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) \
30 DLSYM_FUNCTION(real_ ## name, #name);
31 #define _HOOK_PRE_FD(type, name, fd) \
32 _HOOK_PRE(type, name) \
33 _HOOK_PRE_FD_ALONE(type, name, fd)
34 #define _HOOK_PRE_FD_ALONE(type, name, fd) \
35 handle = check_handle_fd(fd); \
37 handle_fd_pre(fd, handle); \
39 #define _HOOK_PRE_FILE(type, name, file) \
40 _HOOK_PRE(type, name) \
41 handle = check_handle_fd(fileno(file)); \
43 handle_file_pre(file, handle); \
45 /* Save and restore the errno to make sure we return the errno of the original
47 #define _HOOK_POST_FD_ALONE(fd) \
49 int saved_errno = errno; \
50 handle_fd_post(fd, handle); \
51 errno = saved_errno; \
53 #define _HOOK_POST_FD(fd) \
54 _HOOK_POST_FD_ALONE(fd) \
56 #define _HOOK_POST_FILE(file) \
58 int saved_errno = errno; \
59 handle_file_post(file, handle); \
60 errno = saved_errno; \
65 #define HOOK_VOID1(type, name, fd, type1, arg1) \
66 static type (*real_ ## name)(type1); \
67 type name(type1 arg1) { \
69 DLSYM_FUNCTION(real_ ## name, #name); \
70 _HOOK_PRE_FD_ALONE(type, name, fd) \
71 real_ ## name(arg1); \
72 _HOOK_POST_FD_ALONE(fd) \
75 #define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
76 static type (*real_ ## name)(type1, type2, type3); \
77 type name(type1 arg1, type2 arg2, type3 arg3) { \
78 _HOOK_PRE_FD(type, name, fd) \
79 result = real_ ## name(arg1, arg2, arg3); \
83 #define HOOK_FILE1(type, name, file, type1, arg1) \
84 static type (*real_ ## name)(type1); \
85 type name(type1 arg1) { \
86 _HOOK_PRE_FILE(type, name, file) \
87 result = real_ ## name(arg1); \
88 _HOOK_POST_FILE(file) \
90 #define HOOK_FILE2(type, name, file, type1, arg1, type2, arg2) \
91 static type (*real_ ## name)(type1, type2); \
92 type name(type1 arg1, type2 arg2) { \
93 _HOOK_PRE_FILE(type, name, file) \
94 result = real_ ## name(arg1, arg2); \
95 _HOOK_POST_FILE(file) \
97 #define HOOK_FILE3(type, name, file, type1, arg1, type2, arg2, type3, arg3) \
98 static type (*real_ ## name)(type1, type2, type3); \
99 type name(type1 arg1, type2 arg2, type3 arg3) { \
100 _HOOK_PRE_FILE(type, name, file) \
101 result = real_ ## name(arg1, arg2, arg3); \
102 _HOOK_POST_FILE(file) \
104 #define HOOK_FILE4(type, name, file, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
105 static type (*real_ ## name)(type1, type2, type3, type4); \
106 type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
107 _HOOK_PRE_FILE(type, name, file) \
108 result = real_ ## name(arg1, arg2, arg3, arg4); \
109 _HOOK_POST_FILE(file) \
112 #define HOOK_VAR_FILE1(type, name, file, func, type1, arg1) \
113 static type (*real_ ## func)(type1, va_list); \
114 type name(type1 arg1, ...) { \
116 _HOOK_PRE_FILE(type, func, file) \
117 va_start(ap, arg1); \
118 result = real_ ## func(arg1, ap); \
120 _HOOK_POST_FILE(file) \
122 #define HOOK_VAR_FILE2(type, name, file, func, type1, arg1, type2, arg2) \
123 static type (*real_ ## func)(type1, type2, va_list); \
124 type name(type1 arg1, type2 arg2, ...) { \
126 _HOOK_PRE_FILE(type, func, file) \
127 va_start(ap, arg2); \
128 result = real_ ## func(arg1, arg2, ap); \
130 _HOOK_POST_FILE(file) \
132 #define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
133 static type (*real_ ## func)(type1, type2, type3, va_list); \
134 type name(type1 arg1, type2 arg2, type3 arg3, ...) \
137 _HOOK_PRE_FILE(type, func, file) \
138 va_start(ap, arg3); \
139 result = real_ ## func(arg1, arg2, arg3, ap); \
141 _HOOK_POST_FILE(file) \