/[gentoo-projects]/pax-utils/scanelf.c
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Revision 1.73 - (show annotations) (download) (as text)
Sat Jun 4 13:52:54 2005 UTC (9 years, 1 month ago) by solar
Branch: MAIN
Changes since 1.72: +20 -20 lines
File MIME type: text/x-csrc
- Lets rename *stack* to phdr as the scope of the function has changed quite a bit from initial creation

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 1.72 2005/06/04 06:23:06 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 1.72 2005/06/04 06:23:06 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_phdr = 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 *find_lib = NULL;
77 static char *out_format = NULL;
78 static char *search_path = NULL;
79
80
81
82 /* sub-funcs for scanelf_file() */
83 static char *scanelf_file_pax(elfobj *elf, char *found_pax)
84 {
85 static char *paxflags;
86 static char ret[7];
87 unsigned long i, shown;
88
89
90 if (!show_pax) return NULL;
91
92 shown = 0;
93 memset(&ret, 0, sizeof(ret));
94
95 if (elf->phdr) {
96 #define SHOW_PAX(B) \
97 if (elf->elf_class == ELFCLASS ## B) { \
98 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
99 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
100 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
101 if (EGET(phdr[i].p_type) != PT_PAX_FLAGS) \
102 continue; \
103 if (be_quiet && (EGET(phdr[i].p_flags) == 10240)) \
104 continue; \
105 memcpy(ret, pax_short_pf_flags(EGET(phdr[i].p_flags)), 6); \
106 *found_pax = 1; \
107 ++shown; \
108 break; \
109 } \
110 }
111 SHOW_PAX(32)
112 SHOW_PAX(64)
113 }
114
115 /* fall back to EI_PAX if no PT_PAX was found */
116 if (!*ret) {
117 paxflags = pax_short_hf_flags(EI_PAX_FLAGS(elf));
118 if (!be_quiet || (be_quiet && EI_PAX_FLAGS(elf))) {
119 *found_pax = 1;
120 return paxflags;
121 }
122 strncpy(ret, paxflags, sizeof(ret));
123 // ++shown;
124 }
125
126 if (be_quiet && !shown)
127 return NULL;
128 return ret;
129
130 }
131 static char *scanelf_file_phdr(elfobj *elf, char *found_phdr, char *found_relro, char *found_load)
132 {
133 static char ret[12];
134 char *found;
135 unsigned long i, off, shown, check_flags;
136 unsigned char multi_stack, multi_relro, multi_load;
137
138 if (!show_phdr) return NULL;
139
140 memcpy(ret, "--- --- ---\0", 12);
141
142 shown = 0;
143 multi_stack = multi_relro = multi_load = 0;
144
145 if (elf->phdr) {
146 #define SHOW_PHDR(B) \
147 if (elf->elf_class == ELFCLASS ## B) { \
148 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
149 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
150 uint32_t flags; \
151 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
152 if (EGET(phdr[i].p_type) == PT_GNU_STACK) { \
153 if (multi_stack++) warnf("%s: multiple PT_GNU_STACK's !?", elf->filename); \
154 found = found_phdr; \
155 off = 0; \
156 check_flags = PF_X; \
157 } else if (EGET(phdr[i].p_type) == PT_GNU_RELRO) { \
158 if (multi_relro++) warnf("%s: multiple PT_GNU_RELRO's !?", elf->filename); \
159 found = found_relro; \
160 off = 4; \
161 check_flags = PF_X; \
162 } else if (EGET(phdr[i].p_type) == PT_LOAD) { \
163 if (multi_load++ > 2) warnf("%s: more than 2 PT_LOAD's !?", elf->filename); \
164 found = found_load; \
165 off = 8; \
166 check_flags = PF_W|PF_X; \
167 } else \
168 continue; \
169 flags = EGET(phdr[i].p_flags); \
170 if (be_quiet && ((flags & check_flags) != check_flags)) \
171 continue; \
172 memcpy(ret+off, gnu_short_stack_flags(flags), 3); \
173 *found = 1; \
174 ++shown; \
175 } \
176 }
177 SHOW_PHDR(32)
178 SHOW_PHDR(64)
179 }
180
181 if (be_quiet && !shown)
182 return NULL;
183 else
184 return ret;
185 }
186 static char *scanelf_file_textrel(elfobj *elf, char *found_textrel)
187 {
188 static char ret[] = "TEXTREL";
189 unsigned long i;
190
191 if (!show_textrel) return NULL;
192
193 if (elf->phdr) {
194 #define SHOW_TEXTREL(B) \
195 if (elf->elf_class == ELFCLASS ## B) { \
196 Elf ## B ## _Dyn *dyn; \
197 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
198 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
199 Elf ## B ## _Off offset; \
200 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
201 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
202 offset = EGET(phdr[i].p_offset); \
203 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
204 dyn = DYN ## B (elf->data + offset); \
205 while (EGET(dyn->d_tag) != DT_NULL) { \
206 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
207 *found_textrel = 1; \
208 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
209 return (be_wewy_wewy_quiet ? NULL : ret); \
210 } \
211 ++dyn; \
212 } \
213 } }
214 SHOW_TEXTREL(32)
215 SHOW_TEXTREL(64)
216 }
217
218 if (be_quiet || be_wewy_wewy_quiet)
219 return NULL;
220 else
221 return (char *)" - ";
222 }
223 static void scanelf_file_rpath(elfobj *elf, char *found_rpath, char **ret, size_t *ret_len)
224 {
225 unsigned long i, s;
226 char *rpath, *runpath, **r;
227 void *strtbl_void;
228
229 if (!show_rpath) return;
230
231 strtbl_void = elf_findsecbyname(elf, ".dynstr");
232 rpath = runpath = NULL;
233
234 if (elf->phdr && strtbl_void) {
235 #define SHOW_RPATH(B) \
236 if (elf->elf_class == ELFCLASS ## B) { \
237 Elf ## B ## _Dyn *dyn; \
238 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
239 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
240 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
241 Elf ## B ## _Off offset; \
242 Elf ## B ## _Xword word; \
243 /* Scan all the program headers */ \
244 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
245 /* Just scan dynamic headers */ \
246 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
247 offset = EGET(phdr[i].p_offset); \
248 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
249 /* Just scan dynamic RPATH/RUNPATH headers */ \
250 dyn = DYN ## B (elf->data + offset); \
251 while ((word=EGET(dyn->d_tag)) != DT_NULL) { \
252 if (word == DT_RPATH) { \
253 r = &rpath; \
254 } else if (word == DT_RUNPATH) { \
255 r = &runpath; \
256 } else { \
257 ++dyn; \
258 continue; \
259 } \
260 /* Verify the memory is somewhat sane */ \
261 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
262 if (offset < (Elf ## B ## _Off)elf->len) { \
263 if (*r) warn("ELF has multiple %s's !?", get_elfdtype(word)); \
264 *r = (char*)(elf->data + offset); \
265 /* If quiet, don't output paths in ld.so.conf */ \
266 if (be_quiet) { \
267 size_t len; \
268 char *start, *end; \
269 for (s = 0; *r && ldpaths[s]; ++s) { \
270 /* scan each path in : delimited list */ \
271 start = *r; \
272 end = strchr(start, ':'); \
273 while ((start && ((end = strchr(start, ':')) != NULL)) || start) { \
274 len = (end ? abs(end - start) : strlen(start)); \
275 if (!strncmp(ldpaths[s], start, len) && !ldpaths[s][len]) { \
276 *r = (end ? end + 1 : NULL); \
277 break; \
278 } \
279 start = (end ? start + len + 1 : NULL); \
280 } \
281 } \
282 } \
283 if (*r) *found_rpath = 1; \
284 } \
285 ++dyn; \
286 } \
287 } }
288 SHOW_RPATH(32)
289 SHOW_RPATH(64)
290 }
291
292 if (be_wewy_wewy_quiet) return;
293
294 if (rpath && runpath) {
295 if (!strcmp(rpath, runpath)) {
296 xstrcat(ret, runpath, ret_len);
297 } else {
298 fprintf(stderr, "RPATH [%s] != RUNPATH [%s]\n", rpath, runpath);
299 xchrcat(ret, '{', ret_len);
300 xstrcat(ret, rpath, ret_len);
301 xchrcat(ret, ',', ret_len);
302 xstrcat(ret, runpath, ret_len);
303 xchrcat(ret, '}', ret_len);
304 }
305 } else if (rpath || runpath)
306 xstrcat(ret, (runpath ? runpath : rpath), ret_len);
307 else if (!be_quiet)
308 xstrcat(ret, " - ", ret_len);
309 }
310 static char *scanelf_file_needed_lib(elfobj *elf, char *found_needed, char *found_lib, int op, char **ret, size_t *ret_len)
311 {
312 unsigned long i;
313 char *needed;
314 void *strtbl_void;
315
316 if ((op==0 && !show_needed) || (op==1 && !find_lib)) return NULL;
317
318 strtbl_void = elf_findsecbyname(elf, ".dynstr");
319
320 if (elf->phdr && strtbl_void) {
321 #define SHOW_NEEDED(B) \
322 if (elf->elf_class == ELFCLASS ## B) { \
323 Elf ## B ## _Dyn *dyn; \
324 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
325 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
326 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
327 Elf ## B ## _Off offset; \
328 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
329 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
330 offset = EGET(phdr[i].p_offset); \
331 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
332 dyn = DYN ## B (elf->data + offset); \
333 while (EGET(dyn->d_tag) != DT_NULL) { \
334 if (EGET(dyn->d_tag) == DT_NEEDED) { \
335 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
336 if (offset >= (Elf ## B ## _Off)elf->len) { \
337 ++dyn; \
338 continue; \
339 } \
340 needed = (char*)(elf->data + offset); \
341 if (op == 0) { \
342 if (!be_wewy_wewy_quiet) { \
343 if (*found_needed) xchrcat(ret, ',', ret_len); \
344 xstrcat(ret, needed, ret_len); \
345 } \
346 *found_needed = 1; \
347 } else { \
348 if (strcmp(find_lib, needed)) return NULL; \
349 *found_lib = 1; \
350 return (be_wewy_wewy_quiet ? NULL : find_lib); \
351 } \
352 } \
353 ++dyn; \
354 } \
355 } }
356 SHOW_NEEDED(32)
357 SHOW_NEEDED(64)
358 }
359
360 return NULL;
361 }
362 static char *scanelf_file_interp(elfobj *elf, char *found_interp)
363 {
364 void *strtbl_void;
365
366 if (!show_interp) return NULL;
367
368 strtbl_void = elf_findsecbyname(elf, ".interp");
369
370 if (strtbl_void) {
371 #define SHOW_INTERP(B) \
372 if (elf->elf_class == ELFCLASS ## B) { \
373 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
374 *found_interp = 1; \
375 return (be_wewy_wewy_quiet ? NULL : elf->data + EGET(strtbl->sh_offset)); \
376 }
377 SHOW_INTERP(32)
378 SHOW_INTERP(64)
379 }
380 return NULL;
381 }
382 static char *scanelf_file_bind(elfobj *elf, char *found_bind)
383 {
384 unsigned long i;
385 struct stat s;
386
387 if (!show_bind) return NULL;
388 if (!elf->phdr) return NULL;
389
390 #define SHOW_BIND(B) \
391 if (elf->elf_class == ELFCLASS ## B) { \
392 Elf ## B ## _Dyn *dyn; \
393 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
394 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
395 Elf ## B ## _Off offset; \
396 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
397 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
398 offset = EGET(phdr[i].p_offset); \
399 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
400 dyn = DYN ## B (elf->data + offset); \
401 while (EGET(dyn->d_tag) != DT_NULL) { \
402 if (EGET(dyn->d_tag) == DT_BIND_NOW || \
403 (EGET(dyn->d_tag) == DT_FLAGS && EGET(dyn->d_un.d_val) & DF_BIND_NOW)) \
404 { \
405 if (be_quiet) return NULL; \
406 *found_bind = 1; \
407 return (char *)(be_wewy_wewy_quiet ? NULL : "NOW"); \
408 } \
409 ++dyn; \
410 } \
411 } \
412 }
413 SHOW_BIND(32)
414 SHOW_BIND(64)
415
416 if (be_wewy_wewy_quiet) return NULL;
417
418 if (be_quiet && !fstat(elf->fd, &s) && !(s.st_mode & S_ISUID || s.st_mode & S_ISGID)) {
419 return NULL;
420 } else {
421 *found_bind = 1;
422 return (char *) "LAZY";
423 }
424 }
425 static char *scanelf_file_sym(elfobj *elf, char *found_sym)
426 {
427 unsigned long i;
428 void *symtab_void, *strtab_void;
429
430 if (!find_sym) return NULL;
431
432 /* debug sections */
433 symtab_void = elf_findsecbyname(elf, ".symtab");
434 strtab_void = elf_findsecbyname(elf, ".strtab");
435 /* fall back to runtime sections */
436 if (!symtab_void || !strtab_void) {
437 symtab_void = elf_findsecbyname(elf, ".dynsym");
438 strtab_void = elf_findsecbyname(elf, ".dynstr");
439 }
440
441 if (symtab_void && strtab_void) {
442 char *base, *basemem;
443 basemem = xstrdup(elf->filename);
444 base = basename(basemem);
445 #define FIND_SYM(B) \
446 if (elf->elf_class == ELFCLASS ## B) { \
447 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
448 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
449 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
450 unsigned long cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
451 char *symname; \
452 for (i = 0; i < cnt; ++i) { \
453 if (sym->st_name) { \
454 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
455 if (*find_sym == '*') { \
456 printf("%s(%s) %5lX %15s %s\n", \
457 ((*found_sym == 0) ? "\n\t" : "\t"), \
458 base, \
459 (long)sym->st_size, \
460 (char *)get_elfstttype(sym->st_info), \
461 symname); \
462 *found_sym = 1; \
463 } else if ((strcmp(find_sym, symname) == 0) || \
464 (strcmp(symname, versioned_symname) == 0)) \
465 (*found_sym)++; \
466 } \
467 ++sym; \
468 } }
469 FIND_SYM(32)
470 FIND_SYM(64)
471 free(basemem);
472 }
473
474 if (be_wewy_wewy_quiet) return NULL;
475
476 if (*find_sym != '*' && *found_sym)
477 return find_sym;
478 if (be_quiet)
479 return NULL;
480 else
481 return (char *)" - ";
482 }
483 /* scan an elf file and show all the fun stuff */
484 #define prints(str) write(fileno(stdout), str, strlen(str))
485 static void scanelf_file(const char *filename)
486 {
487 unsigned long i;
488 char found_pax, found_phdr, found_relro, found_load, found_textrel,
489 found_rpath, found_needed, found_interp, found_bind,
490 found_sym, found_lib, found_file;
491 elfobj *elf;
492 struct stat st;
493 static char *out_buffer = NULL;
494 static size_t out_len;
495
496 /* make sure 'filename' exists */
497 if (lstat(filename, &st) == -1) {
498 if (be_verbose > 2) printf("%s: does not exist\n", filename);
499 return;
500 }
501 /* always handle regular files and handle symlinked files if no -y */
502 if (S_ISLNK(st.st_mode)) {
503 if (!scan_symlink) return;
504 stat(filename, &st);
505 }
506 if (!S_ISREG(st.st_mode)) {
507 if (be_verbose > 2) printf("%s: skipping non-file\n", filename);
508 return;
509 }
510
511 found_pax = found_phdr = found_relro = found_load = \
512 found_textrel = found_rpath = found_needed = found_interp = \
513 found_bind = found_sym = found_lib = found_file = 0;
514
515 /* verify this is real ELF */
516 if ((elf = readelf(filename)) == NULL) {
517 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
518 return;
519 }
520
521 if (be_verbose > 1)
522 printf("%s: scanning file {%s,%s}\n", filename,
523 get_elfeitype(EI_CLASS, elf->elf_class),
524 get_elfeitype(EI_DATA, elf->data[EI_DATA]));
525 else if (be_verbose)
526 printf("%s: scanning file\n", filename);
527
528 /* init output buffer */
529 if (!out_buffer) {
530 out_len = sizeof(char) * 80;
531 out_buffer = (char*)xmalloc(out_len);
532 }
533 *out_buffer = '\0';
534
535 /* show the header */
536 if (!be_quiet && show_banner) {
537 for (i = 0; out_format[i]; ++i) {
538 if (!IS_MODIFIER(out_format[i])) continue;
539
540 switch (out_format[++i]) {
541 case '%': break;
542 case '#': break;
543 case 'F':
544 case 'p':
545 case 'f': prints("FILE "); found_file = 1; break;
546 case 'o': prints(" TYPE "); break;
547 case 'x': prints(" PAX "); break;
548 case 'e': prints("STK/REL/PTL "); break;
549 case 't': prints("TEXTREL "); break;
550 case 'r': prints("RPATH "); break;
551 case 'n': prints("NEEDED "); break;
552 case 'i': prints("INTERP "); break;
553 case 'b': prints("BIND "); break;
554 case 's': prints("SYM "); break;
555 case 'N': prints("LIB "); break;
556 }
557 }
558 if (!found_file) prints("FILE ");
559 prints("\n");
560 found_file = 0;
561 show_banner = 0;
562 }
563
564 /* dump all the good stuff */
565 for (i = 0; out_format[i]; ++i) {
566 const char *out;
567 const char *tmp;
568
569 /* make sure we trim leading spaces in quiet mode */
570 if (be_quiet && *out_buffer == ' ' && !out_buffer[1])
571 *out_buffer = '\0';
572
573 if (!IS_MODIFIER(out_format[i])) {
574 xchrcat(&out_buffer, out_format[i], &out_len);
575 continue;
576 }
577
578 out = NULL;
579 be_wewy_wewy_quiet = (out_format[i] == '#');
580 switch (out_format[++i]) {
581 case '%':
582 case '#':
583 xchrcat(&out_buffer, out_format[i], &out_len); break;
584 case 'F':
585 if (be_wewy_wewy_quiet) break;
586 found_file = 1;
587 xstrcat(&out_buffer, filename, &out_len);
588 break;
589 case 'p':
590 if (be_wewy_wewy_quiet) break;
591 found_file = 1;
592 tmp = filename;
593 if (search_path) {
594 ssize_t len_search = strlen(search_path);
595 ssize_t len_file = strlen(filename);
596 if (!strncmp(filename, search_path, len_search) && \
597 len_file > len_search)
598 tmp += len_search;
599 if (*tmp == '/' && search_path[len_search-1] == '/') tmp++;
600 }
601 xstrcat(&out_buffer, tmp, &out_len);
602 break;
603 case 'f':
604 if (be_wewy_wewy_quiet) break;
605 found_file = 1;
606 tmp = strrchr(filename, '/');
607 tmp = (tmp == NULL ? filename : tmp+1);
608 xstrcat(&out_buffer, tmp, &out_len);
609 break;
610 case 'o': out = get_elfetype(elf); break;
611 case 'x': out = scanelf_file_pax(elf, &found_pax); break;
612 case 'e': out = scanelf_file_phdr(elf, &found_phdr, &found_relro, &found_load); break;
613 case 't': out = scanelf_file_textrel(elf, &found_textrel); break;
614 case 'r': scanelf_file_rpath(elf, &found_rpath, &out_buffer, &out_len); break;
615 case 'n':
616 case 'N': out = scanelf_file_needed_lib(elf, &found_needed, &found_lib, (out_format[i]=='N'), &out_buffer, &out_len); break;
617 case 'i': out = scanelf_file_interp(elf, &found_interp); break;
618 case 'b': out = scanelf_file_bind(elf, &found_bind); break;
619 case 's': out = scanelf_file_sym(elf, &found_sym); break;
620 }
621 if (out) xstrcat(&out_buffer, out, &out_len);
622 }
623
624 #define FOUND_SOMETHING() \
625 (found_pax || found_phdr || found_relro || found_load || found_textrel || \
626 found_rpath || found_needed || found_interp || found_bind || found_sym || found_lib)
627
628 if (!found_file && (!be_quiet || (be_quiet && FOUND_SOMETHING()))) {
629 xchrcat(&out_buffer, ' ', &out_len);
630 xstrcat(&out_buffer, filename, &out_len);
631 }
632 if (!be_quiet || (be_quiet && FOUND_SOMETHING()))
633 puts(out_buffer);
634
635 unreadelf(elf);
636 }
637
638 /* scan a directory for ET_EXEC files and print when we find one */
639 static void scanelf_dir(const char *path)
640 {
641 register DIR *dir;
642 register struct dirent *dentry;
643 struct stat st_top, st;
644 char buf[_POSIX_PATH_MAX];
645 size_t pathlen = 0, len = 0;
646
647 /* make sure path exists */
648 if (lstat(path, &st_top) == -1) {
649 if (be_verbose > 2) printf("%s: does not exist\n", path);
650 return;
651 }
652
653 /* ok, if it isn't a directory, assume we can open it */
654 if (!S_ISDIR(st_top.st_mode)) {
655 scanelf_file(path);
656 return;
657 }
658
659 /* now scan the dir looking for fun stuff */
660 if ((dir = opendir(path)) == NULL) {
661 warnf("could not opendir %s: %s", path, strerror(errno));
662 return;
663 }
664 if (be_verbose) printf("%s: scanning dir\n", path);
665
666 pathlen = strlen(path);
667 while ((dentry = readdir(dir))) {
668 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
669 continue;
670 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
671 if (len >= sizeof(buf)) {
672 warnf("Skipping '%s': len > sizeof(buf); %u > %u\n", path, len, sizeof(buf));
673 continue;
674 }
675 sprintf(buf, "%s/%s", path, dentry->d_name);
676 if (lstat(buf, &st) != -1) {
677 if (S_ISREG(st.st_mode))
678 scanelf_file(buf);
679 else if (dir_recurse && S_ISDIR(st.st_mode)) {
680 if (dir_crossmount || (st_top.st_dev == st.st_dev))
681 scanelf_dir(buf);
682 }
683 }
684 }
685 closedir(dir);
686 }
687
688 static int scanelf_from_file(char *filename)
689 {
690 FILE *fp = NULL;
691 char *p;
692 char path[_POSIX_PATH_MAX];
693
694 if (((strcmp(filename, "-")) == 0) && (ttyname(0) == NULL))
695 fp = stdin;
696 else if ((fp = fopen(filename, "r")) == NULL)
697 return 1;
698
699 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
700 if ((p = strchr(path, '\n')) != NULL)
701 *p = 0;
702 search_path = path;
703 scanelf_dir(path);
704 }
705 if (fp != stdin)
706 fclose(fp);
707 return 0;
708 }
709
710 static void load_ld_so_conf()
711 {
712 FILE *fp = NULL;
713 char *p;
714 char path[_POSIX_PATH_MAX];
715 int i = 0;
716
717 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
718 return;
719
720 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
721 if (*path != '/')
722 continue;
723
724 if ((p = strrchr(path, '\r')) != NULL)
725 *p = 0;
726 if ((p = strchr(path, '\n')) != NULL)
727 *p = 0;
728
729 ldpaths[i++] = xstrdup(path);
730
731 if (i + 1 == sizeof(ldpaths) / sizeof(*ldpaths))
732 break;
733 }
734 ldpaths[i] = NULL;
735
736 fclose(fp);
737 }
738
739 /* scan /etc/ld.so.conf for paths */
740 static void scanelf_ldpath()
741 {
742 char scan_l, scan_ul, scan_ull;
743 int i = 0;
744
745 if (!ldpaths[0])
746 err("Unable to load any paths from ld.so.conf");
747
748 scan_l = scan_ul = scan_ull = 0;
749
750 while (ldpaths[i]) {
751 if (!scan_l && !strcmp(ldpaths[i], "/lib")) scan_l = 1;
752 if (!scan_ul && !strcmp(ldpaths[i], "/usr/lib")) scan_ul = 1;
753 if (!scan_ull && !strcmp(ldpaths[i], "/usr/local/lib")) scan_ull = 1;
754 scanelf_dir(ldpaths[i]);
755 ++i;
756 }
757
758 if (!scan_l) scanelf_dir("/lib");
759 if (!scan_ul) scanelf_dir("/usr/lib");
760 if (!scan_ull) scanelf_dir("/usr/local/lib");
761 }
762
763 /* scan env PATH for paths */
764 static void scanelf_envpath()
765 {
766 char *path, *p;
767
768 path = getenv("PATH");
769 if (!path)
770 err("PATH is not set in your env !");
771 path = xstrdup(path);
772
773 while ((p = strrchr(path, ':')) != NULL) {
774 scanelf_dir(p + 1);
775 *p = 0;
776 }
777
778 free(path);
779 }
780
781
782
783 /* usage / invocation handling functions */
784 #define PARSE_FLAGS "plRmyxetrnibs:N:aqvF:f:o:BhV"
785 #define a_argument required_argument
786 static struct option const long_opts[] = {
787 {"path", no_argument, NULL, 'p'},
788 {"ldpath", no_argument, NULL, 'l'},
789 {"recursive", no_argument, NULL, 'R'},
790 {"mount", no_argument, NULL, 'm'},
791 {"symlink", no_argument, NULL, 'y'},
792 {"pax", no_argument, NULL, 'x'},
793 {"header", no_argument, NULL, 'e'},
794 {"textrel", no_argument, NULL, 't'},
795 {"rpath", no_argument, NULL, 'r'},
796 {"needed", no_argument, NULL, 'n'},
797 {"interp", no_argument, NULL, 'i'},
798 {"bind", no_argument, NULL, 'b'},
799 {"symbol", a_argument, NULL, 's'},
800 {"lib", a_argument, NULL, 'N'},
801 {"all", no_argument, NULL, 'a'},
802 {"quiet", no_argument, NULL, 'q'},
803 {"verbose", no_argument, NULL, 'v'},
804 {"format", a_argument, NULL, 'F'},
805 {"from", a_argument, NULL, 'f'},
806 {"file", a_argument, NULL, 'o'},
807 {"nobanner", no_argument, NULL, 'B'},
808 {"help", no_argument, NULL, 'h'},
809 {"version", no_argument, NULL, 'V'},
810 {NULL, no_argument, NULL, 0x0}
811 };
812
813 static const char *opts_help[] = {
814 "Scan all directories in PATH environment",
815 "Scan all directories in /etc/ld.so.conf",
816 "Scan directories recursively",
817 "Don't recursively cross mount points",
818 "Don't scan symlinks\n",
819 "Print PaX markings",
820 "Print GNU_STACK/PT_LOAD markings",
821 "Print TEXTREL information",
822 "Print RPATH information",
823 "Print NEEDED information",
824 "Print INTERP information",
825 "Print BIND information",
826 "Find a specified symbol",
827 "Find a specified library",
828 "Print all scanned info (-x -e -t -r -n -i -b)\n",
829 "Only output 'bad' things",
830 "Be verbose (can be specified more than once)",
831 "Use specified format for output",
832 "Read input stream from a filename",
833 "Write output stream to a filename",
834 "Don't display the header",
835 "Print this help and exit",
836 "Print version and exit",
837 NULL
838 };
839
840 /* display usage and exit */
841 static void usage(int status)
842 {
843 unsigned long i;
844 printf("* Scan ELF binaries for stuff\n\n"
845 "Usage: %s [options] <dir1/file1> [dir2 dirN fileN ...]\n\n", argv0);
846 printf("Options: -[%s]\n", PARSE_FLAGS);
847 for (i = 0; long_opts[i].name; ++i)
848 if (long_opts[i].has_arg == no_argument)
849 printf(" -%c, --%-13s* %s\n", long_opts[i].val,
850 long_opts[i].name, opts_help[i]);
851 else
852 printf(" -%c, --%-6s <arg> * %s\n", long_opts[i].val,
853 long_opts[i].name, opts_help[i]);
854
855 if (status != EXIT_SUCCESS)
856 exit(status);
857
858 puts("\nThe format modifiers for the -F option are:");
859 puts(" F Filename \tx PaX Flags \te STACK/RELRO");
860 puts(" t TEXTREL \tr RPATH \tn NEEDED");
861 puts(" i INTERP \tb BIND \ts symbol");
862 puts(" N library \to Type");
863 puts(" p filename (with search path removed)");
864 puts(" f base filename");
865 puts("Prefix each modifier with '%' (verbose) or '#' (silent)");
866
867 exit(status);
868 }
869
870 /* parse command line arguments and preform needed actions */
871 static void parseargs(int argc, char *argv[])
872 {
873 int i;
874 char *from_file = NULL;
875
876 opterr = 0;
877 while ((i=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
878 switch (i) {
879
880 case 'V':
881 printf("%s compiled %s\n%s\n"
882 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
883 __FILE__, __DATE__, rcsid, argv0);
884 exit(EXIT_SUCCESS);
885 break;
886 case 'h': usage(EXIT_SUCCESS); break;
887 case 'f':
888 if (from_file) err("Don't specify -f twice");
889 from_file = xstrdup(optarg);
890 break;
891 case 'o': {
892 FILE *fp = NULL;
893 if ((fp = freopen(optarg, "w", stdout)) == NULL)
894 err("Could not open output stream '%s': %s", optarg, strerror(errno));
895 SET_STDOUT(fp);
896 break;
897 }
898
899 case 's': {
900 size_t len;
901 if (find_sym) err("Don't specify -s twice");
902 find_sym = xstrdup(optarg);
903 len = strlen(find_sym) + 1;
904 versioned_symname = (char*)xmalloc(sizeof(char) * (len+1));
905 sprintf(versioned_symname, "%s@", find_sym);
906 break;
907 }
908 case 'N': {
909 if (find_lib) err("Don't specify -N twice");
910 find_lib = xstrdup(optarg);
911 break;
912 }
913
914 case 'F': {
915 if (out_format) err("Don't specify -F twice");
916 out_format = xstrdup(optarg);
917 break;
918 }
919
920 case 'y': scan_symlink = 0; break;
921 case 'B': show_banner = 0; break;
922 case 'l': scan_ldpath = 1; break;
923 case 'p': scan_envpath = 1; break;
924 case 'R': dir_recurse = 1; break;
925 case 'm': dir_crossmount = 0; break;
926 case 'x': show_pax = 1; break;
927 case 'e': show_phdr = 1; break;
928 case 't': show_textrel = 1; break;
929 case 'r': show_rpath = 1; break;
930 case 'n': show_needed = 1; break;
931 case 'i': show_interp = 1; break;
932 case 'b': show_bind = 1; break;
933 case 'q': be_quiet = 1; break;
934 case 'v': be_verbose = (be_verbose % 20) + 1; break;
935 case 'a': show_pax = show_phdr = show_textrel = show_rpath = \
936 show_needed = show_interp = show_bind = 1; break;
937
938 case ':':
939 err("Option missing parameter\n");
940 case '?':
941 err("Unknown option\n");
942 default:
943 err("Unhandled option '%c'", i);
944 }
945 }
946
947 /* let the format option override all other options */
948 if (out_format) {
949 show_pax = show_phdr = show_textrel = show_rpath = \
950 show_needed = show_interp = show_bind = 0;
951 for (i = 0; out_format[i]; ++i) {
952 if (!IS_MODIFIER(out_format[i])) continue;
953
954 switch (out_format[++i]) {
955 case '%': break;
956 case '#': break;
957 case 'F': break;
958 case 'p': break;
959 case 'f': break;
960 case 's': break;
961 case 'N': break;
962 case 'o': break;
963 case 'x': show_pax = 1; break;
964 case 'e': show_phdr = 1; break;
965 case 't': show_textrel = 1; break;
966 case 'r': show_rpath = 1; break;
967 case 'n': show_needed = 1; break;
968 case 'i': show_interp = 1; break;
969 case 'b': show_bind = 1; break;
970 default:
971 err("Invalid format specifier '%c' (byte %i)",
972 out_format[i], i+1);
973 }
974 }
975
976 /* construct our default format */
977 } else {
978 size_t fmt_len = 30;
979 out_format = (char*)xmalloc(sizeof(char) * fmt_len);
980 if (!be_quiet) xstrcat(&out_format, "%o ", &fmt_len);
981 if (show_pax) xstrcat(&out_format, "%x ", &fmt_len);
982 if (show_phdr) xstrcat(&out_format, "%e ", &fmt_len);
983 if (show_textrel) xstrcat(&out_format, "%t ", &fmt_len);
984 if (show_rpath) xstrcat(&out_format, "%r ", &fmt_len);
985 if (show_needed) xstrcat(&out_format, "%n ", &fmt_len);
986 if (show_interp) xstrcat(&out_format, "%i ", &fmt_len);
987 if (show_bind) xstrcat(&out_format, "%b ", &fmt_len);
988 if (find_sym) xstrcat(&out_format, "%s ", &fmt_len);
989 if (find_lib) xstrcat(&out_format, "%N ", &fmt_len);
990 if (!be_quiet) xstrcat(&out_format, "%F ", &fmt_len);
991 }
992 if (be_verbose > 2) printf("Format: %s\n", out_format);
993
994 /* now lets actually do the scanning */
995 if (scan_ldpath || (show_rpath && be_quiet))
996 load_ld_so_conf();
997 if (scan_ldpath) scanelf_ldpath();
998 if (scan_envpath) scanelf_envpath();
999 if (from_file) {
1000 scanelf_from_file(from_file);
1001 free(from_file);
1002 from_file = *argv;
1003 }
1004 if (optind == argc && !scan_ldpath && !scan_envpath && !from_file)
1005 err("Nothing to scan !?");
1006 while (optind < argc) {
1007 search_path = argv[optind++];
1008 scanelf_dir(search_path);
1009 }
1010
1011 /* clean up */
1012 if (find_sym) {
1013 free(find_sym);
1014 free(versioned_symname);
1015 }
1016 if (find_lib) free(find_lib);
1017 if (out_format) free(out_format);
1018 for (i = 0; ldpaths[i]; ++i)
1019 free(ldpaths[i]);
1020 }
1021
1022
1023
1024 /* utility funcs */
1025 static char *xstrdup(const char *s)
1026 {
1027 char *ret = strdup(s);
1028 if (!ret) err("Could not strdup(): %s", strerror(errno));
1029 return ret;
1030 }
1031
1032 static void *xmalloc(size_t size)
1033 {
1034 void *ret = malloc(size);
1035 if (!ret) err("Could not malloc() %li bytes", (unsigned long)size);
1036 return ret;
1037 }
1038
1039 static void xstrcat(char **dst, const char *src, size_t *curr_len)
1040 {
1041 size_t new_len;
1042
1043 new_len = strlen(*dst) + strlen(src);
1044 if (*curr_len <= new_len) {
1045 *curr_len = new_len + (*curr_len / 2);
1046 *dst = realloc(*dst, *curr_len);
1047 if (!*dst)
1048 err("could not realloc %li bytes", (unsigned long)*curr_len);
1049 }
1050
1051 strcat(*dst, src);
1052 }
1053
1054 static inline void xchrcat(char **dst, const char append, size_t *curr_len)
1055 {
1056 static char my_app[2];
1057 my_app[0] = append;
1058 my_app[1] = '\0';
1059 xstrcat(dst, my_app, curr_len);
1060 }
1061
1062
1063
1064 int main(int argc, char *argv[])
1065 {
1066 if (argc < 2)
1067 usage(EXIT_FAILURE);
1068 parseargs(argc, argv);
1069 fclose(stdout);
1070 #ifdef __BOUNDS_CHECKING_ON
1071 warn("The calls to add/delete heap should be off by 1 due to the out_buffer not being freed in scanelf_file()");
1072 #endif
1073 return EXIT_SUCCESS;
1074 }

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