lib/libc/rpc/clnt_unix.c

   1 /*
   2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3  * unrestricted use provided that this legend is included on all tape
   4  * media and as a part of the software program in whole or part.  Users
   5  * may copy or modify Sun RPC without charge, but are not authorized
   6  * to license or distribute it to anyone else except as part of a product or
   7  * program developed by the user.
   8  *
   9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12  *
  13  * Sun RPC is provided with no support and without any obligation on the
  14  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15  * modification or enhancement.
  16  *
  17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19  * OR ANY PART THEREOF.
  20  *
  21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22  * or profits or other special, indirect and consequential damages, even if
  23  * Sun has been advised of the possibility of such damages.
  24  *
  25  * Sun Microsystems, Inc.
  26  * 2550 Garcia Avenue
  27  * Mountain View, California  94043
  28  *
  29  * @(#)clnt_unix.c 1.37 87/10/05 Copyr 1984 Sun Micro
  30  * @(#)clnt_unix.c      2.2 88/08/01 4.0 RPCSRC
  31  * $FreeBSD: src/lib/libc/rpc/clnt_unix.c,v 1.5 2000/01/27 23:06:37 jasone Exp $
  32  * $DragonFly: src/lib/libc/rpc/clnt_unix.c,v 1.5 2005/11/13 12:27:04 swildner Exp $
  33  */
  34
  35 /*
  36  * clnt_unix.c, Implements a AF_UNIX based, client side RPC.
  37  *
  38  * Copyright (C) 1984, Sun Microsystems, Inc.
  39  *
  40  * AF_UNIX based RPC supports 'batched calls'.
  41  * A sequence of calls may be batched-up in a send buffer.  The rpc call
  42  * return immediately to the client even though the call was not necessarily
  43  * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
  44  * the rpc timeout value is zero (see clnt.h, rpc).
  45  *
  46  * Clients should NOT casually batch calls that in fact return results; that is,
  47  * the server side should be aware that a call is batched and not produce any
  48  * return message.  Batched calls that produce many result messages can
  49  * deadlock (netlock) the client and the server....
  50  *
  51  * Now go hang yourself.
  52  */
  53
  54 #include "namespace.h"
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <unistd.h>
  58 #include <string.h>
  59 #include <rpc/rpc.h>
  60 #include <sys/uio.h>
  61 #include <sys/socket.h>
  62 #include <sys/un.h>
  63 #include <netdb.h>
  64 #include <errno.h>
  65 #include <rpc/pmap_clnt.h>
  66 #include "un-namespace.h"
  67
  68 #define MCALL_MSG_SIZE 24
  69
  70 static int      readunix();
  71 static int      writeunix();
  72
  73 static enum clnt_stat   clntunix_call();
  74 static void             clntunix_abort();
  75 static void             clntunix_geterr();
  76 static bool_t           clntunix_freeres();
  77 static bool_t           clntunix_control();
  78 static void             clntunix_destroy();
  79
  80 static struct clnt_ops unix_ops = {
  81         clntunix_call,
  82         clntunix_abort,
  83         clntunix_geterr,
  84         clntunix_freeres,
  85         clntunix_destroy,
  86         clntunix_control
  87 };
  88
  89 struct ct_data {
  90         int             ct_sock;
  91         bool_t          ct_closeit;
  92         struct timeval  ct_wait;
  93         bool_t          ct_waitset;       /* wait set by clnt_control? */
  94         struct sockaddr_un ct_addr;
  95         struct rpc_err  ct_error;
  96         char            ct_mcall[MCALL_MSG_SIZE];       /* marshalled callmsg */
  97         u_int           ct_mpos;                        /* pos after marshal */
  98         XDR             ct_xdrs;
  99 };
 100
 101 /*
 102  * Create a client handle for a unix/ip connection.
 103  * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 104  * connected to raddr.  If *sockp non-negative then
 105  * raddr is ignored.  The rpc/unix package does buffering
 106  * similar to stdio, so the client must pick send and receive buffer sizes,];
 107  * 0 => use the default.
 108  * If raddr->sin_port is 0, then a binder on the remote machine is
 109  * consulted for the right port number.
 110  * NB: *sockp is copied into a private area.
 111  * NB: It is the clients responsibility to close *sockp.
 112  * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 113  * something more useful.
 114  */
 115 CLIENT *
 116 clntunix_create(struct sockaddr_un *raddr, u_long prog, u_long vers, int *sockp,
 117                 u_int sendsz, u_int recvsz)
 118 {
 119         CLIENT *h;
 120         struct ct_data *ct = NULL;
 121         struct timeval now;
 122         struct rpc_msg call_msg;
 123         static u_int32_t disrupt;
 124         int len;
 125
 126         if (disrupt == 0)
 127                 disrupt = (u_int32_t)(long)raddr;
 128
 129         h  = (CLIENT *)mem_alloc(sizeof(*h));
 130         if (h == NULL) {
 131                 fprintf(stderr, "clntunix_create: out of memory\n");
 132                 rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 133                 rpc_createerr.cf_error.re_errno = errno;
 134                 goto fooy;
 135         }
 136         ct = (struct ct_data *)mem_alloc(sizeof(*ct));
 137         if (ct == NULL) {
 138                 fprintf(stderr, "clntunix_create: out of memory\n");
 139                 rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 140                 rpc_createerr.cf_error.re_errno = errno;
 141                 goto fooy;
 142         }
 143
 144         /*
 145          * If no socket given, open one
 146          */
 147         if (*sockp < 0) {
 148                 *sockp = _socket(AF_UNIX, SOCK_STREAM, 0);
 149                 len = strlen(raddr->sun_path) + sizeof(raddr->sun_family) +
 150                         sizeof(raddr->sun_len) + 1;
 151                 raddr->sun_len = len;
 152                 if ((*sockp < 0)
 153                     || (_connect(*sockp, (struct sockaddr *)raddr, len) < 0)) {
 154                         rpc_createerr.cf_stat = RPC_SYSTEMERROR;
 155                         rpc_createerr.cf_error.re_errno = errno;
 156                         if (*sockp != -1)
 157                                 _close(*sockp);
 158                         goto fooy;
 159                 }
 160                 ct->ct_closeit = TRUE;
 161         } else {
 162                 ct->ct_closeit = FALSE;
 163         }
 164
 165         /*
 166          * Set up private data struct
 167          */
 168         ct->ct_sock = *sockp;
 169         ct->ct_wait.tv_usec = 0;
 170         ct->ct_waitset = FALSE;
 171         ct->ct_addr = *raddr;
 172
 173         /*
 174          * Initialize call message
 175          */
 176         gettimeofday(&now, (struct timezone *)0);
 177         call_msg.rm_xid = (++disrupt) ^ getpid() ^ now.tv_sec ^ now.tv_usec;
 178         call_msg.rm_direction = CALL;
 179         call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
 180         call_msg.rm_call.cb_prog = prog;
 181         call_msg.rm_call.cb_vers = vers;
 182
 183         /*
 184          * pre-serialize the static part of the call msg and stash it away
 185          */
 186         xdrmem_create(&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
 187             XDR_ENCODE);
 188         if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
 189                 if (ct->ct_closeit) {
 190                         _close(*sockp);
 191                 }
 192                 goto fooy;
 193         }
 194         ct->ct_mpos = XDR_GETPOS(&(ct->ct_xdrs));
 195         XDR_DESTROY(&(ct->ct_xdrs));
 196
 197         /*
 198          * Create a client handle which uses xdrrec for serialization
 199          * and authnone for authentication.
 200          */
 201         xdrrec_create(&(ct->ct_xdrs), sendsz, recvsz,
 202             (caddr_t)ct, readunix, writeunix);
 203         h->cl_ops = &unix_ops;
 204         h->cl_private = (caddr_t) ct;
 205         h->cl_auth = authnone_create();
 206         return (h);
 207
 208 fooy:
 209         /*
 210          * Something goofed, free stuff and barf
 211          */
 212         if (ct)
 213                 mem_free((caddr_t)ct, sizeof(struct ct_data));
 214         if (h)
 215                 mem_free((caddr_t)h, sizeof(CLIENT));
 216         return ((CLIENT *)NULL);
 217 }
 218
 219 static enum clnt_stat
 220 clntunix_call(CLIENT *h, u_long proc, xdrproc_t xdr_args, caddr_t args_ptr,
 221               xdrproc_t xdr_results, caddr_t results_ptr,
 222               struct timeval timeout)
 223 {
 224         struct ct_data *ct = (struct ct_data *) h->cl_private;
 225         XDR *xdrs = &(ct->ct_xdrs);
 226         struct rpc_msg reply_msg;
 227         u_long x_id;
 228         u_int32_t *msg_x_id = (u_int32_t *)(ct->ct_mcall);      /* yuk */
 229         bool_t shipnow;
 230         int refreshes = 2;
 231
 232         if (!ct->ct_waitset) {
 233                 ct->ct_wait = timeout;
 234         }
 235
 236         shipnow =
 237             (xdr_results == (xdrproc_t)0 && timeout.tv_sec == 0
 238             && timeout.tv_usec == 0) ? FALSE : TRUE;
 239
 240 call_again:
 241         xdrs->x_op = XDR_ENCODE;
 242         ct->ct_error.re_status = RPC_SUCCESS;
 243         x_id = ntohl(--(*msg_x_id));
 244         if ((! XDR_PUTBYTES(xdrs, ct->ct_mcall, ct->ct_mpos)) ||
 245             (! XDR_PUTLONG(xdrs, (long *)&proc)) ||
 246             (! AUTH_MARSHALL(h->cl_auth, xdrs)) ||
 247             (! (*xdr_args)(xdrs, args_ptr))) {
 248                 if (ct->ct_error.re_status == RPC_SUCCESS)
 249                         ct->ct_error.re_status = RPC_CANTENCODEARGS;
 250                 xdrrec_endofrecord(xdrs, TRUE);
 251                 return (ct->ct_error.re_status);
 252         }
 253         if (! xdrrec_endofrecord(xdrs, shipnow))
 254                 return (ct->ct_error.re_status = RPC_CANTSEND);
 255         if (! shipnow)
 256                 return (RPC_SUCCESS);
 257         /*
 258          * Hack to provide rpc-based message passing
 259          */
 260         if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
 261                 return(ct->ct_error.re_status = RPC_TIMEDOUT);
 262         }
 263
 264
 265         /*
 266          * Keep receiving until we get a valid transaction id
 267          */
 268         xdrs->x_op = XDR_DECODE;
 269         while (TRUE) {
 270                 reply_msg.acpted_rply.ar_verf = _null_auth;
 271                 reply_msg.acpted_rply.ar_results.where = NULL;
 272                 reply_msg.acpted_rply.ar_results.proc = xdr_void;
 273                 if (! xdrrec_skiprecord(xdrs))
 274                         return (ct->ct_error.re_status);
 275                 /* now decode and validate the response header */
 276                 if (! xdr_replymsg(xdrs, &reply_msg)) {
 277                         if (ct->ct_error.re_status == RPC_SUCCESS)
 278                                 continue;
 279                         return (ct->ct_error.re_status);
 280                 }
 281                 if (reply_msg.rm_xid == x_id)
 282                         break;
 283         }
 284
 285         /*
 286          * process header
 287          */
 288         _seterr_reply(&reply_msg, &(ct->ct_error));
 289         if (ct->ct_error.re_status == RPC_SUCCESS) {
 290                 if (! AUTH_VALIDATE(h->cl_auth, &reply_msg.acpted_rply.ar_verf)) {
 291                         ct->ct_error.re_status = RPC_AUTHERROR;
 292                         ct->ct_error.re_why = AUTH_INVALIDRESP;
 293                 } else if (! (*xdr_results)(xdrs, results_ptr)) {
 294                         if (ct->ct_error.re_status == RPC_SUCCESS)
 295                                 ct->ct_error.re_status = RPC_CANTDECODERES;
 296                 }
 297                 /* free verifier ... */
 298                 if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
 299                         xdrs->x_op = XDR_FREE;
 300                         xdr_opaque_auth(xdrs, &(reply_msg.acpted_rply.ar_verf));
 301                 }
 302         }  /* end successful completion */
 303         else {
 304                 /* maybe our credentials need to be refreshed ... */
 305                 if (refreshes-- && AUTH_REFRESH(h->cl_auth))
 306                         goto call_again;
 307         }  /* end of unsuccessful completion */
 308         return (ct->ct_error.re_status);
 309 }
 310
 311 static void
 312 clntunix_geterr(CLIENT *h, struct rpc_err *errp)
 313 {
 314         struct ct_data *ct =
 315             (struct ct_data *) h->cl_private;
 316
 317         *errp = ct->ct_error;
 318 }
 319
 320 static bool_t
 321 clntunix_freeres(CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
 322 {
 323         struct ct_data *ct = (struct ct_data *)cl->cl_private;
 324         XDR *xdrs = &(ct->ct_xdrs);
 325
 326         xdrs->x_op = XDR_FREE;
 327         return ((*xdr_res)(xdrs, res_ptr));
 328 }
 329
 330 static void
 331 clntunix_abort(void)
 332 {
 333 }
 334
 335
 336 static bool_t
 337 clntunix_control(CLIENT *cl, int request, char *info)
 338 {
 339         struct ct_data *ct = (struct ct_data *)cl->cl_private;
 340         struct timeval *tv;
 341         int len;
 342
 343         switch (request) {
 344         case CLSET_FD_CLOSE:
 345                 ct->ct_closeit = TRUE;
 346                 break;
 347         case CLSET_FD_NCLOSE:
 348                 ct->ct_closeit = FALSE;
 349                 break;
 350         case CLSET_TIMEOUT:
 351                 if (info == NULL)
 352                         return(FALSE);
 353                 tv = (struct timeval *)info;
 354                 ct->ct_wait.tv_sec = tv->tv_sec;
 355                 ct->ct_wait.tv_usec = tv->tv_usec;
 356                 ct->ct_waitset = TRUE;
 357                 break;
 358         case CLGET_TIMEOUT:
 359                 if (info == NULL)
 360                         return(FALSE);
 361                 *(struct timeval *)info = ct->ct_wait;
 362                 break;
 363         case CLGET_SERVER_ADDR:
 364                 if (info == NULL)
 365                         return(FALSE);
 366                 *(struct sockaddr_un *)info = ct->ct_addr;
 367                 break;
 368         case CLGET_FD:
 369                 if (info == NULL)
 370                         return(FALSE);
 371                 *(int *)info = ct->ct_sock;
 372                 break;
 373         case CLGET_XID:
 374                 /*
 375                  * use the knowledge that xid is the
 376                  * first element in the call structure *.
 377                  * This will get the xid of the PREVIOUS call
 378                  */
 379                 if (info == NULL)
 380                         return(FALSE);
 381                 *(u_long *)info = ntohl(*(u_long *)ct->ct_mcall);
 382                 break;
 383         case CLSET_XID:
 384                 /* This will set the xid of the NEXT call */
 385                 if (info == NULL)
 386                         return(FALSE);
 387                 *(u_long *)ct->ct_mcall =  htonl(*(u_long *)info - 1);
 388                 /* decrement by 1 as clntunix_call() increments once */
 389         case CLGET_VERS:
 390                 /*
 391                  * This RELIES on the information that, in the call body,
 392                  * the version number field is the fifth field from the
 393                  * begining of the RPC header. MUST be changed if the
 394                  * call_struct is changed
 395                  */
 396                 if (info == NULL)
 397                         return(FALSE);
 398                 *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
 399                                                 4 * BYTES_PER_XDR_UNIT));
 400                 break;
 401         case CLSET_VERS:
 402                 if (info == NULL)
 403                         return(FALSE);
 404                 *(u_long *)(ct->ct_mcall + 4 * BYTES_PER_XDR_UNIT)
 405                                 = htonl(*(u_long *)info);
 406                 break;
 407         case CLGET_PROG:
 408                 /*
 409                  * This RELIES on the information that, in the call body,
 410                  * the program number field is the  field from the
 411                  * begining of the RPC header. MUST be changed if the
 412                  * call_struct is changed
 413                  */
 414                 if (info == NULL)
 415                         return(FALSE);
 416                 *(u_long *)info = ntohl(*(u_long *)(ct->ct_mcall +
 417                                                 3 * BYTES_PER_XDR_UNIT));
 418                 break;
 419         case CLSET_PROG:
 420                 if (info == NULL)
 421                         return(FALSE);
 422                 *(u_long *)(ct->ct_mcall + 3 * BYTES_PER_XDR_UNIT)
 423                                 = htonl(*(u_long *)info);
 424                 break;
 425         case CLGET_LOCAL_ADDR:
 426                 len = sizeof(struct sockaddr);
 427                 if (_getsockname(ct->ct_sock, (struct sockaddr *)info, &len) <0)
 428                         return(FALSE);
 429                 break;
 430         case CLGET_RETRY_TIMEOUT:
 431         case CLSET_RETRY_TIMEOUT:
 432         case CLGET_SVC_ADDR:
 433         case CLSET_SVC_ADDR:
 434         case CLSET_PUSH_TIMOD:
 435         case CLSET_POP_TIMOD:
 436         default:
 437                 return (FALSE);
 438         }
 439         return (TRUE);
 440 }
 441
 442
 443 static void
 444 clntunix_destroy(CLIENT *h)
 445 {
 446         struct ct_data *ct =
 447             (struct ct_data *) h->cl_private;
 448
 449         if (ct->ct_closeit) {
 450                 _close(ct->ct_sock);
 451         }
 452         XDR_DESTROY(&(ct->ct_xdrs));
 453         mem_free((caddr_t)ct, sizeof(struct ct_data));
 454         mem_free((caddr_t)h, sizeof(CLIENT));
 455 }
 456
 457 /*
 458  * _read() and _write() are replaced with _recvmsg()/_sendmsg() so that
 459  * we can pass ancillary control data. In this case, the data constists
 460  * of credential information which the kernel will fill in for us.
 461  * XXX: This code is specific to FreeBSD and will not work on other
 462  * platforms without the requisite kernel modifications.
 463  */
 464 struct cmessage {
 465         struct cmsghdr cmsg;
 466         struct cmsgcred cmcred;
 467 };
 468
 469 static int
 470 __msgread(int sock, void *buf, size_t cnt)
 471 {
 472         struct iovec iov[1];
 473         struct msghdr msg;
 474         struct cmessage cm;
 475
 476         bzero((char *)&cm, sizeof(cm));
 477         iov[0].iov_base = buf;
 478         iov[0].iov_len = cnt;
 479
 480         msg.msg_iov = iov;
 481         msg.msg_iovlen = 1;
 482         msg.msg_name = NULL;
 483         msg.msg_namelen = 0;
 484         msg.msg_control = (caddr_t)&cm;
 485         msg.msg_controllen = sizeof(struct cmessage);
 486         msg.msg_flags = 0;
 487
 488         return(_recvmsg(sock, &msg, 0));
 489 }
 490
 491 static int
 492 __msgwrite(int sock, void *buf, size_t cnt)
 493 {
 494         struct iovec iov[1];
 495         struct msghdr msg;
 496         struct cmessage cm;
 497
 498         bzero((char *)&cm, sizeof(cm));
 499         iov[0].iov_base = buf;
 500         iov[0].iov_len = cnt;
 501
 502         cm.cmsg.cmsg_type = SCM_CREDS;
 503         cm.cmsg.cmsg_level = SOL_SOCKET;
 504         cm.cmsg.cmsg_len = sizeof(struct cmessage);
 505
 506         msg.msg_iov = iov;
 507         msg.msg_iovlen = 1;
 508         msg.msg_name = NULL;
 509         msg.msg_namelen = 0;
 510         msg.msg_control = (caddr_t)&cm;
 511         msg.msg_controllen = sizeof(struct cmessage);
 512         msg.msg_flags = 0;
 513
 514         return(_sendmsg(sock, &msg, 0));
 515 }
 516
 517 /*
 518  * Interface between xdr serializer and unix connection.
 519  * Behaves like the system calls, read & write, but keeps some error state
 520  * around for the rpc level.
 521  */
 522 static int
 523 readunix(struct ct_data *ct, caddr_t buf, int len)
 524 {
 525         fd_set *fds, readfds;
 526         struct timeval start, after, duration, delta, tmp, tv;
 527         int r, save_errno;
 528
 529         if (len == 0)
 530                 return (0);
 531
 532         if (ct->ct_sock + 1 > FD_SETSIZE) {
 533                 int bytes = howmany(ct->ct_sock + 1, NFDBITS) * sizeof(fd_mask);
 534                 fds = (fd_set *)malloc(bytes);
 535                 if (fds == NULL)
 536                         return (-1);
 537                 memset(fds, 0, bytes);
 538         } else {
 539                 fds = &readfds;
 540                 FD_ZERO(fds);
 541         }
 542
 543         gettimeofday(&start, NULL);
 544         delta = ct->ct_wait;
 545         while (TRUE) {
 546                 /* XXX we know the other bits are still clear */
 547                 FD_SET(ct->ct_sock, fds);
 548                 tv = delta;     /* in case select writes back */
 549                 r = _select(ct->ct_sock+1, fds, NULL, NULL, &tv);
 550                 save_errno = errno;
 551
 552                 gettimeofday(&after, NULL);
 553                 timersub(&start, &after, &duration);
 554                 timersub(&delta, &duration, &tmp);
 555                 delta = tmp;
 556                 if (delta.tv_sec < 0 || !timerisset(&delta))
 557                         r = 0;
 558
 559                 switch (r) {
 560                 case 0:
 561                         if (fds != &readfds)
 562                                 free(fds);
 563                         ct->ct_error.re_status = RPC_TIMEDOUT;
 564                         return (-1);
 565
 566                 case -1:
 567                         if (errno == EINTR)
 568                                 continue;
 569                         if (fds != &readfds)
 570                                 free(fds);
 571                         ct->ct_error.re_status = RPC_CANTRECV;
 572                         ct->ct_error.re_errno = save_errno;
 573                         return (-1);
 574                 }
 575                 break;
 576         }
 577         switch (len = __msgread(ct->ct_sock, buf, len)) {
 578
 579         case 0:
 580                 /* premature eof */
 581                 ct->ct_error.re_errno = ECONNRESET;
 582                 ct->ct_error.re_status = RPC_CANTRECV;
 583                 len = -1;  /* it's really an error */
 584                 break;
 585
 586         case -1:
 587                 ct->ct_error.re_errno = errno;
 588                 ct->ct_error.re_status = RPC_CANTRECV;
 589                 break;
 590         }
 591         return (len);
 592 }
 593
 594 static int
 595 writeunix(struct ct_data *ct, caddr_t buf, int len)
 596 {
 597         int i, cnt;
 598
 599         for (cnt = len; cnt > 0; cnt -= i, buf += i) {
 600                 if ((i = __msgwrite(ct->ct_sock, buf, cnt)) == -1) {
 601                         ct->ct_error.re_errno = errno;
 602                         ct->ct_error.re_status = RPC_CANTSEND;
 603                         return (-1);
 604                 }
 605         }
 606         return (len);
 607 }