X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=support%2Fnfs%2Fsvc_create.c;h=b3f75edc2f9608577da0ea5734011d719c827bc5;hp=59ba505b48bfc2adc243de2eb97c259220c382d3;hb=656028f9925f5817c5a37565d27159973db84ec3;hpb=1296be71ebae4c0d7da61cc1077d97562d3bc549

diff --git a/support/nfs/svc_create.c b/support/nfs/svc_create.c
index 59ba505..b3f75ed 100644
--- a/support/nfs/svc_create.c
+++ b/support/nfs/svc_create.c
@@ -27,6 +27,7 @@
 #include <memory.h>
 #include <signal.h>
 #include <unistd.h>
+#include <errno.h>
 #include <netdb.h>
 
 #include <netinet/in.h>
@@ -41,11 +42,68 @@
 #include "tcpwrapper.h"
 #endif
 
+#include "sockaddr.h"
 #include "rpcmisc.h"
 #include "xlog.h"
 
 #ifdef HAVE_LIBTIRPC
 
+#define SVC_CREATE_XPRT_CACHE_SIZE	(8)
+static SVCXPRT *svc_create_xprt_cache[SVC_CREATE_XPRT_CACHE_SIZE] = { NULL, };
+
+/*
+ * Cache an SVC xprt, in case there are more programs or versions to
+ * register against it.
+ */
+static void
+svc_create_cache_xprt(SVCXPRT *xprt)
+{
+	unsigned int i;
+
+	/* Check if we've already got this one... */
+	for (i = 0; i < SVC_CREATE_XPRT_CACHE_SIZE; i++)
+		if (svc_create_xprt_cache[i] == xprt)
+			return;
+
+	/* No, we don't.  Cache it. */
+	for (i = 0; i < SVC_CREATE_XPRT_CACHE_SIZE; i++)
+		if (svc_create_xprt_cache[i] == NULL) {
+			svc_create_xprt_cache[i] = xprt;
+			return;
+		}
+
+	xlog(L_ERROR, "%s: Failed to cache an xprt", __func__);
+}
+
+/*
+ * Find a previously cached SVC xprt structure with the given bind address
+ * and transport semantics.
+ *
+ * Returns pointer to a cached SVC xprt.
+ *
+ * If no matching SVC XPRT can be found, NULL is returned.
+ */
+static SVCXPRT *
+svc_create_find_xprt(const struct sockaddr *bindaddr, const struct netconfig *nconf)
+{
+	unsigned int i;
+
+	for (i = 0; i < SVC_CREATE_XPRT_CACHE_SIZE; i++) {
+		SVCXPRT *xprt = svc_create_xprt_cache[i];
+		struct sockaddr *sap;
+
+		if (xprt == NULL)
+			continue;
+		if (strcmp(nconf->nc_netid, xprt->xp_netid) != 0)
+			continue;
+		sap = (struct sockaddr *)xprt->xp_ltaddr.buf;
+		if (!nfs_compare_sockaddr(bindaddr, sap))
+			continue;
+		return xprt;
+	}
+	return NULL;
+}
+
 /*
  * Set up an appropriate bind address, given @port and @nconf.
  *
@@ -98,17 +156,113 @@ svc_create_bindaddr(struct netconfig *nconf, const uint16_t port)
 	return ai;
 }
 
+/*
+ * Create a listener socket on a specific bindaddr, and set
+ * special socket options to allow it to share the same port
+ * as other listeners.
+ *
+ * Returns an open, bound, and possibly listening network
+ * socket on success.
+ *
+ * Otherwise returns -1 if some error occurs.
+ */
+static int
+svc_create_sock(const struct sockaddr *sap, socklen_t salen,
+		struct netconfig *nconf)
+{
+	int fd, type, protocol;
+	int one = 1;
+
+	switch(nconf->nc_semantics) {
+	case NC_TPI_CLTS:
+		type = SOCK_DGRAM;
+		break;
+	case NC_TPI_COTS_ORD:
+		type = SOCK_STREAM;
+		break;
+	default:
+		xlog(D_GENERAL, "%s: Unrecognized bind address semantics: %u",
+			__func__, nconf->nc_semantics);
+		return -1;
+	}
+
+	if (strcmp(nconf->nc_proto, NC_UDP) == 0)
+		protocol = (int)IPPROTO_UDP;
+	else if (strcmp(nconf->nc_proto, NC_TCP) == 0)
+		protocol = (int)IPPROTO_TCP;
+	else {
+		xlog(D_GENERAL, "%s: Unrecognized bind address protocol: %s",
+			__func__, nconf->nc_proto);
+		return -1;
+	}
+
+	fd = socket((int)sap->sa_family, type, protocol);
+	if (fd == -1) {
+		xlog(L_ERROR, "Could not make a socket: (%d) %m",
+			errno);
+		return -1;
+	}
+
+#ifdef IPV6_SUPPORTED
+	if (sap->sa_family == AF_INET6) {
+		if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
+				&one, sizeof(one)) == -1) {
+			xlog(L_ERROR, "Failed to set IPV6_V6ONLY: (%d) %m",
+				errno);
+			(void)close(fd);
+			return -1;
+		}
+	}
+#endif	/* IPV6_SUPPORTED */
+
+	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
+		       &one, sizeof(one)) == -1) {
+		xlog(L_ERROR, "Failed to set SO_REUSEADDR: (%d) %m",
+			errno);
+		(void)close(fd);
+		return -1;
+	}
+
+	if (bind(fd, sap, salen) == -1) {
+		xlog(L_ERROR, "Could not bind socket: (%d) %m",
+			errno);
+		(void)close(fd);
+		return -1;
+	}
+
+	if (nconf->nc_semantics == NC_TPI_COTS_ORD)
+		if (listen(fd, SOMAXCONN) == -1) {
+			xlog(L_ERROR, "Could not listen on socket: (%d) %m",
+				errno);
+			(void)close(fd);
+			return -1;
+		}
+
+	return fd;
+}
+
+/*
+ * The simple case is allowing the TI-RPC library to create a
+ * transport itself, given just the bind address and transport
+ * semantics.
+ *
+ * Our local xprt cache is ignored in this path, since the
+ * caller is not interested in sharing listeners or ports, and
+ * the library automatically avoids ports already in use.
+ *
+ * Returns the count of started listeners (one or zero).
+ */
 static unsigned int
-svc_create_nconf(const char *name, const rpcprog_t program,
+svc_create_nconf_rand_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 netconfig *nconf)
 {
 	struct t_bind bindaddr;
 	struct addrinfo *ai;
 	SVCXPRT	*xprt;
 
-	ai = svc_create_bindaddr(nconf, port);
+	ai = svc_create_bindaddr(nconf, 0);
 	if (ai == NULL)
 		return 0;
 
@@ -119,7 +273,7 @@ svc_create_nconf(const char *name, const rpcprog_t program,
 	freeaddrinfo(ai);
 	if (xprt == NULL) {
 		xlog(D_GENERAL, "Failed to create listener xprt "
-				"(%s, %u, %s)", name, version, nconf->nc_netid);
+			"(%s, %u, %s)", name, version, nconf->nc_netid);
 		return 0;
 	}
 
@@ -133,6 +287,93 @@ svc_create_nconf(const char *name, const rpcprog_t program,
 	return 1;
 }
 
+/*
+ * 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);
+}
+
 /**
  * nfs_svc_create - start up RPC svc listeners
  * @name: C string containing name of new service
@@ -145,8 +386,7 @@ svc_create_nconf(const char *name, const rpcprog_t program,
  * the RPC dispatcher.  Returns the number of started network transports.
  */
 unsigned int
-nfs_svc_create(__attribute__((unused)) char *name,
-		const rpcprog_t program, const rpcvers_t version,
+nfs_svc_create(char *name, const rpcprog_t program, const rpcvers_t version,
 		void (*dispatch)(struct svc_req *, SVCXPRT *),
 		const uint16_t port)
 {