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_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         u32                     *accept_statp;
 268
 269         rpc_stat = rpc_success;
 270
 271         if (argv->iov_len < 6*4)
 272                 goto err_short_len;
 273
 274         /* setup response xdr_buf.
 275          * Initially it has just one page
 276          */
 277         svc_take_page(rqstp); /* must succeed */
 278         resv->iov_base = page_address(rqstp->rq_respages[0]);
 279         resv->iov_len = 0;
 280         rqstp->rq_res.pages = rqstp->rq_respages+1;
 281         rqstp->rq_res.len = 0;
 282         rqstp->rq_res.page_base = 0;
 283         rqstp->rq_res.page_len = 0;
 284         rqstp->rq_res.tail[0].iov_len = 0;
 285         /* tcp needs a space for the record length... */
 286         if (rqstp->rq_prot == IPPROTO_TCP)
 287                 svc_putu32(resv, 0);
 288
 289         rqstp->rq_xid = svc_getu32(argv);
 290         svc_putu32(resv, rqstp->rq_xid);
 291
 292         dir  = ntohl(svc_getu32(argv));
 293         vers = ntohl(svc_getu32(argv));
 294
 295         /* First words of reply: */
 296         svc_putu32(resv, xdr_one);              /* REPLY */
 297
 298         if (dir != 0)           /* direction != CALL */
 299                 goto err_bad_dir;
 300         if (vers != 2)          /* RPC version number */
 301                 goto err_bad_rpc;
 302
 303         /* Save position in case we later decide to reject: */
 304         accept_statp = resv->iov_base + resv->iov_len;
 305
 306         svc_putu32(resv, xdr_zero);             /* ACCEPT */
 307
 308         rqstp->rq_prog = prog = ntohl(svc_getu32(argv));        /* program number */
 309         rqstp->rq_vers = vers = ntohl(svc_getu32(argv));        /* version number */
 310         rqstp->rq_proc = proc = ntohl(svc_getu32(argv));        /* procedure number */
 311
 312         progp = serv->sv_program;
 313         /*
 314          * Decode auth data, and add verifier to reply buffer.
 315          * We do this before anything else in order to get a decent
 316          * auth verifier.
 317          */
 318         auth_res = svc_authenticate(rqstp, &auth_stat);
 319         /* Also give the program a chance to reject this call: */
 320         if (auth_res == SVC_OK) {
 321                 auth_stat = rpc_autherr_badcred;
 322                 auth_res = progp->pg_authenticate(rqstp);
 323         }
 324         switch (auth_res) {
 325         case SVC_OK:
 326                 break;
 327         case SVC_GARBAGE:
 328                 rpc_stat = rpc_garbage_args;
 329                 goto err_bad;
 330         case SVC_SYSERR:
 331                 rpc_stat = rpc_system_err;
 332                 goto err_bad;
 333         case SVC_DENIED:
 334                 goto err_bad_auth;
 335         case SVC_DROP:
 336                 goto dropit;
 337         case SVC_COMPLETE:
 338                 goto sendit;
 339         }
 340
 341         if (prog != progp->pg_prog)
 342                 goto err_bad_prog;
 343
 344         if (vers >= progp->pg_nvers ||
 345           !(versp = progp->pg_vers[vers]))
 346                 goto err_bad_vers;
 347
 348         procp = versp->vs_proc + proc;
 349         if (proc >= versp->vs_nproc || !procp->pc_func)
 350                 goto err_bad_proc;
 351         rqstp->rq_server   = serv;
 352         rqstp->rq_procinfo = procp;
 353
 354         /* Syntactic check complete */
 355         serv->sv_stats->rpccnt++;
 356
 357         /* Build the reply header. */
 358         statp = resv->iov_base +resv->iov_len;
 359         svc_putu32(resv, rpc_success);          /* RPC_SUCCESS */
 360
 361         /* Bump per-procedure stats counter */
 362         procp->pc_count++;
 363
 364         /* Initialize storage for argp and resp */
 365         memset(rqstp->rq_argp, 0, procp->pc_argsize);
 366         memset(rqstp->rq_resp, 0, procp->pc_ressize);
 367
 368         /* un-reserve some of the out-queue now that we have a
 369          * better idea of reply size
 370          */
 371         if (procp->pc_xdrressize)
 372                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
 373
 374         /* Call the function that processes the request. */
 375         if (!versp->vs_dispatch) {
 376                 /* Decode arguments */
 377                 xdr = procp->pc_decode;
 378                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
 379                         goto err_garbage;
 380
 381                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 382
 383                 /* Encode reply */
 384                 if (*statp == rpc_success && (xdr = procp->pc_encode)
 385                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
 386                         dprintk("svc: failed to encode reply\n");
 387                         /* serv->sv_stats->rpcsystemerr++; */
 388                         *statp = rpc_system_err;
 389                 }
 390         } else {
 391                 dprintk("svc: calling dispatcher\n");
 392                 if (!versp->vs_dispatch(rqstp, statp)) {
 393                         /* Release reply info */
 394                         if (procp->pc_release)
 395                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 396                         goto dropit;
 397                 }
 398         }
 399
 400         /* Check RPC status result */
 401         if (*statp != rpc_success)
 402                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
 403
 404         /* Release reply info */
 405         if (procp->pc_release)
 406                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 407
 408         if (procp->pc_encode == NULL)
 409                 goto dropit;
 410
 411  sendit:
 412         if (svc_authorise(rqstp))
 413                 goto dropit;
 414         return svc_send(rqstp);
 415
 416  dropit:
 417         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
 418         dprintk("svc: svc_process dropit\n");
 419         svc_drop(rqstp);
 420         return 0;
 421
 422 err_short_len:
 423 #ifdef RPC_PARANOIA
 424         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
 425 #endif
 426         goto dropit;                    /* drop request */
 427
 428 err_bad_dir:
 429 #ifdef RPC_PARANOIA
 430         printk("svc: bad direction %d, dropping request\n", dir);
 431 #endif
 432         serv->sv_stats->rpcbadfmt++;
 433         goto dropit;                    /* drop request */
 434
 435 err_bad_rpc:
 436         serv->sv_stats->rpcbadfmt++;
 437         svc_putu32(resv, xdr_one);      /* REJECT */
 438         svc_putu32(resv, xdr_zero);     /* RPC_MISMATCH */
 439         svc_putu32(resv, xdr_two);      /* Only RPCv2 supported */
 440         svc_putu32(resv, xdr_two);
 441         goto sendit;
 442
 443 err_bad_auth:
 444         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 445         serv->sv_stats->rpcbadauth++;
 446         /* Restore write pointer to location of accept status: */
 447         xdr_ressize_check(rqstp, accept_statp);
 448         svc_putu32(resv, xdr_one);      /* REJECT */
 449         svc_putu32(resv, xdr_one);      /* AUTH_ERROR */
 450         svc_putu32(resv, auth_stat);    /* status */
 451         goto sendit;
 452
 453 err_bad_prog:
 454 #ifdef RPC_PARANOIA
 455         if (prog != 100227 || progp->pg_prog != 100003)
 456                 printk("svc: unknown program %d (me %d)\n", prog, progp->pg_prog);
 457         /* else it is just a Solaris client seeing if ACLs are supported */
 458 #endif
 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 }