testsuite/path.c

   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
  40 static inline bool need_trap(const char *path)
  41 {
  42         return path != NULL && path[0] == '/'
  43                 && !strstartswith(path, ABS_TOP_BUILDDIR);
  44 }
  45
  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
  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
  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