Ignore SIGPIPE, EPIPE must suffice as error.

Calling longjmp() from a signal handler is unsafe.

svn path=/branches/BRANCH_6-3/; revision=4893

diff --git a/NEWS b/NEWS
index 8a733baecf6dc118a479406bca2f7a1dc01545a4..6d8f922a9b3ba0a338bb2f93e398527635d55756 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -104,6 +104,9 @@ fetchmail 6.3.5 (not yet released):
   now reported to the TTY where fetchmail was started from.
 * fetchmail now complains and aborts when it cannot properly daemonize itself.
 * fix compilation on systems that don't know struct addrinfo (Solaris 2.6).
+* ignore SIGPIPE signals and rely on functions to return EPIPE instead. This is
+  necessary because the former longjmp() from the signal handler is unsafe and
+  makes the whole fetchmail behavior undefined after the event.
 
 # CHANGES:
 * Rename all fetchmail-internal lock_* functions to fm_lock_*. Obsoletes

diff --git a/driver.c b/driver.c
index c1d38a41766ef2c38ebab9ac9334d98c297eaceb..ae4b7e69c380dfc59ae2b374eb1ce53e9c2e5370 100644 (file)
--- a/driver.c
+++ b/driver.c
@@ -55,7 +55,6 @@
 
 /* throw types for runtime errors */
 #define THROW_TIMEOUT  1               /* server timed out */
-#define THROW_SIGPIPE  2               /* SIGPIPE on stream socket */
 
 /* magic values for the message length array */
 #define MSGLEN_UNKNOWN 0               /* length unknown (0 is impossible) */
@@ -110,18 +109,14 @@ static RETSIGTYPE timeout_handler (int signal)
     (void)signal;
     if(stage != STAGE_IDLE) {
        timeoutcount++;
+       /* XXX FIXME: this siglongjmp must die - it's not safe to be
+        * called from a function handler and breaks, for instance,
+        * getaddrinfo() */
        siglongjmp(restart, THROW_TIMEOUT);
     } else
        idletimeout = 1;
 }
 
-static RETSIGTYPE sigpipe_handler (int signal)
-/* handle SIGPIPE signal indicating a broken stream socket */
-{
-    (void)signal;
-    siglongjmp(restart, THROW_SIGPIPE);
-}
-
 #define CLEANUP_TIMEOUT 60 /* maximum timeout during cleanup */
 
 static int cleanupSockClose (int fd)
@@ -845,7 +840,6 @@ static int do_session(
     int tmperr;
     int deletions = 0, js;
     const char *msg;
-    SIGHANDLERTYPE pipesave;
     SIGHANDLERTYPE alrmsave;
 
     ctl->server.base_protocol = proto;
@@ -859,9 +853,6 @@ static int do_session(
     alrmsave = set_signal_handler(SIGALRM, timeout_handler);
     mytimeout = ctl->server.timeout;
 
-    /* set up the broken-pipe timeout */
-    pipesave = set_signal_handler(SIGPIPE, sigpipe_handler);
-
     if ((js = sigsetjmp(restart,1)))
     {
        /* exception caught */
@@ -878,14 +869,7 @@ static int do_session(
            freeaddrinfo(ai1); ai1 = NULL;
        }
        
-       if (js == THROW_SIGPIPE)
-       {
-           set_signal_handler(SIGPIPE, SIG_IGN);
-           report(stdout,
-                  GT_("SIGPIPE thrown from an MDA or a stream socket error\n"));
-           wait(0);
-       }
-       else if (js == THROW_TIMEOUT)
+       if (js == THROW_TIMEOUT)
        {
            if (phase == OPEN_WAIT)
                report(stdout,
@@ -939,7 +923,7 @@ static int do_session(
     }
     else
     {
-       /* setjmp returned zero -> normal operation */
+       /* sigsetjmp returned zero -> normal operation */
        char buf[MSGBUFSIZE+1], *realhost;
        int count, newm, bytes;
        int fetches, dispatches, oldphase;
@@ -1581,7 +1565,6 @@ closeUp:
 
     set_timeout(0); /* cancel any pending alarm */
     set_signal_handler(SIGALRM, alrmsave);
-    set_signal_handler(SIGPIPE, pipesave);
     return(err);
 }