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Revision 1.31 - (hide annotations) (download) (as text)
Wed Apr 6 02:01:52 2005 UTC (9 years, 5 months ago) by solar
Branch: MAIN
Changes since 1.30: +4 -6 lines
File MIME type: text/x-csrc
- just use 1 libc call to fill buf

1 solar 1.1 /*
2     * Copyright 2003 Ned Ludd <solar@gentoo.org>
3 vapier 1.8 * Copyright 1999-2005 Gentoo Foundation
4 solar 1.1 * Distributed under the terms of the GNU General Public License v2
5 solar 1.31 * $Header: /var/cvsroot/gentoo-projects/pax-utils/scanelf.c,v 1.30 2005/04/05 16:15:31 solar Exp $
6 solar 1.1 *
7     ********************************************************************
8     * This program is free software; you can redistribute it and/or
9     * modify it under the terms of the GNU General Public License as
10     * published by the Free Software Foundation; either version 2 of the
11     * License, or (at your option) any later version.
12     *
13     * This program is distributed in the hope that it will be useful, but
14     * WITHOUT ANY WARRANTY; without even the implied warranty of
15     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16     * General Public License for more details.
17     *
18     * You should have received a copy of the GNU General Public License
19     * along with this program; if not, write to the Free Software
20     * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
21     * MA 02111-1307, USA.
22     */
23    
24     #include <stdio.h>
25     #include <stdlib.h>
26     #include <sys/types.h>
27 solar 1.28 #define __USE_GNU
28 solar 1.1 #include <string.h>
29 vapier 1.10 #include <errno.h>
30 solar 1.1 #include <unistd.h>
31     #include <sys/stat.h>
32     #include <dirent.h>
33     #include <getopt.h>
34 solar 1.20 #include <assert.h>
35 solar 1.21
36 solar 1.1 #include "paxelf.h"
37    
38 solar 1.31 static const char *rcsid = "$Id: scanelf.c,v 1.30 2005/04/05 16:15:31 solar Exp $";
39 vapier 1.10
40    
41     /* helper functions for showing errors */
42 vapier 1.18 #define argv0 "scanelf" /*((*argv != NULL) ? argv[0] : __FILE__ "\b\b")*/
43 vapier 1.10 #define warn(fmt, args...) \
44     fprintf(stderr, "%s: " fmt "\n", argv0, ## args)
45     #define warnf(fmt, args...) warn("%s(): " fmt, __FUNCTION__, ## args)
46     #define err(fmt, args...) \
47     do { \
48     warn(fmt, ## args); \
49     exit(EXIT_FAILURE); \
50     } while (0)
51    
52    
53    
54     /* prototypes */
55     static void scanelf_file(const char *filename);
56     static void scanelf_dir(const char *path);
57     static void scanelf_ldpath();
58     static void scanelf_envpath();
59     static void usage(int status);
60     static void parseargs(int argc, char *argv[]);
61    
62     /* variables to control behavior */
63     static char scan_ldpath = 0;
64     static char scan_envpath = 0;
65     static char dir_recurse = 0;
66 vapier 1.14 static char dir_crossmount = 1;
67 vapier 1.10 static char show_pax = 0;
68     static char show_stack = 0;
69     static char show_textrel = 0;
70     static char show_rpath = 0;
71 solar 1.16 static char show_banner = 1;
72 vapier 1.10 static char be_quiet = 0;
73 vapier 1.14 static char be_verbose = 0;
74 vapier 1.27 static char *find_sym = NULL;
75 vapier 1.10
76 solar 1.1
77    
78 vapier 1.10 /* scan an elf file and show all the fun stuff */
79     static void scanelf_file(const char *filename)
80 solar 1.6 {
81 vapier 1.10 int i;
82 vapier 1.27 char found_pax, found_stack, found_relro, found_textrel, found_rpath, found_sym;
83 vapier 1.26 elfobj *elf;
84 vapier 1.10
85 vapier 1.27 found_pax = found_stack = found_relro = found_textrel = found_rpath = found_sym = 0;
86 solar 1.12
87 vapier 1.10 /* verify this is real ELF */
88 vapier 1.14 if ((elf = readelf(filename)) == NULL) {
89 vapier 1.26 if (be_verbose > 2) printf("%s: not an ELF\n", filename);
90 vapier 1.10 return;
91 vapier 1.14 }
92    
93 vapier 1.26 if (be_verbose > 1)
94     printf("%s: {%s,%s} scanning file\n", filename,
95     get_elfeitype(elf, EI_CLASS, elf->elf_class),
96     get_elfeitype(elf, EI_DATA, elf->data[EI_DATA]));
97     else if (be_verbose)
98     printf("%s: scanning file\n", filename);
99 vapier 1.10
100     /* show the header */
101 solar 1.16 if (!be_quiet && show_banner) {
102 vapier 1.23 printf(" TYPE ");
103     if (show_pax) printf(" PAX ");
104     if (show_stack) printf(" STK/REL ");
105     if (show_textrel) printf("TEXTREL ");
106     if (show_rpath) printf("RPATH ");
107     printf(" FILE\n");
108 solar 1.16 show_banner = 0;
109 vapier 1.10 }
110    
111     /* dump all the good stuff */
112     if (!be_quiet)
113 vapier 1.26 printf("%-7s ", get_elfetype(elf));
114 vapier 1.10
115 vapier 1.14 if (show_pax) {
116     char *paxflags = pax_short_hf_flags(PAX_FLAGS(elf));
117     if (!be_quiet || (be_quiet && strncmp(paxflags, "PeMRxS", 6))) {
118     found_pax = 1;
119     printf("%s ", pax_short_hf_flags(PAX_FLAGS(elf)));
120     }
121     }
122 vapier 1.10
123     /* stack fun */
124     if (show_stack) {
125 vapier 1.26 #define SHOW_STACK(B) \
126     if (elf->elf_class == ELFCLASS ## B) { \
127     Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
128     Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
129     for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
130     if (EGET(phdr[i].p_type) != PT_GNU_STACK && \
131     EGET(phdr[i].p_type) != PT_GNU_RELRO) continue; \
132     if (be_quiet && !(EGET(phdr[i].p_flags) & PF_X)) \
133     continue; \
134     if (EGET(phdr[i].p_type) == PT_GNU_STACK) \
135     found_stack = 1; \
136     if (EGET(phdr[i].p_type) == PT_GNU_RELRO) \
137     found_relro = 1; \
138     printf("%s ", gnu_short_stack_flags(EGET(phdr[i].p_flags))); \
139     } \
140 vapier 1.10 }
141 vapier 1.26 SHOW_STACK(32)
142     SHOW_STACK(64)
143 vapier 1.23 if (!be_quiet && !found_stack) printf("--- ");
144     if (!be_quiet && !found_relro) printf("--- ");
145 vapier 1.10 }
146    
147     /* textrel fun */
148     if (show_textrel) {
149 vapier 1.26 #define SHOW_TEXTREL(B) \
150     if (elf->elf_class == ELFCLASS ## B) { \
151     Elf ## B ## _Dyn *dyn; \
152     Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
153     Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
154     for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
155     if (phdr[i].p_type != PT_DYNAMIC) continue; \
156     dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
157     while (EGET(dyn->d_tag) != DT_NULL) { \
158     if (EGET(dyn->d_tag) == DT_TEXTREL) { /*dyn->d_tag != DT_FLAGS)*/ \
159     found_textrel = 1; \
160     /*if (dyn->d_un.d_val & DF_TEXTREL)*/ \
161     printf("TEXTREL "); \
162     } \
163     ++dyn; \
164     } \
165     } }
166     SHOW_TEXTREL(32)
167     SHOW_TEXTREL(64)
168 vapier 1.23 if (!be_quiet && !found_textrel) printf("------- ");
169 vapier 1.10 }
170    
171     /* rpath fun */
172     /* TODO: if be_quiet, only output RPATH's which aren't in /etc/ld.so.conf */
173     if (show_rpath) {
174 vapier 1.23 char *rpath, *runpath;
175 vapier 1.26 void *strtbl_void = elf_findsecbyname(elf, ".dynstr");
176 vapier 1.23 rpath = runpath = NULL;
177 vapier 1.10
178 vapier 1.26 if (strtbl_void) {
179     #define SHOW_RPATH(B) \
180     if (elf->elf_class == ELFCLASS ## B) { \
181     Elf ## B ## _Dyn *dyn; \
182     Elf ## B ## _Ehdr *ehdr = EHDR ## B (elf->ehdr); \
183     Elf ## B ## _Phdr *phdr = PHDR ## B (elf->phdr); \
184     Elf ## B ## _Shdr *strtbl = SHDR ## B (strtbl_void); \
185     for (i = 0; i < EGET(ehdr->e_phnum); i++) { \
186     if (EGET(phdr[i].p_type) != PT_DYNAMIC) continue; \
187     dyn = DYN ## B (elf->data + EGET(phdr[i].p_offset)); \
188     while (EGET(dyn->d_tag) != DT_NULL) { \
189     if (EGET(dyn->d_tag) == DT_RPATH) { \
190     rpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
191     found_rpath = 1; \
192     } else if (EGET(dyn->d_tag) == DT_RUNPATH) { \
193     runpath = elf->data + EGET(strtbl->sh_offset) + EGET(dyn->d_un.d_ptr); \
194     found_rpath = 1; \
195     } \
196     ++dyn; \
197     } \
198     } }
199     SHOW_RPATH(32)
200     SHOW_RPATH(64)
201 vapier 1.10 }
202 vapier 1.23 if (rpath && runpath) {
203     if (!strcmp(rpath, runpath))
204     printf("%-5s ", runpath);
205     else {
206     fprintf(stderr, "%s's RPATH [%s] != RUNPATH [%s]\n", filename, rpath, runpath);
207     printf("{%s,%s} ", rpath, runpath);
208     }
209     } else if (rpath || runpath)
210     printf("%-5s ", (runpath ? runpath : rpath));
211     else if (!be_quiet && !found_rpath)
212     printf(" - ");
213 vapier 1.10 }
214    
215 vapier 1.27 if (find_sym) {
216     void *symtab_void, *strtab_void;
217 vapier 1.29 char *versioned_symname = malloc(strlen(find_sym)+2);
218 solar 1.28
219     sprintf(versioned_symname, "%s@", find_sym);
220 vapier 1.27 symtab_void = elf_findsecbyname(elf, ".symtab");
221     strtab_void = elf_findsecbyname(elf, ".strtab");
222    
223     if (symtab_void && strtab_void) {
224     #define FIND_SYM(B) \
225     if (elf->elf_class == ELFCLASS ## B) { \
226     Elf ## B ## _Shdr *symtab = SHDR ## B (symtab_void); \
227     Elf ## B ## _Shdr *strtab = SHDR ## B (strtab_void); \
228     Elf ## B ## _Sym *sym = SYM ## B (elf->data + EGET(symtab->sh_offset)); \
229     int cnt = EGET(symtab->sh_size) / EGET(symtab->sh_entsize); \
230     char *symname; \
231     for (i = 0; i < cnt; ++i) { \
232     if (sym->st_name) { \
233     symname = (char *)(elf->data + EGET(strtab->sh_offset) + EGET(sym->st_name)); \
234 solar 1.28 if (*find_sym == '*') { \
235     printf("%s(%s) %5lX %15s %s\n", ((found_sym == 0) ? "\n\t" : "\t"), \
236     (char *) basename(filename), \
237     (long)sym->st_size, (char *) get_elfstttype(sym->st_info & 0xF), \
238     symname); \
239     found_sym = 1; \
240     } \
241     if ((strcmp(find_sym, symname) == 0) || \
242     (strncmp(symname, versioned_symname, strlen(versioned_symname)) == 0)) \
243     found_sym++; \
244 vapier 1.27 } \
245     ++sym; \
246     } }
247     FIND_SYM(32)
248     FIND_SYM(64)
249     }
250 solar 1.28 free(versioned_symname);
251 vapier 1.29 if (*find_sym != '*') {
252     if (found_sym)
253     printf(" %s ", find_sym);
254     else if (!be_quiet)
255     printf(" - ");
256     }
257 vapier 1.27 }
258 vapier 1.10
259 vapier 1.29 if (!be_quiet || found_pax || found_stack || found_textrel || found_rpath || found_sym)
260 solar 1.28 printf("%s\n", filename);
261    
262 vapier 1.10 unreadelf(elf);
263 solar 1.6 }
264    
265 solar 1.1 /* scan a directory for ET_EXEC files and print when we find one */
266 vapier 1.10 static void scanelf_dir(const char *path)
267 solar 1.1 {
268 vapier 1.10 register DIR *dir;
269     register struct dirent *dentry;
270 vapier 1.14 struct stat st_top, st;
271 solar 1.21 char buf[_POSIX_PATH_MAX];
272 solar 1.20 size_t len = 0;
273 vapier 1.10
274     /* make sure path exists */
275 vapier 1.14 if (lstat(path, &st_top) == -1)
276 vapier 1.10 return;
277 solar 1.11
278 vapier 1.10 /* ok, if it isn't a directory, assume we can open it */
279 vapier 1.14 if (!S_ISDIR(st_top.st_mode)) {
280 vapier 1.10 scanelf_file(path);
281     return;
282     }
283    
284     /* now scan the dir looking for fun stuff */
285     if ((dir = opendir(path)) == NULL) {
286     warnf("could not opendir %s: %s", path, strerror(errno));
287     return;
288     }
289 vapier 1.15 if (be_verbose) printf("%s: scanning dir\n", path);
290 solar 1.11
291 vapier 1.10 while ((dentry = readdir(dir))) {
292     if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
293     continue;
294     len = (strlen(path) + 2 + strlen(dentry->d_name));
295 solar 1.31 if (len >= sizeof(buf)) warn("len > sizeof(buf); %d %d = %s\n", len, sizeof(buf), path);
296 solar 1.20 assert(len < sizeof(buf));
297 solar 1.31 sprintf(buf, "%s/%s", path, dentry->d_name);
298 solar 1.20 if (lstat(buf, &st) != -1) {
299 vapier 1.10 if (S_ISREG(st.st_mode))
300 solar 1.20 scanelf_file(buf);
301 vapier 1.10 else if (dir_recurse && S_ISDIR(st.st_mode)) {
302 vapier 1.14 if (dir_crossmount || (st_top.st_dev == st.st_dev))
303 solar 1.20 scanelf_dir(buf);
304 vapier 1.10 }
305     }
306     }
307     closedir(dir);
308 solar 1.1 }
309    
310 vapier 1.10 /* scan /etc/ld.so.conf for paths */
311     static void scanelf_ldpath()
312     {
313 vapier 1.17 char scan_l, scan_ul, scan_ull;
314 vapier 1.10 char *path, *p;
315     FILE *fp;
316    
317     if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
318     err("Unable to open ld.so.conf: %s", strerror(errno));
319    
320 vapier 1.17 scan_l = scan_ul = scan_ull = 0;
321    
322 solar 1.30 if ((path = malloc(_POSIX_PATH_MAX)) == NULL) {
323     warn("Can not malloc() memory for ldpath scanning");
324     return;
325     }
326 vapier 1.10 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL)
327     if (*path == '/') {
328     if ((p = strrchr(path, '\r')) != NULL)
329     *p = 0;
330     if ((p = strrchr(path, '\n')) != NULL)
331     *p = 0;
332 vapier 1.17 if (!scan_l && !strcmp(path, "/lib")) scan_l = 1;
333     if (!scan_ul && !strcmp(path, "/usr/lib")) scan_ul = 1;
334     if (!scan_ull && !strcmp(path, "/usr/local/lib")) scan_ull = 1;
335 vapier 1.10 scanelf_dir(path);
336     }
337     free(path);
338    
339 vapier 1.17 if (!scan_l) scanelf_dir("/lib");
340     if (!scan_ul) scanelf_dir("/usr/lib");
341     if (!scan_ull) scanelf_dir("/usr/local/lib");
342    
343 vapier 1.10 fclose(fp);
344     }
345 solar 1.1
346 vapier 1.10 /* scan env PATH for paths */
347     static void scanelf_envpath()
348 solar 1.1 {
349 vapier 1.10 char *path, *p;
350    
351     path = getenv("PATH");
352     if (!path)
353     err("PATH is not set in your env !");
354    
355     if ((path = strdup(path)) == NULL)
356     err("stdup failed: %s", strerror(errno));
357    
358     while ((p = strrchr(path, ':')) != NULL) {
359     scanelf_dir(p + 1);
360     *p = 0;
361     }
362 vapier 1.17
363 vapier 1.10 free(path);
364 solar 1.1 }
365    
366    
367 vapier 1.10
368     /* usage / invocation handling functions */
369 vapier 1.27 #define PARSE_FLAGS "plRmxetrs:aqvo:BhV"
370     #define a_argument required_argument
371 vapier 1.10 static struct option const long_opts[] = {
372     {"path", no_argument, NULL, 'p'},
373     {"ldpath", no_argument, NULL, 'l'},
374     {"recursive", no_argument, NULL, 'R'},
375 vapier 1.14 {"mount", no_argument, NULL, 'm'},
376 vapier 1.10 {"pax", no_argument, NULL, 'x'},
377 solar 1.16 {"header", no_argument, NULL, 'e'},
378 vapier 1.10 {"textrel", no_argument, NULL, 't'},
379     {"rpath", no_argument, NULL, 'r'},
380 vapier 1.27 {"symbol", a_argument, NULL, 's'},
381 vapier 1.10 {"all", no_argument, NULL, 'a'},
382     {"quiet", no_argument, NULL, 'q'},
383 vapier 1.14 {"verbose", no_argument, NULL, 'v'},
384 vapier 1.27 {"file", a_argument, NULL, 'o'},
385 solar 1.16 {"nobanner", no_argument, NULL, 'B'},
386 vapier 1.10 {"help", no_argument, NULL, 'h'},
387     {"version", no_argument, NULL, 'V'},
388     {NULL, no_argument, NULL, 0x0}
389     };
390     static char *opts_help[] = {
391     "Scan all directories in PATH environment",
392     "Scan all directories in /etc/ld.so.conf",
393 vapier 1.14 "Scan directories recursively",
394     "Don't recursively cross mount points\n",
395 vapier 1.10 "Print PaX markings",
396     "Print GNU_STACK markings",
397     "Print TEXTREL information",
398     "Print RPATH information",
399 vapier 1.27 "Find a specified symbol",
400 solar 1.16 "Print all scanned info (-x -e -t -r)\n",
401 vapier 1.14 "Only output 'bad' things",
402     "Be verbose (can be specified more than once)",
403 vapier 1.24 "Write output stream to a filename",
404 vapier 1.14 "Don't display the header",
405 vapier 1.10 "Print this help and exit",
406     "Print version and exit",
407     NULL
408     };
409    
410     /* display usage and exit */
411     static void usage(int status)
412 solar 1.1 {
413 vapier 1.10 int i;
414 vapier 1.27 printf(" Scan ELF binaries for stuff\n"
415 vapier 1.10 "Usage: %s [options] <dir1> [dir2 dirN ...]\n\n", argv0);
416 vapier 1.23 printf("Options:\n");
417 vapier 1.10 for (i = 0; long_opts[i].name; ++i)
418 vapier 1.27 if (long_opts[i].has_arg == no_argument)
419     printf(" -%c, --%-13s %s\n", long_opts[i].val,
420     long_opts[i].name, opts_help[i]);
421     else
422     printf(" -%c, --%-6s <arg> %s\n", long_opts[i].val,
423     long_opts[i].name, opts_help[i]);
424 vapier 1.10 exit(status);
425 solar 1.1 }
426    
427     /* parse command line arguments and preform needed actions */
428 vapier 1.10 static void parseargs(int argc, char *argv[])
429     {
430     int flag;
431    
432     opterr = 0;
433     while ((flag=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
434     switch (flag) {
435    
436     case 'V': /* version info */
437 solar 1.19 printf("%s compiled %s\n%s\n"
438     "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
439     __FILE__, __DATE__, rcsid, argv0);
440 vapier 1.10 exit(EXIT_SUCCESS);
441     break;
442     case 'h': usage(EXIT_SUCCESS); break;
443    
444 vapier 1.24 case 'o': {
445 solar 1.21 FILE *fp = NULL;
446     fp = freopen(optarg, "w", stdout);
447 vapier 1.24 if (fp == NULL)
448     err("Could not open output stream '%s': %s", optarg, strerror(errno));
449     stdout = fp;
450 solar 1.21 break;
451     }
452 vapier 1.24
453 vapier 1.27 case 's': find_sym = strdup(optarg); break;
454    
455 solar 1.16 case 'B': show_banner = 0; break;
456 vapier 1.10 case 'l': scan_ldpath = 1; break;
457     case 'p': scan_envpath = 1; break;
458     case 'R': dir_recurse = 1; break;
459 vapier 1.14 case 'm': dir_crossmount = 0; break;
460 vapier 1.10 case 'x': show_pax = 1; break;
461 solar 1.16 case 'e': show_stack = 1; break;
462 vapier 1.10 case 't': show_textrel = 1; break;
463     case 'r': show_rpath = 1; break;
464     case 'q': be_quiet = 1; break;
465 vapier 1.14 case 'v': be_verbose = (be_verbose % 20) + 1; break;
466 vapier 1.10 case 'a': show_pax = show_stack = show_textrel = show_rpath = 1; break;
467    
468     case ':':
469     warn("Option missing parameter");
470     usage(EXIT_FAILURE);
471     break;
472     case '?':
473     warn("Unknown option");
474     usage(EXIT_FAILURE);
475     break;
476     default:
477     err("Unhandled option '%c'", flag);
478     break;
479     }
480     }
481    
482 vapier 1.14 if (be_quiet && be_verbose)
483     err("You can be quiet or you can be verbose, not both, stupid");
484    
485 vapier 1.10 if (scan_ldpath) scanelf_ldpath();
486     if (scan_envpath) scanelf_envpath();
487 vapier 1.25 if (optind == argc && !scan_ldpath && !scan_envpath)
488     err("Nothing to scan !?");
489 vapier 1.10 while (optind < argc)
490     scanelf_dir(argv[optind++]);
491 vapier 1.27
492     if (find_sym) free(find_sym);
493 vapier 1.10 }
494    
495    
496    
497     int main(int argc, char *argv[])
498 solar 1.1 {
499 vapier 1.10 if (argc < 2)
500     usage(EXIT_FAILURE);
501     parseargs(argc, argv);
502 solar 1.21 fclose(stdout);
503 vapier 1.10 return EXIT_SUCCESS;
504 solar 1.1 }

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