erspan: set bso bit based on mirrored packet's len

Before the patch, the erspan BSO bit (Bad/Short/Oversized) is not
handled.  BSO has 4 possible values:
  00 --> Good frame with no error, or unknown integrity
  11 --> Payload is a Bad Frame with CRC or Alignment Error
  01 --> Payload is a Short Frame
  10 --> Payload is an Oversized Frame

Based the short/oversized definitions in RFC1757, the patch sets
the bso bit based on the mirrored packet's size.

Reported-by: Xiaoyan Jin <xiaoyanj@vmware.com>
Signed-off-by: William Tu <u9012063@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
William Tu 2018-05-18 19:41:01 -07:00 committed by David S. Miller
parent 2c71ab4bb4
commit d48f1958ab
1 changed files with 28 additions and 0 deletions

View File

@ -219,6 +219,33 @@ static inline __be32 erspan_get_timestamp(void)
return htonl((u32)h_usecs);
}
/* ERSPAN BSO (Bad/Short/Oversized), see RFC1757
* 00b --> Good frame with no error, or unknown integrity
* 01b --> Payload is a Short Frame
* 10b --> Payload is an Oversized Frame
* 11b --> Payload is a Bad Frame with CRC or Alignment Error
*/
enum erspan_bso {
BSO_NOERROR = 0x0,
BSO_SHORT = 0x1,
BSO_OVERSIZED = 0x2,
BSO_BAD = 0x3,
};
static inline u8 erspan_detect_bso(struct sk_buff *skb)
{
/* BSO_BAD is not handled because the frame CRC
* or alignment error information is in FCS.
*/
if (skb->len < ETH_ZLEN)
return BSO_SHORT;
if (skb->len > ETH_FRAME_LEN)
return BSO_OVERSIZED;
return BSO_NOERROR;
}
static inline void erspan_build_header_v2(struct sk_buff *skb,
u32 id, u8 direction, u16 hwid,
bool truncate, bool is_ipv4)
@ -248,6 +275,7 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
vlan_tci = ntohs(qp->tci);
}
bso = erspan_detect_bso(skb);
skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
ershdr = (struct erspan_base_hdr *)skb->data;
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);