/*
* Macros to hook functions.
*
* Copyright (C) 2013-2014 Simon Ruderich
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
#ifndef MACROS_H
#define MACROS_H 1
/* Hook the function by creating a function with the same name. With
* LD_PRELOAD our function will be preferred. The original function is stored
* in a static variable (real_*). Any function called in these macros must
* make sure to restore the errno if it changes it.
*
* "Pseudo code" for the following macros. is the name of the hooked
* function, is either a file descriptor or a FILE pointer.
*
* if (!real_) {
* real_ = dlsym_function();
* if (!initialized) {
* init_from_environment();
* }
* }
* if (tracked_fds_find()) {
* if (force_write_to_non_tty) {
* handle = 1;
* } else {
* handle = isatty_noinline();
* }
* } else {
* handle = 0;
* }
*
* if (handle) {
* handle__pre();
* }
* result = real_();
* if (handle) {
* handle__post();
* }
* return result;
*/
#define _HOOK_PRE(type, name, fd) \
int handle; \
if (unlikely(!(real_ ## name ))) { \
*(void **) (&(real_ ## name)) = dlsym_function(#name); \
/* Initialize our data while we're at it. */ \
if (unlikely(!initialized)) { \
init_from_environment(); \
} \
} \
/* Check if this fd should be handled. */ \
if (unlikely(tracked_fds_find(fd))) { \
if (unlikely(force_write_to_non_tty)) { \
handle = 1; \
} else { \
handle = isatty_noinline(fd); \
} \
} else { \
handle = 0; \
}
#define _HOOK_PRE_FD(type, name, fd) \
type result; \
_HOOK_PRE_FD_(type, name, fd)
#define _HOOK_PRE_FD_(type, name, fd) \
_HOOK_PRE(type, name, fd) \
if (unlikely(handle)) { \
handle_fd_pre(fd); \
}
#define _HOOK_PRE_FILE(type, name, file) \
type result; \
_HOOK_PRE(type, name, fileno(file)) \
if (unlikely(handle)) { \
handle_file_pre(file); \
}
#define _HOOK_POST_FD_(fd) \
if (unlikely(handle)) { \
handle_fd_post(fd); \
}
#define _HOOK_POST_FD(fd) \
_HOOK_POST_FD_(fd) \
return result;
#define _HOOK_POST_FILE(file) \
if (unlikely(handle)) { \
handle_file_post(file); \
} \
return result;
#define HOOK_FUNC_DEF1(type, name, type1, arg1) \
static type (*real_ ## name)(type1); \
type name(type1) visibility_protected; \
type name(type1 arg1)
#define HOOK_FUNC_DEF2(type, name, type1, arg1, type2, arg2) \
static type (*real_ ## name)(type1, type2); \
type name(type1, type2) visibility_protected; \
type name(type1 arg1, type2 arg2)
#define HOOK_FUNC_DEF3(type, name, type1, arg1, type2, arg2, type3, arg3) \
static type (*real_ ## name)(type1, type2, type3); \
type name(type1, type2, type3) visibility_protected; \
type name(type1 arg1, type2 arg2, type3 arg3)
#define HOOK_FUNC_DEF4(type, name, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
static type (*real_ ## name)(type1, type2, type3, type4); \
type name(type1, type2, type3, type4) visibility_protected; \
type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4)
#define HOOK_FUNC_VAR_DEF2(type, name, type1, arg1, type2, arg2) \
static type (*real_ ## name)(type1, type2, ...); \
type name(type1, type2, ...) visibility_protected; \
type name(type1 arg1, type2 arg2, ...)
#define HOOK_FUNC_SIMPLE3(type, name, type1, arg1, type2, arg2, type3, arg3) \
type name(type1, type2, type3) visibility_protected; \
type name(type1 arg1, type2 arg2, type3 arg3)
#define HOOK_FUNC_VAR_SIMPLE1(type, name, type1, arg1) \
type name(type1, ...) visibility_protected; \
type name(type1 arg1, ...)
#define HOOK_FUNC_VAR_SIMPLE2(type, name, type1, arg1, type2, arg2) \
type name(type1, type2, ...) visibility_protected; \
type name(type1 arg1, type2 arg2, ...)
#define HOOK_FUNC_VAR_SIMPLE3(type, name, type1, arg1, type2, arg2, type3, arg3) \
type name(type1, type2, type3, ...) visibility_protected; \
type name(type1 arg1, type2 arg2, type3 arg3, ...)
#define HOOK_VOID1(type, name, fd, type1, arg1) \
HOOK_FUNC_DEF1(type, name, type1, arg1) { \
_HOOK_PRE_FD_(type, name, fd) \
real_ ## name(arg1); \
_HOOK_POST_FD_(fd) \
}
#define HOOK_VOID2(type, name, fd, type1, arg1, type2, arg2) \
HOOK_FUNC_DEF2(type, name, type1, arg1, type2, arg2) { \
_HOOK_PRE_FD_(type, name, fd) \
real_ ## name(arg1, arg2); \
_HOOK_POST_FD_(fd) \
}
#define HOOK_VOID3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
HOOK_FUNC_DEF3(type, name, type1, arg1, type2, arg2, type3, arg3) { \
_HOOK_PRE_FD_(type, name, fd) \
real_ ## name(arg1, arg2, arg3); \
_HOOK_POST_FD_(fd) \
}
#define HOOK_VAR_VOID1(type, name, fd, func, type1, arg1) \
HOOK_FUNC_VAR_SIMPLE1(type, name, type1, arg1) { \
va_list ap; \
va_start(ap, arg1); \
func(arg1, ap); \
va_end(ap); \
}
#define HOOK_VAR_VOID2(type, name, fd, func, type1, arg1, type2, arg2) \
HOOK_FUNC_VAR_SIMPLE2(type, name, type1, arg1, type2, arg2) { \
va_list ap; \
va_start(ap, arg2); \
func(arg1, arg2, ap); \
va_end(ap); \
}
#define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
HOOK_FUNC_DEF3(type, name, type1, arg1, type2, arg2, type3, arg3) { \
_HOOK_PRE_FD(type, name, fd) \
result = real_ ## name(arg1, arg2, arg3); \
_HOOK_POST_FD(fd) \
}
#define HOOK_FILE1(type, name, file, type1, arg1) \
HOOK_FUNC_DEF1(type, name, type1, arg1) { \
_HOOK_PRE_FILE(type, name, file) \
result = real_ ## name(arg1); \
_HOOK_POST_FILE(file) \
}
#define HOOK_FILE2(type, name, file, type1, arg1, type2, arg2) \
HOOK_FUNC_DEF2(type, name, type1, arg1, type2, arg2) { \
_HOOK_PRE_FILE(type, name, file) \
result = real_ ## name(arg1, arg2); \
_HOOK_POST_FILE(file) \
}
#define HOOK_FILE3(type, name, file, type1, arg1, type2, arg2, type3, arg3) \
HOOK_FUNC_DEF3(type, name, type1, arg1, type2, arg2, type3, arg3) { \
_HOOK_PRE_FILE(type, name, file) \
result = real_ ## name(arg1, arg2, arg3); \
_HOOK_POST_FILE(file) \
}
#define HOOK_FILE4(type, name, file, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
HOOK_FUNC_DEF4(type, name, type1, arg1, type2, arg2, type3, arg3, type4, arg4) { \
_HOOK_PRE_FILE(type, name, file) \
result = real_ ## name(arg1, arg2, arg3, arg4); \
_HOOK_POST_FILE(file) \
}
#define HOOK_VAR_FILE1(type, name, file, func, type1, arg1) \
HOOK_FUNC_VAR_SIMPLE1(type, name, type1, arg1) { \
va_list ap; \
va_start(ap, arg1); \
type result = func(arg1, ap); \
va_end(ap); \
return result; \
}
#define HOOK_VAR_FILE2(type, name, file, func, type1, arg1, type2, arg2) \
HOOK_FUNC_VAR_SIMPLE2(type, name, type1, arg1, type2, arg2) { \
va_list ap; \
va_start(ap, arg2); \
type result = func(arg1, arg2, ap); \
va_end(ap); \
return result; \
}
#define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
HOOK_FUNC_VAR_SIMPLE3(type, name, type1, arg1, type2, arg2, type3, arg3) { \
va_list ap; \
va_start(ap, arg3); \
type result = func(arg1, arg2, arg3, ap); \
va_end(ap); \
return result; \
}
#endif