source3/modules/vfs_virusfilter_clamav.c

   1 /*
   2    Samba-VirusFilter VFS modules
   3    ClamAV clamd support
   4    Copyright (C) 2010-2016 SATOH Fumiyasu @ OSS Technology Corp., Japan
   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 /* Default values for standard "extra" configuration variables */
  21
  22 #ifdef CLAMAV_DEFAULT_SOCKET_PATH
  23 #  define VIRUSFILTER_DEFAULT_SOCKET_PATH       CLAMAV_DEFAULT_SOCKET_PATH
  24 #else
  25 #  define VIRUSFILTER_DEFAULT_SOCKET_PATH       "/var/run/clamav/clamd.ctl"
  26 #endif
  27
  28 #include "modules/vfs_virusfilter_common.h"
  29 #include "modules/vfs_virusfilter_utils.h"
  30
  31 static int virusfilter_clamav_connect(struct vfs_handle_struct *handle,
  32                                       struct virusfilter_config *config,
  33                                       const char *svc,
  34                                       const char *user)
  35 {
  36
  37         /* To use clamd "zXXXX" commands */
  38         virusfilter_io_set_writel_eol(config->io_h, "\0", 1);
  39         virusfilter_io_set_readl_eol(config->io_h, "\0", 1);
  40
  41         return 0;
  42 }
  43
  44 static virusfilter_result virusfilter_clamav_scan_init(
  45         struct virusfilter_config *config)
  46 {
  47         struct virusfilter_io_handle *io_h = config->io_h;
  48         bool ok;
  49
  50         DBG_INFO("clamd: Connecting to socket: %s\n",
  51                  config->socket_path);
  52
  53         become_root();
  54         ok = virusfilter_io_connect_path(io_h, config->socket_path);
  55         unbecome_root();
  56
  57         if (!ok) {
  58                 DBG_ERR("clamd: Connecting to socket failed: %s: %s\n",
  59                         config->socket_path, strerror(errno));
  60                 return VIRUSFILTER_RESULT_ERROR;
  61         }
  62
  63         DBG_INFO("clamd: Connected\n");
  64
  65         return VIRUSFILTER_RESULT_OK;
  66 }
  67
  68 static void virusfilter_clamav_scan_end(
  69         struct virusfilter_config *config)
  70 {
  71         struct virusfilter_io_handle *io_h = config->io_h;
  72
  73         DBG_INFO("clamd: Disconnecting\n");
  74
  75         virusfilter_io_disconnect(io_h);
  76 }
  77
  78 static virusfilter_result virusfilter_clamav_scan(
  79         struct vfs_handle_struct *handle,
  80         struct virusfilter_config *config,
  81         const struct files_struct *fsp,
  82         char **reportp)
  83 {
  84         char *cwd_fname = fsp->conn->cwd_fname->base_name;
  85         const char *fname = fsp->fsp_name->base_name;
  86         size_t filepath_len = strlen(cwd_fname) + 1 /* slash */ + strlen(fname);
  87         struct virusfilter_io_handle *io_h = config->io_h;
  88         virusfilter_result result = VIRUSFILTER_RESULT_CLEAN;
  89         char *report = NULL;
  90         char *reply = NULL;
  91         char *reply_msg = NULL;
  92         char *reply_token;
  93         bool ok;
  94
  95         DBG_INFO("Scanning file: %s/%s\n", cwd_fname, fname);
  96
  97         ok = virusfilter_io_writefl_readl(io_h, &reply, "zSCAN %s/%s",
  98                                           cwd_fname, fname);
  99         if (!ok) {
 100                 DBG_ERR("clamd: zSCAN: I/O error: %s\n", strerror(errno));
 101                 result = VIRUSFILTER_RESULT_ERROR;
 102                 report = talloc_asprintf(talloc_tos(),
 103                                          "Scanner I/O error: %s\n",
 104                                          strerror(errno));
 105                 goto virusfilter_clamav_scan_return;
 106         }
 107
 108         if (reply[filepath_len] != ':' ||
 109             reply[filepath_len+1] != ' ')
 110         {
 111                 DBG_ERR("clamd: zSCAN: Invalid reply: %s\n",
 112                         reply);
 113                 result = VIRUSFILTER_RESULT_ERROR;
 114                 report = talloc_asprintf(talloc_tos(),
 115                                          "Scanner communication error");
 116                 goto virusfilter_clamav_scan_return;
 117         }
 118         reply_msg = reply + filepath_len + 2;
 119
 120         reply_token = strrchr(reply, ' ');
 121
 122         if (reply_token == NULL) {
 123                 DBG_ERR("clamd: zSCAN: Invalid reply: %s\n",
 124                         reply);
 125                 result = VIRUSFILTER_RESULT_ERROR;
 126                 report = talloc_asprintf(talloc_tos(),
 127                                          "Scanner communication error");
 128                 goto virusfilter_clamav_scan_return;
 129         }
 130         *reply_token = '\0';
 131         reply_token++;
 132
 133         if (strcmp(reply_token, "OK") == 0) {
 134
 135                 /* <FILEPATH>: OK */
 136                 result = VIRUSFILTER_RESULT_CLEAN;
 137                 report = talloc_asprintf(talloc_tos(), "Clean");
 138         } else if (strcmp(reply_token, "FOUND") == 0) {
 139
 140                 /* <FILEPATH>: <REPORT> FOUND */
 141                 result = VIRUSFILTER_RESULT_INFECTED;
 142                 report = talloc_strdup(talloc_tos(), reply_msg);
 143         } else if (strcmp(reply_token, "ERROR") == 0) {
 144
 145                 /* <FILEPATH>: <REPORT> ERROR */
 146                 DBG_ERR("clamd: zSCAN: Error: %s\n", reply_msg);
 147                 result = VIRUSFILTER_RESULT_ERROR;
 148                 report = talloc_asprintf(talloc_tos(),
 149                                          "Scanner error: %s\t", reply_msg);
 150         } else {
 151                 DBG_ERR("clamd: zSCAN: Invalid reply: %s\n", reply_token);
 152                 result = VIRUSFILTER_RESULT_ERROR;
 153                 report = talloc_asprintf(talloc_tos(),
 154                                          "Scanner communication error");
 155         }
 156
 157 virusfilter_clamav_scan_return:
 158         TALLOC_FREE(reply);
 159         if (report == NULL) {
 160                 *reportp = talloc_asprintf(talloc_tos(),
 161                                            "Scanner report memory error");
 162         } else {
 163                 *reportp = report;
 164         }
 165
 166         return result;
 167 }
 168
 169 static struct virusfilter_backend_fns virusfilter_backend_clamav = {
 170         .connect = virusfilter_clamav_connect,
 171         .disconnect = NULL,
 172         .scan_init = virusfilter_clamav_scan_init,
 173         .scan = virusfilter_clamav_scan,
 174         .scan_end = virusfilter_clamav_scan_end,
 175 };
 176
 177 int virusfilter_clamav_init(struct virusfilter_config *config)
 178 {
 179         struct virusfilter_backend *backend = NULL;
 180
 181         if (config->socket_path == NULL) {
 182                 config->socket_path = VIRUSFILTER_DEFAULT_SOCKET_PATH;
 183         }
 184
 185         backend = talloc_zero(config, struct virusfilter_backend);
 186         if (backend == NULL) {
 187                 return -1;
 188         }
 189
 190         backend->fns = &virusfilter_backend_clamav;
 191         backend->name = "clamav";
 192
 193         config->backend = backend;
 194         return 0;
 195 }