autofs-5.0.3 - fix interface config buffer size

From: Ian Kent <raven@themaw.net>

When getting the interface configuration information autofs uses a

fixed size buffer for the interface information. If there are many

interfaces this causes the check to fail.

---

 CHANGELOG            |    1 +

 modules/replicated.c |   51 ++++++++++++++++++++++++++++++++++++++++++--------

 2 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index d2fe0a6..5b0f265 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -34,6 +34,7 @@

 - update replicated server selection documentation.

 - use /dev/urandom instead of /dev/random.

 - check for mtab pointing to /proc/mounts.

+- dynamically allocate interface config buffer.

 14/01/2008 autofs-5.0.3

 -----------------------

diff --git a/modules/replicated.c b/modules/replicated.c

index 362ab1b..ad1ede2 100644

--- a/modules/replicated.c

+++ b/modules/replicated.c

@@ -95,6 +95,41 @@ void seed_random(void)

 	return;

 }

+static int alloc_ifreq(struct ifconf *ifc, int sock)

+{

+	int ret, lastlen = 0, len = MAX_IFC_BUF;

+	char err_buf[MAX_ERR_BUF], *buf;

+

+	while (1) {

+		buf = malloc(len);

+		if (!buf) {

+			char *estr = strerror_r(errno, err_buf, MAX_ERR_BUF);

+			logerr("malloc: %s", estr);

+			return 0;

+		}

+

+		ifc->ifc_len = sizeof(buf);

+		ifc->ifc_req = (struct ifreq *) buf;

+

+		ret = ioctl(sock, SIOCGIFCONF, ifc);

+		if (ret == -1) {

+			char *estr = strerror_r(errno, err_buf, MAX_ERR_BUF);

+			logerr("ioctl: %s", estr);

+			free(buf);

+			return 0;

+		}

+

+		if (ifc->ifc_len == lastlen)

+			break;

+

+		lastlen = ifc->ifc_len;

+		len += MAX_IFC_BUF;

+		free(buf);

+	}

+

+	return 1;

+}

+

 static unsigned int get_proximity(const char *host_addr, int addr_len)

 {

 	struct sockaddr_in *msk_addr, *if_addr;

@@ -122,12 +157,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 		fcntl(sock, F_SETFD, cl_flags);

 	}

-	ifc.ifc_len = sizeof(buf);

-	ifc.ifc_req = (struct ifreq *) buf;

-	ret = ioctl(sock, SIOCGIFCONF, &ifc;;

-	if (ret == -1) {

-		char *estr = strerror_r(errno, buf, MAX_ERR_BUF);

-		logerr("ioctl: %s", estr);

+	if (!alloc_ifreq(&ifc, sock)) {

 		close(sock);

 		return PROXIMITY_ERROR;

 	}

@@ -138,7 +168,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 	i = 0;

 	ptr = (char *) &ifc.ifc_buf[0];

-	while (ptr < buf + ifc.ifc_len) {

+	while (ptr < (char *) ifc.ifc_req + ifc.ifc_len) {

 		ifr = (struct ifreq *) ptr;

 		switch (ifr->ifr_addr.sa_family) {

@@ -147,6 +177,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 			ret = memcmp(&if_addr->sin_addr, hst_addr, addr_len);

 			if (!ret) {

 				close(sock);

+				free(ifc.ifc_req);

 				return PROXIMITY_LOCAL;

 			}

 			break;

@@ -162,7 +193,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 	i = 0;

 	ptr = (char *) &ifc.ifc_buf[0];

-	while (ptr < buf + ifc.ifc_len) {

+	while (ptr < (char *) ifc.ifc_req + ifc.ifc_len) {

 		ifr = (struct ifreq *) ptr;

 		switch (ifr->ifr_addr.sa_family) {

@@ -178,6 +209,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 				char *estr = strerror_r(errno, buf, MAX_ERR_BUF);

 				logerr("ioctl: %s", estr);

 				close(sock);

+				free(ifc.ifc_req);

 				return PROXIMITY_ERROR;

 			}

@@ -186,6 +218,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 			if ((ia & mask) == (ha & mask)) {

 				close(sock);

+				free(ifc.ifc_req);

 				return PROXIMITY_SUBNET;

 			}

@@ -208,6 +241,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 			if ((ia & mask) == (ha & mask)) {

 				close(sock);

+				free(ifc.ifc_req);

 				return PROXIMITY_NET;

 			}

 			break;

@@ -221,6 +255,7 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 	}

 	close(sock);

+	free(ifc.ifc_req);

 	return PROXIMITY_OTHER;

 }