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         {       "EBADF",        EBADF   },
  32 };
  33
  34 static int find_unix_error_from_string(const char *err_str)
  35 {
  36         int i;
  37
  38         for (i = 0; i < ARRAY_SIZE(unix_error_map_array); i++) {
  39                 struct unix_error_map *m = &unix_error_map_array[i];
  40
  41                 if (strequal(err_str, m->err_str)) {
  42                         return m->error;
  43                 }
  44         }
  45
  46         return 0;
  47 }
  48
  49 static int inject_unix_error(const char *vfs_func, vfs_handle_struct *handle)
  50 {
  51         const char *err_str;
  52
  53         err_str = lp_parm_const_string(SNUM(handle->conn),
  54                                        "error_inject", vfs_func, NULL);
  55
  56         if (err_str != NULL) {
  57                 int error;
  58
  59                 error = find_unix_error_from_string(err_str);
  60                 if (error != 0) {
  61                         DBG_WARNING("Returning error %s for VFS function %s\n",
  62                                     err_str, vfs_func);
  63                         return error;
  64                 }
  65
  66                 if (strequal(err_str, "panic")) {
  67                         DBG_ERR("Panic in VFS function %s\n", vfs_func);
  68                         smb_panic("error_inject");
  69                 }
  70
  71                 DBG_ERR("Unknown error inject %s requested "
  72                         "for vfs function %s\n", err_str, vfs_func);
  73         }
  74
  75         return 0;
  76 }
  77
  78 static int vfs_error_inject_chdir(vfs_handle_struct *handle,
  79                                   const struct smb_filename *smb_fname)
  80 {
  81         int error;
  82
  83         error = inject_unix_error("chdir", handle);
  84         if (error != 0) {
  85                 errno = error;
  86                 return -1;
  87         }
  88
  89         return SMB_VFS_NEXT_CHDIR(handle, smb_fname);
  90 }
  91
  92 static ssize_t vfs_error_inject_pwrite(vfs_handle_struct *handle,
  93                                        files_struct *fsp,
  94                                        const void *data,
  95                                        size_t n,
  96                                        off_t offset)
  97 {
  98         int error;
  99
 100         error = inject_unix_error("pwrite", handle);
 101         if (error != 0) {
 102                 errno = error;
 103                 return -1;
 104         }
 105
 106         return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 107 }
 108
 109 static struct vfs_fn_pointers vfs_error_inject_fns = {
 110         .chdir_fn = vfs_error_inject_chdir,
 111         .pwrite_fn = vfs_error_inject_pwrite,
 112 };
 113
 114 static_decl_vfs;
 115 NTSTATUS vfs_error_inject_init(TALLOC_CTX *ctx)
 116 {
 117         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "error_inject",
 118                                 &vfs_error_inject_fns);
 119 }