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Commit 7c92de8e authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
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flow_dissector: Move GRE dissection into a separate function 

Make the main flow_dissect function a bit smaller and move the GRE
dissection into a separate function.
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c5ef188e
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Showing with 134 additions and 110 deletions
net/core/flow_dissector.c
View file @ 7c92de8e
......@@ -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: {
......
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