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
   4 /*
   5  * Copyright (c) 1995 Gordon Ross, Adam Glass
   6  * Copyright (c) 1992 Regents of the University of California.
   7  * All rights reserved.
   8  *
   9  * This software was developed by the Computer Systems Engineering group
  10  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  11  * contributed to Berkeley.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *      This product includes software developed by the University of
  24  *      California, Lawrence Berkeley Laboratory and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  * partially based on:
  42  *      libnetboot/rpc.c
  43  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
  44  */
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/malloc.h>
  49 #include <sys/mbuf.h>
  50 #include <sys/socket.h>
  51 #include <sys/socketvar.h>
  52 #include <sys/uio.h>
  53 #include <sys/fcntl.h>
  54
  55 #include <net/if.h>
  56 #include <netinet/in.h>
  57
  58 #include "rpcv2.h"
  59 #include "krpc.h"
  60 #include "xdr_subs.h"
  61
  62 /*
  63  * Kernel support for Sun RPC
  64  *
  65  * Used currently for bootstrapping in nfs diskless configurations.
  66  */
  67
  68 /*
  69  * Generic RPC headers
  70  */
  71
  72 struct auth_info {
  73         u_int32_t       authtype;       /* auth type */
  74         u_int32_t       authlen;        /* auth length */
  75 };
  76
  77 struct auth_unix {
  78         int32_t   ua_time;
  79         int32_t   ua_hostname;  /* null */
  80         int32_t   ua_uid;
  81         int32_t   ua_gid;
  82         int32_t   ua_gidlist;   /* null */
  83 };
  84
  85 struct rpc_call {
  86         u_int32_t       rp_xid;         /* request transaction id */
  87         int32_t         rp_direction;   /* call direction (0) */
  88         u_int32_t       rp_rpcvers;     /* rpc version (2) */
  89         u_int32_t       rp_prog;        /* program */
  90         u_int32_t       rp_vers;        /* version */
  91         u_int32_t       rp_proc;        /* procedure */
  92         struct  auth_info rpc_auth;
  93         struct  auth_unix rpc_unix;
  94         struct  auth_info rpc_verf;
  95 };
  96
  97 struct rpc_reply {
  98         u_int32_t rp_xid;               /* request transaction id */
  99         int32_t  rp_direction;          /* call direction (1) */
 100         int32_t  rp_astatus;            /* accept status (0: accepted) */
 101         union {
 102                 u_int32_t rpu_errno;
 103                 struct {
 104                         struct auth_info rok_auth;
 105                         u_int32_t       rok_status;
 106                 } rpu_rok;
 107         } rp_u;
 108 };
 109 #define rp_errno  rp_u.rpu_errno
 110 #define rp_auth   rp_u.rpu_rok.rok_auth
 111 #define rp_status rp_u.rpu_rok.rok_status
 112
 113 #define MIN_REPLY_HDR 16        /* xid, dir, astat, errno */
 114
 115 /*
 116  * What is the longest we will wait before re-sending a request?
 117  * Note this is also the frequency of "RPC timeout" messages.
 118  * The re-send loop count sup linearly to this maximum, so the
 119  * first complaint will happen after (1+2+3+4+5)=15 seconds.
 120  */
 121 #define MAX_RESEND_DELAY 5      /* seconds */
 122
 123 /*
 124  * Call portmap to lookup a port number for a particular rpc program
 125  * Returns non-zero error on failure.
 126  */
 127 int
 128 krpc_portmap(struct sockaddr_in *sin,   /* server address */
 129              u_int prog, u_int vers,    /* host order */
 130              u_int16_t *portp,          /* network order */
 131              struct thread *td)
 132 {
 133         struct sdata {
 134                 u_int32_t prog;         /* call program */
 135                 u_int32_t vers;         /* call version */
 136                 u_int32_t proto;        /* call protocol */
 137                 u_int32_t port;         /* call port (unused) */
 138         } *sdata;
 139         struct rdata {
 140                 u_int16_t pad;
 141                 u_int16_t port;
 142         } *rdata;
 143         struct mbuf *m;
 144         int error;
 145
 146         /* The portmapper port is fixed. */
 147         if (prog == PMAPPROG) {
 148                 *portp = htons(PMAPPORT);
 149                 return 0;
 150         }
 151
 152         m = m_get(M_WAITOK, MT_DATA);
 153         if (m == NULL)
 154                 return ENOBUFS;
 155         sdata = mtod(m, struct sdata *);
 156         m->m_len = sizeof(*sdata);
 157
 158         /* Do the RPC to get it. */
 159         sdata->prog = txdr_unsigned(prog);
 160         sdata->vers = txdr_unsigned(vers);
 161         sdata->proto = txdr_unsigned(IPPROTO_UDP);
 162         sdata->port = 0;
 163
 164         sin->sin_port = htons(PMAPPORT);
 165         error = krpc_call(sin, PMAPPROG, PMAPVERS,
 166                                           PMAPPROC_GETPORT, &m, NULL, td);
 167         if (error)
 168                 return error;
 169
 170         if (m->m_len < sizeof(*rdata)) {
 171                 m = m_pullup(m, sizeof(*rdata));
 172                 if (m == NULL)
 173                         return ENOBUFS;
 174         }
 175         rdata = mtod(m, struct rdata *);
 176         *portp = rdata->port;
 177
 178         m_freem(m);
 179         return 0;
 180 }
 181
 182 /*
 183  * Do a remote procedure call (RPC) and wait for its reply.
 184  * If from_p is non-null, then we are doing broadcast, and
 185  * the address from whence the response came is saved there.
 186  */
 187 int
 188 krpc_call(struct sockaddr_in *sa, u_int prog, u_int vers, u_int func,
 189           struct mbuf **data,           /* input/output */
 190           struct sockaddr **from_p,     /* output */
 191           struct thread *td)
 192 {
 193         struct socket *so;
 194         struct sockaddr_in *sin, ssin;
 195         struct sockaddr *from;
 196         struct mbuf *m, *mhead;
 197         struct rpc_call *call;
 198         struct rpc_reply *reply;
 199         struct sockopt sopt;
 200         struct timeval tv;
 201         struct sockbuf sio;
 202         int error, rcvflg, timo, secs, len;
 203         static u_int32_t static_xid = ~0xFF;
 204         u_int32_t xid;
 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         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(M_WAITOK, 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         do {
 284                 xid = atomic_fetchadd_int(&static_xid, 1);
 285         } while (xid == 0);
 286         call->rp_xid = txdr_unsigned(xid);
 287         /* call->rp_direction = 0; */
 288         call->rp_rpcvers = txdr_unsigned(2);
 289         call->rp_prog = txdr_unsigned(prog);
 290         call->rp_vers = txdr_unsigned(vers);
 291         call->rp_proc = txdr_unsigned(func);
 292         /* rpc_auth part (auth_unix as root) */
 293         call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
 294         call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
 295         /* rpc_verf part (auth_null) */
 296         call->rpc_verf.authtype = 0;
 297         call->rpc_verf.authlen  = 0;
 298
 299         /*
 300          * Setup packet header
 301          */
 302         len = 0;
 303         m = mhead;
 304         while (m) {
 305                 len += m->m_len;
 306                 m = m->m_next;
 307         }
 308         mhead->m_pkthdr.len = len;
 309         mhead->m_pkthdr.rcvif = NULL;
 310
 311         /*
 312          * Send it, repeatedly, until a reply is received,
 313          * but delay each re-send by an increasing amount.
 314          * If the delay hits the maximum, start complaining.
 315          */
 316         timo = 0;
 317         for (;;) {
 318                 /* Send RPC request (or re-send). */
 319                 m = m_copym(mhead, 0, M_COPYALL, M_WAITOK);
 320                 if (m == NULL) {
 321                         error = ENOBUFS;
 322                         goto out;
 323                 }
 324                 error = sosend(so, (struct sockaddr *)sa, NULL, m,
 325                                NULL, 0, td);
 326                 if (error) {
 327                         kprintf("krpc_call: sosend: %d\n", error);
 328                         goto out;
 329                 }
 330                 m = NULL;
 331
 332                 /* Determine new timeout. */
 333                 if (timo < MAX_RESEND_DELAY)
 334                         timo++;
 335                 else {
 336                         saddr = ntohl(sa->sin_addr.s_addr);
 337                         kprintf("RPC timeout for server %d.%d.%d.%d\n",
 338                                (saddr >> 24) & 255,
 339                                (saddr >> 16) & 255,
 340                                (saddr >> 8) & 255,
 341                                saddr & 255);
 342                 }
 343
 344                 /*
 345                  * Wait for up to timo seconds for a reply.
 346                  * The socket receive timeout was set to 1 second.
 347                  */
 348                 secs = timo;
 349                 while (secs > 0) {
 350                         if (from) {
 351                                 kfree(from, M_SONAME);
 352                                 from = NULL;
 353                         }
 354                         if (m) {
 355                                 m_freem(m);
 356                                 m = NULL;
 357                         }
 358                         len = 1 << 16;
 359                         sbinit(&sio, len);
 360                         rcvflg = 0;
 361                         error = soreceive(so, &from, NULL, &sio, NULL, &rcvflg);
 362                         if (error == EWOULDBLOCK) {
 363                                 secs--;
 364                                 continue;
 365                         }
 366                         if (error)
 367                                 goto out;
 368                         len -= sio.sb_cc;
 369                         m = sio.sb_mb;
 370
 371                         /* Does the reply contain at least a header? */
 372                         if (len < MIN_REPLY_HDR)
 373                                 continue;
 374                         if (m->m_len < MIN_REPLY_HDR)
 375                                 continue;
 376                         reply = mtod(m, struct rpc_reply *);
 377
 378                         /* Is it the right reply? */
 379                         if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
 380                                 continue;
 381
 382                         if (reply->rp_xid != txdr_unsigned(xid))
 383                                 continue;
 384
 385                         /* Was RPC accepted? (authorization OK) */
 386                         if (reply->rp_astatus != 0) {
 387                                 error = fxdr_unsigned(u_int32_t, reply->rp_errno);
 388                                 kprintf("rpc denied, error=%d\n", error);
 389                                 continue;
 390                         }
 391
 392                         /* Did the call succeed? */
 393                         if (reply->rp_status != 0) {
 394                                 error = fxdr_unsigned(u_int32_t, reply->rp_status);
 395                                 if (error == RPC_PROGMISMATCH) {
 396                                   error = EBADRPC;
 397                                   goto out;
 398                                 }
 399                                 kprintf("rpc denied, status=%d\n", error);
 400                                 continue;
 401                         }
 402
 403                         goto gotreply;  /* break two levels */
 404
 405                 } /* while secs */
 406         } /* forever send/receive */
 407
 408         error = ETIMEDOUT;
 409         goto out;
 410
 411  gotreply:
 412
 413         /*
 414          * Get RPC reply header into first mbuf,
 415          * get its length, then strip it off.
 416          */
 417         len = sizeof(*reply);
 418         if (m->m_len < len) {
 419                 m = m_pullup(m, len);
 420                 if (m == NULL) {
 421                         error = ENOBUFS;
 422                         goto out;
 423                 }
 424         }
 425         reply = mtod(m, struct rpc_reply *);
 426         if (reply->rp_auth.authtype != 0) {
 427                 len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
 428                 len = (len + 3) & ~3; /* XXX? */
 429         }
 430         m_adj(m, len);
 431
 432         /* result */
 433         *data = m;
 434         if (from_p) {
 435                 *from_p = from;
 436                 from = NULL;
 437         }
 438
 439  out:
 440         if (mhead) m_freem(mhead);
 441         if (from) kfree(from, M_SONAME);
 442         soclose(so, FNONBLOCK);
 443         return error;
 444 }
 445
 446 /*
 447  * eXternal Data Representation routines.
 448  * (but with non-standard args...)
 449  */
 450
 451 /*
 452  * String representation for RPC.
 453  */
 454 struct xdr_string {
 455         u_int32_t len;          /* length without null or padding */
 456         char data[4];   /* data (longer, of course) */
 457     /* data is padded to a long-word boundary */
 458 };
 459
 460 struct mbuf *
 461 xdr_string_encode(char *str, int len)
 462 {
 463         struct mbuf *m;
 464         struct xdr_string *xs;
 465         int dlen;       /* padded string length */
 466         int mlen;       /* message length */
 467
 468         dlen = (len + 3) & ~3;
 469         mlen = dlen + 4;
 470
 471         if (mlen > MCLBYTES)            /* If too big, we just can't do it. */
 472                 return (NULL);
 473
 474         m = m_getl(mlen, M_WAITOK, MT_DATA, 0, NULL);
 475         xs = mtod(m, struct xdr_string *);
 476         m->m_len = mlen;
 477         xs->len = txdr_unsigned(len);
 478         bcopy(str, xs->data, len);
 479         return (m);
 480 }