xref: /freebsd/usr.bin/etdump/etdump.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * Copyright (c) 2018 iXsystems, Inc.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <err.h>
31 #include <getopt.h>
32 #include <libgen.h>
33 #include <stdbool.h>
34 #include <stdio.h>
35 
36 #include "cd9660.h"
37 #include "cd9660_eltorito.h"
38 
39 #include "etdump.h"
40 
41 const char *
42 system_id_string(u_char system_id)
43 {
44 
45 	switch (system_id) {
46 	case ET_SYS_X86:
47 		return ("i386");
48 	case ET_SYS_PPC:
49 		return ("powerpc");
50 	case ET_SYS_MAC:
51 		return ("mac");
52 	case ET_SYS_EFI:
53 		return ("efi");
54 	default:
55 		return ("invalid");
56 	}
57 }
58 
59 const char *
60 media_type_string(u_char media_type)
61 {
62 
63 	switch (media_type) {
64 	case ET_MEDIA_NOEM:
65 		return ("no emulation");
66 	case ET_MEDIA_12FDD:
67 		return ("1.2MB FDD");
68 	case ET_MEDIA_144FDD:
69 		return ("1.44MB FDD");
70 	case ET_MEDIA_288FDD:
71 		return ("2.88MB FDD");
72 	case ET_MEDIA_HDD:
73 		return ("HDD");
74 	default:
75 		return ("invalid");
76 	}
77 }
78 
79 static int
80 read_sector(FILE *iso, daddr_t sector, char *buffer)
81 {
82 
83 	if (fseek(iso, sector * ISO_DEFAULT_BLOCK_SIZE, SEEK_SET) != 0) {
84 		return (errno);
85 	}
86 	if (fread(buffer, ISO_DEFAULT_BLOCK_SIZE, 1, iso) != 1) {
87 		return (errno);
88 	}
89 	return (0);
90 }
91 
92 static bool
93 boot_catalog_valid(char *entry)
94 {
95 	boot_catalog_validation_entry *ve;
96 	int16_t		checksum, sum;
97 	unsigned char	*csptr;
98 	size_t		i;
99 
100 	ve = (boot_catalog_validation_entry *)entry;
101 
102 	checksum = isonum_721(ve->checksum);
103 	cd9660_721(0, ve->checksum);
104 	csptr = (unsigned char *)ve;
105 
106 	for (i = sum = 0; i < sizeof(*ve); i += 2) {
107 		sum += (int16_t)csptr[i];
108 		sum += 256 * (int16_t)csptr[i + 1];
109 	}
110 	if (sum + checksum != 0) {
111 		return (false);
112 	}
113 
114 	cd9660_721(checksum, ve->checksum);
115 	return (true);
116 }
117 
118 static int
119 dump_section(char *buffer, size_t bufsize, size_t offset, FILE *outfile,
120     const char *filename, struct outputter *outputter)
121 {
122 	boot_catalog_section_header *sh;
123 	u_char platform_id;
124 	int i;
125 	size_t entry_offset;
126 	boot_catalog_section_entry *entry;
127 
128 	if (offset + sizeof(boot_catalog_section_header) > bufsize)
129 		errx(1, "%s: section header out of bounds", filename);
130 	sh = (boot_catalog_section_header *)&buffer[offset];
131 	if (outputter->output_section != NULL) {
132 		outputter->output_section(outfile, filename, sh);
133 	}
134 
135 	platform_id = sh->platform_id[0];
136 
137 	if (outputter->output_entry != NULL) {
138 		for (i = 1; i <= (int)sh->num_section_entries[0]; i++) {
139 			entry_offset = offset + i * ET_BOOT_ENTRY_SIZE;
140 			if (entry_offset + sizeof(boot_catalog_section_entry) >
141 			    bufsize)
142 				errx(1, "%s: section entry out of bounds",
143 				    filename);
144 			entry =
145 			    (boot_catalog_section_entry *)&buffer[entry_offset];
146 			outputter->output_entry(outfile, filename, entry,
147 			    platform_id, false);
148 		}
149 	}
150 
151 	return (1 + (int)sh->num_section_entries[0]);
152 }
153 
154 static void
155 dump_eltorito(FILE *iso, const char *filename, FILE *outfile,
156     struct outputter *outputter)
157 {
158 	char buffer[ISO_DEFAULT_BLOCK_SIZE], *entry;
159 	boot_volume_descriptor *bvd;
160 	daddr_t boot_catalog;
161 	size_t offset;
162 	int entry_count;
163 
164 	if (read_sector(iso, 17, buffer) != 0)
165 		err(1, "failed to read from image");
166 
167 	bvd = (boot_volume_descriptor *)buffer;
168 	if (memcmp(bvd->identifier, ISO_VOLUME_DESCRIPTOR_STANDARD_ID, 5) != 0)
169 		warnx("%s: not a valid ISO", filename);
170 	if (bvd->boot_record_indicator[0] != ISO_VOLUME_DESCRIPTOR_BOOT)
171 		warnx("%s: not an El Torito bootable ISO", filename);
172 	if (memcmp(bvd->boot_system_identifier, ET_ID, 23) != 0)
173 		warnx("%s: not an El Torito bootable ISO", filename);
174 
175 	boot_catalog = isonum_731(bvd->boot_catalog_pointer);
176 
177 	if (read_sector(iso, boot_catalog, buffer) != 0)
178 		err(1, "failed to read from image");
179 
180 	entry = buffer;
181 	offset = 0;
182 
183 	if (!boot_catalog_valid(entry))
184 		warnx("%s: boot catalog checksum is invalid", filename);
185 
186 	if (outputter->output_image != NULL)
187 		outputter->output_image(outfile, filename, bvd);
188 
189 	offset += ET_BOOT_ENTRY_SIZE;
190 	entry = &buffer[offset];
191 	if (outputter->output_entry != NULL)
192 		outputter->output_entry(outfile, filename,
193 		    (boot_catalog_section_entry *)entry, 0, true);
194 
195 	offset += ET_BOOT_ENTRY_SIZE;
196 
197 	while (offset < ISO_DEFAULT_BLOCK_SIZE) {
198 		entry = &buffer[offset];
199 
200 		if ((uint8_t)entry[0] != ET_SECTION_HEADER_MORE &&
201 		    (uint8_t)entry[0] != ET_SECTION_HEADER_LAST)
202 			break;
203 
204 		entry_count = dump_section(buffer, sizeof(buffer), offset,
205 		    outfile, filename, outputter);
206 
207 		offset += entry_count * ET_BOOT_ENTRY_SIZE;
208 	}
209 }
210 
211 static void
212 usage(const char *progname)
213 {
214 	char *path;
215 
216 	path = strdup(progname);
217 
218 	fprintf(stderr, "usage: %s [-f format] [-o filename] filename [...]\n",
219 	    basename(path));
220 	fprintf(stderr, "\tsupported output formats: shell, text\n");
221 	exit(1);
222 }
223 
224 int
225 main(int argc, char **argv)
226 {
227 	int ch, i;
228 	FILE *outfile, *iso;
229 	struct outputter *outputter;
230 
231 	outfile = stdout;
232 	outputter = output_text;
233 
234 	static struct option longopts[] = {
235 		{ "format",	required_argument,	NULL,	'f' },
236 		{ "output",	required_argument,	NULL,	'o' },
237 		{ NULL,		0,			NULL,	0 },
238 	};
239 
240 	while ((ch = getopt_long(argc, argv, "f:o:", longopts, NULL)) != -1) {
241 		switch (ch) {
242 		case 'f':
243 			if (strcmp(optarg, "shell") == 0)
244 				outputter = output_shell;
245 			else if (strcmp(optarg, "text") == 0)
246 				outputter = output_text;
247 			else
248 				usage(argv[0]);
249 			break;
250 		case 'o':
251 			if (strcmp(optarg, "-") == 0) {
252 				outfile = stdout;
253 			} else if ((outfile = fopen(optarg, "w")) == NULL) {
254 				err(1, "unable to open %s for output", optarg);
255 			}
256 			break;
257 		default:
258 			usage(argv[0]);
259 		}
260 	}
261 
262 	argc -= optind;
263 	argv += optind;
264 
265 	for (i = 0; i < argc; i++) {
266 		if (strcmp(argv[i], "-") == 0) {
267 			iso = stdin;
268 		} else {
269 			iso = fopen(argv[i], "r");
270 			if (iso == NULL)
271 				err(1, "could not open %s", argv[i]);
272 		}
273 		dump_eltorito(iso, argv[i], outfile, outputter);
274 	}
275 }
276