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 #define __KERNEL_SYSCALLS__
  10 #include <linux/linkage.h>
  11 #include <linux/sched.h>
  12 #include <linux/errno.h>
  13 #include <linux/net.h>
  14 #include <linux/in.h>
  15 #include <linux/unistd.h>
  16 #include <linux/mm.h>
  17
  18 #include <linux/sunrpc/types.h>
  19 #include <linux/sunrpc/xdr.h>
  20 #include <linux/sunrpc/stats.h>
  21 #include <linux/sunrpc/svcsock.h>
  22 #include <linux/sunrpc/clnt.h>
  23
  24 #define RPCDBG_FACILITY RPCDBG_SVCDSP
  25 #define RPC_PARANOIA 1
  26
  27 /*
  28  * Create an RPC service
  29  */
  30 struct svc_serv *
  31 svc_create(struct svc_program *prog, unsigned int bufsize)
  32 {
  33         struct svc_serv *serv;
  34         int vers;
  35         unsigned int xdrsize;
  36
  37         if (!(serv = (struct svc_serv *) kmalloc(sizeof(*serv), GFP_KERNEL)))
  38                 return NULL;
  39         memset(serv, 0, sizeof(*serv));
  40         serv->sv_program   = prog;
  41         serv->sv_nrthreads = 1;
  42         serv->sv_stats     = prog->pg_stats;
  43         serv->sv_bufsz     = bufsize? bufsize : 4096;
  44         prog->pg_lovers = prog->pg_nvers-1;
  45         xdrsize = 0;
  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         serv->sv_xdrsize   = xdrsize;
  55         INIT_LIST_HEAD(&serv->sv_threads);
  56         INIT_LIST_HEAD(&serv->sv_sockets);
  57         INIT_LIST_HEAD(&serv->sv_tempsocks);
  58         INIT_LIST_HEAD(&serv->sv_permsocks);
  59         spin_lock_init(&serv->sv_lock);
  60
  61         serv->sv_name      = prog->pg_name;
  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         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 iovec *          argv = &rqstp->rq_arg.head[0];
 261         struct iovec *          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
 267         rpc_stat = rpc_success;
 268
 269         if (argv->iov_len < 6*4)
 270                 goto err_short_len;
 271
 272         /* setup response xdr_buf.
 273          * Initially it has just one page
 274          */
 275         svc_take_page(rqstp); /* must succeed */
 276         resv->iov_base = page_address(rqstp->rq_respages[0]);
 277         resv->iov_len = 0;
 278         rqstp->rq_res.pages = rqstp->rq_respages+1;
 279         rqstp->rq_res.len = 0;
 280         rqstp->rq_res.page_base = 0;
 281         rqstp->rq_res.page_len = 0;
 282         rqstp->rq_res.tail[0].iov_len = 0;
 283         /* tcp needs a space for the record length... */
 284         if (rqstp->rq_prot == IPPROTO_TCP)
 285                 svc_putu32(resv, 0);
 286
 287         rqstp->rq_xid = svc_getu32(argv);
 288         svc_putu32(resv, rqstp->rq_xid);
 289
 290         dir  = ntohl(svc_getu32(argv));
 291         vers = ntohl(svc_getu32(argv));
 292
 293         /* First words of reply: */
 294         svc_putu32(resv, xdr_one);              /* REPLY */
 295
 296         if (dir != 0)           /* direction != CALL */
 297                 goto err_bad_dir;
 298         if (vers != 2)          /* RPC version number */
 299                 goto err_bad_rpc;
 300
 301         svc_putu32(resv, xdr_zero);             /* ACCEPT */
 302
 303         rqstp->rq_prog = prog = ntohl(svc_getu32(argv));        /* program number */
 304         rqstp->rq_vers = vers = ntohl(svc_getu32(argv));        /* version number */
 305         rqstp->rq_proc = proc = ntohl(svc_getu32(argv));        /* procedure number */
 306
 307         /*
 308          * Decode auth data, and add verifier to reply buffer.
 309          * We do this before anything else in order to get a decent
 310          * auth verifier.
 311          */
 312         switch (svc_authenticate(rqstp, &auth_stat)) {
 313         case SVC_OK:
 314                 break;
 315         case SVC_GARBAGE:
 316                 rpc_stat = rpc_garbage_args;
 317                 goto err_bad;
 318         case SVC_SYSERR:
 319                 rpc_stat = rpc_system_err;
 320                 goto err_bad;
 321         case SVC_DENIED:
 322                 goto err_bad_auth;
 323         case SVC_DROP:
 324                 goto dropit;
 325         }
 326
 327         progp = serv->sv_program;
 328         if (prog != progp->pg_prog)
 329                 goto err_bad_prog;
 330
 331         if (vers >= progp->pg_nvers ||
 332           !(versp = progp->pg_vers[vers]))
 333                 goto err_bad_vers;
 334
 335         procp = versp->vs_proc + proc;
 336         if (proc >= versp->vs_nproc || !procp->pc_func)
 337                 goto err_bad_proc;
 338         rqstp->rq_server   = serv;
 339         rqstp->rq_procinfo = procp;
 340
 341         /* Syntactic check complete */
 342         serv->sv_stats->rpccnt++;
 343
 344         /* Build the reply header. */
 345         statp = resv->iov_base +resv->iov_len;
 346         svc_putu32(resv, rpc_success);          /* RPC_SUCCESS */
 347
 348         /* Bump per-procedure stats counter */
 349         procp->pc_count++;
 350
 351         /* Initialize storage for argp and resp */
 352         memset(rqstp->rq_argp, 0, procp->pc_argsize);
 353         memset(rqstp->rq_resp, 0, procp->pc_ressize);
 354
 355         /* un-reserve some of the out-queue now that we have a
 356          * better idea of reply size
 357          */
 358         if (procp->pc_xdrressize)
 359                 svc_reserve(rqstp, procp->pc_xdrressize<<2);
 360
 361         /* Call the function that processes the request. */
 362         if (!versp->vs_dispatch) {
 363                 /* Decode arguments */
 364                 xdr = procp->pc_decode;
 365                 if (xdr && !xdr(rqstp, argv->iov_base, rqstp->rq_argp))
 366                         goto err_garbage;
 367
 368                 *statp = procp->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
 369
 370                 /* Encode reply */
 371                 if (*statp == rpc_success && (xdr = procp->pc_encode)
 372                  && !xdr(rqstp, resv->iov_base+resv->iov_len, rqstp->rq_resp)) {
 373                         dprintk("svc: failed to encode reply\n");
 374                         /* serv->sv_stats->rpcsystemerr++; */
 375                         *statp = rpc_system_err;
 376                 }
 377         } else {
 378                 dprintk("svc: calling dispatcher\n");
 379                 if (!versp->vs_dispatch(rqstp, statp)) {
 380                         /* Release reply info */
 381                         if (procp->pc_release)
 382                                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 383                         goto dropit;
 384                 }
 385         }
 386
 387         /* Check RPC status result */
 388         if (*statp != rpc_success)
 389                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
 390
 391         /* Release reply info */
 392         if (procp->pc_release)
 393                 procp->pc_release(rqstp, NULL, rqstp->rq_resp);
 394
 395         if (procp->pc_encode == NULL)
 396                 goto dropit;
 397
 398  sendit:
 399         if (svc_authorise(rqstp))
 400                 goto dropit;
 401         return svc_send(rqstp);
 402
 403  dropit:
 404         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
 405         dprintk("svc: svc_process dropit\n");
 406         svc_drop(rqstp);
 407         return 0;
 408
 409 err_short_len:
 410 #ifdef RPC_PARANOIA
 411         printk("svc: short len %Zd, dropping request\n", argv->iov_len);
 412 #endif
 413         goto dropit;                    /* drop request */
 414
 415 err_bad_dir:
 416 #ifdef RPC_PARANOIA
 417         printk("svc: bad direction %d, dropping request\n", dir);
 418 #endif
 419         serv->sv_stats->rpcbadfmt++;
 420         goto dropit;                    /* drop request */
 421
 422 err_bad_rpc:
 423         serv->sv_stats->rpcbadfmt++;
 424         svc_putu32(resv, xdr_one);      /* REJECT */
 425         svc_putu32(resv, xdr_zero);     /* RPC_MISMATCH */
 426         svc_putu32(resv, xdr_two);      /* Only RPCv2 supported */
 427         svc_putu32(resv, xdr_two);
 428         goto sendit;
 429
 430 err_bad_auth:
 431         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 432         serv->sv_stats->rpcbadauth++;
 433         resv->iov_len -= 4;
 434         svc_putu32(resv, xdr_one);      /* REJECT */
 435         svc_putu32(resv, xdr_one);      /* AUTH_ERROR */
 436         svc_putu32(resv, auth_stat);    /* status */
 437         goto sendit;
 438
 439 err_bad_prog:
 440 #ifdef RPC_PARANOIA
 441         if (prog != 100227 || progp->pg_prog != 100003)
 442                 printk("svc: unknown program %d (me %d)\n", prog, progp->pg_prog);
 443         /* else it is just a Solaris client seeing if ACLs are supported */
 444 #endif
 445         serv->sv_stats->rpcbadfmt++;
 446         svc_putu32(resv, rpc_prog_unavail);
 447         goto sendit;
 448
 449 err_bad_vers:
 450 #ifdef RPC_PARANOIA
 451         printk("svc: unknown version (%d)\n", vers);
 452 #endif
 453         serv->sv_stats->rpcbadfmt++;
 454         svc_putu32(resv, rpc_prog_mismatch);
 455         svc_putu32(resv, htonl(progp->pg_lovers));
 456         svc_putu32(resv, htonl(progp->pg_hivers));
 457         goto sendit;
 458
 459 err_bad_proc:
 460 #ifdef RPC_PARANOIA
 461         printk("svc: unknown procedure (%d)\n", proc);
 462 #endif
 463         serv->sv_stats->rpcbadfmt++;
 464         svc_putu32(resv, rpc_proc_unavail);
 465         goto sendit;
 466
 467 err_garbage:
 468 #ifdef RPC_PARANOIA
 469         printk("svc: failed to decode args\n");
 470 #endif
 471         rpc_stat = rpc_garbage_args;
 472 err_bad:
 473         serv->sv_stats->rpcbadfmt++;
 474         svc_putu32(resv, rpc_stat);
 475         goto sendit;
 476 }