1 files changed, 143 insertions, 0 deletions
diff --git a/src/common/linux/file_id.cc b/src/common/linux/file_id.cc
new file mode 100644
index 00000000..db074fe1
--- /dev/null
+++ b/src/common/linux/file_id.cc
@@ -0,0 +1,143 @@
+// 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 <cassert>
+#include <cstdio>
+#include <elf.h>
+#include <fcntl.h>
+#include <link.h>
+#include <sys/mman.h>
+#include <openssl/md5.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common/linux/file_id.h"
+
+namespace google_breakpad {
+
+static bool FindElfTextSection(const void *elf_mapped_base,
+                               const void **text_start,
+                               int *text_size) {
+  assert(elf_mapped_base);
+  assert(text_start);
+  assert(text_size);
+
+  const unsigned char *elf_base =
+    static_cast<const unsigned char *>(elf_mapped_base);
+  const ElfW(Ehdr) *elf_header =
+    reinterpret_cast<const ElfW(Ehdr) *>(elf_base);
+  if (memcmp(elf_header, ELFMAG, SELFMAG) != 0)
+    return false;
+  *text_start = NULL;
+  *text_size = 0;
+  const ElfW(Shdr) *sections =
+    reinterpret_cast<const ElfW(Shdr) *>(elf_base + elf_header->e_shoff);
+  const char *text_section_name = ".text";
+  int name_len = strlen(text_section_name);
+  const ElfW(Shdr) *string_section = sections + elf_header->e_shstrndx;
+  const ElfW(Shdr) *text_section = NULL;
+  for (int i = 0; i < elf_header->e_shnum; ++i) {
+    if (sections[i].sh_type == SHT_PROGBITS) {
+      const char *section_name = (char*)(elf_base +
+                                         string_section->sh_offset +
+                                         sections[i].sh_name);
+      if (!strncmp(section_name, text_section_name, name_len)) {
+        text_section = &sections[i];
+        break;
+      }
+    }
+  }
+  if (text_section != NULL && text_section->sh_size > 0) {
+    int text_section_size = text_section->sh_size;
+    *text_start = elf_base + text_section->sh_offset;
+    *text_size = text_section_size;
+  }
+  return true;
+}
+
+FileID::FileID(const char *path) {
+  strncpy(path_, path, sizeof(path_));
+}
+
+bool FileID::ElfFileIdentifier(unsigned char identifier[16]) {
+  int fd = open(path_, O_RDONLY);
+  if (fd < 0)
+    return false;
+  struct stat st;
+  if (fstat(fd, &st) != 0 && st.st_size <= 0) {
+    close(fd);
+    return false;
+  }
+  void *base = mmap(NULL, st.st_size,
+                    PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
+  if (!base) {
+    close(fd);
+    return false;
+  }
+  bool success = false;
+  const void *text_section = NULL;
+  int text_size = 0;
+  if (FindElfTextSection(base, &text_section, &text_size) && (text_size > 0)) {
+    MD5_CTX md5;
+    MD5_Init(&md5);
+    MD5_Update(&md5, text_section, text_size);
+    MD5_Final(identifier, &md5);
+    success = true;
+  }
+
+  close(fd);
+  munmap(base, st.st_size);
+  return success;
+}
+
+// static
+void FileID::ConvertIdentifierToString(const unsigned char identifier[16],
+                                       char *buffer, int buffer_length) {
+  int buffer_idx = 0;
+  for (int idx = 0; (buffer_idx < buffer_length) && (idx < 16); ++idx) {
+    int hi = (identifier[idx] >> 4) & 0x0F;
+    int lo = (identifier[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