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mirror of https://git.FreeBSD.org/src.git synced 2024-12-22 11:17:19 +00:00
freebsd/sys/netinet/tcp_debug.c
Gleb Smirnoff 8f134647ca Switch the entire IPv4 stack to keep the IP packet header
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

  After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

  After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by:	luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by:	ray, Olivier Cochard-Labbe <olivier cochard.me>
2012-10-22 21:09:03 +00:00

224 lines
5.8 KiB
C

/*-
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)tcp_debug.c 8.1 (Berkeley) 6/10/93
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_tcpdebug.h"
#ifdef TCPDEBUG
/* load symbolic names */
#define PRUREQUESTS
#define TCPSTATES
#define TCPTIMERS
#define TANAMES
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#include <netinet/tcp_debug.h>
#ifdef TCPDEBUG
static int tcpconsdebug = 0;
#endif
/*
* Global ring buffer of TCP debugging state. Each entry captures a snapshot
* of TCP connection state at any given moment. tcp_debx addresses at the
* next available slot. There is no explicit export of this data structure;
* it will be read via /dev/kmem by debugging tools.
*/
static struct tcp_debug tcp_debug[TCP_NDEBUG];
static int tcp_debx;
/*
* All global state is protected by tcp_debug_mtx; tcp_trace() is split into
* two parts, one of which saves connection and other state into the global
* array (locked by tcp_debug_mtx).
*/
struct mtx tcp_debug_mtx;
MTX_SYSINIT(tcp_debug_mtx, &tcp_debug_mtx, "tcp_debug_mtx", MTX_DEF);
/*
* Save TCP state at a given moment; optionally, both tcpcb and TCP packet
* header state will be saved.
*/
void
tcp_trace(short act, short ostate, struct tcpcb *tp, void *ipgen,
struct tcphdr *th, int req)
{
#ifdef INET6
int isipv6;
#endif /* INET6 */
tcp_seq seq, ack;
int len, flags;
struct tcp_debug *td;
mtx_lock(&tcp_debug_mtx);
td = &tcp_debug[tcp_debx++];
if (tcp_debx == TCP_NDEBUG)
tcp_debx = 0;
bzero(td, sizeof(*td));
#ifdef INET6
isipv6 = (ipgen != NULL && ((struct ip *)ipgen)->ip_v == 6) ? 1 : 0;
#endif /* INET6 */
td->td_family =
#ifdef INET6
(isipv6 != 0) ? AF_INET6 :
#endif
AF_INET;
#ifdef INET
td->td_time = iptime();
#endif
td->td_act = act;
td->td_ostate = ostate;
td->td_tcb = (caddr_t)tp;
if (tp != NULL)
td->td_cb = *tp;
if (ipgen != NULL) {
switch (td->td_family) {
#ifdef INET
case AF_INET:
bcopy(ipgen, &td->td_ti.ti_i, sizeof(td->td_ti.ti_i));
break;
#endif
#ifdef INET6
case AF_INET6:
bcopy(ipgen, td->td_ip6buf, sizeof(td->td_ip6buf));
break;
#endif
}
}
if (th != NULL) {
switch (td->td_family) {
#ifdef INET
case AF_INET:
td->td_ti.ti_t = *th;
break;
#endif
#ifdef INET6
case AF_INET6:
td->td_ti6.th = *th;
break;
#endif
}
}
td->td_req = req;
mtx_unlock(&tcp_debug_mtx);
#ifdef TCPDEBUG
if (tcpconsdebug == 0)
return;
if (tp != NULL)
printf("%p %s:", tp, tcpstates[ostate]);
else
printf("???????? ");
printf("%s ", tanames[act]);
switch (act) {
case TA_INPUT:
case TA_OUTPUT:
case TA_DROP:
if (ipgen == NULL || th == NULL)
break;
seq = th->th_seq;
ack = th->th_ack;
len =
#ifdef INET6
isipv6 ? ntohs(((struct ip6_hdr *)ipgen)->ip6_plen) :
#endif
ntohs(((struct ip *)ipgen)->ip_len);
if (act == TA_OUTPUT) {
seq = ntohl(seq);
ack = ntohl(ack);
}
if (act == TA_OUTPUT)
len -= sizeof (struct tcphdr);
if (len)
printf("[%x..%x)", seq, seq+len);
else
printf("%x", seq);
printf("@%x, urp=%x", ack, th->th_urp);
flags = th->th_flags;
if (flags) {
char *cp = "<";
#define pf(f) { \
if (th->th_flags & TH_##f) { \
printf("%s%s", cp, #f); \
cp = ","; \
} \
}
pf(SYN); pf(ACK); pf(FIN); pf(RST); pf(PUSH); pf(URG);
printf(">");
}
break;
case TA_USER:
printf("%s", prurequests[req&0xff]);
if ((req & 0xff) == PRU_SLOWTIMO)
printf("<%s>", tcptimers[req>>8]);
break;
}
if (tp != NULL)
printf(" -> %s", tcpstates[tp->t_state]);
/* print out internal state of tp !?! */
printf("\n");
if (tp == NULL)
return;
printf(
"\trcv_(nxt,wnd,up) (%lx,%lx,%lx) snd_(una,nxt,max) (%lx,%lx,%lx)\n",
(u_long)tp->rcv_nxt, tp->rcv_wnd, (u_long)tp->rcv_up,
(u_long)tp->snd_una, (u_long)tp->snd_nxt, (u_long)tp->snd_max);
printf("\tsnd_(wl1,wl2,wnd) (%lx,%lx,%lx)\n",
(u_long)tp->snd_wl1, (u_long)tp->snd_wl2, tp->snd_wnd);
#endif /* TCPDEBUG */
}