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 handle = check_handle_fd(fd); \
35 handle_fd_pre(fd, handle); \
37 #define _HOOK_PRE_FILE(type, name, file) \
38 _HOOK_PRE(type, name) \
39 handle = check_handle_fd(fileno(file)); \
41 handle_file_pre(file, handle); \
43 /* Save and restore the errno to make sure we return the errno of the original
45 #define _HOOK_POST_FD(fd) \
47 int saved_errno = errno; \
48 handle_fd_post(fd, handle); \
49 errno = saved_errno; \
52 #define _HOOK_POST_FILE(file) \
54 int saved_errno = errno; \
55 handle_file_post(file, handle); \
56 errno = saved_errno; \
61 #define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
62 static type (*real_ ## name)(type1, type2, type3); \
63 type name(type1 arg1, type2 arg2, type3 arg3) { \
64 _HOOK_PRE_FD(type, name, fd) \
65 result = real_ ## name(arg1, arg2, arg3); \
69 #define HOOK_FILE1(type, name, file, type1, arg1) \
70 static type (*real_ ## name)(type1); \
71 type name(type1 arg1) { \
72 _HOOK_PRE_FILE(type, name, file) \
73 result = real_ ## name(arg1); \
74 _HOOK_POST_FILE(file) \
76 #define HOOK_FILE2(type, name, file, type1, arg1, type2, arg2) \
77 static type (*real_ ## name)(type1, type2); \
78 type name(type1 arg1, type2 arg2) { \
79 _HOOK_PRE_FILE(type, name, file) \
80 result = real_ ## name(arg1, arg2); \
81 _HOOK_POST_FILE(file) \
83 #define HOOK_FILE3(type, name, file, type1, arg1, type2, arg2, type3, arg3) \
84 static type (*real_ ## name)(type1, type2, type3); \
85 type name(type1 arg1, type2 arg2, type3 arg3) { \
86 _HOOK_PRE_FILE(type, name, file) \
87 result = real_ ## name(arg1, arg2, arg3); \
88 _HOOK_POST_FILE(file) \
90 #define HOOK_FILE4(type, name, file, type1, arg1, type2, arg2, type3, arg3, type4, arg4) \
91 static type (*real_ ## name)(type1, type2, type3, type4); \
92 type name(type1 arg1, type2 arg2, type3 arg3, type4 arg4) { \
93 _HOOK_PRE_FILE(type, name, file) \
94 result = real_ ## name(arg1, arg2, arg3, arg4); \
95 _HOOK_POST_FILE(file) \
98 #define HOOK_VAR_FILE1(type, name, file, func, type1, arg1) \
99 static type (*real_ ## func)(type1, va_list); \
100 type name(type1 arg1, ...) { \
102 _HOOK_PRE_FILE(type, func, file) \
103 va_start(ap, arg1); \
104 result = real_ ## func(arg1, ap); \
106 _HOOK_POST_FILE(file) \
108 #define HOOK_VAR_FILE2(type, name, file, func, type1, arg1, type2, arg2) \
109 static type (*real_ ## func)(type1, type2, va_list); \
110 type name(type1 arg1, type2 arg2, ...) { \
112 _HOOK_PRE_FILE(type, func, file) \
113 va_start(ap, arg2); \
114 result = real_ ## func(arg1, arg2, ap); \
116 _HOOK_POST_FILE(file) \
118 #define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
119 static type (*real_ ## func)(type1, type2, type3, va_list); \
120 type name(type1 arg1, type2 arg2, type3 arg3, ...) \
123 _HOOK_PRE_FILE(type, func, file) \
124 va_start(ap, arg3); \
125 result = real_ ## func(arg1, arg2, arg3, ap); \
127 _HOOK_POST_FILE(file) \