blob: 02d51fa1154565c1b7dcfffcbb897df94bdf661a [file] [log] [blame]
/*
* ebtablesd.c, January 2005
*
* Author: Bart De Schuymer
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <errno.h>
#include "include/ebtables_u.h"
#define OPT_KERNELDATA 0x800 /* Also defined in ebtables.c */
static struct ebt_u_replace replace[3];
#define OPEN_METHOD_FILE 1
#define OPEN_METHOD_KERNEL 2
static int open_method[3];
void ebt_early_init_once();
static void sigpipe_handler(int sig)
{
}
static void copy_table_names()
{
strcpy(replace[0].name, "filter");
strcpy(replace[1].name, "nat");
strcpy(replace[2].name, "broute");
}
int main(int argc_, char *argv_[])
{
char *argv[EBTD_ARGC_MAX], *args[4], name[] = "mkdir",
mkdir_option[] = "-p", mkdir_dir[] = EBTD_PIPE_DIR,
cmdline[EBTD_CMDLINE_MAXLN];
int readfd, base = 0, offset = 0, n = 0, quotemode = 0;
/* Make sure the pipe directory exists */
args[0] = name;
args[1] = mkdir_option;
args[2] = mkdir_dir;
args[3] = NULL;
switch (fork()) {
case 0:
execvp(args[0], args);
/* Not usually reached */
exit(0);
case -1:
return -1;
default: /* Parent */
wait(NULL);
}
if (mkfifo(EBTD_PIPE, 0600) < 0 && errno != EEXIST) {
printf("Error creating FIFO " EBTD_PIPE "\n");
goto do_exit;
}
if ((readfd = open(EBTD_PIPE, O_RDONLY | O_NONBLOCK, 0)) == -1) {
perror("open");
goto do_exit;
}
if (signal(SIGPIPE, sigpipe_handler) == SIG_ERR) {
perror("signal");
goto do_exit;
}
ebt_silent = 1;
copy_table_names();
ebt_early_init_once();
while (1) {
int n2, i, argc, table_nr, ntot;
/* base == 0 */
ntot = read(readfd, cmdline+offset, EBTD_CMDLINE_MAXLN-offset-1);
if (ntot <= 0)
continue;
ntot += offset;
continue_read:
/* Put '\0' between arguments. */
for (; offset < ntot; n++, offset++) {
if (cmdline[offset] == '\"') {
quotemode ^= 1;
cmdline[offset] = '\0';
} else if (!quotemode && cmdline[offset] == ' ') {
cmdline[offset] = '\0';
} else if (cmdline[offset] == '\n') {
if (quotemode)
ebt_print_error("ebtablesd: wrong number of \" delimiters");
cmdline[offset] = '\0';
break;
}
}
if (n == 0) {
if (offset == ntot) {
/* The ntot bytes were parsed and ended with '\n' */
base = 0;
offset = 0;
continue;
}
offset++;
base = offset;
n = 0;
goto continue_read;
}
if (offset == ntot) { /* The ntot bytes were parsed but no complete rule is yet specified */
if (base == 0) {
ebt_print_error("ebtablesd: the maximum command line length is %d", EBTD_CMDLINE_MAXLN-1);
goto write_msg;
}
memmove(cmdline, cmdline+base+offset, ntot-offset);
offset -= base;
offset++;
base = 0;
continue;
}
table_nr = 0;
n2 = 0;
argc = 0;
while (n2 < n && argc < EBTD_ARGC_MAX) {
if (*(cmdline + base + n2) == '\0') {
n2++;
continue;
}
argv[argc++] = cmdline + base + n2;
n2 += strlen(cmdline + base + n2) + 1;
}
offset++; /* Move past the '\n' */
base = offset;
if (argc > EBTD_ARGC_MAX) {
ebt_print_error("ebtablesd: maximum %d arguments "
"allowed", EBTD_ARGC_MAX - 1);
goto write_msg;
}
if (argc == 1) {
ebt_print_error("ebtablesd: no arguments");
goto write_msg;
}
/* Parse the options */
if (!strcmp(argv[1], "-t")) {
if (argc < 3) {
ebt_print_error("ebtablesd: -t but no table");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
table_nr = i;
} else if (!strcmp(argv[1], "free")) {
if (argc != 3) {
ebt_print_error("ebtablesd: command free "
"needs exactly one argument");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
if (!(replace[i].flags & OPT_KERNELDATA)) {
ebt_print_error("ebtablesd: table %s has not "
"been opened");
goto write_msg;
}
ebt_cleanup_replace(&replace[i]);
copy_table_names();
replace[i].flags &= ~OPT_KERNELDATA;
goto write_msg;
} else if (!strcmp(argv[1], "open")) {
if (argc != 3) {
ebt_print_error("ebtablesd: command open "
"needs exactly one argument");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
if (replace[i].flags & OPT_KERNELDATA) {
ebt_print_error("ebtablesd: table %s needs to "
"be freed before it can be "
"opened");
goto write_msg;
}
if (!ebt_get_kernel_table(&replace[i], 0)) {
replace[i].flags |= OPT_KERNELDATA;
open_method[i] = OPEN_METHOD_KERNEL;
}
goto write_msg;
} else if (!strcmp(argv[1], "fopen")) {
struct ebt_u_replace tmp;
memset(&tmp, 0, sizeof(tmp));
if (argc != 4) {
ebt_print_error("ebtablesd: command fopen "
"needs exactly two arguments");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
if (replace[i].flags & OPT_KERNELDATA) {
ebt_print_error("ebtablesd: table %s needs to "
"be freed before it can be "
"opened");
goto write_msg;
}
tmp.filename = (char *)malloc(strlen(argv[3]) + 1);
if (!tmp.filename) {
ebt_print_error("Out of memory");
goto write_msg;
}
strcpy(tmp.filename, argv[3]);
strcpy(tmp.name, "filter");
tmp.command = 'L'; /* Make sure retrieve_from_file()
* doesn't complain about wrong
* table name */
ebt_get_kernel_table(&tmp, 0);
free(tmp.filename);
tmp.filename = NULL;
if (ebt_errormsg[0] != '\0')
goto write_msg;
if (strcmp(tmp.name, argv[2])) {
ebt_print_error("ebtablesd: opened file with "
"wrong table name '%s'", tmp.name);
ebt_cleanup_replace(&tmp);
goto write_msg;
}
replace[i] = tmp;
replace[i].command = '\0';
replace[i].flags |= OPT_KERNELDATA;
open_method[i] = OPEN_METHOD_FILE;
goto write_msg;
} else if (!strcmp(argv[1], "commit")) {
if (argc != 3) {
ebt_print_error("ebtablesd: command commit "
"needs exactly one argument");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
if (!(replace[i].flags & OPT_KERNELDATA)) {
ebt_print_error("ebtablesd: table %s has not "
"been opened");
goto write_msg;
}
/* The counters from the kernel are useless if we
* didn't start from a kernel table */
if (open_method[i] == OPEN_METHOD_FILE)
replace[i].num_counters = 0;
ebt_deliver_table(&replace[i]);
if (ebt_errormsg[0] == '\0' && open_method[i] == OPEN_METHOD_KERNEL)
ebt_deliver_counters(&replace[i]);
goto write_msg;
} else if (!strcmp(argv[1], "fcommit")) {
if (argc != 4) {
ebt_print_error("ebtablesd: command commit "
"needs exactly two argument");
goto write_msg;
}
for (i = 0; i < 3; i++)
if (!strcmp(replace[i].name, argv[2]))
break;
if (i == 3) {
ebt_print_error("ebtablesd: table '%s' was "
"not recognized", argv[2]);
goto write_msg;
}
if (!(replace[i].flags & OPT_KERNELDATA)) {
ebt_print_error("ebtablesd: table %s has not "
"been opened");
goto write_msg;
}
replace[i].filename = (char *)malloc(strlen(argv[3]) + 1);
if (!replace[i].filename) {
ebt_print_error("Out of memory");
goto write_msg;
}
strcpy(replace[i].filename, argv[3]);
ebt_deliver_table(&replace[i]);
if (ebt_errormsg[0] == '\0' && open_method[i] == OPEN_METHOD_KERNEL)
ebt_deliver_counters(&replace[i]);
free(replace[i].filename);
replace[i].filename = NULL;
goto write_msg;
}else if (!strcmp(argv[1], "quit")) {
if (argc != 2) {
ebt_print_error("ebtablesd: command quit does "
"not take any arguments");
goto write_msg;
}
break;
}
if (!(replace[table_nr].flags & OPT_KERNELDATA)) {
ebt_print_error("ebtablesd: table %s has not been "
"opened", replace[table_nr].name);
goto write_msg;
}
optind = 0; /* Setting optind = 1 causes serious annoyances */
do_command(argc, argv, EXEC_STYLE_DAEMON, &replace[table_nr]);
ebt_reinit_extensions();
write_msg:
#ifndef SILENT_DAEMON
if (ebt_errormsg[0] != '\0')
printf("%s.\n", ebt_errormsg);
#endif
ebt_errormsg[0]= '\0';
n = 0;
goto continue_read;
}
do_exit:
unlink(EBTD_PIPE);
return 0;
}