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.h: Define the google_breakpad::SafeReadLink function, |
31 | // which wraps sys_readlink and gurantees the result is NULL-terminated. |
32 | |
33 | #ifndef COMMON_LINUX_SAFE_READLINK_H_ |
34 | #define COMMON_LINUX_SAFE_READLINK_H_ |
35 | |
36 | #include <stddef.h> |
37 | |
38 | namespace google_breakpad { |
39 | |
40 | // This function wraps sys_readlink() and performs the same functionalty, |
41 | // but guarantees |buffer| is NULL-terminated if sys_readlink() returns |
42 | // no error. It takes the same arguments as sys_readlink(), but unlike |
43 | // sys_readlink(), it returns true on success. |
44 | // |
45 | // |buffer_size| specifies the size of |buffer| in bytes. As this function |
46 | // always NULL-terminates |buffer| on success, |buffer_size| should be |
47 | // at least one byte longer than the expected path length (e.g. PATH_MAX, |
48 | // which is typically defined as the maximum length of a path name |
49 | // including the NULL byte). |
50 | // |
51 | // The implementation of this function calls sys_readlink() instead of |
52 | // readlink(), it can thus be used in the context where calling to libc |
53 | // functions is discouraged. |
54 | bool SafeReadLink(const char* path, char* buffer, size_t buffer_size); |
55 | |
56 | // Same as the three-argument version of SafeReadLink() but deduces the |
57 | // size of |buffer| if it is a char array of known size. |
58 | template <size_t N> |
59 | bool SafeReadLink(const char* path, char (&buffer)[N]) { |
60 | return SafeReadLink(path, buffer, sizeof(buffer)); |
61 | } |
62 | |
63 | } // namespace google_breakpad |
64 | |
65 | #endif // COMMON_LINUX_SAFE_READLINK_H_ |
66 | |