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 3009 2014-03-23 01:49:59Z 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)(unsigned char *_d, size_t _dsz, unsigned char *_s, 48 size_t _c, int _swap); 49 50 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 51 52 if (e == NULL) { 53 LIBELF_SET_ERROR(ARGUMENT, 0); 54 return (NULL); 55 } 56 57 if ((phdr = (ec == ELFCLASS32 ? 58 (void *) e->e_u.e_elf.e_phdr.e_phdr32 : 59 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL) 60 return (phdr); 61 62 /* 63 * Check the PHDR related fields in the EHDR for sanity. 64 */ 65 66 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) 67 return (NULL); 68 69 phnum = e->e_u.e_elf.e_nphdr; 70 71 if (ec == ELFCLASS32) { 72 eh32 = (Elf32_Ehdr *) ehdr; 73 phoff = (uint64_t) eh32->e_phoff; 74 } else { 75 eh64 = (Elf64_Ehdr *) ehdr; 76 phoff = (uint64_t) eh64->e_phoff; 77 } 78 79 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version); 80 81 assert(fsz > 0); 82 83 if ((uint64_t) e->e_rawsize < (phoff + fsz)) { 84 LIBELF_SET_ERROR(HEADER, 0); 85 return (NULL); 86 } 87 88 msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT); 89 90 assert(msz > 0); 91 92 if ((phdr = calloc(phnum, msz)) == NULL) { 93 LIBELF_SET_ERROR(RESOURCE, 0); 94 return (NULL); 95 } 96 97 if (ec == ELFCLASS32) 98 e->e_u.e_elf.e_phdr.e_phdr32 = phdr; 99 else 100 e->e_u.e_elf.e_phdr.e_phdr64 = phdr; 101 102 103 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec); 104 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum, 105 e->e_byteorder != LIBELF_PRIVATE(byteorder)); 106 107 return (phdr); 108 } 109 110 void * 111 _libelf_newphdr(Elf *e, int ec, size_t count) 112 { 113 void *ehdr, *newphdr, *oldphdr; 114 size_t msz; 115 116 if (e == NULL) { 117 LIBELF_SET_ERROR(ARGUMENT, 0); 118 return (NULL); 119 } 120 121 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) { 122 LIBELF_SET_ERROR(SEQUENCE, 0); 123 return (NULL); 124 } 125 126 assert(e->e_class == ec); 127 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 128 assert(e->e_version == EV_CURRENT); 129 130 msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version); 131 132 assert(msz > 0); 133 134 newphdr = NULL; 135 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) { 136 LIBELF_SET_ERROR(RESOURCE, 0); 137 return (NULL); 138 } 139 140 if (ec == ELFCLASS32) { 141 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL) 142 free(oldphdr); 143 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr; 144 } else { 145 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL) 146 free(oldphdr); 147 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr; 148 } 149 150 e->e_u.e_elf.e_nphdr = count; 151 152 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY); 153 154 return (newphdr); 155 } 156