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wireshark/capture_loop.c

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/* capture_loop.c
* The actual capturing loop, getting packets and storing it
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/** @file
*
* Capture loop (internal interface).
*
* It will open the input and output files, capture the packets,
* change ringbuffer output files while capturing and close all files again.
*
* The input file can be a network interface or capture pipe (unix only).
* The output file can be a single or a ringbuffer file handled by wiretap.
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_LIBPCAP
#include <string.h>
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
#include <signal.h>
#include <errno.h>
#include <setjmp.h>
#include <glib.h>
#include <pcap.h>
#include "pcapio.h"
#include "capture-pcap-util.h"
#include "capture.h"
#include "capture_sync.h"
#include "conditions.h"
#include "capture_stop_conditions.h"
#include "ringbuffer.h"
#include "simple_dialog.h"
#include "tempfile.h"
#include "log.h"
#include "file_util.h"
#include "capture_loop.h"
/*
* Standard secondary message for unexpected errors.
*/
static const char please_report[] =
"Please report this to the Wireshark developers";
/*
* This needs to be static, so that the SIGUSR1 handler can clear the "go"
* flag.
*/
static loop_data ld;
/*
* Timeout, in milliseconds, for reads from the stream of captured packets.
*/
#define CAP_READ_TIMEOUT 250
static void capture_loop_packet_cb(u_char *user, const struct pcap_pkthdr *phdr,
const u_char *pd);
static void capture_loop_get_errmsg(char *errmsg, int errmsglen, const char *fname,
int err, gboolean is_close);
#ifndef _WIN32
/* Take care of byte order in the libpcap headers read from pipes.
* (function taken from wiretap/libpcap.c) */
static void
cap_pipe_adjust_header(gboolean byte_swapped, struct pcap_hdr *hdr, struct pcaprec_hdr *rechdr)
{
if (byte_swapped) {
/* Byte-swap the record header fields. */
rechdr->ts_sec = BSWAP32(rechdr->ts_sec);
rechdr->ts_usec = BSWAP32(rechdr->ts_usec);
rechdr->incl_len = BSWAP32(rechdr->incl_len);
rechdr->orig_len = BSWAP32(rechdr->orig_len);
}
/* In file format version 2.3, the "incl_len" and "orig_len" fields were
swapped, in order to match the BPF header layout.
Unfortunately, some files were, according to a comment in the "libpcap"
source, written with version 2.3 in their headers but without the
interchanged fields, so if "incl_len" is greater than "orig_len" - which
would make no sense - we assume that we need to swap them. */
if (hdr->version_major == 2 &&
(hdr->version_minor < 3 ||
(hdr->version_minor == 3 && rechdr->incl_len > rechdr->orig_len))) {
guint32 temp;
temp = rechdr->orig_len;
rechdr->orig_len = rechdr->incl_len;
rechdr->incl_len = temp;
}
}
/* Mimic pcap_open_live() for pipe captures
* We check if "pipename" is "-" (stdin) or a FIFO, open it, and read the
* header.
* N.B. : we can't read the libpcap formats used in RedHat 6.1 or SuSE 6.3
* because we can't seek on pipes (see wiretap/libpcap.c for details) */
static int
cap_pipe_open_live(char *pipename, struct pcap_hdr *hdr, loop_data *ld,
char *errmsg, int errmsgl)
{
struct stat pipe_stat;
int fd;
guint32 magic;
int b, sel_ret;
unsigned int bytes_read;
fd_set rfds;
struct timeval timeout;
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: %s", pipename);
/*
* XXX (T)Wireshark blocks until we return
*/
if (strcmp(pipename, "-") == 0)
fd = 0; /* read from stdin */
else {
if (eth_stat(pipename, &pipe_stat) < 0) {
if (errno == ENOENT || errno == ENOTDIR)
ld->cap_pipe_err = PIPNEXIST;
else {
g_snprintf(errmsg, errmsgl,
"The capture session could not be initiated "
"due to error on pipe: %s", strerror(errno));
ld->cap_pipe_err = PIPERR;
}
return -1;
}
if (! S_ISFIFO(pipe_stat.st_mode)) {
if (S_ISCHR(pipe_stat.st_mode)) {
/*
* Assume the user specified an interface on a system where
* interfaces are in /dev. Pretend we haven't seen it.
*/
ld->cap_pipe_err = PIPNEXIST;
} else {
g_snprintf(errmsg, errmsgl,
"The capture session could not be initiated because\n"
"\"%s\" is neither an interface nor a pipe", pipename);
ld->cap_pipe_err = PIPERR;
}
return -1;
}
fd = eth_open(pipename, O_RDONLY | O_NONBLOCK, 0000 /* no creation so don't matter */);
if (fd == -1) {
g_snprintf(errmsg, errmsgl,
"The capture session could not be initiated "
"due to error on pipe open: %s", strerror(errno));
ld->cap_pipe_err = PIPERR;
return -1;
}
}
ld->from_cap_pipe = TRUE;
/* read the pcap header */
FD_ZERO(&rfds);
bytes_read = 0;
while (bytes_read < sizeof magic) {
FD_SET(fd, &rfds);
timeout.tv_sec = 0;
timeout.tv_usec = CAP_READ_TIMEOUT*1000;
sel_ret = select(fd+1, &rfds, NULL, NULL, &timeout);
if (sel_ret < 0) {
g_snprintf(errmsg, errmsgl,
"Unexpected error from select: %s", strerror(errno));
goto error;
} else if (sel_ret > 0) {
b = read(fd, ((char *)&magic)+bytes_read, sizeof magic-bytes_read);
if (b <= 0) {
if (b == 0)
g_snprintf(errmsg, errmsgl, "End of file on pipe during open");
else
g_snprintf(errmsg, errmsgl, "Error on pipe during open: %s",
strerror(errno));
goto error;
}
bytes_read += b;
}
}
switch (magic) {
case PCAP_MAGIC:
/* Host that wrote it has our byte order, and was running
a program using either standard or ss990417 libpcap. */
ld->cap_pipe_byte_swapped = FALSE;
ld->cap_pipe_modified = FALSE;
break;
case PCAP_MODIFIED_MAGIC:
/* Host that wrote it has our byte order, but was running
a program using either ss990915 or ss991029 libpcap. */
ld->cap_pipe_byte_swapped = FALSE;
ld->cap_pipe_modified = TRUE;
break;
case PCAP_SWAPPED_MAGIC:
/* Host that wrote it has a byte order opposite to ours,
and was running a program using either standard or
ss990417 libpcap. */
ld->cap_pipe_byte_swapped = TRUE;
ld->cap_pipe_modified = FALSE;
break;
case PCAP_SWAPPED_MODIFIED_MAGIC:
/* Host that wrote it out has a byte order opposite to
ours, and was running a program using either ss990915
or ss991029 libpcap. */
ld->cap_pipe_byte_swapped = TRUE;
ld->cap_pipe_modified = TRUE;
break;
default:
/* Not a "libpcap" type we know about. */
g_snprintf(errmsg, errmsgl, "Unrecognized libpcap format");
goto error;
}
/* Read the rest of the header */
bytes_read = 0;
while (bytes_read < sizeof(struct pcap_hdr)) {
FD_SET(fd, &rfds);
timeout.tv_sec = 0;
timeout.tv_usec = CAP_READ_TIMEOUT*1000;
sel_ret = select(fd+1, &rfds, NULL, NULL, &timeout);
if (sel_ret < 0) {
g_snprintf(errmsg, errmsgl,
"Unexpected error from select: %s", strerror(errno));
goto error;
} else if (sel_ret > 0) {
b = read(fd, ((char *)hdr)+bytes_read,
sizeof(struct pcap_hdr) - bytes_read);
if (b <= 0) {
if (b == 0)
g_snprintf(errmsg, errmsgl, "End of file on pipe during open");
else
g_snprintf(errmsg, errmsgl, "Error on pipe during open: %s",
strerror(errno));
goto error;
}
bytes_read += b;
}
}
if (ld->cap_pipe_byte_swapped) {
/* Byte-swap the header fields about which we care. */
hdr->version_major = BSWAP16(hdr->version_major);
hdr->version_minor = BSWAP16(hdr->version_minor);
hdr->snaplen = BSWAP32(hdr->snaplen);
hdr->network = BSWAP32(hdr->network);
}
ld->linktype = hdr->network;
if (hdr->version_major < 2) {
g_snprintf(errmsg, errmsgl, "Unable to read old libpcap format");
goto error;
}
ld->cap_pipe_state = STATE_EXPECT_REC_HDR;
ld->cap_pipe_err = PIPOK;
return fd;
error:
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: error %s", errmsg);
ld->cap_pipe_err = PIPERR;
eth_close(fd);
return -1;
}
/* We read one record from the pipe, take care of byte order in the record
* header, write the record to the capture file, and update capture statistics. */
int
cap_pipe_dispatch(loop_data *ld, guchar *data, char *errmsg, int errmsgl)
{
struct pcap_pkthdr phdr;
int b;
enum { PD_REC_HDR_READ, PD_DATA_READ, PD_PIPE_EOF, PD_PIPE_ERR,
PD_ERR } result;
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_dispatch");
#endif
switch (ld->cap_pipe_state) {
case STATE_EXPECT_REC_HDR:
ld->cap_pipe_bytes_to_read = ld->cap_pipe_modified ?
sizeof(struct pcaprec_modified_hdr) : sizeof(struct pcaprec_hdr);
ld->cap_pipe_bytes_read = 0;
ld->cap_pipe_state = STATE_READ_REC_HDR;
/* Fall through */
case STATE_READ_REC_HDR:
b = read(ld->cap_pipe_fd, ((char *)&ld->cap_pipe_rechdr)+ld->cap_pipe_bytes_read,
ld->cap_pipe_bytes_to_read - ld->cap_pipe_bytes_read);
if (b <= 0) {
if (b == 0)
result = PD_PIPE_EOF;
else
result = PD_PIPE_ERR;
break;
}
if ((ld->cap_pipe_bytes_read += b) < ld->cap_pipe_bytes_to_read)
return 0;
result = PD_REC_HDR_READ;
break;
case STATE_EXPECT_DATA:
ld->cap_pipe_bytes_read = 0;
ld->cap_pipe_state = STATE_READ_DATA;
/* Fall through */
case STATE_READ_DATA:
b = read(ld->cap_pipe_fd, data+ld->cap_pipe_bytes_read,
ld->cap_pipe_rechdr.hdr.incl_len - ld->cap_pipe_bytes_read);
if (b <= 0) {
if (b == 0)
result = PD_PIPE_EOF;
else
result = PD_PIPE_ERR;
break;
}
if ((ld->cap_pipe_bytes_read += b) < ld->cap_pipe_rechdr.hdr.incl_len)
return 0;
result = PD_DATA_READ;
break;
default:
g_snprintf(errmsg, errmsgl, "cap_pipe_dispatch: invalid state");
result = PD_ERR;
} /* switch (ld->cap_pipe_state) */
/*
* We've now read as much data as we were expecting, so process it.
*/
switch (result) {
case PD_REC_HDR_READ:
/* We've read the header. Take care of byte order. */
cap_pipe_adjust_header(ld->cap_pipe_byte_swapped, &ld->cap_pipe_hdr,
&ld->cap_pipe_rechdr.hdr);
if (ld->cap_pipe_rechdr.hdr.incl_len > WTAP_MAX_PACKET_SIZE) {
g_snprintf(errmsg, errmsgl, "Frame %u too long (%d bytes)",
ld->packet_count+1, ld->cap_pipe_rechdr.hdr.incl_len);
break;
}
ld->cap_pipe_state = STATE_EXPECT_DATA;
return 0;
case PD_DATA_READ:
/* Fill in a "struct pcap_pkthdr", and process the packet. */
phdr.ts.tv_sec = ld->cap_pipe_rechdr.hdr.ts_sec;
phdr.ts.tv_usec = ld->cap_pipe_rechdr.hdr.ts_usec;
phdr.caplen = ld->cap_pipe_rechdr.hdr.incl_len;
phdr.len = ld->cap_pipe_rechdr.hdr.orig_len;
ld->packet_cb((u_char *)ld, &phdr, data);
ld->cap_pipe_state = STATE_EXPECT_REC_HDR;
return 1;
case PD_PIPE_EOF:
ld->cap_pipe_err = PIPEOF;
return -1;
case PD_PIPE_ERR:
g_snprintf(errmsg, errmsgl, "Error reading from pipe: %s",
strerror(errno));
/* Fall through */
case PD_ERR:
break;
}
ld->cap_pipe_err = PIPERR;
/* Return here rather than inside the switch to prevent GCC warning */
return -1;
}
#endif /* not _WIN32 */
/* open the capture input file (pcap or capture pipe) */
gboolean
capture_loop_open_input(capture_options *capture_opts, loop_data *ld,
char *errmsg, size_t errmsg_len,
char *secondary_errmsg, size_t secondary_errmsg_len)
{
gchar open_err_str[PCAP_ERRBUF_SIZE];
gchar *sync_msg_str;
#ifdef _WIN32
gchar *sync_secondary_msg_str;
#endif
const char *set_linktype_err_str;
#ifdef _WIN32
int err;
WORD wVersionRequested;
WSADATA wsaData;
#else
static const char ppamsg[] = "can't find PPA for ";
const char *libpcap_warn;
#endif
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_open_input : %s", capture_opts->iface);
/* XXX - opening Winsock on twireshark? */
/* Initialize Windows Socket if we are in a WIN32 OS
This needs to be done before querying the interface for network/netmask */
#ifdef _WIN32
/* XXX - do we really require 1.1 or earlier?
Are there any versions that support only 2.0 or higher? */
wVersionRequested = MAKEWORD(1, 1);
err = WSAStartup(wVersionRequested, &wsaData);
if (err != 0) {
switch (err) {
case WSASYSNOTREADY:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: Network system not ready for network communication");
break;
case WSAVERNOTSUPPORTED:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: Windows Sockets version %u.%u not supported",
LOBYTE(wVersionRequested), HIBYTE(wVersionRequested));
break;
case WSAEINPROGRESS:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: Blocking operation is in progress");
break;
case WSAEPROCLIM:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: Limit on the number of tasks supported by this WinSock implementation has been reached");
break;
case WSAEFAULT:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: Bad pointer passed to WSAStartup");
break;
default:
g_snprintf(errmsg, errmsg_len,
"Couldn't initialize Windows Sockets: error %d", err);
break;
}
g_snprintf(secondary_errmsg, secondary_errmsg_len, please_report);
return FALSE;
}
#endif
/* Open the network interface to capture from it.
Some versions of libpcap may put warnings into the error buffer
if they succeed; to tell if that's happened, we have to clear
the error buffer, and check if it's still a null string. */
open_err_str[0] = '\0';
ld->pcap_h = pcap_open_live(capture_opts->iface,
capture_opts->has_snaplen ? capture_opts->snaplen :
WTAP_MAX_PACKET_SIZE,
capture_opts->promisc_mode, CAP_READ_TIMEOUT,
open_err_str);
if (ld->pcap_h != NULL) {
/* we've opened "iface" as a network device */
#ifdef _WIN32
/* try to set the capture buffer size */
if (pcap_setbuff(ld->pcap_h, capture_opts->buffer_size * 1024 * 1024) != 0) {
sync_secondary_msg_str = g_strdup_printf(
"The capture buffer size of %luMB seems to be too high for your machine,\n"
"the default of 1MB will be used.\n"
"\n"
"Nonetheless, the capture is started.\n",
capture_opts->buffer_size);
report_capture_error("Couldn't set the capture buffer size!",
sync_secondary_msg_str);
g_free(sync_secondary_msg_str);
}
#endif
/* setting the data link type only works on real interfaces */
if (capture_opts->linktype != -1) {
set_linktype_err_str = set_pcap_linktype(ld->pcap_h, capture_opts->iface,
capture_opts->linktype);
if (set_linktype_err_str != NULL) {
g_snprintf(errmsg, errmsg_len, "Unable to set data link type (%s).",
set_linktype_err_str);
g_snprintf(secondary_errmsg, secondary_errmsg_len, please_report);
return FALSE;
}
}
ld->linktype = get_pcap_linktype(ld->pcap_h, capture_opts->iface);
} else {
/* We couldn't open "iface" as a network device. */
#ifdef _WIN32
/* On Windows, we don't support capturing on pipes, so we give up. */
/* On Win32 OSes, the capture devices are probably available to all
users; don't warn about permissions problems.
Do, however, warn about the lack of 64-bit support, and warn that
WAN devices aren't supported. */
g_snprintf(errmsg, errmsg_len,
"The capture session could not be initiated.\n"
"\"%s\"",
open_err_str);
g_snprintf(secondary_errmsg, secondary_errmsg_len,
"\n"
"Please check that \"%s\" is the proper interface.\n"
"\n"
"\n"
"Help can be found at:\n"
"\n"
" http://wiki.wireshark.org/CaptureSetup\n"
"\n"
"64-bit Windows:\n"
"WinPcap does not support 64-bit Windows; you will have to use some other\n"
"tool to capture traffic, such as netcap.\n"
"For netcap details see: http://support.microsoft.com/?id=310875\n"
"\n"
"Modem (PPP/WAN):\n"
"Note that version 3.0 of WinPcap, and earlier versions of WinPcap, don't\n"
"support capturing on PPP/WAN interfaces on Windows NT 4.0 / 2000 / XP /\n"
"Server 2003.\n"
"WinPcap 3.1 has support for it on Windows 2000 / XP / Server 2003, but has no\n"
"support for it on Windows NT 4.0 or Windows Vista (Beta 1).",
capture_opts->iface);
return FALSE;
#else
/* try to open iface as a pipe */
ld->cap_pipe_fd = cap_pipe_open_live(capture_opts->iface, &ld->cap_pipe_hdr, ld, errmsg, errmsg_len);
if (ld->cap_pipe_fd == -1) {
if (ld->cap_pipe_err == PIPNEXIST) {
/* Pipe doesn't exist, so output message for interface */
/* If we got a "can't find PPA for X" message, warn the user (who
is running (T)Wireshark on HP-UX) that they don't have a version
of libpcap that properly handles HP-UX (libpcap 0.6.x and later
versions, which properly handle HP-UX, say "can't find /dev/dlpi
PPA for X" rather than "can't find PPA for X"). */
if (strncmp(open_err_str, ppamsg, sizeof ppamsg - 1) == 0)
libpcap_warn =
"\n\n"
"You are running (T)Wireshark with a version of the libpcap library\n"
"that doesn't handle HP-UX network devices well; this means that\n"
"(T)Wireshark may not be able to capture packets.\n"
"\n"
"To fix this, you should install libpcap 0.6.2, or a later version\n"
"of libpcap, rather than libpcap 0.4 or 0.5.x. It is available in\n"
"packaged binary form from the Software Porting And Archive Centre\n"
"for HP-UX; the Centre is at http://hpux.connect.org.uk/ - the page\n"
"at the URL lists a number of mirror sites.";
else
libpcap_warn = "";
g_snprintf(errmsg, errmsg_len,
"The capture session could not be initiated (%s).", open_err_str);
g_snprintf(secondary_errmsg, secondary_errmsg_len,
"Please check to make sure you have sufficient permissions, and that you have\n"
"the proper interface or pipe specified.%s", libpcap_warn);
}
/*
* Else pipe (or file) does exist and cap_pipe_open_live() has
* filled in errmsg
*/
return FALSE;
} else
/* cap_pipe_open_live() succeeded; don't want
error message from pcap_open_live() */
open_err_str[0] = '\0';
#endif
}
/* XXX - will this work for twireshark? */
#ifdef MUST_DO_SELECT
if (!ld->from_cap_pipe) {
#ifdef HAVE_PCAP_GET_SELECTABLE_FD
ld->pcap_fd = pcap_get_selectable_fd(ld->pcap_h);
#else
ld->pcap_fd = pcap_fileno(ld->pcap_h);
#endif
}
#endif
/* Does "open_err_str" contain a non-empty string? If so, "pcap_open_live()"
returned a warning; print it, but keep capturing. */
if (open_err_str[0] != '\0') {
sync_msg_str = g_strdup_printf("%s.", open_err_str);
report_capture_error(sync_msg_str, "");
g_free(sync_msg_str);
}
return TRUE;
}
/* close the capture input file (pcap or capture pipe) */
static void capture_loop_close_input(loop_data *ld) {
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_input");
#ifndef _WIN32
/* if open, close the capture pipe "input file" */
if (ld->cap_pipe_fd >= 0) {
g_assert(ld->from_cap_pipe);
eth_close(ld->cap_pipe_fd);
}
#endif
/* if open, close the pcap "input file" */
if(ld->pcap_h != NULL) {
g_assert(!ld->from_cap_pipe);
pcap_close(ld->pcap_h);
}
#ifdef _WIN32
/* Shut down windows sockets */
WSACleanup();
#endif
}
/* init the capture filter */
initfilter_status_t capture_loop_init_filter(pcap_t *pcap_h, gboolean from_cap_pipe, const gchar * iface, gchar * cfilter) {
bpf_u_int32 netnum, netmask;
gchar lookup_net_err_str[PCAP_ERRBUF_SIZE];
struct bpf_program fcode;
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_filter: %s", cfilter);
/* capture filters only work on real interfaces */
if (cfilter && !from_cap_pipe) {
/* A capture filter was specified; set it up. */
if (pcap_lookupnet(iface, &netnum, &netmask, lookup_net_err_str) < 0) {
/*
* Well, we can't get the netmask for this interface; it's used
* only for filters that check for broadcast IP addresses, so
* we just punt and use 0. It might be nice to warn the user,
* but that's a pain in a GUI application, as it'd involve popping
* up a message box, and it's not clear how often this would make
* a difference (only filters that check for IP broadcast addresses
* use the netmask).
*/
/*cmdarg_err(
"Warning: Couldn't obtain netmask info (%s).", lookup_net_err_str);*/
netmask = 0;
}
if (pcap_compile(pcap_h, &fcode, cfilter, 1, netmask) < 0) {
/* Treat this specially - our caller might try to compile this
as a display filter and, if that succeeds, warn the user that
the display and capture filter syntaxes are different. */
return INITFILTER_BAD_FILTER;
}
if (pcap_setfilter(pcap_h, &fcode) < 0) {
#ifdef HAVE_PCAP_FREECODE
pcap_freecode(&fcode);
#endif
return INITFILTER_OTHER_ERROR;
}
#ifdef HAVE_PCAP_FREECODE
pcap_freecode(&fcode);
#endif
}
return INITFILTER_NO_ERROR;
}
/* set up to write to the already-opened capture output file/files */
gboolean capture_loop_init_output(capture_options *capture_opts, int save_file_fd, loop_data *ld, char *errmsg, int errmsg_len) {
int file_snaplen;
int err;
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_output");
/* get snaplen */
#ifndef _WIN32
if (ld->from_cap_pipe) {
file_snaplen = ld->cap_pipe_hdr.snaplen;
} else
#endif
{
file_snaplen = pcap_snapshot(ld->pcap_h);
}
/* Set up to write to the capture file. */
if (capture_opts->multi_files_on) {
ld->pdh = ringbuf_init_libpcap_fdopen(ld->linktype, file_snaplen,
&ld->bytes_written, &err);
} else {
ld->pdh = libpcap_fdopen(save_file_fd, ld->linktype, file_snaplen,
&ld->bytes_written, &err);
}
if (ld->pdh == NULL) {
/* We couldn't set up to write to the capture file. */
/* XXX - use cf_open_error_message from twireshark instead? */
switch (err) {
case WTAP_ERR_CANT_OPEN:
strcpy(errmsg, "The file to which the capture would be saved"
" couldn't be created for some unknown reason.");
break;
case WTAP_ERR_SHORT_WRITE:
strcpy(errmsg, "A full header couldn't be written to the file"
" to which the capture would be saved.");
break;
default:
if (err < 0) {
g_snprintf(errmsg, errmsg_len,
"The file to which the capture would be"
" saved (\"%s\") could not be opened: Error %d.",
capture_opts->save_file, err);
} else {
g_snprintf(errmsg, errmsg_len,
"The file to which the capture would be"
" saved (\"%s\") could not be opened: %s.",
capture_opts->save_file, strerror(err));
}
break;
}
return FALSE;
}
return TRUE;
}
gboolean capture_loop_close_output(capture_options *capture_opts, loop_data *ld, int *err_close) {
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_close_output");
if (capture_opts->multi_files_on) {
return ringbuf_libpcap_dump_close(&capture_opts->save_file, err_close);
} else {
return libpcap_dump_close(ld->pdh, err_close);
}
}
/* dispatch incoming packets (pcap or capture pipe) */
static int
capture_loop_dispatch(capture_options *capture_opts _U_, loop_data *ld,
char *errmsg, int errmsg_len) {
int inpkts;
#ifndef _WIN32
fd_set set1;
struct timeval timeout;
int sel_ret;
guchar pcap_data[WTAP_MAX_PACKET_SIZE];
#endif
#ifndef _WIN32
if (ld->from_cap_pipe) {
/* dispatch from capture pipe */
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from capture pipe");
#endif
FD_ZERO(&set1);
FD_SET(ld->cap_pipe_fd, &set1);
timeout.tv_sec = 0;
timeout.tv_usec = CAP_READ_TIMEOUT*1000;
sel_ret = select(ld->cap_pipe_fd+1, &set1, NULL, NULL, &timeout);
if (sel_ret <= 0) {
inpkts = 0;
if (sel_ret < 0 && errno != EINTR) {
g_snprintf(errmsg, errmsg_len,
"Unexpected error from select: %s", strerror(errno));
report_capture_error(errmsg, please_report);
ld->go = FALSE;
}
} else {
/*
* "select()" says we can read from the pipe without blocking
*/
inpkts = cap_pipe_dispatch(ld, pcap_data, errmsg, errmsg_len);
if (inpkts < 0) {
ld->go = FALSE;
}
}
}
else
#endif /* _WIN32 */
{
/* dispatch from pcap */
#ifdef MUST_DO_SELECT
/*
* If we have "pcap_get_selectable_fd()", we use it to get the
* descriptor on which to select; if that's -1, it means there
* is no descriptor on which you can do a "select()" (perhaps
* because you're capturing on a special device, and that device's
* driver unfortunately doesn't support "select()", in which case
* we don't do the select - which means it might not be possible
* to stop a capture until a packet arrives. If that's unacceptable,
* plead with whoever supplies the software for that device to add
* "select()" support, or upgrade to libpcap 0.8.1 or later, and
* rebuild Wireshark or get a version built with libpcap 0.8.1 or
* later, so it can use pcap_breakloop().
*/
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_dispatch with select");
#endif
if (ld->pcap_fd != -1) {
FD_ZERO(&set1);
FD_SET(ld->pcap_fd, &set1);
sel_ret = select(ld->pcap_fd+1, &set1, NULL, NULL, NULL);
if (sel_ret > 0) {
/*
* "select()" says we can read from it without blocking; go for
* it.
*
* We don't have pcap_breakloop(), so we only process one packet
* per pcap_dispatch() call, to allow a signal to stop the
* processing immediately, rather than processing all packets
* in a batch before quitting.
*/
inpkts = pcap_dispatch(ld->pcap_h, 1, ld->packet_cb, (u_char *)ld);
if (inpkts < 0) {
ld->pcap_err = TRUE;
ld->go = FALSE; /* error or pcap_breakloop() - stop capturing */
}
} else {
inpkts = 0;
if (sel_ret < 0 && errno != EINTR) {
g_snprintf(errmsg, errmsg_len,
"Unexpected error from select: %s", strerror(errno));
report_capture_error(errmsg, please_report);
ld->go = FALSE;
}
}
}
else
#endif /* MUST_DO_SELECT */
{
/* dispatch from pcap without select */
#if 1
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_dispatch");
#endif
#ifdef _WIN32
/*
* On Windows, we don't support asynchronously telling a process to
* stop capturing; instead, we check for an indication on a pipe
* after processing packets. We therefore process only one packet
* at a time, so that we can check the pipe after every packet.
*/
inpkts = pcap_dispatch(ld->pcap_h, 1, ld->packet_cb, (u_char *) ld);
#else
inpkts = pcap_dispatch(ld->pcap_h, -1, ld->packet_cb, (u_char *) ld);
#endif
if (inpkts < 0) {
if (inpkts == -1) {
/* Error, rather than pcap_breakloop(). */
ld->pcap_err = TRUE;
}
ld->go = FALSE; /* error or pcap_breakloop() - stop capturing */
}
#else /* pcap_next_ex */
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: from pcap_next_ex");
#endif
/* XXX - this is currently unused, as there is some confusion with pcap_next_ex() vs. pcap_dispatch() */
/*
* WinPcap's remote capturing feature doesn't work with pcap_dispatch(),
* see http://wiki.wireshark.org/CaptureSetup_2fWinPcapRemote
* This should be fixed in the WinPcap 4.0 alpha release.
*
* For reference, an example remote interface:
* rpcap://[1.2.3.4]/\Device\NPF_{39993D68-7C9B-4439-A329-F2D888DA7C5C}
*/
/* emulate dispatch from pcap */
{
int in;
struct pcap_pkthdr *pkt_header;
u_char *pkt_data;
inpkts = 0;
in = 0;
while(ld->go &&
(in = pcap_next_ex(ld->pcap_h, &pkt_header, &pkt_data)) == 1) {
ld->packet_cb( (u_char *) ld, pkt_header, pkt_data);
inpkts++;
}
if(in < 0) {
ld->pcap_err = TRUE;
ld->go = FALSE;
inpkts = in;
}
}
#endif /* pcap_next_ex */
}
}
#ifdef LOG_CAPTURE_VERBOSE
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_dispatch: %d new packet%s", inpkts, plurality(inpkts, "", "s"));
#endif
return inpkts;
}
/* open the output file (temporary/specified name/ringbuffer/named pipe/stdout) */
/* Returns TRUE if the file opened successfully, FALSE otherwise. */
gboolean
capture_loop_open_output(capture_options *capture_opts, int *save_file_fd,
char *errmsg, int errmsg_len) {
char tmpname[128+1];
gchar *capfile_name;
gboolean is_tempfile;
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_open_output: %s",
(capture_opts->save_file) ? capture_opts->save_file : "");
if (capture_opts->save_file != NULL) {
/* We return to the caller while the capture is in progress.
* Therefore we need to take a copy of save_file in
* case the caller destroys it after we return.
*/
capfile_name = g_strdup(capture_opts->save_file);
if (strcmp(capfile_name, "-") == 0) {
/* Write to the standard output. */
if (capture_opts->multi_files_on) {
/* ringbuffer is enabled; that doesn't work with standard output */
g_snprintf(errmsg, errmsg_len,
"Ring buffer requested, but capture is being written to the standard output.");
g_free(capfile_name);
return FALSE;
} else {
*save_file_fd = 1;
}
} else {
if (capture_opts->multi_files_on) {
/* ringbuffer is enabled */
*save_file_fd = ringbuf_init(capfile_name,
(capture_opts->has_ring_num_files) ? capture_opts->ring_num_files : 0);
/* we need the ringbuf name */
if(*save_file_fd != -1) {
g_free(capfile_name);
capfile_name = g_strdup(ringbuf_current_filename());
}
} else {
/* Try to open/create the specified file for use as a capture buffer. */
*save_file_fd = open(capfile_name, O_RDWR|O_BINARY|O_TRUNC|O_CREAT,
0600);
}
}
is_tempfile = FALSE;
} else {
/* Choose a random name for the temporary capture buffer */
*save_file_fd = create_tempfile(tmpname, sizeof tmpname, "ether");
capfile_name = g_strdup(tmpname);
is_tempfile = TRUE;
}
/* did we fail to open the output file? */
if (*save_file_fd == -1) {
if (is_tempfile) {
g_snprintf(errmsg, errmsg_len,
"The temporary file to which the capture would be saved (\"%s\") "
"could not be opened: %s.", capfile_name, strerror(errno));
} else {
if (capture_opts->multi_files_on) {
ringbuf_error_cleanup();
}
g_snprintf(errmsg, errmsg_len,
"The file to which the capture would be saved (\"%s\") "
"could not be opened: %s.", capfile_name,
strerror(errno));
}
g_free(capfile_name);
return FALSE;
}
if(capture_opts->save_file != NULL) {
g_free(capture_opts->save_file);
}
capture_opts->save_file = capfile_name;
/* capture_opts.save_file is "g_free"ed later, which is equivalent to
"g_free(capfile_name)". */
return TRUE;
}
#ifndef _WIN32
static void
capture_loop_stop_signal_handler(int signo _U_)
{
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Signal: Stop capture");
capture_loop_stop();
}
#endif
#ifdef _WIN32
#define TIME_GET() GetTickCount()
#else
#define TIME_GET() time(NULL)
#endif
/* Do the low-level work of a capture.
Returns TRUE if it succeeds, FALSE otherwise. */
int
capture_loop_start(capture_options *capture_opts, gboolean *stats_known, struct pcap_stat *stats)
{
#ifndef _WIN32
struct sigaction act;
#endif
time_t upd_time, cur_time;
time_t start_time;
int err_close;
int inpkts;
gint inpkts_to_sync_pipe = 0; /* packets not already send out to the sync_pipe */
condition *cnd_file_duration = NULL;
condition *cnd_autostop_files = NULL;
condition *cnd_autostop_size = NULL;
condition *cnd_autostop_duration = NULL;
guint32 autostop_files = 0;
gboolean write_ok;
gboolean close_ok;
gboolean cfilter_error = FALSE;
char errmsg[4096+1];
char secondary_errmsg[4096+1];
int save_file_fd = -1;
/* init the loop data */
ld.go = TRUE;
ld.packet_count = 0;
if (capture_opts->has_autostop_packets)
ld.packet_max = capture_opts->autostop_packets;
else
ld.packet_max = 0; /* no limit */
ld.err = 0; /* no error seen yet */
ld.wtap_linktype = WTAP_ENCAP_UNKNOWN;
ld.pcap_err = FALSE;
ld.from_cap_pipe = FALSE;
ld.pdh = NULL;
#ifndef _WIN32
ld.cap_pipe_fd = -1;
#endif
#ifdef MUST_DO_SELECT
ld.pcap_fd = 0;
#endif
ld.packet_cb = capture_loop_packet_cb;
/* We haven't yet gotten the capture statistics. */
*stats_known = FALSE;
#ifndef _WIN32
/*
* Catch SIGUSR1, so that we exit cleanly if the parent process
* kills us with it due to the user selecting "Capture->Stop".
*/
act.sa_handler = capture_loop_stop_signal_handler;
/*
* Arrange that system calls not get restarted, because when
* our signal handler returns we don't want to restart
* a call that was waiting for packets to arrive.
*/
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
sigaction(SIGUSR1, &act, NULL);
#endif /* _WIN32 */
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop starting ...");
capture_opts_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, capture_opts);
/* open the "input file" from network interface or capture pipe */
if (!capture_loop_open_input(capture_opts, &ld, errmsg, sizeof(errmsg),
secondary_errmsg, sizeof(secondary_errmsg))) {
goto error;
}
/* init the input filter from the network interface (capture pipe will do nothing) */
switch (capture_loop_init_filter(ld.pcap_h, ld.from_cap_pipe, capture_opts->iface, capture_opts->cfilter)) {
case INITFILTER_NO_ERROR:
break;
case INITFILTER_BAD_FILTER:
cfilter_error = TRUE;
g_snprintf(errmsg, sizeof(errmsg), "%s", pcap_geterr(ld.pcap_h));
*secondary_errmsg = '\0';
goto error;
case INITFILTER_OTHER_ERROR:
g_snprintf(errmsg, sizeof(errmsg), "Can't install filter (%s).",
pcap_geterr(ld.pcap_h));
g_snprintf(secondary_errmsg, sizeof(secondary_errmsg), "%s", please_report);
goto error;
}
/* If we're supposed to write to a capture file, open it for output
(temporary/specified name/ringbuffer) */
if (capture_opts->saving_to_file) {
if (!capture_loop_open_output(capture_opts, &save_file_fd, errmsg, sizeof(errmsg))) {
*secondary_errmsg = '\0';
goto error;
}
/* set up to write to the already-opened capture output file/files */
if (!capture_loop_init_output(capture_opts, save_file_fd, &ld, errmsg, sizeof(errmsg))) {
*secondary_errmsg = '\0';
goto error;
}
/* XXX - capture SIGTERM and close the capture, in case we're on a
Linux 2.0[.x] system and you have to explicitly close the capture
stream in order to turn promiscuous mode off? We need to do that
in other places as well - and I don't think that works all the
time in any case, due to libpcap bugs. */
/* Well, we should be able to start capturing.
Sync out the capture file, so the header makes it to the file system,
and send a "capture started successfully and capture file created"
message to our parent so that they'll open the capture file and
update its windows to indicate that we have a live capture in
progress. */
libpcap_dump_flush(ld.pdh, NULL);
report_new_capture_file(capture_opts->save_file);
}
/* initialize capture stop (and alike) conditions */
init_capture_stop_conditions();
/* create stop conditions */
if (capture_opts->has_autostop_filesize)
cnd_autostop_size =
cnd_new(CND_CLASS_CAPTURESIZE,(long)capture_opts->autostop_filesize * 1024);
if (capture_opts->has_autostop_duration)
cnd_autostop_duration =
cnd_new(CND_CLASS_TIMEOUT,(gint32)capture_opts->autostop_duration);
if (capture_opts->multi_files_on) {
if (capture_opts->has_file_duration)
cnd_file_duration =
cnd_new(CND_CLASS_TIMEOUT, capture_opts->file_duration);
if (capture_opts->has_autostop_files)
cnd_autostop_files =
cnd_new(CND_CLASS_CAPTURESIZE, capture_opts->autostop_files);
}
/* init the time values */
start_time = TIME_GET();
upd_time = TIME_GET();
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop running!");
/* WOW, everything is prepared! */
/* please fasten your seat belts, we will enter now the actual capture loop */
while (ld.go) {
/* dispatch incoming packets */
inpkts = capture_loop_dispatch(capture_opts, &ld, errmsg, sizeof(errmsg));
#ifdef _WIN32
/* any news from our parent (signal pipe)? -> just stop the capture */
if (!signal_pipe_check_running()) {
ld.go = FALSE;
}
#endif
if (inpkts > 0) {
inpkts_to_sync_pipe += inpkts;
/* check capture size condition */
if (cnd_autostop_size != NULL &&
cnd_eval(cnd_autostop_size, (guint32)ld.bytes_written)){
/* Capture size limit reached, do we have another file? */
if (capture_opts->multi_files_on) {
if (cnd_autostop_files != NULL &&
cnd_eval(cnd_autostop_files, ++autostop_files)) {
/* no files left: stop here */
ld.go = FALSE;
continue;
}
/* Switch to the next ringbuffer file */
if (ringbuf_switch_file(&ld.pdh, &capture_opts->save_file,
&save_file_fd, &ld.bytes_written, &ld.err)) {
/* File switch succeeded: reset the conditions */
cnd_reset(cnd_autostop_size);
if (cnd_file_duration) {
cnd_reset(cnd_file_duration);
}
libpcap_dump_flush(ld.pdh, NULL);
report_packet_count(inpkts_to_sync_pipe);
inpkts_to_sync_pipe = 0;
report_new_capture_file(capture_opts->save_file);
} else {
/* File switch failed: stop here */
ld.go = FALSE;
continue;
}
} else {
/* single file, stop now */
ld.go = FALSE;
continue;
}
} /* cnd_autostop_size */
if (capture_opts->output_to_pipe) {
libpcap_dump_flush(ld.pdh, NULL);
}
} /* inpkts */
/* Only update once a second (Win32: 500ms) so as not to overload slow displays */
cur_time = TIME_GET();
#ifdef _WIN32
if ( (cur_time - upd_time) > 500) {
#else
if (cur_time - upd_time > 0) {
#endif
upd_time = cur_time;
/*if (pcap_stats(pch, stats) >= 0) {
*stats_known = TRUE;
}*/
/* Let the parent process know. */
if (inpkts_to_sync_pipe) {
/* do sync here */
libpcap_dump_flush(ld.pdh, NULL);
/* Send our parent a message saying we've written out "inpkts_to_sync_pipe"
packets to the capture file. */
report_packet_count(inpkts_to_sync_pipe);
inpkts_to_sync_pipe = 0;
}
/* check capture duration condition */
if (cnd_autostop_duration != NULL && cnd_eval(cnd_autostop_duration)) {
/* The maximum capture time has elapsed; stop the capture. */
ld.go = FALSE;
continue;
}
/* check capture file duration condition */
if (cnd_file_duration != NULL && cnd_eval(cnd_file_duration)) {
/* duration limit reached, do we have another file? */
if (capture_opts->multi_files_on) {
if (cnd_autostop_files != NULL &&
cnd_eval(cnd_autostop_files, ++autostop_files)) {
/* no files left: stop here */
ld.go = FALSE;
continue;
}
/* Switch to the next ringbuffer file */
if (ringbuf_switch_file(&ld.pdh, &capture_opts->save_file,
&save_file_fd, &ld.bytes_written, &ld.err)) {
/* file switch succeeded: reset the conditions */
cnd_reset(cnd_file_duration);
if(cnd_autostop_size)
cnd_reset(cnd_autostop_size);
libpcap_dump_flush(ld.pdh, NULL);
report_packet_count(inpkts_to_sync_pipe);
inpkts_to_sync_pipe = 0;
report_new_capture_file(capture_opts->save_file);
} else {
/* File switch failed: stop here */
ld.go = FALSE;
continue;
}
} else {
/* single file, stop now */
ld.go = FALSE;
continue;
}
} /* cnd_file_duration */
}
} /* while (ld.go) */
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopping ...");
/* delete stop conditions */
if (cnd_file_duration != NULL)
cnd_delete(cnd_file_duration);
if (cnd_autostop_files != NULL)
cnd_delete(cnd_autostop_files);
if (cnd_autostop_size != NULL)
cnd_delete(cnd_autostop_size);
if (cnd_autostop_duration != NULL)
cnd_delete(cnd_autostop_duration);
/* did we had a pcap (input) error? */
if (ld.pcap_err) {
g_snprintf(errmsg, sizeof(errmsg), "Error while capturing packets: %s",
pcap_geterr(ld.pcap_h));
report_capture_error(errmsg, please_report);
}
#ifndef _WIN32
else if (ld.from_cap_pipe && ld.cap_pipe_err == PIPERR)
report_capture_error(errmsg, "");
#endif
/* did we had an error while capturing? */
if (ld.err == 0) {
write_ok = TRUE;
} else {
capture_loop_get_errmsg(errmsg, sizeof(errmsg), capture_opts->save_file, ld.err,
FALSE);
report_capture_error(errmsg, please_report);
write_ok = FALSE;
}
if (capture_opts->saving_to_file) {
/* close the wiretap (output) file */
close_ok = capture_loop_close_output(capture_opts, &ld, &err_close);
} else
close_ok = TRUE;
/* there might be packets not yet notified to the parent */
/* (do this after closing the file, so all packets are already flushed) */
if(inpkts_to_sync_pipe) {
report_packet_count(inpkts_to_sync_pipe);
inpkts_to_sync_pipe = 0;
}
/* If we've displayed a message about a write error, there's no point
in displaying another message about an error on close. */
if (!close_ok && write_ok) {
capture_loop_get_errmsg(errmsg, sizeof(errmsg), capture_opts->save_file, err_close,
TRUE);
report_capture_error(errmsg, "");
}
/*
* XXX We exhibit different behaviour between normal mode and sync mode
* when the pipe is stdin and not already at EOF. If we're a child, the
* parent's stdin isn't closed, so if the user starts another capture,
* cap_pipe_open_live() will very likely not see the expected magic bytes and
* will say "Unrecognized libpcap format". On the other hand, in normal
* mode, cap_pipe_open_live() will say "End of file on pipe during open".
*/
/* get packet drop statistics from pcap */
if(ld.pcap_h != NULL) {
g_assert(!ld.from_cap_pipe);
/* Get the capture statistics, so we know how many packets were
dropped. */
if (pcap_stats(ld.pcap_h, stats) >= 0) {
*stats_known = TRUE;
/* Let the parent process know. */
report_packet_drops(stats->ps_drop);
} else {
g_snprintf(errmsg, sizeof(errmsg),
"Can't get packet-drop statistics: %s",
pcap_geterr(ld.pcap_h));
report_capture_error(errmsg, please_report);
}
}
/* close the input file (pcap or capture pipe) */
capture_loop_close_input(&ld);
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopped!");
/* ok, if the write and the close were successful. */
return write_ok && close_ok;
error:
if (capture_opts->multi_files_on) {
/* cleanup ringbuffer */
ringbuf_error_cleanup();
} else {
/* We can't use the save file, and we have no FILE * for the stream
to close in order to close it, so close the FD directly. */
if(save_file_fd != -1) {
eth_close(save_file_fd);
}
/* We couldn't even start the capture, so get rid of the capture
file. */
if(capture_opts->save_file != NULL) {
eth_unlink(capture_opts->save_file);
g_free(capture_opts->save_file);
}
}
capture_opts->save_file = NULL;
if (cfilter_error)
report_cfilter_error(capture_opts->cfilter, errmsg);
else
report_capture_error(errmsg, secondary_errmsg);
/* close the input file (pcap or cap_pipe) */
capture_loop_close_input(&ld);
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_INFO, "Capture loop stopped with error");
return FALSE;
}
void capture_loop_stop(void)
{
#ifdef HAVE_PCAP_BREAKLOOP
pcap_breakloop(ld.pcap_h);
#else
ld.go = FALSE;
#endif
}
static void
capture_loop_get_errmsg(char *errmsg, int errmsglen, const char *fname,
int err, gboolean is_close)
{
switch (err) {
case ENOSPC:
g_snprintf(errmsg, errmsglen,
"Not all the packets could be written to the file"
" to which the capture was being saved\n"
"(\"%s\") because there is no space left on the file system\n"
"on which that file resides.",
fname);
break;
#ifdef EDQUOT
case EDQUOT:
g_snprintf(errmsg, errmsglen,
"Not all the packets could be written to the file"
" to which the capture was being saved\n"
"(\"%s\") because you are too close to, or over,"
" your disk quota\n"
"on the file system on which that file resides.",
fname);
break;
#endif
case WTAP_ERR_CANT_CLOSE:
g_snprintf(errmsg, errmsglen,
"The file to which the capture was being saved"
" couldn't be closed for some unknown reason.");
break;
case WTAP_ERR_SHORT_WRITE:
g_snprintf(errmsg, errmsglen,
"Not all the packets could be written to the file"
" to which the capture was being saved\n"
"(\"%s\").",
fname);
break;
default:
if (is_close) {
g_snprintf(errmsg, errmsglen,
"The file to which the capture was being saved\n"
"(\"%s\") could not be closed: %s.",
fname, wtap_strerror(err));
} else {
g_snprintf(errmsg, errmsglen,
"An error occurred while writing to the file"
" to which the capture was being saved\n"
"(\"%s\"): %s.",
fname, wtap_strerror(err));
}
break;
}
}
/* one packet was captured, process it */
static void
capture_loop_packet_cb(u_char *user, const struct pcap_pkthdr *phdr,
const u_char *pd)
{
loop_data *ld = (loop_data *) user;
int err;
/* if the user told us to stop after x packets, do we have enough? */
ld->packet_count++;
if ((ld->packet_max > 0) && (ld->packet_count >= ld->packet_max))
{
ld->go = FALSE;
}
if (ld->pdh) {
/* We're supposed to write the packet to a file; do so.
If this fails, set "ld->go" to FALSE, to stop the capture, and set
"ld->err" to the error. */
if (!libpcap_write_packet(ld->pdh, phdr, pd, &ld->bytes_written, &err)) {
ld->go = FALSE;
ld->err = err;
}
}
}
#endif /* HAVE_LIBPCAP */
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