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Date: Thu, 24 Sep 2015 16:42:01 -0700
From: Pravin Shelar <pshelar@...ira.com>
To: Thomas F Herbert <thomasfherbert@...il.com>
Cc: netdev <netdev@...r.kernel.org>, therbert@...hat.com,
"dev@...nvswitch.org" <dev@...nvswitch.org>
Subject: Re: [PATCH 3/3] 802.1AD: Flow handling, actions, vlan parsing and
netlink attributes
On Thu, Sep 24, 2015 at 10:58 AM, Thomas F Herbert
<thomasfherbert@...il.com> wrote:
> Add support for 802.1ad including the ability to push and pop double
> tagged vlans. Add support for 802.1ad to netlink parsing and flow
> conversion. Uses double nested encap attributes to represent double
> tagged vlan. Inner TPID encoded along with ctci in nested attributes.
>
> Signed-off-by: Thomas F Herbert <thomasfherbert@...il.com>
> ---
> net/openvswitch/flow.c | 83 +++++++++++++++++----
> net/openvswitch/flow.h | 5 ++
> net/openvswitch/flow_netlink.c | 166 ++++++++++++++++++++++++++++++++++++++---
> 3 files changed, 230 insertions(+), 24 deletions(-)
>
> diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
> index c8db44a..db58e47 100644
> --- a/net/openvswitch/flow.c
> +++ b/net/openvswitch/flow.c
> @@ -305,21 +305,77 @@ static bool icmp6hdr_ok(struct sk_buff *skb)
> static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
> {
> struct qtag_prefix {
> - __be16 eth_type; /* ETH_P_8021Q */
> + __be16 eth_type; /* ETH_P_8021Q or ETH_P_8021AD */
> __be16 tci;
> };
> - struct qtag_prefix *qp;
> + struct qtag_prefix *qp = (struct qtag_prefix *)skb->data;
>
> - if (unlikely(skb->len < sizeof(struct qtag_prefix) + sizeof(__be16)))
> + struct qinqtag_prefix {
> + __be16 eth_type; /* ETH_P_8021Q or ETH_P_8021AD */
> + __be16 tci;
> + __be16 inner_tpid; /* ETH_P_8021Q */
> + __be16 ctci;
> + };
> +
> + if (likely(skb_vlan_tag_present(skb))) {
> + key->eth.tci = htons(skb->vlan_tci);
> +
> + /* Case where upstream
> + * processing has already stripped the outer vlan tag.
> + */
> + if (unlikely(skb->vlan_proto == htons(ETH_P_8021AD))) {
> + if (unlikely(skb->len < sizeof(struct qtag_prefix) +
> + sizeof(__be16))) {
> + key->eth.tci = 0;
> + return 0;
> + }
> +
> + if (unlikely(!pskb_may_pull(skb,
> + sizeof(struct qtag_prefix) +
> + sizeof(__be16))))
> + return -ENOMEM;
> +
qp pointer is no longer valid after pskb_may_pull() call.
> + key->eth.cvlan.ctci =
> + qp->tci | htons(VLAN_TAG_PRESENT);
> + key->eth.cvlan.c_tpid = qp->eth_type;
> +
> + __skb_pull(skb, sizeof(struct qtag_prefix));
> + }
> return 0;
> + }
>
> - if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
> - sizeof(__be16))))
> - return -ENOMEM;
>
> - qp = (struct qtag_prefix *) skb->data;
> - key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
> - __skb_pull(skb, sizeof(struct qtag_prefix));
qp access is done without skb_may_pull() call.
> + if (qp->eth_type == htons(ETH_P_8021AD)) {
> + struct qinqtag_prefix *qinqp =
> + (struct qinqtag_prefix *)skb->data;
> +
> + if (unlikely(skb->len < sizeof(struct qinqtag_prefix) +
> + sizeof(__be16)))
> + return 0;
> +
> + if (unlikely(!pskb_may_pull(skb, sizeof(struct qinqtag_prefix) +
> + sizeof(__be16))))
> + return -ENOMEM;
same as above qinqp pointer is not valid after psk_may_pull().
> + key->eth.tci = qinqp->tci | htons(VLAN_TAG_PRESENT);
> + key->eth.cvlan.ctci = qinqp->ctci | htons(VLAN_TAG_PRESENT);
> + key->eth.cvlan.c_tpid = qinqp->inner_tpid;
> +
> + __skb_pull(skb, sizeof(struct qinqtag_prefix));
> +
> + return 0;
> + }
> + if (qp->eth_type == htons(ETH_P_8021Q)) {
> + if (unlikely(skb->len < sizeof(struct qtag_prefix) +
> + sizeof(__be16)))
> + return -ENOMEM;
> +
> + if (unlikely(!pskb_may_pull(skb, sizeof(struct qtag_prefix) +
> + sizeof(__be16))))
> + return 0;
same issue as above.
> + key->eth.tci = qp->tci | htons(VLAN_TAG_PRESENT);
> +
> + __skb_pull(skb, sizeof(struct qtag_prefix));
> + }
>
> return 0;
> }
...
> diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h
> index fe527d2..2c491e8 100644
> --- a/net/openvswitch/flow.h
> +++ b/net/openvswitch/flow.h
> @@ -69,6 +69,11 @@ struct sw_flow_key {
> u8 src[ETH_ALEN]; /* Ethernet source address. */
> u8 dst[ETH_ALEN]; /* Ethernet destination address. */
> __be16 tci; /* 0 if no VLAN, VLAN_TAG_PRESENT set otherwise. */
> + struct {
> + __be16 c_tpid; /* Vlan DL_type 802.1q or 802.1ad */
> + __be16 ctci; /* 0 if no CVLAN, VLAN_TAG_PRESENT */
Lets call c_tpid type and ctci tci, to keep naming consistent with outer vlan.
> + /* set otherwise. */
> + } cvlan;
> __be16 type; /* Ethernet frame type. */
> } eth;
> union {
> diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
> index c92d6a2..5fe415d 100644
> --- a/net/openvswitch/flow_netlink.c
> +++ b/net/openvswitch/flow_netlink.c
...
> @@ -1064,6 +1085,80 @@ static void mask_set_nlattr(struct nlattr *attr, u8 val)
> nlattr_set(attr, val, ovs_key_lens);
> }
>
> +static int parse_vlan_from_nlattrs(const struct nlattr **nla,
> + struct sw_flow_match *match,
> + u64 *key_attrs, bool *ie_valid,
> + const struct nlattr **a, bool is_mask,
> + bool log)
> +{
> + int err;
> + const struct nlattr *encap;
> +
> + *ie_valid = false;
> + if (!is_mask) {
> + u64 v_attrs = 0;
> +
> + err = parse_flow_nlattrs(*nla, a, &v_attrs, log);
> + if (err)
> + return err;
> + /* Another encap attribute here indicates
> + * the presence of a double tagged vlan.
> + */
> + if ((v_attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) &&
> + eth_type_vlan(nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]))) {
> + if (!((v_attrs & (1ULL << OVS_KEY_ATTR_VLAN)) &&
> + (v_attrs & (1ULL << OVS_KEY_ATTR_ENCAP)))) {
> + OVS_NLERR(log, "Invalid Inner VLAN frame");
> + return -EINVAL;
> + }
> + encap = a[OVS_KEY_ATTR_ENCAP];
> + v_attrs &= ~(1 << OVS_KEY_ATTR_ENCAP);
> +
> + err = cust_vlan_from_nlattrs(match, a, is_mask, log);
> + if (err)
> + return err;
> + *ie_valid = true;
> + *nla = encap;
> +
> + /* Insure that tci key attribute isn't
> + * overwritten by encapsulated customer tci.
> + * Ethertype is cleared because it is c_tpid.
> + */
> + v_attrs &= ~(1 << OVS_KEY_ATTR_VLAN);
> + v_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
> + }
> + *key_attrs |= v_attrs;
> +
> + } else {
> + u64 mask_v_attrs = 0;
> +
> + err = parse_flow_mask_nlattrs(*nla, a, &mask_v_attrs, log);
> + if (err)
> + return err;
> +
> + if (mask_v_attrs & 1 << OVS_KEY_ATTR_ENCAP) {
> + if (!*ie_valid) {
> + OVS_NLERR(log, "Encap mask attribute is set for non-CVLAN frame.");
> + err = -EINVAL;
No need to set err it is not read again.
> + return err;
> + }
At the beginning of this same function ie_valid is set to false. So
this case always return error resulting failure in flow install. This
make me wonder if you ever tested this code with multiple encap
traffic.
> + encap = a[OVS_KEY_ATTR_ENCAP];
> + mask_v_attrs &= ~(1 << OVS_KEY_ATTR_ENCAP);
> +
> + err = cust_vlan_from_nlattrs(match, a, is_mask, log);
> + if (err)
> + return err;
> + *nla = encap;
> +
> + mask_v_attrs &= ~(1ULL << OVS_KEY_ATTR_VLAN);
> + mask_v_attrs &= ~(1ULL << OVS_KEY_ATTR_ETHERTYPE);
> + }
> +
> + *key_attrs |= mask_v_attrs;
> + }
> + return 0;
> +}
> +
> /**
> * ovs_nla_get_match - parses Netlink attributes into a flow key and
> * mask. In case the 'mask' is NULL, the flow is treated as exact match
> @@ -1091,6 +1186,7 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
> u64 key_attrs = 0;
> u64 mask_attrs = 0;
> bool encap_valid = false;
> + bool i_encap_valid = false;
> int err;
>
> err = parse_flow_nlattrs(nla_key, a, &key_attrs, log);
> @@ -1099,11 +1195,11 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
>
> if ((key_attrs & (1 << OVS_KEY_ATTR_ETHERNET)) &&
> (key_attrs & (1 << OVS_KEY_ATTR_ETHERTYPE)) &&
> - (nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]) == htons(ETH_P_8021Q))) {
> + eth_type_vlan(nla_get_be16(a[OVS_KEY_ATTR_ETHERTYPE]))) {
> __be16 tci;
>
> - if (!((key_attrs & (1 << OVS_KEY_ATTR_VLAN)) &&
> - (key_attrs & (1 << OVS_KEY_ATTR_ENCAP)))) {
> + if (!((key_attrs & (1ULL << OVS_KEY_ATTR_VLAN)) &&
> + (key_attrs & (1ULL << OVS_KEY_ATTR_ENCAP)))) {
> OVS_NLERR(log, "Invalid Vlan frame.");
> return -EINVAL;
> }
> @@ -1115,9 +1211,19 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
> encap_valid = true;
>
> if (tci & htons(VLAN_TAG_PRESENT)) {
> - err = parse_flow_nlattrs(encap, a, &key_attrs, log);
> + err = parse_vlan_from_nlattrs(&encap, match, &key_attrs,
> + &i_encap_valid, a, false,
> + log);
> if (err)
> return err;
> +
> + if (i_encap_valid) {
> + err = parse_flow_nlattrs(encap, a,
> + &key_attrs,
> + log);
> + if (err)
> + return err;
> + }
Can you call this function from parse_vlan_from_nlattrs()? This will
eliminate following call site too.
> } else if (!tci) {
> /* Corner case for truncated 802.1Q header. */
> if (nla_len(encap)) {
> @@ -1188,10 +1294,21 @@ int ovs_nla_get_match(struct net *net, struct sw_flow_match *match,
> if (eth_type == htons(0xffff)) {
> mask_attrs &= ~(1 << OVS_KEY_ATTR_ETHERTYPE);
> encap = a[OVS_KEY_ATTR_ENCAP];
> - err = parse_flow_mask_nlattrs(encap, a,
> - &mask_attrs, log);
> + err = parse_vlan_from_nlattrs(&encap, match,
> + &mask_attrs,
> + &i_encap_valid,
> + a, true, log);
> if (err)
> goto free_newmask;
> +
> + if (i_encap_valid) {
> + err =
> + parse_flow_mask_nlattrs(encap, a,
> + &mask_attrs,
> + log);
> + if (err)
> + goto free_newmask;
> + }
> } else {
> OVS_NLERR(log, "VLAN frames must have an exact match on the TPID (mask=%x).",
> ntohs(eth_type));
> @@ -1320,6 +1437,7 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
> {
> struct ovs_key_ethernet *eth_key;
> struct nlattr *nla, *encap;
> + struct nlattr *in_encap = NULL;
>
> if (nla_put_u32(skb, OVS_KEY_ATTR_RECIRC_ID, output->recirc_id))
> goto nla_put_failure;
> @@ -1368,17 +1486,42 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
> ether_addr_copy(eth_key->eth_src, output->eth.src);
> ether_addr_copy(eth_key->eth_dst, output->eth.dst);
>
> - if (swkey->eth.tci || swkey->eth.type == htons(ETH_P_8021Q)) {
> + if (swkey->eth.tci || eth_type_vlan(swkey->eth.type)) {
> __be16 eth_type;
> - eth_type = !is_mask ? htons(ETH_P_8021Q) : htons(0xffff);
> +
> + if (swkey->eth.cvlan.ctci ||
> + eth_type_vlan(swkey->eth.cvlan.c_tpid))
> + eth_type = !is_mask ? htons(ETH_P_8021AD) :
> + htons(0xffff);
> + else
> + eth_type = !is_mask ? htons(ETH_P_8021Q) :
> + htons(0xffff);
> +
Here we can directly dump output->eth.type to netlink. No need to
check for inner encap.
> if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE, eth_type) ||
> nla_put_be16(skb, OVS_KEY_ATTR_VLAN, output->eth.tci))
> goto nla_put_failure;
> encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> if (!swkey->eth.tci)
> goto unencap;
> - } else
> + if (swkey->eth.cvlan.ctci || eth_type_vlan(swkey->eth.type)) {
> + __be16 eth_type;
> +
> + /* Customer tci is nested but uses same key attribute.
> + */
> + eth_type = !is_mask ? htons(ETH_P_8021Q) :
> + htons(0xffff);
We can just dump eth_type from output key into netlink attribute
rather than deriving it from other values.
> + if (nla_put_be16(skb, OVS_KEY_ATTR_ETHERTYPE,
> + eth_type) ||
> + nla_put_be16(skb, OVS_KEY_ATTR_VLAN,
> + output->eth.cvlan.ctci))
> + goto nla_put_failure;
> + in_encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> + if (!swkey->eth.cvlan.ctci)
> + goto unencap;
> + }
> + } else {
> encap = NULL;
> + }
>
> if (swkey->eth.type == htons(ETH_P_802_2)) {
> /*
> @@ -1525,6 +1668,8 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
> unencap:
> if (encap)
> nla_nest_end(skb, encap);
> + if (in_encap)
> + nla_nest_end(skb, in_encap);
>
> return 0;
>
> @@ -2174,7 +2319,8 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr,
>
> case OVS_ACTION_ATTR_PUSH_VLAN:
> vlan = nla_data(a);
> - if (vlan->vlan_tpid != htons(ETH_P_8021Q))
> + if ((vlan->vlan_tpid != htons(ETH_P_8021Q)) &&
> + (vlan->vlan_tpid != htons(ETH_P_8021AD)))
> return -EINVAL;
This is open coded negative eth_type_vlan() function.
You also need to update packet_length() in vport-netdev.c
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