flow_dissector: Jump to exit code in __skb_flow_dissect
Instead of returning immediately (on a parsing failure for instance) we
jump to cleanup code. This always sets protocol values in key_control
(even on a failure there is still valid information in the key_tags that
was set before the problem was hit).
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 151b6e4..22f3d76 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -130,6 +130,7 @@
struct flow_dissector_key_tags *key_tags;
struct flow_dissector_key_keyid *key_keyid;
u8 ip_proto = 0;
+ bool ret = false;
if (!data) {
data = skb->data;
@@ -171,7 +172,7 @@
ip:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph || iph->ihl < 5)
- return false;
+ goto out_bad;
nhoff += iph->ihl * 4;
ip_proto = iph->protocol;
@@ -197,7 +198,7 @@
ipv6:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph)
- return false;
+ goto out_bad;
ip_proto = iph->nexthdr;
nhoff += sizeof(struct ipv6hdr);
@@ -234,7 +235,7 @@
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
if (!vlan)
- return false;
+ goto out_bad;
if (skb_flow_dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_VLANID)) {
@@ -256,7 +257,7 @@
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
- return false;
+ goto out_bad;
proto = hdr->proto;
nhoff += PPPOE_SES_HLEN;
switch (proto) {
@@ -265,7 +266,7 @@
case htons(PPP_IPV6):
goto ipv6;
default:
- return false;
+ goto out_bad;
}
}
case htons(ETH_P_TIPC): {
@@ -275,9 +276,7 @@
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
- return false;
- key_basic->n_proto = proto;
- key_control->thoff = (u16)nhoff;
+ goto out_bad;
if (skb_flow_dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
@@ -287,7 +286,7 @@
key_addrs->tipcaddrs.srcnode = hdr->srcnode;
key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
}
- return true;
+ goto out_good;
}
case htons(ETH_P_MPLS_UC):
@@ -297,7 +296,7 @@
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
hlen, &_hdr);
if (!hdr)
- return false;
+ goto out_bad;
if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
@@ -310,21 +309,17 @@
htonl(MPLS_LS_LABEL_MASK);
}
- key_basic->n_proto = proto;
- key_basic->ip_proto = ip_proto;
- key_control->thoff = (u16)nhoff;
-
- return true;
+ goto out_good;
}
- return true;
+ goto out_good;
}
case htons(ETH_P_FCOE):
key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
/* fall through */
default:
- return false;
+ goto out_bad;
}
ip_proto_again:
@@ -337,7 +332,7 @@
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
- return false;
+ goto out_bad;
/*
* Only look inside GRE if version zero and no
* routing
@@ -357,7 +352,7 @@
data, hlen, &_keyid);
if (!keyid)
- return false;
+ goto out_bad;
if (skb_flow_dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_GRE_KEYID)) {
@@ -378,7 +373,7 @@
sizeof(_eth),
data, hlen, &_eth);
if (!eth)
- return false;
+ goto out_bad;
proto = eth->h_proto;
nhoff += sizeof(*eth);
}
@@ -395,7 +390,7 @@
opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
data, hlen, &_opthdr);
if (!opthdr)
- return false;
+ goto out_bad;
ip_proto = opthdr[0];
nhoff += (opthdr[1] + 1) << 3;
@@ -415,10 +410,6 @@
break;
}
- key_basic->n_proto = proto;
- key_basic->ip_proto = ip_proto;
- key_control->thoff = (u16)nhoff;
-
if (skb_flow_dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_PORTS)) {
key_ports = skb_flow_dissector_target(flow_dissector,
@@ -428,7 +419,15 @@
data, hlen);
}
- return true;
+out_good:
+ ret = true;
+
+out_bad:
+ key_basic->n_proto = proto;
+ key_basic->ip_proto = ip_proto;
+ key_control->thoff = (u16)nhoff;
+
+ return ret;
}
EXPORT_SYMBOL(__skb_flow_dissect);