source3/modules/vfs_error_inject.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Samba VFS module for error injection in VFS calls
   4  *  Copyright (C) Christof Schmitt 2017
   5  *
   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.
  10  *
  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.
  15  *
  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/>.
  18  */
  19
  20 #include "includes.h"
  21 #include "smbd/smbd.h"
  22
  23 #undef DBGC_CLASS
  24 #define DBGC_CLASS DBGC_VFS
  25
  26 struct unix_error_map {
  27         const char *err_str;
  28         int error;
  29 } unix_error_map_array[] = {
  30         {       "ESTALE",       ESTALE  },
  31 };
  32
  33 static int find_unix_error_from_string(const char *err_str)
  34 {
  35         int i;
  36
  37         for (i = 0; i < ARRAY_SIZE(unix_error_map_array); i++) {
  38                 struct unix_error_map *m = &unix_error_map_array[i];
  39
  40                 if (strequal(err_str, m->err_str)) {
  41                         return m->error;
  42                 }
  43         }
  44
  45         return 0;
  46 }
  47
  48 static int inject_unix_error(const char *vfs_func, vfs_handle_struct *handle)
  49 {
  50         const char *err_str;
  51
  52         err_str = lp_parm_const_string(SNUM(handle->conn),
  53                                        "error_inject", vfs_func, NULL);
  54
  55         if (err_str != NULL) {
  56                 int error;
  57
  58                 error = find_unix_error_from_string(err_str);
  59                 if (error != 0) {
  60                         DBG_WARNING("Returning error %s for VFS function %s\n",
  61                                     err_str, vfs_func);
  62                         return error;
  63                 }
  64
  65                 if (strequal(err_str, "panic")) {
  66                         DBG_ERR("Panic in VFS function %s\n", vfs_func);
  67                         smb_panic("error_inject");
  68                 }
  69
  70                 DBG_ERR("Unknown error inject %s requested "
  71                         "for vfs function %s\n", err_str, vfs_func);
  72         }
  73
  74         return 0;
  75 }
  76
  77 static int vfs_error_inject_chdir(vfs_handle_struct *handle,
  78                                   const struct smb_filename *smb_fname)
  79 {
  80         int error;
  81
  82         error = inject_unix_error("chdir", handle);
  83         if (error != 0) {
  84                 errno = error;
  85                 return -1;
  86         }
  87
  88         return SMB_VFS_NEXT_CHDIR(handle, smb_fname);
  89 }
  90
  91 static ssize_t vfs_error_inject_pwrite(vfs_handle_struct *handle,
  92                                        files_struct *fsp,
  93                                        const void *data,
  94                                        size_t n,
  95                                        off_t offset)
  96 {
  97         int error;
  98
  99         error = inject_unix_error("pwrite", handle);
 100         if (error != 0) {
 101                 errno = error;
 102                 return -1;
 103         }
 104
 105         return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 106 }
 107
 108 static struct vfs_fn_pointers vfs_error_inject_fns = {
 109         .chdir_fn = vfs_error_inject_chdir,
 110         .pwrite_fn = vfs_error_inject_pwrite,
 111 };
 112
 113 static_decl_vfs;
 114 NTSTATUS vfs_error_inject_init(TALLOC_CTX *ctx)
 115 {
 116         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "error_inject",
 117                                 &vfs_error_inject_fns);
 118 }