diff options
Diffstat (limited to 'support/nfs/getport.c')
| -rw-r--r-- | support/nfs/getport.c | 1127 |
1 files changed, 1127 insertions, 0 deletions
diff --git a/support/nfs/getport.c b/support/nfs/getport.c new file mode 100644 index 0000000..813f7bf --- /dev/null +++ b/support/nfs/getport.c @@ -0,0 +1,1127 @@ +/* + * Provide a variety of APIs that query an rpcbind daemon to + * discover RPC service ports and allowed protocol version + * numbers. + * + * Copyright (C) 2008 Oracle Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 0211-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include <sys/types.h> +#include <sys/time.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> + +#include <sys/socket.h> +#include <netinet/in.h> +#include <netdb.h> +#include <arpa/inet.h> + +#include <rpc/rpc.h> +#include <rpc/pmap_prot.h> + +#ifdef HAVE_LIBTIRPC +#include <netconfig.h> +#include <rpc/rpcb_prot.h> +#endif + +#include "sockaddr.h" +#include "nfsrpc.h" +#include "nfslib.h" + +/* + * Try a local socket first to access the local rpcbind daemon + * + * Rpcbind's local socket service does not seem to be working. + * Disable this logic for now. + */ +#ifdef HAVE_LIBTIRPC +#undef NFS_GP_LOCAL +#else /* !HAVE_LIBTIRPC */ +#undef NFS_GP_LOCAL +#endif /* !HAVE_LIBTIRPC */ + +#ifdef HAVE_LIBTIRPC +static const rpcvers_t default_rpcb_version = RPCBVERS_4; +#else /* !HAVE_LIBTIRPC */ +static const rpcvers_t default_rpcb_version = PMAPVERS; +#endif /* !HAVE_LIBTIRPC */ + +/* + * Historical: Map TCP connect timeouts to timeout + * error code used by UDP. + */ +static void +nfs_gp_map_tcp_errorcodes(const unsigned short protocol) +{ + if (protocol != IPPROTO_TCP) + return; + + switch (rpc_createerr.cf_error.re_errno) { + case ETIMEDOUT: + rpc_createerr.cf_stat = RPC_TIMEDOUT; + break; + case ECONNREFUSED: + rpc_createerr.cf_stat = RPC_CANTRECV; + break; + } +} + +/* + * There's no easy way to tell how the local system's networking + * and rpcbind is configured (ie. whether we want to use IPv6 or + * IPv4 loopback to contact RPC services on the local host). We + * punt and simply try to look up "localhost". + * + * Returns TRUE on success. + */ +static int nfs_gp_loopback_address(struct sockaddr *sap, socklen_t *salen) +{ + struct addrinfo *gai_results; + int ret = 0; + + if (getaddrinfo("localhost", NULL, NULL, &gai_results)) + return 0; + + if (*salen >= gai_results->ai_addrlen) { + memcpy(sap, gai_results->ai_addr, + gai_results->ai_addrlen); + *salen = gai_results->ai_addrlen; + ret = 1; + } + + nfs_freeaddrinfo(gai_results); + return ret; +} + +/* + * Look up a network service in /etc/services and return the + * network-order port number of that service. + */ +static in_port_t nfs_gp_getservbyname(const char *service, + const unsigned short protocol) +{ + const struct addrinfo gai_hint = { + .ai_family = AF_INET, + .ai_protocol = protocol, + .ai_flags = AI_PASSIVE, + }; + struct addrinfo *gai_results; + const struct sockaddr_in *sin; + in_port_t port; + + if (getaddrinfo(NULL, service, &gai_hint, &gai_results) != 0) + return 0; + + sin = (const struct sockaddr_in *)gai_results->ai_addr; + port = sin->sin_port; + + nfs_freeaddrinfo(gai_results); + return port; +} + +/* + * Discover the port number that should be used to contact an + * rpcbind service. This will detect if the port has a local + * value that may have been set in /etc/services. + * + * Returns network byte-order port number of rpcbind service + * on this system. + */ +static in_port_t nfs_gp_get_rpcb_port(const unsigned short protocol) +{ + static const char *rpcb_netnametbl[] = { + "rpcbind", + "portmapper", + "sunrpc", + NULL, + }; + unsigned int i; + + for (i = 0; rpcb_netnametbl[i] != NULL; i++) { + in_port_t port; + + port = nfs_gp_getservbyname(rpcb_netnametbl[i], protocol); + if (port != 0) + return port; + } + + return (in_port_t)htons((uint16_t)PMAPPORT); +} + +/* + * Set up an RPC client for communicating with an rpcbind daemon at + * @sap over @transport with protocol version @version. + * + * Returns a pointer to a prepared RPC client if successful, and + * @timeout is initialized; caller must destroy a non-NULL returned RPC + * client. Otherwise returns NULL, and rpc_createerr.cf_stat is set to + * reflect the error. + */ +static CLIENT *nfs_gp_get_rpcbclient(struct sockaddr *sap, + const socklen_t salen, + const unsigned short transport, + const rpcvers_t version, + struct timeval *timeout) +{ + static const char *rpcb_pgmtbl[] = { + "rpcbind", + "portmap", + "portmapper", + "sunrpc", + NULL, + }; + rpcprog_t rpcb_prog = nfs_getrpcbyname(RPCBPROG, rpcb_pgmtbl); + CLIENT *clnt; + + nfs_set_port(sap, ntohs(nfs_gp_get_rpcb_port(transport))); + clnt = nfs_get_rpcclient(sap, salen, transport, rpcb_prog, + version, timeout); + nfs_gp_map_tcp_errorcodes(transport); + return clnt; +} + +/** + * nfs_get_proto - Convert a netid to an address family and protocol number + * @netid: C string containing a netid + * @family: OUT: address family + * @protocol: OUT: protocol number + * + * Returns 1 and fills in @protocol if the netid was recognized; + * otherwise zero is returned. + */ +#ifdef HAVE_LIBTIRPC +int +nfs_get_proto(const char *netid, sa_family_t *family, unsigned long *protocol) +{ + struct netconfig *nconf; + struct protoent *proto; + + /* + * IANA does not define a protocol number for rdma netids, + * since "rdma" is not an IP protocol. + */ + if (strcmp(netid, "rdma") == 0) { + *family = AF_INET; + *protocol = NFSPROTO_RDMA; + return 1; + } + if (strcmp(netid, "rdma6") == 0) { + *family = AF_INET6; + *protocol = NFSPROTO_RDMA; + return 1; + } + + nconf = getnetconfigent(netid); + if (nconf == NULL) + return 0; + + proto = getprotobyname(nconf->nc_proto); + if (proto == NULL) { + freenetconfigent(nconf); + return 0; + } + + *family = AF_UNSPEC; + if (strcmp(nconf->nc_protofmly, NC_INET) == 0) + *family = AF_INET; + if (strcmp(nconf->nc_protofmly, NC_INET6) == 0) + *family = AF_INET6; + freenetconfigent(nconf); + + *protocol = (unsigned long)proto->p_proto; + return 1; +} +#else /* !HAVE_LIBTIRPC */ +int +nfs_get_proto(const char *netid, sa_family_t *family, unsigned long *protocol) +{ + struct protoent *proto; + + /* + * IANA does not define a protocol number for rdma netids, + * since "rdma" is not an IP protocol. + */ + if (strcmp(netid, "rdma") == 0) { + *family = AF_INET; + *protocol = NFSPROTO_RDMA; + return 1; + } + + proto = getprotobyname(netid); + if (proto == NULL) + return 0; + + *family = AF_INET; + *protocol = (unsigned long)proto->p_proto; + return 1; +} +#endif /* !HAVE_LIBTIRPC */ + +/** + * nfs_get_netid - Convert a protocol family and protocol name to a netid + * @family: protocol family + * @protocol: protocol number + * + * One of the arguments passed when querying remote rpcbind services + * via rpcbind v3 or v4 is a netid string. This replaces the pm_prot + * field used in legacy PMAP_GETPORT calls. + * + * RFC 1833 says netids are not standard but rather defined on the local + * host. There are, however, standard definitions for nc_protofmly and + * nc_proto that can be used to derive a netid string on the local host, + * based on the contents of /etc/netconfig. + * + * Walk through the local netconfig database and grab the netid of the + * first entry that matches @family and @protocol and whose netid string + * fits in the provided buffer. + * + * Returns a '\0'-terminated string if successful. Caller must + * free the returned string. Otherwise NULL is returned, and + * rpc_createerr.cf_stat is set to reflect the error. + */ +#ifdef HAVE_LIBTIRPC +char *nfs_get_netid(const sa_family_t family, const unsigned long protocol) +{ + char *nc_protofmly, *nc_proto, *nc_netid; + struct netconfig *nconf; + struct protoent *proto; + void *handle; + + switch (family) { + case AF_LOCAL: + case AF_INET: + nc_protofmly = NC_INET; + break; + case AF_INET6: + nc_protofmly = NC_INET6; + break; + default: + goto out; + } + + proto = getprotobynumber(protocol); + if (proto == NULL) + goto out; + nc_proto = proto->p_name; + + handle = setnetconfig(); + while ((nconf = getnetconfig(handle)) != NULL) { + + if (nconf->nc_protofmly != NULL && + strcmp(nconf->nc_protofmly, nc_protofmly) != 0) + continue; + if (nconf->nc_proto != NULL && + strcmp(nconf->nc_proto, nc_proto) != 0) + continue; + + nc_netid = strdup(nconf->nc_netid); + endnetconfig(handle); + + if (nc_netid == NULL) + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + return nc_netid; + } + endnetconfig(handle); + +out: + rpc_createerr.cf_stat = RPC_UNKNOWNPROTO; + return NULL; +} +#else /* !HAVE_LIBTIRPC */ +char *nfs_get_netid(const sa_family_t family, const unsigned long protocol) +{ + struct protoent *proto; + char *netid; + + if (family != AF_INET) + goto out; + proto = getprotobynumber((int)protocol); + if (proto == NULL) + goto out; + + netid = strdup(proto->p_name); + if (netid == NULL) + rpc_createerr.cf_stat = RPC_SYSTEMERROR; + return netid; + +out: + rpc_createerr.cf_stat = RPC_UNKNOWNPROTO; + return NULL; +} +#endif /* !HAVE_LIBTIRPC */ + +/* + * Extract a port number from a universal address, and terminate the + * string in @addrstr just after the address part. + * + * Returns -1 if unsuccesful; otherwise a decoded port number (possibly 0) + * is returned. + */ +static int nfs_gp_universal_porthelper(char *addrstr) +{ + char *p, *endptr; + unsigned long portlo, porthi; + int port = -1; + + p = strrchr(addrstr, '.'); + if (p == NULL) + goto out; + portlo = strtoul(p + 1, &endptr, 10); + if (*endptr != '\0' || portlo > 255) + goto out; + *p = '\0'; + + p = strrchr(addrstr, '.'); + if (p == NULL) + goto out; + porthi = strtoul(p + 1, &endptr, 10); + if (*endptr != '\0' || porthi > 255) + goto out; + *p = '\0'; + port = (porthi << 8) | portlo; + +out: + return port; +} + +/** + * nfs_universal2port - extract port number from a "universal address" + * @uaddr: '\0'-terminated C string containing a universal address + * + * Universal addresses (defined in RFC 1833) are used when calling an + * rpcbind daemon via protocol versions 3 or 4.. + * + * Returns -1 if unsuccesful; otherwise a decoded port number (possibly 0) + * is returned. + */ +int nfs_universal2port(const char *uaddr) +{ + char *addrstr; + int port = -1; + + addrstr = strdup(uaddr); + if (addrstr != NULL) { + port = nfs_gp_universal_porthelper(addrstr); + free(addrstr); + } + return port; +} + +/** + * nfs_sockaddr2universal - convert a sockaddr to a "universal address" + * @sap: pointer to a socket address + * + * Universal addresses (defined in RFC 1833) are used when calling an + * rpcbind daemon via protocol versions 3 or 4.. + * + * Returns a '\0'-terminated string if successful; caller must free + * the returned string. Otherwise NULL is returned and + * rpc_createerr.cf_stat is set to reflect the error. + * + * inet_ntop(3) is used here, since getnameinfo(3) is not available + * in some earlier glibc releases, and we don't require support for + * scope IDs for universal addresses. + */ +char *nfs_sockaddr2universal(const struct sockaddr *sap) +{ + const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap; + const struct sockaddr_un *sun = (const struct sockaddr_un *)sap; + const struct sockaddr_in *sin = (const struct sockaddr_in *)sap; + char buf[INET6_ADDRSTRLEN + 8 /* for port information */]; + uint16_t port; + size_t count; + char *result; + int len; + + switch (sap->sa_family) { + case AF_LOCAL: + return strndup(sun->sun_path, sizeof(sun->sun_path)); + case AF_INET: + if (inet_ntop(AF_INET, (const void *)&sin->sin_addr.s_addr, + buf, (socklen_t)sizeof(buf)) == NULL) + goto out_err; + port = ntohs(sin->sin_port); + break; + case AF_INET6: + if (inet_ntop(AF_INET6, (const void *)&sin6->sin6_addr, + buf, (socklen_t)sizeof(buf)) == NULL) + goto out_err; + port = ntohs(sin6->sin6_port); + break; + default: + goto out_err; + } + + count = sizeof(buf) - strlen(buf); + len = snprintf(buf + strlen(buf), count, ".%u.%u", + (unsigned)(port >> 8), (unsigned)(port & 0xff)); + /* before glibc 2.0.6, snprintf(3) could return -1 */ + if (len < 0 || (size_t)len > count) + goto out_err; + + result = strdup(buf); + if (result != NULL) + return result; + +out_err: + rpc_createerr.cf_stat = RPC_N2AXLATEFAILURE; + return NULL; +} + +/* + * Send a NULL request to the indicated RPC service. + * + * Returns 1 if the service responded; otherwise 0; + */ +static int nfs_gp_ping(CLIENT *client, struct timeval timeout) +{ + enum clnt_stat status; + + status = CLNT_CALL(client, NULLPROC, + (xdrproc_t)xdr_void, NULL, + (xdrproc_t)xdr_void, NULL, + timeout); + + if (status != RPC_SUCCESS) { + rpc_createerr.cf_stat = status; + CLNT_GETERR(client, &rpc_createerr.cf_error); + } + return (int)(status == RPC_SUCCESS); +} + +#ifdef HAVE_LIBTIRPC + +/* + * Initialize the rpcb argument for a GETADDR request. + * + * Returns 1 if successful, and caller must free strings pointed + * to by r_netid and r_addr; otherwise 0. + */ +static int nfs_gp_init_rpcb_parms(const struct sockaddr *sap, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol, + struct rpcb *parms) +{ + char *netid, *addr; + + netid = nfs_get_netid(sap->sa_family, protocol); + if (netid == NULL) + return 0; + + addr = nfs_sockaddr2universal(sap); + if (addr == NULL) { + free(netid); + return 0; + } + + memset(parms, 0, sizeof(*parms)); + parms->r_prog = program; + parms->r_vers = version; + parms->r_netid = netid; + parms->r_addr = addr; + parms->r_owner = ""; + + return 1; +} + +static void nfs_gp_free_rpcb_parms(struct rpcb *parms) +{ + free(parms->r_netid); + free(parms->r_addr); +} + +/* + * Try rpcbind GETADDR via version 4. If that fails, try same + * request via version 3. + * + * Returns non-zero port number on success; otherwise returns + * zero. rpccreateerr is set to reflect the nature of the error. + */ +static unsigned short nfs_gp_rpcb_getaddr(CLIENT *client, + struct rpcb *parms, + struct timeval timeout) +{ + rpcvers_t rpcb_version; + struct rpc_err rpcerr; + int port = 0; + + for (rpcb_version = RPCBVERS_4; + rpcb_version >= RPCBVERS_3; + rpcb_version--) { + enum clnt_stat status; + char *uaddr = NULL; + + CLNT_CONTROL(client, CLSET_VERS, (void *)&rpcb_version); + status = CLNT_CALL(client, (rpcproc_t)RPCBPROC_GETADDR, + (xdrproc_t)xdr_rpcb, (void *)parms, + (xdrproc_t)xdr_wrapstring, (void *)&uaddr, + timeout); + + switch (status) { + case RPC_SUCCESS: + if ((uaddr == NULL) || (uaddr[0] == '\0')) { + rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED; + return 0; + } + + port = nfs_universal2port(uaddr); + xdr_free((xdrproc_t)xdr_wrapstring, (char *)&uaddr); + if (port == -1) { + rpc_createerr.cf_stat = RPC_N2AXLATEFAILURE; + return 0; + } + return (unsigned short)port; + case RPC_PROGVERSMISMATCH: + clnt_geterr(client, &rpcerr); + if (rpcerr.re_vers.low > RPCBVERS4) + return 0; + continue; + case RPC_PROCUNAVAIL: + case RPC_PROGUNAVAIL: + continue; + default: + /* Most likely RPC_TIMEDOUT or RPC_CANTRECV */ + rpc_createerr.cf_stat = status; + clnt_geterr(client, &rpc_createerr.cf_error); + return 0; + } + + } + + if (port == 0) { + rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED; + clnt_geterr(client, &rpc_createerr.cf_error); + } + return port; +} + +#endif /* HAVE_LIBTIRPC */ + +/* + * Try GETPORT request via rpcbind version 2. + * + * Returns non-zero port number on success; otherwise returns + * zero. rpccreateerr is set to reflect the nature of the error. + */ +static unsigned long nfs_gp_pmap_getport(CLIENT *client, + struct pmap *parms, + struct timeval timeout) +{ + enum clnt_stat status; + unsigned long port; + + status = CLNT_CALL(client, (rpcproc_t)PMAPPROC_GETPORT, + (xdrproc_t)xdr_pmap, (void *)parms, + (xdrproc_t)xdr_u_long, (void *)&port, + timeout); + + if (status != RPC_SUCCESS) { + rpc_createerr.cf_stat = status; + CLNT_GETERR(client, &rpc_createerr.cf_error); + port = 0; + } else if (port == 0) + rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED; + + return port; +} + +#ifdef HAVE_LIBTIRPC + +static unsigned short nfs_gp_getport_rpcb(CLIENT *client, + const struct sockaddr *sap, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol, + struct timeval timeout) +{ + unsigned short port = 0; + struct rpcb parms; + + if (nfs_gp_init_rpcb_parms(sap, program, version, + protocol, &parms) != 0) { + port = nfs_gp_rpcb_getaddr(client, &parms, timeout); + nfs_gp_free_rpcb_parms(&parms); + } + + return port; +} + +#endif /* HAVE_LIBTIRPC */ + +static unsigned long nfs_gp_getport_pmap(CLIENT *client, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol, + struct timeval timeout) +{ + struct pmap parms = { + .pm_prog = program, + .pm_vers = version, + .pm_prot = protocol, + }; + rpcvers_t pmap_version = PMAPVERS; + + CLNT_CONTROL(client, CLSET_VERS, (void *)&pmap_version); + return nfs_gp_pmap_getport(client, &parms, timeout); +} + +/* + * Try an AF_INET6 request via rpcbind v4/v3; try an AF_INET + * request via rpcbind v2. + * + * Returns non-zero port number on success; otherwise returns + * zero. rpccreateerr is set to reflect the nature of the error. + */ +static unsigned short nfs_gp_getport(CLIENT *client, + const struct sockaddr *sap, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol, + struct timeval timeout) +{ + switch (sap->sa_family) { +#ifdef HAVE_LIBTIRPC + case AF_INET6: + return nfs_gp_getport_rpcb(client, sap, program, + version, protocol, timeout); +#endif /* HAVE_LIBTIRPC */ + case AF_INET: + return nfs_gp_getport_pmap(client, program, version, + protocol, timeout); + } + + rpc_createerr.cf_stat = RPC_UNKNOWNADDR; + return 0; +} + +/** + * nfs_rpc_ping - Determine if RPC service is responding to requests + * @sap: pointer to address of server to query (port is already filled in) + * @salen: length of server address + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: requested IPPROTO_ value of transport protocol + * @timeout: pointer to request timeout (NULL means use default timeout) + * + * Returns 1 if the remote service responded without an error; otherwise + * zero. + */ +int nfs_rpc_ping(const struct sockaddr *sap, const socklen_t salen, + const rpcprog_t program, const rpcvers_t version, + const unsigned short protocol, const struct timeval *timeout) +{ + union nfs_sockaddr address; + struct sockaddr *saddr = &address.sa; + CLIENT *client; + struct timeval tout = { -1, 0 }; + int result = 0; + + if (timeout != NULL) + tout = *timeout; + + nfs_clear_rpc_createerr(); + + memcpy(saddr, sap, (size_t)salen); + client = nfs_get_rpcclient(saddr, salen, protocol, + program, version, &tout); + if (client != NULL) { + result = nfs_gp_ping(client, tout); + nfs_gp_map_tcp_errorcodes(protocol); + CLNT_DESTROY(client); + } + + return result; +} + +/** + * nfs_getport - query server's rpcbind to get port number for an RPC service + * @sap: pointer to address of server to query + * @salen: length of server's address + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: IPPROTO_ value of requested transport protocol + * + * Uses any acceptable rpcbind version to discover the port number for the + * RPC service described by the given [program, version, transport] tuple. + * Uses a quick timeout and an ephemeral source port. Supports AF_INET and + * AF_INET6 server addresses. + * + * Returns a positive integer representing the port number of the RPC + * service advertised by the server (in host byte order), or zero if the + * service is not advertised or there was some problem querying the server's + * rpcbind daemon. rpccreateerr is set to reflect the underlying cause of + * the error. + * + * There are a variety of ways to choose which transport and rpcbind versions + * to use. We chose to conserve local resources and try to avoid incurring + * timeouts. + * + * Transport + * To provide rudimentary support for traversing firewalls, query the remote + * using the same transport as the requested service. This provides some + * guarantee that the requested transport is available between this client + * and the server, and if the caller specifically requests TCP, for example, + * this may be becuase a firewall is in place that blocks UDP traffic. We + * could try both, but that could involve a lengthy timeout in several cases, + * and would often consume an extra ephemeral port. + * + * Rpcbind version + * To avoid using up too many ephemeral ports, AF_INET queries use tried-and- + * true rpcbindv2, and don't try the newer versions; and AF_INET6 queries use + * rpcbindv4, then rpcbindv3 on the same socket. The newer rpcbind protocol + * versions can adequately detect if a remote RPC service does not support + * AF_INET6 at all. The rpcbind socket is re-used in an attempt to keep the + * overall number of consumed ephemeral ports low. + */ +unsigned short nfs_getport(const struct sockaddr *sap, + const socklen_t salen, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol) +{ + union nfs_sockaddr address; + struct sockaddr *saddr = &address.sa; + struct timeval timeout = { -1, 0 }; + unsigned short port = 0; + CLIENT *client; + + nfs_clear_rpc_createerr(); + + memcpy(saddr, sap, (size_t)salen); + client = nfs_gp_get_rpcbclient(saddr, salen, protocol, + default_rpcb_version, &timeout); + if (client != NULL) { + port = nfs_gp_getport(client, saddr, program, + version, protocol, timeout); + CLNT_DESTROY(client); + } + + return port; +} + +/** + * nfs_getport_ping - query server's rpcbind and do RPC ping to verify result + * @sap: IN: pointer to address of server to query; + * OUT: pointer to updated address + * @salen: length of server's address + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: IPPROTO_ value of requested transport protocol + * + * Uses any acceptable rpcbind version to discover the port number for the + * RPC service described by the given [program, version, transport] tuple. + * Uses a quick timeout and an ephemeral source port. Supports AF_INET and + * AF_INET6 server addresses. + * + * Returns a 1 and sets the port number in the passed-in server address + * if both the query and the ping were successful; otherwise zero. + * rpccreateerr is set to reflect the underlying cause of the error. + */ +int nfs_getport_ping(struct sockaddr *sap, const socklen_t salen, + const rpcprog_t program, const rpcvers_t version, + const unsigned short protocol) +{ + struct timeval timeout = { -1, 0 }; + unsigned short port = 0; + CLIENT *client; + int result = 0; + + nfs_clear_rpc_createerr(); + + client = nfs_gp_get_rpcbclient(sap, salen, protocol, + default_rpcb_version, &timeout); + if (client != NULL) { + port = nfs_gp_getport(client, sap, program, + version, protocol, timeout); + CLNT_DESTROY(client); + client = NULL; + } + + if (port != 0) { + union nfs_sockaddr address; + struct sockaddr *saddr = &address.sa; + + memcpy(saddr, sap, (size_t)salen); + nfs_set_port(saddr, port); + + nfs_clear_rpc_createerr(); + + client = nfs_get_rpcclient(saddr, salen, protocol, + program, version, &timeout); + if (client != NULL) { + result = nfs_gp_ping(client, timeout); + nfs_gp_map_tcp_errorcodes(protocol); + CLNT_DESTROY(client); + } + } + + if (result) + nfs_set_port(sap, port); + + return result; +} + +/** + * nfs_getlocalport - query local rpcbind to get port number for an RPC service + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: IPPROTO_ value of requested transport protocol + * + * Uses any acceptable rpcbind version to discover the port number for the + * RPC service described by the given [program, version, transport] tuple. + * Uses a quick timeout and an ephemeral source port. Supports AF_INET and + * AF_INET6 local addresses. + * + * Returns a positive integer representing the port number of the RPC + * service advertised by the server (in host byte order), or zero if the + * service is not advertised or there was some problem querying the server's + * rpcbind daemon. rpccreateerr is set to reflect the underlying cause of + * the error. + * + * Try an AF_LOCAL connection first. The rpcbind daemon implementation should + * listen on AF_LOCAL. + * + * If that doesn't work (for example, if portmapper is running, or rpcbind + * isn't listening on /run/rpcbind.sock), send a query via UDP to localhost + * (UDP doesn't leave a socket in TIME_WAIT, and the timeout is a relatively + * short 3 seconds). + */ +unsigned short nfs_getlocalport(const rpcprot_t program, + const rpcvers_t version, + const unsigned short protocol) +{ + union nfs_sockaddr address; + struct sockaddr *lb_addr = &address.sa; + socklen_t lb_len = sizeof(*lb_addr); + unsigned short port = 0; + +#ifdef NFS_GP_LOCAL + const struct sockaddr_un sun = { + .sun_family = AF_LOCAL, + .sun_path = _PATH_RPCBINDSOCK, + }; + const struct sockaddr *sap = (struct sockaddr *)&sun; + const socklen_t salen = SUN_LEN(&sun); + CLIENT *client; + struct timeval timeout = { -1, 0 }; + + nfs_clear_rpc_createerr(); + + client = nfs_gp_get_rpcbclient(sap, salen, 0, RPCBVERS_4, &timeout); + if (client != NULL) { + struct rpcb parms; + + if (nfs_gp_init_rpcb_parms(sap, program, version, + protocol, &parms) != 0) { + port = nfs_gp_rpcb_getaddr(client, &parms, timeout); + nfs_gp_free_rpcb_parms(&parms); + } + CLNT_DESTROY(client); + } +#endif /* NFS_GP_LOCAL */ + + if (port == 0) { + nfs_clear_rpc_createerr(); + + if (nfs_gp_loopback_address(lb_addr, &lb_len)) { + port = nfs_getport(lb_addr, lb_len, + program, version, protocol); + } else + rpc_createerr.cf_stat = RPC_UNKNOWNADDR; + } + + return port; +} + +/** + * nfs_rpcb_getaddr - query rpcbind via rpcbind versions 4 and 3 + * @sap: pointer to address of server to query + * @salen: length of server address + * @transport: transport protocol to use for the query + * @addr: pointer to r_addr address + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: requested IPPROTO_ value of transport protocol + * @timeout: pointer to request timeout (NULL means use default timeout) + * + * Returns a positive integer representing the port number of the RPC + * service advertised by the server (in host byte order), or zero if the + * service is not advertised or there was some problem querying the + * server's rpcbind daemon. rpccreateerr is set to reflect the + * underlying cause of the error. + * + * This function provides similar functionality to nfs_pmap_getport(), + * but performs the rpcbind lookup via rpcbind version 4. If the server + * doesn't support rpcbind version 4, it will retry with version 3. + * The GETADDR procedure is exactly the same in these two versions of + * the rpcbind protocol, so the socket, RPC client, and arguments are + * re-used when retrying, saving ephemeral port space. + * + * These RPC procedures take a universal address as an argument, so the + * query will fail if the remote rpcbind daemon doesn't find an entry + * with a matching address. A matching address includes an ANYADDR + * address of the same address family. In this way an RPC server can + * advertise via rpcbind that it does not support AF_INET6. + */ +#ifdef HAVE_LIBTIRPC + +unsigned short nfs_rpcb_getaddr(const struct sockaddr *sap, + const socklen_t salen, + const unsigned short transport, + const struct sockaddr *addr, + const rpcprog_t program, + const rpcvers_t version, + const unsigned short protocol, + const struct timeval *timeout) +{ + union nfs_sockaddr address; + struct sockaddr *saddr = &address.sa; + CLIENT *client; + struct rpcb parms; + struct timeval tout = { -1, 0 }; + unsigned short port = 0; + + if (timeout != NULL) + tout = *timeout; + + nfs_clear_rpc_createerr(); + + memcpy(saddr, sap, (size_t)salen); + client = nfs_gp_get_rpcbclient(saddr, salen, transport, + RPCBVERS_4, &tout); + if (client != NULL) { + if (nfs_gp_init_rpcb_parms(addr, program, version, + protocol, &parms) != 0) { + port = nfs_gp_rpcb_getaddr(client, &parms, tout); + nfs_gp_free_rpcb_parms(&parms); + } + CLNT_DESTROY(client); + } + + return port; +} + +#else /* !HAVE_LIBTIRPC */ + +unsigned short nfs_rpcb_getaddr(__attribute__((unused)) const struct sockaddr *sap, + __attribute__((unused)) const socklen_t salen, + __attribute__((unused)) const unsigned short transport, + __attribute__((unused)) const struct sockaddr *addr, + __attribute__((unused)) const rpcprog_t program, + __attribute__((unused)) const rpcvers_t version, + __attribute__((unused)) const unsigned short protocol, + __attribute__((unused)) const struct timeval *timeout) +{ + nfs_clear_rpc_createerr(); + + rpc_createerr.cf_stat = RPC_UNKNOWNADDR; + return 0; +} + +#endif /* !HAVE_LIBTIRPC */ + +/** + * nfs_pmap_getport - query rpcbind via the portmap protocol (rpcbindv2) + * @sin: pointer to AF_INET address of server to query + * @transport: transport protocol to use for the query + * @program: requested RPC program number + * @version: requested RPC version number + * @protocol: requested IPPROTO_ value of transport protocol + * @timeout: pointer to request timeout (NULL means use default timeout) + * + * Returns a positive integer representing the port number of the RPC service + * advertised by the server (in host byte order), or zero if the service is + * not advertised or there was some problem querying the server's rpcbind + * daemon. rpccreateerr is set to reflect the underlying cause of the error. + * + * nfs_pmap_getport() is very similar to pmap_getport(), except that: + * + * 1. This version always tries to use an ephemeral port, since reserved + * ports are not needed for GETPORT queries. This conserves the very + * limited reserved port space, helping reduce failed socket binds + * during mount storms. + * + * 2. This version times out quickly by default. It time-limits the + * connect process as well as the actual RPC call, and even allows the + * caller to specify the timeout. + * + * 3. This version shares code with the rpcbindv3 and rpcbindv4 query + * functions. It can use a TI-RPC generated CLIENT. + */ +unsigned long nfs_pmap_getport(const struct sockaddr_in *sin, + const unsigned short transport, + const unsigned long program, + const unsigned long version, + const unsigned long protocol, + const struct timeval *timeout) +{ + struct sockaddr_in address; + struct sockaddr *saddr = (struct sockaddr *)&address; + CLIENT *client; + struct pmap parms = { + .pm_prog = program, + .pm_vers = version, + .pm_prot = protocol, + }; + struct timeval tout = { -1, 0 }; + unsigned long port = 0; + + if (timeout != NULL) + tout = *timeout; + + nfs_clear_rpc_createerr(); + + memcpy(saddr, sin, sizeof(address)); + client = nfs_gp_get_rpcbclient(saddr, (socklen_t)sizeof(*sin), + transport, PMAPVERS, &tout); + if (client != NULL) { + port = nfs_gp_pmap_getport(client, &parms, tout); + CLNT_DESTROY(client); + } + + return port; +} + +static const char *nfs_ns_pgmtbl[] = { + "status", + NULL, +}; + +/* + * nfs_probe_statd - use nfs_pmap_getport to see if statd is running locally + * + * Returns non-zero if statd is running locally. + */ +int nfs_probe_statd(void) +{ + struct sockaddr_in addr = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + }; + rpcprog_t program = nfs_getrpcbyname(NSMPROG, nfs_ns_pgmtbl); + + return nfs_getport_ping((struct sockaddr *)(char *)&addr, sizeof(addr), + program, (rpcvers_t)1, IPPROTO_UDP); +} |