1// Copyright (c) 2009, 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// This header provides replacements for libc functions that we need. We if
31// call the libc functions directly we risk crashing in the dynamic linker as
32// it tries to resolve uncached PLT entries.
33
34#ifndef CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_
35#define CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_
36
37#include <stdint.h>
38#include <limits.h>
39#include <sys/types.h>
40
41extern "C" {
42
43extern size_t my_strlen(const char* s);
44
45extern int my_strcmp(const char* a, const char* b);
46
47extern int my_strncmp(const char* a, const char* b, size_t len);
48
49// Parse a non-negative integer.
50// result: (output) the resulting non-negative integer
51// s: a NUL terminated string
52// Return true iff successful.
53extern bool my_strtoui(int* result, const char* s);
54
55// Return the length of the given unsigned integer when expressed in base 10.
56extern unsigned my_uint_len(uintmax_t i);
57
58// Convert an unsigned integer to a string
59// output: (output) the resulting string is written here. This buffer must be
60// large enough to hold the resulting string. Call |my_uint_len| to get the
61// required length.
62// i: the unsigned integer to serialise.
63// i_len: the length of the integer in base 10 (see |my_uint_len|).
64extern void my_uitos(char* output, uintmax_t i, unsigned i_len);
65
66extern const char* my_strchr(const char* haystack, char needle);
67
68extern const char* my_strrchr(const char* haystack, char needle);
69
70// Read a hex value
71// result: (output) the resulting value
72// s: a string
73// Returns a pointer to the first invalid charactor.
74extern const char* my_read_hex_ptr(uintptr_t* result, const char* s);
75
76extern const char* my_read_decimal_ptr(uintptr_t* result, const char* s);
77
78extern void my_memset(void* ip, char c, size_t len);
79
80extern void* my_memchr(const void* src, int c, size_t len);
81
82// The following are considered safe to use in a compromised environment.
83// Besides, this gives the compiler an opportunity to optimize their calls.
84#define my_memcpy memcpy
85#define my_memmove memmove
86#define my_memcmp memcmp
87
88extern size_t my_strlcpy(char* s1, const char* s2, size_t len);
89
90extern size_t my_strlcat(char* s1, const char* s2, size_t len);
91
92extern int my_isspace(int ch);
93
94} // extern "C"
95
96#endif // CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_
97