From d48f1958ab7d9fb896d86f0241f0dc83dc3a63de Mon Sep 17 00:00:00 2001 From: William Tu Date: Fri, 18 May 2018 19:41:01 -0700 Subject: [PATCH] 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 Signed-off-by: William Tu Signed-off-by: David S. Miller --- include/net/erspan.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/include/net/erspan.h b/include/net/erspan.h index d044aa60cc76..b39643ef4c95 100644 --- a/include/net/erspan.h +++ b/include/net/erspan.h @@ -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);