/[gentoo-projects]/pax-utils/scanelf.c
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Revision 1.71 - (show annotations) (download) (as text)
Sat Jun 4 02:50:50 2005 UTC (9 years, 1 month ago) by vapier
Branch: MAIN
Changes since 1.70: +31 -16 lines
File MIME type: text/x-csrc
add support for checking if the PT_LOAD program header is +wx

1 /*
2 * Copyright 2003-2005 Gentoo Foundation
3 * Distributed under the terms of the GNU General Public License v2
4 * $Header: /var/cvsroot/gentoo-projects/pax-utils/scanelf.c,v 1.70 2005/06/03 23:41:59 vapier Exp $
5 *
6 ********************************************************************
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
20 * MA 02111-1307, USA.
21 */
22
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <sys/types.h>
26 #include <libgen.h>
27 #include <limits.h>
28 #define __USE_GNU
29 #include <string.h>
30 #include <errno.h>
31 #include <unistd.h>
32 #include <sys/stat.h>
33 #include <dirent.h>
34 #include <getopt.h>
35 #include <assert.h>
36 #include "paxelf.h"
37
38 static const char *rcsid = "$Id: scanelf.c,v 1.70 2005/06/03 23:41:59 vapier Exp $";
39 #define argv0 "scanelf"
40
41 #define IS_MODIFIER(c) (c == '%' || c == '#')
42
43
44
45 /* prototypes */
46 static void scanelf_file(const char *filename);
47 static void scanelf_dir(const char *path);
48 static void scanelf_ldpath();
49 static void scanelf_envpath();
50 static void usage(int status);
51 static void parseargs(int argc, char *argv[]);
52 static char *xstrdup(const char *s);
53 static void *xmalloc(size_t size);
54 static void xstrcat(char **dst, const char *src, size_t *curr_len);
55 static inline void xchrcat(char **dst, const char append, size_t *curr_len);
56
57 /* variables to control behavior */
58 static char *ldpaths[256];
59 static char scan_ldpath = 0;
60 static char scan_envpath = 0;
61 static char scan_symlink = 1;
62 static char dir_recurse = 0;
63 static char dir_crossmount = 1;
64 static char show_pax = 0;
65 static char show_stack = 0;
66 static char show_textrel = 0;
67 static char show_rpath = 0;
68 static char show_needed = 0;
69 static char show_interp = 0;
70 static char show_bind = 0;
71 static char show_banner = 1;
72 static char be_quiet = 0;
73 static char be_verbose = 0;
74 static char be_wewy_wewy_quiet = 0;
75 static char *find_sym = NULL, *versioned_symname = NULL;
76 static char *out_format = NULL;
77 static char *search_path = NULL;
78
79
80
81 /* sub-funcs for scanelf_file() */
82 static char *scanelf_file_pax(elfobj *elf, char *found_pax)
83 {
84 static char *paxflags;
85 static char ret[7];
86 unsigned long i, shown;
87
88
89 if (!show_pax) return NULL;
90
91 shown = 0;
92 memset(&ret, 0, sizeof(ret));
93
94 if (elf->phdr) {
95 #define SHOW_PAX(B) \
96 if (elf->elf_class == ELFCLASS ## B) { \
97 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
98 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
99 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
100 if (EGET(phdr[i].p_type) != PT_PAX_FLAGS) \
101 continue; \
102 if (be_quiet && (EGET(phdr[i].p_flags) == 10240)) \
103 continue; \
104 memcpy(ret, pax_short_pf_flags(EGET(phdr[i].p_flags)), 6); \
105 *found_pax = 1; \
106 ++shown; \
107 break; \
108 } \
109 }
110 SHOW_PAX(32)
111 SHOW_PAX(64)
112 }
113
114 /* fall back to EI_PAX if no PT_PAX was found */
115 if (!*ret) {
116 paxflags = pax_short_hf_flags(EI_PAX_FLAGS(elf));
117 if (!be_quiet || (be_quiet && EI_PAX_FLAGS(elf))) {
118 *found_pax = 1;
119 return paxflags;
120 }
121 strncpy(ret, paxflags, sizeof(ret));
122 // ++shown;
123 }
124
125 if (be_quiet && !shown)
126 return NULL;
127 return ret;
128
129 }
130 static char *scanelf_file_stack(elfobj *elf, char *found_stack, char *found_relro, char *found_load)
131 {
132 static char ret[12];
133 char *found;
134 unsigned long i, off, shown, check_flags;
135 unsigned char multi_stack, multi_relro, multi_load;
136
137 if (!show_stack) return NULL;
138
139 memcpy(ret, "--- --- ---\0", 12);
140
141 shown = 0;
142 multi_stack = multi_relro = multi_load = 0;
143
144 if (elf->phdr) {
145 #define SHOW_STACK(B) \
146 if (elf->elf_class == ELFCLASS ## B) { \
147 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
148 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
149 uint32_t flags; \
150 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
151 if (EGET(phdr[i].p_type) == PT_GNU_STACK) { \
152 if (multi_stack++) warnf("%s: multiple PT_GNU_STACK's !?", elf->filename); \
153 found = found_stack; \
154 off = 0; \
155 check_flags = PF_X; \
156 } else if (EGET(phdr[i].p_type) == PT_GNU_RELRO) { \
157 if (multi_relro++) warnf("%s: multiple PT_GNU_RELRO's !?", elf->filename); \
158 found = found_relro; \
159 off = 4; \
160 check_flags = PF_X; \
161 } else if (EGET(phdr[i].p_type) == PT_LOAD) { \
162 if (multi_load++ > 2) warnf("%s: more than 2 PT_LOAD's !?", elf->filename); \
163 found = found_load; \
164 off = 8; \
165 check_flags = PF_W|PF_X; \
166 } else \
167 continue; \
168 flags = EGET(phdr[i].p_flags); \
169 if (be_quiet && ((flags & check_flags) != check_flags)) \
170 continue; \
171 memcpy(ret+off, gnu_short_stack_flags(flags), 3); \
172 *found = 1; \
173 ++shown; \
174 } \
175 }
176 SHOW_STACK(32)
177 SHOW_STACK(64)
178 }
179
180 if (be_quiet && !shown)
181 return NULL;
182 else
183 return ret;
184 }
185 static char *scanelf_file_textrel(elfobj *elf, char *found_textrel)
186 {
187 static char ret[] = "TEXTREL";
188 unsigned long i;
189
190 if (!show_textrel) return NULL;
191
192 if (elf->phdr) {
193 #define SHOW_TEXTREL(B) \
194 if (elf->elf_class == ELFCLASS ## B) { \
195 Elf ## B ## _Dyn *dyn; \
196 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
197 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
198 Elf ## B ## _Off offset; \
199 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
200 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
201 offset = EGET(phdr[i].p_offset); \
202 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
203 dyn = DYN ## B (elf->data + offset); \
204 while (EGET(dyn->d_tag) != DT_NULL) { \
205 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
206 *found_textrel = 1; \
207 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
208 return (be_wewy_wewy_quiet ? NULL : ret); \
209 } \
210 ++dyn; \
211 } \
212 } }
213 SHOW_TEXTREL(32)
214 SHOW_TEXTREL(64)
215 }
216
217 if (be_quiet || be_wewy_wewy_quiet)
218 return NULL;
219 else
220 return (char *)" - ";
221 }
222 static void scanelf_file_rpath(elfobj *elf, char *found_rpath, char **ret, size_t *ret_len)
223 {
224 unsigned long i, s;
225 char *rpath, *runpath, **r;
226 void *strtbl_void;
227
228 if (!show_rpath) return;
229
230 strtbl_void = elf_findsecbyname(elf, ".dynstr");
231 rpath = runpath = NULL;
232
233 if (elf->phdr && strtbl_void) {
234 #define SHOW_RPATH(B) \
235 if (elf->elf_class == ELFCLASS ## B) { \
236 Elf ## B ## _Dyn *dyn; \
237 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
238 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
239 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
240 Elf ## B ## _Off offset; \
241 Elf ## B ## _Xword word; \
242 /* Scan all the program headers */ \
243 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
244 /* Just scan dynamic headers */ \
245 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
246 offset = EGET(phdr[i].p_offset); \
247 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
248 /* Just scan dynamic RPATH/RUNPATH headers */ \
249 dyn = DYN ## B (elf->data + offset); \
250 while ((word=EGET(dyn->d_tag)) != DT_NULL) { \
251 if (word == DT_RPATH) { \
252 r = &rpath; \
253 } else if (word == DT_RUNPATH) { \
254 r = &runpath; \
255 } else { \
256 ++dyn; \
257 continue; \
258 } \
259 /* Verify the memory is somewhat sane */ \
260 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
261 if (offset < (Elf ## B ## _Off)elf->len) { \
262 if (*r) warn("ELF has multiple %s's !?", get_elfdtype(word)); \
263 *r = (char*)(elf->data + offset); \
264 /* If quiet, don't output paths in ld.so.conf */ \
265 if (be_quiet) { \
266 size_t len; \
267 char *start, *end; \
268 for (s = 0; *r && ldpaths[s]; ++s) { \
269 /* scan each path in : delimited list */ \
270 start = *r; \
271 end = strchr(start, ':'); \
272 while ((start && ((end = strchr(start, ':')) != NULL)) || start) { \
273 len = (end ? abs(end - start) : strlen(start)); \
274 if (!strncmp(ldpaths[s], start, len) && !ldpaths[s][len]) { \
275 *r = (end ? end + 1 : NULL); \
276 break; \
277 } \
278 start = (end ? start + len + 1 : NULL); \
279 } \
280 } \
281 } \
282 if (*r) *found_rpath = 1; \
283 } \
284 ++dyn; \
285 } \
286 } }
287 SHOW_RPATH(32)
288 SHOW_RPATH(64)
289 }
290
291 if (be_wewy_wewy_quiet) return;
292
293 if (rpath && runpath) {
294 if (!strcmp(rpath, runpath)) {
295 xstrcat(ret, runpath, ret_len);
296 } else {
297 fprintf(stderr, "RPATH [%s] != RUNPATH [%s]\n", rpath, runpath);
298 xchrcat(ret, '{', ret_len);
299 xstrcat(ret, rpath, ret_len);
300 xchrcat(ret, ',', ret_len);
301 xstrcat(ret, runpath, ret_len);
302 xchrcat(ret, '}', ret_len);
303 }
304 } else if (rpath || runpath)
305 xstrcat(ret, (runpath ? runpath : rpath), ret_len);
306 else if (!be_quiet)
307 xstrcat(ret, " - ", ret_len);
308 }
309 static void scanelf_file_needed(elfobj *elf, char *found_needed, char **ret, size_t *ret_len)
310 {
311 unsigned long i;
312 char *needed;
313 void *strtbl_void;
314
315 if (!show_needed) return;
316
317 strtbl_void = elf_findsecbyname(elf, ".dynstr");
318
319 if (elf->phdr && strtbl_void) {
320 #define SHOW_NEEDED(B) \
321 if (elf->elf_class == ELFCLASS ## B) { \
322 Elf ## B ## _Dyn *dyn; \
323 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
324 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
325 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
326 Elf ## B ## _Off offset; \
327 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
328 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
329 offset = EGET(phdr[i].p_offset); \
330 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
331 dyn = DYN ## B (elf->data + offset); \
332 while (EGET(dyn->d_tag) != DT_NULL) { \
333 if (EGET(dyn->d_tag) == DT_NEEDED) { \
334 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
335 if (offset >= (Elf ## B ## _Off)elf->len) { \
336 ++dyn; \
337 continue; \
338 } \
339 needed = (char*)(elf->data + offset); \
340 if (*found_needed) xchrcat(ret, ',', ret_len); \
341 if (!be_wewy_wewy_quiet) xstrcat(ret, needed, ret_len); \
342 *found_needed = 1; \
343 } \
344 ++dyn; \
345 } \
346 } }
347 SHOW_NEEDED(32)
348 SHOW_NEEDED(64)
349 }
350 }
351 static char *scanelf_file_interp(elfobj *elf, char *found_interp)
352 {
353 void *strtbl_void;
354
355 if (!show_interp) return NULL;
356
357 strtbl_void = elf_findsecbyname(elf, ".interp");
358
359 if (strtbl_void) {
360 #define SHOW_INTERP(B) \
361 if (elf->elf_class == ELFCLASS ## B) { \
362 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
363 *found_interp = 1; \
364 return (be_wewy_wewy_quiet ? NULL : elf->data + EGET(strtbl->sh_offset)); \
365 }
366 SHOW_INTERP(32)
367 SHOW_INTERP(64)
368 }
369 return NULL;
370 }
371 static char *scanelf_file_bind(elfobj *elf, char *found_bind)
372 {
373 unsigned long i;
374 struct stat s;
375
376 if (!show_bind) return NULL;
377 if (!elf->phdr) return NULL;
378
379 #define SHOW_BIND(B) \
380 if (elf->elf_class == ELFCLASS ## B) { \
381 Elf ## B ## _Dyn *dyn; \
382 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
383 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
384 Elf ## B ## _Off offset; \
385 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
386 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
387 offset = EGET(phdr[i].p_offset); \
388 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
389 dyn = DYN ## B (elf->data + offset); \
390 while (EGET(dyn->d_tag) != DT_NULL) { \
391 if (EGET(dyn->d_tag) == DT_BIND_NOW || \
392 (EGET(dyn->d_tag) == DT_FLAGS && EGET(dyn->d_un.d_val) & DF_BIND_NOW)) \
393 { \
394 if (be_quiet) return NULL; \
395 *found_bind = 1; \
396 return (char *)(be_wewy_wewy_quiet ? NULL : "NOW"); \
397 } \
398 ++dyn; \
399 } \
400 } \
401 }
402 SHOW_BIND(32)
403 SHOW_BIND(64)
404
405 if (be_wewy_wewy_quiet) return NULL;
406
407 if (be_quiet && !fstat(elf->fd, &s) && !(s.st_mode & S_ISUID || s.st_mode & S_ISGID)) {
408 return NULL;
409 } else {
410 *found_bind = 1;
411 return (char *) "LAZY";
412 }
413 }
414 static char *scanelf_file_sym(elfobj *elf, char *found_sym, const char *filename)
415 {
416 unsigned long i;
417 void *symtab_void, *strtab_void;
418
419 if (!find_sym) return NULL;
420
421 /* debug sections */
422 symtab_void = elf_findsecbyname(elf, ".symtab");
423 strtab_void = elf_findsecbyname(elf, ".strtab");
424 /* fall back to runtime sections */
425 if (!symtab_void || !strtab_void) {
426 symtab_void = elf_findsecbyname(elf, ".dynsym");
427 strtab_void = elf_findsecbyname(elf, ".dynstr");
428 }
429
430 if (symtab_void && strtab_void) {
431 char *base, *basemem;
432 basemem = xstrdup(filename);
433 base = basename(basemem);
434 #define FIND_SYM(B) \
435 if (elf->elf_class == ELFCLASS ## B) { \
436 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
437 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
438 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
439 unsigned long cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
440 char *symname; \
441 for (i = 0; i < cnt; ++i) { \
442 if (sym->st_name) { \
443 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
444 if (*find_sym == '*') { \
445 printf("%s(%s) %5lX %15s %s\n", \
446 ((*found_sym == 0) ? "\n\t" : "\t"), \
447 base, \
448 (long)sym->st_size, \
449 (char *)get_elfstttype(sym->st_info), \
450 symname); \
451 *found_sym = 1; \
452 } else if ((strcmp(find_sym, symname) == 0) || \
453 (strcmp(symname, versioned_symname) == 0)) \
454 (*found_sym)++; \
455 } \
456 ++sym; \
457 } }
458 FIND_SYM(32)
459 FIND_SYM(64)
460 free(basemem);
461 }
462
463 if (be_wewy_wewy_quiet) return NULL;
464
465 if (*find_sym != '*' && *found_sym)
466 return find_sym;
467 if (be_quiet)
468 return NULL;
469 else
470 return (char *)" - ";
471 }
472 /* scan an elf file and show all the fun stuff */
473 #define prints(str) write(fileno(stdout), str, strlen(str))
474 static void scanelf_file(const char *filename)
475 {
476 unsigned long i;
477 char found_pax, found_stack, found_relro, found_load, found_textrel,
478 found_rpath, found_needed, found_interp, found_bind,
479 found_sym, found_file;
480 elfobj *elf;
481 struct stat st;
482 static char *out_buffer = NULL;
483 static size_t out_len;
484
485 /* make sure 'filename' exists */
486 if (lstat(filename, &st) == -1) {
487 if (be_verbose > 2) printf("%s: does not exist\n", filename);
488 return;
489 }
490 /* always handle regular files and handle symlinked files if no -y */
491 if (S_ISLNK(st.st_mode)) {
492 if (!scan_symlink) return;
493 stat(filename, &st);
494 }
495 if (!S_ISREG(st.st_mode)) {
496 if (be_verbose > 2) printf("%s: skipping non-file\n", filename);
497 return;
498 }
499
500 found_pax = found_stack = found_relro = found_load = \
501 found_textrel = found_rpath = found_needed = found_interp = \
502 found_bind = found_sym = found_file = 0;
503
504 /* verify this is real ELF */
505 if ((elf = readelf(filename)) == NULL) {
506 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
507 return;
508 }
509
510 if (be_verbose > 1)
511 printf("%s: scanning file {%s,%s}\n", filename,
512 get_elfeitype(EI_CLASS, elf->elf_class),
513 get_elfeitype(EI_DATA, elf->data[EI_DATA]));
514 else if (be_verbose)
515 printf("%s: scanning file\n", filename);
516
517 /* init output buffer */
518 if (!out_buffer) {
519 out_len = sizeof(char) * 80;
520 out_buffer = (char*)xmalloc(out_len);
521 }
522 *out_buffer = '\0';
523
524 /* show the header */
525 if (!be_quiet && show_banner) {
526 for (i = 0; out_format[i]; ++i) {
527 if (!IS_MODIFIER(out_format[i])) continue;
528
529 switch (out_format[++i]) {
530 case '%': break;
531 case '#': break;
532 case 'F':
533 case 'p':
534 case 'f': prints("FILE "); found_file = 1; break;
535 case 'o': prints(" TYPE "); break;
536 case 'x': prints(" PAX "); break;
537 case 'e': prints("STK/REL/PTL "); break;
538 case 't': prints("TEXTREL "); break;
539 case 'r': prints("RPATH "); break;
540 case 'n': prints("NEEDED "); break;
541 case 'i': prints("INTERP "); break;
542 case 'b': prints("BIND "); break;
543 case 's': prints("SYM "); break;
544 }
545 }
546 if (!found_file) prints("FILE ");
547 prints("\n");
548 found_file = 0;
549 show_banner = 0;
550 }
551
552 /* dump all the good stuff */
553 for (i = 0; out_format[i]; ++i) {
554 const char *out;
555 const char *tmp;
556
557 /* make sure we trim leading spaces in quiet mode */
558 if (be_quiet && *out_buffer == ' ' && !out_buffer[1])
559 *out_buffer = '\0';
560
561 if (!IS_MODIFIER(out_format[i])) {
562 xchrcat(&out_buffer, out_format[i], &out_len);
563 continue;
564 }
565
566 out = NULL;
567 be_wewy_wewy_quiet = (out_format[i] == '#');
568 switch (out_format[++i]) {
569 case '%':
570 case '#':
571 xchrcat(&out_buffer, out_format[i], &out_len); break;
572 case 'F':
573 if (be_wewy_wewy_quiet) break;
574 found_file = 1;
575 xstrcat(&out_buffer, filename, &out_len);
576 break;
577 case 'p':
578 if (be_wewy_wewy_quiet) break;
579 found_file = 1;
580 tmp = filename;
581 if (search_path) {
582 ssize_t len_search = strlen(search_path);
583 ssize_t len_file = strlen(filename);
584 if (!strncmp(filename, search_path, len_search) && \
585 len_file > len_search)
586 tmp += len_search;
587 if (*tmp == '/' && search_path[len_search-1] == '/') tmp++;
588 }
589 xstrcat(&out_buffer, tmp, &out_len);
590 break;
591 case 'f':
592 if (be_wewy_wewy_quiet) break;
593 found_file = 1;
594 tmp = strrchr(filename, '/');
595 tmp = (tmp == NULL ? filename : tmp+1);
596 xstrcat(&out_buffer, tmp, &out_len);
597 break;
598 case 'o': out = get_elfetype(elf); break;
599 case 'x': out = scanelf_file_pax(elf, &found_pax); break;
600 case 'e': out = scanelf_file_stack(elf, &found_stack, &found_relro, &found_load); break;
601 case 't': out = scanelf_file_textrel(elf, &found_textrel); break;
602 case 'r': scanelf_file_rpath(elf, &found_rpath, &out_buffer, &out_len); break;
603 case 'n': scanelf_file_needed(elf, &found_needed, &out_buffer, &out_len); break;
604 case 'i': out = scanelf_file_interp(elf, &found_interp); break;
605 case 'b': out = scanelf_file_bind(elf, &found_bind); break;
606 case 's': out = scanelf_file_sym(elf, &found_sym, filename); break;
607 }
608 if (out) xstrcat(&out_buffer, out, &out_len);
609 }
610
611 #define FOUND_SOMETHING() \
612 (found_pax || found_stack || found_relro || found_load || found_textrel || \
613 found_rpath || found_needed || found_interp || found_bind || found_sym)
614
615 if (!found_file && (!be_quiet || (be_quiet && FOUND_SOMETHING()))) {
616 xchrcat(&out_buffer, ' ', &out_len);
617 xstrcat(&out_buffer, filename, &out_len);
618 }
619 if (!be_quiet || (be_quiet && FOUND_SOMETHING()))
620 puts(out_buffer);
621
622 unreadelf(elf);
623 }
624
625 /* scan a directory for ET_EXEC files and print when we find one */
626 static void scanelf_dir(const char *path)
627 {
628 register DIR *dir;
629 register struct dirent *dentry;
630 struct stat st_top, st;
631 char buf[_POSIX_PATH_MAX];
632 size_t pathlen = 0, len = 0;
633
634 /* make sure path exists */
635 if (lstat(path, &st_top) == -1) {
636 if (be_verbose > 2) printf("%s: does not exist\n", path);
637 return;
638 }
639
640 /* ok, if it isn't a directory, assume we can open it */
641 if (!S_ISDIR(st_top.st_mode)) {
642 scanelf_file(path);
643 return;
644 }
645
646 /* now scan the dir looking for fun stuff */
647 if ((dir = opendir(path)) == NULL) {
648 warnf("could not opendir %s: %s", path, strerror(errno));
649 return;
650 }
651 if (be_verbose) printf("%s: scanning dir\n", path);
652
653 pathlen = strlen(path);
654 while ((dentry = readdir(dir))) {
655 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
656 continue;
657 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
658 if (len >= sizeof(buf)) {
659 warnf("Skipping '%s': len > sizeof(buf); %d > %d\n", path, (int)len, (int)sizeof(buf));
660 continue;
661 }
662 sprintf(buf, "%s/%s", path, dentry->d_name);
663 if (lstat(buf, &st) != -1) {
664 if (S_ISREG(st.st_mode))
665 scanelf_file(buf);
666 else if (dir_recurse && S_ISDIR(st.st_mode)) {
667 if (dir_crossmount || (st_top.st_dev == st.st_dev))
668 scanelf_dir(buf);
669 }
670 }
671 }
672 closedir(dir);
673 }
674
675 static int scanelf_from_file(char *filename)
676 {
677 FILE *fp = NULL;
678 char *p;
679 char path[_POSIX_PATH_MAX];
680
681 if (((strcmp(filename, "-")) == 0) && (ttyname(0) == NULL))
682 fp = stdin;
683 else if ((fp = fopen(filename, "r")) == NULL)
684 return 1;
685
686 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
687 if ((p = strchr(path, '\n')) != NULL)
688 *p = 0;
689 search_path = path;
690 scanelf_dir(path);
691 }
692 if (fp != stdin)
693 fclose(fp);
694 return 0;
695 }
696
697 static void load_ld_so_conf()
698 {
699 FILE *fp = NULL;
700 char *p;
701 char path[_POSIX_PATH_MAX];
702 int i = 0;
703
704 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
705 return;
706
707 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
708 if (*path != '/')
709 continue;
710
711 if ((p = strrchr(path, '\r')) != NULL)
712 *p = 0;
713 if ((p = strchr(path, '\n')) != NULL)
714 *p = 0;
715
716 ldpaths[i++] = xstrdup(path);
717
718 if (i + 1 == sizeof(ldpaths) / sizeof(*ldpaths))
719 break;
720 }
721 ldpaths[i] = NULL;
722
723 fclose(fp);
724 }
725
726 /* scan /etc/ld.so.conf for paths */
727 static void scanelf_ldpath()
728 {
729 char scan_l, scan_ul, scan_ull;
730 int i = 0;
731
732 if (!ldpaths[0])
733 err("Unable to load any paths from ld.so.conf");
734
735 scan_l = scan_ul = scan_ull = 0;
736
737 while (ldpaths[i]) {
738 if (!scan_l && !strcmp(ldpaths[i], "/lib")) scan_l = 1;
739 if (!scan_ul && !strcmp(ldpaths[i], "/usr/lib")) scan_ul = 1;
740 if (!scan_ull && !strcmp(ldpaths[i], "/usr/local/lib")) scan_ull = 1;
741 scanelf_dir(ldpaths[i]);
742 ++i;
743 }
744
745 if (!scan_l) scanelf_dir("/lib");
746 if (!scan_ul) scanelf_dir("/usr/lib");
747 if (!scan_ull) scanelf_dir("/usr/local/lib");
748 }
749
750 /* scan env PATH for paths */
751 static void scanelf_envpath()
752 {
753 char *path, *p;
754
755 path = getenv("PATH");
756 if (!path)
757 err("PATH is not set in your env !");
758 path = xstrdup(path);
759
760 while ((p = strrchr(path, ':')) != NULL) {
761 scanelf_dir(p + 1);
762 *p = 0;
763 }
764
765 free(path);
766 }
767
768
769
770 /* usage / invocation handling functions */
771 #define PARSE_FLAGS "plRmyxetrnibs:aqvF:f:o:BhV"
772 #define a_argument required_argument
773 static struct option const long_opts[] = {
774 {"path", no_argument, NULL, 'p'},
775 {"ldpath", no_argument, NULL, 'l'},
776 {"recursive", no_argument, NULL, 'R'},
777 {"mount", no_argument, NULL, 'm'},
778 {"symlink", no_argument, NULL, 'y'},
779 {"pax", no_argument, NULL, 'x'},
780 {"header", no_argument, NULL, 'e'},
781 {"textrel", no_argument, NULL, 't'},
782 {"rpath", no_argument, NULL, 'r'},
783 {"needed", no_argument, NULL, 'n'},
784 {"interp", no_argument, NULL, 'i'},
785 {"bind", no_argument, NULL, 'b'},
786 {"symbol", a_argument, NULL, 's'},
787 {"all", no_argument, NULL, 'a'},
788 {"quiet", no_argument, NULL, 'q'},
789 {"verbose", no_argument, NULL, 'v'},
790 {"format", a_argument, NULL, 'F'},
791 {"from", a_argument, NULL, 'f'},
792 {"file", a_argument, NULL, 'o'},
793 {"nobanner", no_argument, NULL, 'B'},
794 {"help", no_argument, NULL, 'h'},
795 {"version", no_argument, NULL, 'V'},
796 {NULL, no_argument, NULL, 0x0}
797 };
798
799 static const char *opts_help[] = {
800 "Scan all directories in PATH environment",
801 "Scan all directories in /etc/ld.so.conf",
802 "Scan directories recursively",
803 "Don't recursively cross mount points",
804 "Don't scan symlinks\n",
805 "Print PaX markings",
806 "Print GNU_STACK/PT_LOAD markings",
807 "Print TEXTREL information",
808 "Print RPATH information",
809 "Print NEEDED information",
810 "Print INTERP information",
811 "Print BIND information",
812 "Find a specified symbol",
813 "Print all scanned info (-x -e -t -r -n -i -b)\n",
814 "Only output 'bad' things",
815 "Be verbose (can be specified more than once)",
816 "Use specified format for output",
817 "Read input stream from a filename",
818 "Write output stream to a filename",
819 "Don't display the header",
820 "Print this help and exit",
821 "Print version and exit",
822 NULL
823 };
824
825 /* display usage and exit */
826 static void usage(int status)
827 {
828 unsigned long i;
829 printf("* Scan ELF binaries for stuff\n\n"
830 "Usage: %s [options] <dir1/file1> [dir2 dirN fileN ...]\n\n", argv0);
831 printf("Options: -[%s]\n", PARSE_FLAGS);
832 for (i = 0; long_opts[i].name; ++i)
833 if (long_opts[i].has_arg == no_argument)
834 printf(" -%c, --%-13s* %s\n", long_opts[i].val,
835 long_opts[i].name, opts_help[i]);
836 else
837 printf(" -%c, --%-6s <arg> * %s\n", long_opts[i].val,
838 long_opts[i].name, opts_help[i]);
839
840 if (status != EXIT_SUCCESS)
841 exit(status);
842
843 puts("\nThe format modifiers for the -F option are:");
844 puts(" F Filename \tx PaX Flags \te STACK/RELRO");
845 puts(" t TEXTREL \tr RPATH \tn NEEDED");
846 puts(" i INTERP \tb BIND \ts symbol");
847 puts(" p filename (with search path removed)");
848 puts(" f base filename");
849 puts("Prefix each modifier with '%' (verbose) or '#' (silent)");
850
851 exit(status);
852 }
853
854 /* parse command line arguments and preform needed actions */
855 static void parseargs(int argc, char *argv[])
856 {
857 int i;
858 char *from_file = NULL;
859
860 opterr = 0;
861 while ((i=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
862 switch (i) {
863
864 case 'V':
865 printf("%s compiled %s\n%s\n"
866 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
867 __FILE__, __DATE__, rcsid, argv0);
868 exit(EXIT_SUCCESS);
869 break;
870 case 'h': usage(EXIT_SUCCESS); break;
871 case 'f':
872 if (from_file) err("Don't specify -f twice");
873 from_file = xstrdup(optarg);
874 break;
875 case 'o': {
876 FILE *fp = NULL;
877 if ((fp = freopen(optarg, "w", stdout)) == NULL)
878 err("Could not open output stream '%s': %s", optarg, strerror(errno));
879 SET_STDOUT(fp);
880 break;
881 }
882
883 case 's': {
884 size_t len;
885 if (find_sym) err("Don't specify -s twice");
886 find_sym = xstrdup(optarg);
887 len = strlen(find_sym) + 1;
888 versioned_symname = (char*)xmalloc(sizeof(char) * (len+1));
889 sprintf(versioned_symname, "%s@", find_sym);
890 break;
891 }
892
893 case 'F': {
894 if (out_format) err("Don't specify -F twice");
895 out_format = xstrdup(optarg);
896 break;
897 }
898
899 case 'y': scan_symlink = 0; break;
900 case 'B': show_banner = 0; break;
901 case 'l': scan_ldpath = 1; break;
902 case 'p': scan_envpath = 1; break;
903 case 'R': dir_recurse = 1; break;
904 case 'm': dir_crossmount = 0; break;
905 case 'x': show_pax = 1; break;
906 case 'e': show_stack = 1; break;
907 case 't': show_textrel = 1; break;
908 case 'r': show_rpath = 1; break;
909 case 'n': show_needed = 1; break;
910 case 'i': show_interp = 1; break;
911 case 'b': show_bind = 1; break;
912 case 'q': be_quiet = 1; break;
913 case 'v': be_verbose = (be_verbose % 20) + 1; break;
914 case 'a': show_pax = show_stack = show_textrel = show_rpath = \
915 show_needed = show_interp = show_bind = 1; break;
916
917 case ':':
918 err("Option missing parameter\n");
919 case '?':
920 err("Unknown option\n");
921 default:
922 err("Unhandled option '%c'", i);
923 }
924 }
925
926 /* let the format option override all other options */
927 if (out_format) {
928 show_pax = show_stack = show_textrel = show_rpath = \
929 show_needed = show_interp = show_bind = 0;
930 for (i = 0; out_format[i]; ++i) {
931 if (!IS_MODIFIER(out_format[i])) continue;
932
933 switch (out_format[++i]) {
934 case '%': break;
935 case '#': break;
936 case 'F': break;
937 case 'p': break;
938 case 'f': break;
939 case 's': break;
940 case 'o': break;
941 case 'x': show_pax = 1; break;
942 case 'e': show_stack = 1; break;
943 case 't': show_textrel = 1; break;
944 case 'r': show_rpath = 1; break;
945 case 'n': show_needed = 1; break;
946 case 'i': show_interp = 1; break;
947 case 'b': show_bind = 1; break;
948 default:
949 err("Invalid format specifier '%c' (byte %i)",
950 out_format[i], i+1);
951 }
952 }
953
954 /* construct our default format */
955 } else {
956 size_t fmt_len = 30;
957 out_format = (char*)xmalloc(sizeof(char) * fmt_len);
958 if (!be_quiet) xstrcat(&out_format, "%o ", &fmt_len);
959 if (show_pax) xstrcat(&out_format, "%x ", &fmt_len);
960 if (show_stack) xstrcat(&out_format, "%e ", &fmt_len);
961 if (show_textrel) xstrcat(&out_format, "%t ", &fmt_len);
962 if (show_rpath) xstrcat(&out_format, "%r ", &fmt_len);
963 if (show_needed) xstrcat(&out_format, "%n ", &fmt_len);
964 if (show_interp) xstrcat(&out_format, "%i ", &fmt_len);
965 if (show_bind) xstrcat(&out_format, "%b ", &fmt_len);
966 if (find_sym) xstrcat(&out_format, "%s ", &fmt_len);
967 if (!be_quiet) xstrcat(&out_format, "%F ", &fmt_len);
968 }
969 if (be_verbose > 2) printf("Format: %s\n", out_format);
970
971 /* now lets actually do the scanning */
972 if (scan_ldpath || (show_rpath && be_quiet))
973 load_ld_so_conf();
974 if (scan_ldpath) scanelf_ldpath();
975 if (scan_envpath) scanelf_envpath();
976 if (from_file) {
977 scanelf_from_file(from_file);
978 free(from_file);
979 from_file = *argv;
980 }
981 if (optind == argc && !scan_ldpath && !scan_envpath && !from_file)
982 err("Nothing to scan !?");
983 while (optind < argc) {
984 search_path = argv[optind++];
985 scanelf_dir(search_path);
986 }
987
988 /* clean up */
989 if (find_sym) {
990 free(find_sym);
991 free(versioned_symname);
992 }
993 if (out_format) free(out_format);
994 for (i = 0; ldpaths[i]; ++i)
995 free(ldpaths[i]);
996 }
997
998
999
1000 /* utility funcs */
1001 static char *xstrdup(const char *s)
1002 {
1003 char *ret = strdup(s);
1004 if (!ret) err("Could not strdup(): %s", strerror(errno));
1005 return ret;
1006 }
1007
1008 static void *xmalloc(size_t size)
1009 {
1010 void *ret = malloc(size);
1011 if (!ret) err("Could not malloc() %li bytes", (unsigned long)size);
1012 return ret;
1013 }
1014
1015 static void xstrcat(char **dst, const char *src, size_t *curr_len)
1016 {
1017 size_t new_len;
1018
1019 new_len = strlen(*dst) + strlen(src);
1020 if (*curr_len <= new_len) {
1021 *curr_len = new_len + (*curr_len / 2);
1022 *dst = realloc(*dst, *curr_len);
1023 if (!*dst)
1024 err("could not realloc %li bytes", (unsigned long)*curr_len);
1025 }
1026
1027 strcat(*dst, src);
1028 }
1029
1030 static inline void xchrcat(char **dst, const char append, size_t *curr_len)
1031 {
1032 static char my_app[2];
1033 my_app[0] = append;
1034 my_app[1] = '\0';
1035 xstrcat(dst, my_app, curr_len);
1036 }
1037
1038
1039 int main(int argc, char *argv[])
1040 {
1041 if (argc < 2)
1042 usage(EXIT_FAILURE);
1043 parseargs(argc, argv);
1044 fclose(stdout);
1045 #ifdef __BOUNDS_CHECKING_ON
1046 warn("The calls to add/delete heap should be off by 1 due to the out_buffer not being freed in scanelf_file()");
1047 #endif
1048 return EXIT_SUCCESS;
1049 }

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