1 /*
2 * Copyright (C) 2012-2013 ProFUSION embedded systems
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include <assert.h>
19 #include <dirent.h>
20 #include <dlfcn.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <stdarg.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31
32 #include <shared/util.h>
33
34 #include "testsuite.h"
35
36 static void *nextlib;
37 static const char *rootpath;
38 static size_t rootpathlen;
39
need_trap(const char * path)40 static inline bool need_trap(const char *path)
41 {
42 return path != NULL && path[0] == '/'
43 && !strstartswith(path, ABS_TOP_BUILDDIR);
44 }
45
trap_path(const char * path,char buf[PATH_MAX * 2])46 static const char *trap_path(const char *path, char buf[PATH_MAX * 2])
47 {
48 size_t len;
49
50 if (!need_trap(path))
51 return path;
52
53 len = strlen(path);
54
55 if (len + rootpathlen > PATH_MAX * 2) {
56 errno = ENAMETOOLONG;
57 return NULL;
58 }
59
60 memcpy(buf, rootpath, rootpathlen);
61 strcpy(buf + rootpathlen, path);
62 return buf;
63 }
64
get_rootpath(const char * f)65 static bool get_rootpath(const char *f)
66 {
67 if (rootpath != NULL)
68 return true;
69
70 rootpath = getenv(S_TC_ROOTFS);
71 if (rootpath == NULL) {
72 ERR("TRAP %s(): missing export %s?\n", f, S_TC_ROOTFS);
73 errno = ENOENT;
74 return false;
75 }
76
77 rootpathlen = strlen(rootpath);
78
79 return true;
80 }
81
get_libc_func(const char * f)82 static void *get_libc_func(const char *f)
83 {
84 void *fp;
85
86 if (nextlib == NULL) {
87 #ifdef RTLD_NEXT
88 nextlib = RTLD_NEXT;
89 #else
90 nextlib = dlopen("libc.so.6", RTLD_LAZY);
91 #endif
92 }
93
94 fp = dlsym(nextlib, f);
95 assert(fp);
96
97 return fp;
98 }
99
100 /* wrapper template for a function with one "const char* path" argument */
101 #define WRAP_1ARG(rettype, failret, name) \
102 TS_EXPORT rettype name(const char *path) \
103 { \
104 const char *p; \
105 char buf[PATH_MAX * 2]; \
106 static rettype (*_fn)(const char*); \
107 \
108 if (!get_rootpath(__func__)) \
109 return failret; \
110 _fn = get_libc_func(#name); \
111 p = trap_path(path, buf); \
112 if (p == NULL) \
113 return failret; \
114 return (*_fn)(p); \
115 }
116
117 /* wrapper template for a function with "const char* path" and another argument */
118 #define WRAP_2ARGS(rettype, failret, name, arg2t) \
119 TS_EXPORT rettype name(const char *path, arg2t arg2) \
120 { \
121 const char *p; \
122 char buf[PATH_MAX * 2]; \
123 static rettype (*_fn)(const char*, arg2t arg2); \
124 \
125 if (!get_rootpath(__func__)) \
126 return failret; \
127 _fn = get_libc_func(#name); \
128 p = trap_path(path, buf); \
129 if (p == NULL) \
130 return failret; \
131 return (*_fn)(p, arg2); \
132 }
133
134 /* wrapper template for open family */
135 #define WRAP_OPEN(suffix) \
136 TS_EXPORT int open ## suffix (const char *path, int flags, ...) \
137 { \
138 const char *p; \
139 char buf[PATH_MAX * 2]; \
140 static int (*_fn)(const char *path, int flags, ...); \
141 \
142 if (!get_rootpath(__func__)) \
143 return -1; \
144 _fn = get_libc_func("open" #suffix); \
145 p = trap_path(path, buf); \
146 if (p == NULL) \
147 return -1; \
148 \
149 if (flags & O_CREAT) { \
150 mode_t mode; \
151 va_list ap; \
152 \
153 va_start(ap, flags); \
154 mode = va_arg(ap, mode_t); \
155 va_end(ap); \
156 return _fn(p, flags, mode); \
157 } \
158 \
159 return _fn(p, flags); \
160 }
161
162 /* wrapper template for __xstat family */
163 #define WRAP_VERSTAT(prefix, suffix) \
164 TS_EXPORT int prefix ## stat ## suffix (int ver, \
165 const char *path, \
166 struct stat ## suffix *st) \
167 { \
168 const char *p; \
169 char buf[PATH_MAX * 2]; \
170 static int (*_fn)(int ver, const char *path, \
171 struct stat ## suffix *); \
172 _fn = get_libc_func(#prefix "stat" #suffix); \
173 \
174 if (!get_rootpath(__func__)) \
175 return -1; \
176 p = trap_path(path, buf); \
177 if (p == NULL) \
178 return -1; \
179 \
180 return _fn(ver, p, st); \
181 }
182
183 WRAP_1ARG(DIR*, NULL, opendir);
184
185 WRAP_2ARGS(FILE*, NULL, fopen, const char*);
186 WRAP_2ARGS(int, -1, mkdir, mode_t);
187 WRAP_2ARGS(int, -1, access, int);
188 WRAP_2ARGS(int, -1, stat, struct stat*);
189 WRAP_2ARGS(int, -1, lstat, struct stat*);
190 #ifndef _FILE_OFFSET_BITS
191 WRAP_2ARGS(int, -1, stat64, struct stat64*);
192 WRAP_2ARGS(int, -1, lstat64, struct stat64*);
193 WRAP_OPEN(64);
194 #endif
195
196 WRAP_OPEN();
197
198 #ifdef HAVE___XSTAT
199 WRAP_VERSTAT(__x,);
200 WRAP_VERSTAT(__lx,);
201 #ifndef _FILE_OFFSET_BITS
202 WRAP_VERSTAT(__x,64);
203 WRAP_VERSTAT(__lx,64);
204 #endif
205 #endif
206