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Cross-Referenced Linux and Device Driver Code

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  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_program   = prog;
 39         serv->sv_nrthreads = 1;
 40         serv->sv_stats     = prog->pg_stats;
 41         serv->sv_bufsz     = bufsize? bufsize : 4096;
 42         prog->pg_lovers = prog->pg_nvers-1;
 43         xdrsize = 0;
 44         for (vers=0; vers<prog->pg_nvers ; vers++)
 45                 if (prog->pg_vers[vers]) {
 46                         prog->pg_hivers = vers;
 47                         if (prog->pg_lovers > vers)
 48                                 prog->pg_lovers = vers;
 49                         if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
 50                                 xdrsize = prog->pg_vers[vers]->vs_xdrsize;
 51                 }
 52         serv->sv_xdrsize   = xdrsize;
 53         INIT_LIST_HEAD(&serv->sv_threads);
 54         INIT_LIST_HEAD(&serv->sv_sockets);
 55         INIT_LIST_HEAD(&serv->sv_tempsocks);
 56         INIT_LIST_HEAD(&serv->sv_permsocks);
 57         spin_lock_init(&serv->sv_lock);
 58 
 59         serv->sv_name      = prog->pg_name;
 60 
 61         /* Remove any stale portmap registrations */
 62         svc_register(serv, 0, 0);
 63 
 64         return serv;
 65 }
 66 
 67 /*
 68  * Destroy an RPC service
 69  */
 70 void
 71 svc_destroy(struct svc_serv *serv)
 72 {
 73         struct svc_sock *svsk;
 74 
 75         dprintk("RPC: svc_destroy(%s, %d)\n",
 76                                 serv->sv_program->pg_name,
 77                                 serv->sv_nrthreads);
 78 
 79         if (serv->sv_nrthreads) {
 80                 if (--(serv->sv_nrthreads) != 0) {
 81                         svc_sock_update_bufs(serv);
 82                         return;
 83                 }
 84         } else
 85                 printk("svc_destroy: no threads for serv=%p!\n", serv);
 86 
 87         while (!list_empty(&serv->sv_tempsocks)) {
 88                 svsk = list_entry(serv->sv_tempsocks.next,
 89                                   struct svc_sock,
 90                                   sk_list);
 91                 svc_delete_socket(svsk);
 92         }
 93         while (!list_empty(&serv->sv_permsocks)) {
 94                 svsk = list_entry(serv->sv_permsocks.next,
 95                                   struct svc_sock,
 96                                   sk_list);
 97                 svc_delete_socket(svsk);
 98         }
 99         
100         cache_clean_deferred(serv);
101 
102         /* Unregister service with the portmapper */
103         svc_register(serv, 0, 0);
104         kfree(serv);
105 }
106 
107 /*
108  * Allocate an RPC server's buffer space.
109  * We allocate pages and place them in rq_argpages.
110  */
111 static int
112 svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
113 {
114         int pages;
115         int arghi;
116         
117         if (size > RPCSVC_MAXPAYLOAD)
118                 size = RPCSVC_MAXPAYLOAD;
119         pages = 2 + (size+ PAGE_SIZE -1) / PAGE_SIZE;
120         rqstp->rq_argused = 0;
121         rqstp->rq_resused = 0;
122         arghi = 0;
123         if (pages > RPCSVC_MAXPAGES)
124                 BUG();
125         while (pages) {
126                 struct page *p = alloc_page(GFP_KERNEL);
127                 if (!p)
128                         break;
129                 rqstp->rq_argpages[arghi++] = p;
130                 pages--;
131         }
132         rqstp->rq_arghi = arghi;
133         return ! pages;
134 }
135 
136 /*
137  * Release an RPC server buffer
138  */
139 static void
140 svc_release_buffer(struct svc_rqst *rqstp)
141 {
142         while (rqstp->rq_arghi)
143                 put_page(rqstp->rq_argpages[--rqstp->rq_arghi]);
144         while (rqstp->rq_resused) {
145                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
146                         continue;
147                 put_page(rqstp->rq_respages[rqstp->rq_resused]);
148         }
149         rqstp->rq_argused = 0;
150 }
151 
152 /*
153  * Create a server thread
154  */
155 int
156 svc_create_thread(svc_thread_fn func, struct svc_serv *serv)
157 {
158         struct svc_rqst *rqstp;
159         int             error = -ENOMEM;
160 
161         rqstp = kmalloc(sizeof(*rqstp), GFP_KERNEL);
162         if (!rqstp)
163                 goto out;
164 
165         memset(rqstp, 0, sizeof(*rqstp));
166         init_waitqueue_head(&rqstp->rq_wait);
167 
168         if (!(rqstp->rq_argp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
169          || !(rqstp->rq_resp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
170          || !svc_init_buffer(rqstp, serv->sv_bufsz))
171                 goto out_thread;
172 
173         serv->sv_nrthreads++;
174         rqstp->rq_server = serv;
175         error = kernel_thread((int (*)(void *)) func, rqstp, 0);
176         if (error < 0)
177                 goto out_thread;
178         svc_sock_update_bufs(serv);
179         error = 0;
180 out:
181         return error;
182 
183 out_thread:
184         svc_exit_thread(rqstp);
185         goto out;
186 }
187 
188 /*
189  * Destroy an RPC server thread
190  */
191 void
192 svc_exit_thread(struct svc_rqst *rqstp)
193 {
194         struct svc_serv *serv = rqstp->rq_server;
195 
196         svc_release_buffer(rqstp);
197         if (rqstp->rq_resp)
198                 kfree(rqstp->rq_resp);
199         if (rqstp->rq_argp)
200                 kfree(rqstp->rq_argp);
201         if (rqstp->rq_auth_data)
202                 kfree(rqstp->rq_auth_data);
203         kfree(rqstp);
204 
205         /* Release the server */
206         if (serv)
207                 svc_destroy(serv);
208 }
209 
210 /*
211  * Register an RPC service with the local portmapper.
212  * To unregister a service, call this routine with 
213  * proto and port == 0.
214  */
215 int
216 svc_register(struct svc_serv *serv, int proto, unsigned short port)
217 {
218         struct svc_program      *progp;
219         unsigned long           flags;
220         int                     i, error = 0, dummy;
221 
222         progp = serv->sv_program;
223 
224         dprintk("RPC: svc_register(%s, %s, %d)\n",
225                 progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);
226 
227         if (!port)
228                 clear_thread_flag(TIF_SIGPENDING);
229 
230         for (i = 0; i < progp->pg_nvers; i++) {
231                 if (progp->pg_vers[i] == NULL)
232                         continue;
233                 error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
234                 if (error < 0)
235                         break;
236                 if (port && !dummy) {
237                         error = -EACCES;
238                         break;
239                 }
240         }
241 
242         if (!port) {
243                 spin_lock_irqsave(&current->sighand->siglock, flags);
244                 recalc_sigpending();
245                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
246         }
247 
248         return error;
249 }
250 
251 /*
252  * Process the RPC request.
253  */
254 int
255 svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
256 {
257         struct svc_program      *progp;
258         struct svc_version      *versp = NULL;  /* compiler food */
259         struct svc_procedure    *procp = NULL;
260         struct kvec *           argv = &rqstp->rq_arg.head[0];
261         struct kvec *           resv = &rqstp->rq_res.head[0];
262         kxdrproc_t              xdr;
263         u32                     *statp;
264         u32                     dir, prog, vers, proc,
265                                 auth_stat, rpc_stat;
266         int                     auth_res;
267 
268         rpc_stat = rpc_success;
269 
270         if (argv->iov_len < 6*4)
271                 goto err_short_len;
272 
273         /* setup response xdr_buf.
274          * Initially it has just one page 
275          */
276         svc_take_page(rqstp); /* must succeed */
277         resv->iov_base = page_address(rqstp->rq_respages[0]);
278         resv->iov_len = 0;
279         rqstp->rq_res.pages = rqstp->rq_respages+1;
280         rqstp->rq_res.len = 0;
281         rqstp->rq_res.page_base = 0;
282         rqstp->rq_res.page_len = 0;
283         rqstp->rq_res.tail[0].iov_len = 0;
284         /* tcp needs a space for the record length... */
285         if (rqstp->rq_prot == IPPROTO_TCP)
286                 svc_putu32(resv, 0);
287 
288         rqstp->rq_xid = svc_getu32(argv);
289         svc_putu32(resv, rqstp->rq_xid);
290 
291         dir  = ntohl(svc_getu32(argv));
292         vers = ntohl(svc_getu32(argv));
293 
294         /* First words of reply: */
295         svc_putu32(resv, xdr_one);              /* REPLY */
296 
297         if (dir != 0)           /* direction != CALL */
298                 goto err_bad_dir;
299         if (vers != 2)          /* RPC version number */
300                 goto err_bad_rpc;
301 
302         svc_putu32(resv, xdr_zero);             /* ACCEPT */
303 
304         rqstp->rq_prog = prog = ntohl(svc_getu32(argv));        /* program number */
305         rqstp->rq_vers = vers = ntohl(svc_getu32(argv));        /* version number */
306         rqstp->rq_proc = proc = ntohl(svc_getu32(argv));        /* procedure number */
307 
308         progp = serv->sv_program;
309         /*
310          * Decode auth data, and add verifier to reply buffer.
311          * We do this before anything else in order to get a decent
312          * auth verifier.
313          */
314         if (progp->pg_authenticate != NULL)
315                 auth_res = progp->pg_authenticate(rqstp, &auth_stat);
316         else
317                 auth_res = svc_authenticate(rqstp, &auth_stat);
318         switch (auth_res) {
319         case SVC_OK:
320                 break;
321         case SVC_GARBAGE:
322                 rpc_stat = rpc_garbage_args;
323                 goto err_bad;
324         case SVC_SYSERR:
325                 rpc_stat = rpc_system_err;
326                 goto err_bad;
327         case SVC_DENIED:
328                 goto err_bad_auth;
329         case SVC_DROP:
330                 goto dropit;
331         case SVC_COMPLETE:
332                 goto sendit;
333         }
334                 
335         if (prog != progp->pg_prog)
336                 goto err_bad_prog;
337 
338         if (vers >= progp->pg_nvers ||
339           !(versp = progp->pg_vers[vers]))
340                 goto err_bad_vers;
341 
342         procp = versp->vs_proc + proc;
343         if (proc >= versp->vs_nproc || !procp->pc_func)
344                 goto err_bad_proc;
345         rqstp->rq_server   = serv;
346         rqstp->rq_procinfo = procp;
347 
348         /* Syntactic check complete */
349         serv->sv_stats->rpccnt++;
350 
351         /* Build the reply header. */
352         statp = resv->iov_base +resv->iov_len;
353         svc_putu32(resv, rpc_success);          /* RPC_SUCCESS */
354 
355         /* Bump per-procedure stats counter */
356         procp->pc_count++;
357 
358         /* Initialize storage for argp and resp */
359         memset(rqstp->rq_argp, 0, procp->pc_argsize);
360         memset(rqstp->rq_resp, 0, procp->pc_ressize);
361 
362         /* un-reserve some of the out-queue now that we have a 
363          * better idea of reply size
364          */
365         if (procp->pc_xdrressize)
366                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
367 
368         /* Call the function that processes the request. */
369         if (!versp->vs_dispatch) {
370                 /* Decode arguments */
371                 xdr = procp->pc_decode;
372                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
373                         goto err_garbage;
374 
375                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
376 
377                 /* Encode reply */
378                 if (*statp == rpc_success && (xdr = procp->pc_encode)
379                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
380                         dprintk("svc: failed to encode reply\n");
381                         /* serv->sv_stats->rpcsystemerr++; */
382                         *statp = rpc_system_err;
383                 }
384         } else {
385                 dprintk("svc: calling dispatcher\n");
386                 if (!versp->vs_dispatch(rqstp, statp)) {
387                         /* Release reply info */
388                         if (procp->pc_release)
389                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
390                         goto dropit;
391                 }
392         }
393 
394         /* Check RPC status result */
395         if (*statp != rpc_success)
396                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
397 
398         /* Release reply info */
399         if (procp->pc_release)
400                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
401 
402         if (procp->pc_encode == NULL)
403                 goto dropit;
404 
405  sendit:
406         if (svc_authorise(rqstp))
407                 goto dropit;
408         return svc_send(rqstp);
409 
410  dropit:
411         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
412         dprintk("svc: svc_process dropit\n");
413         svc_drop(rqstp);
414         return 0;
415 
416 err_short_len:
417 #ifdef RPC_PARANOIA
418         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
419 #endif
420         goto dropit;                    /* drop request */
421 
422 err_bad_dir:
423 #ifdef RPC_PARANOIA
424         printk("svc: bad direction %d, dropping request\n", dir);
425 #endif
426         serv->sv_stats->rpcbadfmt++;
427         goto dropit;                    /* drop request */
428 
429 err_bad_rpc:
430         serv->sv_stats->rpcbadfmt++;
431         svc_putu32(resv, xdr_one);      /* REJECT */
432         svc_putu32(resv, xdr_zero);     /* RPC_MISMATCH */
433         svc_putu32(resv, xdr_two);      /* Only RPCv2 supported */
434         svc_putu32(resv, xdr_two);
435         goto sendit;
436 
437 err_bad_auth:
438         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
439         serv->sv_stats->rpcbadauth++;
440         resv->iov_len -= 4;
441         svc_putu32(resv, xdr_one);      /* REJECT */
442         svc_putu32(resv, xdr_one);      /* AUTH_ERROR */
443         svc_putu32(resv, auth_stat);    /* status */
444         goto sendit;
445 
446 err_bad_prog:
447 #ifdef RPC_PARANOIA
448         if (prog != 100227 || progp->pg_prog != 100003)
449                 printk("svc: unknown program %d (me %d)\n", prog, progp->pg_prog);
450         /* else it is just a Solaris client seeing if ACLs are supported */
451 #endif
452         serv->sv_stats->rpcbadfmt++;
453         svc_putu32(resv, rpc_prog_unavail);
454         goto sendit;
455 
456 err_bad_vers:
457 #ifdef RPC_PARANOIA
458         printk("svc: unknown version (%d)\n", vers);
459 #endif
460         serv->sv_stats->rpcbadfmt++;
461         svc_putu32(resv, rpc_prog_mismatch);
462         svc_putu32(resv, htonl(progp->pg_lovers));
463         svc_putu32(resv, htonl(progp->pg_hivers));
464         goto sendit;
465 
466 err_bad_proc:
467 #ifdef RPC_PARANOIA
468         printk("svc: unknown procedure (%d)\n", proc);
469 #endif
470         serv->sv_stats->rpcbadfmt++;
471         svc_putu32(resv, rpc_proc_unavail);
472         goto sendit;
473 
474 err_garbage:
475 #ifdef RPC_PARANOIA
476         printk("svc: failed to decode args\n");
477 #endif
478         rpc_stat = rpc_garbage_args;
479 err_bad:
480         serv->sv_stats->rpcbadfmt++;
481         svc_putu32(resv, rpc_stat);
482         goto sendit;
483 }
484 
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