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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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