lib: plug logging hole during startup

zlog_* doesn't work in startup before we've loaded the real logging
configuration.  Add some code to log to stderr for that window of time.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/lib/libfrr.c b/lib/libfrr.c
index 6ebf837a1d86e945fdb8125bf93c7addb6e38bfd..55d77847524cc65835f3c9c4487c85aad9b8a09d 100644 (file)
--- a/lib/libfrr.c
+++ b/lib/libfrr.c
@@ -693,6 +693,9 @@ void frr_run(struct thread_master *master)
                daemon_ctl_sock = -1;
        }
 
+       /* end fixed stderr startup logging */
+       zlog_startup_stderr = false;
+
        struct thread thread;
        while (thread_fetch(master, &thread))
                thread_call(&thread);

diff --git a/lib/log.c b/lib/log.c
index 28e086535412218f70dbde14dc2fed64f9cf65c5..c64bdff46665dfb0d97849dd945c6b367e6a5b95 100644 (file)
--- a/lib/log.c
+++ b/lib/log.c
@@ -41,6 +41,7 @@ DEFINE_MTYPE_STATIC(LIB, ZLOG, "Logging")
 static int logfile_fd = -1; /* Used in signal handler. */
 
 struct zlog *zlog_default = NULL;
+bool zlog_startup_stderr = true;
 
 const char *zlog_priority[] = {
        "emergencies",   "alerts",      "critical",  "errors", "warnings",
@@ -172,6 +173,25 @@ static void time_print(FILE *fp, struct timestamp_control *ctl)
 }
 
 
+static void vzlog_file(struct zlog *zl, struct timestamp_control *tsctl,
+                      const char *proto_str, int record_priority,
+                      int priority, FILE *fp, const char *format,
+                      va_list args)
+{
+       va_list ac;
+
+       time_print(fp, tsctl);
+       if (record_priority)
+               fprintf(fp, "%s: ", zlog_priority[priority]);
+
+       fprintf(fp, "%s", proto_str);
+       va_copy(ac, args);
+       vfprintf(fp, format, ac);
+       va_end(ac);
+       fprintf(fp, "\n");
+       fflush(fp);
+}
+
 /* va_list version of zlog. */
 void vzlog(int priority, const char *format, va_list args)
 {
@@ -210,32 +230,21 @@ void vzlog(int priority, const char *format, va_list args)
                sprintf(proto_str, "%s: ", zl->protoname);
 
        /* File output. */
-       if ((priority <= zl->maxlvl[ZLOG_DEST_FILE]) && zl->fp) {
-               va_list ac;
-               time_print(zl->fp, &tsctl);
-               if (zl->record_priority)
-                       fprintf(zl->fp, "%s: ", zlog_priority[priority]);
-               fprintf(zl->fp, "%s", proto_str);
-               va_copy(ac, args);
-               vfprintf(zl->fp, format, ac);
-               va_end(ac);
-               fprintf(zl->fp, "\n");
-               fflush(zl->fp);
-       }
-
-       /* stdout output. */
-       if (priority <= zl->maxlvl[ZLOG_DEST_STDOUT]) {
-               va_list ac;
-               time_print(stdout, &tsctl);
-               if (zl->record_priority)
-                       fprintf(stdout, "%s: ", zlog_priority[priority]);
-               fprintf(stdout, "%s", proto_str);
-               va_copy(ac, args);
-               vfprintf(stdout, format, ac);
-               va_end(ac);
-               fprintf(stdout, "\n");
-               fflush(stdout);
-       }
+       if ((priority <= zl->maxlvl[ZLOG_DEST_FILE]) && zl->fp)
+               vzlog_file(zl, &tsctl, proto_str, zl->record_priority,
+                               priority, zl->fp, format, args);
+
+       /* fixed-config logging to stderr while we're stating up & haven't
+        * daemonized / reached mainloop yet
+        *
+        * note the "else" on stdout output -- we don't want to print the same
+        * message to both stderr and stdout. */
+       if (zlog_startup_stderr && priority <= LOG_WARNING)
+               vzlog_file(zl, &tsctl, proto_str, 1,
+                               priority, stderr, format, args);
+       else if (priority <= zl->maxlvl[ZLOG_DEST_STDOUT])
+               vzlog_file(zl, &tsctl, proto_str, zl->record_priority,
+                               priority, stdout, format, args);
 
        /* Terminal monitor. */
        if (priority <= zl->maxlvl[ZLOG_DEST_MONITOR])

diff --git a/lib/log.h b/lib/log.h
index d872ce56d695b77422c42ce007bc0bd7a5028de6..07eb6d5bd5605420387820306630b3ae369d8ee7 100644 (file)
--- a/lib/log.h
+++ b/lib/log.h
@@ -24,6 +24,7 @@
 
 #include <syslog.h>
 #include <stdint.h>
+#include <stdbool.h>
 #include <stdio.h>
 
 /* Here is some guidance on logging levels to use:
@@ -54,6 +55,8 @@ typedef enum {
 } zlog_dest_t;
 #define ZLOG_NUM_DESTS         (ZLOG_DEST_FILE+1)
 
+extern bool zlog_startup_stderr;
+
 /* Message structure. */
 struct message {
        int key;