3411. [tuning] Use IPV6_USE_MIN_MTU or equivalent with TCP in addition ...

Squashed commit of the following:

commit bcbe9ae7a99e1f7f4236a22739a793b51ace8684
Author: Mark Andrews <marka@isc.org>
Date:   Wed Oct 31 15:10:53 2012 +1100

    Use IPV6_USE_MIN_MTU for TCP as well as UDP

diff --git a/CHANGES b/CHANGES
index 9ea3a70191d52cb0459059072671fb1147e5b6c8..becaa95aed4d927c40b6ce9ba1d145f018ba9e2c 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3411.  [tuning]        Use IPV6_USE_MIN_MTU or equivalent with TCP in addition
+                       to UDP. [RT #31690]
+
 3410.  [bug]           Addressed Coverity warnings. [RT #31626]
 
 3409.  [contrib]       contrib/dane/mkdane.sh: Tool to generate TLSA RR's

diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index ffe7e02f5fcb1c3758b7fb58f6cecc7c273066e8..794374ee618879e1fa2e2c5a6d686b86f9f82acd 100644 (file)
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -2262,6 +2262,28 @@ clear_bsdcompat(void) {
 }
 #endif
 
+static void
+use_min_mtu(isc__socket_t *sock) {
+#ifdef IPV6_USE_MIN_MTU
+       /* use minimum MTU */
+       if (sock->pf == AF_INET6) {
+               int on = 1;
+               (void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
+                               (void *)&on, sizeof(on));
+       }
+#endif
+#if defined(IPV6_MTU)
+       /*
+        * Use minimum MTU on IPv6 sockets.
+        */
+       if (sock->pf == AF_INET6) {
+               int mtu = 1280;
+               (void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_MTU,
+                                &mtu, sizeof(mtu));
+       }
+#endif
+}
+
 static isc_result_t
 opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
           isc__socket_t *dup_socket)
@@ -2270,7 +2292,7 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
        char strbuf[ISC_STRERRORSIZE];
        const char *err = "socket";
        int tries = 0;
-#if defined(USE_CMSG) || defined(SO_BSDCOMPAT)
+#if defined(USE_CMSG) || defined(SO_BSDCOMPAT) || defined(SO_NOSIGPIPE)
        int on = 1;
 #endif
 #if defined(SO_RCVBUF)
@@ -2426,6 +2448,11 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
        }
 #endif
 
+       /*
+        * Use minimum mtu if possible.
+        */
+       use_min_mtu(sock);
+
 #if defined(USE_CMSG) || defined(SO_RCVBUF)
        if (sock->type == isc_sockettype_udp) {
 
@@ -2490,32 +2517,6 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
                }
 #endif /* IPV6_RECVPKTINFO */
 #endif /* ISC_PLATFORM_HAVEIN6PKTINFO */
-#ifdef IPV6_USE_MIN_MTU        /* RFC 3542, not too common yet*/
-               /* use minimum MTU */
-               if (sock->pf == AF_INET6 &&
-                   setsockopt(sock->fd, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
-                              (void *)&on, sizeof(on)) < 0) {
-                       isc__strerror(errno, strbuf, sizeof(strbuf));
-                       UNEXPECTED_ERROR(__FILE__, __LINE__,
-                                        "setsockopt(%d, IPV6_USE_MIN_MTU) "
-                                        "%s: %s", sock->fd,
-                                        isc_msgcat_get(isc_msgcat,
-                                                       ISC_MSGSET_GENERAL,
-                                                       ISC_MSG_FAILED,
-                                                       "failed"),
-                                        strbuf);
-               }
-#endif
-#if defined(IPV6_MTU)
-               /*
-                * Use minimum MTU on IPv6 sockets.
-                */
-               if (sock->pf == AF_INET6) {
-                       int mtu = 1280;
-                       (void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_MTU,
-                                        &mtu, sizeof(mtu));
-               }
-#endif
 #if defined(IPV6_MTU_DISCOVER) && defined(IPV6_PMTUDISC_DONT)
                /*
                 * Turn off Path MTU discovery on IPv6/UDP sockets.
@@ -3312,6 +3313,11 @@ internal_accept(isc_task_t *me, isc_event_t *ev) {
                NEWCONNSOCK(dev)->bound = 1;
                NEWCONNSOCK(dev)->connected = 1;
 
+               /*
+                * Use minimum mtu if possible.
+                */
+               use_min_mtu(NEWCONNSOCK(dev));
+
                /*
                 * Save away the remote address
                 */

diff --git a/lib/isc/win32/socket.c b/lib/isc/win32/socket.c
index ffcefb0606c83ad797dd0f9b9da3879c4a86d953..1803de4f7bd11284b5e02a5f0ed9bcf408a27c54 100644 (file)
--- a/lib/isc/win32/socket.c
+++ b/lib/isc/win32/socket.c
@@ -1431,6 +1431,18 @@ startio_send(isc_socket_t *sock, isc_socketevent_t *dev, int *nbytes,
        return (status);
 }
 
+static void
+use_min_mtu(isc__socket_t *sock) {
+#ifdef IPV6_USE_MIN_MTU
+       /* use minimum MTU */
+       if (sock->pf == AF_INET6) {
+               int on = 1;
+               (void)setsockopt(sock->fd, IPPROTO_IPV6, IPV6_USE_MIN_MTU,
+                               (void *)&on, sizeof(on));
+       }
+#endif
+}
+
 static isc_result_t
 allocate_socket(isc_socketmgr_t *manager, isc_sockettype_t type,
                isc_socket_t **socketp) {
@@ -1737,6 +1749,10 @@ socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
                return (result);
        }
 
+       /*
+        * Use minimum mtu if possible.
+        */
+       use_min_mtu(sock);
 
 #if defined(USE_CMSG) || defined(SO_RCVBUF)
        if (type == isc_sockettype_udp) {
@@ -1774,14 +1790,6 @@ socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
                                         strbuf);
                }
 #endif /* IPV6_RECVPKTINFO */
-#ifdef IPV6_USE_MIN_MTU        /*2292bis, not too common yet*/
-               /* use minimum MTU */
-               if (pf == AF_INET6) {
-                       (void)setsockopt(sock->fd, IPPROTO_IPV6,
-                                        IPV6_USE_MIN_MTU,
-                                        (char *)&on, sizeof(on));
-               }
-#endif
 #endif /* ISC_PLATFORM_HAVEIPV6 */
 #endif /* defined(USE_CMSG) */
 
@@ -2068,6 +2076,11 @@ internal_accept(isc_socket_t *sock, IoCompletionInfo *lpo, int accept_errno) {
        result = make_nonblock(adev->newsocket->fd);
        INSIST(result == ISC_R_SUCCESS);
 
+       /*
+        * Use minimum mtu if possible.
+        */
+       use_min_mtu(adev->newsocket);
+
        INSIST(setsockopt(nsock->fd, SOL_SOCKET, SO_UPDATE_ACCEPT_CONTEXT,
                          (char *)&sock->fd, sizeof(sock->fd)) == 0);