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subr_tftproot.c revision 1.23
      1 /*	$NetBSD: subr_tftproot.c,v 1.23 2019/01/20 21:26:13 bad Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 Emmanuel Dreyfus, all rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. All advertising materials mentioning features or use of this software
     15  *    must display the following acknowledgement:
     16  *	This product includes software developed by Emmanuel Dreyfus
     17  * 4. The name of the author may not be used to endorse or promote
     18  *    products derived from this software without specific prior written
     19  *    permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS''
     22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
     25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31  * POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 /*
     35  * Download the root RAMdisk through TFTP at root mount time
     36  */
     37 
     38 #include "opt_tftproot.h"
     39 #include "opt_md.h"
     40 
     41 #include <sys/cdefs.h>
     42 __KERNEL_RCSID(0, "$NetBSD: subr_tftproot.c,v 1.23 2019/01/20 21:26:13 bad Exp $");
     43 
     44 #include <sys/param.h>
     45 #include <sys/types.h>
     46 #include <sys/vnode.h>
     47 #include <sys/mount.h>
     48 #include <sys/lwp.h>
     49 #include <sys/kmem.h>
     50 #include <sys/mbuf.h>
     51 #include <sys/timevar.h>
     52 #include <sys/socketvar.h>
     53 
     54 #include <net/if.h>
     55 
     56 #include <dev/md.h>
     57 
     58 #include <netinet/in.h>
     59 
     60 #include <nfs/rpcv2.h>
     61 
     62 #include <nfs/nfsproto.h>
     63 #include <nfs/nfs.h>
     64 #include <nfs/nfsmount.h>
     65 #include <nfs/nfsdiskless.h>
     66 #include <nfs/nfs_var.h>
     67 
     68 /*
     69  * Copied from <lib/libsa/tftp.h>
     70  */
     71 
     72 #define SEGSIZE         512             /* data segment size */
     73 
     74 /*
     75  * Packet types.
     76  */
     77 #define RRQ     01                      /* read request */
     78 #define WRQ     02                      /* write request */
     79 #define DATA    03                      /* data packet */
     80 #define ACK     04                      /* acknowledgement */
     81 #define ERROR   05                      /* error code */
     82 
     83 struct  tftphdr {
     84         short   th_opcode;              /* packet type */
     85         union {
     86                 unsigned short tu_block; /* block # */
     87                 short   tu_code;        /* error code */
     88                 char    tu_stuff[1];    /* request packet stuff */
     89         } th_u;
     90         char    th_data[1];             /* data or error string */
     91 } __packed;
     92 
     93 #define th_block        th_u.tu_block
     94 #define th_code         th_u.tu_code
     95 #define th_stuff        th_u.tu_stuff
     96 #define th_msg          th_data
     97 
     98 #define IPPORT_TFTP 69
     99 
    100 #ifdef TFTPROOT_DEBUG
    101 #define DPRINTF(x) printf x
    102 #else
    103 #define DPRINTF(x)
    104 #endif
    105 
    106 struct tftproot_handle {
    107 	struct nfs_diskless *trh_nd;
    108 	void *trh_base;
    109 	size_t trh_len;
    110 	unsigned short trh_block;
    111 	int trh_flags;
    112 };
    113 
    114 #define TRH_FINISHED	1
    115 
    116 int tftproot_dhcpboot(device_t);
    117 
    118 static int tftproot_getfile(struct tftproot_handle *, struct lwp *);
    119 static int tftproot_recv(struct mbuf **, void *);
    120 
    121 int
    122 tftproot_dhcpboot(device_t bootdv)
    123 {
    124 	struct nfs_diskless *nd = NULL;
    125 	struct ifnet *ifp = NULL;
    126 	struct lwp *l;
    127 	struct tftproot_handle trh;
    128 	device_t dv;
    129 	int error = -1;
    130 
    131 	if (rootspec != NULL) {
    132 		int s = pserialize_read_enter();
    133 		IFNET_READER_FOREACH(ifp)
    134 			if (strcmp(rootspec, ifp->if_xname) == 0)
    135 				break;
    136 		pserialize_read_exit(s);
    137 	}
    138 
    139 	if ((ifp == NULL) &&
    140 	    (bootdv != NULL && device_class(bootdv) == DV_IFNET)) {
    141 		int s = pserialize_read_enter();
    142 		IFNET_READER_FOREACH(ifp)
    143 			if (strcmp(device_xname(bootdv), ifp->if_xname) == 0)
    144 				break;
    145 		pserialize_read_exit(s);
    146 	}
    147 
    148 	if (ifp == NULL) {
    149 		DPRINTF(("%s():%d ifp is NULL\n", __func__, __LINE__));
    150 		goto out;
    151 	}
    152 
    153 	dv = device_find_by_xname(ifp->if_xname);
    154 
    155 	if ((dv == NULL) || (device_class(dv) != DV_IFNET)) {
    156 		DPRINTF(("%s():%d cannot find device for interface %s\n",
    157 		    __func__, __LINE__, ifp->if_xname));
    158 		goto out;
    159 	}
    160 
    161 	root_device = dv;
    162 
    163 	l = curlwp; /* XXX */
    164 
    165 	nd = kmem_zalloc(sizeof(*nd), KM_SLEEP);
    166 	nd->nd_ifp = ifp;
    167 	nd->nd_nomount = 1;
    168 
    169 	if ((error = nfs_boot_init(nd, l)) != 0) {
    170 		DPRINTF(("%s():%d nfs_boot_init returned %d\n",
    171 		    __func__, __LINE__, error));
    172 		goto out;
    173 	}
    174 
    175 	/*
    176 	 * Strip leading "tftp:"
    177 	 */
    178 #define PREFIX "tftp:"
    179 	if (strstr(nd->nd_bootfile, PREFIX) == nd->nd_bootfile)
    180 		(void)memmove(nd->nd_bootfile,
    181 			      nd->nd_bootfile + (sizeof(PREFIX) - 1),
    182 			      sizeof(nd->nd_bootfile) - sizeof(PREFIX));
    183 #undef PREFIX
    184 
    185 	printf("tftproot: bootfile=%s\n", nd->nd_bootfile);
    186 
    187 	memset(&trh, 0, sizeof(trh));
    188 	trh.trh_nd = nd;
    189 	trh.trh_block = 1;
    190 
    191 	if ((error = tftproot_getfile(&trh, l)) != 0) {
    192 		DPRINTF(("%s():%d tftproot_getfile returned %d\n",
    193 		    __func__, __LINE__, error));
    194 		goto out;
    195 	}
    196 
    197 	error = 0;
    198 
    199 out:
    200 	if (nd)
    201 		kmem_free(nd, sizeof(*nd));
    202 
    203 	return error;
    204 }
    205 
    206 static int
    207 tftproot_getfile(struct tftproot_handle *trh, struct lwp *l)
    208 {
    209 	struct socket *so = NULL;
    210 	struct mbuf *m_serv = NULL;
    211 	struct mbuf *m_outbuf = NULL;
    212 	struct sockaddr_in sin;
    213 	struct tftphdr *tftp;
    214 	size_t packetlen, namelen;
    215 	int error = -1;
    216 	const char octetstr[] = "octet";
    217 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
    218 	char *cp;
    219 
    220 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, l, NULL)) != 0) {
    221 		DPRINTF(("%s():%d socreate returned %d\n",
    222 		    __func__, __LINE__, error));
    223 		goto out;
    224 	}
    225 
    226 	/*
    227 	 * Set timeout
    228 	 */
    229 	if ((error = nfs_boot_setrecvtimo(so))) {
    230 		DPRINTF(("%s():%d SO_RCVTIMEO failed %d\n",
    231 		    __func__, __LINE__, error));
    232 		goto out;
    233 	}
    234 
    235 	/*
    236 	 * Set server address and port
    237 	 */
    238 	memcpy(&sin, &trh->trh_nd->nd_root.ndm_saddr, sizeof(sin));
    239 	sin.sin_port = htons(IPPORT_TFTP);
    240 
    241 	/*
    242 	 * Set send buffer, prepare the TFTP packet
    243 	 */
    244 	namelen = strlen(trh->trh_nd->nd_bootfile) + 1;
    245 	packetlen = sizeof(tftp->th_opcode) + namelen + sizeof(octetstr);
    246 	if (packetlen > MSIZE) {
    247 		DPRINTF(("%s():%d boot filename too long (%ld bytes)\n",
    248 		    __func__, __LINE__, (long)namelen));
    249 		error = E2BIG;
    250 		goto out;
    251 	}
    252 
    253 	m_outbuf = m_gethdr(M_WAIT, MT_DATA);
    254 	m_clget(m_outbuf, M_WAIT);
    255 	m_outbuf->m_len = packetlen;
    256 	m_outbuf->m_pkthdr.len = packetlen;
    257 	m_reset_rcvif(m_outbuf);
    258 
    259 	tftp = mtod(m_outbuf, struct tftphdr *);
    260 	memset(tftp, 0, packetlen);
    261 
    262 	tftp->th_opcode = htons((short)RRQ);
    263 	cp = tftp->th_stuff;
    264 	(void)strncpy(cp,  trh->trh_nd->nd_bootfile, namelen);
    265 	cp += namelen;
    266 	(void)strncpy(cp, octetstr, sizeof(octetstr));
    267 
    268 	/*
    269 	 * Perform the file transfer
    270 	 */
    271 	printf("tftproot: download %s:%s ",
    272 	    inet_ntoa(sin.sin_addr), trh->trh_nd->nd_bootfile);
    273 
    274 	do {
    275 		/*
    276 		 * Show progress for every 200 blocks (100kB)
    277 		 */
    278 #ifndef TFTPROOT_PROGRESS
    279 #define TFTPROOT_PROGRESS 200
    280 #endif
    281 		if ((trh->trh_block % TFTPROOT_PROGRESS) == 0)
    282 			twiddle();
    283 
    284 		/*
    285 		 * Send the packet and receive the answer.
    286 		 * We get the sender address here, which should be
    287 		 * the same server with a different port
    288 		 */
    289 		if ((error = nfs_boot_sendrecv(so, &sin, NULL, m_outbuf,
    290 		    tftproot_recv, NULL, &m_serv, trh, l)) != 0) {
    291 			DPRINTF(("%s():%d sendrecv failed %d\n",
    292 			    __func__, __LINE__, error));
    293 			goto out;
    294 		}
    295 
    296 		/*
    297 		 * Accommodate the packet length for acks.
    298 		 * This is really needed only on first pass
    299 		 */
    300 		m_outbuf->m_len = hdrlen;
    301 		m_outbuf->m_pkthdr.len = hdrlen;
    302 		tftp->th_opcode = htons((short)ACK);
    303 		tftp->th_block = htons(trh->trh_block);
    304 
    305 
    306 		/*
    307 		 * Check for termination
    308 		 */
    309 		if (trh->trh_flags & TRH_FINISHED)
    310 			break;
    311 
    312 		trh->trh_block++;
    313 	} while (1/* CONSTCOND */);
    314 
    315 	printf("\n");
    316 
    317 	/*
    318 	 * Ack the last block. Ignore errors, as we already have the whole
    319 	 * file.
    320 	 */
    321 	if ((error = (*so->so_send)(so, mtod(m_serv, struct sockaddr *), NULL,
    322 	    m_outbuf, NULL, 0, l)) != 0) {
    323 		DPRINTF(("%s():%d tftproot: sosend returned %d\n",
    324 		    __func__, __LINE__, error));
    325 	}
    326 
    327 	/* Freed by the protocol */
    328 	m_outbuf = NULL;
    329 
    330 	/*
    331 	 * And use it as the root ramdisk.
    332 	 */
    333 	DPRINTF(("%s():%d RAMdisk loaded: %ld@%p\n",
    334 	    __func__, __LINE__, trh->trh_len, trh->trh_base));
    335 	md_root_setconf(trh->trh_base, trh->trh_len);
    336 
    337 	error = 0;
    338 out:
    339 	if (m_serv)
    340 		m_freem(m_serv);
    341 
    342 	if (m_outbuf)
    343 		m_freem(m_outbuf);
    344 
    345 	if (so)
    346 		soclose(so);
    347 
    348 	return error;
    349 }
    350 
    351 static int
    352 tftproot_recv(struct mbuf **mp, void *ctx)
    353 {
    354 	struct tftproot_handle *trh = ctx;
    355 	struct tftphdr *tftp;
    356 	struct mbuf *m = *mp;
    357 	size_t newlen;
    358 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
    359 
    360 	/*
    361 	 * Check for short packet
    362 	 */
    363 	if (m->m_pkthdr.len < hdrlen) {
    364 		DPRINTF(("%s():%d short reply (%d bytes)\n",
    365 		    __func__, __LINE__, m->m_pkthdr.len));
    366 		return -1;
    367 	}
    368 
    369 	/*
    370 	 * Check for packet too large for being a TFTP packet
    371 	 */
    372 	if (m->m_pkthdr.len > hdrlen + SEGSIZE) {
    373 		DPRINTF(("%s():%d packet too big (%d bytes)\n",
    374 		    __func__, __LINE__, m->m_pkthdr.len));
    375 		return -1;
    376 	}
    377 
    378 
    379 	/*
    380 	 * Examine the TFTP header
    381 	 */
    382 	if (m->m_len > sizeof(*tftp)) {
    383 		if ((m = *mp = m_pullup(m, sizeof(*tftp))) == NULL) {
    384 			DPRINTF(("%s():%d m_pullup failed\n",
    385 			    __func__, __LINE__));
    386 			return -1;
    387 		}
    388 	}
    389 	tftp = mtod(m, struct tftphdr *);
    390 
    391 	/*
    392 	 * We handle data or error
    393 	 */
    394 	switch(ntohs(tftp->th_opcode)) {
    395 	case DATA:
    396 		break;
    397 
    398 	case ERROR: {
    399 		char errbuf[SEGSIZE + 1];
    400 		int i;
    401 
    402 		for (i = 0; i < SEGSIZE; i++) {
    403 			if ((tftp->th_data[i] < ' ') ||
    404 			    (tftp->th_data[i] > '~')) {
    405 				errbuf[i] = '\0';
    406 				break;
    407 			}
    408 			errbuf[i] = tftp->th_data[i];
    409 		}
    410 		errbuf[SEGSIZE] = '\0';
    411 
    412 		printf("tftproot: TFTP server returned error %d, %s\n",
    413 		    ntohs(tftp->th_code), errbuf);
    414 
    415 		return -1;
    416 		break;
    417 	}
    418 
    419 	default:
    420 		DPRINTF(("%s():%d unexpected tftp reply opcode %d\n",
    421 		    __func__, __LINE__, ntohs(tftp->th_opcode)));
    422 		return -1;
    423 		break;
    424 	}
    425 
    426 	/*
    427 	 * Check for last packet, which does not fill the whole space
    428 	 */
    429 	if (m->m_pkthdr.len < hdrlen + SEGSIZE) {
    430 		DPRINTF(("%s():%d last chunk (%d bytes)\n",
    431 		    __func__, __LINE__, m->m_pkthdr.len));
    432 		trh->trh_flags |= TRH_FINISHED;
    433 	}
    434 
    435 
    436 	if (ntohs(tftp->th_block) != trh->trh_block) {
    437 		DPRINTF(("%s():%d expected block %d, got block %d\n",
    438 		    __func__, __LINE__, trh->trh_block, ntohs(tftp->th_block)));
    439 		return -1;
    440 	}
    441 
    442 	/*
    443 	 * Grow the receiving buffer to accommodate new data
    444 	 */
    445 	newlen = trh->trh_len + (m->m_pkthdr.len - hdrlen);
    446 	if ((trh->trh_base = realloc(trh->trh_base,
    447 	    newlen, M_TEMP, M_WAITOK)) == NULL) {
    448 		DPRINTF(("%s():%d failed to realloc %ld bytes\n",
    449 		    __func__, __LINE__, (long)newlen));
    450 		return -1;
    451 	}
    452 
    453 	/*
    454 	 * Copy the data
    455 	 */
    456 	m_copydata(m, hdrlen, m->m_pkthdr.len - hdrlen,
    457 		   (char *)trh->trh_base + trh->trh_len);
    458 	trh->trh_len = newlen;
    459 
    460 	return 0;
    461 }
    462 
    463