From f753f6f0e21d859b513beb244e747a5c42a8d56f Mon Sep 17 00:00:00 2001
From: Roger Dingledine <arma@torproject.org>
Date: Thu, 23 Sep 2004 03:51:45 +0000
Subject: [PATCH] bugfix: when we run out of disk space, or other log writing
 error, don't crash. just stop logging to that log and continue.

nick, can you find the bug i've cleverly hidden in this commit?


svn:r2365
---
 src/common/log.c | 51 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/src/common/log.c b/src/common/log.c
index 26038b166a..ce7e7b68b2 100644
--- a/src/common/log.c
+++ b/src/common/log.c
@@ -139,22 +139,32 @@ logv(int severity, const char *funcname, const char *format, va_list ap)
   logfile_t *lf;
 
   assert(format);
-  for (lf = logfiles; lf; lf = lf->next) {
-    if (severity < lf->loglevel || severity > lf->max_loglevel)
+  lf = logfiles;
+  while(lf) {
+    if (severity < lf->loglevel || severity > lf->max_loglevel) {
+      lf = lf->next;
       continue;
-    if (!lf->file)
+    }
+    if (!lf->file) {
+      lf = lf->next;
       continue;
+    }
 
     if (!formatted) {
-      format_msg(buf, 10024, severity, funcname, format, ap);
+      format_msg(buf, sizeof(buf), severity, funcname, format, ap);
       formatted = 1;
     }
-    if(fputs(buf, lf->file) == EOF) { /* error */
-      assert(0); /* XXX */
-    }
-    if(fflush(lf->file) == EOF) { /* error */
-      /* don't log the error! */
-      assert(0); /* XXX fail for now. what's better to do? */
+    if(fputs(buf, lf->file) == EOF ||
+       fflush(lf->file) == EOF) { /* error */
+      /* don't log the error! Blow away this log entry and continue. */
+      logfile_t *victim = lf;
+      lf = victim->next;
+      if(victim == logfiles)
+        logfiles = lf;
+      tor_free(victim->filename);
+      tor_free(victim);
+    } else {
+      lf = lf->next;
     }
   }
 }
@@ -194,13 +204,24 @@ void close_logs()
 /** Close and re-open all log files; used to rotate logs on SIGHUP. */
 void reset_logs()
 {
-  logfile_t *lf;
-  for (lf = logfiles; lf; lf = lf->next) {
+  logfile_t *lf = logfiles;
+  while(lf) {
     if (lf->needs_close) {
-      fclose(lf->file);
-      lf->file = fopen(lf->filename, "a");
-      log_tor_version(lf, 1);
+      if(fclose(lf->file)==EOF ||
+        !(lf->file = fopen(lf->filename, "a"))) {
+        /* error. don't log it. delete the log entry and continue. */
+        logfile_t *victim = lf;
+        lf = victim->next;
+        if(victim == logfiles)
+          logfiles = lf;
+        tor_free(victim->filename);
+        tor_free(victim);
+        continue;
+      } else {
+        log_tor_version(lf, 1);
+      }
     }
+    lf = lf->next;
   }
 }