tests/virusbmock.c

   1 /*
   2  * Copyright (C) 2014 Red Hat, Inc.
   3  *
   4  * This library 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 library 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
  16  * <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <config.h>
  20
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <dirent.h>
  24 #include <dlfcn.h>
  25 #include <fcntl.h>
  26
  27 #include "viralloc.h"
  28 #include "virfile.h"
  29 #include "virstring.h"
  30 #include "virusb.h"
  31
  32 #define USB_SYSFS "/sys/bus/usb"
  33 #define FAKE_USB_SYSFS "virusbtestdata/sys_bus_usb"
  34
  35 static int (*realopen)(const char *pathname, int flags, ...);
  36 static DIR *(*realopendir)(const char *name);
  37
  38 static void init_syms(void)
  39 {
  40     if (realopen)
  41         return;
  42
  43     realopen = dlsym(RTLD_NEXT, "open");
  44     realopendir = dlsym(RTLD_NEXT, "opendir");
  45     if (!realopen || !realopendir) {
  46         fprintf(stderr, "Error getting symbols");
  47         abort();
  48     }
  49 }
  50
  51 static char *get_fake_path(const char *real_path)
  52 {
  53     const char *p = NULL;
  54     char *path = NULL;
  55
  56     if ((p = STRSKIP(real_path, USB_SYSFS)) &&
  57         virAsprintfQuiet(&path, "%s/%s/%s", abs_srcdir, FAKE_USB_SYSFS, p) < 0)
  58         goto error;
  59     else if (!p && VIR_STRDUP_QUIET(path, real_path) < 0)
  60         goto error;
  61
  62     return path;
  63
  64  error:
  65     errno = ENOMEM;
  66     return NULL;
  67 }
  68
  69 DIR *opendir(const char *name)
  70 {
  71     char *path;
  72     DIR* ret;
  73
  74     init_syms();
  75
  76     path = get_fake_path(name);
  77
  78     ret = realopendir(path);
  79     VIR_FREE(path);
  80     return ret;
  81 }
  82
  83 int open(const char *pathname, int flags, ...)
  84 {
  85     char *path;
  86     int ret;
  87     va_list ap;
  88     mode_t mode = 0;
  89
  90     init_syms();
  91
  92     path = get_fake_path(pathname);
  93     if (!path)
  94         return -1;
  95
  96     /* The mode argument is mandatory when O_CREAT is set in flags,
  97      * otherwise the argument is ignored.
  98      */
  99     if (flags & O_CREAT) {
 100         va_start(ap, flags);
 101         mode = (mode_t) va_arg(ap, int);
 102         va_end(ap);
 103     }
 104
 105     ret = realopen(path, flags, mode);
 106
 107     VIR_FREE(path);
 108     return ret;
 109 }