datapath: Pad OVS_PACKET_ATTR_PACKET if linear copy was performed

[cascardo/ovs.git] / datapath / datapath.c

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 0714a99..9e9c73a 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -110,10 +110,9 @@ int lockdep_ovsl_is_held(void)
 #endif
 
 static struct vport *new_vport(const struct vport_parms *);
-static int queue_gso_packets(struct net *, int dp_ifindex, struct sk_buff *,
+static int queue_gso_packets(struct datapath *dp, struct sk_buff *,
                             const struct dp_upcall_info *);
-static int queue_userspace_packet(struct net *, int dp_ifindex,
-                                 struct sk_buff *,
+static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,
                                  const struct dp_upcall_info *);
 
 /* Must be called with rcu_read_lock or ovs_mutex. */
@@ -279,7 +278,6 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
                  const struct dp_upcall_info *upcall_info)
 {
        struct dp_stats_percpu *stats;
-       int dp_ifindex;
        int err;
 
        if (upcall_info->portid == 0) {
@@ -287,16 +285,10 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
                goto err;
        }
 
-       dp_ifindex = get_dpifindex(dp);
-       if (!dp_ifindex) {
-               err = -ENODEV;
-               goto err;
-       }
-
        if (!skb_is_gso(skb))
-               err = queue_userspace_packet(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
+               err = queue_userspace_packet(dp, skb, upcall_info);
        else
-               err = queue_gso_packets(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
+               err = queue_gso_packets(dp, skb, upcall_info);
        if (err)
                goto err;
 
@@ -312,8 +304,7 @@ err:
        return err;
 }
 
-static int queue_gso_packets(struct net *net, int dp_ifindex,
-                            struct sk_buff *skb,
+static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
                             const struct dp_upcall_info *upcall_info)
 {
        unsigned short gso_type = skb_shinfo(skb)->gso_type;
@@ -322,14 +313,14 @@ static int queue_gso_packets(struct net *net, int dp_ifindex,
        struct sk_buff *segs, *nskb;
        int err;
 
-       segs = __skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM, false);
+       segs = __skb_gso_segment(skb, NETIF_F_SG, false);
        if (IS_ERR(segs))
                return PTR_ERR(segs);
 
        /* Queue all of the segments. */
        skb = segs;
        do {
-               err = queue_userspace_packet(net, dp_ifindex, skb, upcall_info);
+               err = queue_userspace_packet(dp, skb, upcall_info);
                if (err)
                        break;
 
@@ -382,11 +373,11 @@ static size_t key_attr_size(void)
                + nla_total_size(28); /* OVS_KEY_ATTR_ND */
 }
 
-static size_t upcall_msg_size(const struct sk_buff *skb,
-                             const struct nlattr *userdata)
+static size_t upcall_msg_size(const struct nlattr *userdata,
+                             unsigned int hdrlen)
 {
        size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
-               + nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */
+               + nla_total_size(hdrlen) /* OVS_PACKET_ATTR_PACKET */
                + nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */
 
        /* OVS_PACKET_ATTR_USERDATA */
@@ -396,8 +387,7 @@ static size_t upcall_msg_size(const struct sk_buff *skb,
        return size;
 }
 
-static int queue_userspace_packet(struct net *net, int dp_ifindex,
-                                 struct sk_buff *skb,
+static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
                                  const struct dp_upcall_info *upcall_info)
 {
        struct ovs_header *upcall;
@@ -406,12 +396,17 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex,
        struct nlattr *nla;
        struct genl_info info = {
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,14,0)
-               .dst_sk = net->genl_sock,
+               .dst_sk = ovs_dp_get_net(dp)->genl_sock,
 #endif
                .snd_portid = upcall_info->portid,
        };
-       size_t len;
-       int err;
+       size_t len, plen;
+       unsigned int hlen;
+       int err, dp_ifindex;
+
+       dp_ifindex = get_dpifindex(dp);
+       if (!dp_ifindex)
+               return -ENODEV;
 
        if (vlan_tx_tag_present(skb)) {
                nskb = skb_clone(skb, GFP_ATOMIC);
@@ -432,7 +427,21 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex,
                goto out;
        }
 
-       len = upcall_msg_size(skb, upcall_info->userdata);
+       /* Complete checksum if needed */
+       if (skb->ip_summed == CHECKSUM_PARTIAL &&
+           (err = skb_checksum_help(skb)))
+               goto out;
+
+       /* Older versions of OVS user space enforce alignment of the last
+        * Netlink attribute to NLA_ALIGNTO which would require extensive
+        * padding logic. Only perform zerocopy if padding is not required.
+        */
+       if (dp->user_features & OVS_DP_F_UNALIGNED)
+               hlen = skb_zerocopy_headlen(skb);
+       else
+               hlen = skb->len;
+
+       len = upcall_msg_size(upcall_info->userdata, hlen);
        user_skb = genlmsg_new_unicast(len, &info, GFP_ATOMIC);
        if (!user_skb) {
                err = -ENOMEM;
@@ -452,13 +461,24 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex,
                          nla_len(upcall_info->userdata),
                          nla_data(upcall_info->userdata));
 
-       nla = __nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, skb->len);
+       /* Only reserve room for attribute header, packet data is added
+        * in skb_zerocopy() */
+       if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) {
+               err = -ENOBUFS;
+               goto out;
+       }
+       nla->nla_len = nla_attr_size(skb->len);
+
+       skb_zerocopy(user_skb, skb, skb->len, hlen);
 
-       skb_copy_and_csum_dev(skb, nla_data(nla));
+       /* Pad OVS_PACKET_ATTR_PACKET if linear copy was performed */
+       if (!(dp->user_features & OVS_DP_F_UNALIGNED) &&
+           (plen = (ALIGN(user_skb->len, NLA_ALIGNTO) - user_skb->len)) > 0)
+               memset(skb_put(user_skb, plen), 0, plen);
 
-       genlmsg_end(user_skb, upcall);
-       err = genlmsg_unicast(net, user_skb, upcall_info->portid);
+       ((struct nlmsghdr *) user_skb->data)->nlmsg_len = user_skb->len;
 
+       err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
 out:
        kfree_skb(nskb);
        return err;