text: /*
   * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
   *	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.
   */
  #ifndef lint
  static const char rcsid[] _U_ =
      "@(#) $Header: /tcpdump/master/libpcap/pcap-nit.c,v 1.62 2008-04-14 20:40:58 guy Exp $ (LBL)";
  #endif
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include <sys/types.h>
  #include <sys/time.h>
  #include <sys/timeb.h>
  #include <sys/file.h>
  #include <sys/ioctl.h>
  #include <sys/socket.h>
  
  #include <net/if.h>
  #include <net/nit.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 <ctype.h>
  #include <errno.h>
  #include <stdio.h>
  
  #include "pcap-int.h"
  
  #ifdef HAVE_OS_PROTO_H
  #include "os-proto.h"
  #endif
  
  /*
   * The chunk size for NIT.  This is the amount of buffering
   * done for read calls.
   */
  #define CHUNKSIZE (2*1024)
  
  /*
   * The total buffer space used by NIT.
   */
  #define BUFSPACE (4*CHUNKSIZE)
  
  /* Forwards */
  static int nit_setflags(int, int, int, char *);
  
  static int
  pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
  {
  
  	/*
  	 * "ps_recv" counts packets handed to the filter, not 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_drop" presumably counts packets dropped by the socket
  	 * because of flow control requirements or resource exhaustion;
  	 * it doesn't count packets dropped by the interface driver.
  	 * As filtering is done in userland, it counts packets regardless
  	 * of whether they would've passed the filter.
  	 *
  	 * These statistics don't include packets not yet read from the
  	 * kernel by libpcap or packets not yet read from libpcap by the
  	 * application.
  	 */
  	*ps = p->md.stat;
  	return (0);
  }
  
  static int
  pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  {
  	register int cc, n;
  	register u_char *bp, *cp, *ep;
  	register struct nit_hdr *nh;
  	register int caplen;
  
  	cc = p->cc;
  	if (cc == 0) {
  		cc = read(p->fd, (char *)p->buffer, p->bufsize);
  		if (cc < 0) {
  			if (errno == EWOULDBLOCK)
  				return (0);
  			snprintf(p->errbuf, sizeof(p->errbuf), "pcap_read: %s",
  				pcap_strerror(errno));
  			return (-1);
  		}
  		bp = p->buffer;
  	} else
  		bp = p->bp;
  
  	/*
  	 * Loop through each packet.  The increment expression
  	 * rounds up to the next int boundary past the end of
  	 * the previous packet.
  	 */
  	n = 0;
  	ep = bp + cc;
  	while (bp < ep) {
  		/*
  		 * Has "pcap_breakloop()" been called?
  		 * If so, return immediately - if we haven't read any
  		 * packets, clear the flag and return -2 to indicate
  		 * that we were told to break out of the loop, otherwise
  		 * leave the flag set, so that the *next* call will break
  		 * out of the loop without having read any packets, and
  		 * return the number of packets we've processed so far.
  		 */
  		if (p->break_loop) {
  			if (n == 0) {
  				p->break_loop = 0;
  				return (-2);
  			} else {
  				p->cc = ep - bp;
  				p->bp = bp;
  				return (n);
  			}
  		}
  
  		nh = (struct nit_hdr *)bp;
  		cp = bp + sizeof(*nh);
  
  		switch (nh->nh_state) {
  
  		case NIT_CATCH:
  			break;
  
  		case NIT_NOMBUF:
  		case NIT_NOCLUSTER:
  		case NIT_NOSPACE:
  			p->md.stat.ps_drop = nh->nh_dropped;
  			continue;
  
  		case NIT_SEQNO:
  			continue;
  
  		default:
  			snprintf(p->errbuf, sizeof(p->errbuf),
  			    "bad nit state %d", nh->nh_state);
  			return (-1);
  		}
  		++p->md.stat.ps_recv;
  		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
  		    sizeof(int) - 1) & ~(sizeof(int) - 1));
  
  		caplen = nh->nh_wirelen;
  		if (caplen > p->snapshot)
  			caplen = p->snapshot;
  		if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
  			struct pcap_pkthdr h;
  			h.ts = nh->nh_timestamp;
  			h.len = nh->nh_wirelen;
  			h.caplen = caplen;
  			(*callback)(user, &h, cp);
  			if (++n >= cnt && cnt > 0) {
  				p->cc = ep - bp;
  				p->bp = bp;
  				return (n);
  			}
  		}
  	}
  	p->cc = 0;
  	return (n);
  }
  
  static int
  pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
  {
  	struct sockaddr sa;
  	int ret;
  
  	memset(&sa, 0, sizeof(sa));
  	strncpy(sa.sa_data, device, sizeof(sa.sa_data));
  	ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
  	if (ret == -1) {
  		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send: %s",
  		    pcap_strerror(errno));
  		return (-1);
  	}
  	return (ret);
  }                           
  
  static int
  nit_setflags(int fd, int promisc, int to_ms, char *ebuf)
  {
  	struct nit_ioc nioc;
  
  	memset(&nioc, 0, sizeof(nioc));
  	nioc.nioc_bufspace = BUFSPACE;
  	nioc.nioc_chunksize = CHUNKSIZE;
  	nioc.nioc_typetomatch = NT_ALLTYPES;
  	nioc.nioc_snaplen = p->snapshot;
  	nioc.nioc_bufalign = sizeof(int);
  	nioc.nioc_bufoffset = 0;
  
  	if (to_ms != 0) {
  		nioc.nioc_flags |= NF_TIMEOUT;
  		nioc.nioc_timeout.tv_sec = to_ms / 1000;
  		nioc.nioc_timeout.tv_usec = (to_ms * 1000) % 1000000;
  	}
  	if (promisc)
  		nioc.nioc_flags |= NF_PROMISC;
  
  	if (ioctl(fd, SIOCSNIT, &nioc) < 0) {
  		snprintf(ebuf, PCAP_ERRBUF_SIZE, "SIOCSNIT: %s",
  		    pcap_strerror(errno));
  		return (-1);
  	}
  	return (0);
  }
  
  static int
  pcap_activate_nit(pcap_t *p)
  {
  	int fd;
  	struct sockaddr_nit snit;
  
  	if (p->opt.rfmon) {
  		/*
  		 * No monitor mode on SunOS 3.x or earlier (no
  		 * Wi-Fi *devices* for the hardware that supported
  		 * them!).
  		 */
  		return (PCAP_ERROR_RFMON_NOTSUP);
  	}
  
  	if (p->snapshot < 96)
  		/*
  		 * NIT requires a snapshot length of at least 96.
  		 */
  		p->snapshot = 96;
  
  	memset(p, 0, sizeof(*p));
  	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
  	if (fd < 0) {
  		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  		    "socket: %s", pcap_strerror(errno));
  		goto bad;
  	}
  	snit.snit_family = AF_NIT;
  	(void)strncpy(snit.snit_ifname, p->opt.source, NITIFSIZ);
  
  	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
  		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  		    "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
  		goto bad;
  	}
  	nit_setflags(p->fd, p->opt.promisc, p->md.timeout, p->errbuf);
  
  	/*
  	 * NIT supports only ethernets.
  	 */
  	p->linktype = DLT_EN10MB;
  
  	p->bufsize = BUFSPACE;
  	p->buffer = (u_char *)malloc(p->bufsize);
  	if (p->buffer == NULL) {
  		strlcpy(p->errbuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
  		goto bad;
  	}
  
  	/*
  	 * "p->fd" is a socket, so "select()" should work on it.
  	 */
  	p->selectable_fd = p->fd;
  
  	/*
  	 * 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).
  	 */
  	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;
  	}
  
  	p->read_op = pcap_read_nit;
  	p->inject_op = pcap_inject_nit;
  	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_nit;
  
  	return (0);
   bad:
  	pcap_cleanup_live_common(p);
  	return (PCAP_ERROR);
  }
  
  pcap_t *
  pcap_create(const char *device, char *ebuf)
  {
  	pcap_t *p;
  
  	p = pcap_create_common(device, ebuf);
  	if (p == NULL)
  		return (NULL);
  
  	p->activate_op = pcap_activate_nit;
  	return (p);
  }
  
  int
  pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
  {
  	return (0);
  }
  