diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index f3e591c611de..4271f8d1da7a 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -109,15 +109,12 @@ static inline unsigned long idx_to_kaddr(struct xenvif *vif, return (unsigned long)pfn_to_kaddr(idx_to_pfn(vif, idx)); } -/* - * This is the amount of packet we copy rather than map, so that the - * guest can't fiddle with the contents of the headers while we do - * packet processing on them (netfilter, routing, etc). +/* This is a miniumum size for the linear area to avoid lots of + * calls to __pskb_pull_tail() as we set up checksum offsets. The + * value 128 was chosen as it covers all IPv4 and most likely + * IPv6 headers. */ -#define PKT_PROT_LEN (ETH_HLEN + \ - VLAN_HLEN + \ - sizeof(struct iphdr) + MAX_IPOPTLEN + \ - sizeof(struct tcphdr) + MAX_TCP_OPTION_SPACE) +#define PKT_PROT_LEN 128 static u16 frag_get_pending_idx(skb_frag_t *frag) { @@ -1118,14 +1115,214 @@ static int xenvif_set_skb_gso(struct xenvif *vif, return 0; } +static inline void maybe_pull_tail(struct sk_buff *skb, unsigned int len) +{ + if (skb_is_nonlinear(skb) && skb_headlen(skb) < len) { + /* If we need to pullup then pullup to the max, so we + * won't need to do it again. + */ + int target = min_t(int, skb->len, MAX_TCP_HEADER); + __pskb_pull_tail(skb, target - skb_headlen(skb)); + } +} + +static int checksum_setup_ip(struct xenvif *vif, struct sk_buff *skb, + int recalculate_partial_csum) +{ + struct iphdr *iph = (void *)skb->data; + unsigned int header_size; + unsigned int off; + int err = -EPROTO; + + off = sizeof(struct iphdr); + + header_size = skb->network_header + off + MAX_IPOPTLEN; + maybe_pull_tail(skb, header_size); + + off = iph->ihl * 4; + + switch (iph->protocol) { + case IPPROTO_TCP: + if (!skb_partial_csum_set(skb, off, + offsetof(struct tcphdr, check))) + goto out; + + if (recalculate_partial_csum) { + struct tcphdr *tcph = tcp_hdr(skb); + + header_size = skb->network_header + + off + + sizeof(struct tcphdr); + maybe_pull_tail(skb, header_size); + + tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, + skb->len - off, + IPPROTO_TCP, 0); + } + break; + case IPPROTO_UDP: + if (!skb_partial_csum_set(skb, off, + offsetof(struct udphdr, check))) + goto out; + + if (recalculate_partial_csum) { + struct udphdr *udph = udp_hdr(skb); + + header_size = skb->network_header + + off + + sizeof(struct udphdr); + maybe_pull_tail(skb, header_size); + + udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, + skb->len - off, + IPPROTO_UDP, 0); + } + break; + default: + if (net_ratelimit()) + netdev_err(vif->dev, + "Attempting to checksum a non-TCP/UDP packet, " + "dropping a protocol %d packet\n", + iph->protocol); + goto out; + } + + err = 0; + +out: + return err; +} + +static int checksum_setup_ipv6(struct xenvif *vif, struct sk_buff *skb, + int recalculate_partial_csum) +{ + int err = -EPROTO; + struct ipv6hdr *ipv6h = (void *)skb->data; + u8 nexthdr; + unsigned int header_size; + unsigned int off; + bool fragment; + bool done; + + done = false; + + off = sizeof(struct ipv6hdr); + + header_size = skb->network_header + off; + maybe_pull_tail(skb, header_size); + + nexthdr = ipv6h->nexthdr; + + while ((off <= sizeof(struct ipv6hdr) + ntohs(ipv6h->payload_len)) && + !done) { + switch (nexthdr) { + case IPPROTO_DSTOPTS: + case IPPROTO_HOPOPTS: + case IPPROTO_ROUTING: { + struct ipv6_opt_hdr *hp = (void *)(skb->data + off); + + header_size = skb->network_header + + off + + sizeof(struct ipv6_opt_hdr); + maybe_pull_tail(skb, header_size); + + nexthdr = hp->nexthdr; + off += ipv6_optlen(hp); + break; + } + case IPPROTO_AH: { + struct ip_auth_hdr *hp = (void *)(skb->data + off); + + header_size = skb->network_header + + off + + sizeof(struct ip_auth_hdr); + maybe_pull_tail(skb, header_size); + + nexthdr = hp->nexthdr; + off += (hp->hdrlen+2)<<2; + break; + } + case IPPROTO_FRAGMENT: + fragment = true; + /* fall through */ + default: + done = true; + break; + } + } + + if (!done) { + if (net_ratelimit()) + netdev_err(vif->dev, "Failed to parse packet header\n"); + goto out; + } + + if (fragment) { + if (net_ratelimit()) + netdev_err(vif->dev, "Packet is a fragment!\n"); + goto out; + } + + switch (nexthdr) { + case IPPROTO_TCP: + if (!skb_partial_csum_set(skb, off, + offsetof(struct tcphdr, check))) + goto out; + + if (recalculate_partial_csum) { + struct tcphdr *tcph = tcp_hdr(skb); + + header_size = skb->network_header + + off + + sizeof(struct tcphdr); + maybe_pull_tail(skb, header_size); + + tcph->check = ~csum_ipv6_magic(&ipv6h->saddr, + &ipv6h->daddr, + skb->len - off, + IPPROTO_TCP, 0); + } + break; + case IPPROTO_UDP: + if (!skb_partial_csum_set(skb, off, + offsetof(struct udphdr, check))) + goto out; + + if (recalculate_partial_csum) { + struct udphdr *udph = udp_hdr(skb); + + header_size = skb->network_header + + off + + sizeof(struct udphdr); + maybe_pull_tail(skb, header_size); + + udph->check = ~csum_ipv6_magic(&ipv6h->saddr, + &ipv6h->daddr, + skb->len - off, + IPPROTO_UDP, 0); + } + break; + default: + if (net_ratelimit()) + netdev_err(vif->dev, + "Attempting to checksum a non-TCP/UDP packet, " + "dropping a protocol %d packet\n", + nexthdr); + goto out; + } + + err = 0; + +out: + return err; +} + static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) { - struct iphdr *iph; int err = -EPROTO; int recalculate_partial_csum = 0; - /* - * A GSO SKB must be CHECKSUM_PARTIAL. However some buggy + /* A GSO SKB must be CHECKSUM_PARTIAL. However some buggy * peers can fail to set NETRXF_csum_blank when sending a GSO * frame. In this case force the SKB to CHECKSUM_PARTIAL and * recalculate the partial checksum. @@ -1140,46 +1337,11 @@ static int checksum_setup(struct xenvif *vif, struct sk_buff *skb) if (skb->ip_summed != CHECKSUM_PARTIAL) return 0; - if (skb->protocol != htons(ETH_P_IP)) - goto out; + if (skb->protocol == htons(ETH_P_IP)) + err = checksum_setup_ip(vif, skb, recalculate_partial_csum); + else if (skb->protocol == htons(ETH_P_IPV6)) + err = checksum_setup_ipv6(vif, skb, recalculate_partial_csum); - iph = (void *)skb->data; - switch (iph->protocol) { - case IPPROTO_TCP: - if (!skb_partial_csum_set(skb, 4 * iph->ihl, - offsetof(struct tcphdr, check))) - goto out; - - if (recalculate_partial_csum) { - struct tcphdr *tcph = tcp_hdr(skb); - tcph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, - skb->len - iph->ihl*4, - IPPROTO_TCP, 0); - } - break; - case IPPROTO_UDP: - if (!skb_partial_csum_set(skb, 4 * iph->ihl, - offsetof(struct udphdr, check))) - goto out; - - if (recalculate_partial_csum) { - struct udphdr *udph = udp_hdr(skb); - udph->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, - skb->len - iph->ihl*4, - IPPROTO_UDP, 0); - } - break; - default: - if (net_ratelimit()) - netdev_err(vif->dev, - "Attempting to checksum a non-TCP/UDP packet, dropping a protocol %d packet\n", - iph->protocol); - goto out; - } - - err = 0; - -out: return err; } @@ -1428,12 +1590,7 @@ static int xenvif_tx_submit(struct xenvif *vif, int budget) xenvif_fill_frags(vif, skb); - /* - * If the initial fragment was < PKT_PROT_LEN then - * pull through some bytes from the other fragments to - * increase the linear region to PKT_PROT_LEN bytes. - */ - if (skb_headlen(skb) < PKT_PROT_LEN && skb_is_nonlinear(skb)) { + if (skb_is_nonlinear(skb) && skb_headlen(skb) < PKT_PROT_LEN) { int target = min_t(int, skb->len, PKT_PROT_LEN); __pskb_pull_tail(skb, target - skb_headlen(skb)); } diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index ad27b15242cd..108e7523017a 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -105,6 +105,15 @@ static int netback_probe(struct xenbus_device *dev, goto abort_transaction; } + /* We support partial checksum setup for IPv6 packets */ + err = xenbus_printf(xbt, dev->nodename, + "feature-ipv6-csum-offload", + "%d", 1); + if (err) { + message = "writing feature-ipv6-csum-offload"; + goto abort_transaction; + } + /* We support rx-copy path. */ err = xenbus_printf(xbt, dev->nodename, "feature-rx-copy", "%d", 1);