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rpc.c revision 1.10
      1 /*	$NetBSD: rpc.c,v 1.10 1995/09/23 03:36:11 gwr 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 #include <nfs/rpcv2.h>
     57 #include <nfs/nfsv2.h>
     58 #include <nfs/xdr_subs.h>
     59 
     60 #include <string.h>
     61 
     62 #include "stand.h"
     63 #include "net.h"
     64 #include "netif.h"
     65 #include "rpc.h"
     66 
     67 struct auth_info {
     68 	int32_t 	authtype;	/* auth type */
     69 	u_int32_t	authlen;	/* auth length */
     70 };
     71 
     72 struct auth_unix {
     73 	int32_t   ua_time;
     74 	int32_t   ua_hostname;	/* null */
     75 	int32_t   ua_uid;
     76 	int32_t   ua_gid;
     77 	int32_t   ua_gidlist;	/* null */
     78 };
     79 
     80 struct rpc_call {
     81 	u_int32_t	rp_xid;		/* request transaction id */
     82 	int32_t 	rp_direction;	/* call direction (0) */
     83 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
     84 	u_int32_t	rp_prog;	/* program */
     85 	u_int32_t	rp_vers;	/* version */
     86 	u_int32_t	rp_proc;	/* procedure */
     87 };
     88 
     89 struct rpc_reply {
     90 	u_int32_t	rp_xid;		/* request transaction id */
     91 	int32_t 	rp_direction;	/* call direction (1) */
     92 	int32_t 	rp_astatus;	/* accept status (0: accepted) */
     93 	union {
     94 		u_int32_t	rpu_errno;
     95 		struct {
     96 			struct auth_info rok_auth;
     97 			u_int32_t	rok_status;
     98 		} rpu_rok;
     99 	} rp_u;
    100 };
    101 
    102 /* Local forwards */
    103 static	ssize_t recvrpc __P((struct iodesc *, void *, size_t, time_t));
    104 static	int rpc_getport __P((struct iodesc *, n_long, n_long));
    105 
    106 int rpc_xid;
    107 int rpc_port = 0x400;	/* predecrement */
    108 
    109 /*
    110  * Make a rpc call; return length of answer
    111  * Note: Caller must leave room for headers.
    112  */
    113 ssize_t
    114 rpc_call(d, prog, vers, proc, sdata, slen, rdata, rlen)
    115 	register struct iodesc *d;
    116 	register n_long prog, vers, proc;
    117 	register void *sdata;
    118 	register size_t slen;
    119 	register void *rdata;
    120 	register size_t rlen;
    121 {
    122 	register ssize_t cc;
    123 	struct auth_info *auth;
    124 	struct rpc_call *call;
    125 	struct rpc_reply *reply;
    126 	char *send_head, *send_tail;
    127 	char *recv_head, *recv_tail;
    128 	n_long x;
    129 	int port;	/* host order */
    130 
    131 #ifdef RPC_DEBUG
    132 	if (debug)
    133 		printf("rpc_call: prog=0x%x vers=%d proc=%d\n",
    134 			prog, vers, proc);
    135 #endif
    136 
    137 	port = rpc_getport(d, prog, vers);
    138 	if (port == -1)
    139 		return (-1);
    140 
    141 	d->destport = htons(port);
    142 
    143 	/*
    144 	 * Prepend authorization stuff and headers.
    145 	 * Note, must prepend things in reverse order.
    146 	 */
    147 	send_head = sdata;
    148 	send_tail = (char *)sdata + slen;
    149 
    150 	/* Auth verifier is always auth_null */
    151 	send_head -= sizeof(*auth);
    152 	auth = (struct auth_info *)send_head;
    153 	auth->authtype = htonl(RPCAUTH_NULL);
    154 	auth->authlen = 0;
    155 
    156 #if 1
    157 	/* Auth credentials: always auth unix (as root) */
    158 	send_head -= sizeof(struct auth_unix);
    159 	bzero(send_head, sizeof(struct auth_unix));
    160 	send_head -= sizeof(*auth);
    161 	auth = (struct auth_info *)send_head;
    162 	auth->authtype = htonl(RPCAUTH_UNIX);
    163 	auth->authlen = htonl(sizeof(struct auth_unix));
    164 #else
    165 	/* Auth credentials: always auth_null (XXX OK?) */
    166 	send_head -= sizeof(*auth);
    167 	auth = send_head;
    168 	auth->authtype = htonl(RPCAUTH_NULL);
    169 	auth->authlen = 0;
    170 #endif
    171 
    172 	/* RPC call structure. */
    173 	send_head -= sizeof(*call);
    174 	call = (struct rpc_call *)send_head;
    175 	rpc_xid++;
    176 	call->rp_xid       = htonl(rpc_xid);
    177 	call->rp_direction = htonl(RPC_CALL);
    178 	call->rp_rpcvers   = htonl(RPC_VER2);
    179 	call->rp_prog = htonl(prog);
    180 	call->rp_vers = htonl(vers);
    181 	call->rp_proc = htonl(proc);
    182 
    183 	/* Make room for the rpc_reply header. */
    184 	recv_head = rdata;
    185 	recv_tail = (char *)rdata + rlen;
    186 	recv_head -= sizeof(*reply);
    187 
    188 	cc = sendrecv(d,
    189 	    sendudp, send_head, ((int)send_tail - (int)send_head),
    190 	    recvrpc, recv_head, ((int)recv_tail - (int)recv_head));
    191 
    192 #ifdef RPC_DEBUG
    193 	if (debug)
    194 		printf("callrpc: cc=%d rlen=%d\n", cc, rlen);
    195 #endif
    196 	if (cc == -1)
    197 		return (-1);
    198 
    199 	if (cc <= sizeof(*reply)) {
    200 		errno = EBADRPC;
    201 		return (-1);
    202 	}
    203 
    204 	recv_tail = recv_head + cc;
    205 
    206 	/*
    207 	 * Check the RPC reply status.
    208 	 * The xid, dir, astatus were already checked.
    209 	 */
    210 	reply = (struct rpc_reply *)recv_head;
    211 	auth = &reply->rp_u.rpu_rok.rok_auth;
    212 	x = ntohl(auth->authlen);
    213 	if (x != 0) {
    214 #ifdef RPC_DEBUG
    215 		if (debug)
    216 			printf("callrpc: reply auth != NULL\n");
    217 #endif
    218 		errno = EBADRPC;
    219 		return(-1);
    220 	}
    221 	x = ntohl(reply->rp_u.rpu_rok.rok_status);
    222 	if (x != 0) {
    223 		printf("callrpc: error = %d\n", x);
    224 		errno = EBADRPC;
    225 		return(-1);
    226 	}
    227 	recv_head += sizeof(*reply);
    228 
    229 	return (ssize_t)((int)recv_tail - (int)recv_head);
    230 }
    231 
    232 /*
    233  * Returns true if packet is the one we're waiting for.
    234  * This just checks the XID, direction, acceptance.
    235  * Remaining checks are done by callrpc
    236  */
    237 static ssize_t
    238 recvrpc(d, pkt, len, tleft)
    239 	register struct iodesc *d;
    240 	register void *pkt;
    241 	register size_t len;
    242 	time_t tleft;
    243 {
    244 	register struct rpc_reply *reply;
    245 	ssize_t	n;
    246 	long	x;
    247 
    248 	errno = 0;
    249 #ifdef RPC_DEBUG
    250 	if (debug)
    251 		printf("recvrpc: called len=%d\n", len);
    252 #endif
    253 
    254 	n = readudp(d, pkt, len, tleft);
    255 	if (n <= (4 * 4))
    256 		return -1;
    257 
    258 	reply = (struct rpc_reply *)pkt;
    259 
    260 	x = ntohl(reply->rp_xid);
    261 	if (x != rpc_xid) {
    262 #ifdef RPC_DEBUG
    263 		if (debug)
    264 			printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid);
    265 #endif
    266 		return -1;
    267 	}
    268 
    269 	x = ntohl(reply->rp_direction);
    270 	if (x != RPC_REPLY) {
    271 #ifdef RPC_DEBUG
    272 		if (debug)
    273 			printf("recvrpc: rp_direction %d != REPLY\n", x);
    274 #endif
    275 		return -1;
    276 	}
    277 
    278 	x = ntohl(reply->rp_astatus);
    279 	if (x != RPC_MSGACCEPTED) {
    280 		errno = ntohl(reply->rp_u.rpu_errno);
    281 		printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno);
    282 		return -1;
    283 	}
    284 
    285 	/* Return data count (thus indicating success) */
    286 	return (n);
    287 }
    288 
    289 /*
    290  * Given a pointer to a reply just received,
    291  * dig out the IP address/port from the headers.
    292  */
    293 void
    294 rpc_fromaddr(pkt, addr, port)
    295 	void		*pkt;
    296 	struct in_addr	*addr;
    297 	u_short		*port;
    298 {
    299 	struct hackhdr {
    300 		/* Tail of IP header: just IP addresses */
    301 		n_long ip_src;
    302 		n_long ip_dst;
    303 		/* UDP header: */
    304 		u_int16_t uh_sport;		/* source port */
    305 		u_int16_t uh_dport;		/* destination port */
    306 		int16_t	  uh_ulen;		/* udp length */
    307 		u_int16_t uh_sum;		/* udp checksum */
    308 		/* RPC reply header: */
    309 		struct rpc_reply rpc;
    310 	} *hhdr;
    311 
    312 	hhdr = ((struct hackhdr *)pkt) - 1;
    313 	addr->s_addr = hhdr->ip_src;
    314 	*port = hhdr->uh_sport;
    315 }
    316 
    317 /*
    318  * RPC Portmapper cache
    319  */
    320 #define PMAP_NUM 8			/* need at most 5 pmap entries */
    321 
    322 int rpc_pmap_num;
    323 struct pmap_list {
    324 	struct in_addr	addr;	/* server, net order */
    325 	u_long	prog;		/* host order */
    326 	u_long	vers;		/* host order */
    327 	int 	port;		/* host order */
    328 } rpc_pmap_list[PMAP_NUM];
    329 
    330 /* return port number in host order, or -1 */
    331 int
    332 rpc_pmap_getcache(addr, prog, vers)
    333 	struct in_addr	addr;	/* server, net order */
    334 	u_long		prog;	/* host order */
    335 	u_long		vers;	/* host order */
    336 {
    337 	struct pmap_list *pl;
    338 
    339 	for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) {
    340 		if (pl->addr.s_addr == addr.s_addr &&
    341 			pl->prog == prog && pl->vers == vers )
    342 		{
    343 			return (pl->port);
    344 		}
    345 	}
    346 	return (-1);
    347 }
    348 
    349 void
    350 rpc_pmap_putcache(addr, prog, vers, port)
    351 	struct in_addr	addr;	/* server, net order */
    352 	u_long		prog;	/* host order */
    353 	u_long		vers;	/* host order */
    354 	int 		port;	/* host order */
    355 {
    356 	struct pmap_list *pl;
    357 
    358 	/* Don't overflow cache... */
    359 	if (rpc_pmap_num >= PMAP_NUM) {
    360 		/* ... just re-use the last entry. */
    361 		rpc_pmap_num = PMAP_NUM - 1;
    362 #ifdef	RPC_DEBUG
    363 		printf("rpc_pmap_putcache: cache overflow\n");
    364 #endif
    365 	}
    366 
    367 	pl = &rpc_pmap_list[rpc_pmap_num];
    368 	rpc_pmap_num++;
    369 
    370 	/* Cache answer */
    371 	pl->addr = addr;
    372 	pl->prog = prog;
    373 	pl->vers = vers;
    374 	pl->port = port;
    375 }
    376 
    377 
    378 /*
    379  * Request a port number from the port mapper.
    380  * Returns the port in host order.
    381  */
    382 int
    383 rpc_getport(d, prog, vers)
    384 	register struct iodesc *d;
    385 	n_long prog;	/* host order */
    386 	n_long vers;	/* host order */
    387 {
    388 	struct args {
    389 		n_long	prog;		/* call program */
    390 		n_long	vers;		/* call version */
    391 		n_long	proto;		/* call protocol */
    392 		n_long	port;		/* call port (unused) */
    393 	} *args;
    394 	struct res {
    395 		n_long port;
    396 	} *res;
    397 	struct {
    398 		n_long	h[RPC_HEADER_WORDS];
    399 		struct args d;
    400 	} sdata;
    401 	struct {
    402 		n_long	h[RPC_HEADER_WORDS];
    403 		struct res d;
    404 		n_long  pad;
    405 	} rdata;
    406 	ssize_t cc;
    407 	int port;
    408 
    409 #ifdef RPC_DEBUG
    410 	if (debug)
    411 		printf("getport: prog=0x%x vers=%d\n", prog, vers);
    412 #endif
    413 
    414 	/* This one is fixed forever. */
    415 	if (prog == PMAPPROG)
    416 		return (PMAPPORT);
    417 
    418 	/* Try for cached answer first */
    419 	port = rpc_pmap_getcache(d->destip, prog, vers);
    420 	if (port != -1)
    421 		return (port);
    422 
    423 	args = &sdata.d;
    424 	args->prog = htonl(prog);
    425 	args->vers = htonl(vers);
    426 	args->proto = htonl(IPPROTO_UDP);
    427 	args->port = 0;
    428 	res = &rdata.d;
    429 
    430 	cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT,
    431 		args, sizeof(*args), res, sizeof(*res));
    432 	if (cc < sizeof(*res)) {
    433 		printf("getport: %s", strerror(errno));
    434 		errno = EBADRPC;
    435 		return (-1);
    436 	}
    437 	port = (int)ntohl(res->port);
    438 
    439 	rpc_pmap_putcache(d->destip, prog, vers, port);
    440 
    441 	return (port);
    442 }
    443