From a6e544b0a88b53114bfa5a57e21b7be7a8dfc9d0 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 1 Sep 2015 09:24:26 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/core/flow_dissector.c | 51 +++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 26 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 151b6e48b81f..22f3d768b459 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -130,6 +130,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb, 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 @@ again: 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 @@ ip: 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 @@ ipv6: 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 @@ ipv6: } *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 @@ ipv6: case htons(PPP_IPV6): goto ipv6; default: - return false; + goto out_bad; } } case htons(ETH_P_TIPC): { @@ -275,9 +276,7 @@ ipv6: } *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 @@ ipv6: 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 @@ mpls: 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 @@ mpls: 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 @@ ip_proto_again: 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 @@ ip_proto_again: 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 @@ ip_proto_again: sizeof(_eth), data, hlen, &_eth); if (!eth) - return false; + goto out_bad; proto = eth->h_proto; nhoff += sizeof(*eth); } @@ -395,7 +390,7 @@ ip_proto_again: 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 @@ ip_proto_again: 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 @@ ip_proto_again: 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); -- 2.20.1