add dstlimit extension (kernel code in patch-o-matic soon)
diff --git a/extensions/.dstlimit-test b/extensions/.dstlimit-test
new file mode 100755
index 0000000..b7c8ef9
--- /dev/null
+++ b/extensions/.dstlimit-test
@@ -0,0 +1,2 @@
+#! /bin/sh
+[ -f $KERNEL_DIR/net/ipv4/netfilter/ipt_dstlimit.c ] && echo dstlimit
diff --git a/extensions/libipt_dstlimit.c b/extensions/libipt_dstlimit.c
new file mode 100644
index 0000000..225da4d
--- /dev/null
+++ b/extensions/libipt_dstlimit.c
@@ -0,0 +1,306 @@
+/* iptables match extension for limiting packets per destination
+ *
+ * (C) 2003 by Harald Welte <laforge@netfilter.org>
+ *
+ * Development of this code was funded by Astaro AG, http://www.astaro.com/
+ *
+ * Based on ipt_limit.c by
+ * Jérôme de Vivie <devivie@info.enserb.u-bordeaux.fr>
+ * Hervé Eychenne <rv@wallfire.org>
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <stddef.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_dstlimit.h>
+
+#define IPT_DSTLIMIT_BURST 5
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"dstlimit v%s options:\n"
+"--dstlimit <avg> max average match rate\n"
+" [Packets per second unless followed by \n"
+" /sec /minute /hour /day postfixes]\n"
+"--dstlimit-mode <mode> mode (destip|destip-destport)\n"
+"[--dstlimit-burst <num>] number to match in a burst, default %u\n"
+"[--dstlimit-htable-size <num>] number of hashtable buckets\n"
+"[--dstlimit-htable-max <num>] number of hashtable entries\n"
+"[--dstlimit-htable-gcinterval] interval between garbage collection runs\n"
+"[--dstlimit-htable-expire] after which time are idle entries expired?\n"
+"\n", IPTABLES_VERSION, IPT_DSTLIMIT_BURST);
+}
+
+static struct option opts[] = {
+ { "dstlimit", 1, 0, '%' },
+ { "dstlimit-burst", 1, 0, '$' },
+ { "dstlimit-htable-size", 1, 0, '&' },
+ { "dstlimit-htable-max", 1, 0, '*' },
+ { "dstlimit-htable-gcinterval", 1, 0, '(' },
+ { "dstlimit-htable-expire", 1, 0, ')' },
+ { "dstlimit-mode", 1, 0, '_' },
+ { 0 }
+};
+
+static
+int parse_rate(const char *rate, u_int32_t *val)
+{
+ const char *delim;
+ u_int32_t r;
+ u_int32_t mult = 1; /* Seconds by default. */
+
+ delim = strchr(rate, '/');
+ if (delim) {
+ if (strlen(delim+1) == 0)
+ return 0;
+
+ if (strncasecmp(delim+1, "second", strlen(delim+1)) == 0)
+ mult = 1;
+ else if (strncasecmp(delim+1, "minute", strlen(delim+1)) == 0)
+ mult = 60;
+ else if (strncasecmp(delim+1, "hour", strlen(delim+1)) == 0)
+ mult = 60*60;
+ else if (strncasecmp(delim+1, "day", strlen(delim+1)) == 0)
+ mult = 24*60*60;
+ else
+ return 0;
+ }
+ r = atoi(rate);
+ if (!r)
+ return 0;
+
+ /* This would get mapped to infinite (1/day is minimum they
+ can specify, so we're ok at that end). */
+ if (r / mult > IPT_DSTLIMIT_SCALE)
+ exit_error(PARAMETER_PROBLEM, "Rate too fast `%s'\n", rate);
+
+ *val = IPT_DSTLIMIT_SCALE * mult / r;
+ return 1;
+}
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+ struct ipt_dstlimit_info *r = (struct ipt_dstlimit_info *)m->data;
+
+ r->burst = IPT_DSTLIMIT_BURST;
+
+ /* Can't cache this */
+ *nfcache |= NFC_UNKNOWN;
+}
+
+#define PARAM_LIMIT 0x00000001
+#define PARAM_BURST 0x00000002
+#define PARAM_MODE 0x00000004
+#define PARAM_SIZE 0x00000010
+#define PARAM_MAX 0x00000020
+#define PARAM_GCINTERVAL 0x00000040
+#define PARAM_EXPIRE 0x00000080
+
+/* 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,
+ unsigned int *nfcache,
+ struct ipt_entry_match **match)
+{
+ struct ipt_dstlimit_info *r =
+ (struct ipt_dstlimit_info *)(*match)->data;
+ unsigned int num;
+
+ switch(c) {
+ case '%':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --dstlimit");
+ if (!parse_rate(optarg, &r->avg))
+ exit_error(PARAMETER_PROBLEM,
+ "bad rate `%s'", optarg);
+ *flags |= PARAM_LIMIT;
+ break;
+
+ case '$':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --dstlimit-burst");
+
+ if (string_to_number(optarg, 0, 10000, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-burst `%s'", optarg);
+ r->burst = num;
+ *flags |= PARAM_BURST;
+ break;
+ case '&':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --dstlimit-htable-size");
+
+ if (string_to_number(optarg, 0, 0xffffffff, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-htable-size: `%s'", optarg);
+ r->hinfo.size = num;
+ *flags |= PARAM_SIZE;
+ break;
+ case '*':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM,
+ "Unexpected `!' after --dstlimit-htable-max");
+ if (string_to_number(optarg, 0, 0xffffffff, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-htable-max: `%s'", optarg);
+ r->hinfo.max = num;
+ *flags |= PARAM_MAX;
+ break;
+ case '(':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM, "Unexpected `!' after "
+ "--dstlimit-htable-gcinterval");
+ if (string_to_number(optarg, 0, 0xffffffff, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-htable-gcinterval: `%s'",
+ optarg);
+ /* FIXME: not HZ dependent!! */
+ r->hinfo.gc_interval = num;
+ *flags |= PARAM_GCINTERVAL;
+ break;
+ case ')':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM, "Unexpected `!' after "
+ "--dstlimit-htable-expire");
+ if (string_to_number(optarg, 0, 0xffffffff, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-htable-expire: `%s'", optarg);
+ /* FIXME: not HZ dependent */
+ r->hinfo.expire = num;
+ *flags |= PARAM_EXPIRE;
+ break;
+ case '_':
+ if (check_inverse(optarg, &invert, NULL, 0))
+ exit_error(PARAMETER_PROBLEM, "Unexpected `!' after "
+ "--dstlimit-mode");
+ if (!strcmp(optarg, "destip"))
+ r->mode = IPT_DSTLIMIT_MODE_DIP;
+ else if (!strcmp(optarg, "destip-destport"))
+ r->mode = IPT_DSTLIMIT_MODE_DIP_DPT;
+ else
+ exit_error(PARAMETER_PROBLEM,
+ "bad --dstlimit-mode: `%s'\n", optarg);
+ *flags |= PARAM_MODE;
+ break;
+ default:
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Final check; nothing. */
+static void final_check(unsigned int flags)
+{
+ if (!(flags & PARAM_LIMIT))
+ exit_error(PARAMETER_PROBLEM,
+ "You have to specify --dstlimit-rate");
+ if (!(flags & PARAM_MODE))
+ exit_error(PARAMETER_PROBLEM,
+ "You have to specify --dstlimit-mode");
+}
+
+static struct rates
+{
+ const char *name;
+ u_int32_t mult;
+} rates[] = { { "day", IPT_DSTLIMIT_SCALE*24*60*60 },
+ { "hour", IPT_DSTLIMIT_SCALE*60*60 },
+ { "min", IPT_DSTLIMIT_SCALE*60 },
+ { "sec", IPT_DSTLIMIT_SCALE } };
+
+static void print_rate(u_int32_t period)
+{
+ unsigned int i;
+
+ for (i = 1; i < sizeof(rates)/sizeof(struct rates); i++) {
+ if (period > rates[i].mult
+ || rates[i].mult/period < rates[i].mult%period)
+ break;
+ }
+
+ printf("%u/%s ", rates[i-1].mult / period, rates[i-1].name);
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ struct ipt_dstlimit_info *r =
+ (struct ipt_dstlimit_info *)match->data;
+ printf("limit: avg "); print_rate(r->avg);
+ printf("burst %u ", r->burst);
+ switch (r->mode) {
+ case IPT_DSTLIMIT_MODE_DIP:
+ printf("mode dstip ");
+ break;
+ case IPT_DSTLIMIT_MODE_DIP_DPT:
+ printf("mode dstip-dstport ");
+ break;
+ }
+ printf("htable-size %u ", r->hinfo.size);
+ printf("htable-max %u ", r->hinfo.max);
+ printf("htable-gcinterval %u ", r->hinfo.gc_interval);
+ printf("htable-expire %u ", r->hinfo.expire);
+}
+
+/* FIXME: Make minimalist: only print rate if not default --RR */
+static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+ struct ipt_dstlimit_info *r =
+ (struct ipt_dstlimit_info *)match->data;
+
+ printf("--limit "); print_rate(r->avg);
+ if (r->burst != IPT_DSTLIMIT_BURST)
+ printf("--limit-burst %u ", r->burst);
+ switch (r->mode) {
+ case IPT_DSTLIMIT_MODE_DIP:
+ printf("--mode dstip ");
+ break;
+ case IPT_DSTLIMIT_MODE_DIP_DPT:
+ printf("--mode dstip-dstport ");
+ break;
+ }
+ printf("--htable-size %u ", r->hinfo.size);
+ printf("--htable-max %u ", r->hinfo.max);
+ printf("--htable-gcinterval %u", r->hinfo.gc_interval);
+ printf("--htable-expire %u ", r->hinfo.expire);
+}
+
+static
+struct iptables_match dstlimit
+= { NULL,
+ "dstlimit",
+ IPTABLES_VERSION,
+ IPT_ALIGN(sizeof(struct ipt_dstlimit_info)),
+ IPT_ALIGN(sizeof(struct ipt_dstlimit_info)),
+ //offsetof(struct ipt_dstlimit_info, prev),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_match(&dstlimit);
+}