sys/vfs/nfs/krpc_subr.c

   1 /*      $NetBSD: krpc_subr.c,v 1.12.4.1 1996/06/07 00:52:26 cgd Exp $   */
   2 /* $FreeBSD: src/sys/nfs/krpc_subr.c,v 1.13.2.1 2000/11/20 21:17:14 tegge Exp $ */
   3 /* $DragonFly: src/sys/vfs/nfs/krpc_subr.c,v 1.12 2007/04/22 01:13:17 dillon Exp $      */
   4
   5 /*
   6  * Copyright (c) 1995 Gordon Ross, Adam Glass
   7  * Copyright (c) 1992 Regents of the University of California.
   8  * All rights reserved.
   9  *
  10  * This software was developed by the Computer Systems Engineering group
  11  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  12  * contributed to Berkeley.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions
  16  * are met:
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above copyright
  20  *    notice, this list of conditions and the following disclaimer in the
  21  *    documentation and/or other materials provided with the distribution.
  22  * 3. All advertising materials mentioning features or use of this software
  23  *    must display the following acknowledgement:
  24  *      This product includes software developed by the University of
  25  *      California, Lawrence Berkeley Laboratory and its contributors.
  26  * 4. Neither the name of the University nor the names of its contributors
  27  *    may be used to endorse or promote products derived from this software
  28  *    without specific prior written permission.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  40  * SUCH DAMAGE.
  41  *
  42  * partially based on:
  43  *      libnetboot/rpc.c
  44  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
  45  */
  46
  47 #include <sys/param.h>
  48 #include <sys/systm.h>
  49 #include <sys/malloc.h>
  50 #include <sys/mbuf.h>
  51 #include <sys/socket.h>
  52 #include <sys/socketvar.h>
  53 #include <sys/uio.h>
  54 #include <sys/fcntl.h>
  55
  56 #include <net/if.h>
  57 #include <netinet/in.h>
  58
  59 #include "rpcv2.h"
  60 #include "krpc.h"
  61 #include "xdr_subs.h"
  62
  63 /*
  64  * Kernel support for Sun RPC
  65  *
  66  * Used currently for bootstrapping in nfs diskless configurations.
  67  */
  68
  69 /*
  70  * Generic RPC headers
  71  */
  72
  73 struct auth_info {
  74         u_int32_t       authtype;       /* auth type */
  75         u_int32_t       authlen;        /* auth length */
  76 };
  77
  78 struct auth_unix {
  79         int32_t   ua_time;
  80         int32_t   ua_hostname;  /* null */
  81         int32_t   ua_uid;
  82         int32_t   ua_gid;
  83         int32_t   ua_gidlist;   /* null */
  84 };
  85
  86 struct rpc_call {
  87         u_int32_t       rp_xid;         /* request transaction id */
  88         int32_t         rp_direction;   /* call direction (0) */
  89         u_int32_t       rp_rpcvers;     /* rpc version (2) */
  90         u_int32_t       rp_prog;        /* program */
  91         u_int32_t       rp_vers;        /* version */
  92         u_int32_t       rp_proc;        /* procedure */
  93         struct  auth_info rpc_auth;
  94         struct  auth_unix rpc_unix;
  95         struct  auth_info rpc_verf;
  96 };
  97
  98 struct rpc_reply {
  99         u_int32_t rp_xid;               /* request transaction id */
 100         int32_t  rp_direction;          /* call direction (1) */
 101         int32_t  rp_astatus;            /* accept status (0: accepted) */
 102         union {
 103                 u_int32_t rpu_errno;
 104                 struct {
 105                         struct auth_info rok_auth;
 106                         u_int32_t       rok_status;
 107                 } rpu_rok;
 108         } rp_u;
 109 };
 110 #define rp_errno  rp_u.rpu_errno
 111 #define rp_auth   rp_u.rpu_rok.rok_auth
 112 #define rp_status rp_u.rpu_rok.rok_status
 113
 114 #define MIN_REPLY_HDR 16        /* xid, dir, astat, errno */
 115
 116 /*
 117  * What is the longest we will wait before re-sending a request?
 118  * Note this is also the frequency of "RPC timeout" messages.
 119  * The re-send loop count sup linearly to this maximum, so the
 120  * first complaint will happen after (1+2+3+4+5)=15 seconds.
 121  */
 122 #define MAX_RESEND_DELAY 5      /* seconds */
 123
 124 /*
 125  * Call portmap to lookup a port number for a particular rpc program
 126  * Returns non-zero error on failure.
 127  */
 128 int
 129 krpc_portmap(struct sockaddr_in *sin,   /* server address */
 130              u_int prog, u_int vers,    /* host order */
 131              u_int16_t *portp,          /* network order */
 132              struct thread *td)
 133 {
 134         struct sdata {
 135                 u_int32_t prog;         /* call program */
 136                 u_int32_t vers;         /* call version */
 137                 u_int32_t proto;        /* call protocol */
 138                 u_int32_t port;         /* call port (unused) */
 139         } *sdata;
 140         struct rdata {
 141                 u_int16_t pad;
 142                 u_int16_t port;
 143         } *rdata;
 144         struct mbuf *m;
 145         int error;
 146
 147         /* The portmapper port is fixed. */
 148         if (prog == PMAPPROG) {
 149                 *portp = htons(PMAPPORT);
 150                 return 0;
 151         }
 152
 153         m = m_get(MB_WAIT, MT_DATA);
 154         if (m == NULL)
 155                 return ENOBUFS;
 156         sdata = mtod(m, struct sdata *);
 157         m->m_len = sizeof(*sdata);
 158
 159         /* Do the RPC to get it. */
 160         sdata->prog = txdr_unsigned(prog);
 161         sdata->vers = txdr_unsigned(vers);
 162         sdata->proto = txdr_unsigned(IPPROTO_UDP);
 163         sdata->port = 0;
 164
 165         sin->sin_port = htons(PMAPPORT);
 166         error = krpc_call(sin, PMAPPROG, PMAPVERS,
 167                                           PMAPPROC_GETPORT, &m, NULL, td);
 168         if (error)
 169                 return error;
 170
 171         if (m->m_len < sizeof(*rdata)) {
 172                 m = m_pullup(m, sizeof(*rdata));
 173                 if (m == NULL)
 174                         return ENOBUFS;
 175         }
 176         rdata = mtod(m, struct rdata *);
 177         *portp = rdata->port;
 178
 179         m_freem(m);
 180         return 0;
 181 }
 182
 183 /*
 184  * Do a remote procedure call (RPC) and wait for its reply.
 185  * If from_p is non-null, then we are doing broadcast, and
 186  * the address from whence the response came is saved there.
 187  */
 188 int
 189 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
 190           struct mbuf **data,           /* input/output */
 191           struct sockaddr **from_p,     /* output */
 192           struct thread *td)
 193 {
 194         struct socket *so;
 195         struct sockaddr_in *sin, ssin;
 196         struct sockaddr *from;
 197         struct mbuf *m, *nam, *mhead;
 198         struct rpc_call *call;
 199         struct rpc_reply *reply;
 200         struct sockopt sopt;
 201         struct timeval tv;
 202         struct sockbuf sio;
 203         int error, rcvflg, timo, secs, len;
 204         static u_int32_t xid = ~0xFF;
 205         u_int16_t tport;
 206         u_int32_t saddr;
 207
 208         /*
 209          * Validate address family.
 210          * Sorry, this is INET specific...
 211          */
 212         if (sa->sin_family != AF_INET)
 213                 return (EAFNOSUPPORT);
 214
 215         /* Free at end if not null. */
 216         nam = mhead = NULL;
 217         from = NULL;
 218
 219         /*
 220          * Create socket and set its recieve timeout.
 221          */
 222         if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, td)))
 223                 goto out;
 224
 225         tv.tv_sec = 1;
 226         tv.tv_usec = 0;
 227         bzero(&sopt, sizeof sopt);
 228         sopt.sopt_level = SOL_SOCKET;
 229         sopt.sopt_name = SO_RCVTIMEO;
 230         sopt.sopt_val = &tv;
 231         sopt.sopt_valsize = sizeof tv;
 232
 233         if ((error = sosetopt(so, &sopt)) != 0)
 234                 goto out;
 235
 236         /*
 237          * Enable broadcast if necessary.
 238          */
 239         if (from_p) {
 240                 int on = 1;
 241                 sopt.sopt_name = SO_BROADCAST;
 242                 sopt.sopt_val = &on;
 243                 sopt.sopt_valsize = sizeof on;
 244                 if ((error = sosetopt(so, &sopt)) != 0)
 245                         goto out;
 246         }
 247
 248         /*
 249          * Bind the local endpoint to a reserved port,
 250          * because some NFS servers refuse requests from
 251          * non-reserved (non-privileged) ports.
 252          */
 253         sin = &ssin;
 254         bzero(sin, sizeof *sin);
 255         sin->sin_len = sizeof(*sin);
 256         sin->sin_family = AF_INET;
 257         sin->sin_addr.s_addr = INADDR_ANY;
 258         tport = IPPORT_RESERVED;
 259         do {
 260                 tport--;
 261                 sin->sin_port = htons(tport);
 262                 error = sobind(so, (struct sockaddr *)sin, td);
 263         } while (error == EADDRINUSE &&
 264                          tport > IPPORT_RESERVED / 2);
 265         if (error) {
 266                 kprintf("bind failed\n");
 267                 goto out;
 268         }
 269
 270         /*
 271          * Setup socket address for the server.
 272          */
 273
 274         /*
 275          * Prepend RPC message header.
 276          */
 277         mhead = m_gethdr(MB_WAIT, MT_DATA);
 278         mhead->m_next = *data;
 279         call = mtod(mhead, struct rpc_call *);
 280         mhead->m_len = sizeof(*call);
 281         bzero((caddr_t)call, sizeof(*call));
 282         /* rpc_call part */
 283         xid++;
 284         call->rp_xid = txdr_unsigned(xid);
 285         /* call->rp_direction = 0; */
 286         call->rp_rpcvers = txdr_unsigned(2);
 287         call->rp_prog = txdr_unsigned(prog);
 288         call->rp_vers = txdr_unsigned(vers);
 289         call->rp_proc = txdr_unsigned(func);
 290         /* rpc_auth part (auth_unix as root) */
 291         call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
 292         call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
 293         /* rpc_verf part (auth_null) */
 294         call->rpc_verf.authtype = 0;
 295         call->rpc_verf.authlen  = 0;
 296
 297         /*
 298          * Setup packet header
 299          */
 300         len = 0;
 301         m = mhead;
 302         while (m) {
 303                 len += m->m_len;
 304                 m = m->m_next;
 305         }
 306         mhead->m_pkthdr.len = len;
 307         mhead->m_pkthdr.rcvif = NULL;
 308
 309         /*
 310          * Send it, repeatedly, until a reply is received,
 311          * but delay each re-send by an increasing amount.
 312          * If the delay hits the maximum, start complaining.
 313          */
 314         timo = 0;
 315         for (;;) {
 316                 /* Send RPC request (or re-send). */
 317                 m = m_copym(mhead, 0, M_COPYALL, MB_WAIT);
 318                 if (m == NULL) {
 319                         error = ENOBUFS;
 320                         goto out;
 321                 }
 322                 error = sosend(so, (struct sockaddr *)sa, NULL, m,
 323                                NULL, 0, td);
 324                 if (error) {
 325                         kprintf("krpc_call: sosend: %d\n", error);
 326                         goto out;
 327                 }
 328                 m = NULL;
 329
 330                 /* Determine new timeout. */
 331                 if (timo < MAX_RESEND_DELAY)
 332                         timo++;
 333                 else {
 334                         saddr = ntohl(sa->sin_addr.s_addr);
 335                         kprintf("RPC timeout for server %d.%d.%d.%d\n",
 336                                (saddr >> 24) & 255,
 337                                (saddr >> 16) & 255,
 338                                (saddr >> 8) & 255,
 339                                saddr & 255);
 340                 }
 341
 342                 /*
 343                  * Wait for up to timo seconds for a reply.
 344                  * The socket receive timeout was set to 1 second.
 345                  */
 346                 secs = timo;
 347                 while (secs > 0) {
 348                         if (from) {
 349                                 FREE(from, M_SONAME);
 350                                 from = NULL;
 351                         }
 352                         if (m) {
 353                                 m_freem(m);
 354                                 m = NULL;
 355                         }
 356                         len = 1 << 16;
 357                         sbinit(&sio, len);
 358                         rcvflg = 0;
 359                         error = soreceive(so, &from, NULL, &sio, NULL, &rcvflg);
 360                         if (error == EWOULDBLOCK) {
 361                                 secs--;
 362                                 continue;
 363                         }
 364                         if (error)
 365                                 goto out;
 366                         len -= sio.sb_cc;
 367                         m = sio.sb_mb;
 368
 369                         /* Does the reply contain at least a header? */
 370                         if (len < MIN_REPLY_HDR)
 371                                 continue;
 372                         if (m->m_len < MIN_REPLY_HDR)
 373                                 continue;
 374                         reply = mtod(m, struct rpc_reply *);
 375
 376                         /* Is it the right reply? */
 377                         if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
 378                                 continue;
 379
 380                         if (reply->rp_xid != txdr_unsigned(xid))
 381                                 continue;
 382
 383                         /* Was RPC accepted? (authorization OK) */
 384                         if (reply->rp_astatus != 0) {
 385                                 error = fxdr_unsigned(u_int32_t, reply->rp_errno);
 386                                 kprintf("rpc denied, error=%d\n", error);
 387                                 continue;
 388                         }
 389
 390                         /* Did the call succeed? */
 391                         if (reply->rp_status != 0) {
 392                                 error = fxdr_unsigned(u_int32_t, reply->rp_status);
 393                                 if (error == RPC_PROGMISMATCH) {
 394                                   error = EBADRPC;
 395                                   goto out;
 396                                 }
 397                                 kprintf("rpc denied, status=%d\n", error);
 398                                 continue;
 399                         }
 400
 401                         goto gotreply;  /* break two levels */
 402
 403                 } /* while secs */
 404         } /* forever send/receive */
 405
 406         error = ETIMEDOUT;
 407         goto out;
 408
 409  gotreply:
 410
 411         /*
 412          * Get RPC reply header into first mbuf,
 413          * get its length, then strip it off.
 414          */
 415         len = sizeof(*reply);
 416         if (m->m_len < len) {
 417                 m = m_pullup(m, len);
 418                 if (m == NULL) {
 419                         error = ENOBUFS;
 420                         goto out;
 421                 }
 422         }
 423         reply = mtod(m, struct rpc_reply *);
 424         if (reply->rp_auth.authtype != 0) {
 425                 len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
 426                 len = (len + 3) & ~3; /* XXX? */
 427         }
 428         m_adj(m, len);
 429
 430         /* result */
 431         *data = m;
 432         if (from_p) {
 433                 *from_p = from;
 434                 from = NULL;
 435         }
 436
 437  out:
 438         if (mhead) m_freem(mhead);
 439         if (from) kfree(from, M_SONAME);
 440         soclose(so, FNONBLOCK);
 441         return error;
 442 }
 443
 444 /*
 445  * eXternal Data Representation routines.
 446  * (but with non-standard args...)
 447  */
 448
 449 /*
 450  * String representation for RPC.
 451  */
 452 struct xdr_string {
 453         u_int32_t len;          /* length without null or padding */
 454         char data[4];   /* data (longer, of course) */
 455     /* data is padded to a long-word boundary */
 456 };
 457
 458 struct mbuf *
 459 xdr_string_encode(char *str, int len)
 460 {
 461         struct mbuf *m;
 462         struct xdr_string *xs;
 463         int dlen;       /* padded string length */
 464         int mlen;       /* message length */
 465
 466         dlen = (len + 3) & ~3;
 467         mlen = dlen + 4;
 468
 469         if (mlen > MCLBYTES)            /* If too big, we just can't do it. */
 470                 return (NULL);
 471
 472         m = m_getl(mlen, MB_WAIT, MT_DATA, 0, NULL);
 473         xs = mtod(m, struct xdr_string *);
 474         m->m_len = mlen;
 475         xs->len = txdr_unsigned(len);
 476         bcopy(str, xs->data, len);
 477         return (m);
 478 }