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         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 }