sm-notify: IPv6 support in reserved port binding in smn_create_socket()

[nfs-utils.git] / utils / statd / sm-notify.c

diff --git a/utils/statd/sm-notify.c b/utils/statd/sm-notify.c
index 462ba7987fef96036ba79f7662694787e37fac76..928d1c56f03bff687ec90adef071d78a0313720b 100644 (file)
--- a/utils/statd/sm-notify.c
+++ b/utils/statd/sm-notify.c
@@ -49,6 +49,7 @@ struct nsm_host {
 
 static char            nsm_hostname[256];
 static int             nsm_state;
+static int             nsm_family = AF_INET;
 static int             opt_debug = 0;
 static _Bool           opt_update_state = true;
 static unsigned int    opt_max_retry = 15 * 60;
@@ -141,6 +142,99 @@ smn_get_host(const char *hostname,
        return 1;
 }
 
+#ifdef IPV6_SUPPORTED
+static int smn_socket(void)
+{
+       int sock;
+
+       /*
+        * Use an AF_INET socket if IPv6 is disabled on the
+        * local system.
+        */
+       sock = socket(AF_INET6, SOCK_DGRAM, 0);
+       if (sock == -1) {
+               if (errno != EAFNOSUPPORT) {
+                       xlog(L_ERROR, "Failed to create RPC socket: %m");
+                       return -1;
+               }
+               sock = socket(AF_INET, SOCK_DGRAM, 0);
+               if (sock < 0) {
+                       xlog(L_ERROR, "Failed to create RPC socket: %m");
+                       return -1;
+               }
+       } else
+               nsm_family = AF_INET6;
+
+       if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1) {
+               xlog(L_ERROR, "fcntl(3) on RPC socket failed: %m");
+               goto out_close;
+       }
+
+       /*
+        * TI-RPC over IPv6 (udp6/tcp6) does not handle IPv4.  However,
+        * since sm-notify open-codes all of its RPC support, it can
+        * use a single socket and let the local network stack provide
+        * the correct mapping between address families automatically.
+        * This is the same thing that is done in the kernel.
+        */
+       if (nsm_family == AF_INET6) {
+               const int zero = 0;
+               socklen_t zerolen = (socklen_t)sizeof(zero);
+
+               if (setsockopt(sock, SOL_IPV6, IPV6_V6ONLY,
+                                       (char *)&zero, zerolen) == -1) {
+                       xlog(L_ERROR, "setsockopt(3) on RPC socket failed: %m");
+                       goto out_close;
+               }
+       }
+
+       return sock;
+
+out_close:
+       (void)close(sock);
+       return -1;
+}
+#else  /* !IPV6_SUPPORTED */
+static int smn_socket(void)
+{
+       int sock;
+
+       sock = socket(AF_INET, SOCK_DGRAM, 0);
+       if (sock == -1) {
+               xlog(L_ERROR, "Failed to create RPC socket: %m");
+               return -1;
+       }
+
+       if (fcntl(sock, F_SETFL, O_NONBLOCK) == -1) {
+               xlog(L_ERROR, "fcntl(3) on RPC socket failed: %m");
+               (void)close(sock);
+               return -1;
+       }
+
+       return sock;
+}
+#endif /* !IPV6_SUPPORTED */
+
+#ifdef HAVE_LIBTIRPC
+static int
+smn_bindresvport(int sock, struct sockaddr *sap)
+{
+       return bindresvport_sa(sock, sap);
+}
+
+#else  /* !HAVE_LIBTIRPC */
+static int
+smn_bindresvport(int sock, struct sockaddr *sap)
+{
+       if (sap->sa_family != AF_INET) {
+               errno = EAFNOSUPPORT;
+               return -1;
+       }
+
+       return bindresvport(sock, (struct sockaddr_in *)(char *)sap);
+}
+#endif /* !HAVE_LIBTIRPC */
+
 /*
  * Prepare a socket for sending RPC requests
  *
@@ -155,12 +249,9 @@ smn_create_socket(const char *srcaddr, const uint16_t srcport)
        int sock, retry_cnt = 0;
 
 retry:
-       sock = socket(AF_INET, SOCK_DGRAM, 0);
-       if (sock < 0) {
-               xlog(L_ERROR, "Failed to create RPC socket: %m");
+       sock = smn_socket();
+       if (sock == -1)
                return -1;
-       }
-       fcntl(sock, F_SETFL, O_NONBLOCK);
 
        memset(&address, 0, sizeof(address));
        local_addr->sa_family = AF_INET;        /* Default to IPv4 */
@@ -194,7 +285,14 @@ retry:
        } else {
                struct servent *se;
                struct sockaddr_in *sin = (struct sockaddr_in *)local_addr;
-               (void) bindresvport(sock, sin);
+
+               if (smn_bindresvport(sock, local_addr) == -1) {
+                       xlog(L_ERROR,
+                               "bindresvport on RPC socket failed: %m");
+                       (void)close(sock);
+                       return -1;
+               }
+
                /* try to avoid known ports */
                se = getservbyport(sin->sin_port, "udp");
                if (se && retry_cnt < 100) {