elf_begin.c revision 4484
14484Sbinkertn@umich.edu/*- 24484Sbinkertn@umich.edu * Copyright (c) 2006 Joseph Koshy 34484Sbinkertn@umich.edu * All rights reserved. 44484Sbinkertn@umich.edu * 54484Sbinkertn@umich.edu * Redistribution and use in source and binary forms, with or without 64484Sbinkertn@umich.edu * modification, are permitted provided that the following conditions 74484Sbinkertn@umich.edu * are met: 84484Sbinkertn@umich.edu * 1. Redistributions of source code must retain the above copyright 94484Sbinkertn@umich.edu * notice, this list of conditions and the following disclaimer. 104484Sbinkertn@umich.edu * 2. Redistributions in binary form must reproduce the above copyright 114484Sbinkertn@umich.edu * notice, this list of conditions and the following disclaimer in the 124484Sbinkertn@umich.edu * documentation and/or other materials provided with the distribution. 134484Sbinkertn@umich.edu * 144484Sbinkertn@umich.edu * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 154484Sbinkertn@umich.edu * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 164484Sbinkertn@umich.edu * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 174484Sbinkertn@umich.edu * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 184484Sbinkertn@umich.edu * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 194484Sbinkertn@umich.edu * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 204484Sbinkertn@umich.edu * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 214484Sbinkertn@umich.edu * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 224484Sbinkertn@umich.edu * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 234484Sbinkertn@umich.edu * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 244484Sbinkertn@umich.edu * SUCH DAMAGE. 254484Sbinkertn@umich.edu */ 264484Sbinkertn@umich.edu 274484Sbinkertn@umich.edu 284484Sbinkertn@umich.edu#include <sys/types.h> 294484Sbinkertn@umich.edu#include <sys/errno.h> 304484Sbinkertn@umich.edu#include <sys/mman.h> 314484Sbinkertn@umich.edu#include <sys/stat.h> 324484Sbinkertn@umich.edu 334484Sbinkertn@umich.edu#include <ar.h> 344484Sbinkertn@umich.edu#include <ctype.h> 354484Sbinkertn@umich.edu#include "libelf.h" 364484Sbinkertn@umich.edu 374484Sbinkertn@umich.edu#include "_libelf.h" 384484Sbinkertn@umich.edu 394484Sbinkertn@umich.edustatic Elf * 404484Sbinkertn@umich.edu_libelf_open_object(int fd, Elf_Cmd c) 414484Sbinkertn@umich.edu{ 424484Sbinkertn@umich.edu Elf *e; 434484Sbinkertn@umich.edu void *m; 444484Sbinkertn@umich.edu struct stat sb; 454484Sbinkertn@umich.edu 464484Sbinkertn@umich.edu /* 474484Sbinkertn@umich.edu * 'Raw' files are always mapped with 'PROT_READ'. At 484484Sbinkertn@umich.edu * elf_update(3) time for files opened with ELF_C_RDWR the 494484Sbinkertn@umich.edu * mapping is unmapped, file data is written to using write(2) 504484Sbinkertn@umich.edu * and then the raw data is immediately mapped back in. 514484Sbinkertn@umich.edu */ 524484Sbinkertn@umich.edu if (fstat(fd, &sb) < 0) { 534484Sbinkertn@umich.edu LIBELF_SET_ERROR(IO, errno); 544484Sbinkertn@umich.edu return (NULL); 554484Sbinkertn@umich.edu } 564484Sbinkertn@umich.edu 574484Sbinkertn@umich.edu m = NULL; 584484Sbinkertn@umich.edu if ((m = mmap(NULL, (size_t) sb.st_size, PROT_READ, MAP_PRIVATE, fd, 594484Sbinkertn@umich.edu (off_t) 0)) == MAP_FAILED) { 604484Sbinkertn@umich.edu LIBELF_SET_ERROR(IO, errno); 614484Sbinkertn@umich.edu return (NULL); 624484Sbinkertn@umich.edu } 634484Sbinkertn@umich.edu 644484Sbinkertn@umich.edu if ((e = elf_memory(m, (size_t) sb.st_size)) == NULL) { 654484Sbinkertn@umich.edu (void) munmap(m, (size_t) sb.st_size); 664484Sbinkertn@umich.edu return (NULL); 674484Sbinkertn@umich.edu } 684484Sbinkertn@umich.edu 694484Sbinkertn@umich.edu e->e_flags |= LIBELF_F_MMAP; 704484Sbinkertn@umich.edu e->e_fd = fd; 714484Sbinkertn@umich.edu e->e_cmd = c; 724484Sbinkertn@umich.edu 734484Sbinkertn@umich.edu if (c == ELF_C_RDWR && e->e_kind == ELF_K_AR) { 744484Sbinkertn@umich.edu (void) elf_end(e); 754484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 764484Sbinkertn@umich.edu return (NULL); 774484Sbinkertn@umich.edu } 784484Sbinkertn@umich.edu 794484Sbinkertn@umich.edu return (e); 804484Sbinkertn@umich.edu} 814484Sbinkertn@umich.edu 824484Sbinkertn@umich.eduElf * 834484Sbinkertn@umich.eduelf_begin(int fd, Elf_Cmd c, Elf *a) 844484Sbinkertn@umich.edu{ 854484Sbinkertn@umich.edu Elf *e; 864484Sbinkertn@umich.edu 874484Sbinkertn@umich.edu e = NULL; 884484Sbinkertn@umich.edu 894484Sbinkertn@umich.edu if (LIBELF_PRIVATE(version) == EV_NONE) { 904484Sbinkertn@umich.edu LIBELF_SET_ERROR(SEQUENCE, 0); 914484Sbinkertn@umich.edu return (NULL); 924484Sbinkertn@umich.edu } 934484Sbinkertn@umich.edu 944484Sbinkertn@umich.edu switch (c) { 954484Sbinkertn@umich.edu case ELF_C_NULL: 964484Sbinkertn@umich.edu return (NULL); 974484Sbinkertn@umich.edu 984484Sbinkertn@umich.edu case ELF_C_WRITE: 994484Sbinkertn@umich.edu 1004484Sbinkertn@umich.edu if (a != NULL) { /* not allowed for ar(1) archives. */ 1014484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 1024484Sbinkertn@umich.edu return (NULL); 1034484Sbinkertn@umich.edu } 1044484Sbinkertn@umich.edu 1054484Sbinkertn@umich.edu /* 1064484Sbinkertn@umich.edu * Check writeability of `fd' immediately and fail if 1074484Sbinkertn@umich.edu * not writeable. 1084484Sbinkertn@umich.edu */ 1094484Sbinkertn@umich.edu if (ftruncate(fd, (off_t) 0) < 0) { 1104484Sbinkertn@umich.edu LIBELF_SET_ERROR(IO, errno); 1114484Sbinkertn@umich.edu return (NULL); 1124484Sbinkertn@umich.edu } 1134484Sbinkertn@umich.edu 1144484Sbinkertn@umich.edu if ((e = _libelf_allocate_elf()) != NULL) { 1154484Sbinkertn@umich.edu _libelf_init_elf(e, ELF_K_ELF); 1164484Sbinkertn@umich.edu e->e_byteorder = LIBELF_PRIVATE(byteorder); 1174484Sbinkertn@umich.edu e->e_fd = fd; 1184484Sbinkertn@umich.edu e->e_cmd = c; 1194484Sbinkertn@umich.edu } 1204484Sbinkertn@umich.edu return (e); 1214484Sbinkertn@umich.edu 1224484Sbinkertn@umich.edu case ELF_C_RDWR: 1234484Sbinkertn@umich.edu if (a != NULL) { /* not allowed for ar(1) archives. */ 1244484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 1254484Sbinkertn@umich.edu return (NULL); 1264484Sbinkertn@umich.edu } 1274484Sbinkertn@umich.edu /*FALLTHROUGH*/ 1284484Sbinkertn@umich.edu case ELF_C_READ: 1294484Sbinkertn@umich.edu /* 1304484Sbinkertn@umich.edu * Descriptor `a' could be for a regular ELF file, or 1314484Sbinkertn@umich.edu * for an ar(1) archive. 1324484Sbinkertn@umich.edu */ 1334484Sbinkertn@umich.edu if (a && (a->e_fd != fd || c != a->e_cmd)) { 1344484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 1354484Sbinkertn@umich.edu return (NULL); 1364484Sbinkertn@umich.edu } 1374484Sbinkertn@umich.edu 1384484Sbinkertn@umich.edu break; 1394484Sbinkertn@umich.edu 1404484Sbinkertn@umich.edu default: 1414484Sbinkertn@umich.edu LIBELF_SET_ERROR(ARGUMENT, 0); 1424484Sbinkertn@umich.edu return (NULL); 1434484Sbinkertn@umich.edu 1444484Sbinkertn@umich.edu } 1454484Sbinkertn@umich.edu 1464484Sbinkertn@umich.edu if (a == NULL) 1474484Sbinkertn@umich.edu e = _libelf_open_object(fd, c); 1484484Sbinkertn@umich.edu else if (a->e_kind == ELF_K_AR) 1494484Sbinkertn@umich.edu e = _libelf_ar_open_member(fd, c, a); 1504484Sbinkertn@umich.edu else 1514484Sbinkertn@umich.edu (e = a)->e_activations++; 1524484Sbinkertn@umich.edu 1534484Sbinkertn@umich.edu return (e); 1544484Sbinkertn@umich.edu} 155