gluster: IPv6 single stack support

Summary:
- This diff changes all locations in the code to prefer inet6 family
  instead of inet.  This will allow change GlusterFS to operate
  via IPv6 instead of IPv4 for all internal operations while still
  being able to serve (FUSE or NFS) clients via IPv4.
- The changes apply to NFS as well.
- This diff ports D1892990, D1897341 & D1896522 to the 3.8 branch.

Test Plan: Prove tests!

Reviewers: dph, rwareing

Signed-off-by: Shreyas Siravara <sshreyas@fb.com>

Change-Id: I34fdaaeb33c194782255625e00616faf75d60c33
Reviewed-on: http://review.gluster.org/16059
Reviewed-by: Shreyas Siravara <sshreyas@fb.com>
Tested-by: Shreyas Siravara <sshreyas@fb.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

5 files changed, 131 insertions, 3 deletions

diff --git a/rpc/rpc-lib/src/rpc-transport.c b/rpc/rpc-lib/src/rpc-transport.c
index 22324fb9994..1bae2eddfca 100644
--- a/rpc/rpc-lib/src/rpc-transport.c
+++ b/rpc/rpc-lib/src/rpc-transport.c
@@ -672,6 +672,11 @@ rpc_transport_inet_options_build (dict_t **options, const char *hostname,
         dict_t          *dict = NULL;
         char            *host = NULL;
         int             ret = -1;
+#ifdef IPV6_DEFAULT
+        char            *addr_family = "inet6";
+#else
+        char            *addr_family = "inet";
+#endif
 
         GF_ASSERT (options);
         GF_ASSERT (hostname);
@@ -701,6 +706,13 @@ rpc_transport_inet_options_build (dict_t **options, const char *hostname,
                 goto out;
         }
 
+        ret = dict_set_str (dict, "address-family", addr_family);
+        if (ret) {
+                gf_log (THIS->name, GF_LOG_WARNING,
+                        "failed to set address-family to %s", addr_family);
+                goto out;
+        }
+
         ret = dict_set_str (dict, "transport-type", "socket");
         if (ret) {
                 gf_log (THIS->name, GF_LOG_WARNING,
diff --git a/rpc/rpc-lib/src/rpcsvc.c b/rpc/rpc-lib/src/rpcsvc.c
index f07e745a4b3..9dc3bff427c 100644
--- a/rpc/rpc-lib/src/rpcsvc.c
+++ b/rpc/rpc-lib/src/rpcsvc.c
@@ -37,6 +37,10 @@
 #include <stdarg.h>
 #include <stdio.h>
 
+#ifdef IPV6_DEFAULT
+#include <netconfig.h>
+#endif
+
 #include "xdr-rpcclnt.h"
 #include "glusterfs-acl.h"
 
@@ -1363,6 +1367,82 @@ rpcsvc_error_reply (rpcsvc_request_t *req)
         return rpcsvc_submit_generic (req, &dummyvec, 0, NULL, 0, NULL);
 }
 
+#ifdef IPV6_DEFAULT
+int
+rpcsvc_program_register_rpcbind6 (rpcsvc_program_t *newprog, uint32_t port)
+{
+        const int IP_BUF_LEN = 64;
+        char addr_buf[IP_BUF_LEN];
+
+        int err = 0;
+        bool_t success = 0;
+        struct netconfig *nc;
+        struct netbuf *nb;
+
+        if (!newprog) {
+                goto out;
+        }
+
+        nc = getnetconfigent ("tcp6");
+        if (!nc) {
+                err = -1;
+                goto out;
+        }
+
+
+        err = sprintf (addr_buf, "::.%d.%d", port >> 8 & 0xff,
+                       port & 0xff);
+        if (err < 0) {
+                err = -1;
+                goto out;
+        }
+
+        nb = uaddr2taddr (nc, addr_buf);
+        if (!nb) {
+                err = -1;
+                goto out;
+        }
+
+        success = rpcb_set (newprog->prognum, newprog->progver, nc, nb);
+        if (!success) {
+                gf_log (GF_RPCSVC, GF_LOG_ERROR, "Could not register the IPv6"
+                                                 " service with rpcbind");
+        }
+
+        err = 0;
+
+out:
+        return err;
+}
+
+int
+rpcsvc_program_unregister_rpcbind6 (rpcsvc_program_t *newprog)
+{
+        int err = 0;
+        bool_t success = 0;
+        struct netconfig *nc;
+
+        if (!newprog) {
+                goto out;
+        }
+
+        nc = getnetconfigent ("tcp6");
+        if (!nc) {
+                err = -1;
+                goto out;
+        }
+
+        success = rpcb_unset (newprog->prognum, newprog->progver, nc);
+        if (!success) {
+                gf_log (GF_RPCSVC, GF_LOG_ERROR, "Could not unregister the IPv6"
+                                                 " service with rpcbind");
+        }
+
+        err = 0;
+out:
+        return err;
+}
+#endif
 
 /* Register the program with the local portmapper service. */
 int
@@ -1527,7 +1607,14 @@ rpcsvc_program_unregister (rpcsvc_t *svc, rpcsvc_program_t *program)
                         " program failed");
                 goto out;
         }
-
+#ifdef IPV6_DEFAULT
+        ret = rpcsvc_program_unregister_rpcbind6 (program);
+        if (ret == -1) {
+                gf_log (GF_RPCSVC, GF_LOG_ERROR, "rpcbind (ipv6)"
+                        " unregistration of program failed");
+                goto out;
+        }
+#endif
         pthread_mutex_lock (&svc->rpclock);
         {
                 list_for_each_entry (prog, &svc->programs, program) {
diff --git a/rpc/rpc-lib/src/rpcsvc.h b/rpc/rpc-lib/src/rpcsvc.h
index 02e467e68a7..1032df03b0e 100644
--- a/rpc/rpc-lib/src/rpcsvc.h
+++ b/rpc/rpc-lib/src/rpcsvc.h
@@ -437,6 +437,11 @@ rpcsvc_listener_destroy (rpcsvc_listener_t *listener);
 extern int
 rpcsvc_program_register_portmap (rpcsvc_program_t *newprog, uint32_t port);
 
+#ifdef IPV6_DEFAULT
+extern int
+rpcsvc_program_register_rpcbind6 (rpcsvc_program_t *newprog, uint32_t port);
+#endif
+
 extern int
 rpcsvc_program_unregister_portmap (rpcsvc_program_t *newprog);
 
diff --git a/rpc/rpc-transport/socket/src/name.c b/rpc/rpc-transport/socket/src/name.c
index 0e34dc211fe..056eb790628 100644
--- a/rpc/rpc-transport/socket/src/name.c
+++ b/rpc/rpc-transport/socket/src/name.c
@@ -557,6 +557,14 @@ server_fill_address_family (rpc_transport_t *this, sa_family_t *sa_family)
         data_t  *address_family_data = NULL;
         int32_t  ret                 = -1;
 
+#ifdef IPV6_DEFAULT
+        char *addr_family            = "inet6";
+        sa_family_t default_family   = AF_INET6;
+#else
+        char *addr_family            = "inet";
+        sa_family_t default_family   = AF_INET;
+#endif
+
         GF_VALIDATE_OR_GOTO ("socket", sa_family, out);
 
         address_family_data = dict_get (this->options,
@@ -581,8 +589,9 @@ server_fill_address_family (rpc_transport_t *this, sa_family_t *sa_family)
                 }
         } else {
                 gf_log (this->name, GF_LOG_DEBUG,
-                        "option address-family not specified, defaulting to inet");
-                *sa_family = AF_INET;
+                        "option address-family not specified, "
+                        "defaulting to %s", addr_family);
+                *sa_family = default_family;
         }
 
         ret = 0;
diff --git a/rpc/rpc-transport/socket/src/socket.c b/rpc/rpc-transport/socket/src/socket.c
index 4244883a5db..bfcc01b73b7 100644
--- a/rpc/rpc-transport/socket/src/socket.c
+++ b/rpc/rpc-transport/socket/src/socket.c
@@ -3009,6 +3009,21 @@ socket_connect (rpc_transport_t *this, int port)
                         }
                 }
 
+                /* Make sure we are not vulnerable to someone setting
+                 * net.ipv6.bindv6only to 1 so that gluster services are
+                 * avalable over IPv4 & IPv6.
+                 */
+                int disable_v6only = 0;
+
+                if (setsockopt (priv->sock, IPPROTO_IPV6, IPV6_V6ONLY,
+                                (void *)&disable_v6only,
+                                sizeof (disable_v6only)) < 0) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                               "Error disabling sockopt IPV6_V6ONLY: \"%s\"",
+                               strerror (errno));
+                }
+
+
                 if (priv->nodelay && (sa_family != AF_UNIX)) {
                         ret = __socket_nodelay (priv->sock);