Add support for avast malware scanner. Bug 1033

[exim.git] / src / src / malware.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003-2014 */
/* License: GPL */

/* Code for calling virus (malware) scanners. Called from acl.c. */

#include "exim.h"
#ifdef WITH_CONTENT_SCAN

typedef enum {M_FPROTD, M_DRWEB, M_AVES, M_FSEC, M_KAVD, M_CMDL,
		M_SOPHIE, M_CLAMD, M_SOCK, M_MKSD, M_AVAST} scanner_t;
typedef enum {MC_NONE, MC_TCP, MC_UNIX, MC_STRM} contype_t;
static struct scan
{
  scanner_t	scancode;
  const uschar * name;
  const uschar * options_default;
  contype_t	conn;
} m_scans[] =
{
  { M_FPROTD,	US"f-protd",	US"localhost 10200-10204",	      MC_TCP },
  { M_DRWEB,	US"drweb",	US"/usr/local/drweb/run/drwebd.sock", MC_STRM },
  { M_AVES,	US"aveserver",	US"/var/run/aveserver",		      MC_UNIX },
  { M_FSEC,	US"fsecure",	US"/var/run/.fsav",		      MC_UNIX },
  { M_KAVD,	US"kavdaemon",	US"/var/run/AvpCtl",		      MC_UNIX },
  { M_CMDL,	US"cmdline",	NULL,				      MC_NONE },
  { M_SOPHIE,	US"sophie",	US"/var/run/sophie",		      MC_UNIX },
  { M_CLAMD,	US"clamd",	US"/tmp/clamd",			      MC_NONE },
  { M_SOCK,	US"sock",	US"/tmp/malware.sock",		      MC_STRM },
  { M_MKSD,	US"mksd",	NULL,				      MC_NONE },
  { M_AVAST,	US"avast",	US"/var/run/avast/scan.sock",	      MC_STRM },
  { -1,		NULL,		NULL, MC_NONE }		/* end-marker */
};

/* The maximum number of clamd servers that are supported in the configuration */
#define MAX_CLAMD_SERVERS 32
#define MAX_CLAMD_SERVERS_S "32"
/* Maximum length of the hostname that can be specified in the clamd address list */
#define MAX_CLAMD_ADDRESS_LENGTH 64
#define MAX_CLAMD_ADDRESS_LENGTH_S "64"

typedef struct clamd_address_container {
  uschar tcp_addr[MAX_CLAMD_ADDRESS_LENGTH+1];
  unsigned int tcp_port;
} clamd_address_container;

/* declaration of private routines */
static int mksd_scan_packed(struct scan * scanent, int sock, uschar *scan_filename);
static int malware_internal(uschar **listptr, uschar *eml_filename, BOOL faking);

#ifndef nelements
# define nelements(arr) (sizeof(arr) / sizeof(arr[0]))
#endif


#define        MALWARE_TIMEOUT             120


#define DRWEBD_SCAN_CMD             (1)     /* scan file, buffer or diskfile */
#define DRWEBD_RETURN_VIRUSES       (1<<0)   /* ask daemon return to us viruses names from report */
#define DRWEBD_IS_MAIL              (1<<19)  /* say to daemon that format is "archive MAIL" */

#define DERR_READ_ERR               (1<<0)   /* read error */
#define DERR_NOMEMORY               (1<<2)   /* no memory */
#define DERR_TIMEOUT                (1<<9)   /* scan timeout has run out */
#define DERR_BAD_CALL               (1<<15)  /* wrong command */

/* Routine to check whether a system is big- or little-endian.
   Ripped from http://www.faqs.org/faqs/graphics/fileformats-faq/part4/section-7.html
   Needed for proper kavdaemon implementation. Sigh. */
#define BIG_MY_ENDIAN      0
#define LITTLE_MY_ENDIAN   1
static int test_byte_order(void);
static inline int
test_byte_order()
{
  short int word = 0x0001;
  char *byte = (char *) &word;
  return(byte[0] ? LITTLE_MY_ENDIAN : BIG_MY_ENDIAN);
}

BOOL malware_ok = FALSE;

/* Gross hacks for the -bmalware option; perhaps we should just create
the scan directory normally for that case, but look into rigging up the
needed header variables if not already set on the command-line? */
extern int spool_mbox_ok;
extern uschar spooled_message_id[17];

/*************************************************
*          Scan an email for malware             *
*************************************************/

/* This is the normal interface for scanning an email, which doesn't need a
filename; it's a wrapper around the malware_file function.

Arguments:
  listptr     the list of options to the "malware = ..." ACL condition

Returns:      Exim message processing code (OK, FAIL, DEFER, ...)
              where true means malware was found (condition applies)
*/
int
malware(uschar **listptr)
{
  uschar * scan_filename;
  int ret;

  scan_filename = string_sprintf("%s/scan/%s/%s.eml",
		    spool_directory, message_id, message_id);
  ret = malware_internal(listptr, scan_filename, FALSE);
  if (ret == DEFER) av_failed = TRUE;

  return ret;
}


/*************************************************
*          Scan a file for malware               *
*************************************************/

/* This is a test wrapper for scanning an email, which is not used in
normal processing.  Scan any file, using the Exim scanning interface.
This function tampers with various global variables so is unsafe to use
in any other context.

Arguments:
  eml_filename  a file holding the message to be scanned

Returns:        Exim message processing code (OK, FAIL, DEFER, ...)
                where true means malware was found (condition applies)
*/
int
malware_in_file(uschar *eml_filename)
{
  uschar *scan_options[2];
  uschar message_id_buf[64];
  int ret;

  scan_options[0] = US"*";
  scan_options[1] = NULL;

  /* spool_mbox() assumes various parameters exist, when creating
  the relevant directory and the email within */
  (void) string_format(message_id_buf, sizeof(message_id_buf),
      "dummy-%d", vaguely_random_number(INT_MAX));
  message_id = message_id_buf;
  sender_address = US"malware-sender@example.net";
  return_path = US"";
  recipients_list = NULL;
  receive_add_recipient(US"malware-victim@example.net", -1);
  enable_dollar_recipients = TRUE;

  ret = malware_internal(scan_options, eml_filename, TRUE);

  Ustrncpy(spooled_message_id, message_id, sizeof(spooled_message_id));
  spool_mbox_ok = 1;
  /* don't set no_mbox_unspool; at present, there's no way for it to become
  set, but if that changes, then it should apply to these tests too */
  unspool_mbox();

  /* silence static analysis tools */
  message_id = NULL;

  return ret;
}


static inline int
malware_errlog_defer(const uschar * str)
{
  log_write(0, LOG_MAIN|LOG_PANIC, "malware acl condition: %s", str);
  return DEFER;
}

static int
m_errlog_defer(struct scan * scanent, const uschar * str)
{
  return malware_errlog_defer(string_sprintf("%s: %s", scanent->name, str));
}
static int
m_errlog_defer_3(struct scan * scanent, const uschar * str,
	int fd_to_close)
{
  (void) close(fd_to_close);
  return m_errlog_defer(scanent, str);
}

/*************************************************/

/* Only used by the Clamav code, which is working from a list of servers and
uses the returned in_addr to get a second connection to the same system.
*/
static inline int
m_tcpsocket(const uschar * hostname, unsigned int port,
	host_item * host, uschar ** errstr)
{
  return ip_connectedsocket(SOCK_STREAM, hostname, port, port, 5, host, errstr);
}

static int
m_tcpsocket_fromdef(const uschar * hostport, uschar ** errstr)
{
  int scan;
  uschar hostname[256];
  unsigned int portlow, porthigh;

  /* extract host and port part */
  scan = sscanf(CS hostport, "%255s %u-%u", hostname, &portlow, &porthigh);
  if ( scan != 3 ) {
    if ( scan != 2 ) {
      *errstr = string_sprintf("invalid socket '%s'", hostport);
      return -1;
    }
    porthigh = portlow;
  }

  return ip_connectedsocket(SOCK_STREAM, hostname, portlow, porthigh,
			    5, NULL, errstr);
}

static int
m_unixsocket(const uschar * path, uschar ** errstr)
{
  int sock;
  struct sockaddr_un server;

  if ((sock = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
    *errstr = US"can't open UNIX socket.";
    return -1;
  }

  server.sun_family = AF_UNIX;
  Ustrncpy(server.sun_path, path, sizeof(server.sun_path)-1);
  server.sun_path[sizeof(server.sun_path)-1] = '\0';
  if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0) {
    int err = errno;
    (void)close(sock);
    *errstr =  string_sprintf("unable to connect to UNIX socket (%s): %s",
		  path, strerror(err));
    return -1;
    }
  return sock;
}

static inline int
m_streamsocket(const uschar * spec, uschar ** errstr)
{
  return *spec == '/'
    ? m_unixsocket(spec, errstr) : m_tcpsocket_fromdef(spec, errstr);
}

static int
m_sock_send(int sock, uschar * buf, int cnt, uschar ** errstr)
{
  if (send(sock, buf, cnt, 0) < 0) {
    int err = errno;
    (void)close(sock);
    *errstr = string_sprintf("unable to send to socket (%s): %s",
	   buf, strerror(err));
    return -1;
    }
  return sock;
}

static const pcre *
m_pcre_compile(const uschar * re, uschar ** errstr)
{
  const uschar * rerror;
  int roffset;
  const pcre * cre;

  cre = pcre_compile(CS re, PCRE_COPT, (const char **)&rerror, &roffset, NULL);
  if (!cre)
    *errstr= string_sprintf("regular expression error in '%s': %s at offset %d",
	re, rerror, roffset);
  return cre;
}

uschar *
m_pcre_exec(const pcre * cre, uschar * text)
{
  int ovector[10*3];
  int i = pcre_exec(cre, NULL, CS text, Ustrlen(text), 0, 0,
		ovector, nelements(ovector));
  uschar * substr = NULL;
  if (i >= 2)				/* Got it */
    pcre_get_substring(CS text, ovector, i, 1, (const char **) &substr);
  return substr;
}

static const pcre *
m_pcre_nextinlist(uschar ** list, int * sep, char * listerr, uschar ** errstr)
{
  const uschar * list_ele;
  const pcre * cre = NULL;

  if (!(list_ele = string_nextinlist(list, sep, NULL, 0)))
    *errstr = US listerr;
  else
    cre = m_pcre_compile(CUS list_ele, errstr);
  return cre;
}

/*************************************************
*          Scan content for malware              *
*************************************************/

/* This is an internal interface for scanning an email; the normal interface
is via malware(), or there's malware_in_file() used for testing/debugging.

Arguments:
  listptr       the list of options to the "malware = ..." ACL condition
  eml_filename  the file holding the email to be scanned
  faking        whether or not we're faking this up for the -bmalware test

Returns:        Exim message processing code (OK, FAIL, DEFER, ...)
                where true means malware was found (condition applies)
*/
static int
malware_internal(uschar **listptr, uschar *eml_filename, BOOL faking)
{
  int sep = 0;
  uschar *list = *listptr;
  uschar *av_scanner_work = av_scanner;
  uschar *scanner_name;
  uschar *malware_regex;
  uschar malware_regex_default[] = ".+";
  unsigned long mbox_size;
  FILE *mbox_file;
  const pcre *re;
  uschar * errstr;
  struct scan * scanent;
  const uschar * scanner_options;
  int sock = -1;

  /* make sure the eml mbox file is spooled up */
  if (!(mbox_file = spool_mbox(&mbox_size, faking ? eml_filename : NULL)))
    return malware_errlog_defer(US"error while creating mbox spool file");

  /* none of our current scanners need the mbox
     file as a stream, so we can close it right away */
  (void)fclose(mbox_file);

  /* extract the malware regex to match against from the option list */
  if (!(malware_regex = string_nextinlist(&list, &sep, NULL, 0)))
    return FAIL;		/* empty means "don't match anything" */

  /* parse 1st option */
    if ( (strcmpic(malware_regex,US"false") == 0) ||
       (Ustrcmp(malware_regex,"0") == 0) )
    return FAIL;		/* explicitly no matching */

  /* special cases (match anything except empty) */
  if ( (strcmpic(malware_regex,US"true") == 0) ||
       (Ustrcmp(malware_regex,"*") == 0) ||
       (Ustrcmp(malware_regex,"1") == 0) )
    malware_regex = malware_regex_default;

  /* Reset sep that is set by previous string_nextinlist() call */
  sep = 0;

  /* compile the regex, see if it works */
  if (!(re = m_pcre_compile(malware_regex, &errstr)))
    return malware_errlog_defer(errstr);

  /* if av_scanner starts with a dollar, expand it first */
  if (*av_scanner == '$') {
    if (!(av_scanner_work = expand_string(av_scanner)))
      return malware_errlog_defer(
           string_sprintf("av_scanner starts with $, but expansion failed: %s",
	   expand_string_message));

    debug_printf("Expanded av_scanner global: %s\n", av_scanner_work);
    /* disable result caching in this case */
    malware_name = NULL;
    malware_ok = FALSE;
  }

  /* Do not scan twice (unless av_scanner is dynamic). */
  if (!malware_ok) {

    /* find the scanner type from the av_scanner option */
    if (!(scanner_name = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
      return malware_errlog_defer(US"av_scanner configuration variable is empty");

    for (scanent = m_scans; ; scanent++) {
      if (!scanent->name)
	return malware_errlog_defer(string_sprintf("unknown scanner type '%s'",
	  scanner_name));
      if (strcmpic(scanner_name, US scanent->name) != 0)
	continue;
      if (!(scanner_options = string_nextinlist(&av_scanner_work, &sep, NULL, 0)))
	scanner_options = scanent->options_default;
      if (scanent->conn == MC_NONE)
	break;
      switch(scanent->conn)
      {
      case MC_TCP:  sock = m_tcpsocket_fromdef(scanner_options, &errstr); break;
      case MC_UNIX: sock = m_unixsocket(scanner_options, &errstr);	  break;
      case MC_STRM: sock = m_streamsocket(scanner_options, &errstr);	  break;
      default: /* compiler quietening */ break;
      }
      if (sock < 0)
	return m_errlog_defer(scanent, errstr);
      break;
    }
    DEBUG(D_lookup) debug_printf("Malware scan: %s\n", scanner_name);

    switch (scanent->scancode) {
    case M_FPROTD: /* "f-protd" scanner type -------------------------------- */
      {
	uschar *fp_scan_option;
	unsigned int detected=0, par_count=0;
	uschar * scanrequest;
	uschar buf[32768], *strhelper, *strhelper2;
	uschar * malware_name_internal = NULL;

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s GET\n", scanner_name);
	scanrequest = string_sprintf("GET %s", eml_filename);

	while ((fp_scan_option = string_nextinlist(&av_scanner_work, &sep,
			      NULL, 0))) {
	  scanrequest = string_sprintf("%s%s%s", scanrequest,
				    par_count ? "%20" : "?", fp_scan_option);
	  par_count++;
	}
	scanrequest = string_sprintf("%s HTTP/1.0\r\n\r\n", scanrequest);

	/* send scan request */
	if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	/* We get a lot of empty lines, so we need this hack to check for any data at all */
	while( recv(sock, buf, 1, MSG_PEEK) > 0 ) {
	  if ( recv_line(sock, buf, sizeof(buf)) > 0) {
	    if ( Ustrstr(buf, US"<detected type=\"") != NULL )
	      detected = 1;
	    else if ( detected && (strhelper = Ustrstr(buf, US"<name>")) ) {
	      if ((strhelper2 = Ustrstr(buf, US"</name>")) != NULL) {
		*strhelper2 = '\0';
		malware_name_internal = string_copy(strhelper+6);
	      }
	    } else if ( Ustrstr(buf, US"<summary code=\"") )
		malware_name = Ustrstr(buf, US"<summary code=\"11\">")
		  ? malware_name_internal : NULL;
	  }
	}
	break;
      }	/* f-protd */

    case M_DRWEB: /* "drweb" scanner type ----------------------------------- */
    /* v0.1 - added support for tcp sockets          */
    /* v0.0 - initial release -- support for unix sockets      */
      {
	int result;
	off_t fsize;
	unsigned int fsize_uint;
	uschar * tmpbuf, *drweb_fbuf;
	int drweb_rc, drweb_cmd, drweb_flags = 0x0000, drweb_fd,
	    drweb_vnum, drweb_slen, drweb_fin = 0x0000;
	unsigned long bread;
	const pcre *drweb_re;

	/* prepare variables */
	drweb_cmd = htonl(DRWEBD_SCAN_CMD);
	drweb_flags = htonl(DRWEBD_RETURN_VIRUSES | DRWEBD_IS_MAIL);

	if (*scanner_options != '/') {

	  /* calc file size */
	  if ((drweb_fd = open(CS eml_filename, O_RDONLY)) == -1)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't open spool file %s: %s",
		eml_filename, strerror(errno)),
	      sock);

	  if ((fsize = lseek(drweb_fd, 0, SEEK_END)) == -1) {
	    int err = errno;
	    (void)close(drweb_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't seek spool file %s: %s",
		eml_filename, strerror(err)),
	      sock);
	  }
	  fsize_uint = (unsigned int) fsize;
	  if ((off_t)fsize_uint != fsize) {
	    (void)close(drweb_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("seeking spool file %s, size overflow",
		eml_filename),
	      sock);
	  }
	  drweb_slen = htonl(fsize);
	  lseek(drweb_fd, 0, SEEK_SET);

	  DEBUG(D_acl) debug_printf("Malware scan: issuing %s remote scan [%s]\n",
	      scanner_name, scanner_options);

	  /* send scan request */
	  if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
	      (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
	      (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0) ||
	      (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0)) {
	    (void)close(drweb_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send commands to socket (%s)", scanner_options),
	      sock);
	  }

	  if (!(drweb_fbuf = (uschar *) malloc (fsize_uint))) {
	    (void)close(drweb_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to allocate memory %u for file (%s)",
		fsize_uint, eml_filename),
	      sock);
	  }

	  if ((result = read (drweb_fd, drweb_fbuf, fsize)) == -1) {
	    int err = errno;
	    (void)close(drweb_fd);
	    free(drweb_fbuf);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't read spool file %s: %s",
		eml_filename, strerror(err)),
	      sock);
	  }
	  (void)close(drweb_fd);

	  /* send file body to socket */
	  if (send(sock, drweb_fbuf, fsize, 0) < 0) {
	    free(drweb_fbuf);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send file body to socket (%s)", scanner_options),
	    sock);
	  }
	  (void)close(drweb_fd);

	} else {

	  drweb_slen = htonl(Ustrlen(eml_filename));

	  DEBUG(D_acl) debug_printf("Malware scan: issuing %s local scan [%s]\n",
	      scanner_name, scanner_options);

	  /* send scan request */
	  if ((send(sock, &drweb_cmd, sizeof(drweb_cmd), 0) < 0) ||
	      (send(sock, &drweb_flags, sizeof(drweb_flags), 0) < 0) ||
	      (send(sock, &drweb_slen, sizeof(drweb_slen), 0) < 0) ||
	      (send(sock, eml_filename, Ustrlen(eml_filename), 0) < 0) ||
	      (send(sock, &drweb_fin, sizeof(drweb_fin), 0) < 0))
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send commands to socket (%s)", scanner_options),
	      sock);
	}

	/* wait for result */
	if ((bread = recv(sock, &drweb_rc, sizeof(drweb_rc), 0) != sizeof(drweb_rc)))
	  return m_errlog_defer_3(scanent,
		      US"unable to read return code", sock);
	drweb_rc = ntohl(drweb_rc);

	if ((bread = recv(sock, &drweb_vnum, sizeof(drweb_vnum), 0) != sizeof(drweb_vnum)))
	  return m_errlog_defer_3(scanent,
			      US"unable to read the number of viruses", sock);
	drweb_vnum = ntohl(drweb_vnum);

	/* "virus(es) found" if virus number is > 0 */
	if (drweb_vnum) {
	  int i;

	  /* setup default virus name */
	  malware_name = US"unknown";

	  /* set up match regex */
	  drweb_re = m_pcre_compile(US"infected\\swith\\s*(.+?)$", &errstr);

	  /* read and concatenate virus names into one string */
	  for (i=0;i<drweb_vnum;i++)
	  {
	    int size = 0, off = 0, ovector[10*3];
	    /* read the size of report */
	    if ((bread = recv(sock, &drweb_slen, sizeof(drweb_slen), 0) != sizeof(drweb_slen)))
	      return m_errlog_defer_3(scanent,
				US"cannot read report size", sock);
	    drweb_slen = ntohl(drweb_slen);
	    tmpbuf = store_get(drweb_slen);

	    /* read report body */
	    if ((bread = recv(sock, tmpbuf, drweb_slen, 0)) != drweb_slen)
	      return m_errlog_defer_3(scanent,
				US"cannot read report string", sock);
	    tmpbuf[drweb_slen] = '\0';

	    /* try matcher on the line, grab substring */
	    result = pcre_exec(drweb_re, NULL, CS tmpbuf, Ustrlen(tmpbuf), 0, 0,
				    ovector, nelements(ovector));
	    if (result >= 2) {
	      const char * pre_malware_nb;

	      pcre_get_substring(CS tmpbuf, ovector, result, 1, &pre_malware_nb);

	      if (i==0)	/* the first name we just copy to malware_name */
		malware_name = string_append(NULL, &size, &off,
					    1, pre_malware_nb);

	      else	/* concatenate each new virus name to previous */
		malware_name = string_append(malware_name, &size, &off,
					    2, "/", pre_malware_nb);

	      pcre_free_substring(pre_malware_nb);
	    }
	  }
	}
	else {
	  const char *drweb_s = NULL;

	  if (drweb_rc & DERR_READ_ERR) drweb_s = "read error";
	  if (drweb_rc & DERR_NOMEMORY) drweb_s = "no memory";
	  if (drweb_rc & DERR_TIMEOUT)  drweb_s = "timeout";
	  if (drweb_rc & DERR_BAD_CALL) drweb_s = "wrong command";
	  /* retcodes DERR_SYMLINK, DERR_NO_REGFILE, DERR_SKIPPED.
	   * DERR_TOO_BIG, DERR_TOO_COMPRESSED, DERR_SPAM,
	   * DERR_CRC_ERROR, DERR_READSOCKET, DERR_WRITE_ERR
	   * and others are ignored */
	  if (drweb_s)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("drweb daemon retcode 0x%x (%s)", drweb_rc, drweb_s),
	      sock);

	  /* no virus found */
	  malware_name = NULL;
	}
	break;
      }	/* drweb */

    case M_AVES: /* "aveserver" scanner type -------------------------------- */
      {
	uschar buf[32768];
	int result;

	/* read aveserver's greeting and see if it is ready (2xx greeting) */
	recv_line(sock, buf, sizeof(buf));

	if (buf[0] != '2')		/* aveserver is having problems */
	  return m_errlog_defer_3(scanent,
	    string_sprintf("unavailable (Responded: %s).",
			    ((buf[0] != 0) ? buf : (uschar *)"nothing") ),
	    sock);

	/* prepare our command */
	(void)string_format(buf, sizeof(buf), "SCAN bPQRSTUW %s\r\n",
						  eml_filename);

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s SCAN\n", scanner_name);

	/* and send it */
	if (m_sock_send(sock, buf, Ustrlen(buf), &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	malware_name = NULL;
	result = 0;
	/* read response lines, find malware name and final response */
	while (recv_line(sock, buf, sizeof(buf)) > 0) {
	  debug_printf("aveserver: %s\n", buf);
	  if (buf[0] == '2')
	    break;
	  if (buf[0] == '5') {		/* aveserver is having problems */
	    result = m_errlog_defer(scanent,
	       string_sprintf("unable to scan file %s (Responded: %s).",
			       eml_filename, buf));
	    break;
	  } else if (Ustrncmp(buf,"322",3) == 0) {
	    uschar *p = Ustrchr(&buf[4],' ');
	    *p = '\0';
	    malware_name = string_copy(&buf[4]);
	  }
	}

	/* and send it */
	if (m_sock_send(sock, US"quit\r\n", 6, &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	/* read aveserver's greeting and see if it is ready (2xx greeting) */
	recv_line(sock, buf, sizeof(buf));

	if (buf[0] != '2')		/* aveserver is having problems */
	  return m_errlog_defer_3(scanent,
	    string_sprintf("unable to quit dialogue (Responded: %s).",
			  ((buf[0] != 0) ? buf : (uschar *)"nothing") ),
	    sock);

	if (result == DEFER) {
	  (void)close(sock);
	  return DEFER;
	}
	break;
      }	/* aveserver */

    case M_FSEC: /* "fsecure" scanner type ---------------------------------- */
      {
	int i, j, bread = 0;
	uschar * file_name;
	uschar av_buffer[1024];
	const pcre * fs_inf;
	static uschar *cmdopt[] = { US"CONFIGURE\tARCHIVE\t1\n",
					US"CONFIGURE\tTIMEOUT\t0\n",
					US"CONFIGURE\tMAXARCH\t5\n",
					US"CONFIGURE\tMIME\t1\n" };

	malware_name = NULL;

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s scan [%s]\n",
	    scanner_name, scanner_options);

	/* pass options */
	memset(av_buffer, 0, sizeof(av_buffer));
	for (i=0; i != nelements(cmdopt); i++) {

	  if (m_sock_send(sock, cmdopt[i], Ustrlen(cmdopt[i]), &errstr) < 0)
	    return m_errlog_defer(scanent, errstr);

	  bread = ip_recv(sock, av_buffer, sizeof(av_buffer), MALWARE_TIMEOUT);
	  if (bread >0) av_buffer[bread]='\0';
	  if (bread < 0)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to read answer %d (%s)", i, strerror(errno)),
	      sock);
	  for (j=0;j<bread;j++)
	    if((av_buffer[j]=='\r')||(av_buffer[j]=='\n'))
	      av_buffer[j] ='@';
	}

	/* pass the mailfile to fsecure */
	file_name = string_sprintf("SCAN\t%s\n", eml_filename);

	if (m_sock_send(sock, file_name, Ustrlen(file_name), &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	/* set up match */
	/* todo also SUSPICION\t */
	fs_inf = m_pcre_compile(US"\\S{0,5}INFECTED\\t[^\\t]*\\t([^\\t]+)\\t\\S*$", &errstr);

	/* read report, linewise */
	do {
	  i = 0;
	  memset(av_buffer, 0, sizeof(av_buffer));
	  do {
	    if ((bread= ip_recv(sock, &av_buffer[i], 1, MALWARE_TIMEOUT)) < 0)
	      return m_errlog_defer_3(scanent,
		string_sprintf("unable to read result (%s)", strerror(errno)),
		sock);
	  } while (++i < sizeof(av_buffer)-1  &&  av_buffer[i-1] != '\n');
	  av_buffer[i-1] = '\0';

	  /* Really search for virus again? */
	  if (malware_name == NULL)
	    /* try matcher on the line, grab substring */
	    malware_name = m_pcre_exec(fs_inf, av_buffer);
	}
	while (Ustrstr(av_buffer, "OK\tScan ok.") == NULL);
	break;
      }	/* fsecure */

    case M_KAVD: /* "kavdaemon" scanner type -------------------------------- */
      {
	time_t t;
	uschar tmpbuf[1024];
	uschar * scanrequest;
	int kav_rc;
	unsigned long kav_reportlen, bread;
	const pcre *kav_re;
	uschar *p;

	/* get current date and time, build scan request */
	time(&t);
	/* pdp note: before the eml_filename parameter, this scanned the
	directory; not finding documentation, so we'll strip off the directory.
	The side-effect is that the test framework scanning may end up in
	scanning more than was requested, but for the normal interface, this is
	fine. */

	strftime(CS tmpbuf, sizeof(tmpbuf), "%d %b %H:%M:%S", localtime(&t));
	scanrequest = string_sprintf("<0>%s:%s", CS tmpbuf, eml_filename);
	p = Ustrrchr(scanrequest, '/');
	if (p)
	  *p = '\0';

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s scan [%s]\n",
	    scanner_name, scanner_options);

	/* send scan request */
	if (m_sock_send(sock, scanrequest, Ustrlen(scanrequest)+1, &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	/* wait for result */
	if ((bread = recv(sock, tmpbuf, 2, 0) != 2))
	  return m_errlog_defer_3(scanent,
			      US"unable to read 2 bytes from socket.", sock);

	/* get errorcode from one nibble */
	kav_rc = tmpbuf[ test_byte_order()==LITTLE_MY_ENDIAN ? 0 : 1 ] & 0x0F;
	switch(kav_rc)
	{
	case 5: case 6: /* improper kavdaemon configuration */
	  return m_errlog_defer_3(scanent,
		  US"please reconfigure kavdaemon to NOT disinfect or remove infected files.",
		  sock);
	case 1:
	  return m_errlog_defer_3(scanent,
		  US"reported 'scanning not completed' (code 1).", sock);
	case 7:
	  return m_errlog_defer_3(scanent,
		  US"reported 'kavdaemon damaged' (code 7).", sock);
	}

	/* code 8 is not handled, since it is ambigous. It appears mostly on
	bounces where part of a file has been cut off */

	/* "virus found" return codes (2-4) */
	if ((kav_rc > 1) && (kav_rc < 5)) {
	  int report_flag = 0;

	  /* setup default virus name */
	  malware_name = US"unknown";

	  report_flag = tmpbuf[ test_byte_order() == LITTLE_MY_ENDIAN ? 1 : 0 ];

	  /* read the report, if available */
	  if( report_flag == 1 ) {
	    /* read report size */
	    if ((bread = recv(sock, &kav_reportlen, 4, 0)) != 4)
	      return m_errlog_defer_3(scanent,
		    US"cannot read report size", sock);

	    /* it's possible that avp returns av_buffer[1] == 1 but the
	    reportsize is 0 (!?) */
	    if (kav_reportlen > 0) {
	      /* set up match regex, depends on retcode */
	      kav_re = m_pcre_compile( kav_rc == 3
				       ? US"suspicion:\\s*(.+?)\\s*$"
				       : US"infected:\\s*(.+?)\\s*$",
				       &errstr );

	      /* read report, linewise */
	      while (kav_reportlen > 0) {
		bread = 0;
		while ( recv(sock, &tmpbuf[bread], 1, 0) == 1 ) {
		  kav_reportlen--;
		  if ( (tmpbuf[bread] == '\n') || (bread > 1021) ) break;
		  bread++;
		}
		bread++;
		tmpbuf[bread] = '\0';

		/* try matcher on the line, grab substring */
		if ((malware_name = m_pcre_exec(kav_re, tmpbuf)))
		  break;
	      }
	    }
	  }
	}
	else /* no virus found */
	  malware_name = NULL;

	break;
      }

    case M_CMDL: /* "cmdline" scanner type ---------------------------------- */
      {
	const uschar *cmdline_scanner = scanner_options;
	const pcre *cmdline_trigger_re;
	const pcre *cmdline_regex_re;
	uschar * file_name;
	uschar * commandline;
	void (*eximsigchld)(int);
	void (*eximsigpipe)(int);
	FILE *scanner_out = NULL;
	FILE *scanner_record = NULL;
	uschar linebuffer[32767];
	int trigger = 0;
	uschar *p;

	if (!cmdline_scanner)
	  return m_errlog_defer(scanent, errstr);

	/* find scanner output trigger */
	cmdline_trigger_re = m_pcre_nextinlist(&av_scanner_work, &sep,
				  "missing trigger specification", &errstr);
	if (!cmdline_trigger_re)
	  return m_errlog_defer(scanent, errstr);

	/* find scanner name regex */
	cmdline_regex_re = m_pcre_nextinlist(&av_scanner_work, &sep,
			    "missing virus name regex specification", &errstr);
	if (!cmdline_regex_re)
	  return m_errlog_defer(scanent, errstr);

	/* prepare scanner call; despite the naming, file_name holds a directory
	name which is documented as the value given to %s. */

	file_name = string_copy(eml_filename);
	p = Ustrrchr(file_name, '/');
	if (p)
	  *p = '\0';
	commandline = string_sprintf(CS cmdline_scanner, file_name);

	/* redirect STDERR too */
	commandline = string_sprintf("%s 2>&1", commandline);

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s scan [%s]\n", scanner_name, commandline);

	/* store exims signal handlers */
	eximsigchld = signal(SIGCHLD,SIG_DFL);
	eximsigpipe = signal(SIGPIPE,SIG_DFL);

	if (!(scanner_out = popen(CS commandline,"r"))) {
	  int err = errno;
	  signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
	  return m_errlog_defer(scanent,
	    string_sprintf("call (%s) failed: %s.", commandline, strerror(err)));
	}

	file_name = string_sprintf("%s/scan/%s/%s_scanner_output",
				  spool_directory, message_id, message_id);
	scanner_record = modefopen(file_name, "wb", SPOOL_MODE);

	if (scanner_record == NULL) {
	  int err = errno;
	  (void) pclose(scanner_out);
	  signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
	  return m_errlog_defer(scanent,
	    string_sprintf("opening scanner output file (%s) failed: %s.",
	      file_name, strerror(err)));
	}

	/* look for trigger while recording output */
	while(fgets(CS linebuffer, sizeof(linebuffer), scanner_out)) {
	  if ( Ustrlen(linebuffer) > fwrite(linebuffer, 1, Ustrlen(linebuffer), scanner_record) ) {
	    /* short write */
	    (void) pclose(scanner_out);
	    signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
	    return m_errlog_defer(scanent,
	      string_sprintf("short write on scanner output file (%s).", file_name));
	  }
	  /* try trigger match */
	  if (!trigger && regex_match_and_setup(cmdline_trigger_re, linebuffer, 0, -1))
	    trigger = 1;
	}

	(void)fclose(scanner_record);
	sep = pclose(scanner_out);
	signal(SIGCHLD,eximsigchld); signal(SIGPIPE,eximsigpipe);
	if (sep != 0)
	    return m_errlog_defer(scanent,
		sep == -1
		? string_sprintf("running scanner failed: %s", strerror(sep))
		: string_sprintf("scanner returned error code: %d", sep));

	if (trigger) {
	  uschar * s;
	  /* setup default virus name */
	  malware_name = US"unknown";

	  /* re-open the scanner output file, look for name match */
	  scanner_record = fopen(CS file_name, "rb");
	  while(fgets(CS linebuffer, sizeof(linebuffer), scanner_record)) {
	    /* try match */
	    if ((s = m_pcre_exec(cmdline_regex_re, linebuffer)))
	      malware_name = s;
	  }
	  (void)fclose(scanner_record);
	}
	else /* no virus found */
	  malware_name = NULL;
	break;
      }	/* cmdline */

    case M_SOPHIE: /* "sophie" scanner type --------------------------------- */
      {
	int bread = 0;
	uschar *p;
	uschar * file_name;
	uschar av_buffer[1024];

	/* pass the scan directory to sophie */
	file_name = string_copy(eml_filename);
	if ((p = Ustrrchr(file_name, '/')))
	  *p = '\0';

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s scan [%s]\n",
	    scanner_name, scanner_options);

	if (  write(sock, file_name, Ustrlen(file_name)) < 0
	   || write(sock, "\n", 1) != 1
	   )
	  return m_errlog_defer_3(scanent,
	    string_sprintf("unable to write to UNIX socket (%s)", scanner_options),
	    sock);

	/* wait for result */
	memset(av_buffer, 0, sizeof(av_buffer));
	if ((!(bread = ip_recv(sock, av_buffer, sizeof(av_buffer), MALWARE_TIMEOUT)) > 0))
	  return m_errlog_defer_3(scanent,
	    string_sprintf("unable to read from UNIX socket (%s)", scanner_options),
	    sock);

	/* infected ? */
	if (av_buffer[0] == '1') {
	  uschar * s = Ustrchr(av_buffer, '\n');
	  if (s)
	    *s = '\0';
	  malware_name = string_copy(&av_buffer[2]);
	}
	else if (!strncmp(CS av_buffer, "-1", 2))
	  return m_errlog_defer_3(scanent, US"scanner reported error", sock);
	else /* all ok, no virus */
	  malware_name = NULL;

	break;
      }

    case M_CLAMD: /* "clamd" scanner type ----------------------------------- */
      {
      /* This code was originally contributed by David Saez */
      /* There are three scanning methods available to us:
       *  (1) Use the SCAN command, pointing to a file in the filesystem
       *  (2) Use the STREAM command, send the data on a separate port
       *  (3) Use the zINSTREAM command, send the data inline
       * The zINSTREAM command was introduced with ClamAV 0.95, which marked
       * STREAM deprecated; see: http://wiki.clamav.net/bin/view/Main/UpgradeNotes095
       * In Exim, we use SCAN if using a Unix-domain socket or explicitly told that
       * the TCP-connected daemon is actually local; otherwise we use zINSTREAM unless
       * WITH_OLD_CLAMAV_STREAM is defined.
       * See Exim bug 926 for details.  */

	uschar *p, *vname, *result_tag, *response_end;
	int bread=0;
	uschar * file_name;
	uschar av_buffer[1024];
	uschar *hostname = US"";
	host_item connhost;
	uschar *clamav_fbuf;
	int clam_fd, result;
	off_t fsize;
	unsigned int fsize_uint;
	BOOL use_scan_command = FALSE;
	clamd_address_container * clamd_address_vector[MAX_CLAMD_SERVERS];
	int current_server;
	int num_servers = 0;
  #ifdef WITH_OLD_CLAMAV_STREAM
	unsigned int port;
	uschar av_buffer2[1024];
	int sockData;
  #else
	uint32_t send_size, send_final_zeroblock;
  #endif

	if (*scanner_options == '/')
	  /* Local file; so we def want to use_scan_command and don't want to try
	   * passing IP/port combinations */
	  use_scan_command = TRUE;
	else {
	  const uschar *address = scanner_options;
	  uschar address_buffer[MAX_CLAMD_ADDRESS_LENGTH + 20];

	  /* Go through the rest of the list of host/port and construct an array
	   * of servers to try. The first one is the bit we just passed from
	   * scanner_options so process that first and then scan the remainder of
	   * the address buffer */
	  do {
	    clamd_address_container *this_clamd;

	    /* The 'local' option means use the SCAN command over the network
	     * socket (ie common file storage in use) */
	    if (strcmpic(address,US"local") == 0) {
	      use_scan_command = TRUE;
	      continue;
	    }

	    /* XXX: If unsuccessful we should free this memory */
	    this_clamd =
		(clamd_address_container *)store_get(sizeof(clamd_address_container));

	    /* extract host and port part */
	    if( sscanf(CS address, "%" MAX_CLAMD_ADDRESS_LENGTH_S "s %u",
		   this_clamd->tcp_addr, &(this_clamd->tcp_port)) != 2 ) {
	      (void) m_errlog_defer(scanent,
			  string_sprintf("invalid address '%s'", address));
	      continue;
	    }

	    clamd_address_vector[num_servers] = this_clamd;
	    num_servers++;
	    if (num_servers >= MAX_CLAMD_SERVERS) {
	      (void) m_errlog_defer(scanent,
		    US"More than " MAX_CLAMD_SERVERS_S " clamd servers "
		    "specified; only using the first " MAX_CLAMD_SERVERS_S );
	      break;
	    }
	  } while ((address = string_nextinlist(&av_scanner_work, &sep,
					  address_buffer,
					  sizeof(address_buffer))) != NULL);

	  /* check if we have at least one server */
	  if (!num_servers)
	    return m_errlog_defer(scanent,
	      US"no useable server addresses in malware configuration option.");
	}

	/* See the discussion of response formats below to see why we really don't
	like colons in filenames when passing filenames to ClamAV. */
	if (use_scan_command && Ustrchr(eml_filename, ':'))
	  return m_errlog_defer(scanent,
	    string_sprintf("local/SCAN mode incompatible with" \
	      " : in path to email filename [%s]", eml_filename));

	/* We have some network servers specified */
	if (num_servers) {

	  /* Confirmed in ClamAV source (0.95.3) that the TCPAddr option of clamd
	   * only supports AF_INET, but we should probably be looking to the
	   * future and rewriting this to be protocol-independent anyway. */

	  while ( num_servers > 0 ) {
	    /* Randomly pick a server to start with */
	    current_server = random_number( num_servers );

	    debug_printf("trying server name %s, port %u\n",
			 clamd_address_vector[current_server]->tcp_addr,
			 clamd_address_vector[current_server]->tcp_port);

	    /* Lookup the host. This is to ensure that we connect to the same IP
	     * on both connections (as one host could resolve to multiple ips) */
	    sock= m_tcpsocket(clamd_address_vector[current_server]->tcp_addr,
				clamd_address_vector[current_server]->tcp_port,
				&connhost, &errstr);
	    if (sock >= 0) {
	      /* Connection successfully established with a server */
	      hostname = clamd_address_vector[current_server]->tcp_addr;
	      break;
	    }

	    (void) m_errlog_defer(scanent, errstr);

	    /* Remove the server from the list. XXX We should free the memory */
	    num_servers--;
	    int i;
	    for( i = current_server; i < num_servers; i++ )
	      clamd_address_vector[i] = clamd_address_vector[i+1];
	  }

	  if ( num_servers == 0 )
	    return m_errlog_defer(scanent, US"all servers failed");

	} else {
	  if ((sock = m_unixsocket(scanner_options, &errstr)) < 0)
	    return m_errlog_defer(scanent, errstr);
	}

	/* have socket in variable "sock"; command to use is semi-independent of
	 * the socket protocol.  We use SCAN if is local (either Unix/local
	 * domain socket, or explicitly told local) else we stream the data.
	 * How we stream the data depends upon how we were built.  */

	if (!use_scan_command) {

  #ifdef WITH_OLD_CLAMAV_STREAM
	  /* "STREAM\n" command, get back a "PORT <N>\n" response, send data to
	   * that port on a second connection; then in the scan-method-neutral
	   * part, read the response back on the original connection. */

	  DEBUG(D_acl) debug_printf("Malware scan: issuing %s old-style remote scan (PORT)\n",
	      scanner_name);

	  /* Pass the string to ClamAV (7 = "STREAM\n") */
	  if (m_sock_send(sock, US"STREAM\n", 7, &errstr) < 0)
	    return m_errlog_defer(scanent, errstr);

	  memset(av_buffer2, 0, sizeof(av_buffer2));
	  bread = ip_recv(sock, av_buffer2, sizeof(av_buffer2), MALWARE_TIMEOUT);

	  if (bread < 0)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to read PORT from socket (%s)",
		  strerror(errno)),
	      sock);

	  if (bread == sizeof(av_buffer2))
	    return m_errlog_defer_3(scanent, "buffer too small", sock);

	  if (!(*av_buffer2))
	    return m_errlog_defer_3(scanent, "ClamAV returned null", sock);

	  av_buffer2[bread] = '\0';
	  if( sscanf(CS av_buffer2, "PORT %u\n", &port) != 1 )
	    return m_errlog_defer_3(scanent,
	      string_sprintf("Expected port information from clamd, got '%s'",
		av_buffer2),
	      sock);

	  sockData = m_tcpsocket(connhost.address, port, NULL, &errstr);
	  if (sockData < 0)
	    return m_errlog_defer_3(scanent, errstr, sock);

  #define CLOSE_SOCKDATA (void)close(sockData)
  #else /* WITH_OLD_CLAMAV_STREAM not defined */
	  /* New protocol: "zINSTREAM\n" followed by a sequence of <length><data>
	  chunks, <n> a 4-byte number (network order), terminated by a zero-length
	  chunk. */

	  DEBUG(D_acl) debug_printf("Malware scan: issuing %s new-style remote scan (zINSTREAM)\n",
	      scanner_name);

	  /* Pass the string to ClamAV (10 = "zINSTREAM\0") */
	  if (send(sock, "zINSTREAM", 10, 0) < 0)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send zINSTREAM to socket (%s)",
		strerror(errno)),
	      sock);

  #define CLOSE_SOCKDATA /**/
  #endif

	  /* calc file size */
	  if ((clam_fd = open(CS eml_filename, O_RDONLY)) < 0) {
	    int err = errno;
	    CLOSE_SOCKDATA;
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't open spool file %s: %s",
		eml_filename, strerror(err)),
	      sock);
	  }
	  if ((fsize = lseek(clam_fd, 0, SEEK_END)) < 0) {
	    int err = errno;
	    CLOSE_SOCKDATA; (void)close(clam_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't seek spool file %s: %s",
		eml_filename, strerror(err)),
	      sock);
	  }
	  fsize_uint = (unsigned int) fsize;
	  if ((off_t)fsize_uint != fsize) {
	    CLOSE_SOCKDATA; (void)close(clam_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("seeking spool file %s, size overflow",
		eml_filename),
	      sock);
	  }
	  lseek(clam_fd, 0, SEEK_SET);

	  if (!(clamav_fbuf = (uschar *) malloc (fsize_uint))) {
	    CLOSE_SOCKDATA; (void)close(clam_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to allocate memory %u for file (%s)",
		fsize_uint, eml_filename),
	      sock);
	  }

	  if ((result = read(clam_fd, clamav_fbuf, fsize_uint)) < 0) {
	    int err = errno;
	    free(clamav_fbuf); CLOSE_SOCKDATA; (void)close(clam_fd);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("can't read spool file %s: %s",
		eml_filename, strerror(err)),
	      sock);
	  }
	  (void)close(clam_fd);

	  /* send file body to socket */
  #ifdef WITH_OLD_CLAMAV_STREAM
	  if (send(sockData, clamav_fbuf, fsize_uint, 0) < 0) {
	    free(clamav_fbuf); CLOSE_SOCKDATA;
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send file body to socket (%s:%u)",
		hostname, port),
	      sock);
	  }
  #else
	  send_size = htonl(fsize_uint);
	  send_final_zeroblock = 0;
	  if ((send(sock, &send_size, sizeof(send_size), 0) < 0) ||
	      (send(sock, clamav_fbuf, fsize_uint, 0) < 0) ||
	      (send(sock, &send_final_zeroblock, sizeof(send_final_zeroblock), 0) < 0))
	    {
	    free(clamav_fbuf);
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to send file body to socket (%s)", hostname),
	      sock);
	    }
  #endif

	  free(clamav_fbuf);

	  CLOSE_SOCKDATA;
  #undef CLOSE_SOCKDATA

	} else { /* use scan command */
	  /* Send a SCAN command pointing to a filename; then in the then in the
	   * scan-method-neutral part, read the response back */

  /* ================================================================= */

	  /* Prior to the reworking post-Exim-4.72, this scanned a directory,
	  which dates to when ClamAV needed us to break apart the email into the
	  MIME parts (eg, with the now deprecated demime condition coming first).
	  Some time back, ClamAV gained the ability to deconstruct the emails, so
	  doing this would actually have resulted in the mail attachments being
	  scanned twice, in the broken out files and from the original .eml.
	  Since ClamAV now handles emails (and has for quite some time) we can
	  just use the email file itself. */
	  /* Pass the string to ClamAV (7 = "SCAN \n" + \0) */
	  file_name = string_sprintf("SCAN %s\n", eml_filename);

	  DEBUG(D_acl) debug_printf("Malware scan: issuing %s local-path scan [%s]\n",
	      scanner_name, scanner_options);

	  if (send(sock, file_name, Ustrlen(file_name), 0) < 0)
	    return m_errlog_defer_3(scanent,
	      string_sprintf("unable to write to socket (%s)", strerror(errno)),
	      sock);

	  /* Do not shut down the socket for writing; a user report noted that
	   * clamd 0.70 does not react well to this. */
	}
	/* Commands have been sent, no matter which scan method or connection
	 * type we're using; now just read the result, independent of method. */

	/* Read the result */
	memset(av_buffer, 0, sizeof(av_buffer));
	bread = ip_recv(sock, av_buffer, sizeof(av_buffer), MALWARE_TIMEOUT);
	(void)close(sock);
	sock = -1;

	if (!(bread > 0))
	  return m_errlog_defer(scanent,
	    string_sprintf("unable to read from socket (%s)", strerror(errno)));

	if (bread == sizeof(av_buffer))
	  return m_errlog_defer(scanent, US"buffer too small");
	/* We're now assured of a NULL at the end of av_buffer */

	/* Check the result. ClamAV returns one of two result formats.
	In the basic mode, the response is of the form:
	  infected: -> "<filename>: <virusname> FOUND"
	  not-infected: -> "<filename>: OK"
	  error: -> "<filename>: <errcode> ERROR
	If the ExtendedDetectionInfo option has been turned on, then we get:
	  "<filename>: <virusname>(<virushash>:<virussize>) FOUND"
	for the infected case.  Compare:
  /tmp/eicar.com: Eicar-Test-Signature FOUND
  /tmp/eicar.com: Eicar-Test-Signature(44d88612fea8a8f36de82e1278abb02f:68) FOUND

	In the streaming case, clamd uses the filename "stream" which you should
	be able to verify with { ktrace clamdscan --stream /tmp/eicar.com }.  (The
	client app will replace "stream" with the original filename before returning
	results to stdout, but the trace shows the data).

	We will assume that the pathname passed to clamd from Exim does not contain
	a colon.  We will have whined loudly above if the eml_filename does (and we're
	passing a filename to clamd). */

	if (!(*av_buffer))
	  return m_errlog_defer(scanent, US"ClamAV returned null");

	/* strip newline at the end (won't be present for zINSTREAM)
	(also any trailing whitespace, which shouldn't exist, but we depend upon
	this below, so double-check) */
	p = av_buffer + Ustrlen(av_buffer) - 1;
	if (*p == '\n') *p = '\0';

	DEBUG(D_acl) debug_printf("Malware response: %s\n", av_buffer);

	while (isspace(*--p) && (p > av_buffer))
	  *p = '\0';
	if (*p) ++p;
	response_end = p;

	/* colon in returned output? */
	if((p = Ustrchr(av_buffer,':')) == NULL)
	  return m_errlog_defer(scanent,
	    string_sprintf("ClamAV returned malformed result (missing colon): %s",
		    av_buffer));

	/* strip filename */
	while (*p && isspace(*++p)) /**/;
	vname = p;

	/* It would be bad to encounter a virus with "FOUND" in part of the name,
	but we should at least be resistant to it. */
	p = Ustrrchr(vname, ' ');
	result_tag = p ? p+1 : vname;

	if (Ustrcmp(result_tag, "FOUND") == 0) {
	  /* p should still be the whitespace before the result_tag */
	  while (isspace(*p)) --p;
	  *++p = '\0';
	  /* Strip off the extended information too, which will be in parens
	  after the virus name, with no intervening whitespace. */
	  if (*--p == ')') {
	    /* "(hash:size)", so previous '(' will do; if not found, we have
	    a curious virus name, but not an error. */
	    p = Ustrrchr(vname, '(');
	    if (p)
	      *p = '\0';
	  }
	  malware_name = string_copy(vname);
	  DEBUG(D_acl) debug_printf("Malware found, name \"%s\"\n", malware_name);

	} else if (Ustrcmp(result_tag, "ERROR") == 0)
	  return m_errlog_defer(scanent,
	    string_sprintf("ClamAV returned: %s", av_buffer));

	else if (Ustrcmp(result_tag, "OK") == 0) {
	  /* Everything should be OK */
	  malware_name = NULL;
	  DEBUG(D_acl) debug_printf("Malware not found\n");

	} else
	  return m_errlog_defer(scanent,
	    string_sprintf("unparseable response from ClamAV: {%s}", av_buffer));

	break;
      } /* clamd */

    case M_SOCK: /* "sock" scanner type ------------------------------------- */
      /* This code was derived by Martin Poole from the clamd code contributed
         by David Saez and the cmdline code
      */
      {
	int bread;
	uschar * commandline;
	uschar av_buffer[1024];
	uschar * linebuffer;
	uschar * sockline_scanner;
	uschar sockline_scanner_default[] = "%s\n";
	const pcre *sockline_trig_re;
	const pcre *sockline_name_re;

	/* find scanner command line */
	if ((sockline_scanner = string_nextinlist(&av_scanner_work, &sep,
					    NULL, 0)))
	{	/* check for no expansions apart from one %s */
	  uschar * s = Ustrchr(sockline_scanner, '%');
	  if (s++)
	    if ((*s != 's' && *s != '%') || Ustrchr(s+1, '%'))
	      return m_errlog_defer_3(scanent,
				    US"unsafe sock scanner call spec", sock);
	}
	else
	  sockline_scanner = sockline_scanner_default;

	/* find scanner output trigger */
	sockline_trig_re = m_pcre_nextinlist(&av_scanner_work, &sep,
				  "missing trigger specification", &errstr);
	if (!sockline_trig_re)
	  return m_errlog_defer_3(scanent, errstr, sock);

	/* find virus name regex */
	sockline_name_re = m_pcre_nextinlist(&av_scanner_work, &sep,
			    "missing virus name regex specification", &errstr);
	if (!sockline_name_re)
	  return m_errlog_defer_3(scanent, errstr, sock);

	/* prepare scanner call - security depends on expansions check above */
	commandline = string_sprintf("%s/scan/%s/%s.eml", spool_directory, message_id, message_id);
	commandline = string_sprintf( CS sockline_scanner, CS commandline);


	/* Pass the command string to the socket */
	if (m_sock_send(sock, commandline, Ustrlen(commandline), &errstr) < 0)
	  return m_errlog_defer(scanent, errstr);

	/* Read the result */
	memset(av_buffer, 0, sizeof(av_buffer));
	bread = read(sock, av_buffer, sizeof(av_buffer));

	if (!(bread > 0))
	  return m_errlog_defer_3(scanent,
	    string_sprintf("unable to read from socket (%s)", strerror(errno)),
	    sock);

	if (bread == sizeof(av_buffer))
	  return m_errlog_defer_3(scanent, US"buffer too small", sock);
	linebuffer = string_copy(av_buffer);

	/* try trigger match */
	if (regex_match_and_setup(sockline_trig_re, linebuffer, 0, -1)) {
	  if (!(malware_name = m_pcre_exec(sockline_name_re, av_buffer)))
	    malware_name = US "unknown";
	}
	else /* no virus found */
	  malware_name = NULL;
	break;
      }

    case M_MKSD: /* "mksd" scanner type ------------------------------------- */
      {
	char *mksd_options_end;
	int mksd_maxproc = 1;  /* default, if no option supplied */
	int sock;
	int retval;

	if (scanner_options) {
	  mksd_maxproc = (int)strtol(CS scanner_options, &mksd_options_end, 10);
	  if (  *scanner_options == '\0'
	     || *mksd_options_end != '\0'
	     || mksd_maxproc < 1
	     || mksd_maxproc > 32
	     )
	    return m_errlog_defer(scanent,
	      string_sprintf("invalid option '%s'", scanner_options));
	}

	if((sock = m_unixsocket(US "/var/run/mksd/socket", &errstr)) < 0)
	  return m_errlog_defer(scanent, errstr);

	malware_name = NULL;

	DEBUG(D_acl) debug_printf("Malware scan: issuing %s scan\n", scanner_name);

	if ((retval = mksd_scan_packed(scanent, sock, eml_filename)) != OK) {
	  close (sock);
	  return retval;
	}
	break;
      }
    case M_AVAST: /* "avast" scanner type ----------------------------------- */
      {
      int ovector[1*3];
      uschar buf[1024];
      uschar * scanrequest;
      const pcre * avast_clean_re, * avast_virus_re;
      enum {AVA_HELO, AVA_OPT, AVA_RSP, AVA_DONE} avast_stage;

      /* According to Martin Tuma @avast the protocol uses "escaped
      whitespace", that is, every embedded whitespace is backslash
      escaped, as well as backslash is protected by backslash.
      The returned lines contain the name of the scanned file, a tab
      and the [ ] marker.
      [+] - not infected
      [L] - infected
      [E] - some error occured
      Such marker follows the first non-escaped TAB.  */
      if (  !(avast_clean_re =
		m_pcre_compile(US"(?!\\\\)\\t\\[\\+\\]", &errstr))
	 || !(avast_virus_re =
		m_pcre_compile(US"(?!\\\\)\\t\\[L\\]\\d\\.\\d\\t\\d\\s(.*)",
		  &errstr))
	 )
	return malware_errlog_defer(errstr);

      /* wait for result */
      for (avast_stage = AVA_HELO; recv_line(sock, buf, sizeof(buf)) > 0; )
	{
	int slen = Ustrlen(buf);
	if (slen >= 1) 
	  {
	  DEBUG(D_acl) debug_printf("got from avast: %s\n", buf);
	  switch (avast_stage)
	    {
	    case AVA_HELO:
	      if (Ustrncmp(buf, "220", 3) != 0)
		goto endloop;			/* require a 220 */
	      goto sendreq;

	    case AVA_OPT:
	      if (Ustrncmp(buf, "210", 3) == 0)
		break;				/* ignore 210 responses */
	      if (Ustrncmp(buf, "200", 3) != 0)
		goto endloop;			/* require a 200 */

	    sendreq:
	      {
	      int len;
	      /* Check for another option to send. Newline-terminate it. */
	      if ((scanrequest = string_nextinlist(&av_scanner_work, &sep,
				NULL, 0)))
		{
		scanrequest = string_sprintf("%s\n", scanrequest);
		avast_stage = AVA_OPT;		/* just sent option */
		}
	      else
		{
		scanrequest = string_sprintf("SCAN %s/scan/%s\n",
		    spool_directory, message_id);
		avast_stage = AVA_RSP;		/* just sent command */
		}

	      /* send config-cmd or scan-request to socket */
	      len = Ustrlen(scanrequest);
	      if (send(sock, scanrequest, len, 0) < 0)
		{
		scanrequest[len-1] = '\0';
		return m_errlog_defer_3(scanent, string_sprintf(
		      "unable to send request '%s' to socket (%s): %s",
		      scanrequest, scanner_options, strerror(errno)), sock);
		}
	      break;
	      }

	    case AVA_RSP:
	      if (Ustrncmp(buf, "210", 3) == 0)
		break;  /* ignore the "210 SCAN DATA" message */

	      if (pcre_exec(avast_clean_re, NULL, CS buf, slen,
		    0, 0, ovector, nelements(ovector)) > 0)
		break;

	      if ((malware_name = m_pcre_exec(avast_virus_re, buf)))
		{ /* remove backslash in front of [whitespace|backslash] */
		uschar * p, * p0;
		for (p = malware_name; *p; ++p) 
		  if (*p == '\\' && (isspace(p[1]) || p[1] == '\\'))
		    for (p0 = p; *p0; ++p0) *p0 = p0[1];
		
		avast_stage = AVA_DONE;
		goto endloop;
		}

	      if (Ustrncmp(buf, "200 SCAN OK", 11) == 0) 
		{ /* we're done finally */
		if (send(sock, "QUIT\n", 5, 0) < 0) /* courtesy */
		  return m_errlog_defer_3(scanent, string_sprintf(
			      "unable to send quit request to socket (%s): %s",
			      scanner_options, strerror(errno)),
			      sock);
		malware_name = NULL;
		avast_stage = AVA_DONE;
		goto endloop;
		}

	      /* here for any unexpected response from the scanner */
	      goto endloop;
	    }
	}
      }
      endloop:

      switch(avast_stage)
	{
        case AVA_HELO:	
	case AVA_OPT:
	case AVA_RSP:	return m_errlog_defer_3(scanent, string_sprintf(
			  "invalid response from scanner: %s\n", buf), sock);
	default:	break;
	}
      }
    }	/* scanner type switch */

    if (sock >= 0)
      (void) close (sock);
    malware_ok = TRUE;			/* set "been here, done that" marker */
  }

  /* match virus name against pattern (caseless ------->----------v) */
  if (malware_name && regex_match_and_setup(re, malware_name, 0, -1))
    {
    DEBUG(D_acl) debug_printf("Matched regex to malware [%s] [%s]\n", malware_regex, malware_name);
    return OK;
    }
  else
    return FAIL;
}


/* simple wrapper for reading lines from sockets */
int
recv_line(int sock, uschar *buffer, int size)
{
  uschar *p = buffer;

  memset(buffer,0,size);
  /* read until \n */
  while(recv(sock,p,1,0) > -1) {
    if ((p-buffer) > (size-2)) break;
    if (*p == '\n') break;
    if (*p != '\r') p++;
  }
  *p = '\0';

  return (p-buffer);
}


/* ============= private routines for the "mksd" scanner type ============== */

#include <sys/uio.h>

static inline int
mksd_writev (int sock, struct iovec *iov, int iovcnt)
{
  int i;

  for (;;) {
    do
      i = writev (sock, iov, iovcnt);
    while ((i < 0) && (errno == EINTR));
    if (i <= 0) {
      (void) malware_errlog_defer(US"unable to write to mksd UNIX socket (/var/run/mksd/socket)");
      return -1;
    }

    for (;;)
      if (i >= iov->iov_len) {
        if (--iovcnt == 0)
          return 0;
        i -= iov->iov_len;
        iov++;
      } else {
        iov->iov_len -= i;
        iov->iov_base = CS iov->iov_base + i;
        break;
      }
  }
}

static inline int
mksd_read_lines (int sock, uschar *av_buffer, int av_buffer_size)
{
  int offset = 0;
  int i;

  do {
    if ((i = recv (sock, av_buffer+offset, av_buffer_size-offset, 0)) <= 0) {
      (void) malware_errlog_defer(US"unable to read from mksd UNIX socket (/var/run/mksd/socket)");
      return -1;
    }

    offset += i;
    /* offset == av_buffer_size -> buffer full */
    if (offset == av_buffer_size) {
      (void) malware_errlog_defer(US"malformed reply received from mksd");
      return -1;
    }
  } while (av_buffer[offset-1] != '\n');

  av_buffer[offset] = '\0';
  return offset;
}

static inline int
mksd_parse_line(struct scan * scanent, char *line)
{
  char *p;

  switch (*line) {
    case 'O': /* OK */
      return OK;

    case 'E':
    case 'A': /* ERR */
      if ((p = strchr (line, '\n')) != NULL)
        *p = '\0';
      return m_errlog_defer(scanent,
	string_sprintf("scanner failed: %s", line));

    default: /* VIR */
      if ((p = strchr (line, '\n')) != NULL) {
        *p = '\0';
        if (((p-line) > 5) && (line[3] == ' '))
          if (((p = strchr (line+4, ' ')) != NULL) && ((p-line) > 4)) {
            *p = '\0';
            malware_name = string_copy(US line+4);
            return OK;
          }
      }
      return m_errlog_defer(scanent,
	string_sprintf("malformed reply received: %s", line));
  }
}

static int
mksd_scan_packed(struct scan * scanent, int sock, uschar *scan_filename)
{
  struct iovec iov[3];
  const char *cmd = "MSQ\n";
  uschar av_buffer[1024];

  iov[0].iov_base = (void *) cmd;
  iov[0].iov_len = 3;
  iov[1].iov_base = CS scan_filename;
  iov[1].iov_len = Ustrlen(scan_filename);
  iov[2].iov_base = (void *) (cmd + 3);
  iov[2].iov_len = 1;

  if (mksd_writev (sock, iov, 3) < 0)
    return DEFER;

  if (mksd_read_lines (sock, av_buffer, sizeof (av_buffer)) < 0)
    return DEFER;

  return mksd_parse_line (scanent, CS av_buffer);
}

#endif /*WITH_CONTENT_SCAN*/
/*
 * vi: aw ai sw=2
 */