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 <limits.h> 30 #include <stdint.h> 31 32 #include "_libelf.h" 33 34 ELFTC_VCSID("$Id: gelf_dyn.c 3732 2019-04-22 11:08:38Z jkoshy $"); 35 36 GElf_Dyn * 37 gelf_getdyn(Elf_Data *ed, int ndx, GElf_Dyn *dst) 38 { 39 int ec; 40 Elf *e; 41 size_t msz; 42 Elf_Scn *scn; 43 Elf32_Dyn *dyn32; 44 Elf64_Dyn *dyn64; 45 uint32_t sh_type; 46 struct _Libelf_Data *d; 47 48 d = (struct _Libelf_Data *) ed; 49 50 if (d == NULL || ndx < 0 || dst == NULL || 51 (scn = d->d_scn) == NULL || 52 (e = scn->s_elf) == NULL) { 53 LIBELF_SET_ERROR(ARGUMENT, 0); 54 return (NULL); 55 } 56 57 ec = e->e_class; 58 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 59 60 if (ec == ELFCLASS32) 61 sh_type = scn->s_shdr.s_shdr32.sh_type; 62 else 63 sh_type = scn->s_shdr.s_shdr64.sh_type; 64 65 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) { 66 LIBELF_SET_ERROR(ARGUMENT, 0); 67 return (NULL); 68 } 69 70 if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0) 71 return (NULL); 72 73 assert(ndx >= 0); 74 75 if (msz * (size_t) ndx >= d->d_data.d_size) { 76 LIBELF_SET_ERROR(ARGUMENT, 0); 77 return (NULL); 78 } 79 80 if (ec == ELFCLASS32) { 81 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx; 82 83 dst->d_tag = dyn32->d_tag; 84 dst->d_un.d_val = (Elf64_Xword) dyn32->d_un.d_val; 85 86 } else { 87 88 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx; 89 90 *dst = *dyn64; 91 } 92 93 return (dst); 94 } 95 96 int 97 gelf_update_dyn(Elf_Data *ed, int ndx, GElf_Dyn *ds) 98 { 99 int ec; 100 Elf *e; 101 size_t msz; 102 Elf_Scn *scn; 103 Elf32_Dyn *dyn32; 104 Elf64_Dyn *dyn64; 105 uint32_t sh_type; 106 struct _Libelf_Data *d; 107 108 d = (struct _Libelf_Data *) ed; 109 110 if (d == NULL || ndx < 0 || ds == NULL || 111 (scn = d->d_scn) == NULL || 112 (e = scn->s_elf) == NULL) { 113 LIBELF_SET_ERROR(ARGUMENT, 0); 114 return (0); 115 } 116 117 ec = e->e_class; 118 assert(ec == ELFCLASS32 || ec == ELFCLASS64); 119 120 if (ec == ELFCLASS32) 121 sh_type = scn->s_shdr.s_shdr32.sh_type; 122 else 123 sh_type = scn->s_shdr.s_shdr64.sh_type; 124 125 if (_libelf_xlate_shtype(sh_type) != ELF_T_DYN) { 126 LIBELF_SET_ERROR(ARGUMENT, 0); 127 return (0); 128 } 129 130 if ((msz = _libelf_msize(ELF_T_DYN, ec, e->e_version)) == 0) 131 return (0); 132 133 assert(ndx >= 0); 134 135 if (msz * (size_t) ndx >= d->d_data.d_size) { 136 LIBELF_SET_ERROR(ARGUMENT, 0); 137 return (0); 138 } 139 140 if (ec == ELFCLASS32) { 141 dyn32 = (Elf32_Dyn *) d->d_data.d_buf + ndx; 142 143 LIBELF_COPY_S32(dyn32, ds, d_tag); 144 LIBELF_COPY_U32(dyn32, ds, d_un.d_val); 145 } else { 146 dyn64 = (Elf64_Dyn *) d->d_data.d_buf + ndx; 147 148 *dyn64 = *ds; 149 } 150 151 return (1); 152 } 153