/[gentoo-projects]/pax-utils/scanelf.c
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Revision 1.77 - (show annotations) (download) (as text)
Wed Jun 8 05:43:01 2005 UTC (9 years, 3 months ago) by vapier
Branch: MAIN
Changes since 1.76: +39 -30 lines
File MIME type: text/x-csrc
make sure REL is an offset inside the symtab before using and create a func to pick the better sym/tab headers based on size

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 1.76 2005/06/08 04:24:19 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 1.76 2005/06/08 04:24:19 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_textrels = 0;
72 static char show_banner = 1;
73 static char be_quiet = 0;
74 static char be_verbose = 0;
75 static char be_wewy_wewy_quiet = 0;
76 static char *find_sym = NULL, *versioned_symname = NULL;
77 static char *find_lib = NULL;
78 static char *out_format = NULL;
79 static char *search_path = NULL;
80
81
82
83 /* sub-funcs for scanelf_file() */
84 static void scanelf_file_get_symtabs(elfobj *elf, void **sym, void **tab)
85 {
86 /* find the best SHT_DYNSYM and SHT_STRTAB sections */
87 #define GET_SYMTABS(B) \
88 if (elf->elf_class == ELFCLASS ## B) { \
89 Elf ## B ## _Shdr *symtab, *strtab, *dynsym, *dynstr; \
90 /* debug sections */ \
91 symtab = SHDR ## B (elf_findsecbyname(elf, ".symtab")); \
92 strtab = SHDR ## B (elf_findsecbyname(elf, ".strtab")); \
93 /* runtime sections */ \
94 dynsym = SHDR ## B (elf_findsecbyname(elf, ".dynsym")); \
95 dynstr = SHDR ## B (elf_findsecbyname(elf, ".dynstr")); \
96 if (symtab && dynsym) { \
97 *sym = (void*)((EGET(symtab->sh_size) > EGET(dynsym->sh_size)) ? symtab : dynsym); \
98 } else { \
99 *sym = (void*)(symtab ? symtab : dynsym); \
100 } \
101 if (strtab && dynstr) { \
102 *tab = (void*)((EGET(strtab->sh_size) > EGET(dynstr->sh_size)) ? strtab : dynstr); \
103 } else { \
104 *tab = (void*)(strtab ? strtab : dynstr); \
105 } \
106 }
107 GET_SYMTABS(32)
108 GET_SYMTABS(64)
109 }
110 static char *scanelf_file_pax(elfobj *elf, char *found_pax)
111 {
112 static char *paxflags;
113 static char ret[7];
114 unsigned long i, shown;
115
116
117 if (!show_pax) return NULL;
118
119 shown = 0;
120 memset(&ret, 0, sizeof(ret));
121
122 if (elf->phdr) {
123 #define SHOW_PAX(B) \
124 if (elf->elf_class == ELFCLASS ## B) { \
125 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
126 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
127 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
128 if (EGET(phdr[i].p_type) != PT_PAX_FLAGS) \
129 continue; \
130 if (be_quiet && (EGET(phdr[i].p_flags) == 10240)) \
131 continue; \
132 memcpy(ret, pax_short_pf_flags(EGET(phdr[i].p_flags)), 6); \
133 *found_pax = 1; \
134 ++shown; \
135 break; \
136 } \
137 }
138 SHOW_PAX(32)
139 SHOW_PAX(64)
140 }
141
142 /* fall back to EI_PAX if no PT_PAX was found */
143 if (!*ret) {
144 paxflags = pax_short_hf_flags(EI_PAX_FLAGS(elf));
145 if (!be_quiet || (be_quiet && EI_PAX_FLAGS(elf))) {
146 *found_pax = 1;
147 return paxflags;
148 }
149 strncpy(ret, paxflags, sizeof(ret));
150 // ++shown;
151 }
152
153 if (be_quiet && !shown)
154 return NULL;
155 return ret;
156
157 }
158 static char *scanelf_file_phdr(elfobj *elf, char *found_phdr, char *found_relro, char *found_load)
159 {
160 static char ret[12];
161 char *found;
162 unsigned long i, off, shown, check_flags;
163 unsigned char multi_stack, multi_relro, multi_load;
164
165 if (!show_phdr) return NULL;
166
167 memcpy(ret, "--- --- ---\0", 12);
168
169 shown = 0;
170 multi_stack = multi_relro = multi_load = 0;
171
172 if (elf->phdr) {
173 #define SHOW_PHDR(B) \
174 if (elf->elf_class == ELFCLASS ## B) { \
175 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
176 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
177 uint32_t flags; \
178 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
179 if (EGET(phdr[i].p_type) == PT_GNU_STACK) { \
180 if (multi_stack++) warnf("%s: multiple PT_GNU_STACK's !?", elf->filename); \
181 found = found_phdr; \
182 off = 0; \
183 check_flags = PF_X; \
184 } else if (EGET(phdr[i].p_type) == PT_GNU_RELRO) { \
185 if (multi_relro++) warnf("%s: multiple PT_GNU_RELRO's !?", elf->filename); \
186 found = found_relro; \
187 off = 4; \
188 check_flags = PF_X; \
189 } else if (EGET(phdr[i].p_type) == PT_LOAD) { \
190 if (multi_load++ > 2) warnf("%s: more than 2 PT_LOAD's !?", elf->filename); \
191 found = found_load; \
192 off = 8; \
193 check_flags = PF_W|PF_X; \
194 } else \
195 continue; \
196 flags = EGET(phdr[i].p_flags); \
197 if (be_quiet && ((flags & check_flags) != check_flags)) \
198 continue; \
199 memcpy(ret+off, gnu_short_stack_flags(flags), 3); \
200 *found = 1; \
201 ++shown; \
202 } \
203 }
204 SHOW_PHDR(32)
205 SHOW_PHDR(64)
206 }
207
208 if (be_quiet && !shown)
209 return NULL;
210 else
211 return ret;
212 }
213 static char *scanelf_file_textrel(elfobj *elf, char *found_textrel)
214 {
215 static char ret[] = "TEXTREL";
216 unsigned long i;
217
218 if (!show_textrel) return NULL;
219
220 if (elf->phdr) {
221 #define SHOW_TEXTREL(B) \
222 if (elf->elf_class == ELFCLASS ## B) { \
223 Elf ## B ## _Dyn *dyn; \
224 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
225 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
226 Elf ## B ## _Off offset; \
227 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
228 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
229 offset = EGET(phdr[i].p_offset); \
230 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
231 dyn = DYN ## B (elf->data + offset); \
232 while (EGET(dyn->d_tag) != DT_NULL) { \
233 if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
234 *found_textrel = 1; \
235 /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
236 return (be_wewy_wewy_quiet ? NULL : ret); \
237 } \
238 ++dyn; \
239 } \
240 } }
241 SHOW_TEXTREL(32)
242 SHOW_TEXTREL(64)
243 }
244
245 if (be_quiet || be_wewy_wewy_quiet)
246 return NULL;
247 else
248 return (char *)" - ";
249 }
250 static char *scanelf_file_textrels(elfobj *elf, char *found_textrels)
251 {
252 unsigned long p, s, r, rmax;
253 void *symtab_void, *strtab_void;
254
255 if (!show_textrels) return NULL;
256
257 scanelf_file_get_symtabs(elf, &symtab_void, &strtab_void);
258
259 if (symtab_void && strtab_void && elf->phdr && elf->shdr) {
260 #define SHOW_TEXTRELS(B) \
261 if (elf->elf_class == ELFCLASS ## B) { \
262 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
263 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
264 Elf ## B ## _Shdr *shdr = SHDR ## B (elf->shdr); \
265 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
266 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
267 Elf ## B ## _Rel *rel; \
268 Elf ## B ## _Rela *rela; \
269 /* search the section headers for relocations */ \
270 for (s = 0; s < EGET(ehdr->e_shnum); ++s) { \
271 uint32_t sh_type = EGET(shdr[s].sh_type); \
272 if (sh_type == SHT_REL) { \
273 rel = REL ## B (elf->data + EGET(shdr[s].sh_offset)); \
274 rela = NULL; \
275 rmax = EGET(shdr[s].sh_size) / sizeof(*rel); \
276 } else if (sh_type == SHT_RELA) { \
277 rel = NULL; \
278 rela = RELA ## B (elf->data + EGET(shdr[s].sh_offset)); \
279 rmax = EGET(shdr[s].sh_size) / sizeof(*rela); \
280 } else \
281 continue; \
282 /* search the program headers for PT_LOAD headers */ \
283 for (p = 0; p < EGET(ehdr->e_phnum); ++p) { \
284 Elf ## B ## _Addr vaddr; \
285 uint ## B ## _t memsz; \
286 if (EGET(phdr[p].p_type) != PT_LOAD) continue; \
287 if (EGET(phdr[p].p_flags) & PF_W) continue; \
288 vaddr = EGET(phdr[p].p_vaddr); \
289 memsz = EGET(phdr[p].p_memsz); \
290 *found_textrels = 1; \
291 /* now see if any of the relocs are in the PT_LOAD */ \
292 for (r = 0; r < rmax; ++r) { \
293 unsigned long sym_max; \
294 Elf ## B ## _Addr offset_tmp; \
295 Elf ## B ## _Sym *func; \
296 Elf ## B ## _Sym *sym; \
297 Elf ## B ## _Addr r_offset; \
298 uint ## B ## _t r_info; \
299 if (sh_type == SHT_REL) { \
300 r_offset = EGET(rel[r].r_offset); \
301 r_info = EGET(rel[r].r_info); \
302 } else { \
303 r_offset = EGET(rela[r].r_offset); \
304 r_info = EGET(rela[r].r_info); \
305 } \
306 /* make sure this relocation is inside of the .text */ \
307 if (r_offset < vaddr || r_offset >= vaddr + memsz) continue; \
308 /* locate this relocation symbol name */ \
309 sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
310 sym_max = ELF ## B ## _R_SYM(r_info); \
311 if (sym_max * EGET(symtab->sh_entsize) < symtab->sh_size) \
312 sym += sym_max; \
313 else \
314 sym = NULL; \
315 sym_max = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
316 /* show the raw details about this reloc */ \
317 printf("\tTEXTREL %s: ", elf->base_filename); \
318 if (sym && sym->st_name) \
319 printf("%s", (char*)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name))); \
320 else \
321 printf("(NULL: fake?)"); \
322 printf(" [0x%lX]", (unsigned long)r_offset); \
323 /* now try to find the closest symbol that this rel is probably in */ \
324 sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
325 func = NULL; \
326 offset_tmp = 0; \
327 while (sym_max--) { \
328 if (EGET(sym->st_value) < r_offset && EGET(sym->st_value) > offset_tmp) { \
329 func = sym; \
330 offset_tmp = EGET(sym->st_value); \
331 } \
332 ++sym; \
333 } \
334 printf(" in "); \
335 if (func && func->st_name) \
336 printf("%s", (char*)(elf->data + EGET(strtab->sh_offset) + EGET(func->st_name))); \
337 else \
338 printf("(NULL: fake?)"); \
339 printf(" [0x%lX]\n", (unsigned long)offset_tmp); \
340 } \
341 } \
342 } }
343 SHOW_TEXTRELS(32)
344 SHOW_TEXTRELS(64)
345 }
346
347 return NULL;
348 }
349 static void scanelf_file_rpath(elfobj *elf, char *found_rpath, char **ret, size_t *ret_len)
350 {
351 unsigned long i, s;
352 char *rpath, *runpath, **r;
353 void *strtbl_void;
354
355 if (!show_rpath) return;
356
357 strtbl_void = elf_findsecbyname(elf, ".dynstr");
358 rpath = runpath = NULL;
359
360 if (elf->phdr && strtbl_void) {
361 #define SHOW_RPATH(B) \
362 if (elf->elf_class == ELFCLASS ## B) { \
363 Elf ## B ## _Dyn *dyn; \
364 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
365 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
366 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
367 Elf ## B ## _Off offset; \
368 Elf ## B ## _Xword word; \
369 /* Scan all the program headers */ \
370 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
371 /* Just scan dynamic headers */ \
372 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
373 offset = EGET(phdr[i].p_offset); \
374 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
375 /* Just scan dynamic RPATH/RUNPATH headers */ \
376 dyn = DYN ## B (elf->data + offset); \
377 while ((word=EGET(dyn->d_tag)) != DT_NULL) { \
378 if (word == DT_RPATH) { \
379 r = &rpath; \
380 } else if (word == DT_RUNPATH) { \
381 r = &runpath; \
382 } else { \
383 ++dyn; \
384 continue; \
385 } \
386 /* Verify the memory is somewhat sane */ \
387 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
388 if (offset < (Elf ## B ## _Off)elf->len) { \
389 if (*r) warn("ELF has multiple %s's !?", get_elfdtype(word)); \
390 *r = (char*)(elf->data + offset); \
391 /* If quiet, don't output paths in ld.so.conf */ \
392 if (be_quiet) { \
393 size_t len; \
394 char *start, *end; \
395 /* note that we only 'chop' off leading known paths. */ \
396 /* since *r is read-only memory, we can only move the ptr forward. */ \
397 start = *r; \
398 /* scan each path in : delimited list */ \
399 while (start) { \
400 end = strchr(start, ':'); \
401 len = (end ? abs(end - start) : strlen(start)); \
402 for (s = 0; ldpaths[s]; ++s) { \
403 if (!strncmp(ldpaths[s], start, len) && !ldpaths[s][len]) { \
404 *r = (end ? end + 1 : NULL); \
405 break; \
406 } \
407 } \
408 if (!*r || !ldpaths[s] || !end) \
409 start = NULL; \
410 else \
411 start = start + len + 1; \
412 } \
413 } \
414 if (*r) *found_rpath = 1; \
415 } \
416 ++dyn; \
417 } \
418 } }
419 SHOW_RPATH(32)
420 SHOW_RPATH(64)
421 }
422
423 if (be_wewy_wewy_quiet) return;
424
425 if (rpath && runpath) {
426 if (!strcmp(rpath, runpath)) {
427 xstrcat(ret, runpath, ret_len);
428 } else {
429 fprintf(stderr, "RPATH [%s] != RUNPATH [%s]\n", rpath, runpath);
430 xchrcat(ret, '{', ret_len);
431 xstrcat(ret, rpath, ret_len);
432 xchrcat(ret, ',', ret_len);
433 xstrcat(ret, runpath, ret_len);
434 xchrcat(ret, '}', ret_len);
435 }
436 } else if (rpath || runpath)
437 xstrcat(ret, (runpath ? runpath : rpath), ret_len);
438 else if (!be_quiet)
439 xstrcat(ret, " - ", ret_len);
440 }
441 static char *scanelf_file_needed_lib(elfobj *elf, char *found_needed, char *found_lib, int op, char **ret, size_t *ret_len)
442 {
443 unsigned long i;
444 char *needed;
445 void *strtbl_void;
446
447 if ((op==0 && !show_needed) || (op==1 && !find_lib)) return NULL;
448
449 strtbl_void = elf_findsecbyname(elf, ".dynstr");
450
451 if (elf->phdr && strtbl_void) {
452 #define SHOW_NEEDED(B) \
453 if (elf->elf_class == ELFCLASS ## B) { \
454 Elf ## B ## _Dyn *dyn; \
455 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
456 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
457 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
458 Elf ## B ## _Off offset; \
459 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
460 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
461 offset = EGET(phdr[i].p_offset); \
462 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
463 dyn = DYN ## B (elf->data + offset); \
464 while (EGET(dyn->d_tag) != DT_NULL) { \
465 if (EGET(dyn->d_tag) == DT_NEEDED) { \
466 offset = EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
467 if (offset >= (Elf ## B ## _Off)elf->len) { \
468 ++dyn; \
469 continue; \
470 } \
471 needed = (char*)(elf->data + offset); \
472 if (op == 0) { \
473 if (!be_wewy_wewy_quiet) { \
474 if (*found_needed) xchrcat(ret, ',', ret_len); \
475 xstrcat(ret, needed, ret_len); \
476 } \
477 *found_needed = 1; \
478 } else { \
479 if (strcmp(find_lib, needed)) return NULL; \
480 *found_lib = 1; \
481 return (be_wewy_wewy_quiet ? NULL : find_lib); \
482 } \
483 } \
484 ++dyn; \
485 } \
486 } }
487 SHOW_NEEDED(32)
488 SHOW_NEEDED(64)
489 }
490
491 return NULL;
492 }
493 static char *scanelf_file_interp(elfobj *elf, char *found_interp)
494 {
495 void *strtbl_void;
496
497 if (!show_interp) return NULL;
498
499 strtbl_void = elf_findsecbyname(elf, ".interp");
500
501 if (strtbl_void) {
502 #define SHOW_INTERP(B) \
503 if (elf->elf_class == ELFCLASS ## B) { \
504 Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
505 *found_interp = 1; \
506 return (be_wewy_wewy_quiet ? NULL : elf->data + EGET(strtbl->sh_offset)); \
507 }
508 SHOW_INTERP(32)
509 SHOW_INTERP(64)
510 }
511 return NULL;
512 }
513 static char *scanelf_file_bind(elfobj *elf, char *found_bind)
514 {
515 unsigned long i;
516 struct stat s;
517
518 if (!show_bind) return NULL;
519 if (!elf->phdr) return NULL;
520
521 #define SHOW_BIND(B) \
522 if (elf->elf_class == ELFCLASS ## B) { \
523 Elf ## B ## _Dyn *dyn; \
524 Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
525 Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
526 Elf ## B ## _Off offset; \
527 for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
528 if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
529 offset = EGET(phdr[i].p_offset); \
530 if (offset >= elf->len - sizeof(Elf ## B ## _Dyn)) continue; \
531 dyn = DYN ## B (elf->data + offset); \
532 while (EGET(dyn->d_tag) != DT_NULL) { \
533 if (EGET(dyn->d_tag) == DT_BIND_NOW || \
534 (EGET(dyn->d_tag) == DT_FLAGS && EGET(dyn->d_un.d_val) & DF_BIND_NOW)) \
535 { \
536 if (be_quiet) return NULL; \
537 *found_bind = 1; \
538 return (char *)(be_wewy_wewy_quiet ? NULL : "NOW"); \
539 } \
540 ++dyn; \
541 } \
542 } \
543 }
544 SHOW_BIND(32)
545 SHOW_BIND(64)
546
547 if (be_wewy_wewy_quiet) return NULL;
548
549 if (be_quiet && !fstat(elf->fd, &s) && !(s.st_mode & S_ISUID || s.st_mode & S_ISGID)) {
550 return NULL;
551 } else {
552 *found_bind = 1;
553 return (char *) "LAZY";
554 }
555 }
556 static char *scanelf_file_sym(elfobj *elf, char *found_sym)
557 {
558 unsigned long i;
559 void *symtab_void, *strtab_void;
560
561 if (!find_sym) return NULL;
562
563 scanelf_file_get_symtabs(elf, &symtab_void, &strtab_void);
564
565 if (symtab_void && strtab_void) {
566 #define FIND_SYM(B) \
567 if (elf->elf_class == ELFCLASS ## B) { \
568 Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
569 Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
570 Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
571 unsigned long cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
572 char *symname; \
573 for (i = 0; i < cnt; ++i) { \
574 if (sym->st_name) { \
575 symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
576 if (*find_sym == '*') { \
577 printf("%s(%s) %5lX %15s %s\n", \
578 ((*found_sym == 0) ? "\n\t" : "\t"), \
579 elf->base_filename, \
580 (long)sym->st_size, \
581 (char *)get_elfstttype(sym->st_info), \
582 symname); \
583 *found_sym = 1; \
584 } else if ((strcmp(find_sym, symname) == 0) || \
585 (strcmp(symname, versioned_symname) == 0)) \
586 (*found_sym)++; \
587 } \
588 ++sym; \
589 } }
590 FIND_SYM(32)
591 FIND_SYM(64)
592 }
593
594 if (be_wewy_wewy_quiet) return NULL;
595
596 if (*find_sym != '*' && *found_sym)
597 return find_sym;
598 if (be_quiet)
599 return NULL;
600 else
601 return (char *)" - ";
602 }
603 /* scan an elf file and show all the fun stuff */
604 #define prints(str) write(fileno(stdout), str, strlen(str))
605 static void scanelf_file(const char *filename)
606 {
607 unsigned long i;
608 char found_pax, found_phdr, found_relro, found_load, found_textrel,
609 found_rpath, found_needed, found_interp, found_bind,
610 found_sym, found_lib, found_file, found_textrels;
611 elfobj *elf;
612 struct stat st;
613 static char *out_buffer = NULL;
614 static size_t out_len;
615
616 /* make sure 'filename' exists */
617 if (lstat(filename, &st) == -1) {
618 if (be_verbose > 2) printf("%s: does not exist\n", filename);
619 return;
620 }
621 /* always handle regular files and handle symlinked files if no -y */
622 if (S_ISLNK(st.st_mode)) {
623 if (!scan_symlink) return;
624 stat(filename, &st);
625 }
626 if (!S_ISREG(st.st_mode)) {
627 if (be_verbose > 2) printf("%s: skipping non-file\n", filename);
628 return;
629 }
630
631 found_pax = found_phdr = found_relro = found_load = found_textrel = \
632 found_rpath = found_needed = found_interp = found_bind = \
633 found_sym = found_lib = found_file = found_textrels = 0;
634
635 /* verify this is real ELF */
636 if ((elf = readelf(filename)) == NULL) {
637 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
638 return;
639 }
640
641 if (be_verbose > 1)
642 printf("%s: scanning file {%s,%s}\n", filename,
643 get_elfeitype(EI_CLASS, elf->elf_class),
644 get_elfeitype(EI_DATA, elf->data[EI_DATA]));
645 else if (be_verbose)
646 printf("%s: scanning file\n", filename);
647
648 /* init output buffer */
649 if (!out_buffer) {
650 out_len = sizeof(char) * 80;
651 out_buffer = (char*)xmalloc(out_len);
652 }
653 *out_buffer = '\0';
654
655 /* show the header */
656 if (!be_quiet && show_banner) {
657 for (i = 0; out_format[i]; ++i) {
658 if (!IS_MODIFIER(out_format[i])) continue;
659
660 switch (out_format[++i]) {
661 case '%': break;
662 case '#': break;
663 case 'F':
664 case 'p':
665 case 'f': prints("FILE "); found_file = 1; break;
666 case 'o': prints(" TYPE "); break;
667 case 'x': prints(" PAX "); break;
668 case 'e': prints("STK/REL/PTL "); break;
669 case 't': prints("TEXTREL "); break;
670 case 'r': prints("RPATH "); break;
671 case 'n': prints("NEEDED "); break;
672 case 'i': prints("INTERP "); break;
673 case 'b': prints("BIND "); break;
674 case 's': prints("SYM "); break;
675 case 'N': prints("LIB "); break;
676 case 'T': prints("TEXTRELS "); break;
677 default: warnf("'%c' has no title ?", out_format[i]);
678 }
679 }
680 if (!found_file) prints("FILE ");
681 prints("\n");
682 found_file = 0;
683 show_banner = 0;
684 }
685
686 /* dump all the good stuff */
687 for (i = 0; out_format[i]; ++i) {
688 const char *out;
689 const char *tmp;
690
691 /* make sure we trim leading spaces in quiet mode */
692 if (be_quiet && *out_buffer == ' ' && !out_buffer[1])
693 *out_buffer = '\0';
694
695 if (!IS_MODIFIER(out_format[i])) {
696 xchrcat(&out_buffer, out_format[i], &out_len);
697 continue;
698 }
699
700 out = NULL;
701 be_wewy_wewy_quiet = (out_format[i] == '#');
702 switch (out_format[++i]) {
703 case '%':
704 case '#':
705 xchrcat(&out_buffer, out_format[i], &out_len); break;
706 case 'F':
707 found_file = 1;
708 if (be_wewy_wewy_quiet) break;
709 xstrcat(&out_buffer, filename, &out_len);
710 break;
711 case 'p':
712 found_file = 1;
713 if (be_wewy_wewy_quiet) break;
714 tmp = filename;
715 if (search_path) {
716 ssize_t len_search = strlen(search_path);
717 ssize_t len_file = strlen(filename);
718 if (!strncmp(filename, search_path, len_search) && \
719 len_file > len_search)
720 tmp += len_search;
721 if (*tmp == '/' && search_path[len_search-1] == '/') tmp++;
722 }
723 xstrcat(&out_buffer, tmp, &out_len);
724 break;
725 case 'f':
726 found_file = 1;
727 if (be_wewy_wewy_quiet) break;
728 tmp = strrchr(filename, '/');
729 tmp = (tmp == NULL ? filename : tmp+1);
730 xstrcat(&out_buffer, tmp, &out_len);
731 break;
732 case 'o': out = get_elfetype(elf); break;
733 case 'x': out = scanelf_file_pax(elf, &found_pax); break;
734 case 'e': out = scanelf_file_phdr(elf, &found_phdr, &found_relro, &found_load); break;
735 case 't': out = scanelf_file_textrel(elf, &found_textrel); break;
736 case 'T': out = scanelf_file_textrels(elf, &found_textrels); break;
737 case 'r': scanelf_file_rpath(elf, &found_rpath, &out_buffer, &out_len); break;
738 case 'n':
739 case 'N': out = scanelf_file_needed_lib(elf, &found_needed, &found_lib, (out_format[i]=='N'), &out_buffer, &out_len); break;
740 case 'i': out = scanelf_file_interp(elf, &found_interp); break;
741 case 'b': out = scanelf_file_bind(elf, &found_bind); break;
742 case 's': out = scanelf_file_sym(elf, &found_sym); break;
743 default: warnf("'%c' has no scan code?", out_format[i]);
744 }
745 if (out) xstrcat(&out_buffer, out, &out_len);
746 }
747
748 #define FOUND_SOMETHING() \
749 (found_pax || found_phdr || found_relro || found_load || found_textrel || \
750 found_rpath || found_needed || found_interp || found_bind || \
751 found_sym || found_lib || found_textrels)
752
753 if (!found_file && (!be_quiet || (be_quiet && FOUND_SOMETHING()))) {
754 xchrcat(&out_buffer, ' ', &out_len);
755 xstrcat(&out_buffer, filename, &out_len);
756 }
757 if (!be_quiet || (be_quiet && FOUND_SOMETHING()))
758 puts(out_buffer);
759
760 unreadelf(elf);
761 }
762
763 /* scan a directory for ET_EXEC files and print when we find one */
764 static void scanelf_dir(const char *path)
765 {
766 register DIR *dir;
767 register struct dirent *dentry;
768 struct stat st_top, st;
769 char buf[_POSIX_PATH_MAX];
770 size_t pathlen = 0, len = 0;
771
772 /* make sure path exists */
773 if (lstat(path, &st_top) == -1) {
774 if (be_verbose > 2) printf("%s: does not exist\n", path);
775 return;
776 }
777
778 /* ok, if it isn't a directory, assume we can open it */
779 if (!S_ISDIR(st_top.st_mode)) {
780 scanelf_file(path);
781 return;
782 }
783
784 /* now scan the dir looking for fun stuff */
785 if ((dir = opendir(path)) == NULL) {
786 warnf("could not opendir %s: %s", path, strerror(errno));
787 return;
788 }
789 if (be_verbose) printf("%s: scanning dir\n", path);
790
791 pathlen = strlen(path);
792 while ((dentry = readdir(dir))) {
793 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
794 continue;
795 len = (pathlen + 1 + strlen(dentry->d_name) + 1);
796 if (len >= sizeof(buf)) {
797 warnf("Skipping '%s': len > sizeof(buf); %lu > %lu\n", path,
798 (unsigned long)len, (unsigned long)sizeof(buf));
799 continue;
800 }
801 sprintf(buf, "%s/%s", path, dentry->d_name);
802 if (lstat(buf, &st) != -1) {
803 if (S_ISREG(st.st_mode))
804 scanelf_file(buf);
805 else if (dir_recurse && S_ISDIR(st.st_mode)) {
806 if (dir_crossmount || (st_top.st_dev == st.st_dev))
807 scanelf_dir(buf);
808 }
809 }
810 }
811 closedir(dir);
812 }
813
814 static int scanelf_from_file(char *filename)
815 {
816 FILE *fp = NULL;
817 char *p;
818 char path[_POSIX_PATH_MAX];
819
820 if (((strcmp(filename, "-")) == 0) && (ttyname(0) == NULL))
821 fp = stdin;
822 else if ((fp = fopen(filename, "r")) == NULL)
823 return 1;
824
825 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
826 if ((p = strchr(path, '\n')) != NULL)
827 *p = 0;
828 search_path = path;
829 scanelf_dir(path);
830 }
831 if (fp != stdin)
832 fclose(fp);
833 return 0;
834 }
835
836 static void load_ld_so_conf()
837 {
838 FILE *fp = NULL;
839 char *p;
840 char path[_POSIX_PATH_MAX];
841 int i = 0;
842
843 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
844 return;
845
846 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL) {
847 if (*path != '/')
848 continue;
849
850 if ((p = strrchr(path, '\r')) != NULL)
851 *p = 0;
852 if ((p = strchr(path, '\n')) != NULL)
853 *p = 0;
854
855 ldpaths[i++] = xstrdup(path);
856
857 if (i + 1 == sizeof(ldpaths) / sizeof(*ldpaths))
858 break;
859 }
860 ldpaths[i] = NULL;
861
862 fclose(fp);
863 }
864
865 /* scan /etc/ld.so.conf for paths */
866 static void scanelf_ldpath()
867 {
868 char scan_l, scan_ul, scan_ull;
869 int i = 0;
870
871 if (!ldpaths[0])
872 err("Unable to load any paths from ld.so.conf");
873
874 scan_l = scan_ul = scan_ull = 0;
875
876 while (ldpaths[i]) {
877 if (!scan_l && !strcmp(ldpaths[i], "/lib")) scan_l = 1;
878 if (!scan_ul && !strcmp(ldpaths[i], "/usr/lib")) scan_ul = 1;
879 if (!scan_ull && !strcmp(ldpaths[i], "/usr/local/lib")) scan_ull = 1;
880 scanelf_dir(ldpaths[i]);
881 ++i;
882 }
883
884 if (!scan_l) scanelf_dir("/lib");
885 if (!scan_ul) scanelf_dir("/usr/lib");
886 if (!scan_ull) scanelf_dir("/usr/local/lib");
887 }
888
889 /* scan env PATH for paths */
890 static void scanelf_envpath()
891 {
892 char *path, *p;
893
894 path = getenv("PATH");
895 if (!path)
896 err("PATH is not set in your env !");
897 path = xstrdup(path);
898
899 while ((p = strrchr(path, ':')) != NULL) {
900 scanelf_dir(p + 1);
901 *p = 0;
902 }
903
904 free(path);
905 }
906
907
908
909 /* usage / invocation handling functions */
910 #define PARSE_FLAGS "plRmyxetrnibs:N:TaqvF:f:o:BhV"
911 #define a_argument required_argument
912 static struct option const long_opts[] = {
913 {"path", no_argument, NULL, 'p'},
914 {"ldpath", no_argument, NULL, 'l'},
915 {"recursive", no_argument, NULL, 'R'},
916 {"mount", no_argument, NULL, 'm'},
917 {"symlink", no_argument, NULL, 'y'},
918 {"pax", no_argument, NULL, 'x'},
919 {"header", no_argument, NULL, 'e'},
920 {"textrel", no_argument, NULL, 't'},
921 {"rpath", no_argument, NULL, 'r'},
922 {"needed", no_argument, NULL, 'n'},
923 {"interp", no_argument, NULL, 'i'},
924 {"bind", no_argument, NULL, 'b'},
925 {"symbol", a_argument, NULL, 's'},
926 {"lib", a_argument, NULL, 'N'},
927 {"textrels", no_argument, NULL, 'T'},
928 {"all", no_argument, NULL, 'a'},
929 {"quiet", no_argument, NULL, 'q'},
930 {"verbose", no_argument, NULL, 'v'},
931 {"format", a_argument, NULL, 'F'},
932 {"from", a_argument, NULL, 'f'},
933 {"file", a_argument, NULL, 'o'},
934 {"nobanner", no_argument, NULL, 'B'},
935 {"help", no_argument, NULL, 'h'},
936 {"version", no_argument, NULL, 'V'},
937 {NULL, no_argument, NULL, 0x0}
938 };
939
940 static const char *opts_help[] = {
941 "Scan all directories in PATH environment",
942 "Scan all directories in /etc/ld.so.conf",
943 "Scan directories recursively",
944 "Don't recursively cross mount points",
945 "Don't scan symlinks\n",
946 "Print PaX markings",
947 "Print GNU_STACK/PT_LOAD markings",
948 "Print TEXTREL information",
949 "Print RPATH information",
950 "Print NEEDED information",
951 "Print INTERP information",
952 "Print BIND information",
953 "Find a specified symbol",
954 "Find a specified library",
955 "Locate cause of TEXTREL",
956 "Print all scanned info (-x -e -t -r -n -i -b)\n",
957 "Only output 'bad' things",
958 "Be verbose (can be specified more than once)",
959 "Use specified format for output",
960 "Read input stream from a filename",
961 "Write output stream to a filename",
962 "Don't display the header",
963 "Print this help and exit",
964 "Print version and exit",
965 NULL
966 };
967
968 /* display usage and exit */
969 static void usage(int status)
970 {
971 unsigned long i;
972 printf("* Scan ELF binaries for stuff\n\n"
973 "Usage: %s [options] <dir1/file1> [dir2 dirN fileN ...]\n\n", argv0);
974 printf("Options: -[%s]\n", PARSE_FLAGS);
975 for (i = 0; long_opts[i].name; ++i)
976 if (long_opts[i].has_arg == no_argument)
977 printf(" -%c, --%-13s* %s\n", long_opts[i].val,
978 long_opts[i].name, opts_help[i]);
979 else
980 printf(" -%c, --%-6s <arg> * %s\n", long_opts[i].val,
981 long_opts[i].name, opts_help[i]);
982
983 if (status != EXIT_SUCCESS)
984 exit(status);
985
986 puts("\nThe format modifiers for the -F option are:");
987 puts(" F Filename \tx PaX Flags \te STACK/RELRO");
988 puts(" t TEXTREL \tr RPATH \tn NEEDED");
989 puts(" i INTERP \tb BIND \ts symbol");
990 puts(" N library \to Type \tT TEXTRELs");
991 puts(" p filename (with search path removed)");
992 puts(" f base filename");
993 puts("Prefix each modifier with '%' (verbose) or '#' (silent)");
994
995 exit(status);
996 }
997
998 /* parse command line arguments and preform needed actions */
999 static void parseargs(int argc, char *argv[])
1000 {
1001 int i;
1002 char *from_file = NULL;
1003
1004 opterr = 0;
1005 while ((i=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
1006 switch (i) {
1007
1008 case 'V':
1009 printf("%s compiled %s\n%s\n"
1010 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
1011 __FILE__, __DATE__, rcsid, argv0);
1012 exit(EXIT_SUCCESS);
1013 break;
1014 case 'h': usage(EXIT_SUCCESS); break;
1015 case 'f':
1016 if (from_file) err("Don't specify -f twice");
1017 from_file = xstrdup(optarg);
1018 break;
1019 case 'o': {
1020 FILE *fp = NULL;
1021 if ((fp = freopen(optarg, "w", stdout)) == NULL)
1022 err("Could not open output stream '%s': %s", optarg, strerror(errno));
1023 SET_STDOUT(fp);
1024 break;
1025 }
1026
1027 case 's': {
1028 size_t len;
1029 if (find_sym) err("Don't specify -s twice");
1030 find_sym = xstrdup(optarg);
1031 len = strlen(find_sym) + 1;
1032 versioned_symname = (char*)xmalloc(sizeof(char) * (len+1));
1033 sprintf(versioned_symname, "%s@", find_sym);
1034 break;
1035 }
1036 case 'N': {
1037 if (find_lib) err("Don't specify -N twice");
1038 find_lib = xstrdup(optarg);
1039 break;
1040 }
1041
1042 case 'F': {
1043 if (out_format) err("Don't specify -F twice");
1044 out_format = xstrdup(optarg);
1045 break;
1046 }
1047
1048 case 'y': scan_symlink = 0; break;
1049 case 'B': show_banner = 0; break;
1050 case 'l': scan_ldpath = 1; break;
1051 case 'p': scan_envpath = 1; break;
1052 case 'R': dir_recurse = 1; break;
1053 case 'm': dir_crossmount = 0; break;
1054 case 'x': show_pax = 1; break;
1055 case 'e': show_phdr = 1; break;
1056 case 't': show_textrel = 1; break;
1057 case 'r': show_rpath = 1; break;
1058 case 'n': show_needed = 1; break;
1059 case 'i': show_interp = 1; break;
1060 case 'b': show_bind = 1; break;
1061 case 'T': show_textrels = 1; break;
1062 case 'q': be_quiet = 1; break;
1063 case 'v': be_verbose = (be_verbose % 20) + 1; break;
1064 case 'a': show_pax = show_phdr = show_textrel = show_rpath = \
1065 show_needed = show_interp = show_bind = 1; break;
1066
1067 case ':':
1068 err("Option missing parameter\n");
1069 case '?':
1070 err("Unknown option\n");
1071 default:
1072 err("Unhandled option '%c'", i);
1073 }
1074 }
1075
1076 /* let the format option override all other options */
1077 if (out_format) {
1078 show_pax = show_phdr = show_textrel = show_rpath = \
1079 show_needed = show_interp = show_bind = show_textrels = 0;
1080 for (i = 0; out_format[i]; ++i) {
1081 if (!IS_MODIFIER(out_format[i])) continue;
1082
1083 switch (out_format[++i]) {
1084 case '%': break;
1085 case '#': break;
1086 case 'F': break;
1087 case 'p': break;
1088 case 'f': break;
1089 case 's': break;
1090 case 'N': break;
1091 case 'o': break;
1092 case 'x': show_pax = 1; break;
1093 case 'e': show_phdr = 1; break;
1094 case 't': show_textrel = 1; break;
1095 case 'r': show_rpath = 1; break;
1096 case 'n': show_needed = 1; break;
1097 case 'i': show_interp = 1; break;
1098 case 'b': show_bind = 1; break;
1099 case 'T': show_textrels = 1; break;
1100 default:
1101 err("Invalid format specifier '%c' (byte %i)",
1102 out_format[i], i+1);
1103 }
1104 }
1105
1106 /* construct our default format */
1107 } else {
1108 size_t fmt_len = 30;
1109 out_format = (char*)xmalloc(sizeof(char) * fmt_len);
1110 if (!be_quiet) xstrcat(&out_format, "%o ", &fmt_len);
1111 if (show_pax) xstrcat(&out_format, "%x ", &fmt_len);
1112 if (show_phdr) xstrcat(&out_format, "%e ", &fmt_len);
1113 if (show_textrel) xstrcat(&out_format, "%t ", &fmt_len);
1114 if (show_rpath) xstrcat(&out_format, "%r ", &fmt_len);
1115 if (show_needed) xstrcat(&out_format, "%n ", &fmt_len);
1116 if (show_interp) xstrcat(&out_format, "%i ", &fmt_len);
1117 if (show_bind) xstrcat(&out_format, "%b ", &fmt_len);
1118 if (show_textrels) xstrcat(&out_format, "%T ", &fmt_len);
1119 if (find_sym) xstrcat(&out_format, "%s ", &fmt_len);
1120 if (find_lib) xstrcat(&out_format, "%N ", &fmt_len);
1121 if (!be_quiet) xstrcat(&out_format, "%F ", &fmt_len);
1122 }
1123 if (be_verbose > 2) printf("Format: %s\n", out_format);
1124
1125 /* now lets actually do the scanning */
1126 if (scan_ldpath || (show_rpath && be_quiet))
1127 load_ld_so_conf();
1128 if (scan_ldpath) scanelf_ldpath();
1129 if (scan_envpath) scanelf_envpath();
1130 if (from_file) {
1131 scanelf_from_file(from_file);
1132 free(from_file);
1133 from_file = *argv;
1134 }
1135 if (optind == argc && !scan_ldpath && !scan_envpath && !from_file)
1136 err("Nothing to scan !?");
1137 while (optind < argc) {
1138 search_path = argv[optind++];
1139 scanelf_dir(search_path);
1140 }
1141
1142 /* clean up */
1143 if (find_sym) {
1144 free(find_sym);
1145 free(versioned_symname);
1146 }
1147 if (find_lib) free(find_lib);
1148 if (out_format) free(out_format);
1149 for (i = 0; ldpaths[i]; ++i)
1150 free(ldpaths[i]);
1151 }
1152
1153
1154
1155 /* utility funcs */
1156 static char *xstrdup(const char *s)
1157 {
1158 char *ret = strdup(s);
1159 if (!ret) err("Could not strdup(): %s", strerror(errno));
1160 return ret;
1161 }
1162
1163 static void *xmalloc(size_t size)
1164 {
1165 void *ret = malloc(size);
1166 if (!ret) err("Could not malloc() %li bytes", (unsigned long)size);
1167 return ret;
1168 }
1169
1170 static void xstrcat(char **dst, const char *src, size_t *curr_len)
1171 {
1172 size_t new_len;
1173
1174 new_len = strlen(*dst) + strlen(src);
1175 if (*curr_len <= new_len) {
1176 *curr_len = new_len + (*curr_len / 2);
1177 *dst = realloc(*dst, *curr_len);
1178 if (!*dst)
1179 err("could not realloc %li bytes", (unsigned long)*curr_len);
1180 }
1181
1182 strcat(*dst, src);
1183 }
1184
1185 static inline void xchrcat(char **dst, const char append, size_t *curr_len)
1186 {
1187 static char my_app[2];
1188 my_app[0] = append;
1189 my_app[1] = '\0';
1190 xstrcat(dst, my_app, curr_len);
1191 }
1192
1193
1194
1195 int main(int argc, char *argv[])
1196 {
1197 if (argc < 2)
1198 usage(EXIT_FAILURE);
1199 parseargs(argc, argv);
1200 fclose(stdout);
1201 #ifdef __BOUNDS_CHECKING_ON
1202 warn("The calls to add/delete heap should be off by 1 due to the out_buffer not being freed in scanelf_file()");
1203 #endif
1204 return EXIT_SUCCESS;
1205 }

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