[ovs-dev] [PATCH 1/2] datapath: Add support for tun_key to Open vSwitch datapath

Kyle Mestery (kmestery) kmestery at cisco.com
Thu Oct 11 21:44:29 UTC 2012


On Oct 11, 2012, at 4:32 PM, Pravin Shelar <pshelar at nicira.com> wrote:
> On Thu, Oct 11, 2012 at 1:52 PM, Kyle Mestery (kmestery)
> <kmestery at cisco.com> wrote:
>> 
>> On Oct 10, 2012, at 6:23 PM, Pravin Shelar <pshelar at nicira.com> wrote:
>> 
>>> Patch looks good, I have few comments inlined.
>>> 
>>> 
>>> On Tue, Oct 9, 2012 at 11:49 AM, Kyle Mestery <kmestery at cisco.com> wrote:
>>>> This is a first pass at providing a tun_key which can be
>>>> used as the basis for flow-based tunnelling. The
>>>> tun_key includes and replaces the tun_id in both struct
>>>> ovs_skb_cb and struct sw_tun_key.
>>>> 
>>>> This patch allows all existing tun_id behaviour to still work. Existing
>>>> users of tun_id are redirected to tun_key->tun_id to retain compatibility.
>>>> However, when the userspace code is updated to make use of the new tun_key,
>>>> the old behaviour will be deprecated and removed.
>>>> 
>>>> NOTE: With these changes, the tunneling code no longer assumes input and
>>>> output keys are symmetric.  If they are not, PMTUD needs to be disabled
>>>> for tunneling to work.
>>>> 
>>>> Signed-off-by: Kyle Mestery <kmestery at cisco.com>
>>>> Cc: Simon Horman <horms at verge.net.au>
>>>> Cc: Jesse Gross <jesse at nicira.com>
>>>> ---
>>>> V6:
>>>> - Fix more comments addressed from Jesse.
>>>> V5:
>>>> - Address another round of comments from Jesse.
>>>> V4:
>>>> - Address 2 comments from Jesse:
>>>> - When processing actions, if OVS_CB(skb)->tun_key is NULL, point it at one
>>>>   on the stack temporarily. This goes away when we remove the ability to set
>>>>   tun_id outside the scope of tun_key.
>>>> - Move tun_key to the end of struct sw_flow_key.
>>>> V3:
>>>> - Fix issues found during review by Jesse.
>>>> - Add a NEWS entry around tunnel code no longer assuming symmetric input and
>>>> output tunnel keys.
>>>> 
>>>> V2:
>>>> - Fix blank line addition/removal found by Simon.
>>>> - Fix hex printing output found by Simon.
>>>> ---
>>>> NEWS                        |   3 ++
>>>> datapath/actions.c          |  38 +++++++++++++----
>>>> datapath/datapath.c         |  10 ++++-
>>>> datapath/datapath.h         |   5 ++-
>>>> datapath/flow.c             |  64 ++++++++++++++++++++++++----
>>>> datapath/flow.h             |  12 ++++--
>>>> datapath/tunnel.c           | 101 ++++++++++++++++++++++++++++----------------
>>>> datapath/tunnel.h           |  15 ++++++-
>>>> datapath/vport-capwap.c     |  12 +++---
>>>> datapath/vport-gre.c        |  15 ++++---
>>>> datapath/vport.c            |   2 +-
>>>> include/linux/openvswitch.h |  18 +++++++-
>>>> lib/dpif-netdev.c           |   1 +
>>>> lib/odp-util.c              |  15 ++++++-
>>>> lib/odp-util.h              |   3 +-
>>>> 15 files changed, 235 insertions(+), 79 deletions(-)
>>>> 
>>>> diff --git a/NEWS b/NEWS
>>>> index 29fd9f3..ae831e3 100644
>>>> --- a/NEWS
>>>> +++ b/NEWS
>>>> @@ -1,5 +1,8 @@
>>>> post-v1.8.0
>>>> ------------------------
>>>> +    - The tunneling code no longer assumes input and output keys are symmetric.
>>>> +      If they are not, PMTUD needs to be disabled for tunneling to work. Note
>>>> +      this only applies to flow-based keys.
>>>>    - FreeBSD is now a supported platform, thanks to code contributions from
>>>>      Gaetano Catalli, Ed Maste, and Giuseppe Lettieri.
>>>>    - ovs-bugtool: New --ovs option to report only OVS related information.
>>>> diff --git a/datapath/actions.c b/datapath/actions.c
>>>> index ec9b595..fa8c10d 100644
>>>> --- a/datapath/actions.c
>>>> +++ b/datapath/actions.c
>>>> @@ -37,7 +37,8 @@
>>>> #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,
>>>> +                       struct ovs_key_ipv4_tunnel *tun_key, bool keep_skb);
>>>> 
>>>> static int make_writable(struct sk_buff *skb, int write_len)
>>>> {
>>>> @@ -329,11 +330,14 @@ 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),
>>>> +                                                OVS_CB(skb)->tun_key,
>>>> +                                                true);
>>>> }
>>>> 
>>>> static int execute_set_action(struct sk_buff *skb,
>>>> -                                const struct nlattr *nested_attr)
>>>> +                                const struct nlattr *nested_attr,
>>>> +                                struct ovs_key_ipv4_tunnel *tun_key)
>>>> {
>>>>       int err = 0;
>>>> 
>>>> @@ -343,7 +347,21 @@ static int execute_set_action(struct sk_buff *skb,
>>>>               break;
>>>> 
>>>>       case OVS_KEY_ATTR_TUN_ID:
>>>> -               OVS_CB(skb)->tun_id = nla_get_be64(nested_attr);
>>>> +               if (OVS_CB(skb)->tun_key == NULL) {
>>>> +                       /* If tun_key is NULL for this skb, assign it to
>>>> +                        * a value the caller passed in for action processing
>>>> +                        * and output. This can disappear once we drop support
>>>> +                        * for setting tun_id outside of tun_key.
>>>> +                        */
>>>> +                       memset(tun_key, 0, sizeof(struct ovs_key_ipv4_tunnel));
>>>> +                       OVS_CB(skb)->tun_key = tun_key;
>>>> +               }
>>>> +
>>>> +               OVS_CB(skb)->tun_key->tun_id = nla_get_be64(nested_attr);
>>>> +               break;
>>>> +
>>>> +       case OVS_KEY_ATTR_IPV4_TUNNEL:
>>>> +               OVS_CB(skb)->tun_key = nla_data(nested_attr);
>>>>               break;
>>>> 
>>>>       case OVS_KEY_ATTR_ETHERNET:
>>>> @@ -368,7 +386,8 @@ static int execute_set_action(struct sk_buff *skb,
>>>> 
>>>> /* 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)
>>>> +                       const struct nlattr *attr, int len,
>>>> +                       struct ovs_key_ipv4_tunnel *tun_key, bool keep_skb)
>>>> {
>>>>       /* Every output action needs a separate clone of 'skb', but the common
>>>>        * case is just a single output action, so that doing a clone and
>>>> @@ -407,7 +426,7 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
>>>>                       break;
>>>> 
>>>>               case OVS_ACTION_ATTR_SET:
>>>> -                       err = execute_set_action(skb, nla_data(a));
>>>> +                       err = execute_set_action(skb, nla_data(a), tun_key);
>>>>                       break;
>>>> 
>>>>               case OVS_ACTION_ATTR_SAMPLE:
>>>> @@ -458,6 +477,9 @@ int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb)
>>>>       struct sw_flow_actions *acts = rcu_dereference(OVS_CB(skb)->flow->sf_acts);
>>>>       struct loop_counter *loop;
>>>>       int error;
>>>> +       struct ovs_key_ipv4_tunnel tun_key;
>>>> +
>>>> +        memset(&tun_key, 0, sizeof(tun_key));
>>>> 
>>> tun key will zeroed while executing tunnel set action, Do we still
>>> need to zero it here?
>>> 
>>>>       /* Check whether we've looped too much. */
>>>>       loop = &__get_cpu_var(loop_counters);
>>>> @@ -469,9 +491,9 @@ int ovs_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);
>>>> +                                        acts->actions_len, &tun_key, false);
>>>> 
>>>>       /* Check whether sub-actions looped too much. */
>>>>       if (unlikely(loop->looping))
>>>> diff --git a/datapath/datapath.c b/datapath/datapath.c
>>>> index a6915fb..d8a198e 100644
>>>> --- a/datapath/datapath.c
>>>> +++ b/datapath/datapath.c
>>>> @@ -587,12 +587,20 @@ static int validate_set(const struct nlattr *a,
>>>> 
>>>>       switch (key_type) {
>>>>       const struct ovs_key_ipv4 *ipv4_key;
>>>> +       const struct ovs_key_ipv4_tunnel *tun_key;
>>>> 
>>>>       case OVS_KEY_ATTR_PRIORITY:
>>>>       case OVS_KEY_ATTR_TUN_ID:
>>>>       case OVS_KEY_ATTR_ETHERNET:
>>>>               break;
>>>> 
>>>> +       case OVS_KEY_ATTR_IPV4_TUNNEL:
>>>> +               tun_key = nla_data(ovs_key);
>>>> +               if (!tun_key->ipv4_dst) {
>>>> +                       return -EINVAL;
>>>> +               }
>>>> +               break;
>>>> +
>>>>       case OVS_KEY_ATTR_IPV4:
>>>>               if (flow_key->eth.type != htons(ETH_P_IP))
>>>>                       return -EINVAL;
>>>> @@ -785,7 +793,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
>>>> 
>>>>       err = ovs_flow_metadata_from_nlattrs(&flow->key.phy.priority,
>>>>                                            &flow->key.phy.in_port,
>>>> -                                            &flow->key.phy.tun_id,
>>>> +                                            &flow->key.tun.tun_key,
>>>>                                            a[OVS_PACKET_ATTR_KEY]);
>>>>       if (err)
>>>>               goto err_flow_put;
>>>> diff --git a/datapath/datapath.h b/datapath/datapath.h
>>>> index affbf0e..c5df12d 100644
>>>> --- a/datapath/datapath.h
>>>> +++ b/datapath/datapath.h
>>>> @@ -96,7 +96,8 @@ struct datapath {
>>>> /**
>>>> * struct ovs_skb_cb - OVS data in skb CB
>>>> * @flow: The flow associated with this packet.  May be %NULL if no flow.
>>>> - * @tun_id: ID of the tunnel that encapsulated this packet.  It is 0 if the
>>>> + * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
>>>> + * packet is not being tunneled.
>>>> * @ip_summed: Consistently stores L4 checksumming status across different
>>>> * kernel versions.
>>>> * @csum_start: Stores the offset from which to start checksumming independent
>>>> @@ -107,7 +108,7 @@ struct datapath {
>>>> */
>>>> struct ovs_skb_cb {
>>>>       struct sw_flow          *flow;
>>>> -       __be64                  tun_id;
>>>> +       struct ovs_key_ipv4_tunnel  *tun_key;
>>>> #ifdef NEED_CSUM_NORMALIZE
>>>>       enum csum_type          ip_summed;
>>>>       u16                     csum_start;
>>>> diff --git a/datapath/flow.c b/datapath/flow.c
>>>> index d07337c..376f4be 100644
>>>> --- a/datapath/flow.c
>>>> +++ b/datapath/flow.c
>>>> @@ -629,7 +629,8 @@ int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
>>>>       memset(key, 0, sizeof(*key));
>>>> 
>>>>       key->phy.priority = skb->priority;
>>>> -       key->phy.tun_id = OVS_CB(skb)->tun_id;
>>>> +       if (OVS_CB(skb)->tun_key)
>>>> +               key->tun.tun_key = *OVS_CB(skb)->tun_key;
>>>>       key->phy.in_port = in_port;
>>>> 
>>>>       skb_reset_mac_header(skb);
>>>> @@ -847,6 +848,7 @@ const int ovs_key_lens[OVS_KEY_ATTR_MAX + 1] = {
>>>> 
>>>>       /* Not upstream. */
>>>>       [OVS_KEY_ATTR_TUN_ID] = sizeof(__be64),
>>>> +       [OVS_KEY_ATTR_IPV4_TUNNEL] = sizeof(struct ovs_key_ipv4_tunnel),
>>>> };
>>>> 
>>>> static int ipv4_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_len,
>>>> @@ -1022,9 +1024,30 @@ int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
>>>>               swkey->phy.in_port = DP_MAX_PORTS;
>>>>       }
>>>> 
>>>> -       if (attrs & (1ULL << OVS_KEY_ATTR_TUN_ID)) {
>>>> -               swkey->phy.tun_id = nla_get_be64(a[OVS_KEY_ATTR_TUN_ID]);
>>>> +       /* OVS_KEY_ATTR_TUN_ID and OVS_KEY_ATTR_IPV4_TUNEL must both arrive
>>>> +        * together.
>>>> +        */
>>>> +       if (attrs & (1ULL << OVS_KEY_ATTR_TUN_ID) &&
>>>> +           attrs & (1ULL << OVS_KEY_ATTR_IPV4_TUNNEL)) {
>>>> +               struct ovs_key_ipv4_tunnel *tun_key;
>>>> +               __be64 tun_id = 0;
>>>> +               tun_key = nla_data(a[OVS_KEY_ATTR_IPV4_TUNNEL]);
>>>> +               tun_id = nla_get_be64(a[OVS_KEY_ATTR_TUN_ID]);
>>>> +
>>>> +               if (tun_id != tun_key->tun_id)
>>>> +                       return -EINVAL;
>>>> +
>>>> +               swkey->tun.tun_key = *tun_key;
>>>>               attrs &= ~(1ULL << OVS_KEY_ATTR_TUN_ID);
>>>> +               attrs &= ~(1ULL << OVS_KEY_ATTR_IPV4_TUNNEL);
>>>> +       } else if (attrs & (1ULL << OVS_KEY_ATTR_TUN_ID)) {
>>>> +               swkey->tun.tun_key.tun_id = nla_get_be64(a[OVS_KEY_ATTR_TUN_ID]);
>>>> +               attrs &= ~(1ULL << OVS_KEY_ATTR_TUN_ID);
>>>> +       } else if (attrs & (1ULL << OVS_KEY_ATTR_IPV4_TUNNEL)) {
>>>> +               struct ovs_key_ipv4_tunnel *tun_key;
>>>> +               tun_key = nla_data(a[OVS_KEY_ATTR_IPV4_TUNNEL]);
>>>> +               swkey->tun.tun_key = *tun_key;
>>>> +               attrs &= ~(1ULL << OVS_KEY_ATTR_IPV4_TUNNEL);
>>>>       }
>>> 
>>> While validating set action OVS_KEY_ATTR_IPV4_TUNNEL, we are checking
>>> for ipv4_dst, I think we need similar check here.
>>> 
>>>> 
>>>>       /* Data attributes. */
>>>> @@ -1162,14 +1185,16 @@ int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
>>>> * get the metadata, that is, the parts of the flow key that cannot be
>>>> * extracted from the packet itself.
>>>> */
>>>> -int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port, __be64 *tun_id,
>>>> +int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port,
>>>> +                                  struct ovs_key_ipv4_tunnel *tun_key,
>>>>                                  const struct nlattr *attr)
>>>> {
>>>>       const struct nlattr *nla;
>>>>       int rem;
>>>> +       __be64 tun_id = 0;
>>>> 
>>>>       *in_port = DP_MAX_PORTS;
>>>> -       *tun_id = 0;
>>>> +       memset(tun_key, 0, sizeof(*tun_key));
>>>>       *priority = 0;
>>>> 
>>>>       nla_for_each_nested(nla, attr, rem) {
>>>> @@ -1185,7 +1210,20 @@ int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port, __be64 *tun_id,
>>>>                               break;
>>>> 
>>>>                       case OVS_KEY_ATTR_TUN_ID:
>>>> -                               *tun_id = nla_get_be64(nla);
>>>> +                               tun_id = nla_get_be64(nla);
>>>> +                               if ((tun_key->tun_flags & FLOW_TNL_F_KEY) &&
>>>> +                                   tun_key->tun_id != tun_id)
>>>> +                                       return -EINVAL;
>>>> +                               break;
>>>> +
>>>> +                       case OVS_KEY_ATTR_IPV4_TUNNEL:
>>>> +                               if (tun_key->tun_flags & FLOW_TNL_F_KEY)
>>>> +                                       tun_id = tun_key->tun_id;
>>>> +                               memcpy(tun_key, nla_data(nla),
>>>> +                                      sizeof(*tun_key));
>>>> +                               if ((tun_key->tun_flags & FLOW_TNL_F_KEY) &&
>>>> +                                   tun_id != tun_key->tun_id)
>>>> +                                       return -EINVAL;
>>>>                               break;
>>>> 
>>>>                       case OVS_KEY_ATTR_IN_PORT:
>>>> @@ -1210,10 +1248,20 @@ int ovs_flow_to_nlattrs(const struct sw_flow_key *swkey, struct sk_buff *skb)
>>>>           nla_put_u32(skb, OVS_KEY_ATTR_PRIORITY, swkey->phy.priority))
>>>>               goto nla_put_failure;
>>>> 
>>>> -       if (swkey->phy.tun_id != cpu_to_be64(0) &&
>>>> -           nla_put_be64(skb, OVS_KEY_ATTR_TUN_ID, swkey->phy.tun_id))
>>>> +        if ((swkey->tun.tun_key.tun_flags & FLOW_TNL_F_KEY) &&
>>>> +           nla_put_be64(skb, OVS_KEY_ATTR_TUN_ID, swkey->tun.tun_key.tun_id))
>>>>               goto nla_put_failure;
>>>> 
>>>> +       if (swkey->tun.tun_key.ipv4_dst) {
>>>> +               struct ovs_key_ipv4_tunnel *tun_key;
>>>> +               nla = nla_reserve(skb, OVS_KEY_ATTR_IPV4_TUNNEL,
>>>> +                                 sizeof(*tun_key));
>>>> +               if (!nla)
>>>> +                       goto nla_put_failure;
>>>> +               tun_key = nla_data(nla);
>>>> +               *tun_key = swkey->tun.tun_key;
>>>> +       }
>>>> +
>>> 
>>> Why are we sending both OVS_KEY_ATTR_TUN_ID and
>>> OVS_KEY_ATTR_IPV4_TUNNEL attributed here?
>>> we could first check for ipv4_dst else for FLOW_TNL_F_KEY in flow key.
>>> 
>>>>       if (swkey->phy.in_port != DP_MAX_PORTS &&
>>>>           nla_put_u32(skb, OVS_KEY_ATTR_IN_PORT, swkey->phy.in_port))
>>>>               goto nla_put_failure;
>>>> diff --git a/datapath/flow.h b/datapath/flow.h
>>>> index 02c563a..4430b32 100644
>>>> --- a/datapath/flow.h
>>>> +++ b/datapath/flow.h
>>>> @@ -42,10 +42,12 @@ struct sw_flow_actions {
>>>> 
>>>> struct sw_flow_key {
>>>>       struct {
>>>> -               __be64  tun_id;         /* Encapsulating tunnel ID. */
>>>>               u32     priority;       /* Packet QoS priority. */
>>>>               u16     in_port;        /* Input switch port (or DP_MAX_PORTS). */
>>>>       } phy;
>>>> +        struct {
>>>> +               struct ovs_key_ipv4_tunnel tun_key;  /* Encapsulating tunnel key. */
>>>> +       } tun;
>>>>       struct {
>>>>               u8     src[ETH_ALEN];   /* Ethernet source address. */
>>>>               u8     dst[ETH_ALEN];   /* Ethernet destination address. */
>>>> @@ -150,6 +152,7 @@ u64 ovs_flow_used_time(unsigned long flow_jiffies);
>>>> *                         ------  ---  ------  -----
>>>> *  OVS_KEY_ATTR_PRIORITY      4    --     4      8
>>>> *  OVS_KEY_ATTR_TUN_ID        8    --     4     12
>>>> + *  OVS_KEY_ATTR_IPV4_TUNNEL  24    --     4     28
>>>> *  OVS_KEY_ATTR_IN_PORT       4    --     4      8
>>>> *  OVS_KEY_ATTR_ETHERNET     12    --     4     16
>>>> *  OVS_KEY_ATTR_ETHERTYPE     2     2     4      8  (outer VLAN ethertype)
>>>> @@ -160,14 +163,15 @@ u64 ovs_flow_used_time(unsigned long flow_jiffies);
>>>> *  OVS_KEY_ATTR_ICMPV6        2     2     4      8
>>>> *  OVS_KEY_ATTR_ND           28    --     4     32
>>>> *  -------------------------------------------------
>>>> - *  total                                       156
>>>> + *  total                                       184
>>>> */
>>>> -#define FLOW_BUFSIZE 156
>>>> +#define FLOW_BUFSIZE 184
>>>> 
>>>> int ovs_flow_to_nlattrs(const struct sw_flow_key *, struct sk_buff *);
>>>> int ovs_flow_from_nlattrs(struct sw_flow_key *swkey, int *key_lenp,
>>>>                     const struct nlattr *);
>>>> -int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port, __be64 *tun_id,
>>>> +int ovs_flow_metadata_from_nlattrs(u32 *priority, u16 *in_port,
>>>> +                                  struct ovs_key_ipv4_tunnel *tun_key,
>>>>                                  const struct nlattr *);
>>>> 
>>>> #define MAX_ACTIONS_BUFSIZE    (16 * 1024)
>>>> diff --git a/datapath/tunnel.c b/datapath/tunnel.c
>>>> index d651c11..739f098 100644
>>>> --- a/datapath/tunnel.c
>>>> +++ b/datapath/tunnel.c
>>>> @@ -367,9 +367,9 @@ struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
>>>>       return NULL;
>>> ñ>  }
>>>> 
>>>> -static void ecn_decapsulate(struct sk_buff *skb, u8 tos)
>>>> +static void ecn_decapsulate(struct sk_buff *skb)
>>>> {
>>>> -       if (unlikely(INET_ECN_is_ce(tos))) {
>>>> +       if (unlikely(INET_ECN_is_ce(OVS_CB(skb)->tun_key->ipv4_tos))) {
>>>>               __be16 protocol = skb->protocol;
>>>> 
>>>>               skb_set_network_header(skb, ETH_HLEN);
>>>> @@ -416,7 +416,7 @@ static void ecn_decapsulate(struct sk_buff *skb, u8 tos)
>>>> * - skb->csum does not include the inner Ethernet header.
>>>> * - The layer pointers are undefined.
>>>> */
>>>> -void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos)
>>>> +void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb)
>>>> {
>>>>       struct ethhdr *eh;
>>>> 
>>>> @@ -433,7 +433,7 @@ void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos)
>>>>       skb_clear_rxhash(skb);
>>>>       secpath_reset(skb);
>>>> 
>>>> -       ecn_decapsulate(skb, tos);
>>>> +       ecn_decapsulate(skb);
>>>>       vlan_set_tci(skb, 0);
>>>> 
>>>>       if (unlikely(compute_ip_summed(skb, false))) {
>>>> @@ -613,7 +613,7 @@ static void ipv6_build_icmp(struct sk_buff *skb, struct sk_buff *nskb,
>>>> 
>>>> bool ovs_tnl_frag_needed(struct vport *vport,
>>>>                        const struct tnl_mutable_config *mutable,
>>>> -                        struct sk_buff *skb, unsigned int mtu, __be64 flow_key)
>>>> +                        struct sk_buff *skb, unsigned int mtu)
>>>> {
>>>>       unsigned int eth_hdr_len = ETH_HLEN;
>>>>       unsigned int total_length = 0, header_length = 0, payload_length;
>>>> @@ -697,17 +697,6 @@ bool ovs_tnl_frag_needed(struct vport *vport,
>>>>               ipv6_build_icmp(skb, nskb, mtu, payload_length);
>>>> #endif
>>>> 
>>>> -       /*
>>>> -        * Assume that flow based keys are symmetric with respect to input
>>>> -        * and output and use the key that we were going to put on the
>>>> -        * outgoing packet for the fake received packet.  If the keys are
>>>> -        * not symmetric then PMTUD needs to be disabled since we won't have
>>>> -        * any way of synthesizing packets.
>>>> -        */
>>>> -       if ((mutable->flags & (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION)) ==
>>>> -           (TNL_F_IN_KEY_MATCH | TNL_F_OUT_KEY_ACTION))
>>>> -               OVS_CB(nskb)->tun_id = flow_key;
>>>> -
>>>>       if (unlikely(compute_ip_summed(nskb, false))) {
>>>>               kfree_skb(nskb);
>>>>               return false;
>>>> @@ -723,12 +712,20 @@ static bool check_mtu(struct sk_buff *skb,
>>>>                     const struct tnl_mutable_config *mutable,
>>>>                     const struct rtable *rt, __be16 *frag_offp)
>>>> {
>>>> -       bool df_inherit = mutable->flags & TNL_F_DF_INHERIT;
>>>> +       bool df_inherit;
>>>>       bool pmtud = mutable->flags & TNL_F_PMTUD;
>>>> -       __be16 frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
>>>> +       __be16 frag_off;
>>>>       int mtu = 0;
>>>>       unsigned int packet_length = skb->len - ETH_HLEN;
>>>> 
>>>> +       if (OVS_CB(skb)->tun_key->ipv4_dst != 0) {
>>>> +               df_inherit = false;
>>>> +               frag_off = OVS_CB(skb)->tun_key->tun_flags & FLOW_TNL_F_DONT_FRAGMENT;
>>>> +       } else {
>>>> +               df_inherit = mutable->flags & TNL_F_DF_INHERIT;
>>>> +               frag_off = mutable->flags & TNL_F_DF_DEFAULT ? htons(IP_DF) : 0;
>>>> +        }
>>>> +
>>> Why not set pmtud to false incase of flow-based tunneling like you did
>>> it for df_inherit?
>>> 
>>>>       /* Allow for one level of tagging in the packet length. */
>>>>       if (!vlan_tx_tag_present(skb) &&
>>>>           eth_hdr(skb)->h_proto == htons(ETH_P_8021Q))
>>>> @@ -760,8 +757,7 @@ static bool check_mtu(struct sk_buff *skb,
>>>>                       mtu = max(mtu, IP_MIN_MTU);
>>>> 
>>>>                       if (packet_length > mtu &&
>>>> -                           ovs_tnl_frag_needed(vport, mutable, skb, mtu,
>>>> -                                               OVS_CB(skb)->tun_id))
>>>> +                           ovs_tnl_frag_needed(vport, mutable, skb, mtu))
>>>>                               return false;
>>>>               }
>>>>       }
>>>> @@ -777,8 +773,7 @@ static bool check_mtu(struct sk_buff *skb,
>>>>                       mtu = max(mtu, IPV6_MIN_MTU);
>>>> 
>>>>                       if (packet_length > mtu &&
>>>> -                           ovs_tnl_frag_needed(vport, mutable, skb, mtu,
>>>> -                                               OVS_CB(skb)->tun_id))
>>>> +                           ovs_tnl_frag_needed(vport, mutable, skb, mtu))
>>>>                               return false;
>>>>               }
>>>>       }
>>>> @@ -1000,15 +995,16 @@ unlock:
>>>> }
>>>> 
>>>> static struct rtable *__find_route(const struct tnl_mutable_config *mutable,
>>>> -                                  u8 ipproto, u8 tos)
>>>> +                                  __be32 saddr, __be32 daddr, u8 ipproto,
>>>> +                                  u8 tos)
>>>> {
>>>>       /* Tunnel configuration keeps DSCP part of TOS bits, But Linux
>>>>        * router expect RT_TOS bits only. */
>>>> 
>>>> #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,39)
>>>>       struct flowi fl = { .nl_u = { .ip4_u = {
>>>> -                                       .daddr = mutable->key.daddr,
>>>> -                                       .saddr = mutable->key.saddr,
>>>> +                                       .daddr = daddr,
>>>> +                                       .saddr = saddr,
>>>>                                       .tos   = RT_TOS(tos) } },
>>>>                                       .proto = ipproto };
>>>>       struct rtable *rt;
>>>> @@ -1018,8 +1014,8 @@ static struct rtable *__find_route(const struct tnl_mutable_config *mutable,
>>>> 
>>>>       return rt;
>>>> #else
>>>> -       struct flowi4 fl = { .daddr = mutable->key.daddr,
>>>> -                            .saddr = mutable->key.saddr,
>>>> +       struct flowi4 fl = { .daddr = daddr,
>>>> +                            .saddr = saddr,
>>>>                            .flowi4_tos = RT_TOS(tos),
>>>>                            .flowi4_proto = ipproto };
>>>> 
>>>> @@ -1029,7 +1025,8 @@ static struct rtable *__find_route(const struct tnl_mutable_config *mutable,
>>>> 
>>>> static struct rtable *find_route(struct vport *vport,
>>>>                                const struct tnl_mutable_config *mutable,
>>>> -                                u8 tos, struct tnl_cache **cache)
>>>> +                                __be32 saddr, __be32 daddr, u8 tos,
>>>> +                                struct tnl_cache **cache)
>>>> {
>>>>       struct tnl_vport *tnl_vport = tnl_vport_priv(vport);
>>>>       struct tnl_cache *cur_cache = rcu_dereference(tnl_vport->cache);
>>>> @@ -1037,18 +1034,21 @@ static struct rtable *find_route(struct vport *vport,
>>>>       *cache = NULL;
>>>>       tos = RT_TOS(tos);
>>>> 
>>>> -       if (likely(tos == RT_TOS(mutable->tos) &&
>>>> -           check_cache_valid(cur_cache, mutable))) {
>>>> +       if (daddr == mutable->key.daddr && saddr == mutable->key.saddr &&
>>>> +           tos == RT_TOS(mutable->tos) &&
>>>> +           check_cache_valid(cur_cache, mutable)) {
>>>>               *cache = cur_cache;
>>>>               return cur_cache->rt;
>>>>       } else {
>>>>               struct rtable *rt;
>>>> 
>>>> -               rt = __find_route(mutable, tnl_vport->tnl_ops->ipproto, tos);
>>>> +               rt = __find_route(mutable, saddr, daddr,
>>>> +                                 tnl_vport->tnl_ops->ipproto, tos);
>>>>               if (IS_ERR(rt))
>>>>                       return NULL;
>>>> 
>>>> -               if (likely(tos == RT_TOS(mutable->tos)))
>>>> +               if (daddr == mutable->key.daddr && saddr == mutable->key.saddr &&
>>>> +                   tos == RT_TOS(mutable->tos))
>>>>                       *cache = build_cache(vport, mutable, rt);
>>>> 
>>> I am not sure why checks are added on saddr and daddr here?
>>> header caching is not set in case of flow based tunneling to
>>> build_cache call is no-op anyways.
>>> 
>>>>               return rt;
>>>> @@ -1178,8 +1178,11 @@ int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
>>>>       struct rtable *rt;
>>>>       struct dst_entry *unattached_dst = NULL;
>>>>       struct tnl_cache *cache;
>>>> +       struct ovs_key_ipv4_tunnel tun_key;
>>>>       int sent_len = 0;
>>>>       __be16 frag_off = 0;
>>>> +       __be32 daddr;
>>>> +       __be32 saddr;
>>>>       u8 ttl;
>>>>       u8 inner_tos;
>>>>       u8 tos;
>>>> @@ -1207,6 +1210,13 @@ int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
>>>>       }
>>>> #endif
>>>> 
>>>> +       /* If OVS_CB(skb)->tun_key is NULL, point it at the local tun_key here,
>>>> +        * and zero it out.
>>>> +        */
>>>> +       if (OVS_CB(skb)->tun_key == NULL) {
>>>> +               memset(&tun_key, 0, sizeof(tun_key));
>>>> +               OVS_CB(skb)->tun_key = &tun_key;
>>>> +       }
>>>>       /* ToS */
>>>>       if (skb->protocol == htons(ETH_P_IP))
>>>>               inner_tos = ip_hdr(skb)->tos;
>>>> @@ -1219,11 +1229,23 @@ int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
>>>> 
>>>>       if (mutable->flags & TNL_F_TOS_INHERIT)
>>>>               tos = inner_tos;
>>>> +       else if (OVS_CB(skb)->tun_key->ipv4_dst != 0)
>>>> +               tos = OVS_CB(skb)->tun_key->ipv4_tos;
>>>>       else
>>>>               tos = mutable->tos;
>>>> 
>>>> +       if (OVS_CB(skb)->tun_key->ipv4_dst != 0)
>>>> +               daddr = OVS_CB(skb)->tun_key->ipv4_dst;
>>>> +       else
>>>> +               daddr = mutable->key.daddr;
>>>> +
>>>> +       if (OVS_CB(skb)->tun_key->ipv4_dst != 0)
>>>> +               saddr = OVS_CB(skb)->tun_key->ipv4_src;
>>>> +       else
>>>> +               saddr = mutable->key.saddr;
>>>> +
>>> 
>>> It will be easier to read if we have one if check on
>>> OVS_CB(skb)->tun_key->ipv4_dst which is retrieve all tunnel parameter
>>> for flow-based tunning and else block for campat code.
>>> 
>>>>       /* Route lookup */
>>>> -       rt = find_route(vport, mutable, tos, &cache);
>>>> +       rt = find_route(vport, mutable, saddr, daddr, tos, &cache);
>>>>       if (unlikely(!rt))
>>>>               goto error_free;
>>>>       if (unlikely(!cache))
>>>> @@ -1260,9 +1282,13 @@ int ovs_tnl_send(struct vport *vport, struct sk_buff *skb)
>>>>       }
>>>> 
>>>>       /* TTL */
>>>> -       ttl = mutable->ttl;
>>>> -       if (!ttl)
>>>> -               ttl = ip4_dst_hoplimit(&rt_dst(rt));
>>>> +       if (OVS_CB(skb)->tun_key->ipv4_dst != 0)
>>>> +               ttl = OVS_CB(skb)->tun_key->ipv4_ttl;
>>>> +       else {
>>>> +               ttl = mutable->ttl;
>>>> +               if (!ttl)
>>>> +                       ttl = ip4_dst_hoplimit(&rt_dst(rt));
>>>> +       }
>>>> 
>>>>       if (mutable->flags & TNL_F_TTL_INHERIT) {
>>> 
>>> This check could be in the compat code block, so it is less confusing.
>>> 
>>>>               if (skb->protocol == htons(ETH_P_IP))
>>>> @@ -1442,7 +1468,8 @@ static int tnl_set_config(struct net *net, struct nlattr *options,
>>>>               struct net_device *dev;
>>>>               struct rtable *rt;
>>>> 
>>>> -               rt = __find_route(mutable, tnl_ops->ipproto, mutable->tos);
>>>> +               rt = __find_route(mutable, mutable->key.saddr, mutable->key.daddr,
>>>> +                                 tnl_ops->ipproto, mutable->tos);
>>>>               if (IS_ERR(rt))
>>>>                       return -EADDRNOTAVAIL;
>>>>               dev = rt_dst(rt).dev;
>>>> diff --git a/datapath/tunnel.h b/datapath/tunnel.h
>>>> index 1924017..b7858d3 100644
>>>> --- a/datapath/tunnel.h
>>>> +++ b/datapath/tunnel.h
>>>> @@ -269,14 +269,14 @@ int ovs_tnl_set_addr(struct vport *vport, const unsigned char *addr);
>>>> const char *ovs_tnl_get_name(const struct vport *vport);
>>>> const unsigned char *ovs_tnl_get_addr(const struct vport *vport);
>>>> int ovs_tnl_send(struct vport *vport, struct sk_buff *skb);
>>>> -void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos);
>>>> +void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb);
>>>> 
>>>> struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
>>>>                               __be64 key, int tunnel_type,
>>>>                               const struct tnl_mutable_config **mutable);
>>>> bool ovs_tnl_frag_needed(struct vport *vport,
>>>>                        const struct tnl_mutable_config *mutable,
>>>> -                        struct sk_buff *skb, unsigned int mtu, __be64 flow_key);
>>>> +                        struct sk_buff *skb, unsigned int mtu);
>>>> void ovs_tnl_free_linked_skbs(struct sk_buff *skb);
>>>> 
>>>> int ovs_tnl_init(void);
>>>> @@ -286,4 +286,15 @@ static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport)
>>>>       return vport_priv(vport);
>>>> }
>>>> 
>>>> +static inline void tnl_tun_key_init(struct ovs_key_ipv4_tunnel *tun_key,
>>>> +                                   const struct iphdr *iph, __be64 tun_id)
>>>> +{
>>>> +       tun_key->tun_id = tun_id;
>>>> +       tun_key->ipv4_src = iph->saddr;
>>>> +       tun_key->ipv4_dst = iph->daddr;
>>>> +       tun_key->ipv4_tos = iph->tos;
>>>> +       tun_key->ipv4_ttl = iph->ttl;
>>>> +       tun_key->tun_flags = 0;
>>>> +}
>>>> +
>>>> #endif /* tunnel.h */
>>>> diff --git a/datapath/vport-capwap.c b/datapath/vport-capwap.c
>>>> index 05a099d..fbf50d9 100644
>>>> --- a/datapath/vport-capwap.c
>>>> +++ b/datapath/vport-capwap.c
>>>> @@ -220,7 +220,7 @@ static struct sk_buff *capwap_update_header(const struct vport *vport,
>>>>               struct capwaphdr_wsi *wsi = (struct capwaphdr_wsi *)(cwh + 1);
>>>>               struct capwaphdr_wsi_key *opt = (struct capwaphdr_wsi_key *)(wsi + 1);
>>>> 
>>>> -               opt->key = OVS_CB(skb)->tun_id;
>>>> +               opt->key = OVS_CB(skb)->tun_key->tun_id;
>>>>       }
>>>> 
>>>>       udph->len = htons(skb->len - skb_transport_offset(skb));
>>>> @@ -316,6 +316,7 @@ static int capwap_rcv(struct sock *sk, struct sk_buff *skb)
>>>>       struct vport *vport;
>>>>       const struct tnl_mutable_config *mutable;
>>>>       struct iphdr *iph;
>>>> +       struct ovs_key_ipv4_tunnel tun_key;
>>>>       __be64 key = 0;
>>>> 
>>>>       if (unlikely(!pskb_may_pull(skb, CAPWAP_MIN_HLEN + ETH_HLEN)))
>>>> @@ -333,12 +334,11 @@ static int capwap_rcv(struct sock *sk, struct sk_buff *skb)
>>>>               goto error;
>>>>       }
>>>> 
>>>> -       if (mutable->flags & TNL_F_IN_KEY_MATCH)
>>>> -               OVS_CB(skb)->tun_id = key;
>>>> -       else
>>>> -               OVS_CB(skb)->tun_id = 0;
>>>> +       tnl_tun_key_init(&tun_key, iph,
>>>> +                    mutable->flags & TNL_F_IN_KEY_MATCH ? key : 0);
>>>> +       OVS_CB(skb)->tun_key = &tun_key;
>>>> 
>>>> -       ovs_tnl_rcv(vport, skb, iph->tos);
>>>> +       ovs_tnl_rcv(vport, skb);
>>>>       goto out;
>>>> 
>>>> error:
>>>> diff --git a/datapath/vport-gre.c b/datapath/vport-gre.c
>>>> index ab89c5b..8076b1d 100644
>>>> --- a/datapath/vport-gre.c
>>>> +++ b/datapath/vport-gre.c
>>>> @@ -103,7 +103,7 @@ static struct sk_buff *gre_update_header(const struct vport *vport,
>>>> 
>>>>       /* Work backwards over the options so the checksum is last. */
>>>>       if (mutable->flags & TNL_F_OUT_KEY_ACTION)
>>>> -               *options = be64_get_low32(OVS_CB(skb)->tun_id);
>>>> +               *options = be64_get_low32(OVS_CB(skb)->tun_key->tun_id);
>>>> 
>>> Here we do need check if we doing flow-based tunneling. in case of
>>> flow-based tunneling mutable is shared between all tunnels, so there
>>> is no-way to we can do port specific flags check from mutable. about
>>> GRE checksum, we need to check for FLOW_TNL_F_CSUM flag for doing
>>> checksum on a packet.
>>> 
>>>>       if (mutable->out_key || mutable->flags & TNL_F_OUT_KEY_ACTION)
>>>>               options--;
>>>> @@ -285,7 +285,7 @@ static void gre_err(struct sk_buff *skb, u32 info)
>>>> #endif
>>>> 
>>>>       __skb_pull(skb, tunnel_hdr_len);
>>>> -       ovs_tnl_frag_needed(vport, mutable, skb, mtu, key);
>>>> +       ovs_tnl_frag_needed(vport, mutable, skb, mtu);
>>>>       __skb_push(skb, tunnel_hdr_len);
>>>> 
>>> same here, tunnel_hdr_len is stored in mutable which is going to be
>>> shared for all tunnels for a type in flow based tunneling, so we need
>>> to calculate it on packet send.
>>> 
>> I looked, and in the context of this function, tunnel_hdr_len is actually calculated
>> by the static function parse_header(), which actually is looking at the packet to
>> find it. Now, in the broader context, mutable does have a tunnel header as a part
>> of it, and if that's the tunnel header length you are concerned about, I agree we
>> need to address that. Can you confirm?
>> 
> 
> Right, I misplaced this comment. While rcv is tunnel_hlen is right, on
> send side tunnel_hlen needs fix.
> 
Calculating header length for each packet transmit doesn't seem efficient, but we may have
to go that route. Any ideas here?

Thanks,
Kyle
 
> Thanks,
> Pravin.





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