Sat, Jul 02, 2016 at 04:34:25PM CEST, j...@mojatatu.com wrote:
>From: Jamal Hadi Salim <j...@mojatatu.com>
>
>Often redirecting or mirroring requires that we set the dstMAC address
>of the target device. While it is possible to pipe to a pedit action,
>this patch obsoletes the need for that. This is a justified feature because
>the dst MAC addresses rewrite is such a common use case.
We can't we have set of actions each doing its own job? I don't like
merging functionality into actions :(
>
>Sample usage:
>sudo $TC filter add dev $ETH parent 1: protocol ip prio 10 \
>u32 match ip protocol 1 0xff flowid 1:2 \
>action mirred egress redirect dev $SPANPORT dst 02:15:15:15:15:15
>
>This will match all icmp packets going out on dev $ETH and
>redirect them to dev $SPANPORT while setting their dst MAC address
>to 02:15:15:15:15:15
>
>Signed-off-by: Jamal Hadi Salim <j...@mojatatu.com>
>---
> include/net/tc_act/tc_mirred.h | 4 +++-
> include/uapi/linux/tc_act/tc_mirred.h | 7 ++++---
> net/sched/act_mirred.c | 24 +++++++++++++++++++++++-
> 3 files changed, 30 insertions(+), 5 deletions(-)
>
>diff --git a/include/net/tc_act/tc_mirred.h b/include/net/tc_act/tc_mirred.h
>index e891835..7e8bced 100644
>--- a/include/net/tc_act/tc_mirred.h
>+++ b/include/net/tc_act/tc_mirred.h
>@@ -6,10 +6,12 @@
>
> struct tcf_mirred {
> struct tcf_common common;
>+ struct net_device __rcu *tcfm_dev;
> int tcfm_eaction;
> int tcfm_ifindex;
> int tcfm_ok_push;
>- struct net_device __rcu *tcfm_dev;
>+ u8 eth_dst[ETH_ALEN];
>+ /* XXX 6 bytes hole here*/
> struct list_head tcfm_list;
> };
> #define to_mirred(a) \
>diff --git a/include/uapi/linux/tc_act/tc_mirred.h
>b/include/uapi/linux/tc_act/tc_mirred.h
>index 3d7a2b3..aaca1ff 100644
>--- a/include/uapi/linux/tc_act/tc_mirred.h
>+++ b/include/uapi/linux/tc_act/tc_mirred.h
>@@ -9,20 +9,21 @@
> #define TCA_EGRESS_MIRROR 2 /* mirror packet to EGRESS */
> #define TCA_INGRESS_REDIR 3 /* packet redirect to INGRESS*/
> #define TCA_INGRESS_MIRROR 4 /* mirror packet to INGRESS */
>-
>
>+
> struct tc_mirred {
> tc_gen;
> int eaction; /* one of IN/EGRESS_MIRROR/REDIR */
> __u32 ifindex; /* ifindex of egress port */
> };
>-
>
>+
> enum {
> TCA_MIRRED_UNSPEC,
> TCA_MIRRED_TM,
> TCA_MIRRED_PARMS,
> TCA_MIRRED_PAD,
>+ TCA_MIRRED_DMAC,
> __TCA_MIRRED_MAX
> };
> #define TCA_MIRRED_MAX (__TCA_MIRRED_MAX - 1)
>-
>
>+
> #endif
>diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
>index 5b135d3..1cc14f5 100644
>--- a/net/sched/act_mirred.c
>+++ b/net/sched/act_mirred.c
>@@ -49,6 +49,7 @@ static void tcf_mirred_release(struct tc_action *a, int bind)
>
> static const struct nla_policy mirred_policy[TCA_MIRRED_MAX + 1] = {
> [TCA_MIRRED_PARMS] = { .len = sizeof(struct tc_mirred) },
>+ [TCA_MIRRED_DMAC] = { .len = ETH_ALEN},
> };
>
> static int mirred_net_id;
>@@ -64,15 +65,24 @@ static int tcf_mirred_init(struct net *net, struct nlattr
>*nla,
> struct net_device *dev;
> int ret, ok_push = 0;
> bool exists = false;
>+ u8 *daddr = NULL;
>
> if (nla == NULL)
> return -EINVAL;
>+
> ret = nla_parse_nested(tb, TCA_MIRRED_MAX, nla, mirred_policy);
> if (ret < 0)
> return ret;
>+
> if (tb[TCA_MIRRED_PARMS] == NULL)
> return -EINVAL;
>+
> parm = nla_data(tb[TCA_MIRRED_PARMS]);
>+ if (tb[TCA_MIRRED_DMAC]) {
>+ daddr = nla_data(tb[TCA_MIRRED_DMAC]);
>+ if (is_zero_ether_addr(daddr))
>+ return -EINVAL;
>+ }
>
> exists = tcf_hash_check(tn, parm->index, a, bind);
> if (exists && bind)
>@@ -126,6 +136,9 @@ static int tcf_mirred_init(struct net *net, struct nlattr
>*nla,
> }
> m = to_mirred(a);
>
>+ if (daddr)
>+ ether_addr_copy(m->eth_dst, daddr);
>+
> ASSERT_RTNL();
> m->tcf_action = parm->action;
> m->tcfm_eaction = parm->eaction;
>@@ -190,6 +203,9 @@ static int tcf_mirred(struct sk_buff *skb, const struct
>tc_action *a,
>
> skb2->skb_iif = skb->dev->ifindex;
> skb2->dev = dev;
>+ if (!is_zero_ether_addr(m->eth_dst))
>+ ether_addr_copy(eth_hdr(skb2)->h_dest, m->eth_dst);
>+
> err = dev_queue_xmit(skb2);
>
> if (err) {
>@@ -203,7 +219,8 @@ out:
> return retval;
> }
>
>-static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int
>bind, int ref)
>+static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind,
>+ int ref)
> {
> unsigned char *b = skb_tail_pointer(skb);
> struct tcf_mirred *m = a->priv;
>@@ -220,6 +237,11 @@ static int tcf_mirred_dump(struct sk_buff *skb, struct
>tc_action *a, int bind, i
> if (nla_put(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt))
> goto nla_put_failure;
>
>+ if (!is_zero_ether_addr(m->eth_dst)) {
>+ if (nla_put(skb, TCA_MIRRED_DMAC, ETH_ALEN, m->eth_dst))
>+ goto nla_put_failure;
>+ }
>+
> tcf_tm_dump(&t, &m->tcf_tm);
> if (nla_put_64bit(skb, TCA_MIRRED_TM, sizeof(t), &t, TCA_MIRRED_PAD))
> goto nla_put_failure;
>--
>1.9.1
>
