datapath: Suppress sparse complaints about address spaces.
[sliver-openvswitch.git] / datapath / datapath.c
index 7b8687d..9d6ab86 100644 (file)
@@ -44,6 +44,7 @@
 #include <linux/compat.h>
 
 #include "openvswitch/datapath-protocol.h"
+#include "checksum.h"
 #include "datapath.h"
 #include "actions.h"
 #include "flow.h"
@@ -66,7 +67,7 @@ EXPORT_SYMBOL(dp_ioctl_hook);
  * It is safe to access the datapath and vport structures with just
  * dp_mutex.
  */
-static struct datapath *dps[ODP_MAX];
+static struct datapath __rcu *dps[ODP_MAX];
 static DEFINE_MUTEX(dp_mutex);
 
 static int new_vport(struct datapath *, struct odp_port *, int port_no);
@@ -76,7 +77,8 @@ struct datapath *get_dp(int dp_idx)
 {
        if (dp_idx < 0 || dp_idx >= ODP_MAX)
                return NULL;
-       return rcu_dereference(dps[dp_idx]);
+       return rcu_dereference_check(dps[dp_idx], rcu_read_lock_held() ||
+                                        lockdep_is_held(&dp_mutex));
 }
 EXPORT_SYMBOL_GPL(get_dp);
 
@@ -92,10 +94,15 @@ static struct datapath *get_dp_locked(int dp_idx)
        return dp;
 }
 
+static struct tbl *get_table_protected(struct datapath *dp)
+{
+       return rcu_dereference_protected(dp->table, lockdep_is_held(&dp->mutex));
+}
+
 /* Must be called with rcu_read_lock or RTNL lock. */
 const char *dp_name(const struct datapath *dp)
 {
-       return vport_get_name(dp->ports[ODPP_LOCAL]);
+       return vport_get_name(rcu_dereference_rtnl(dp->ports[ODPP_LOCAL]));
 }
 
 static inline size_t br_nlmsg_size(void)
@@ -138,7 +145,8 @@ static int dp_fill_ifinfo(struct sk_buff *skb,
        hdr->ifi_change = 0;
 
        NLA_PUT_STRING(skb, IFLA_IFNAME, vport_get_name(port));
-       NLA_PUT_U32(skb, IFLA_MASTER, vport_get_ifindex(dp->ports[ODPP_LOCAL]));
+       NLA_PUT_U32(skb, IFLA_MASTER,
+               vport_get_ifindex(rtnl_dereference(dp->ports[ODPP_LOCAL])));
        NLA_PUT_U32(skb, IFLA_MTU, vport_get_mtu(port));
 #ifdef IFLA_OPERSTATE
        NLA_PUT_U8(skb, IFLA_OPERSTATE,
@@ -262,15 +270,17 @@ static int create_dp(int dp_idx, const char __user *devnamep)
 
        dp->drop_frags = 0;
        dp->stats_percpu = alloc_percpu(struct dp_stats_percpu);
-       if (!dp->stats_percpu)
+       if (!dp->stats_percpu) {
+               err = -ENOMEM;
                goto err_destroy_local_port;
+       }
 
        rcu_assign_pointer(dps[dp_idx], dp);
+       dp_sysfs_add_dp(dp);
+
        mutex_unlock(&dp_mutex);
        rtnl_unlock();
 
-       dp_sysfs_add_dp(dp);
-
        return 0;
 
 err_destroy_local_port:
@@ -492,7 +502,8 @@ void dp_process_received_packet(struct vport *p, struct sk_buff *skb)
                flow_node = tbl_lookup(rcu_dereference(dp->table), &key,
                                        flow_hash(&key), flow_cmp);
                if (unlikely(!flow_node)) {
-                       dp_output_control(dp, skb, _ODPL_MISS_NR, OVS_CB(skb)->tun_id);
+                       dp_output_control(dp, skb, _ODPL_MISS_NR,
+                                        (__force u64)OVS_CB(skb)->tun_id);
                        stats_counter_off = offsetof(struct dp_stats_percpu, n_missed);
                        goto out;
                }
@@ -500,6 +511,7 @@ void dp_process_received_packet(struct vport *p, struct sk_buff *skb)
                OVS_CB(skb)->flow = flow_cast(flow_node);
        }
 
+       stats_counter_off = offsetof(struct dp_stats_percpu, n_hit);
        flow_used(OVS_CB(skb)->flow, skb);
 
        acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
@@ -510,13 +522,13 @@ void dp_process_received_packet(struct vport *p, struct sk_buff *skb)
                loop->looping = true;
        if (unlikely(loop->looping)) {
                loop_suppress(dp, acts);
+               kfree_skb(skb);
                goto out_loop;
        }
 
        /* Execute actions. */
        execute_actions(dp, skb, &OVS_CB(skb)->flow->key, acts->actions,
-                       acts->n_actions);
-       stats_counter_off = offsetof(struct dp_stats_percpu, n_hit);
+                       acts->actions_len);
 
        /* Check whether sub-actions looped too much. */
        if (unlikely(loop->looping))
@@ -540,175 +552,10 @@ 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,
-                                int queue_no, u32 arg)
+                                int queue_no, u64 arg)
 {
        struct sk_buff *nskb;
        int port_no;
@@ -733,7 +580,6 @@ static int queue_control_packets(struct sk_buff *skb, struct sk_buff_head *queue
                header->type = queue_no;
                header->length = skb->len;
                header->port = port_no;
-               header->reserved = 0;
                header->arg = arg;
                skb_queue_tail(queue, skb);
 
@@ -751,7 +597,7 @@ err_kfree_skbs:
 }
 
 int dp_output_control(struct datapath *dp, struct sk_buff *skb, int queue_no,
-                     u32 arg)
+                     u64 arg)
 {
        struct dp_stats_percpu *stats;
        struct sk_buff_head *queue;
@@ -774,16 +620,12 @@ int dp_output_control(struct datapath *dp, struct sk_buff *skb, int queue_no,
         * userspace may try to stuff a 64kB packet into a 1500-byte MTU. */
        if (skb_is_gso(skb)) {
                struct sk_buff *nskb = skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM);
-               if (nskb) {
-                       kfree_skb(skb);
-                       skb = nskb;
-                       if (unlikely(IS_ERR(skb))) {
-                               err = PTR_ERR(skb);
-                               goto err;
-                       }
-               } else {
-                       /* XXX This case might not be possible.  It's hard to
-                        * tell from the skb_gso_segment() code and comment. */
+               
+               kfree_skb(skb);
+               skb = nskb;
+               if (IS_ERR(skb)) {
+                       err = PTR_ERR(skb);
+                       goto err;
                }
        }
 
@@ -808,7 +650,7 @@ err:
 
 static int flush_flows(struct datapath *dp)
 {
-       struct tbl *old_table = rcu_dereference(dp->table);
+       struct tbl *old_table = get_table_protected(dp);
        struct tbl *new_table;
 
        new_table = tbl_create(0);
@@ -822,50 +664,76 @@ static int flush_flows(struct datapath *dp)
        return 0;
 }
 
-static int validate_actions(const struct sw_flow_actions *actions)
-{
-       unsigned int i;
-
-       for (i = 0; i < actions->n_actions; i++) {
-               const union odp_action *a = &actions->actions[i];
-
-               switch (a->type) {
-               case ODPAT_CONTROLLER:
-               case ODPAT_STRIP_VLAN:
-               case ODPAT_SET_DL_SRC:
-               case ODPAT_SET_DL_DST:
-               case ODPAT_SET_NW_SRC:
-               case ODPAT_SET_NW_DST:
-               case ODPAT_SET_TP_SRC:
-               case ODPAT_SET_TP_DST:
-               case ODPAT_SET_TUNNEL:
-               case ODPAT_SET_PRIORITY:
-               case ODPAT_POP_PRIORITY:
-               case ODPAT_DROP_SPOOFED_ARP:
-                       /* No validation needed. */
-                       break;
+static int validate_actions(const struct nlattr *actions, u32 actions_len)
+{
+        const struct nlattr *a;
+        int rem;
+
+        nla_for_each_attr(a, actions, actions_len, rem) {
+                static const u32 action_lens[ODPAT_MAX + 1] = {
+                        [ODPAT_OUTPUT] = 4,
+                        [ODPAT_CONTROLLER] = 8,
+                        [ODPAT_SET_DL_TCI] = 2,
+                        [ODPAT_STRIP_VLAN] = 0,
+                        [ODPAT_SET_DL_SRC] = ETH_ALEN,
+                        [ODPAT_SET_DL_DST] = ETH_ALEN,
+                        [ODPAT_SET_NW_SRC] = 4,
+                        [ODPAT_SET_NW_DST] = 4,
+                        [ODPAT_SET_NW_TOS] = 1,
+                        [ODPAT_SET_TP_SRC] = 2,
+                        [ODPAT_SET_TP_DST] = 2,
+                        [ODPAT_SET_TUNNEL] = 8,
+                        [ODPAT_SET_PRIORITY] = 4,
+                        [ODPAT_POP_PRIORITY] = 0,
+                        [ODPAT_DROP_SPOOFED_ARP] = 0,
+                };
+                int type = nla_type(a);
+
+                if (type > ODPAT_MAX || nla_len(a) != action_lens[type])
+                        return -EINVAL;
+
+                switch (type) {
+               case ODPAT_UNSPEC:
+                       return -EINVAL;
 
-               case ODPAT_OUTPUT:
-                       if (a->output.port >= DP_MAX_PORTS)
+                case ODPAT_CONTROLLER:
+                case ODPAT_STRIP_VLAN:
+                case ODPAT_SET_DL_SRC:
+                case ODPAT_SET_DL_DST:
+                case ODPAT_SET_NW_SRC:
+                case ODPAT_SET_NW_DST:
+                case ODPAT_SET_TP_SRC:
+                case ODPAT_SET_TP_DST:
+                case ODPAT_SET_TUNNEL:
+                case ODPAT_SET_PRIORITY:
+                case ODPAT_POP_PRIORITY:
+                case ODPAT_DROP_SPOOFED_ARP:
+                        /* No validation needed. */
+                        break;
+
+                case ODPAT_OUTPUT:
+                        if (nla_get_u32(a) >= DP_MAX_PORTS)
+                                return -EINVAL;
+
+                case ODPAT_SET_DL_TCI:
+                       if (nla_get_be16(a) & htons(VLAN_CFI_MASK))
                                return -EINVAL;
-                       break;
+                        break;
 
-               case ODPAT_SET_DL_TCI:
-                       if (a->dl_tci.tci & htons(VLAN_CFI_MASK))
-                               return -EINVAL;
-                       break;
+                case ODPAT_SET_NW_TOS:
+                        if (nla_get_u8(a) & INET_ECN_MASK)
+                                return -EINVAL;
+                        break;
 
-               case ODPAT_SET_NW_TOS:
-                       if (a->nw_tos.nw_tos & INET_ECN_MASK)
-                               return -EINVAL;
-                       break;
+                default:
+                        return -EOPNOTSUPP;
+                }
+        }
 
-               default:
-                       return -EOPNOTSUPP;
-               }
-       }
+        if (rem > 0)
+                return -EINVAL;
 
-       return 0;
+        return 0;
 }
 
 static struct sw_flow_actions *get_actions(const struct odp_flow *flow)
@@ -873,16 +741,17 @@ static struct sw_flow_actions *get_actions(const struct odp_flow *flow)
        struct sw_flow_actions *actions;
        int error;
 
-       actions = flow_actions_alloc(flow->n_actions);
+       actions = flow_actions_alloc(flow->actions_len);
        error = PTR_ERR(actions);
        if (IS_ERR(actions))
                goto error;
 
        error = -EFAULT;
-       if (copy_from_user(actions->actions, flow->actions,
-                          flow->n_actions * sizeof(union odp_action)))
+       if (copy_from_user(actions->actions,
+                          (struct nlattr __user __force *)flow->actions,
+                          flow->actions_len))
                goto error_free_actions;
-       error = validate_actions(actions);
+       error = validate_actions(actions->actions, actions->actions_len);
        if (error)
                goto error_free_actions;
 
@@ -928,7 +797,7 @@ static void clear_stats(struct sw_flow *flow)
 
 static int expand_table(struct datapath *dp)
 {
-       struct tbl *old_table = rcu_dereference(dp->table);
+       struct tbl *old_table = get_table_protected(dp);
        struct tbl *new_table;
 
        new_table = tbl_expand(old_table);
@@ -948,9 +817,11 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf,
        struct sw_flow *flow;
        struct tbl *table;
        int error;
+       u32 hash;
 
-       table = rcu_dereference(dp->table);
-       flow_node = tbl_lookup(table, &uf->flow.key, flow_hash(&uf->flow.key), flow_cmp);
+       hash = flow_hash(&uf->flow.key);
+       table = get_table_protected(dp);
+       flow_node = tbl_lookup(table, &uf->flow.key, hash, flow_cmp);
        if (!flow_node) {
                /* No such flow. */
                struct sw_flow_actions *acts;
@@ -964,7 +835,7 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf,
                        error = expand_table(dp);
                        if (error)
                                goto error;
-                       table = rcu_dereference(dp->table);
+                       table = get_table_protected(dp);
                }
 
                /* Allocate flow. */
@@ -984,7 +855,7 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf,
                rcu_assign_pointer(flow->sf_acts, acts);
 
                /* Put flow in bucket. */
-               error = tbl_insert(table, &flow->tbl_node, flow_hash(&flow->key));
+               error = tbl_insert(table, &flow->tbl_node, hash);
                if (error)
                        goto error_free_flow_acts;
 
@@ -1005,10 +876,12 @@ static int do_put_flow(struct datapath *dp, struct odp_flow_put *uf,
                error = PTR_ERR(new_acts);
                if (IS_ERR(new_acts))
                        goto error;
-               old_acts = rcu_dereference(flow->sf_acts);
-               if (old_acts->n_actions != new_acts->n_actions ||
+
+               old_acts = rcu_dereference_protected(flow->sf_acts,
+                                                    lockdep_is_held(&dp->mutex));
+               if (old_acts->actions_len != new_acts->actions_len ||
                    memcmp(old_acts->actions, new_acts->actions,
-                          sizeof(union odp_action) * old_acts->n_actions)) {
+                          old_acts->actions_len)) {
                        rcu_assign_pointer(flow->sf_acts, new_acts);
                        flow_deferred_free_acts(old_acts);
                } else {
@@ -1054,14 +927,15 @@ static int put_flow(struct datapath *dp, struct odp_flow_put __user *ufp)
        return 0;
 }
 
-static int do_answer_query(struct sw_flow *flow, u32 query_flags,
+static int do_answer_query(struct datapath *dp, struct sw_flow *flow,
+                          u32 query_flags,
                           struct odp_flow_stats __user *ustats,
-                          union odp_action __user *actions,
-                          u32 __user *n_actionsp)
+                          struct nlattr __user *actions,
+                          u32 __user *actions_lenp)
 {
        struct sw_flow_actions *sf_acts;
        struct odp_flow_stats stats;
-       u32 n_actions;
+       u32 actions_len;
 
        spin_lock_bh(&flow->lock);
        get_stats(flow, &stats);
@@ -1071,37 +945,37 @@ static int do_answer_query(struct sw_flow *flow, u32 query_flags,
        spin_unlock_bh(&flow->lock);
 
        if (copy_to_user(ustats, &stats, sizeof(struct odp_flow_stats)) ||
-           get_user(n_actions, n_actionsp))
+           get_user(actions_len, actions_lenp))
                return -EFAULT;
 
-       if (!n_actions)
+       if (!actions_len)
                return 0;
 
-       sf_acts = rcu_dereference(flow->sf_acts);
-       if (put_user(sf_acts->n_actions, n_actionsp) ||
+       sf_acts = rcu_dereference_protected(flow->sf_acts,
+                                           lockdep_is_held(&dp->mutex));
+       if (put_user(sf_acts->actions_len, actions_lenp) ||
            (actions && copy_to_user(actions, sf_acts->actions,
-                                    sizeof(union odp_action) *
-                                    min(sf_acts->n_actions, n_actions))))
+                                    min(sf_acts->actions_len, actions_len))))
                return -EFAULT;
 
        return 0;
 }
 
-static int answer_query(struct sw_flow *flow, u32 query_flags,
-                       struct odp_flow __user *ufp)
+static int answer_query(struct datapath *dp, struct sw_flow *flow,
+                       u32 query_flags, struct odp_flow __user *ufp)
 {
-       union odp_action *actions;
+       struct nlattr __user *actions;
 
-       if (get_user(actions, &ufp->actions))
+       if (get_user(actions, (struct nlattr __user * __user *)&ufp->actions))
                return -EFAULT;
 
-       return do_answer_query(flow, query_flags, 
-                              &ufp->stats, actions, &ufp->n_actions);
+       return do_answer_query(dp, flow, query_flags, 
+                              &ufp->stats, actions, &ufp->actions_len);
 }
 
 static struct sw_flow *do_del_flow(struct datapath *dp, struct odp_flow_key *key)
 {
-       struct tbl *table = rcu_dereference(dp->table);
+       struct tbl *table = get_table_protected(dp);
        struct tbl_node *flow_node;
        int error;
 
@@ -1133,18 +1007,18 @@ static int del_flow(struct datapath *dp, struct odp_flow __user *ufp)
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       error = answer_query(flow, 0, ufp);
+       error = answer_query(dp, flow, 0, ufp);
        flow_deferred_free(flow);
        return error;
 }
 
 static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
 {
-       struct tbl *table = rcu_dereference(dp->table);
+       struct tbl *table = get_table_protected(dp);
        u32 i;
 
        for (i = 0; i < flowvec->n_flows; i++) {
-               struct odp_flow __user *ufp = &flowvec->flows[i];
+               struct odp_flow __user *ufp = (struct odp_flow __user __force *)&flowvec->flows[i];
                struct odp_flow uf;
                struct tbl_node *flow_node;
                int error;
@@ -1156,7 +1030,7 @@ static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec
                if (!flow_node)
                        error = put_user(ENOENT, &ufp->stats.error);
                else
-                       error = answer_query(flow_cast(flow_node), uf.flags, ufp);
+                       error = answer_query(dp, flow_cast(flow_node), uf.flags, ufp);
                if (error)
                        return -EFAULT;
        }
@@ -1164,6 +1038,7 @@ static int do_query_flows(struct datapath *dp, const struct odp_flowvec *flowvec
 }
 
 struct list_flows_cbdata {
+       struct datapath *dp;
        struct odp_flow __user *uflows;
        u32 n_flows;
        u32 listed_flows;
@@ -1178,7 +1053,7 @@ static int list_flow(struct tbl_node *node, void *cbdata_)
 
        if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key))
                return -EFAULT;
-       error = answer_query(flow, 0, ufp);
+       error = answer_query(cbdata->dp, flow, 0, ufp);
        if (error)
                return error;
 
@@ -1195,11 +1070,12 @@ static int do_list_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
        if (!flowvec->n_flows)
                return 0;
 
-       cbdata.uflows = flowvec->flows;
+       cbdata.dp = dp;
+       cbdata.uflows = (struct odp_flow __user __force*)flowvec->flows;
        cbdata.n_flows = flowvec->n_flows;
        cbdata.listed_flows = 0;
 
-       error = tbl_foreach(rcu_dereference(dp->table), list_flow, &cbdata);
+       error = tbl_foreach(get_table_protected(dp), list_flow, &cbdata);
        return error ? error : cbdata.listed_flows;
 }
 
@@ -1237,18 +1113,18 @@ static int do_execute(struct datapath *dp, const struct odp_execute *execute)
        if (execute->length < ETH_HLEN || execute->length > 65535)
                goto error;
 
-       actions = flow_actions_alloc(execute->n_actions);
+       actions = flow_actions_alloc(execute->actions_len);
        if (IS_ERR(actions)) {
                err = PTR_ERR(actions);
                goto error;
        }
 
        err = -EFAULT;
-       if (copy_from_user(actions->actions, execute->actions,
-                          execute->n_actions * sizeof *execute->actions))
+       if (copy_from_user(actions->actions,
+           (struct nlattr __user __force *)execute->actions, execute->actions_len))
                goto error_free_actions;
 
-       err = validate_actions(actions);
+       err = validate_actions(actions->actions, execute->actions_len);
        if (err)
                goto error_free_actions;
 
@@ -1258,7 +1134,8 @@ static int do_execute(struct datapath *dp, const struct odp_execute *execute)
                goto error_free_actions;
 
        err = -EFAULT;
-       if (copy_from_user(skb_put(skb, execute->length), execute->data,
+       if (copy_from_user(skb_put(skb, execute->length),
+                          (const void __user __force *)execute->data,
                           execute->length))
                goto error_free_skb;
 
@@ -1278,7 +1155,7 @@ static int do_execute(struct datapath *dp, const struct odp_execute *execute)
                goto error_free_skb;
 
        rcu_read_lock();
-       err = execute_actions(dp, skb, &key, actions->actions, actions->n_actions);
+       err = execute_actions(dp, skb, &key, actions->actions, actions->actions_len);
        rcu_read_unlock();
 
        kfree(actions);
@@ -1304,7 +1181,7 @@ static int execute_packet(struct datapath *dp, const struct odp_execute __user *
 
 static int get_dp_stats(struct datapath *dp, struct odp_stats __user *statsp)
 {
-       struct tbl *table = rcu_dereference(dp->table);
+       struct tbl *table = get_table_protected(dp);
        struct odp_stats stats;
        int i;
 
@@ -1462,7 +1339,8 @@ static int list_ports(struct datapath *dp, struct odp_portvec __user *upv)
        if (copy_from_user(&pv, upv, sizeof pv))
                return -EFAULT;
 
-       retval = do_list_ports(dp, pv.ports, pv.n_ports);
+       retval = do_list_ports(dp, (struct odp_port __user __force *)pv.ports,
+                              pv.n_ports);
        if (retval < 0)
                return retval;
 
@@ -1662,11 +1540,11 @@ static int compat_get_flow(struct odp_flow *flow, const struct compat_odp_flow _
            __copy_from_user(&flow->stats, &compat->stats, sizeof(struct odp_flow_stats)) ||
            __copy_from_user(&flow->key, &compat->key, sizeof(struct odp_flow_key)) ||
            __get_user(actions, &compat->actions) ||
-           __get_user(flow->n_actions, &compat->n_actions) ||
+           __get_user(flow->actions_len, &compat->actions_len) ||
            __get_user(flow->flags, &compat->flags))
                return -EFAULT;
 
-       flow->actions = compat_ptr(actions);
+       flow->actions = (struct nlattr __force *)compat_ptr(actions);
        return 0;
 }
 
@@ -1691,7 +1569,8 @@ static int compat_put_flow(struct datapath *dp, struct compat_odp_flow_put __use
        return 0;
 }
 
-static int compat_answer_query(struct sw_flow *flow, u32 query_flags,
+static int compat_answer_query(struct datapath *dp, struct sw_flow *flow,
+                              u32 query_flags,
                               struct compat_odp_flow __user *ufp)
 {
        compat_uptr_t actions;
@@ -1699,8 +1578,8 @@ static int compat_answer_query(struct sw_flow *flow, u32 query_flags,
        if (get_user(actions, &ufp->actions))
                return -EFAULT;
 
-       return do_answer_query(flow, query_flags, &ufp->stats,
-                              compat_ptr(actions), &ufp->n_actions);
+       return do_answer_query(dp, flow, query_flags, &ufp->stats,
+                              compat_ptr(actions), &ufp->actions_len);
 }
 
 static int compat_del_flow(struct datapath *dp, struct compat_odp_flow __user *ufp)
@@ -1716,14 +1595,16 @@ static int compat_del_flow(struct datapath *dp, struct compat_odp_flow __user *u
        if (IS_ERR(flow))
                return PTR_ERR(flow);
 
-       error = compat_answer_query(flow, 0, ufp);
+       error = compat_answer_query(dp, flow, 0, ufp);
        flow_deferred_free(flow);
        return error;
 }
 
-static int compat_query_flows(struct datapath *dp, struct compat_odp_flow *flows, u32 n_flows)
+static int compat_query_flows(struct datapath *dp,
+                             struct compat_odp_flow __user *flows,
+                             u32 n_flows)
 {
-       struct tbl *table = rcu_dereference(dp->table);
+       struct tbl *table = get_table_protected(dp);
        u32 i;
 
        for (i = 0; i < n_flows; i++) {
@@ -1739,7 +1620,8 @@ static int compat_query_flows(struct datapath *dp, struct compat_odp_flow *flows
                if (!flow_node)
                        error = put_user(ENOENT, &ufp->stats.error);
                else
-                       error = compat_answer_query(flow_cast(flow_node), uf.flags, ufp);
+                       error = compat_answer_query(dp, flow_cast(flow_node),
+                                                   uf.flags, ufp);
                if (error)
                        return -EFAULT;
        }
@@ -1747,6 +1629,7 @@ static int compat_query_flows(struct datapath *dp, struct compat_odp_flow *flows
 }
 
 struct compat_list_flows_cbdata {
+       struct datapath *dp;
        struct compat_odp_flow __user *uflows;
        u32 n_flows;
        u32 listed_flows;
@@ -1761,7 +1644,7 @@ static int compat_list_flow(struct tbl_node *node, void *cbdata_)
 
        if (copy_to_user(&ufp->key, &flow->key, sizeof flow->key))
                return -EFAULT;
-       error = compat_answer_query(flow, 0, ufp);
+       error = compat_answer_query(cbdata->dp, flow, 0, ufp);
        if (error)
                return error;
 
@@ -1770,7 +1653,8 @@ static int compat_list_flow(struct tbl_node *node, void *cbdata_)
        return 0;
 }
 
-static int compat_list_flows(struct datapath *dp, struct compat_odp_flow *flows, u32 n_flows)
+static int compat_list_flows(struct datapath *dp,
+                            struct compat_odp_flow __user *flows, u32 n_flows)
 {
        struct compat_list_flows_cbdata cbdata;
        int error;
@@ -1778,17 +1662,18 @@ static int compat_list_flows(struct datapath *dp, struct compat_odp_flow *flows,
        if (!n_flows)
                return 0;
 
+       cbdata.dp = dp;
        cbdata.uflows = flows;
        cbdata.n_flows = n_flows;
        cbdata.listed_flows = 0;
 
-       error = tbl_foreach(rcu_dereference(dp->table), compat_list_flow, &cbdata);
+       error = tbl_foreach(get_table_protected(dp), compat_list_flow, &cbdata);
        return error ? error : cbdata.listed_flows;
 }
 
 static int compat_flowvec_ioctl(struct datapath *dp, unsigned long argp,
                                int (*function)(struct datapath *,
-                                               struct compat_odp_flow *,
+                                               struct compat_odp_flow __user *,
                                                u32 n_flows))
 {
        struct compat_odp_flowvec __user *uflowvec;
@@ -1823,13 +1708,13 @@ static int compat_execute(struct datapath *dp, const struct compat_odp_execute _
 
        if (!access_ok(VERIFY_READ, uexecute, sizeof(struct compat_odp_execute)) ||
            __get_user(actions, &uexecute->actions) ||
-           __get_user(execute.n_actions, &uexecute->n_actions) ||
+           __get_user(execute.actions_len, &uexecute->actions_len) ||
            __get_user(data, &uexecute->data) ||
            __get_user(execute.length, &uexecute->length))
                return -EFAULT;
 
-       execute.actions = compat_ptr(actions);
-       execute.data = compat_ptr(data);
+       execute.actions = (struct nlattr __force *)compat_ptr(actions);
+       execute.data = (const void __force *)compat_ptr(data);
 
        return do_execute(dp, &execute);
 }
@@ -2002,13 +1887,12 @@ fault:
        return -EFAULT;
 }
 
-ssize_t openvswitch_read(struct file *f, char __user *buf, size_t nbytes,
-                     loff_t *ppos)
+static ssize_t openvswitch_read(struct file *f, char __user *buf,
+                               size_t nbytes, loff_t *ppos)
 {
-       /* XXX is there sufficient synchronization here? */
        int listeners = get_listen_mask(f);
        int dp_idx = iminor(f->f_dentry->d_inode);
-       struct datapath *dp = get_dp(dp_idx);
+       struct datapath *dp = get_dp_locked(dp_idx);
        struct sk_buff *skb;
        size_t copy_bytes, tot_copy_bytes;
        int retval;
@@ -2045,21 +1929,19 @@ ssize_t openvswitch_read(struct file *f, char __user *buf, size_t nbytes,
                }
        }
 success:
+       mutex_unlock(&dp->mutex);
+
        copy_bytes = tot_copy_bytes = min_t(size_t, skb->len, nbytes);
 
        retval = 0;
        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);
+                       csum_start -= skb_headroom(skb);
+
                        BUG_ON(csum_start >= skb_headlen(skb));
                        retval = skb_copy_and_csum_datagram(skb, csum_start, buf + csum_start,
                                                            copy_bytes - csum_start, &csum);
@@ -2069,7 +1951,8 @@ success:
                                copy_bytes = csum_start;
                                csump = (__sum16 __user *)(buf + csum_start + csum_offset);
 
-                               BUG_ON((char *)csump + sizeof(__sum16) > buf + nbytes);
+                               BUG_ON((char __user *)csump + sizeof(__sum16) >
+                                       buf + nbytes);
                                put_user(csum_fold(csum), csump);
                        }
                } else
@@ -2077,7 +1960,7 @@ success:
        }
 
        if (!retval) {
-               struct iovec __user iov;
+               struct iovec iov;
 
                iov.iov_base = buf;
                iov.iov_len = copy_bytes;
@@ -2088,16 +1971,17 @@ success:
                retval = tot_copy_bytes;
 
        kfree_skb(skb);
+       return retval;
 
 error:
+       mutex_unlock(&dp->mutex);
        return retval;
 }
 
 static unsigned int openvswitch_poll(struct file *file, poll_table *wait)
 {
-       /* XXX is there sufficient synchronization here? */
        int dp_idx = iminor(file->f_dentry->d_inode);
-       struct datapath *dp = get_dp(dp_idx);
+       struct datapath *dp = get_dp_locked(dp_idx);
        unsigned int mask;
 
        if (dp) {
@@ -2105,21 +1989,20 @@ static unsigned int openvswitch_poll(struct file *file, poll_table *wait)
                poll_wait(file, &dp->waitqueue, wait);
                if (dp_has_packet_of_interest(dp, get_listen_mask(file)))
                        mask |= POLLIN | POLLRDNORM;
+               mutex_unlock(&dp->mutex);
        } else {
                mask = POLLIN | POLLRDNORM | POLLHUP;
        }
        return mask;
 }
 
-struct file_operations openvswitch_fops = {
-       /* XXX .aio_read = openvswitch_aio_read, */
+static struct file_operations openvswitch_fops = {
        .read  = openvswitch_read,
        .poll  = openvswitch_poll,
        .unlocked_ioctl = openvswitch_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl = openvswitch_compat_ioctl,
 #endif
-       /* XXX .fasync = openvswitch_fasync, */
 };
 
 static int major;