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-rw-r--r--extensions/libxt_tcp.c69
1 files changed, 39 insertions, 30 deletions
diff --git a/extensions/libxt_tcp.c b/extensions/libxt_tcp.c
index 0b115cdd..32bbd684 100644
--- a/extensions/libxt_tcp.c
+++ b/extensions/libxt_tcp.c
@@ -225,13 +225,18 @@ print_port(uint16_t port, int numeric)
printf("%s", service);
}
+static bool skip_ports_match(uint16_t min, uint16_t max, bool inv)
+{
+ return min == 0 && max == UINT16_MAX && !inv;
+}
+
static void
print_ports(const char *name, uint16_t min, uint16_t max,
int invert, int numeric)
{
const char *inv = invert ? "!" : "";
- if (min != 0 || max != 0xFFFF || invert) {
+ if (!skip_ports_match(min, max, invert)) {
printf(" %s", name);
if (min == max) {
printf(":%s", inv);
@@ -315,10 +320,11 @@ tcp_print(const void *ip, const struct xt_entry_match *match, int numeric)
static void tcp_save(const void *ip, const struct xt_entry_match *match)
{
const struct xt_tcp *tcpinfo = (struct xt_tcp *)match->data;
+ bool inv_srcpt = tcpinfo->invflags & XT_TCP_INV_SRCPT;
+ bool inv_dstpt = tcpinfo->invflags & XT_TCP_INV_DSTPT;
- if (tcpinfo->spts[0] != 0
- || tcpinfo->spts[1] != 0xFFFF) {
- if (tcpinfo->invflags & XT_TCP_INV_SRCPT)
+ if (!skip_ports_match(tcpinfo->spts[0], tcpinfo->spts[1], inv_srcpt)) {
+ if (inv_srcpt)
printf(" !");
if (tcpinfo->spts[0]
!= tcpinfo->spts[1])
@@ -330,9 +336,8 @@ static void tcp_save(const void *ip, const struct xt_entry_match *match)
tcpinfo->spts[0]);
}
- if (tcpinfo->dpts[0] != 0
- || tcpinfo->dpts[1] != 0xFFFF) {
- if (tcpinfo->invflags & XT_TCP_INV_DSTPT)
+ if (!skip_ports_match(tcpinfo->dpts[0], tcpinfo->dpts[1], inv_dstpt)) {
+ if (inv_dstpt)
printf(" !");
if (tcpinfo->dpts[0]
!= tcpinfo->dpts[1])
@@ -380,10 +385,9 @@ static void print_tcp_xlate(struct xt_xlate *xl, uint8_t flags)
for (i = 0; (flags & tcp_flag_names_xlate[i].flag) == 0; i++);
- if (have_flag)
- xt_xlate_add(xl, ",");
-
- xt_xlate_add(xl, "%s", tcp_flag_names_xlate[i].name);
+ xt_xlate_add(xl, "%s%s",
+ have_flag ? "," : "",
+ tcp_flag_names_xlate[i].name);
have_flag = 1;
flags &= ~tcp_flag_names_xlate[i].flag;
@@ -398,50 +402,55 @@ static int tcp_xlate(struct xt_xlate *xl,
{
const struct xt_tcp *tcpinfo =
(const struct xt_tcp *)params->match->data;
- char *space= "";
+ bool inv_srcpt = tcpinfo->invflags & XT_TCP_INV_SRCPT;
+ bool inv_dstpt = tcpinfo->invflags & XT_TCP_INV_DSTPT;
+ bool xlated = false;
- if (tcpinfo->spts[0] != 0 || tcpinfo->spts[1] != 0xffff) {
+ if (!skip_ports_match(tcpinfo->spts[0], tcpinfo->spts[1], inv_srcpt)) {
if (tcpinfo->spts[0] != tcpinfo->spts[1]) {
xt_xlate_add(xl, "tcp sport %s%u-%u",
- tcpinfo->invflags & XT_TCP_INV_SRCPT ?
- "!= " : "",
+ inv_srcpt ? "!= " : "",
tcpinfo->spts[0], tcpinfo->spts[1]);
} else {
xt_xlate_add(xl, "tcp sport %s%u",
- tcpinfo->invflags & XT_TCP_INV_SRCPT ?
- "!= " : "",
+ inv_srcpt ? "!= " : "",
tcpinfo->spts[0]);
}
- space = " ";
+ xlated = true;
}
- if (tcpinfo->dpts[0] != 0 || tcpinfo->dpts[1] != 0xffff) {
+ if (!skip_ports_match(tcpinfo->dpts[0], tcpinfo->dpts[1], inv_dstpt)) {
if (tcpinfo->dpts[0] != tcpinfo->dpts[1]) {
- xt_xlate_add(xl, "%stcp dport %s%u-%u", space,
- tcpinfo->invflags & XT_TCP_INV_DSTPT ?
- "!= " : "",
+ xt_xlate_add(xl, "tcp dport %s%u-%u",
+ inv_dstpt ? "!= " : "",
tcpinfo->dpts[0], tcpinfo->dpts[1]);
} else {
- xt_xlate_add(xl, "%stcp dport %s%u", space,
- tcpinfo->invflags & XT_TCP_INV_DSTPT ?
- "!= " : "",
+ xt_xlate_add(xl, "tcp dport %s%u",
+ inv_dstpt ? "!= " : "",
tcpinfo->dpts[0]);
}
- space = " ";
+ xlated = true;
}
- /* XXX not yet implemented */
- if (tcpinfo->option || (tcpinfo->invflags & XT_TCP_INV_OPTION))
- return 0;
+ if (tcpinfo->option) {
+ xt_xlate_add(xl, "tcp option %u %s", tcpinfo->option,
+ tcpinfo->invflags & XT_TCP_INV_OPTION ?
+ "missing" : "exists");
+ xlated = true;
+ }
if (tcpinfo->flg_mask || (tcpinfo->invflags & XT_TCP_INV_FLAGS)) {
- xt_xlate_add(xl, "%stcp flags %s", space,
+ xt_xlate_add(xl, "tcp flags %s",
tcpinfo->invflags & XT_TCP_INV_FLAGS ? "!= ": "");
print_tcp_xlate(xl, tcpinfo->flg_cmp);
xt_xlate_add(xl, " / ");
print_tcp_xlate(xl, tcpinfo->flg_mask);
+ xlated = true;
}
+ if (!xlated)
+ xt_xlate_add(xl, "meta l4proto tcp");
+
return 1;
}