+/*
+ * If a port is specified on the command line, that port value will be
+ * the same for all listeners created here. Create each listener
+ * socket in advance and set SO_REUSEADDR, rather than allowing the
+ * RPC library to create the listeners for us on a randomly chosen
+ * port via svc_tli_create(RPC_ANYFD).
+ *
+ * Some callers want to listen for more than one RPC version using the
+ * same port number. For example, mountd could want to listen for MNT
+ * version 1, 2, and 3 requests. This means mountd must use the same
+ * set of listener sockets for multiple RPC versions, since, on one
+ * system, you can't have two listener sockets with the exact same
+ * bind address (and port) and transport protocol.
+ *
+ * To accomplish this, this function caches xprts as they are created.
+ * This cache is checked to see if a previously created xprt can be
+ * used, before creating a new xprt for this [program, version]. If
+ * there is a cached xprt with the same bindaddr and transport
+ * semantics, we simply register the new version with that xprt,
+ * rather than creating a fresh xprt for it.
+ *
+ * The xprt cache implemented here is local to a process. Two
+ * separate RPC daemons can not share a set of listeners.
+ *
+ * Returns the count of started listeners (one or zero).
+ */
+static unsigned int
+svc_create_nconf_fixed_port(const char *name, const rpcprog_t program,
+ const rpcvers_t version,
+ void (*dispatch)(struct svc_req *, SVCXPRT *),
+ const uint16_t port, struct netconfig *nconf)
+{
+ struct addrinfo *ai;
+ SVCXPRT *xprt;
+
+ ai = svc_create_bindaddr(nconf, port);
+ if (ai == NULL)
+ return 0;
+
+ xprt = svc_create_find_xprt(ai->ai_addr, nconf);
+ if (xprt == NULL) {
+ int fd;
+
+ fd = svc_create_sock(ai->ai_addr, ai->ai_addrlen, nconf);
+ if (fd == -1)
+ goto out_free;
+
+ xprt = svc_tli_create(fd, nconf, NULL, 0, 0);
+ if (xprt == NULL) {
+ xlog(D_GENERAL, "Failed to create listener xprt "
+ "(%s, %u, %s)", name, version, nconf->nc_netid);
+ (void)close(fd);
+ goto out_free;
+ }
+ }
+
+ if (!svc_reg(xprt, program, version, dispatch, nconf)) {
+ /* svc_reg(3) destroys @xprt in this case */
+ xlog(D_GENERAL, "Failed to register (%s, %u, %s)",
+ name, version, nconf->nc_netid);
+ goto out_free;
+ }
+
+ svc_create_cache_xprt(xprt);
+
+ freeaddrinfo(ai);
+ return 1;
+
+out_free:
+ freeaddrinfo(ai);
+ return 0;
+}
+
+static unsigned int
+svc_create_nconf(const char *name, const rpcprog_t program,
+ const rpcvers_t version,
+ void (*dispatch)(struct svc_req *, SVCXPRT *),
+ const uint16_t port, struct netconfig *nconf)
+{
+ if (port != 0)
+ return svc_create_nconf_fixed_port(name, program,
+ version, dispatch, port, nconf);
+
+ return svc_create_nconf_rand_port(name, program,
+ version, dispatch, nconf);
+}
+