/* * linux/net/sunrpc/rpcclnt.c * * This file contains the high-level RPC interface. * It is modeled as a finite state machine to support both synchronous * and asynchronous requests. * * - RPC header generation and argument serialization. * - Credential refresh. * - TCP reconnect handling (when finished). * - Retry of operation when it is suspected the operation failed because * of uid squashing on the server, or when the credentials were stale * and need to be refreshed, or when a packet was damaged in transit. * This may be have to be moved to the VFS layer. * * NB: BSD uses a more intelligent approach to guessing when a request * or reply has been lost by keeping the RTO estimate for each procedure. * We currently make do with a constant timeout value. * * Copyright (C) 1992,1993 Rick Sladkey * Copyright (C) 1995,1996 Olaf Kirch */ #include #include #include #include #include #include #include #include #define RPC_SLACK_SPACE 1024 /* total overkill */ #ifdef RPC_DEBUG # define RPCDBG_FACILITY RPCDBG_CALL #endif static DECLARE_WAIT_QUEUE_HEAD(destroy_wait); static void call_bind(struct rpc_task *task); static void call_reserve(struct rpc_task *task); static void call_reserveresult(struct rpc_task *task); static void call_allocate(struct rpc_task *task); static void call_encode(struct rpc_task *task); static void call_decode(struct rpc_task *task); static void call_transmit(struct rpc_task *task); static void call_receive(struct rpc_task *task); static void call_status(struct rpc_task *task); static void call_refresh(struct rpc_task *task); static void call_refreshresult(struct rpc_task *task); static void call_timeout(struct rpc_task *task); static void call_reconnect(struct rpc_task *task); static u32 * call_header(struct rpc_task *task); static u32 * call_verify(struct rpc_task *task); /* * Create an RPC client * FIXME: This should also take a flags argument (as in task->tk_flags). * It's called (among others) from pmap_create_client, which may in * turn be called by an async task. In this case, rpciod should not be * made to sleep too long. */ struct rpc_clnt * rpc_create_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, int flavor) { struct rpc_version *version; struct rpc_clnt *clnt = NULL; dprintk("RPC: creating %s client for %s (xprt %p)\n", program->name, servname, xprt); if (!xprt) goto out; if (vers >= program->nrvers || !(version = program->version[vers])) goto out; clnt = (struct rpc_clnt *) rpc_allocate(0, sizeof(*clnt)); if (!clnt) goto out_no_clnt; memset(clnt, 0, sizeof(*clnt)); clnt->cl_xprt = xprt; clnt->cl_procinfo = version->procs; clnt->cl_maxproc = version->nrprocs; clnt->cl_server = servname; clnt->cl_protname = program->name; clnt->cl_port = xprt->addr.sin_port; clnt->cl_prog = program->number; clnt->cl_vers = version->number; clnt->cl_prot = IPPROTO_UDP; clnt->cl_stats = program->stats; clnt->cl_bindwait = RPC_INIT_WAITQ("bindwait"); if (!clnt->cl_port) clnt->cl_autobind = 1; if (!rpcauth_create(flavor, clnt)) goto out_no_auth; /* save the nodename */ clnt->cl_nodelen = strlen(system_utsname.nodename); if (clnt->cl_nodelen > UNX_MAXNODENAME) clnt->cl_nodelen = UNX_MAXNODENAME; memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen); out: return clnt; out_no_clnt: printk("RPC: out of memory in rpc_create_client\n"); goto out; out_no_auth: printk("RPC: Couldn't create auth handle (flavor %d)\n", flavor); rpc_free(clnt); clnt = NULL; goto out; } /* * Properly shut down an RPC client, terminating all outstanding * requests. Note that we must be certain that cl_oneshot and * cl_dead are cleared, or else the client would be destroyed * when the last task releases it. */ int rpc_shutdown_client(struct rpc_clnt *clnt) { dprintk("RPC: shutting down %s client for %s\n", clnt->cl_protname, clnt->cl_server); while (clnt->cl_users) { #ifdef RPC_DEBUG printk("rpc_shutdown_client: client %s, tasks=%d\n", clnt->cl_protname, clnt->cl_users); #endif /* Don't let rpc_release_client destroy us */ clnt->cl_oneshot = 0; clnt->cl_dead = 0; rpc_killall_tasks(clnt); sleep_on(&destroy_wait); } return rpc_destroy_client(clnt); } /* * Delete an RPC client */ int rpc_destroy_client(struct rpc_clnt *clnt) { dprintk("RPC: destroying %s client for %s\n", clnt->cl_protname, clnt->cl_server); if (clnt->cl_auth) { rpcauth_destroy(clnt->cl_auth); clnt->cl_auth = NULL; } if (clnt->cl_xprt) { xprt_destroy(clnt->cl_xprt); clnt->cl_xprt = NULL; } rpc_free(clnt); return 0; } /* * Release an RPC client */ void rpc_release_client(struct rpc_clnt *clnt) { dprintk("RPC: rpc_release_client(%p, %d)\n", clnt, clnt->cl_users); if (clnt->cl_users) { if (--(clnt->cl_users) > 0) return; } else printk("rpc_release_client: %s client already free??\n", clnt->cl_protname); wake_up(&destroy_wait); if (clnt->cl_oneshot || clnt->cl_dead) rpc_destroy_client(clnt); } /* * Default callback for async RPC calls */ static void rpc_default_callback(struct rpc_task *task) { rpc_release_task(task); } /* * Export the signal mask handling for aysnchronous code that * sleeps on RPC calls */ void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset) { unsigned long sigallow = sigmask(SIGKILL); unsigned long irqflags; /* Turn off various signals */ if (clnt->cl_intr) { struct k_sigaction *action = current->sig->action; if (action[SIGINT-1].sa.sa_handler == SIG_DFL) sigallow |= sigmask(SIGINT); if (action[SIGQUIT-1].sa.sa_handler == SIG_DFL) sigallow |= sigmask(SIGQUIT); } spin_lock_irqsave(¤t->sigmask_lock, irqflags); *oldset = current->blocked; siginitsetinv(¤t->blocked, sigallow & ~oldset->sig[0]); recalc_sigpending(current); spin_unlock_irqrestore(¤t->sigmask_lock, irqflags); } void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset) { unsigned long irqflags; spin_lock_irqsave(¤t->sigmask_lock, irqflags); current->blocked = *oldset; recalc_sigpending(current); spin_unlock_irqrestore(¤t->sigmask_lock, irqflags); } /* * New rpc_call implementation */ int rpc_do_call(struct rpc_clnt *clnt, u32 proc, void *argp, void *resp, int flags, rpc_action func, void *data) { struct rpc_task my_task, *task = &my_task; sigset_t oldset; int async, status; /* If this client is slain all further I/O fails */ if (clnt->cl_dead) return -EIO; rpc_clnt_sigmask(clnt, &oldset); /* Create/initialize a new RPC task */ if ((async = (flags & RPC_TASK_ASYNC)) != 0) { if (!func) func = rpc_default_callback; status = -ENOMEM; if (!(task = rpc_new_task(clnt, func, flags))) goto out; task->tk_calldata = data; } else { rpc_init_task(task, clnt, NULL, flags); } /* Bind the user cred, set up the call info struct and * execute the task */ if (rpcauth_lookupcred(task) != NULL) { rpc_call_setup(task, proc, argp, resp, 0); rpc_execute(task); } else async = 0; status = 0; if (!async) { status = task->tk_status; rpc_release_task(task); } out: rpc_clnt_sigunmask(clnt, &oldset); return status; } void rpc_call_setup(struct rpc_task *task, u32 proc, void *argp, void *resp, int flags) { task->tk_action = call_bind; task->tk_proc = proc; task->tk_argp = argp; task->tk_resp = resp; task->tk_flags |= flags; /* Increment call count */ rpcproc_count(task->tk_client, proc)++; } /* * Restart an (async) RPC call. Usually called from within the * exit handler. */ void rpc_restart_call(struct rpc_task *task) { if (task->tk_flags & RPC_TASK_KILLED) { rpc_release_task(task); return; } task->tk_action = call_bind; rpcproc_count(task->tk_client, task->tk_proc)++; } /* * 0. Get the server port number if not yet set */ static void call_bind(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; task->tk_action = call_reserve; task->tk_status = 0; if (!clnt->cl_port) rpc_getport(task, clnt); } /* * 1. Reserve an RPC call slot */ static void call_reserve(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; dprintk("RPC: %4d call_reserve\n", task->tk_pid); if (!clnt->cl_port) { printk(KERN_NOTICE "%s: couldn't bind to server %s - %s.\n", clnt->cl_protname, clnt->cl_server, clnt->cl_softrtry? "giving up" : "retrying"); if (!clnt->cl_softrtry) { rpc_delay(task, 5*HZ); return; } rpc_exit(task, -EIO); return; } if (!rpcauth_uptodatecred(task)) { task->tk_action = call_refresh; return; } task->tk_action = call_reserveresult; task->tk_timeout = clnt->cl_timeout.to_resrvval; task->tk_status = 0; clnt->cl_stats->rpccnt++; xprt_reserve(task); } /* * 1b. Grok the result of xprt_reserve() */ static void call_reserveresult(struct rpc_task *task) { dprintk("RPC: %4d call_reserveresult (status %d)\n", task->tk_pid, task->tk_status); /* * After a call to xprt_reserve(), we must have either * a request slot or else an error status. */ if ((task->tk_status >= 0 && !task->tk_rqstp) || (task->tk_status < 0 && task->tk_rqstp)) printk("call_reserveresult: status=%d, request=%p??\n", task->tk_status, task->tk_rqstp); if (task->tk_status >= 0) { task->tk_action = call_allocate; goto out; } else if (task->tk_status == -EAGAIN) { task->tk_timeout = task->tk_client->cl_timeout.to_resrvval; task->tk_status = 0; xprt_reserve(task); goto out; } else if (task->tk_status == -ETIMEDOUT) { dprintk("RPC: task timed out\n"); task->tk_action = call_timeout; goto out; } else { task->tk_action = NULL; } if (!task->tk_rqstp) { printk("RPC: task has no request, exit EIO\n"); rpc_exit(task, -EIO); } out: return; } /* * 2. Allocate the buffer. For details, see sched.c:rpc_malloc. * (Note: buffer memory is freed in rpc_task_release). */ static void call_allocate(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; unsigned int bufsiz; dprintk("RPC: %4d call_allocate (status %d)\n", task->tk_pid, task->tk_status); task->tk_action = call_encode; if (task->tk_buffer) return; /* FIXME: compute buffer requirements more exactly using * auth->au_wslack */ bufsiz = rpcproc_bufsiz(clnt, task->tk_proc) + RPC_SLACK_SPACE; if ((task->tk_buffer = rpc_malloc(task, bufsiz)) != NULL) return; printk("RPC: buffer allocation failed for task %p\n", task); if (!signalled()) { xprt_release(task); task->tk_action = call_reserve; rpc_delay(task, HZ); return; } rpc_exit(task, -ERESTARTSYS); } /* * 3. Encode arguments of an RPC call */ static void call_encode(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; struct rpc_rqst *req = task->tk_rqstp; unsigned int bufsiz; kxdrproc_t encode; int status; u32 *p; dprintk("RPC: %4d call_encode (status %d)\n", task->tk_pid, task->tk_status); task->tk_action = call_transmit; /* Default buffer setup */ bufsiz = rpcproc_bufsiz(clnt, task->tk_proc)+RPC_SLACK_SPACE; req->rq_svec[0].iov_base = task->tk_buffer; req->rq_svec[0].iov_len = bufsiz; req->rq_slen = 0; req->rq_snr = 1; req->rq_rvec[0].iov_base = task->tk_buffer; req->rq_rvec[0].iov_len = bufsiz; req->rq_rlen = bufsiz; req->rq_rnr = 1; if (task->tk_proc > clnt->cl_maxproc) { printk(KERN_WARNING "%s (vers %d): bad procedure number %d\n", clnt->cl_protname, clnt->cl_vers, task->tk_proc); rpc_exit(task, -EIO); return; } /* Encode header and provided arguments */ encode = rpcproc_encode(clnt, task->tk_proc); if (!(p = call_header(task))) { printk("RPC: call_header failed, exit EIO\n"); rpc_exit(task, -EIO); } else if ((status = encode(req, p, task->tk_argp)) < 0) { printk(KERN_WARNING "%s: can't encode arguments: %d\n", clnt->cl_protname, -status); rpc_exit(task, status); } } /* * 4. Transmit the RPC request */ static void call_transmit(struct rpc_task *task) { dprintk("RPC: %4d call_transmit (status %d)\n", task->tk_pid, task->tk_status); task->tk_action = call_receive; task->tk_status = 0; xprt_transmit(task); } /* * 5. Wait for the RPC reply */ static void call_receive(struct rpc_task *task) { dprintk("RPC: %4d call_receive (status %d)\n", task->tk_pid, task->tk_status); task->tk_action = call_status; /* In case of error, evaluate status */ if (task->tk_status < 0) return; /* If we have no decode function, this means we're performing * a void call (a la lockd message passing). */ if (!rpcproc_decode(task->tk_client, task->tk_proc)) { rpc_remove_wait_queue(task); /* remove from xprt_pending */ task->tk_action = NULL; return; } xprt_receive(task); } /* * 6. Sort out the RPC call status */ static void call_status(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; struct rpc_rqst *req; int status = task->tk_status; dprintk("RPC: %4d call_status (status %d)\n", task->tk_pid, task->tk_status); if (status >= 0) { task->tk_action = call_decode; } else if (status == -ETIMEDOUT) { task->tk_action = call_timeout; } else if (status == -EAGAIN) { if (!(req = task->tk_rqstp)) task->tk_action = call_reserve; else if (!task->tk_buffer) task->tk_action = call_allocate; else if (req->rq_damaged) task->tk_action = call_encode; else task->tk_action = call_transmit; } else if (status == -ENOTCONN) { task->tk_action = call_reconnect; } else if (status == -ECONNREFUSED && clnt->cl_autobind) { task->tk_action = call_bind; clnt->cl_port = 0; } else { if (clnt->cl_chatty) printk("%s: RPC call returned error %d\n", clnt->cl_protname, -status); task->tk_action = NULL; return; } } /* * 6a. Handle RPC timeout * We do not release the request slot, so we keep using the * same XID for all retransmits. */ static void call_timeout(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; struct rpc_rqst *req = task->tk_rqstp; if (req) { struct rpc_timeout *to = &req->rq_timeout; if (xprt_adjust_timeout(to)) { dprintk("RPC: %4d call_timeout (minor timeo)\n", task->tk_pid); goto minor_timeout; } to->to_initval <<= 1; if (to->to_initval > to->to_maxval) to->to_initval = to->to_maxval; } dprintk("RPC: %4d call_timeout (major timeo)\n", task->tk_pid); if (clnt->cl_softrtry) { if (clnt->cl_chatty && !task->tk_exit) printk("%s: server %s not responding, timed out\n", clnt->cl_protname, clnt->cl_server); rpc_exit(task, -EIO); return; } if (clnt->cl_chatty && !(task->tk_flags & RPC_CALL_MAJORSEEN)) { task->tk_flags |= RPC_CALL_MAJORSEEN; if (req) printk("%s: server %s not responding, still trying\n", clnt->cl_protname, clnt->cl_server); else printk("%s: task %d can't get a request slot\n", clnt->cl_protname, task->tk_pid); } if (clnt->cl_autobind) clnt->cl_port = 0; minor_timeout: if (!clnt->cl_port) { task->tk_action = call_bind; } else if (!req) { task->tk_action = call_reserve; } else if (req->rq_damaged) { task->tk_action = call_encode; clnt->cl_stats->rpcretrans++; } else { task->tk_action = call_transmit; clnt->cl_stats->rpcretrans++; } task->tk_status = 0; } /* * 6b. Reconnect to the RPC server (TCP case) */ static void call_reconnect(struct rpc_task *task) { dprintk("RPC: %4d call_reconnect status %d\n", task->tk_pid, task->tk_status); if (task->tk_status == 0) { task->tk_action = call_status; task->tk_status = -EAGAIN; return; } task->tk_client->cl_stats->netreconn++; xprt_reconnect(task); } /* * 7. Decode the RPC reply */ static void call_decode(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; struct rpc_rqst *req = task->tk_rqstp; kxdrproc_t decode = rpcproc_decode(clnt, task->tk_proc); u32 *p; dprintk("RPC: %4d call_decode (status %d)\n", task->tk_pid, task->tk_status); if (clnt->cl_chatty && (task->tk_flags & RPC_CALL_MAJORSEEN)) { printk("%s: server %s OK\n", clnt->cl_protname, clnt->cl_server); task->tk_flags &= ~RPC_CALL_MAJORSEEN; } if (task->tk_status < 12) { printk("%s: too small RPC reply size (%d bytes)\n", clnt->cl_protname, task->tk_status); rpc_exit(task, -EIO); return; } /* Verify the RPC header */ if (!(p = call_verify(task))) return; /* * The following is an NFS-specific hack to cater for setuid * processes whose uid is mapped to nobody on the server. */ if (task->tk_client->cl_prog == 100003 && (ntohl(*p) == NFSERR_ACCES || ntohl(*p) == NFSERR_PERM)) { if (RPC_IS_SETUID(task) && (task->tk_suid_retry)--) { dprintk("RPC: %4d retry squashed uid\n", task->tk_pid); task->tk_flags ^= RPC_CALL_REALUID; task->tk_action = call_encode; return; } } task->tk_action = NULL; task->tk_status = decode(req, p, task->tk_resp); dprintk("RPC: %4d call_decode result %d\n", task->tk_pid, task->tk_status); } /* * 8. Refresh the credentials if rejected by the server */ static void call_refresh(struct rpc_task *task) { dprintk("RPC: %4d call_refresh\n", task->tk_pid); xprt_release(task); /* Must do to obtain new XID */ task->tk_action = call_refreshresult; task->tk_status = 0; task->tk_client->cl_stats->rpcauthrefresh++; rpcauth_refreshcred(task); } /* * 8a. Process the results of a credential refresh */ static void call_refreshresult(struct rpc_task *task) { dprintk("RPC: %4d call_refreshresult (status %d)\n", task->tk_pid, task->tk_status); if (task->tk_status < 0) { task->tk_status = -EACCES; task->tk_action = NULL; } else task->tk_action = call_reserve; } /* * Call header serialization */ static u32 * call_header(struct rpc_task *task) { struct rpc_clnt *clnt = task->tk_client; struct rpc_xprt *xprt = clnt->cl_xprt; u32 *p = task->tk_buffer; /* FIXME: check buffer size? */ if (xprt->stream) *p++ = 0; /* fill in later */ *p++ = task->tk_rqstp->rq_xid; /* XID */ *p++ = htonl(RPC_CALL); /* CALL */ *p++ = htonl(RPC_VERSION); /* RPC version */ *p++ = htonl(clnt->cl_prog); /* program number */ *p++ = htonl(clnt->cl_vers); /* program version */ *p++ = htonl(task->tk_proc); /* procedure */ return rpcauth_marshcred(task, p); } /* * Reply header verification */ static u32 * call_verify(struct rpc_task *task) { u32 *p = task->tk_buffer, n; p += 1; /* skip XID */ if ((n = ntohl(*p++)) != RPC_REPLY) { printk("call_verify: not an RPC reply: %x\n", n); goto garbage; } if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) { int error = -EACCES; if ((n = ntohl(*p++)) != RPC_AUTH_ERROR) { printk("call_verify: RPC call rejected: %x\n", n); } else switch ((n = ntohl(*p++))) { case RPC_AUTH_REJECTEDCRED: case RPC_AUTH_REJECTEDVERF: if (!task->tk_cred_retry--) break; dprintk("RPC: %4d call_verify: retry stale creds\n", task->tk_pid); rpcauth_invalcred(task); task->tk_action = call_refresh; return NULL; case RPC_AUTH_BADCRED: case RPC_AUTH_BADVERF: /* possibly garbled cred/verf? */ if (!task->tk_garb_retry--) break; dprintk("RPC: %4d call_verify: retry garbled creds\n", task->tk_pid); task->tk_action = call_encode; return NULL; case RPC_AUTH_TOOWEAK: printk("call_verify: server requires stronger " "authentication.\n"); default: printk("call_verify: unknown auth error: %x\n", n); error = -EIO; } dprintk("RPC: %4d call_verify: call rejected %d\n", task->tk_pid, n); rpc_exit(task, error); return NULL; } if (!(p = rpcauth_checkverf(task, p))) { printk("call_verify: auth check failed\n"); goto garbage; /* bad verifier, retry */ } switch ((n = ntohl(*p++))) { case RPC_SUCCESS: return p; case RPC_GARBAGE_ARGS: break; /* retry */ default: printk("call_verify: server accept status: %x\n", n); /* Also retry */ } garbage: dprintk("RPC: %4d call_verify: server saw garbage\n", task->tk_pid); task->tk_client->cl_stats->rpcgarbage++; if (task->tk_garb_retry--) { printk("RPC: garbage, retrying %4d\n", task->tk_pid); task->tk_action = call_encode; return NULL; } printk("RPC: garbage, exit EIO\n"); rpc_exit(task, -EIO); return NULL; }