linux_libc_support.h

// Copyright (c) 2009, Google Inc.

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//

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// modification, are permitted provided that the following conditions are

// met:

//

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// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

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// this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

// This header provides replacements for libc functions that we need. We if

// call the libc functions directly we risk crashing in the dynamic linker as

// it tries to resolve uncached PLT entries.

#ifndef CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_

#define CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_

#include <stdint.h>

#include <limits.h>

#include <sys/types.h>

extern "C" {

extern size_t my_strlen(const char* s);

extern int my_strcmp(const char* a, const char* b);

extern int my_strncmp(const char* a, const char* b, size_t len);

// Parse a non-negative integer.

//   result: (output) the resulting non-negative integer

//   s: a NUL terminated string

// Return true iff successful.

extern bool my_strtoui(int* result, const char* s);

// Return the length of the given unsigned integer when expressed in base 10.

extern unsigned my_uint_len(uintmax_t i);

// Convert an unsigned integer to a string

//   output: (output) the resulting string is written here. This buffer must be

//     large enough to hold the resulting string. Call |my_uint_len| to get the

//     required length.

//   i: the unsigned integer to serialise.

//   i_len: the length of the integer in base 10 (see |my_uint_len|).

extern void my_uitos(char* output, uintmax_t i, unsigned i_len);

extern const char* my_strchr(const char* haystack, char needle);

extern const char* my_strrchr(const char* haystack, char needle);

extern const char *my_strstr(const char *haystack, const char *needle);

// Read a hex value

//   result: (output) the resulting value

//   s: a string

// Returns a pointer to the first invalid charactor.

extern const char* my_read_hex_ptr(uintptr_t* result, const char* s);

extern const char* my_read_decimal_ptr(uintptr_t* result, const char* s);

extern void my_memset(void* ip, char c, size_t len);

extern void* my_memchr(const void* src, int c, size_t len);

// The following are considered safe to use in a compromised environment.

// Besides, this gives the compiler an opportunity to optimize their calls.

#define my_memcpy  memcpy

#define my_memmove memmove

#define my_memcmp  memcmp

extern size_t my_strlcpy(char* s1, const char* s2, size_t len);

extern size_t my_strlcat(char* s1, const char* s2, size_t len);

extern int my_isspace(int ch);

}  // extern "C"

#endif  // CLIENT_LINUX_LINUX_LIBC_SUPPORT_H_