netdev - [PATCH net-next] erspan: set bso bit based on mirrored packet's len

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1526342076-43714-1-git-send-email-u9012063@gmail.com>
Date:   Mon, 14 May 2018 16:54:36 -0700
From:   William Tu <u9012063@...il.com>
To:     netdev@...r.kernel.org
Subject: [PATCH net-next] 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@...are.com>
Signed-off-by: William Tu <u9012063@...il.com>
---
 include/net/erspan.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/net/erspan.h b/include/net/erspan.h
index d044aa60cc76..5eb95f78ad45 100644
--- a/include/net/erspan.h
+++ b/include/net/erspan.h
@@ -219,6 +219,30 @@ static inline __be32 erspan_get_timestamp(void)
 	return htonl((u32)h_usecs);
 }
 
+/* ERSPAN BSO (Bad/Short/Oversized)
+ *   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,
+	BSO_SHORT,
+	BSO_OVERSIZED,
+	BSO_BAD,
+};
+
+static inline u8 erspan_detect_bso(struct sk_buff *skb)
+{
+	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 +272,7 @@ 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);
-- 
2.7.4