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         kfree(rqstp->rq_resp);
 200         kfree(rqstp->rq_argp);
 201         kfree(rqstp->rq_auth_data);
 202         kfree(rqstp);
 203
 204         /* Release the server */
 205         if (serv)
 206                 svc_destroy(serv);
 207 }
 208
 209 /*
 210  * Register an RPC service with the local portmapper.
 211  * To unregister a service, call this routine with
 212  * proto and port == 0.
 213  */
 214 int
 215 svc_register(struct svc_serv *serv, int proto, unsigned short port)
 216 {
 217         struct svc_program      *progp;
 218         unsigned long           flags;
 219         int                     i, error = 0, dummy;
 220
 221         progp = serv->sv_program;
 222
 223         dprintk("RPC: svc_register(%s, %s, %d)\n",
 224                 progp->pg_name, proto == IPPROTO_UDP? "udp" : "tcp", port);
 225
 226         if (!port)
 227                 clear_thread_flag(TIF_SIGPENDING);
 228
 229         for (i = 0; i < progp->pg_nvers; i++) {
 230                 if (progp->pg_vers[i] == NULL)
 231                         continue;
 232                 error = rpc_register(progp->pg_prog, i, proto, port, &dummy);
 233                 if (error < 0)
 234                         break;
 235                 if (port && !dummy) {
 236                         error = -EACCES;
 237                         break;
 238                 }
 239         }
 240
 241         if (!port) {
 242                 spin_lock_irqsave(&current->sighand->siglock, flags);
 243                 recalc_sigpending();
 244                 spin_unlock_irqrestore(&current->sighand->siglock, flags);
 245         }
 246
 247         return error;
 248 }
 249
 250 /*
 251  * Process the RPC request.
 252  */
 253 int
 254 svc_process(struct svc_serv *serv, struct svc_rqst *rqstp)
 255 {
 256         struct svc_program      *progp;
 257         struct svc_version      *versp = NULL;  /* compiler food */
 258         struct svc_procedure    *procp = NULL;
 259         struct kvec *           argv = &rqstp->rq_arg.head[0];
 260         struct kvec *           resv = &rqstp->rq_res.head[0];
 261         kxdrproc_t              xdr;
 262         u32                     *statp;
 263         u32                     dir, prog, vers, proc,
 264                                 auth_stat, rpc_stat;
 265         int                     auth_res;
 266         u32                     *accept_statp;
 267
 268         rpc_stat = rpc_success;
 269
 270         if (argv->iov_len < 6*4)
 271                 goto err_short_len;
 272
 273         /* setup response xdr_buf.
 274          * Initially it has just one page
 275          */
 276         svc_take_page(rqstp); /* must succeed */
 277         resv->iov_base = page_address(rqstp->rq_respages[0]);
 278         resv->iov_len = 0;
 279         rqstp->rq_res.pages = rqstp->rq_respages+1;
 280         rqstp->rq_res.len = 0;
 281         rqstp->rq_res.page_base = 0;
 282         rqstp->rq_res.page_len = 0;
 283         rqstp->rq_res.buflen = PAGE_SIZE;
 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         for (progp = serv->sv_program; progp; progp = progp->pg_next)
 315                 if (prog == progp->pg_prog)
 316                         break;
 317
 318         /*
 319          * Decode auth data, and add verifier to reply buffer.
 320          * We do this before anything else in order to get a decent
 321          * auth verifier.
 322          */
 323         auth_res = svc_authenticate(rqstp, &auth_stat);
 324         /* Also give the program a chance to reject this call: */
 325         if (auth_res == SVC_OK && progp) {
 326                 auth_stat = rpc_autherr_badcred;
 327                 auth_res = progp->pg_authenticate(rqstp);
 328         }
 329         switch (auth_res) {
 330         case SVC_OK:
 331                 break;
 332         case SVC_GARBAGE:
 333                 rpc_stat = rpc_garbage_args;
 334                 goto err_bad;
 335         case SVC_SYSERR:
 336                 rpc_stat = rpc_system_err;
 337                 goto err_bad;
 338         case SVC_DENIED:
 339                 goto err_bad_auth;
 340         case SVC_DROP:
 341                 goto dropit;
 342         case SVC_COMPLETE:
 343                 goto sendit;
 344         }
 345
 346         if (progp == NULL)
 347                 goto err_bad_prog;
 348
 349         if (vers >= progp->pg_nvers ||
 350           !(versp = progp->pg_vers[vers]))
 351                 goto err_bad_vers;
 352
 353         procp = versp->vs_proc + proc;
 354         if (proc >= versp->vs_nproc || !procp->pc_func)
 355                 goto err_bad_proc;
 356         rqstp->rq_server   = serv;
 357         rqstp->rq_procinfo = procp;
 358
 359         /* Syntactic check complete */
 360         serv->sv_stats->rpccnt++;
 361
 362         /* Build the reply header. */
 363         statp = resv->iov_base +resv->iov_len;
 364         svc_putu32(resv, rpc_success);          /* RPC_SUCCESS */
 365
 366         /* Bump per-procedure stats counter */
 367         procp->pc_count++;
 368
 369         /* Initialize storage for argp and resp */
 370         memset(rqstp->rq_argp, 0, procp->pc_argsize);
 371         memset(rqstp->rq_resp, 0, procp->pc_ressize);
 372
 373         /* un-reserve some of the out-queue now that we have a
 374          * better idea of reply size
 375          */
 376         if (procp->pc_xdrressize)
 377                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
 378
 379         /* Call the function that processes the request. */
 380         if (!versp->vs_dispatch) {
 381                 /* Decode arguments */
 382                 xdr = procp->pc_decode;
 383                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
 384                         goto err_garbage;
 385
 386                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 387
 388                 /* Encode reply */
 389                 if (*statp == rpc_success && (xdr = procp->pc_encode)
 390                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
 391                         dprintk("svc: failed to encode reply\n");
 392                         /* serv->sv_stats->rpcsystemerr++; */
 393                         *statp = rpc_system_err;
 394                 }
 395         } else {
 396                 dprintk("svc: calling dispatcher\n");
 397                 if (!versp->vs_dispatch(rqstp, statp)) {
 398                         /* Release reply info */
 399                         if (procp->pc_release)
 400                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 401                         goto dropit;
 402                 }
 403         }
 404
 405         /* Check RPC status result */
 406         if (*statp != rpc_success)
 407                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
 408
 409         /* Release reply info */
 410         if (procp->pc_release)
 411                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 412
 413         if (procp->pc_encode == NULL)
 414                 goto dropit;
 415
 416  sendit:
 417         if (svc_authorise(rqstp))
 418                 goto dropit;
 419         return svc_send(rqstp);
 420
 421  dropit:
 422         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
 423         dprintk("svc: svc_process dropit\n");
 424         svc_drop(rqstp);
 425         return 0;
 426
 427 err_short_len:
 428 #ifdef RPC_PARANOIA
 429         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
 430 #endif
 431         goto dropit;                    /* drop request */
 432
 433 err_bad_dir:
 434 #ifdef RPC_PARANOIA
 435         printk("svc: bad direction %d, dropping request\n", dir);
 436 #endif
 437         serv->sv_stats->rpcbadfmt++;
 438         goto dropit;                    /* drop request */
 439
 440 err_bad_rpc:
 441         serv->sv_stats->rpcbadfmt++;
 442         svc_putu32(resv, xdr_one);      /* REJECT */
 443         svc_putu32(resv, xdr_zero);     /* RPC_MISMATCH */
 444         svc_putu32(resv, xdr_two);      /* Only RPCv2 supported */
 445         svc_putu32(resv, xdr_two);
 446         goto sendit;
 447
 448 err_bad_auth:
 449         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 450         serv->sv_stats->rpcbadauth++;
 451         /* Restore write pointer to location of accept status: */
 452         xdr_ressize_check(rqstp, accept_statp);
 453         svc_putu32(resv, xdr_one);      /* REJECT */
 454         svc_putu32(resv, xdr_one);      /* AUTH_ERROR */
 455         svc_putu32(resv, auth_stat);    /* status */
 456         goto sendit;
 457
 458 err_bad_prog:
 459         dprintk("svc: unknown program %d\n", prog);
 460         serv->sv_stats->rpcbadfmt++;
 461         svc_putu32(resv, rpc_prog_unavail);
 462         goto sendit;
 463
 464 err_bad_vers:
 465 #ifdef RPC_PARANOIA
 466         printk("svc: unknown version (%d)\n", vers);
 467 #endif
 468         serv->sv_stats->rpcbadfmt++;
 469         svc_putu32(resv, rpc_prog_mismatch);
 470         svc_putu32(resv, htonl(progp->pg_lovers));
 471         svc_putu32(resv, htonl(progp->pg_hivers));
 472         goto sendit;
 473
 474 err_bad_proc:
 475 #ifdef RPC_PARANOIA
 476         printk("svc: unknown procedure (%d)\n", proc);
 477 #endif
 478         serv->sv_stats->rpcbadfmt++;
 479         svc_putu32(resv, rpc_proc_unavail);
 480         goto sendit;
 481
 482 err_garbage:
 483 #ifdef RPC_PARANOIA
 484         printk("svc: failed to decode args\n");
 485 #endif
 486         rpc_stat = rpc_garbage_args;
 487 err_bad:
 488         serv->sv_stats->rpcbadfmt++;
 489         svc_putu32(resv, rpc_stat);
 490         goto sendit;
 491 }