only set non-blocking on netlink socket

There is no need to increase buffer size or set non-blocking on the
netlink command socket. This reduces the number of system calls per
transaction.

1 files changed, 50 insertions, 133 deletions

diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 954e0791..71d26a76 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -114,75 +114,64 @@ set_ifindex(struct interface *ifp, unsigned int ifi_index)
   ifp->ifindex = ifi_index;
 }
 
-/* Make socket for Linux netlink interface. */
 static int
-netlink_socket (struct nlsock *nl, unsigned long groups)
+netlink_recvbuf (struct nlsock *nl, uint32_t newsize)
 {
+  u_int32_t oldsize;
+  socklen_t newlen = sizeof(newsize);
+  socklen_t oldlen = sizeof(oldsize);
   int ret;
-  struct sockaddr_nl snl;
-  int sock;
-  int namelen;
-  int save_errno;
 
-  sock = socket (AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
-  if (sock < 0)
+  ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &oldsize, &oldlen);
+  if (ret < 0)
     {
-      zlog (NULL, LOG_ERR, "Can't open %s socket: %s", nl->name,
-            safe_strerror (errno));
+      zlog (NULL, LOG_ERR, "Can't get %s receive buffer size: %s", nl->name,
+	    safe_strerror (errno));
       return -1;
     }
 
-  ret = fcntl (sock, F_SETFL, O_NONBLOCK);
+  ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &nl_rcvbufsize,
+		   sizeof(nl_rcvbufsize));
   if (ret < 0)
     {
-      zlog (NULL, LOG_ERR, "Can't set %s socket flags: %s", nl->name,
-            safe_strerror (errno));
-      close (sock);
+      zlog (NULL, LOG_ERR, "Can't set %s receive buffer size: %s", nl->name,
+	    safe_strerror (errno));
       return -1;
     }
 
-  /* Set receive buffer size if it's set from command line */
-  if (nl_rcvbufsize)
+  ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &newsize, &newlen);
+  if (ret < 0)
     {
-      u_int32_t oldsize, oldlen;
-      u_int32_t newsize, newlen;
+      zlog (NULL, LOG_ERR, "Can't get %s receive buffer size: %s", nl->name,
+	    safe_strerror (errno));
+      return -1;
+    }
 
-      oldlen = sizeof(oldsize);
-      newlen = sizeof(newsize);
+  zlog (NULL, LOG_INFO,
+	"Setting netlink socket receive buffer size: %u -> %u",
+	oldsize, newsize);
+  return 0;
+}
 
-      ret = getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &oldsize, &oldlen);
-      if (ret < 0)
-	{
-	  zlog (NULL, LOG_ERR, "Can't get %s receive buffer size: %s", nl->name,
-		safe_strerror (errno));
-	  close (sock);
-	  return -1;
-	}
-
-      ret = setsockopt(sock, SOL_SOCKET, SO_RCVBUF, &nl_rcvbufsize,
-		       sizeof(nl_rcvbufsize));
-      if (ret < 0)
-	{
-	  zlog (NULL, LOG_ERR, "Can't set %s receive buffer size: %s", nl->name,
-		safe_strerror (errno));
-	  close (sock);
-	  return -1;
-	}
-
-      ret = getsockopt(sock, SOL_SOCKET, SO_RCVBUF, &newsize, &newlen);
-      if (ret < 0)
-	{
-	  zlog (NULL, LOG_ERR, "Can't get %s receive buffer size: %s", nl->name,
-		safe_strerror (errno));
-	  close (sock);
-	  return -1;
-	}
+/* Make socket for Linux netlink interface. */
+static int
+netlink_socket (struct nlsock *nl, unsigned long groups)
+{
+  int ret;
+  struct sockaddr_nl snl;
+  int sock;
+  int namelen;
+  int save_errno;
 
-      zlog (NULL, LOG_INFO,
-	    "Setting netlink socket receive buffer size: %u -> %u",
-	    oldsize, newsize);
+  sock = socket (AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+  if (sock < 0)
+    {
+      zlog (NULL, LOG_ERR, "Can't open %s socket: %s", nl->name,
+            safe_strerror (errno));
+      return -1;
     }
 
+
   memset (&snl, 0, sizeof snl);
   snl.nl_family = AF_NETLINK;
   snl.nl_groups = groups;
@@ -223,41 +212,6 @@ netlink_socket (struct nlsock *nl, unsigned long groups)
   return ret;
 }
 
-int
-set_netlink_blocking (struct nlsock *nl, int *flags)
-{
-
-  /* Change socket flags for blocking I/O.  */
-  if ((*flags = fcntl (nl->sock, F_GETFL, 0)) < 0)
-    {
-      zlog (NULL, LOG_ERR, "%s:%i F_GETFL error: %s",
-            __FUNCTION__, __LINE__, safe_strerror (errno));
-      return -1;
-    }
-  *flags &= ~O_NONBLOCK;
-  if (fcntl (nl->sock, F_SETFL, *flags) < 0)
-    {
-      zlog (NULL, LOG_ERR, "%s:%i F_SETFL error: %s",
-            __FUNCTION__, __LINE__, safe_strerror (errno));
-      return -1;
-    }
-  return 0;
-}
-
-int
-set_netlink_nonblocking (struct nlsock *nl, int *flags)
-{
-  /* Restore socket flags for nonblocking I/O */
-  *flags |= O_NONBLOCK;
-  if (fcntl (nl->sock, F_SETFL, *flags) < 0)
-    {
-      zlog (NULL, LOG_ERR, "%s:%i F_SETFL error: %s",
-            __FUNCTION__, __LINE__, safe_strerror (errno));
-      return -1;
-    }
-  return 0;
-}
-
 /* Get type specified information from netlink. */
 static int
 netlink_request (int family, int type, struct nlsock *nl)
@@ -343,6 +297,7 @@ netlink_parse_info (int (*filter) (struct sockaddr_nl *, struct nlmsghdr *),
             continue;
           if (errno == EWOULDBLOCK || errno == EAGAIN)
             break;
+
           zlog (NULL, LOG_ERR, "%s recvmsg overrun: %s",
 	  	nl->name, safe_strerror(errno));
           continue;
@@ -1110,18 +1065,6 @@ int
 interface_lookup_netlink (void)
 {
   int ret;
-  int flags;
-  int snb_ret;
-
-  /* 
-   * Change netlink socket flags to blocking to ensure we get 
-   * a reply via nelink_parse_info
-   */
-  snb_ret = set_netlink_blocking (&netlink_cmd, &flags);
-  if (snb_ret < 0)
-    zlog (NULL, LOG_WARNING,
-          "%s:%i Warning: Could not set netlink socket to blocking.",
-          __FUNCTION__, __LINE__);
 
   /* Get interface information. */
   ret = netlink_request (AF_PACKET, RTM_GETLINK, &netlink_cmd);
@@ -1149,9 +1092,6 @@ interface_lookup_netlink (void)
     return ret;
 #endif /* HAVE_IPV6 */
 
-  /* restore socket flags */
-  if (snb_ret == 0)
-    set_netlink_nonblocking (&netlink_cmd, &flags);
   return 0;
 }
 
@@ -1161,18 +1101,6 @@ int
 netlink_route_read (void)
 {
   int ret;
-  int flags;
-  int snb_ret;
-
-  /* 
-   * Change netlink socket flags to blocking to ensure we get 
-   * a reply via nelink_parse_info
-   */
-  snb_ret = set_netlink_blocking (&netlink_cmd, &flags);
-  if (snb_ret < 0)
-    zlog (NULL, LOG_WARNING,
-          "%s:%i Warning: Could not set netlink socket to blocking.",
-          __FUNCTION__, __LINE__);
 
   /* Get IPv4 routing table. */
   ret = netlink_request (AF_INET, RTM_GETROUTE, &netlink_cmd);
@@ -1192,9 +1120,6 @@ netlink_route_read (void)
     return ret;
 #endif /* HAVE_IPV6 */
 
-  /* restore flags */
-  if (snb_ret == 0)
-    set_netlink_nonblocking (&netlink_cmd, &flags);
   return 0;
 }
 
@@ -1277,8 +1202,6 @@ netlink_talk (struct nlmsghdr *n, struct nlsock *nl)
   struct sockaddr_nl snl;
   struct iovec iov = { (void *) n, n->nlmsg_len };
   struct msghdr msg = { (void *) &snl, sizeof snl, &iov, 1, NULL, 0, 0 };
-  int flags = 0;
-  int snb_ret;
   int save_errno;
 
   memset (&snl, 0, sizeof snl);
@@ -1309,27 +1232,12 @@ netlink_talk (struct nlmsghdr *n, struct nlsock *nl)
       return -1;
     }
 
-  /* 
-   * Change socket flags for blocking I/O. 
-   * This ensures we wait for a reply in netlink_parse_info().
-   */
-  snb_ret = set_netlink_blocking (nl, &flags);
-  if (snb_ret < 0)
-    zlog (NULL, LOG_WARNING,
-          "%s:%i Warning: Could not set netlink socket to blocking.",
-          __FUNCTION__, __LINE__);
 
   /* 
    * Get reply from netlink socket. 
    * The reply should either be an acknowlegement or an error.
    */
-  status = netlink_parse_info (netlink_talk_filter, nl);
-
-  /* Restore socket flags for nonblocking I/O */
-  if (snb_ret == 0)
-    set_netlink_nonblocking (nl, &flags);
-
-  return status;
+  return netlink_parse_info (netlink_talk_filter, nl);
 }
 
 /* Routing table change via netlink interface. */
@@ -1997,6 +1905,15 @@ kernel_init (void)
   /* Register kernel socket. */
   if (netlink.sock > 0)
     {
+      /* Only want non-blocking on the netlink event socket */
+      if (fcntl (netlink.sock, F_SETFL, O_NONBLOCK) < 0)
+	zlog (NULL, LOG_ERR, "Can't set %s socket flags: %s", netlink.name,
+		safe_strerror (errno));
+
+      /* Set receive buffer size if it's set from command line */
+      if (nl_rcvbufsize)
+	netlink_recvbuf (&netlink, nl_rcvbufsize);
+
       netlink_install_filter (netlink.sock, netlink_cmd.snl.nl_pid);
       thread_add_read (zebrad.master, kernel_read, NULL, netlink.sock);
     }