Restore local kernel "prog" filtering lost in r332099.

This behavior is most relevant for ipfw(4) as documented in syslog.conf(5).
The recent addition of property-based regex filters in r359327 is a
fine workaround for this but the behavior was present since 1997 and
documented.

This only fixes local matching of the "kernel program". It does not
change the forwarded format at all. On the remote side it will still
be "kernel: ipfw:" and not be parsed as a kernel message. This matches
old behavior.

MFC after:	2 weeks
Reviewed by:	markj
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D24286
This commit is contained in:
bdrewery 2020-04-28 16:07:15 +00:00
parent 44b4ea5525
commit 3998e1ca9c

View File

@ -137,6 +137,7 @@ __FBSDID("$FreeBSD$");
#include <paths.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@ -206,6 +207,7 @@ static STAILQ_HEAD(, socklist) shead = STAILQ_HEAD_INITIALIZER(shead);
#define IGN_CONS 0x001 /* don't print on console */
#define SYNC_FILE 0x002 /* do fsync on file after printing */
#define MARK 0x008 /* this message is a mark */
#define ISKERNEL 0x010 /* kernel generated message */
/* Timestamps of log entries. */
struct logtime {
@ -1151,19 +1153,19 @@ parsemsg_rfc5424(const char *from, int pri, char *msg)
}
/*
* Trims the application name ("TAG" in RFC 3164 terminology) and
* process ID from a message if present.
* Returns the length of the application name ("TAG" in RFC 3164
* terminology) and process ID from a message if present.
*/
static void
parsemsg_rfc3164_app_name_procid(char **msg, const char **app_name,
const char **procid) {
char *m, *app_name_begin, *procid_begin;
parsemsg_rfc3164_get_app_name_procid(const char *msg, size_t *app_name_length_p,
ptrdiff_t *procid_begin_offset_p, size_t *procid_length_p)
{
const char *m, *procid_begin;
size_t app_name_length, procid_length;
m = *msg;
m = msg;
/* Application name. */
app_name_begin = m;
app_name_length = strspn(m,
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@ -1191,12 +1193,52 @@ parsemsg_rfc3164_app_name_procid(char **msg, const char **app_name,
if (m[0] != ':' || m[1] != ' ')
goto bad;
*app_name_length_p = app_name_length;
if (procid_begin_offset_p != NULL)
*procid_begin_offset_p =
procid_begin == NULL ? 0 : procid_begin - msg;
if (procid_length_p != NULL)
*procid_length_p = procid_length;
return;
bad:
*app_name_length_p = 0;
if (procid_begin_offset_p != NULL)
*procid_begin_offset_p = 0;
if (procid_length_p != NULL)
*procid_length_p = 0;
}
/*
* Trims the application name ("TAG" in RFC 3164 terminology) and
* process ID from a message if present.
*/
static void
parsemsg_rfc3164_app_name_procid(char **msg, const char **app_name,
const char **procid)
{
char *m, *app_name_begin, *procid_begin;
size_t app_name_length, procid_length;
ptrdiff_t procid_begin_offset;
m = *msg;
app_name_begin = m;
parsemsg_rfc3164_get_app_name_procid(app_name_begin, &app_name_length,
&procid_begin_offset, &procid_length);
if (app_name_length == 0)
goto bad;
procid_begin = procid_begin_offset == 0 ? NULL :
app_name_begin + procid_begin_offset;
/* Split strings from input. */
app_name_begin[app_name_length] = '\0';
if (procid_begin != 0)
m += app_name_length + 1;
if (procid_begin != NULL) {
procid_begin[procid_length] = '\0';
m += procid_length + 2;
}
*msg = m + 2;
*msg = m + 1;
*app_name = app_name_begin;
*procid = procid_begin;
return;
@ -1401,7 +1443,7 @@ printsys(char *msg)
long n;
int flags, isprintf, pri;
flags = SYNC_FILE; /* fsync after write */
flags = ISKERNEL | SYNC_FILE; /* fsync after write */
p = msg;
pri = DEFSPRI;
isprintf = 1;
@ -1551,7 +1593,7 @@ logmsg(int pri, const struct logtime *timestamp, const char *hostname,
struct filed *f;
size_t savedlen;
int fac, prilev;
char saved[MAXSVLINE];
char saved[MAXSVLINE], kernel_app_name[100];
dprintf("logmsg: pri %o, flags %x, from %s, msg %s\n",
pri, flags, hostname, msg);
@ -1576,6 +1618,23 @@ logmsg(int pri, const struct logtime *timestamp, const char *hostname,
prilev = LOG_PRI(pri);
/*
* Lookup kernel app name from log prefix if present.
* This is only used for local program specification matching.
*/
if (flags & ISKERNEL) {
size_t kernel_app_name_length;
parsemsg_rfc3164_get_app_name_procid(msg,
&kernel_app_name_length, NULL, NULL);
if (kernel_app_name_length != 0) {
strlcpy(kernel_app_name, msg,
MIN(sizeof(kernel_app_name),
kernel_app_name_length + 1));
} else
kernel_app_name[0] = '\0';
}
/* log the message to the particular outputs */
if (!Initialized) {
f = &consfile;
@ -1622,7 +1681,10 @@ logmsg(int pri, const struct logtime *timestamp, const char *hostname,
continue;
/* skip messages with the incorrect program name */
if (skip_message(app_name == NULL ? "" : app_name,
if (flags & ISKERNEL && kernel_app_name[0] != '\0') {
if (skip_message(kernel_app_name, f->f_program, 1))
continue;
} else if (skip_message(app_name == NULL ? "" : app_name,
f->f_program, 1))
continue;