Merge pull request #10680 from FRRouting/mergify/bp/dev/8.2/pr-10667

Bufsize (backport #10667)

doc/user/zebra.rst

@@ -78,6 +78,11 @@ Besides the common invocation options (:ref:`common-invocation-options`), the
    protocols about route installation/update on ack received from
    the linux kernel or from offload notification.
 
+.. option:: -s <SIZE>, --nl-bufsize <SIZE>
+
+   Allow zebra to modify the default receive buffer size to SIZE
+   in bytes.  Under *BSD only the -s option is available.
+
 .. _interface-commands:
 
 Configuration Addresses behaviour

zebra/kernel_netlink.c

@@ -154,7 +154,6 @@ static const struct message rttype_str[] = {{RTN_UNSPEC, "none"},
 					    {0}};
 
 extern struct thread_master *master;
-extern uint32_t nl_rcvbufsize;
 
 extern struct zebra_privs_t zserv_privs;
 
@@ -251,12 +250,11 @@ static int netlink_recvbuf(struct nlsock *nl, uint32_t newsize)
 	/* Try force option (linux >= 2.6.14) and fall back to normal set */
 	frr_with_privs(&zserv_privs) {
 		ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUFFORCE,
-				 &nl_rcvbufsize,
-				 sizeof(nl_rcvbufsize));
+				 &rcvbufsize, sizeof(rcvbufsize));
 	}
 	if (ret < 0)
-		ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF,
-				 &nl_rcvbufsize, sizeof(nl_rcvbufsize));
+		ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &rcvbufsize,
+				 sizeof(rcvbufsize));
 	if (ret < 0) {
 		flog_err_sys(EC_LIB_SOCKET,
 			     "Can't set %s receive buffer size: %s", nl->name,
@@ -1624,11 +1622,11 @@ void kernel_init(struct zebra_ns *zns)
 			 errno);
 
 	/* Set receive buffer size if it's set from command line */
-	if (nl_rcvbufsize) {
-		netlink_recvbuf(&zns->netlink, nl_rcvbufsize);
-		netlink_recvbuf(&zns->netlink_cmd, nl_rcvbufsize);
-		netlink_recvbuf(&zns->netlink_dplane_out, nl_rcvbufsize);
-		netlink_recvbuf(&zns->netlink_dplane_in, nl_rcvbufsize);
+	if (rcvbufsize) {
+		netlink_recvbuf(&zns->netlink, rcvbufsize);
+		netlink_recvbuf(&zns->netlink_cmd, rcvbufsize);
+		netlink_recvbuf(&zns->netlink_dplane_out, rcvbufsize);
+		netlink_recvbuf(&zns->netlink_dplane_in, rcvbufsize);
 	}
 
 	/* Set filter for inbound sockets, to exclude events we've generated

zebra/kernel_socket.c

@@ -1409,6 +1409,9 @@ static int kernel_read(struct thread *thread)
 /* Make routing socket. */
 static void routing_socket(struct zebra_ns *zns)
 {
+	uint32_t default_rcvbuf;
+	socklen_t optlen;
+
 	frr_with_privs(&zserv_privs) {
 		routing_sock = ns_socket(AF_ROUTE, SOCK_RAW, 0, zns->ns_id);
 
@@ -1443,6 +1446,23 @@ static void routing_socket(struct zebra_ns *zns)
 	/*if (fcntl (routing_sock, F_SETFL, O_NONBLOCK) < 0)
 	  zlog_warn ("Can't set O_NONBLOCK to routing socket");*/
 
+	/*
+	 * Attempt to set a more useful receive buffer size
+	 */
+	optlen = sizeof(default_rcvbuf);
+	if (getsockopt(routing_sock, SOL_SOCKET, SO_RCVBUF, &default_rcvbuf,
+		       &optlen) == -1)
+		flog_err_sys(EC_LIB_SOCKET,
+			     "routing_sock sockopt SOL_SOCKET SO_RCVBUF");
+	else {
+		for (; rcvbufsize > default_rcvbuf &&
+		       setsockopt(routing_sock, SOL_SOCKET, SO_RCVBUF,
+				  &rcvbufsize, sizeof(rcvbufsize)) == -1 &&
+		       errno == ENOBUFS;
+		     rcvbufsize /= 2)
+			;
+	}
+
 	/* kernel_read needs rewrite. */
 	thread_add_read(zrouter.master, kernel_read, NULL, routing_sock, NULL);
 }

zebra/main.c

@@ -78,10 +78,12 @@ int graceful_restart;
 
 bool v6_rr_semantics = false;
 
+/* Receive buffer size for kernel control sockets */
 #ifdef HAVE_NETLINK
-/* Receive buffer size for netlink socket */
-uint32_t nl_rcvbufsize = 4194304;
-#endif /* HAVE_NETLINK */
+uint32_t rcvbufsize = 4194304;
+#else
+uint32_t rcvbufsize = 128 * 1024;
+#endif
 
 #define OPTION_V6_RR_SEMANTICS 2000
 #define OPTION_ASIC_OFFLOAD    2001
@@ -294,9 +296,9 @@ int main(int argc, char **argv)
 	frr_preinit(&zebra_di, argc, argv);
 
 	frr_opt_add(
-		"baz:e:rK:"
+		"baz:e:rK:s:"
 #ifdef HAVE_NETLINK
-		"s:n"
+		"n"
 #endif
 		,
 		longopts,
@@ -308,9 +310,11 @@ int main(int argc, char **argv)
 		"  -K, --graceful_restart   Graceful restart at the kernel level, timer in seconds for expiration\n"
 		"  -A, --asic-offload       FRR is interacting with an asic underneath the linux kernel\n"
 #ifdef HAVE_NETLINK
-		"  -n, --vrfwnetns          Use NetNS as VRF backend\n"
 		"  -s, --nl-bufsize         Set netlink receive buffer size\n"
+		"  -n, --vrfwnetns          Use NetNS as VRF backend\n"
 		"      --v6-rr-semantics    Use v6 RR semantics\n"
+#else
+		"  -s,                      Set kernel socket receive buffer size\n"
 #endif /* HAVE_NETLINK */
 	);
 
@@ -359,10 +363,10 @@ int main(int argc, char **argv)
 		case 'K':
 			graceful_restart = atoi(optarg);
 			break;
-#ifdef HAVE_NETLINK
 		case 's':
-			nl_rcvbufsize = atoi(optarg);
+			rcvbufsize = atoi(optarg);
 			break;
+#ifdef HAVE_NETLINK
 		case 'n':
 			vrf_configure_backend(VRF_BACKEND_NETNS);
 			break;

zebra/zebra_router.h

@@ -214,6 +214,7 @@ struct zebra_router {
 #define GRACEFUL_RESTART_TIME 60
 
 extern struct zebra_router zrouter;
+extern uint32_t rcvbufsize;
 
 extern void zebra_router_init(bool asic_offload, bool notify_on_ack);
 extern void zebra_router_cleanup(void);