|  | /* | 
|  | * linux/net/sunrpc/pmap_clnt.c | 
|  | * | 
|  | * In-kernel RPC portmapper client. | 
|  | * | 
|  | * Portmapper supports version 2 of the rpcbind protocol (RFC 1833). | 
|  | * | 
|  | * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> | 
|  | */ | 
|  |  | 
|  | #include <linux/types.h> | 
|  | #include <linux/socket.h> | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/errno.h> | 
|  | #include <linux/uio.h> | 
|  | #include <linux/in.h> | 
|  | #include <linux/sunrpc/clnt.h> | 
|  | #include <linux/sunrpc/sched.h> | 
|  |  | 
|  | #ifdef RPC_DEBUG | 
|  | # define RPCDBG_FACILITY	RPCDBG_PMAP | 
|  | #endif | 
|  |  | 
|  | #define PMAP_SET		1 | 
|  | #define PMAP_UNSET		2 | 
|  | #define PMAP_GETPORT		3 | 
|  |  | 
|  | struct portmap_args { | 
|  | u32			pm_prog; | 
|  | u32			pm_vers; | 
|  | u32			pm_prot; | 
|  | unsigned short		pm_port; | 
|  | struct rpc_xprt *	pm_xprt; | 
|  | }; | 
|  |  | 
|  | static struct rpc_procinfo	pmap_procedures[]; | 
|  | static struct rpc_clnt *	pmap_create(char *, struct sockaddr_in *, int, int); | 
|  | static void			pmap_getport_done(struct rpc_task *, void *); | 
|  | static struct rpc_program	pmap_program; | 
|  |  | 
|  | static void pmap_getport_prepare(struct rpc_task *task, void *calldata) | 
|  | { | 
|  | struct portmap_args *map = calldata; | 
|  | struct rpc_message msg = { | 
|  | .rpc_proc	= &pmap_procedures[PMAP_GETPORT], | 
|  | .rpc_argp	= map, | 
|  | .rpc_resp	= &map->pm_port, | 
|  | }; | 
|  |  | 
|  | rpc_call_setup(task, &msg, 0); | 
|  | } | 
|  |  | 
|  | static inline struct portmap_args *pmap_map_alloc(void) | 
|  | { | 
|  | return kmalloc(sizeof(struct portmap_args), GFP_NOFS); | 
|  | } | 
|  |  | 
|  | static inline void pmap_map_free(struct portmap_args *map) | 
|  | { | 
|  | kfree(map); | 
|  | } | 
|  |  | 
|  | static void pmap_map_release(void *data) | 
|  | { | 
|  | pmap_map_free(data); | 
|  | } | 
|  |  | 
|  | static const struct rpc_call_ops pmap_getport_ops = { | 
|  | .rpc_call_prepare	= pmap_getport_prepare, | 
|  | .rpc_call_done		= pmap_getport_done, | 
|  | .rpc_release		= pmap_map_release, | 
|  | }; | 
|  |  | 
|  | static inline void pmap_wake_portmap_waiters(struct rpc_xprt *xprt, int status) | 
|  | { | 
|  | xprt_clear_binding(xprt); | 
|  | rpc_wake_up_status(&xprt->binding, status); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpc_getport - 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 rpc_getport(struct rpc_task *task) | 
|  | { | 
|  | struct rpc_clnt *clnt = task->tk_client; | 
|  | struct rpc_xprt *xprt = task->tk_xprt; | 
|  | struct sockaddr_in addr; | 
|  | struct portmap_args *map; | 
|  | struct rpc_clnt	*pmap_clnt; | 
|  | struct rpc_task *child; | 
|  | int status; | 
|  |  | 
|  | dprintk("RPC: %4d rpc_getport(%s, %u, %u, %d)\n", | 
|  | task->tk_pid, clnt->cl_server, | 
|  | clnt->cl_prog, clnt->cl_vers, xprt->prot); | 
|  |  | 
|  | /* Autobind on cloned rpc clients is discouraged */ | 
|  | BUG_ON(clnt->cl_parent != clnt); | 
|  |  | 
|  | status = -EACCES;		/* tell caller to check again */ | 
|  | if (xprt_test_and_set_binding(xprt)) | 
|  | goto bailout_nowake; | 
|  |  | 
|  | /* Put self on queue before sending rpcbind request, in case | 
|  | * pmap_getport_done completes before we return from rpc_run_task */ | 
|  | rpc_sleep_on(&xprt->binding, task, NULL, NULL); | 
|  |  | 
|  | /* Someone else may have bound if we slept */ | 
|  | status = 0; | 
|  | if (xprt_bound(xprt)) | 
|  | goto bailout_nofree; | 
|  |  | 
|  | status = -ENOMEM; | 
|  | map = pmap_map_alloc(); | 
|  | if (!map) | 
|  | goto bailout_nofree; | 
|  | map->pm_prog = clnt->cl_prog; | 
|  | map->pm_vers = clnt->cl_vers; | 
|  | map->pm_prot = xprt->prot; | 
|  | map->pm_port = 0; | 
|  | map->pm_xprt = xprt_get(xprt); | 
|  |  | 
|  | rpc_peeraddr(clnt, (struct sockaddr *) &addr, sizeof(addr)); | 
|  | pmap_clnt = pmap_create(clnt->cl_server, &addr, map->pm_prot, 0); | 
|  | status = PTR_ERR(pmap_clnt); | 
|  | if (IS_ERR(pmap_clnt)) | 
|  | goto bailout; | 
|  |  | 
|  | status = -EIO; | 
|  | child = rpc_run_task(pmap_clnt, RPC_TASK_ASYNC, &pmap_getport_ops, map); | 
|  | if (IS_ERR(child)) | 
|  | goto bailout; | 
|  | rpc_put_task(child); | 
|  |  | 
|  | task->tk_xprt->stat.bind_count++; | 
|  | return; | 
|  |  | 
|  | bailout: | 
|  | pmap_map_free(map); | 
|  | xprt_put(xprt); | 
|  | bailout_nofree: | 
|  | pmap_wake_portmap_waiters(xprt, status); | 
|  | bailout_nowake: | 
|  | task->tk_status = status; | 
|  | } | 
|  |  | 
|  | #ifdef CONFIG_ROOT_NFS | 
|  | /** | 
|  | * rpc_getport_external - obtain the port for a given 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 | 
|  | * | 
|  | * This one is called from outside the RPC client in a synchronous task context. | 
|  | */ | 
|  | int rpc_getport_external(struct sockaddr_in *sin, __u32 prog, __u32 vers, int prot) | 
|  | { | 
|  | struct portmap_args map = { | 
|  | .pm_prog	= prog, | 
|  | .pm_vers	= vers, | 
|  | .pm_prot	= prot, | 
|  | .pm_port	= 0 | 
|  | }; | 
|  | struct rpc_message msg = { | 
|  | .rpc_proc	= &pmap_procedures[PMAP_GETPORT], | 
|  | .rpc_argp	= &map, | 
|  | .rpc_resp	= &map.pm_port, | 
|  | }; | 
|  | struct rpc_clnt	*pmap_clnt; | 
|  | char		hostname[32]; | 
|  | int		status; | 
|  |  | 
|  | dprintk("RPC:      rpc_getport_external(%u.%u.%u.%u, %u, %u, %d)\n", | 
|  | NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot); | 
|  |  | 
|  | sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(sin->sin_addr.s_addr)); | 
|  | pmap_clnt = pmap_create(hostname, sin, prot, 0); | 
|  | if (IS_ERR(pmap_clnt)) | 
|  | return PTR_ERR(pmap_clnt); | 
|  |  | 
|  | /* Setup the call info struct */ | 
|  | status = rpc_call_sync(pmap_clnt, &msg, 0); | 
|  |  | 
|  | if (status >= 0) { | 
|  | if (map.pm_port != 0) | 
|  | return map.pm_port; | 
|  | status = -EACCES; | 
|  | } | 
|  | return status; | 
|  | } | 
|  | #endif | 
|  |  | 
|  | /* | 
|  | * Portmapper child task invokes this callback via tk_exit. | 
|  | */ | 
|  | static void pmap_getport_done(struct rpc_task *child, void *data) | 
|  | { | 
|  | struct portmap_args *map = data; | 
|  | struct rpc_xprt *xprt = map->pm_xprt; | 
|  | int status = child->tk_status; | 
|  |  | 
|  | if (status < 0) { | 
|  | /* Portmapper not available */ | 
|  | xprt->ops->set_port(xprt, 0); | 
|  | } else if (map->pm_port == 0) { | 
|  | /* Requested RPC service wasn't registered */ | 
|  | xprt->ops->set_port(xprt, 0); | 
|  | status = -EACCES; | 
|  | } else { | 
|  | /* Succeeded */ | 
|  | xprt->ops->set_port(xprt, map->pm_port); | 
|  | xprt_set_bound(xprt); | 
|  | status = 0; | 
|  | } | 
|  |  | 
|  | dprintk("RPC: %4d pmap_getport_done(status %d, port %u)\n", | 
|  | child->tk_pid, status, map->pm_port); | 
|  |  | 
|  | pmap_wake_portmap_waiters(xprt, status); | 
|  | xprt_put(xprt); | 
|  | } | 
|  |  | 
|  | /** | 
|  | * rpc_register - set or unset a port registration with the local portmapper | 
|  | * @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. | 
|  | */ | 
|  | int rpc_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 portmap_args	map = { | 
|  | .pm_prog	= prog, | 
|  | .pm_vers	= vers, | 
|  | .pm_prot	= prot, | 
|  | .pm_port	= port, | 
|  | }; | 
|  | struct rpc_message msg = { | 
|  | .rpc_proc	= &pmap_procedures[port ? PMAP_SET : PMAP_UNSET], | 
|  | .rpc_argp	= &map, | 
|  | .rpc_resp	= okay, | 
|  | }; | 
|  | struct rpc_clnt		*pmap_clnt; | 
|  | int error = 0; | 
|  |  | 
|  | dprintk("RPC: registering (%u, %u, %d, %u) with portmapper.\n", | 
|  | prog, vers, prot, port); | 
|  |  | 
|  | pmap_clnt = pmap_create("localhost", &sin, IPPROTO_UDP, 1); | 
|  | if (IS_ERR(pmap_clnt)) { | 
|  | error = PTR_ERR(pmap_clnt); | 
|  | dprintk("RPC: couldn't create pmap client. Error = %d\n", error); | 
|  | return error; | 
|  | } | 
|  |  | 
|  | error = rpc_call_sync(pmap_clnt, &msg, 0); | 
|  |  | 
|  | if (error < 0) { | 
|  | printk(KERN_WARNING | 
|  | "RPC: failed to contact portmap (errno %d).\n", | 
|  | error); | 
|  | } | 
|  | dprintk("RPC: registration status %d/%d\n", error, *okay); | 
|  |  | 
|  | /* Client deleted automatically because cl_oneshot == 1 */ | 
|  | return error; | 
|  | } | 
|  |  | 
|  | static struct rpc_clnt *pmap_create(char *hostname, struct sockaddr_in *srvaddr, int proto, int privileged) | 
|  | { | 
|  | struct rpc_create_args args = { | 
|  | .protocol	= proto, | 
|  | .address	= (struct sockaddr *)srvaddr, | 
|  | .addrsize	= sizeof(*srvaddr), | 
|  | .servername	= hostname, | 
|  | .program	= &pmap_program, | 
|  | .version	= RPC_PMAP_VERSION, | 
|  | .authflavor	= RPC_AUTH_UNIX, | 
|  | .flags		= (RPC_CLNT_CREATE_ONESHOT | | 
|  | RPC_CLNT_CREATE_NOPING), | 
|  | }; | 
|  |  | 
|  | srvaddr->sin_port = htons(RPC_PMAP_PORT); | 
|  | if (!privileged) | 
|  | args.flags |= RPC_CLNT_CREATE_NONPRIVPORT; | 
|  | return rpc_create(&args); | 
|  | } | 
|  |  | 
|  | /* | 
|  | * XDR encode/decode functions for PMAP | 
|  | */ | 
|  | static int xdr_encode_mapping(struct rpc_rqst *req, __be32 *p, struct portmap_args *map) | 
|  | { | 
|  | dprintk("RPC: xdr_encode_mapping(%u, %u, %u, %u)\n", | 
|  | map->pm_prog, map->pm_vers, map->pm_prot, map->pm_port); | 
|  | *p++ = htonl(map->pm_prog); | 
|  | *p++ = htonl(map->pm_vers); | 
|  | *p++ = htonl(map->pm_prot); | 
|  | *p++ = htonl(map->pm_port); | 
|  |  | 
|  | req->rq_slen = xdr_adjust_iovec(req->rq_svec, p); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int xdr_decode_port(struct rpc_rqst *req, __be32 *p, unsigned short *portp) | 
|  | { | 
|  | *portp = (unsigned short) ntohl(*p++); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int xdr_decode_bool(struct rpc_rqst *req, __be32 *p, unsigned int *boolp) | 
|  | { | 
|  | *boolp = (unsigned int) ntohl(*p++); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static struct rpc_procinfo	pmap_procedures[] = { | 
|  | [PMAP_SET] = { | 
|  | .p_proc		= PMAP_SET, | 
|  | .p_encode		= (kxdrproc_t) xdr_encode_mapping, | 
|  | .p_decode		= (kxdrproc_t) xdr_decode_bool, | 
|  | .p_bufsiz		= 4, | 
|  | .p_count		= 1, | 
|  | .p_statidx		= PMAP_SET, | 
|  | .p_name		= "SET", | 
|  | }, | 
|  | [PMAP_UNSET] = { | 
|  | .p_proc		= PMAP_UNSET, | 
|  | .p_encode		= (kxdrproc_t) xdr_encode_mapping, | 
|  | .p_decode		= (kxdrproc_t) xdr_decode_bool, | 
|  | .p_bufsiz		= 4, | 
|  | .p_count		= 1, | 
|  | .p_statidx		= PMAP_UNSET, | 
|  | .p_name		= "UNSET", | 
|  | }, | 
|  | [PMAP_GETPORT] = { | 
|  | .p_proc		= PMAP_GETPORT, | 
|  | .p_encode		= (kxdrproc_t) xdr_encode_mapping, | 
|  | .p_decode		= (kxdrproc_t) xdr_decode_port, | 
|  | .p_bufsiz		= 4, | 
|  | .p_count		= 1, | 
|  | .p_statidx		= PMAP_GETPORT, | 
|  | .p_name		= "GETPORT", | 
|  | }, | 
|  | }; | 
|  |  | 
|  | static struct rpc_version	pmap_version2 = { | 
|  | .number		= 2, | 
|  | .nrprocs	= 4, | 
|  | .procs		= pmap_procedures | 
|  | }; | 
|  |  | 
|  | static struct rpc_version *	pmap_version[] = { | 
|  | NULL, | 
|  | NULL, | 
|  | &pmap_version2 | 
|  | }; | 
|  |  | 
|  | static struct rpc_stat		pmap_stats; | 
|  |  | 
|  | static struct rpc_program	pmap_program = { | 
|  | .name		= "portmap", | 
|  | .number		= RPC_PMAP_PROGRAM, | 
|  | .nrvers		= ARRAY_SIZE(pmap_version), | 
|  | .version	= pmap_version, | 
|  | .stats		= &pmap_stats, | 
|  | }; |