ure: improve transmit checksum offloading

Apparently, the name of the variable l4off was correct. Providing the
offset to the TCP or UDP header allows the transmit checksum offload to
work for TCP/IPv4, TCP/IPv6, UDP/IPv4, and UDP/IPv6.

Reported by:		vishwin
Reviewed by:		vishwin
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D55187

1 files changed, 10 insertions, 6 deletions

diff --git a/sys/dev/usb/net/if_ure.c b/sys/dev/usb/net/if_ure.c
index 3dea88eb10f1..92160fe9b1d2 100644
--- a/sys/dev/usb/net/if_ure.c
+++ b/sys/dev/usb/net/if_ure.c
@@ -24,6 +24,8 @@
  * SUCH DAMAGE.
  */
 
+#include "opt_inet6.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bus.h>
@@ -44,6 +46,10 @@
 /* needed for checksum offload */
 #include <netinet/in.h>
 #include <netinet/ip.h>
+#ifdef INET6
+#include <netinet/ip6.h>
+#include <netinet6/ip6_var.h>
+#endif
 
 #include <dev/mii/mii.h>
 #include <dev/mii/miivar.h>
@@ -62,8 +68,6 @@
 
 #include "miibus_if.h"
 
-#include "opt_inet6.h"
-
 #ifdef USB_DEBUG
 static int ure_debug = 0;
 
@@ -2179,7 +2183,6 @@ ure_txcsum(struct mbuf *m, int caps, uint32_t *regout)
 	struct ip ip;
 	struct ether_header *eh;
 	int flags;
-	uint32_t data;
 	uint32_t reg;
 	int l3off, l4off;
 	uint16_t type;
@@ -2214,10 +2217,9 @@ ure_txcsum(struct mbuf *m, int caps, uint32_t *regout)
 	if (flags & CSUM_IP)
 		reg |= URE_TXPKT_IPV4_CS;
 
-	data = m->m_pkthdr.csum_data;
 	if (flags & (CSUM_IP_TCP | CSUM_IP_UDP)) {
 		m_copydata(m, l3off, sizeof ip, (caddr_t)&ip);
-		l4off = l3off + (ip.ip_hl << 2) + data;
+		l4off = l3off + (ip.ip_hl << 2);
 		if (__predict_false(l4off > URE_L4_OFFSET_MAX))
 			return (1);
 
@@ -2230,7 +2232,9 @@ ure_txcsum(struct mbuf *m, int caps, uint32_t *regout)
 	}
 #ifdef INET6
 	else if (flags & (CSUM_IP6_TCP | CSUM_IP6_UDP)) {
-		l4off = l3off + data;
+		l4off = ip6_lasthdr(m, l3off, IPPROTO_IPV6, NULL);
+		if (__predict_false(l4off < 0))
+			return (1);
 		if (__predict_false(l4off > URE_L4_OFFSET_MAX))
 			return (1);