[PATCH 4.9 016/102] netfilter: nf_nat_h323: fix logical-not-parentheses warning

From: Greg Kroah-Hartman
Date: Fri Apr 06 2018 - 10:50:15 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

commit eee6ebbac18a189ef33d25ea9b8bcae176515e49 upstream.

Clang produces the following warning:

net/ipv4/netfilter/nf_nat_h323.c:553:6: error:
logical not is only applied to the left hand side of this comparison
[-Werror,-Wlogical-not-parentheses]
if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
^
add parentheses after the '!' to evaluate the comparison first
add parentheses around left hand side expression to silence this warning

There's not necessarily a bug here, but it's cleaner to return early,
ex:

if (x)
return
...

rather than:

if (x == 0)
...
else
return

Also added a return code check that seemed to be missing in one
instance.

Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Cc: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/ipv4/netfilter/nf_nat_h323.c | 57 ++++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 27 deletions(-)

--- a/net/ipv4/netfilter/nf_nat_h323.c
+++ b/net/ipv4/netfilter/nf_nat_h323.c
@@ -252,16 +252,16 @@ static int nat_rtp_rtcp(struct sk_buff *
if (set_h245_addr(skb, protoff, data, dataoff, taddr,
&ct->tuplehash[!dir].tuple.dst.u3,
htons((port & htons(1)) ? nated_port + 1 :
- nated_port)) == 0) {
- /* Save ports */
- info->rtp_port[i][dir] = rtp_port;
- info->rtp_port[i][!dir] = htons(nated_port);
- } else {
+ nated_port))) {
nf_ct_unexpect_related(rtp_exp);
nf_ct_unexpect_related(rtcp_exp);
return -1;
}

+ /* Save ports */
+ info->rtp_port[i][dir] = rtp_port;
+ info->rtp_port[i][!dir] = htons(nated_port);
+
/* Success */
pr_debug("nf_nat_h323: expect RTP %pI4:%hu->%pI4:%hu\n",
&rtp_exp->tuple.src.u3.ip,
@@ -370,15 +370,15 @@ static int nat_h245(struct sk_buff *skb,
/* Modify signal */
if (set_h225_addr(skb, protoff, data, dataoff, taddr,
&ct->tuplehash[!dir].tuple.dst.u3,
- htons(nated_port)) == 0) {
- /* Save ports */
- info->sig_port[dir] = port;
- info->sig_port[!dir] = htons(nated_port);
- } else {
+ htons(nated_port))) {
nf_ct_unexpect_related(exp);
return -1;
}

+ /* Save ports */
+ info->sig_port[dir] = port;
+ info->sig_port[!dir] = htons(nated_port);
+
pr_debug("nf_nat_q931: expect H.245 %pI4:%hu->%pI4:%hu\n",
&exp->tuple.src.u3.ip,
ntohs(exp->tuple.src.u.tcp.port),
@@ -462,24 +462,27 @@ static int nat_q931(struct sk_buff *skb,
/* Modify signal */
if (set_h225_addr(skb, protoff, data, 0, &taddr[idx],
&ct->tuplehash[!dir].tuple.dst.u3,
- htons(nated_port)) == 0) {
- /* Save ports */
- info->sig_port[dir] = port;
- info->sig_port[!dir] = htons(nated_port);
-
- /* Fix for Gnomemeeting */
- if (idx > 0 &&
- get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
- (ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
- set_h225_addr(skb, protoff, data, 0, &taddr[0],
- &ct->tuplehash[!dir].tuple.dst.u3,
- info->sig_port[!dir]);
- }
- } else {
+ htons(nated_port))) {
nf_ct_unexpect_related(exp);
return -1;
}

+ /* Save ports */
+ info->sig_port[dir] = port;
+ info->sig_port[!dir] = htons(nated_port);
+
+ /* Fix for Gnomemeeting */
+ if (idx > 0 &&
+ get_h225_addr(ct, *data, &taddr[0], &addr, &port) &&
+ (ntohl(addr.ip) & 0xff000000) == 0x7f000000) {
+ if (set_h225_addr(skb, protoff, data, 0, &taddr[0],
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ info->sig_port[!dir])) {
+ nf_ct_unexpect_related(exp);
+ return -1;
+ }
+ }
+
/* Success */
pr_debug("nf_nat_ras: expect Q.931 %pI4:%hu->%pI4:%hu\n",
&exp->tuple.src.u3.ip,
@@ -550,9 +553,9 @@ static int nat_callforwarding(struct sk_
}

/* Modify signal */
- if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
- &ct->tuplehash[!dir].tuple.dst.u3,
- htons(nated_port)) == 0) {
+ if (set_h225_addr(skb, protoff, data, dataoff, taddr,
+ &ct->tuplehash[!dir].tuple.dst.u3,
+ htons(nated_port))) {
nf_ct_unexpect_related(exp);
return -1;
}