Freeaddrinfo() fix for Uli Zappe's bug.

This might fix Debian Bug#294547 and Bug#377135.

svn path=/branches/BRANCH_6-3/; revision=4880

10 files changed, 55 insertions, 30 deletions

diff --git a/NEWS b/NEWS
index bcb00beb..f278b29a 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,8 @@ change.  MA = Matthias Andree, ESR = Eric S. Raymond, RF = Rob Funk.)
 * Kerberos IV support may be removed from a future fetchmail release.
 * SIGHUP wakeup may be removed from a future fetchmail release and cause it
   to terminate.
+* Support for operating systems that are not sufficiently POSIX compliant may be
+  removed or operation on such systems may be suboptimal for future releases.
 
 --------------------------------------------------------------------------------
 
@@ -100,6 +102,8 @@ fetchmail 6.3.5 (not yet released):
   service name and the port number. Log the latter when trying to connect in
   verbose mode, too.
 * Keep syslog output at one line per message (this works if no errors occur).
+* Track getaddrinfo() results to properly free them after timeouts,
+  reported by Uli Zappe.  This MIGHT fix Debian Bug#294547 and Bug#377135.
 
 # CHANGES:
 * Rename all fetchmail-internal lock_* functions to fm_lock_*. Obsoletes
diff --git a/TODO.txt b/TODO.txt
index 2156f2d2..f8993ce4 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,4 +1,3 @@
-- debian bug #377135/freeaddrinfo()?
 - log/print warning if fetchmail uses TLS without configuration,
   to avoid users being surprised (see Debian Bug#294547).
 - allow full user@domain mappings in multidrop matching
@@ -6,8 +5,6 @@
   multidrop problems on fetchmail-users
 - Patterson: --logfile w/ ~/blah confuses fetchmail;
   see thread [fetchmail-users] option -v not working...
-- Uli Zappe: [fetchmail-users] [BUG] fetchmail daemon does not resume
-  fetching after a network outage (has probable analysis)
 - check recent list mail
 - check Debian BTS and other bug trackers
 - better logging (log all headers)
diff --git a/checkalias.c b/checkalias.c
index 8214b40a..1f0495b9 100644
--- a/checkalias.c
+++ b/checkalias.c
@@ -83,14 +83,14 @@ found:
     return rc;
 }
 
-int is_host_alias(const char *name, struct query *ctl)
+int is_host_alias(const char *name, struct query *ctl, struct addrinfo **res)
 /* determine whether name is a DNS alias of the mailserver for this query */
 {
     struct mxentry	*mxp, *mxrecords;
     struct idlist	*idl;
     size_t		namelen;
     int			e;
-    struct addrinfo	hints, *res, *res_st;
+    struct addrinfo	hints, *res_st;
 
     struct hostdata *lead_server =
 	ctl->server.lead_server ? ctl->server.lead_server : &ctl->server;
@@ -160,11 +160,11 @@ int is_host_alias(const char *name, struct query *ctl)
     hints.ai_socktype=SOCK_STREAM;
     hints.ai_flags=AI_CANONNAME;
 
-    e = getaddrinfo(name, NULL, &hints, &res);
+    e = getaddrinfo(name, NULL, &hints, res);
     if (e == 0)
     {
-	int rr = (strcasecmp(ctl->server.truename, res->ai_canonname) == 0);
-	freeaddrinfo(res);
+	int rr = (strcasecmp(ctl->server.truename, (*res)->ai_canonname) == 0);
+	freeaddrinfo(*res); *res = NULL;
 	if (rr)
 	    goto match;
         else if (ctl->server.checkalias && 0 == getaddrinfo(ctl->server.truename, NULL, &hints, &res_st))
diff --git a/driver.c b/driver.c
index 5d765986..c9d3e6a0 100644
--- a/driver.c
+++ b/driver.c
@@ -70,6 +70,8 @@ int batchcount;		/* count of messages sent in current batch */
 flag peek_capable;	/* can we peek for better error recovery? */
 int mailserver_socket_temp = -1;	/* socket to free if connect timeout */ 
 
+struct addrinfo *ai0, *ai1;	/* clean these up after signal */
+
 static volatile int timeoutcount = 0;	/* count consecutive timeouts */
 static volatile int idletimeout = 0;	/* timeout occured in idle stage? */
 
@@ -878,6 +880,14 @@ static int do_session(
 	sigfillset(&allsigs);
 	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
 #endif /* HAVE_SIGPROCMASK */
+
+	if (ai0) {
+	    freeaddrinfo(ai0); ai0 = NULL;
+	}
+
+	if (ai1) {
+	    freeaddrinfo(ai1); ai1 = NULL;
+	}
 	
 	if (js == THROW_SIGPIPE)
 	{
@@ -1053,7 +1063,7 @@ static int do_session(
 	    (void)sleep(1);
 	if ((mailserver_socket = SockOpen(realhost, 
 			     ctl->server.service ? ctl->server.service : ( ctl->use_ssl ? ctl->server.base_protocol->sslservice : ctl->server.base_protocol->service ),
-			     ctl->server.plugin)) == -1)
+			     ctl->server.plugin, &ai0)) == -1)
 	{
 	    char	errbuf[BUFSIZ];
 	    int err_no = errno;
diff --git a/fetchmail-FAQ.html b/fetchmail-FAQ.html
index dce7b38c..df7d3f8c 100644
--- a/fetchmail-FAQ.html
+++ b/fetchmail-FAQ.html
@@ -2487,15 +2487,9 @@ declaration <tt>auth password</tt> in your .fetchmailrc.</p>
 <h2><a id="R13" name="R13">R13. What does "Interrupted system call"
 	mean?</a></h2>
 
-<p>Fetchmail 6.3.5 and newer gave up on the older timeout handling which
-could cause unstable behavior. Instead, timeouts now interrupt
-long-running functions and are reported as "Interrupted system
-call".</p>
-
-<p>While this loses accuracy of timeout reporting, there is
-unfortunately no safe way for C to make extensive use of error
-reporting, and the amount of code that would need to be added is too
-large for a stable series as 6.3.X is.</p>
+<p>Non-fatal signals (such as timers set by fetchmail itself) can
+interrupt long-running functions and will then be reported as
+"Interrupted system call". These can sometimes be timeouts.</p>
 
 <hr/>
 <h1>Hangs and lockups</h1>
diff --git a/fetchmail.h b/fetchmail.h
index 1191bd34..2ea7972e 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -23,6 +23,13 @@
 # endif
 #endif
 
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NET_SOCKET_H
+#include <net/socket.h>
+#endif
+#include <netdb.h>
 #include <stdio.h>
 
 /* Import Trio if needed */
@@ -651,7 +658,9 @@ void escapes(const char *, char *);
 char *visbuf(const char *);
 const char *showproto(int);
 void dump_config(struct runctl *runp, struct query *querylist);
-int is_host_alias(const char *, struct query *);
+int is_host_alias(const char *, struct query *, struct addrinfo **);
+
+extern struct addrinfo *ai0, *ai1;
 
 /** Try to obtain fully qualified hostname of current host. Exit with
  * PS_DNS if \a required is true and there is a DNS error. Exit with
diff --git a/sink.c b/sink.c
index 3e0ac359..2e36e57e 100644
--- a/sink.c
+++ b/sink.c
@@ -141,7 +141,7 @@ int smtp_open(struct query *ctl)
 			portnum = cp;
 		}
 		if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,
-				ctl->server.plugout)) == -1)
+				ctl->server.plugout, &ai1)) == -1)
 		{
 		    xfree(parsed_host);
 		    continue;
@@ -179,7 +179,7 @@ int smtp_open(struct query *ctl)
 	    else
 	    {
 		if ((ctl->smtp_socket = SockOpen(parsed_host,portnum,
-				ctl->server.plugout)) == -1)
+				ctl->server.plugout, &ai1)) == -1)
 		{
 		    xfree(parsed_host);
 		    continue;
@@ -279,7 +279,7 @@ static int send_bouncemail(struct query *ctl, struct msgblk *msg,
     /* we need only SMTP for this purpose */
     /* XXX FIXME: hardcoding localhost is nonsense if smtphost can be
      * configured */
-    if ((sock = SockOpen("localhost", SMTP_PORT, NULL)) == -1)
+    if ((sock = SockOpen("localhost", SMTP_PORT, NULL, &ai1)) == -1)
 	return(FALSE);
 
     if (SMTP_ok(sock, SMTP_MODE) != SM_OK)
diff --git a/socket.c b/socket.c
index ee9600fd..080f1888 100644
--- a/socket.c
+++ b/socket.c
@@ -264,19 +264,20 @@ int UnixOpen(const char *path)
 }
 
 int SockOpen(const char *host, const char *service,
-	     const char *plugin)
+	     const char *plugin, struct addrinfo **ai0)
 {
-    struct addrinfo *ai, *ai0, req;
+    struct addrinfo *ai, req;
     int i, acterr = 0;
 
 #ifdef HAVE_SOCKETPAIR
     if (plugin)
 	return handle_plugin(host,service,plugin);
 #endif /* HAVE_SOCKETPAIR */
+
     memset(&req, 0, sizeof(struct addrinfo));
     req.ai_socktype = SOCK_STREAM;
 
-    i = getaddrinfo(host, service, &req, &ai0);
+    i = getaddrinfo(host, service, &req, ai0);
     if (i) {
 	report(stderr, GT_("getaddrinfo(\"%s\",\"%s\") error: %s\n"),
 		host, service, gai_strerror(i));
@@ -286,7 +287,7 @@ int SockOpen(const char *host, const char *service,
     }
 
     i = -1;
-    for (ai = ai0; ai; ai = ai->ai_next) {
+    for (ai = *ai0; ai; ai = ai->ai_next) {
 	char buf[80],pb[80];
 	int gnie;
 
@@ -339,7 +340,8 @@ int SockOpen(const char *host, const char *service,
 	break;
     }
 
-    freeaddrinfo(ai0);
+    freeaddrinfo(*ai0);
+    *ai0 = NULL;
 
     if (i == -1)
 	errno = acterr;
diff --git a/socket.h b/socket.h
index d4fc947e..fb86b17e 100644
--- a/socket.h
+++ b/socket.h
@@ -7,8 +7,16 @@
 #ifndef SOCKET__
 #define SOCKET__
 
+#include <config.h>
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#elif HAVE_NET_SOCKET_H
+#include <net/socket.h>
+#endif
+#include <netdb.h>
+
 /* Create a new client socket; returns -1 on error */
-int SockOpen(const char *host, const char *service, const char *plugin);
+int SockOpen(const char *host, const char *service, const char *plugin, struct addrinfo **);
 
 /* Returns 1 if this socket is OK, 0 if it isn't select()able
  * on - probably because it's been closed. You should
diff --git a/transact.c b/transact.c
index b16f4238..f29fa5b9 100644
--- a/transact.c
+++ b/transact.c
@@ -150,7 +150,7 @@ static void find_server_names(const char *hdr,
 		     * not, skip this name.  If it is, we'll keep
 		     * going and try to find a mapping to a client name.
 		     */
-		    if (!is_host_alias(atsign+1, ctl))
+		    if (!is_host_alias(atsign+1, ctl, &ai0))
 		    {
 			save_str(xmit_names, cp, XMIT_REJECT);
 			reject_count++;
@@ -190,6 +190,7 @@ static char *parse_received(struct query *ctl, char *bufp)
 {
     char *base, *ok = (char *)NULL;
     static char rbuf[HOSTLEN + USERNAMELEN + 4]; 
+    struct addrinfo *ai0;
 
 #define RBUF_WRITE(value) if (tp < rbuf+sizeof(rbuf)-1) *tp++=value
 
@@ -237,7 +238,7 @@ static char *parse_received(struct query *ctl, char *bufp)
 	 * recipient name after a following "for".  Otherwise
 	 * punt.
 	 */
-	if (is_host_alias(rbuf, ctl))
+	if (is_host_alias(rbuf, ctl, &ai0))
 	{
 	    if (outlevel >= O_DEBUG)
 		report(stdout,