xref: /netbsd-src/sys/kern/subr_tftproot.c (revision 4d12bfcd155352508213ace5ccc59ce930ea2974)
1 /*	$NetBSD: subr_tftproot.c,v 1.12 2012/12/01 11:41:50 mbalmer 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 1.12 2012/12/01 11:41:50 mbalmer Exp $");
43 
44 #include <sys/param.h>
45 #include <sys/types.h>
46 #include <sys/mount.h>
47 #include <sys/lwp.h>
48 #include <sys/kmem.h>
49 #include <sys/mbuf.h>
50 #include <sys/timevar.h>
51 #include <sys/socketvar.h>
52 
53 #include <net/if.h>
54 
55 #include <dev/md.h>
56 
57 #include <netinet/in.h>
58 
59 #include <nfs/rpcv2.h>
60 
61 #include <nfs/nfsproto.h>
62 #include <nfs/nfs.h>
63 #include <nfs/nfsmount.h>
64 #include <nfs/nfsdiskless.h>
65 #include <nfs/nfs_var.h>
66 
67 extern void       mdattach(int);
68 
69 /*
70  * Copied from <lib/libsa/tftp.h>
71  */
72 
73 #define SEGSIZE         512             /* data segment size */
74 
75 /*
76  * Packet types.
77  */
78 #define RRQ     01                      /* read request */
79 #define WRQ     02                      /* write request */
80 #define DATA    03                      /* data packet */
81 #define ACK     04                      /* acknowledgement */
82 #define ERROR   05                      /* error code */
83 
84 struct  tftphdr {
85         short   th_opcode;              /* packet type */
86         union {
87                 unsigned short tu_block; /* block # */
88                 short   tu_code;        /* error code */
89                 char    tu_stuff[1];    /* request packet stuff */
90         } th_u;
91         char    th_data[1];             /* data or error string */
92 } __packed;
93 
94 #define th_block        th_u.tu_block
95 #define th_code         th_u.tu_code
96 #define th_stuff        th_u.tu_stuff
97 #define th_msg          th_data
98 
99 #define IPPORT_TFTP 69
100 
101 #ifdef TFTPROOT_DEBUG
102 #define DPRINTF(x) printf x
103 #else
104 #define DPRINTF(x)
105 #endif
106 
107 struct tftproot_handle {
108 	struct nfs_diskless *trh_nd;
109 	void *trh_base;
110 	size_t trh_len;
111 	unsigned short trh_block;
112 	int trh_flags;
113 };
114 
115 #define TRH_FINISHED	1
116 
117 int tftproot_dhcpboot(device_t);
118 
119 static int tftproot_getfile(struct tftproot_handle *, struct lwp *);
120 static int tftproot_recv(struct mbuf *, void *);
121 
122 int
123 tftproot_dhcpboot(device_t bootdv)
124 {
125 	struct nfs_diskless *nd = NULL;
126 	struct ifnet *ifp = NULL;
127 	struct lwp *l;
128 	struct tftproot_handle trh;
129 	device_t dv;
130 	int error = -1;
131 
132 	if (rootspec != NULL) {
133 		IFNET_FOREACH(ifp)
134 			if (strcmp(rootspec, ifp->if_xname) == 0)
135 				break;
136 	}
137 
138 	if ((ifp == NULL) &&
139 	    (bootdv != NULL && device_class(bootdv) == DV_IFNET)) {
140 		IFNET_FOREACH(ifp)
141 			if (strcmp(device_xname(bootdv), ifp->if_xname) == 0)
142 				break;
143 	}
144 
145 	if (ifp == NULL) {
146 		DPRINTF(("%s():%d ifp is NULL\n", __func__, __LINE__));
147 		goto out;
148 	}
149 
150 	dv = device_find_by_xname(ifp->if_xname);
151 
152 	if ((dv == NULL) || (device_class(dv) != DV_IFNET)) {
153 		DPRINTF(("%s():%d cannot find device for interface %s\n",
154 		    __func__, __LINE__, ifp->if_xname));
155 		goto out;
156 	}
157 
158 	root_device = dv;
159 
160 	l = curlwp; /* XXX */
161 
162 	nd = kmem_zalloc(sizeof(*nd), KM_SLEEP);
163 	nd->nd_ifp = ifp;
164 	nd->nd_nomount = 1;
165 
166 	if ((error = nfs_boot_init(nd, l)) != 0) {
167 		DPRINTF(("%s():%d nfs_boot_init returned %d\n",
168 		    __func__, __LINE__, error));
169 		goto out;
170 	}
171 
172 	/*
173 	 * Strip leading "tftp:"
174 	 */
175 #define PREFIX "tftp:"
176 	if (strstr(nd->nd_bootfile, PREFIX) == nd->nd_bootfile)
177 		(void)memmove(nd->nd_bootfile,
178 			      nd->nd_bootfile + (sizeof(PREFIX) - 1),
179 			      sizeof(nd->nd_bootfile) - sizeof(PREFIX));
180 #undef PREFIX
181 
182 	printf("tftproot: bootfile=%s\n", nd->nd_bootfile);
183 
184 	memset(&trh, 0, sizeof(trh));
185 	trh.trh_nd = nd;
186 	trh.trh_block = 1;
187 
188 	if ((error = tftproot_getfile(&trh, l)) != 0) {
189 		DPRINTF(("%s():%d tftproot_getfile returned %d\n",
190 		    __func__, __LINE__, error));
191 		goto out;
192 	}
193 
194 	error = 0;
195 
196 out:
197 	if (nd)
198 		kmem_free(nd, sizeof(*nd));
199 
200 	return error;
201 }
202 
203 static int
204 tftproot_getfile(struct tftproot_handle *trh, struct lwp *l)
205 {
206 	struct socket *so = NULL;
207 	struct mbuf *m_serv = NULL;
208 	struct mbuf *m_outbuf = NULL;
209 	struct sockaddr_in *sin;
210 	struct tftphdr *tftp;
211 	size_t packetlen, namelen;
212 	int error = -1;
213 	const char octetstr[] = "octet";
214 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
215 	char *cp;
216 
217 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, l, NULL)) != 0) {
218 		DPRINTF(("%s():%d socreate returned %d\n",
219 		    __func__, __LINE__, error));
220 		goto out;
221 	}
222 
223 	/*
224 	 * Set timeout
225 	 */
226 	if ((error = nfs_boot_setrecvtimo(so))) {
227 		DPRINTF(("%s():%d SO_RCVTIMEO failed %d\n",
228 		    __func__, __LINE__, error));
229 		goto out;
230 	}
231 
232 	/*
233 	 * Set server address and port
234 	 */
235 	m_serv = m_get(M_WAIT, MT_SONAME);
236 	m_serv->m_len = sizeof(*sin);
237 	sin = mtod(m_serv, struct sockaddr_in *);
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 		goto out;
250 	}
251 
252 	m_outbuf = m_gethdr(M_WAIT, MT_DATA);
253 	m_clget(m_outbuf, M_WAIT);
254 	m_outbuf->m_len = packetlen;
255 	m_outbuf->m_pkthdr.len = packetlen;
256 	m_outbuf->m_pkthdr.rcvif = NULL;
257 
258 	tftp = mtod(m_outbuf, struct tftphdr *);
259 	memset(tftp, 0, packetlen);
260 
261 	tftp->th_opcode = htons((short)RRQ);
262 	cp = tftp->th_stuff;
263 	(void)strncpy(cp,  trh->trh_nd->nd_bootfile, namelen);
264 	cp += namelen;
265 	(void)strncpy(cp, octetstr, sizeof(octetstr));
266 
267 	/*
268 	 * Perform the file transfer
269 	 */
270 	sin = (struct sockaddr_in *)&trh->trh_nd->nd_root.ndm_saddr;
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, m_serv, 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 		 * Accomodate 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. so_send frees m_outbuf, therefore
319 	 * we do not want to free it ourselves.
320 	 * Ignore errors, as we already have the whole file.
321 	 */
322 	if ((error = (*so->so_send)(so, m_serv, NULL,
323 	    m_outbuf, NULL, 0, l)) != 0)
324 		DPRINTF(("%s():%d tftproot: sosend returned %d\n",
325 		    __func__, __LINE__, error));
326 	else
327 		m_outbuf = NULL;
328 
329 	/*
330 	 * And use it as the root ramdisk.
331 	 */
332 	DPRINTF(("%s():%d RAMdisk loaded: %ld@%p\n",
333 	    __func__, __LINE__, trh->trh_len, trh->trh_base));
334 	md_root_setconf(trh->trh_base, trh->trh_len);
335 	mdattach(0);
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 *m, void *ctx)
353 {
354 	struct tftproot_handle *trh = ctx;
355 	struct tftphdr *tftp;
356 	size_t newlen;
357 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
358 
359 	/*
360 	 * Check for short packet
361 	 */
362 	if (m->m_pkthdr.len < hdrlen) {
363 		DPRINTF(("%s():%d short reply (%d bytes)\n",
364 		    __func__, __LINE__, m->m_pkthdr.len));
365 		return -1;
366 	}
367 
368 	/*
369 	 * Check for packet too large for being a TFTP packet
370 	 */
371 	if (m->m_pkthdr.len > hdrlen + SEGSIZE) {
372 		DPRINTF(("%s():%d packet too big (%d bytes)\n",
373 		    __func__, __LINE__, m->m_pkthdr.len));
374 		return -1;
375 	}
376 
377 
378 	/*
379 	 * Examine the TFTP header
380 	 */
381 	if (m->m_len > sizeof(*tftp)) {
382 		if ((m = m_pullup(m, sizeof(*tftp))) == NULL) {
383 			DPRINTF(("%s():%d m_pullup failed\n",
384 			    __func__, __LINE__));
385 			return -1;
386 		}
387 	}
388 	tftp = mtod(m, struct tftphdr *);
389 
390 	/*
391 	 * We handle data or error
392 	 */
393 	switch(ntohs(tftp->th_opcode)) {
394 	case DATA:
395 		break;
396 
397 	case ERROR: {
398 		char errbuf[SEGSIZE + 1];
399 		int i;
400 
401 		for (i = 0; i < SEGSIZE; i++) {
402 			if ((tftp->th_data[i] < ' ') ||
403 			    (tftp->th_data[i] > '~')) {
404 				errbuf[i] = '\0';
405 				break;
406 			}
407 			errbuf[i] = tftp->th_data[i];
408 		}
409 		errbuf[SEGSIZE] = '\0';
410 
411 		printf("tftproot: TFTP server returned error %d, %s\n",
412 		    ntohs(tftp->th_code), errbuf);
413 
414 		return -1;
415 		break;
416 	}
417 
418 	default:
419 		DPRINTF(("%s():%d unexpected tftp reply opcode %d\n",
420 		    __func__, __LINE__, ntohs(tftp->th_opcode)));
421 		return -1;
422 		break;
423 	}
424 
425 	/*
426 	 * Check for last packet, which does not fill the whole space
427 	 */
428 	if (m->m_pkthdr.len < hdrlen + SEGSIZE) {
429 		DPRINTF(("%s():%d last chunk (%d bytes)\n",
430 		    __func__, __LINE__, m->m_pkthdr.len));
431 		trh->trh_flags |= TRH_FINISHED;
432 	}
433 
434 
435 	if (ntohs(tftp->th_block) != trh->trh_block) {
436 		DPRINTF(("%s():%d expected block %d, got block %d\n",
437 		    __func__, __LINE__, trh->trh_block, ntohs(tftp->th_block)));
438 		return -1;
439 	}
440 
441 	/*
442 	 * Grow the receiving buffer to accommodate new data
443 	 */
444 	newlen = trh->trh_len + (m->m_pkthdr.len - hdrlen);
445 	if ((trh->trh_base = realloc(trh->trh_base,
446 	    newlen, M_TEMP, M_WAITOK)) == NULL) {
447 		DPRINTF(("%s():%d failed to realloc %ld bytes\n",
448 		    __func__, __LINE__, (long)newlen));
449 		return -1;
450 	}
451 
452 	/*
453 	 * Copy the data
454 	 */
455 	m_copydata(m, hdrlen, m->m_pkthdr.len - hdrlen,
456 		   (char *)trh->trh_base + trh->trh_len);
457 	trh->trh_len = newlen;
458 
459 	return 0;
460 }
461 
462