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krpc_subr.c revision 1.27
      1 /*	$NetBSD: krpc_subr.c,v 1.27 2003/02/26 06:31:18 matt 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/cdefs.h>
     46 __KERNEL_RCSID(0, "$NetBSD: krpc_subr.c,v 1.27 2003/02/26 06:31:18 matt Exp $");
     47 
     48 #include <sys/param.h>
     49 #include <sys/systm.h>
     50 #include <sys/ioctl.h>
     51 #include <sys/proc.h>
     52 #include <sys/mount.h>
     53 #include <sys/mbuf.h>
     54 #include <sys/reboot.h>
     55 #include <sys/socket.h>
     56 #include <sys/socketvar.h>
     57 
     58 #include <netinet/in.h>
     59 
     60 #include <nfs/rpcv2.h>
     61 #include <nfs/krpc.h>
     62 #include <nfs/xdr_subs.h>
     63 #include <nfs/nfsproto.h> /* XXX NFSX_V3FHMAX for next */
     64 #include <nfs/nfs.h>
     65 #include <nfs/nfsmount.h>
     66 #include <nfs/nfsdiskless.h> /* XXX decl nfs_boot_sendrecv */
     67 
     68 /*
     69  * Kernel support for Sun RPC
     70  *
     71  * Used currently for bootstrapping in nfs diskless configurations.
     72  */
     73 
     74 /*
     75  * Generic RPC headers
     76  */
     77 
     78 struct auth_info {
     79 	u_int32_t 	authtype;	/* auth type */
     80 	u_int32_t	authlen;	/* auth length */
     81 };
     82 
     83 struct auth_unix {
     84 	int32_t   ua_time;
     85 	int32_t   ua_hostname;	/* null */
     86 	int32_t   ua_uid;
     87 	int32_t   ua_gid;
     88 	int32_t   ua_gidlist;	/* null */
     89 };
     90 
     91 struct rpc_call {
     92 	u_int32_t	rp_xid;		/* request transaction id */
     93 	int32_t 	rp_direction;	/* call direction (0) */
     94 	u_int32_t	rp_rpcvers;	/* rpc version (2) */
     95 	u_int32_t	rp_prog;	/* program */
     96 	u_int32_t	rp_vers;	/* version */
     97 	u_int32_t	rp_proc;	/* procedure */
     98 	struct	auth_info rpc_auth;
     99 	struct	auth_unix rpc_unix;
    100 	struct	auth_info rpc_verf;
    101 };
    102 
    103 struct rpc_reply {
    104 	u_int32_t rp_xid;		/* request transaction id */
    105 	int32_t  rp_direction;		/* call direction (1) */
    106 	int32_t  rp_astatus;		/* accept status (0: accepted) */
    107 	union {
    108 		/* rejected */
    109 		struct {
    110 			u_int32_t rej_stat;
    111 			u_int32_t rej_val1;
    112 			u_int32_t rej_val2;
    113 		} rpu_rej;
    114 		/* accepted */
    115 		struct {
    116 			struct auth_info rok_auth;
    117 			u_int32_t	rok_status;
    118 		} rpu_rok;
    119 	} rp_u;
    120 };
    121 #define rp_rstat  rp_u.rpu_rej.rej_stat
    122 #define rp_auth   rp_u.rpu_rok.rok_auth
    123 #define rp_status rp_u.rpu_rok.rok_status
    124 
    125 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
    126 
    127 static int krpccheck __P((struct mbuf*, void*));
    128 
    129 /*
    130  * Call portmap to lookup a port number for a particular rpc program
    131  * Returns non-zero error on failure.
    132  */
    133 int
    134 krpc_portmap(sin,  prog, vers, proto, portp)
    135 	struct sockaddr_in *sin;		/* server address */
    136 	u_int prog, vers, proto;	/* host order */
    137 	u_int16_t *portp;	/* network order */
    138 {
    139 	struct sdata {
    140 		u_int32_t prog;		/* call program */
    141 		u_int32_t vers;		/* call version */
    142 		u_int32_t proto;	/* call protocol */
    143 		u_int32_t port;		/* call port (unused) */
    144 	} *sdata;
    145 	struct rdata {
    146 		u_int16_t pad;
    147 		u_int16_t port;
    148 	} *rdata;
    149 	struct mbuf *m;
    150 	int error;
    151 
    152 	/* The portmapper port is fixed. */
    153 	if (prog == PMAPPROG) {
    154 		*portp = htons(PMAPPORT);
    155 		return 0;
    156 	}
    157 
    158 	m = m_get(M_WAIT, MT_DATA);
    159 	sdata = mtod(m, struct sdata *);
    160 	m->m_len = sizeof(*sdata);
    161 
    162 	/* Do the RPC to get it. */
    163 	sdata->prog = txdr_unsigned(prog);
    164 	sdata->vers = txdr_unsigned(vers);
    165 	sdata->proto = txdr_unsigned(proto);
    166 	sdata->port = 0;
    167 
    168 	sin->sin_port = htons(PMAPPORT);
    169 	error = krpc_call(sin, PMAPPROG, PMAPVERS,
    170 					  PMAPPROC_GETPORT, &m, NULL);
    171 	if (error)
    172 		return error;
    173 
    174 	if (m->m_len < sizeof(*rdata)) {
    175 		m = m_pullup(m, sizeof(*rdata));
    176 		if (m == NULL)
    177 			return ENOBUFS;
    178 	}
    179 	rdata = mtod(m, struct rdata *);
    180 	*portp = rdata->port;
    181 
    182 	m_freem(m);
    183 	return 0;
    184 }
    185 
    186 static int krpccheck(m, context)
    187 struct mbuf *m;
    188 void *context;
    189 {
    190 	struct rpc_reply *reply;
    191 
    192 	/* Does the reply contain at least a header? */
    193 	if (m->m_pkthdr.len < MIN_REPLY_HDR)
    194 		return(-1);
    195 	if (m->m_len < sizeof(struct rpc_reply)) {
    196 		m = m_pullup(m, sizeof(struct rpc_reply));
    197 		if (m == NULL)
    198 			return(-1);
    199 	}
    200 	reply = mtod(m, struct rpc_reply *);
    201 
    202 	/* Is it the right reply? */
    203 	if (reply->rp_direction != txdr_unsigned(RPC_REPLY))
    204 		return(-1);
    205 
    206 	if (reply->rp_xid != txdr_unsigned(*(u_int32_t*)context))
    207 		return(-1);
    208 
    209 	return(0);
    210 }
    211 
    212 /*
    213  * Do a remote procedure call (RPC) and wait for its reply.
    214  * If from_p is non-null, then we are doing broadcast, and
    215  * the address from whence the response came is saved there.
    216  */
    217 int
    218 krpc_call(sa, prog, vers, func, data, from_p)
    219 	struct sockaddr_in *sa;
    220 	u_int prog, vers, func;
    221 	struct mbuf **data;	/* input/output */
    222 	struct mbuf **from_p;	/* output */
    223 {
    224 	struct socket *so;
    225 	struct sockaddr_in *sin;
    226 	struct mbuf *m, *nam, *mhead, *from;
    227 	struct rpc_call *call;
    228 	struct rpc_reply *reply;
    229 	int error, len;
    230 	static u_int32_t xid = ~0xFF;
    231 	u_int16_t tport;
    232 
    233 	/*
    234 	 * Validate address family.
    235 	 * Sorry, this is INET specific...
    236 	 */
    237 	if (sa->sin_family != AF_INET)
    238 		return (EAFNOSUPPORT);
    239 
    240 	/* Free at end if not null. */
    241 	nam = mhead = NULL;
    242 	from = NULL;
    243 
    244 	/*
    245 	 * Create socket and set its receive timeout.
    246 	 */
    247 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
    248 		goto out;
    249 
    250 	if ((error = nfs_boot_setrecvtimo(so)))
    251 		goto out;
    252 
    253 	/*
    254 	 * Enable broadcast if necessary.
    255 	 */
    256 	if (from_p) {
    257 		if ((error = nfs_boot_enbroadcast(so)))
    258 			goto out;
    259 	}
    260 
    261 	/*
    262 	 * Bind the local endpoint to a reserved port,
    263 	 * because some NFS servers refuse requests from
    264 	 * non-reserved (non-privileged) ports.
    265 	 */
    266 	tport = IPPORT_RESERVED;
    267 	do {
    268 		tport--;
    269 		error = nfs_boot_sobind_ipport(so, tport);
    270 	} while (error == EADDRINUSE &&
    271 			 tport > IPPORT_RESERVED / 2);
    272 	if (error) {
    273 		printf("bind failed\n");
    274 		goto out;
    275 	}
    276 
    277 	/*
    278 	 * Setup socket address for the server.
    279 	 */
    280 	nam = m_get(M_WAIT, MT_SONAME);
    281 	sin = mtod(nam, struct sockaddr_in *);
    282 	memcpy((caddr_t)sin, (caddr_t)sa,
    283 		  (nam->m_len = sa->sin_len));
    284 
    285 	/*
    286 	 * Prepend RPC message header.
    287 	 */
    288 	mhead = m_gethdr(M_WAIT, MT_DATA);
    289 	mhead->m_next = *data;
    290 	call = mtod(mhead, struct rpc_call *);
    291 	mhead->m_len = sizeof(*call);
    292 	memset((caddr_t)call, 0, sizeof(*call));
    293 	/* rpc_call part */
    294 	xid++;
    295 	call->rp_xid = txdr_unsigned(xid);
    296 	/* call->rp_direction = 0; */
    297 	call->rp_rpcvers = txdr_unsigned(2);
    298 	call->rp_prog = txdr_unsigned(prog);
    299 	call->rp_vers = txdr_unsigned(vers);
    300 	call->rp_proc = txdr_unsigned(func);
    301 	/* rpc_auth part (auth_unix as root) */
    302 	call->rpc_auth.authtype = txdr_unsigned(RPCAUTH_UNIX);
    303 	call->rpc_auth.authlen  = txdr_unsigned(sizeof(struct auth_unix));
    304 	/* rpc_verf part (auth_null) */
    305 	call->rpc_verf.authtype = 0;
    306 	call->rpc_verf.authlen  = 0;
    307 
    308 	/*
    309 	 * Setup packet header
    310 	 */
    311 	len = 0;
    312 	m = mhead;
    313 	while (m) {
    314 		len += m->m_len;
    315 		m = m->m_next;
    316 	}
    317 	mhead->m_pkthdr.len = len;
    318 	mhead->m_pkthdr.rcvif = NULL;
    319 
    320 	error = nfs_boot_sendrecv(so, nam, 0, mhead, krpccheck, &m, &from, &xid);
    321 	if (error)
    322 		goto out;
    323 
    324 	/* m_pullup() was done in krpccheck() */
    325 	reply = mtod(m, struct rpc_reply *);
    326 
    327 	/* Was RPC accepted? (authorization OK) */
    328 	if (reply->rp_astatus != 0) {
    329 		/* Note: This is NOT an error code! */
    330 		error = fxdr_unsigned(u_int32_t, reply->rp_rstat);
    331 		switch (error) {
    332 		    case RPC_MISMATCH:
    333 			/* .re_status = RPC_VERSMISMATCH; */
    334 			error = ERPCMISMATCH;
    335 			break;
    336 		    case RPC_AUTHERR:
    337 			/* .re_status = RPC_AUTHERROR; */
    338 			error = EAUTH;
    339 			break;
    340 		    default:
    341 			/* unexpected */
    342 			error = EBADRPC;
    343 			break;
    344 		}
    345 		goto out;
    346 	}
    347 
    348 	/* Did the call succeed? */
    349 	if (reply->rp_status != 0) {
    350 		/* Note: This is NOT an error code! */
    351 		error = fxdr_unsigned(u_int32_t, reply->rp_status);
    352 		switch (error) {
    353 		    case RPC_PROGUNAVAIL:
    354 			error = EPROGUNAVAIL;
    355 			break;
    356 		    case RPC_PROGMISMATCH:
    357 			error = EPROGMISMATCH;
    358 			break;
    359 		    case RPC_PROCUNAVAIL:
    360 			error = EPROCUNAVAIL;
    361 			break;
    362 		    case RPC_GARBAGE:
    363 		    default:
    364 			error = EBADRPC;
    365 		}
    366 		goto out;
    367 	}
    368 
    369 	/*
    370 	 * OK, we have received a good reply!
    371 	 * Get its length, then strip it off.
    372 	 */
    373 	len = sizeof(*reply);
    374 	if (reply->rp_auth.authtype != 0) {
    375 		len += fxdr_unsigned(u_int32_t, reply->rp_auth.authlen);
    376 		len = (len + 3) & ~3; /* XXX? */
    377 	}
    378 	m_adj(m, len);
    379 
    380 	/* result */
    381 	*data = m;
    382 	if (from_p) {
    383 		*from_p = from;
    384 		from = NULL;
    385 	}
    386 
    387  out:
    388 	if (nam) m_freem(nam);
    389 	if (mhead) m_freem(mhead);
    390 	if (from) m_freem(from);
    391 	soclose(so);
    392 	return error;
    393 }
    394 
    395 /*
    396  * eXternal Data Representation routines.
    397  * (but with non-standard args...)
    398  */
    399 
    400 /*
    401  * String representation for RPC.
    402  */
    403 struct xdr_string {
    404 	u_int32_t len;		/* length without null or padding */
    405 	char data[4];	/* data (longer, of course) */
    406     /* data is padded to a long-word boundary */
    407 };
    408 
    409 struct mbuf *
    410 xdr_string_encode(str, len)
    411 	char *str;
    412 	int len;
    413 {
    414 	struct mbuf *m;
    415 	struct xdr_string *xs;
    416 	int dlen;	/* padded string length */
    417 	int mlen;	/* message length */
    418 
    419 	dlen = (len + 3) & ~3;
    420 	mlen = dlen + 4;
    421 
    422 	if (mlen > MCLBYTES)		/* If too big, we just can't do it. */
    423 		return (NULL);
    424 
    425 	m = m_get(M_WAIT, MT_DATA);
    426 	if (mlen > MLEN) {
    427 		m_clget(m, M_WAIT);
    428 		if ((m->m_flags & M_EXT) == 0) {
    429 			(void) m_free(m);	/* There can be only one. */
    430 			return (NULL);
    431 		}
    432 	}
    433 	xs = mtod(m, struct xdr_string *);
    434 	m->m_len = mlen;
    435 	xs->len = txdr_unsigned(len);
    436 	memcpy(xs->data, str, len);
    437 	return (m);
    438 }
    439 
    440 struct mbuf *
    441 xdr_string_decode(m, str, len_p)
    442 	struct mbuf *m;
    443 	char *str;
    444 	int *len_p;		/* bufsize - 1 */
    445 {
    446 	struct xdr_string *xs;
    447 	int mlen;	/* message length */
    448 	int slen;	/* string length */
    449 
    450 	if (m->m_len < 4) {
    451 		m = m_pullup(m, 4);
    452 		if (m == NULL)
    453 			return (NULL);
    454 	}
    455 	xs = mtod(m, struct xdr_string *);
    456 	slen = fxdr_unsigned(u_int32_t, xs->len);
    457 	mlen = 4 + ((slen + 3) & ~3);
    458 
    459 	if (slen > *len_p)
    460 		slen = *len_p;
    461 	m_copydata(m, 4, slen, str);
    462 	m_adj(m, mlen);
    463 
    464 	str[slen] = '\0';
    465 	*len_p = slen;
    466 
    467 	return (m);
    468 }
    469 
    470 
    471 /*
    472  * Inet address in RPC messages
    473  * (Note, really four ints, NOT chars.  Blech.)
    474  */
    475 struct xdr_inaddr {
    476 	u_int32_t atype;
    477 	u_int32_t addr[4];
    478 };
    479 
    480 struct mbuf *
    481 xdr_inaddr_encode(ia)
    482 	struct in_addr *ia;		/* already in network order */
    483 {
    484 	struct mbuf *m;
    485 	struct xdr_inaddr *xi;
    486 	u_int8_t *cp;
    487 	u_int32_t *ip;
    488 
    489 	m = m_get(M_WAIT, MT_DATA);
    490 	xi = mtod(m, struct xdr_inaddr *);
    491 	m->m_len = sizeof(*xi);
    492 	xi->atype = txdr_unsigned(1);
    493 	ip = xi->addr;
    494 	cp = (u_int8_t *)&ia->s_addr;
    495 	*ip++ = txdr_unsigned(*cp++);
    496 	*ip++ = txdr_unsigned(*cp++);
    497 	*ip++ = txdr_unsigned(*cp++);
    498 	*ip++ = txdr_unsigned(*cp++);
    499 
    500 	return (m);
    501 }
    502 
    503 struct mbuf *
    504 xdr_inaddr_decode(m, ia)
    505 	struct mbuf *m;
    506 	struct in_addr *ia;		/* already in network order */
    507 {
    508 	struct xdr_inaddr *xi;
    509 	u_int8_t *cp;
    510 	u_int32_t *ip;
    511 
    512 	if (m->m_len < sizeof(*xi)) {
    513 		m = m_pullup(m, sizeof(*xi));
    514 		if (m == NULL)
    515 			return (NULL);
    516 	}
    517 	xi = mtod(m, struct xdr_inaddr *);
    518 	if (xi->atype != txdr_unsigned(1)) {
    519 		ia->s_addr = INADDR_ANY;
    520 		goto out;
    521 	}
    522 	ip = xi->addr;
    523 	cp = (u_int8_t *)&ia->s_addr;
    524 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    525 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    526 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    527 	*cp++ = fxdr_unsigned(u_int8_t, *ip++);
    528 
    529 out:
    530 	m_adj(m, sizeof(*xi));
    531 	return (m);
    532 }
    533