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rpc.c revision 1.20
      1 /*	$NetBSD: rpc.c,v 1.20 1999/11/13 21:17:57 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992 Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Lawrence Berkeley Laboratory and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  *
     39  * @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
     40  */
     41 
     42 /*
     43  * RPC functions used by NFS and bootparams.
     44  * Note that bootparams requires the ability to find out the
     45  * address of the server from which its response has come.
     46  * This is supported by keeping the IP/UDP headers in the
     47  * buffer space provided by the caller.  (See rpc_fromaddr)
     48  */
     49 
     50 #include <sys/param.h>
     51 #include <sys/socket.h>
     52 
     53 #include <netinet/in.h>
     54 #include <netinet/in_systm.h>
     55 
     56 #ifdef _STANDALONE
     57 #include <lib/libkern/libkern.h>
     58 #else
     59 #include <string.h>
     60 #endif
     61 
     62 #include "rpcv2.h"
     63 
     64 #include "stand.h"
     65 #include "net.h"
     66 #include "netif.h"
     67 #include "rpc.h"
     68 
     69 struct auth_info {
     70 	int32_t 	authtype;	/* auth type */
     71 	u_int32_t	authlen;	/* auth length */
     72 };
     73 
     74 struct auth_unix {
     75 	int32_t   ua_time;
     76 	int32_t   ua_hostname;	/* null */
     77 	int32_t   ua_uid;
     78 	int32_t   ua_gid;
     79 	int32_t   ua_gidlist;	/* null */
     80 };
     81 
     82 struct rpc_call {
     83 	u_int32_t	rp_xid;		/* request transaction id */
     84 	int32_t 	rp_direction;	/* call direction (0) */
     85 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
     86 	u_int32_t	rp_prog;	/* program */
     87 	u_int32_t	rp_vers;	/* version */
     88 	u_int32_t	rp_proc;	/* procedure */
     89 };
     90 
     91 struct rpc_reply {
     92 	u_int32_t	rp_xid;		/* request transaction id */
     93 	int32_t 	rp_direction;	/* call direction (1) */
     94 	int32_t 	rp_astatus;	/* accept status (0: accepted) */
     95 	union {
     96 		u_int32_t	rpu_errno;
     97 		struct {
     98 			struct auth_info rok_auth;
     99 			u_int32_t	rok_status;
    100 		} rpu_rok;
    101 	} rp_u;
    102 };
    103 
    104 /* Local forwards */
    105 static	ssize_t recvrpc __P((struct iodesc *, void *, size_t, time_t));
    106 static	int rpc_getport __P((struct iodesc *, n_long, n_long));
    107 
    108 int rpc_xid;
    109 int rpc_port = 0x400;	/* predecrement */
    110 
    111 /*
    112  * Make a rpc call; return length of answer
    113  * Note: Caller must leave room for headers.
    114  */
    115 ssize_t
    116 rpc_call(d, prog, vers, proc, sdata, slen, rdata, rlen)
    117 	register struct iodesc *d;
    118 	register n_long prog, vers, proc;
    119 	register void *sdata;
    120 	register size_t slen;
    121 	register void *rdata;
    122 	register size_t rlen;
    123 {
    124 	register ssize_t cc;
    125 	struct auth_info *auth;
    126 	struct rpc_call *call;
    127 	struct rpc_reply *reply;
    128 	char *send_head, *send_tail;
    129 	char *recv_head, *recv_tail;
    130 	n_long x;
    131 	int port;	/* host order */
    132 
    133 #ifdef RPC_DEBUG
    134 	if (debug)
    135 		printf("rpc_call: prog=0x%x vers=%d proc=%d\n",
    136 		    prog, vers, proc);
    137 #endif
    138 
    139 	port = rpc_getport(d, prog, vers);
    140 	if (port == -1)
    141 		return (-1);
    142 
    143 	d->destport = htons(port);
    144 
    145 	/*
    146 	 * Prepend authorization stuff and headers.
    147 	 * Note, must prepend things in reverse order.
    148 	 */
    149 	send_head = sdata;
    150 	send_tail = (char *)sdata + slen;
    151 
    152 	/* Auth verifier is always auth_null */
    153 	send_head -= sizeof(*auth);
    154 	auth = (struct auth_info *)send_head;
    155 	auth->authtype = htonl(RPCAUTH_NULL);
    156 	auth->authlen = 0;
    157 
    158 #if 1
    159 	/* Auth credentials: always auth unix (as root) */
    160 	send_head -= sizeof(struct auth_unix);
    161 	bzero(send_head, sizeof(struct auth_unix));
    162 	send_head -= sizeof(*auth);
    163 	auth = (struct auth_info *)send_head;
    164 	auth->authtype = htonl(RPCAUTH_UNIX);
    165 	auth->authlen = htonl(sizeof(struct auth_unix));
    166 #else
    167 	/* Auth credentials: always auth_null (XXX OK?) */
    168 	send_head -= sizeof(*auth);
    169 	auth = send_head;
    170 	auth->authtype = htonl(RPCAUTH_NULL);
    171 	auth->authlen = 0;
    172 #endif
    173 
    174 	/* RPC call structure. */
    175 	send_head -= sizeof(*call);
    176 	call = (struct rpc_call *)send_head;
    177 	rpc_xid++;
    178 	call->rp_xid       = htonl(rpc_xid);
    179 	call->rp_direction = htonl(RPC_CALL);
    180 	call->rp_rpcvers   = htonl(RPC_VER2);
    181 	call->rp_prog = htonl(prog);
    182 	call->rp_vers = htonl(vers);
    183 	call->rp_proc = htonl(proc);
    184 
    185 	/* Make room for the rpc_reply header. */
    186 	recv_head = rdata;
    187 	recv_tail = (char *)rdata + rlen;
    188 	recv_head -= sizeof(*reply);
    189 
    190 	cc = sendrecv(d,
    191 	    sendudp, send_head, send_tail - send_head,
    192 	    recvrpc, recv_head, recv_tail - recv_head);
    193 
    194 #ifdef RPC_DEBUG
    195 	if (debug)
    196 		printf("callrpc: cc=%ld rlen=%lu\n", (long)cc, (u_long)rlen);
    197 #endif
    198 	if (cc == -1)
    199 		return (-1);
    200 
    201 	if (cc <= sizeof(*reply)) {
    202 		errno = EBADRPC;
    203 		return (-1);
    204 	}
    205 
    206 	recv_tail = recv_head + cc;
    207 
    208 	/*
    209 	 * Check the RPC reply status.
    210 	 * The xid, dir, astatus were already checked.
    211 	 */
    212 	reply = (struct rpc_reply *)recv_head;
    213 	auth = &reply->rp_u.rpu_rok.rok_auth;
    214 	x = ntohl(auth->authlen);
    215 	if (x != 0) {
    216 #ifdef RPC_DEBUG
    217 		if (debug)
    218 			printf("callrpc: reply auth != NULL\n");
    219 #endif
    220 		errno = EBADRPC;
    221 		return(-1);
    222 	}
    223 	x = ntohl(reply->rp_u.rpu_rok.rok_status);
    224 	if (x != 0) {
    225 		printf("callrpc: error = %d\n", x);
    226 		errno = EBADRPC;
    227 		return(-1);
    228 	}
    229 	recv_head += sizeof(*reply);
    230 
    231 	return (ssize_t)(recv_tail - recv_head);
    232 }
    233 
    234 /*
    235  * Returns true if packet is the one we're waiting for.
    236  * This just checks the XID, direction, acceptance.
    237  * Remaining checks are done by callrpc
    238  */
    239 static ssize_t
    240 recvrpc(d, pkt, len, tleft)
    241 	register struct iodesc *d;
    242 	register void *pkt;
    243 	register size_t len;
    244 	time_t tleft;
    245 {
    246 	register struct rpc_reply *reply;
    247 	ssize_t	n;
    248 	int	x;
    249 
    250 	errno = 0;
    251 #ifdef RPC_DEBUG
    252 	if (debug)
    253 		printf("recvrpc: called len=%lu\n", (u_long)len);
    254 #endif
    255 
    256 	n = readudp(d, pkt, len, tleft);
    257 	if (n <= (4 * 4))
    258 		return -1;
    259 
    260 	reply = (struct rpc_reply *)pkt;
    261 
    262 	x = ntohl(reply->rp_xid);
    263 	if (x != rpc_xid) {
    264 #ifdef RPC_DEBUG
    265 		if (debug)
    266 			printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid);
    267 #endif
    268 		return -1;
    269 	}
    270 
    271 	x = ntohl(reply->rp_direction);
    272 	if (x != RPC_REPLY) {
    273 #ifdef RPC_DEBUG
    274 		if (debug)
    275 			printf("recvrpc: rp_direction %d != REPLY\n", x);
    276 #endif
    277 		return -1;
    278 	}
    279 
    280 	x = ntohl(reply->rp_astatus);
    281 	if (x != RPC_MSGACCEPTED) {
    282 		errno = ntohl(reply->rp_u.rpu_errno);
    283 		printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
    284 		return -1;
    285 	}
    286 
    287 	/* Return data count (thus indicating success) */
    288 	return (n);
    289 }
    290 
    291 /*
    292  * Given a pointer to a reply just received,
    293  * dig out the IP address/port from the headers.
    294  */
    295 void
    296 rpc_fromaddr(pkt, addr, port)
    297 	void		*pkt;
    298 	struct in_addr	*addr;
    299 	u_short		*port;
    300 {
    301 	struct hackhdr {
    302 		/* Tail of IP header: just IP addresses */
    303 		n_long ip_src;
    304 		n_long ip_dst;
    305 		/* UDP header: */
    306 		u_int16_t uh_sport;		/* source port */
    307 		u_int16_t uh_dport;		/* destination port */
    308 		int16_t	  uh_ulen;		/* udp length */
    309 		u_int16_t uh_sum;		/* udp checksum */
    310 		/* RPC reply header: */
    311 		struct rpc_reply rpc;
    312 	} *hhdr;
    313 
    314 	hhdr = ((struct hackhdr *)pkt) - 1;
    315 	addr->s_addr = hhdr->ip_src;
    316 	*port = hhdr->uh_sport;
    317 }
    318 
    319 /*
    320  * RPC Portmapper cache
    321  */
    322 #define PMAP_NUM 8			/* need at most 5 pmap entries */
    323 
    324 int rpc_pmap_num;
    325 struct pmap_list {
    326 	struct in_addr	addr;	/* server, net order */
    327 	u_int	prog;		/* host order */
    328 	u_int	vers;		/* host order */
    329 	int 	port;		/* host order */
    330 } rpc_pmap_list[PMAP_NUM];
    331 
    332 /* return port number in host order, or -1 */
    333 int
    334 rpc_pmap_getcache(addr, prog, vers)
    335 	struct in_addr	addr;	/* server, net order */
    336 	u_int		prog;	/* host order */
    337 	u_int		vers;	/* host order */
    338 {
    339 	struct pmap_list *pl;
    340 
    341 	for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
    342 		if (pl->addr.s_addr == addr.s_addr &&
    343 			pl->prog == prog && pl->vers == vers )
    344 		{
    345 			return (pl->port);
    346 		}
    347 	}
    348 	return (-1);
    349 }
    350 
    351 void
    352 rpc_pmap_putcache(addr, prog, vers, port)
    353 	struct in_addr	addr;	/* server, net order */
    354 	u_int		prog;	/* host order */
    355 	u_int		vers;	/* host order */
    356 	int 		port;	/* host order */
    357 {
    358 	struct pmap_list *pl;
    359 
    360 	/* Don't overflow cache... */
    361 	if (rpc_pmap_num >= PMAP_NUM) {
    362 		/* ... just re-use the last entry. */
    363 		rpc_pmap_num = PMAP_NUM - 1;
    364 #ifdef	RPC_DEBUG
    365 		printf("rpc_pmap_putcache: cache overflow\n");
    366 #endif
    367 	}
    368 
    369 	pl = &rpc_pmap_list[rpc_pmap_num];
    370 	rpc_pmap_num++;
    371 
    372 	/* Cache answer */
    373 	pl->addr = addr;
    374 	pl->prog = prog;
    375 	pl->vers = vers;
    376 	pl->port = port;
    377 }
    378 
    379 
    380 /*
    381  * Request a port number from the port mapper.
    382  * Returns the port in host order.
    383  */
    384 int
    385 rpc_getport(d, prog, vers)
    386 	register struct iodesc *d;
    387 	n_long prog;	/* host order */
    388 	n_long vers;	/* host order */
    389 {
    390 	struct args {
    391 		n_long	prog;		/* call program */
    392 		n_long	vers;		/* call version */
    393 		n_long	proto;		/* call protocol */
    394 		n_long	port;		/* call port (unused) */
    395 	} *args;
    396 	struct res {
    397 		n_long port;
    398 	} *res;
    399 	struct {
    400 		n_long	h[RPC_HEADER_WORDS];
    401 		struct args d;
    402 	} sdata;
    403 	struct {
    404 		n_long	h[RPC_HEADER_WORDS];
    405 		struct res d;
    406 		n_long  pad;
    407 	} rdata;
    408 	ssize_t cc;
    409 	int port;
    410 
    411 #ifdef RPC_DEBUG
    412 	if (debug)
    413 		printf("getport: prog=0x%x vers=%d\n", prog, vers);
    414 #endif
    415 
    416 	/* This one is fixed forever. */
    417 	if (prog == PMAPPROG)
    418 		return (PMAPPORT);
    419 
    420 	/* Try for cached answer first */
    421 	port = rpc_pmap_getcache(d->destip, prog, vers);
    422 	if (port != -1)
    423 		return (port);
    424 
    425 	args = &sdata.d;
    426 	args->prog = htonl(prog);
    427 	args->vers = htonl(vers);
    428 	args->proto = htonl(IPPROTO_UDP);
    429 	args->port = 0;
    430 	res = &rdata.d;
    431 
    432 	cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
    433 		args, sizeof(*args), res, sizeof(*res));
    434 	if (cc < sizeof(*res)) {
    435 		printf("getport: %s", strerror(errno));
    436 		errno = EBADRPC;
    437 		return (-1);
    438 	}
    439 	port = (int)ntohl(res->port);
    440 
    441 	rpc_pmap_putcache(d->destip, prog, vers, port);
    442 
    443 	return (port);
    444 }
    445