/*
 * mod_clamav - ClamAV virus scanning module for ProFTPD
 * Copyright (c) 2005-2016, Joseph Benden <joe@thrallingpenguin.com>
 * Copyright (c) 2012-2013, TJ Saunders <tj@castaglia.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
 *
 * Furthermore, Joseph Benden gives permission to link this program with
 * ClamAV, and distribute the resulting executable, without including the
 * source code for ClamAV in the source distribution.
 *
 * ClamAV is available at http://www.clamav.net/
 *
 * Thanks to TJ Saunders for his helpful comments and suggestions!
 *
 * DO NOT EDIT THE LINE BELOW
 */
#include "conf.h"
#include "privs.h"
#include <libgen.h>
#include <sys/types.h>
#include "mod_clamav.h"

/**
 * Module version and declaration
 */
#define MOD_CLAMAV_VERSION "mod_clamav/0.14rc2"
module clamav_module;

/**
 * Global variables
 */
static int clamd_sockd = 0, is_remote = 0;
static char *clamd_host = NULL;
static int clamd_port = 0;
static unsigned long long clamd_minsize = 0, clamd_maxsize = 0;
static int clam_errno;
static int remove_on_failure = 0;
static const char *trace_channel = "clamav";

/**
 * Local declarations
 */
static unsigned long parse_nbytes(char *nbytes_str, char *units_str);
static int clamavd_result(int sockd, const char *abs_filename, const char *rel_filename);
static int clamavd_connect_check(int sockd);
static int clamavd_scan(int sockd, const char *abs_filename, const char *rel_filename);
static int clamavd_connect(void);

/**
 * Read the returned information from Clamavd.
 */
static int clamavd_result(int sockd, const char *abs_filename, const char *rel_filename) {
  int infected = 0, waserror = 0, ret;
  char buff[4096], *pt, *pt1;
  FILE *fd = 0;

  (void) pr_trace_msg("clamav", 1, "clamavd_result (sockd %d, abs_filename '%s', rel_filename '%s')", sockd, abs_filename, rel_filename);

  if ((fd=fdopen(dup(sockd), "r")) == NULL) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": error: Cant open descriptor for reading: %d",
               errno);
    return -1;
  }

  memset(buff, '\0', sizeof(buff));
  if (fgets(buff, sizeof(buff) - 1, fd)) {
    if (strstr(buff, "FOUND\n")) {
      const char *proto;

      ++infected;

      pt = strrchr(buff, ':');
      if (pt)
        *pt = 0;

      /* Delete the infected upload */
      /* TODO: delete only the hiddenstore file, not
         the actual file.
      */
      if ((ret=pr_fsio_unlink(rel_filename))!=0) {
        pr_log_pri(PR_LOG_ERR,
                   MOD_CLAMAV_VERSION ": notice: unlink() failed (%d): %s",
                   errno, strerror(errno));
      }

      /* clean up the response */
      pt += 2;
      pt1 = strstr(pt, " FOUND");
      if (pt1) {
        *pt1 = 0;
      }

      /* Generate a custom event for any listeners
       * (e.g. mod_ban) which might be listening. Pass
       * in the string containing the virus
       * information.
       */
      pr_event_generate("mod_clamav.virus-found", pt);

      /* Inform the client the file contained a
       * virus (only for FTP/FTPS connections.)
       */
      proto = pr_session_get_protocol(0);
      if (strncmp(proto, "ftp", 3) == 0 ||
          strncmp(proto, "ftps", 4) == 0) {
        pr_response_send(R_550, "Virus Detected and Removed: %s", pt);
      }

      /* Log the fact */
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": Virus '%s' found in '%s'", pt, abs_filename);
    } else if (strstr(buff, "ERROR\n") != NULL ||
               strstr(buff, "UNKNOWN COMMAND") != NULL) {
      char *err = buff, *errend;

      errend = strstr(err, " ERROR");
      if (errend) {
        *errend = 0;
      }
      errend = strstr(err, " UNKNOWN COMMAND");
      if (errend) {
        *errend = 0;
      }

      pr_log_pri(PR_LOG_ERR, MOD_CLAMAV_VERSION ": Clamd Error: %s", err);
      waserror = 1;

      pr_trace_msg("clamav", 1, "Clamd scanner was not able to function; please check that Clamd is functioning before filing a bug report.");
    }
  }
  fclose(fd);
  return infected ? infected : (waserror ? -1 : 0);
}

/**
 * Test the connection with Clamd.
 */
static int clamavd_connect_check(int sockd) {
  FILE *fd = NULL;
  char buff[32];

  (void) pr_trace_msg("clamav", 6, "clamavd_connect_check (sockd %d)",
                      sockd);

  if (sockd == -1)
    return 0;

  if (write(sockd, "PING\n", 5) <= 0) {
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Clamd did not accept PING (%d): %s",
                 errno, strerror(errno));
    close(sockd);
    clamd_sockd = -1;
    clam_errno = errno;
    return 0;
  }

  if ((fd = fdopen(dup(sockd), "r")) == NULL) {
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Clamd can not open descriptor for reading (%d): %s",
                 errno, strerror(errno));
    close(sockd);
    clamd_sockd = -1;
    clam_errno = errno;
    return 0;
  }

  if (fgets(buff, sizeof(buff), fd)) {
    if (strstr(buff, "PONG")) {
      fclose(fd);
      return 1;
    }
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Clamd return unknown response to PING: '%s'", buff);
  }

  pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Clamd did not respond to fgets (%d): %s",
               errno, strerror(errno));
  fclose(fd);
  close(sockd);
  clamd_sockd = -1;
  clam_errno = errno;
  return 0;
}

/**
 * Request Clamavd to perform a scan of the file contents.
 */
static int clamavd_scan_stream(int sockd, const char *abs_filename,
                               const char *rel_filename) {
  u_int32_t len = 0;
  char *buf;
  size_t bufsz = 4096;
  long res;
  FILE *fd;

  if (!clamavd_connect_check(sockd)) {
    if ((clamd_sockd = clamavd_connect()) < 0) {
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot re-connect to Clamd (%d): %s",
                 errno, strerror(errno));
      clam_errno = errno;
      return -1;
    }
    sockd = clamd_sockd;
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Successfully reconnected to Clamd.");
    clam_errno = 0;
  }

  if (write(sockd, "nINSTREAM\n", 10) <= 0) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": Cannot write to the Clamd socket: %d", errno);
    clam_errno = errno;
    return -1;
  }

  fd = fopen(rel_filename, "r");
  if (!fd) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": Cannot open file '%s' errno=%d.", rel_filename, errno);
    clam_errno = errno;
    return -1;
  }

  /* rewind file descriptor */
  fseek(fd, 0, SEEK_SET);

  buf = malloc(bufsz);
  if (!buf) {
    pr_log_pri(PR_LOG_CRIT, "Out of memory!");
    pr_session_end(1);
  }

  /* send file contents using protocol defined by Clamd */
  while ((res = fread(buf, 1, bufsz, fd)) > 0) {
    len = htonl(res);
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Streaming %" PR_LU " bytes (%d, %u) to Clamd.", res, len, sizeof(len));
    if (write(sockd, (void *) &len, sizeof(len)) <= 0) {
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": Cannot write byte count to Clamd socket: %d", errno);
      clam_errno = errno;
      fclose(fd);
      free(buf);
      return -1;
    }
    if (write(sockd, buf, res) != res) {
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": Cannot stream file to Clamd socket: %d", errno);
      clam_errno = errno;
      fclose(fd);
      free(buf);
      return -1;
    }
    if (feof(fd)) break;
  }
  fclose(fd);
  free(buf);

  /* send null length byte, to terminate stream */
  len = 0;
  if (write(sockd, (void *) &len, sizeof(len)) <= 0) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": Cannot write termination byte to Clamd socket: %d", errno);
    clam_errno = errno;
    return -1;
  }
  if (write(sockd, "\n", 1) <= 0) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": Cannot write terminating return. %d", errno);
  }

  /* interpret results */
  return clamavd_result(sockd, abs_filename, rel_filename);
}

/**
 * Request Clamavd to perform a scan.
 */
static int clamavd_scan(int sockd, const char *abs_filename,
                        const char *rel_filename) {
  char *scancmd = NULL;

  scancmd = calloc(strlen(abs_filename) + 20, sizeof(char));
  if (!scancmd) {
    pr_log_pri(PR_LOG_ERR, MOD_CLAMAV_VERSION ": error: Cannot allocate memory.");
    return -1;
  }

  (void) pr_trace_msg("clamav", 6, "abs_filename '%s' being scanned.",
                      abs_filename);

  sprintf(scancmd, "SCAN %s\n", abs_filename);

  if (!clamavd_connect_check(sockd)) {
    if ((clamd_sockd = clamavd_connect()) < 0) {
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot re-connect to Clamd (%d): %s",
                 errno, strerror(errno));
      clam_errno = errno;
      free(scancmd);
      scancmd = NULL;
      return -1;
    }
    sockd = clamd_sockd;

    (void) pr_trace_msg("clamav", 4, "Successfully reconnected to the ClamAV scanner.");

    clam_errno = 0;
  }

  if (write(sockd, scancmd, strlen(scancmd)) <= 0) {
    pr_log_pri(PR_LOG_ERR,
               MOD_CLAMAV_VERSION ": error: Cannot write to the Clamd socket: %d", errno);
    free(scancmd);
    scancmd = NULL;
    clam_errno = errno;
    return -1;
  }

  free(scancmd);
  scancmd = NULL;
  return clamavd_result(sockd, abs_filename, rel_filename);
}

/**
 * Connect a socket to ClamAVd.
 */
static int clamavd_connect(void) {
  struct sockaddr_un server;
  struct sockaddr_in server2;
  struct hostent *he;
  int sockd, *port;

  /**
   * We will set the global socket to non-connected, just in-case.
   */
  clamd_sockd = -1;

  memset((char*)&server, 0, sizeof(server));
  memset((char*)&server2, 0, sizeof(server2));

  clamd_host = (char *) get_param_ptr(CURRENT_CONF, "ClamLocalSocket", TRUE);
  if (!clamd_host) {
    clamd_host = (char *) get_param_ptr(CURRENT_CONF, "ClamServer", TRUE);
    if (!clamd_host) {
      pr_log_pri(PR_LOG_INFO,
                 MOD_CLAMAV_VERSION ": warning: No local socket or server was specified.");
      return -1;
    }
    is_remote = 1;
    if ((port = (int *) get_param_ptr(CURRENT_CONF, "ClamPort", TRUE)) <= 0)
      clamd_port = 3310;
    else
      clamd_port = *port;

    (void) pr_trace_msg("clamav", 4, "Connecting to remote ClamAV scanner on host '%s' and port %d.", clamd_host, clamd_port);
  } else {
    (void) pr_trace_msg("clamav", 4, "Connecting to local ClamAV scanner on unix socket '%s'.", clamd_host);
  }

  PRIVS_ROOT;

  if (is_remote == 0) {
    /* Local Socket */
    server.sun_family = AF_UNIX;
    strncpy(server.sun_path, clamd_host, sizeof(server.sun_path));

    if ((sockd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
      PRIVS_RELINQUISH;
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot create socket connection to Clamd (%d): %s",
                 errno, strerror(errno));
      clam_errno = errno;
      return -1;
    }

    if (connect(sockd, (struct sockaddr *)&server, sizeof(struct sockaddr_un)) < 0) {
      close(sockd);
      PRIVS_RELINQUISH;
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot connect to Clamd (%d): %s", errno, strerror(errno));
      clam_errno = errno;
      return -1;
    }
  } else {
    /* Remote Socket */
    server2.sin_family = AF_INET;
    server2.sin_port = htons(clamd_port);

    if ((sockd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
      PRIVS_RELINQUISH;
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot create socket connection Clamd (%d): %s",
                 errno, strerror(errno));
      clam_errno = errno;
      return -1;
    }

    if ((he = gethostbyname(clamd_host)) == 0) {
      close(sockd);
      PRIVS_RELINQUISH;
      pr_log_pri(PR_LOG_ERR, MOD_CLAMAV_VERSION ": error: Cannot resolve hostname '%s'", clamd_host);
      clam_errno = errno;
      return -1;
    }
    server2.sin_addr = *(struct in_addr *) he->h_addr_list[0];

    if (connect(sockd, (struct sockaddr *)&server2, sizeof(struct sockaddr_in)) < 0) {
      close(sockd);
      PRIVS_RELINQUISH;
      pr_log_pri(PR_LOG_ERR,
                 MOD_CLAMAV_VERSION ": error: Cannot connect to Clamd (%d): %s",
                 errno, strerror(errno));
      clam_errno = errno;
      return -1;
    }
  }

  PRIVS_RELINQUISH;

  clam_errno = 0;

  return sockd;
}

/**
 * Entry point of mod_xfer during an upload
 */
static int clamav_fsio_close(pr_fh_t *fh, int fd) {
  char *abs_path = NULL, *rel_path = NULL;
  struct stat st;
  int do_scan = FALSE, res;
  config_rec *c = NULL;
  unsigned long *minsize, *maxsize;

  /* We're only interested in STOR, APPE, and maybe STOU commands. */
  if (session.curr_cmd) {
    if (strcmp(session.curr_cmd, C_STOR) == 0 ||
        strcmp(session.curr_cmd, C_APPE) == 0 ||
        strcmp(session.curr_cmd, C_STOU) == 0) {
      do_scan = TRUE;
    }
  }

  if (!do_scan) {
    return close(fd);
  }

  /* Make sure the data is written to disk, so that the fstat(2) picks
   * up the size properly.
   */
  if (fsync(fd) < 0) {
    int xerrno = errno;

    pr_trace_msg(trace_channel, 9, "fsync(2) error on fd %d (path '%s'): %s",
                 fd, fh->fh_path, strerror(xerrno));

    errno = xerrno;
    return -1;
  }

  pr_fs_clear_cache();
  if (pr_fsio_fstat(fh, &st) < 0) {
    int xerrno = errno;

    pr_trace_msg(trace_channel, 9, "pr_fsio_fstat() error on fd %d (path '%s'): %s",
                 fd, fh->fh_path, strerror(xerrno));

    errno = xerrno;
    return -1;
  }

  if (close(fd) < 0) {
    return -1;
  }

  c = find_config(CURRENT_CONF, CONF_PARAM, "ClamAV", FALSE);
  if (!c || !*(int *)(c->argv[0])) {
    (void) pr_trace_msg("clamav", 8, "skipping ClamAV virus scan.");

    return 0;
  }

  c = find_config(CURRENT_CONF, CONF_PARAM, "ClamFailsafe", FALSE);
  if (!c || *(int *)(c->argv[0]))
    remove_on_failure = 1;
  else
    remove_on_failure = 0;

  (void) pr_trace_msg("clamav", 8, "fail-safe mode is %s.",
                      (remove_on_failure ? "ON" : "OFF"));

  /**
   * Figure out the absolute path of our directory.
   */
  char buf[PR_TUNABLE_PATH_MAX + 1];
  getcwd(buf, PR_TUNABLE_PATH_MAX);
  abs_path = fh->fh_path;
  if (abs_path) {
    (void) pr_trace_msg("clamav", 8, "vwd=%s fh_path=%s chroot=%s cwd=%s buf=%s",
                        pr_fs_getvwd(), abs_path, session.chroot_path, pr_fs_getcwd(),
                        buf);
    if (strcmp(buf, pr_fs_getcwd()) != 0) {
      if (strcmp(pr_fs_getcwd(), "/") != 0) {
        char *pos = strstr(buf, pr_fs_getcwd());
        if (pos) {
          *pos = 0;
        }
      }

      abs_path = pdircat(fh->fh_pool, buf, abs_path, NULL);
    } else if (strcmp(buf, pr_fs_getcwd()) == 0 && session.chroot_path)
      abs_path = pdircat(fh->fh_pool, session.chroot_path, abs_path, NULL);
  }
  rel_path = pstrdup(fh->fh_pool, fh->fh_path);

  (void) pr_trace_msg("clamav", 6, "absolute path is '%s' and relative path is '%s'.", abs_path, rel_path);

  /**
   * Handle min/max settings
   */
  if ((minsize = (unsigned long *) get_param_ptr(CURRENT_CONF, "ClamMinSize", TRUE)) == 0UL)
    clamd_minsize = 0;
  else
    clamd_minsize = *minsize;

  if ((maxsize = (unsigned long *) get_param_ptr(CURRENT_CONF, "ClamMaxSize", TRUE)) == 0UL)
    clamd_maxsize = 0;
  else
    clamd_maxsize = *maxsize;

  (void) pr_trace_msg("clamav", 6, "ClamMinSize=%" PR_LU " ClamMaxSize=%" PR_LU " Filesize=%" PR_LU, clamd_minsize, clamd_maxsize, (pr_off_t) st.st_size);

  if (clamd_minsize > 0) {
    /* test the minimum size */
    if (st.st_size < clamd_minsize) {
      pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": File is too small, skipping virus scan. min = %" PR_LU " size = %" PR_LU,
                   clamd_minsize, (pr_off_t) st.st_size);
      return 0;
    }
  }

  if (clamd_maxsize > 0) {
    /* test the maximum size */
    if (st.st_size > clamd_maxsize) {
      pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": File is too large, skipping virus scan. max = %" PR_LU " size = %" PR_LU,
                   clamd_maxsize, (pr_off_t) st.st_size);
      return 0;
    }
  }

  (void) pr_trace_msg("clamav", 1, "Going to virus scan absolute filename of '%s' and a relative filename of '%s'.", abs_path, rel_path);

  clam_errno = 0;
  c = find_config(CURRENT_CONF, CONF_PARAM, "ClamStream", FALSE);
  if (c && *(int *)(c->argv[0])) {
    res = clamavd_scan_stream(clamd_sockd, abs_path, rel_path);
  } else {
    res = clamavd_scan(clamd_sockd, abs_path, rel_path);
  }
  if (res < 0) {
    if (remove_on_failure) {
      pr_log_debug(DEBUG4,
                   MOD_CLAMAV_VERSION ": removing failed upload of filename = '%s' with relative filename = '%s'.", abs_path, rel_path);
      if (clam_errno && pr_fsio_unlink(rel_path)!=0) {
        pr_log_pri(PR_LOG_ERR,
                   MOD_CLAMAV_VERSION ": notice    : unlink() failed (%d): %s",
                   errno, strerror(errno));
      }
    }
    errno = EPERM;
    return -1;
  }

  if (clam_errno == 0)
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": No virus detected in filename = '%s'.", abs_path);
  else
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": Skipped virus scan due to errno = %d", clam_errno);

  return 0;
}

/**
 * Parse string size description and return value.
 */
static unsigned long parse_nbytes(char *nbytes_str, char *units_str) {
  long res;
  unsigned long nbytes;
  char *endp = NULL;
  float units_factor = 0.0;

  /* clear any previous local errors */
  clam_errno = 0;

  /* first, check the given units to determine the correct multiplier
   */
  if (!strcasecmp("Gb", units_str)) {
    units_factor = 1024.0 * 1024.0 * 1024.0;

  } else if (!strcasecmp("Mb", units_str)) {
    units_factor = 1024.0 * 1024.0;

  } else if (!strcasecmp("Kb", units_str)) {
    units_factor = 1024.0;

  } else if (!strcasecmp("b", units_str)) {
    units_factor = 1.0;

  } else {
    clam_errno = EINVAL;
    return 0;
  }

  /* make sure a number was given */
  if (!isdigit((int) *nbytes_str)) {
    clam_errno = EINVAL;
    return 0;
  }

  /* knowing the factor, now convert the given number string to a real
   * number
   */
  res = strtol(nbytes_str, &endp, 10);

  if (errno == ERANGE) {
    clam_errno = ERANGE;
    return 0;
  }

  if (endp && *endp) {
    clam_errno = EINVAL;
    return 0;
  }

  /* don't bother to apply the factor if that will cause the number to
   * overflow
   */
  if (res > (ULONG_MAX / units_factor)) {
    clam_errno = ERANGE;
    return 0;
  }

  nbytes = (unsigned long) res * units_factor;
  return nbytes;
}

/**
 * Configuration setter: ClamAV
 */
MODRET set_clamav(cmd_rec *cmd) {
  int engine = -1;
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_LIMIT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  if ((engine = get_boolean(cmd,1)) == -1)
    CONF_ERROR(cmd, "expected Boolean parameter");

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(unsigned char));
  *((unsigned char *) c->argv[0]) = engine;
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamStream
 */
MODRET set_clamstream(cmd_rec *cmd) {
  int use_stream = -1;
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_LIMIT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  if ((use_stream = get_boolean(cmd,1)) == -1)
    CONF_ERROR(cmd, "expected Boolean parameter");

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(unsigned char));
  *((unsigned char *) c->argv[0]) = use_stream;
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamFailsafe
 */
MODRET set_clamfailsafe(cmd_rec *cmd) {
  int use_failsafe = -1;
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_LIMIT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  if ((use_failsafe = get_boolean(cmd, 1)) == -1)
    CONF_ERROR(cmd, "expected Boolean parameter");

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(unsigned char));
  *((unsigned char *) c->argv[0]) = use_failsafe;
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamLocalSocket
 */
MODRET set_clamavd_local_socket(cmd_rec *cmd) {
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  c = add_config_param_str("ClamLocalSocket", 1, (void *) cmd->argv[1]);
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamServer
 */
MODRET set_clamavd_server(cmd_rec *cmd) {
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  c = add_config_param_str("ClamServer", 1, (void *) cmd->argv[1]);
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamPort
 */
MODRET set_clamavd_port(cmd_rec *cmd) {
  config_rec *c = NULL;

  CHECK_ARGS(cmd, 1);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(int));
  *((int *) c->argv[0]) = (int) atol(cmd->argv[1]);
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamMinSize
 */
MODRET set_clamavd_minsize(cmd_rec *cmd) {
  config_rec *c = NULL;
  unsigned long nbytes = 0;

  CHECK_ARGS(cmd, 2);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  if ((nbytes = parse_nbytes(cmd->argv[1], cmd->argv[2])) == 0) {
    char ulong_max[80] = {'\0'};
    sprintf(ulong_max, "%lu", (unsigned long) ULONG_MAX);

    if (clam_errno == EINVAL)
      CONF_ERROR(cmd, "invalid parameters");

    if (clam_errno == ERANGE)
      CONF_ERROR(cmd, pstrcat(cmd->tmp_pool,
                              "number of bytes must be between 0 and ",
                              ulong_max, NULL));
  }

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(unsigned long));
  *((unsigned long *) c->argv[0]) = nbytes;
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * Configuration setter: ClamMaxSize
 */
MODRET set_clamavd_maxsize(cmd_rec *cmd) {
  config_rec *c = NULL;
  unsigned long nbytes = 0;

  CHECK_ARGS(cmd, 2);
  CHECK_CONF(cmd, CONF_ROOT|CONF_VIRTUAL|CONF_GLOBAL|CONF_DIR);

  if ((nbytes = parse_nbytes(cmd->argv[1], cmd->argv[2])) == 0) {
    char ulong_max[80] = {'\0'};
    sprintf(ulong_max, "%lu", (unsigned long) ULONG_MAX);

    if (clam_errno == EINVAL)
      CONF_ERROR(cmd, "invalid parameters");

    if (clam_errno == ERANGE)
      CONF_ERROR(cmd, pstrcat(cmd->tmp_pool,
                              "number of bytes must be between 0 and ",
                              ulong_max, NULL));
  }

  c = add_config_param(cmd->argv[0], 1, NULL);
  c->argv[0] = pcalloc(c->pool, sizeof(unsigned long));
  *((unsigned long *) c->argv[0]) = nbytes;
  c->flags |= CF_MERGEDOWN;

  return PR_HANDLED(cmd);
}

/**
 * End FTP Session
 */
static void clamav_shutdown(const void *event_data, void *user_data) {
  if (clamd_sockd != -1) {
    close(clamd_sockd);
    clamd_sockd = -1;
    pr_log_debug(DEBUG4, MOD_CLAMAV_VERSION ": debug: disconnected from Clamd");
  }
}

/**
 * Start FTP Session
 */
static int clamav_sess_init(void) {
  pr_fs_t *fs;

  is_remote = 0; clamd_sockd = -1;

  pr_event_register(&clamav_module, "core.exit", clamav_shutdown, NULL);

  fs = pr_register_fs(session.pool, "clamav", "/");
  if (fs) {
    fs->close = clamav_fsio_close;
  }

  return 0;
}

static conftable clamav_conftab[] = {
  { "ClamAV", set_clamav, NULL },
  { "ClamFailsafe", set_clamfailsafe, NULL },
  { "ClamLocalSocket", set_clamavd_local_socket, NULL },
  { "ClamServer", set_clamavd_server, NULL },
  { "ClamPort", set_clamavd_port, NULL },
  { "ClamMinSize", set_clamavd_minsize, NULL },
  { "ClamMaxSize", set_clamavd_maxsize, NULL },
  { "ClamStream", set_clamstream, NULL },
  { NULL }
};

module clamav_module = {
  NULL,              /* Always NULL */
  NULL,              /* Always NULL */
  0x20,              /* module api version */
  "clamav",          /* module name */
  clamav_conftab,    /* module configuration handler table */
  NULL,              /* module command handler table */
  NULL,              /* module authentication handler table */
  NULL,              /* module initialization */
  clamav_sess_init,  /* session initialization */
  MOD_CLAMAV_VERSION /* module version */
};