1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if 0
33#ifndef lint
34static const char copyright[] =
35"@(#) Copyright (c) 1980, 1993\n\
36	The Regents of the University of California.  All rights reserved.\n";
37#endif /* not lint */
38
39#ifndef lint
40static char sccsid[] = "From: @(#)swapon.c	8.1 (Berkeley) 6/5/93";
41#endif /* not lint */
42#endif
43#include <sys/cdefs.h>
44__FBSDID("$FreeBSD$");
45
46#include <sys/param.h>
47#include <sys/capsicum.h>
48#include <sys/disk.h>
49#include <sys/socket.h>
50#include <sys/sysctl.h>
51
52#include <assert.h>
53#include <capsicum_helpers.h>
54#include <err.h>
55#include <errno.h>
56#include <fcntl.h>
57#include <ifaddrs.h>
58#include <netdb.h>
59#include <paths.h>
60#include <stdbool.h>
61#include <stdint.h>
62#include <stdio.h>
63#include <stdlib.h>
64#include <string.h>
65#include <sysexits.h>
66#include <unistd.h>
67
68#include <arpa/inet.h>
69
70#include <net/if.h>
71#include <net/if_dl.h>
72#include <net/route.h>
73
74#include <netinet/in.h>
75#include <netinet/netdump/netdump.h>
76
77#ifdef HAVE_CRYPTO
78#include <openssl/err.h>
79#include <openssl/pem.h>
80#include <openssl/rsa.h>
81#endif
82
83static int	verbose;
84
85static void _Noreturn
86usage(void)
87{
88	fprintf(stderr,
89    "usage: dumpon [-v] [-k <pubkey>] [-Zz] <device>\n"
90    "       dumpon [-v] [-k <pubkey>] [-Zz]\n"
91    "              [-g <gateway>] -s <server> -c <client> <iface>\n"
92    "       dumpon [-v] off\n"
93    "       dumpon [-v] -l\n");
94	exit(EX_USAGE);
95}
96
97/*
98 * Look for a default route on the specified interface.
99 */
100static char *
101find_gateway(const char *ifname)
102{
103	struct ifaddrs *ifa, *ifap;
104	struct rt_msghdr *rtm;
105	struct sockaddr *sa;
106	struct sockaddr_dl *sdl;
107	struct sockaddr_in *dst, *mask, *gw;
108	char *buf, *next, *ret;
109	size_t sz;
110	int error, i, ifindex, mib[7];
111
112	/* First look up the interface index. */
113	if (getifaddrs(&ifap) != 0)
114		err(EX_OSERR, "getifaddrs");
115	for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
116		if (ifa->ifa_addr->sa_family != AF_LINK)
117			continue;
118		if (strcmp(ifa->ifa_name, ifname) == 0) {
119			sdl = (struct sockaddr_dl *)(void *)ifa->ifa_addr;
120			ifindex = sdl->sdl_index;
121			break;
122		}
123	}
124	if (ifa == NULL)
125		errx(1, "couldn't find interface index for '%s'", ifname);
126	freeifaddrs(ifap);
127
128	/* Now get the IPv4 routing table. */
129	mib[0] = CTL_NET;
130	mib[1] = PF_ROUTE;
131	mib[2] = 0;
132	mib[3] = AF_INET;
133	mib[4] = NET_RT_DUMP;
134	mib[5] = 0;
135	mib[6] = -1; /* FIB */
136
137	for (;;) {
138		if (sysctl(mib, nitems(mib), NULL, &sz, NULL, 0) != 0)
139			err(EX_OSERR, "sysctl(NET_RT_DUMP)");
140		buf = malloc(sz);
141		error = sysctl(mib, nitems(mib), buf, &sz, NULL, 0);
142		if (error == 0)
143			break;
144		if (errno != ENOMEM)
145			err(EX_OSERR, "sysctl(NET_RT_DUMP)");
146		free(buf);
147	}
148
149	ret = NULL;
150	for (next = buf; next < buf + sz; next += rtm->rtm_msglen) {
151		rtm = (struct rt_msghdr *)(void *)next;
152		if (rtm->rtm_version != RTM_VERSION)
153			continue;
154		if ((rtm->rtm_flags & RTF_GATEWAY) == 0 ||
155		    rtm->rtm_index != ifindex)
156			continue;
157
158		dst = gw = mask = NULL;
159		sa = (struct sockaddr *)(rtm + 1);
160		for (i = 0; i < RTAX_MAX; i++) {
161			if ((rtm->rtm_addrs & (1 << i)) != 0) {
162				switch (i) {
163				case RTAX_DST:
164					dst = (void *)sa;
165					break;
166				case RTAX_GATEWAY:
167					gw = (void *)sa;
168					break;
169				case RTAX_NETMASK:
170					mask = (void *)sa;
171					break;
172				}
173			}
174			sa = (struct sockaddr *)((char *)sa + SA_SIZE(sa));
175		}
176
177		if (dst->sin_addr.s_addr == INADDR_ANY &&
178		    mask->sin_addr.s_addr == 0) {
179			ret = inet_ntoa(gw->sin_addr);
180			break;
181		}
182	}
183	free(buf);
184	return (ret);
185}
186
187static void
188check_size(int fd, const char *fn)
189{
190	int name[] = { CTL_HW, HW_PHYSMEM };
191	size_t namelen = nitems(name);
192	unsigned long physmem;
193	size_t len;
194	off_t mediasize;
195	int minidump;
196
197	len = sizeof(minidump);
198	if (sysctlbyname("debug.minidump", &minidump, &len, NULL, 0) == 0 &&
199	    minidump == 1)
200		return;
201	len = sizeof(physmem);
202	if (sysctl(name, namelen, &physmem, &len, NULL, 0) != 0)
203		err(EX_OSERR, "can't get memory size");
204	if (ioctl(fd, DIOCGMEDIASIZE, &mediasize) != 0)
205		err(EX_OSERR, "%s: can't get size", fn);
206	if ((uintmax_t)mediasize < (uintmax_t)physmem) {
207		if (verbose)
208			printf("%s is smaller than physical memory\n", fn);
209		exit(EX_IOERR);
210	}
211}
212
213#ifdef HAVE_CRYPTO
214static void
215genkey(const char *pubkeyfile, struct diocskerneldump_arg *kdap)
216{
217	FILE *fp;
218	RSA *pubkey;
219
220	assert(pubkeyfile != NULL);
221	assert(kdap != NULL);
222
223	fp = NULL;
224	pubkey = NULL;
225
226	fp = fopen(pubkeyfile, "r");
227	if (fp == NULL)
228		err(1, "Unable to open %s", pubkeyfile);
229
230	if (caph_enter() < 0)
231		err(1, "Unable to enter capability mode");
232
233	pubkey = RSA_new();
234	if (pubkey == NULL) {
235		errx(1, "Unable to allocate an RSA structure: %s",
236		    ERR_error_string(ERR_get_error(), NULL));
237	}
238
239	pubkey = PEM_read_RSA_PUBKEY(fp, &pubkey, NULL, NULL);
240	fclose(fp);
241	fp = NULL;
242	if (pubkey == NULL)
243		errx(1, "Unable to read data from %s.", pubkeyfile);
244
245	kdap->kda_encryptedkeysize = RSA_size(pubkey);
246	if (kdap->kda_encryptedkeysize > KERNELDUMP_ENCKEY_MAX_SIZE) {
247		errx(1, "Public key has to be at most %db long.",
248		    8 * KERNELDUMP_ENCKEY_MAX_SIZE);
249	}
250
251	kdap->kda_encryptedkey = calloc(1, kdap->kda_encryptedkeysize);
252	if (kdap->kda_encryptedkey == NULL)
253		err(1, "Unable to allocate encrypted key");
254
255	kdap->kda_encryption = KERNELDUMP_ENC_AES_256_CBC;
256	arc4random_buf(kdap->kda_key, sizeof(kdap->kda_key));
257	if (RSA_public_encrypt(sizeof(kdap->kda_key), kdap->kda_key,
258	    kdap->kda_encryptedkey, pubkey,
259	    RSA_PKCS1_PADDING) != (int)kdap->kda_encryptedkeysize) {
260		errx(1, "Unable to encrypt the one-time key.");
261	}
262	RSA_free(pubkey);
263}
264#endif
265
266static void
267listdumpdev(void)
268{
269	char dumpdev[PATH_MAX];
270	struct netdump_conf ndconf;
271	size_t len;
272	const char *sysctlname = "kern.shutdown.dumpdevname";
273	int fd;
274
275	len = sizeof(dumpdev);
276	if (sysctlbyname(sysctlname, &dumpdev, &len, NULL, 0) != 0) {
277		if (errno == ENOMEM) {
278			err(EX_OSERR, "Kernel returned too large of a buffer for '%s'\n",
279				sysctlname);
280		} else {
281			err(EX_OSERR, "Sysctl get '%s'\n", sysctlname);
282		}
283	}
284	if (strlen(dumpdev) == 0)
285		(void)strlcpy(dumpdev, _PATH_DEVNULL, sizeof(dumpdev));
286
287	if (verbose)
288		printf("kernel dumps on ");
289	printf("%s\n", dumpdev);
290
291	/* If netdump is enabled, print the configuration parameters. */
292	if (verbose) {
293		fd = open(_PATH_NETDUMP, O_RDONLY);
294		if (fd < 0) {
295			if (errno != ENOENT)
296				err(EX_OSERR, "opening %s", _PATH_NETDUMP);
297			return;
298		}
299		if (ioctl(fd, NETDUMPGCONF, &ndconf) != 0) {
300			if (errno != ENXIO)
301				err(EX_OSERR, "ioctl(NETDUMPGCONF)");
302			(void)close(fd);
303			return;
304		}
305
306		printf("server address: %s\n", inet_ntoa(ndconf.ndc_server));
307		printf("client address: %s\n", inet_ntoa(ndconf.ndc_client));
308		printf("gateway address: %s\n", inet_ntoa(ndconf.ndc_gateway));
309		(void)close(fd);
310	}
311}
312
313static int
314opendumpdev(const char *arg, char *dumpdev)
315{
316	int fd, i;
317
318	if (strncmp(arg, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
319		strlcpy(dumpdev, arg, PATH_MAX);
320	else {
321		i = snprintf(dumpdev, PATH_MAX, "%s%s", _PATH_DEV, arg);
322		if (i < 0)
323			err(EX_OSERR, "%s", arg);
324		if (i >= PATH_MAX)
325			errc(EX_DATAERR, EINVAL, "%s", arg);
326	}
327
328	fd = open(dumpdev, O_RDONLY);
329	if (fd < 0)
330		err(EX_OSFILE, "%s", dumpdev);
331	return (fd);
332}
333
334int
335main(int argc, char *argv[])
336{
337	char dumpdev[PATH_MAX];
338	struct diocskerneldump_arg _kda, *kdap;
339	struct netdump_conf ndconf;
340	struct addrinfo hints, *res;
341	const char *dev, *pubkeyfile, *server, *client, *gateway;
342	int ch, error, fd;
343	bool enable, gzip, list, netdump, zstd;
344
345	gzip = list = netdump = zstd = false;
346	kdap = NULL;
347	pubkeyfile = NULL;
348	server = client = gateway = NULL;
349
350	while ((ch = getopt(argc, argv, "c:g:k:ls:vZz")) != -1)
351		switch ((char)ch) {
352		case 'c':
353			client = optarg;
354			break;
355		case 'g':
356			gateway = optarg;
357			break;
358		case 'k':
359			pubkeyfile = optarg;
360			break;
361		case 'l':
362			list = true;
363			break;
364		case 's':
365			server = optarg;
366			break;
367		case 'v':
368			verbose = 1;
369			break;
370		case 'Z':
371			zstd = true;
372			break;
373		case 'z':
374			gzip = true;
375			break;
376		default:
377			usage();
378		}
379
380	if (gzip && zstd)
381		errx(EX_USAGE, "The -z and -Z options are mutually exclusive.");
382
383	argc -= optind;
384	argv += optind;
385
386	if (list) {
387		listdumpdev();
388		exit(EX_OK);
389	}
390
391	if (argc != 1)
392		usage();
393
394#ifndef HAVE_CRYPTO
395	if (pubkeyfile != NULL)
396		errx(EX_UNAVAILABLE,"Unable to use the public key."
397				    " Recompile dumpon with OpenSSL support.");
398#endif
399
400	if (server != NULL && client != NULL) {
401		enable = true;
402		dev = _PATH_NETDUMP;
403		netdump = true;
404		kdap = &ndconf.ndc_kda;
405	} else if (server == NULL && client == NULL && argc > 0) {
406		enable = strcmp(argv[0], "off") != 0;
407		dev = enable ? argv[0] : _PATH_DEVNULL;
408		netdump = false;
409		kdap = &_kda;
410	} else
411		usage();
412
413	fd = opendumpdev(dev, dumpdev);
414	if (!netdump && !gzip)
415		check_size(fd, dumpdev);
416
417	bzero(kdap, sizeof(*kdap));
418	kdap->kda_enable = 0;
419	if (ioctl(fd, DIOCSKERNELDUMP, kdap) != 0)
420		err(EX_OSERR, "ioctl(DIOCSKERNELDUMP)");
421	if (!enable)
422		exit(EX_OK);
423
424	explicit_bzero(kdap, sizeof(*kdap));
425	kdap->kda_enable = 1;
426	kdap->kda_compression = KERNELDUMP_COMP_NONE;
427	if (zstd)
428		kdap->kda_compression = KERNELDUMP_COMP_ZSTD;
429	else if (gzip)
430		kdap->kda_compression = KERNELDUMP_COMP_GZIP;
431
432	if (netdump) {
433		memset(&hints, 0, sizeof(hints));
434		hints.ai_family = AF_INET;
435		hints.ai_protocol = IPPROTO_UDP;
436		res = NULL;
437		error = getaddrinfo(server, NULL, &hints, &res);
438		if (error != 0)
439			err(1, "%s", gai_strerror(error));
440		if (res == NULL)
441			errx(1, "failed to resolve '%s'", server);
442		server = inet_ntoa(
443		    ((struct sockaddr_in *)(void *)res->ai_addr)->sin_addr);
444		freeaddrinfo(res);
445
446		if (strlcpy(ndconf.ndc_iface, argv[0],
447		    sizeof(ndconf.ndc_iface)) >= sizeof(ndconf.ndc_iface))
448			errx(EX_USAGE, "invalid interface name '%s'", argv[0]);
449		if (inet_aton(server, &ndconf.ndc_server) == 0)
450			errx(EX_USAGE, "invalid server address '%s'", server);
451		if (inet_aton(client, &ndconf.ndc_client) == 0)
452			errx(EX_USAGE, "invalid client address '%s'", client);
453
454		if (gateway == NULL) {
455			gateway = find_gateway(argv[0]);
456			if (gateway == NULL) {
457				if (verbose)
458					printf(
459				    "failed to look up gateway for %s\n",
460					    server);
461				gateway = server;
462			}
463		}
464		if (inet_aton(gateway, &ndconf.ndc_gateway) == 0)
465			errx(EX_USAGE, "invalid gateway address '%s'", gateway);
466
467#ifdef HAVE_CRYPTO
468		if (pubkeyfile != NULL)
469			genkey(pubkeyfile, kdap);
470#endif
471		error = ioctl(fd, NETDUMPSCONF, &ndconf);
472		if (error != 0)
473			error = errno;
474		explicit_bzero(kdap->kda_encryptedkey,
475		    kdap->kda_encryptedkeysize);
476		free(kdap->kda_encryptedkey);
477		explicit_bzero(kdap, sizeof(*kdap));
478		if (error != 0)
479			errc(EX_OSERR, error, "ioctl(NETDUMPSCONF)");
480	} else {
481#ifdef HAVE_CRYPTO
482		if (pubkeyfile != NULL)
483			genkey(pubkeyfile, kdap);
484#endif
485		error = ioctl(fd, DIOCSKERNELDUMP, kdap);
486		if (error != 0)
487			error = errno;
488		explicit_bzero(kdap->kda_encryptedkey,
489		    kdap->kda_encryptedkeysize);
490		free(kdap->kda_encryptedkey);
491		explicit_bzero(kdap, sizeof(*kdap));
492		if (error != 0)
493			errc(EX_OSERR, error, "ioctl(DIOCSKERNELDUMP)");
494	}
495	if (verbose)
496		printf("kernel dumps on %s\n", dumpdev);
497
498	exit(EX_OK);
499}
500