#include <linux/compat.h>
#include "openvswitch/datapath-protocol.h"
+#include "checksum.h"
#include "datapath.h"
#include "actions.h"
#include "flow.h"
local_bh_enable();
}
-#if defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID)
-/* This code is based on skb_checksum_setup() from Xen's net/dev/core.c. We
- * can't call this function directly because it isn't exported in all
- * versions. */
-int vswitch_skb_checksum_setup(struct sk_buff *skb)
-{
- struct iphdr *iph;
- unsigned char *th;
- int err = -EPROTO;
- __u16 csum_start, csum_offset;
-
- if (!skb->proto_csum_blank)
- return 0;
-
- if (skb->protocol != htons(ETH_P_IP))
- goto out;
-
- if (!pskb_may_pull(skb, skb_network_header(skb) + sizeof(struct iphdr) - skb->data))
- goto out;
-
- iph = ip_hdr(skb);
- th = skb_network_header(skb) + 4 * iph->ihl;
-
- csum_start = th - skb->head;
- switch (iph->protocol) {
- case IPPROTO_TCP:
- csum_offset = offsetof(struct tcphdr, check);
- break;
- case IPPROTO_UDP:
- csum_offset = offsetof(struct udphdr, check);
- break;
- default:
- if (net_ratelimit())
- pr_err("Attempting to checksum a non-TCP/UDP packet, "
- "dropping a protocol %d packet",
- iph->protocol);
- goto out;
- }
-
- if (!pskb_may_pull(skb, th + csum_offset + 2 - skb->data))
- goto out;
-
- skb->ip_summed = CHECKSUM_PARTIAL;
- skb->proto_csum_blank = 0;
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
- skb->csum_start = csum_start;
- skb->csum_offset = csum_offset;
-#else
- skb_set_transport_header(skb, csum_start - skb_headroom(skb));
- skb->csum = csum_offset;
-#endif
-
- err = 0;
-
-out:
- return err;
-}
-#endif /* CONFIG_XEN && HAVE_PROTO_DATA_VALID */
-
- /* Types of checksums that we can receive (these all refer to L4 checksums):
- * 1. CHECKSUM_NONE: Device that did not compute checksum, contains full
- * (though not verified) checksum in packet but not in skb->csum. Packets
- * from the bridge local port will also have this type.
- * 2. CHECKSUM_COMPLETE (CHECKSUM_HW): Good device that computes checksums,
- * also the GRE module. This is the same as CHECKSUM_NONE, except it has
- * a valid skb->csum. Importantly, both contain a full checksum (not
- * verified) in the packet itself. The only difference is that if the
- * packet gets to L4 processing on this machine (not in DomU) we won't
- * have to recompute the checksum to verify. Most hardware devices do not
- * produce packets with this type, even if they support receive checksum
- * offloading (they produce type #5).
- * 3. CHECKSUM_PARTIAL (CHECKSUM_HW): Packet without full checksum and needs to
- * be computed if it is sent off box. Unfortunately on earlier kernels,
- * this case is impossible to distinguish from #2, despite having opposite
- * meanings. Xen adds an extra field on earlier kernels (see #4) in order
- * to distinguish the different states.
- * 4. CHECKSUM_UNNECESSARY (with proto_csum_blank true): This packet was
- * generated locally by a Xen DomU and has a partial checksum. If it is
- * handled on this machine (Dom0 or DomU), then the checksum will not be
- * computed. If it goes off box, the checksum in the packet needs to be
- * completed. Calling skb_checksum_setup converts this to CHECKSUM_HW
- * (CHECKSUM_PARTIAL) so that the checksum can be completed. In later
- * kernels, this combination is replaced with CHECKSUM_PARTIAL.
- * 5. CHECKSUM_UNNECESSARY (with proto_csum_blank false): Packet with a correct
- * full checksum or using a protocol without a checksum. skb->csum is
- * undefined. This is common from devices with receive checksum
- * offloading. This is somewhat similar to CHECKSUM_NONE, except that
- * nobody will try to verify the checksum with CHECKSUM_UNNECESSARY.
- *
- * Note that on earlier kernels, CHECKSUM_COMPLETE and CHECKSUM_PARTIAL are
- * both defined as CHECKSUM_HW. Normally the meaning of CHECKSUM_HW is clear
- * based on whether it is on the transmit or receive path. After the datapath
- * it will be intepreted as CHECKSUM_PARTIAL. If the packet already has a
- * checksum, we will panic. Since we can receive packets with checksums, we
- * assume that all CHECKSUM_HW packets have checksums and map them to
- * CHECKSUM_NONE, which has a similar meaning (the it is only different if the
- * packet is processed by the local IP stack, in which case it will need to
- * be reverified). If we receive a packet with CHECKSUM_HW that really means
- * CHECKSUM_PARTIAL, it will be sent with the wrong checksum. However, there
- * shouldn't be any devices that do this with bridging. */
-void compute_ip_summed(struct sk_buff *skb, bool xmit)
-{
- /* For our convenience these defines change repeatedly between kernel
- * versions, so we can't just copy them over... */
- switch (skb->ip_summed) {
- case CHECKSUM_NONE:
- OVS_CB(skb)->ip_summed = OVS_CSUM_NONE;
- break;
- case CHECKSUM_UNNECESSARY:
- OVS_CB(skb)->ip_summed = OVS_CSUM_UNNECESSARY;
- break;
-#ifdef CHECKSUM_HW
- /* In theory this could be either CHECKSUM_PARTIAL or CHECKSUM_COMPLETE.
- * However, on the receive side we should only get CHECKSUM_PARTIAL
- * packets from Xen, which uses some special fields to represent this
- * (see below). Since we can only make one type work, pick the one
- * that actually happens in practice.
- *
- * On the transmit side (basically after skb_checksum_setup()
- * has been run or on internal dev transmit), packets with
- * CHECKSUM_COMPLETE aren't generated, so assume CHECKSUM_PARTIAL. */
- case CHECKSUM_HW:
- if (!xmit)
- OVS_CB(skb)->ip_summed = OVS_CSUM_COMPLETE;
- else
- OVS_CB(skb)->ip_summed = OVS_CSUM_PARTIAL;
-
- break;
-#else
- case CHECKSUM_COMPLETE:
- OVS_CB(skb)->ip_summed = OVS_CSUM_COMPLETE;
- break;
- case CHECKSUM_PARTIAL:
- OVS_CB(skb)->ip_summed = OVS_CSUM_PARTIAL;
- break;
-#endif
- default:
- pr_err("unknown checksum type %d\n", skb->ip_summed);
- /* None seems the safest... */
- OVS_CB(skb)->ip_summed = OVS_CSUM_NONE;
- }
-
-#if defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID)
- /* Xen has a special way of representing CHECKSUM_PARTIAL on older
- * kernels. It should not be set on the transmit path though. */
- if (skb->proto_csum_blank)
- OVS_CB(skb)->ip_summed = OVS_CSUM_PARTIAL;
-
- WARN_ON_ONCE(skb->proto_csum_blank && xmit);
-#endif
-}
-
-/* This function closely resembles skb_forward_csum() used by the bridge. It
- * is slightly different because we are only concerned with bridging and not
- * other types of forwarding and can get away with slightly more optimal
- * behavior.*/
-void forward_ip_summed(struct sk_buff *skb)
-{
-#ifdef CHECKSUM_HW
- if (OVS_CB(skb)->ip_summed == OVS_CSUM_COMPLETE)
- skb->ip_summed = CHECKSUM_NONE;
-#endif
-}
-
/* Append each packet in 'skb' list to 'queue'. There will be only one packet
* unless we broke up a GSO packet. */
static int queue_control_packets(struct sk_buff *skb, struct sk_buff_head *queue,
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (copy_bytes == skb->len) {
__wsum csum = 0;
- unsigned int csum_start, csum_offset;
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
- csum_start = skb->csum_start - skb_headroom(skb);
- csum_offset = skb->csum_offset;
-#else
- csum_start = skb_transport_header(skb) - skb->data;
- csum_offset = skb->csum;
-#endif
+ u16 csum_start, csum_offset;
+
+ get_skb_csum_pointers(skb, &csum_start, &csum_offset);
BUG_ON(csum_start >= skb_headlen(skb));
retval = skb_copy_and_csum_datagram(skb, csum_start, buf + csum_start,
copy_bytes - csum_start, &csum);
git://git.onelab.eu / sliver-openvswitch.git / blobdiff