Tools: hv: fix send/recv buffer allocation

hv_kvp_daemon fails to start in current openSuSE 13.1 snapshots because the kvp_send_buffer is too small to hold cn_msg+hv_kvp_msg, the very first sendmsg returns with EFAULT. In addition it fixes the Network info tab in Windows Server 2012R2 in SLES11. Adjust the code in kvp and vss daemon to allocate the needed buffers at runtime. To keep the code simple, the buffer_len includes also the nlmsghdr, although only the recv_buffer needs this extra space. Signed-off-by: Olaf Hering <[email protected]> Signed-off-by: K. Y. Srinivasan <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
vbatts · Aug 2, 2013 · b4919a5 · b4919a5
1 parent cfc2599
commit b4919a5
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Showing 2 changed files with 24 additions and 6 deletions.
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
@@ -79,8 +79,6 @@ enum {
 	DNS
 };
 
-static char kvp_send_buffer[4096];
-static char kvp_recv_buffer[4096 * 2];
 static struct sockaddr_nl addr;
 static int in_hand_shake = 1;
 
@@ -1437,10 +1435,21 @@ int main(void)
 	int	pool;
 	char	*if_name;
 	struct hv_kvp_ipaddr_value *kvp_ip_val;
+	char *kvp_send_buffer;
+	char *kvp_recv_buffer;
+	size_t kvp_recv_buffer_len;
 
 	daemon(1, 0);
 	openlog("KVP", 0, LOG_USER);
 	syslog(LOG_INFO, "KVP starting; pid is:%d", getpid());
+
+	kvp_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + sizeof(struct hv_kvp_msg);
+	kvp_send_buffer = calloc(1, kvp_recv_buffer_len);
+	kvp_recv_buffer = calloc(1, kvp_recv_buffer_len);
+	if (!(kvp_send_buffer && kvp_recv_buffer)) {
+		syslog(LOG_ERR, "Failed to allocate netlink buffers");
+		exit(EXIT_FAILURE);
+	}
 	/*
 	 * Retrieve OS release information.
 	 */
@@ -1514,7 +1523,7 @@ int main(void)
 				continue;
 		}
 
-		len = recvfrom(fd, kvp_recv_buffer, sizeof(kvp_recv_buffer), 0,
+		len = recvfrom(fd, kvp_recv_buffer, kvp_recv_buffer_len, 0,
 				addr_p, &addr_l);
 
 		if (len < 0) {

diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
@@ -38,8 +38,6 @@
 #include <linux/netlink.h>
 #include <syslog.h>
 
-static char vss_recv_buffer[4096];
-static char vss_send_buffer[4096];
 static struct sockaddr_nl addr;
 
 #ifndef SOL_NETLINK
@@ -147,13 +145,24 @@ int main(void)
 	struct cn_msg	*incoming_cn_msg;
 	int	op;
 	struct hv_vss_msg *vss_msg;
+	char *vss_send_buffer;
+	char *vss_recv_buffer;
+	size_t vss_recv_buffer_len;
 
 	if (daemon(1, 0))
 		return 1;
 
 	openlog("Hyper-V VSS", 0, LOG_USER);
 	syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());
 
+	vss_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + sizeof(struct hv_vss_msg);
+	vss_send_buffer = calloc(1, vss_recv_buffer_len);
+	vss_recv_buffer = calloc(1, vss_recv_buffer_len);
+	if (!(vss_send_buffer && vss_recv_buffer)) {
+		syslog(LOG_ERR, "Failed to allocate netlink buffers");
+		exit(EXIT_FAILURE);
+	}
+
 	fd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
 	if (fd < 0) {
 		syslog(LOG_ERR, "netlink socket creation failed; error:%d %s",
@@ -215,7 +224,7 @@ int main(void)
 				continue;
 		}
 
-		len = recvfrom(fd, vss_recv_buffer, sizeof(vss_recv_buffer), 0,
+		len = recvfrom(fd, vss_recv_buffer, vss_recv_buffer_len, 0,
 				addr_p, &addr_l);
 
 		if (len < 0) {