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