From: Asias He <asias.hejun@gmail.com>
Date: Wed, 29 Jun 2011 08:47:24 +0000 (+0800)
Subject: kvm tools: Implement uip_csum_tcp() to calculate TCP checksum
X-Git-Tag: next-20110824~3^2~168
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=68c44a69719bb50d971acd8b365d7d87e3ca6e3f;p=karo-tx-linux.git

kvm tools: Implement uip_csum_tcp() to calculate TCP checksum

Signed-off-by: Asias He <asias.hejun@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
---

diff --git a/tools/kvm/include/kvm/uip.h b/tools/kvm/include/kvm/uip.h
index 46cec2096d1a..37c87c697b26 100644
--- a/tools/kvm/include/kvm/uip.h
+++ b/tools/kvm/include/kvm/uip.h
@@ -28,8 +28,10 @@
 /*
  * IP package maxium len == 64 KBytes
  * IP header == 20 Bytes
+ * TCP header == 20 Bytes
  * UDP header == 8 Bytes
  */
+#define UIP_MAX_TCP_PAYLOAD	(64*1024 - 20 - 20 - 1)
 #define UIP_MAX_UDP_PAYLOAD	(64*1024 - 20 -  8 - 1)
 
 struct uip_eth_addr {
@@ -269,6 +271,7 @@ int uip_tx_do_arp(struct uip_tx_arg *arg);
 
 u16 uip_csum_icmp(struct uip_icmp *icmp);
 u16 uip_csum_udp(struct uip_udp *udp);
+u16 uip_csum_tcp(struct uip_tcp *tcp);
 u16 uip_csum_ip(struct uip_ip *ip);
 
 struct uip_buf *uip_buf_set_used(struct uip_info *info, struct uip_buf *buf);
diff --git a/tools/kvm/uip/csum.c b/tools/kvm/uip/csum.c
index a152a0f85372..7ca8badaaeee 100644
--- a/tools/kvm/uip/csum.c
+++ b/tools/kvm/uip/csum.c
@@ -60,3 +60,33 @@ u16 uip_csum_udp(struct uip_udp *udp)
 	}
 
 }
+
+u16 uip_csum_tcp(struct uip_tcp *tcp)
+{
+	struct uip_pseudo_hdr hdr;
+	struct uip_ip *ip;
+	u16 tcp_len;
+	u8 *pad;
+
+	ip	  = &tcp->ip;
+	tcp_len   = ntohs(ip->len) - uip_ip_hdrlen(ip);
+
+	hdr.sip   = ip->sip;
+	hdr.dip	  = ip->dip;
+	hdr.zero  = 0;
+	hdr.proto = ip->proto;
+	hdr.len   = htons(tcp_len);
+
+	if (tcp_len > UIP_MAX_TCP_PAYLOAD + 20)
+		pr_warning("tcp_len(%d) is too large", tcp_len);
+
+	if (tcp_len % 2) {
+		pad = (u8 *)&tcp->sport + tcp_len;
+		*pad = 0;
+		memcpy((u8 *)&tcp->sport + tcp_len + 1, &hdr, sizeof(hdr));
+		return uip_csum(0, (u8 *)&tcp->sport, tcp_len + 1 + sizeof(hdr));
+	} else {
+		memcpy((u8 *)&tcp->sport + tcp_len, &hdr, sizeof(hdr));
+		return uip_csum(0, (u8 *)&tcp->sport, tcp_len + sizeof(hdr));
+	}
+}