/[gentoo-projects]/pax-utils/scanelf.c
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Revision 1.33 - (show annotations) (download) (as text)
Sun Apr 10 15:15:40 2005 UTC (9 years, 5 months ago) by solar
Branch: MAIN
Changes since 1.32: +15 -9 lines
File MIME type: text/x-csrc
- free orig pointer locations and not ptr that has been incremented. Use puts/fputs in place of printf() when no format identifier is used. Don't scan symlinks in scanelf_file()

1 /*
2 * Copyright 2003 Ned Ludd <solar@gentoo.org>
3 * Copyright 1999-2005 Gentoo Foundation
4 * Distributed under the terms of the GNU General Public License v2
5 * $Header: /var/cvsroot/gentoo-projects/pax-utils/scanelf.c,v 1.32 2005/04/07 00:01:40 vapier Exp $
6 *
7 ********************************************************************
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
21 * MA 02111-1307, USA.
22 */
23
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <sys/types.h>
27 #define __USE_GNU
28 #include <string.h>
29 #include <errno.h>
30 #include <unistd.h>
31 #include <sys/stat.h>
32 #include <dirent.h>
33 #include <getopt.h>
34 #include <assert.h>
35
36 #include "paxelf.h"
37
38 static const char *rcsid = "$Id: scanelf.c,v 1.32 2005/04/07 00:01:40 vapier Exp $";
39
40
41 /* helper functions for showing errors */
42 #define argv0 "scanelf" /*((*argv != NULL) ? argv[0] : __FILE__ "\b\b")*/
43 #define warn(fmt, args...) \
44 fprintf(stderr, "%s: " fmt "\n", argv0, ## args)
45 #define warnf(fmt, args...) warn("%s(): " fmt, __FUNCTION__, ## args)
46 #define err(fmt, args...) \
47 do { \
48 warn(fmt, ## args); \
49 exit(EXIT_FAILURE); \
50 } while (0)
51
52
53
54 /* prototypes */
55 static void scanelf_file(const char *filename);
56 static void scanelf_dir(const char *path);
57 static void scanelf_ldpath();
58 static void scanelf_envpath();
59 static void usage(int status);
60 static void parseargs(int argc, char *argv[]);
61
62 /* variables to control behavior */
63 static char scan_ldpath = 0;
64 static char scan_envpath = 0;
65 static char dir_recurse = 0;
66 static char dir_crossmount = 1;
67 static char show_pax = 0;
68 static char show_stack = 0;
69 static char show_textrel = 0;
70 static char show_rpath = 0;
71 static char show_needed = 0;
72 static char show_banner = 1;
73 static char be_quiet = 0;
74 static char be_verbose = 0;
75 static char *find_sym = NULL;
76
77
78
79 /* scan an elf file and show all the fun stuff */
80 static void scanelf_file(const char *filename)
81 {
82 int i;
83 char found_pax, found_stack, found_relro, found_textrel,
84 found_rpath, found_needed, found_sym;
85 elfobj *elf;
86 struct stat st;
87
88 /* make sure path exists */
89 if (lstat(filename, &st) == -1)
90 return;
91 if (!S_ISREG(st.st_mode))
92 return;
93 found_pax = found_stack = found_relro = found_textrel = \
94 found_rpath = found_needed = found_sym = 0;
95
96 /* verify this is real ELF */
97 if ((elf = readelf(filename)) == NULL) {
98 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
99 return;
100 }
101
102 if (be_verbose > 1)
103 printf("%s: {%s,%s} scanning file\n", filename,
104 get_elfeitype(elf, EI_CLASS, elf->elf_class),
105 get_elfeitype(elf, EI_DATA, elf->data[EI_DATA]));
106 else if (be_verbose)
107 printf("%s: scanning file\n", filename);
108
109 /* show the header */
110 if (!be_quiet && show_banner) {
111 printf(" TYPE ");
112 if (show_pax) printf(" PAX ");
113 if (show_stack) printf("STK/REL ");
114 if (show_textrel) printf("TEXTREL ");
115 if (show_rpath) printf("RPATH ");
116 if (show_needed) printf("NEEDED ");
117 printf(" FILE\n");
118 show_banner = 0;
119 }
120
121 /* dump all the good stuff */
122 if (!be_quiet)
123 printf("%-7s ", get_elfetype(elf));
124
125 if (show_pax) {
126 char *paxflags = pax_short_hf_flags(PAX_FLAGS(elf));
127 if (!be_quiet || (be_quiet && strncmp(paxflags, "PeMRxS", 6))) {
128 found_pax = 1;
129 printf("%s ", pax_short_hf_flags(PAX_FLAGS(elf)));
130 }
131 }
132
133 /* stack fun */
134 if (show_stack) {
135 #define SHOW_STACK(B) \
136 if (elf->elf_class == ELFCLASS ## B) { \
137 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
138 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
139 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
140 if (EGET(phdr[i].p_type) != PT_GNU_STACK && \
141 EGET(phdr[i].p_type) != PT_GNU_RELRO) continue; \
142 if (be_quiet && !(EGET(phdr[i].p_flags) & PF_X)) \
143 continue; \
144 if (EGET(phdr[i].p_type) == PT_GNU_STACK) \
145 found_stack = 1; \
146 if (EGET(phdr[i].p_type) == PT_GNU_RELRO) \
147 found_relro = 1; \
148 printf("%s ", gnu_short_stack_flags(EGET(phdr[i].p_flags))); \
149 } \
150 }
151 SHOW_STACK(32)
152 SHOW_STACK(64)
153 if (!be_quiet && !found_stack) printf("--- ");
154 if (!be_quiet && !found_relro) printf("--- ");
155 }
156
157 /* textrel fun */
158 if (show_textrel) {
159 #define SHOW_TEXTREL(B) \
160 if (elf->elf_class == ELFCLASS ## B) { \
161 Elf ## B ## _Dyn *dyn; \
162 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
163 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
164 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
165 if (phdr[i].p_type != PT_DYNAMIC) continue; \
166 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
167 while (EGET(dyn->d_tag) != DT_NULL) { \
168 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
169 found_textrel = 1; \
170 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
171 fputs("TEXTREL ", stdout); \
172 } \
173 ++dyn; \
174 } \
175 } }
176 SHOW_TEXTREL(32)
177 SHOW_TEXTREL(64)
178 if (!be_quiet && !found_textrel) fputs("------- ", stdout);
179 }
180
181 /* rpath fun */
182 /* TODO: if be_quiet, only output RPATH's which aren't in /etc/ld.so.conf */
183 if (show_rpath) {
184 char *rpath, *runpath;
185 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
186 rpath = runpath = NULL;
187
188 if (strtbl_void) {
189 #define SHOW_RPATH(B) \
190 if (elf->elf_class == ELFCLASS ## B) { \
191 Elf ## B ## _Dyn *dyn; \
192 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
193 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
194 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
195 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
196 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
197 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
198 while (EGET(dyn->d_tag) != DT_NULL) { \
199 if (EGET(dyn->d_tag) == DT_RPATH) { \
200 rpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
201 found_rpath = 1; \
202 } else if (EGET(dyn->d_tag) == DT_RUNPATH) { \
203 runpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
204 found_rpath = 1; \
205 } \
206 ++dyn; \
207 } \
208 } }
209 SHOW_RPATH(32)
210 SHOW_RPATH(64)
211 }
212 if (rpath && runpath) {
213 if (!strcmp(rpath, runpath))
214 printf("%-5s ", runpath);
215 else {
216 fprintf(stderr, "%s's RPATH [%s] != RUNPATH [%s]\n", filename, rpath, runpath);
217 printf("{%s,%s} ", rpath, runpath);
218 }
219 } else if (rpath || runpath)
220 printf("%-5s ", (runpath ? runpath : rpath));
221 else if (!be_quiet && !found_rpath)
222 printf(" - ");
223 }
224
225 /* print out all the NEEDED entries */
226 if (show_needed) {
227 char *needed;
228 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
229
230 if (strtbl_void) {
231 #define SHOW_NEEDED(B) \
232 if (elf->elf_class == ELFCLASS ## B) { \
233 Elf ## B ## _Dyn *dyn; \
234 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
235 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
236 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
237 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
238 if (be_verbose && EGET(phdr[i].p_type) == PT_INTERP) { \
239 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
240 printf("%s\n", elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr)); \
241 exit(0); \
242 } \
243 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
244 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
245 while (EGET(dyn->d_tag) != DT_NULL) { \
246 if (EGET(dyn->d_tag) == DT_NEEDED) { \
247 needed = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
248 if (found_needed) printf(","); \
249 printf("%s", needed); \
250 found_needed = 1; \
251 } \
252 ++dyn; \
253 } \
254 } }
255 SHOW_NEEDED(32)
256 SHOW_NEEDED(64)
257 }
258 if (!be_quiet && !found_needed)
259 printf(" - ");
260 else if (found_needed)
261 printf(" ");
262 }
263
264 /* search the symbol table for a specified symbol */
265 if (find_sym) {
266 void *symtab_void, *strtab_void;
267 char *versioned_symname;
268 size_t len;
269
270 len = strlen(find_sym) + 1;
271 versioned_symname = (char *)malloc(sizeof(char) * (len+1));
272 if (!versioned_symname) {
273 warnf("Could not malloc() mem for sym scan");
274 return;
275 }
276 sprintf(versioned_symname, "%s@", find_sym);
277
278 symtab_void = elf_findsecbyname(elf, ".symtab");
279 strtab_void = elf_findsecbyname(elf, ".strtab");
280
281 if (symtab_void && strtab_void) {
282 #define FIND_SYM(B) \
283 if (elf->elf_class == ELFCLASS ## B) { \
284 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
285 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
286 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
287 int cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
288 char *symname; \
289 for (i = 0; i < cnt; ++i) { \
290 if (sym->st_name) { \
291 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
292 if (*find_sym == '*') { \
293 printf("%s(%s) %5lX %15s %s\n", \
294 ((found_sym == 0) ? "\n\t" : "\t"), \
295 (char *)basename(filename), \
296 (long)sym->st_size, \
297 (char *)get_elfstttype(sym->st_info), \
298 symname); \
299 found_sym = 1; \
300 } else if ((strcmp(find_sym, symname) == 0) || \
301 (strncmp(symname, versioned_symname, len) == 0)) \
302 found_sym++; \
303 } \
304 ++sym; \
305 } }
306 FIND_SYM(32)
307 FIND_SYM(64)
308 }
309 free(versioned_symname);
310 if (*find_sym != '*') {
311 if (found_sym)
312 printf(" %s ", find_sym);
313 else if (!be_quiet)
314 fputs(" - ", stdout);
315 }
316 }
317
318 if (!be_quiet || found_pax || found_stack || found_textrel || \
319 found_rpath || found_needed || found_sym)
320 puts(filename);
321
322 unreadelf(elf);
323 }
324
325 /* scan a directory for ET_EXEC files and print when we find one */
326 static void scanelf_dir(const char *path)
327 {
328 register DIR *dir;
329 register struct dirent *dentry;
330 struct stat st_top, st;
331 char buf[_POSIX_PATH_MAX];
332 size_t pathlen = 0, len = 0;
333
334 /* make sure path exists */
335 if (lstat(path, &st_top) == -1)
336 return;
337
338 /* ok, if it isn't a directory, assume we can open it */
339 if (!S_ISDIR(st_top.st_mode)) {
340 scanelf_file(path);
341 return;
342 }
343
344 /* now scan the dir looking for fun stuff */
345 if ((dir = opendir(path)) == NULL) {
346 warnf("could not opendir %s: %s", path, strerror(errno));
347 return;
348 }
349 if (be_verbose) printf("%s: scanning dir\n", path);
350
351 pathlen = strlen(path);
352 while ((dentry = readdir(dir))) {
353 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
354 continue;
355 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
356 if (len >= sizeof(buf)) {
357 warnf("Skipping '%s': len > sizeof(buf); %d > %d\n", path, (int)len, (int)sizeof(buf));
358 continue;
359 }
360 sprintf(buf, "%s/%s", path, dentry->d_name);
361 if (lstat(buf, &st) != -1) {
362 if (S_ISREG(st.st_mode))
363 scanelf_file(buf);
364 else if (dir_recurse && S_ISDIR(st.st_mode)) {
365 if (dir_crossmount || (st_top.st_dev == st.st_dev))
366 scanelf_dir(buf);
367 }
368 }
369 }
370 closedir(dir);
371 }
372
373 /* scan /etc/ld.so.conf for paths */
374 static void scanelf_ldpath()
375 {
376 char scan_l, scan_ul, scan_ull;
377 char *path, *p;
378 FILE *fp;
379
380 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
381 err("Unable to open ld.so.conf: %s", strerror(errno));
382
383 scan_l = scan_ul = scan_ull = 0;
384
385 if ((path = malloc(_POSIX_PATH_MAX)) == NULL) {
386 warn("Can not malloc() memory for ldpath scanning");
387 return;
388 }
389 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL)
390 if (*path == '/') {
391 if ((p = strrchr(path, '\r')) != NULL)
392 *p = 0;
393 if ((p = strrchr(path, '\n')) != NULL)
394 *p = 0;
395 if (!scan_l && !strcmp(path, "/lib")) scan_l = 1;
396 if (!scan_ul && !strcmp(path, "/usr/lib")) scan_ul = 1;
397 if (!scan_ull && !strcmp(path, "/usr/local/lib")) scan_ull = 1;
398 scanelf_dir(path);
399 }
400 free(path);
401 fclose(fp);
402
403 if (!scan_l) scanelf_dir("/lib");
404 if (!scan_ul) scanelf_dir("/usr/lib");
405 if (!scan_ull) scanelf_dir("/usr/local/lib");
406 }
407
408 /* scan env PATH for paths */
409 static void scanelf_envpath()
410 {
411 char *orig_path, *path, *p;
412
413 path = getenv("PATH");
414 if (!path)
415 err("PATH is not set in your env !");
416
417 if ((orig_path = path = strdup(path)) == NULL)
418 err("strdup failed: %s", strerror(errno));
419
420 while ((p = strrchr(path, ':')) != NULL) {
421 scanelf_dir(p + 1);
422 *p = 0;
423 }
424
425 free(orig_path);
426 }
427
428
429
430 /* usage / invocation handling functions */
431 #define PARSE_FLAGS "plRmxetrns:aqvo:BhV"
432 #define a_argument required_argument
433 static struct option const long_opts[] = {
434 {"path", no_argument, NULL, 'p'},
435 {"ldpath", no_argument, NULL, 'l'},
436 {"recursive", no_argument, NULL, 'R'},
437 {"mount", no_argument, NULL, 'm'},
438 {"pax", no_argument, NULL, 'x'},
439 {"header", no_argument, NULL, 'e'},
440 {"textrel", no_argument, NULL, 't'},
441 {"rpath", no_argument, NULL, 'r'},
442 {"needed", no_argument, NULL, 'n'},
443 {"symbol", a_argument, NULL, 's'},
444 {"all", no_argument, NULL, 'a'},
445 {"quiet", no_argument, NULL, 'q'},
446 {"verbose", no_argument, NULL, 'v'},
447 {"file", a_argument, NULL, 'o'},
448 {"nobanner", no_argument, NULL, 'B'},
449 {"help", no_argument, NULL, 'h'},
450 {"version", no_argument, NULL, 'V'},
451 {NULL, no_argument, NULL, 0x0}
452 };
453 static char *opts_help[] = {
454 "Scan all directories in PATH environment",
455 "Scan all directories in /etc/ld.so.conf",
456 "Scan directories recursively",
457 "Don't recursively cross mount points\n",
458 "Print PaX markings",
459 "Print GNU_STACK markings",
460 "Print TEXTREL information",
461 "Print RPATH information",
462 "Print NEEDED information",
463 "Find a specified symbol",
464 "Print all scanned info (-x -e -t -r)\n",
465 "Only output 'bad' things",
466 "Be verbose (can be specified more than once)",
467 "Write output stream to a filename",
468 "Don't display the header",
469 "Print this help and exit",
470 "Print version and exit",
471 NULL
472 };
473
474 /* display usage and exit */
475 static void usage(int status)
476 {
477 int i;
478 printf(" Scan ELF binaries for stuff\n"
479 "Usage: %s [options] <dir1> [dir2 dirN ...]\n\n", argv0);
480 printf("Options:\n");
481 for (i = 0; long_opts[i].name; ++i)
482 if (long_opts[i].has_arg == no_argument)
483 printf(" -%c, --%-13s %s\n", long_opts[i].val,
484 long_opts[i].name, opts_help[i]);
485 else
486 printf(" -%c, --%-6s <arg> %s\n", long_opts[i].val,
487 long_opts[i].name, opts_help[i]);
488 exit(status);
489 }
490
491 /* parse command line arguments and preform needed actions */
492 static void parseargs(int argc, char *argv[])
493 {
494 int flag;
495
496 opterr = 0;
497 while ((flag=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
498 switch (flag) {
499
500 case 'V': /* version info */
501 printf("%s compiled %s\n%s\n"
502 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
503 __FILE__, __DATE__, rcsid, argv0);
504 exit(EXIT_SUCCESS);
505 break;
506 case 'h': usage(EXIT_SUCCESS); break;
507
508 case 'o': {
509 FILE *fp = NULL;
510 fp = freopen(optarg, "w", stdout);
511 if (fp == NULL)
512 err("Could not open output stream '%s': %s", optarg, strerror(errno));
513 stdout = fp;
514 break;
515 }
516
517 case 's': find_sym = strdup(optarg); break;
518
519 case 'B': show_banner = 0; break;
520 case 'l': scan_ldpath = 1; break;
521 case 'p': scan_envpath = 1; break;
522 case 'R': dir_recurse = 1; break;
523 case 'm': dir_crossmount = 0; break;
524 case 'x': show_pax = 1; break;
525 case 'e': show_stack = 1; break;
526 case 't': show_textrel = 1; break;
527 case 'r': show_rpath = 1; break;
528 case 'n': show_needed = 1; break;
529 case 'q': be_quiet = 1; break;
530 case 'v': be_verbose = (be_verbose % 20) + 1; break;
531 case 'a': show_pax = show_stack = show_textrel = show_needed = show_rpath = 1; break;
532
533 case ':':
534 warn("Option missing parameter");
535 usage(EXIT_FAILURE);
536 break;
537 case '?':
538 warn("Unknown option");
539 usage(EXIT_FAILURE);
540 break;
541 default:
542 err("Unhandled option '%c'", flag);
543 break;
544 }
545 }
546
547 if (be_quiet && be_verbose)
548 err("You can be quiet or you can be verbose, not both, stupid");
549
550 if (scan_ldpath) scanelf_ldpath();
551 if (scan_envpath) scanelf_envpath();
552 if (optind == argc && !scan_ldpath && !scan_envpath)
553 err("Nothing to scan !?");
554 while (optind < argc)
555 scanelf_dir(argv[optind++]);
556
557 if (find_sym) free(find_sym);
558 }
559
560
561
562 int main(int argc, char *argv[])
563 {
564 if (argc < 2)
565 usage(EXIT_FAILURE);
566 parseargs(argc, argv);
567 fclose(stdout);
568 return EXIT_SUCCESS;
569 }

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