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Revision 1.24 - (show annotations) (download) (as text)
Sun Apr 3 18:42:27 2005 UTC (9 years, 3 months ago) by vapier
Branch: MAIN
Changes since 1.23: +10 -12 lines
File MIME type: text/x-csrc
make -o failure abort

1 /*
2 * Copyright 2003 Ned Ludd <solar@gentoo.org>
3 * Copyright 1999-2005 Gentoo Foundation
4 * Distributed under the terms of the GNU General Public License v2
5 * $Header: /var/cvsroot/gentoo-projects/pax-utils/scanelf.c,v 1.23 2005/04/03 18:27:45 vapier Exp $
6 *
7 ********************************************************************
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of the
11 * License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
21 * MA 02111-1307, USA.
22 */
23
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <sys/types.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <sys/stat.h>
31 #include <dirent.h>
32 #include <getopt.h>
33 #include <assert.h>
34
35 #include "paxelf.h"
36
37 static const char *rcsid = "$Id: scanelf.c,v 1.23 2005/04/03 18:27:45 vapier Exp $";
38
39
40 /* helper functions for showing errors */
41 #define argv0 "scanelf" /*((*argv != NULL) ? argv[0] : __FILE__ "\b\b")*/
42 #define warn(fmt, args...) \
43 fprintf(stderr, "%s: " fmt "\n", argv0, ## args)
44 #define warnf(fmt, args...) warn("%s(): " fmt, __FUNCTION__, ## args)
45 #define err(fmt, args...) \
46 do { \
47 warn(fmt, ## args); \
48 exit(EXIT_FAILURE); \
49 } while (0)
50
51
52
53 /* prototypes */
54 static void scanelf_file(const char *filename);
55 static void scanelf_dir(const char *path);
56 static void scanelf_ldpath();
57 static void scanelf_envpath();
58 static void usage(int status);
59 static void parseargs(int argc, char *argv[]);
60
61 /* variables to control behavior */
62 static char scan_ldpath = 0;
63 static char scan_envpath = 0;
64 static char dir_recurse = 0;
65 static char dir_crossmount = 1;
66 static char show_pax = 0;
67 static char show_stack = 0;
68 static char show_textrel = 0;
69 static char show_rpath = 0;
70 static char show_banner = 1;
71 static char be_quiet = 0;
72 static char be_verbose = 0;
73
74
75
76 /* scan an elf file and show all the fun stuff */
77 static void scanelf_file(const char *filename)
78 {
79 int i;
80 char found_pax, found_stack, found_relro, found_textrel, found_rpath;
81 Elf_Dyn *dyn;
82 elfobj *elf = NULL;
83
84 found_pax = found_stack = found_relro = found_textrel = found_rpath = 0;
85
86 /* verify this is real ELF */
87 if ((elf = readelf(filename)) == NULL) {
88 if (be_verbose > 1) printf("%s: not an ELF\n", filename);
89 return;
90 }
91
92 if (be_verbose) printf("%s: scanning file\n", filename);
93
94 /* show the header */
95 if (!be_quiet && show_banner) {
96 printf(" TYPE ");
97 if (show_pax) printf(" PAX ");
98 if (show_stack) printf(" STK/REL ");
99 if (show_textrel) printf("TEXTREL ");
100 if (show_rpath) printf("RPATH ");
101 printf(" FILE\n");
102 show_banner = 0;
103 }
104
105 /* dump all the good stuff */
106 if (!be_quiet)
107 printf("%-7s ", get_elfetype(elf->ehdr->e_type));
108
109 if (show_pax) {
110 char *paxflags = pax_short_hf_flags(PAX_FLAGS(elf));
111 if (!be_quiet || (be_quiet && strncmp(paxflags, "PeMRxS", 6))) {
112 found_pax = 1;
113 printf("%s ", pax_short_hf_flags(PAX_FLAGS(elf)));
114 }
115 }
116
117 /* stack fun */
118 if (show_stack) {
119 for (i = 0; i < elf->ehdr->e_phnum; i++) {
120 if (elf->phdr[i].p_type != PT_GNU_STACK && \
121 elf->phdr[i].p_type != PT_GNU_RELRO) continue;
122
123 if (be_quiet && !(elf->phdr[i].p_flags & PF_X))
124 continue;
125
126 if (elf->phdr[i].p_type == PT_GNU_STACK)
127 found_stack = 1;
128 if (elf->phdr[i].p_type == PT_GNU_RELRO)
129 found_relro = 1;
130
131 printf("%s ", gnu_short_stack_flags(elf->phdr[i].p_flags));
132 }
133 if (!be_quiet && !found_stack) printf("--- ");
134 if (!be_quiet && !found_relro) printf("--- ");
135 }
136
137 /* textrel fun */
138 if (show_textrel) {
139 for (i = 0; i < elf->ehdr->e_phnum; i++) {
140 if (elf->phdr[i].p_type != PT_DYNAMIC) continue;
141
142 dyn = (Elf_Dyn *)(elf->data + elf->phdr[i].p_offset);
143 while (dyn->d_tag != DT_NULL) {
144 if (dyn->d_tag == DT_TEXTREL) { //dyn->d_tag != DT_FLAGS)
145 found_textrel = 1;
146 // if (dyn->d_un.d_val & DF_TEXTREL)
147 printf("TEXTREL ");
148 }
149 ++dyn;
150 }
151 }
152 if (!be_quiet && !found_textrel) printf("------- ");
153 }
154
155 /* rpath fun */
156 /* TODO: if be_quiet, only output RPATH's which aren't in /etc/ld.so.conf */
157 if (show_rpath) {
158 char *rpath, *runpath;
159 Elf_Shdr *strtbl = elf_findsecbyname(elf, ".dynstr");
160 rpath = runpath = NULL;
161
162 if (strtbl)
163 for (i = 0; i < elf->ehdr->e_phnum; i++) {
164 if (elf->phdr[i].p_type != PT_DYNAMIC) continue;
165
166 dyn = (Elf_Dyn *)(elf->data + elf->phdr[i].p_offset);
167 while (dyn->d_tag != DT_NULL) {
168 if (dyn->d_tag == DT_RPATH) { //|| dyn->d_tag != DT_RUNPATH)
169 rpath = elf->data + strtbl->sh_offset + dyn->d_un.d_ptr;
170 found_rpath = 1;
171 } else if (dyn->d_tag == DT_RUNPATH) {
172 runpath = elf->data + strtbl->sh_offset + dyn->d_un.d_ptr;
173 found_rpath = 1;
174 }
175 ++dyn;
176 }
177 }
178 if (rpath && runpath) {
179 if (!strcmp(rpath, runpath))
180 printf("%-5s ", runpath);
181 else {
182 fprintf(stderr, "%s's RPATH [%s] != RUNPATH [%s]\n", filename, rpath, runpath);
183 printf("{%s,%s} ", rpath, runpath);
184 }
185 } else if (rpath || runpath)
186 printf("%-5s ", (runpath ? runpath : rpath));
187 else if (!be_quiet && !found_rpath)
188 printf(" - ");
189 }
190
191 if (!be_quiet || found_pax || found_stack || found_textrel || found_rpath)
192 puts(filename);
193
194 unreadelf(elf);
195 }
196
197 /* scan a directory for ET_EXEC files and print when we find one */
198 static void scanelf_dir(const char *path)
199 {
200 register DIR *dir;
201 register struct dirent *dentry;
202 struct stat st_top, st;
203 char buf[_POSIX_PATH_MAX];
204 size_t len = 0;
205
206 /* make sure path exists */
207 if (lstat(path, &st_top) == -1)
208 return;
209
210 /* ok, if it isn't a directory, assume we can open it */
211 if (!S_ISDIR(st_top.st_mode)) {
212 scanelf_file(path);
213 return;
214 }
215
216 /* now scan the dir looking for fun stuff */
217 if ((dir = opendir(path)) == NULL) {
218 warnf("could not opendir %s: %s", path, strerror(errno));
219 return;
220 }
221 if (be_verbose) printf("%s: scanning dir\n", path);
222
223 while ((dentry = readdir(dir))) {
224 if (!strcmp(dentry->d_name, ".") || !strcmp(dentry->d_name, ".."))
225 continue;
226 len = (strlen(path) + 2 + strlen(dentry->d_name));
227 assert(len < sizeof(buf));
228 strncpy(buf, path, len);
229 strncat(buf, "/", len);
230 strncat(buf, dentry->d_name, len);
231 buf[sizeof(buf)] = 0;
232 if (lstat(buf, &st) != -1) {
233 if (S_ISREG(st.st_mode))
234 scanelf_file(buf);
235 else if (dir_recurse && S_ISDIR(st.st_mode)) {
236 if (dir_crossmount || (st_top.st_dev == st.st_dev))
237 scanelf_dir(buf);
238 }
239 }
240 }
241 closedir(dir);
242 }
243
244 /* scan /etc/ld.so.conf for paths */
245 static void scanelf_ldpath()
246 {
247 char scan_l, scan_ul, scan_ull;
248 char *path, *p;
249 FILE *fp;
250
251 if ((fp = fopen("/etc/ld.so.conf", "r")) == NULL)
252 err("Unable to open ld.so.conf: %s", strerror(errno));
253
254 scan_l = scan_ul = scan_ull = 0;
255
256 path = malloc(_POSIX_PATH_MAX);
257 while ((fgets(path, _POSIX_PATH_MAX, fp)) != NULL)
258 if (*path == '/') {
259 if ((p = strrchr(path, '\r')) != NULL)
260 *p = 0;
261 if ((p = strrchr(path, '\n')) != NULL)
262 *p = 0;
263 if (!scan_l && !strcmp(path, "/lib")) scan_l = 1;
264 if (!scan_ul && !strcmp(path, "/usr/lib")) scan_ul = 1;
265 if (!scan_ull && !strcmp(path, "/usr/local/lib")) scan_ull = 1;
266 scanelf_dir(path);
267 }
268 free(path);
269
270 if (!scan_l) scanelf_dir("/lib");
271 if (!scan_ul) scanelf_dir("/usr/lib");
272 if (!scan_ull) scanelf_dir("/usr/local/lib");
273
274 fclose(fp);
275 }
276
277 /* scan env PATH for paths */
278 static void scanelf_envpath()
279 {
280 char *path, *p;
281
282 path = getenv("PATH");
283 if (!path)
284 err("PATH is not set in your env !");
285
286 if ((path = strdup(path)) == NULL)
287 err("stdup failed: %s", strerror(errno));
288
289 while ((p = strrchr(path, ':')) != NULL) {
290 scanelf_dir(p + 1);
291 *p = 0;
292 }
293
294 free(path);
295 }
296
297
298
299 /* usage / invocation handling functions */
300 #define PARSE_FLAGS "plRmxetraqvo:BhV"
301 static struct option const long_opts[] = {
302 {"path", no_argument, NULL, 'p'},
303 {"ldpath", no_argument, NULL, 'l'},
304 {"recursive", no_argument, NULL, 'R'},
305 {"mount", no_argument, NULL, 'm'},
306 {"pax", no_argument, NULL, 'x'},
307 {"header", no_argument, NULL, 'e'},
308 {"textrel", no_argument, NULL, 't'},
309 {"rpath", no_argument, NULL, 'r'},
310 {"all", no_argument, NULL, 'a'},
311 {"quiet", no_argument, NULL, 'q'},
312 {"verbose", no_argument, NULL, 'v'},
313 {"file",required_argument, NULL, 'o'},
314 {"nobanner", no_argument, NULL, 'B'},
315 {"help", no_argument, NULL, 'h'},
316 {"version", no_argument, NULL, 'V'},
317 {NULL, no_argument, NULL, 0x0}
318 };
319 static char *opts_help[] = {
320 "Scan all directories in PATH environment",
321 "Scan all directories in /etc/ld.so.conf",
322 "Scan directories recursively",
323 "Don't recursively cross mount points\n",
324 "Print PaX markings",
325 "Print GNU_STACK markings",
326 "Print TEXTREL information",
327 "Print RPATH information",
328 "Print all scanned info (-x -e -t -r)\n",
329 "Only output 'bad' things",
330 "Be verbose (can be specified more than once)",
331 "Write output stream to a filename",
332 "Don't display the header",
333 "Print this help and exit",
334 "Print version and exit",
335 NULL
336 };
337
338 /* display usage and exit */
339 static void usage(int status)
340 {
341 int i;
342 printf(" Scan ELF binaries for stuff\n\n"
343 "Usage: %s [options] <dir1> [dir2 dirN ...]\n\n", argv0);
344 printf("Options:\n");
345 for (i = 0; long_opts[i].name; ++i)
346 printf(" -%c, --%-12s %s\n", long_opts[i].val,
347 long_opts[i].name, opts_help[i]);
348 #ifdef MANLYPAGE
349 for (i = 0; long_opts[i].name; ++i)
350 printf(".TP\n\\fB\\-%c, \\-\\-%s\\fR\n%s\n", long_opts[i].val,
351 long_opts[i].name, opts_help[i]);
352 #endif
353 exit(status);
354 }
355
356 /* parse command line arguments and preform needed actions */
357 static void parseargs(int argc, char *argv[])
358 {
359 int flag;
360
361 opterr = 0;
362 while ((flag=getopt_long(argc, argv, PARSE_FLAGS, long_opts, NULL)) != -1) {
363 switch (flag) {
364
365 case 'V': /* version info */
366 printf("%s compiled %s\n%s\n"
367 "%s written for Gentoo Linux by <solar and vapier @ gentoo.org>\n",
368 __FILE__, __DATE__, rcsid, argv0);
369 exit(EXIT_SUCCESS);
370 break;
371 case 's': /* reserved for -s, --symbol= */
372 case 'h': usage(EXIT_SUCCESS); break;
373
374 case 'o': {
375 FILE *fp = NULL;
376 fp = freopen(optarg, "w", stdout);
377 if (fp == NULL)
378 err("Could not open output stream '%s': %s", optarg, strerror(errno));
379 stdout = fp;
380 break;
381 }
382
383 case 'B': show_banner = 0; break;
384 case 'l': scan_ldpath = 1; break;
385 case 'p': scan_envpath = 1; break;
386 case 'R': dir_recurse = 1; break;
387 case 'm': dir_crossmount = 0; break;
388 case 'x': show_pax = 1; break;
389 case 'e': show_stack = 1; break;
390 case 't': show_textrel = 1; break;
391 case 'r': show_rpath = 1; break;
392 case 'q': be_quiet = 1; break;
393 case 'v': be_verbose = (be_verbose % 20) + 1; break;
394 case 'a': show_pax = show_stack = show_textrel = show_rpath = 1; break;
395
396 case ':':
397 warn("Option missing parameter");
398 usage(EXIT_FAILURE);
399 break;
400 case '?':
401 warn("Unknown option");
402 usage(EXIT_FAILURE);
403 break;
404 default:
405 err("Unhandled option '%c'", flag);
406 break;
407 }
408 }
409
410 if (be_quiet && be_verbose)
411 err("You can be quiet or you can be verbose, not both, stupid");
412
413 if (scan_ldpath) scanelf_ldpath();
414 if (scan_envpath) scanelf_envpath();
415 while (optind < argc)
416 scanelf_dir(argv[optind++]);
417 }
418
419
420
421 int main(int argc, char *argv[])
422 {
423 if (argc < 2)
424 usage(EXIT_FAILURE);
425 parseargs(argc, argv);
426 fclose(stdout);
427 return EXIT_SUCCESS;
428 }

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