X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=datapath%2Fdatapath.c;h=c8b50889a4937e9cb6dc64b683f07718dabd4ce0;hb=dfdfc8d43d102f4b5851d26773c1786ee2b13877;hp=7b8687d651e74a967fe331ad9e9e9ef7de968267;hpb=7237e4f4b6155eb4854cebc0a45fe845f0950b40;p=openvswitch diff --git a/datapath/datapath.c b/datapath/datapath.c index 7b8687d6..c8b50889 100644 --- a/datapath/datapath.c +++ b/datapath/datapath.c @@ -44,6 +44,7 @@ #include #include "openvswitch/datapath-protocol.h" +#include "checksum.h" #include "datapath.h" #include "actions.h" #include "flow.h" @@ -540,171 +541,6 @@ out: 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, @@ -2051,15 +1887,9 @@ success: 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);