1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
4 * Copyright 2010 Intel Corporation; author: H. Peter Anvin
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, Inc., 53 Temple Place Ste 330,
9 * Boston MA 02111-1307, USA; either version 2 of the License, or
10 * (at your option) any later version; incorporated herein by reference.
11 *
12 * ----------------------------------------------------------------------- */
13
14 /*
15 * syslinux.c - Linux installer program for SYSLINUX
16 *
17 * This program now requires mtools. It turned out to be a lot
18 * easier to deal with than dealing with needing mount privileges.
19 * We need device write permission anyway.
20 */
21
22 #define _GNU_SOURCE
23 #include <alloca.h>
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <getopt.h>
27 #include <inttypes.h>
28 #include <mntent.h>
29 #include <paths.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <stdlib.h>
33 #include <sysexits.h>
34 #include <syslog.h>
35 #include <unistd.h>
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/wait.h>
39
40 #include "syslinux.h"
41 #include "libfat.h"
42 #include "setadv.h"
43 #include "syslxopt.h"
44 #include "syslxfs.h"
45
46 char *program; /* Name of program */
47 pid_t mypid;
48
die(const char * msg)49 void __attribute__ ((noreturn)) die(const char *msg)
50 {
51 fprintf(stderr, "%s: %s\n", program, msg);
52 exit(1);
53 }
54
die_err(const char * msg)55 void __attribute__ ((noreturn)) die_err(const char *msg)
56 {
57 fprintf(stderr, "%s: %s: %s\n", program, msg, strerror(errno));
58 exit(1);
59 }
60
61 /*
62 * read/write wrapper functions
63 */
xpread(int fd,void * buf,size_t count,off_t offset)64 ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
65 {
66 char *bufp = (char *)buf;
67 ssize_t rv;
68 ssize_t done = 0;
69
70 while (count) {
71 rv = pread(fd, bufp, count, offset);
72 if (rv == 0) {
73 die("short read");
74 } else if (rv == -1) {
75 if (errno == EINTR) {
76 continue;
77 } else {
78 die(strerror(errno));
79 }
80 } else {
81 bufp += rv;
82 offset += rv;
83 done += rv;
84 count -= rv;
85 }
86 }
87
88 return done;
89 }
90
xpwrite(int fd,const void * buf,size_t count,off_t offset)91 ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
92 {
93 const char *bufp = (const char *)buf;
94 ssize_t rv;
95 ssize_t done = 0;
96
97 while (count) {
98 rv = pwrite(fd, bufp, count, offset);
99 if (rv == 0) {
100 die("short write");
101 } else if (rv == -1) {
102 if (errno == EINTR) {
103 continue;
104 } else {
105 die(strerror(errno));
106 }
107 } else {
108 bufp += rv;
109 offset += rv;
110 done += rv;
111 count -= rv;
112 }
113 }
114
115 return done;
116 }
117
118 /*
119 * Version of the read function suitable for libfat
120 */
libfat_xpread(intptr_t pp,void * buf,size_t secsize,libfat_sector_t sector)121 int libfat_xpread(intptr_t pp, void *buf, size_t secsize,
122 libfat_sector_t sector)
123 {
124 off_t offset = (off_t) sector * secsize + opt.offset;
125 return xpread(pp, buf, secsize, offset);
126 }
127
move_file(char * filename)128 static int move_file(char *filename)
129 {
130 char target_file[4096], command[5120];
131 char *cp = target_file, *ep = target_file + sizeof target_file - 16;
132 const char *sd;
133 int slash = 1;
134 int status;
135
136 cp += sprintf(cp, "'s:/");
137 for (sd = opt.directory; *sd; sd++) {
138 if (*sd == '/' || *sd == '\\') {
139 if (slash)
140 continue; /* Remove duplicated slashes */
141 slash = 1;
142 } else if (*sd == '\'' || *sd == '!') {
143 slash = 0;
144 if (cp < ep)
145 *cp++ = '\'';
146 if (cp < ep)
147 *cp++ = '\\';
148 if (cp < ep)
149 *cp++ = *sd;
150 if (cp < ep)
151 *cp++ = '\'';
152 continue;
153 } else {
154 slash = 0;
155 }
156
157 if (cp < ep)
158 *cp++ = *sd;
159 }
160 if (!slash)
161 *cp++ = '/';
162 sprintf(cp, "%s'", filename);
163
164 /* This command may fail legitimately */
165 sprintf(command, "mattrib -h -r -s %s 2>/dev/null", target_file);
166 status = system(command);
167 (void)status; /* Keep _FORTIFY_SOURCE happy */
168
169 sprintf(command, "mmove -D o -D O s:/%s %s", filename, target_file);
170 status = system(command);
171
172 if (!WIFEXITED(status) || WEXITSTATUS(status)) {
173 fprintf(stderr,
174 "%s: warning: unable to move %s\n", program, filename);
175
176 sprintf(command, "mattrib +r +h +s s:/%s", filename);
177 status = system(command);
178 } else {
179 sprintf(command, "mattrib +r +h +s %s", target_file);
180 status = system(command);
181 }
182
183 return status;
184 }
185
main(int argc,char * argv[])186 int main(int argc, char *argv[])
187 {
188 static unsigned char sectbuf[SECTOR_SIZE];
189 int dev_fd;
190 struct stat st;
191 int status;
192 const char *tmpdir;
193 char *mtools_conf;
194 int mtc_fd;
195 FILE *mtc, *mtp;
196 struct libfat_filesystem *fs;
197 libfat_sector_t s, *secp;
198 libfat_sector_t *sectors;
199 int32_t ldlinux_cluster;
200 int nsectors;
201 const char *errmsg;
202 int ldlinux_sectors, patch_sectors;
203 int i;
204
205 (void)argc; /* Unused */
206
207 mypid = getpid();
208 program = argv[0];
209
210 parse_options(argc, argv, MODE_SYSLINUX);
211
212 if (!opt.device)
213 usage(EX_USAGE, MODE_SYSLINUX);
214
215 if (opt.sectors || opt.heads || opt.reset_adv || opt.set_once
216 || (opt.update_only > 0) || opt.menu_save) {
217 fprintf(stderr,
218 "At least one specified option not yet implemented"
219 " for this installer.\n");
220 exit(1);
221 }
222
223 /*
224 * Temp directory of choice...
225 */
226 tmpdir = getenv("TMPDIR");
227 if (!tmpdir) {
228 #ifdef P_tmpdir
229 tmpdir = P_tmpdir;
230 #elif defined(_PATH_TMP)
231 tmpdir = _PATH_TMP;
232 #else
233 tmpdir = "/tmp";
234 #endif
235 }
236
237 /*
238 * First make sure we can open the device at all, and that we have
239 * read/write permission.
240 */
241 dev_fd = open(opt.device, O_RDWR);
242 if (dev_fd < 0 || fstat(dev_fd, &st) < 0) {
243 die_err(opt.device);
244 exit(1);
245 }
246
247 if (!opt.force && !S_ISBLK(st.st_mode) && !S_ISREG(st.st_mode)) {
248 fprintf(stderr,
249 "%s: not a block device or regular file (use -f to override)\n",
250 opt.device);
251 exit(1);
252 }
253
254 xpread(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
255
256 /*
257 * Check to see that what we got was indeed an MS-DOS boot sector/superblock
258 */
259 if ((errmsg = syslinux_check_bootsect(sectbuf, NULL))) {
260 die(errmsg);
261 }
262
263 /*
264 * Create an mtools configuration file
265 */
266 if (asprintf(&mtools_conf, "%s//syslinux-mtools-XXXXXX", tmpdir) < 0 ||
267 !mtools_conf)
268 die_err(tmpdir);
269
270 mtc_fd = mkstemp(mtools_conf);
271 if (mtc_fd < 0 || !(mtc = fdopen(mtc_fd, "w")))
272 die_err(mtools_conf);
273
274 fprintf(mtc,
275 /* These are needed for some flash memories */
276 "MTOOLS_SKIP_CHECK=1\n"
277 "MTOOLS_FAT_COMPATIBILITY=1\n"
278 "drive s:\n"
279 " file=\"/proc/%lu/fd/%d\"\n"
280 " offset=%llu\n",
281 (unsigned long)mypid,
282 dev_fd, (unsigned long long)opt.offset);
283
284 if (ferror(mtc) || fclose(mtc))
285 die_err(mtools_conf);
286
287 /*
288 * Run mtools to create the LDLINUX.SYS file
289 */
290 if (setenv("MTOOLSRC", mtools_conf, 1)) {
291 perror(program);
292 exit(1);
293 }
294
295 /*
296 * Create a vacuous ADV in memory. This should be smarter.
297 */
298 syslinux_reset_adv(syslinux_adv);
299
300 /* This command may fail legitimately */
301 status = system("mattrib -h -r -s s:/ldlinux.sys 2>/dev/null");
302 (void)status; /* Keep _FORTIFY_SOURCE happy */
303
304 mtp = popen("mcopy -D o -D O -o - s:/ldlinux.sys", "w");
305 if (!mtp ||
306 fwrite((const void _force *)syslinux_ldlinux,
307 1, syslinux_ldlinux_len, mtp)
308 != syslinux_ldlinux_len ||
309 fwrite((const void _force *)syslinux_adv,
310 1, 2 * ADV_SIZE, mtp)
311 != 2 * ADV_SIZE ||
312 (status = pclose(mtp), !WIFEXITED(status) || WEXITSTATUS(status))) {
313 die("failed to create ldlinux.sys");
314 }
315
316 /*
317 * Now, use libfat to create a block map
318 */
319 ldlinux_sectors = (syslinux_ldlinux_len + 2 * ADV_SIZE
320 + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
321 sectors = calloc(ldlinux_sectors, sizeof *sectors);
322 fs = libfat_open(libfat_xpread, dev_fd);
323 ldlinux_cluster = libfat_searchdir(fs, 0, "LDLINUX SYS", NULL);
324 secp = sectors;
325 nsectors = 0;
326 s = libfat_clustertosector(fs, ldlinux_cluster);
327 while (s && nsectors < ldlinux_sectors) {
328 *secp++ = s;
329 nsectors++;
330 s = libfat_nextsector(fs, s);
331 }
332 libfat_close(fs);
333
334 /* Patch ldlinux.sys and the boot sector */
335 i = syslinux_patch(sectors, nsectors, opt.stupid_mode, opt.raid_mode,
336 opt.directory, NULL);
337 patch_sectors = (i + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
338
339 /* Write the now-patched first sectors of ldlinux.sys */
340 for (i = 0; i < patch_sectors; i++) {
341 xpwrite(dev_fd, (const char _force *)syslinux_ldlinux
342 + i * SECTOR_SIZE, SECTOR_SIZE,
343 opt.offset + ((off_t) sectors[i] << SECTOR_SHIFT));
344 }
345
346 /* Move ldlinux.sys to the desired location */
347 if (opt.directory) {
348 status = move_file("ldlinux.sys");
349 } else {
350 status = system("mattrib +r +h +s s:/ldlinux.sys");
351 }
352
353 if (!WIFEXITED(status) || WEXITSTATUS(status)) {
354 fprintf(stderr,
355 "%s: warning: failed to set system bit on ldlinux.sys\n",
356 program);
357 }
358
359 /* This command may fail legitimately */
360 status = system("mattrib -h -r -s s:/ldlinux.c32 2>/dev/null");
361 (void)status; /* Keep _FORTIFY_SOURCE happy */
362
363 mtp = popen("mcopy -D o -D O -o - s:/ldlinux.c32", "w");
364 if (!mtp || fwrite((const char _force *)syslinux_ldlinuxc32,
365 1, syslinux_ldlinuxc32_len, mtp)
366 != syslinux_ldlinuxc32_len ||
367 (status = pclose(mtp), !WIFEXITED(status) || WEXITSTATUS(status))) {
368 die("failed to create ldlinux.c32");
369 }
370
371 /* Move ldlinux.c32 to the desired location */
372 if (opt.directory) {
373 status = move_file("ldlinux.c32");
374 } else {
375 status = system("mattrib +r +h +s s:/ldlinux.c32");
376 }
377
378 if (!WIFEXITED(status) || WEXITSTATUS(status)) {
379 fprintf(stderr,
380 "%s: warning: failed to set system bit on ldlinux.c32\n",
381 program);
382 }
383
384 /*
385 * Cleanup
386 */
387 unlink(mtools_conf);
388
389 /*
390 * To finish up, write the boot sector
391 */
392
393 /* Read the superblock again since it might have changed while mounted */
394 xpread(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
395
396 /* Copy the syslinux code into the boot sector */
397 syslinux_make_bootsect(sectbuf, VFAT);
398
399 /* Write new boot sector */
400 xpwrite(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
401
402 close(dev_fd);
403 sync();
404
405 /* Done! */
406
407 return 0;
408 }
409