xref: /freebsd/usr.bin/etdump/etdump.c (revision 0629b152762b06325dd75a41bcb0a2789514141b)
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 	fseek(iso, sector * ISO_DEFAULT_BLOCK_SIZE, SEEK_SET);
84 	if (fread(buffer, ISO_DEFAULT_BLOCK_SIZE, 1, iso) != 1) {
85 		return (errno);
86 	}
87 	return (0);
88 }
89 
90 static bool
91 boot_catalog_valid(char *entry)
92 {
93 	boot_catalog_validation_entry *ve;
94 	int16_t		checksum, sum;
95 	unsigned char	*csptr;
96 	size_t		i;
97 
98 	ve = (boot_catalog_validation_entry *)entry;
99 
100 	checksum = isonum_721(ve->checksum);
101 	cd9660_721(0, ve->checksum);
102 	csptr = (unsigned char *)ve;
103 
104 	for (i = sum = 0; i < sizeof(*ve); i += 2) {
105 		sum += (int16_t)csptr[i];
106 		sum += 256 * (int16_t)csptr[i + 1];
107 	}
108 	if (sum + checksum != 0) {
109 		return (false);
110 	}
111 
112 	cd9660_721(checksum, ve->checksum);
113 	return (true);
114 }
115 
116 static int
117 dump_section(char *buffer, size_t offset, FILE *outfile, const char *filename,
118     struct outputter *outputter)
119 {
120 	boot_catalog_section_header *sh;
121 	u_char platform_id;
122 	int i;
123 	size_t entry_offset;
124 	boot_catalog_section_entry *entry;
125 
126 	sh = (boot_catalog_section_header *)&buffer[offset];
127 	if (outputter->output_section != NULL) {
128 		outputter->output_section(outfile, filename, sh);
129 	}
130 
131 	platform_id = sh->platform_id[0];
132 
133 	if (outputter->output_entry != NULL) {
134 		for (i = 1; i <= (int)sh->num_section_entries[0]; i++) {
135 			entry_offset = offset + i * ET_BOOT_ENTRY_SIZE;
136 			entry =
137 			    (boot_catalog_section_entry *)&buffer[entry_offset];
138 			outputter->output_entry(outfile, filename, entry,
139 			    platform_id, false);
140 		}
141 	}
142 
143 	return (1 + (int)sh->num_section_entries[0]);
144 }
145 
146 static void
147 dump_eltorito(FILE *iso, const char *filename, FILE *outfile,
148     struct outputter *outputter)
149 {
150 	char buffer[ISO_DEFAULT_BLOCK_SIZE], *entry;
151 	boot_volume_descriptor *bvd;
152 	daddr_t boot_catalog;
153 	size_t offset;
154 	int entry_count;
155 
156 	if (read_sector(iso, 17, buffer) != 0)
157 		err(1, "failed to read from image");
158 
159 	bvd = (boot_volume_descriptor *)buffer;
160 	if (memcmp(bvd->identifier, ISO_VOLUME_DESCRIPTOR_STANDARD_ID, 5) != 0)
161 		warnx("%s: not a valid ISO", filename);
162 	if (bvd->boot_record_indicator[0] != ISO_VOLUME_DESCRIPTOR_BOOT)
163 		warnx("%s: not an El Torito bootable ISO", filename);
164 	if (memcmp(bvd->boot_system_identifier, ET_ID, 23) != 0)
165 		warnx("%s: not an El Torito bootable ISO", filename);
166 
167 	boot_catalog = isonum_731(bvd->boot_catalog_pointer);
168 
169 	if (read_sector(iso, boot_catalog, buffer) != 0)
170 		err(1, "failed to read from image");
171 
172 	entry = buffer;
173 	offset = 0;
174 
175 	if (!boot_catalog_valid(entry))
176 		warnx("%s: boot catalog checksum is invalid", filename);
177 
178 	if (outputter->output_image != NULL)
179 		outputter->output_image(outfile, filename, bvd);
180 
181 	offset += ET_BOOT_ENTRY_SIZE;
182 	entry = &buffer[offset];
183 	if (outputter->output_entry != NULL)
184 		outputter->output_entry(outfile, filename,
185 		    (boot_catalog_section_entry *)entry, 0, true);
186 
187 	offset += ET_BOOT_ENTRY_SIZE;
188 
189 	while (offset < ISO_DEFAULT_BLOCK_SIZE) {
190 		entry = &buffer[offset];
191 
192 		if ((uint8_t)entry[0] != ET_SECTION_HEADER_MORE &&
193 		    (uint8_t)entry[0] != ET_SECTION_HEADER_LAST)
194 			break;
195 
196 		entry_count = dump_section(buffer, offset, outfile, filename,
197 		    outputter);
198 
199 		offset += entry_count * ET_BOOT_ENTRY_SIZE;
200 	}
201 }
202 
203 static void
204 usage(const char *progname)
205 {
206 	char *path;
207 
208 	path = strdup(progname);
209 
210 	fprintf(stderr, "usage: %s [-f format] [-o filename] filename [...]\n",
211 	    basename(path));
212 	fprintf(stderr, "\tsupported output formats: shell, text\n");
213 	exit(1);
214 }
215 
216 int
217 main(int argc, char **argv)
218 {
219 	int ch, i;
220 	FILE *outfile, *iso;
221 	struct outputter *outputter;
222 
223 	outfile = stdout;
224 	outputter = output_text;
225 
226 	static struct option longopts[] = {
227 		{ "format",	required_argument,	NULL,	'f' },
228 		{ "output",	required_argument,	NULL,	'o' },
229 		{ NULL,		0,			NULL,	0 },
230 	};
231 
232 	while ((ch = getopt_long(argc, argv, "f:o:", longopts, NULL)) != -1) {
233 		switch (ch) {
234 		case 'f':
235 			if (strcmp(optarg, "shell") == 0)
236 				outputter = output_shell;
237 			else if (strcmp(optarg, "text") == 0)
238 				outputter = output_text;
239 			else
240 				usage(argv[0]);
241 			break;
242 		case 'o':
243 			if (strcmp(optarg, "-") == 0) {
244 				outfile = stdout;
245 			} else if ((outfile = fopen(optarg, "w")) == NULL) {
246 				err(1, "unable to open %s for output", optarg);
247 			}
248 			break;
249 		default:
250 			usage(argv[0]);
251 		}
252 	}
253 
254 	argc -= optind;
255 	argv += optind;
256 
257 	for (i = 0; i < argc; i++) {
258 		printf("%d %s\n", optind, argv[i]);
259 		if (strcmp(argv[i], "-") == 0) {
260 			iso = stdin;
261 		} else {
262 			iso = fopen(argv[i], "r");
263 			if (iso == NULL)
264 				err(1, "could not open %s", argv[1]);
265 		}
266 		dump_eltorito(iso, argv[i], outfile, outputter);
267 	}
268 }
269