1 /*- 2 * Copyright (c) 2006,2008 Joseph Koshy 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 13 * 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 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 29 #include <assert.h> 30 #include <gelf.h> 31 #include <libelf.h> 32 #include <stdlib.h> 33 34 #include "_libelf.h" 35 36 ELFTC_VCSID("$Id: libelf_phdr.c 2931 2013-03-23 11:41:07Z jkoshy $"); 37 38 void * 39 _libelf_getphdr(Elf *e, int ec) 40 { 41 size_t phnum; 42 size_t fsz, msz; 43 uint64_t phoff; 44 Elf32_Ehdr *eh32; 45 Elf64_Ehdr *eh64; 46 void *ehdr, *phdr; 47 int (*xlator)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); 48 49 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 50 51 if (e == NULL) { 52 LIBELF_SET_ERROR(ARGUMENT, 0); 53 return (NULL); 54 } 55 56 if ((phdr = (ec == ELFCLASS32 ? 57 (void *) e->e_u.e_elf.e_phdr.e_phdr32 : 58 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL) 59 return (phdr); 60 61 /* 62 * Check the PHDR related fields in the EHDR for sanity. 63 */ 64 65 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) 66 return (NULL); 67 68 phnum = e->e_u.e_elf.e_nphdr; 69 70 if (ec == ELFCLASS32) { 71 eh32 = (Elf32_Ehdr *) ehdr; 72 phoff = (uint64_t) eh32->e_phoff; 73 } else { 74 eh64 = (Elf64_Ehdr *) ehdr; 75 phoff = (uint64_t) eh64->e_phoff; 76 } 77 78 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version); 79 80 assert(fsz > 0); 81 82 if ((uint64_t) e->e_rawsize < (phoff + fsz)) { 83 LIBELF_SET_ERROR(HEADER, 0); 84 return (NULL); 85 } 86 87 msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT); 88 89 assert(msz > 0); 90 91 if ((phdr = calloc(phnum, msz)) == NULL) { 92 LIBELF_SET_ERROR(RESOURCE, 0); 93 return (NULL); 94 } 95 96 if (ec == ELFCLASS32) 97 e->e_u.e_elf.e_phdr.e_phdr32 = phdr; 98 else 99 e->e_u.e_elf.e_phdr.e_phdr64 = phdr; 100 101 102 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec); 103 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum, 104 e->e_byteorder != LIBELF_PRIVATE(byteorder)); 105 106 return (phdr); 107 } 108 109 void * 110 _libelf_newphdr(Elf *e, int ec, size_t count) 111 { 112 void *ehdr, *newphdr, *oldphdr; 113 size_t msz; 114 115 if (e == NULL) { 116 LIBELF_SET_ERROR(ARGUMENT, 0); 117 return (NULL); 118 } 119 120 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) { 121 LIBELF_SET_ERROR(SEQUENCE, 0); 122 return (NULL); 123 } 124 125 assert(e->e_class == ec); 126 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 127 assert(e->e_version == EV_CURRENT); 128 129 msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version); 130 131 assert(msz > 0); 132 133 newphdr = NULL; 134 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) { 135 LIBELF_SET_ERROR(RESOURCE, 0); 136 return (NULL); 137 } 138 139 if (ec == ELFCLASS32) { 140 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL) 141 free(oldphdr); 142 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr; 143 } else { 144 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL) 145 free(oldphdr); 146 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr; 147 } 148 149 e->e_u.e_elf.e_nphdr = count; 150 151 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY); 152 153 return (newphdr); 154 } 155