xref: /openbmc/linux/net/sunrpc/svc.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /*
2  * linux/net/sunrpc/svc.c
3  *
4  * High-level RPC service routines
5  *
6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7  */
8 
9 #include <linux/linkage.h>
10 #include <linux/sched.h>
11 #include <linux/errno.h>
12 #include <linux/net.h>
13 #include <linux/in.h>
14 #include <linux/mm.h>
15 
16 #include <linux/sunrpc/types.h>
17 #include <linux/sunrpc/xdr.h>
18 #include <linux/sunrpc/stats.h>
19 #include <linux/sunrpc/svcsock.h>
20 #include <linux/sunrpc/clnt.h>
21 
22 #define RPCDBG_FACILITY	RPCDBG_SVCDSP
23 #define RPC_PARANOIA 1
24 
25 /*
26  * Create an RPC service
27  */
28 struct svc_serv *
29 svc_create(struct svc_program *prog, unsigned int bufsize)
30 {
31 	struct svc_serv	*serv;
32 	int vers;
33 	unsigned int xdrsize;
34 
35 	if (!(serv = (struct svc_serv *) kmalloc(sizeof(*serv), GFP_KERNEL)))
36 		return NULL;
37 	memset(serv, 0, sizeof(*serv));
38 	serv->sv_name      = prog->pg_name;
39 	serv->sv_program   = prog;
40 	serv->sv_nrthreads = 1;
41 	serv->sv_stats     = prog->pg_stats;
42 	serv->sv_bufsz	   = bufsize? bufsize : 4096;
43 	xdrsize = 0;
44 	while (prog) {
45 		prog->pg_lovers = prog->pg_nvers-1;
46 		for (vers=0; vers<prog->pg_nvers ; vers++)
47 			if (prog->pg_vers[vers]) {
48 				prog->pg_hivers = vers;
49 				if (prog->pg_lovers > vers)
50 					prog->pg_lovers = vers;
51 				if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
52 					xdrsize = prog->pg_vers[vers]->vs_xdrsize;
53 			}
54 		prog = prog->pg_next;
55 	}
56 	serv->sv_xdrsize   = xdrsize;
57 	INIT_LIST_HEAD(&serv->sv_threads);
58 	INIT_LIST_HEAD(&serv->sv_sockets);
59 	INIT_LIST_HEAD(&serv->sv_tempsocks);
60 	INIT_LIST_HEAD(&serv->sv_permsocks);
61 	spin_lock_init(&serv->sv_lock);
62 
63 	/* Remove any stale portmap registrations */
64 	svc_register(serv, 0, 0);
65 
66 	return serv;
67 }
68 
69 /*
70  * Destroy an RPC service
71  */
72 void
73 svc_destroy(struct svc_serv *serv)
74 {
75 	struct svc_sock	*svsk;
76 
77 	dprintk("RPC: svc_destroy(%s, %d)\n",
78 				serv->sv_program->pg_name,
79 				serv->sv_nrthreads);
80 
81 	if (serv->sv_nrthreads) {
82 		if (--(serv->sv_nrthreads) != 0) {
83 			svc_sock_update_bufs(serv);
84 			return;
85 		}
86 	} else
87 		printk("svc_destroy: no threads for serv=%p!\n", serv);
88 
89 	while (!list_empty(&serv->sv_tempsocks)) {
90 		svsk = list_entry(serv->sv_tempsocks.next,
91 				  struct svc_sock,
92 				  sk_list);
93 		svc_delete_socket(svsk);
94 	}
95 	while (!list_empty(&serv->sv_permsocks)) {
96 		svsk = list_entry(serv->sv_permsocks.next,
97 				  struct svc_sock,
98 				  sk_list);
99 		svc_delete_socket(svsk);
100 	}
101 
102 	cache_clean_deferred(serv);
103 
104 	/* Unregister service with the portmapper */
105 	svc_register(serv, 0, 0);
106 	kfree(serv);
107 }
108 
109 /*
110  * Allocate an RPC server's buffer space.
111  * We allocate pages and place them in rq_argpages.
112  */
113 static int
114 svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
115 {
116 	int pages;
117 	int arghi;
118 
119 	if (size > RPCSVC_MAXPAYLOAD)
120 		size = RPCSVC_MAXPAYLOAD;
121 	pages = 2 + (size+ PAGE_SIZE -1) / PAGE_SIZE;
122 	rqstp->rq_argused = 0;
123 	rqstp->rq_resused = 0;
124 	arghi = 0;
125 	if (pages > RPCSVC_MAXPAGES)
126 		BUG();
127 	while (pages) {
128 		struct page *p = alloc_page(GFP_KERNEL);
129 		if (!p)
130 			break;
131 		rqstp->rq_argpages[arghi++] = p;
132 		pages--;
133 	}
134 	rqstp->rq_arghi = arghi;
135 	return ! pages;
136 }
137 
138 /*
139  * Release an RPC server buffer
140  */
141 static void
142 svc_release_buffer(struct svc_rqst *rqstp)
143 {
144 	while (rqstp->rq_arghi)
145 		put_page(rqstp->rq_argpages[--rqstp->rq_arghi]);
146 	while (rqstp->rq_resused) {
147 		if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
148 			continue;
149 		put_page(rqstp->rq_respages[rqstp->rq_resused]);
150 	}
151 	rqstp->rq_argused = 0;
152 }
153 
154 /*
155  * Create a server thread
156  */
157 int
158 svc_create_thread(svc_thread_fn func, struct svc_serv *serv)
159 {
160 	struct svc_rqst	*rqstp;
161 	int		error = -ENOMEM;
162 
163 	rqstp = kmalloc(sizeof(*rqstp), GFP_KERNEL);
164 	if (!rqstp)
165 		goto out;
166 
167 	memset(rqstp, 0, sizeof(*rqstp));
168 	init_waitqueue_head(&rqstp->rq_wait);
169 
170 	if (!(rqstp->rq_argp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
171 	 || !(rqstp->rq_resp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
172 	 || !svc_init_buffer(rqstp, serv->sv_bufsz))
173 		goto out_thread;
174 
175 	serv->sv_nrthreads++;
176 	rqstp->rq_server = serv;
177 	error = kernel_thread((int (*)(void *)) func, rqstp, 0);
178 	if (error < 0)
179 		goto out_thread;
180 	svc_sock_update_bufs(serv);
181 	error = 0;
182 out:
183 	return error;
184 
185 out_thread:
186 	svc_exit_thread(rqstp);
187 	goto out;
188 }
189 
190 /*
191  * Destroy an RPC server thread
192  */
193 void
194 svc_exit_thread(struct svc_rqst *rqstp)
195 {
196 	struct svc_serv	*serv = rqstp->rq_server;
197 
198 	svc_release_buffer(rqstp);
199 	if (rqstp->rq_resp)
200 		kfree(rqstp->rq_resp);
201 	if (rqstp->rq_argp)
202 		kfree(rqstp->rq_argp);
203 	if (rqstp->rq_auth_data)
204 		kfree(rqstp->rq_auth_data);
205 	kfree(rqstp);
206 
207 	/* Release the server */
208 	if (serv)
209 		svc_destroy(serv);
210 }
211 
212 /*
213  * Register an RPC service with the local portmapper.
214  * To unregister a service, call this routine with
215  * proto and port == 0.
216  */
217 int
218 svc_register(struct svc_serv *serv, int proto, unsigned short port)
219 {
220 	struct svc_program	*progp;
221 	unsigned long		flags;
222 	int			i, error = 0, dummy;
223 
224 	progp = serv->sv_program;
225 
226 	dprintk("RPC: svc_register(%s, %s, %d)\n",
227 		progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);
228 
229 	if (!port)
230 		clear_thread_flag(TIF_SIGPENDING);
231 
232 	for (i = 0; i < progp->pg_nvers; i++) {
233 		if (progp->pg_vers[i] == NULL)
234 			continue;
235 		error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
236 		if (error < 0)
237 			break;
238 		if (port && !dummy) {
239 			error = -EACCES;
240 			break;
241 		}
242 	}
243 
244 	if (!port) {
245 		spin_lock_irqsave(&current->sighand->siglock, flags);
246 		recalc_sigpending();
247 		spin_unlock_irqrestore(&current->sighand->siglock, flags);
248 	}
249 
250 	return error;
251 }
252 
253 /*
254  * Process the RPC request.
255  */
256 int
257 svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
258 {
259 	struct svc_program	*progp;
260 	struct svc_version	*versp = NULL;	/* compiler food */
261 	struct svc_procedure	*procp = NULL;
262 	struct kvec *		argv = &rqstp->rq_arg.head[0];
263 	struct kvec *		resv = &rqstp->rq_res.head[0];
264 	kxdrproc_t		xdr;
265 	u32			*statp;
266 	u32			dir, prog, vers, proc,
267 				auth_stat, rpc_stat;
268 	int			auth_res;
269 	u32			*accept_statp;
270 
271 	rpc_stat = rpc_success;
272 
273 	if (argv->iov_len < 6*4)
274 		goto err_short_len;
275 
276 	/* setup response xdr_buf.
277 	 * Initially it has just one page
278 	 */
279 	svc_take_page(rqstp); /* must succeed */
280 	resv->iov_base = page_address(rqstp->rq_respages[0]);
281 	resv->iov_len = 0;
282 	rqstp->rq_res.pages = rqstp->rq_respages+1;
283 	rqstp->rq_res.len = 0;
284 	rqstp->rq_res.page_base = 0;
285 	rqstp->rq_res.page_len = 0;
286 	rqstp->rq_res.buflen = PAGE_SIZE;
287 	rqstp->rq_res.tail[0].iov_len = 0;
288 	/* tcp needs a space for the record length... */
289 	if (rqstp->rq_prot == IPPROTO_TCP)
290 		svc_putu32(resv, 0);
291 
292 	rqstp->rq_xid = svc_getu32(argv);
293 	svc_putu32(resv, rqstp->rq_xid);
294 
295 	dir  = ntohl(svc_getu32(argv));
296 	vers = ntohl(svc_getu32(argv));
297 
298 	/* First words of reply: */
299 	svc_putu32(resv, xdr_one);		/* REPLY */
300 
301 	if (dir != 0)		/* direction != CALL */
302 		goto err_bad_dir;
303 	if (vers != 2)		/* RPC version number */
304 		goto err_bad_rpc;
305 
306 	/* Save position in case we later decide to reject: */
307 	accept_statp = resv->iov_base + resv->iov_len;
308 
309 	svc_putu32(resv, xdr_zero);		/* ACCEPT */
310 
311 	rqstp->rq_prog = prog = ntohl(svc_getu32(argv));	/* program number */
312 	rqstp->rq_vers = vers = ntohl(svc_getu32(argv));	/* version number */
313 	rqstp->rq_proc = proc = ntohl(svc_getu32(argv));	/* procedure number */
314 
315 	progp = serv->sv_program;
316 	/*
317 	 * Decode auth data, and add verifier to reply buffer.
318 	 * We do this before anything else in order to get a decent
319 	 * auth verifier.
320 	 */
321 	auth_res = svc_authenticate(rqstp, &auth_stat);
322 	/* Also give the program a chance to reject this call: */
323 	if (auth_res == SVC_OK) {
324 		auth_stat = rpc_autherr_badcred;
325 		auth_res = progp->pg_authenticate(rqstp);
326 	}
327 	switch (auth_res) {
328 	case SVC_OK:
329 		break;
330 	case SVC_GARBAGE:
331 		rpc_stat = rpc_garbage_args;
332 		goto err_bad;
333 	case SVC_SYSERR:
334 		rpc_stat = rpc_system_err;
335 		goto err_bad;
336 	case SVC_DENIED:
337 		goto err_bad_auth;
338 	case SVC_DROP:
339 		goto dropit;
340 	case SVC_COMPLETE:
341 		goto sendit;
342 	}
343 
344 	for (progp = serv->sv_program; progp; progp = progp->pg_next)
345 		if (prog == progp->pg_prog)
346 			break;
347 	if (progp == NULL)
348 		goto err_bad_prog;
349 
350 	if (vers >= progp->pg_nvers ||
351 	  !(versp = progp->pg_vers[vers]))
352 		goto err_bad_vers;
353 
354 	procp = versp->vs_proc + proc;
355 	if (proc >= versp->vs_nproc || !procp->pc_func)
356 		goto err_bad_proc;
357 	rqstp->rq_server   = serv;
358 	rqstp->rq_procinfo = procp;
359 
360 	/* Syntactic check complete */
361 	serv->sv_stats->rpccnt++;
362 
363 	/* Build the reply header. */
364 	statp = resv->iov_base +resv->iov_len;
365 	svc_putu32(resv, rpc_success);		/* RPC_SUCCESS */
366 
367 	/* Bump per-procedure stats counter */
368 	procp->pc_count++;
369 
370 	/* Initialize storage for argp and resp */
371 	memset(rqstp->rq_argp, 0, procp->pc_argsize);
372 	memset(rqstp->rq_resp, 0, procp->pc_ressize);
373 
374 	/* un-reserve some of the out-queue now that we have a
375 	 * better idea of reply size
376 	 */
377 	if (procp->pc_xdrressize)
378 		svc_reserve(rqstp, procp->pc_xdrressize<<2);
379 
380 	/* Call the function that processes the request. */
381 	if (!versp->vs_dispatch) {
382 		/* Decode arguments */
383 		xdr = procp->pc_decode;
384 		if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
385 			goto err_garbage;
386 
387 		*statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
388 
389 		/* Encode reply */
390 		if (*statp == rpc_success && (xdr = procp->pc_encode)
391 		 && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
392 			dprintk("svc: failed to encode reply\n");
393 			/* serv->sv_stats->rpcsystemerr++; */
394 			*statp = rpc_system_err;
395 		}
396 	} else {
397 		dprintk("svc: calling dispatcher\n");
398 		if (!versp->vs_dispatch(rqstp, statp)) {
399 			/* Release reply info */
400 			if (procp->pc_release)
401 				procp->pc_release(rqstp, NULL, rqstp->rq_resp);
402 			goto dropit;
403 		}
404 	}
405 
406 	/* Check RPC status result */
407 	if (*statp != rpc_success)
408 		resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
409 
410 	/* Release reply info */
411 	if (procp->pc_release)
412 		procp->pc_release(rqstp, NULL, rqstp->rq_resp);
413 
414 	if (procp->pc_encode == NULL)
415 		goto dropit;
416 
417  sendit:
418 	if (svc_authorise(rqstp))
419 		goto dropit;
420 	return svc_send(rqstp);
421 
422  dropit:
423 	svc_authorise(rqstp);	/* doesn't hurt to call this twice */
424 	dprintk("svc: svc_process dropit\n");
425 	svc_drop(rqstp);
426 	return 0;
427 
428 err_short_len:
429 #ifdef RPC_PARANOIA
430 	printk("svc: short len %Zd, dropping request\n", argv->iov_len);
431 #endif
432 	goto dropit;			/* drop request */
433 
434 err_bad_dir:
435 #ifdef RPC_PARANOIA
436 	printk("svc: bad direction %d, dropping request\n", dir);
437 #endif
438 	serv->sv_stats->rpcbadfmt++;
439 	goto dropit;			/* drop request */
440 
441 err_bad_rpc:
442 	serv->sv_stats->rpcbadfmt++;
443 	svc_putu32(resv, xdr_one);	/* REJECT */
444 	svc_putu32(resv, xdr_zero);	/* RPC_MISMATCH */
445 	svc_putu32(resv, xdr_two);	/* Only RPCv2 supported */
446 	svc_putu32(resv, xdr_two);
447 	goto sendit;
448 
449 err_bad_auth:
450 	dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
451 	serv->sv_stats->rpcbadauth++;
452 	/* Restore write pointer to location of accept status: */
453 	xdr_ressize_check(rqstp, accept_statp);
454 	svc_putu32(resv, xdr_one);	/* REJECT */
455 	svc_putu32(resv, xdr_one);	/* AUTH_ERROR */
456 	svc_putu32(resv, auth_stat);	/* status */
457 	goto sendit;
458 
459 err_bad_prog:
460 	dprintk("svc: unknown program %d\n", prog);
461 	serv->sv_stats->rpcbadfmt++;
462 	svc_putu32(resv, rpc_prog_unavail);
463 	goto sendit;
464 
465 err_bad_vers:
466 #ifdef RPC_PARANOIA
467 	printk("svc: unknown version (%d)\n", vers);
468 #endif
469 	serv->sv_stats->rpcbadfmt++;
470 	svc_putu32(resv, rpc_prog_mismatch);
471 	svc_putu32(resv, htonl(progp->pg_lovers));
472 	svc_putu32(resv, htonl(progp->pg_hivers));
473 	goto sendit;
474 
475 err_bad_proc:
476 #ifdef RPC_PARANOIA
477 	printk("svc: unknown procedure (%d)\n", proc);
478 #endif
479 	serv->sv_stats->rpcbadfmt++;
480 	svc_putu32(resv, rpc_proc_unavail);
481 	goto sendit;
482 
483 err_garbage:
484 #ifdef RPC_PARANOIA
485 	printk("svc: failed to decode args\n");
486 #endif
487 	rpc_stat = rpc_garbage_args;
488 err_bad:
489 	serv->sv_stats->rpcbadfmt++;
490 	svc_putu32(resv, rpc_stat);
491 	goto sendit;
492 }
493