/[gentoo-projects]/pax-utils/scanelf.c
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Revision 1.62 - (show annotations) (download) (as text)
Sun May 29 06:25:48 2005 UTC (8 years, 10 months ago) by vapier
Branch: MAIN
Changes since 1.61: +8 -2 lines
File MIME type: text/x-csrc
add some more checks to make sure people dont double specify options and make us malloc extra memory

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 1.61 2005/05/28 22:09:36 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 #include <libgen.h>
28 #include <limits.h>
29 #define __USE_GNU
30 #include <string.h>
31 #include <errno.h>
32 #include <unistd.h>
33 #include <sys/stat.h>
34 #include <dirent.h>
35 #include <getopt.h>
36 #include <assert.h>
37 #include "paxelf.h"
38
39 static const char *rcsid = "$Id: scanelf.c,v 1.61 2005/05/28 22:09:36 solar Exp $";
40 #define argv0 "scanelf"
41
42
43
44 /* prototypes */
45 static void scanelf_file(const char *filename);
46 static void scanelf_dir(const char *path);
47 static void scanelf_ldpath();
48 static void scanelf_envpath();
49 static void usage(int status);
50 static void parseargs(int argc, char *argv[]);
51 static char *xstrdup(const char *s);
52 static void *xmalloc(size_t size);
53 static void xstrcat(char **dst, const char *src, size_t *curr_len);
54 static inline void xchrcat(char **dst, const char append, size_t *curr_len);
55
56 /* variables to control behavior */
57 static char *ldpaths[256];
58 static char scan_ldpath = 0;
59 static char scan_envpath = 0;
60 static char scan_symlink = 1;
61 static char dir_recurse = 0;
62 static char dir_crossmount = 1;
63 static char show_pax = 0;
64 static char show_stack = 0;
65 static char show_textrel = 0;
66 static char show_rpath = 0;
67 static char show_needed = 0;
68 static char show_interp = 0;
69 static char show_bind = 0;
70 static char show_banner = 1;
71 static char be_quiet = 0;
72 static char be_verbose = 0;
73 static char *find_sym = NULL, *versioned_symname = NULL;
74 static char *out_format = NULL;
75
76
77 /* sub-funcs for scanelf_file() */
78 static char *scanelf_file_pax(elfobj *elf, char *found_pax)
79 {
80 static char *paxflags;
81 static char ret[7];
82 unsigned long i, shown;
83
84
85 if (!show_pax) return NULL;
86
87 shown = 0;
88 memset(&ret, 0, sizeof(ret));
89
90 if (elf->phdr) {
91 #define SHOW_PAX(B) \
92 if (elf->elf_class == ELFCLASS ## B) { \
93 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
94 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
95 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
96 if (EGET(phdr[i].p_type) != PT_PAX_FLAGS) \
97 continue; \
98 if (be_quiet && (EGET(phdr[i].p_flags) == 10240)) \
99 continue; \
100 memcpy(ret, pax_short_pf_flags(EGET(phdr[i].p_flags)), 6); \
101 *found_pax = 1; \
102 ++shown; \
103 break; \
104 } \
105 }
106 SHOW_PAX(32)
107 SHOW_PAX(64)
108 }
109
110 /* fall back to EI_PAX if no PT_PAX was found */
111 if (!*ret) {
112 paxflags = pax_short_hf_flags(EI_PAX_FLAGS(elf));
113 if (!be_quiet || (be_quiet && EI_PAX_FLAGS(elf))) {
114 *found_pax = 1;
115 return paxflags;
116 }
117 strncpy(ret, paxflags, sizeof(ret));
118 // ++shown;
119 }
120
121 if (be_quiet && !shown)
122 return NULL;
123 return ret;
124
125 }
126 static char *scanelf_file_stack(elfobj *elf, char *found_stack, char *found_relro)
127 {
128 static char ret[8] = "--- ---";
129 char *found;
130 unsigned long i, off, shown;
131
132 if (!show_stack) return NULL;
133
134 shown = 0;
135
136 if (elf->phdr) {
137 #define SHOW_STACK(B) \
138 if (elf->elf_class == ELFCLASS ## B) { \
139 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
140 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
141 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
142 if (EGET(phdr[i].p_type) == PT_GNU_STACK) { \
143 found = found_stack; \
144 off = 0; \
145 } else if (EGET(phdr[i].p_type) == PT_GNU_RELRO) { \
146 found = found_relro; \
147 off = 4; \
148 } else \
149 continue; \
150 if (be_quiet && !(EGET(phdr[i].p_flags) & PF_X)) \
151 continue; \
152 memcpy(ret+off, gnu_short_stack_flags(EGET(phdr[i].p_flags)), 3); \
153 *found = 1; \
154 ++shown; \
155 } \
156 }
157 SHOW_STACK(32)
158 SHOW_STACK(64)
159 }
160
161 if (be_quiet && !shown)
162 return NULL;
163 else
164 return ret;
165 }
166 static char *scanelf_file_textrel(elfobj *elf, char *found_textrel)
167 {
168 static char *ret = "TEXTREL";
169 unsigned long i;
170
171 if (!show_textrel) return NULL;
172
173 if (elf->phdr) {
174 #define SHOW_TEXTREL(B) \
175 if (elf->elf_class == ELFCLASS ## B) { \
176 Elf ## B ## _Dyn *dyn; \
177 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
178 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
179 Elf ## B ## _Off offset; \
180 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
181 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
182 offset = EGET(phdr[i].p_offset); \
183 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
184 dyn = DYN ## B (elf->data + offset); \
185 while (EGET(dyn->d_tag) != DT_NULL) { \
186 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
187 *found_textrel = 1; \
188 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
189 return ret; \
190 } \
191 ++dyn; \
192 } \
193 } }
194 SHOW_TEXTREL(32)
195 SHOW_TEXTREL(64)
196 }
197
198 if (be_quiet)
199 return NULL;
200 else
201 return " - ";
202 }
203 static void scanelf_file_rpath(elfobj *elf, char *found_rpath, char **ret, size_t *ret_len)
204 {
205 /* TODO: when checking RPATH entries, check each subpath (between :) in ld.so.conf */
206 unsigned long i, s;
207 char *rpath, *runpath, **r;
208 void *strtbl_void;
209
210 if (!show_rpath) return;
211
212 strtbl_void = elf_findsecbyname(elf, ".dynstr");
213 rpath = runpath = NULL;
214
215 if (elf->phdr && strtbl_void) {
216 #define SHOW_RPATH(B) \
217 if (elf->elf_class == ELFCLASS ## B) { \
218 Elf ## B ## _Dyn *dyn; \
219 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
220 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
221 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
222 Elf ## B ## _Off offset; \
223 Elf ## B ## _Xword word; \
224 /* Scan all the program headers */ \
225 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
226 /* Just scan dynamic headers */ \
227 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
228 offset = EGET(phdr[i].p_offset); \
229 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
230 /* Just scan dynamic RPATH/RUNPATH headers */ \
231 dyn = DYN ## B (elf->data + offset); \
232 while ((word=EGET(dyn->d_tag)) != DT_NULL) { \
233 if (word == DT_RPATH) { \
234 r = &rpath; \
235 } else if (word == DT_RUNPATH) { \
236 r = &runpath; \
237 } else { \
238 ++dyn; \
239 continue; \
240 } \
241 /* Verify the memory is somewhat sane */ \
242 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
243 if (offset < elf->len) { \
244 if (*r) warn("ELF has multiple %s's !?", get_elfdtype(word)); \
245 *r = (char*)(elf->data + offset); \
246 /* If quiet, don't output paths in ld.so.conf */ \
247 if (be_quiet) \
248 for (s = 0; ldpaths[s]; ++s) \
249 if (!strcmp(ldpaths[s], *r)) { \
250 *r = NULL; \
251 break; \
252 } \
253 if (*r) *found_rpath = 1; \
254 } \
255 ++dyn; \
256 } \
257 } }
258 SHOW_RPATH(32)
259 SHOW_RPATH(64)
260 }
261
262 if (rpath && runpath) {
263 if (!strcmp(rpath, runpath)) {
264 xstrcat(ret, runpath, ret_len);
265 } else {
266 fprintf(stderr, "RPATH [%s] != RUNPATH [%s]\n", rpath, runpath);
267 xchrcat(ret, '{', ret_len);
268 xstrcat(ret, rpath, ret_len);
269 xchrcat(ret, ',', ret_len);
270 xstrcat(ret, runpath, ret_len);
271 xchrcat(ret, '}', ret_len);
272 }
273 } else if (rpath || runpath)
274 xstrcat(ret, (runpath ? runpath : rpath), ret_len);
275 else if (!be_quiet)
276 xstrcat(ret, " - ", ret_len);
277 }
278 static void scanelf_file_needed(elfobj *elf, char *found_needed, char **ret, size_t *ret_len)
279 {
280 unsigned long i;
281 char *needed;
282 void *strtbl_void;
283
284 if (!show_needed) return;
285
286 strtbl_void = elf_findsecbyname(elf, ".dynstr");
287
288 if (elf->phdr && strtbl_void) {
289 #define SHOW_NEEDED(B) \
290 if (elf->elf_class == ELFCLASS ## B) { \
291 Elf ## B ## _Dyn *dyn; \
292 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
293 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
294 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
295 Elf ## B ## _Off offset; \
296 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
297 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
298 offset = EGET(phdr[i].p_offset); \
299 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
300 dyn = DYN ## B (elf->data + offset); \
301 while (EGET(dyn->d_tag) != DT_NULL) { \
302 if (EGET(dyn->d_tag) == DT_NEEDED) { \
303 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
304 if (offset >= elf->len) { \
305 ++dyn; \
306 continue; \
307 } \
308 needed = (char*)(elf->data + offset); \
309 if (*found_needed) xchrcat(ret, ',', ret_len); \
310 xstrcat(ret, needed, ret_len); \
311 *found_needed = 1; \
312 } \
313 ++dyn; \
314 } \
315 } }
316 SHOW_NEEDED(32)
317 SHOW_NEEDED(64)
318 }
319 }
320 static char *scanelf_file_interp(elfobj *elf, char *found_interp)
321 {
322 void *strtbl_void;
323
324 if (!show_interp) return NULL;
325
326 strtbl_void = elf_findsecbyname(elf, ".interp");
327
328 if (strtbl_void) {
329 #define SHOW_INTERP(B) \
330 if (elf->elf_class == ELFCLASS ## B) { \
331 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
332 *found_interp = 1; \
333 return elf->data + EGET(strtbl->sh_offset); \
334 }
335 SHOW_INTERP(32)
336 SHOW_INTERP(64)
337 }
338 return NULL;
339 }
340 static char *scanelf_file_bind(elfobj *elf, char *found_bind)
341 {
342 unsigned long i;
343 struct stat s;
344
345 if (!show_bind) return NULL;
346 if (!elf->phdr) return NULL;
347
348 #define SHOW_BIND(B) \
349 if (elf->elf_class == ELFCLASS ## B) { \
350 Elf ## B ## _Dyn *dyn; \
351 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
352 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
353 Elf ## B ## _Off offset; \
354 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
355 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
356 offset = EGET(phdr[i].p_offset); \
357 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
358 dyn = DYN ## B (elf->data + offset); \
359 while (EGET(dyn->d_tag) != DT_NULL) { \
360 if (EGET(dyn->d_tag) == DT_BIND_NOW || \
361 (EGET(dyn->d_tag) == DT_FLAGS && EGET(dyn->d_un.d_val) & DF_BIND_NOW)) \
362 { \
363 if (be_quiet) return NULL; \
364 *found_bind = 1; \
365 return "NOW"; \
366 } \
367 ++dyn; \
368 } \
369 } \
370 }
371 SHOW_BIND(32)
372 SHOW_BIND(64)
373
374 if (be_quiet && !fstat(elf->fd, &s) && !(s.st_mode & S_ISUID || s.st_mode & S_ISGID)) {
375 return NULL;
376 } else {
377 *found_bind = 1;
378 return "LAZY";
379 }
380 }
381 static char *scanelf_file_sym(elfobj *elf, char *found_sym, const char *filename)
382 {
383 unsigned long i;
384 void *symtab_void, *strtab_void;
385
386 if (!find_sym) return NULL;
387
388 symtab_void = elf_findsecbyname(elf, ".symtab");
389 strtab_void = elf_findsecbyname(elf, ".strtab");
390
391 if (symtab_void && strtab_void) {
392 char *base, *basemem;
393 basemem = xstrdup(filename);
394 base = basename(basemem);
395 #define FIND_SYM(B) \
396 if (elf->elf_class == ELFCLASS ## B) { \
397 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
398 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
399 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
400 unsigned long cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
401 char *symname; \
402 for (i = 0; i < cnt; ++i) { \
403 if (sym->st_name) { \
404 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
405 if (*find_sym == '*') { \
406 printf("%s(%s) %5lX %15s %s\n", \
407 ((*found_sym == 0) ? "\n\t" : "\t"), \
408 base, \
409 (long)sym->st_size, \
410 (char *)get_elfstttype(sym->st_info), \
411 symname); \
412 *found_sym = 1; \
413 } else if ((strcmp(find_sym, symname) == 0) || \
414 (strcmp(symname, versioned_symname) == 0)) \
415 (*found_sym)++; \
416 } \
417 ++sym; \
418 } }
419 FIND_SYM(32)
420 FIND_SYM(64)
421 free(basemem);
422 }
423 if (*find_sym != '*' && *found_sym)
424 return find_sym;
425 if (be_quiet)
426 return NULL;
427 else
428 return " - ";
429 }
430 /* scan an elf file and show all the fun stuff */
431 // #define prints(str) fputs(str, stdout)
432 #define prints(str) write(fileno(stdout), str, strlen(str))
433 static void scanelf_file(const char *filename)
434 {
435 unsigned long i;
436 char found_pax, found_stack, found_relro, found_textrel,
437 found_rpath, found_needed, found_interp, found_bind,
438 found_sym, found_file;
439 elfobj *elf;
440 struct stat st;
441 static char *out_buffer = NULL;
442 static size_t out_len;
443
444 /* make sure 'filename' exists */
445 if (lstat(filename, &st) == -1) {
446 if (be_verbose > 2) printf("%s: does not exist\n", filename);
447 return;
448 }
449 /* always handle regular files and handle symlinked files if no -y */
450 if (S_ISLNK(st.st_mode)) {
451 if (!scan_symlink) return;
452 stat(filename, &st);
453 }
454 if (!S_ISREG(st.st_mode)) {
455 if (be_verbose > 2) printf("%s: skipping non-file\n", filename);
456 return;
457 }
458
459 found_pax = found_stack = found_relro = found_textrel = \
460 found_rpath = found_needed = found_interp = found_bind = \
461 found_sym = found_file = 0;
462
463 /* verify this is real ELF */
464 if ((elf = readelf(filename)) == NULL) {
465 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
466 return;
467 }
468
469 if (be_verbose > 1)
470 printf("%s: scanning file {%s,%s}\n", filename,
471 get_elfeitype(elf, EI_CLASS, elf->elf_class),
472 get_elfeitype(elf, EI_DATA, elf->data[EI_DATA]));
473 else if (be_verbose)
474 printf("%s: scanning file\n", filename);
475
476 /* init output buffer */
477 if (!out_buffer) {
478 out_len = sizeof(char) * 80;
479 out_buffer = (char*)xmalloc(out_len);
480 }
481 *out_buffer = '\0';
482
483 /* show the header */
484 if (!be_quiet && show_banner) {
485 for (i = 0; out_format[i]; ++i) {
486 if (out_format[i] != '%') continue;
487
488 switch (out_format[++i]) {
489 case '%': break;
490 case 'F': prints("FILE "); found_file = 1; break;
491 case 'o': prints(" TYPE "); break;
492 case 'x': prints(" PAX "); break;
493 case 'e': prints("STK/REL "); break;
494 case 't': prints("TEXTREL "); break;
495 case 'r': prints("RPATH "); break;
496 case 'n': prints("NEEDED "); break;
497 case 'i': prints("INTERP "); break;
498 case 'b': prints("BIND "); break;
499 case 's': prints("SYM "); break;
500 }
501 }
502 if (!found_file) prints("FILE ");
503 prints("\n");
504 found_file = 0;
505 show_banner = 0;
506 }
507
508 /* dump all the good stuff */
509 for (i = 0; out_format[i]; ++i) {
510 const char *out;
511
512 /* make sure we trim leading spaces in quiet mode */
513 if (be_quiet && *out_buffer == ' ' && !out_buffer[1])
514 *out_buffer = '\0';
515
516 if (out_format[i] != '%') {
517 xchrcat(&out_buffer, out_format[i], &out_len);
518 continue;
519 }
520
521 out = NULL;
522 switch (out_format[++i]) {
523 case '%': xchrcat(&out_buffer, '%', &out_len); break;
524 case 'F': found_file = 1; xstrcat(&out_buffer, filename, &out_len); break;
525 case 'o': out = get_elfetype(elf); break;
526 case 'x': out = scanelf_file_pax(elf, &found_pax); break;
527 case 'e': out = scanelf_file_stack(elf, &found_stack, &found_relro); break;
528 case 't': out = scanelf_file_textrel(elf, &found_textrel); break;
529 case 'r': scanelf_file_rpath(elf, &found_rpath, &out_buffer, &out_len); break;
530 case 'n': scanelf_file_needed(elf, &found_needed, &out_buffer, &out_len); break;
531 case 'i': out = scanelf_file_interp(elf, &found_interp); break;
532 case 'b': out = scanelf_file_bind(elf, &found_bind); break;
533 case 's': out = scanelf_file_sym(elf, &found_sym, filename); break;
534 }
535 if (out) xstrcat(&out_buffer, out, &out_len);
536 }
537
538 #define FOUND_SOMETHING() \
539 (found_pax || found_stack || found_textrel || found_rpath || \
540 found_needed || found_interp || found_bind || found_sym)
541
542 if (!found_file && (!be_quiet || (be_quiet && FOUND_SOMETHING()))) {
543 xchrcat(&out_buffer, ' ', &out_len);
544 xstrcat(&out_buffer, filename, &out_len);
545 }
546 if (!be_quiet || (be_quiet && FOUND_SOMETHING()))
547 puts(out_buffer);
548
549 unreadelf(elf);
550 }
551
552 /* scan a directory for ET_EXEC files and print when we find one */
553 static void scanelf_dir(const char *path)
554 {
555 register DIR *dir;
556 register struct dirent *dentry;
557 struct stat st_top, st;
558 char buf[_POSIX_PATH_MAX];
559 size_t pathlen = 0, len = 0;
560
561 /* make sure path exists */
562 if (lstat(path, &st_top) == -1) {
563 if (be_verbose > 2) printf("%s: does not exist\n", path);
564 return;
565 }
566
567 /* ok, if it isn't a directory, assume we can open it */
568 if (!S_ISDIR(st_top.st_mode)) {
569 scanelf_file(path);
570 return;
571 }
572
573 /* now scan the dir looking for fun stuff */
574 if ((dir = opendir(path)) == NULL) {
575 warnf("could not opendir %s: %s", path, strerror(errno));
576 return;
577 }
578 if (be_verbose) printf("%s: scanning dir\n", path);
579
580 pathlen = strlen(path);
581 while ((dentry = readdir(dir))) {
582 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
583 continue;
584 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
585 if (len >= sizeof(buf)) {
586 warnf("Skipping '%s': len > sizeof(buf); %d > %d\n", path, (int)len, (int)sizeof(buf));
587 continue;
588 }
589 sprintf(buf, "%s/%s", path, dentry->d_name);
590 if (lstat(buf, &st) != -1) {
591 if (S_ISREG(st.st_mode))
592 scanelf_file(buf);
593 else if (dir_recurse && S_ISDIR(st.st_mode)) {
594 if (dir_crossmount || (st_top.st_dev == st.st_dev))
595 scanelf_dir(buf);
596 }
597 }
598 }
599 closedir(dir);
600 }
601
602 static int scanelf_from_file(char *filename)
603 {
604 FILE *fp = NULL;
605 char *p;
606 char path[_POSIX_PATH_MAX];
607
608 if (((strcmp(filename, "-")) == 0) && (ttyname(0) == NULL))
609 fp = stdin;
610 else if ((fp = fopen(filename, "r")) == NULL)
611 return 1;
612
613 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
614 if ((p = strchr(path, '\n')) != NULL)
615 *p = 0;
616 scanelf_dir(path);
617 }
618 if (fp != stdin)
619 fclose(fp);
620 return 0;
621 }
622
623 static void load_ld_so_conf()
624 {
625 FILE *fp = NULL;
626 char *p;
627 char path[_POSIX_PATH_MAX];
628 int i = 0;
629
630 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
631 return;
632
633 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
634 if (*path != '/')
635 continue;
636
637 if ((p = strrchr(path, '\r')) != NULL)
638 *p = 0;
639 if ((p = strchr(path, '\n')) != NULL)
640 *p = 0;
641
642 ldpaths[i++] = xstrdup(path);
643
644 if (i + 1 == sizeof(ldpaths) / sizeof(*ldpaths))
645 break;
646 }
647 ldpaths[i] = NULL;
648
649 fclose(fp);
650 }
651
652 /* scan /etc/ld.so.conf for paths */
653 static void scanelf_ldpath()
654 {
655 char scan_l, scan_ul, scan_ull;
656 int i = 0;
657
658 if (!ldpaths[0])
659 err("Unable to load any paths from ld.so.conf");
660
661 scan_l = scan_ul = scan_ull = 0;
662
663 while (ldpaths[i]) {
664 if (!scan_l && !strcmp(ldpaths[i], "/lib")) scan_l = 1;
665 if (!scan_ul && !strcmp(ldpaths[i], "/usr/lib")) scan_ul = 1;
666 if (!scan_ull && !strcmp(ldpaths[i], "/usr/local/lib")) scan_ull = 1;
667 scanelf_dir(ldpaths[i]);
668 ++i;
669 }
670
671 if (!scan_l) scanelf_dir("/lib");
672 if (!scan_ul) scanelf_dir("/usr/lib");
673 if (!scan_ull) scanelf_dir("/usr/local/lib");
674 }
675
676 /* scan env PATH for paths */
677 static void scanelf_envpath()
678 {
679 char *path, *p;
680
681 path = getenv("PATH");
682 if (!path)
683 err("PATH is not set in your env !");
684 path = xstrdup(path);
685
686 while ((p = strrchr(path, ':')) != NULL) {
687 scanelf_dir(p + 1);
688 *p = 0;
689 }
690
691 free(path);
692 }
693
694
695
696 /* usage / invocation handling functions */
697 #define PARSE_FLAGS "plRmyxetrnibs:aqvF:f:o:BhV"
698 #define a_argument required_argument
699 static struct option const long_opts[] = {
700 {"path", no_argument, NULL, 'p'},
701 {"ldpath", no_argument, NULL, 'l'},
702 {"recursive", no_argument, NULL, 'R'},
703 {"mount", no_argument, NULL, 'm'},
704 {"symlink", no_argument, NULL, 'y'},
705 {"pax", no_argument, NULL, 'x'},
706 {"header", no_argument, NULL, 'e'},
707 {"textrel", no_argument, NULL, 't'},
708 {"rpath", no_argument, NULL, 'r'},
709 {"needed", no_argument, NULL, 'n'},
710 {"interp", no_argument, NULL, 'i'},
711 {"bind", no_argument, NULL, 'b'},
712 {"symbol", a_argument, NULL, 's'},
713 {"all", no_argument, NULL, 'a'},
714 {"quiet", no_argument, NULL, 'q'},
715 {"verbose", no_argument, NULL, 'v'},
716 {"format", a_argument, NULL, 'F'},
717 {"from", a_argument, NULL, 'f'},
718 {"file", a_argument, NULL, 'o'},
719 {"nobanner", no_argument, NULL, 'B'},
720 {"help", no_argument, NULL, 'h'},
721 {"version", no_argument, NULL, 'V'},
722 {NULL, no_argument, NULL, 0x0}
723 };
724
725 static char *opts_help[] = {
726 "Scan all directories in PATH environment",
727 "Scan all directories in /etc/ld.so.conf",
728 "Scan directories recursively",
729 "Don't recursively cross mount points",
730 "Don't scan symlinks\n",
731 "Print PaX markings",
732 "Print GNU_STACK markings",
733 "Print TEXTREL information",
734 "Print RPATH information",
735 "Print NEEDED information",
736 "Print INTERP information",
737 "Print BIND information",
738 "Find a specified symbol",
739 "Print all scanned info (-x -e -t -r -n -i -b)\n",
740 "Only output 'bad' things",
741 "Be verbose (can be specified more than once)",
742 "Use specified format for output",
743 "Read input stream from a filename",
744 "Write output stream to a filename",
745 "Don't display the header",
746 "Print this help and exit",
747 "Print version and exit",
748 NULL
749 };
750
751 /* display usage and exit */
752 static void usage(int status)
753 {
754 unsigned long i;
755 printf("* Scan ELF binaries for stuff\n\n"
756 "Usage: %s [options] <dir1/file1> [dir2 dirN fileN ...]\n\n", argv0);
757 printf("Options: -[%s]\n", PARSE_FLAGS);
758 for (i = 0; long_opts[i].name; ++i)
759 if (long_opts[i].has_arg == no_argument)
760 printf(" -%c, --%-13s* %s\n", long_opts[i].val,
761 long_opts[i].name, opts_help[i]);
762 else
763 printf(" -%c, --%-6s <arg> * %s\n", long_opts[i].val,
764 long_opts[i].name, opts_help[i]);
765
766 if (status != EXIT_SUCCESS)
767 exit(status);
768
769 puts("\nThe format modifiers for the -F option are:");
770 puts(" %F Filename \t%x PaX Flags \t%e STACK/RELRO");
771 puts(" %t TEXTREL \t%r RPATH \t%n NEEDED");
772 puts(" %i INTERP \t%b BIND \t%s symbol");
773
774 exit(status);
775 }
776
777 /* parse command line arguments and preform needed actions */
778 static void parseargs(int argc, char *argv[])
779 {
780 int i;
781 char *from_file = NULL;
782
783 opterr = 0;
784 while ((i=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
785 switch (i) {
786
787 case 'V':
788 printf("%s compiled %s\n%s\n"
789 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
790 __FILE__, __DATE__, rcsid, argv0);
791 exit(EXIT_SUCCESS);
792 break;
793 case 'h': usage(EXIT_SUCCESS); break;
794 case 'f':
795 if (from_file == NULL)
796 from_file = xstrdup(optarg);
797 else
798 err("Don't specify -f twice");
799 break;
800 case 'o': {
801 FILE *fp = NULL;
802 fp = freopen(optarg, "w", stdout);
803 if (fp == NULL)
804 err("Could not open output stream '%s': %s", optarg, strerror(errno));
805 stdout = fp;
806 break;
807 }
808
809 case 's': {
810 size_t len;
811 if (!find_sym)
812 err("Don't specify -s twice");
813 find_sym = xstrdup(optarg);
814 len = strlen(find_sym) + 1;
815 versioned_symname = (char*)xmalloc(sizeof(char) * (len+1));
816 sprintf(versioned_symname, "%s@", find_sym);
817 break;
818 }
819
820 case 'F': {
821 if (!out_format)
822 out_format = xstrdup(optarg);
823 else
824 err("Don't specify -F twice");
825 break;
826 }
827
828 case 'y': scan_symlink = 0; break;
829 case 'B': show_banner = 0; break;
830 case 'l': scan_ldpath = 1; break;
831 case 'p': scan_envpath = 1; break;
832 case 'R': dir_recurse = 1; break;
833 case 'm': dir_crossmount = 0; break;
834 case 'x': show_pax = 1; break;
835 case 'e': show_stack = 1; break;
836 case 't': show_textrel = 1; break;
837 case 'r': show_rpath = 1; break;
838 case 'n': show_needed = 1; break;
839 case 'i': show_interp = 1; break;
840 case 'b': show_bind = 1; break;
841 case 'q': be_quiet = 1; break;
842 case 'v': be_verbose = (be_verbose % 20) + 1; break;
843 case 'a': show_pax = show_stack = show_textrel = show_rpath = \
844 show_needed = show_interp = show_bind = 1; break;
845
846 case ':':
847 err("Option missing parameter\n");
848 case '?':
849 err("Unknown option\n");
850 default:
851 err("Unhandled option '%c'", i);
852 }
853 }
854
855 /* let the format option override all other options */
856 if (out_format) {
857 show_pax = show_stack = show_textrel = show_rpath = \
858 show_needed = show_interp = show_bind = 0;
859 for (i = 0; out_format[i]; ++i) {
860 if (out_format[i] != '%') continue;
861
862 switch (out_format[++i]) {
863 case '%': break;
864 case 'F': break;
865 case 's': break;
866 case 'o': break;
867 case 'x': show_pax = 1; break;
868 case 'e': show_stack = 1; break;
869 case 't': show_textrel = 1; break;
870 case 'r': show_rpath = 1; break;
871 case 'n': show_needed = 1; break;
872 case 'i': show_interp = 1; break;
873 case 'b': show_bind = 1; break;
874 default:
875 err("Invalid format specifier '%c' (byte %i)",
876 out_format[i], i+1);
877 }
878 }
879
880 /* construct our default format */
881 } else {
882 size_t fmt_len = 30;
883 out_format = (char*)xmalloc(sizeof(char) * fmt_len);
884 if (!be_quiet) xstrcat(&out_format, "%o ", &fmt_len);
885 if (show_pax) xstrcat(&out_format, "%x ", &fmt_len);
886 if (show_stack) xstrcat(&out_format, "%e ", &fmt_len);
887 if (show_textrel) xstrcat(&out_format, "%t ", &fmt_len);
888 if (show_rpath) xstrcat(&out_format, "%r ", &fmt_len);
889 if (show_needed) xstrcat(&out_format, "%n ", &fmt_len);
890 if (show_interp) xstrcat(&out_format, "%i ", &fmt_len);
891 if (show_bind) xstrcat(&out_format, "%b ", &fmt_len);
892 if (find_sym) xstrcat(&out_format, "%s ", &fmt_len);
893 if (!be_quiet) xstrcat(&out_format, "%F ", &fmt_len);
894 }
895 if (be_verbose > 2) printf("Format: %s\n", out_format);
896
897 /* now lets actually do the scanning */
898 if (scan_ldpath || (show_rpath && be_quiet))
899 load_ld_so_conf();
900 if (scan_ldpath) scanelf_ldpath();
901 if (scan_envpath) scanelf_envpath();
902 if (from_file) {
903 scanelf_from_file(from_file);
904 free(from_file);
905 from_file = *argv;
906 }
907 if (optind == argc && !scan_ldpath && !scan_envpath && !from_file)
908 err("Nothing to scan !?");
909 while (optind < argc)
910 scanelf_dir(argv[optind++]);
911
912 /* clean up */
913 if (find_sym) {
914 free(find_sym);
915 free(versioned_symname);
916 }
917 if (out_format) free(out_format);
918 for (i = 0; ldpaths[i]; ++i)
919 free(ldpaths[i]);
920 }
921
922
923
924 /* utility funcs */
925 static char *xstrdup(const char *s)
926 {
927 char *ret = strdup(s);
928 if (!ret) err("Could not strdup(): %s", strerror(errno));
929 return ret;
930 }
931
932 static void *xmalloc(size_t size)
933 {
934 void *ret = malloc(size);
935 if (!ret) err("Could not malloc() %li bytes", (unsigned long)size);
936 return ret;
937 }
938
939 static void xstrcat(char **dst, const char *src, size_t *curr_len)
940 {
941 long new_len;
942
943 new_len = strlen(*dst) + strlen(src);
944 if (*curr_len <= new_len) {
945 *curr_len = new_len + (*curr_len / 2);
946 *dst = realloc(*dst, *curr_len);
947 if (!*dst)
948 err("could not realloc %li bytes", (unsigned long)*curr_len);
949 }
950
951 strcat(*dst, src);
952 }
953
954 static inline void xchrcat(char **dst, const char append, size_t *curr_len)
955 {
956 static char my_app[2];
957 my_app[0] = append;
958 my_app[1] = '\0';
959 xstrcat(dst, my_app, curr_len);
960 }
961
962
963 int main(int argc, char *argv[])
964 {
965 if (argc < 2)
966 usage(EXIT_FAILURE);
967 parseargs(argc, argv);
968 fclose(stdout);
969 #ifdef __BOUNDS_CHECKING_ON
970 warn("The calls to add/delete heap should be off by 1 due to the out_buffer not being freed in scanelf_file()");
971 #endif
972 return EXIT_SUCCESS;
973 }

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