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krpc_subr.c revision 1.18
      1 /*	$NetBSD: krpc_subr.c,v 1.18 1996/10/13 01:39:03 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Gordon Ross, Adam Glass
      5  * Copyright (c) 1992 Regents of the University of California.
      6  * All rights reserved.
      7  *
      8  * This software was developed by the Computer Systems Engineering group
      9  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     10  * contributed to Berkeley.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Lawrence Berkeley Laboratory and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  * partially based on:
     41  *      libnetboot/rpc.c
     42  *               @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp  (LBL)
     43  */
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/conf.h>
     48 #include <sys/ioctl.h>
     49 #include <sys/proc.h>
     50 #include <sys/mount.h>
     51 #include <sys/mbuf.h>
     52 #include <sys/reboot.h>
     53 #include <sys/socket.h>
     54 #include <sys/socketvar.h>
     55 
     56 #include <net/if.h>
     57 #include <netinet/in.h>
     58 
     59 #include <nfs/rpcv2.h>
     60 #include <nfs/krpc.h>
     61 #include <nfs/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(sin,  prog, vers, portp)
    130 	struct sockaddr_in *sin;		/* server address */
    131 	u_int prog, vers;	/* host order */
    132 	u_int16_t *portp;	/* network order */
    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(M_WAIT, MT_DATA);
    154 	sdata = mtod(m, struct sdata *);
    155 	m->m_len = sizeof(*sdata);
    156 
    157 	/* Do the RPC to get it. */
    158 	sdata->prog = txdr_unsigned(prog);
    159 	sdata->vers = txdr_unsigned(vers);
    160 	sdata->proto = txdr_unsigned(IPPROTO_UDP);
    161 	sdata->port = 0;
    162 
    163 	sin->sin_port = htons(PMAPPORT);
    164 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
    165 					  PMAPPROC_GETPORT, &m, NULL);
    166 	if (error)
    167 		return error;
    168 
    169 	if (m->m_len < sizeof(*rdata)) {
    170 		m = m_pullup(m, sizeof(*rdata));
    171 		if (m == NULL)
    172 			return ENOBUFS;
    173 	}
    174 	rdata = mtod(m, struct rdata *);
    175 	*portp = rdata->port;
    176 
    177 	m_freem(m);
    178 	return 0;
    179 }
    180 
    181 /*
    182  * Do a remote procedure call (RPC) and wait for its reply.
    183  * If from_p is non-null, then we are doing broadcast, and
    184  * the address from whence the response came is saved there.
    185  */
    186 int
    187 krpc_call(sa, prog, vers, func, data, from_p)
    188 	struct sockaddr_in *sa;
    189 	u_int prog, vers, func;
    190 	struct mbuf **data;	/* input/output */
    191 	struct mbuf **from_p;	/* output */
    192 {
    193 	struct socket *so;
    194 	struct sockaddr_in *sin;
    195 	struct mbuf *m, *nam, *mhead, *from;
    196 	struct rpc_call *call;
    197 	struct rpc_reply *reply;
    198 	struct uio auio;
    199 	int error, rcvflg, timo, secs, len;
    200 	static u_int32_t xid = ~0xFF;
    201 	u_int16_t tport;
    202 	struct timeval *tv;
    203 
    204 	/*
    205 	 * Validate address family.
    206 	 * Sorry, this is INET specific...
    207 	 */
    208 	if (sa->sin_family != AF_INET)
    209 		return (EAFNOSUPPORT);
    210 
    211 	/* Free at end if not null. */
    212 	nam = mhead = NULL;
    213 	from = NULL;
    214 
    215 	/*
    216 	 * Create socket and set its recieve timeout.
    217 	 */
    218 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
    219 		goto out;
    220 
    221 	m = m_get(M_WAIT, MT_SOOPTS);
    222 	tv = mtod(m, struct timeval *);
    223 	m->m_len = sizeof(*tv);
    224 	tv->tv_sec = 1;
    225 	tv->tv_usec = 0;
    226 	if ((error = sosetopt(so, SOL_SOCKET, SO_RCVTIMEO, m)))
    227 		goto out;
    228 
    229 	/*
    230 	 * Enable broadcast if necessary.
    231 	 */
    232 	if (from_p) {
    233 		int32_t *on;
    234 		m = m_get(M_WAIT, MT_SOOPTS);
    235 		on = mtod(m, int32_t *);
    236 		m->m_len = sizeof(*on);
    237 		*on = 1;
    238 		if ((error = sosetopt(so, SOL_SOCKET, SO_BROADCAST, m)))
    239 			goto out;
    240 	}
    241 
    242 	/*
    243 	 * Bind the local endpoint to a reserved port,
    244 	 * because some NFS servers refuse requests from
    245 	 * non-reserved (non-privileged) ports.
    246 	 */
    247 	m = m_getclr(M_WAIT, MT_SONAME);
    248 	sin = mtod(m, struct sockaddr_in *);
    249 	sin->sin_len = m->m_len = sizeof(*sin);
    250 	sin->sin_family = AF_INET;
    251 	sin->sin_addr.s_addr = INADDR_ANY;
    252 	tport = IPPORT_RESERVED;
    253 	do {
    254 		tport--;
    255 		sin->sin_port = htons(tport);
    256 		error = sobind(so, m);
    257 	} while (error == EADDRINUSE &&
    258 			 tport > IPPORT_RESERVED / 2);
    259 	m_freem(m);
    260 	if (error) {
    261 		printf("bind failed\n");
    262 		goto out;
    263 	}
    264 
    265 	/*
    266 	 * Setup socket address for the server.
    267 	 */
    268 	nam = m_get(M_WAIT, MT_SONAME);
    269 	sin = mtod(nam, struct sockaddr_in *);
    270 	bcopy((caddr_t)sa, (caddr_t)sin,
    271 		  (nam->m_len = sa->sin_len));
    272 
    273 	/*
    274 	 * Prepend RPC message header.
    275 	 */
    276 	mhead = m_gethdr(M_WAIT, MT_DATA);
    277 	mhead->m_next = *data;
    278 	call = mtod(mhead, struct rpc_call *);
    279 	mhead->m_len = sizeof(*call);
    280 	bzero((caddr_t)call, sizeof(*call));
    281 	/* rpc_call part */
    282 	xid++;
    283 	call->rp_xid = txdr_unsigned(xid);
    284 	/* call->rp_direction = 0; */
    285 	call->rp_rpcvers = txdr_unsigned(2);
    286 	call->rp_prog = txdr_unsigned(prog);
    287 	call->rp_vers = txdr_unsigned(vers);
    288 	call->rp_proc = txdr_unsigned(func);
    289 	/* rpc_auth part (auth_unix as root) */
    290 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
    291 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
    292 	/* rpc_verf part (auth_null) */
    293 	call->rpc_verf.authtype = 0;
    294 	call->rpc_verf.authlen  = 0;
    295 
    296 	/*
    297 	 * Setup packet header
    298 	 */
    299 	len = 0;
    300 	m = mhead;
    301 	while (m) {
    302 		len += m->m_len;
    303 		m = m->m_next;
    304 	}
    305 	mhead->m_pkthdr.len = len;
    306 	mhead->m_pkthdr.rcvif = NULL;
    307 
    308 	/*
    309 	 * Send it, repeatedly, until a reply is received,
    310 	 * but delay each re-send by an increasing amount.
    311 	 * If the delay hits the maximum, start complaining.
    312 	 */
    313 	timo = 0;
    314 	for (;;) {
    315 		/* Send RPC request (or re-send). */
    316 		m = m_copym(mhead, 0, M_COPYALL, M_WAIT);
    317 		if (m == NULL) {
    318 			error = ENOBUFS;
    319 			goto out;
    320 		}
    321 		error = sosend(so, nam, NULL, m, NULL, 0);
    322 		if (error) {
    323 			printf("krpc_call: sosend: %d\n", error);
    324 			goto out;
    325 		}
    326 		m = NULL;
    327 
    328 		/* Determine new timeout. */
    329 		if (timo < MAX_RESEND_DELAY)
    330 			timo++;
    331 		else
    332 			printf("RPC timeout for server 0x%x\n",
    333 			       ntohl(sin->sin_addr.s_addr));
    334 
    335 		/*
    336 		 * Wait for up to timo seconds for a reply.
    337 		 * The socket receive timeout was set to 1 second.
    338 		 */
    339 		secs = timo;
    340 		while (secs > 0) {
    341 			if (from) {
    342 				m_freem(from);
    343 				from = NULL;
    344 			}
    345 			if (m) {
    346 				m_freem(m);
    347 				m = NULL;
    348 			}
    349 			auio.uio_resid = len = 1<<16;
    350 			rcvflg = 0;
    351 			error = soreceive(so, &from, &auio, &m, NULL, &rcvflg);
    352 			if (error == EWOULDBLOCK) {
    353 				secs--;
    354 				continue;
    355 			}
    356 			if (error)
    357 				goto out;
    358 			len -= auio.uio_resid;
    359 
    360 			/* Does the reply contain at least a header? */
    361 			if (len < MIN_REPLY_HDR)
    362 				continue;
    363 			if (m->m_len < MIN_REPLY_HDR)
    364 				continue;
    365 			reply = mtod(m, struct rpc_reply *);
    366 
    367 			/* Is it the right reply? */
    368 			if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
    369 				continue;
    370 
    371 			if (reply->rp_xid != txdr_unsigned(xid))
    372 				continue;
    373 
    374 			/* Was RPC accepted? (authorization OK) */
    375 			if (reply->rp_astatus != 0) {
    376 				error = fxdr_unsigned(u_int32_t, reply->rp_errno);
    377 				printf("rpc denied, error=%d\n", error);
    378 				continue;
    379 			}
    380 
    381 			/* Did the call succeed? */
    382 			if (reply->rp_status != 0) {
    383 				error = fxdr_unsigned(u_int32_t, reply->rp_status);
    384 				printf("rpc denied, status=%d\n", error);
    385 				continue;
    386 			}
    387 
    388 			goto gotreply;	/* break two levels */
    389 
    390 		} /* while secs */
    391 	} /* forever send/receive */
    392 
    393 	error = ETIMEDOUT;
    394 	goto out;
    395 
    396  gotreply:
    397 
    398 	/*
    399 	 * Get RPC reply header into first mbuf,
    400 	 * get its length, then strip it off.
    401 	 */
    402 	len = sizeof(*reply);
    403 	if (m->m_len < len) {
    404 		m = m_pullup(m, len);
    405 		if (m == NULL) {
    406 			error = ENOBUFS;
    407 			goto out;
    408 		}
    409 	}
    410 	reply = mtod(m, struct rpc_reply *);
    411 	if (reply->rp_auth.authtype != 0) {
    412 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
    413 		len = (len + 3) & ~3; /* XXX? */
    414 	}
    415 	m_adj(m, len);
    416 
    417 	/* result */
    418 	*data = m;
    419 	if (from_p) {
    420 		*from_p = from;
    421 		from = NULL;
    422 	}
    423 
    424  out:
    425 	if (nam) m_freem(nam);
    426 	if (mhead) m_freem(mhead);
    427 	if (from) m_freem(from);
    428 	soclose(so);
    429 	return error;
    430 }
    431 
    432 /*
    433  * eXternal Data Representation routines.
    434  * (but with non-standard args...)
    435  */
    436 
    437 /*
    438  * String representation for RPC.
    439  */
    440 struct xdr_string {
    441 	u_int32_t len;		/* length without null or padding */
    442 	char data[4];	/* data (longer, of course) */
    443     /* data is padded to a long-word boundary */
    444 };
    445 
    446 struct mbuf *
    447 xdr_string_encode(str, len)
    448 	char *str;
    449 	int len;
    450 {
    451 	struct mbuf *m;
    452 	struct xdr_string *xs;
    453 	int dlen;	/* padded string length */
    454 	int mlen;	/* message length */
    455 
    456 	dlen = (len + 3) & ~3;
    457 	mlen = dlen + 4;
    458 
    459 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
    460 		return (NULL);
    461 
    462 	m = m_get(M_WAIT, MT_DATA);
    463 	if (mlen > MLEN) {
    464 		MCLGET(m, M_WAIT);
    465 		if ((m->m_flags & M_EXT) == 0) {
    466 			(void) m_free(m);	/* There can be only one. */
    467 			return (NULL);
    468 		}
    469 	}
    470 	xs = mtod(m, struct xdr_string *);
    471 	m->m_len = mlen;
    472 	xs->len = txdr_unsigned(len);
    473 	bcopy(str, xs->data, len);
    474 	return (m);
    475 }
    476 
    477 struct mbuf *
    478 xdr_string_decode(m, str, len_p)
    479 	struct mbuf *m;
    480 	char *str;
    481 	int *len_p;		/* bufsize - 1 */
    482 {
    483 	struct xdr_string *xs;
    484 	int mlen;	/* message length */
    485 	int slen;	/* string length */
    486 
    487 	if (m->m_len < 4) {
    488 		m = m_pullup(m, 4);
    489 		if (m == NULL)
    490 			return (NULL);
    491 	}
    492 	xs = mtod(m, struct xdr_string *);
    493 	slen = fxdr_unsigned(u_int32_t, xs->len);
    494 	mlen = 4 + ((slen + 3) & ~3);
    495 
    496 	if (slen > *len_p)
    497 		slen = *len_p;
    498 	m_copydata(m, 4, slen, str);
    499 	m_adj(m, mlen);
    500 
    501 	str[slen] = '\0';
    502 	*len_p = slen;
    503 
    504 	return (m);
    505 }
    506 
    507 
    508 /*
    509  * Inet address in RPC messages
    510  * (Note, really four ints, NOT chars.  Blech.)
    511  */
    512 struct xdr_inaddr {
    513 	u_int32_t atype;
    514 	u_int32_t addr[4];
    515 };
    516 
    517 struct mbuf *
    518 xdr_inaddr_encode(ia)
    519 	struct in_addr *ia;		/* already in network order */
    520 {
    521 	struct mbuf *m;
    522 	struct xdr_inaddr *xi;
    523 	u_int8_t *cp;
    524 	u_int32_t *ip;
    525 
    526 	m = m_get(M_WAIT, MT_DATA);
    527 	xi = mtod(m, struct xdr_inaddr *);
    528 	m->m_len = sizeof(*xi);
    529 	xi->atype = txdr_unsigned(1);
    530 	ip = xi->addr;
    531 	cp = (u_int8_t *)&ia->s_addr;
    532 	*ip++ = txdr_unsigned(*cp++);
    533 	*ip++ = txdr_unsigned(*cp++);
    534 	*ip++ = txdr_unsigned(*cp++);
    535 	*ip++ = txdr_unsigned(*cp++);
    536 
    537 	return (m);
    538 }
    539 
    540 struct mbuf *
    541 xdr_inaddr_decode(m, ia)
    542 	struct mbuf *m;
    543 	struct in_addr *ia;		/* already in network order */
    544 {
    545 	struct xdr_inaddr *xi;
    546 	u_int8_t *cp;
    547 	u_int32_t *ip;
    548 
    549 	if (m->m_len < sizeof(*xi)) {
    550 		m = m_pullup(m, sizeof(*xi));
    551 		if (m == NULL)
    552 			return (NULL);
    553 	}
    554 	xi = mtod(m, struct xdr_inaddr *);
    555 	if (xi->atype != txdr_unsigned(1)) {
    556 		ia->s_addr = INADDR_ANY;
    557 		goto out;
    558 	}
    559 	ip = xi->addr;
    560 	cp = (u_int8_t *)&ia->s_addr;
    561 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    562 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    563 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    564 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    565 
    566 out:
    567 	m_adj(m, sizeof(*xi));
    568 	return (m);
    569 }
    570