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 DLSYM_FUNCTION(real_ ## name, #name);
30 #define _HOOK_PRE_FD(type, name, fd) \
32 _HOOK_PRE_FD_(type, name, fd)
33 #define _HOOK_PRE_FD_(type, name, fd) \
34 _HOOK_PRE(type, name) \
35 handle = check_handle_fd(fd); \
37 handle_fd_pre(fd, handle); \
39 #define _HOOK_PRE_FILE(type, name, file) \
41 _HOOK_PRE(type, name) \
42 handle = check_handle_fd(fileno(file)); \
44 handle_file_pre(file, handle); \
46 /* Save and restore the errno to make sure we return the errno of the original
48 #define _HOOK_POST_FD_(fd) \
50 int saved_errno = errno; \
51 handle_fd_post(fd, handle); \
52 errno = saved_errno; \
54 #define _HOOK_POST_FD(fd) \
57 #define _HOOK_POST_FILE(file) \
59 int saved_errno = errno; \
60 handle_file_post(file, handle); \
61 errno = saved_errno; \
66 #define HOOK_VOID1(type, name, fd, type1, arg1) \
67 static type (*real_ ## name)(type1); \
68 type name(type1 arg1) { \
69 _HOOK_PRE_FD_(type, name, fd) \
70 real_ ## name(arg1); \
74 #define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
75 static type (*real_ ## name)(type1, type2, type3); \
76 type name(type1 arg1, type2 arg2, type3 arg3) { \
77 _HOOK_PRE_FD(type, name, fd) \
78 result = real_ ## name(arg1, arg2, arg3); \
82 #define HOOK_FILE1(type, name, file, type1, arg1) \
83 static type (*real_ ## name)(type1); \
84 type name(type1 arg1) { \
85 _HOOK_PRE_FILE(type, name, file) \
86 result = real_ ## name(arg1); \
87 _HOOK_POST_FILE(file) \
89 #define HOOK_FILE2(type, name, file, type1, arg1, type2, arg2) \
90 static type (*real_ ## name)(type1, type2); \
91 type name(type1 arg1, type2 arg2) { \
92 _HOOK_PRE_FILE(type, name, file) \
93 result = real_ ## name(arg1, arg2); \
94 _HOOK_POST_FILE(file) \
96 #define HOOK_FILE3(type, name, file, type1, arg1, type2, arg2, type3, arg3) \
97 static type (*real_ ## name)(type1, type2, type3); \
98 type name(type1 arg1, type2 arg2, type3 arg3) { \
99 _HOOK_PRE_FILE(type, name, file) \
100 result = real_ ## name(arg1, arg2, arg3); \
101 _HOOK_POST_FILE(file) \
103 #define HOOK_FILE4(type, name, file, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
104 static type (*real_ ## name)(type1, type2, type3, type4); \
105 type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
106 _HOOK_PRE_FILE(type, name, file) \
107 result = real_ ## name(arg1, arg2, arg3, arg4); \
108 _HOOK_POST_FILE(file) \
111 #define HOOK_VAR_FILE1(type, name, file, func, type1, arg1) \
112 static type (*real_ ## func)(type1, va_list); \
113 type name(type1 arg1, ...) { \
115 _HOOK_PRE_FILE(type, func, file) \
116 va_start(ap, arg1); \
117 result = real_ ## func(arg1, ap); \
119 _HOOK_POST_FILE(file) \
121 #define HOOK_VAR_FILE2(type, name, file, func, type1, arg1, type2, arg2) \
122 static type (*real_ ## func)(type1, type2, va_list); \
123 type name(type1 arg1, type2 arg2, ...) { \
125 _HOOK_PRE_FILE(type, func, file) \
126 va_start(ap, arg2); \
127 result = real_ ## func(arg1, arg2, ap); \
129 _HOOK_POST_FILE(file) \
131 #define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
132 static type (*real_ ## func)(type1, type2, type3, va_list); \
133 type name(type1 arg1, type2 arg2, type3 arg3, ...) \
136 _HOOK_PRE_FILE(type, func, file) \
137 va_start(ap, arg3); \
138 result = real_ ## func(arg1, arg2, arg3, ap); \
140 _HOOK_POST_FILE(file) \