common/linux/file_id.cc - breakpad/breakpad/src - Git at Google

 // Copyright (c) 2006, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 // copyright notice, this list of conditions and the following disclaimer
 // in the documentation and/or other materials provided with the
 // distribution.
 //     * Neither the name of Google Inc. nor the names of its
 // contributors may be used to endorse or promote products derived from
 // this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 //
 // file_id.cc: Return a unique identifier for a file
 //
 // See file_id.h for documentation
 //

 #include "common/linux/file_id.h"

 #include <arpa/inet.h>
 #include <assert.h>
 #include <elf.h>
 #include <fcntl.h>
 #if defined(__ANDROID__)
 #include "client/linux/android_link.h"
 #else
 #include <link.h>
 #endif
 #include <stdio.h>
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <unistd.h>

 #include <algorithm>

 #include "common/linux/linux_libc_support.h"
 #include "third_party/lss/linux_syscall_support.h"

 namespace google_breakpad {

 #ifndef NT_GNU_BUILD_ID
 #define NT_GNU_BUILD_ID 3
 #endif

 FileID::FileID(const char* path) {
   strncpy(path_, path, sizeof(path_));
 }

 struct ElfClass32 {
   typedef Elf32_Ehdr Ehdr;
   typedef Elf32_Nhdr Nhdr;
   typedef Elf32_Shdr Shdr;
   static const int kClass = ELFCLASS32;
 };

 struct ElfClass64 {
   typedef Elf64_Ehdr Ehdr;
   typedef Elf64_Nhdr Nhdr;
   typedef Elf64_Shdr Shdr;
   static const int kClass = ELFCLASS64;
 };

 // These six functions are also used inside the crashed process, so be safe
 // and use the syscall/libc wrappers instead of direct syscalls or libc.
 template<typename ElfClass>
 static void FindElfClassSection(const char *elf_base,
                                 const char *section_name,
                                 uint32_t section_type,
                                 const void **section_start,
                                 int *section_size) {
   typedef typename ElfClass::Ehdr Ehdr;
   typedef typename ElfClass::Shdr Shdr;

   assert(elf_base);
   assert(section_start);
   assert(section_size);

   assert(my_strncmp(elf_base, ELFMAG, SELFMAG) == 0);

   int name_len = my_strlen(section_name);

   const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
   assert(elf_header->e_ident[EI_CLASS] == ElfClass::kClass);

   const Shdr* sections =
       reinterpret_cast<const Shdr*>(elf_base + elf_header->e_shoff);
   const Shdr* string_section = sections + elf_header->e_shstrndx;

   const Shdr* section = NULL;
   for (int i = 0; i < elf_header->e_shnum; ++i) {
     if (sections[i].sh_type == section_type) {
       const char* current_section_name = (char*)(elf_base +
                                                  string_section->sh_offset +
                                                  sections[i].sh_name);
       if (!my_strncmp(current_section_name, section_name, name_len)) {
         section = &sections[i];
         break;
       }
     }
   }
   if (section != NULL && section->sh_size > 0) {
     *section_start = elf_base + section->sh_offset;
     *section_size = section->sh_size;
   }
 }

 // Attempt to find a section named |section_name| of type |section_type|
 // in the ELF binary data at |elf_mapped_base|. On success, returns true
 // and sets |*section_start| to point to the start of the section data,
 // and |*section_size| to the size of the section's data. If |elfclass|
 // is not NULL, set |*elfclass| to the ELF file class.
 static bool FindElfSection(const void *elf_mapped_base,
                            const char *section_name,
                            uint32_t section_type,
                            const void **section_start,
                            int *section_size,
                            int *elfclass) {
   assert(elf_mapped_base);
   assert(section_start);
   assert(section_size);

   *section_start = NULL;
   *section_size = 0;

   const char* elf_base =
     static_cast<const char*>(elf_mapped_base);
   const ElfW(Ehdr)* elf_header =
     reinterpret_cast<const ElfW(Ehdr)*>(elf_base);
   if (my_strncmp(elf_base, ELFMAG, SELFMAG) != 0)
     return false;

   if (elfclass) {
     *elfclass = elf_header->e_ident[EI_CLASS];
   }

   if (elf_header->e_ident[EI_CLASS] == ELFCLASS32) {
     FindElfClassSection<ElfClass32>(elf_base, section_name, section_type,
                                     section_start, section_size);
     return *section_start != NULL;
   } else if (elf_header->e_ident[EI_CLASS] == ELFCLASS64) {
     FindElfClassSection<ElfClass64>(elf_base, section_name, section_type,
                                     section_start, section_size);
     return *section_start != NULL;
   }

   return false;
 }

 template<typename ElfClass>
 static bool ElfClassBuildIDNoteIdentifier(const void *section,
                                           uint8_t identifier[kMDGUIDSize]) {
   typedef typename ElfClass::Nhdr Nhdr;

   const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
   if (note_header->n_type != NT_GNU_BUILD_ID ||
       note_header->n_descsz == 0) {
     return false;
   }

   const char* build_id = reinterpret_cast<const char*>(section) +
     sizeof(Nhdr) + note_header->n_namesz;
   // Copy as many bits of the build ID as will fit
   // into the GUID space.
   my_memset(identifier, 0, kMDGUIDSize);
   memcpy(identifier, build_id,
          std::min(kMDGUIDSize, (size_t)note_header->n_descsz));

   return true;
 }

 // Attempt to locate a .note.gnu.build-id section in an ELF binary
 // and copy as many bytes of it as will fit into |identifier|.
 static bool FindElfBuildIDNote(const void *elf_mapped_base,
                                uint8_t identifier[kMDGUIDSize]) {
   void* note_section;
   int note_size, elfclass;
   if (!FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
                       (const void**)&note_section, &note_size, &elfclass) ||
       note_size == 0) {
     return false;
   }

   if (elfclass == ELFCLASS32) {
     return ElfClassBuildIDNoteIdentifier<ElfClass32>(note_section, identifier);
   } else if (elfclass == ELFCLASS64) {
     return ElfClassBuildIDNoteIdentifier<ElfClass64>(note_section, identifier);
   }

   return false;
 }

 // Attempt to locate the .text section of an ELF binary and generate
 // a simple hash by XORing the first page worth of bytes into |identifier|.
 static bool HashElfTextSection(const void *elf_mapped_base,
                                uint8_t identifier[kMDGUIDSize]) {
   void* text_section;
   int text_size;
   if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
                       (const void**)&text_section, &text_size, NULL) ||
       text_size == 0) {
     return false;
   }

   my_memset(identifier, 0, kMDGUIDSize);
   const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
   const uint8_t* ptr_end = ptr + std::min(text_size, 4096);
   while (ptr < ptr_end) {
     for (unsigned i = 0; i < kMDGUIDSize; i++)
       identifier[i] ^= ptr[i];
     ptr += kMDGUIDSize;
   }
   return true;
 }

 // static
 bool FileID::ElfFileIdentifierFromMappedFile(void* base,
                                              uint8_t identifier[kMDGUIDSize]) {
   // Look for a build id note first.
   if (FindElfBuildIDNote(base, identifier))
     return true;

   // Fall back on hashing the first page of the text section.
   return HashElfTextSection(base, identifier);
 }

 bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
   int fd = open(path_, O_RDONLY);
   if (fd < 0)
     return false;
   struct stat st;
   if (fstat(fd, &st) != 0) {
     close(fd);
     return false;
   }
   void* base = mmap(NULL, st.st_size,
                     PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
   close(fd);
   if (base == MAP_FAILED)
     return false;

   bool success = ElfFileIdentifierFromMappedFile(base, identifier);
   munmap(base, st.st_size);
   return success;
 }

 // static
 void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],
                                        char* buffer, int buffer_length) {
   uint8_t identifier_swapped[kMDGUIDSize];

   // Endian-ness swap to match dump processor expectation.
   memcpy(identifier_swapped, identifier, kMDGUIDSize);
   uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
   *data1 = htonl(*data1);
   uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
   *data2 = htons(*data2);
   uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
   *data3 = htons(*data3);

   int buffer_idx = 0;
   for (unsigned int idx = 0;
        (buffer_idx < buffer_length) && (idx < kMDGUIDSize);
        ++idx) {
     int hi = (identifier_swapped[idx] >> 4) & 0x0F;
     int lo = (identifier_swapped[idx]) & 0x0F;

     if (idx == 4 || idx == 6 || idx == 8 || idx == 10)
       buffer[buffer_idx++] = '-';

     buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi;
     buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo;
   }

   // NULL terminate
   buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;
 }

 }  // namespace google_breakpad
	// Copyright (c) 2006, Google Inc.
	// All rights reserved.
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are
	// met:
	//
	// * Redistributions of source code must retain the above copyright
	// notice, this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above
	// copyright notice, this list of conditions and the following disclaimer
	// in the documentation and/or other materials provided with the
	// distribution.
	// * Neither the name of Google Inc. nor the names of its
	// contributors may be used to endorse or promote products derived from
	// this software without specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	//
	// file_id.cc: Return a unique identifier for a file
	//
	// See file_id.h for documentation
	//

	#include "common/linux/file_id.h"

	#include <arpa/inet.h>
	#include <assert.h>
	#include <elf.h>
	#include <fcntl.h>
	#if defined(__ANDROID__)
	#include "client/linux/android_link.h"
	#else
	#include <link.h>
	#endif
	#include <stdio.h>
	#include <string.h>
	#include <sys/mman.h>
	#include <sys/stat.h>
	#include <unistd.h>

	#include <algorithm>

	#include "common/linux/linux_libc_support.h"
	#include "third_party/lss/linux_syscall_support.h"

	namespace google_breakpad {

	#ifndef NT_GNU_BUILD_ID
	#define NT_GNU_BUILD_ID 3
	#endif

	FileID::FileID(const char* path) {
	strncpy(path_, path, sizeof(path_));
	}

	struct ElfClass32 {
	typedef Elf32_Ehdr Ehdr;
	typedef Elf32_Nhdr Nhdr;
	typedef Elf32_Shdr Shdr;
	static const int kClass = ELFCLASS32;
	};

	struct ElfClass64 {
	typedef Elf64_Ehdr Ehdr;
	typedef Elf64_Nhdr Nhdr;
	typedef Elf64_Shdr Shdr;
	static const int kClass = ELFCLASS64;
	};

	// These six functions are also used inside the crashed process, so be safe
	// and use the syscall/libc wrappers instead of direct syscalls or libc.
	template<typename ElfClass>
	static void FindElfClassSection(const char *elf_base,
	const char *section_name,
	uint32_t section_type,
	const void **section_start,
	int *section_size) {
	typedef typename ElfClass::Ehdr Ehdr;
	typedef typename ElfClass::Shdr Shdr;

	assert(elf_base);
	assert(section_start);
	assert(section_size);

	assert(my_strncmp(elf_base, ELFMAG, SELFMAG) == 0);

	int name_len = my_strlen(section_name);

	const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
	assert(elf_header->e_ident[EI_CLASS] == ElfClass::kClass);

	const Shdr* sections =
	reinterpret_cast<const Shdr*>(elf_base + elf_header->e_shoff);
	const Shdr* string_section = sections + elf_header->e_shstrndx;

	const Shdr* section = NULL;
	for (int i = 0; i < elf_header->e_shnum; ++i) {
	if (sections[i].sh_type == section_type) {
	const char* current_section_name = (char*)(elf_base +
	string_section->sh_offset +
	sections[i].sh_name);
	if (!my_strncmp(current_section_name, section_name, name_len)) {
	section = &sections[i];
	break;
	}
	}
	}
	if (section != NULL && section->sh_size > 0) {
	*section_start = elf_base + section->sh_offset;
	*section_size = section->sh_size;
	}
	}

	// Attempt to find a section named \|section_name\| of type \|section_type\|
	// in the ELF binary data at \|elf_mapped_base\|. On success, returns true
	// and sets \|*section_start\| to point to the start of the section data,
	// and \|*section_size\| to the size of the section's data. If \|elfclass\|
	// is not NULL, set \|*elfclass\| to the ELF file class.
	static bool FindElfSection(const void *elf_mapped_base,
	const char *section_name,
	uint32_t section_type,
	const void **section_start,
	int *section_size,
	int *elfclass) {
	assert(elf_mapped_base);
	assert(section_start);
	assert(section_size);

	*section_start = NULL;
	*section_size = 0;

	const char* elf_base =
	static_cast<const char*>(elf_mapped_base);
	const ElfW(Ehdr)* elf_header =
	reinterpret_cast<const ElfW(Ehdr)*>(elf_base);
	if (my_strncmp(elf_base, ELFMAG, SELFMAG) != 0)
	return false;

	if (elfclass) {
	*elfclass = elf_header->e_ident[EI_CLASS];
	}

	if (elf_header->e_ident[EI_CLASS] == ELFCLASS32) {
	FindElfClassSection<ElfClass32>(elf_base, section_name, section_type,
	section_start, section_size);
	return *section_start != NULL;
	} else if (elf_header->e_ident[EI_CLASS] == ELFCLASS64) {
	FindElfClassSection<ElfClass64>(elf_base, section_name, section_type,
	section_start, section_size);
	return *section_start != NULL;
	}

	return false;
	}

	template<typename ElfClass>
	static bool ElfClassBuildIDNoteIdentifier(const void *section,
	uint8_t identifier[kMDGUIDSize]) {
	typedef typename ElfClass::Nhdr Nhdr;

	const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
	if (note_header->n_type != NT_GNU_BUILD_ID \|\|
	note_header->n_descsz == 0) {
	return false;
	}

	const char* build_id = reinterpret_cast<const char*>(section) +
	sizeof(Nhdr) + note_header->n_namesz;
	// Copy as many bits of the build ID as will fit
	// into the GUID space.
	my_memset(identifier, 0, kMDGUIDSize);
	memcpy(identifier, build_id,
	std::min(kMDGUIDSize, (size_t)note_header->n_descsz));

	return true;
	}

	// Attempt to locate a .note.gnu.build-id section in an ELF binary
	// and copy as many bytes of it as will fit into \|identifier\|.
	static bool FindElfBuildIDNote(const void *elf_mapped_base,
	uint8_t identifier[kMDGUIDSize]) {
	void* note_section;
	int note_size, elfclass;
	if (!FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
	(const void**)&note_section, &note_size, &elfclass) \|\|
	note_size == 0) {
	return false;
	}

	if (elfclass == ELFCLASS32) {
	return ElfClassBuildIDNoteIdentifier<ElfClass32>(note_section, identifier);
	} else if (elfclass == ELFCLASS64) {
	return ElfClassBuildIDNoteIdentifier<ElfClass64>(note_section, identifier);
	}

	return false;
	}

	// Attempt to locate the .text section of an ELF binary and generate
	// a simple hash by XORing the first page worth of bytes into \|identifier\|.
	static bool HashElfTextSection(const void *elf_mapped_base,
	uint8_t identifier[kMDGUIDSize]) {
	void* text_section;
	int text_size;
	if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
	(const void**)&text_section, &text_size, NULL) \|\|
	text_size == 0) {
	return false;
	}

	my_memset(identifier, 0, kMDGUIDSize);
	const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
	const uint8_t* ptr_end = ptr + std::min(text_size, 4096);
	while (ptr < ptr_end) {
	for (unsigned i = 0; i < kMDGUIDSize; i++)
	identifier[i] ^= ptr[i];
	ptr += kMDGUIDSize;
	}
	return true;
	}

	// static
	bool FileID::ElfFileIdentifierFromMappedFile(void* base,
	uint8_t identifier[kMDGUIDSize]) {
	// Look for a build id note first.
	if (FindElfBuildIDNote(base, identifier))
	return true;

	// Fall back on hashing the first page of the text section.
	return HashElfTextSection(base, identifier);
	}

	bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
	int fd = open(path_, O_RDONLY);
	if (fd < 0)
	return false;
	struct stat st;
	if (fstat(fd, &st) != 0) {
	close(fd);
	return false;
	}
	void* base = mmap(NULL, st.st_size,
	PROT_READ \| PROT_WRITE, MAP_PRIVATE, fd, 0);
	close(fd);
	if (base == MAP_FAILED)
	return false;

	bool success = ElfFileIdentifierFromMappedFile(base, identifier);
	munmap(base, st.st_size);
	return success;
	}

	// static
	void FileID::ConvertIdentifierToString(const uint8_t identifier[kMDGUIDSize],
	char* buffer, int buffer_length) {
	uint8_t identifier_swapped[kMDGUIDSize];

	// Endian-ness swap to match dump processor expectation.
	memcpy(identifier_swapped, identifier, kMDGUIDSize);
	uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
	data1 = htonl(data1);
	uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
	data2 = htons(data2);
	uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
	data3 = htons(data3);

	int buffer_idx = 0;
	for (unsigned int idx = 0;
	(buffer_idx < buffer_length) && (idx < kMDGUIDSize);
	++idx) {
	int hi = (identifier_swapped[idx] >> 4) & 0x0F;
	int lo = (identifier_swapped[idx]) & 0x0F;

	if (idx == 4 \|\| idx == 6 \|\| idx == 8 \|\| idx == 10)
	buffer[buffer_idx++] = '-';

	buffer[buffer_idx++] = (hi >= 10) ? 'A' + hi - 10 : '0' + hi;
	buffer[buffer_idx++] = (lo >= 10) ? 'A' + lo - 10 : '0' + lo;
	}

	// NULL terminate
	buffer[(buffer_idx < buffer_length) ? buffer_idx : buffer_idx - 1] = 0;
	}

	} // namespace google_breakpad