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-rw-r--r--extensions/libipt_ULOG.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/extensions/libipt_ULOG.c b/extensions/libipt_ULOG.c
new file mode 100644
index 00000000..f4d39fcd
--- /dev/null
+++ b/extensions/libipt_ULOG.c
@@ -0,0 +1,163 @@
+/* Shared library add-on to iptables to add ULOG 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_ULOG.h>
+
+#define ULOG_DEFAULT_NLGROUP 1
+
+
+void print_groups(unsigned int gmask)
+{
+ int b;
+ unsigned int test;
+
+ for (b = 31; b >= 0; b--)
+ {
+ test = (1 << b);
+ if (gmask & test)
+ printf("%d ", b + 1);
+ }
+}
+
+/* Function which prints out usage message. */
+static void help(void)
+{
+ printf(
+"ULOG v%s options:\n"
+" --ulog-nlgroup nlgroup NETLINK grouo used for logging\n"
+" --ulog-prefix prefix Prefix log messages with this prefix.\n\n",
+NETFILTER_VERSION);
+}
+
+static struct option opts[] = {
+ { "ulog-nlgroup", 1, 0, '!' },
+ { "ulog-prefix", 1, 0, '#' },
+ { 0 }
+};
+
+/* Initialize the target. */
+static void init(struct ipt_entry_target *t, unsigned int *nfcache)
+{
+ struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *)t->data;
+
+ loginfo->nl_group = ULOG_DEFAULT_NLGROUP;
+
+ /* Can't cache this */
+ *nfcache |= NFC_UNKNOWN;
+}
+
+#define IPT_LOG_OPT_NLGROUP 0x01
+#define IPT_LOG_OPT_PREFIX 0x02
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int parse(int c, char **argv, int invert, unsigned int *flags,
+ const struct ipt_entry *entry,
+ struct ipt_entry_target **target)
+{
+ struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *)(*target)->data;
+ int group_d;
+
+ switch (c) {
+ case '!':
+ if (*flags & IPT_LOG_OPT_NLGROUP)
+ exit_error(PARAMETER_PROBLEM,
+ "Can't specify --ulog-nlgroup twice");
+
+ if (check_inverse(optarg, &invert))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --ulog-nlgroup");
+ group_d = atoi(optarg);
+ if (group_d > 32 || group_d < 1)
+ exit_error(PARAMETER_PROBLEM,
+ "--ulog-nlgroup has to be between 1 and 32");
+
+ loginfo->nl_group = (1 << (group_d -1));
+
+ *flags |= IPT_LOG_OPT_NLGROUP;
+ break;
+
+ case '#':
+ if (*flags & IPT_LOG_OPT_PREFIX)
+ exit_error(PARAMETER_PROBLEM,
+ "Can't specify --ulog-prefix twice");
+
+ if (check_inverse(optarg, &invert))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --ulog-prefix");
+
+ if (strlen(optarg) > sizeof(loginfo->prefix) - 1)
+ exit_error(PARAMETER_PROBLEM,
+ "Maximum prefix length %u for --ulog-prefix",
+ sizeof(loginfo->prefix) - 1);
+
+ strcpy(loginfo->prefix, optarg);
+ *flags |= IPT_LOG_OPT_PREFIX;
+ break;
+ }
+ return 1;
+}
+
+/* Final check; nothing. */
+static void final_check(unsigned int flags)
+{
+}
+
+/* Saves the union ipt_targinfo in parsable form to stdout. */
+static void save(const struct ipt_ip *ip, const struct ipt_entry_target *target)
+{
+ const struct ipt_ulog_info *loginfo
+ = (const struct ipt_ulog_info *)target->data;
+
+ if (strcmp(loginfo->prefix, "") != 0)
+ printf("--ulog-prefix %s ", loginfo->prefix);
+
+ if (loginfo->nl_group != ULOG_DEFAULT_NLGROUP)
+ {
+ printf("--ulog-nlgroup ");
+ print_groups(loginfo->nl_group);
+ printf("\n");
+ }
+}
+
+/* Prints out the targinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_target *target,
+ int numeric)
+{
+ const struct ipt_ulog_info *loginfo
+ = (const struct ipt_ulog_info *)target->data;
+
+ printf("ULOG ");
+ printf("nlgroup ");
+ print_groups(loginfo->nl_group);
+ if (strcmp(loginfo->prefix, "") != 0)
+ printf("prefix `%s' ", loginfo->prefix);
+}
+
+struct iptables_target ulog
+= { NULL,
+ "ULOG",
+ NETFILTER_VERSION,
+ IPT_ALIGN(sizeof(struct ipt_ulog_info)),
+ IPT_ALIGN(sizeof(struct ipt_ulog_info)),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_target(&ulog);
+}