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-rw-r--r--extensions/libipt_tos.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/extensions/libipt_tos.c b/extensions/libipt_tos.c
new file mode 100644
index 00000000..eb62081e
--- /dev/null
+++ b/extensions/libipt_tos.c
@@ -0,0 +1,171 @@
+/* Shared library add-on to iptables to add TOS matching support. */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ipt_tos.h>
+
+/* TOS names and values. */
+struct TOS_value
+{
+ unsigned char TOS;
+ const char *name;
+} TOS_values[] = {
+ { IPTOS_LOWDELAY, "Minimize-Delay" },
+ { IPTOS_THROUGHPUT, "Maximize-Throughput" },
+ { IPTOS_RELIABILITY, "Maximize-Reliability" },
+ { IPTOS_MINCOST, "Minimize-Cost" },
+ { IPTOS_NORMALSVC, "Normal-Service" },
+};
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ unsigned int i;
+
+ printf(
+"TOS match v%s options:\n"
+"[!] --tos value Match Type of Service field from one of the\n"
+" following numeric or descriptive values:\n",
+NETFILTER_VERSION);
+
+ for (i = 0; i < sizeof(TOS_values)/sizeof(struct TOS_value);i++)
+ printf(" %s %u (0x%02x)\n",
+ TOS_values[i].name,
+ TOS_values[i].TOS,
+ TOS_values[i].TOS);
+ fputc('\n', stdout);
+}
+
+static struct option opts[] = {
+ { "tos", 1, 0, '1' },
+ {0}
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+ *nfcache |= NFC_IP_TOS;
+}
+
+static void
+parse_tos(const unsigned char *s, struct ipt_tos_info *info)
+{
+ unsigned int i;
+ int tos = string_to_number(s, 0, 255);
+
+ if (tos != -1) {
+ if (tos == IPTOS_LOWDELAY
+ || tos == IPTOS_THROUGHPUT
+ || tos == IPTOS_RELIABILITY
+ || tos == IPTOS_MINCOST
+ || tos == IPTOS_NORMALSVC) {
+ info->tos = (u_int8_t )tos;
+ return;
+ }
+ } else {
+ for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
+ if (strcasecmp(s,TOS_values[i].name) == 0) {
+ info->tos = TOS_values[i].TOS;
+ return;
+ }
+ }
+ exit_error(PARAMETER_PROBLEM, "Bad TOS value `%s'", s);
+}
+
+/* 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_tos_info *tosinfo = (struct ipt_tos_info *)(*match)->data;
+
+ switch (c) {
+ case '1':
+ if (check_inverse(optarg, &invert))
+ optind++;
+ parse_tos(argv[optind-1], tosinfo);
+ if (invert)
+ tosinfo->invert = 1;
+ *flags = 1;
+ break;
+
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static void
+print_tos(u_int8_t tos, int invert, int numeric)
+{
+ unsigned int i;
+
+ if (invert)
+ fputc('!', stdout);
+
+ if (!numeric) {
+ for (i = 0; i<sizeof(TOS_values)/sizeof(struct TOS_value); i++)
+ if (TOS_values[i].TOS == tos) {
+ printf("%s ", TOS_values[i].name);
+ return;
+ }
+ }
+ printf("0x%02x ", tos);
+}
+
+/* Final check; must have specified --tos. */
+static void
+final_check(unsigned int flags)
+{
+ if (!flags)
+ exit_error(PARAMETER_PROBLEM,
+ "TOS match: You must specify `--tos'");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ printf("TOS match ");
+ print_tos(((struct ipt_tos_info *)match->data)->tos,
+ ((struct ipt_tos_info *)match->data)->invert, numeric);
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+ printf("--tos ");
+ print_tos(((struct ipt_tos_info *)match->data)->tos,
+ ((struct ipt_tos_info *)match->data)->invert, 0);
+}
+
+struct iptables_match tos
+= { NULL,
+ "tos",
+ NETFILTER_VERSION,
+ sizeof(struct ipt_tos_info),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void _init(void)
+{
+ register_match(&tos);
+}