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 <assert.h> 28 #include <gelf.h> 29 #include <libelf.h> 30 #include <stdlib.h> 31 32 #include "_libelf.h" 33 34 ELFTC_VCSID("$Id: libelf_phdr.c 3174 2015-03-27 17:13:41Z emaste $"); 35 36 void * 37 _libelf_getphdr(Elf *e, int ec) 38 { 39 size_t phnum; 40 size_t fsz, msz; 41 uint64_t phoff; 42 Elf32_Ehdr *eh32; 43 Elf64_Ehdr *eh64; 44 void *ehdr, *phdr; 45 int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s, 46 size_t _c, int _swap); 47 48 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 49 50 if (e == NULL) { 51 LIBELF_SET_ERROR(ARGUMENT, 0); 52 return (NULL); 53 } 54 55 if ((phdr = (ec == ELFCLASS32 ? 56 (void *) e->e_u.e_elf.e_phdr.e_phdr32 : 57 (void *) e->e_u.e_elf.e_phdr.e_phdr64)) != NULL) 58 return (phdr); 59 60 /* 61 * Check the PHDR related fields in the EHDR for sanity. 62 */ 63 64 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) 65 return (NULL); 66 67 phnum = e->e_u.e_elf.e_nphdr; 68 69 if (ec == ELFCLASS32) { 70 eh32 = (Elf32_Ehdr *) ehdr; 71 phoff = (uint64_t) eh32->e_phoff; 72 } else { 73 eh64 = (Elf64_Ehdr *) ehdr; 74 phoff = (uint64_t) eh64->e_phoff; 75 } 76 77 fsz = gelf_fsize(e, ELF_T_PHDR, phnum, e->e_version); 78 79 assert(fsz > 0); 80 81 if ((uint64_t) e->e_rawsize < (phoff + fsz)) { 82 LIBELF_SET_ERROR(HEADER, 0); 83 return (NULL); 84 } 85 86 msz = _libelf_msize(ELF_T_PHDR, ec, EV_CURRENT); 87 88 assert(msz > 0); 89 90 if ((phdr = calloc(phnum, msz)) == NULL) { 91 LIBELF_SET_ERROR(RESOURCE, 0); 92 return (NULL); 93 } 94 95 if (ec == ELFCLASS32) 96 e->e_u.e_elf.e_phdr.e_phdr32 = phdr; 97 else 98 e->e_u.e_elf.e_phdr.e_phdr64 = phdr; 99 100 101 xlator = _libelf_get_translator(ELF_T_PHDR, ELF_TOMEMORY, ec); 102 (*xlator)(phdr, phnum * msz, e->e_rawfile + phoff, phnum, 103 e->e_byteorder != LIBELF_PRIVATE(byteorder)); 104 105 return (phdr); 106 } 107 108 void * 109 _libelf_newphdr(Elf *e, int ec, size_t count) 110 { 111 void *ehdr, *newphdr, *oldphdr; 112 size_t msz; 113 114 if (e == NULL) { 115 LIBELF_SET_ERROR(ARGUMENT, 0); 116 return (NULL); 117 } 118 119 if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL) { 120 LIBELF_SET_ERROR(SEQUENCE, 0); 121 return (NULL); 122 } 123 124 assert(e->e_class == ec); 125 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 126 assert(e->e_version == EV_CURRENT); 127 128 msz = _libelf_msize(ELF_T_PHDR, ec, e->e_version); 129 130 assert(msz > 0); 131 132 newphdr = NULL; 133 if (count > 0 && (newphdr = calloc(count, msz)) == NULL) { 134 LIBELF_SET_ERROR(RESOURCE, 0); 135 return (NULL); 136 } 137 138 if (ec == ELFCLASS32) { 139 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr32) != NULL) 140 free(oldphdr); 141 e->e_u.e_elf.e_phdr.e_phdr32 = (Elf32_Phdr *) newphdr; 142 } else { 143 if ((oldphdr = (void *) e->e_u.e_elf.e_phdr.e_phdr64) != NULL) 144 free(oldphdr); 145 e->e_u.e_elf.e_phdr.e_phdr64 = (Elf64_Phdr *) newphdr; 146 } 147 148 e->e_u.e_elf.e_nphdr = count; 149 150 elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY); 151 152 return (newphdr); 153 } 154