xref: /f-stack/freebsd/netinet/tcp_debug.c (revision ebf5cedb)
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  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_tcpdebug.h"
39 
40 #ifdef TCPDEBUG
41 /* load symbolic names */
42 #define PRUREQUESTS
43 #define TCPSTATES
44 #define	TCPTIMERS
45 #define	TANAMES
46 #endif
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/lock.h>
52 #include <sys/mbuf.h>
53 #include <sys/mutex.h>
54 #include <sys/protosw.h>
55 #include <sys/socket.h>
56 
57 #include <netinet/in.h>
58 #include <netinet/in_systm.h>
59 #include <netinet/ip.h>
60 #ifdef INET6
61 #include <netinet/ip6.h>
62 #endif
63 #include <netinet/ip_var.h>
64 #include <netinet/tcp.h>
65 #include <netinet/tcp_fsm.h>
66 #include <netinet/tcp_timer.h>
67 #include <netinet/tcp_var.h>
68 #include <netinet/tcpip.h>
69 #include <netinet/tcp_debug.h>
70 
71 #ifdef TCPDEBUG
72 static int		tcpconsdebug = 0;
73 #endif
74 
75 /*
76  * Global ring buffer of TCP debugging state.  Each entry captures a snapshot
77  * of TCP connection state at any given moment.  tcp_debx addresses at the
78  * next available slot.  There is no explicit export of this data structure;
79  * it will be read via /dev/kmem by debugging tools.
80  */
81 static struct tcp_debug	tcp_debug[TCP_NDEBUG];
82 static int		tcp_debx;
83 
84 /*
85  * All global state is protected by tcp_debug_mtx; tcp_trace() is split into
86  * two parts, one of which saves connection and other state into the global
87  * array (locked by tcp_debug_mtx).
88  */
89 struct mtx		tcp_debug_mtx;
90 MTX_SYSINIT(tcp_debug_mtx, &tcp_debug_mtx, "tcp_debug_mtx", MTX_DEF);
91 
92 /*
93  * Save TCP state at a given moment; optionally, both tcpcb and TCP packet
94  * header state will be saved.
95  */
96 void
97 tcp_trace(short act, short ostate, struct tcpcb *tp, void *ipgen,
98     struct tcphdr *th, int req)
99 {
100 #ifdef INET6
101 	int isipv6;
102 #endif /* INET6 */
103 	tcp_seq seq, ack;
104 	int len, flags;
105 	struct tcp_debug *td;
106 
107 	mtx_lock(&tcp_debug_mtx);
108 	td = &tcp_debug[tcp_debx++];
109 	if (tcp_debx == TCP_NDEBUG)
110 		tcp_debx = 0;
111 	bzero(td, sizeof(*td));
112 #ifdef INET6
113 	isipv6 = (ipgen != NULL && ((struct ip *)ipgen)->ip_v == 6) ? 1 : 0;
114 #endif /* INET6 */
115 	td->td_family =
116 #ifdef INET6
117 	    (isipv6 != 0) ? AF_INET6 :
118 #endif
119 	    AF_INET;
120 #ifdef INET
121 	td->td_time = iptime();
122 #endif
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 #ifdef INET
131 		case AF_INET:
132 			bcopy(ipgen, &td->td_ti.ti_i, sizeof(td->td_ti.ti_i));
133 			break;
134 #endif
135 #ifdef INET6
136 		case AF_INET6:
137 			bcopy(ipgen, td->td_ip6buf, sizeof(td->td_ip6buf));
138 			break;
139 #endif
140 		}
141 	}
142 	if (th != NULL) {
143 		switch (td->td_family) {
144 #ifdef INET
145 		case AF_INET:
146 			td->td_ti.ti_t = *th;
147 			break;
148 #endif
149 #ifdef INET6
150 		case AF_INET6:
151 			td->td_ti6.th = *th;
152 			break;
153 #endif
154 		}
155 	}
156 	td->td_req = req;
157 	mtx_unlock(&tcp_debug_mtx);
158 #ifdef TCPDEBUG
159 	if (tcpconsdebug == 0)
160 		return;
161 	if (tp != NULL)
162 		printf("%p %s:", tp, tcpstates[ostate]);
163 	else
164 		printf("???????? ");
165 	printf("%s ", tanames[act]);
166 	switch (act) {
167 	case TA_INPUT:
168 	case TA_OUTPUT:
169 	case TA_DROP:
170 		if (ipgen == NULL || th == NULL)
171 			break;
172 		seq = th->th_seq;
173 		ack = th->th_ack;
174 		len =
175 #ifdef INET6
176 		    isipv6 ? ntohs(((struct ip6_hdr *)ipgen)->ip6_plen) :
177 #endif
178 		    ntohs(((struct ip *)ipgen)->ip_len);
179 		if (act == TA_OUTPUT) {
180 			seq = ntohl(seq);
181 			ack = ntohl(ack);
182 		}
183 		if (act == TA_OUTPUT)
184 			len -= sizeof (struct tcphdr);
185 		if (len)
186 			printf("[%x..%x)", seq, seq+len);
187 		else
188 			printf("%x", seq);
189 		printf("@%x, urp=%x", ack, th->th_urp);
190 		flags = th->th_flags;
191 		if (flags) {
192 			char *cp = "<";
193 #define pf(f) {					\
194 	if (th->th_flags & TH_##f) {		\
195 		printf("%s%s", cp, #f);		\
196 		cp = ",";			\
197 	}					\
198 }
199 			pf(SYN); pf(ACK); pf(FIN); pf(RST); pf(PUSH); pf(URG);
200 			printf(">");
201 		}
202 		break;
203 
204 	case TA_USER:
205 		printf("%s", prurequests[req&0xff]);
206 		if ((req & 0xff) == PRU_SLOWTIMO)
207 			printf("<%s>", tcptimers[req>>8]);
208 		break;
209 	}
210 	if (tp != NULL)
211 		printf(" -> %s", tcpstates[tp->t_state]);
212 	/* print out internal state of tp !?! */
213 	printf("\n");
214 	if (tp == NULL)
215 		return;
216 	printf(
217 	"\trcv_(nxt,wnd,up) (%lx,%lx,%lx) snd_(una,nxt,max) (%lx,%lx,%lx)\n",
218 	    (u_long)tp->rcv_nxt, tp->rcv_wnd, (u_long)tp->rcv_up,
219 	    (u_long)tp->snd_una, (u_long)tp->snd_nxt, (u_long)tp->snd_max);
220 	printf("\tsnd_(wl1,wl2,wnd) (%lx,%lx,%lx)\n",
221 	    (u_long)tp->snd_wl1, (u_long)tp->snd_wl2, tp->snd_wnd);
222 #endif /* TCPDEBUG */
223 }
224