1 // Copyright (c) 2011, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 9 // notice, this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above 11 // copyright notice, this list of conditions and the following disclaimer 12 // in the documentation and/or other materials provided with the 13 // distribution. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 16 // this software without specific prior written permission. 17 // 18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30 // safe_readlink.cc: Implement google_breakpad::SafeReadLink. 31 // See safe_readlink.h for details. 32 33 #include <stddef.h> 34 35 #include "third_party/lss/linux_syscall_support.h" 36 37 namespace google_breakpad { 38 39 bool SafeReadLink(const char* path, char* buffer, size_t buffer_size) { 40 // sys_readlink() does not add a NULL byte to |buffer|. In order to return 41 // a NULL-terminated string in |buffer|, |buffer_size| should be at least 42 // one byte longer than the expected path length. Also, sys_readlink() 43 // returns the actual path length on success, which does not count the 44 // NULL byte, so |result_size| should be less than |buffer_size|. 45 ssize_t result_size = sys_readlink(path, buffer, buffer_size); 46 if (result_size >= 0 && static_cast<size_t>(result_size) < buffer_size) { 47 buffer[result_size] = '\0'; 48 return true; 49 } 50 return false; 51 } 52 53 } // namespace google_breakpad 54
