From 4f2e8bc7656ff64402329de5364ec4502d8007d9 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Thu, 3 Jan 2008 12:12:27 +0000 Subject: syslogd: don't die if remote host's IP cannot be resolved. retry resolutions every two minutes instead. function old new delta syslogd_main 865 904 +39 timestamp_and_log 324 313 -11 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/1 up/down: 39/-11) Total: 28 bytes --- sysklogd/syslogd.c | 100 +++++++++++++++++++++++++++++++++-------------------- 1 file changed, 63 insertions(+), 37 deletions(-) (limited to 'sysklogd') diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c index 5998732bd..7000e9301 100644 --- a/sysklogd/syslogd.c +++ b/sysklogd/syslogd.c @@ -42,7 +42,10 @@ * (semaphores are down but do_mark routine tries to down them again) */ #undef SYSLOGD_MARK -enum { MAX_READ = 256 }; +enum { + MAX_READ = 256, + DNS_WAIT_SEC = 2 * 60, +}; /* Semaphore operation structures */ struct shbuf_ds { @@ -86,6 +89,12 @@ struct init_globals { struct globals { GLOBALS + +#if ENABLE_FEATURE_REMOTE_LOG + unsigned last_dns_resolve; + char *remoteAddrStr; +#endif + #if ENABLE_FEATURE_IPC_SYSLOG struct shbuf_ds *shbuf; #endif @@ -128,6 +137,9 @@ static const struct init_globals init_data = { }; #define G (*ptr_to_globals) +#define INIT_G() do { \ + PTR_TO_GLOBALS = memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data)); \ +} while (0) /* Options */ @@ -140,7 +152,7 @@ enum { USE_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s USE_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b USE_FEATURE_REMOTE_LOG( OPTBIT_remote ,) // -R - USE_FEATURE_REMOTE_LOG( OPTBIT_localtoo ,) // -L + USE_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L USE_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C OPT_mark = 1 << OPTBIT_mark , @@ -151,7 +163,7 @@ enum { OPT_filesize = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0, OPT_rotatecnt = USE_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0, OPT_remotelog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_remote )) + 0, - OPT_locallog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_localtoo )) + 0, + OPT_locallog = USE_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0, OPT_circularlog = USE_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0, }; #define OPTION_STR "m:nO:l:S" \ @@ -163,12 +175,11 @@ enum { #define OPTION_DECL *opt_m, *opt_l \ USE_FEATURE_ROTATE_LOGFILE(,*opt_s) \ USE_FEATURE_ROTATE_LOGFILE(,*opt_b) \ - USE_FEATURE_REMOTE_LOG( ,*opt_R) \ USE_FEATURE_IPC_SYSLOG( ,*opt_C = NULL) #define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \ USE_FEATURE_ROTATE_LOGFILE(,&opt_s) \ USE_FEATURE_ROTATE_LOGFILE(,&opt_b) \ - USE_FEATURE_REMOTE_LOG( ,&opt_R) \ + USE_FEATURE_REMOTE_LOG( ,&G.remoteAddrStr) \ USE_FEATURE_IPC_SYSLOG( ,&opt_C) @@ -387,6 +398,9 @@ static void timestamp_and_log(int pri, char *msg, int len) { char *timestamp; + if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog)) + return; + if (len < 16 || msg[3] != ' ' || msg[6] != ' ' || msg[9] != ':' || msg[12] != ':' || msg[15] != ' ' ) { @@ -400,18 +414,14 @@ static void timestamp_and_log(int pri, char *msg, int len) timestamp[15] = '\0'; /* Log message locally (to file or shared mem) */ - if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) { - if (LOG_PRI(pri) < G.logLevel) { - if (option_mask32 & OPT_small) - sprintf(G.printbuf, "%s %s\n", timestamp, msg); - else { - char res[20]; - parse_fac_prio_20(pri, res); - sprintf(G.printbuf, "%s %s %s %s\n", timestamp, G.localHostName, res, msg); - } - log_locally(G.printbuf); - } + if (option_mask32 & OPT_small) + sprintf(G.printbuf, "%s %s\n", timestamp, msg); + else { + char res[20]; + parse_fac_prio_20(pri, res); + sprintf(G.printbuf, "%s %s %s %s\n", timestamp, G.localHostName, res, msg); } + log_locally(G.printbuf); } static void split_escape_and_log(char *tmpbuf, int len) @@ -443,8 +453,10 @@ static void split_escape_and_log(char *tmpbuf, int len) *q++ = c; } *q = '\0'; + /* Now log it */ - timestamp_and_log(pri, G.parsebuf, q - G.parsebuf); + if (LOG_PRI(pri) < G.logLevel) + timestamp_and_log(pri, G.parsebuf, q - G.parsebuf); } } @@ -495,6 +507,24 @@ static NOINLINE int create_socket(void) return sock_fd; } +#if ENABLE_FEATURE_REMOTE_LOG +static int try_to_resolve_remote(void) +{ + if (!G.remoteAddr) { + unsigned now = monotonic_sec(); + + /* Don't resolve name too often - DNS timeouts can be big */ + if ((now - G.last_dns_resolve) < DNS_WAIT_SEC) + return -1; + G.last_dns_resolve = now; + G.remoteAddr = host2sockaddr(G.remoteAddrStr, 514); + if (!G.remoteAddr) + return -1; + } + return socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0); +} +#endif + static void do_syslogd(void) ATTRIBUTE_NORETURN; static void do_syslogd(void) { @@ -505,10 +535,7 @@ static void do_syslogd(void) signal(SIGTERM, quit_signal); signal(SIGQUIT, quit_signal); signal(SIGHUP, SIG_IGN); - signal(SIGCHLD, SIG_IGN); -#ifdef SIGCLD - signal(SIGCLD, SIG_IGN); -#endif + /* signal(SIGCHLD, SIG_IGN); - why? */ #ifdef SYSLOGD_MARK signal(SIGALRM, do_mark); alarm(G.markInterval); @@ -554,19 +581,21 @@ static void do_syslogd(void) #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 */ - if (G.remoteAddr) { + if (G.remoteAddrStr) { if (-1 == G.remoteFD) { - G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0); - } - if (-1 != G.remoteFD) { - /* send message to remote logger, ignore possible error */ - sendto(G.remoteFD, G.recvbuf, sz, MSG_DONTWAIT, - &G.remoteAddr->sa, G.remoteAddr->len); + G.remoteFD = try_to_resolve_remote(); + if (-1 == G.remoteFD) + goto no_luck; } + /* send message to remote logger, ignore possible error */ + sendto(G.remoteFD, G.recvbuf, sz, MSG_DONTWAIT, + &G.remoteAddr->sa, G.remoteAddr->len); + no_luck: ; } #endif - split_escape_and_log(G.recvbuf, sz); - } /* for */ + if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) + split_escape_and_log(G.recvbuf, sz); + } /* for (;;) */ } int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; @@ -575,7 +604,10 @@ int syslogd_main(int argc, char **argv) char OPTION_DECL; char *p; - PTR_TO_GLOBALS = memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data)); + INIT_G(); +#if ENABLE_FEATURE_REMOTE_LOG + G.last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1; +#endif /* do normal option parsing */ opt_complementary = "=0"; /* no non-option params */ @@ -595,12 +627,6 @@ int syslogd_main(int argc, char **argv) if (option_mask32 & OPT_rotatecnt) // -b G.logFileRotate = xatou_range(opt_b, 0, 99); #endif -#if ENABLE_FEATURE_REMOTE_LOG - if (option_mask32 & OPT_remotelog) { // -R - G.remoteAddr = xhost2sockaddr(opt_R, 514); - } - //if (option_mask32 & OPT_locallog) // -L -#endif #if ENABLE_FEATURE_IPC_SYSLOG if (opt_C) // -Cn G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024; -- cgit v1.2.3