ebtablesd.c - manifest_repos/ebtables - Git at Google

 /*
  * 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;
 }
	/*
	* 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;
	}