Mercurial > pub > dyncall > dyncall
annotate dynload/dynload_syms_elf.c @ 315:3840e0188520
- allowing lookup of running executable's path by passing NULL to dynload's dlGetLibraryPath()
| author | Tassilo Philipp |
|---|---|
| date | Wed, 06 Nov 2019 14:13:49 +0100 |
| parents | f5577f6bf97a |
| children | 2c2b51819aad |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 | |
| 3 Package: dyncall | |
| 4 Library: dynload | |
| 5 File: dynload/dynload_syms_elf.c | |
| 6 Description: | |
| 7 License: | |
| 8 | |
| 281 | 9 Copyright (c) 2007-2018 Daniel Adler <dadler@uni-goettingen.de>, |
| 0 | 10 Tassilo Philipp <tphilipp@potion-studios.com>, |
| 11 Olivier Chafik <olivier.chafik@gmail.com> | |
| 12 | |
| 13 Permission to use, copy, modify, and distribute this software for any | |
| 14 purpose with or without fee is hereby granted, provided that the above | |
| 15 copyright notice and this permission notice appear in all copies. | |
| 16 | |
| 17 THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
| 18 WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
| 19 MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
| 20 ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
| 21 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
| 22 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
| 23 OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
| 24 | |
| 25 */ | |
| 26 | |
| 27 | |
| 28 | |
| 29 #include "../autovar/autovar_OS.h" | |
| 30 | |
| 31 /* | |
| 32 | |
| 33 dynamic symbol resolver for elf | |
| 34 | |
| 35 */ | |
| 36 | |
| 37 #include "dynload.h" | |
| 38 #if defined(OS_OpenBSD) | |
| 39 # include <stdint.h> | |
| 40 # include <elf_abi.h> | |
|
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41 #elif defined(OS_NetBSD) |
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42 # include <stddef.h> |
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43 # include <elf.h> |
| 0 | 44 #elif defined(OS_SunOS) |
| 45 # include <libelf.h> | |
| 46 #elif defined(OS_BeOS) | |
| 47 # include <elf32.h> | |
| 48 #else | |
| 49 # include <elf.h> | |
| 50 #endif | |
| 51 | |
| 52 #if defined(__GLIBC__) | |
| 53 # define _GNU_SOURCE | |
| 54 # define __USE_GNU | |
| 55 #endif | |
| 56 | |
| 57 #include "dynload_alloc.h" | |
| 58 | |
| 59 #include <assert.h> | |
| 60 #include <fcntl.h> | |
| 61 #include <dlfcn.h> | |
| 62 #include <stdio.h> | |
| 63 #include <string.h> | |
| 64 #include <sys/stat.h> | |
| 65 #include <sys/types.h> | |
| 66 #include <sys/mman.h> | |
| 67 #include <unistd.h> | |
| 68 | |
| 69 /* run-time configuration 64/32 */ | |
| 70 #if defined(OS_OpenBSD) | |
| 71 #else | |
| 72 # include "../autovar/autovar_ABI.h" | |
| 73 # ifdef ABI_ELF64 | |
| 74 | |
| 75 typedef Elf64_Ehdr Elf_Ehdr; | |
| 76 typedef Elf64_Phdr Elf_Phdr; | |
| 77 typedef Elf64_Shdr Elf_Shdr; | |
| 78 typedef Elf64_Sym Elf_Sym; | |
| 79 # ifndef OS_SunOS | |
| 80 typedef Elf64_Dyn Elf_Dyn; | |
| 81 # endif | |
| 82 typedef Elf64_Sxword Elf_tag; | |
| 83 typedef Elf64_Addr Elf_Addr; | |
| 84 | |
| 85 # else | |
| 86 # if defined(OS_BeOS) | |
| 87 typedef struct Elf32_Ehdr Elf_Ehdr; | |
| 88 typedef struct Elf32_Phdr Elf_Phdr; | |
| 89 typedef struct Elf32_Shdr Elf_Shdr; | |
| 90 typedef struct Elf32_Sym Elf_Sym; | |
| 91 typedef struct Elf32_Dyn Elf_Dyn; | |
| 92 typedef Elf32_Sword Elf_tag; | |
| 93 typedef Elf32_Addr Elf_Addr; | |
| 94 | |
| 95 # else | |
| 96 | |
| 97 typedef Elf32_Ehdr Elf_Ehdr; | |
| 98 typedef Elf32_Phdr Elf_Phdr; | |
| 99 typedef Elf32_Shdr Elf_Shdr; | |
| 100 typedef Elf32_Sym Elf_Sym; | |
| 101 # ifndef OS_SunOS | |
| 102 typedef Elf32_Dyn Elf_Dyn; | |
| 103 # endif | |
| 104 typedef Elf32_Sword Elf_tag; | |
| 105 typedef Elf32_Addr Elf_Addr; | |
| 106 | |
| 107 # endif | |
| 108 # endif | |
| 109 #endif | |
| 110 | |
| 111 | |
| 112 struct DLSyms_ | |
| 113 { | |
| 114 const char* pStrTab; | |
| 115 Elf_Sym* pSymTab; | |
| 116 size_t strTabSize; | |
| 117 size_t nSymbols; | |
| 118 Elf_Ehdr* pElf_Ehdr; /* pointer to elf header */ | |
| 119 int file; /* fd of lib */ | |
| 120 size_t fileSize; /* filesize of open lib */ | |
| 121 }; | |
| 122 | |
| 123 | |
| 124 DLSyms* dlSymsInit(const char* libPath) | |
| 125 { | |
| 126 unsigned char* pMem; | |
| 127 int i; | |
| 128 struct stat st; | |
| 129 Elf_Shdr* pS; | |
| 231 | 130 DLSyms* pSyms; |
| 131 | |
| 132 if(stat(libPath, &st) == -1) | |
| 133 return NULL; | |
| 134 | |
| 135 i = open(libPath, O_RDONLY); | |
| 136 if(i == -1) | |
| 137 return NULL; | |
| 138 | |
| 139 pSyms = (DLSyms*)dlAllocMem(sizeof(DLSyms)); | |
| 0 | 140 memset(pSyms, 0, sizeof(DLSyms)); |
| 231 | 141 pSyms->file = i; |
| 0 | 142 pSyms->fileSize = st.st_size; |
| 143 pSyms->pElf_Ehdr = (Elf_Ehdr*) mmap((void*) NULL, pSyms->fileSize, PROT_READ, MAP_SHARED, pSyms->file, 0); | |
| 144 | |
| 145 #ifdef ABI_ELF32 | |
| 146 assert(pSyms->pElf_Ehdr->e_ident[EI_CLASS] == ELFCLASS32); | |
| 147 #else | |
| 148 assert(pSyms->pElf_Ehdr->e_ident[EI_CLASS] == ELFCLASS64); | |
| 149 #endif | |
| 150 | |
| 151 assert(pSyms->pElf_Ehdr->e_phoff > 0); | |
| 152 assert(pSyms->pElf_Ehdr->e_shoff > 0); | |
| 153 | |
| 154 | |
| 155 pMem = (unsigned char*)pSyms->pElf_Ehdr; | |
| 156 | |
| 157 /* traverse section headers */ | |
| 158 pS = (Elf_Shdr*) ( pMem + pSyms->pElf_Ehdr->e_shoff ); | |
| 159 /* skip section 0 which is always zero due to the Elf standard. */ | |
| 160 for (i = 1; i < pSyms->pElf_Ehdr->e_shnum; i++) | |
| 161 { | |
| 162 Elf_Shdr* pSection = &pS[i]; | |
| 231 | 163 void* pSectionContent = ((char*)pMem) + pSection->sh_offset; |
| 0 | 164 switch (pSection->sh_type) |
| 165 { | |
| 166 case SHT_DYNSYM: | |
| 167 if (!pSyms->pSymTab) { | |
| 168 pSyms->pSymTab = (Elf_Sym*)pSectionContent; | |
| 169 pSyms->nSymbols = pSection->sh_size / pSection->sh_entsize; | |
| 170 } | |
| 171 break; | |
| 172 case SHT_STRTAB: | |
|
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173 /* Do not trust pSyms->pElf_Ehdr->e_shstrndx! */ |
| 0 | 174 if (!pSyms->pStrTab) { |
| 175 pSyms->pStrTab = (const char*)pSectionContent; | |
| 176 pSyms->strTabSize = pSection->sh_size; | |
| 177 } | |
| 178 break; | |
| 179 } | |
| 180 if (pSyms->pSymTab && pSyms->pStrTab) | |
| 181 break; | |
| 182 } | |
| 183 return pSyms; | |
| 184 } | |
| 185 | |
| 186 | |
| 187 void dlSymsCleanup(DLSyms* pSyms) | |
| 188 { | |
| 189 if(pSyms) { | |
| 190 munmap((void*) pSyms->pElf_Ehdr, pSyms->fileSize); | |
| 191 close(pSyms->file); | |
| 192 dlFreeMem(pSyms); | |
| 193 } | |
| 194 } | |
| 195 | |
| 196 | |
| 197 int dlSymsCount(DLSyms* pSyms) | |
| 198 { | |
| 231 | 199 return pSyms ? pSyms->nSymbols : 0; |
| 0 | 200 } |
| 201 | |
| 202 | |
| 203 const char* dlSymsName(DLSyms* pSyms, int index) | |
| 204 { | |
| 205 int str_index; | |
| 206 if(!pSyms || !pSyms->pSymTab || index < 0 || index >= pSyms->nSymbols) | |
| 207 return NULL; | |
| 231 | 208 |
| 0 | 209 str_index = pSyms->pSymTab[index].st_name; |
| 210 if (str_index < 0 || str_index >= pSyms->strTabSize) | |
| 211 return NULL; | |
| 212 return &pSyms->pStrTab[str_index]; | |
| 213 } | |
| 214 | |
| 215 | |
| 216 const char* dlSymsNameFromValue(DLSyms* pSyms, void* value) | |
| 217 { | |
| 218 Dl_info info; | |
| 219 return (dladdr(value, &info) && (value == info.dli_saddr)) | |
| 220 ? info.dli_sname | |
| 221 : NULL; | |
| 222 } | |
| 223 |