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            void (*shutdown)(struct svc_serv *serv))
  31 {
  32         struct svc_serv *serv;
  33         int vers;
  34         unsigned int xdrsize;
  35
  36         if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
  37                 return NULL;
  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         serv->sv_shutdown  = shutdown;
  44         xdrsize = 0;
  45         while (prog) {
  46                 prog->pg_lovers = prog->pg_nvers-1;
  47                 for (vers=0; vers<prog->pg_nvers ; vers++)
  48                         if (prog->pg_vers[vers]) {
  49                                 prog->pg_hivers = vers;
  50                                 if (prog->pg_lovers > vers)
  51                                         prog->pg_lovers = vers;
  52                                 if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
  53                                         xdrsize = prog->pg_vers[vers]->vs_xdrsize;
  54                         }
  55                 prog = prog->pg_next;
  56         }
  57         serv->sv_xdrsize   = xdrsize;
  58         INIT_LIST_HEAD(&serv->sv_threads);
  59         INIT_LIST_HEAD(&serv->sv_sockets);
  60         INIT_LIST_HEAD(&serv->sv_tempsocks);
  61         INIT_LIST_HEAD(&serv->sv_permsocks);
  62         init_timer(&serv->sv_temptimer);
  63         spin_lock_init(&serv->sv_lock);
  64
  65         /* Remove any stale portmap registrations */
  66         svc_register(serv, 0, 0);
  67
  68         return serv;
  69 }
  70
  71 /*
  72  * Destroy an RPC service
  73  */
  74 void
  75 svc_destroy(struct svc_serv *serv)
  76 {
  77         struct svc_sock *svsk;
  78
  79         dprintk("RPC: svc_destroy(%s, %d)\n",
  80                                 serv->sv_program->pg_name,
  81                                 serv->sv_nrthreads);
  82
  83         if (serv->sv_nrthreads) {
  84                 if (--(serv->sv_nrthreads) != 0) {
  85                         svc_sock_update_bufs(serv);
  86                         return;
  87                 }
  88         } else
  89                 printk("svc_destroy: no threads for serv=%p!\n", serv);
  90
  91         del_timer_sync(&serv->sv_temptimer);
  92
  93         while (!list_empty(&serv->sv_tempsocks)) {
  94                 svsk = list_entry(serv->sv_tempsocks.next,
  95                                   struct svc_sock,
  96                                   sk_list);
  97                 svc_delete_socket(svsk);
  98         }
  99         if (serv->sv_shutdown)
 100                 serv->sv_shutdown(serv);
 101
 102         while (!list_empty(&serv->sv_permsocks)) {
 103                 svsk = list_entry(serv->sv_permsocks.next,
 104                                   struct svc_sock,
 105                                   sk_list);
 106                 svc_delete_socket(svsk);
 107         }
 108
 109         cache_clean_deferred(serv);
 110
 111         /* Unregister service with the portmapper */
 112         svc_register(serv, 0, 0);
 113         kfree(serv);
 114 }
 115
 116 /*
 117  * Allocate an RPC server's buffer space.
 118  * We allocate pages and place them in rq_argpages.
 119  */
 120 static int
 121 svc_init_buffer(struct svc_rqst *rqstp, unsigned int size)
 122 {
 123         int pages;
 124         int arghi;
 125
 126         if (size > RPCSVC_MAXPAYLOAD)
 127                 size = RPCSVC_MAXPAYLOAD;
 128         pages = 2 + (size+ PAGE_SIZE -1) / PAGE_SIZE;
 129         rqstp->rq_argused = 0;
 130         rqstp->rq_resused = 0;
 131         arghi = 0;
 132         BUG_ON(pages > RPCSVC_MAXPAGES);
 133         while (pages) {
 134                 struct page *p = alloc_page(GFP_KERNEL);
 135                 if (!p)
 136                         break;
 137                 rqstp->rq_argpages[arghi++] = p;
 138                 pages--;
 139         }
 140         rqstp->rq_arghi = arghi;
 141         return ! pages;
 142 }
 143
 144 /*
 145  * Release an RPC server buffer
 146  */
 147 static void
 148 svc_release_buffer(struct svc_rqst *rqstp)
 149 {
 150         while (rqstp->rq_arghi)
 151                 put_page(rqstp->rq_argpages[--rqstp->rq_arghi]);
 152         while (rqstp->rq_resused) {
 153                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 154                         continue;
 155                 put_page(rqstp->rq_respages[rqstp->rq_resused]);
 156         }
 157         rqstp->rq_argused = 0;
 158 }
 159
 160 /*
 161  * Create a server thread
 162  */
 163 int
 164 svc_create_thread(svc_thread_fn func, struct svc_serv *serv)
 165 {
 166         struct svc_rqst *rqstp;
 167         int             error = -ENOMEM;
 168
 169         rqstp = kzalloc(sizeof(*rqstp), GFP_KERNEL);
 170         if (!rqstp)
 171                 goto out;
 172
 173         init_waitqueue_head(&rqstp->rq_wait);
 174
 175         if (!(rqstp->rq_argp = kmalloc(serv->sv_xdrsize, GFP_KERNEL))
 176          || !(rqstp->rq_resp = kmalloc(serv->sv_xdrsize, GFP_KERNEL))
 177          || !svc_init_buffer(rqstp, serv->sv_bufsz))
 178                 goto out_thread;
 179
 180         serv->sv_nrthreads++;
 181         rqstp->rq_server = serv;
 182         error = kernel_thread((int (*)(void *)) func, rqstp, 0);
 183         if (error < 0)
 184                 goto out_thread;
 185         svc_sock_update_bufs(serv);
 186         error = 0;
 187 out:
 188         return error;
 189
 190 out_thread:
 191         svc_exit_thread(rqstp);
 192         goto out;
 193 }
 194
 195 /*
 196  * Destroy an RPC server thread
 197  */
 198 void
 199 svc_exit_thread(struct svc_rqst *rqstp)
 200 {
 201         struct svc_serv *serv = rqstp->rq_server;
 202
 203         svc_release_buffer(rqstp);
 204         kfree(rqstp->rq_resp);
 205         kfree(rqstp->rq_argp);
 206         kfree(rqstp->rq_auth_data);
 207         kfree(rqstp);
 208
 209         /* Release the server */
 210         if (serv)
 211                 svc_destroy(serv);
 212 }
 213
 214 /*
 215  * Register an RPC service with the local portmapper.
 216  * To unregister a service, call this routine with
 217  * proto and port == 0.
 218  */
 219 int
 220 svc_register(struct svc_serv *serv, int proto, unsigned short port)
 221 {
 222         struct svc_program      *progp;
 223         unsigned long           flags;
 224         int                     i, error = 0, dummy;
 225
 226         progp = serv->sv_program;
 227
 228         dprintk("RPC: svc_register(%s, %s, %d)\n",
 229                 progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);
 230
 231         if (!port)
 232                 clear_thread_flag(TIF_SIGPENDING);
 233
 234         for (i = 0; i < progp->pg_nvers; i++) {
 235                 if (progp->pg_vers[i] == NULL)
 236                         continue;
 237                 error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
 238                 if (error < 0)
 239                         break;
 240                 if (port && !dummy) {
 241                         error = -EACCES;
 242                         break;
 243                 }
 244         }
 245
 246         if (!port) {
 247                 spin_lock_irqsave(&current->sighand->siglock, flags);
 248                 recalc_sigpending();
 249                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 250         }
 251
 252         return error;
 253 }
 254
 255 /*
 256  * Process the RPC request.
 257  */
 258 int
 259 svc_process(struct svc_rqst *rqstp)
 260 {
 261         struct svc_program      *progp;
 262         struct svc_version      *versp = NULL;  /* compiler food */
 263         struct svc_procedure    *procp = NULL;
 264         struct kvec *           argv = &rqstp->rq_arg.head[0];
 265         struct kvec *           resv = &rqstp->rq_res.head[0];
 266         struct svc_serv         *serv = rqstp->rq_server;
 267         kxdrproc_t              xdr;
 268         __be32                  *statp;
 269         u32                     dir, prog, vers, proc;
 270         __be32                  auth_stat, rpc_stat;
 271         int                     auth_res;
 272         __be32                  *accept_statp;
 273
 274         rpc_stat = rpc_success;
 275
 276         if (argv->iov_len < 6*4)
 277                 goto err_short_len;
 278
 279         /* setup response xdr_buf.
 280          * Initially it has just one page
 281          */
 282         svc_take_page(rqstp); /* must succeed */
 283         resv->iov_base = page_address(rqstp->rq_respages[0]);
 284         resv->iov_len = 0;
 285         rqstp->rq_res.pages = rqstp->rq_respages+1;
 286         rqstp->rq_res.len = 0;
 287         rqstp->rq_res.page_base = 0;
 288         rqstp->rq_res.page_len = 0;
 289         rqstp->rq_res.buflen = PAGE_SIZE;
 290         rqstp->rq_res.tail[0].iov_base = NULL;
 291         rqstp->rq_res.tail[0].iov_len = 0;
 292         /* Will be turned off only in gss privacy case: */
 293         rqstp->rq_sendfile_ok = 1;
 294         /* tcp needs a space for the record length... */
 295         if (rqstp->rq_prot == IPPROTO_TCP)
 296                 svc_putnl(resv, 0);
 297
 298         rqstp->rq_xid = svc_getu32(argv);
 299         svc_putu32(resv, rqstp->rq_xid);
 300
 301         dir  = svc_getnl(argv);
 302         vers = svc_getnl(argv);
 303
 304         /* First words of reply: */
 305         svc_putnl(resv, 1);             /* REPLY */
 306
 307         if (dir != 0)           /* direction != CALL */
 308                 goto err_bad_dir;
 309         if (vers != 2)          /* RPC version number */
 310                 goto err_bad_rpc;
 311
 312         /* Save position in case we later decide to reject: */
 313         accept_statp = resv->iov_base + resv->iov_len;
 314
 315         svc_putnl(resv, 0);             /* ACCEPT */
 316
 317         rqstp->rq_prog = prog = svc_getnl(argv);        /* program number */
 318         rqstp->rq_vers = vers = svc_getnl(argv);        /* version number */
 319         rqstp->rq_proc = proc = svc_getnl(argv);        /* procedure number */
 320
 321         progp = serv->sv_program;
 322
 323         for (progp = serv->sv_program; progp; progp = progp->pg_next)
 324                 if (prog == progp->pg_prog)
 325                         break;
 326
 327         /*
 328          * Decode auth data, and add verifier to reply buffer.
 329          * We do this before anything else in order to get a decent
 330          * auth verifier.
 331          */
 332         auth_res = svc_authenticate(rqstp, &auth_stat);
 333         /* Also give the program a chance to reject this call: */
 334         if (auth_res == SVC_OK && progp) {
 335                 auth_stat = rpc_autherr_badcred;
 336                 auth_res = progp->pg_authenticate(rqstp);
 337         }
 338         switch (auth_res) {
 339         case SVC_OK:
 340                 break;
 341         case SVC_GARBAGE:
 342                 rpc_stat = rpc_garbage_args;
 343                 goto err_bad;
 344         case SVC_SYSERR:
 345                 rpc_stat = rpc_system_err;
 346                 goto err_bad;
 347         case SVC_DENIED:
 348                 goto err_bad_auth;
 349         case SVC_DROP:
 350                 goto dropit;
 351         case SVC_COMPLETE:
 352                 goto sendit;
 353         }
 354
 355         if (progp == NULL)
 356                 goto err_bad_prog;
 357
 358         if (vers >= progp->pg_nvers ||
 359           !(versp = progp->pg_vers[vers]))
 360                 goto err_bad_vers;
 361
 362         procp = versp->vs_proc + proc;
 363         if (proc >= versp->vs_nproc || !procp->pc_func)
 364                 goto err_bad_proc;
 365         rqstp->rq_server   = serv;
 366         rqstp->rq_procinfo = procp;
 367
 368         /* Syntactic check complete */
 369         serv->sv_stats->rpccnt++;
 370
 371         /* Build the reply header. */
 372         statp = resv->iov_base +resv->iov_len;
 373         svc_putnl(resv, RPC_SUCCESS);
 374
 375         /* Bump per-procedure stats counter */
 376         procp->pc_count++;
 377
 378         /* Initialize storage for argp and resp */
 379         memset(rqstp->rq_argp, 0, procp->pc_argsize);
 380         memset(rqstp->rq_resp, 0, procp->pc_ressize);
 381
 382         /* un-reserve some of the out-queue now that we have a
 383          * better idea of reply size
 384          */
 385         if (procp->pc_xdrressize)
 386                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
 387
 388         /* Call the function that processes the request. */
 389         if (!versp->vs_dispatch) {
 390                 /* Decode arguments */
 391                 xdr = procp->pc_decode;
 392                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
 393                         goto err_garbage;
 394
 395                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 396
 397                 /* Encode reply */
 398                 if (*statp == rpc_success && (xdr = procp->pc_encode)
 399                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
 400                         dprintk("svc: failed to encode reply\n");
 401                         /* serv->sv_stats->rpcsystemerr++; */
 402                         *statp = rpc_system_err;
 403                 }
 404         } else {
 405                 dprintk("svc: calling dispatcher\n");
 406                 if (!versp->vs_dispatch(rqstp, statp)) {
 407                         /* Release reply info */
 408                         if (procp->pc_release)
 409                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 410                         goto dropit;
 411                 }
 412         }
 413
 414         /* Check RPC status result */
 415         if (*statp != rpc_success)
 416                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
 417
 418         /* Release reply info */
 419         if (procp->pc_release)
 420                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 421
 422         if (procp->pc_encode == NULL)
 423                 goto dropit;
 424
 425  sendit:
 426         if (svc_authorise(rqstp))
 427                 goto dropit;
 428         return svc_send(rqstp);
 429
 430  dropit:
 431         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
 432         dprintk("svc: svc_process dropit\n");
 433         svc_drop(rqstp);
 434         return 0;
 435
 436 err_short_len:
 437 #ifdef RPC_PARANOIA
 438         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
 439 #endif
 440         goto dropit;                    /* drop request */
 441
 442 err_bad_dir:
 443 #ifdef RPC_PARANOIA
 444         printk("svc: bad direction %d, dropping request\n", dir);
 445 #endif
 446         serv->sv_stats->rpcbadfmt++;
 447         goto dropit;                    /* drop request */
 448
 449 err_bad_rpc:
 450         serv->sv_stats->rpcbadfmt++;
 451         svc_putnl(resv, 1);     /* REJECT */
 452         svc_putnl(resv, 0);     /* RPC_MISMATCH */
 453         svc_putnl(resv, 2);     /* Only RPCv2 supported */
 454         svc_putnl(resv, 2);
 455         goto sendit;
 456
 457 err_bad_auth:
 458         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 459         serv->sv_stats->rpcbadauth++;
 460         /* Restore write pointer to location of accept status: */
 461         xdr_ressize_check(rqstp, accept_statp);
 462         svc_putnl(resv, 1);     /* REJECT */
 463         svc_putnl(resv, 1);     /* AUTH_ERROR */
 464         svc_putnl(resv, ntohl(auth_stat));      /* status */
 465         goto sendit;
 466
 467 err_bad_prog:
 468         dprintk("svc: unknown program %d\n", prog);
 469         serv->sv_stats->rpcbadfmt++;
 470         svc_putnl(resv, RPC_PROG_UNAVAIL);
 471         goto sendit;
 472
 473 err_bad_vers:
 474 #ifdef RPC_PARANOIA
 475         printk("svc: unknown version (%d)\n", vers);
 476 #endif
 477         serv->sv_stats->rpcbadfmt++;
 478         svc_putnl(resv, RPC_PROG_MISMATCH);
 479         svc_putnl(resv, progp->pg_lovers);
 480         svc_putnl(resv, progp->pg_hivers);
 481         goto sendit;
 482
 483 err_bad_proc:
 484 #ifdef RPC_PARANOIA
 485         printk("svc: unknown procedure (%d)\n", proc);
 486 #endif
 487         serv->sv_stats->rpcbadfmt++;
 488         svc_putnl(resv, RPC_PROC_UNAVAIL);
 489         goto sendit;
 490
 491 err_garbage:
 492 #ifdef RPC_PARANOIA
 493         printk("svc: failed to decode args\n");
 494 #endif
 495         rpc_stat = rpc_garbage_args;
 496 err_bad:
 497         serv->sv_stats->rpcbadfmt++;
 498         svc_putnl(resv, ntohl(rpc_stat));
 499         goto sendit;
 500 }