* Synchronisation between Wireshark capture parent and child instances
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#define WS_LOG_DOMAIN LOG_DOMAIN_CAPTURE
#include <wireshark.h>
#ifdef HAVE_LIBPCAP
#include <glib.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <ws_exit_codes.h>
#include <wsutil/strtoi.h>
#include <wsutil/ws_assert.h>
#ifdef _WIN32
#include <wsutil/unicode-utils.h>
#include <wsutil/win32-utils.h>
#include <wsutil/ws_pipe.h>
#else
#include <glib-unix.h>
#endif
#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#include "capture/capture-pcap-util.h"
#ifndef _WIN32
* Define various POSIX macros (and, in the case of WCOREDUMP, non-POSIX
* macros) on UNIX systems that don't have them.
*/
#ifndef WIFEXITED
# define WIFEXITED(status) (((status) & 0177) == 0)
#endif
#ifndef WIFSTOPPED
# define WIFSTOPPED(status) (((status) & 0177) == 0177)
#endif
#ifndef WIFSIGNALED
# define WIFSIGNALED(status) (!WIFSTOPPED(status) && !WIFEXITED(status))
#endif
#ifndef WEXITSTATUS
# define WEXITSTATUS(status) ((status) >> 8)
#endif
#ifndef WTERMSIG
# define WTERMSIG(status) ((status) & 0177)
#endif
#ifndef WCOREDUMP
# define WCOREDUMP(status) ((status) & 0200)
#endif
#ifndef WSTOPSIG
# define WSTOPSIG(status) ((status) >> 8)
#endif
#endif
#include <epan/packet.h>
#include <epan/prefs.h>
#include "file.h"
#include "ui/capture.h"
#include <capture/capture_sync.h>
#include "sync_pipe.h"
#ifdef _WIN32
#include "capture/capture-wpcap.h"
#endif
#include "ui/ws_ui_util.h"
#include <wsutil/filesystem.h>
#include <wsutil/file_util.h>
#include <wsutil/report_message.h>
#include "extcap.h"
#ifdef _WIN32
#include <process.h>
#endif
#include <wsutil/ws_pipe.h>
#ifdef _WIN32
static int create_dummy_signal_pipe(char **msg);
static HANDLE dummy_signal_pipe;
static char *dummy_control_id;
#else
static const char *sync_pipe_signame(int);
#endif
* data pipe. Ensure that it's large enough for the indicator and header
* plus maximum message size.
*/
#define PIPE_BUF_SIZE (SP_MAX_MSG_LEN+4)
static gboolean sync_pipe_input_cb(GIOChannel *pipe_io, capture_session *cap_session);
static int sync_pipe_wait_for_child(ws_process_id fork_child, char **msgp);
static void pipe_convert_header(const unsigned char *header, int header_len, char *indicator, int *block_len);
static ssize_t pipe_read_block(GIOChannel *pipe_io, char *indicator, int len, char *msg,
char **err_msg);
static void (*fetch_dumpcap_pid)(ws_process_id);
void
capture_session_init(capture_session *cap_session, capture_file *cf,
new_file_fn new_file, new_packets_fn new_packets,
drops_fn drops, error_fn error,
cfilter_error_fn cfilter_error, closed_fn closed)
{
cap_session->cf = cf;
cap_session->fork_child = WS_INVALID_PID;
cap_session->pipe_input_id = 0;
#ifdef _WIN32
cap_session->signal_pipe_write_fd = -1;
#endif
cap_session->state = CAPTURE_STOPPED;
#ifndef _WIN32
cap_session->owner = getuid();
cap_session->group = getgid();
#endif
cap_session->count = 0;
cap_session->count_pending = 0;
cap_session->session_will_restart = false;
cap_session->new_file = new_file;
cap_session->new_packets = new_packets;
cap_session->drops = drops;
cap_session->error = error;
cap_session->cfilter_error = cfilter_error;
cap_session->closed = closed;
cap_session->frame_cksum = NULL;
}
void capture_process_finished(capture_session *cap_session)
{
capture_options *capture_opts = cap_session->capture_opts;
interface_options *interface_opts;
GString *message;
unsigned i;
if (!extcap_session_stop(cap_session)) {
return;
}
if (cap_session->fork_child != WS_INVALID_PID) {
if (capture_opts->stop_after_extcaps) {
capture_opts->stop_after_extcaps = false;
sync_pipe_stop(cap_session);
}
return;
}
message = g_string_new(capture_opts->closed_msg);
for (i = 0; i < capture_opts->ifaces->len; i++) {
interface_opts = &g_array_index(capture_opts->ifaces, interface_options, i);
if (interface_opts->if_type != IF_EXTCAP) {
continue;
}
if ((interface_opts->extcap_stderr != NULL) &&
(interface_opts->extcap_stderr->len > 0)) {
if (message->len > 0) {
g_string_append(message, "\n");
}
g_string_append(message, "Error from extcap pipe: ");
g_string_append(message, interface_opts->extcap_stderr->str);
}
}
cap_session->closed(cap_session, message->str);
g_string_free(message, TRUE);
g_free(capture_opts->closed_msg);
capture_opts->closed_msg = NULL;
capture_opts->stop_after_extcaps = false;
}
*/
static char **
sync_pipe_add_arg(char **args, int *argc, const char *arg)
{
pointers, *not* counting the NULL pointer at the end, so we have
to add 2 in order to get the new size of the array, including the
new pointer and the terminating NULL pointer. */
args = (char **)g_realloc( (void *) args, (*argc + 2) * sizeof (char *));
is the one at the index specified by "*argc". */
args[*argc] = g_strdup(arg);
(*argc)++;
element we added. */
args[*argc] = NULL;
return args;
}
* current logger. Keep this in sync with the format used in
* dumpcap_log_writer. (We might want to do more proper serialization
* of more than just the log level.)
*/
static void
sync_pipe_handle_log_msg(const char *buffer) {
const char *log_msg = NULL;
const char* end;
uint32_t level = 0;
if (ws_strtou32(buffer, &end, &level) && end[0] == ':') {
log_msg = end + 1;
}
ws_log(LOG_DOMAIN_CAPCHILD, level, "%s", log_msg);
}
static char **
init_pipe_args(int *argc) {
char *exename;
char **argv;
exename = get_executable_path("dumpcap");
if (exename == NULL) {
return NULL;
}
terminating NULL pointer. */
*argc = 0;
argv = (char **)g_malloc(sizeof (char *));
*argv = NULL;
argv = sync_pipe_add_arg(argv, argc, exename);
* set to log in the main program. (It might be in the special noisy
* or debug filter, so we can't just check the overall level.)
*/
for (enum ws_log_level level = LOG_LEVEL_NOISY; level != _LOG_LEVEL_LAST; level++) {
if (ws_log_msg_is_active(LOG_DOMAIN_CAPCHILD, level)) {
argv = sync_pipe_add_arg(argv, argc, "--log-level");
argv = sync_pipe_add_arg(argv, argc, ws_log_level_to_string(level));
break;
}
}
g_free(exename);
return argv;
}
static gboolean
pipe_io_cb(GIOChannel *pipe_io, GIOCondition condition _U_, void * user_data)
{
capture_session *cap_session = (capture_session *)user_data;
if (!sync_pipe_input_cb(pipe_io, cap_session)) {
cap_session->pipe_input_id = 0;
return G_SOURCE_REMOVE;
}
return G_SOURCE_CONTINUE;
}
* Open two pipes to dumpcap with the supplied arguments, one for its
* standard output and one for its standard error.
*
* On success, *msg is unchanged and 0 is returned; data_read_fd,
* message_read_fd, and fork_child point to the standard output pipe's
* file descriptor, the standard error pipe's file descriptor, and
* the child's PID/handle, respectively.
*
* On failure, *msg points to an error message for the failure, and -1 is
* returned, in which case *msg must be freed with g_free().
*/
#define ARGV_NUMBER_LEN 24
static int
#ifdef _WIN32
sync_pipe_open_command(char **argv, int *data_read_fd,
GIOChannel **message_read_io, int *signal_write_fd,
ws_process_id *fork_child, GArray *ifaces,
char **msg, void(*update_cb)(void))
#else
sync_pipe_open_command(char **argv, int *data_read_fd,
GIOChannel **message_read_io, int *signal_write_fd _U_,
ws_process_id *fork_child, GArray *ifaces _U_,
char **msg, void(*update_cb)(void))
#endif
{
enum PIPES { PIPE_READ, PIPE_WRITE };
int message_read_fd = -1;
char sync_id[ARGV_NUMBER_LEN];
#ifdef _WIN32
HANDLE sync_pipe[2];
HANDLE data_pipe[2];
int signal_pipe_write_fd = -1;
HANDLE signal_pipe;
char control_id[ARGV_NUMBER_LEN];
char *signal_pipe_name;
size_t i_handles = 0;
HANDLE *handles;
GString *args = g_string_sized_new(200);
char *quoted_arg;
SECURITY_ATTRIBUTES sa;
STARTUPINFO si;
PROCESS_INFORMATION pi;
int i;
unsigned j;
interface_options *interface_opts;
#else
int sync_pipe[2];
int data_pipe[2];
#endif
*fork_child = WS_INVALID_PID;
if (data_read_fd != NULL) {
*data_read_fd = -1;
}
*message_read_io = NULL;
ws_debug("sync_pipe_open_command");
if (!msg) {
g_strfreev(argv);
#ifdef _WIN32
g_string_free(args, TRUE);
#endif
return -1;
}
#ifdef _WIN32
sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.bInheritHandle = false;
sa.lpSecurityDescriptor = NULL;
if (! CreatePipe(&sync_pipe[PIPE_READ], &sync_pipe[PIPE_WRITE], &sa, PIPE_BUF_SIZE)) {
*msg = ws_strdup_printf("Couldn't create sync pipe: %s",
win32strerror(GetLastError()));
g_strfreev(argv);
return -1;
}
* Associate a C run-time file handle with the Windows HANDLE for the
* read side of the message pipe.
*
* (See http://www.flounder.com/handles.htm for information on various
* types of file handle in C/C++ on Windows.)
*/
message_read_fd = _open_osfhandle( (intptr_t) sync_pipe[PIPE_READ], _O_BINARY);
if (message_read_fd == -1) {
*msg = ws_strdup_printf("Couldn't get C file handle for message read pipe: %s", g_strerror(errno));
g_strfreev(argv);
CloseHandle(sync_pipe[PIPE_READ]);
CloseHandle(sync_pipe[PIPE_WRITE]);
return -1;
}
if (data_read_fd != NULL) {
if (! CreatePipe(&data_pipe[PIPE_READ], &data_pipe[PIPE_WRITE], &sa, PIPE_BUF_SIZE)) {
*msg = ws_strdup_printf("Couldn't create data pipe: %s",
win32strerror(GetLastError()));
g_strfreev(argv);
ws_close(message_read_fd);
CloseHandle(sync_pipe[PIPE_WRITE]);
return -1;
}
* Associate a C run-time file handle with the Windows HANDLE for the
* read side of the data pipe.
*
* (See http://www.flounder.com/handles.htm for information on various
* types of file handle in C/C++ on Windows.)
*/
*data_read_fd = _open_osfhandle( (intptr_t) data_pipe[PIPE_READ], _O_BINARY);
if (*data_read_fd == -1) {
*msg = ws_strdup_printf("Couldn't get C file handle for data read pipe: %s", g_strerror(errno));
g_strfreev(argv);
CloseHandle(data_pipe[PIPE_READ]);
CloseHandle(data_pipe[PIPE_WRITE]);
ws_close(message_read_fd);
CloseHandle(sync_pipe[PIPE_WRITE]);
return -1;
}
}
if (signal_write_fd != NULL) {
snprintf(control_id, ARGV_NUMBER_LEN, "%ld", GetCurrentProcessId());
signal_pipe_name = ws_strdup_printf(SIGNAL_PIPE_FORMAT, control_id);
signal_pipe = CreateNamedPipe(utf_8to16(signal_pipe_name),
PIPE_ACCESS_OUTBOUND, PIPE_TYPE_BYTE, 1, 65535, 65535, 0, NULL);
g_free(signal_pipe_name);
if (signal_pipe == INVALID_HANDLE_VALUE) {
*msg = ws_strdup_printf("Couldn't create signal pipe: %s",
win32strerror(GetLastError()));
g_strfreev(argv);
ws_close(message_read_fd);
CloseHandle(sync_pipe[PIPE_WRITE]);
return -1;
}
* Associate a C run-time file handle with the Windows HANDLE for the
* read side of the message pipe.
*
* (See http://www.flounder.com/handles.htm for information on various
* types of file handle in C/C++ on Windows.)
*/
signal_pipe_write_fd = _open_osfhandle( (intptr_t) signal_pipe, _O_BINARY);
if (signal_pipe_write_fd == -1) {
*msg = ws_strdup_printf("Couldn't get C file handle for sync pipe: %s", g_strerror(errno));
g_strfreev(argv);
ws_close(message_read_fd);
CloseHandle(sync_pipe[PIPE_WRITE]);
CloseHandle(signal_pipe);
return -1;
}
}
memset(&si, 0, sizeof(si));
si.cb = sizeof(si);
memset(&pi, 0, sizeof(pi));
#ifdef DEBUG_CHILD
si.dwFlags = STARTF_USESHOWWINDOW;
si.wShowWindow = SW_SHOW;
#else
si.dwFlags = STARTF_USESTDHANDLES|STARTF_USESHOWWINDOW;
si.wShowWindow = SW_HIDE;
if (data_read_fd == NULL) {
si.hStdInput = GetStdHandle(STD_INPUT_HANDLE);
si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
} else {
si.hStdInput = NULL;
si.hStdOutput = data_pipe[PIPE_WRITE];
}
si.hStdError = GetStdHandle(STD_ERROR_HANDLE);
* process as it does in the parent process. It also has the same value."
* https://learn.microsoft.com/en-us/windows/win32/procthread/inheritance
* When converted to a file descriptor (via _open_osfhandle), the fd
* value is not necessarily the same in the two processes, but the handle
* value can be shared.
* A HANDLE is a void* though "64-bit versions of Windows use 32-bit handles
* for interoperability... only the lower 32 bits are significant, so it is
* safe to truncate the handle... or sign-extend the handle"
* https://learn.microsoft.com/en-us/windows/win32/winprog64/interprocess-communication
* So it should be fine to call PtrToLong instead of casting to intptr_t.
* https://learn.microsoft.com/en-us/windows/win32/WinProg64/rules-for-using-pointers
*/
int argc = g_strv_length(argv);
argv = sync_pipe_add_arg(argv, &argc, "-Z");
snprintf(sync_id, ARGV_NUMBER_LEN, "%ld", PtrToLong(sync_pipe[PIPE_WRITE]));
argv = sync_pipe_add_arg(argv, &argc, sync_id);
#endif
if (ifaces) {
for (j = 0; j < ifaces->len; j++) {
interface_opts = &g_array_index(ifaces, interface_options, j);
if (interface_opts->extcap_fifo != NULL) {
i_handles++;
}
}
}
handles = g_new(HANDLE, 3 + i_handles);
i_handles = 0;
if (si.hStdInput) {
handles[i_handles++] = si.hStdInput;
}
if (si.hStdOutput && (si.hStdOutput != si.hStdInput)) {
handles[i_handles++] = si.hStdOutput;
}
handles[i_handles++] = sync_pipe[PIPE_WRITE];
if (ifaces) {
for (j = 0; j < ifaces->len; j++) {
interface_opts = &g_array_index(ifaces, interface_options, j);
if (interface_opts->extcap_fifo != NULL) {
handles[i_handles++] = interface_opts->extcap_pipe_h;
}
}
}
for(i=0; argv[i] != 0; i++) {
if(i != 0) g_string_append_c(args, ' ');
quoted_arg = protect_arg(argv[i]);
g_string_append(args, quoted_arg);
g_free(quoted_arg);
}
if(!win32_create_process(argv[0], args->str, NULL, NULL, i_handles, handles,
CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi)) {
*msg = ws_strdup_printf("Couldn't run %s in child process: %s",
args->str, win32strerror(GetLastError()));
if (data_read_fd) {
ws_close(*data_read_fd);
CloseHandle(data_pipe[PIPE_WRITE]);
} else {
ws_close(signal_pipe_write_fd);
}
ws_close(message_read_fd);
CloseHandle(sync_pipe[PIPE_WRITE]);
g_strfreev(argv);
g_string_free(args, TRUE);
g_free(handles);
return -1;
}
*fork_child = pi.hProcess;
CloseHandle(pi.hThread);
g_strfreev(argv);
g_string_free(args, TRUE);
g_free(handles);
if (signal_write_fd != NULL) {
*signal_write_fd = signal_pipe_write_fd;
}
#else
if (pipe(sync_pipe) < 0) {
*msg = ws_strdup_printf("Couldn't create sync pipe: %s", g_strerror(errno));
g_strfreev(argv);
return -1;
}
if (data_read_fd != NULL) {
if (pipe(data_pipe) < 0) {
*msg = ws_strdup_printf("Couldn't create data pipe: %s", g_strerror(errno));
g_strfreev(argv);
ws_close(sync_pipe[PIPE_READ]);
ws_close(sync_pipe[PIPE_WRITE]);
return -1;
}
}
if ((*fork_child = fork()) == 0) {
* Child process - run dumpcap with the right arguments to make
* it just capture with the specified capture parameters
*/
if (data_read_fd != NULL) {
dup2(data_pipe[PIPE_WRITE], 1);
ws_close(data_pipe[PIPE_READ]);
ws_close(data_pipe[PIPE_WRITE]);
}
ws_close(sync_pipe[PIPE_READ]);
#ifndef DEBUG_CHILD
int argc = g_strv_length(argv);
argv = sync_pipe_add_arg(argv, &argc, "-Z");
snprintf(sync_id, ARGV_NUMBER_LEN, "%d", sync_pipe[PIPE_WRITE]);
argv = sync_pipe_add_arg(argv, &argc, sync_id);
#endif
execv(argv[0], argv);
sync_pipe_write_int_msg(sync_pipe[PIPE_WRITE], SP_EXEC_FAILED, errno);
to the X server (and cause stuff buffered up by our parent but
not yet sent to be sent, as that stuff should only be sent by
our parent). We've sent an error message to the parent, so
we exit with an exit status of 1 (any exit status other than
0 or 1 will cause an additional message to report that exit
status, over and above the error message we sent to the parent). */
_exit(1);
}
g_strfreev(argv);
if (fetch_dumpcap_pid && *fork_child > 0)
fetch_dumpcap_pid(*fork_child);
if (data_read_fd != NULL) {
*data_read_fd = data_pipe[PIPE_READ];
}
message_read_fd = sync_pipe[PIPE_READ];
#endif
sync pipe. */
open, and thus they completely close, and thus return to us
an EOF indication, if the child closes them (either deliberately
or by exiting abnormally). */
#ifdef _WIN32
if (data_read_fd != NULL) {
CloseHandle(data_pipe[PIPE_WRITE]);
}
CloseHandle(sync_pipe[PIPE_WRITE]);
#else
if (data_read_fd != NULL) {
ws_close(data_pipe[PIPE_WRITE]);
}
ws_close(sync_pipe[PIPE_WRITE]);
#endif
if (*fork_child == WS_INVALID_PID) {
*msg = ws_strdup_printf("Couldn't create child process: %s", g_strerror(errno));
if (data_read_fd != NULL) {
ws_close(*data_read_fd);
}
#ifdef _WIN32
if (signal_write_fd != NULL) {
ws_close(signal_pipe_write_fd);
}
#endif
ws_close(message_read_fd);
return -1;
}
#ifdef _WIN32
*message_read_io = g_io_channel_win32_new_fd(message_read_fd);
#else
*message_read_io = g_io_channel_unix_new(message_read_fd);
#endif
g_io_channel_set_encoding(*message_read_io, NULL, NULL);
g_io_channel_set_buffered(*message_read_io, false);
g_io_channel_set_close_on_unref(*message_read_io, true);
if (update_cb) update_cb();
return 0;
}
bool
sync_pipe_start(capture_options *capture_opts, GPtrArray *capture_comments,
capture_session *cap_session, info_data_t* cap_data,
void (*update_cb)(void))
{
#ifdef _WIN32
size_t i_handles = 0;
char control_id[ARGV_NUMBER_LEN];
#endif
GIOChannel *sync_pipe_read_io;
int argc;
char **argv;
int i;
unsigned j;
interface_options *interface_opts;
if (capture_opts->ifaces->len > 1)
capture_opts->use_pcapng = true;
ws_debug("sync_pipe_start");
capture_opts_log(LOG_DOMAIN_CAPTURE, LOG_LEVEL_DEBUG, capture_opts);
cap_session->fork_child = WS_INVALID_PID;
cap_session->capture_opts = capture_opts;
if (!extcap_init_interfaces(cap_session)) {
report_failure("Unable to init extcaps. (tmp fifo already exists?)");
return false;
}
argv = init_pipe_args(&argc);
if (!argv) {
report_failure("We don't know where to find dumpcap.");
return false;
}
if (capture_opts->ifaces->len > 1)
argv = sync_pipe_add_arg(argv, &argc, "-t");
argv = sync_pipe_add_arg(argv, &argc, "-F");
if (capture_opts->use_pcapng)
argv = sync_pipe_add_arg(argv, &argc, "pcapng");
else
argv = sync_pipe_add_arg(argv, &argc, "pcap");
if (capture_comments != NULL) {
for (j = 0; j < capture_comments->len; j++) {
argv = sync_pipe_add_arg(argv, &argc, "--capture-comment");
argv = sync_pipe_add_arg(argv, &argc, (char*)g_ptr_array_index(capture_comments, j));
}
}
if (capture_opts->temp_dir) {
argv = sync_pipe_add_arg(argv, &argc, "--temp-dir");
argv = sync_pipe_add_arg(argv, &argc, capture_opts->temp_dir);
}
if (capture_opts->multi_files_on) {
if (capture_opts->has_autostop_filesize) {
char sfilesize[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(sfilesize, ARGV_NUMBER_LEN, "filesize:%u",capture_opts->autostop_filesize);
argv = sync_pipe_add_arg(argv, &argc, sfilesize);
}
if (capture_opts->has_file_duration) {
char sfile_duration[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(sfile_duration, ARGV_NUMBER_LEN, "duration:%f",capture_opts->file_duration);
argv = sync_pipe_add_arg(argv, &argc, sfile_duration);
}
if (capture_opts->has_file_interval) {
char sfile_interval[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(sfile_interval, ARGV_NUMBER_LEN, "interval:%d",capture_opts->file_interval);
argv = sync_pipe_add_arg(argv, &argc, sfile_interval);
}
if (capture_opts->has_file_packets) {
char sfile_packets[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(sfile_packets, ARGV_NUMBER_LEN, "packets:%d",capture_opts->file_packets);
argv = sync_pipe_add_arg(argv, &argc, sfile_packets);
}
if (capture_opts->has_ring_num_files) {
char sring_num_files[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(sring_num_files, ARGV_NUMBER_LEN, "files:%d",capture_opts->ring_num_files);
argv = sync_pipe_add_arg(argv, &argc, sring_num_files);
}
if (capture_opts->print_file_names) {
char *print_name = g_strdup_printf("printname:%s", capture_opts->print_name_to);
argv = sync_pipe_add_arg(argv, &argc, "-b");
argv = sync_pipe_add_arg(argv, &argc, print_name);
g_free(print_name);
}
if (capture_opts->has_nametimenum) {
char nametimenum[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-b");
snprintf(nametimenum, ARGV_NUMBER_LEN, "nametimenum:2");
argv = sync_pipe_add_arg(argv, &argc, nametimenum);
}
if (capture_opts->has_autostop_files) {
char sautostop_files[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-a");
snprintf(sautostop_files, ARGV_NUMBER_LEN, "files:%d",capture_opts->autostop_files);
argv = sync_pipe_add_arg(argv, &argc, sautostop_files);
}
} else {
if (capture_opts->has_autostop_filesize) {
char sautostop_filesize[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-a");
snprintf(sautostop_filesize, ARGV_NUMBER_LEN, "filesize:%u",capture_opts->autostop_filesize);
argv = sync_pipe_add_arg(argv, &argc, sautostop_filesize);
}
}
if (capture_opts->has_autostop_packets) {
char scount[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-c");
snprintf(scount, ARGV_NUMBER_LEN, "%d",capture_opts->autostop_packets);
argv = sync_pipe_add_arg(argv, &argc, scount);
}
if (capture_opts->has_autostop_duration) {
char sautostop_duration[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-a");
snprintf(sautostop_duration, ARGV_NUMBER_LEN, "duration:%f",capture_opts->autostop_duration);
argv = sync_pipe_add_arg(argv, &argc, sautostop_duration);
}
if (capture_opts->has_autostop_written_packets) {
char scount[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-a");
snprintf(scount, ARGV_NUMBER_LEN, "packets:%d",capture_opts->autostop_written_packets);
argv = sync_pipe_add_arg(argv, &argc, scount);
}
if (capture_opts->group_read_access) {
argv = sync_pipe_add_arg(argv, &argc, "-g");
}
if (capture_opts->update_interval != DEFAULT_UPDATE_INTERVAL) {
char scount[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "--update-interval");
snprintf(scount, ARGV_NUMBER_LEN, "%d", capture_opts->update_interval);
argv = sync_pipe_add_arg(argv, &argc, scount);
}
for (j = 0; j < capture_opts->ifaces->len; j++) {
interface_opts = &g_array_index(capture_opts->ifaces, interface_options, j);
argv = sync_pipe_add_arg(argv, &argc, "-i");
if (interface_opts->extcap_fifo != NULL)
{
#ifdef _WIN32
char *pipe = ws_strdup_printf("%s%" PRIuMAX, EXTCAP_PIPE_PREFIX, (uintmax_t)interface_opts->extcap_pipe_h);
argv = sync_pipe_add_arg(argv, &argc, pipe);
g_free(pipe);
i_handles++;
#else
argv = sync_pipe_add_arg(argv, &argc, interface_opts->extcap_fifo);
#endif
argv = sync_pipe_add_arg(argv, &argc, "--ifname");
argv = sync_pipe_add_arg(argv, &argc, interface_opts->name);
}
else
argv = sync_pipe_add_arg(argv, &argc, interface_opts->name);
if (interface_opts->descr != NULL)
{
* use for the temporary filename. */
argv = sync_pipe_add_arg(argv, &argc, "--ifdescr");
argv = sync_pipe_add_arg(argv, &argc, interface_opts->descr);
}
if (interface_opts->cfilter != NULL && strlen(interface_opts->cfilter) != 0) {
argv = sync_pipe_add_arg(argv, &argc, "-f");
argv = sync_pipe_add_arg(argv, &argc, interface_opts->cfilter);
}
if (interface_opts->has_snaplen) {
char ssnap[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-s");
snprintf(ssnap, ARGV_NUMBER_LEN, "%d", interface_opts->snaplen);
argv = sync_pipe_add_arg(argv, &argc, ssnap);
}
if (interface_opts->linktype != -1) {
const char *linktype = linktype_val_to_name(interface_opts->linktype);
if ( linktype != NULL )
{
argv = sync_pipe_add_arg(argv, &argc, "-y");
argv = sync_pipe_add_arg(argv, &argc, linktype);
}
}
if (!interface_opts->promisc_mode) {
argv = sync_pipe_add_arg(argv, &argc, "-p");
}
#ifdef CAN_SET_CAPTURE_BUFFER_SIZE
if (interface_opts->buffer_size != DEFAULT_CAPTURE_BUFFER_SIZE) {
char buffer_size[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-B");
if(interface_opts->buffer_size == 0x00)
interface_opts->buffer_size = DEFAULT_CAPTURE_BUFFER_SIZE;
snprintf(buffer_size, ARGV_NUMBER_LEN, "%d", interface_opts->buffer_size);
argv = sync_pipe_add_arg(argv, &argc, buffer_size);
}
#endif
#ifdef HAVE_PCAP_CREATE
if (interface_opts->monitor_mode) {
argv = sync_pipe_add_arg(argv, &argc, "-I");
}
#endif
#ifdef HAVE_PCAP_REMOTE
if (interface_opts->datatx_udp)
argv = sync_pipe_add_arg(argv, &argc, "-u");
if (!interface_opts->nocap_rpcap)
argv = sync_pipe_add_arg(argv, &argc, "-r");
if (interface_opts->auth_type == CAPTURE_AUTH_PWD) {
char sauth[256];
argv = sync_pipe_add_arg(argv, &argc, "-A");
snprintf(sauth, sizeof(sauth), "%s:%s",
interface_opts->auth_username,
interface_opts->auth_password);
argv = sync_pipe_add_arg(argv, &argc, sauth);
}
#endif
#ifdef HAVE_PCAP_SETSAMPLING
if (interface_opts->sampling_method != CAPTURE_SAMP_NONE) {
char ssampling[ARGV_NUMBER_LEN];
argv = sync_pipe_add_arg(argv, &argc, "-m");
snprintf(ssampling, ARGV_NUMBER_LEN, "%s:%d",
interface_opts->sampling_method == CAPTURE_SAMP_BY_COUNT ? "count" :
interface_opts->sampling_method == CAPTURE_SAMP_BY_TIMER ? "timer" :
"undef",
interface_opts->sampling_param);
argv = sync_pipe_add_arg(argv, &argc, ssampling);
}
#endif
if (interface_opts->timestamp_type) {
argv = sync_pipe_add_arg(argv, &argc, "--time-stamp-type");
argv = sync_pipe_add_arg(argv, &argc, interface_opts->timestamp_type);
}
}
#ifndef DEBUG_CHILD
#ifdef _WIN32
argv = sync_pipe_add_arg(argv, &argc, "--signal-pipe");
snprintf(control_id, ARGV_NUMBER_LEN, "%ld", GetCurrentProcessId());
argv = sync_pipe_add_arg(argv, &argc, control_id);
#endif
#endif
if (capture_opts->save_file) {
argv = sync_pipe_add_arg(argv, &argc, "-w");
argv = sync_pipe_add_arg(argv, &argc, capture_opts->save_file);
}
for (i = 0; i < argc; i++) {
ws_debug("argv[%d]: %s", i, argv[i]);
}
if (capture_opts->compress_type) {
argv = sync_pipe_add_arg(argv, &argc, "--compress-type");
argv = sync_pipe_add_arg(argv, &argc, capture_opts->compress_type);
}
int ret;
char* msg;
#ifdef _WIN32
ret = sync_pipe_open_command(argv, NULL, &sync_pipe_read_io, &cap_session->signal_pipe_write_fd,
&cap_session->fork_child, capture_opts->ifaces, &msg, update_cb);
#else
ret = sync_pipe_open_command(argv, NULL, &sync_pipe_read_io, NULL,
&cap_session->fork_child, NULL, &msg, update_cb);
#endif
if (ret == -1) {
report_failure("%s", msg);
g_free(msg);
return false;
}
sync pipe. */
cap_session->fork_child_status = 0;
cap_session->cap_data_info = cap_data;
arrange that our callback be called whenever it's possible
to read from the sync pipe, so that it's called when
the child process wants to tell us something. */
if (cap_session->pipe_input_id) {
g_source_remove(cap_session->pipe_input_id);
cap_session->pipe_input_id = 0;
}
cap_session->pipe_input_id = g_io_add_watch(sync_pipe_read_io, G_IO_IN | G_IO_HUP, pipe_io_cb, cap_session);
g_io_channel_unref(sync_pipe_read_io);
return true;
}
* Close the pipes we're using to read from dumpcap, and wait for it
* to exit. On success, *msgp is unchanged, and the exit status of
* dumpcap is returned. On failure (which includes "dumpcap exited
* due to being killed by a signal or an exception"), *msgp points
* to an error message for the failure, and -1 is returned. In the
* latter case, *msgp must be freed with g_free().
*/
static int
sync_pipe_close_command(int *data_read_fd, GIOChannel *message_read_io,
ws_process_id *fork_child, char **msgp)
{
ws_close(*data_read_fd);
if (message_read_io != NULL)
g_io_channel_unref(message_read_io);
#ifdef _WIN32
sync_pipe_kill(*fork_child);
#endif
return sync_pipe_wait_for_child(*fork_child, msgp);
}
* Run dumpcap with the supplied arguments.
*
* On success, *data points to a buffer containing the dumpcap output,
* *primary_msg and *secondary_message are NULL, and 0 is returned; *data
* must be freed with g_free().
*
* On failure, *data is NULL, *primary_msg points to an error message,
* *secondary_msg either points to an additional error message or is
* NULL, and -1 is returned; *primary_msg, and *secondary_msg if not NULL,
* must be freed with g_free().
*/
static int
sync_pipe_run_command_actual(char **argv, char **data, char **primary_msg,
char **secondary_msg, void(*update_cb)(void))
{
char *msg;
int data_pipe_read_fd, ret;
GIOChannel *sync_pipe_read_io;
ws_process_id fork_child;
char *wait_msg;
char *buffer = g_malloc(PIPE_BUF_SIZE + 1);
ssize_t nread;
char indicator;
int32_t exec_errno = 0;
int primary_msg_len;
char *primary_msg_text;
int secondary_msg_len;
char *secondary_msg_text;
char *combined_msg;
GString *data_buf = NULL;
ssize_t count;
if (buffer == NULL) {
* at least on a RELEASE build, some versions of gcc don't think that
* happens.
*/
*primary_msg = ws_strdup_printf("Couldn't allocate memory for dumpcap output buffer: %s",
g_strerror(errno));
*secondary_msg = NULL;
*data = NULL;
return -1;
}
ret = sync_pipe_open_command(argv, &data_pipe_read_fd, &sync_pipe_read_io, NULL,
&fork_child, NULL, &msg, update_cb);
if (ret == -1) {
*primary_msg = msg;
*secondary_msg = NULL;
*data = NULL;
g_free(buffer);
return -1;
}
* We were able to set up to read dumpcap's output. Do so.
*
* First, wait for an SP_ERROR_MSG message or SP_SUCCESS message.
*/
do {
nread = pipe_read_block(sync_pipe_read_io, &indicator, SP_MAX_MSG_LEN,
buffer, primary_msg);
if(nread <= 0) {
all from the sync pipe, so we're not going to be getting any
data or error message from the child process. Pick up its
exit status, and complain.
We don't have to worry about killing the child, if the sync pipe
returned an error. Usually this error is caused as the child killed
itself while going down. Even in the rare cases that this isn't the
case, the child will get an error when writing to the broken pipe
the next time, cleaning itself up then. */
g_io_channel_unref(sync_pipe_read_io);
ret = sync_pipe_wait_for_child(fork_child, &wait_msg);
if(nread == 0) {
before giving us any data to read. If ret is -1, we report
that as a bad exit (e.g., exiting due to a signal); otherwise,
we report it as a premature exit. */
if (ret == -1)
*primary_msg = wait_msg;
else
*primary_msg = g_strdup("Child dumpcap closed sync pipe prematurely");
} else {
both the sync pipe I/O error and the wait error. */
if (ret == -1) {
combined_msg = ws_strdup_printf("%s\n\n%s", *primary_msg, wait_msg);
g_free(*primary_msg);
g_free(wait_msg);
*primary_msg = combined_msg;
}
}
*secondary_msg = NULL;
*data = NULL;
g_free(buffer);
return -1;
}
switch(indicator) {
case SP_EXEC_FAILED:
* Exec of dumpcap failed. Get the errno for the failure.
*/
if (!ws_strtoi32(buffer, NULL, &exec_errno)) {
ws_warning("Invalid errno: %s", buffer);
}
* Pick up the child status.
*/
ret = sync_pipe_close_command(&data_pipe_read_fd, sync_pipe_read_io,
&fork_child, &msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
*primary_msg = msg;
*secondary_msg = NULL;
} else {
* Child process failed, but returned the expected exit status.
* Return the messages it gave us, and indicate failure.
*/
*primary_msg = ws_strdup_printf("Couldn't run dumpcap in child process: %s",
g_strerror(exec_errno));
*secondary_msg = NULL;
ret = -1;
}
*data = NULL;
break;
case SP_ERROR_MSG:
* Error from dumpcap; there will be a primary message and a
* secondary message.
*/
pipe_convert_header((unsigned char*)buffer, 4, &indicator, &primary_msg_len);
primary_msg_text = buffer+4;
pipe_convert_header((unsigned char*)primary_msg_text + primary_msg_len, 4, &indicator,
&secondary_msg_len);
secondary_msg_text = primary_msg_text + primary_msg_len + 4;
* Pick up the child status.
*/
ret = sync_pipe_close_command(&data_pipe_read_fd, sync_pipe_read_io,
&fork_child, &msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
*primary_msg = msg;
*secondary_msg = NULL;
} else {
* Child process failed, but returned the expected exit status.
* Return the messages it gave us, and indicate failure.
*/
*primary_msg = g_strdup(primary_msg_text);
*secondary_msg = g_strdup(secondary_msg_text);
ret = -1;
}
*data = NULL;
break;
case SP_LOG_MSG:
* Log from dumpcap; pass to our log
*/
sync_pipe_handle_log_msg(buffer);
break;
case SP_SUCCESS:
data_buf = g_string_new("");
while ((count = ws_read(data_pipe_read_fd, buffer, PIPE_BUF_SIZE)) > 0) {
buffer[count] = '\0';
g_string_append(data_buf, buffer);
}
* Pick up the child status.
*/
ret = sync_pipe_close_command(&data_pipe_read_fd, sync_pipe_read_io,
&fork_child, &msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
*primary_msg = msg;
*secondary_msg = NULL;
g_string_free(data_buf, TRUE);
*data = NULL;
} else {
* Child process succeeded.
*/
*primary_msg = NULL;
*secondary_msg = NULL;
*data = g_string_free(data_buf, FALSE);
}
break;
default:
* Pick up the child status.
*/
ret = sync_pipe_close_command(&data_pipe_read_fd, sync_pipe_read_io,
&fork_child, &msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
*primary_msg = msg;
*secondary_msg = NULL;
} else {
* Child process returned an unknown status.
*/
*primary_msg = ws_strdup_printf("dumpcap process gave an unexpected message type: 0x%02x",
indicator);
*secondary_msg = NULL;
ret = -1;
}
*data = NULL;
break;
}
} while (indicator != SP_SUCCESS && ret != -1);
g_free(buffer);
return ret;
}
* redirects to sync_pipe_run_command_actual()
*/
static int
sync_pipe_run_command(char **argv, char **data, char **primary_msg,
char **secondary_msg, void (*update_cb)(void))
{
int ret, i;
int64_t start_time;
double elapsed;
int logging_enabled;
logging_enabled = ws_log_msg_is_active(WS_LOG_DOMAIN, LOG_LEVEL_INFO);
if (logging_enabled) {
start_time = g_get_monotonic_time();
ws_debug("sync_pipe_run_command() starts");
for (i=0; argv[i] != 0; i++) {
ws_noisy(" argv[%d]: %s", i, argv[i]);
}
}
ret = sync_pipe_run_command_actual(argv, data, primary_msg, secondary_msg, update_cb);
if (logging_enabled) {
elapsed = (g_get_monotonic_time() - start_time) / 1e6;
ws_debug("sync_pipe_run_command() ends, taking %.3fs, result=%d", elapsed, ret);
}
return ret;
}
int
sync_interface_set_80211_chan(const char *iface, const char *freq, const char *type,
const char *center_freq1, const char *center_freq2,
char **data, char **primary_msg,
char **secondary_msg, void (*update_cb)(void))
{
int argc, ret;
char **argv;
char *opt;
argv = init_pipe_args(&argc);
if (!argv) {
*primary_msg = g_strdup("We don't know where to find dumpcap.");
*secondary_msg = NULL;
*data = NULL;
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, "-i");
argv = sync_pipe_add_arg(argv, &argc, iface);
if (center_freq2)
opt = ws_strdup_printf("%s,%s,%s,%s", freq, type, center_freq1, center_freq2);
else if (center_freq1)
opt = ws_strdup_printf("%s,%s,%s", freq, type, center_freq1);
else if (type)
opt = ws_strdup_printf("%s,%s", freq, type);
else
opt = g_strdup(freq);
if (!opt) {
*primary_msg = g_strdup("Out of mem.");
*secondary_msg = NULL;
*data = NULL;
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, "-k");
argv = sync_pipe_add_arg(argv, &argc, opt);
ret = sync_pipe_run_command(argv, data, primary_msg, secondary_msg, update_cb);
g_free(opt);
return ret;
}
* Get the list of interfaces using dumpcap.
*
* On success, *data points to a buffer containing the dumpcap output,
* *primary_msg and *secondary_msg are NULL, and 0 is returned. *data
* must be freed with g_free().
*
* On failure, *data is NULL, *primary_msg points to an error message,
* *secondary_msg either points to an additional error message or is
* NULL, and -1 is returned; *primary_msg, and *secondary_msg if not NULL,
* must be freed with g_free().
*/
int
sync_interface_list_open(char **data, char **primary_msg,
char **secondary_msg, void (*update_cb)(void))
{
int argc;
char **argv;
int ret;
ws_debug("sync_interface_list_open");
argv = init_pipe_args(&argc);
if (!argv) {
*primary_msg = g_strdup("We don't know where to find dumpcap..");
*secondary_msg = NULL;
*data = NULL;
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, "-D");
ret = sync_pipe_run_command(argv, data, primary_msg, secondary_msg, update_cb);
return ret;
}
* Get the capabilities of an interface using dumpcap.
*
* On success, *data points to a buffer containing the dumpcap output,
* *primary_msg and *secondary_msg are NULL, and 0 is returned. *data
* must be freed with g_free().
*
* On failure, *data is NULL, *primary_msg points to an error message,
* *secondary_msg either points to an additional error message or is
* NULL, and -1 is returned; *primary_msg, and *secondary_msg if not NULL,
* must be freed with g_free().
*/
int
sync_if_capabilities_open(const char *ifname, bool monitor_mode, const char* auth,
char **data, char **primary_msg,
char **secondary_msg, void (*update_cb)(void))
{
int argc;
char **argv;
int ret;
ws_debug("sync_if_capabilities_open");
argv = init_pipe_args(&argc);
if (!argv) {
*primary_msg = g_strdup("We don't know where to find dumpcap.");
*secondary_msg = NULL;
*data = NULL;
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, "-i");
argv = sync_pipe_add_arg(argv, &argc, ifname);
argv = sync_pipe_add_arg(argv, &argc, "-L");
argv = sync_pipe_add_arg(argv, &argc, "--list-time-stamp-types");
if (monitor_mode)
argv = sync_pipe_add_arg(argv, &argc, "-I");
if (auth) {
argv = sync_pipe_add_arg(argv, &argc, "-A");
argv = sync_pipe_add_arg(argv, &argc, auth);
}
ret = sync_pipe_run_command(argv, data, primary_msg, secondary_msg, update_cb);
return ret;
}
int
sync_if_list_capabilities_open(GList *if_queries,
char **data, char **primary_msg,
char **secondary_msg, void (*update_cb)(void))
{
int argc;
char **argv;
int ret;
if_cap_query_t *if_cap_query;
ws_debug("sync_if_list_capabilities_open");
argv = init_pipe_args(&argc);
if (!argv) {
*primary_msg = g_strdup("We don't know where to find dumpcap.");
*secondary_msg = NULL;
*data = NULL;
return -1;
}
for (GList *li = if_queries; li != NULL; li = g_list_next(li)) {
if_cap_query = (if_cap_query_t*)li->data;
argv = sync_pipe_add_arg(argv, &argc, "-i");
argv = sync_pipe_add_arg(argv, &argc, if_cap_query->name);
if (if_cap_query->monitor_mode)
argv = sync_pipe_add_arg(argv, &argc, "-I");
if (if_cap_query->auth_username && if_cap_query->auth_password) {
char sauth[256];
argv = sync_pipe_add_arg(argv, &argc, "-A");
snprintf(sauth, sizeof(sauth), "%s:%s",
if_cap_query->auth_username,
if_cap_query->auth_password);
argv = sync_pipe_add_arg(argv, &argc, sauth);
}
}
argv = sync_pipe_add_arg(argv, &argc, "-L");
argv = sync_pipe_add_arg(argv, &argc, "--list-time-stamp-types");
ret = sync_pipe_run_command(argv, data, primary_msg, secondary_msg, update_cb);
return ret;
}
* Start getting interface statistics using dumpcap. On success, read_fd
* contains the file descriptor for the pipe's stdout, *msg is unchanged,
* and zero is returned. On failure, *msg will point to an error message
* that must be g_free()d, and -1 will be returned.
* If data is not NULL, then it will also be set to point to a JSON
* serialization of the list of local interfaces and their capabilities.
*/
int
sync_interface_stats_open(int *data_read_fd, ws_process_id *fork_child, char **data, char **msg, void (*update_cb)(void))
{
int argc;
char **argv;
int ret;
GIOChannel *message_read_io;
char *wait_msg;
char *buffer = g_malloc(PIPE_BUF_SIZE + 1);
ssize_t nread;
char indicator;
int32_t exec_errno = 0;
int primary_msg_len;
char *primary_msg_text;
int secondary_msg_len;
char *combined_msg;
ws_debug("sync_interface_stats_open");
argv = init_pipe_args(&argc);
if (!argv) {
*msg = g_strdup("We don't know where to find dumpcap.");
g_free(buffer);
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, "-S");
if (data) {
argv = sync_pipe_add_arg(argv, &argc, "-D");
argv = sync_pipe_add_arg(argv, &argc, "-L");
}
#ifndef DEBUG_CHILD
#ifdef _WIN32
argv = sync_pipe_add_arg(argv, &argc, "--signal-pipe");
ret = create_dummy_signal_pipe(msg);
if (ret == -1) {
g_free(buffer);
return -1;
}
argv = sync_pipe_add_arg(argv, &argc, dummy_control_id);
#endif
#endif
ret = sync_pipe_open_command(argv, data_read_fd, &message_read_io, NULL,
fork_child, NULL, msg, update_cb);
if (ret == -1) {
g_free(buffer);
return -1;
}
* We were able to set up to read dumpcap's output. Do so.
*
* First, wait for an SP_ERROR_MSG message or SP_SUCCESS message.
*/
do {
nread = pipe_read_block(message_read_io, &indicator, SP_MAX_MSG_LEN,
buffer, msg);
if(nread <= 0) {
all from the sync pipe, so we're not going to be getting any
data or error message from the child process. Pick up its
exit status, and complain.
We don't have to worry about killing the child, if the sync pipe
returned an error. Usually this error is caused as the child killed
itself while going down. Even in the rare cases that this isn't the
case, the child will get an error when writing to the broken pipe
the next time, cleaning itself up then. */
g_io_channel_unref(message_read_io);
ws_close(*data_read_fd);
ret = sync_pipe_wait_for_child(*fork_child, &wait_msg);
if(nread == 0) {
before giving us any data to read. If ret is -1, we report
that as a bad exit (e.g., exiting due to a signal); otherwise,
we report it as a premature exit. */
if (ret == -1)
*msg = wait_msg;
else
*msg = g_strdup("Child dumpcap closed sync pipe prematurely");
} else {
both the sync pipe I/O error and the wait error. */
if (ret == -1) {
combined_msg = ws_strdup_printf("%s\n\n%s", *msg, wait_msg);
g_free(*msg);
g_free(wait_msg);
*msg = combined_msg;
}
}
g_free(buffer);
return -1;
}
switch(indicator) {
case SP_EXEC_FAILED:
* Exec of dumpcap failed. Get the errno for the failure.
*/
if (!ws_strtoi32(buffer, NULL, &exec_errno)) {
ws_warning("Invalid errno: %s", buffer);
}
*msg = ws_strdup_printf("Couldn't run dumpcap in child process: %s",
g_strerror(exec_errno));
* Pick up the child status.
*/
char *close_msg = NULL;
sync_pipe_close_command(data_read_fd, message_read_io,
fork_child, &close_msg);
* Ignore the error from sync_pipe_close_command, presumably the one
* returned by the child is more pertinent to what went wrong.
*/
g_free(close_msg);
ret = -1;
break;
case SP_ERROR_MSG:
* Error from dumpcap; there will be a primary message and a
* secondary message.
*/
pipe_convert_header((unsigned char*)buffer, 4, &indicator, &primary_msg_len);
primary_msg_text = buffer+4;
pipe_convert_header((unsigned char*)primary_msg_text + primary_msg_len, 4, &indicator,
&secondary_msg_len);
* Pick up the child status.
*/
ret = sync_pipe_close_command(data_read_fd, message_read_io,
fork_child, msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
} else if (ret == WS_EXIT_NO_INTERFACES) {
* No interfaces were found. If that's not the
* result of an error when fetching the local
* interfaces, let the user know.
*/
*msg = g_strdup(primary_msg_text);
} else {
* Child process failed, but returned the expected exit status.
* Return the messages it gave us, and indicate failure.
*/
*msg = g_strdup(primary_msg_text);
ret = -1;
}
g_free(buffer);
return ret;
case SP_LOG_MSG:
* Log from dumpcap; pass to our log
*/
sync_pipe_handle_log_msg(buffer);
break;
case SP_IFACE_LIST:
* Dumpcap giving us the interface list
*/
if (data) {
*data = g_strdup(buffer);
}
break;
case SP_SUCCESS:
g_io_channel_unref(message_read_io);
break;
default:
* Pick up the child status.
*/
ret = sync_pipe_close_command(data_read_fd, message_read_io,
fork_child, msg);
if (ret == -1) {
* Child process failed unexpectedly, or wait failed; msg is the
* error message.
*/
} else {
* Child process returned an unknown status.
*/
*msg = ws_strdup_printf("dumpcap process gave an unexpected message type: 0x%02x",
indicator);
ret = -1;
}
break;
}
} while (indicator != SP_SUCCESS && ret != -1);
g_free(buffer);
return ret;
}
int
sync_interface_stats_close(int *read_fd, ws_process_id *fork_child, char **msg)
{
#ifdef _WIN32
CloseHandle(dummy_signal_pipe);
dummy_signal_pipe = NULL;
#else
* Don't bother waiting for the child. sync_pipe_close_command
* does this for us on Windows.
*/
sync_pipe_kill(*fork_child);
#endif
return sync_pipe_close_command(read_fd, NULL, fork_child, msg);
}
static ssize_t
pipe_read_bytes(GIOChannel *pipe_io, char *bytes, size_t required, char **msg)
{
GError *err = NULL;
size_t newly;
size_t offset = 0;
while(required) {
g_io_channel_read_chars(pipe_io, &bytes[offset], required, &newly, &err);
if (err != NULL) {
ws_debug("read from pipe %p: error(%u): %s", pipe_io, err->code, err->message);
*msg = ws_strdup_printf("Error reading from sync pipe: %s", err->message);
g_clear_error(&err);
return -1;
}
if (newly == 0) {
ws_debug("read from pipe %p: EOF (capture closed?)", pipe_io);
*msg = 0;
return offset;
}
required -= newly;
offset += newly;
}
*msg = NULL;
return offset;
}
* Read a line from a pipe; similar to fgets, but doesn't block.
*
* XXX - just stops reading if there's nothing to be read right now;
* that could conceivably mean that you don't get a complete line.
*/
int
sync_pipe_gets_nonblock(int pipe_fd, char *bytes, int max) {
ssize_t newly;
int offset = -1;
while(offset < max - 1) {
offset++;
if (! ws_pipe_data_available(pipe_fd))
break;
newly = ws_read(pipe_fd, &bytes[offset], 1);
if (newly == 0) {
break;
} else if (newly == -1) {
ws_debug("read from pipe %d: error(%u): %s", pipe_fd, errno, g_strerror(errno));
return -1;
} else if (bytes[offset] == '\n') {
break;
}
}
if (offset >= 0)
bytes[offset] = '\0';
return offset;
}
static void
pipe_convert_header(const unsigned char *header, int header_len _U_, char *indicator, int *block_len) {
ws_assert(header_len == 4);
*indicator = header[0];
*block_len = (header[1]&0xFF)<<16 | (header[2]&0xFF)<<8 | (header[3]&0xFF);
}
(1-byte message indicator, 3-byte message length (excluding length
and indicator field), and the rest is the message) */
static ssize_t
pipe_read_block(GIOChannel *pipe_io, char *indicator, int len, char *msg,
char **err_msg)
{
int required;
ssize_t newly;
char header[4];
newly = pipe_read_bytes(pipe_io, header, 4, err_msg);
if(newly != 4) {
if (newly == 0) {
* Immediate EOF; if the capture child exits normally, this
* is an "I'm done" indication, so don't report it as an
* error.
*/
ws_debug("read %p got an EOF", pipe_io);
return 0;
}
ws_debug("read %p failed to read header: %lu", pipe_io, (long)newly);
if (newly != -1) {
* Short read, but not an immediate EOF.
*/
*err_msg = ws_strdup_printf("Premature EOF reading from sync pipe: got only %ld bytes",
(long)newly);
}
return -1;
}
pipe_convert_header((unsigned char*)header, 4, indicator, &required);
if(required == 0) {
ws_debug("read %p indicator: %c empty value", pipe_io, *indicator);
return 4;
}
if(required > len) {
size_t bytes_read;
GError *err = NULL;
ws_debug("read %p length error, required %d > len %d, header: 0x%02x 0x%02x 0x%02x 0x%02x",
pipe_io, required, len,
header[0], header[1], header[2], header[3]);
g_io_channel_read_chars(pipe_io, msg, len, &bytes_read, &err);
if (err != NULL) {
ws_debug("read from pipe %p: error(%u): %s", pipe_io, err->code, err->message);
g_clear_error(&err);
}
*err_msg = ws_strdup_printf("Message %c from dumpcap with length %d > buffer size %d! Partial message: %s",
*indicator, required, len, msg);
return -1;
}
len = required;
newly = pipe_read_bytes(pipe_io, msg, required, err_msg);
if(newly != required) {
if (newly != -1) {
*err_msg = ws_strdup_printf("Unknown message from dumpcap reading data, try to show it as a string: %s",
msg);
}
return -1;
}
ws_debug("read %p ok indicator: %c len: %u msg: %s", pipe_io, *indicator, len, msg);
*err_msg = NULL;
return newly + 4;
}
us a message, or the sync pipe has closed, meaning the child has
closed it (perhaps because it exited). */
static gboolean
sync_pipe_input_cb(GIOChannel *pipe_io, capture_session *cap_session)
{
int ret;
char *buffer = g_malloc(SP_MAX_MSG_LEN + 1);
ssize_t nread;
char indicator;
int32_t exec_errno = 0;
int primary_len;
char *primary_msg;
int secondary_len;
char *secondary_msg;
char *wait_msg, *combined_msg;
uint32_t npackets = 0;
nread = pipe_read_block(pipe_io, &indicator, SP_MAX_MSG_LEN, buffer,
&primary_msg);
if(nread <= 0) {
If we got a read error or a bad message, nread is -1 and
primary_msg is set to point to an error message. We don't
have to worry about killing the child; usually this error
is caused as the child killed itself while going down.
Even in the rare cases that this isn't the case, the child
will get an error when writing to the broken pipe the next time,
cleaning itself up then.
If we got an EOF, nread is 0 and primary_msg isn't set. This
is an indication that the capture is finished. */
ret = sync_pipe_wait_for_child(cap_session->fork_child, &wait_msg);
if(nread == 0) {
child exited, and not in the middle of a message; we treat
that as an indication that it's done, and only report an
error if ret is -1, in which case wait_msg is the error
message. */
if (ret == -1)
primary_msg = wait_msg;
} else {
both the sync pipe I/O error and the wait error. */
if (ret == -1) {
combined_msg = ws_strdup_printf("%s\n\n%s", primary_msg, wait_msg);
g_free(primary_msg);
g_free(wait_msg);
primary_msg = combined_msg;
}
}
cap_session->fork_child = WS_INVALID_PID;
cap_session->fork_child_status = ret;
#ifdef _WIN32
ws_close(cap_session->signal_pipe_write_fd);
#endif
cap_session->capture_opts->closed_msg = primary_msg;
if (extcap_session_stop(cap_session)) {
capture_process_finished(cap_session);
} else {
extcap_request_stop(cap_session);
}
g_free(buffer);
return false;
}
switch(indicator) {
case SP_FILE:
if(!cap_session->new_file(cap_session, buffer)) {
ws_debug("file failed, closing capture");
alerted. The sync pipe will close after we return false. */
This could mean that the child is creating and deleting files
(ring buffer mode) faster than we can handle it.
That should only be the case for very fast file switches;
We can't do much more than telling the child to stop.
(This is the "emergency brake" if the user e.g. wants to
switch files every second).
This can also happen if the user specified "-", meaning
"standard output", as the capture file. */
sync_pipe_stop(cap_session);
cap_session->closed(cap_session, NULL);
g_free(buffer);
return false;
}
break;
case SP_PACKET_COUNT:
if (!ws_strtou32(buffer, NULL, &npackets)) {
ws_warning("Invalid packets number: %s", buffer);
}
ws_debug("new packets %u", npackets);
cap_session->count += npackets;
cap_session->new_packets(cap_session, npackets);
break;
case SP_EXEC_FAILED:
* Exec of dumpcap failed. Get the errno for the failure.
*/
if (!ws_strtoi32(buffer, NULL, &exec_errno)) {
ws_warning("Invalid errno: %s", buffer);
}
primary_msg = ws_strdup_printf("Couldn't run dumpcap in child process: %s",
g_strerror(exec_errno));
cap_session->error(cap_session, primary_msg, NULL);
break;
case SP_ERROR_MSG:
pipe_convert_header((unsigned char*)buffer, 4, &indicator, &primary_len);
primary_msg = buffer+4;
pipe_convert_header((unsigned char*)primary_msg + primary_len, 4, &indicator, &secondary_len);
secondary_msg = primary_msg + primary_len + 4;
cap_session->error(cap_session, primary_msg, secondary_msg);
break;
case SP_LOG_MSG:
* Log from dumpcap; pass to our log
*/
sync_pipe_handle_log_msg(buffer);
break;
case SP_BAD_FILTER: {
const char *message=NULL;
uint32_t indx = 0;
const char* end;
if (ws_strtou32(buffer, &end, &indx) && end[0] == ':') {
message = end + 1;
}
cap_session->cfilter_error(cap_session, indx, message);
break;
}
case SP_DROPS: {
const char *name = NULL;
const char* end;
uint32_t num = 0;
if (ws_strtou32(buffer, &end, &num) && end[0] == ':') {
name = end + 1;
}
cap_session->drops(cap_session, num, name);
break;
}
default:
if (g_ascii_isprint(indicator))
ws_warning("Unknown indicator '%c'", indicator);
else
ws_warning("Unknown indicator '\\x%02x", indicator);
break;
}
g_free(buffer);
return true;
}
* dumpcap is exiting; wait for it to exit. On success, *msgp is
* unchanged, and the exit status of dumpcap is returned. On
* failure (which includes "dumpcap exited due to being killed by
* a signal or an exception"), *msgp points to an error message
* for the failure, and -1 is returned. In the latter case, *msgp
* must be freed with g_free().
*/
static int
sync_pipe_wait_for_child(ws_process_id fork_child, char **msgp)
{
int fork_child_status;
#ifndef _WIN32
int retry_waitpid = 3;
#endif
int ret = -1;
int64_t start_time;
double elapsed;
start_time = g_get_monotonic_time();
ws_debug("wait till child closed");
ws_assert(fork_child != WS_INVALID_PID);
*msgp = NULL;
#ifdef _WIN32
if (_cwait(&fork_child_status, (intptr_t) fork_child, _WAIT_CHILD) == -1) {
*msgp = ws_strdup_printf("Error from cwait(): %s", g_strerror(errno));
ret = -1;
} else {
* The child exited; return its exit status. Do not treat this as
* an error.
*/
ret = fork_child_status;
if ((fork_child_status & 0xC0000000) == ERROR_SEVERITY_ERROR) {
*msgp = ws_strdup_printf("Child dumpcap process died: %s",
win32strexception(fork_child_status));
ret = -1;
}
}
#else
while (--retry_waitpid >= 0) {
if (waitpid(fork_child, &fork_child_status, 0) != -1) {
if (WIFEXITED(fork_child_status)) {
* The child exited; return its exit status. Do not treat this as
* an error.
*/
ret = WEXITSTATUS(fork_child_status);
} else if (WIFSTOPPED(fork_child_status)) {
*msgp = ws_strdup_printf("Child dumpcap process stopped: %s",
sync_pipe_signame(WSTOPSIG(fork_child_status)));
ret = -1;
} else if (WIFSIGNALED(fork_child_status)) {
*msgp = ws_strdup_printf("Child dumpcap process died: %s%s",
sync_pipe_signame(WTERMSIG(fork_child_status)),
WCOREDUMP(fork_child_status) ? " - core dumped" : "");
ret = -1;
} else {
a signal; what happened here? */
*msgp = ws_strdup_printf("Bad status from waitpid(): %#o",
fork_child_status);
ret = -1;
}
} else {
if (errno == EINTR) {
* Signal interrupted waitpid().
*
* If it's SIGALRM, we just want to keep waiting, in case
* there's some timer using it (e.g., in a GUI toolkit).
*
* If you ^C TShark (or Wireshark), that should deliver
* SIGINT to dumpcap as well. dumpcap catches SIGINT,
* and should clean up and exit, so we should eventually
* see that and clean up and terminate.
*
* If we're sent a SIGTERM, we should (and do) catch it,
* and TShark, at least, calls sync_pipe_stop(). which
* kills dumpcap, so we should eventually see that and
* clean up and terminate.
*/
ws_warning("waitpid returned EINTR. retrying.");
continue;
} else if (errno == ECHILD) {
* The process identified by fork_child either doesn't
* exist any more or isn't our child process (anymore?).
*
* echld might have already reaped the child.
*/
ret = fetch_dumpcap_pid ? 0 : -1;
} else {
*msgp = ws_strdup_printf("Error from waitpid(): %s", g_strerror(errno));
ret = -1;
}
}
break;
}
#endif
elapsed = (g_get_monotonic_time() - start_time) / 1e6;
ws_debug("capture child closed after %.3fs", elapsed);
return ret;
}
#ifndef _WIN32
static const char *
sync_pipe_signame(int sig)
{
const char *sigmsg;
static char sigmsg_buf[6+1+3+1];
switch (sig) {
case SIGHUP:
sigmsg = "Hangup";
break;
case SIGINT:
sigmsg = "Interrupted";
break;
case SIGQUIT:
sigmsg = "Quit";
break;
case SIGILL:
sigmsg = "Illegal instruction";
break;
case SIGTRAP:
sigmsg = "Trace trap";
break;
case SIGABRT:
sigmsg = "Abort";
break;
case SIGFPE:
sigmsg = "Arithmetic exception";
break;
case SIGKILL:
sigmsg = "Killed";
break;
case SIGBUS:
sigmsg = "Bus error";
break;
case SIGSEGV:
sigmsg = "Segmentation violation";
break;
Linux is POSIX compliant. These are not POSIX-defined signals ---
ISO/IEC 9945-1:1990 (IEEE Std 1003.1-1990), paragraph B.3.3.1.1 sez:
``The signals SIGBUS, SIGEMT, SIGIOT, SIGTRAP, and SIGSYS
were omitted from POSIX.1 because their behavior is
implementation dependent and could not be adequately catego-
rized. Conforming implementations may deliver these sig-
nals, but must document the circumstances under which they
are delivered and note any restrictions concerning their
delivery.''
So we only check for SIGSYS on those systems that happen to
implement them (a system can be POSIX-compliant and implement
them, it's just that POSIX doesn't *require* a POSIX-compliant
system to implement them).
*/
#ifdef SIGSYS
case SIGSYS:
sigmsg = "Bad system call";
break;
#endif
case SIGPIPE:
sigmsg = "Broken pipe";
break;
case SIGALRM:
sigmsg = "Alarm clock";
break;
case SIGTERM:
sigmsg = "Terminated";
break;
default:
snprintf(sigmsg_buf, sizeof sigmsg_buf, "Signal %d", sig);
sigmsg = sigmsg_buf;
break;
}
return sigmsg;
}
#endif
#ifdef _WIN32
static int create_dummy_signal_pipe(char **msg) {
char *dummy_signal_pipe_name;
if (dummy_signal_pipe != NULL) return 0;
if (!dummy_control_id) {
dummy_control_id = ws_strdup_printf("%ld.dummy", GetCurrentProcessId());
}
dummy_signal_pipe_name = ws_strdup_printf(SIGNAL_PIPE_FORMAT, dummy_control_id);
dummy_signal_pipe = CreateNamedPipe(utf_8to16(dummy_signal_pipe_name),
PIPE_ACCESS_OUTBOUND, PIPE_TYPE_BYTE, 1, 65535, 65535, 0, NULL);
g_free(dummy_signal_pipe_name);
if (dummy_signal_pipe == INVALID_HANDLE_VALUE) {
*msg = ws_strdup_printf("Couldn't create signal pipe: %s",
win32strerror(GetLastError()));
return -1;
}
return 0;
}
static void
signal_pipe_capquit_to_child(capture_session *cap_session)
{
const char quit_msg[] = "QUIT";
int ret;
ws_debug("signal_pipe_capquit_to_child");
ret = ws_write(cap_session->signal_pipe_write_fd, quit_msg, sizeof quit_msg);
if(ret == -1) {
ws_warning("%d header: error %s", cap_session->signal_pipe_write_fd, win32strerror(GetLastError()));
}
}
#endif
void
sync_pipe_stop(capture_session *cap_session)
{
if (cap_session->fork_child != WS_INVALID_PID) {
#ifndef _WIN32
int sts = kill(cap_session->fork_child, SIGINT);
if (sts != 0) {
ws_warning("Sending SIGINT to child failed: %s\n", g_strerror(errno));
}
#else
#define STOP_SLEEP_TIME 500
DWORD status;
* gracefully.
*/
signal_pipe_capquit_to_child(cap_session);
status = WaitForSingleObject((HANDLE) cap_session->fork_child, STOP_SLEEP_TIME);
if (status != WAIT_OBJECT_0) {
ws_warning("sync_pipe_stop: forcing child to exit");
sync_pipe_kill(cap_session->fork_child);
}
#endif
}
}
void
sync_pipe_kill(ws_process_id fork_child)
{
if (fork_child != WS_INVALID_PID) {
#ifndef _WIN32
int sts = kill(fork_child, SIGTERM);
if (sts != 0) {
ws_warning("Sending SIGTERM to child failed: %s\n", g_strerror(errno));
}
#else
* the clean way would be getting the process id of the child process,
* then getting window handle hWnd of that process (using EnumChildWindows),
* and then do a SendMessage(hWnd, WM_CLOSE, 0, 0)
*
* Unfortunately, I don't know how to get the process id from the
* handle. OpenProcess will get an handle (not a window handle)
* from the process ID; it will not get a window handle from the
* process ID. (How could it? A process can have more than one
* window. For that matter, a process might have *no* windows,
* as a process running dumpcap, the normal child process program,
* probably does.)
*
* Hint: GenerateConsoleCtrlEvent() will only work if both processes are
* running in the same console; that's not necessarily the case for
* us, as we might not be running in a console.
* And this also will require to have the process id.
*/
TerminateProcess((HANDLE) (fork_child), 0);
#endif
}
}
void capture_sync_set_fetch_dumpcap_pid_cb(void(*cb)(ws_process_id pid)) {
fetch_dumpcap_pid = cb;
}
#endif