\
194	}					\
195}
196			pf(SYN); pf(ACK); pf(FIN); pf(RST); pf(PUSH); pf(URG);
197			printf(">");
198		}
199		break;
200
201	case TA_USER:
202		printf("%s", prurequests[req&0xff]);
203		if ((req & 0xff) == PRU_SLOWTIMO)
204			printf("<%s>", tcptimers[req>>8]);
205		break;
206	}
207	if (tp != NULL)
208		printf(" -> %s", tcpstates[tp->t_state]);
209	/* print out internal state of tp !?! */
210	printf("\n");
211	if (tp == NULL)
212		return;
213	printf(
214	"\trcv_(nxt,wnd,up) (%lx,%lx,%lx) snd_(una,nxt,max) (%lx,%lx,%lx)\n",
215	    (u_long)tp->rcv_nxt, tp->rcv_wnd, (u_long)tp->rcv_up,
216	    (u_long)tp->snd_una, (u_long)tp->snd_nxt, (u_long)tp->snd_max);
217	printf("\tsnd_(wl1,wl2,wnd) (%lx,%lx,%lx)\n",
218	    (u_long)tp->snd_wl1, (u_long)tp->snd_wl2, tp->snd_wnd);
219#endif /* TCPDEBUG */
220}
221