@@ -362,6 +362,85 @@ static void tcp_save(const void *ip, const struct xt_entry_match *match)
}
}
+static const struct tcp_flag_names tcp_flag_names_xlate[] = {
+ { "fin", 0x01 },
+ { "syn", 0x02 },
+ { "rst", 0x04 },
+ { "psh", 0x08 },
+ { "ack", 0x10 },
+ { "urg", 0x20 },
+};
+
+static void print_tcp_xlate(struct xt_buf *buf, uint8_t flags)
+{
+ int have_flag = 0;
+
+ while (flags) {
+ unsigned int i;
+
+ for (i = 0; (flags & tcp_flag_names_xlate[i].flag) == 0; i++);
+
+ if (have_flag)
+ xt_buf_add(buf, "|");
+
+ xt_buf_add(buf, "%s", tcp_flag_names_xlate[i].name);
+ have_flag = 1;
+
+ flags &= ~tcp_flag_names_xlate[i].flag;
+ }
+
+ if (!have_flag)
+ xt_buf_add(buf, "none");
+}
+
+static int tcp_xlate(const struct xt_entry_match *match, struct xt_buf *buf)
+{
+ const struct xt_tcp *tcpinfo = (const struct xt_tcp *)match->data;
+
+ if (tcpinfo->spts[0] != 0 || tcpinfo->spts[1] != 0xffff) {
+ if (tcpinfo->spts[0] != tcpinfo->spts[1]) {
+ xt_buf_add(buf, "tcp sport %s%u-%u ",
+ tcpinfo->invflags & XT_TCP_INV_SRCPT ?
+ "!= " : "",
+ tcpinfo->spts[0], tcpinfo->spts[1]);
+ } else {
+ xt_buf_add(buf, "tcp sport %s%u ",
+ tcpinfo->invflags & XT_TCP_INV_SRCPT ?
+ "!= " : "",
+ tcpinfo->spts[0]);
+ }
+ }
+
+ if (tcpinfo->dpts[0] != 0 || tcpinfo->dpts[1] != 0xffff) {
+ if (tcpinfo->dpts[0] != tcpinfo->dpts[1]) {
+ xt_buf_add(buf, "tcp dport %s%u-%u ",
+ tcpinfo->invflags & XT_TCP_INV_DSTPT ?
+ "!= " : "",
+ tcpinfo->dpts[0], tcpinfo->dpts[1]);
+ } else {
+ xt_buf_add(buf, "tcp dport %s%u ",
+ tcpinfo->invflags & XT_TCP_INV_DSTPT ?
+ "!= " : "",
+ tcpinfo->dpts[0]);
+ }
+ }
+
+ /* XXX not yet implemented */
+ if (tcpinfo->option || (tcpinfo->invflags & XT_TCP_INV_OPTION))
+ return 0;
+
+ if (tcpinfo->flg_mask || (tcpinfo->invflags & XT_TCP_INV_FLAGS)) {
+ xt_buf_add(buf, "tcp flags & ");
+ print_tcp_xlate(buf, tcpinfo->flg_mask);
+ xt_buf_add(buf, " %s ",
+ tcpinfo->invflags & XT_TCP_INV_FLAGS ? "!= ": "==");
+ print_tcp_xlate(buf, tcpinfo->flg_cmp);
+ xt_buf_add(buf, " ");
+ }
+
+ return 1;
+}
+
static struct xtables_match tcp_match = {
.family = NFPROTO_UNSPEC,
.name = "tcp",
@@ -374,6 +453,7 @@ static struct xtables_match tcp_match = {
.print = tcp_print,
.save = tcp_save,
.extra_opts = tcp_opts,
+ .xlate = tcp_xlate,
};
void
Translation for the TCP option matching is not yet implemented as we don't have a way to match this yet. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- extensions/libxt_tcp.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+)