/*

 * Copyright (c) 1993, 1994, 1995, 1996, 1997

 *	The Regents of the University of California.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that: (1) source code distributions

 * retain the above copyright notice and this paragraph in its entirety, (2)

 * distributions including binary code include the above copyright notice and

 * this paragraph in its entirety in the documentation or other materials

 * provided with the distribution, and (3) all advertising materials mentioning

 * features or use of this software display the following acknowledgement:

 * ``This product includes software developed by the University of California,

 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of

 * the University nor the names of its contributors may be used to endorse

 * or promote products derived from this software without specific prior

 * written permission.

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED

 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <sys/param.h>

#include <sys/file.h>

#include <sys/ioctl.h>

#include <sys/socket.h>

#include <sys/time.h>

#include <net/raw.h>

#include <net/if.h>

#include <netinet/in.h>

#include <netinet/in_systm.h>

#include <netinet/ip.h>

#include <netinet/if_ether.h>

#include <netinet/ip_var.h>

#include <netinet/udp.h>

#include <netinet/udp_var.h>

#include <netinet/tcp.h>

#include <netinet/tcpip.h>

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "pcap-int.h"

#ifdef HAVE_OS_PROTO_H

#include "os-proto.h"

#endif

/*

 * Private data for capturing on snoop devices.

 */

struct pcap_snoop {

	struct pcap_stat stat;

};

static int

pcap_read_snoop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)

{

	struct pcap_snoop *psn = p->priv;

	int cc;

	register struct snoopheader *sh;

	register u_int datalen;

	register u_int caplen;

	register u_char *cp;

again:

	/*

	 * Has "pcap_breakloop()" been called?

	 */

	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);

	}

	cc = read(p->fd, (char *)p->buffer, p->bufsize);

	if (cc < 0) {

		/* Don't choke when we get ptraced */

		switch (errno) {

		case EINTR:

			goto again;

		case EWOULDBLOCK:

			return (0);			/* XXX */

		}

		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),

		    errno, "read");

		return (-1);

	}

	sh = (struct snoopheader *)p->buffer;

	datalen = sh->snoop_packetlen;

	/*

	 * XXX - Sigh, snoop_packetlen is a 16 bit quantity.  If we

	 * got a short length, but read a full sized snoop pakcet,

	 * assume we overflowed and add back the 64K...

	 */

	if (cc == (p->snapshot + sizeof(struct snoopheader)) &&

	    (datalen < p->snapshot))

		datalen += (64 * 1024);

	caplen = (datalen < p->snapshot) ? datalen : p->snapshot;

	cp = (u_char *)(sh + 1) + p->offset;		/* XXX */

	/*

	 * XXX unfortunately snoop loopback isn't exactly like

	 * BSD's.  The address family is encoded in the first 2

	 * bytes rather than the first 4 bytes!  Luckily the last

	 * two snoop loopback bytes are zeroed.

	 */

	if (p->linktype == DLT_NULL && *((short *)(cp + 2)) == 0) {

		u_int *uip = (u_int *)cp;

		*uip >>= 16;

	}

	if (p->fcode.bf_insns == NULL ||

	    bpf_filter(p->fcode.bf_insns, cp, datalen, caplen)) {

		struct pcap_pkthdr h;

		++psn->stat.ps_recv;

		h.ts.tv_sec = sh->snoop_timestamp.tv_sec;

		h.ts.tv_usec = sh->snoop_timestamp.tv_usec;

		h.len = datalen;

		h.caplen = caplen;

		(*callback)(user, &h, cp);

		return (1);

	}

	return (0);

}

static int

pcap_inject_snoop(pcap_t *p, const void *buf, size_t size)

{

	int ret;

	/*

	 * XXX - libnet overwrites the source address with what I

	 * presume is the interface's address; is that required?

	 */

	ret = write(p->fd, buf, size);

	if (ret == -1) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "send");

		return (-1);

	}

	return (ret);

}

static int

pcap_stats_snoop(pcap_t *p, struct pcap_stat *ps)

{

	struct pcap_snoop *psn = p->priv;

	register struct rawstats *rs;

	struct rawstats rawstats;

	rs = &rawstats;

	memset(rs, 0, sizeof(*rs));

	if (ioctl(p->fd, SIOCRAWSTATS, (char *)rs) < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),

		    errno, "SIOCRAWSTATS");

		return (-1);

	}

	/*

	 * "ifdrops" are those dropped by the network interface

	 * due to resource shortages or hardware errors.

	 *

	 * "sbdrops" are those dropped due to socket buffer limits.

	 *

	 * As filter is done in userland, "sbdrops" counts packets

	 * regardless of whether they would've passed the filter.

	 *

	 * XXX - does this count *all* Snoop or Drain sockets,

	 * rather than just this socket?  If not, why does it have

	 * both Snoop and Drain statistics?

	 */

	psn->stat.ps_drop =

	    rs->rs_snoop.ss_ifdrops + rs->rs_snoop.ss_sbdrops +

	    rs->rs_drain.ds_ifdrops + rs->rs_drain.ds_sbdrops;

	/*

	 * "ps_recv" counts only packets that passed the filter.

	 * As filtering is done in userland, this does not include

	 * packets dropped because we ran out of buffer space.

	 */

	*ps = psn->stat;

	return (0);

}

/* XXX can't disable promiscuous */

static int

pcap_activate_snoop(pcap_t *p)

{

	int fd;

	struct sockaddr_raw sr;

	struct snoopfilter sf;

	u_int v;

	int ll_hdrlen;

	int snooplen;

	struct ifreq ifr;

	fd = socket(PF_RAW, SOCK_RAW, RAWPROTO_SNOOP);

	if (fd < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "snoop socket");

		goto bad;

	}

	p->fd = fd;

	memset(&sr, 0, sizeof(sr));

	sr.sr_family = AF_RAW;

	(void)strncpy(sr.sr_ifname, p->opt.device, sizeof(sr.sr_ifname));

	if (bind(fd, (struct sockaddr *)&sr, sizeof(sr))) {

		/*

		 * XXX - there's probably a particular bind error that

		 * means "there's no such device" and a particular bind

		 * error that means "that device doesn't support snoop";

		 * they might be the same error, if they both end up

		 * meaning "snoop doesn't know about that device".

		 */

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "snoop bind");

		goto bad;

	}

	memset(&sf, 0, sizeof(sf));

	if (ioctl(fd, SIOCADDSNOOP, &sf) < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "SIOCADDSNOOP");

		goto bad;

	}

	if (p->opt.buffer_size != 0)

		v = p->opt.buffer_size;

	else

		v = 64 * 1024;	/* default to 64K buffer size */

	(void)setsockopt(fd, SOL_SOCKET, SO_RCVBUF, (char *)&v, sizeof(v));

	/*

	 * XXX hack - map device name to link layer type

	 */

	if (strncmp("et", p->opt.device, 2) == 0 ||	/* Challenge 10 Mbit */

	    strncmp("ec", p->opt.device, 2) == 0 ||	/* Indigo/Indy 10 Mbit,

							   O2 10/100 */

	    strncmp("ef", p->opt.device, 2) == 0 ||	/* O200/2000 10/100 Mbit */

	    strncmp("eg", p->opt.device, 2) == 0 ||	/* Octane/O2xxx/O3xxx Gigabit */

	    strncmp("gfe", p->opt.device, 3) == 0 ||	/* GIO 100 Mbit */

	    strncmp("fxp", p->opt.device, 3) == 0 ||	/* Challenge VME Enet */

	    strncmp("ep", p->opt.device, 2) == 0 ||	/* Challenge 8x10 Mbit EPLEX */

	    strncmp("vfe", p->opt.device, 3) == 0 ||	/* Challenge VME 100Mbit */

	    strncmp("fa", p->opt.device, 2) == 0 ||

	    strncmp("qaa", p->opt.device, 3) == 0 ||

	    strncmp("cip", p->opt.device, 3) == 0 ||

	    strncmp("el", p->opt.device, 2) == 0) {

		p->linktype = DLT_EN10MB;

		p->offset = RAW_HDRPAD(sizeof(struct ether_header));

		ll_hdrlen = sizeof(struct ether_header);

		/*

		 * This is (presumably) a real Ethernet capture; give it a

		 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so

		 * that an application can let you choose it, in case you're

		 * capturing DOCSIS traffic that a Cisco Cable Modem

		 * Termination System is putting out onto an Ethernet (it

		 * doesn't put an Ethernet header onto the wire, it puts raw

		 * DOCSIS frames out on the wire inside the low-level

		 * Ethernet framing).

		 *

		 * XXX - are there any sorts of "fake Ethernet" that have

		 * Ethernet link-layer headers but that *shouldn't offer

		 * DLT_DOCSIS as a Cisco CMTS won't put traffic onto it

		 * or get traffic bridged onto it?  "el" is for ATM LANE

		 * Ethernet devices, so that might be the case for them;

		 * the same applies for "qaa" classical IP devices.  If

		 * "fa" devices are for FORE SPANS, that'd apply to them

		 * as well; what are "cip" devices - some other ATM

		 * Classical IP devices?

		 */

		p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);

		/*

		 * If that fails, just leave the list empty.

		 */

		if (p->dlt_list != NULL) {

			p->dlt_list[0] = DLT_EN10MB;

			p->dlt_list[1] = DLT_DOCSIS;

			p->dlt_count = 2;

		}

	} else if (strncmp("ipg", p->opt.device, 3) == 0 ||

		   strncmp("rns", p->opt.device, 3) == 0 ||	/* O2/200/2000 FDDI */

		   strncmp("xpi", p->opt.device, 3) == 0) {

		p->linktype = DLT_FDDI;

		p->offset = 3;				/* XXX yeah? */

		ll_hdrlen = 13;

	} else if (strncmp("ppp", p->opt.device, 3) == 0) {

		p->linktype = DLT_RAW;

		ll_hdrlen = 0;	/* DLT_RAW meaning "no PPP header, just the IP packet"? */

	} else if (strncmp("qfa", p->opt.device, 3) == 0) {

		p->linktype = DLT_IP_OVER_FC;

		ll_hdrlen = 24;

	} else if (strncmp("pl", p->opt.device, 2) == 0) {

		p->linktype = DLT_RAW;

		ll_hdrlen = 0;	/* Cray UNICOS/mp pseudo link */

	} else if (strncmp("lo", p->opt.device, 2) == 0) {

		p->linktype = DLT_NULL;

		ll_hdrlen = 4;

	} else {

		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,

		    "snoop: unknown physical layer type");

		goto bad;

	}

	if (p->opt.rfmon) {

		/*

		 * No monitor mode on Irix (no Wi-Fi devices on

		 * hardware supported by Irix).

		 */

		return (PCAP_ERROR_RFMON_NOTSUP);

	}

	/*

	 * 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 (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)

		p->snapshot = MAXIMUM_SNAPLEN;

#ifdef SIOCGIFMTU

	/*

	 * XXX - IRIX appears to give you an error if you try to set the

	 * capture length to be greater than the MTU, so let's try to get

	 * the MTU first and, if that succeeds, trim the snap length

	 * to be no greater than the MTU.

	 */

	(void)strncpy(ifr.ifr_name, p->opt.device, sizeof(ifr.ifr_name));

	if (ioctl(fd, SIOCGIFMTU, (char *)&ifr) < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "SIOCGIFMTU");

		goto bad;

	}

	/*

	 * OK, we got it.

	 *

	 * XXX - some versions of IRIX 6.5 define "ifr_mtu" and have an

	 * "ifru_metric" member of the "ifr_ifru" union in an "ifreq"

	 * structure, others don't.

	 *

	 * I've no idea what's going on, so, if "ifr_mtu" isn't defined,

	 * we define it as "ifr_metric", as using that field appears to

	 * work on the versions that lack "ifr_mtu" (and, on those that

	 * don't lack it, "ifru_metric" and "ifru_mtu" are both "int"

	 * members of the "ifr_ifru" union, which suggests that they

	 * may be interchangeable in this case).

	 */

#ifndef ifr_mtu

#define ifr_mtu	ifr_metric

#endif

	if (p->snapshot > ifr.ifr_mtu + ll_hdrlen)

		p->snapshot = ifr.ifr_mtu + ll_hdrlen;

#endif

	/*

	 * The argument to SIOCSNOOPLEN is the number of link-layer

	 * payload bytes to capture - it doesn't count link-layer

	 * header bytes.

	 */

	snooplen = p->snapshot - ll_hdrlen;

	if (snooplen < 0)

		snooplen = 0;

	if (ioctl(fd, SIOCSNOOPLEN, &snooplen) < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "SIOCSNOOPLEN");

		goto bad;

	}

	v = 1;

	if (ioctl(fd, SIOCSNOOPING, &v) < 0) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "SIOCSNOOPING");

		goto bad;

	}

	p->bufsize = 4096;				/* XXX */

	p->buffer = malloc(p->bufsize);

	if (p->buffer == NULL) {

		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,

		    errno, "malloc");

		goto bad;

	}

	/*

	 * "p->fd" is a socket, so "select()" should work on it.

	 */

	p->selectable_fd = p->fd;

	p->read_op = pcap_read_snoop;

	p->inject_op = pcap_inject_snoop;

	p->setfilter_op = install_bpf_program;	/* no kernel filtering */

	p->setdirection_op = NULL;	/* Not implemented. */

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

	p->getnonblock_op = pcap_getnonblock_fd;

	p->setnonblock_op = pcap_setnonblock_fd;

	p->stats_op = pcap_stats_snoop;

	return (0);

 bad:

	pcap_cleanup_live_common(p);

	return (PCAP_ERROR);

}

pcap_t *

pcap_create_interface(const char *device _U_, char *ebuf)

{

	pcap_t *p;

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

	if (p == NULL)

		return (NULL);

	p->activate_op = pcap_activate_snoop;

	return (p);

}

/*

 * XXX - there's probably a particular bind error that means "that device

 * doesn't support snoop"; if so, we should try a bind and use that.

 */

static int

can_be_bound(const char *name _U_)

{

	return (1);

}

static int

get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)

{

	/*

	 * Nothing we can do.

	 * XXX - is there a way to find out whether an adapter has

	 * something plugged into it?

	 */

	return (0);

}

int

pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)

{

	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,

	    get_if_flags));

}

/*

 * Libpcap version string.

 */

const char *

pcap_lib_version(void)

{

	return (PCAP_VERSION_STRING);

}