socsvn commit: r305832 - soc2016/vincenzo/head/sys/dev/netmap

vincenzo at FreeBSD.org vincenzo at FreeBSD.org
Fri Jul 8 15:44:55 UTC 2016


Author: vincenzo
Date: Fri Jul  8 15:44:54 2016
New Revision: 305832
URL: http://svnweb.FreeBSD.org/socsvn/?view=rev&rev=305832

Log:
   freebsd: ptnet_rx_eof: process checksumming offloadings

Modified:
  soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c

Modified: soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c
==============================================================================
--- soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c	Fri Jul  8 15:44:45 2016	(r305831)
+++ soc2016/vincenzo/head/sys/dev/netmap/if_ptnet.c	Fri Jul  8 15:44:54 2016	(r305832)
@@ -63,6 +63,7 @@
 #include <netinet6/ip6_var.h>
 #include <netinet/udp.h>
 #include <netinet/tcp.h>
+#include <netinet/sctp.h>
 
 #include <machine/bus.h>
 #include <machine/resource.h>
@@ -1495,22 +1496,6 @@
 	return 0;
 }
 
-/* This function should be shared with the virtio-net driver. */
-static void
-ptnet_vlan_tag_remove(struct mbuf *m)
-{
-	struct ether_vlan_header *evh;
-
-	evh = mtod(m, struct ether_vlan_header *);
-	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
-	m->m_flags |= M_VLANTAG;
-
-	/* Strip the 802.1Q header. */
-	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
-	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
-	m_adj(m, ETHER_VLAN_ENCAP_LEN);
-}
-
 static int
 ptnet_transmit(struct ifnet *ifp, struct mbuf *m)
 {
@@ -1551,6 +1536,180 @@
 	return ptnet_drain_transmit_queue(pq);
 }
 
+/* This function should be shared with the virtio-net driver. */
+static void
+ptnet_vlan_tag_remove(struct mbuf *m)
+{
+	struct ether_vlan_header *evh;
+
+	evh = mtod(m, struct ether_vlan_header *);
+	m->m_pkthdr.ether_vtag = ntohs(evh->evl_tag);
+	m->m_flags |= M_VLANTAG;
+
+	/* Strip the 802.1Q header. */
+	bcopy((char *) evh, (char *) evh + ETHER_VLAN_ENCAP_LEN,
+	    ETHER_HDR_LEN - ETHER_TYPE_LEN);
+	m_adj(m, ETHER_VLAN_ENCAP_LEN);
+}
+
+/*
+ * Use the checksum offset in the VirtIO header to set the
+ * correct CSUM_* flags.
+ */
+static int
+ptnet_rx_csum_by_offset(struct mbuf *m, uint16_t eth_type, int ip_start,
+			struct virtio_net_hdr *hdr)
+{
+#if defined(INET) || defined(INET6)
+	int offset = hdr->csum_start + hdr->csum_offset;
+#endif
+
+	/* Only do a basic sanity check on the offset. */
+	switch (eth_type) {
+#if defined(INET)
+	case ETHERTYPE_IP:
+		if (__predict_false(offset < ip_start + sizeof(struct ip)))
+			return (1);
+		break;
+#endif
+#if defined(INET6)
+	case ETHERTYPE_IPV6:
+		if (__predict_false(offset < ip_start + sizeof(struct ip6_hdr)))
+			return (1);
+		break;
+#endif
+	default:
+		/* Here we should increment the rx_csum_bad_ethtype counter. */
+		return (1);
+	}
+
+	/*
+	 * Use the offset to determine the appropriate CSUM_* flags. This is
+	 * a bit dirty, but we can get by with it since the checksum offsets
+	 * happen to be different. We assume the host host does not do IPv4
+	 * header checksum offloading.
+	 */
+	switch (hdr->csum_offset) {
+	case offsetof(struct udphdr, uh_sum):
+	case offsetof(struct tcphdr, th_sum):
+		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
+		m->m_pkthdr.csum_data = 0xFFFF;
+		break;
+	case offsetof(struct sctphdr, checksum):
+		m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
+		break;
+	default:
+		/* Here we should increment the rx_csum_bad_offset counter. */
+		return (1);
+	}
+
+	return (0);
+}
+
+static int
+ptnet_rx_csum_by_parse(struct mbuf *m, uint16_t eth_type, int ip_start,
+		       struct virtio_net_hdr *hdr)
+{
+	int offset, proto;
+
+	switch (eth_type) {
+#if defined(INET)
+	case ETHERTYPE_IP: {
+		struct ip *ip;
+		if (__predict_false(m->m_len < ip_start + sizeof(struct ip)))
+			return (1);
+		ip = (struct ip *)(m->m_data + ip_start);
+		proto = ip->ip_p;
+		offset = ip_start + (ip->ip_hl << 2);
+		break;
+	}
+#endif
+#if defined(INET6)
+	case ETHERTYPE_IPV6:
+		if (__predict_false(m->m_len < ip_start +
+		    sizeof(struct ip6_hdr)))
+			return (1);
+		offset = ip6_lasthdr(m, ip_start, IPPROTO_IPV6, &proto);
+		if (__predict_false(offset < 0))
+			return (1);
+		break;
+#endif
+	default:
+		/* Here we should increment the rx_csum_bad_ethtype counter. */
+		return (1);
+	}
+
+	switch (proto) {
+	case IPPROTO_TCP:
+		if (__predict_false(m->m_len < offset + sizeof(struct tcphdr)))
+			return (1);
+		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
+		m->m_pkthdr.csum_data = 0xFFFF;
+		break;
+	case IPPROTO_UDP:
+		if (__predict_false(m->m_len < offset + sizeof(struct udphdr)))
+			return (1);
+		m->m_pkthdr.csum_flags |= CSUM_DATA_VALID | CSUM_PSEUDO_HDR;
+		m->m_pkthdr.csum_data = 0xFFFF;
+		break;
+	case IPPROTO_SCTP:
+		if (__predict_false(m->m_len < offset + sizeof(struct sctphdr)))
+			return (1);
+		m->m_pkthdr.csum_flags |= CSUM_SCTP_VALID;
+		break;
+	default:
+		/*
+		 * For the remaining protocols, FreeBSD does not support
+		 * checksum offloading, so the checksum will be recomputed.
+		 */
+#if 0
+		if_printf(ifp, "cksum offload of unsupported "
+		    "protocol eth_type=%#x proto=%d csum_start=%d "
+		    "csum_offset=%d\n", __func__, eth_type, proto,
+		    hdr->csum_start, hdr->csum_offset);
+#endif
+		break;
+	}
+
+	return (0);
+}
+
+/*
+ * Set the appropriate CSUM_* flags. Unfortunately, the information
+ * provided is not directly useful to us. The VirtIO header gives the
+ * offset of the checksum, which is all Linux needs, but this is not
+ * how FreeBSD does things. We are forced to peek inside the packet
+ * a bit.
+ *
+ * It would be nice if VirtIO gave us the L4 protocol or if FreeBSD
+ * could accept the offsets and let the stack figure it out.
+ */
+static int
+ptnet_rx_csum(struct mbuf *m, struct virtio_net_hdr *hdr)
+{
+	struct ether_header *eh;
+	struct ether_vlan_header *evh;
+	uint16_t eth_type;
+	int offset, error;
+
+	eh = mtod(m, struct ether_header *);
+	eth_type = ntohs(eh->ether_type);
+	if (eth_type == ETHERTYPE_VLAN) {
+		/* BMV: We should handle nested VLAN tags too. */
+		evh = mtod(m, struct ether_vlan_header *);
+		eth_type = ntohs(evh->evl_proto);
+		offset = sizeof(struct ether_vlan_header);
+	} else
+		offset = sizeof(struct ether_header);
+
+	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
+		error = ptnet_rx_csum_by_offset(m, eth_type, offset, hdr);
+	else
+		error = ptnet_rx_csum_by_parse(m, eth_type, offset, hdr);
+
+	return (error);
+}
+
 static unsigned int
 ptnet_rx_discard(struct netmap_kring *kring, unsigned int head)
 {
@@ -1764,6 +1923,11 @@
 			}
 		}
 
+		if (have_vnet_hdr && (vh->flags & (VIRTIO_NET_HDR_F_NEEDS_CSUM
+					| VIRTIO_NET_HDR_F_DATA_VALID))) {
+			ptnet_rx_csum(mhead, vh);
+		}
+
 		PTNET_Q_UNLOCK(pq);
 		(*ifp->if_input)(ifp, mhead);
 		PTNET_Q_LOCK(pq);


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