2 * Macros to hook functions.
4 * Copyright (C) 2013 Simon Ruderich
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 /* Hook the function by creating a function with the same name. With
24 * LD_PRELOAD our function will be preferred. The original function is stored
25 * in a static variable (real_*). */
27 #define _HOOK_PRE(type, name) \
29 int saved_errno = errno; \
30 DLSYM_FUNCTION(real_ ## name, #name);
31 #define _HOOK_PRE_FD(type, name, fd) \
33 _HOOK_PRE_FD_(type, name, fd)
34 #define _HOOK_PRE_FD_(type, name, fd) \
35 _HOOK_PRE(type, name) \
36 handle = check_handle_fd(fd); \
38 handle_fd_pre(fd, handle); \
41 #define _HOOK_PRE_FILE(type, name, file) \
43 _HOOK_PRE(type, name) \
44 handle = check_handle_fd(fileno(file)); \
46 handle_file_pre(file, handle); \
49 /* Save and restore the errno to make sure we return the errno of the original
51 #define _HOOK_POST_FD_(fd) \
53 saved_errno = errno; \
54 handle_fd_post(fd, handle); \
55 errno = saved_errno; \
57 #define _HOOK_POST_FD(fd) \
60 #define _HOOK_POST_FILE(file) \
62 saved_errno = errno; \
63 handle_file_post(file, handle); \
64 errno = saved_errno; \
69 #define HOOK_VOID1(type, name, fd, type1, arg1) \
70 static type (*real_ ## name)(type1); \
71 type name(type1 arg1) { \
72 _HOOK_PRE_FD_(type, name, fd) \
73 real_ ## name(arg1); \
77 #define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
78 static type (*real_ ## name)(type1, type2, type3); \
79 type name(type1 arg1, type2 arg2, type3 arg3) { \
80 _HOOK_PRE_FD(type, name, fd) \
81 result = real_ ## name(arg1, arg2, arg3); \
85 #define HOOK_FILE1(type, name, file, type1, arg1) \
86 static type (*real_ ## name)(type1); \
87 type name(type1 arg1) { \
88 _HOOK_PRE_FILE(type, name, file) \
89 result = real_ ## name(arg1); \
90 _HOOK_POST_FILE(file) \
92 #define HOOK_FILE2(type, name, file, type1, arg1, type2, arg2) \
93 static type (*real_ ## name)(type1, type2); \
94 type name(type1 arg1, type2 arg2) { \
95 _HOOK_PRE_FILE(type, name, file) \
96 result = real_ ## name(arg1, arg2); \
97 _HOOK_POST_FILE(file) \
99 #define HOOK_FILE3(type, name, file, type1, arg1, type2, arg2, type3, arg3) \
100 static type (*real_ ## name)(type1, type2, type3); \
101 type name(type1 arg1, type2 arg2, type3 arg3) { \
102 _HOOK_PRE_FILE(type, name, file) \
103 result = real_ ## name(arg1, arg2, arg3); \
104 _HOOK_POST_FILE(file) \
106 #define HOOK_FILE4(type, name, file, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
107 static type (*real_ ## name)(type1, type2, type3, type4); \
108 type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
109 _HOOK_PRE_FILE(type, name, file) \
110 result = real_ ## name(arg1, arg2, arg3, arg4); \
111 _HOOK_POST_FILE(file) \
114 #define HOOK_VAR_FILE1(type, name, file, func, type1, arg1) \
115 static type (*real_ ## func)(type1, va_list); \
116 type name(type1 arg1, ...) { \
118 _HOOK_PRE_FILE(type, func, file) \
119 va_start(ap, arg1); \
120 result = real_ ## func(arg1, ap); \
122 _HOOK_POST_FILE(file) \
124 #define HOOK_VAR_FILE2(type, name, file, func, type1, arg1, type2, arg2) \
125 static type (*real_ ## func)(type1, type2, va_list); \
126 type name(type1 arg1, type2 arg2, ...) { \
128 _HOOK_PRE_FILE(type, func, file) \
129 va_start(ap, arg2); \
130 result = real_ ## func(arg1, arg2, ap); \
132 _HOOK_POST_FILE(file) \
134 #define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
135 static type (*real_ ## func)(type1, type2, type3, va_list); \
136 type name(type1 arg1, type2 arg2, type3 arg3, ...) \
139 _HOOK_PRE_FILE(type, func, file) \
140 va_start(ap, arg3); \
141 result = real_ ## func(arg1, arg2, arg3, ap); \
143 _HOOK_POST_FILE(file) \