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krpc_subr.c revision 1.3
      1 /*	$NetBSD: krpc_subr.c,v 1.3 1994/06/29 06:42:02 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994 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/conf.h>
     47 #include <sys/ioctl.h>
     48 #include <sys/proc.h>
     49 #include <sys/mount.h>
     50 #include <sys/mbuf.h>
     51 #include <sys/socket.h>
     52 #include <sys/systm.h>
     53 #include <sys/reboot.h>
     54 
     55 #include <net/if.h>
     56 #include <netinet/in.h>
     57 
     58 #include <nfs/rpcv2.h>
     59 
     60 /*
     61  * Kernel support for Sun RPC
     62  *
     63  * Used currently for bootstrapping in nfs diskless configurations.
     64  *
     65  * Note: will not work on variable-sized rpc args/results.
     66  *       implicit size-limit of an mbuf.
     67  */
     68 
     69 #define	PMAPPORT		111
     70 #define	PMAPPROG		100000
     71 #define	PMAPVERS		2
     72 #define	PMAPPROC_GETPORT	3
     73 
     74 /*
     75  * Generic RPC headers
     76  */
     77 
     78 struct auth_info {
     79 	int	rp_atype;		/* auth type */
     80 	u_long	rp_alen;		/* auth length */
     81 };
     82 
     83 struct rpc_call {
     84 	u_long	rp_xid;			/* request transaction id */
     85 	int 	rp_direction;	        /* call direction (0) */
     86 	u_long	rp_rpcvers;		/* rpc version (2) */
     87 	u_long	rp_prog;		/* program */
     88 	u_long	rp_vers;		/* version */
     89 	u_long	rp_proc;		/* procedure */
     90 	struct	auth_info rp_auth;
     91 	struct	auth_info rp_verf;
     92 };
     93 
     94 struct rpc_reply {
     95 	u_long	rp_xid;			/* request transaction id */
     96 	int	rp_direction;		/* call direction (1) */
     97 	int	rp_astatus;		/* accept status (0: accepted) */
     98 	union {
     99 		u_long	rpu_errno;
    100 		struct {
    101 			struct auth_info rp_auth;
    102 			u_long	rp_rstatus;		/* reply status */
    103 		} rpu_ok;
    104 	} rp_u;
    105 };
    106 
    107 #define MIN_REPLY_HDR 16	/* xid, dir, astat, errno */
    108 
    109 /*
    110  * What is the longest we will wait before re-sending a request?
    111  * Note this is also the frequency of "RPC timeout" messages.
    112  * The re-send loop count sup linearly to this maximum, so the
    113  * first complaint will happen after (1+2+3+4+5)=15 seconds.
    114  */
    115 #define	MAX_RESEND_DELAY 5	/* seconds */
    116 
    117 /*
    118  * Call portmap to lookup a port number for a particular rpc program
    119  * Returns non-zero error on failure.
    120  */
    121 int
    122 krpc_portmap(sa,  prog, vers, portp)
    123 	struct sockaddr *sa;		/* server address */
    124 	u_long prog, vers;	/* host order */
    125 	u_short *portp;		/* network order */
    126 {
    127 	struct sdata {
    128 		u_long	prog;		/* call program */
    129 		u_long	vers;		/* call version */
    130 		u_long	proto;		/* call protocol */
    131 		u_long	port;		/* call port (unused) */
    132 	} *sdata;
    133 	struct rdata {
    134 		u_short pad;
    135 		u_short port;
    136 	} *rdata;
    137 	struct mbuf *m;
    138 	int error;
    139 
    140 	/* The portmapper port is fixed. */
    141 	if (prog == PMAPPROG) {
    142 		*portp = htons(PMAPPORT);
    143 		return 0;
    144 	}
    145 
    146 	m = m_gethdr(M_WAIT, MT_DATA);
    147 	if (m == NULL)
    148 		return ENOBUFS;
    149 	m->m_len = sizeof(*sdata);
    150 	m->m_pkthdr.len = m->m_len;
    151 	sdata = mtod(m, struct sdata *);
    152 
    153 	/* Do the RPC to get it. */
    154 	sdata->prog = htonl(prog);
    155 	sdata->vers = htonl(vers);
    156 	sdata->proto = htonl(IPPROTO_UDP);
    157 	sdata->port = 0;
    158 
    159 	error = krpc_call(sa, PMAPPROG, PMAPVERS,
    160 					  PMAPPROC_GETPORT, &m);
    161 	if (error)
    162 		return error;
    163 
    164 	rdata = mtod(m, struct rdata *);
    165 	*portp = rdata->port;
    166 
    167 	m_freem(m);
    168 	return 0;
    169 }
    170 
    171 /*
    172  * Do a remote procedure call (RPC) and wait for its reply.
    173  */
    174 int
    175 krpc_call(sa, prog, vers, func, data)
    176 	struct sockaddr *sa;
    177 	u_long prog, vers, func;
    178 	struct mbuf **data;	/* input/output */
    179 {
    180 	struct socket *so;
    181 	struct sockaddr_in *sin;
    182 	struct timeval *tv;
    183 	struct mbuf *m, *nam, *mhead;
    184 	struct rpc_call *call;
    185 	struct rpc_reply *reply;
    186 	struct uio auio;
    187 	int error, rcvflg, timo, secs, len;
    188 	static u_long xid = ~0xFF;
    189 
    190 	/*
    191 	 * Validate address family.
    192 	 * Sorry, this is INET specific...
    193 	 */
    194 	if (sa->sa_family != AF_INET)
    195 		return (EAFNOSUPPORT);
    196 
    197 	/* Free at end if not null. */
    198 	nam = mhead = NULL;
    199 
    200 	/*
    201 	 * Create socket and set its recieve timeout.
    202 	 */
    203 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0)))
    204 		goto out;
    205 
    206 	m = m_get(M_WAIT, MT_SOOPTS);
    207 	if (m == NULL) {
    208 		error = ENOBUFS;
    209 		goto out;
    210 	}
    211 	tv = mtod(m, struct timeval *);
    212 	m->m_len = sizeof(*tv);
    213 	tv->tv_sec = 1;
    214 	tv->tv_usec = 0;
    215 	if ((error = sosetopt(so, SOL_SOCKET, SO_RCVTIMEO, m)))
    216 		goto out;
    217 
    218 	/*
    219 	 * Setup socket address for the server.
    220 	 */
    221 	nam = m_get(M_WAIT, MT_SONAME);
    222 	if (nam == NULL) {
    223 		error = ENOBUFS;
    224 		goto out;
    225 	}
    226 	sin = mtod(nam, struct sockaddr_in *);
    227 	bcopy((caddr_t)sa, (caddr_t)sin, (nam->m_len = sa->sa_len));
    228 
    229 	/*
    230 	 * Set the port number that the request will use.
    231 	 */
    232 	if ((error = krpc_portmap(sa, prog, vers, &sin->sin_port)))
    233 		goto out;
    234 
    235 	/*
    236 	 * Prepend RPC message header.
    237 	 */
    238 	m = *data;
    239 	*data = NULL;
    240 #ifdef	DIAGNOSTIC
    241 	if ((m->m_flags & M_PKTHDR) == 0)
    242 		panic("krpc_call: send data w/o pkthdr");
    243 	if (m->m_pkthdr.len < m->m_len)
    244 		panic("krpc_call: pkthdr.len not set");
    245 #endif
    246 	mhead = m_prepend(m, sizeof(*call), M_WAIT);
    247 	if (mhead == NULL) {
    248 		error = ENOBUFS;
    249 		goto out;
    250 	}
    251 	mhead->m_pkthdr.len += sizeof(*call);
    252 	mhead->m_pkthdr.rcvif = NULL;
    253 
    254 	/*
    255 	 * Fill in the RPC header
    256 	 */
    257 	call = mtod(mhead, struct rpc_call *);
    258 	bzero((caddr_t)call, sizeof(*call));
    259 	call->rp_xid = ++xid;	/* no need to put in network order */
    260 	/* call->rp_direction = 0; */
    261 	call->rp_rpcvers = htonl(2);
    262 	call->rp_prog = htonl(prog);
    263 	call->rp_vers = htonl(vers);
    264 	call->rp_proc = htonl(func);
    265 	/* call->rp_auth = 0; */
    266 	/* call->rp_verf = 0; */
    267 
    268 	/*
    269 	 * Send it, repeatedly, until a reply is received,
    270 	 * but delay each re-send by an increasing amount.
    271 	 * If the delay hits the maximum, start complaining.
    272 	 */
    273 	timo = 0;
    274 	for (;;) {
    275 		/* Send RPC request (or re-send). */
    276 		m = m_copym(mhead, 0, M_COPYALL, M_WAIT);
    277 		if (m == NULL) {
    278 			error = ENOBUFS;
    279 			goto out;
    280 		}
    281 		error = sosend(so, nam, NULL, m, NULL, 0);
    282 		if (error) {
    283 			printf("krpc_call: sosend: %d\n", error);
    284 			goto out;
    285 		}
    286 		m = NULL;
    287 
    288 		/* Determine new timeout. */
    289 		if (timo < MAX_RESEND_DELAY)
    290 			timo++;
    291 		else
    292 			printf("RPC timeout for server 0x%x\n",
    293 			       ntohl(sin->sin_addr.s_addr));
    294 
    295 		/*
    296 		 * Wait for up to timo seconds for a reply.
    297 		 * The socket receive timeout was set to 1 second.
    298 		 */
    299 		secs = timo;
    300 		while (secs > 0) {
    301 			auio.uio_resid = len = 1<<16;
    302 			rcvflg = 0;
    303 			error = soreceive(so, NULL, &auio, &m, NULL, &rcvflg);
    304 			if (error == EWOULDBLOCK) {
    305 				secs--;
    306 				continue;
    307 			}
    308 			if (error)
    309 				goto out;
    310 			len -= auio.uio_resid;
    311 
    312 			/* Is the reply complete and the right one? */
    313 			if (len < MIN_REPLY_HDR) {
    314 				m_freem(m);
    315 				continue;
    316 			}
    317 			if (m->m_len < MIN_REPLY_HDR) {
    318 				m = m_pullup(m, MIN_REPLY_HDR);
    319 				if (!m)
    320 					continue;
    321 			}
    322 			reply = mtod(m, struct rpc_reply *);
    323 			if ((reply->rp_direction == htonl(RPC_REPLY)) &&
    324 				(reply->rp_xid == xid))
    325 				goto gotreply;	/* break two levels */
    326 		} /* while secs */
    327 	} /* forever send/receive */
    328  gotreply:
    329 
    330 	/*
    331 	 * Make result buffer contiguous.
    332 	 */
    333 #ifdef	DIAGNOSTIC
    334 	if ((m->m_flags & M_PKTHDR) == 0)
    335 		panic("krpc_call: received pkt w/o header?");
    336 #endif
    337 	len = m->m_pkthdr.len;
    338 	if (m->m_len < len) {
    339 		m = m_pullup(m, len);
    340 		if (m == NULL) {
    341 			error = ENOBUFS;
    342 			goto out;
    343 		}
    344 	}
    345 	reply = mtod(m, struct rpc_reply *);
    346 
    347 	/*
    348 	 * Check RPC acceptance and status.
    349 	 */
    350 	if (reply->rp_astatus != 0) {
    351 		error = reply->rp_u.rpu_errno;
    352 		printf("rpc denied, error=%d\n", error);
    353 		m_freem(m);
    354 		goto out;
    355 	}
    356 	if ((error = reply->rp_u.rpu_ok.rp_rstatus) != 0) {
    357 		printf("rpc status=%d\n", error);
    358 		m_freem(m);
    359 		goto out;
    360 	}
    361 
    362 	/*
    363 	 * Strip RPC header
    364 	 */
    365 	len = sizeof(*reply);
    366 	if (reply->rp_u.rpu_ok.rp_auth.rp_atype != 0) {
    367 		len += ntohl(reply->rp_u.rpu_ok.rp_auth.rp_alen);
    368 		len = (len + 3) & ~3; /* XXX? */
    369 	}
    370 	m_adj(m, len);
    371 
    372 	/* result */
    373 	*data = m;
    374 
    375  out:
    376 	if (nam) m_freem(nam);
    377 	if (mhead) m_freem(mhead);
    378 	soclose(so);
    379 	return error;
    380 }
    381