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-rw-r--r--tc/m_nat.c197
1 files changed, 197 insertions, 0 deletions
diff --git a/tc/m_nat.c b/tc/m_nat.c
new file mode 100644
index 0000000..654f9a3
--- /dev/null
+++ b/tc/m_nat.c
@@ -0,0 +1,197 @@
+/*
+ * m_nat.c NAT module
+ *
+ * This program is free software; you can distribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Authors: Herbert Xu <herbert@gondor.apana.org.au>
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include "utils.h"
+#include "tc_util.h"
+#include <linux/tc_act/tc_nat.h>
+
+static void
+explain(void)
+{
+ fprintf(stderr, "Usage: ... nat NAT\n"
+ "NAT := DIRECTION OLD NEW\n"
+ "DIRECTION := { ingress | egress }\n"
+ "OLD := PREFIX\n"
+ "NEW := ADDRESS\n");
+}
+
+static void
+usage(void)
+{
+ explain();
+ exit(-1);
+}
+
+static int
+parse_nat_args(int *argc_p, char ***argv_p, struct tc_nat *sel)
+{
+ int argc = *argc_p;
+ char **argv = *argv_p;
+ inet_prefix addr;
+
+ if (argc <= 0)
+ return -1;
+
+ if (matches(*argv, "egress") == 0)
+ sel->flags |= TCA_NAT_FLAG_EGRESS;
+ else if (matches(*argv, "ingress") != 0)
+ goto bad_val;
+
+ NEXT_ARG();
+
+ if (get_prefix_1(&addr, *argv, AF_INET))
+ goto bad_val;
+
+ sel->old_addr = addr.data[0];
+ sel->mask = htonl(~0u << (32 - addr.bitlen));
+
+ NEXT_ARG();
+
+ if (get_prefix_1(&addr, *argv, AF_INET))
+ goto bad_val;
+
+ sel->new_addr = addr.data[0];
+
+ argc--;
+ argv++;
+
+ *argc_p = argc;
+ *argv_p = argv;
+ return 0;
+
+bad_val:
+ return -1;
+}
+
+static int
+parse_nat(struct action_util *a, int *argc_p, char ***argv_p, int tca_id, struct nlmsghdr *n)
+{
+ struct tc_nat sel = {};
+
+ int argc = *argc_p;
+ char **argv = *argv_p;
+ int ok = 0;
+ struct rtattr *tail;
+
+ while (argc > 0) {
+ if (matches(*argv, "nat") == 0) {
+ NEXT_ARG();
+ if (parse_nat_args(&argc, &argv, &sel)) {
+ fprintf(stderr, "Illegal nat construct (%s)\n",
+ *argv);
+ explain();
+ return -1;
+ }
+ ok++;
+ continue;
+ } else if (matches(*argv, "help") == 0) {
+ usage();
+ } else {
+ break;
+ }
+
+ }
+
+ if (!ok) {
+ explain();
+ return -1;
+ }
+
+ parse_action_control_dflt(&argc, &argv, &sel.action, false, TC_ACT_OK);
+
+ if (argc) {
+ if (matches(*argv, "index") == 0) {
+ NEXT_ARG();
+ if (get_u32(&sel.index, *argv, 10)) {
+ fprintf(stderr, "Nat: Illegal \"index\"\n");
+ return -1;
+ }
+ argc--;
+ argv++;
+ }
+ }
+
+ tail = addattr_nest(n, MAX_MSG, tca_id);
+ addattr_l(n, MAX_MSG, TCA_NAT_PARMS, &sel, sizeof(sel));
+ addattr_nest_end(n, tail);
+
+ *argc_p = argc;
+ *argv_p = argv;
+ return 0;
+}
+
+static int
+print_nat(struct action_util *au, FILE * f, struct rtattr *arg)
+{
+ struct tc_nat *sel;
+ struct rtattr *tb[TCA_NAT_MAX + 1];
+ SPRINT_BUF(buf1);
+ SPRINT_BUF(buf2);
+ int len;
+
+ print_string(PRINT_ANY, "type", " %s ", "nat");
+ if (arg == NULL)
+ return 0;
+
+ parse_rtattr_nested(tb, TCA_NAT_MAX, arg);
+
+ if (tb[TCA_NAT_PARMS] == NULL) {
+ fprintf(stderr, "Missing nat parameters\n");
+ return -1;
+ }
+ sel = RTA_DATA(tb[TCA_NAT_PARMS]);
+
+ len = ffs(sel->mask);
+ len = len ? 33 - len : 0;
+
+ print_string(PRINT_ANY, "direction", "%s",
+ sel->flags & TCA_NAT_FLAG_EGRESS ? "egress" : "ingress");
+
+ snprintf(buf2, sizeof(buf2), "%s/%d",
+ format_host_r(AF_INET, 4, &sel->old_addr, buf1, sizeof(buf1)),
+ len);
+ print_string(PRINT_ANY, "old_addr", " %s", buf2);
+ print_string(PRINT_ANY, "new_addr", " %s",
+ format_host_r(AF_INET, 4, &sel->new_addr, buf1, sizeof(buf1)));
+
+ print_action_control(f, " ", sel->action, "");
+ print_nl();
+ print_uint(PRINT_ANY, "index", "\t index %u", sel->index);
+ print_int(PRINT_ANY, "ref", " ref %d", sel->refcnt);
+ print_int(PRINT_ANY, "bind", " bind %d", sel->bindcnt);
+
+ if (show_stats) {
+ if (tb[TCA_NAT_TM]) {
+ struct tcf_t *tm = RTA_DATA(tb[TCA_NAT_TM]);
+
+ print_tm(f, tm);
+ }
+ }
+
+ print_nl();
+
+ return 0;
+}
+
+struct action_util nat_action_util = {
+ .id = "nat",
+ .parse_aopt = parse_nat,
+ .print_aopt = print_nat,
+};