Move libipt_recent to libxt_recent

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/extensions/libxt_recent.c b/extensions/libxt_recent.c
new file mode 100644
index 0000000..028c563
--- /dev/null
+++ b/extensions/libxt_recent.c
@@ -0,0 +1,233 @@
+/* Shared library add-on to iptables to add recent matching support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <xtables.h>
+#include <linux/netfilter/xt_recent.h>
+
+static const struct option recent_opts[] = {
+	{ .name = "set",      .has_arg = 0, .val = 201 },
+	{ .name = "rcheck",   .has_arg = 0, .val = 202 },
+	{ .name = "update",   .has_arg = 0, .val = 203 },
+	{ .name = "seconds",  .has_arg = 1, .val = 204 },
+	{ .name = "hitcount", .has_arg = 1, .val = 205 },
+	{ .name = "remove",   .has_arg = 0, .val = 206 },
+	{ .name = "rttl",     .has_arg = 0, .val = 207 },
+	{ .name = "name",     .has_arg = 1, .val = 208 },
+	{ .name = "rsource",  .has_arg = 0, .val = 209 },
+	{ .name = "rdest",    .has_arg = 0, .val = 210 },
+	{ .name = NULL }
+};
+
+static void recent_help(void)
+{
+	printf(
+"recent match options:\n"
+"[!] --set                       Add source address to list, always matches.\n"
+"[!] --rcheck                    Match if source address in list.\n"
+"[!] --update                    Match if source address in list, also update last-seen time.\n"
+"[!] --remove                    Match if source address in list, also removes that address from list.\n"
+"    --seconds seconds           For check and update commands above.\n"
+"                                Specifies that the match will only occur if source address last seen within\n"
+"                                the last 'seconds' seconds.\n"
+"    --hitcount hits             For check and update commands above.\n"
+"                                Specifies that the match will only occur if source address seen hits times.\n"
+"                                May be used in conjunction with the seconds option.\n"
+"    --rttl                      For check and update commands above.\n"
+"                                Specifies that the match will only occur if the source address and the TTL\n"
+"                                match between this packet and the one which was set.\n"
+"                                Useful if you have problems with people spoofing their source address in order\n"
+"                                to DoS you via this module.\n"
+"    --name name                 Name of the recent list to be used.  DEFAULT used if none given.\n"
+"    --rsource                   Match/Save the source address of each packet in the recent list table (default).\n"
+"    --rdest                     Match/Save the destination address of each packet in the recent list table.\n"
+"xt_recent by: Stephen Frost <sfrost@snowman.net>.  http://snowman.net/projects/ipt_recent/\n");
+}
+
+static void recent_init(struct xt_entry_match *match)
+{
+	struct xt_recent_mtinfo *info = (void *)(match)->data;
+
+	strncpy(info->name,"DEFAULT", XT_RECENT_NAME_LEN);
+	/* even though XT_RECENT_NAME_LEN is currently defined as 200,
+	 * better be safe, than sorry */
+	info->name[XT_RECENT_NAME_LEN-1] = '\0';
+	info->side = XT_RECENT_SOURCE;
+}
+
+#define RECENT_CMDS \
+	(XT_RECENT_SET | XT_RECENT_CHECK | \
+	XT_RECENT_UPDATE | XT_RECENT_REMOVE)
+
+static int recent_parse(int c, char **argv, int invert, unsigned int *flags,
+                        const void *entry, struct xt_entry_match **match)
+{
+	struct xt_recent_mtinfo *info = (void *)(*match)->data;
+
+	switch (c) {
+		case 201:
+			if (*flags & RECENT_CMDS)
+				exit_error(PARAMETER_PROBLEM,
+					"recent: only one of `--set', `--rcheck' "
+					"`--update' or `--remove' may be set");
+			check_inverse(optarg, &invert, &optind, 0);
+			info->check_set |= XT_RECENT_SET;
+			if (invert) info->invert = 1;
+			*flags |= XT_RECENT_SET;
+			break;
+
+		case 202:
+			if (*flags & RECENT_CMDS)
+				exit_error(PARAMETER_PROBLEM,
+					"recent: only one of `--set', `--rcheck' "
+					"`--update' or `--remove' may be set");
+			check_inverse(optarg, &invert, &optind, 0);
+			info->check_set |= XT_RECENT_CHECK;
+			if(invert) info->invert = 1;
+			*flags |= XT_RECENT_CHECK;
+			break;
+
+		case 203:
+			if (*flags & RECENT_CMDS)
+				exit_error(PARAMETER_PROBLEM,
+					"recent: only one of `--set', `--rcheck' "
+					"`--update' or `--remove' may be set");
+			check_inverse(optarg, &invert, &optind, 0);
+			info->check_set |= XT_RECENT_UPDATE;
+			if (invert) info->invert = 1;
+			*flags |= XT_RECENT_UPDATE;
+			break;
+
+		case 206:
+			if (*flags & RECENT_CMDS)
+				exit_error(PARAMETER_PROBLEM,
+					"recent: only one of `--set', `--rcheck' "
+					"`--update' or `--remove' may be set");
+			check_inverse(optarg, &invert, &optind, 0);
+			info->check_set |= XT_RECENT_REMOVE;
+			if (invert) info->invert = 1;
+			*flags |= XT_RECENT_REMOVE;
+			break;
+
+		case 204:
+			info->seconds = atoi(optarg);
+			break;
+
+		case 205:
+			info->hit_count = atoi(optarg);
+			break;
+
+		case 207:
+			info->check_set |= XT_RECENT_TTL;
+			*flags |= XT_RECENT_TTL;
+			break;
+
+		case 208:
+			strncpy(info->name,optarg, XT_RECENT_NAME_LEN);
+			info->name[XT_RECENT_NAME_LEN-1] = '\0';
+			break;
+
+		case 209:
+			info->side = XT_RECENT_SOURCE;
+			break;
+
+		case 210:
+			info->side = XT_RECENT_DEST;
+			break;
+
+		default:
+			return 0;
+	}
+
+	return 1;
+}
+
+static void recent_check(unsigned int flags)
+{
+	if (!(flags & RECENT_CMDS))
+		exit_error(PARAMETER_PROBLEM,
+			"recent: you must specify one of `--set', `--rcheck' "
+			"`--update' or `--remove'");
+	if ((flags & XT_RECENT_TTL) &&
+	    (flags & (XT_RECENT_SET | XT_RECENT_REMOVE)))
+		exit_error(PARAMETER_PROBLEM,
+		           "recent: --rttl may only be used with --rcheck or "
+		           "--update");
+}
+
+static void recent_print(const void *ip, const struct xt_entry_match *match,
+                         int numeric)
+{
+	const struct xt_recent_mtinfo *info = (const void *)match->data;
+
+	if (info->invert)
+		fputc('!', stdout);
+
+	printf("recent: ");
+	if (info->check_set & XT_RECENT_SET)
+		printf("SET ");
+	if (info->check_set & XT_RECENT_CHECK)
+		printf("CHECK ");
+	if (info->check_set & XT_RECENT_UPDATE)
+		printf("UPDATE ");
+	if (info->check_set & XT_RECENT_REMOVE)
+		printf("REMOVE ");
+	if(info->seconds) printf("seconds: %d ",info->seconds);
+	if(info->hit_count) printf("hit_count: %d ",info->hit_count);
+	if (info->check_set & XT_RECENT_TTL)
+		printf("TTL-Match ");
+	if(info->name) printf("name: %s ",info->name);
+	if (info->side == XT_RECENT_SOURCE)
+		printf("side: source ");
+	if (info->side == XT_RECENT_DEST)
+		printf("side: dest");
+}
+
+static void recent_save(const void *ip, const struct xt_entry_match *match)
+{
+	const struct xt_recent_mtinfo *info = (const void *)match->data;
+
+	if (info->invert)
+		printf("! ");
+
+	if (info->check_set & XT_RECENT_SET)
+		printf("--set ");
+	if (info->check_set & XT_RECENT_CHECK)
+		printf("--rcheck ");
+	if (info->check_set & XT_RECENT_UPDATE)
+		printf("--update ");
+	if (info->check_set & XT_RECENT_REMOVE)
+		printf("--remove ");
+	if(info->seconds) printf("--seconds %d ",info->seconds);
+	if(info->hit_count) printf("--hitcount %d ",info->hit_count);
+	if (info->check_set & XT_RECENT_TTL)
+		printf("--rttl ");
+	if(info->name) printf("--name %s ",info->name);
+	if (info->side == XT_RECENT_SOURCE)
+		printf("--rsource ");
+	if (info->side == XT_RECENT_DEST)
+		printf("--rdest ");
+}
+
+static struct xtables_match recent_mt_reg = {
+    .name          = "recent",
+    .version       = XTABLES_VERSION,
+    .family        = PF_INET,
+    .size          = XT_ALIGN(sizeof(struct xt_recent_mtinfo)),
+    .userspacesize = XT_ALIGN(sizeof(struct xt_recent_mtinfo)),
+    .help          = recent_help,
+    .init          = recent_init,
+    .parse         = recent_parse,
+    .final_check   = recent_check,
+    .print         = recent_print,
+    .save          = recent_save,
+    .extra_opts    = recent_opts,
+};
+
+void _init(void)
+{
+	xtables_register_match(&recent_mt_reg);
+}