/* * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind * protocol * * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and * RFC 3530: "Network File System (NFS) version 4 Protocol" * * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net> * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com> * * Descended from net/sunrpc/pmap_clnt.c, * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> */ #include <linux/module.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/in.h> #include <linux/in6.h> #include <linux/kernel.h> #include <linux/errno.h> #include <linux/sunrpc/clnt.h> #include <linux/sunrpc/sched.h> #include <linux/sunrpc/xprtsock.h> #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_BIND #endif #define RPCBIND_PROGRAM (100000u) #define RPCBIND_PORT (111u) enum { RPCBPROC_NULL, RPCBPROC_SET, RPCBPROC_UNSET, RPCBPROC_GETPORT, RPCBPROC_GETADDR = 3, /* alias for GETPORT */ RPCBPROC_DUMP, RPCBPROC_CALLIT, RPCBPROC_BCAST = 5, /* alias for CALLIT */ RPCBPROC_GETTIME, RPCBPROC_UADDR2TADDR, RPCBPROC_TADDR2UADDR, RPCBPROC_GETVERSADDR, RPCBPROC_INDIRECT, RPCBPROC_GETADDRLIST, RPCBPROC_GETSTAT, }; #define RPCB_HIGHPROC_2 RPCBPROC_CALLIT #define RPCB_HIGHPROC_3 RPCBPROC_TADDR2UADDR #define RPCB_HIGHPROC_4 RPCBPROC_GETSTAT /* * r_owner * * The "owner" is allowed to unset a service in the rpcbind database. * We always use the following (arbitrary) fixed string. */ #define RPCB_OWNER_STRING "rpcb" #define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING) static void rpcb_getport_done(struct rpc_task *, void *); static struct rpc_program rpcb_program; struct rpcbind_args { struct rpc_xprt * r_xprt; u32 r_prog; u32 r_vers; u32 r_prot; unsigned short r_port; const char * r_netid; const char * r_addr; const char * r_owner; }; static struct rpc_procinfo rpcb_procedures2[]; static struct rpc_procinfo rpcb_procedures3[]; struct rpcb_info { int rpc_vers; struct rpc_procinfo * rpc_proc; }; static struct rpcb_info rpcb_next_version[]; static struct rpcb_info rpcb_next_version6[]; static void rpcb_map_release(void *data) { struct rpcbind_args *map = data; xprt_put(map->r_xprt); kfree(map); } static const struct rpc_call_ops rpcb_getport_ops = { .rpc_call_done = rpcb_getport_done, .rpc_release = rpcb_map_release, }; static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status) { xprt_clear_binding(xprt); rpc_wake_up_status(&xprt->binding, status); } static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr, size_t salen, int proto, u32 version, int privileged) { struct rpc_create_args args = { .protocol = proto, .address = srvaddr, .addrsize = salen, .servername = hostname, .program = &rpcb_program, .version = version, .authflavor = RPC_AUTH_UNIX, .flags = RPC_CLNT_CREATE_NOPING, }; switch (srvaddr->sa_family) { case AF_INET: ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT); break; case AF_INET6: ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT); break; default: return NULL; } if (!privileged) args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; return rpc_create(&args); } /** * rpcb_register - set or unset a port registration with the local rpcbind svc * @prog: RPC program number to bind * @vers: RPC version number to bind * @prot: transport protocol to use to make this request * @port: port value to register * @okay: result code * * port == 0 means unregister, port != 0 means register. * * This routine supports only rpcbind version 2. */ int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay) { struct sockaddr_in sin = { .sin_family = AF_INET, .sin_addr.s_addr = htonl(INADDR_LOOPBACK), }; struct rpcbind_args map = { .r_prog = prog, .r_vers = vers, .r_prot = prot, .r_port = port, }; struct rpc_message msg = { .rpc_proc = &rpcb_procedures2[port ? RPCBPROC_SET : RPCBPROC_UNSET], .rpc_argp = &map, .rpc_resp = okay, }; struct rpc_clnt *rpcb_clnt; int error = 0; dprintk("RPC: %sregistering (%u, %u, %d, %u) with local " "rpcbind\n", (port ? "" : "un"), prog, vers, prot, port); rpcb_clnt = rpcb_create("localhost", (struct sockaddr *) &sin, sizeof(sin), XPRT_TRANSPORT_UDP, 2, 1); if (IS_ERR(rpcb_clnt)) return PTR_ERR(rpcb_clnt); error = rpc_call_sync(rpcb_clnt, &msg, 0); rpc_shutdown_client(rpcb_clnt); if (error < 0) printk(KERN_WARNING "RPC: failed to contact local rpcbind " "server (errno %d).\n", -error); dprintk("RPC: registration status %d/%d\n", error, *okay); return error; } /** * rpcb_getport_sync - obtain the port for an RPC service on a given host * @sin: address of remote peer * @prog: RPC program number to bind * @vers: RPC version number to bind * @prot: transport protocol to use to make this request * * Return value is the requested advertised port number, * or a negative errno value. * * Called from outside the RPC client in a synchronous task context. * Uses default timeout parameters specified by underlying transport. * * XXX: Needs to support IPv6 */ int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot) { struct rpcbind_args map = { .r_prog = prog, .r_vers = vers, .r_prot = prot, .r_port = 0, }; struct rpc_message msg = { .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT], .rpc_argp = &map, .rpc_resp = &map.r_port, }; struct rpc_clnt *rpcb_clnt; int status; dprintk("RPC: %s(" NIPQUAD_FMT ", %u, %u, %d)\n", __func__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot); rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin, sizeof(*sin), prot, 2, 0); if (IS_ERR(rpcb_clnt)) return PTR_ERR(rpcb_clnt); status = rpc_call_sync(rpcb_clnt, &msg, 0); rpc_shutdown_client(rpcb_clnt); if (status >= 0) { if (map.r_port != 0) return map.r_port; status = -EACCES; } return status; } EXPORT_SYMBOL_GPL(rpcb_getport_sync); static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, int version) { struct rpc_message msg = { .rpc_proc = rpcb_next_version[version].rpc_proc, .rpc_argp = map, .rpc_resp = &map->r_port, }; struct rpc_task_setup task_setup_data = { .rpc_client = rpcb_clnt, .rpc_message = &msg, .callback_ops = &rpcb_getport_ops, .callback_data = map, .flags = RPC_TASK_ASYNC, }; return rpc_run_task(&task_setup_data); } /** * rpcb_getport_async - obtain the port for a given RPC service on a given host * @task: task that is waiting for portmapper request * * This one can be called for an ongoing RPC request, and can be used in * an async (rpciod) context. */ void rpcb_getport_async(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; u32 bind_version; struct rpc_xprt *xprt = task->tk_xprt; struct rpc_clnt *rpcb_clnt; static struct rpcbind_args *map; struct rpc_task *child; struct sockaddr_storage addr; struct sockaddr *sap = (struct sockaddr *)&addr; size_t salen; int status; struct rpcb_info *info; dprintk("RPC: %5u %s(%s, %u, %u, %d)\n", task->tk_pid, __func__, clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot); /* Autobind on cloned rpc clients is discouraged */ BUG_ON(clnt->cl_parent != clnt); if (xprt_test_and_set_binding(xprt)) { status = -EAGAIN; /* tell caller to check again */ dprintk("RPC: %5u %s: waiting for another binder\n", task->tk_pid, __func__); goto bailout_nowake; } /* Put self on queue before sending rpcbind request, in case * rpcb_getport_done completes before we return from rpc_run_task */ rpc_sleep_on(&xprt->binding, task, NULL); /* Someone else may have bound if we slept */ if (xprt_bound(xprt)) { status = 0; dprintk("RPC: %5u %s: already bound\n", task->tk_pid, __func__); goto bailout_nofree; } salen = rpc_peeraddr(clnt, sap, sizeof(addr)); /* Don't ever use rpcbind v2 for AF_INET6 requests */ switch (sap->sa_family) { case AF_INET: info = rpcb_next_version; break; case AF_INET6: info = rpcb_next_version6; break; default: status = -EAFNOSUPPORT; dprintk("RPC: %5u %s: bad address family\n", task->tk_pid, __func__); goto bailout_nofree; } if (info[xprt->bind_index].rpc_proc == NULL) { xprt->bind_index = 0; status = -EPFNOSUPPORT; dprintk("RPC: %5u %s: no more getport versions available\n", task->tk_pid, __func__); goto bailout_nofree; } bind_version = info[xprt->bind_index].rpc_vers; dprintk("RPC: %5u %s: trying rpcbind version %u\n", task->tk_pid, __func__, bind_version); rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot, bind_version, 0); if (IS_ERR(rpcb_clnt)) { status = PTR_ERR(rpcb_clnt); dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n", task->tk_pid, __func__, PTR_ERR(rpcb_clnt)); goto bailout_nofree; } map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC); if (!map) { status = -ENOMEM; dprintk("RPC: %5u %s: no memory available\n", task->tk_pid, __func__); goto bailout_nofree; } map->r_prog = clnt->cl_prog; map->r_vers = clnt->cl_vers; map->r_prot = xprt->prot; map->r_port = 0; map->r_xprt = xprt_get(xprt); map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID); map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR); map->r_owner = RPCB_OWNER_STRING; /* ignored for GETADDR */ child = rpcb_call_async(rpcb_clnt, map, xprt->bind_index); rpc_release_client(rpcb_clnt); if (IS_ERR(child)) { status = -EIO; dprintk("RPC: %5u %s: rpc_run_task failed\n", task->tk_pid, __func__); goto bailout; } rpc_put_task(child); task->tk_xprt->stat.bind_count++; return; bailout: kfree(map); xprt_put(xprt); bailout_nofree: rpcb_wake_rpcbind_waiters(xprt, status); bailout_nowake: task->tk_status = status; } EXPORT_SYMBOL_GPL(rpcb_getport_async); /* * Rpcbind child task calls this callback via tk_exit. */ static void rpcb_getport_done(struct rpc_task *child, void *data) { struct rpcbind_args *map = data; struct rpc_xprt *xprt = map->r_xprt; int status = child->tk_status; /* Garbage reply: retry with a lesser rpcbind version */ if (status == -EIO) status = -EPROTONOSUPPORT; /* rpcbind server doesn't support this rpcbind protocol version */ if (status == -EPROTONOSUPPORT) xprt->bind_index++; if (status < 0) { /* rpcbind server not available on remote host? */ xprt->ops->set_port(xprt, 0); } else if (map->r_port == 0) { /* Requested RPC service wasn't registered on remote host */ xprt->ops->set_port(xprt, 0); status = -EACCES; } else { /* Succeeded */ xprt->ops->set_port(xprt, map->r_port); xprt_set_bound(xprt); status = 0; } dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n", child->tk_pid, status, map->r_port); rpcb_wake_rpcbind_waiters(xprt, status); } static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p, struct rpcbind_args *rpcb) { dprintk("RPC: rpcb_encode_mapping(%u, %u, %d, %u)\n", rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port); *p++ = htonl(rpcb->r_prog); *p++ = htonl(rpcb->r_vers); *p++ = htonl(rpcb->r_prot); *p++ = htonl(rpcb->r_port); req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); return 0; } static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p, unsigned short *portp) { *portp = (unsigned short) ntohl(*p++); dprintk("RPC: rpcb_decode_getport result %u\n", *portp); return 0; } static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p, unsigned int *boolp) { *boolp = (unsigned int) ntohl(*p++); dprintk("RPC: rpcb_decode_set result %u\n", *boolp); return 0; } static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p, struct rpcbind_args *rpcb) { dprintk("RPC: rpcb_encode_getaddr(%u, %u, %s)\n", rpcb->r_prog, rpcb->r_vers, rpcb->r_addr); *p++ = htonl(rpcb->r_prog); *p++ = htonl(rpcb->r_vers); p = xdr_encode_string(p, rpcb->r_netid); p = xdr_encode_string(p, rpcb->r_addr); p = xdr_encode_string(p, rpcb->r_owner); req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); return 0; } static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p, unsigned short *portp) { char *addr; u32 addr_len; int c, i, f, first, val; *portp = 0; addr_len = ntohl(*p++); /* * Simple sanity check. The smallest possible universal * address is an IPv4 address string containing 11 bytes. */ if (addr_len < 11 || addr_len > RPCBIND_MAXUADDRLEN) goto out_err; /* * Start at the end and walk backwards until the first dot * is encountered. When the second dot is found, we have * both parts of the port number. */ addr = (char *)p; val = 0; first = 1; f = 1; for (i = addr_len - 1; i > 0; i--) { c = addr[i]; if (c >= '0' && c <= '9') { val += (c - '0') * f; f *= 10; } else if (c == '.') { if (first) { *portp = val; val = first = 0; f = 1; } else { *portp |= (val << 8); break; } } } /* * Simple sanity check. If we never saw a dot in the reply, * then this was probably just garbage. */ if (first) goto out_err; dprintk("RPC: rpcb_decode_getaddr port=%u\n", *portp); return 0; out_err: dprintk("RPC: rpcbind server returned malformed reply\n"); return -EIO; } #define RPCB_program_sz (1u) #define RPCB_version_sz (1u) #define RPCB_protocol_sz (1u) #define RPCB_port_sz (1u) #define RPCB_boolean_sz (1u) #define RPCB_netid_sz (1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN)) #define RPCB_addr_sz (1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN)) #define RPCB_ownerstring_sz (1+XDR_QUADLEN(RPCB_MAXOWNERLEN)) #define RPCB_mappingargs_sz RPCB_program_sz+RPCB_version_sz+ \ RPCB_protocol_sz+RPCB_port_sz #define RPCB_getaddrargs_sz RPCB_program_sz+RPCB_version_sz+ \ RPCB_netid_sz+RPCB_addr_sz+ \ RPCB_ownerstring_sz #define RPCB_setres_sz RPCB_boolean_sz #define RPCB_getportres_sz RPCB_port_sz /* * Note that RFC 1833 does not put any size restrictions on the * address string returned by the remote rpcbind database. */ #define RPCB_getaddrres_sz RPCB_addr_sz #define PROC(proc, argtype, restype) \ [RPCBPROC_##proc] = { \ .p_proc = RPCBPROC_##proc, \ .p_encode = (kxdrproc_t) rpcb_encode_##argtype, \ .p_decode = (kxdrproc_t) rpcb_decode_##restype, \ .p_arglen = RPCB_##argtype##args_sz, \ .p_replen = RPCB_##restype##res_sz, \ .p_statidx = RPCBPROC_##proc, \ .p_timer = 0, \ .p_name = #proc, \ } /* * Not all rpcbind procedures described in RFC 1833 are implemented * since the Linux kernel RPC code requires only these. */ static struct rpc_procinfo rpcb_procedures2[] = { PROC(SET, mapping, set), PROC(UNSET, mapping, set), PROC(GETADDR, mapping, getport), }; static struct rpc_procinfo rpcb_procedures3[] = { PROC(SET, mapping, set), PROC(UNSET, mapping, set), PROC(GETADDR, getaddr, getaddr), }; static struct rpc_procinfo rpcb_procedures4[] = { PROC(SET, mapping, set), PROC(UNSET, mapping, set), PROC(GETVERSADDR, getaddr, getaddr), }; static struct rpcb_info rpcb_next_version[] = { #ifdef CONFIG_SUNRPC_BIND34 { 4, &rpcb_procedures4[RPCBPROC_GETVERSADDR] }, { 3, &rpcb_procedures3[RPCBPROC_GETADDR] }, #endif { 2, &rpcb_procedures2[RPCBPROC_GETPORT] }, { 0, NULL }, }; static struct rpcb_info rpcb_next_version6[] = { #ifdef CONFIG_SUNRPC_BIND34 { 4, &rpcb_procedures4[RPCBPROC_GETVERSADDR] }, { 3, &rpcb_procedures3[RPCBPROC_GETADDR] }, #endif { 0, NULL }, }; static struct rpc_version rpcb_version2 = { .number = 2, .nrprocs = RPCB_HIGHPROC_2, .procs = rpcb_procedures2 }; static struct rpc_version rpcb_version3 = { .number = 3, .nrprocs = RPCB_HIGHPROC_3, .procs = rpcb_procedures3 }; static struct rpc_version rpcb_version4 = { .number = 4, .nrprocs = RPCB_HIGHPROC_4, .procs = rpcb_procedures4 }; static struct rpc_version *rpcb_version[] = { NULL, NULL, &rpcb_version2, &rpcb_version3, &rpcb_version4 }; static struct rpc_stat rpcb_stats; static struct rpc_program rpcb_program = { .name = "rpcbind", .number = RPCBIND_PROGRAM, .nrvers = ARRAY_SIZE(rpcb_version), .version = rpcb_version, .stats = &rpcb_stats, };