1538 lines
48 KiB
C
1538 lines
48 KiB
C
/* capture_loop.c
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* The actual capturing loop, getting packets and storing it
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*
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* $Id$
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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/** @file
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*
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* Capture loop (internal interface).
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*
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* It will open the input and output files, capture the packets,
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* change ringbuffer output files while capturing and close all files again.
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*
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* The input file can be a network interface or capture pipe (unix only).
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* The output file can be a single or a ringbuffer file handled by wiretap.
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*
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_LIBPCAP
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#include <string.h>
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#ifdef HAVE_FCNTL_H
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#include <fcntl.h>
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#endif
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#ifdef HAVE_SYS_STAT_H
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# include <sys/stat.h>
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#endif
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#include <signal.h>
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#include <errno.h>
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#include <setjmp.h>
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#include <glib.h>
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#include <pcap.h>
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#include "pcapio.h"
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#include "capture-pcap-util.h"
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#include "capture.h"
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#include "capture_sync.h"
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#include "conditions.h"
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#include "capture_stop_conditions.h"
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#include "ringbuffer.h"
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#include "simple_dialog.h"
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#include "tempfile.h"
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#include "log.h"
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#include "file_util.h"
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#include "capture_loop.h"
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/*
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* Standard secondary message for unexpected errors.
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*/
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static const char please_report[] =
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"Please report this to the Ethereal developers";
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/*
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* This needs to be static, so that the SIGUSR1 handler can clear the "go"
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* flag.
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*/
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static loop_data ld;
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/*
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* Timeout, in milliseconds, for reads from the stream of captured packets.
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*/
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#define CAP_READ_TIMEOUT 250
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static void capture_loop_packet_cb(u_char *user, const struct pcap_pkthdr *phdr,
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const u_char *pd);
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static void capture_loop_get_errmsg(char *errmsg, int errmsglen, const char *fname,
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int err, gboolean is_close);
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#ifndef _WIN32
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/* Take care of byte order in the libpcap headers read from pipes.
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* (function taken from wiretap/libpcap.c) */
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static void
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cap_pipe_adjust_header(gboolean byte_swapped, struct pcap_hdr *hdr, struct pcaprec_hdr *rechdr)
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{
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if (byte_swapped) {
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/* Byte-swap the record header fields. */
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rechdr->ts_sec = BSWAP32(rechdr->ts_sec);
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rechdr->ts_usec = BSWAP32(rechdr->ts_usec);
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rechdr->incl_len = BSWAP32(rechdr->incl_len);
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rechdr->orig_len = BSWAP32(rechdr->orig_len);
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}
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/* In file format version 2.3, the "incl_len" and "orig_len" fields were
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swapped, in order to match the BPF header layout.
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Unfortunately, some files were, according to a comment in the "libpcap"
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source, written with version 2.3 in their headers but without the
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interchanged fields, so if "incl_len" is greater than "orig_len" - which
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would make no sense - we assume that we need to swap them. */
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if (hdr->version_major == 2 &&
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(hdr->version_minor < 3 ||
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(hdr->version_minor == 3 && rechdr->incl_len > rechdr->orig_len))) {
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guint32 temp;
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temp = rechdr->orig_len;
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rechdr->orig_len = rechdr->incl_len;
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rechdr->incl_len = temp;
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}
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}
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/* Mimic pcap_open_live() for pipe captures
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* We check if "pipename" is "-" (stdin) or a FIFO, open it, and read the
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* header.
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* N.B. : we can't read the libpcap formats used in RedHat 6.1 or SuSE 6.3
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* because we can't seek on pipes (see wiretap/libpcap.c for details) */
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static int
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cap_pipe_open_live(char *pipename, struct pcap_hdr *hdr, loop_data *ld,
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char *errmsg, int errmsgl)
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{
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struct stat pipe_stat;
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int fd;
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guint32 magic;
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int b, sel_ret;
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unsigned int bytes_read;
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fd_set rfds;
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struct timeval timeout;
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g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: %s", pipename);
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/*
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* XXX (T)Ethereal blocks until we return
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*/
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if (strcmp(pipename, "-") == 0)
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fd = 0; /* read from stdin */
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else {
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if (eth_stat(pipename, &pipe_stat) < 0) {
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if (errno == ENOENT || errno == ENOTDIR)
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ld->cap_pipe_err = PIPNEXIST;
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else {
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g_snprintf(errmsg, errmsgl,
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"The capture session could not be initiated "
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"due to error on pipe: %s", strerror(errno));
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ld->cap_pipe_err = PIPERR;
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}
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return -1;
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}
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if (! S_ISFIFO(pipe_stat.st_mode)) {
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if (S_ISCHR(pipe_stat.st_mode)) {
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/*
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* Assume the user specified an interface on a system where
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* interfaces are in /dev. Pretend we haven't seen it.
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*/
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ld->cap_pipe_err = PIPNEXIST;
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} else {
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g_snprintf(errmsg, errmsgl,
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"The capture session could not be initiated because\n"
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"\"%s\" is neither an interface nor a pipe", pipename);
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ld->cap_pipe_err = PIPERR;
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}
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return -1;
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}
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fd = eth_open(pipename, O_RDONLY | O_NONBLOCK, 0000 /* no creation so don't matter */);
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if (fd == -1) {
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g_snprintf(errmsg, errmsgl,
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"The capture session could not be initiated "
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"due to error on pipe open: %s", strerror(errno));
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ld->cap_pipe_err = PIPERR;
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return -1;
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}
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}
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ld->from_cap_pipe = TRUE;
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/* read the pcap header */
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FD_ZERO(&rfds);
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bytes_read = 0;
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while (bytes_read < sizeof magic) {
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FD_SET(fd, &rfds);
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timeout.tv_sec = 0;
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timeout.tv_usec = CAP_READ_TIMEOUT*1000;
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sel_ret = select(fd+1, &rfds, NULL, NULL, &timeout);
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if (sel_ret < 0) {
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g_snprintf(errmsg, errmsgl,
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"Unexpected error from select: %s", strerror(errno));
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goto error;
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} else if (sel_ret > 0) {
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b = read(fd, ((char *)&magic)+bytes_read, sizeof magic-bytes_read);
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if (b <= 0) {
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if (b == 0)
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g_snprintf(errmsg, errmsgl, "End of file on pipe during open");
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else
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g_snprintf(errmsg, errmsgl, "Error on pipe during open: %s",
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strerror(errno));
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goto error;
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}
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bytes_read += b;
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}
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}
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switch (magic) {
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case PCAP_MAGIC:
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/* Host that wrote it has our byte order, and was running
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a program using either standard or ss990417 libpcap. */
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ld->cap_pipe_byte_swapped = FALSE;
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ld->cap_pipe_modified = FALSE;
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break;
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case PCAP_MODIFIED_MAGIC:
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/* Host that wrote it has our byte order, but was running
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a program using either ss990915 or ss991029 libpcap. */
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ld->cap_pipe_byte_swapped = FALSE;
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ld->cap_pipe_modified = TRUE;
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break;
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case PCAP_SWAPPED_MAGIC:
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/* Host that wrote it has a byte order opposite to ours,
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and was running a program using either standard or
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ss990417 libpcap. */
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ld->cap_pipe_byte_swapped = TRUE;
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ld->cap_pipe_modified = FALSE;
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break;
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case PCAP_SWAPPED_MODIFIED_MAGIC:
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/* Host that wrote it out has a byte order opposite to
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ours, and was running a program using either ss990915
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or ss991029 libpcap. */
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ld->cap_pipe_byte_swapped = TRUE;
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ld->cap_pipe_modified = TRUE;
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break;
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default:
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/* Not a "libpcap" type we know about. */
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g_snprintf(errmsg, errmsgl, "Unrecognized libpcap format");
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goto error;
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}
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/* Read the rest of the header */
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bytes_read = 0;
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while (bytes_read < sizeof(struct pcap_hdr)) {
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FD_SET(fd, &rfds);
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timeout.tv_sec = 0;
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timeout.tv_usec = CAP_READ_TIMEOUT*1000;
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sel_ret = select(fd+1, &rfds, NULL, NULL, &timeout);
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if (sel_ret < 0) {
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g_snprintf(errmsg, errmsgl,
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"Unexpected error from select: %s", strerror(errno));
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goto error;
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} else if (sel_ret > 0) {
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b = read(fd, ((char *)hdr)+bytes_read,
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sizeof(struct pcap_hdr) - bytes_read);
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if (b <= 0) {
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if (b == 0)
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g_snprintf(errmsg, errmsgl, "End of file on pipe during open");
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else
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g_snprintf(errmsg, errmsgl, "Error on pipe during open: %s",
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strerror(errno));
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goto error;
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}
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bytes_read += b;
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}
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}
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if (ld->cap_pipe_byte_swapped) {
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/* Byte-swap the header fields about which we care. */
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hdr->version_major = BSWAP16(hdr->version_major);
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hdr->version_minor = BSWAP16(hdr->version_minor);
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hdr->snaplen = BSWAP32(hdr->snaplen);
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hdr->network = BSWAP32(hdr->network);
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}
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if (hdr->version_major < 2) {
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g_snprintf(errmsg, errmsgl, "Unable to read old libpcap format");
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goto error;
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}
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ld->cap_pipe_state = STATE_EXPECT_REC_HDR;
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ld->cap_pipe_err = PIPOK;
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return fd;
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error:
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g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_open_live: error %s", errmsg);
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ld->cap_pipe_err = PIPERR;
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eth_close(fd);
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return -1;
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}
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|
|
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/* We read one record from the pipe, take care of byte order in the record
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* header, write the record to the capture file, and update capture statistics. */
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int
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cap_pipe_dispatch(loop_data *ld, guchar *data, char *errmsg, int errmsgl)
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{
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struct pcap_pkthdr phdr;
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int b;
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enum { PD_REC_HDR_READ, PD_DATA_READ, PD_PIPE_EOF, PD_PIPE_ERR,
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PD_ERR } result;
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|
|
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#ifdef LOG_CAPTURE_VERBOSE
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g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "cap_pipe_dispatch");
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#endif
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|
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switch (ld->cap_pipe_state) {
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|
|
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case STATE_EXPECT_REC_HDR:
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ld->cap_pipe_bytes_to_read = ld->cap_pipe_modified ?
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sizeof(struct pcaprec_modified_hdr) : sizeof(struct pcaprec_hdr);
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ld->cap_pipe_bytes_read = 0;
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ld->cap_pipe_state = STATE_READ_REC_HDR;
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/* Fall through */
|
|
|
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case STATE_READ_REC_HDR:
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b = read(ld->cap_pipe_fd, ((char *)&ld->cap_pipe_rechdr)+ld->cap_pipe_bytes_read,
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ld->cap_pipe_bytes_to_read - ld->cap_pipe_bytes_read);
|
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if (b <= 0) {
|
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if (b == 0)
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result = PD_PIPE_EOF;
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else
|
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result = PD_PIPE_ERR;
|
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break;
|
|
}
|
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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;
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/* 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)
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result = PD_PIPE_EOF;
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else
|
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result = PD_PIPE_ERR;
|
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break;
|
|
}
|
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if ((ld->cap_pipe_bytes_read += b) < ld->cap_pipe_rechdr.hdr.incl_len)
|
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return 0;
|
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result = PD_DATA_READ;
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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. */
|
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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 tethereal? */
|
|
|
|
/* 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);
|
|
sync_pipe_errmsg_to_parent("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 this to the Ethereal developers");
|
|
return FALSE;
|
|
}
|
|
}
|
|
} 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.ethereal.com/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)Ethereal 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)Ethereal with a version of the libpcap library\n"
|
|
"that doesn't handle HP-UX network devices well; this means that\n"
|
|
"(T)Ethereal 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 tethereal? */
|
|
#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);
|
|
sync_pipe_errmsg_to_parent(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 pcap_encap;
|
|
int file_snaplen;
|
|
int err;
|
|
|
|
|
|
g_log(LOG_DOMAIN_CAPTURE_CHILD, G_LOG_LEVEL_DEBUG, "capture_loop_init_output");
|
|
|
|
/* get packet encapsulation type and snaplen */
|
|
#ifndef _WIN32
|
|
if (ld->from_cap_pipe) {
|
|
pcap_encap = ld->cap_pipe_hdr.network;
|
|
file_snaplen = ld->cap_pipe_hdr.snaplen;
|
|
} else
|
|
#endif
|
|
{
|
|
pcap_encap = get_pcap_linktype(ld->pcap_h, capture_opts->iface);
|
|
file_snaplen = pcap_snapshot(ld->pcap_h);
|
|
}
|
|
|
|
/* Set up to write to the capture file. */
|
|
ld->linktype = pcap_encap;
|
|
if (capture_opts->multi_files_on) {
|
|
ld->pdh = ringbuf_init_libpcap_fdopen(ld->linktype, file_snaplen, &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 tethereal 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));
|
|
sync_pipe_errmsg_to_parent(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
|
|
/*
|
|
* Sigh. The semantics of the read timeout argument to
|
|
* "pcap_open_live()" aren't particularly well specified by
|
|
* the "pcap" man page - at least with the BSD BPF code, the
|
|
* intent appears to be, at least in part, a way of cutting
|
|
* down the number of reads done on a capture, by blocking
|
|
* until the buffer fills or a timer expires - and the Linux
|
|
* libpcap doesn't actually support it, so we can't use it
|
|
* to break out of the "pcap_dispatch()" every 1/4 of a second
|
|
* or so. Linux's libpcap is not the only libpcap that doesn't
|
|
* support the read timeout.
|
|
*
|
|
* Furthermore, at least on Solaris, the bufmod STREAMS module's
|
|
* read timeout won't go off if no data has arrived, i.e. it cannot
|
|
* be used to guarantee that a read from a DLPI stream will return
|
|
* within a specified amount of time regardless of whether any
|
|
* data arrives or not.
|
|
*
|
|
* Thus, on all platforms other than BSD, we do a "select()" on the
|
|
* file descriptor for the capture, with a timeout of CAP_READ_TIMEOUT
|
|
* milliseconds, or CAP_READ_TIMEOUT*1000 microseconds.
|
|
*
|
|
* "select()", on BPF devices, doesn't work as you might expect;
|
|
* at least on some versions of some flavors of BSD, the timer
|
|
* doesn't start until a read is done, so it won't expire if
|
|
* only a "select()" or "poll()" is posted.
|
|
*
|
|
* 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 Ethereal might block,
|
|
* unable to accept user input, until a packet arrives. If
|
|
* that's unacceptable, plead with whoever supplies the software
|
|
* for that device to add "select()" support.
|
|
*/
|
|
#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);
|
|
timeout.tv_sec = 0;
|
|
timeout.tv_usec = CAP_READ_TIMEOUT*1000;
|
|
sel_ret = select(ld->pcap_fd+1, &set1, NULL, NULL, &timeout);
|
|
if (sel_ret > 0) {
|
|
/*
|
|
* "select()" says we can read from it without blocking; go for
|
|
* it.
|
|
*/
|
|
inpkts = pcap_dispatch(ld->pcap_h, 1, ld->packet_cb, (u_char *)ld);
|
|
if (inpkts < 0) {
|
|
ld->pcap_err = TRUE;
|
|
ld->go = FALSE;
|
|
}
|
|
} else {
|
|
inpkts = 0;
|
|
if (sel_ret < 0 && errno != EINTR) {
|
|
g_snprintf(errmsg, errmsg_len,
|
|
"Unexpected error from select: %s", strerror(errno));
|
|
sync_pipe_errmsg_to_parent(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
|
|
inpkts = pcap_dispatch(ld->pcap_h, 1, ld->packet_cb, (u_char *) ld);
|
|
if (inpkts < 0) {
|
|
ld->pcap_err = TRUE;
|
|
ld->go = FALSE;
|
|
}
|
|
#else
|
|
{
|
|
#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, see http://wiki.ethereal.com/CaptureSetup_2fWinPcapRemote */
|
|
/* 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;
|
|
while( (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
|
|
}
|
|
}
|
|
|
|
#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)
|
|
{
|
|
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".
|
|
*/
|
|
signal(SIGUSR1, capture_loop_stop_signal_handler);
|
|
#endif
|
|
|
|
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;
|
|
}
|
|
|
|
/* open the output file (temporary/specified name/ringbuffer) */
|
|
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);
|
|
sync_pipe_filename_to_parent(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.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);
|
|
sync_pipe_packet_count_to_parent(inpkts_to_sync_pipe);
|
|
inpkts_to_sync_pipe = 0;
|
|
sync_pipe_filename_to_parent(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. */
|
|
sync_pipe_packet_count_to_parent(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.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);
|
|
sync_pipe_packet_count_to_parent(inpkts_to_sync_pipe);
|
|
inpkts_to_sync_pipe = 0;
|
|
sync_pipe_filename_to_parent(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));
|
|
sync_pipe_errmsg_to_parent(errmsg, please_report);
|
|
}
|
|
#ifndef _WIN32
|
|
else if (ld.from_cap_pipe && ld.cap_pipe_err == PIPERR)
|
|
sync_pipe_errmsg_to_parent(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);
|
|
sync_pipe_errmsg_to_parent(errmsg, please_report);
|
|
write_ok = FALSE;
|
|
}
|
|
|
|
/* close the wiretap (output) file */
|
|
close_ok = capture_loop_close_output(capture_opts, &ld, &err_close);
|
|
|
|
/* 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) {
|
|
sync_pipe_packet_count_to_parent(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);
|
|
sync_pipe_errmsg_to_parent(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. */
|
|
sync_pipe_drops_to_parent(stats->ps_drop);
|
|
} else {
|
|
g_snprintf(errmsg, sizeof(errmsg),
|
|
"Can't get packet-drop statistics: %s",
|
|
pcap_geterr(ld.pcap_h));
|
|
sync_pipe_errmsg_to_parent(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)
|
|
sync_pipe_cfilter_error_to_parent(capture_opts->cfilter, errmsg);
|
|
else
|
|
sync_pipe_errmsg_to_parent(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)
|
|
{
|
|
ld.go = FALSE;
|
|
}
|
|
|
|
|
|
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 */
|
|
|