testsuite/path.c

   1 /*
   2  * Copyright (C) 2012  ProFUSION embedded systems
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (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
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <assert.h>
  19 #include <errno.h>
  20 #include <dirent.h>
  21 #include <fcntl.h>
  22 #include <dlfcn.h>
  23 #include <limits.h>
  24 #include <stdlib.h>
  25 #include <stdarg.h>
  26 #include <string.h>
  27 #include <stdio.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <unistd.h>
  31
  32 #include "testsuite.h"
  33
  34 static void *nextlib;
  35 static const char *rootpath;
  36 static size_t rootpathlen;
  37
  38 static inline bool need_trap(const char *path)
  39 {
  40         return path != NULL && path[0] == '/';
  41 }
  42
  43 static const char *trap_path(const char *path, char buf[PATH_MAX * 2])
  44 {
  45         size_t len;
  46
  47         if (!need_trap(path))
  48                 return path;
  49
  50         len = strlen(path);
  51
  52         if (len + rootpathlen > PATH_MAX * 2) {
  53                 errno = ENAMETOOLONG;
  54                 return NULL;
  55         }
  56
  57         memcpy(buf, rootpath, rootpathlen);
  58         strcpy(buf + rootpathlen, path);
  59         return buf;
  60 }
  61
  62 static bool get_rootpath(const char *f)
  63 {
  64         if (rootpath != NULL)
  65                 return true;
  66
  67         rootpath = getenv(S_TC_ROOTFS);
  68         if (rootpath == NULL) {
  69                 ERR("TRAP %s(): missing export %s?\n", f, S_TC_ROOTFS);
  70                 errno = ENOENT;
  71                 return false;
  72         }
  73
  74         rootpathlen = strlen(rootpath);
  75
  76         return true;
  77 }
  78
  79 static void *get_libc_func(const char *f)
  80 {
  81         void *fp;
  82
  83         if (nextlib == NULL) {
  84 #ifdef RTLD_NEXT
  85                 nextlib = RTLD_NEXT;
  86 #else
  87                 nextlib = dlopen("libc.so.6", RTLD_LAZY);
  88 #endif
  89         }
  90
  91         fp = dlsym(nextlib, f);
  92         assert(fp);
  93
  94         return fp;
  95 }
  96
  97 TS_EXPORT FILE *fopen(const char *path, const char *mode)
  98 {
  99         const char *p;
 100         char buf[PATH_MAX * 2];
 101         static int (*_fopen)(const char *path, const char *mode);
 102
 103         if (!get_rootpath(__func__))
 104                 return NULL;
 105
 106         _fopen = get_libc_func("fopen");
 107
 108         p = trap_path(path, buf);
 109         if (p == NULL)
 110                 return NULL;
 111
 112         return (void *) (long) (*_fopen)(p, mode);
 113 }
 114
 115 TS_EXPORT int open(const char *path, int flags, ...)
 116 {
 117         const char *p;
 118         char buf[PATH_MAX * 2];
 119         static int (*_open)(const char *path, int flags, ...);
 120
 121         if (!get_rootpath(__func__))
 122                 return -1;
 123
 124         _open = get_libc_func("open");
 125         p = trap_path(path, buf);
 126         if (p == NULL)
 127                 return -1;
 128
 129         if (flags & O_CREAT) {
 130                 mode_t mode;
 131                 va_list ap;
 132
 133                 va_start(ap, flags);
 134                 mode = va_arg(ap, mode_t);
 135                 va_end(ap);
 136                 _open(p, flags, mode);
 137         }
 138
 139         return _open(p, flags);
 140 }
 141
 142 TS_EXPORT int stat(const char *path, struct stat *st)
 143 {
 144         const char *p;
 145         char buf[PATH_MAX * 2];
 146         static int (*_stat)(const char *path, struct stat *buf);
 147
 148         if (!get_rootpath(__func__))
 149                 return -1;
 150
 151         _stat = get_libc_func("stat");
 152
 153         p = trap_path(path, buf);
 154         if (p == NULL)
 155                 return -1;
 156
 157         return _stat(p, st);
 158 }
 159
 160 #ifdef HAVE___XSTAT
 161 TS_EXPORT int __xstat(int ver, const char *path, struct stat *st)
 162 {
 163         const char *p;
 164         char buf[PATH_MAX * 2];
 165         static int (*_xstat)(int __ver, const char *__filename,
 166                                                 struct stat *__stat_buf);
 167
 168         if (!get_rootpath(__func__))
 169                 return -1;
 170
 171         _xstat = get_libc_func("__xstat");
 172
 173         p = trap_path(path, buf);
 174         if (p == NULL)
 175                 return -1;
 176
 177         return _xstat(ver, p, st);
 178 }
 179 #endif
 180
 181 TS_EXPORT int access(const char *path, int mode)
 182 {
 183         const char *p;
 184         char buf[PATH_MAX * 2];
 185         static int (*_access)(const char *path, int mode);
 186
 187         if (!get_rootpath(__func__))
 188                 return -1;
 189
 190         _access = get_libc_func("access");
 191
 192         p = trap_path(path, buf);
 193         if (p == NULL)
 194                 return -1;
 195
 196         return _access(p, mode);
 197 }
 198
 199 TS_EXPORT DIR *opendir(const char *path)
 200 {
 201         const char *p;
 202         char buf[PATH_MAX * 2];
 203         static int (*_opendir)(const char *path);
 204
 205         if (!get_rootpath(__func__))
 206                 return NULL;
 207
 208         _opendir = get_libc_func("opendir");
 209
 210         p = trap_path(path, buf);
 211         if (p == NULL)
 212                 return NULL;
 213
 214         return (void *)(long)(*_opendir)(p);
 215 }