ovs-xapi-sync: Make pychecker-able.
[sliver-openvswitch.git] / datapath / actions.c
index c578cc4..32e44c0 100644 (file)
 static int do_execute_actions(struct datapath *, struct sk_buff *,
                              struct sw_flow_actions *acts);
 
-static struct sk_buff *make_writable(struct sk_buff *skb, unsigned min_headroom)
+static int make_writable(struct sk_buff *skb, int write_len)
 {
-       if (skb_cloned(skb)) {
-               struct sk_buff *nskb;
-               unsigned headroom = max(min_headroom, skb_headroom(skb));
+       if (!skb_cloned(skb) || skb_clone_writable(skb, write_len))
+               return 0;
 
-               nskb = skb_copy_expand(skb, headroom, skb_tailroom(skb), GFP_ATOMIC);
-               if (nskb) {
-                       set_skb_csum_bits(skb, nskb);
-                       kfree_skb(skb);
-                       return nskb;
-               }
-       } else {
-               unsigned int hdr_len = (skb_transport_offset(skb)
-                                       + sizeof(struct tcphdr));
-               if (pskb_may_pull(skb, min(hdr_len, skb->len)))
-                       return skb;
-       }
-       kfree_skb(skb);
-       return NULL;
+       return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
 }
 
-static struct sk_buff *strip_vlan(struct sk_buff *skb)
+/* remove VLAN header from packet and update csum accrodingly. */
+static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
 {
        struct ethhdr *eh;
+       struct vlan_ethhdr *veth;
+       int err;
 
-       if (vlan_tx_tag_present(skb)) {
-               vlan_set_tci(skb, 0);
-               return skb;
-       }
-
-       if (unlikely(vlan_eth_hdr(skb)->h_vlan_proto != htons(ETH_P_8021Q) ||
-           skb->len < VLAN_ETH_HLEN))
-               return skb;
-
-       skb = make_writable(skb, 0);
-       if (unlikely(!skb))
-               return NULL;
+       err = make_writable(skb, VLAN_ETH_HLEN);
+       if (unlikely(err))
+               return err;
 
        if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
                skb->csum = csum_sub(skb->csum, csum_partial(skb->data
                                        + ETH_HLEN, VLAN_HLEN, 0));
 
+       veth = (struct vlan_ethhdr *) skb->data;
+       *current_tci = veth->h_vlan_TCI;
+
        memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
 
-       eh = (struct ethhdr *)skb_pull(skb, VLAN_HLEN);
+       eh = (struct ethhdr *)__skb_pull(skb, VLAN_HLEN);
 
        skb->protocol = eh->h_proto;
        skb->mac_header += VLAN_HLEN;
 
-       return skb;
+       return 0;
 }
 
-static struct sk_buff *modify_vlan_tci(struct sk_buff *skb, __be16 tci)
+static int pop_vlan(struct sk_buff *skb)
 {
-       struct vlan_ethhdr *vh;
-       __be16 old_tci;
+       __be16 tci;
+       int err;
 
-       if (vlan_tx_tag_present(skb) || skb->protocol != htons(ETH_P_8021Q))
-               return __vlan_hwaccel_put_tag(skb, ntohs(tci));
+       if (likely(vlan_tx_tag_present(skb))) {
+               vlan_set_tci(skb, 0);
+       } else {
+               if (unlikely(skb->protocol != htons(ETH_P_8021Q) ||
+                   skb->len < VLAN_ETH_HLEN))
+                       return 0;
 
-       skb = make_writable(skb, 0);
-       if (unlikely(!skb))
-               return NULL;
+               err = __pop_vlan_tci(skb, &tci);
+               if (err)
+                       return err;
+       }
+       /* move next vlan tag to hw accel tag */
+       if (likely(skb->protocol != htons(ETH_P_8021Q) ||
+           skb->len < VLAN_ETH_HLEN))
+               return 0;
 
-       if (unlikely(skb->len < VLAN_ETH_HLEN))
-               return skb;
+       err = __pop_vlan_tci(skb, &tci);
+       if (unlikely(err))
+               return err;
+
+       __vlan_hwaccel_put_tag(skb, ntohs(tci));
+       return 0;
+}
 
-       vh = vlan_eth_hdr(skb);
+static int push_vlan(struct sk_buff *skb, __be16 new_tci)
+{
+       if (unlikely(vlan_tx_tag_present(skb))) {
+               u16 current_tag;
 
-       old_tci = vh->h_vlan_TCI;
-       vh->h_vlan_TCI = tci;
+               /* push down current VLAN tag */
+               current_tag = vlan_tx_tag_get(skb);
 
-       if (get_ip_summed(skb) == OVS_CSUM_COMPLETE) {
-               __be16 diff[] = { ~old_tci, vh->h_vlan_TCI };
-               skb->csum = ~csum_partial((char *)diff, sizeof(diff), ~skb->csum);
-       }
+               if (!__vlan_put_tag(skb, current_tag))
+                       return -ENOMEM;
 
-       return skb;
+               if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
+                       skb->csum = csum_add(skb->csum, csum_partial(skb->data
+                                       + ETH_HLEN, VLAN_HLEN, 0));
+
+       }
+       __vlan_hwaccel_put_tag(skb, ntohs(new_tci));
+       return 0;
 }
 
 static bool is_ip(struct sk_buff *skb)
@@ -120,7 +124,7 @@ static bool is_ip(struct sk_buff *skb)
 
 static __sum16 *get_l4_checksum(struct sk_buff *skb)
 {
-       u8 nw_proto = OVS_CB(skb)->flow->key.ip.nw_proto;
+       u8 nw_proto = OVS_CB(skb)->flow->key.ip.proto;
        int transport_len = skb->len - skb_transport_offset(skb);
        if (nw_proto == IPPROTO_TCP) {
                if (likely(transport_len >= sizeof(struct tcphdr)))
@@ -132,22 +136,24 @@ static __sum16 *get_l4_checksum(struct sk_buff *skb)
        return NULL;
 }
 
-static struct sk_buff *set_nw_addr(struct sk_buff *skb, const struct nlattr *a)
+static int set_nw_addr(struct sk_buff *skb, const struct nlattr *a)
 {
        __be32 new_nwaddr = nla_get_be32(a);
        struct iphdr *nh;
        __sum16 *check;
        __be32 *nwaddr;
+       int err;
 
        if (unlikely(!is_ip(skb)))
-               return skb;
+               return 0;
 
-       skb = make_writable(skb, 0);
-       if (unlikely(!skb))
-               return NULL;
+       err = make_writable(skb, skb_network_offset(skb) +
+                                sizeof(struct iphdr));
+       if (unlikely(err))
+               return err;
 
        nh = ip_hdr(skb);
-       nwaddr = nla_type(a) == ODP_ACTION_ATTR_SET_NW_SRC ? &nh->saddr : &nh->daddr;
+       nwaddr = nla_type(a) == OVS_ACTION_ATTR_SET_NW_SRC ? &nh->saddr : &nh->daddr;
 
        check = get_l4_checksum(skb);
        if (likely(check))
@@ -158,47 +164,52 @@ static struct sk_buff *set_nw_addr(struct sk_buff *skb, const struct nlattr *a)
 
        *nwaddr = new_nwaddr;
 
-       return skb;
+       return 0;
 }
 
-static struct sk_buff *set_nw_tos(struct sk_buff *skb, u8 nw_tos)
+static int set_nw_tos(struct sk_buff *skb, u8 nw_tos)
 {
+       struct iphdr *nh = ip_hdr(skb);
+       u8 old, new;
+       int err;
+
        if (unlikely(!is_ip(skb)))
-               return skb;
-
-       skb = make_writable(skb, 0);
-       if (skb) {
-               struct iphdr *nh = ip_hdr(skb);
-               u8 *f = &nh->tos;
-               u8 old = *f;
-               u8 new;
-
-               /* Set the DSCP bits and preserve the ECN bits. */
-               new = nw_tos | (nh->tos & INET_ECN_MASK);
-               csum_replace4(&nh->check, (__force __be32)old,
-                                         (__force __be32)new);
-               *f = new;
-       }
-       return skb;
+               return 0;
+
+       err = make_writable(skb, skb_network_offset(skb) +
+                                sizeof(struct iphdr));
+       if (unlikely(err))
+               return err;
+
+       /* Set the DSCP bits and preserve the ECN bits. */
+       old = nh->tos;
+       new = nw_tos | (nh->tos & INET_ECN_MASK);
+       csum_replace4(&nh->check, (__force __be32)old,
+                                 (__force __be32)new);
+       nh->tos = new;
+
+       return 0;
 }
 
-static struct sk_buff *set_tp_port(struct sk_buff *skb, const struct nlattr *a)
+static int set_tp_port(struct sk_buff *skb, const struct nlattr *a)
 {
        struct udphdr *th;
        __sum16 *check;
        __be16 *port;
+       int err;
 
        if (unlikely(!is_ip(skb)))
-               return skb;
+               return 0;
 
-       skb = make_writable(skb, 0);
-       if (unlikely(!skb))
-               return NULL;
+       err = make_writable(skb, skb_transport_offset(skb) +
+                                sizeof(struct tcphdr));
+       if (unlikely(err))
+               return err;
 
        /* Must follow make_writable() since that can move the skb data. */
        check = get_l4_checksum(skb);
        if (unlikely(!check))
-               return skb;
+               return 0;
 
        /*
         * Update port and checksum.
@@ -208,61 +219,32 @@ static struct sk_buff *set_tp_port(struct sk_buff *skb, const struct nlattr *a)
         * supports those protocols.
         */
        th = udp_hdr(skb);
-       port = nla_type(a) == ODP_ACTION_ATTR_SET_TP_SRC ? &th->source : &th->dest;
+       port = nla_type(a) == OVS_ACTION_ATTR_SET_TP_SRC ? &th->source : &th->dest;
        inet_proto_csum_replace2(check, skb, *port, nla_get_be16(a), 0);
        *port = nla_get_be16(a);
        skb_clear_rxhash(skb);
 
-       return skb;
-}
-
-/**
- * is_spoofed_arp - check for invalid ARP packet
- *
- * @skb: skbuff containing an Ethernet packet, with network header pointing
- * just past the Ethernet and optional 802.1Q header.
- *
- * Returns true if @skb is an invalid Ethernet+IPv4 ARP packet: one with screwy
- * or truncated header fields or one whose inner and outer Ethernet address
- * differ.
- */
-static bool is_spoofed_arp(struct sk_buff *skb)
-{
-       struct arp_eth_header *arp;
-
-       if (OVS_CB(skb)->flow->key.eth.type != htons(ETH_P_ARP))
-               return false;
-
-       if (skb_network_offset(skb) + sizeof(struct arp_eth_header) > skb->len)
-               return true;
-
-       arp = (struct arp_eth_header *)skb_network_header(skb);
-       return (arp->ar_hrd != htons(ARPHRD_ETHER) ||
-               arp->ar_pro != htons(ETH_P_IP) ||
-               arp->ar_hln != ETH_ALEN ||
-               arp->ar_pln != 4 ||
-               compare_ether_addr(arp->ar_sha, eth_hdr(skb)->h_source));
+       return 0;
 }
 
-static void do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
+static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
 {
-       struct vport *p;
-
-       if (!skb)
-               goto error;
+       struct vport *vport;
 
-       p = rcu_dereference(dp->ports[out_port]);
-       if (!p)
-               goto error;
+       if (unlikely(!skb))
+               return -ENOMEM;
 
-       vport_send(p, skb);
-       return;
+       vport = rcu_dereference(dp->ports[out_port]);
+       if (unlikely(!vport)) {
+               kfree_skb(skb);
+               return -ENODEV;
+       }
 
-error:
-       kfree_skb(skb);
+       vport_send(vport, skb);
+       return 0;
 }
 
-static int output_control(struct datapath *dp, struct sk_buff *skb, u64 arg)
+static int output_userspace(struct datapath *dp, struct sk_buff *skb, u64 arg)
 {
        struct dp_upcall_info upcall;
 
@@ -270,7 +252,7 @@ static int output_control(struct datapath *dp, struct sk_buff *skb, u64 arg)
        if (!skb)
                return -ENOMEM;
 
-       upcall.cmd = ODP_PACKET_CMD_ACTION;
+       upcall.cmd = OVS_PACKET_CMD_ACTION;
        upcall.key = &OVS_CB(skb)->flow->key;
        upcall.userdata = arg;
        upcall.sample_pool = 0;
@@ -290,89 +272,86 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
        int prev_port = -1;
        u32 priority = skb->priority;
        const struct nlattr *a;
-       int rem, err;
+       int rem;
 
        for (a = acts->actions, rem = acts->actions_len; rem > 0;
             a = nla_next(a, &rem)) {
+               int err = 0;
+
                if (prev_port != -1) {
                        do_output(dp, skb_clone(skb, GFP_ATOMIC), prev_port);
                        prev_port = -1;
                }
 
                switch (nla_type(a)) {
-               case ODP_ACTION_ATTR_OUTPUT:
+               case OVS_ACTION_ATTR_OUTPUT:
                        prev_port = nla_get_u32(a);
                        break;
 
-               case ODP_ACTION_ATTR_CONTROLLER:
-                       err = output_control(dp, skb, nla_get_u64(a));
-                       if (err) {
-                               kfree_skb(skb);
-                               return err;
-                       }
+               case OVS_ACTION_ATTR_USERSPACE:
+                       output_userspace(dp, skb, nla_get_u64(a));
                        break;
 
-               case ODP_ACTION_ATTR_SET_TUNNEL:
+               case OVS_ACTION_ATTR_SET_TUNNEL:
                        OVS_CB(skb)->tun_id = nla_get_be64(a);
                        break;
 
-               case ODP_ACTION_ATTR_SET_DL_TCI:
-                       skb = modify_vlan_tci(skb, nla_get_be16(a));
+               case OVS_ACTION_ATTR_PUSH_VLAN:
+                       err = push_vlan(skb, nla_get_be16(a));
+                       if (unlikely(err)) /* skb already freed */
+                               return err;
                        break;
 
-               case ODP_ACTION_ATTR_STRIP_VLAN:
-                       skb = strip_vlan(skb);
+               case OVS_ACTION_ATTR_POP_VLAN:
+                       err = pop_vlan(skb);
                        break;
 
-               case ODP_ACTION_ATTR_SET_DL_SRC:
-                       skb = make_writable(skb, 0);
-                       if (!skb)
-                               return -ENOMEM;
-                       memcpy(eth_hdr(skb)->h_source, nla_data(a), ETH_ALEN);
+               case OVS_ACTION_ATTR_SET_DL_SRC:
+                       err = make_writable(skb, ETH_HLEN);
+                       if (likely(!err))
+                               memcpy(eth_hdr(skb)->h_source, nla_data(a), ETH_ALEN);
                        break;
 
-               case ODP_ACTION_ATTR_SET_DL_DST:
-                       skb = make_writable(skb, 0);
-                       if (!skb)
-                               return -ENOMEM;
-                       memcpy(eth_hdr(skb)->h_dest, nla_data(a), ETH_ALEN);
+               case OVS_ACTION_ATTR_SET_DL_DST:
+                       err = make_writable(skb, ETH_HLEN);
+                       if (likely(!err))
+                               memcpy(eth_hdr(skb)->h_dest, nla_data(a), ETH_ALEN);
                        break;
 
-               case ODP_ACTION_ATTR_SET_NW_SRC:
-               case ODP_ACTION_ATTR_SET_NW_DST:
-                       skb = set_nw_addr(skb, a);
+               case OVS_ACTION_ATTR_SET_NW_SRC:
+               case OVS_ACTION_ATTR_SET_NW_DST:
+                       err = set_nw_addr(skb, a);
                        break;
 
-               case ODP_ACTION_ATTR_SET_NW_TOS:
-                       skb = set_nw_tos(skb, nla_get_u8(a));
+               case OVS_ACTION_ATTR_SET_NW_TOS:
+                       err = set_nw_tos(skb, nla_get_u8(a));
                        break;
 
-               case ODP_ACTION_ATTR_SET_TP_SRC:
-               case ODP_ACTION_ATTR_SET_TP_DST:
-                       skb = set_tp_port(skb, a);
+               case OVS_ACTION_ATTR_SET_TP_SRC:
+               case OVS_ACTION_ATTR_SET_TP_DST:
+                       err = set_tp_port(skb, a);
                        break;
 
-               case ODP_ACTION_ATTR_SET_PRIORITY:
+               case OVS_ACTION_ATTR_SET_PRIORITY:
                        skb->priority = nla_get_u32(a);
                        break;
 
-               case ODP_ACTION_ATTR_POP_PRIORITY:
+               case OVS_ACTION_ATTR_POP_PRIORITY:
                        skb->priority = priority;
                        break;
+               }
 
-               case ODP_ACTION_ATTR_DROP_SPOOFED_ARP:
-                       if (unlikely(is_spoofed_arp(skb)))
-                               goto exit;
-                       break;
+               if (unlikely(err)) {
+                       kfree_skb(skb);
+                       return err;
                }
-               if (!skb)
-                       return -ENOMEM;
        }
-exit:
+
        if (prev_port != -1)
                do_output(dp, skb, prev_port);
        else
-               kfree_skb(skb);
+               consume_skb(skb);
+
        return 0;
 }
 
@@ -394,7 +373,7 @@ static void sflow_sample(struct datapath *dp, struct sk_buff *skb,
        if (unlikely(!nskb))
                return;
 
-       upcall.cmd = ODP_PACKET_CMD_SAMPLE;
+       upcall.cmd = OVS_PACKET_CMD_SAMPLE;
        upcall.key = &OVS_CB(skb)->flow->key;
        upcall.userdata = 0;
        upcall.sample_pool = atomic_read(&p->sflow_pool);