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 2365 2011-12-29 04:36:44Z 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 *s, size_t sz, int base, size_t *ret)
54 /* skip leading blanks */
55 for (;s < e && (c = *s) == ' '; s++)
62 if (c < '0' || c > '9')
65 if (v >= base) /* Illegal digit. */
77 * Return the translated name for an archive member.
80 _libelf_ar_get_translated_name(const struct ar_hdr *arh, Elf *ar)
84 const char *buf, *p, *q, *r;
85 const size_t bufsize = sizeof(arh->ar_name);
88 assert(ar->e_kind == ELF_K_AR);
89 assert((const char *) arh >= ar->e_rawfile &&
90 (const char *) arh < ar->e_rawfile + ar->e_rawsize);
95 * Check for extended naming.
97 * If the name matches the pattern "^/[0-9]+", it is an
98 * SVR4-style extended name. If the name matches the pattern
99 * "#1/[0-9]+", the entry uses BSD style extended naming.
101 if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
103 * The value in field ar_name is a decimal offset into
104 * the archive string table where the actual name
107 if (_libelf_ar_get_number(buf + 1, bufsize - 1, 10,
109 LIBELF_SET_ERROR(ARCHIVE, 0);
113 if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
114 LIBELF_SET_ERROR(ARCHIVE, 0);
118 p = q = ar->e_u.e_ar.e_rawstrtab + offset;
119 r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;
121 for (; p < r && *p != '/'; p++)
123 len = p - q + 1; /* space for the trailing NUL */
125 if ((s = malloc(len)) == NULL) {
126 LIBELF_SET_ERROR(RESOURCE, 0);
130 (void) strncpy(s, q, len - 1);
134 } else if (IS_EXTENDED_BSD_NAME(buf)) {
135 r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;
137 if (_libelf_ar_get_number(r, bufsize -
138 LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
140 LIBELF_SET_ERROR(ARCHIVE, 0);
145 * Allocate space for the file name plus a
148 if ((s = malloc(len + 1)) == NULL) {
149 LIBELF_SET_ERROR(RESOURCE, 0);
154 * The file name follows the archive header.
156 q = (const char *) (arh + 1);
158 (void) strncpy(s, q, len);
167 * Skip back over trailing blanks from the end of the field.
168 * In the SVR4 format, a '/' is used as a terminator for
171 for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
177 * SVR4 style names: ignore the trailing
178 * character '/', but only if the name is not
179 * one of the special names "/" and "//".
182 (q == (buf + 1) && *buf != '/'))
186 len = q - buf + 2; /* Add space for a trailing NUL. */
188 /* The buffer only had blanks. */
193 if ((s = malloc(len)) == NULL) {
194 LIBELF_SET_ERROR(RESOURCE, 0);
198 (void) strncpy(s, buf, len - 1);
205 * Return the raw name for an archive member, inclusive of any
206 * formatting characters.
209 _libelf_ar_get_raw_name(const struct ar_hdr *arh)
212 const size_t namesz = sizeof(arh->ar_name);
214 if ((rawname = malloc(namesz + 1)) == NULL) {
215 LIBELF_SET_ERROR(RESOURCE, 0);
219 (void) strncpy(rawname, arh->ar_name, namesz);
220 rawname[namesz] = '\0';
225 * Open an 'ar' archive.
228 _libelf_ar_open(Elf *e, int reporterror)
235 _libelf_init_elf(e, ELF_K_AR);
237 e->e_u.e_ar.e_nchildren = 0;
238 e->e_u.e_ar.e_next = (off_t) -1;
241 * Look for special members.
244 s = e->e_rawfile + SARMAG;
245 end = e->e_rawfile + e->e_rawsize;
247 assert(e->e_rawsize > 0);
250 * We use heuristics to determine the flavor of the archive we
253 * SVR4 flavor archives use the name "/ " and "// " for
256 * In BSD flavor archives the symbol table, if present, is the
257 * first archive with name "__.SYMDEF".
260 #define READ_AR_HEADER(S, ARH, SZ, END) \
262 if ((S) + sizeof((ARH)) > (END)) \
264 (void) memcpy(&(ARH), (S), sizeof((ARH))); \
265 if ((ARH).ar_fmag[0] != '`' || (ARH).ar_fmag[1] != '\n') \
267 if (_libelf_ar_get_number((ARH).ar_size, \
268 sizeof((ARH).ar_size), 10, &(SZ)) == 0) \
272 READ_AR_HEADER(s, arh, sz, end);
275 * Handle special archive members for the SVR4 format.
277 if (arh.ar_name[0] == '/') {
281 e->e_flags |= LIBELF_F_AR_VARIANT_SVR4;
286 * The symbol table (file name "/ ") always comes before the
287 * string table (file name "// ").
289 if (arh.ar_name[1] == ' ') {
290 /* "/ " => symbol table. */
291 scanahead = 1; /* The string table to follow. */
294 e->e_u.e_ar.e_rawsymtab = s;
295 e->e_u.e_ar.e_rawsymtabsz = sz;
297 sz = LIBELF_ADJUST_AR_SIZE(sz);
300 } else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
301 /* "// " => string table for long file names. */
303 e->e_u.e_ar.e_rawstrtab = s;
304 e->e_u.e_ar.e_rawstrtabsz = sz;
306 sz = LIBELF_ADJUST_AR_SIZE(sz);
311 * If the string table hasn't been seen yet, look for
312 * it in the next member.
315 READ_AR_HEADER(s, arh, sz, end);
317 /* "// " => string table for long file names. */
318 if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
319 arh.ar_name[2] == ' ') {
323 e->e_u.e_ar.e_rawstrtab = s;
324 e->e_u.e_ar.e_rawstrtabsz = sz;
326 sz = LIBELF_ADJUST_AR_SIZE(sz);
330 } else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
331 sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
333 * BSD style archive symbol table.
336 e->e_u.e_ar.e_rawsymtab = s;
337 e->e_u.e_ar.e_rawsymtabsz = sz;
339 sz = LIBELF_ADJUST_AR_SIZE(sz);
344 * Update the 'next' offset, so that a subsequent elf_begin()
347 e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);
353 e->e_kind = ELF_K_NONE;
357 LIBELF_SET_ERROR(ARCHIVE, 0);