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be048f21e

Denis Vlasenko
Denis Vlasenko
2008-02-26
FAILED Duration: 20s

Subject

syslogd: optional support for dropping dups. closes bug 436.

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Commit Diff GitHub →

include/usage.h +14 -12sysklogd/Config.in +8 -0sysklogd/syslogd.c +32 -9
include/usage.h+14 -12
@@ -3686,22 +3686,24 @@ USE_FEATURE_RUN_PARTS_FANCY("\n -l Prints names of all matching files even when
"[OPTION]..."
#define syslogd_full_usage \
"System logging utility.\n" \
- "Note that this version of syslogd ignores /etc/syslog.conf." \
- "\n\nOptions:" \
- "\n -n Run in foreground" \
- "\n -O FILE Log to given file (default=/var/log/messages)" \
- "\n -l n Set local log level" \
- "\n -S Smaller logging output" \
+ "Note that this version of syslogd ignores /etc/syslog.conf.\n" \
+ "\nOptions:" \
+ "\n -n Run in foreground" \
+ "\n -O FILE Log to given file (default=/var/log/messages)" \
+ "\n -l n Set local log level" \
+ "\n -S Smaller logging output" \
USE_FEATURE_ROTATE_LOGFILE( \
- "\n -s SIZE Max size (KB) before rotate (default=200KB, 0=off)" \
- "\n -b NUM Number of rotated logs to keep (default=1, max=99, 0=purge)") \
+ "\n -s SIZE Max size (KB) before rotate (default=200KB, 0=off)" \
+ "\n -b NUM Number of rotated logs to keep (default=1, max=99, 0=purge)") \
USE_FEATURE_REMOTE_LOG( \
- "\n -R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP)" \
- "\n -L Log locally and via network (default is network only if -R)") \
+ "\n -R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP)" \
+ "\n -L Log locally and via network (default is network only if -R)") \
+ USE_FEATURE_SYSLOGD_DUP( \
+ "\n -D Drop duplicates") \
USE_FEATURE_IPC_SYSLOG( \
- "\n -C[size(KiB)] Log to shared mem buffer (read it using logread)")
+ "\n -C[size(KiB)] Log to shared mem buffer (read it using logread)")
/* NB: -Csize shouldn't have space (because size is optional) */
-/* "\n -m MIN Minutes between MARK lines (default=20, 0=off)" */
+/* "\n -m MIN Minutes between MARK lines (default=20, 0=off)" */
#define syslogd_example_usage \
"$ syslogd -R masterlog:514\n" \
"$ syslogd -R 192.168.1.1:601\n"
sysklogd/Config.in+8 -0
@@ -42,6 +42,14 @@ config FEATURE_REMOTE_LOG
measure to prevent system logs from being tampered with
by an intruder.
+config FEATURE_SYSLOGD_DUP
+ bool "Support -D (drop dups) option"
+ default n
+ depends on SYSLOGD
+ help
+ Option -D instructs syslogd to drop consecutive messages
+ which are totally the same.
+
config FEATURE_IPC_SYSLOG
bool "Circular Buffer support"
default n
sysklogd/syslogd.c+32 -9
@@ -101,7 +101,7 @@ struct globals {
char *hostname;
/* We recv into recvbuf... */
- char recvbuf[MAX_READ];
+ char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
/* ...then copy to parsebuf, escaping control chars */
/* (can grow x2 max) */
char parsebuf[MAX_READ*2];
@@ -152,6 +152,7 @@ enum {
USE_FEATURE_REMOTE_LOG( OPTBIT_remote ,) // -R
USE_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L
USE_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
+ USE_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,) // -D
OPT_mark = 1 << OPTBIT_mark ,
OPT_nofork = 1 << OPTBIT_nofork ,
@@ -163,13 +164,15 @@ enum {
OPT_remotelog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_remote )) + 0,
OPT_locallog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
OPT_circularlog = USE_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
+ OPT_dup = USE_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
};
#define OPTION_STR "m:nO:l:S" \
USE_FEATURE_ROTATE_LOGFILE("s:" ) \
USE_FEATURE_ROTATE_LOGFILE("b:" ) \
USE_FEATURE_REMOTE_LOG( "R:" ) \
USE_FEATURE_REMOTE_LOG( "L" ) \
- USE_FEATURE_IPC_SYSLOG( "C::")
+ USE_FEATURE_IPC_SYSLOG( "C::") \
+ USE_FEATURE_SYSLOGD_DUP( "D" )
#define OPTION_DECL *opt_m, *opt_l \
USE_FEATURE_ROTATE_LOGFILE(,*opt_s) \
USE_FEATURE_ROTATE_LOGFILE(,*opt_b) \
@@ -538,6 +541,13 @@ static void do_syslogd(void) ATTRIBUTE_NORETURN;
static void do_syslogd(void)
{
int sock_fd;
+#if ENABLE_FEATURE_SYSLOGD_DUP
+ int last_sz = -1;
+ char *last_buf;
+ char *recvbuf = G.recvbuf;
+#else
+#define recvbuf (G.recvbuf)
+#endif
/* Set up signal handlers */
bb_signals(0
@@ -561,8 +571,16 @@ static void do_syslogd(void)
for (;;) {
size_t sz;
+
+#if ENABLE_FEATURE_SYSLOGD_DUP
+ last_buf = recvbuf;
+ if (recvbuf == G.recvbuf)
+ recvbuf = G.recvbuf + MAX_READ;
+ else
+ recvbuf = G.recvbuf;
+#endif
read_again:
- sz = safe_read(sock_fd, G.recvbuf, MAX_READ - 1);
+ sz = safe_read(sock_fd, recvbuf, MAX_READ - 1);
if (sz < 0)
bb_perror_msg_and_die("read from /dev/log");
@@ -577,11 +595,16 @@ static void do_syslogd(void)
* IOW: newline is passed verbatim!
* I take it to mean that it's syslogd's job
* to make those look identical in the log files. */
- if (G.recvbuf[sz-1] != '\0' && G.recvbuf[sz-1] != '\n')
+ if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
break;
sz--;
}
- /* TODO: maybe suppress duplicates? */
+#if ENABLE_FEATURE_SYSLOGD_DUP
+ if ((option_mask32 & OPT_dup) && (sz == last_sz))
+ if (memcmp(last_buf, recvbuf, sz) == 0)
+ continue;
+ last_sz = sz;
+#endif
#if ENABLE_FEATURE_REMOTE_LOG
/* We are not modifying log messages in any way before send */
/* Remote site cannot trust _us_ anyway and need to do validation again */
@@ -593,18 +616,18 @@ static void do_syslogd(void)
}
/* Stock syslogd sends it '\n'-terminated
* over network, mimic that */
- G.recvbuf[sz] = '\n';
+ recvbuf[sz] = '\n';
/* send message to remote logger, ignore possible error */
/* TODO: on some errors, close and set G.remoteFD to -1
* so that DNS resolution and connect is retried? */
- sendto(G.remoteFD, G.recvbuf, sz+1, MSG_DONTWAIT,
+ sendto(G.remoteFD, recvbuf, sz+1, MSG_DONTWAIT,
&G.remoteAddr->u.sa, G.remoteAddr->len);
no_luck: ;
}
#endif
if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
- G.recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
- split_escape_and_log(G.recvbuf, sz);
+ recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
+ split_escape_and_log(recvbuf, sz);
}
} /* for (;;) */
}