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Provide a sysctl to toggle reporting of TCP debug logging:

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sys.net.inet.tcp.log_debug = 1

It defaults to enabled for the moment and is to be turned off for
the next release like other diagnostics from development branches.

It is important to note that sysctl sys.net.inet.tcp.log_in_vain
uses the same logging function as log_debug.  Enabling of the former
also causes the latter to engage, but not vice versa.

Use consistent terminology in tcp log messages:

 "ignored" means a segment contains invalid flags/information and
   is dropped without changing state or issuing a reply.

 "rejected" means a segments contains invalid flags/information but
   is causing a reply (usually RST) and may cause a state change.

Approved by:	re (rwatson)
This commit is contained in:
Andre Oppermann 2007-07-28 12:20:39 +00:00
parent cdaf208d09
commit 773673c133
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=171640
3 changed files with 27 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
sys/netinet/tcp_input.c
View File

@ -57,6 +57,8 @@
#include <net/if.h>
#include <net/route.h>
#define TCPSTATES /* for logging */
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_systm.h>
@ -98,7 +100,7 @@ struct tcpstat tcpstat;
SYSCTL_STRUCT(_net_inet_tcp, TCPCTL_STATS, stats, CTLFLAG_RW,
&tcpstat , tcpstat, "TCP statistics (struct tcpstat, netinet/tcp_var.h)");
static int tcp_log_in_vain = 0;
int tcp_log_in_vain = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_in_vain, CTLFLAG_RW,
&tcp_log_in_vain, 0, "Log all incoming TCP segments to closed ports");
@ -662,7 +664,7 @@ tcp_input(struct mbuf *m, int off0)
if ((thflags & TH_SYN) == 0) {
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"SYN is missing, segment rejected\n",
"SYN is missing, segment ignored\n",
s, __func__);
tcpstat.tcps_badsyn++;
goto dropunlock;
@ -694,7 +696,7 @@ tcp_input(struct mbuf *m, int off0)
if ((thflags & TH_FIN) && drop_synfin) {
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"SYN|FIN segment rejected (based on "
"SYN|FIN segment ignored (based on "
"sysctl setting)\n", s, __func__);
tcpstat.tcps_badsyn++;
goto dropunlock;
@ -771,7 +773,7 @@ tcp_input(struct mbuf *m, int off0)
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"Connection attempt from broad- or multicast "
"link layer address rejected\n", s, __func__);
"link layer address ignored\n", s, __func__);
goto dropunlock;
}
if (isipv6) {
@ -781,7 +783,7 @@ tcp_input(struct mbuf *m, int off0)
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"Connection attempt to/from self "
"rejected\n", s, __func__);
"ignored\n", s, __func__);
goto dropunlock;
}
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) ||
@ -789,7 +791,7 @@ tcp_input(struct mbuf *m, int off0)
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"Connection attempt from/to multicast "
"address rejected\n", s, __func__);
"address ignored\n", s, __func__);
goto dropunlock;
}
#endif
@ -799,7 +801,7 @@ tcp_input(struct mbuf *m, int off0)
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"Connection attempt from/to self "
"rejected\n", s, __func__);
"ignored\n", s, __func__);
goto dropunlock;
}
if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
@ -809,7 +811,7 @@ tcp_input(struct mbuf *m, int off0)
if ((s = tcp_log_addrs(&inc, th, NULL, NULL)))
log(LOG_DEBUG, "%s; %s: Listen socket: "
"Connection attempt from/to broad- "
"or multicast address rejected\n",
"or multicast address ignored\n",
s, __func__);
goto dropunlock;
}
@ -1566,8 +1568,16 @@ tcp_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
*/
if ((so->so_state & SS_NOFDREF) &&
tp->t_state > TCPS_CLOSE_WAIT && tlen) {
char *s;
KASSERT(headlocked, ("%s: trimthenstep6: tcp_close.3: head "
"not locked", __func__));
if ((s = tcp_log_addrs(&tp->t_inpcb->inp_inc, th, NULL, NULL))) {
log(LOG_DEBUG, "%s; %s: %s: Received data after socket "
"was closed, sending RST and removing tcpcb\n",
s, __func__, tcpstates[tp->t_state]);
free(s, M_TCPLOG);
}
tp = tcp_close(tp);
tcpstat.tcps_rcvafterclose++;
rstreason = BANDLIM_UNLIMITED;

8
sys/netinet/tcp_subr.c
View File

@ -133,6 +133,10 @@ int tcp_do_rfc1323 = 1;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
&tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions");
static int tcp_log_debug = 1;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
&tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
static int tcp_tcbhashsize = 0;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
&tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
@ -2094,6 +2098,10 @@ tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
2 * INET_ADDRSTRLEN;
#endif /* INET6 */
/* Is logging enabled? */
if (tcp_log_debug == 0 && tcp_log_in_vain == 0)
return (NULL);
s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
if (s == NULL)
return (NULL);

1
sys/netinet/tcp_var.h
View File

@ -494,6 +494,7 @@ MALLOC_DECLARE(M_TCPLOG);
extern struct inpcbhead tcb; /* head of queue of active tcpcb's */
extern struct inpcbinfo tcbinfo;
extern struct tcpstat tcpstat; /* tcp statistics */
extern int tcp_log_in_vain;
extern int tcp_mssdflt; /* XXX */
extern int tcp_minmss;
extern int tcp_delack_enabled;