freebsd-dev/contrib/libpcap/pcap.c
Christian S.J. Peron 154bbe416c Implement zero-copy bpf(4) buffer or "zbuf" support for libpcap. A slightly
different version has been committed upstream in the libpcap vendor branch.
This will allow people to experiment with zero-copy bpf(4) without requiring
external patches.

Note to enable this functionality:

    sysctl net.bpf.zerocopy_enable=1

By default, libpcap will use the legacy buffering method unless this sysctl
variable is set to 1.

For the details about zero-copy bpf(4) implementation see svn change r177548.

Requested by:		many
Discussed with:		sam
In collaboration with:	rwatson
2008-09-16 20:32:29 +00:00

938 lines
26 KiB
C

/*
* Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
* 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 the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.88.2.19 2007/09/19 02:50:52 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef WIN32
#include <pcap-stdinc.h>
#else /* WIN32 */
#include <sys/types.h>
#include <sys/mman.h>
#endif /* WIN32 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#if !defined(_MSC_VER) && !defined(__BORLANDC__)
#include <unistd.h>
#endif
#include <fcntl.h>
#include <errno.h>
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#ifdef MSDOS
#include "pcap-dos.h"
#endif
#include "pcap-int.h"
#ifdef HAVE_DAG_API
#include <dagnew.h>
#include <dagapi.h>
#endif
int
pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
return p->read_op(p, cnt, callback, user);
}
/*
* XXX - is this necessary?
*/
int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
return p->read_op(p, cnt, callback, user);
}
int
pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
register int n;
for (;;) {
if (p->sf.rfile != NULL) {
/*
* 0 means EOF, so don't loop if we get 0.
*/
n = pcap_offline_read(p, cnt, callback, user);
} else {
/*
* XXX keep reading until we get something
* (or an error occurs)
*/
do {
n = p->read_op(p, cnt, callback, user);
} while (n == 0);
}
if (n <= 0)
return (n);
if (cnt > 0) {
cnt -= n;
if (cnt <= 0)
return (0);
}
}
}
struct singleton {
struct pcap_pkthdr *hdr;
const u_char *pkt;
};
static void
pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt)
{
struct singleton *sp = (struct singleton *)userData;
*sp->hdr = *h;
sp->pkt = pkt;
}
const u_char *
pcap_next(pcap_t *p, struct pcap_pkthdr *h)
{
struct singleton s;
s.hdr = h;
if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0)
return (0);
return (s.pkt);
}
struct pkt_for_fakecallback {
struct pcap_pkthdr *hdr;
const u_char **pkt;
};
static void
pcap_fakecallback(u_char *userData, const struct pcap_pkthdr *h,
const u_char *pkt)
{
struct pkt_for_fakecallback *sp = (struct pkt_for_fakecallback *)userData;
*sp->hdr = *h;
*sp->pkt = pkt;
}
int
pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
const u_char **pkt_data)
{
struct pkt_for_fakecallback s;
s.hdr = &p->pcap_header;
s.pkt = pkt_data;
/* Saves a pointer to the packet headers */
*pkt_header= &p->pcap_header;
if (p->sf.rfile != NULL) {
int status;
/* We are on an offline capture */
status = pcap_offline_read(p, 1, pcap_fakecallback,
(u_char *)&s);
/*
* Return codes for pcap_offline_read() are:
* - 0: EOF
* - -1: error
* - >1: OK
* The first one ('0') conflicts with the return code of
* 0 from pcap_read() meaning "no packets arrived before
* the timeout expired", so we map it to -2 so you can
* distinguish between an EOF from a savefile and a
* "no packets arrived before the timeout expired, try
* again" from a live capture.
*/
if (status == 0)
return (-2);
else
return (status);
}
/*
* Return codes for pcap_read() are:
* - 0: timeout
* - -1: error
* - -2: loop was broken out of with pcap_breakloop()
* - >1: OK
* The first one ('0') conflicts with the return code of 0 from
* pcap_offline_read() meaning "end of file".
*/
return (p->read_op(p, 1, pcap_fakecallback, (u_char *)&s));
}
/*
* Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate.
*/
void
pcap_breakloop(pcap_t *p)
{
p->break_loop = 1;
}
int
pcap_datalink(pcap_t *p)
{
return (p->linktype);
}
int
pcap_list_datalinks(pcap_t *p, int **dlt_buffer)
{
if (p->dlt_count == 0) {
/*
* We couldn't fetch the list of DLTs, which means
* this platform doesn't support changing the
* DLT for an interface. Return a list of DLTs
* containing only the DLT this device supports.
*/
*dlt_buffer = (int*)malloc(sizeof(**dlt_buffer));
if (*dlt_buffer == NULL) {
(void)snprintf(p->errbuf, sizeof(p->errbuf),
"malloc: %s", pcap_strerror(errno));
return (-1);
}
**dlt_buffer = p->linktype;
return (1);
} else {
*dlt_buffer = (int*)calloc(sizeof(**dlt_buffer), p->dlt_count);
if (*dlt_buffer == NULL) {
(void)snprintf(p->errbuf, sizeof(p->errbuf),
"malloc: %s", pcap_strerror(errno));
return (-1);
}
(void)memcpy(*dlt_buffer, p->dlt_list,
sizeof(**dlt_buffer) * p->dlt_count);
return (p->dlt_count);
}
}
int
pcap_set_datalink(pcap_t *p, int dlt)
{
int i;
const char *dlt_name;
if (p->dlt_count == 0 || p->set_datalink_op == NULL) {
/*
* We couldn't fetch the list of DLTs, or we don't
* have a "set datalink" operation, which means
* this platform doesn't support changing the
* DLT for an interface. Check whether the new
* DLT is the one this interface supports.
*/
if (p->linktype != dlt)
goto unsupported;
/*
* It is, so there's nothing we need to do here.
*/
return (0);
}
for (i = 0; i < p->dlt_count; i++)
if (p->dlt_list[i] == dlt)
break;
if (i >= p->dlt_count)
goto unsupported;
if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB &&
dlt == DLT_DOCSIS) {
/*
* This is presumably an Ethernet device, as the first
* link-layer type it offers is DLT_EN10MB, and the only
* other type it offers is DLT_DOCSIS. That means that
* we can't tell the driver to supply DOCSIS link-layer
* headers - we're just pretending that's what we're
* getting, as, presumably, we're capturing on a dedicated
* link to a Cisco Cable Modem Termination System, and
* it's putting raw DOCSIS frames on the wire inside low-level
* Ethernet framing.
*/
p->linktype = dlt;
return (0);
}
if (p->set_datalink_op(p, dlt) == -1)
return (-1);
p->linktype = dlt;
return (0);
unsupported:
dlt_name = pcap_datalink_val_to_name(dlt);
if (dlt_name != NULL) {
(void) snprintf(p->errbuf, sizeof(p->errbuf),
"%s is not one of the DLTs supported by this device",
dlt_name);
} else {
(void) snprintf(p->errbuf, sizeof(p->errbuf),
"DLT %d is not one of the DLTs supported by this device",
dlt);
}
return (-1);
}
struct dlt_choice {
const char *name;
const char *description;
int dlt;
};
#define DLT_CHOICE(code, description) { #code, description, code }
#define DLT_CHOICE_SENTINEL { NULL, NULL, 0 }
static struct dlt_choice dlt_choices[] = {
DLT_CHOICE(DLT_NULL, "BSD loopback"),
DLT_CHOICE(DLT_EN10MB, "Ethernet"),
DLT_CHOICE(DLT_IEEE802, "Token ring"),
DLT_CHOICE(DLT_ARCNET, "ARCNET"),
DLT_CHOICE(DLT_SLIP, "SLIP"),
DLT_CHOICE(DLT_PPP, "PPP"),
DLT_CHOICE(DLT_FDDI, "FDDI"),
DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 LLC-encapsulated ATM"),
DLT_CHOICE(DLT_RAW, "Raw IP"),
DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"),
DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"),
DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"),
DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"),
DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"),
DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"),
DLT_CHOICE(DLT_IEEE802_11, "802.11"),
DLT_CHOICE(DLT_FRELAY, "Frame Relay"),
DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"),
DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"),
DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"),
DLT_CHOICE(DLT_LTALK, "Localtalk"),
DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"),
DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"),
DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"),
DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"),
DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus BSD radio information header"),
DLT_CHOICE(DLT_APPLE_IP_OVER_IEEE1394, "Apple IP-over-IEEE 1394"),
DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"),
DLT_CHOICE(DLT_DOCSIS, "DOCSIS"),
DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"),
DLT_CHOICE(DLT_LINUX_LAPD, "Linux vISDN LAPD"),
DLT_CHOICE(DLT_IEEE802_11_RADIO_AVS, "802.11 plus AVS radio information header"),
DLT_CHOICE(DLT_SYMANTEC_FIREWALL, "Symantec Firewall"),
DLT_CHOICE(DLT_JUNIPER_ATM1, "Juniper ATM1 PIC"),
DLT_CHOICE(DLT_JUNIPER_ATM2, "Juniper ATM2 PIC"),
DLT_CHOICE(DLT_JUNIPER_MLPPP, "Juniper Multi-Link PPP"),
DLT_CHOICE(DLT_PPP_PPPD, "PPP for pppd, with direction flag"),
DLT_CHOICE(DLT_JUNIPER_PPPOE, "Juniper PPPoE"),
DLT_CHOICE(DLT_JUNIPER_PPPOE_ATM, "Juniper PPPoE/ATM"),
DLT_CHOICE(DLT_GPRS_LLC, "GPRS LLC"),
DLT_CHOICE(DLT_GPF_T, "GPF-T"),
DLT_CHOICE(DLT_GPF_F, "GPF-F"),
DLT_CHOICE(DLT_JUNIPER_PIC_PEER, "Juniper PIC Peer"),
DLT_CHOICE(DLT_JUNIPER_MLFR, "Juniper Multi-Link Frame Relay"),
DLT_CHOICE(DLT_ERF_ETH, "Ethernet with Endace ERF header"),
DLT_CHOICE(DLT_ERF_POS, "Packet-over-SONET with Endace ERF header"),
DLT_CHOICE(DLT_JUNIPER_GGSN, "Juniper GGSN PIC"),
DLT_CHOICE(DLT_JUNIPER_ES, "Juniper Encryption Services PIC"),
DLT_CHOICE(DLT_JUNIPER_MONITOR, "Juniper Passive Monitor PIC"),
DLT_CHOICE(DLT_JUNIPER_SERVICES, "Juniper Advanced Services PIC"),
DLT_CHOICE(DLT_JUNIPER_MFR, "Juniper FRF.16 Frame Relay"),
DLT_CHOICE(DLT_JUNIPER_ETHER, "Juniper Ethernet"),
DLT_CHOICE(DLT_JUNIPER_PPP, "Juniper PPP"),
DLT_CHOICE(DLT_JUNIPER_FRELAY, "Juniper Frame Relay"),
DLT_CHOICE(DLT_JUNIPER_CHDLC, "Juniper C-HDLC"),
DLT_CHOICE(DLT_MFR, "FRF.16 Frame Relay"),
DLT_CHOICE(DLT_JUNIPER_VP, "Juniper Voice PIC"),
DLT_CHOICE(DLT_MTP2, "SS7 MTP2"),
DLT_CHOICE(DLT_A429, "Arinc 429"),
DLT_CHOICE(DLT_A653_ICM, "Arinc 653 Interpartition Communication"),
DLT_CHOICE(DLT_USB, "USB"),
DLT_CHOICE(DLT_BLUETOOTH_HCI_H4, "Bluetooth HCI UART transport layer"),
DLT_CHOICE(DLT_CAN20B, "Controller Area Network (CAN) v. 2.0B"),
DLT_CHOICE(DLT_MTP2_WITH_PHDR, "SS7 MTP2 with Pseudo-header"),
DLT_CHOICE_SENTINEL
};
/*
* This array is designed for mapping upper and lower case letter
* together for a case independent comparison. The mappings are
* based upon ascii character sequences.
*/
static const u_char charmap[] = {
(u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003',
(u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007',
(u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013',
(u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017',
(u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023',
(u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027',
(u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033',
(u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037',
(u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043',
(u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047',
(u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053',
(u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057',
(u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063',
(u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067',
(u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073',
(u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077',
(u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143',
(u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
(u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
(u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
(u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
(u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
(u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133',
(u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137',
(u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143',
(u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
(u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
(u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
(u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
(u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
(u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173',
(u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177',
(u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203',
(u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207',
(u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213',
(u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217',
(u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223',
(u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227',
(u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233',
(u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237',
(u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243',
(u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247',
(u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253',
(u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257',
(u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263',
(u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267',
(u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273',
(u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277',
(u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343',
(u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
(u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
(u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
(u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
(u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
(u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333',
(u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337',
(u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343',
(u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
(u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
(u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
(u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
(u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
(u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373',
(u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377',
};
int
pcap_strcasecmp(const char *s1, const char *s2)
{
register const u_char *cm = charmap,
*us1 = (const u_char *)s1,
*us2 = (const u_char *)s2;
while (cm[*us1] == cm[*us2++])
if (*us1++ == '\0')
return(0);
return (cm[*us1] - cm[*--us2]);
}
int
pcap_datalink_name_to_val(const char *name)
{
int i;
for (i = 0; dlt_choices[i].name != NULL; i++) {
if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1,
name) == 0)
return (dlt_choices[i].dlt);
}
return (-1);
}
const char *
pcap_datalink_val_to_name(int dlt)
{
int i;
for (i = 0; dlt_choices[i].name != NULL; i++) {
if (dlt_choices[i].dlt == dlt)
return (dlt_choices[i].name + sizeof("DLT_") - 1);
}
return (NULL);
}
const char *
pcap_datalink_val_to_description(int dlt)
{
int i;
for (i = 0; dlt_choices[i].name != NULL; i++) {
if (dlt_choices[i].dlt == dlt)
return (dlt_choices[i].description);
}
return (NULL);
}
int
pcap_snapshot(pcap_t *p)
{
return (p->snapshot);
}
int
pcap_is_swapped(pcap_t *p)
{
return (p->sf.swapped);
}
int
pcap_major_version(pcap_t *p)
{
return (p->sf.version_major);
}
int
pcap_minor_version(pcap_t *p)
{
return (p->sf.version_minor);
}
FILE *
pcap_file(pcap_t *p)
{
return (p->sf.rfile);
}
int
pcap_fileno(pcap_t *p)
{
#ifndef WIN32
return (p->fd);
#else
if (p->adapter != NULL)
return ((int)(DWORD)p->adapter->hFile);
else
return (-1);
#endif
}
#if !defined(WIN32) && !defined(MSDOS)
int
pcap_get_selectable_fd(pcap_t *p)
{
return (p->selectable_fd);
}
#endif
void
pcap_perror(pcap_t *p, char *prefix)
{
fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
}
char *
pcap_geterr(pcap_t *p)
{
return (p->errbuf);
}
int
pcap_getnonblock(pcap_t *p, char *errbuf)
{
return p->getnonblock_op(p, errbuf);
}
/*
* Get the current non-blocking mode setting, under the assumption that
* it's just the standard POSIX non-blocking flag.
*
* We don't look at "p->nonblock", in case somebody tweaked the FD
* directly.
*/
#if !defined(WIN32) && !defined(MSDOS)
int
pcap_getnonblock_fd(pcap_t *p, char *errbuf)
{
int fdflags;
fdflags = fcntl(p->fd, F_GETFL, 0);
if (fdflags == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
pcap_strerror(errno));
return (-1);
}
if (fdflags & O_NONBLOCK)
return (1);
else
return (0);
}
#endif
int
pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
{
return p->setnonblock_op(p, nonblock, errbuf);
}
#if !defined(WIN32) && !defined(MSDOS)
/*
* Set non-blocking mode, under the assumption that it's just the
* standard POSIX non-blocking flag. (This can be called by the
* per-platform non-blocking-mode routine if that routine also
* needs to do some additional work.)
*/
int
pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf)
{
int fdflags;
fdflags = fcntl(p->fd, F_GETFL, 0);
if (fdflags == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
pcap_strerror(errno));
return (-1);
}
if (nonblock)
fdflags |= O_NONBLOCK;
else
fdflags &= ~O_NONBLOCK;
if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
pcap_strerror(errno));
return (-1);
}
return (0);
}
#endif
#ifdef WIN32
/*
* Generate a string for the last Win32-specific error (i.e. an error generated when
* calling a Win32 API).
* For errors occurred during standard C calls, we still use pcap_strerror()
*/
char *
pcap_win32strerror(void)
{
DWORD error;
static char errbuf[PCAP_ERRBUF_SIZE+1];
int errlen;
char *p;
error = GetLastError();
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
PCAP_ERRBUF_SIZE, NULL);
/*
* "FormatMessage()" "helpfully" sticks CR/LF at the end of the
* message. Get rid of it.
*/
errlen = strlen(errbuf);
if (errlen >= 2) {
errbuf[errlen - 1] = '\0';
errbuf[errlen - 2] = '\0';
}
p = strchr(errbuf, '\0');
snprintf (p, sizeof(errbuf)-(p-errbuf), " (%lu)", error);
return (errbuf);
}
#endif
/*
* Not all systems have strerror().
*/
const char *
pcap_strerror(int errnum)
{
#ifdef HAVE_STRERROR
return (strerror(errnum));
#else
extern int sys_nerr;
extern const char *const sys_errlist[];
static char ebuf[20];
if ((unsigned int)errnum < sys_nerr)
return ((char *)sys_errlist[errnum]);
(void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
return(ebuf);
#endif
}
int
pcap_setfilter(pcap_t *p, struct bpf_program *fp)
{
return p->setfilter_op(p, fp);
}
/*
* Set direction flag, which controls whether we accept only incoming
* packets, only outgoing packets, or both.
* Note that, depending on the platform, some or all direction arguments
* might not be supported.
*/
int
pcap_setdirection(pcap_t *p, pcap_direction_t d)
{
if (p->setdirection_op == NULL) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"Setting direction is not implemented on this platform");
return -1;
} else
return p->setdirection_op(p, d);
}
int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
return p->stats_op(p, ps);
}
static int
pcap_stats_dead(pcap_t *p, struct pcap_stat *ps _U_)
{
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"Statistics aren't available from a pcap_open_dead pcap_t");
return (-1);
}
void
pcap_close_common(pcap_t *p)
{
#ifdef BIOCSETBUFMODE
/*
* Check to see if this pcap instance was using the zerocopy buffer
* mode. If it was, delete the mappings. Note that p->buffer
* gets initialized to one of the mmaped regions in this case, so
* do not try and free it directly.
*
* If the regular buffer mode was selected, then it is safe to free
* this memory.
*/
if (p->zerocopy) {
if (p->zbuf1 != MAP_FAILED && p->zbuf1 != NULL)
munmap(p->zbuf1, p->zbufsize);
if (p->zbuf2 != MAP_FAILED && p->zbuf2 != NULL)
munmap(p->zbuf2, p->zbufsize);
p->buffer = NULL;
} else
#endif
if (p->buffer != NULL)
free(p->buffer);
#if !defined(WIN32) && !defined(MSDOS)
if (p->fd >= 0)
close(p->fd);
#endif
}
static void
pcap_close_dead(pcap_t *p _U_)
{
/* Nothing to do. */
}
pcap_t *
pcap_open_dead(int linktype, int snaplen)
{
pcap_t *p;
p = malloc(sizeof(*p));
if (p == NULL)
return NULL;
memset (p, 0, sizeof(*p));
p->snapshot = snaplen;
p->linktype = linktype;
p->stats_op = pcap_stats_dead;
p->close_op = pcap_close_dead;
return p;
}
/*
* API compatible with WinPcap's "send a packet" routine - returns -1
* on error, 0 otherwise.
*
* XXX - what if we get a short write?
*/
int
pcap_sendpacket(pcap_t *p, const u_char *buf, int size)
{
if (p->inject_op(p, buf, size) == -1)
return (-1);
return (0);
}
/*
* API compatible with OpenBSD's "send a packet" routine - returns -1 on
* error, number of bytes written otherwise.
*/
int
pcap_inject(pcap_t *p, const void *buf, size_t size)
{
return (p->inject_op(p, buf, size));
}
void
pcap_close(pcap_t *p)
{
p->close_op(p);
if (p->dlt_list != NULL)
free(p->dlt_list);
pcap_freecode(&p->fcode);
free(p);
}
/*
* We make the version string static, and return a pointer to it, rather
* than exporting the version string directly. On at least some UNIXes,
* if you import data from a shared library into an program, the data is
* bound into the program binary, so if the string in the version of the
* library with which the program was linked isn't the same as the
* string in the version of the library with which the program is being
* run, various undesirable things may happen (warnings, the string
* being the one from the version of the library with which the program
* was linked, or even weirder things, such as the string being the one
* from the library but being truncated).
*/
#ifdef HAVE_VERSION_H
#include "version.h"
#else
static const char pcap_version_string[] = "libpcap version 0.9.8";
#endif
#ifdef WIN32
/*
* XXX - it'd be nice if we could somehow generate the WinPcap and libpcap
* version numbers when building WinPcap. (It'd be nice to do so for
* the packet.dll version number as well.)
*/
static const char wpcap_version_string[] = "4.0";
static const char pcap_version_string_fmt[] =
"WinPcap version %s, based on %s";
static const char pcap_version_string_packet_dll_fmt[] =
"WinPcap version %s (packet.dll version %s), based on %s";
static char *full_pcap_version_string;
const char *
pcap_lib_version(void)
{
char *packet_version_string;
size_t full_pcap_version_string_len;
if (full_pcap_version_string == NULL) {
/*
* Generate the version string.
*/
packet_version_string = PacketGetVersion();
if (strcmp(wpcap_version_string, packet_version_string) == 0) {
/*
* WinPcap version string and packet.dll version
* string are the same; just report the WinPcap
* version.
*/
full_pcap_version_string_len =
(sizeof pcap_version_string_fmt - 4) +
strlen(wpcap_version_string) +
strlen(pcap_version_string);
full_pcap_version_string =
malloc(full_pcap_version_string_len);
sprintf(full_pcap_version_string,
pcap_version_string_fmt, wpcap_version_string,
pcap_version_string);
} else {
/*
* WinPcap version string and packet.dll version
* string are different; that shouldn't be the
* case (the two libraries should come from the
* same version of WinPcap), so we report both
* versions.
*/
full_pcap_version_string_len =
(sizeof pcap_version_string_packet_dll_fmt - 6) +
strlen(wpcap_version_string) +
strlen(packet_version_string) +
strlen(pcap_version_string);
full_pcap_version_string = malloc(full_pcap_version_string_len);
sprintf(full_pcap_version_string,
pcap_version_string_packet_dll_fmt,
wpcap_version_string, packet_version_string,
pcap_version_string);
}
}
return (full_pcap_version_string);
}
#elif defined(MSDOS)
static char *full_pcap_version_string;
const char *
pcap_lib_version (void)
{
char *packet_version_string;
size_t full_pcap_version_string_len;
static char dospfx[] = "DOS-";
if (full_pcap_version_string == NULL) {
/*
* Generate the version string.
*/
full_pcap_version_string_len =
sizeof dospfx + strlen(pcap_version_string);
full_pcap_version_string =
malloc(full_pcap_version_string_len);
strcpy(full_pcap_version_string, dospfx);
strcat(full_pcap_version_string, pcap_version_string);
}
return (full_pcap_version_string);
}
#else /* UN*X */
const char *
pcap_lib_version(void)
{
return (pcap_version_string);
}
#endif