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Revision 1.28 - (show annotations) (download) (as text)
Tue Apr 5 03:41:27 2005 UTC (9 years, 5 months ago) by solar
Branch: MAIN
Changes since 1.27: +23 -13 lines
File MIME type: text/x-csrc
- refine symbol formatting

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 1.27 2005/04/05 01:44:08 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 1.27 2005/04/05 01:44:08 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_banner = 1;
72 static char be_quiet = 0;
73 static char be_verbose = 0;
74 static char *find_sym = NULL;
75
76
77
78 /* scan an elf file and show all the fun stuff */
79 static void scanelf_file(const char *filename)
80 {
81 int i;
82 char found_pax, found_stack, found_relro, found_textrel, found_rpath, found_sym;
83 elfobj *elf;
84
85 found_pax = found_stack = found_relro = found_textrel = found_rpath = found_sym = 0;
86
87 /* verify this is real ELF */
88 if ((elf = readelf(filename)) == NULL) {
89 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
90 return;
91 }
92
93 if (be_verbose > 1)
94 printf("%s: {%s,%s} scanning file\n", filename,
95 get_elfeitype(elf, EI_CLASS, elf->elf_class),
96 get_elfeitype(elf, EI_DATA, elf->data[EI_DATA]));
97 else if (be_verbose)
98 printf("%s: scanning file\n", filename);
99
100 /* show the header */
101 if (!be_quiet && show_banner) {
102 printf(" TYPE ");
103 if (show_pax) printf(" PAX ");
104 if (show_stack) printf(" STK/REL ");
105 if (show_textrel) printf("TEXTREL ");
106 if (show_rpath) printf("RPATH ");
107 printf(" FILE\n");
108 show_banner = 0;
109 }
110
111 /* dump all the good stuff */
112 if (!be_quiet)
113 printf("%-7s ", get_elfetype(elf));
114
115 if (show_pax) {
116 char *paxflags = pax_short_hf_flags(PAX_FLAGS(elf));
117 if (!be_quiet || (be_quiet && strncmp(paxflags, "PeMRxS", 6))) {
118 found_pax = 1;
119 printf("%s ", pax_short_hf_flags(PAX_FLAGS(elf)));
120 }
121 }
122
123 /* stack fun */
124 if (show_stack) {
125 #define SHOW_STACK(B) \
126 if (elf->elf_class == ELFCLASS ## B) { \
127 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
128 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
129 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
130 if (EGET(phdr[i].p_type) != PT_GNU_STACK && \
131 EGET(phdr[i].p_type) != PT_GNU_RELRO) continue; \
132 if (be_quiet && !(EGET(phdr[i].p_flags) & PF_X)) \
133 continue; \
134 if (EGET(phdr[i].p_type) == PT_GNU_STACK) \
135 found_stack = 1; \
136 if (EGET(phdr[i].p_type) == PT_GNU_RELRO) \
137 found_relro = 1; \
138 printf("%s ", gnu_short_stack_flags(EGET(phdr[i].p_flags))); \
139 } \
140 }
141 SHOW_STACK(32)
142 SHOW_STACK(64)
143 if (!be_quiet && !found_stack) printf("--- ");
144 if (!be_quiet && !found_relro) printf("--- ");
145 }
146
147 /* textrel fun */
148 if (show_textrel) {
149 #define SHOW_TEXTREL(B) \
150 if (elf->elf_class == ELFCLASS ## B) { \
151 Elf ## B ## _Dyn *dyn; \
152 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
153 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
154 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
155 if (phdr[i].p_type != PT_DYNAMIC) continue; \
156 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
157 while (EGET(dyn->d_tag) != DT_NULL) { \
158 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
159 found_textrel = 1; \
160 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
161 printf("TEXTREL "); \
162 } \
163 ++dyn; \
164 } \
165 } }
166 SHOW_TEXTREL(32)
167 SHOW_TEXTREL(64)
168 if (!be_quiet && !found_textrel) printf("------- ");
169 }
170
171 /* rpath fun */
172 /* TODO: if be_quiet, only output RPATH's which aren't in /etc/ld.so.conf */
173 if (show_rpath) {
174 char *rpath, *runpath;
175 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
176 rpath = runpath = NULL;
177
178 if (strtbl_void) {
179 #define SHOW_RPATH(B) \
180 if (elf->elf_class == ELFCLASS ## B) { \
181 Elf ## B ## _Dyn *dyn; \
182 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
183 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
184 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
185 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
186 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
187 dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
188 while (EGET(dyn->d_tag) != DT_NULL) { \
189 if (EGET(dyn->d_tag) == DT_RPATH) { \
190 rpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
191 found_rpath = 1; \
192 } else if (EGET(dyn->d_tag) == DT_RUNPATH) { \
193 runpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
194 found_rpath = 1; \
195 } \
196 ++dyn; \
197 } \
198 } }
199 SHOW_RPATH(32)
200 SHOW_RPATH(64)
201 }
202 if (rpath && runpath) {
203 if (!strcmp(rpath, runpath))
204 printf("%-5s ", runpath);
205 else {
206 fprintf(stderr, "%s's RPATH [%s] != RUNPATH [%s]\n", filename, rpath, runpath);
207 printf("{%s,%s} ", rpath, runpath);
208 }
209 } else if (rpath || runpath)
210 printf("%-5s ", (runpath ? runpath : rpath));
211 else if (!be_quiet && !found_rpath)
212 printf(" - ");
213 }
214
215 if (find_sym) {
216 void *symtab_void, *strtab_void;
217 char found_sym = 0;
218 char *versioned_symname = malloc(strlen(find_sym)+1);
219
220 sprintf(versioned_symname, "%s@", find_sym);
221 symtab_void = elf_findsecbyname(elf, ".symtab");
222 strtab_void = elf_findsecbyname(elf, ".strtab");
223
224 if (symtab_void && strtab_void) {
225 #define FIND_SYM(B) \
226 if (elf->elf_class == ELFCLASS ## B) { \
227 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
228 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
229 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
230 int cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
231 char *symname; \
232 for (i = 0; i < cnt; ++i) { \
233 if (sym->st_name) { \
234 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
235 if (*find_sym == '*') { \
236 printf("%s(%s) %5lX %15s %s\n", ((found_sym == 0) ? "\n\t" : "\t"), \
237 (char *) basename(filename), \
238 (long)sym->st_size, (char *) get_elfstttype(sym->st_info & 0xF), \
239 symname); \
240 found_sym = 1; \
241 } \
242 if ((strcmp(find_sym, symname) == 0) || \
243 (strncmp(symname, versioned_symname, strlen(versioned_symname)) == 0)) \
244 found_sym++; \
245 } \
246 ++sym; \
247 } }
248 FIND_SYM(32)
249 FIND_SYM(64)
250 }
251 free(versioned_symname);
252 if (*find_sym != '*')
253 printf(" %s ", (found_sym == 0) ? "-" : find_sym);
254 }
255
256 if (!be_quiet || found_pax || found_stack || found_textrel || found_rpath)
257 printf("%s\n", filename);
258
259 unreadelf(elf);
260 }
261
262 /* scan a directory for ET_EXEC files and print when we find one */
263 static void scanelf_dir(const char *path)
264 {
265 register DIR *dir;
266 register struct dirent *dentry;
267 struct stat st_top, st;
268 char buf[_POSIX_PATH_MAX];
269 size_t len = 0;
270
271 /* make sure path exists */
272 if (lstat(path, &st_top) == -1)
273 return;
274
275 /* ok, if it isn't a directory, assume we can open it */
276 if (!S_ISDIR(st_top.st_mode)) {
277 scanelf_file(path);
278 return;
279 }
280
281 /* now scan the dir looking for fun stuff */
282 if ((dir = opendir(path)) == NULL) {
283 warnf("could not opendir %s: %s", path, strerror(errno));
284 return;
285 }
286 if (be_verbose) printf("%s: scanning dir\n", path);
287
288 while ((dentry = readdir(dir))) {
289 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
290 continue;
291 len = (strlen(path) + 2 + strlen(dentry->d_name));
292 assert(len < sizeof(buf));
293 strncpy(buf, path, len);
294 strncat(buf, "/", len);
295 strncat(buf, dentry->d_name, len);
296 buf[sizeof(buf)] = 0;
297 if (lstat(buf, &st) != -1) {
298 if (S_ISREG(st.st_mode))
299 scanelf_file(buf);
300 else if (dir_recurse && S_ISDIR(st.st_mode)) {
301 if (dir_crossmount || (st_top.st_dev == st.st_dev))
302 scanelf_dir(buf);
303 }
304 }
305 }
306 closedir(dir);
307 }
308
309 /* scan /etc/ld.so.conf for paths */
310 static void scanelf_ldpath()
311 {
312 char scan_l, scan_ul, scan_ull;
313 char *path, *p;
314 FILE *fp;
315
316 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
317 err("Unable to open ld.so.conf: %s", strerror(errno));
318
319 scan_l = scan_ul = scan_ull = 0;
320
321 path = malloc(_POSIX_PATH_MAX);
322 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL)
323 if (*path == '/') {
324 if ((p = strrchr(path, '\r')) != NULL)
325 *p = 0;
326 if ((p = strrchr(path, '\n')) != NULL)
327 *p = 0;
328 if (!scan_l && !strcmp(path, "/lib")) scan_l = 1;
329 if (!scan_ul && !strcmp(path, "/usr/lib")) scan_ul = 1;
330 if (!scan_ull && !strcmp(path, "/usr/local/lib")) scan_ull = 1;
331 scanelf_dir(path);
332 }
333 free(path);
334
335 if (!scan_l) scanelf_dir("/lib");
336 if (!scan_ul) scanelf_dir("/usr/lib");
337 if (!scan_ull) scanelf_dir("/usr/local/lib");
338
339 fclose(fp);
340 }
341
342 /* scan env PATH for paths */
343 static void scanelf_envpath()
344 {
345 char *path, *p;
346
347 path = getenv("PATH");
348 if (!path)
349 err("PATH is not set in your env !");
350
351 if ((path = strdup(path)) == NULL)
352 err("stdup failed: %s", strerror(errno));
353
354 while ((p = strrchr(path, ':')) != NULL) {
355 scanelf_dir(p + 1);
356 *p = 0;
357 }
358
359 free(path);
360 }
361
362
363
364 /* usage / invocation handling functions */
365 #define PARSE_FLAGS "plRmxetrs:aqvo:BhV"
366 #define a_argument required_argument
367 static struct option const long_opts[] = {
368 {"path", no_argument, NULL, 'p'},
369 {"ldpath", no_argument, NULL, 'l'},
370 {"recursive", no_argument, NULL, 'R'},
371 {"mount", no_argument, NULL, 'm'},
372 {"pax", no_argument, NULL, 'x'},
373 {"header", no_argument, NULL, 'e'},
374 {"textrel", no_argument, NULL, 't'},
375 {"rpath", no_argument, NULL, 'r'},
376 {"symbol", a_argument, NULL, 's'},
377 {"all", no_argument, NULL, 'a'},
378 {"quiet", no_argument, NULL, 'q'},
379 {"verbose", no_argument, NULL, 'v'},
380 {"file", a_argument, NULL, 'o'},
381 {"nobanner", no_argument, NULL, 'B'},
382 {"help", no_argument, NULL, 'h'},
383 {"version", no_argument, NULL, 'V'},
384 {NULL, no_argument, NULL, 0x0}
385 };
386 static char *opts_help[] = {
387 "Scan all directories in PATH environment",
388 "Scan all directories in /etc/ld.so.conf",
389 "Scan directories recursively",
390 "Don't recursively cross mount points\n",
391 "Print PaX markings",
392 "Print GNU_STACK markings",
393 "Print TEXTREL information",
394 "Print RPATH information",
395 "Find a specified symbol",
396 "Print all scanned info (-x -e -t -r)\n",
397 "Only output 'bad' things",
398 "Be verbose (can be specified more than once)",
399 "Write output stream to a filename",
400 "Don't display the header",
401 "Print this help and exit",
402 "Print version and exit",
403 NULL
404 };
405
406 /* display usage and exit */
407 static void usage(int status)
408 {
409 int i;
410 printf(" Scan ELF binaries for stuff\n"
411 "Usage: %s [options] <dir1> [dir2 dirN ...]\n\n", argv0);
412 printf("Options:\n");
413 for (i = 0; long_opts[i].name; ++i)
414 if (long_opts[i].has_arg == no_argument)
415 printf(" -%c, --%-13s %s\n", long_opts[i].val,
416 long_opts[i].name, opts_help[i]);
417 else
418 printf(" -%c, --%-6s <arg> %s\n", long_opts[i].val,
419 long_opts[i].name, opts_help[i]);
420 exit(status);
421 }
422
423 /* parse command line arguments and preform needed actions */
424 static void parseargs(int argc, char *argv[])
425 {
426 int flag;
427
428 opterr = 0;
429 while ((flag=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
430 switch (flag) {
431
432 case 'V': /* version info */
433 printf("%s compiled %s\n%s\n"
434 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
435 __FILE__, __DATE__, rcsid, argv0);
436 exit(EXIT_SUCCESS);
437 break;
438 case 'h': usage(EXIT_SUCCESS); break;
439
440 case 'o': {
441 FILE *fp = NULL;
442 fp = freopen(optarg, "w", stdout);
443 if (fp == NULL)
444 err("Could not open output stream '%s': %s", optarg, strerror(errno));
445 stdout = fp;
446 break;
447 }
448
449 case 's': find_sym = strdup(optarg); break;
450
451 case 'B': show_banner = 0; break;
452 case 'l': scan_ldpath = 1; break;
453 case 'p': scan_envpath = 1; break;
454 case 'R': dir_recurse = 1; break;
455 case 'm': dir_crossmount = 0; break;
456 case 'x': show_pax = 1; break;
457 case 'e': show_stack = 1; break;
458 case 't': show_textrel = 1; break;
459 case 'r': show_rpath = 1; break;
460 case 'q': be_quiet = 1; break;
461 case 'v': be_verbose = (be_verbose % 20) + 1; break;
462 case 'a': show_pax = show_stack = show_textrel = show_rpath = 1; break;
463
464 case ':':
465 warn("Option missing parameter");
466 usage(EXIT_FAILURE);
467 break;
468 case '?':
469 warn("Unknown option");
470 usage(EXIT_FAILURE);
471 break;
472 default:
473 err("Unhandled option '%c'", flag);
474 break;
475 }
476 }
477
478 if (be_quiet && be_verbose)
479 err("You can be quiet or you can be verbose, not both, stupid");
480
481 if (scan_ldpath) scanelf_ldpath();
482 if (scan_envpath) scanelf_envpath();
483 if (optind == argc && !scan_ldpath && !scan_envpath)
484 err("Nothing to scan !?");
485 while (optind < argc)
486 scanelf_dir(argv[optind++]);
487
488 if (find_sym) free(find_sym);
489 }
490
491
492
493 int main(int argc, char *argv[])
494 {
495 if (argc < 2)
496 usage(EXIT_FAILURE);
497 parseargs(argc, argv);
498 fclose(stdout);
499 return EXIT_SUCCESS;
500 }

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