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-rw-r--r--extensions/libip6t_state.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/extensions/libip6t_state.c b/extensions/libip6t_state.c
new file mode 100644
index 0000000..84fd1a4
--- /dev/null
+++ b/extensions/libip6t_state.c
@@ -0,0 +1,163 @@
+/* Ugly hack to make state matching for ipv6 work before iptables-1.4.x is finished */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <ip6tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ipt_state.h>
+
+#ifndef IPT_STATE_UNTRACKED
+#define IPT_STATE_UNTRACKED (1 << (IP_CT_NUMBER + 1))
+#endif
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"state v%s options:\n"
+" [!] --state [INVALID|ESTABLISHED|NEW|RELATED|UNTRACKED][,...]\n"
+" State(s) to match\n"
+"\n", IPTABLES_VERSION);
+}
+
+static struct option opts[] = {
+ { "state", 1, 0, '1' },
+ {0}
+};
+
+static int
+parse_state(const char *state, size_t strlen, struct ipt_state_info *sinfo)
+{
+ if (strncasecmp(state, "INVALID", strlen) == 0)
+ sinfo->statemask |= IPT_STATE_INVALID;
+ else if (strncasecmp(state, "NEW", strlen) == 0)
+ sinfo->statemask |= IPT_STATE_BIT(IP_CT_NEW);
+ else if (strncasecmp(state, "ESTABLISHED", strlen) == 0)
+ sinfo->statemask |= IPT_STATE_BIT(IP_CT_ESTABLISHED);
+ else if (strncasecmp(state, "RELATED", strlen) == 0)
+ sinfo->statemask |= IPT_STATE_BIT(IP_CT_RELATED);
+ else if (strncasecmp(state, "UNTRACKED", strlen) == 0)
+ sinfo->statemask |= IPT_STATE_UNTRACKED;
+ else
+ return 0;
+ return 1;
+}
+
+static void
+parse_states(const char *arg, struct ipt_state_info *sinfo)
+{
+ const char *comma;
+
+ while ((comma = strchr(arg, ',')) != NULL) {
+ if (comma == arg || !parse_state(arg, comma-arg, sinfo))
+ exit_error(PARAMETER_PROBLEM, "Bad state `%s'", arg);
+ arg = comma+1;
+ }
+
+ if (strlen(arg) == 0 || !parse_state(arg, strlen(arg), sinfo))
+ exit_error(PARAMETER_PROBLEM, "Bad state `%s'", arg);
+}
+
+/* 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 ip6t_entry *entry,
+ unsigned int *nfcache,
+ struct ip6t_entry_match **match)
+{
+ struct ipt_state_info *sinfo = (struct ipt_state_info *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ check_inverse(optarg, &invert, &optind, 0);
+
+ parse_states(argv[optind-1], sinfo);
+ if (invert)
+ sinfo->statemask = ~sinfo->statemask;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Final check; must have specified --state. */
+static void final_check(unsigned int flags)
+{
+ if (!flags)
+ exit_error(PARAMETER_PROBLEM, "You must specify `--state'");
+}
+
+static void print_state(unsigned int statemask)
+{
+ const char *sep = "";
+
+ if (statemask & IPT_STATE_INVALID) {
+ printf("%sINVALID", sep);
+ sep = ",";
+ }
+ if (statemask & IPT_STATE_BIT(IP_CT_NEW)) {
+ printf("%sNEW", sep);
+ sep = ",";
+ }
+ if (statemask & IPT_STATE_BIT(IP_CT_RELATED)) {
+ printf("%sRELATED", sep);
+ sep = ",";
+ }
+ if (statemask & IPT_STATE_BIT(IP_CT_ESTABLISHED)) {
+ printf("%sESTABLISHED", sep);
+ sep = ",";
+ }
+ if (statemask & IPT_STATE_UNTRACKED) {
+ printf("%sUNTRACKED", sep);
+ sep = ",";
+ }
+ printf(" ");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ip6t_ip6 *ip,
+ const struct ip6t_entry_match *match,
+ int numeric)
+{
+ struct ipt_state_info *sinfo = (struct ipt_state_info *)match->data;
+
+ printf("state ");
+ print_state(sinfo->statemask);
+}
+
+/* Saves the matchinfo in parsable form to stdout. */
+static void save(const struct ip6t_ip6 *ip, const struct ip6t_entry_match *match)
+{
+ struct ipt_state_info *sinfo = (struct ipt_state_info *)match->data;
+
+ printf("--state ");
+ print_state(sinfo->statemask);
+}
+
+static struct ip6tables_match state = {
+ .next = NULL,
+ .name = "state",
+ .version = IPTABLES_VERSION,
+ .size = IP6T_ALIGN(sizeof(struct ipt_state_info)),
+ .userspacesize = IP6T_ALIGN(sizeof(struct ipt_state_info)),
+ .help = &help,
+ .parse = &parse,
+ .final_check = &final_check,
+ .print = &print,
+ .save = &save,
+ .extra_opts = opts
+};
+
+void _init(void)
+{
+ register_match6(&state);
+}