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authorYasuyuki KOZAKAI <yasuyuki@netfilter.org>2007-07-24 07:11:26 +0000
committerYasuyuki KOZAKAI <yasuyuki@netfilter.org>2007-07-24 07:11:26 +0000
commit4489c0d66d9a0e6033c9472fd54df155788010b7 (patch)
tree4ca753e3be4ee84bc6083d3fd2f54107d4bffd98 /extensions/libxt_limit.c
parentba2d891523121b651be54a4ce915bcee33d2ed38 (diff)
Unifies libip[6]t_limit.c into libxt_limit.c.
Diffstat (limited to 'extensions/libxt_limit.c')
-rw-r--r--extensions/libxt_limit.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/extensions/libxt_limit.c b/extensions/libxt_limit.c
new file mode 100644
index 00000000..aa7131d6
--- /dev/null
+++ b/extensions/libxt_limit.c
@@ -0,0 +1,214 @@
+/* Shared library add-on to iptables to add limit support.
+ *
+ * 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 <xtables.h>
+#include <stddef.h>
+#include <linux/netfilter/x_tables.h>
+/* For 64bit kernel / 32bit userspace */
+#include "../include/linux/netfilter/xt_limit.h"
+
+#define XT_LIMIT_AVG "3/hour"
+#define XT_LIMIT_BURST 5
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf(
+"limit v%s options:\n"
+"--limit avg max average match rate: default "XT_LIMIT_AVG"\n"
+" [Packets per second unless followed by \n"
+" /sec /minute /hour /day postfixes]\n"
+"--limit-burst number number to match in a burst, default %u\n"
+"\n", IPTABLES_VERSION, XT_LIMIT_BURST);
+}
+
+static struct option opts[] = {
+ { "limit", 1, 0, '%' },
+ { "limit-burst", 1, 0, '$' },
+ { 0 }
+};
+
+static
+int parse_rate(const char *rate, u_int32_t *val)
+{
+ const char *delim;
+ u_int32_t r;
+ u_int32_t mult = 1; /* Seconds by default. */
+
+ delim = strchr(rate, '/');
+ if (delim) {
+ if (strlen(delim+1) == 0)
+ return 0;
+
+ if (strncasecmp(delim+1, "second", strlen(delim+1)) == 0)
+ mult = 1;
+ else if (strncasecmp(delim+1, "minute", strlen(delim+1)) == 0)
+ mult = 60;
+ else if (strncasecmp(delim+1, "hour", strlen(delim+1)) == 0)
+ mult = 60*60;
+ else if (strncasecmp(delim+1, "day", strlen(delim+1)) == 0)
+ mult = 24*60*60;
+ else
+ return 0;
+ }
+ r = atoi(rate);
+ if (!r)
+ return 0;
+
+ /* This would get mapped to infinite (1/day is minimum they
+ can specify, so we're ok at that end). */
+ if (r / mult > XT_LIMIT_SCALE)
+ exit_error(PARAMETER_PROBLEM, "Rate too fast `%s'\n", rate);
+
+ *val = XT_LIMIT_SCALE * mult / r;
+ return 1;
+}
+
+/* Initialize the match. */
+static void
+init(struct xt_entry_match *m, unsigned int *nfcache)
+{
+ struct xt_rateinfo *r = (struct xt_rateinfo *)m->data;
+
+ parse_rate(XT_LIMIT_AVG, &r->avg);
+ r->burst = XT_LIMIT_BURST;
+
+}
+
+/* FIXME: handle overflow:
+ if (r->avg*r->burst/r->burst != r->avg)
+ exit_error(PARAMETER_PROBLEM,
+ "Sorry: burst too large for that avg rate.\n");
+*/
+
+/* Function which parses command options; returns true if it
+ ate an option */
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry,
+ unsigned int *nfcache,
+ struct xt_entry_match **match)
+{
+ struct xt_rateinfo *r = (struct xt_rateinfo *)(*match)->data;
+ unsigned int num;
+
+ switch(c) {
+ case '%':
+ if (check_inverse(argv[optind-1], &invert, &optind, 0)) break;
+ if (!parse_rate(optarg, &r->avg))
+ exit_error(PARAMETER_PROBLEM,
+ "bad rate `%s'", optarg);
+ break;
+
+ case '$':
+ if (check_inverse(argv[optind-1], &invert, &optind, 0)) break;
+ if (string_to_number(optarg, 0, 10000, &num) == -1)
+ exit_error(PARAMETER_PROBLEM,
+ "bad --limit-burst `%s'", optarg);
+ r->burst = num;
+ break;
+
+ default:
+ return 0;
+ }
+
+ if (invert)
+ exit_error(PARAMETER_PROBLEM,
+ "limit does not support invert");
+
+ return 1;
+}
+
+/* Final check; nothing. */
+static void final_check(unsigned int flags)
+{
+}
+
+static struct rates
+{
+ const char *name;
+ u_int32_t mult;
+} rates[] = { { "day", XT_LIMIT_SCALE*24*60*60 },
+ { "hour", XT_LIMIT_SCALE*60*60 },
+ { "min", XT_LIMIT_SCALE*60 },
+ { "sec", XT_LIMIT_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 void *ip,
+ const struct xt_entry_match *match,
+ int numeric)
+{
+ struct xt_rateinfo *r = (struct xt_rateinfo *)match->data;
+ printf("limit: avg "); print_rate(r->avg);
+ printf("burst %u ", r->burst);
+}
+
+/* FIXME: Make minimalist: only print rate if not default --RR */
+static void save(const void *ip, const struct xt_entry_match *match)
+{
+ struct xt_rateinfo *r = (struct xt_rateinfo *)match->data;
+
+ printf("--limit "); print_rate(r->avg);
+ if (r->burst != XT_LIMIT_BURST)
+ printf("--limit-burst %u ", r->burst);
+}
+
+static struct xtables_match limit = {
+ .next = NULL,
+ .family = AF_INET,
+ .name = "limit",
+ .version = IPTABLES_VERSION,
+ .size = XT_ALIGN(sizeof(struct xt_rateinfo)),
+ .userspacesize = offsetof(struct xt_rateinfo, prev),
+ .help = &help,
+ .init = &init,
+ .parse = &parse,
+ .final_check = &final_check,
+ .print = &print,
+ .save = &save,
+ .extra_opts = opts
+};
+
+static struct xtables_match limit6 = {
+ .next = NULL,
+ .family = AF_INET6,
+ .name = "limit",
+ .version = IPTABLES_VERSION,
+ .size = XT_ALIGN(sizeof(struct xt_rateinfo)),
+ .userspacesize = offsetof(struct xt_rateinfo, prev),
+ .help = &help,
+ .init = &init,
+ .parse = &parse,
+ .final_check = &final_check,
+ .print = &print,
+ .save = &save,
+ .extra_opts = opts
+};
+
+void _init(void)
+{
+ xtables_register_match(&limit);
+ xtables_register_match(&limit6);
+}