datapath: handle recirculation loop detection
[sliver-openvswitch.git] / datapath / actions.c
index 88eca6c..f71f1f6 100644 (file)
@@ -1,35 +1,45 @@
 /*
- * Distributed under the terms of the GNU GPL version 2.
- * Copyright (c) 2007, 2008, 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2007-2014 Nicira, Inc.
  *
- * Significant portions of this file may be copied from parts of the Linux
- * kernel, by Linus Torvalds and others.
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
  */
 
-/* Functions for executing flow actions. */
-
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/skbuff.h>
 #include <linux/in.h>
 #include <linux/ip.h>
 #include <linux/openvswitch.h>
+#include <linux/sctp.h>
 #include <linux/tcp.h>
 #include <linux/udp.h>
 #include <linux/in6.h>
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>
 #include <net/ip.h>
+#include <net/ipv6.h>
 #include <net/checksum.h>
 #include <net/dsfield.h>
+#include <net/sctp/checksum.h>
 
-#include "checksum.h"
 #include "datapath.h"
 #include "vlan.h"
 #include "vport.h"
 
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
-                       const struct nlattr *attr, int len, bool keep_skb);
+                             const struct nlattr *attr, int len, bool keep_skb);
 
 static int make_writable(struct sk_buff *skb, int write_len)
 {
@@ -39,30 +49,29 @@ static int make_writable(struct sk_buff *skb, int write_len)
        return pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
 }
 
-/* remove VLAN header from packet and update csum accrodingly. */
+/* remove VLAN header from packet and update csum accordingly. */
 static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci)
 {
-       struct ethhdr *eh;
-       struct vlan_ethhdr *veth;
+       struct vlan_hdr *vhdr;
        int err;
 
        err = make_writable(skb, VLAN_ETH_HLEN);
        if (unlikely(err))
                return err;
 
-       if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
+       if (skb->ip_summed == CHECKSUM_COMPLETE)
                skb->csum = csum_sub(skb->csum, csum_partial(skb->data
-                                       + ETH_HLEN, VLAN_HLEN, 0));
+                                       + (2 * ETH_ALEN), VLAN_HLEN, 0));
 
-       veth = (struct vlan_ethhdr *) skb->data;
-       *current_tci = veth->h_vlan_TCI;
+       vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN);
+       *current_tci = vhdr->h_vlan_TCI;
 
        memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN);
+       __skb_pull(skb, VLAN_HLEN);
 
-       eh = (struct ethhdr *)__skb_pull(skb, VLAN_HLEN);
-
-       skb->protocol = eh->h_proto;
+       vlan_set_encap_proto(skb, vhdr);
        skb->mac_header += VLAN_HLEN;
+       skb_reset_mac_len(skb);
 
        return 0;
 }
@@ -92,7 +101,7 @@ static int pop_vlan(struct sk_buff *skb)
        if (unlikely(err))
                return err;
 
-       __vlan_hwaccel_put_tag(skb, ntohs(tci));
+       __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci));
        return 0;
 }
 
@@ -104,15 +113,15 @@ static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vla
                /* push down current VLAN tag */
                current_tag = vlan_tx_tag_get(skb);
 
-               if (!__vlan_put_tag(skb, current_tag))
+               if (!__vlan_put_tag(skb, skb->vlan_proto, current_tag))
                        return -ENOMEM;
 
-               if (get_ip_summed(skb) == OVS_CSUM_COMPLETE)
+               if (skb->ip_summed == CHECKSUM_COMPLETE)
                        skb->csum = csum_add(skb->csum, csum_partial(skb->data
-                                       + ETH_HLEN, VLAN_HLEN, 0));
+                                       + (2 * ETH_ALEN), VLAN_HLEN, 0));
 
        }
-       __vlan_hwaccel_put_tag(skb, ntohs(vlan->vlan_tci));
+       __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
        return 0;
 }
 
@@ -124,8 +133,12 @@ static int set_eth_addr(struct sk_buff *skb,
        if (unlikely(err))
                return err;
 
-       memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
-       memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
+       skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
+
+       ether_addr_copy(eth_hdr(skb)->h_source, eth_key->eth_src);
+       ether_addr_copy(eth_hdr(skb)->h_dest, eth_key->eth_dst);
+
+       ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
 
        return 0;
 }
@@ -140,9 +153,16 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
                        inet_proto_csum_replace4(&tcp_hdr(skb)->check, skb,
                                                 *addr, new_addr, 1);
        } else if (nh->protocol == IPPROTO_UDP) {
-               if (likely(transport_len >= sizeof(struct udphdr)))
-                       inet_proto_csum_replace4(&udp_hdr(skb)->check, skb,
-                                                *addr, new_addr, 1);
+               if (likely(transport_len >= sizeof(struct udphdr))) {
+                       struct udphdr *uh = udp_hdr(skb);
+
+                       if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+                               inet_proto_csum_replace4(&uh->check, skb,
+                                                        *addr, new_addr, 1);
+                               if (!uh->check)
+                                       uh->check = CSUM_MANGLED_0;
+                       }
+               }
        }
 
        csum_replace4(&nh->check, *addr, new_addr);
@@ -150,6 +170,53 @@ static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
        *addr = new_addr;
 }
 
+static void update_ipv6_checksum(struct sk_buff *skb, u8 l4_proto,
+                                __be32 addr[4], const __be32 new_addr[4])
+{
+       int transport_len = skb->len - skb_transport_offset(skb);
+
+       if (l4_proto == IPPROTO_TCP) {
+               if (likely(transport_len >= sizeof(struct tcphdr)))
+                       inet_proto_csum_replace16(&tcp_hdr(skb)->check, skb,
+                                                 addr, new_addr, 1);
+       } else if (l4_proto == IPPROTO_UDP) {
+               if (likely(transport_len >= sizeof(struct udphdr))) {
+                       struct udphdr *uh = udp_hdr(skb);
+
+                       if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+                               inet_proto_csum_replace16(&uh->check, skb,
+                                                         addr, new_addr, 1);
+                               if (!uh->check)
+                                       uh->check = CSUM_MANGLED_0;
+                       }
+               }
+       }
+}
+
+static void set_ipv6_addr(struct sk_buff *skb, u8 l4_proto,
+                         __be32 addr[4], const __be32 new_addr[4],
+                         bool recalculate_csum)
+{
+       if (recalculate_csum)
+               update_ipv6_checksum(skb, l4_proto, addr, new_addr);
+
+       skb_clear_rxhash(skb);
+       memcpy(addr, new_addr, sizeof(__be32[4]));
+}
+
+static void set_ipv6_tc(struct ipv6hdr *nh, u8 tc)
+{
+       nh->priority = tc >> 4;
+       nh->flow_lbl[0] = (nh->flow_lbl[0] & 0x0F) | ((tc & 0x0F) << 4);
+}
+
+static void set_ipv6_fl(struct ipv6hdr *nh, u32 fl)
+{
+       nh->flow_lbl[0] = (nh->flow_lbl[0] & 0xF0) | (fl & 0x000F0000) >> 16;
+       nh->flow_lbl[1] = (fl & 0x0000FF00) >> 8;
+       nh->flow_lbl[2] = fl & 0x000000FF;
+}
+
 static void set_ip_ttl(struct sk_buff *skb, struct iphdr *nh, u8 new_ttl)
 {
        csum_replace2(&nh->check, htons(nh->ttl << 8), htons(new_ttl << 8));
@@ -183,6 +250,47 @@ static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
        return 0;
 }
 
+static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
+{
+       struct ipv6hdr *nh;
+       int err;
+       __be32 *saddr;
+       __be32 *daddr;
+
+       err = make_writable(skb, skb_network_offset(skb) +
+                           sizeof(struct ipv6hdr));
+       if (unlikely(err))
+               return err;
+
+       nh = ipv6_hdr(skb);
+       saddr = (__be32 *)&nh->saddr;
+       daddr = (__be32 *)&nh->daddr;
+
+       if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
+               set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
+                             ipv6_key->ipv6_src, true);
+
+       if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
+               unsigned int offset = 0;
+               int flags = OVS_IP6T_FH_F_SKIP_RH;
+               bool recalc_csum = true;
+
+               if (ipv6_ext_hdr(nh->nexthdr))
+                       recalc_csum = ipv6_find_hdr(skb, &offset,
+                                                   NEXTHDR_ROUTING, NULL,
+                                                   &flags) != NEXTHDR_ROUTING;
+
+               set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
+                             ipv6_key->ipv6_dst, recalc_csum);
+       }
+
+       set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
+       set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
+       nh->hop_limit = ipv6_key->ipv6_hlimit;
+
+       return 0;
+}
+
 /* Must follow make_writable() since that can move the skb data. */
 static void set_tp_port(struct sk_buff *skb, __be16 *port,
                         __be16 new_port, __sum16 *check)
@@ -192,8 +300,22 @@ static void set_tp_port(struct sk_buff *skb, __be16 *port,
        skb_clear_rxhash(skb);
 }
 
-static int set_udp_port(struct sk_buff *skb,
-                       const struct ovs_key_udp *udp_port_key)
+static void set_udp_port(struct sk_buff *skb, __be16 *port, __be16 new_port)
+{
+       struct udphdr *uh = udp_hdr(skb);
+
+       if (uh->check && skb->ip_summed != CHECKSUM_PARTIAL) {
+               set_tp_port(skb, port, new_port, &uh->check);
+
+               if (!uh->check)
+                       uh->check = CSUM_MANGLED_0;
+       } else {
+               *port = new_port;
+               skb_clear_rxhash(skb);
+       }
+}
+
+static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
 {
        struct udphdr *uh;
        int err;
@@ -205,16 +327,15 @@ static int set_udp_port(struct sk_buff *skb,
 
        uh = udp_hdr(skb);
        if (udp_port_key->udp_src != uh->source)
-               set_tp_port(skb, &uh->source, udp_port_key->udp_src, &uh->check);
+               set_udp_port(skb, &uh->source, udp_port_key->udp_src);
 
        if (udp_port_key->udp_dst != uh->dest)
-               set_tp_port(skb, &uh->dest, udp_port_key->udp_dst, &uh->check);
+               set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
 
        return 0;
 }
 
-static int set_tcp_port(struct sk_buff *skb,
-                       const struct ovs_key_tcp *tcp_port_key)
+static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
 {
        struct tcphdr *th;
        int err;
@@ -234,6 +355,39 @@ static int set_tcp_port(struct sk_buff *skb,
        return 0;
 }
 
+static int set_sctp(struct sk_buff *skb,
+                    const struct ovs_key_sctp *sctp_port_key)
+{
+       struct sctphdr *sh;
+       int err;
+       unsigned int sctphoff = skb_transport_offset(skb);
+
+       err = make_writable(skb, sctphoff + sizeof(struct sctphdr));
+       if (unlikely(err))
+               return err;
+
+       sh = sctp_hdr(skb);
+       if (sctp_port_key->sctp_src != sh->source ||
+           sctp_port_key->sctp_dst != sh->dest) {
+               __le32 old_correct_csum, new_csum, old_csum;
+
+               old_csum = sh->checksum;
+               old_correct_csum = sctp_compute_cksum(skb, sctphoff);
+
+               sh->source = sctp_port_key->sctp_src;
+               sh->dest = sctp_port_key->sctp_dst;
+
+               new_csum = sctp_compute_cksum(skb, sctphoff);
+
+               /* Carry any checksum errors through. */
+               sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
+
+               skb_clear_rxhash(skb);
+       }
+
+       return 0;
+}
+
 static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
 {
        struct vport *vport;
@@ -241,13 +395,13 @@ static int do_output(struct datapath *dp, struct sk_buff *skb, int out_port)
        if (unlikely(!skb))
                return -ENOMEM;
 
-       vport = rcu_dereference(dp->ports[out_port]);
+       vport = ovs_vport_rcu(dp, out_port);
        if (unlikely(!vport)) {
                kfree_skb(skb);
                return -ENODEV;
        }
 
-       vport_send(vport, skb);
+       ovs_vport_send(vport, skb);
        return 0;
 }
 
@@ -258,10 +412,12 @@ static int output_userspace(struct datapath *dp, struct sk_buff *skb,
        const struct nlattr *a;
        int rem;
 
+       BUG_ON(!OVS_CB(skb)->pkt_key);
+
        upcall.cmd = OVS_PACKET_CMD_ACTION;
-       upcall.key = &OVS_CB(skb)->flow->key;
+       upcall.key = OVS_CB(skb)->pkt_key;
        upcall.userdata = NULL;
-       upcall.pid = 0;
+       upcall.portid = 0;
 
        for (a = nla_data(attr), rem = nla_len(attr); rem > 0;
                 a = nla_next(a, &rem)) {
@@ -271,12 +427,12 @@ static int output_userspace(struct datapath *dp, struct sk_buff *skb,
                        break;
 
                case OVS_USERSPACE_ATTR_PID:
-                       upcall.pid = nla_get_u32(a);
+                       upcall.portid = nla_get_u32(a);
                        break;
                }
        }
 
-       return dp_upcall(dp, skb, &upcall);
+       return ovs_dp_upcall(dp, skb, &upcall);
 }
 
 static int sample(struct datapath *dp, struct sk_buff *skb,
@@ -301,7 +457,22 @@ static int sample(struct datapath *dp, struct sk_buff *skb,
        }
 
        return do_execute_actions(dp, skb, nla_data(acts_list),
-                                                nla_len(acts_list), true);
+                                 nla_len(acts_list), true);
+}
+
+static void execute_hash(struct sk_buff *skb, const struct nlattr *attr)
+{
+       struct sw_flow_key *key = OVS_CB(skb)->pkt_key;
+       struct ovs_action_hash *hash_act = nla_data(attr);
+       u32 hash = 0;
+
+       /* OVS_HASH_ALG_L4 is the only possible hash algorithm.  */
+       hash = skb_get_rxhash(skb);
+       hash = jhash_1word(hash, hash_act->hash_basis);
+       if (!hash)
+               hash = 0x1;
+
+       key->ovs_flow_hash = hash;
 }
 
 static int execute_set_action(struct sk_buff *skb,
@@ -314,8 +485,12 @@ static int execute_set_action(struct sk_buff *skb,
                skb->priority = nla_get_u32(nested_attr);
                break;
 
-       case OVS_KEY_ATTR_TUN_ID:
-               OVS_CB(skb)->tun_id = nla_get_be64(nested_attr);
+       case OVS_KEY_ATTR_SKB_MARK:
+               skb->mark = nla_get_u32(nested_attr);
+               break;
+
+       case OVS_KEY_ATTR_IPV4_TUNNEL:
+               OVS_CB(skb)->tun_key = nla_data(nested_attr);
                break;
 
        case OVS_KEY_ATTR_ETHERNET:
@@ -326,18 +501,46 @@ static int execute_set_action(struct sk_buff *skb,
                err = set_ipv4(skb, nla_data(nested_attr));
                break;
 
+       case OVS_KEY_ATTR_IPV6:
+               err = set_ipv6(skb, nla_data(nested_attr));
+               break;
+
        case OVS_KEY_ATTR_TCP:
-               err = set_tcp_port(skb, nla_data(nested_attr));
+               err = set_tcp(skb, nla_data(nested_attr));
                break;
 
        case OVS_KEY_ATTR_UDP:
-               err = set_udp_port(skb, nla_data(nested_attr));
+               err = set_udp(skb, nla_data(nested_attr));
+               break;
+
+       case OVS_KEY_ATTR_SCTP:
+               err = set_sctp(skb, nla_data(nested_attr));
                break;
        }
 
        return err;
 }
 
+static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
+                                const struct nlattr *a)
+{
+       struct sw_flow_key recirc_key;
+       const struct vport *p = OVS_CB(skb)->input_vport;
+       uint32_t hash = OVS_CB(skb)->pkt_key->ovs_flow_hash;
+       int err;
+
+       err = ovs_flow_extract(skb, p->port_no, &recirc_key);
+       if (err)
+               return err;
+
+       recirc_key.ovs_flow_hash = hash;
+       recirc_key.recirc_id = nla_get_u32(a);
+
+       ovs_dp_process_packet_with_key(skb, &recirc_key, true);
+
+       return 0;
+}
+
 /* Execute a list of actions against 'skb'. */
 static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
                        const struct nlattr *attr, int len, bool keep_skb)
@@ -368,6 +571,10 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
                        output_userspace(dp, skb, a);
                        break;
 
+               case OVS_ACTION_ATTR_HASH:
+                       execute_hash(skb, a);
+                       break;
+
                case OVS_ACTION_ATTR_PUSH_VLAN:
                        err = push_vlan(skb, nla_data(a));
                        if (unlikely(err)) /* skb already freed. */
@@ -378,12 +585,31 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
                        err = pop_vlan(skb);
                        break;
 
+               case OVS_ACTION_ATTR_RECIRC: {
+                       struct sk_buff *recirc_skb;
+                       const bool last_action = (a->nla_len == rem);
+
+                       if (!last_action || keep_skb)
+                               recirc_skb = skb_clone(skb, GFP_ATOMIC);
+                       else
+                               recirc_skb = skb;
+
+                       err = execute_recirc(dp, recirc_skb, a);
+
+                       if (last_action || err)
+                               return err;
+
+                       break;
+               }
+
                case OVS_ACTION_ATTR_SET:
                        err = execute_set_action(skb, nla_data(a));
                        break;
 
                case OVS_ACTION_ATTR_SAMPLE:
                        err = sample(dp, skb, a);
+                       if (unlikely(err)) /* skb already freed. */
+                               return err;
                        break;
                }
 
@@ -405,11 +631,18 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
 }
 
 /* We limit the number of times that we pass into execute_actions()
- * to avoid blowing out the stack in the event that we have a loop. */
-#define MAX_LOOPS 5
+ * to avoid blowing out the stack in the event that we have a loop.
+ *
+ * Each loop adds some (estimated) cost to the kernel stack.
+ * The loop terminates when the max cost is exceeded.
+ * */
+#define RECIRC_STACK_COST 1
+#define DEFAULT_STACK_COST 4
+/* Allow up to 4 regular services, and up to 3 recirculations */
+#define MAX_STACK_COST (DEFAULT_STACK_COST * 4 + RECIRC_STACK_COST * 3)
 
 struct loop_counter {
-       u8 count;               /* Count. */
+       u8 stack_cost;          /* loop stack cost. */
        bool looping;           /* Loop detected? */
 };
 
@@ -418,22 +651,24 @@ static DEFINE_PER_CPU(struct loop_counter, loop_counters);
 static int loop_suppress(struct datapath *dp, struct sw_flow_actions *actions)
 {
        if (net_ratelimit())
-               pr_warn("%s: flow looped %d times, dropping\n",
-                               dp_name(dp), MAX_LOOPS);
+               pr_warn("%s: flow loop detected, dropping\n",
+                               ovs_dp_name(dp));
        actions->actions_len = 0;
        return -ELOOP;
 }
 
 /* Execute a list of actions against 'skb'. */
-int execute_actions(struct datapath *dp, struct sk_buff *skb)
+int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb, bool recirc)
 {
        struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
+       const u8 stack_cost = recirc ? RECIRC_STACK_COST : DEFAULT_STACK_COST;
        struct loop_counter *loop;
        int error;
 
        /* Check whether we've looped too much. */
        loop = &__get_cpu_var(loop_counters);
-       if (unlikely(++loop->count > MAX_LOOPS))
+       loop->stack_cost += stack_cost;
+       if (unlikely(loop->stack_cost > MAX_STACK_COST))
                loop->looping = true;
        if (unlikely(loop->looping)) {
                error = loop_suppress(dp, acts);
@@ -441,7 +676,7 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb)
                goto out_loop;
        }
 
-       OVS_CB(skb)->tun_id = 0;
+       OVS_CB(skb)->tun_key = NULL;
        error = do_execute_actions(dp, skb, acts->actions,
                                         acts->actions_len, false);
 
@@ -450,8 +685,9 @@ int execute_actions(struct datapath *dp, struct sk_buff *skb)
                error = loop_suppress(dp, acts);
 
 out_loop:
-       /* Decrement loop counter. */
-       if (!--loop->count)
+       /* Decrement loop stack cost. */
+       loop->stack_cost -= stack_cost;
+       if (!loop->stack_cost)
                loop->looping = false;
 
        return error;