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Date: Mon, 6 Mar 2017 16:39:55 +0100
From: Jiri Pirko <jiri@...nulli.us>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, tom@...bertland.com,
simon.horman@...ronome.com, eric.dumazet@...il.com,
dinan.gunawardena@...ronome.com, hadarh@...lanox.com, e@...g.me,
fgao@...ai8.com, mlxsw@...lanox.com
Subject: [patch net-next 5/5] flow_dissector: Move GRE dissection into a separate function
From: Jiri Pirko <jiri@...lanox.com>
Make the main flow_dissect function a bit smaller and move the GRE
dissection into a separate function.
Signed-off-by: Jiri Pirko <jiri@...lanox.com>
---
net/core/flow_dissector.c | 244 +++++++++++++++++++++++++---------------------
1 file changed, 134 insertions(+), 110 deletions(-)
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 9120835..5f3ae92 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -116,6 +116,7 @@ EXPORT_SYMBOL(__skb_flow_get_ports);
enum flow_dissect_ret {
FLOW_DISSECT_RET_OUT_GOOD,
FLOW_DISSECT_RET_OUT_BAD,
+ FLOW_DISSECT_RET_OUT_PROTO_AGAIN,
};
static enum flow_dissect_ret
@@ -200,6 +201,128 @@ __skb_flow_dissect_arp(const struct sk_buff *skb,
return FLOW_DISSECT_RET_OUT_GOOD;
}
+static enum flow_dissect_ret
+__skb_flow_dissect_gre(const struct sk_buff *skb,
+ struct flow_dissector_key_control *key_control,
+ struct flow_dissector *flow_dissector,
+ void *target_container, void *data,
+ __be16 *p_proto, int *p_nhoff, int *p_hlen,
+ unsigned int flags)
+{
+ struct flow_dissector_key_keyid *key_keyid;
+ struct gre_base_hdr *hdr, _hdr;
+ int offset = 0;
+ u16 gre_ver;
+
+ hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
+ data, *p_hlen, &_hdr);
+ if (!hdr)
+ return FLOW_DISSECT_RET_OUT_BAD;
+
+ /* Only look inside GRE without routing */
+ if (hdr->flags & GRE_ROUTING)
+ return FLOW_DISSECT_RET_OUT_GOOD;
+
+ /* Only look inside GRE for version 0 and 1 */
+ gre_ver = ntohs(hdr->flags & GRE_VERSION);
+ if (gre_ver > 1)
+ return FLOW_DISSECT_RET_OUT_GOOD;
+
+ *p_proto = hdr->protocol;
+ if (gre_ver) {
+ /* Version1 must be PPTP, and check the flags */
+ if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
+ return FLOW_DISSECT_RET_OUT_GOOD;
+ }
+
+ offset += sizeof(struct gre_base_hdr);
+
+ if (hdr->flags & GRE_CSUM)
+ offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
+ sizeof(((struct gre_full_hdr *) 0)->reserved1);
+
+ if (hdr->flags & GRE_KEY) {
+ const __be32 *keyid;
+ __be32 _keyid;
+
+ keyid = __skb_header_pointer(skb, *p_nhoff + offset,
+ sizeof(_keyid),
+ data, *p_hlen, &_keyid);
+ if (!keyid)
+ return FLOW_DISSECT_RET_OUT_BAD;
+
+ if (dissector_uses_key(flow_dissector,
+ FLOW_DISSECTOR_KEY_GRE_KEYID)) {
+ key_keyid = skb_flow_dissector_target(flow_dissector,
+ FLOW_DISSECTOR_KEY_GRE_KEYID,
+ target_container);
+ if (gre_ver == 0)
+ key_keyid->keyid = *keyid;
+ else
+ key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
+ }
+ offset += sizeof(((struct gre_full_hdr *) 0)->key);
+ }
+
+ if (hdr->flags & GRE_SEQ)
+ offset += sizeof(((struct pptp_gre_header *) 0)->seq);
+
+ if (gre_ver == 0) {
+ if (*p_proto == htons(ETH_P_TEB)) {
+ const struct ethhdr *eth;
+ struct ethhdr _eth;
+
+ eth = __skb_header_pointer(skb, *p_nhoff + offset,
+ sizeof(_eth),
+ data, *p_hlen, &_eth);
+ if (!eth)
+ return FLOW_DISSECT_RET_OUT_BAD;
+ *p_proto = eth->h_proto;
+ offset += sizeof(*eth);
+
+ /* Cap headers that we access via pointers at the
+ * end of the Ethernet header as our maximum alignment
+ * at that point is only 2 bytes.
+ */
+ if (NET_IP_ALIGN)
+ *p_hlen = *p_nhoff + offset;
+ }
+ } else { /* version 1, must be PPTP */
+ u8 _ppp_hdr[PPP_HDRLEN];
+ u8 *ppp_hdr;
+
+ if (hdr->flags & GRE_ACK)
+ offset += sizeof(((struct pptp_gre_header *) 0)->ack);
+
+ ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
+ sizeof(_ppp_hdr),
+ data, *p_hlen, _ppp_hdr);
+ if (!ppp_hdr)
+ return FLOW_DISSECT_RET_OUT_BAD;
+
+ switch (PPP_PROTOCOL(ppp_hdr)) {
+ case PPP_IP:
+ *p_proto = htons(ETH_P_IP);
+ break;
+ case PPP_IPV6:
+ *p_proto = htons(ETH_P_IPV6);
+ break;
+ default:
+ /* Could probably catch some more like MPLS */
+ break;
+ }
+
+ offset += PPP_HDRLEN;
+ }
+
+ *p_nhoff += offset;
+ key_control->flags |= FLOW_DIS_ENCAPSULATION;
+ if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
+ return FLOW_DISSECT_RET_OUT_GOOD;
+
+ return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;
+}
+
/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
@@ -229,7 +352,6 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
struct flow_dissector_key_icmp *key_icmp;
struct flow_dissector_key_tags *key_tags;
struct flow_dissector_key_vlan *key_vlan;
- struct flow_dissector_key_keyid *key_keyid;
bool skip_vlan = false;
u8 ip_proto = 0;
bool ret;
@@ -443,6 +565,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
case FLOW_DISSECT_RET_OUT_GOOD:
goto out_good;
case FLOW_DISSECT_RET_OUT_BAD:
+ default:
goto out_bad;
}
case htons(ETH_P_FCOE):
@@ -460,6 +583,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
case FLOW_DISSECT_RET_OUT_GOOD:
goto out_good;
case FLOW_DISSECT_RET_OUT_BAD:
+ default:
goto out_bad;
}
default:
@@ -468,117 +592,17 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
ip_proto_again:
switch (ip_proto) {
- case IPPROTO_GRE: {
- struct gre_base_hdr *hdr, _hdr;
- u16 gre_ver;
- int offset = 0;
-
- hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
- if (!hdr)
- goto out_bad;
-
- /* Only look inside GRE without routing */
- if (hdr->flags & GRE_ROUTING)
- goto out_good;
-
- /* Only look inside GRE for version 0 and 1 */
- gre_ver = ntohs(hdr->flags & GRE_VERSION);
- if (gre_ver > 1)
+ case IPPROTO_GRE:
+ switch (__skb_flow_dissect_gre(skb, key_control, flow_dissector,
+ target_container, data,
+ &proto, &nhoff, &hlen, flags)) {
+ case FLOW_DISSECT_RET_OUT_GOOD:
goto out_good;
-
- proto = hdr->protocol;
- if (gre_ver) {
- /* Version1 must be PPTP, and check the flags */
- if (!(proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
- goto out_good;
- }
-
- offset += sizeof(struct gre_base_hdr);
-
- if (hdr->flags & GRE_CSUM)
- offset += sizeof(((struct gre_full_hdr *)0)->csum) +
- sizeof(((struct gre_full_hdr *)0)->reserved1);
-
- if (hdr->flags & GRE_KEY) {
- const __be32 *keyid;
- __be32 _keyid;
-
- keyid = __skb_header_pointer(skb, nhoff + offset, sizeof(_keyid),
- data, hlen, &_keyid);
- if (!keyid)
- goto out_bad;
-
- if (dissector_uses_key(flow_dissector,
- FLOW_DISSECTOR_KEY_GRE_KEYID)) {
- key_keyid = skb_flow_dissector_target(flow_dissector,
- FLOW_DISSECTOR_KEY_GRE_KEYID,
- target_container);
- if (gre_ver == 0)
- key_keyid->keyid = *keyid;
- else
- key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
- }
- offset += sizeof(((struct gre_full_hdr *)0)->key);
- }
-
- if (hdr->flags & GRE_SEQ)
- offset += sizeof(((struct pptp_gre_header *)0)->seq);
-
- if (gre_ver == 0) {
- if (proto == htons(ETH_P_TEB)) {
- const struct ethhdr *eth;
- struct ethhdr _eth;
-
- eth = __skb_header_pointer(skb, nhoff + offset,
- sizeof(_eth),
- data, hlen, &_eth);
- if (!eth)
- goto out_bad;
- proto = eth->h_proto;
- offset += sizeof(*eth);
-
- /* Cap headers that we access via pointers at the
- * end of the Ethernet header as our maximum alignment
- * at that point is only 2 bytes.
- */
- if (NET_IP_ALIGN)
- hlen = (nhoff + offset);
- }
- } else { /* version 1, must be PPTP */
- u8 _ppp_hdr[PPP_HDRLEN];
- u8 *ppp_hdr;
-
- if (hdr->flags & GRE_ACK)
- offset += sizeof(((struct pptp_gre_header *)0)->ack);
-
- ppp_hdr = __skb_header_pointer(skb, nhoff + offset,
- sizeof(_ppp_hdr),
- data, hlen, _ppp_hdr);
- if (!ppp_hdr)
- goto out_bad;
-
- switch (PPP_PROTOCOL(ppp_hdr)) {
- case PPP_IP:
- proto = htons(ETH_P_IP);
- break;
- case PPP_IPV6:
- proto = htons(ETH_P_IPV6);
- break;
- default:
- /* Could probably catch some more like MPLS */
- break;
- }
-
- offset += PPP_HDRLEN;
+ case FLOW_DISSECT_RET_OUT_BAD:
+ goto out_bad;
+ case FLOW_DISSECT_RET_OUT_PROTO_AGAIN:
+ goto proto_again;
}
-
- nhoff += offset;
- key_control->flags |= FLOW_DIS_ENCAPSULATION;
- if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
- goto out_good;
-
- goto proto_again;
- }
case NEXTHDR_HOP:
case NEXTHDR_ROUTING:
case NEXTHDR_DEST: {
--
2.7.4
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