2 * Copyright (c) 2006,2009,2010 Joseph Koshy
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS `AS IS' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
35 #include "_libelf_ar.h"
37 ELFTC_VCSID("$Id: libelf_ar_util.c 3013 2014-03-23 06:16:59Z jkoshy $");
40 * Convert a string bounded by `start' and `start+sz' (exclusive) to a
41 * number in the specified base.
44 _libelf_ar_get_number(const char *src, size_t sz, unsigned int base,
49 const unsigned char *e, *s;
53 s = (const unsigned char *) src;
56 /* skip leading blanks */
57 for (;s < e && (c = *s) == ' '; s++)
64 if (c < '0' || c > '9')
67 if (v >= base) /* Illegal digit. */
79 * Return the translated name for an archive member.
82 _libelf_ar_get_translated_name(const struct ar_hdr *arh, Elf *ar)
87 const unsigned char *buf, *p, *q, *r;
88 const size_t bufsize = sizeof(arh->ar_name);
91 assert(ar->e_kind == ELF_K_AR);
92 assert((const unsigned char *) arh >= ar->e_rawfile &&
93 (const unsigned char *) arh < ar->e_rawfile + ar->e_rawsize);
95 buf = (const unsigned char *) arh->ar_name;
98 * Check for extended naming.
100 * If the name matches the pattern "^/[0-9]+", it is an
101 * SVR4-style extended name. If the name matches the pattern
102 * "#1/[0-9]+", the entry uses BSD style extended naming.
104 if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
106 * The value in field ar_name is a decimal offset into
107 * the archive string table where the actual name
110 if (_libelf_ar_get_number((const char *) (buf + 1),
111 bufsize - 1, 10, &offset) == 0) {
112 LIBELF_SET_ERROR(ARCHIVE, 0);
116 if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
117 LIBELF_SET_ERROR(ARCHIVE, 0);
121 p = q = ar->e_u.e_ar.e_rawstrtab + offset;
122 r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;
124 for (; p < r && *p != '/'; p++)
126 len = (size_t) (p - q + 1); /* space for the trailing NUL */
128 if ((s = malloc(len)) == NULL) {
129 LIBELF_SET_ERROR(RESOURCE, 0);
133 (void) strncpy(s, (const char *) q, len - 1);
137 } else if (IS_EXTENDED_BSD_NAME(buf)) {
138 r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;
140 if (_libelf_ar_get_number((const char *) r, bufsize -
141 LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
143 LIBELF_SET_ERROR(ARCHIVE, 0);
148 * Allocate space for the file name plus a
151 if ((s = malloc(len + 1)) == NULL) {
152 LIBELF_SET_ERROR(RESOURCE, 0);
157 * The file name follows the archive header.
159 q = (const unsigned char *) (arh + 1);
161 (void) strncpy(s, (const char *) q, len);
170 * Skip back over trailing blanks from the end of the field.
171 * In the SVR4 format, a '/' is used as a terminator for
174 for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
180 * SVR4 style names: ignore the trailing
181 * character '/', but only if the name is not
182 * one of the special names "/" and "//".
185 (q == (buf + 1) && *buf != '/'))
189 len = (size_t) (q - buf + 2); /* Space for a trailing NUL. */
191 /* The buffer only had blanks. */
192 buf = (const unsigned char *) "";
196 if ((s = malloc(len)) == NULL) {
197 LIBELF_SET_ERROR(RESOURCE, 0);
201 (void) strncpy(s, (const char *) buf, len - 1);
208 * Return the raw name for an archive member, inclusive of any
209 * formatting characters.
212 _libelf_ar_get_raw_name(const struct ar_hdr *arh)
215 const size_t namesz = sizeof(arh->ar_name);
217 if ((rawname = malloc(namesz + 1)) == NULL) {
218 LIBELF_SET_ERROR(RESOURCE, 0);
222 (void) strncpy(rawname, arh->ar_name, namesz);
223 rawname[namesz] = '\0';
228 * Open an 'ar' archive.
231 _libelf_ar_open(Elf *e, int reporterror)
236 unsigned char *s, *end;
238 _libelf_init_elf(e, ELF_K_AR);
240 e->e_u.e_ar.e_nchildren = 0;
241 e->e_u.e_ar.e_next = (off_t) -1;
244 * Look for special members.
247 s = e->e_rawfile + SARMAG;
248 end = e->e_rawfile + e->e_rawsize;
250 assert(e->e_rawsize > 0);
253 * We use heuristics to determine the flavor of the archive we
256 * SVR4 flavor archives use the name "/ " and "// " for
259 * In BSD flavor archives the symbol table, if present, is the
260 * first archive with name "__.SYMDEF".
263 #define READ_AR_HEADER(S, ARH, SZ, END) \
265 if ((S) + sizeof((ARH)) > (END)) \
267 (void) memcpy(&(ARH), (S), sizeof((ARH))); \
268 if ((ARH).ar_fmag[0] != '`' || (ARH).ar_fmag[1] != '\n') \
270 if (_libelf_ar_get_number((char *) (ARH).ar_size, \
271 sizeof((ARH).ar_size), 10, &(SZ)) == 0) \
275 READ_AR_HEADER(s, arh, sz, end);
278 * Handle special archive members for the SVR4 format.
280 if (arh.ar_name[0] == '/') {
284 e->e_flags |= LIBELF_F_AR_VARIANT_SVR4;
289 * The symbol table (file name "/ ") always comes before the
290 * string table (file name "// ").
292 if (arh.ar_name[1] == ' ') {
293 /* "/ " => symbol table. */
294 scanahead = 1; /* The string table to follow. */
297 e->e_u.e_ar.e_rawsymtab = s;
298 e->e_u.e_ar.e_rawsymtabsz = sz;
300 sz = LIBELF_ADJUST_AR_SIZE(sz);
303 } else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
304 /* "// " => string table for long file names. */
306 e->e_u.e_ar.e_rawstrtab = s;
307 e->e_u.e_ar.e_rawstrtabsz = sz;
309 sz = LIBELF_ADJUST_AR_SIZE(sz);
314 * If the string table hasn't been seen yet, look for
315 * it in the next member.
318 READ_AR_HEADER(s, arh, sz, end);
320 /* "// " => string table for long file names. */
321 if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
322 arh.ar_name[2] == ' ') {
326 e->e_u.e_ar.e_rawstrtab = s;
327 e->e_u.e_ar.e_rawstrtabsz = sz;
329 sz = LIBELF_ADJUST_AR_SIZE(sz);
333 } else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
334 sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
336 * BSD style archive symbol table.
339 e->e_u.e_ar.e_rawsymtab = s;
340 e->e_u.e_ar.e_rawsymtabsz = sz;
342 sz = LIBELF_ADJUST_AR_SIZE(sz);
347 * Update the 'next' offset, so that a subsequent elf_begin()
350 e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);
356 e->e_kind = ELF_K_NONE;
360 LIBELF_SET_ERROR(ARCHIVE, 0);