From 4f0f217c1b6a8c888ff8a1c60d1eb36cbdf14490 Mon Sep 17 00:00:00 2001 From: Nathan Binkert Date: Sat, 26 May 2007 18:15:22 -0700 Subject: Get rid of GNU libelf and its autoconf nastiness and replace it with FreeBSD's implementation --HG-- extra : convert_revision : ef9c4551b9a6b54b76a89f286ff9804c55790621 --- ext/libelf/libelf_ar.c | 481 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 481 insertions(+) create mode 100644 ext/libelf/libelf_ar.c (limited to 'ext/libelf/libelf_ar.c') diff --git a/ext/libelf/libelf_ar.c b/ext/libelf/libelf_ar.c new file mode 100644 index 000000000..01e162455 --- /dev/null +++ b/ext/libelf/libelf_ar.c @@ -0,0 +1,481 @@ +/*- + * Copyright (c) 2006 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 +#include +#include +#include "libelf.h" +#include +#include + +#include "_libelf.h" + +#define LIBELF_NALLOC_SIZE 16 + +/* + * `ar' archive handling. + * + * `ar' archives start with signature `ARMAG'. Each archive member is + * preceded by a header containing meta-data for the member. This + * header is described in (struct ar_hdr). The header always + * starts on an even address. File data is padded with "\n" + * characters to keep this invariant. + * + * Special considerations for `ar' archives: + * + * The `ar' header only has space for a 16 character file name. File + * names are terminated with a '/', so this effectively leaves 15 + * characters for the actual file name. In order to accomodate longer + * file names, names may be stored in a separate 'string table' and + * referenced indirectly by a member header. The string table itself + * appears as an archive member with name "// ". An indirect file name + * in an `ar' header matches the pattern "/[0-9]*". The digits form a + * decimal number that corresponds to a byte offset into the string + * table where the actual file name of the object starts. Strings in + * the string table are padded to start on even addresses. + * + * Archives may also have a symbol table (see ranlib(1)), mapping + * program symbols to object files inside the archive. A symbol table + * uses a file name of "/ " in its archive header. The symbol table + * is structured as: + * - a 4-byte count of entries stored as a binary value, MSB first + * - 'n' 4-byte offsets, stored as binary values, MSB first + * - 'n' NUL-terminated strings, for ELF symbol names, stored unpadded. + * + * If the symbol table and string table are is present in an archive + * they must be the very first objects and in that order. + */ + +/* + * Convert a string bounded by `start' and `start+sz' (exclusive) to a + * number in the specified base. + */ +static 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. + */ +static 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. + */ +static 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)); +} + + +Elf_Arhdr * +_libelf_ar_gethdr(Elf *e) +{ + Elf *parent; + struct ar_hdr *arh; + Elf_Arhdr *eh; + size_t n; + + if ((parent = e->e_parent) == NULL) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + arh = (struct ar_hdr *) ((uintptr_t) e->e_rawfile - sizeof(struct ar_hdr)); + + assert((uintptr_t) arh >= (uintptr_t) parent->e_rawfile + SARMAG); + assert((uintptr_t) arh <= (uintptr_t) parent->e_rawfile + parent->e_rawsize - + sizeof(struct ar_hdr)); + + if ((eh = malloc(sizeof(Elf_Arhdr))) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + e->e_arhdr = eh; + eh->ar_name = eh->ar_rawname = NULL; + + if ((eh->ar_name = _libelf_ar_get_name(arh->ar_name, sizeof(arh->ar_name), + parent)) == NULL) + goto error; + + if (_libelf_ar_get_number(arh->ar_uid, sizeof(arh->ar_uid), 10, &n) == 0) + goto error; + eh->ar_uid = (uid_t) n; + + if (_libelf_ar_get_number(arh->ar_gid, sizeof(arh->ar_gid), 10, &n) == 0) + goto error; + eh->ar_gid = (gid_t) n; + + if (_libelf_ar_get_number(arh->ar_mode, sizeof(arh->ar_mode), 8, &n) == 0) + goto error; + eh->ar_mode = (mode_t) n; + + if (_libelf_ar_get_number(arh->ar_size, sizeof(arh->ar_size), 10, &n) == 0) + goto error; + eh->ar_size = n; + + if ((eh->ar_rawname = _libelf_ar_get_string(arh->ar_name, + sizeof(arh->ar_name), 1)) == NULL) + goto error; + + return (eh); + + error: + if (eh) { + if (eh->ar_name) + free(eh->ar_name); + if (eh->ar_rawname) + free(eh->ar_rawname); + free(eh); + } + e->e_arhdr = NULL; + + return (NULL); +} + +Elf * +_libelf_ar_open_member(int fd, Elf_Cmd c, Elf *elf) +{ + Elf *e; + off_t next; + struct ar_hdr *arh; + size_t sz; + + assert(elf->e_kind == ELF_K_AR); + + next = elf->e_u.e_ar.e_next; + + /* + * `next' is only set to zero by elf_next() when the last + * member of an archive is processed. + */ + if (next == (off_t) 0) + return (NULL); + + assert((next & 1) == 0); + + arh = (struct ar_hdr *) (elf->e_rawfile + next); + + 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); + + arh++; /* skip over archive member header */ + + if ((e = elf_memory((char *) arh, sz)) == NULL) + return (NULL); + + e->e_fd = fd; + e->e_cmd = c; + + elf->e_u.e_ar.e_nchildren++; + e->e_parent = elf; + + return (e); +} + +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); +} + +/* + * An ar(1) symbol table has the following layout: + * + * The first 4 bytes are a binary count of the number of entries in the + * symbol table, stored MSB-first. + * + * Then there are 'n' 4-byte binary offsets, also stored MSB first. + * + * Following this, there are 'n' null-terminated strings. + */ + +#define GET_WORD(P, V) do { \ + (V) = 0; \ + (V) = (P)[0]; (V) <<= 8; \ + (V) += (P)[1]; (V) <<= 8; \ + (V) += (P)[2]; (V) <<= 8; \ + (V) += (P)[3]; \ + } while (0) + +#define INTSZ 4 + +Elf_Arsym * +_libelf_ar_process_symtab(Elf *e, size_t *count) +{ + size_t n, nentries, off; + Elf_Arsym *symtab, *sym; + char *p, *s, *end; + + assert(e != NULL); + assert(count != NULL); + + if (e->e_u.e_ar.e_rawsymtabsz < INTSZ) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + p = e->e_u.e_ar.e_rawsymtab; + end = p + e->e_u.e_ar.e_rawsymtabsz; + + GET_WORD(p, nentries); + p += INTSZ; + + if (nentries == 0 || p + nentries * INTSZ >= end) { + LIBELF_SET_ERROR(ARCHIVE, 0); + return (NULL); + } + + /* Allocate space for a nentries + a sentinel. */ + if ((symtab = malloc(sizeof(Elf_Arsym) * (nentries+1))) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + s = p + (nentries * INTSZ); /* start of the string table. */ + + for (n = nentries, sym = symtab; n > 0; n--) { + off = 0; + + GET_WORD(p, off); + + sym->as_off = off; + sym->as_hash = elf_hash(s); + sym->as_name = s; + + p += INTSZ; + sym++; + + for (; s < end && *s++ != '\0';) /* skip to next string */ + ; + if (s > end) { + LIBELF_SET_ERROR(ARCHIVE, 0); + free(symtab); + return (NULL); + } + } + + /* Fill up the sentinel entry. */ + sym->as_name = NULL; + sym->as_hash = ~0UL; + sym->as_off = (off_t) 0; + + *count = e->e_u.e_ar.e_symtabsz = nentries + 1; + e->e_u.e_ar.e_symtab = symtab; + + return (symtab); +} -- cgit v1.2.3