Wrap getaddrinfo() and block SIGALRM where needed.

Also wrap freeaddrinfo() without added functionality.

svn path=/branches/BRANCH_6-3/; revision=4895

10 files changed, 83 insertions, 23 deletions

diff --git a/Makefile.am b/Makefile.am
index c866488c..db06fee0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -39,7 +39,7 @@ libfm_a_SOURCES=	xmalloc.c base64.c rfc822.c report.c rfc2047e.c \
 			servport.c ntlm.h smbbyteorder.h smbdes.h smbmd4.h \
 			smbencrypt.h smbdes.c smbencrypt.c smbmd4.c smbutil.c \
 			libesmtp/gethostbyname.h libesmtp/gethostbyname.c \
-			smbtypes.h
+			smbtypes.h fm_getaddrinfo.c
 libfm_a_LIBADD=		$(EXTRAOBJ)
 libfm_a_DEPENDENCIES=	$(EXTRAOBJ)
 LDADD	=		libfm.a @LIBINTL@ $(LIBOBJS)
diff --git a/NEWS b/NEWS
index 6d8f922a..48d6fc40 100644
--- a/NEWS
+++ b/NEWS
@@ -98,8 +98,9 @@ fetchmail 6.3.5 (not yet released):
   with new polls, and SIGHUP would be ignored for root users. SIGHUP now matches
   documented behavior. SIGUSR1 has always been a wakeup signal for both root
   (undocumented) and non-root users. See also the deprecation warning above.
-* Track getaddrinfo() results to properly free them after timeouts,
-  reported by Uli Zappe.  This MIGHT fix Debian Bug#294547 and Bug#377135.
+* Track getaddrinfo() results to properly free them after timeouts and make sure
+  that getaddrinfo() isn't interrupted by a timeout (which breaks on MacOS X),
+  reported by Uli Zappe.  This should fix Debian Bug#294547 and Bug#377135.
 * --logfile is now handled more carefully, errors opening the logfile are
   now reported to the TTY where fetchmail was started from.
 * fetchmail now complains and aborts when it cannot properly daemonize itself.
diff --git a/checkalias.c b/checkalias.c
index 1f0495b9..80356ed2 100644
--- a/checkalias.c
+++ b/checkalias.c
@@ -36,7 +36,7 @@ static int getaddresses(struct addrinfo **result, const char *name)
     hints.ai_socktype=SOCK_STREAM;
     hints.ai_protocol=PF_UNSPEC;
     hints.ai_family=AF_UNSPEC;
-    return getaddrinfo(name, NULL, &hints, result);
+    return fm_getaddrinfo(name, NULL, &hints, result);
 }
 
 /* XXX FIXME: doesn't detect if an IPv6-mapped IPv4 address
@@ -77,9 +77,9 @@ static int is_ip_alias(const char *name1,const char *name2)
 
 found:
     if (res2)
-	freeaddrinfo(res2);
+	fm_freeaddrinfo(res2);
     if (res1)
-	freeaddrinfo(res1);
+	fm_freeaddrinfo(res1);
     return rc;
 }
 
@@ -160,16 +160,16 @@ int is_host_alias(const char *name, struct query *ctl, struct addrinfo **res)
     hints.ai_socktype=SOCK_STREAM;
     hints.ai_flags=AI_CANONNAME;
 
-    e = getaddrinfo(name, NULL, &hints, res);
+    e = fm_getaddrinfo(name, NULL, &hints, res);
     if (e == 0)
     {
 	int rr = (strcasecmp(ctl->server.truename, (*res)->ai_canonname) == 0);
-	freeaddrinfo(*res); *res = NULL;
+	fm_freeaddrinfo(*res); *res = NULL;
 	if (rr)
 	    goto match;
-        else if (ctl->server.checkalias && 0 == getaddrinfo(ctl->server.truename, NULL, &hints, &res_st))
+        else if (ctl->server.checkalias && 0 == fm_getaddrinfo(ctl->server.truename, NULL, &hints, &res_st))
 	{
-	    freeaddrinfo(res_st);
+	    fm_freeaddrinfo(res_st);
 	    if (outlevel >= O_DEBUG)
 		report(stdout, GT_("Checking if %s is really the same node as %s\n"),ctl->server.truename,name);
 	    if (is_ip_alias(ctl->server.truename,name) == TRUE)
diff --git a/configure.ac b/configure.ac
index 03d0b33c..e5012850 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,7 @@ dnl
 dnl Process this file with autoconf to produce a configure script.
 dnl
 
-AC_INIT([fetchmail],[6.3.5-beta1],[fetchmail-users@lists.berlios.de])
+AC_INIT([fetchmail],[6.3.5-beta2],[fetchmail-users@lists.berlios.de])
 AC_CONFIG_SRCDIR([fetchmail.h])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_LIBOBJ_DIR([.])
@@ -138,7 +138,7 @@ AC_SUBST(EXTRAOBJ)
 
 AC_CHECK_FUNCS(tcsetattr stty setsid geteuid seteuid dnl
   strerror syslog snprintf vprintf vsnprintf vsyslog dnl
-  atexit inet_aton strftime setrlimit socketpair sigprocmask dnl
+  atexit inet_aton strftime setrlimit socketpair dnl
   sigaction strdup setlocale)
 
 AC_CHECK_DECLS(strerror)
@@ -428,6 +428,22 @@ AC_CHECK_FUNCS(getnameinfo inet_ntop)
 AM_CONDITIONAL(NEED_GETADDRINFO, test "$ac_cv_search_getaddrinfo" != "none required")
 AM_CONDITIONAL(NEED_GETNAMEINFO, test "$ac_cv_func_getnameinfo"   != yes)
 
+dnl Check if getaddrinfo is async-signal-safe - most implementations aren't
+if test "$ac_cv_search_getaddrinfo" = "none required" ; then
+    AC_MSG_CHECKING(if your getaddrinfo is async-signal-safe)
+    gai_ts=no
+    dnl we have getaddrinfo() - check if the OS is known to have a async-signal-safe implementation
+    case $target_os in
+	linux*)					gai_ts=yes ;;
+	freebsd5.5|freebsd6*|freebsd7*)		gai_ts=yes ;;
+	solaris2.8|solaris2.9|solaris2.10)	gai_ts=yes ;;
+    esac
+    AC_MSG_RESULT($gai_ts)
+    if test $gai_ts = yes ; then
+	AC_DEFINE(GETADDRINFO_ASYNCSAFE, 1, [define to 1 if you know your getaddrinfo function is async-signal-safe])
+    fi
+fi
+
 # This version of the Kerberos 4 and 5 options addresses the follwing issues:
 # 
 # * Build correctly under Heimdal kerberos if it is compiled with db2 and
diff --git a/driver.c b/driver.c
index ae4b7e69..d3c8c970 100644
--- a/driver.c
+++ b/driver.c
@@ -862,11 +862,11 @@ static int do_session(
 	sigprocmask(SIG_UNBLOCK, &allsigs, NULL);
 
 	if (ai0) {
-	    freeaddrinfo(ai0); ai0 = NULL;
+	    fm_freeaddrinfo(ai0); ai0 = NULL;
 	}
 
 	if (ai1) {
-	    freeaddrinfo(ai1); ai1 = NULL;
+	    fm_freeaddrinfo(ai1); ai1 = NULL;
 	}
 	
 	if (js == THROW_TIMEOUT)
@@ -998,7 +998,7 @@ static int do_session(
 		hints.ai_family = AF_UNSPEC;
 		hints.ai_flags = AI_CANONNAME;
 
-		error = getaddrinfo(ctl->server.queryname, NULL, &hints, &res);
+		error = fm_getaddrinfo(ctl->server.queryname, NULL, &hints, &res);
 		if (error)
 		{
 		    report(stderr,
@@ -1024,7 +1024,7 @@ static int do_session(
 		    ctl->server.trueaddr = (struct sockaddr *)xmalloc(res->ai_addrlen);
 		    ctl->server.trueaddr_len = res->ai_addrlen;
 		    memcpy(ctl->server.trueaddr, res->ai_addr, res->ai_addrlen);
-		    freeaddrinfo(res);
+		    fm_freeaddrinfo(res);
 		}
 	    }
 	}
diff --git a/env.c b/env.c
index 85c992c0..9b9e608c 100644
--- a/env.c
+++ b/env.c
@@ -161,7 +161,7 @@ char *host_fqdn(int required)
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_flags=AI_CANONNAME;
 
-	e = getaddrinfo(tmpbuf, NULL, &hints, &res);
+	e = fm_getaddrinfo(tmpbuf, NULL, &hints, &res);
 	if (e) {
 	    /* exit with error message */
 	    fprintf(stderr,
@@ -177,7 +177,7 @@ char *host_fqdn(int required)
 	}
 
 	result = xstrdup(res->ai_canonname);
-	freeaddrinfo(res);
+	fm_freeaddrinfo(res);
     }
     else
 	result = xstrdup(tmpbuf);
diff --git a/fetchmail.h b/fetchmail.h
index 7c63e22a..cfe6a634 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -759,5 +759,8 @@ int servport(const char *service);
 # define NI_DGRAM	16
 #endif
 
+int fm_getaddrinfo(const char *node, const char *serv, const struct addrinfo *hints, struct addrinfo **res);
+void fm_freeaddrinfo(struct addrinfo *ai);
+
 #endif
 /* fetchmail.h ends here */
diff --git a/fm_getaddrinfo.c b/fm_getaddrinfo.c
new file mode 100644
index 00000000..97cec65c
--- /dev/null
+++ b/fm_getaddrinfo.c
@@ -0,0 +1,40 @@
+#include "config.h"
+#include "fetchmail.h"
+#include "i18n.h"
+
+#include <signal.h>
+#include <errno.h>
+#include <string.h>
+
+/** This is a getaddrinfo() replacement that blocks SIGALRM,
+ * to avoid issues with non-reentrant getaddrinfo() implementations
+ * after SIGALRM timeouts, for instance on MacOS X or NetBSD. */
+int fm_getaddrinfo(const char *node, const char *serv, const struct addrinfo *hints, struct addrinfo **res)
+{
+    int rc;
+
+#ifndef GETADDRINFO_ASYNCSAFE
+    sigset_t ss, os;
+
+    sigemptyset(&ss);
+    sigaddset(&ss, SIGALRM);
+
+    if (sigprocmask(SIG_BLOCK, &ss, &os))
+	report(stderr, GT_("Cannot modify signal mask: %s"), strerror(errno));
+#endif
+
+    rc = getaddrinfo(node, serv, hints, res);
+
+#ifndef GETADDRINFO_ASYNCSAFE
+    if (sigprocmask(SIG_SETMASK, &os, NULL))
+	report(stderr, GT_("Cannot modify signal mask: %s"), strerror(errno));
+#endif
+
+    return rc;
+}
+
+/** this is a debugging freeaddrinfo() wrapper. */
+void fm_freeaddrinfo(struct addrinfo *ai)
+{
+    freeaddrinfo(ai);
+}
diff --git a/servport.c b/servport.c
index 2849f7c2..0a12c640 100644
--- a/servport.c
+++ b/servport.c
@@ -48,7 +48,7 @@ int servport(const char *service) {
 	hints.ai_family = AF_UNSPEC;
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_protocol = IPPROTO_TCP;
-	e = getaddrinfo(NULL, service, &hints, &res);
+	e = fm_getaddrinfo(NULL, service, &hints, &res);
 	if (e) {
 	    report(stderr, GT_("getaddrinfo(NULL, \"%s\") error: %s\n"),
 		    service, gai_strerror(e));
@@ -64,10 +64,10 @@ int servport(const char *service) {
 		break;
 #endif
 		default:
-		    freeaddrinfo(res);
+		    fm_freeaddrinfo(res);
 		    goto err;
 	    }
-	    freeaddrinfo(res);
+	    fm_freeaddrinfo(res);
 	}
     } else {
 	if (u == 0 || u > 65535)
diff --git a/socket.c b/socket.c
index 080f1888..52e9f1cf 100644
--- a/socket.c
+++ b/socket.c
@@ -277,7 +277,7 @@ int SockOpen(const char *host, const char *service,
     memset(&req, 0, sizeof(struct addrinfo));
     req.ai_socktype = SOCK_STREAM;
 
-    i = getaddrinfo(host, service, &req, ai0);
+    i = fm_getaddrinfo(host, service, &req, ai0);
     if (i) {
 	report(stderr, GT_("getaddrinfo(\"%s\",\"%s\") error: %s\n"),
 		host, service, gai_strerror(i));
@@ -340,7 +340,7 @@ int SockOpen(const char *host, const char *service,
 	break;
     }
 
-    freeaddrinfo(*ai0);
+    fm_freeaddrinfo(*ai0);
     *ai0 = NULL;
 
     if (i == -1)