/*

 * pcap-septel.c: Packet capture interface for Intel/Septel card.

 *

 * Authors: Gilbert HOYEK (gil_hoyek@hotmail.com), Elias M. KHOURY

 * (+961 3 485243)

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <sys/param.h>

#include <stdlib.h>

#include <string.h>

#include <errno.h>

#include "pcap-int.h"

#include <ctype.h>

#include <netinet/in.h>

#include <sys/mman.h>

#include <sys/socket.h>

#include <sys/types.h>

#include <unistd.h>

#include <msg.h>

#include <ss7_inc.h>

#include <sysgct.h>

#include <pack.h>

#include <system.h>

#include "pcap-septel.h"

static int septel_setfilter(pcap_t *p, struct bpf_program *fp);

static int septel_stats(pcap_t *p, struct pcap_stat *ps);

static int septel_getnonblock(pcap_t *p);

static int septel_setnonblock(pcap_t *p, int nonblock);

/*

 * Private data for capturing on Septel devices.

 */

struct pcap_septel {

	struct pcap_stat stat;

}

/*

 *  Read at most max_packets from the capture queue and call the callback

 *  for each of them. Returns the number of packets handled, -1 if an

 *  error occured, or -2 if we were told to break out of the loop.

 */

static int septel_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {

  struct pcap_septel *ps = p->priv;

  HDR *h;

  MSG *m;

  int processed = 0 ;

  int t = 0 ;

  /* identifier for the message queue of the module(upe) from which we are capturing

   * packets.These IDs are defined in system.txt . By default it is set to 0x2d

   * so change it to 0xdd for technical reason and therefore the module id for upe becomes:

   * LOCAL        0xdd           * upe - Example user part task */

  unsigned int id = 0xdd;

  /* process the packets */

  do  {

    unsigned short packet_len = 0;

    int caplen = 0;

    int counter = 0;

    struct pcap_pkthdr   pcap_header;

    u_char *dp ;

    /*

     * Has "pcap_breakloop()" been called?

     */

loop:

    if (p->break_loop) {

      /*

       * Yes - clear the flag that indicates that

       * it has, and return -2 to indicate that

       * we were told to break out of the loop.

       */

      p->break_loop = 0;

      return -2;

    }

    /*repeat until a packet is read

     *a NULL message means :

     * when no packet is in queue or all packets in queue already read */

    do  {

      /* receive packet in non-blocking mode

       * GCT_grab is defined in the septel library software */

      h = GCT_grab(id);

      m = (MSG*)h;

      /* a couter is added here to avoid an infinite loop

       * that will cause our capture program GUI to freeze while waiting

       * for a packet*/

      counter++ ;

    }

    while  ((m == NULL)&& (counter< 100)) ;

    if (m != NULL) {

      t = h->type ;

      /* catch only messages with type = 0xcf00 or 0x8f01 corrsponding to ss7 messages*/

      /* XXX = why not use API_MSG_TX_REQ for 0xcf00 and API_MSG_RX_IND

       * for 0x8f01? */

      if ((t != 0xcf00) && (t != 0x8f01)) {

        relm(h);

        goto loop ;

      }

      /* XXX - is API_MSG_RX_IND for an MTP2 or MTP3 message? */

      dp = get_param(m);/* get pointer to MSG parameter area (m->param) */

      packet_len = m->len;

      caplen =  p->snapshot ;

      if (caplen > packet_len) {

        caplen = packet_len;

      }

      /* Run the packet filter if there is one. */

      if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {

        /*  get a time stamp , consisting of :

         *

         *  pcap_header.ts.tv_sec:

         *  ----------------------

         *   a UNIX format time-in-seconds when he packet was captured,

         *   i.e. the number of seconds since Epoch time (January 1,1970, 00:00:00 GMT)

         *

         *  pcap_header.ts.tv_usec :

         *  ------------------------

         *   the number of microseconds since that second

         *   when the packet was captured

         */

        (void)gettimeofday(&pcap_header.ts, NULL);

        /* Fill in our own header data */

        pcap_header.caplen = caplen;

        pcap_header.len = packet_len;

        /* Count the packet. */

        ps->stat.ps_recv++;

        /* Call the user supplied callback function */

        callback(user, &pcap_header, dp);

        processed++ ;

      }

      /* after being processed the packet must be

       *released in order to receive another one */

      relm(h);

    }else

      processed++;

  }

  while (processed < cnt) ;

  return processed ;

}

static int

septel_inject(pcap_t *handle, const void *buf _U_, size_t size _U_)

{

  pcap_strlcpy(handle->errbuf, "Sending packets isn't supported on Septel cards",

          PCAP_ERRBUF_SIZE);

  return (-1);

}

/*

 *  Activate a handle for a live capture from the given Septel device.  Always pass a NULL device

 *  The promisc flag is ignored because Septel cards have built-in tracing.

 *  The timeout is also ignored as it is not supported in hardware.

 *

 *  See also pcap(3).

 */

static pcap_t *septel_activate(pcap_t* handle) {

  /* Initialize some components of the pcap structure. */

  handle->linktype = DLT_MTP2;

  /*

   * Turn a negative snapshot value (invalid), a snapshot value of

   * 0 (unspecified), or a value bigger than the normal maximum

   * value, into the maximum allowed value.

   *

   * If some application really *needs* a bigger snapshot

   * length, we should just increase MAXIMUM_SNAPLEN.

   */

  if (handle->snapshot <= 0 || handle->snapshot > MAXIMUM_SNAPLEN)

    handle->snapshot = MAXIMUM_SNAPLEN;

  handle->bufsize = 0;

  /*

   * "select()" and "poll()" don't work on Septel queues

   */

  handle->selectable_fd = -1;

  handle->read_op = septel_read;

  handle->inject_op = septel_inject;

  handle->setfilter_op = septel_setfilter;

  handle->set_datalink_op = NULL; /* can't change data link type */

  handle->getnonblock_op = septel_getnonblock;

  handle->setnonblock_op = septel_setnonblock;

  handle->stats_op = septel_stats;

  return 0;

}

pcap_t *septel_create(const char *device, char *ebuf, int *is_ours) {

	const char *cp;

	pcap_t *p;

	/* Does this look like the Septel device? */

	cp = strrchr(device, '/');

	if (cp == NULL)

		cp = device;

	if (strcmp(cp, "septel") != 0) {

		/* Nope, it's not "septel" */

		*is_ours = 0;

		return NULL;

	}

	/* OK, it's probably ours. */

	*is_ours = 1;

	p = pcap_create_common(ebuf, sizeof (struct pcap_septel));

	if (p == NULL)

		return NULL;

	p->activate_op = septel_activate;

	/*

	 * Set these up front, so that, even if our client tries

	 * to set non-blocking mode before we're activated, or

	 * query the state of non-blocking mode, they get an error,

	 * rather than having the non-blocking mode option set

	 * for use later.

	 */

	p->getnonblock_op = septel_getnonblock;

	p->setnonblock_op = septel_setnonblock;

	return p;

}

static int septel_stats(pcap_t *p, struct pcap_stat *ps) {

  struct pcap_septel *handlep = p->priv;

  /*handlep->stat.ps_recv = 0;*/

  /*handlep->stat.ps_drop = 0;*/

  *ps = handlep->stat;

  return 0;

}

int

septel_findalldevs(pcap_if_list_t *devlistp, char *errbuf)

{

  /*

   * XXX - do the notions of "up", "running", or "connected" apply here?

   */

  if (add_dev(devlistp,"septel",0,"Intel/Septel device",errbuf) == NULL)

    return -1;

  return 0;

}

/*

 * Installs the given bpf filter program in the given pcap structure.  There is

 * no attempt to store the filter in kernel memory as that is not supported

 * with Septel cards.

 */

static int septel_setfilter(pcap_t *p, struct bpf_program *fp) {

  if (!p)

    return -1;

  if (!fp) {

    strncpy(p->errbuf, "setfilter: No filter specified",

	    sizeof(p->errbuf));

    return -1;

  }

  /* Make our private copy of the filter */

  if (install_bpf_program(p, fp) < 0)

    return -1;

  return (0);

}

/*

 * We don't support non-blocking mode.  I'm not sure what we'd

 * do to support it and, given that we don't support select()/

 * poll()/epoll_wait()/kevent() etc., it probably doesn't

 * matter.

 */

static int

septel_getnonblock(pcap_t *p)

{

  fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");

  return (-1);

}

static int

septel_setnonblock(pcap_t *p, int nonblock _U_)

{

  fprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Non-blocking mode not supported on Septel devices");

  return (-1);

}

#ifdef SEPTEL_ONLY

/*

 * This libpcap build supports only Septel cards, not regular network

 * interfaces.

 */

/*

 * There are no regular interfaces, just Septel interfaces.

 */

int

pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)

{

  return (0);

}

/*

 * Attempts to open a regular interface fail.

 */

pcap_t *

pcap_create_interface(const char *device, char *errbuf)

{

  pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,

                "This version of libpcap only supports Septel cards");

  return (NULL);

}

/*

 * Libpcap version string.

 */

const char *

pcap_lib_version(void)

{

  return (PCAP_VERSION_STRING " (Septel-only)");

}

#endif