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-rw-r--r--pcap-nit.c356
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+/*
+ * 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 1.57.2.1 2005/05/03 18:54:37 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 struct bpf_insn *fcode = p->fcode.bf_insns;
+ 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(fcode, 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 void
+pcap_close_nit(pcap_t *p)
+{
+ pcap_close_common(p);
+ if (p->device != NULL)
+ free(p->device);
+}
+
+pcap_t *
+pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
+ char *ebuf)
+{
+ int fd;
+ struct sockaddr_nit snit;
+ register pcap_t *p;
+
+ p = (pcap_t *)malloc(sizeof(*p));
+ if (p == NULL) {
+ strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
+ return (NULL);
+ }
+
+ if (snaplen < 96)
+ /*
+ * NIT requires a snapshot length of at least 96.
+ */
+ snaplen = 96;
+
+ memset(p, 0, sizeof(*p));
+ p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
+ if (fd < 0) {
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "socket: %s", pcap_strerror(errno));
+ goto bad;
+ }
+ snit.snit_family = AF_NIT;
+ (void)strncpy(snit.snit_ifname, device, NITIFSIZ);
+
+ if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
+ snprintf(ebuf, PCAP_ERRBUF_SIZE,
+ "bind: %s: %s", snit.snit_ifname, pcap_strerror(errno));
+ goto bad;
+ }
+ p->snapshot = snaplen;
+ nit_setflags(p->fd, promisc, to_ms, ebuf);
+
+ /*
+ * NIT supports only ethernets.
+ */
+ p->linktype = DLT_EN10MB;
+
+ p->bufsize = BUFSPACE;
+ p->buffer = (u_char *)malloc(p->bufsize);
+ if (p->buffer == NULL) {
+ strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
+ goto bad;
+ }
+
+ /*
+ * We need the device name in order to send packets.
+ */
+ p->device = strdup(device);
+ if (p->device == NULL) {
+ strlcpy(ebuf, pcap_strerror(errno), PCAP_ERRBUF_SIZE);
+ free(p->buffer);
+ 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;
+ p->close_op = pcap_close_nit;
+
+ return (p);
+ bad:
+ if (fd >= 0)
+ close(fd);
+ free(p);
+ return (NULL);
+}
+
+int
+pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf)
+{
+ return (0);
+}
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