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Diffstat (limited to 'lib/libelf/libelf_ar_util.c')
| -rw-r--r-- | lib/libelf/libelf_ar_util.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/lib/libelf/libelf_ar_util.c b/lib/libelf/libelf_ar_util.c new file mode 100644 index 0000000..3834ac4 --- /dev/null +++ b/lib/libelf/libelf_ar_util.c @@ -0,0 +1,253 @@ +/*- + * Copyright (c) 2006,2009 Joseph Koshy + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS `AS IS' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <ar.h> +#include <assert.h> +#include <libelf.h> +#include <stdlib.h> +#include <string.h> + +#include "_libelf.h" + +/* + * Convert a string bounded by `start' and `start+sz' (exclusive) to a + * number in the specified base. + */ +int +_libelf_ar_get_number(char *s, size_t sz, int base, size_t *ret) +{ + int c, v; + size_t r; + char *e; + + assert(base <= 10); + + e = s + sz; + + /* skip leading blanks */ + for (;s < e && (c = *s) == ' '; s++) + ; + + r = 0L; + for (;s < e; s++) { + if ((c = *s) == ' ') + break; + if (c < '0' || c > '9') + return (0); + v = c - '0'; + if (v >= base) /* Illegal digit. */ + break; + r *= base; + r += v; + } + + *ret = r; + + return (1); +} + +/* + * Retrieve a string from a name field. If `rawname' is set, leave + * ar(1) control characters in. + */ +char * +_libelf_ar_get_string(const char *buf, size_t bufsize, int rawname) +{ + const char *q; + char *r; + size_t sz; + + if (rawname) + sz = bufsize + 1; + else { + /* Skip back over trailing blanks. */ + for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q) + ; + + if (q < buf) { + /* + * If the input buffer only had blanks in it, + * return a zero-length string. + */ + buf = ""; + sz = 1; + } else { + /* + * Remove the trailing '/' character, but only + * if the name isn't one of the special names + * "/" and "//". + */ + if (q > buf + 1 || + (q == (buf + 1) && *buf != '/')) + q--; + + sz = q - buf + 2; /* Space for a trailing NUL. */ + } + } + + if ((r = malloc(sz)) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + (void) strncpy(r, buf, sz); + r[sz - 1] = '\0'; + + return (r); +} + +/* + * Retrieve the full name of the archive member. + */ +char * +_libelf_ar_get_name(char *buf, size_t bufsize, Elf *e) +{ + char c, *q, *r, *s; + size_t len; + size_t offset; + + assert(e->e_kind == ELF_K_AR); + + if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') { + /* + * The value in field ar_name is a decimal offset into + * the archive string table where the actual name + * resides. + */ + if (_libelf_ar_get_number(buf + 1, bufsize - 1, 10, + &offset) == 0) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + if (offset > e->e_u.e_ar.e_rawstrtabsz) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + s = q = e->e_u.e_ar.e_rawstrtab + offset; + r = e->e_u.e_ar.e_rawstrtab + e->e_u.e_ar.e_rawstrtabsz; + + for (s = q; s < r && *s != '/'; s++) + ; + len = s - q + 1; /* space for the trailing NUL */ + + if ((s = malloc(len)) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + (void) strncpy(s, q, len); + s[len - 1] = '\0'; + + return (s); + } + + /* + * Normal 'name' + */ + return (_libelf_ar_get_string(buf, bufsize, 0)); +} + +/* + * Open an 'ar' archive. + */ +Elf * +_libelf_ar_open(Elf *e) +{ + int i; + char *s, *end; + size_t sz; + struct ar_hdr arh; + + e->e_kind = ELF_K_AR; + e->e_u.e_ar.e_nchildren = 0; + e->e_u.e_ar.e_next = (off_t) -1; + + /* + * Look for special members. + */ + + s = e->e_rawfile + SARMAG; + end = e->e_rawfile + e->e_rawsize; + + assert(e->e_rawsize > 0); + + /* + * Look for magic names "/ " and "// " in the first two entries + * of the archive. + */ + for (i = 0; i < 2; i++) { + + if (s + sizeof(arh) > end) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + (void) memcpy(&arh, s, sizeof(arh)); + + if (arh.ar_fmag[0] != '`' || arh.ar_fmag[1] != '\n') { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + if (arh.ar_name[0] != '/') /* not a special symbol */ + break; + + if (_libelf_ar_get_number(arh.ar_size, sizeof(arh.ar_size), + 10, &sz) == 0) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + assert(sz > 0); + + s += sizeof(arh); + + if (arh.ar_name[1] == ' ') { /* "/ " => symbol table */ + + e->e_u.e_ar.e_rawsymtab = s; + e->e_u.e_ar.e_rawsymtabsz = sz; + + } else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') { + + /* "// " => string table for long file names */ + e->e_u.e_ar.e_rawstrtab = s; + e->e_u.e_ar.e_rawstrtabsz = sz; + } + + sz = LIBELF_ADJUST_AR_SIZE(sz); + + s += sz; + } + + e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile); + + return (e); +} |
