diff mbox series

[net-next,1/4] virtio-net: a helper for probing the pseudo-header checksum

Message ID 20230619105738.117733-2-hengqi@linux.alibaba.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series virtio-net: avoid XDP and _F_GUEST_CSUM | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 8 this patch: 9
netdev/cc_maintainers warning 1 maintainers not CCed: virtualization@lists.linux-foundation.org
netdev/build_clang fail Errors and warnings before: 8 this patch: 10
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 8 this patch: 9
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns WARNING: line length of 85 exceeds 80 columns WARNING: line length of 86 exceeds 80 columns WARNING: line length of 88 exceeds 80 columns WARNING: line length of 91 exceeds 80 columns WARNING: line length of 92 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Heng Qi June 19, 2023, 10:57 a.m. UTC 
This helper parses UDP/TCP and calculates the pseudo-header checksum
for virtio-net.

virtio-net currently does not support insertion/deletion of VLANs nor
SCTP checksum offloading.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 95 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

Comments

kernel test robot June 19, 2023, 12:30 p.m. UTC | #1 
Hi Heng,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Heng-Qi/virtio-net-a-helper-for-probing-the-pseudo-header-checksum/20230619-190212
base:   net-next/main
patch link:    https://lore.kernel.org/r/20230619105738.117733-2-hengqi%40linux.alibaba.com
patch subject: [PATCH net-next 1/4] virtio-net: a helper for probing the pseudo-header checksum
config: x86_64-randconfig-r014-20230619 (https://download.01.org/0day-ci/archive/20230619/202306192049.8y7DR5F1-lkp@intel.com/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project.git 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce: (https://download.01.org/0day-ci/archive/20230619/202306192049.8y7DR5F1-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306192049.8y7DR5F1-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/net/virtio_net.c:1648:17: error: call to undeclared function 'csum_ipv6_magic'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
                           uh->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
                                        ^
   drivers/net/virtio_net.c:1648:17: note: did you mean 'csum_tcpudp_magic'?
   include/asm-generic/checksum.h:52:1: note: 'csum_tcpudp_magic' declared here
   csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
   ^
   drivers/net/virtio_net.c:1657:17: error: call to undeclared function 'csum_ipv6_magic'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
                           th->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
                                        ^
   2 errors generated.


vim +/csum_ipv6_magic +1648 drivers/net/virtio_net.c

  1572	
  1573	static int virtnet_flow_dissect_udp_tcp(struct virtnet_info *vi, struct sk_buff *skb)
  1574	{
  1575		struct net_device *dev = vi->dev;
  1576		struct flow_keys_basic keys;
  1577		struct udphdr *uh;
  1578		struct tcphdr *th;
  1579		int len, offset;
  1580	
  1581		/* The flow dissector needs this information. */
  1582		skb->dev = dev;
  1583		skb_reset_mac_header(skb);
  1584		skb->protocol = dev_parse_header_protocol(skb);
  1585		/* virtio-net does not need to resolve VLAN. */
  1586		skb_set_network_header(skb, ETH_HLEN);
  1587		if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
  1588						      NULL, 0, 0, 0, 0))
  1589			return -EINVAL;
  1590	
  1591		/* 1. Pseudo-header checksum calculation requires:
  1592		 *    (1) saddr/daddr (2) IP_PROTO (3) length of transport payload
  1593		 * 2. We don't parse SCTP because virtio-net currently doesn't
  1594		 *    support CRC offloading for SCTP.
  1595		 */
  1596		if (keys.basic.n_proto == htons(ETH_P_IP)) {
  1597			struct iphdr *iph;
  1598	
  1599			/* Flow dissector has verified that there is an IP header. */
  1600			iph = ip_hdr(skb);
  1601			if (iph->version != 4 || !pskb_may_pull(skb, iph->ihl * 4))
  1602				return -EINVAL;
  1603	
  1604			skb->transport_header = skb->mac_header + keys.control.thoff;
  1605			offset = skb_transport_offset(skb);
  1606			len = skb->len - offset;
  1607			if (keys.basic.ip_proto == IPPROTO_UDP) {
  1608				if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
  1609					return -EINVAL;
  1610	
  1611				uh = udp_hdr(skb);
  1612				skb->csum_offset = offsetof(struct udphdr, check);
  1613				/* Although uh->len is already the 3rd parameter for the calculation
  1614				 * of the pseudo-header checksum, we have already calculated the
  1615				 * length of the transport layer, so use 'len' here directly.
  1616				 */
  1617				uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
  1618						IPPROTO_UDP, 0);
  1619			} else if (keys.basic.ip_proto == IPPROTO_TCP) {
  1620				if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
  1621					return -EINVAL;
  1622	
  1623				th = tcp_hdr(skb);
  1624				skb->csum_offset = offsetof(struct tcphdr, check);
  1625				th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
  1626						IPPROTO_TCP, 0);
  1627			} /* virtio-net doesn't support checksums for SCTP hw offloading.*/
  1628		} else if (keys.basic.n_proto == htons(ETH_P_IPV6)) {
  1629			struct ipv6hdr *ip6h;
  1630	
  1631			ip6h = ipv6_hdr(skb);
  1632			if (ip6h->version != 6)
  1633				return -EINVAL;
  1634	
  1635			/* We have skipped the possible extension headers for IPv6.
  1636			 * If there is a Routing Header, the tx's check value is calculated by
  1637			 * final_dst, and that value is the rx's daddr.
  1638			 */
  1639			skb->transport_header = skb->mac_header + keys.control.thoff;
  1640			offset = skb_transport_offset(skb);
  1641			len = skb->len - offset;
  1642			if (keys.basic.ip_proto == IPPROTO_UDP) {
  1643				if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
  1644					return -EINVAL;
  1645	
  1646				uh = udp_hdr(skb);
  1647				skb->csum_offset = offsetof(struct udphdr, check);
> 1648				uh->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
  1649						(const struct in6_addr *)&ip6h->daddr,
  1650						len, IPPROTO_UDP, 0);
  1651			} else if (keys.basic.ip_proto == IPPROTO_TCP) {
  1652				if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
  1653					return -EINVAL;
  1654	
  1655				th = tcp_hdr(skb);
  1656				skb->csum_offset = offsetof(struct tcphdr, check);
  1657				th->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
  1658						(const struct in6_addr *)&ip6h->daddr,
  1659						len, IPPROTO_TCP, 0);
  1660			}
  1661		}
  1662	
  1663		skb->csum_start = skb->transport_header;
  1664	
  1665		return 0;
  1666	}
  1667
kernel test robot June 19, 2023, 12:30 p.m. UTC | #2 
Hi Heng,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Heng-Qi/virtio-net-a-helper-for-probing-the-pseudo-header-checksum/20230619-190212
base:   net-next/main
patch link:    https://lore.kernel.org/r/20230619105738.117733-2-hengqi%40linux.alibaba.com
patch subject: [PATCH net-next 1/4] virtio-net: a helper for probing the pseudo-header checksum
config: m68k-randconfig-r021-20230619 (https://download.01.org/0day-ci/archive/20230619/202306192049.l2eaZ7od-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230619/202306192049.l2eaZ7od-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306192049.l2eaZ7od-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/net/virtio_net.c: In function 'virtnet_flow_dissect_udp_tcp':
>> drivers/net/virtio_net.c:1648:38: error: implicit declaration of function 'csum_ipv6_magic'; did you mean 'csum_tcpudp_magic'? [-Werror=implicit-function-declaration]
    1648 |                         uh->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
         |                                      ^~~~~~~~~~~~~~~
         |                                      csum_tcpudp_magic
   drivers/net/virtio_net.c: At top level:
   drivers/net/virtio_net.c:1573:12: warning: 'virtnet_flow_dissect_udp_tcp' defined but not used [-Wunused-function]
    1573 | static int virtnet_flow_dissect_udp_tcp(struct virtnet_info *vi, struct sk_buff *skb)
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +1648 drivers/net/virtio_net.c

  1572	
  1573	static int virtnet_flow_dissect_udp_tcp(struct virtnet_info *vi, struct sk_buff *skb)
  1574	{
  1575		struct net_device *dev = vi->dev;
  1576		struct flow_keys_basic keys;
  1577		struct udphdr *uh;
  1578		struct tcphdr *th;
  1579		int len, offset;
  1580	
  1581		/* The flow dissector needs this information. */
  1582		skb->dev = dev;
  1583		skb_reset_mac_header(skb);
  1584		skb->protocol = dev_parse_header_protocol(skb);
  1585		/* virtio-net does not need to resolve VLAN. */
  1586		skb_set_network_header(skb, ETH_HLEN);
  1587		if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
  1588						      NULL, 0, 0, 0, 0))
  1589			return -EINVAL;
  1590	
  1591		/* 1. Pseudo-header checksum calculation requires:
  1592		 *    (1) saddr/daddr (2) IP_PROTO (3) length of transport payload
  1593		 * 2. We don't parse SCTP because virtio-net currently doesn't
  1594		 *    support CRC offloading for SCTP.
  1595		 */
  1596		if (keys.basic.n_proto == htons(ETH_P_IP)) {
  1597			struct iphdr *iph;
  1598	
  1599			/* Flow dissector has verified that there is an IP header. */
  1600			iph = ip_hdr(skb);
  1601			if (iph->version != 4 || !pskb_may_pull(skb, iph->ihl * 4))
  1602				return -EINVAL;
  1603	
  1604			skb->transport_header = skb->mac_header + keys.control.thoff;
  1605			offset = skb_transport_offset(skb);
  1606			len = skb->len - offset;
  1607			if (keys.basic.ip_proto == IPPROTO_UDP) {
  1608				if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
  1609					return -EINVAL;
  1610	
  1611				uh = udp_hdr(skb);
  1612				skb->csum_offset = offsetof(struct udphdr, check);
  1613				/* Although uh->len is already the 3rd parameter for the calculation
  1614				 * of the pseudo-header checksum, we have already calculated the
  1615				 * length of the transport layer, so use 'len' here directly.
  1616				 */
  1617				uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
  1618						IPPROTO_UDP, 0);
  1619			} else if (keys.basic.ip_proto == IPPROTO_TCP) {
  1620				if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
  1621					return -EINVAL;
  1622	
  1623				th = tcp_hdr(skb);
  1624				skb->csum_offset = offsetof(struct tcphdr, check);
  1625				th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
  1626						IPPROTO_TCP, 0);
  1627			} /* virtio-net doesn't support checksums for SCTP hw offloading.*/
  1628		} else if (keys.basic.n_proto == htons(ETH_P_IPV6)) {
  1629			struct ipv6hdr *ip6h;
  1630	
  1631			ip6h = ipv6_hdr(skb);
  1632			if (ip6h->version != 6)
  1633				return -EINVAL;
  1634	
  1635			/* We have skipped the possible extension headers for IPv6.
  1636			 * If there is a Routing Header, the tx's check value is calculated by
  1637			 * final_dst, and that value is the rx's daddr.
  1638			 */
  1639			skb->transport_header = skb->mac_header + keys.control.thoff;
  1640			offset = skb_transport_offset(skb);
  1641			len = skb->len - offset;
  1642			if (keys.basic.ip_proto == IPPROTO_UDP) {
  1643				if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
  1644					return -EINVAL;
  1645	
  1646				uh = udp_hdr(skb);
  1647				skb->csum_offset = offsetof(struct udphdr, check);
> 1648				uh->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
  1649						(const struct in6_addr *)&ip6h->daddr,
  1650						len, IPPROTO_UDP, 0);
  1651			} else if (keys.basic.ip_proto == IPPROTO_TCP) {
  1652				if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
  1653					return -EINVAL;
  1654	
  1655				th = tcp_hdr(skb);
  1656				skb->csum_offset = offsetof(struct tcphdr, check);
  1657				th->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
  1658						(const struct in6_addr *)&ip6h->daddr,
  1659						len, IPPROTO_TCP, 0);
  1660			}
  1661		}
  1662	
  1663		skb->csum_start = skb->transport_header;
  1664	
  1665		return 0;
  1666	}
  1667
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5a7f7a76b920..36cae78f6311 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1568,6 +1568,101 @@  static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash *hdr_hash,
 	skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type);
 }
 
+static int virtnet_flow_dissect_udp_tcp(struct virtnet_info *vi, struct sk_buff *skb)
+{
+	struct net_device *dev = vi->dev;
+	struct flow_keys_basic keys;
+	struct udphdr *uh;
+	struct tcphdr *th;
+	int len, offset;
+
+	/* The flow dissector needs this information. */
+	skb->dev = dev;
+	skb_reset_mac_header(skb);
+	skb->protocol = dev_parse_header_protocol(skb);
+	/* virtio-net does not need to resolve VLAN. */
+	skb_set_network_header(skb, ETH_HLEN);
+	if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
+					      NULL, 0, 0, 0, 0))
+		return -EINVAL;
+
+	/* 1. Pseudo-header checksum calculation requires:
+	 *    (1) saddr/daddr (2) IP_PROTO (3) length of transport payload
+	 * 2. We don't parse SCTP because virtio-net currently doesn't
+	 *    support CRC offloading for SCTP.
+	 */
+	if (keys.basic.n_proto == htons(ETH_P_IP)) {
+		struct iphdr *iph;
+
+		/* Flow dissector has verified that there is an IP header. */
+		iph = ip_hdr(skb);
+		if (iph->version != 4 || !pskb_may_pull(skb, iph->ihl * 4))
+			return -EINVAL;
+
+		skb->transport_header = skb->mac_header + keys.control.thoff;
+		offset = skb_transport_offset(skb);
+		len = skb->len - offset;
+		if (keys.basic.ip_proto == IPPROTO_UDP) {
+			if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
+				return -EINVAL;
+
+			uh = udp_hdr(skb);
+			skb->csum_offset = offsetof(struct udphdr, check);
+			/* Although uh->len is already the 3rd parameter for the calculation
+			 * of the pseudo-header checksum, we have already calculated the
+			 * length of the transport layer, so use 'len' here directly.
+			 */
+			uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
+					IPPROTO_UDP, 0);
+		} else if (keys.basic.ip_proto == IPPROTO_TCP) {
+			if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
+				return -EINVAL;
+
+			th = tcp_hdr(skb);
+			skb->csum_offset = offsetof(struct tcphdr, check);
+			th->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, len,
+					IPPROTO_TCP, 0);
+		} /* virtio-net doesn't support checksums for SCTP hw offloading.*/
+	} else if (keys.basic.n_proto == htons(ETH_P_IPV6)) {
+		struct ipv6hdr *ip6h;
+
+		ip6h = ipv6_hdr(skb);
+		if (ip6h->version != 6)
+			return -EINVAL;
+
+		/* We have skipped the possible extension headers for IPv6.
+		 * If there is a Routing Header, the tx's check value is calculated by
+		 * final_dst, and that value is the rx's daddr.
+		 */
+		skb->transport_header = skb->mac_header + keys.control.thoff;
+		offset = skb_transport_offset(skb);
+		len = skb->len - offset;
+		if (keys.basic.ip_proto == IPPROTO_UDP) {
+			if (!pskb_may_pull(skb, offset + sizeof(struct udphdr)))
+				return -EINVAL;
+
+			uh = udp_hdr(skb);
+			skb->csum_offset = offsetof(struct udphdr, check);
+			uh->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
+					(const struct in6_addr *)&ip6h->daddr,
+					len, IPPROTO_UDP, 0);
+		} else if (keys.basic.ip_proto == IPPROTO_TCP) {
+			if (!pskb_may_pull(skb, offset + sizeof(struct tcphdr)))
+				return -EINVAL;
+
+			th = tcp_hdr(skb);
+			skb->csum_offset = offsetof(struct tcphdr, check);
+			th->check = ~csum_ipv6_magic((const struct in6_addr *)&ip6h->saddr,
+					(const struct in6_addr *)&ip6h->daddr,
+					len, IPPROTO_TCP, 0);
+		}
+	}
+
+	skb->csum_start = skb->transport_header;
+
+	return 0;
+}
+
 static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq,
 			void *buf, unsigned int len, void **ctx,
 			unsigned int *xdp_xmit,