net/sunrpc/svc.c

   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         BUG_ON(pages > RPCSVC_MAXPAGES);
 126         while (pages) {
 127                 struct page *p = alloc_page(GFP_KERNEL);
 128                 if (!p)
 129                         break;
 130                 rqstp->rq_argpages[arghi++] = p;
 131                 pages--;
 132         }
 133         rqstp->rq_arghi = arghi;
 134         return ! pages;
 135 }
 136
 137 /*
 138  * Release an RPC server buffer
 139  */
 140 static void
 141 svc_release_buffer(struct svc_rqst *rqstp)
 142 {
 143         while (rqstp->rq_arghi)
 144                 put_page(rqstp->rq_argpages[--rqstp->rq_arghi]);
 145         while (rqstp->rq_resused) {
 146                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 147                         continue;
 148                 put_page(rqstp->rq_respages[rqstp->rq_resused]);
 149         }
 150         rqstp->rq_argused = 0;
 151 }
 152
 153 /*
 154  * Create a server thread
 155  */
 156 int
 157 svc_create_thread(svc_thread_fn func, struct svc_serv *serv)
 158 {
 159         struct svc_rqst *rqstp;
 160         int             error = -ENOMEM;
 161
 162         rqstp = kmalloc(sizeof(*rqstp), GFP_KERNEL);
 163         if (!rqstp)
 164                 goto out;
 165
 166         memset(rqstp, 0, sizeof(*rqstp));
 167         init_waitqueue_head(&rqstp->rq_wait);
 168
 169         if (!(rqstp->rq_argp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
 170          || !(rqstp->rq_resp = (u32 *) kmalloc(serv->sv_xdrsize, GFP_KERNEL))
 171          || !svc_init_buffer(rqstp, serv->sv_bufsz))
 172                 goto out_thread;
 173
 174         serv->sv_nrthreads++;
 175         rqstp->rq_server = serv;
 176         error = kernel_thread((int (*)(void *)) func, rqstp, 0);
 177         if (error < 0)
 178                 goto out_thread;
 179         svc_sock_update_bufs(serv);
 180         error = 0;
 181 out:
 182         return error;
 183
 184 out_thread:
 185         svc_exit_thread(rqstp);
 186         goto out;
 187 }
 188
 189 /*
 190  * Destroy an RPC server thread
 191  */
 192 void
 193 svc_exit_thread(struct svc_rqst *rqstp)
 194 {
 195         struct svc_serv *serv = rqstp->rq_server;
 196
 197         svc_release_buffer(rqstp);
 198         kfree(rqstp->rq_resp);
 199         kfree(rqstp->rq_argp);
 200         kfree(rqstp->rq_auth_data);
 201         kfree(rqstp);
 202
 203         /* Release the server */
 204         if (serv)
 205                 svc_destroy(serv);
 206 }
 207
 208 /*
 209  * Register an RPC service with the local portmapper.
 210  * To unregister a service, call this routine with
 211  * proto and port == 0.
 212  */
 213 int
 214 svc_register(struct svc_serv *serv, int proto, unsigned short port)
 215 {
 216         struct svc_program      *progp;
 217         unsigned long           flags;
 218         int                     i, error = 0, dummy;
 219
 220         progp = serv->sv_program;
 221
 222         dprintk("RPC: svc_register(%s, %s, %d)\n",
 223                 progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);
 224
 225         if (!port)
 226                 clear_thread_flag(TIF_SIGPENDING);
 227
 228         for (i = 0; i < progp->pg_nvers; i++) {
 229                 if (progp->pg_vers[i] == NULL)
 230                         continue;
 231                 error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
 232                 if (error < 0)
 233                         break;
 234                 if (port && !dummy) {
 235                         error = -EACCES;
 236                         break;
 237                 }
 238         }
 239
 240         if (!port) {
 241                 spin_lock_irqsave(&current->sighand->siglock, flags);
 242                 recalc_sigpending();
 243                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 244         }
 245
 246         return error;
 247 }
 248
 249 /*
 250  * Process the RPC request.
 251  */
 252 int
 253 svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
 254 {
 255         struct svc_program      *progp;
 256         struct svc_version      *versp = NULL;  /* compiler food */
 257         struct svc_procedure    *procp = NULL;
 258         struct kvec *           argv = &rqstp->rq_arg.head[0];
 259         struct kvec *           resv = &rqstp->rq_res.head[0];
 260         kxdrproc_t              xdr;
 261         u32                     *statp;
 262         u32                     dir, prog, vers, proc,
 263                                 auth_stat, rpc_stat;
 264         int                     auth_res;
 265         u32                     *accept_statp;
 266
 267         rpc_stat = rpc_success;
 268
 269         if (argv->iov_len < 6*4)
 270                 goto err_short_len;
 271
 272         /* setup response xdr_buf.
 273          * Initially it has just one page
 274          */
 275         svc_take_page(rqstp); /* must succeed */
 276         resv->iov_base = page_address(rqstp->rq_respages[0]);
 277         resv->iov_len = 0;
 278         rqstp->rq_res.pages = rqstp->rq_respages+1;
 279         rqstp->rq_res.len = 0;
 280         rqstp->rq_res.page_base = 0;
 281         rqstp->rq_res.page_len = 0;
 282         rqstp->rq_res.buflen = PAGE_SIZE;
 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         /* Save position in case we later decide to reject: */
 303         accept_statp = resv->iov_base + resv->iov_len;
 304
 305         svc_putu32(resv, xdr_zero);             /* ACCEPT */
 306
 307         rqstp->rq_prog = prog = ntohl(svc_getu32(argv));        /* program number */
 308         rqstp->rq_vers = vers = ntohl(svc_getu32(argv));        /* version number */
 309         rqstp->rq_proc = proc = ntohl(svc_getu32(argv));        /* procedure number */
 310
 311         progp = serv->sv_program;
 312
 313         for (progp = serv->sv_program; progp; progp = progp->pg_next)
 314                 if (prog == progp->pg_prog)
 315                         break;
 316
 317         /*
 318          * Decode auth data, and add verifier to reply buffer.
 319          * We do this before anything else in order to get a decent
 320          * auth verifier.
 321          */
 322         auth_res = svc_authenticate(rqstp, &auth_stat);
 323         /* Also give the program a chance to reject this call: */
 324         if (auth_res == SVC_OK && progp) {
 325                 auth_stat = rpc_autherr_badcred;
 326                 auth_res = progp->pg_authenticate(rqstp);
 327         }
 328         switch (auth_res) {
 329         case SVC_OK:
 330                 break;
 331         case SVC_GARBAGE:
 332                 rpc_stat = rpc_garbage_args;
 333                 goto err_bad;
 334         case SVC_SYSERR:
 335                 rpc_stat = rpc_system_err;
 336                 goto err_bad;
 337         case SVC_DENIED:
 338                 goto err_bad_auth;
 339         case SVC_DROP:
 340                 goto dropit;
 341         case SVC_COMPLETE:
 342                 goto sendit;
 343         }
 344
 345         if (progp == NULL)
 346                 goto err_bad_prog;
 347
 348         if (vers >= progp->pg_nvers ||
 349           !(versp = progp->pg_vers[vers]))
 350                 goto err_bad_vers;
 351
 352         procp = versp->vs_proc + proc;
 353         if (proc >= versp->vs_nproc || !procp->pc_func)
 354                 goto err_bad_proc;
 355         rqstp->rq_server   = serv;
 356         rqstp->rq_procinfo = procp;
 357
 358         /* Syntactic check complete */
 359         serv->sv_stats->rpccnt++;
 360
 361         /* Build the reply header. */
 362         statp = resv->iov_base +resv->iov_len;
 363         svc_putu32(resv, rpc_success);          /* RPC_SUCCESS */
 364
 365         /* Bump per-procedure stats counter */
 366         procp->pc_count++;
 367
 368         /* Initialize storage for argp and resp */
 369         memset(rqstp->rq_argp, 0, procp->pc_argsize);
 370         memset(rqstp->rq_resp, 0, procp->pc_ressize);
 371
 372         /* un-reserve some of the out-queue now that we have a
 373          * better idea of reply size
 374          */
 375         if (procp->pc_xdrressize)
 376                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
 377
 378         /* Call the function that processes the request. */
 379         if (!versp->vs_dispatch) {
 380                 /* Decode arguments */
 381                 xdr = procp->pc_decode;
 382                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
 383                         goto err_garbage;
 384
 385                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 386
 387                 /* Encode reply */
 388                 if (*statp == rpc_success && (xdr = procp->pc_encode)
 389                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
 390                         dprintk("svc: failed to encode reply\n");
 391                         /* serv->sv_stats->rpcsystemerr++; */
 392                         *statp = rpc_system_err;
 393                 }
 394         } else {
 395                 dprintk("svc: calling dispatcher\n");
 396                 if (!versp->vs_dispatch(rqstp, statp)) {
 397                         /* Release reply info */
 398                         if (procp->pc_release)
 399                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 400                         goto dropit;
 401                 }
 402         }
 403
 404         /* Check RPC status result */
 405         if (*statp != rpc_success)
 406                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
 407
 408         /* Release reply info */
 409         if (procp->pc_release)
 410                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 411
 412         if (procp->pc_encode == NULL)
 413                 goto dropit;
 414
 415  sendit:
 416         if (svc_authorise(rqstp))
 417                 goto dropit;
 418         return svc_send(rqstp);
 419
 420  dropit:
 421         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
 422         dprintk("svc: svc_process dropit\n");
 423         svc_drop(rqstp);
 424         return 0;
 425
 426 err_short_len:
 427 #ifdef RPC_PARANOIA
 428         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
 429 #endif
 430         goto dropit;                    /* drop request */
 431
 432 err_bad_dir:
 433 #ifdef RPC_PARANOIA
 434         printk("svc: bad direction %d, dropping request\n", dir);
 435 #endif
 436         serv->sv_stats->rpcbadfmt++;
 437         goto dropit;                    /* drop request */
 438
 439 err_bad_rpc:
 440         serv->sv_stats->rpcbadfmt++;
 441         svc_putu32(resv, xdr_one);      /* REJECT */
 442         svc_putu32(resv, xdr_zero);     /* RPC_MISMATCH */
 443         svc_putu32(resv, xdr_two);      /* Only RPCv2 supported */
 444         svc_putu32(resv, xdr_two);
 445         goto sendit;
 446
 447 err_bad_auth:
 448         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 449         serv->sv_stats->rpcbadauth++;
 450         /* Restore write pointer to location of accept status: */
 451         xdr_ressize_check(rqstp, accept_statp);
 452         svc_putu32(resv, xdr_one);      /* REJECT */
 453         svc_putu32(resv, xdr_one);      /* AUTH_ERROR */
 454         svc_putu32(resv, auth_stat);    /* status */
 455         goto sendit;
 456
 457 err_bad_prog:
 458         dprintk("svc: unknown program %d\n", prog);
 459         serv->sv_stats->rpcbadfmt++;
 460         svc_putu32(resv, rpc_prog_unavail);
 461         goto sendit;
 462
 463 err_bad_vers:
 464 #ifdef RPC_PARANOIA
 465         printk("svc: unknown version (%d)\n", vers);
 466 #endif
 467         serv->sv_stats->rpcbadfmt++;
 468         svc_putu32(resv, rpc_prog_mismatch);
 469         svc_putu32(resv, htonl(progp->pg_lovers));
 470         svc_putu32(resv, htonl(progp->pg_hivers));
 471         goto sendit;
 472
 473 err_bad_proc:
 474 #ifdef RPC_PARANOIA
 475         printk("svc: unknown procedure (%d)\n", proc);
 476 #endif
 477         serv->sv_stats->rpcbadfmt++;
 478         svc_putu32(resv, rpc_proc_unavail);
 479         goto sendit;
 480
 481 err_garbage:
 482 #ifdef RPC_PARANOIA
 483         printk("svc: failed to decode args\n");
 484 #endif
 485         rpc_stat = rpc_garbage_args;
 486 err_bad:
 487         serv->sv_stats->rpcbadfmt++;
 488         svc_putu32(resv, rpc_stat);
 489         goto sendit;
 490 }