xref: /netbsd-src/sys/kern/subr_tftproot.c (revision c9496f6b604074a9451a67df576a5b423068e71e)
1 /*	$NetBSD: subr_tftproot.c,v 1.19 2016/10/31 15:27:24 maxv 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 1.19 2016/10/31 15:27:24 maxv 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 extern void       mdattach(int);
69 
70 /*
71  * Copied from <lib/libsa/tftp.h>
72  */
73 
74 #define SEGSIZE         512             /* data segment size */
75 
76 /*
77  * Packet types.
78  */
79 #define RRQ     01                      /* read request */
80 #define WRQ     02                      /* write request */
81 #define DATA    03                      /* data packet */
82 #define ACK     04                      /* acknowledgement */
83 #define ERROR   05                      /* error code */
84 
85 struct  tftphdr {
86         short   th_opcode;              /* packet type */
87         union {
88                 unsigned short tu_block; /* block # */
89                 short   tu_code;        /* error code */
90                 char    tu_stuff[1];    /* request packet stuff */
91         } th_u;
92         char    th_data[1];             /* data or error string */
93 } __packed;
94 
95 #define th_block        th_u.tu_block
96 #define th_code         th_u.tu_code
97 #define th_stuff        th_u.tu_stuff
98 #define th_msg          th_data
99 
100 #define IPPORT_TFTP 69
101 
102 #ifdef TFTPROOT_DEBUG
103 #define DPRINTF(x) printf x
104 #else
105 #define DPRINTF(x)
106 #endif
107 
108 struct tftproot_handle {
109 	struct nfs_diskless *trh_nd;
110 	void *trh_base;
111 	size_t trh_len;
112 	unsigned short trh_block;
113 	int trh_flags;
114 };
115 
116 #define TRH_FINISHED	1
117 
118 int tftproot_dhcpboot(device_t);
119 
120 static int tftproot_getfile(struct tftproot_handle *, struct lwp *);
121 static int tftproot_recv(struct mbuf **, void *);
122 
123 int
124 tftproot_dhcpboot(device_t bootdv)
125 {
126 	struct nfs_diskless *nd = NULL;
127 	struct ifnet *ifp = NULL;
128 	struct lwp *l;
129 	struct tftproot_handle trh;
130 	device_t dv;
131 	int error = -1;
132 
133 	if (rootspec != NULL) {
134 		int s = pserialize_read_enter();
135 		IFNET_READER_FOREACH(ifp)
136 			if (strcmp(rootspec, ifp->if_xname) == 0)
137 				break;
138 		pserialize_read_exit(s);
139 	}
140 
141 	if ((ifp == NULL) &&
142 	    (bootdv != NULL && device_class(bootdv) == DV_IFNET)) {
143 		int s = pserialize_read_enter();
144 		IFNET_READER_FOREACH(ifp)
145 			if (strcmp(device_xname(bootdv), ifp->if_xname) == 0)
146 				break;
147 		pserialize_read_exit(s);
148 	}
149 
150 	if (ifp == NULL) {
151 		DPRINTF(("%s():%d ifp is NULL\n", __func__, __LINE__));
152 		goto out;
153 	}
154 
155 	dv = device_find_by_xname(ifp->if_xname);
156 
157 	if ((dv == NULL) || (device_class(dv) != DV_IFNET)) {
158 		DPRINTF(("%s():%d cannot find device for interface %s\n",
159 		    __func__, __LINE__, ifp->if_xname));
160 		goto out;
161 	}
162 
163 	root_device = dv;
164 
165 	l = curlwp; /* XXX */
166 
167 	nd = kmem_zalloc(sizeof(*nd), KM_SLEEP);
168 	nd->nd_ifp = ifp;
169 	nd->nd_nomount = 1;
170 
171 	if ((error = nfs_boot_init(nd, l)) != 0) {
172 		DPRINTF(("%s():%d nfs_boot_init returned %d\n",
173 		    __func__, __LINE__, error));
174 		goto out;
175 	}
176 
177 	/*
178 	 * Strip leading "tftp:"
179 	 */
180 #define PREFIX "tftp:"
181 	if (strstr(nd->nd_bootfile, PREFIX) == nd->nd_bootfile)
182 		(void)memmove(nd->nd_bootfile,
183 			      nd->nd_bootfile + (sizeof(PREFIX) - 1),
184 			      sizeof(nd->nd_bootfile) - sizeof(PREFIX));
185 #undef PREFIX
186 
187 	printf("tftproot: bootfile=%s\n", nd->nd_bootfile);
188 
189 	memset(&trh, 0, sizeof(trh));
190 	trh.trh_nd = nd;
191 	trh.trh_block = 1;
192 
193 	if ((error = tftproot_getfile(&trh, l)) != 0) {
194 		DPRINTF(("%s():%d tftproot_getfile returned %d\n",
195 		    __func__, __LINE__, error));
196 		goto out;
197 	}
198 
199 	error = 0;
200 
201 out:
202 	if (nd)
203 		kmem_free(nd, sizeof(*nd));
204 
205 	return error;
206 }
207 
208 static int
209 tftproot_getfile(struct tftproot_handle *trh, struct lwp *l)
210 {
211 	struct socket *so = NULL;
212 	struct mbuf *m_serv = NULL;
213 	struct mbuf *m_outbuf = NULL;
214 	struct sockaddr_in sin;
215 	struct tftphdr *tftp;
216 	size_t packetlen, namelen;
217 	int error = -1;
218 	const char octetstr[] = "octet";
219 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
220 	char *cp;
221 
222 	if ((error = socreate(AF_INET, &so, SOCK_DGRAM, 0, l, NULL)) != 0) {
223 		DPRINTF(("%s():%d socreate returned %d\n",
224 		    __func__, __LINE__, error));
225 		goto out;
226 	}
227 
228 	/*
229 	 * Set timeout
230 	 */
231 	if ((error = nfs_boot_setrecvtimo(so))) {
232 		DPRINTF(("%s():%d SO_RCVTIMEO failed %d\n",
233 		    __func__, __LINE__, error));
234 		goto out;
235 	}
236 
237 	/*
238 	 * Set server address and port
239 	 */
240 	memcpy(&sin, &trh->trh_nd->nd_root.ndm_saddr, sizeof(sin));
241 	sin.sin_port = htons(IPPORT_TFTP);
242 
243 	/*
244 	 * Set send buffer, prepare the TFTP packet
245 	 */
246 	namelen = strlen(trh->trh_nd->nd_bootfile) + 1;
247 	packetlen = sizeof(tftp->th_opcode) + namelen + sizeof(octetstr);
248 	if (packetlen > MSIZE) {
249 		DPRINTF(("%s():%d boot filename too long (%ld bytes)\n",
250 		    __func__, __LINE__, (long)namelen));
251 		goto out;
252 	}
253 
254 	m_outbuf = m_gethdr(M_WAIT, MT_DATA);
255 	m_clget(m_outbuf, M_WAIT);
256 	m_outbuf->m_len = packetlen;
257 	m_outbuf->m_pkthdr.len = packetlen;
258 	m_reset_rcvif(m_outbuf);
259 
260 	tftp = mtod(m_outbuf, struct tftphdr *);
261 	memset(tftp, 0, packetlen);
262 
263 	tftp->th_opcode = htons((short)RRQ);
264 	cp = tftp->th_stuff;
265 	(void)strncpy(cp,  trh->trh_nd->nd_bootfile, namelen);
266 	cp += namelen;
267 	(void)strncpy(cp, octetstr, sizeof(octetstr));
268 
269 	/*
270 	 * Perform the file transfer
271 	 */
272 	printf("tftproot: download %s:%s ",
273 	    inet_ntoa(sin.sin_addr), trh->trh_nd->nd_bootfile);
274 
275 	do {
276 		/*
277 		 * Show progress for every 200 blocks (100kB)
278 		 */
279 #ifndef TFTPROOT_PROGRESS
280 #define TFTPROOT_PROGRESS 200
281 #endif
282 		if ((trh->trh_block % TFTPROOT_PROGRESS) == 0)
283 			twiddle();
284 
285 		/*
286 		 * Send the packet and receive the answer.
287 		 * We get the sender address here, which should be
288 		 * the same server with a different port
289 		 */
290 		if ((error = nfs_boot_sendrecv(so, &sin, NULL, m_outbuf,
291 		    tftproot_recv, NULL, &m_serv, trh, l)) != 0) {
292 			DPRINTF(("%s():%d sendrecv failed %d\n",
293 			    __func__, __LINE__, error));
294 			goto out;
295 		}
296 
297 		/*
298 		 * Accomodate the packet length for acks.
299 		 * This is really needed only on first pass
300 		 */
301 		m_outbuf->m_len = hdrlen;
302 		m_outbuf->m_pkthdr.len = hdrlen;
303 		tftp->th_opcode = htons((short)ACK);
304 		tftp->th_block = htons(trh->trh_block);
305 
306 
307 		/*
308 		 * Check for termination
309 		 */
310 		if (trh->trh_flags & TRH_FINISHED)
311 			break;
312 
313 		trh->trh_block++;
314 	} while (1/* CONSTCOND */);
315 
316 	printf("\n");
317 
318 	/*
319 	 * Ack the last block. Ignore errors, as we already have the whole
320 	 * file.
321 	 */
322 	if ((error = (*so->so_send)(so, mtod(m_serv, struct sockaddr *), NULL,
323 	    m_outbuf, NULL, 0, l)) != 0)
324 		DPRINTF(("%s():%d tftproot: sosend returned %d\n",
325 		    __func__, __LINE__, error));
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 	mdattach(0);
337 
338 	error = 0;
339 out:
340 	if (m_serv)
341 		m_freem(m_serv);
342 
343 	if (m_outbuf)
344 		m_freem(m_outbuf);
345 
346 	if (so)
347 		soclose(so);
348 
349 	return error;
350 }
351 
352 static int
353 tftproot_recv(struct mbuf **mp, void *ctx)
354 {
355 	struct tftproot_handle *trh = ctx;
356 	struct tftphdr *tftp;
357 	struct mbuf *m = *mp;
358 	size_t newlen;
359 	size_t hdrlen = sizeof(*tftp) - sizeof(tftp->th_data);
360 
361 	/*
362 	 * Check for short packet
363 	 */
364 	if (m->m_pkthdr.len < hdrlen) {
365 		DPRINTF(("%s():%d short reply (%d bytes)\n",
366 		    __func__, __LINE__, m->m_pkthdr.len));
367 		return -1;
368 	}
369 
370 	/*
371 	 * Check for packet too large for being a TFTP packet
372 	 */
373 	if (m->m_pkthdr.len > hdrlen + SEGSIZE) {
374 		DPRINTF(("%s():%d packet too big (%d bytes)\n",
375 		    __func__, __LINE__, m->m_pkthdr.len));
376 		return -1;
377 	}
378 
379 
380 	/*
381 	 * Examine the TFTP header
382 	 */
383 	if (m->m_len > sizeof(*tftp)) {
384 		if ((m = *mp = m_pullup(m, sizeof(*tftp))) == NULL) {
385 			DPRINTF(("%s():%d m_pullup failed\n",
386 			    __func__, __LINE__));
387 			return -1;
388 		}
389 	}
390 	tftp = mtod(m, struct tftphdr *);
391 
392 	/*
393 	 * We handle data or error
394 	 */
395 	switch(ntohs(tftp->th_opcode)) {
396 	case DATA:
397 		break;
398 
399 	case ERROR: {
400 		char errbuf[SEGSIZE + 1];
401 		int i;
402 
403 		for (i = 0; i < SEGSIZE; i++) {
404 			if ((tftp->th_data[i] < ' ') ||
405 			    (tftp->th_data[i] > '~')) {
406 				errbuf[i] = '\0';
407 				break;
408 			}
409 			errbuf[i] = tftp->th_data[i];
410 		}
411 		errbuf[SEGSIZE] = '\0';
412 
413 		printf("tftproot: TFTP server returned error %d, %s\n",
414 		    ntohs(tftp->th_code), errbuf);
415 
416 		return -1;
417 		break;
418 	}
419 
420 	default:
421 		DPRINTF(("%s():%d unexpected tftp reply opcode %d\n",
422 		    __func__, __LINE__, ntohs(tftp->th_opcode)));
423 		return -1;
424 		break;
425 	}
426 
427 	/*
428 	 * Check for last packet, which does not fill the whole space
429 	 */
430 	if (m->m_pkthdr.len < hdrlen + SEGSIZE) {
431 		DPRINTF(("%s():%d last chunk (%d bytes)\n",
432 		    __func__, __LINE__, m->m_pkthdr.len));
433 		trh->trh_flags |= TRH_FINISHED;
434 	}
435 
436 
437 	if (ntohs(tftp->th_block) != trh->trh_block) {
438 		DPRINTF(("%s():%d expected block %d, got block %d\n",
439 		    __func__, __LINE__, trh->trh_block, ntohs(tftp->th_block)));
440 		return -1;
441 	}
442 
443 	/*
444 	 * Grow the receiving buffer to accommodate new data
445 	 */
446 	newlen = trh->trh_len + (m->m_pkthdr.len - hdrlen);
447 	if ((trh->trh_base = realloc(trh->trh_base,
448 	    newlen, M_TEMP, M_WAITOK)) == NULL) {
449 		DPRINTF(("%s():%d failed to realloc %ld bytes\n",
450 		    __func__, __LINE__, (long)newlen));
451 		return -1;
452 	}
453 
454 	/*
455 	 * Copy the data
456 	 */
457 	m_copydata(m, hdrlen, m->m_pkthdr.len - hdrlen,
458 		   (char *)trh->trh_base + trh->trh_len);
459 	trh->trh_len = newlen;
460 
461 	return 0;
462 }
463 
464