[zebra:linux] clean up blocking setting of netlink sockets
2008-08-16 Stephen Hemminger <stephen.hemminger@vyatta.com>
* zebra/rt_netlink.c: This change removes the overhead of twiddling
the socket twice on every route change. The netlink support has
two sockets, one is used for request/response and should always
block. The other is used for asynchronous notification and should
always be non-blocking.
Signed-off-by: Paul Jakma <paul@quagga.net>
diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index 592dfe2..fe55d43 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -130,14 +130,6 @@
return -1;
}
- ret = fcntl (sock, F_SETFL, O_NONBLOCK);
- if (ret < 0)
- {
- zlog (NULL, LOG_ERR, "Can't set %s socket flags: %s", nl->name,
- safe_strerror (errno));
- close (sock);
- return -1;
- }
/* Set receive buffer size if it's set from command line */
if (nl_rcvbufsize)
@@ -221,41 +213,6 @@
return ret;
}
-static 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;
-}
-
-static 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)
@@ -1098,18 +1055,6 @@
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);
@@ -1137,9 +1082,6 @@
return ret;
#endif /* HAVE_IPV6 */
- /* restore socket flags */
- if (snb_ret == 0)
- set_netlink_nonblocking (&netlink_cmd, &flags);
return 0;
}
@@ -1149,18 +1091,6 @@
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);
@@ -1180,9 +1110,6 @@
return ret;
#endif /* HAVE_IPV6 */
- /* restore flags */
- if (snb_ret == 0)
- set_netlink_nonblocking (&netlink_cmd, &flags);
return 0;
}
@@ -1265,8 +1192,6 @@
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);
@@ -1297,27 +1222,12 @@
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. */
@@ -1983,6 +1893,11 @@
/* 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));
+
netlink_install_filter (netlink.sock, netlink_cmd.snl.nl_pid);
thread_add_read (zebrad.master, kernel_read, NULL, netlink.sock);
}