gso: Update tunnel segmentation to support Tx checksum offload
[cascardo/linux.git] / net / ipv4 / ip_gre.c
index 2a83591..1f6eab6 100644 (file)
@@ -121,103 +121,8 @@ static int ipgre_tunnel_init(struct net_device *dev);
 static int ipgre_net_id __read_mostly;
 static int gre_tap_net_id __read_mostly;
 
-static __sum16 check_checksum(struct sk_buff *skb)
-{
-       __sum16 csum = 0;
-
-       switch (skb->ip_summed) {
-       case CHECKSUM_COMPLETE:
-               csum = csum_fold(skb->csum);
-
-               if (!csum)
-                       break;
-               /* Fall through. */
-
-       case CHECKSUM_NONE:
-               skb->csum = 0;
-               csum = __skb_checksum_complete(skb);
-               skb->ip_summed = CHECKSUM_COMPLETE;
-               break;
-       }
-
-       return csum;
-}
-
-static int ip_gre_calc_hlen(__be16 o_flags)
-{
-       int addend = 4;
-
-       if (o_flags&TUNNEL_CSUM)
-               addend += 4;
-       if (o_flags&TUNNEL_KEY)
-               addend += 4;
-       if (o_flags&TUNNEL_SEQ)
-               addend += 4;
-       return addend;
-}
-
-static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
-                           bool *csum_err, int *hdr_len)
-{
-       unsigned int ip_hlen = ip_hdrlen(skb);
-       const struct gre_base_hdr *greh;
-       __be32 *options;
-
-       if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
-               return -EINVAL;
-
-       greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
-       if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
-               return -EINVAL;
-
-       tpi->flags = gre_flags_to_tnl_flags(greh->flags);
-       *hdr_len = ip_gre_calc_hlen(tpi->flags);
-
-       if (!pskb_may_pull(skb, *hdr_len))
-               return -EINVAL;
-
-       greh = (struct gre_base_hdr *)(skb_network_header(skb) + ip_hlen);
-
-       tpi->proto = greh->protocol;
-
-       options = (__be32 *)(greh + 1);
-       if (greh->flags & GRE_CSUM) {
-               if (check_checksum(skb)) {
-                       *csum_err = true;
-                       return -EINVAL;
-               }
-               options++;
-       }
-
-       if (greh->flags & GRE_KEY) {
-               tpi->key = *options;
-               options++;
-       } else
-               tpi->key = 0;
-
-       if (unlikely(greh->flags & GRE_SEQ)) {
-               tpi->seq = *options;
-               options++;
-       } else
-               tpi->seq = 0;
-
-       /* WCCP version 1 and 2 protocol decoding.
-        * - Change protocol to IP
-        * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
-        */
-       if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
-               tpi->proto = htons(ETH_P_IP);
-               if ((*(u8 *)options & 0xF0) != 0x40) {
-                       *hdr_len += 4;
-                       if (!pskb_may_pull(skb, *hdr_len))
-                               return -EINVAL;
-               }
-       }
-
-       return 0;
-}
-
-static void ipgre_err(struct sk_buff *skb, u32 info)
+static int ipgre_err(struct sk_buff *skb, u32 info,
+                    const struct tnl_ptk_info *tpi)
 {
 
        /* All the routers (except for Linux) return only
@@ -239,26 +144,18 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
        const int type = icmp_hdr(skb)->type;
        const int code = icmp_hdr(skb)->code;
        struct ip_tunnel *t;
-       struct tnl_ptk_info tpi;
-       int hdr_len;
-       bool csum_err = false;
-
-       if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len)) {
-               if (!csum_err)          /* ignore csum errors. */
-                       return;
-       }
 
        switch (type) {
        default:
        case ICMP_PARAMETERPROB:
-               return;
+               return PACKET_RCVD;
 
        case ICMP_DEST_UNREACH:
                switch (code) {
                case ICMP_SR_FAILED:
                case ICMP_PORT_UNREACH:
                        /* Impossible event. */
-                       return;
+                       return PACKET_RCVD;
                default:
                        /* All others are translated to HOST_UNREACH.
                           rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -269,138 +166,61 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
                break;
        case ICMP_TIME_EXCEEDED:
                if (code != ICMP_EXC_TTL)
-                       return;
+                       return PACKET_RCVD;
                break;
 
        case ICMP_REDIRECT:
                break;
        }
 
-       if (tpi.proto == htons(ETH_P_TEB))
+       if (tpi->proto == htons(ETH_P_TEB))
                itn = net_generic(net, gre_tap_net_id);
        else
                itn = net_generic(net, ipgre_net_id);
 
        iph = (const struct iphdr *)skb->data;
-       t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
-                            iph->daddr, iph->saddr, tpi.key);
+       t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+                            iph->daddr, iph->saddr, tpi->key);
 
        if (t == NULL)
-               return;
+               return PACKET_REJECT;
 
-       if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
-               ipv4_update_pmtu(skb, dev_net(skb->dev), info,
-                                t->parms.link, 0, IPPROTO_GRE, 0);
-               return;
-       }
-       if (type == ICMP_REDIRECT) {
-               ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
-                             IPPROTO_GRE, 0);
-               return;
-       }
        if (t->parms.iph.daddr == 0 ||
            ipv4_is_multicast(t->parms.iph.daddr))
-               return;
+               return PACKET_RCVD;
 
        if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
-               return;
+               return PACKET_RCVD;
 
        if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
                t->err_count++;
        else
                t->err_count = 1;
        t->err_time = jiffies;
+       return PACKET_RCVD;
 }
 
-static int ipgre_rcv(struct sk_buff *skb)
+static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 {
        struct net *net = dev_net(skb->dev);
        struct ip_tunnel_net *itn;
        const struct iphdr *iph;
        struct ip_tunnel *tunnel;
-       struct tnl_ptk_info tpi;
-       int hdr_len;
-       bool csum_err = false;
-
-       if (parse_gre_header(skb, &tpi, &csum_err, &hdr_len) < 0)
-               goto drop;
 
-       if (tpi.proto == htons(ETH_P_TEB))
+       if (tpi->proto == htons(ETH_P_TEB))
                itn = net_generic(net, gre_tap_net_id);
        else
                itn = net_generic(net, ipgre_net_id);
 
        iph = ip_hdr(skb);
-       tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi.flags,
-                                 iph->saddr, iph->daddr, tpi.key);
+       tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+                                 iph->saddr, iph->daddr, tpi->key);
 
        if (tunnel) {
-               ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
-               return 0;
-       }
-       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
-drop:
-       kfree_skb(skb);
-       return 0;
-}
-
-static struct sk_buff *handle_offloads(struct ip_tunnel *tunnel, struct sk_buff *skb)
-{
-       int err;
-
-       if (skb_is_gso(skb)) {
-               err = skb_unclone(skb, GFP_ATOMIC);
-               if (unlikely(err))
-                       goto error;
-               skb_shinfo(skb)->gso_type |= SKB_GSO_GRE;
-               return skb;
-       } else if (skb->ip_summed == CHECKSUM_PARTIAL &&
-                  tunnel->parms.o_flags&TUNNEL_CSUM) {
-               err = skb_checksum_help(skb);
-               if (unlikely(err))
-                       goto error;
-       } else if (skb->ip_summed != CHECKSUM_PARTIAL)
-               skb->ip_summed = CHECKSUM_NONE;
-
-       return skb;
-
-error:
-       kfree_skb(skb);
-       return ERR_PTR(err);
-}
-
-static struct sk_buff *gre_build_header(struct sk_buff *skb,
-                                       const struct tnl_ptk_info *tpi,
-                                       int hdr_len)
-{
-       struct gre_base_hdr *greh;
-
-       skb_push(skb, hdr_len);
-
-       greh = (struct gre_base_hdr *)skb->data;
-       greh->flags = tnl_flags_to_gre_flags(tpi->flags);
-       greh->protocol = tpi->proto;
-
-       if (tpi->flags&(TUNNEL_KEY|TUNNEL_CSUM|TUNNEL_SEQ)) {
-               __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);
-
-               if (tpi->flags&TUNNEL_SEQ) {
-                       *ptr = tpi->seq;
-                       ptr--;
-               }
-               if (tpi->flags&TUNNEL_KEY) {
-                       *ptr = tpi->key;
-                       ptr--;
-               }
-               if (tpi->flags&TUNNEL_CSUM &&
-                   !(skb_shinfo(skb)->gso_type & SKB_GSO_GRE)) {
-                       *(__sum16 *)ptr = 0;
-                       *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0,
-                                                                skb->len, 0));
-               }
+               ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error);
+               return PACKET_RCVD;
        }
-
-       return skb;
+       return PACKET_REJECT;
 }
 
 static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
@@ -410,11 +230,6 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
        struct ip_tunnel *tunnel = netdev_priv(dev);
        struct tnl_ptk_info tpi;
 
-       if (likely(!skb->encapsulation)) {
-               skb_reset_inner_headers(skb);
-               skb->encapsulation = 1;
-       }
-
        tpi.flags = tunnel->parms.o_flags;
        tpi.proto = proto;
        tpi.key = tunnel->parms.o_key;
@@ -423,13 +238,9 @@ static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
        tpi.seq = htonl(tunnel->o_seqno);
 
        /* Push GRE header. */
-       skb = gre_build_header(skb, &tpi, tunnel->hlen);
-       if (unlikely(!skb)) {
-               dev->stats.tx_dropped++;
-               return;
-       }
+       gre_build_header(skb, &tpi, tunnel->hlen);
 
-       ip_tunnel_xmit(skb, dev, tnl_params);
+       ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
 }
 
 static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
@@ -438,7 +249,7 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
        struct ip_tunnel *tunnel = netdev_priv(dev);
        const struct iphdr *tnl_params;
 
-       skb = handle_offloads(tunnel, skb);
+       skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
        if (IS_ERR(skb))
                goto out;
 
@@ -477,7 +288,7 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
 {
        struct ip_tunnel *tunnel = netdev_priv(dev);
 
-       skb = handle_offloads(tunnel, skb);
+       skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM));
        if (IS_ERR(skb))
                goto out;
 
@@ -503,10 +314,11 @@ static int ipgre_tunnel_ioctl(struct net_device *dev,
 
        if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
                return -EFAULT;
-       if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
-           p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
-           ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING))) {
-               return -EINVAL;
+       if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
+               if (p.iph.version != 4 || p.iph.protocol != IPPROTO_GRE ||
+                   p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
+                   ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
+                       return -EINVAL;
        }
        p.i_flags = gre_flags_to_tnl_flags(p.i_flags);
        p.o_flags = gre_flags_to_tnl_flags(p.o_flags);
@@ -708,9 +520,10 @@ static int ipgre_tunnel_init(struct net_device *dev)
        return ip_tunnel_init(dev);
 }
 
-static const struct gre_protocol ipgre_protocol = {
-       .handler     = ipgre_rcv,
-       .err_handler = ipgre_err,
+static struct gre_cisco_protocol ipgre_protocol = {
+       .handler        = ipgre_rcv,
+       .err_handler    = ipgre_err,
+       .priority       = 0,
 };
 
 static int __net_init ipgre_init_net(struct net *net)
@@ -978,7 +791,7 @@ static int __init ipgre_init(void)
        if (err < 0)
                goto pnet_tap_faied;
 
-       err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
+       err = gre_cisco_register(&ipgre_protocol);
        if (err < 0) {
                pr_info("%s: can't add protocol\n", __func__);
                goto add_proto_failed;
@@ -997,7 +810,7 @@ static int __init ipgre_init(void)
 tap_ops_failed:
        rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
-       gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
+       gre_cisco_unregister(&ipgre_protocol);
 add_proto_failed:
        unregister_pernet_device(&ipgre_tap_net_ops);
 pnet_tap_faied:
@@ -1009,8 +822,7 @@ static void __exit ipgre_fini(void)
 {
        rtnl_link_unregister(&ipgre_tap_ops);
        rtnl_link_unregister(&ipgre_link_ops);
-       if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
-               pr_info("%s: can't remove protocol\n", __func__);
+       gre_cisco_unregister(&ipgre_protocol);
        unregister_pernet_device(&ipgre_tap_net_ops);
        unregister_pernet_device(&ipgre_net_ops);
 }