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Revision 1.32 - (show annotations) (download) (as text)
Thu Apr 7 00:01:40 2005 UTC (9 years, 7 months ago) by vapier
Branch: MAIN
Changes since 1.31: +85 -26 lines
File MIME type: text/x-csrc
merge some fixes from tigger and add support for dumping DT_NEEDED information

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 1.31 2005/04/06 02:01:52 solar 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 1.31 2005/04/06 02:01:52 solar 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
87 found_pax = found_stack = found_relro = found_textrel = \
88 found_rpath = found_needed = found_sym = 0;
89
90 /* verify this is real ELF */
91 if ((elf = readelf(filename)) == NULL) {
92 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
93 return;
94 }
95
96 if (be_verbose > 1)
97 printf("%s: {%s,%s} scanning file\n", filename,
98 get_elfeitype(elf, EI_CLASS, elf->elf_class),
99 get_elfeitype(elf, EI_DATA, elf->data[EI_DATA]));
100 else if (be_verbose)
101 printf("%s: scanning file\n", filename);
102
103 /* show the header */
104 if (!be_quiet && show_banner) {
105 printf(" TYPE ");
106 if (show_pax) printf(" PAX ");
107 if (show_stack) printf("STK/REL ");
108 if (show_textrel) printf("TEXTREL ");
109 if (show_rpath) printf("RPATH ");
110 if (show_needed) printf("NEEDED ");
111 printf(" FILE\n");
112 show_banner = 0;
113 }
114
115 /* dump all the good stuff */
116 if (!be_quiet)
117 printf("%-7s ", get_elfetype(elf));
118
119 if (show_pax) {
120 char *paxflags = pax_short_hf_flags(PAX_FLAGS(elf));
121 if (!be_quiet || (be_quiet && strncmp(paxflags, "PeMRxS", 6))) {
122 found_pax = 1;
123 printf("%s ", pax_short_hf_flags(PAX_FLAGS(elf)));
124 }
125 }
126
127 /* stack fun */
128 if (show_stack) {
129 #define SHOW_STACK(B) \
130 if (elf->elf_class == ELFCLASS ## B) { \
131 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
132 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
133 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
134 if (EGET(phdr[i].p_type) != PT_GNU_STACK && \
135 EGET(phdr[i].p_type) != PT_GNU_RELRO) continue; \
136 if (be_quiet && !(EGET(phdr[i].p_flags) & PF_X)) \
137 continue; \
138 if (EGET(phdr[i].p_type) == PT_GNU_STACK) \
139 found_stack = 1; \
140 if (EGET(phdr[i].p_type) == PT_GNU_RELRO) \
141 found_relro = 1; \
142 printf("%s ", gnu_short_stack_flags(EGET(phdr[i].p_flags))); \
143 } \
144 }
145 SHOW_STACK(32)
146 SHOW_STACK(64)
147 if (!be_quiet && !found_stack) printf("--- ");
148 if (!be_quiet && !found_relro) printf("--- ");
149 }
150
151 /* textrel fun */
152 if (show_textrel) {
153 #define SHOW_TEXTREL(B) \
154 if (elf->elf_class == ELFCLASS ## B) { \
155 Elf ## B ## _Dyn *dyn; \
156 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
157 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
158 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
159 if (phdr[i].p_type != PT_DYNAMIC) continue; \
160 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
161 while (EGET(dyn->d_tag) != DT_NULL) { \
162 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
163 found_textrel = 1; \
164 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
165 printf("TEXTREL "); \
166 } \
167 ++dyn; \
168 } \
169 } }
170 SHOW_TEXTREL(32)
171 SHOW_TEXTREL(64)
172 if (!be_quiet && !found_textrel) printf("------- ");
173 }
174
175 /* rpath fun */
176 /* TODO: if be_quiet, only output RPATH's which aren't in /etc/ld.so.conf */
177 if (show_rpath) {
178 char *rpath, *runpath;
179 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
180 rpath = runpath = NULL;
181
182 if (strtbl_void) {
183 #define SHOW_RPATH(B) \
184 if (elf->elf_class == ELFCLASS ## B) { \
185 Elf ## B ## _Dyn *dyn; \
186 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
187 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
188 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
189 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
190 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
191 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
192 while (EGET(dyn->d_tag) != DT_NULL) { \
193 if (EGET(dyn->d_tag) == DT_RPATH) { \
194 rpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
195 found_rpath = 1; \
196 } else if (EGET(dyn->d_tag) == DT_RUNPATH) { \
197 runpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
198 found_rpath = 1; \
199 } \
200 ++dyn; \
201 } \
202 } }
203 SHOW_RPATH(32)
204 SHOW_RPATH(64)
205 }
206 if (rpath && runpath) {
207 if (!strcmp(rpath, runpath))
208 printf("%-5s ", runpath);
209 else {
210 fprintf(stderr, "%s's RPATH [%s] != RUNPATH [%s]\n", filename, rpath, runpath);
211 printf("{%s,%s} ", rpath, runpath);
212 }
213 } else if (rpath || runpath)
214 printf("%-5s ", (runpath ? runpath : rpath));
215 else if (!be_quiet && !found_rpath)
216 printf(" - ");
217 }
218
219 /* print out all the NEEDED entries */
220 if (show_needed) {
221 char *needed;
222 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
223
224 if (strtbl_void) {
225 #define SHOW_NEEDED(B) \
226 if (elf->elf_class == ELFCLASS ## B) { \
227 Elf ## B ## _Dyn *dyn; \
228 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
229 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
230 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
231 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
232 if (be_verbose && EGET(phdr[i].p_type) == PT_INTERP) { \
233 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
234 printf("%s\n", elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr)); \
235 exit(0); \
236 } \
237 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
238 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
239 while (EGET(dyn->d_tag) != DT_NULL) { \
240 if (EGET(dyn->d_tag) == DT_NEEDED) { \
241 needed = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
242 if (found_needed) printf(","); \
243 printf("%s", needed); \
244 found_needed = 1; \
245 } \
246 ++dyn; \
247 } \
248 } }
249 SHOW_NEEDED(32)
250 SHOW_NEEDED(64)
251 }
252 if (!be_quiet && !found_needed)
253 printf(" - ");
254 else if (found_needed)
255 printf(" ");
256 }
257
258 /* search the symbol table for a specified symbol */
259 if (find_sym) {
260 void *symtab_void, *strtab_void;
261 char *versioned_symname;
262 size_t len;
263
264 len = strlen(find_sym) + 1;
265 versioned_symname = (char *)malloc(sizeof(char) * (len+1));
266 if (!versioned_symname) {
267 warnf("Could not malloc() mem for sym scan");
268 return;
269 }
270 sprintf(versioned_symname, "%s@", find_sym);
271
272 symtab_void = elf_findsecbyname(elf, ".symtab");
273 strtab_void = elf_findsecbyname(elf, ".strtab");
274
275 if (symtab_void && strtab_void) {
276 #define FIND_SYM(B) \
277 if (elf->elf_class == ELFCLASS ## B) { \
278 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
279 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
280 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
281 int cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
282 char *symname; \
283 for (i = 0; i < cnt; ++i) { \
284 if (sym->st_name) { \
285 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
286 if (*find_sym == '*') { \
287 printf("%s(%s) %5lX %15s %s\n", \
288 ((found_sym == 0) ? "\n\t" : "\t"), \
289 (char *)basename(filename), \
290 (long)sym->st_size, \
291 (char *)get_elfstttype(sym->st_info), \
292 symname); \
293 found_sym = 1; \
294 } else if ((strcmp(find_sym, symname) == 0) || \
295 (strncmp(symname, versioned_symname, len) == 0)) \
296 found_sym++; \
297 } \
298 ++sym; \
299 } }
300 FIND_SYM(32)
301 FIND_SYM(64)
302 }
303 free(versioned_symname);
304 if (*find_sym != '*') {
305 if (found_sym)
306 printf(" %s ", find_sym);
307 else if (!be_quiet)
308 printf(" - ");
309 }
310 }
311
312 if (!be_quiet || found_pax || found_stack || found_textrel || \
313 found_rpath || found_needed || found_sym)
314 printf("%s\n", filename);
315
316 unreadelf(elf);
317 }
318
319 /* scan a directory for ET_EXEC files and print when we find one */
320 static void scanelf_dir(const char *path)
321 {
322 register DIR *dir;
323 register struct dirent *dentry;
324 struct stat st_top, st;
325 char buf[_POSIX_PATH_MAX];
326 size_t pathlen = 0, len = 0;
327
328 /* make sure path exists */
329 if (lstat(path, &st_top) == -1)
330 return;
331
332 /* ok, if it isn't a directory, assume we can open it */
333 if (!S_ISDIR(st_top.st_mode)) {
334 scanelf_file(path);
335 return;
336 }
337
338 /* now scan the dir looking for fun stuff */
339 if ((dir = opendir(path)) == NULL) {
340 warnf("could not opendir %s: %s", path, strerror(errno));
341 return;
342 }
343 if (be_verbose) printf("%s: scanning dir\n", path);
344
345 pathlen = strlen(path);
346 while ((dentry = readdir(dir))) {
347 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
348 continue;
349 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
350 if (len >= sizeof(buf)) {
351 warnf("Skipping '%s': len > sizeof(buf); %d > %d\n", path, (int)len, (int)sizeof(buf));
352 continue;
353 }
354 sprintf(buf, "%s/%s", path, dentry->d_name);
355 if (lstat(buf, &st) != -1) {
356 if (S_ISREG(st.st_mode))
357 scanelf_file(buf);
358 else if (dir_recurse && S_ISDIR(st.st_mode)) {
359 if (dir_crossmount || (st_top.st_dev == st.st_dev))
360 scanelf_dir(buf);
361 }
362 }
363 }
364 closedir(dir);
365 }
366
367 /* scan /etc/ld.so.conf for paths */
368 static void scanelf_ldpath()
369 {
370 char scan_l, scan_ul, scan_ull;
371 char *path, *p;
372 FILE *fp;
373
374 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
375 err("Unable to open ld.so.conf: %s", strerror(errno));
376
377 scan_l = scan_ul = scan_ull = 0;
378
379 if ((path = malloc(_POSIX_PATH_MAX)) == NULL) {
380 warn("Can not malloc() memory for ldpath scanning");
381 return;
382 }
383 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL)
384 if (*path == '/') {
385 if ((p = strrchr(path, '\r')) != NULL)
386 *p = 0;
387 if ((p = strrchr(path, '\n')) != NULL)
388 *p = 0;
389 if (!scan_l && !strcmp(path, "/lib")) scan_l = 1;
390 if (!scan_ul && !strcmp(path, "/usr/lib")) scan_ul = 1;
391 if (!scan_ull && !strcmp(path, "/usr/local/lib")) scan_ull = 1;
392 scanelf_dir(path);
393 }
394 free(path);
395 fclose(fp);
396
397 if (!scan_l) scanelf_dir("/lib");
398 if (!scan_ul) scanelf_dir("/usr/lib");
399 if (!scan_ull) scanelf_dir("/usr/local/lib");
400 }
401
402 /* scan env PATH for paths */
403 static void scanelf_envpath()
404 {
405 char *path, *p;
406
407 path = getenv("PATH");
408 if (!path)
409 err("PATH is not set in your env !");
410
411 if ((path = strdup(path)) == NULL)
412 err("strdup failed: %s", strerror(errno));
413
414 while ((p = strrchr(path, ':')) != NULL) {
415 scanelf_dir(p + 1);
416 *p = 0;
417 }
418
419 free(path);
420 }
421
422
423
424 /* usage / invocation handling functions */
425 #define PARSE_FLAGS "plRmxetrns:aqvo:BhV"
426 #define a_argument required_argument
427 static struct option const long_opts[] = {
428 {"path", no_argument, NULL, 'p'},
429 {"ldpath", no_argument, NULL, 'l'},
430 {"recursive", no_argument, NULL, 'R'},
431 {"mount", no_argument, NULL, 'm'},
432 {"pax", no_argument, NULL, 'x'},
433 {"header", no_argument, NULL, 'e'},
434 {"textrel", no_argument, NULL, 't'},
435 {"rpath", no_argument, NULL, 'r'},
436 {"needed", no_argument, NULL, 'n'},
437 {"symbol", a_argument, NULL, 's'},
438 {"all", no_argument, NULL, 'a'},
439 {"quiet", no_argument, NULL, 'q'},
440 {"verbose", no_argument, NULL, 'v'},
441 {"file", a_argument, NULL, 'o'},
442 {"nobanner", no_argument, NULL, 'B'},
443 {"help", no_argument, NULL, 'h'},
444 {"version", no_argument, NULL, 'V'},
445 {NULL, no_argument, NULL, 0x0}
446 };
447 static char *opts_help[] = {
448 "Scan all directories in PATH environment",
449 "Scan all directories in /etc/ld.so.conf",
450 "Scan directories recursively",
451 "Don't recursively cross mount points\n",
452 "Print PaX markings",
453 "Print GNU_STACK markings",
454 "Print TEXTREL information",
455 "Print RPATH information",
456 "Print NEEDED information",
457 "Find a specified symbol",
458 "Print all scanned info (-x -e -t -r)\n",
459 "Only output 'bad' things",
460 "Be verbose (can be specified more than once)",
461 "Write output stream to a filename",
462 "Don't display the header",
463 "Print this help and exit",
464 "Print version and exit",
465 NULL
466 };
467
468 /* display usage and exit */
469 static void usage(int status)
470 {
471 int i;
472 printf(" Scan ELF binaries for stuff\n"
473 "Usage: %s [options] <dir1> [dir2 dirN ...]\n\n", argv0);
474 printf("Options:\n");
475 for (i = 0; long_opts[i].name; ++i)
476 if (long_opts[i].has_arg == no_argument)
477 printf(" -%c, --%-13s %s\n", long_opts[i].val,
478 long_opts[i].name, opts_help[i]);
479 else
480 printf(" -%c, --%-6s <arg> %s\n", long_opts[i].val,
481 long_opts[i].name, opts_help[i]);
482 exit(status);
483 }
484
485 /* parse command line arguments and preform needed actions */
486 static void parseargs(int argc, char *argv[])
487 {
488 int flag;
489
490 opterr = 0;
491 while ((flag=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
492 switch (flag) {
493
494 case 'V': /* version info */
495 printf("%s compiled %s\n%s\n"
496 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
497 __FILE__, __DATE__, rcsid, argv0);
498 exit(EXIT_SUCCESS);
499 break;
500 case 'h': usage(EXIT_SUCCESS); break;
501
502 case 'o': {
503 FILE *fp = NULL;
504 fp = freopen(optarg, "w", stdout);
505 if (fp == NULL)
506 err("Could not open output stream '%s': %s", optarg, strerror(errno));
507 stdout = fp;
508 break;
509 }
510
511 case 's': find_sym = strdup(optarg); break;
512
513 case 'B': show_banner = 0; break;
514 case 'l': scan_ldpath = 1; break;
515 case 'p': scan_envpath = 1; break;
516 case 'R': dir_recurse = 1; break;
517 case 'm': dir_crossmount = 0; break;
518 case 'x': show_pax = 1; break;
519 case 'e': show_stack = 1; break;
520 case 't': show_textrel = 1; break;
521 case 'r': show_rpath = 1; break;
522 case 'n': show_needed = 1; break;
523 case 'q': be_quiet = 1; break;
524 case 'v': be_verbose = (be_verbose % 20) + 1; break;
525 case 'a': show_pax = show_stack = show_textrel = show_needed = show_rpath = 1; break;
526
527 case ':':
528 warn("Option missing parameter");
529 usage(EXIT_FAILURE);
530 break;
531 case '?':
532 warn("Unknown option");
533 usage(EXIT_FAILURE);
534 break;
535 default:
536 err("Unhandled option '%c'", flag);
537 break;
538 }
539 }
540
541 if (be_quiet && be_verbose)
542 err("You can be quiet or you can be verbose, not both, stupid");
543
544 if (scan_ldpath) scanelf_ldpath();
545 if (scan_envpath) scanelf_envpath();
546 if (optind == argc && !scan_ldpath && !scan_envpath)
547 err("Nothing to scan !?");
548 while (optind < argc)
549 scanelf_dir(argv[optind++]);
550
551 if (find_sym) free(find_sym);
552 }
553
554
555
556 int main(int argc, char *argv[])
557 {
558 if (argc < 2)
559 usage(EXIT_FAILURE);
560 parseargs(argc, argv);
561 fclose(stdout);
562 return EXIT_SUCCESS;
563 }

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