~ubuntu-branches/ubuntu/lucid/iptables/lucid

/* Shared library add-on to iptables to add LOG support. */

#include <stdio.h>

#include <netdb.h>

#include <string.h>

#include <stdlib.h>

#include <syslog.h>

#include <getopt.h>

#include <iptables.h>

#include <linux/netfilter_ipv4/ip_tables.h>

#include <linux/netfilter_ipv4/ipt_LOG.h>

#define LOG_DEFAULT_LEVEL LOG_WARNING

#ifndef IPT_LOG_UID /* Old kernel */

#define IPT_LOG_UID	0x08	/* Log UID owning local socket */

#undef  IPT_LOG_MASK

#define IPT_LOG_MASK	0x0f

#endif

/* Function which prints out usage message. */

static void LOG_help(void)

{

	printf(

"LOG target options:\n"

" --log-level level		Level of logging (numeric or see syslog.conf)\n"

" --log-prefix prefix		Prefix log messages with this prefix.\n\n"

" --log-tcp-sequence		Log TCP sequence numbers.\n\n"

" --log-tcp-options		Log TCP options.\n\n"

" --log-ip-options		Log IP options.\n\n"

" --log-uid			Log UID owning the local socket.\n\n");

}

static const struct option LOG_opts[] = {

	{ .name = "log-level",        .has_arg = 1, .val = '!' },

	{ .name = "log-prefix",       .has_arg = 1, .val = '#' },

	{ .name = "log-tcp-sequence", .has_arg = 0, .val = '1' },

	{ .name = "log-tcp-options",  .has_arg = 0, .val = '2' },

	{ .name = "log-ip-options",   .has_arg = 0, .val = '3' },

	{ .name = "log-uid",          .has_arg = 0, .val = '4' },

	{ .name = NULL }

};

/* Initialize the target. */

static void LOG_init(struct xt_entry_target *t)

{

	struct ipt_log_info *loginfo = (struct ipt_log_info *)t->data;

	loginfo->level = LOG_DEFAULT_LEVEL;

}

struct ipt_log_names {

	const char *name;

	unsigned int level;

};

static const struct ipt_log_names ipt_log_names[]

= { { .name = "alert",   .level = LOG_ALERT },

    { .name = "crit",    .level = LOG_CRIT },

    { .name = "debug",   .level = LOG_DEBUG },

    { .name = "emerg",   .level = LOG_EMERG },

    { .name = "error",   .level = LOG_ERR },		/* DEPRECATED */

    { .name = "info",    .level = LOG_INFO },

    { .name = "notice",  .level = LOG_NOTICE },

    { .name = "panic",   .level = LOG_EMERG },		/* DEPRECATED */

    { .name = "warning", .level = LOG_WARNING }

};

static u_int8_t

parse_level(const char *level)

{

	unsigned int lev = -1;

	unsigned int set = 0;

	if (string_to_number(level, 0, 7, &lev) == -1) {

		unsigned int i = 0;

		for (i = 0;

		     i < sizeof(ipt_log_names) / sizeof(struct ipt_log_names);

		     i++) {

			if (strncasecmp(level, ipt_log_names[i].name,

					strlen(level)) == 0) {

				if (set++)

					exit_error(PARAMETER_PROBLEM,

						   "log-level `%s' ambiguous",

						   level);

				lev = ipt_log_names[i].level;

			}

		}

		if (!set)

			exit_error(PARAMETER_PROBLEM,

				   "log-level `%s' unknown", level);

	}

	return (u_int8_t)lev;

}

#define IPT_LOG_OPT_LEVEL 0x01

#define IPT_LOG_OPT_PREFIX 0x02

#define IPT_LOG_OPT_TCPSEQ 0x04

#define IPT_LOG_OPT_TCPOPT 0x08

#define IPT_LOG_OPT_IPOPT 0x10

#define IPT_LOG_OPT_UID 0x20

/* Function which parses command options; returns true if it

   ate an option */

static int LOG_parse(int c, char **argv, int invert, unsigned int *flags,

                     const void *entry, struct xt_entry_target **target)

{

	struct ipt_log_info *loginfo = (struct ipt_log_info *)(*target)->data;

	switch (c) {

	case '!':

		if (*flags & IPT_LOG_OPT_LEVEL)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-level twice");

		if (check_inverse(optarg, &invert, NULL, 0))

			exit_error(PARAMETER_PROBLEM,

				   "Unexpected `!' after --log-level");

		loginfo->level = parse_level(optarg);

		*flags |= IPT_LOG_OPT_LEVEL;

		break;

	case '#':

		if (*flags & IPT_LOG_OPT_PREFIX)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-prefix twice");

		if (check_inverse(optarg, &invert, NULL, 0))

			exit_error(PARAMETER_PROBLEM,

				   "Unexpected `!' after --log-prefix");

		if (strlen(optarg) > sizeof(loginfo->prefix) - 1)

			exit_error(PARAMETER_PROBLEM,

				   "Maximum prefix length %u for --log-prefix",

				   (unsigned int)sizeof(loginfo->prefix) - 1);

		if (strlen(optarg) == 0)

			exit_error(PARAMETER_PROBLEM,

				   "No prefix specified for --log-prefix");

		if (strlen(optarg) != strlen(strtok(optarg, "\n")))

			exit_error(PARAMETER_PROBLEM,

				   "Newlines not allowed in --log-prefix");

		strcpy(loginfo->prefix, optarg);

		*flags |= IPT_LOG_OPT_PREFIX;

		break;

	case '1':

		if (*flags & IPT_LOG_OPT_TCPSEQ)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-tcp-sequence "

				   "twice");

		loginfo->logflags |= IPT_LOG_TCPSEQ;

		*flags |= IPT_LOG_OPT_TCPSEQ;

		break;

	case '2':

		if (*flags & IPT_LOG_OPT_TCPOPT)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-tcp-options twice");

		loginfo->logflags |= IPT_LOG_TCPOPT;

		*flags |= IPT_LOG_OPT_TCPOPT;

		break;

	case '3':

		if (*flags & IPT_LOG_OPT_IPOPT)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-ip-options twice");

		loginfo->logflags |= IPT_LOG_IPOPT;

		*flags |= IPT_LOG_OPT_IPOPT;

		break;

	case '4':

		if (*flags & IPT_LOG_OPT_UID)

			exit_error(PARAMETER_PROBLEM,

				   "Can't specify --log-uid twice");

		loginfo->logflags |= IPT_LOG_UID;

		*flags |= IPT_LOG_OPT_UID;

		break;

	default:

		return 0;

	}

	return 1;

}

/* Prints out the targinfo. */

static void LOG_print(const void *ip, const struct xt_entry_target *target,

                      int numeric)

{

	const struct ipt_log_info *loginfo

		= (const struct ipt_log_info *)target->data;

	unsigned int i = 0;

	printf("LOG ");

	if (numeric)

		printf("flags %u level %u ",

		       loginfo->logflags, loginfo->level);

	else {

		for (i = 0;

		     i < sizeof(ipt_log_names) / sizeof(struct ipt_log_names);

		     i++) {

			if (loginfo->level == ipt_log_names[i].level) {

				printf("level %s ", ipt_log_names[i].name);

				break;

			}

		}

		if (i == sizeof(ipt_log_names) / sizeof(struct ipt_log_names))

			printf("UNKNOWN level %u ", loginfo->level);

		if (loginfo->logflags & IPT_LOG_TCPSEQ)

			printf("tcp-sequence ");

		if (loginfo->logflags & IPT_LOG_TCPOPT)

			printf("tcp-options ");

		if (loginfo->logflags & IPT_LOG_IPOPT)

			printf("ip-options ");

		if (loginfo->logflags & IPT_LOG_UID)

			printf("uid ");

		if (loginfo->logflags & ~(IPT_LOG_MASK))

			printf("unknown-flags ");

	}

	if (strcmp(loginfo->prefix, "") != 0)

		printf("prefix `%s' ", loginfo->prefix);

}

/* Saves the union ipt_targinfo in parsable form to stdout. */

static void LOG_save(const void *ip, const struct xt_entry_target *target)

{

	const struct ipt_log_info *loginfo

		= (const struct ipt_log_info *)target->data;

	if (strcmp(loginfo->prefix, "") != 0) {

		printf("--log-prefix ");

		save_string(loginfo->prefix);

	}

	if (loginfo->level != LOG_DEFAULT_LEVEL)

		printf("--log-level %d ", loginfo->level);

	if (loginfo->logflags & IPT_LOG_TCPSEQ)

		printf("--log-tcp-sequence ");

	if (loginfo->logflags & IPT_LOG_TCPOPT)

		printf("--log-tcp-options ");

	if (loginfo->logflags & IPT_LOG_IPOPT)

		printf("--log-ip-options ");

	if (loginfo->logflags & IPT_LOG_UID)

		printf("--log-uid ");

}

static struct xtables_target log_tg_reg = {

    .name          = "LOG",

    .version       = XTABLES_VERSION,

    .family        = PF_INET,

    .size          = XT_ALIGN(sizeof(struct ipt_log_info)),

    .userspacesize = XT_ALIGN(sizeof(struct ipt_log_info)),

    .help          = LOG_help,

    .init          = LOG_init,

    .parse         = LOG_parse,

    .print         = LOG_print,

    .save          = LOG_save,

    .extra_opts    = LOG_opts,

};

void _init(void)

{

	xtables_register_target(&log_tg_reg);

}