Sun, Jan 15, 2017 at 03:01:19PM CET, j...@mojatatu.com wrote:
>From: Jamal Hadi Salim <j...@mojatatu.com>
>
>Introduce optional 128-bit action cookie.
>Like all other cookie schemes in the networking world (eg in protocols
>like http or existing kernel fib protocol field, etc) the idea is to save
>user state that when retrieved serves as a correlator. The kernel
>_should not_ intepret it.  The user can store whatever they wish in the
>128 bits.
>
>Sample exercise(showing variable length use of cookie)
>
>.. create an accept action with cookie a1b2c3d4
>sudo $TC actions add action ok index 1 cookie a1b2c3d4
>
>.. dump all gact actions..
>sudo $TC -s actions ls action gact
>
>       action order 0: gact action pass
>        random type none pass val 0
>        index 1 ref 1 bind 0 installed 5 sec used 5 sec
>       Action statistics:
>       Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>       backlog 0b 0p requeues 0
>       cookie a1b2c3d4
>
>.. bind the accept action to a filter..
>sudo $TC filter add dev lo parent ffff: protocol ip prio 1 \
>u32 match ip dst 127.0.0.1/32 flowid 1:1 action gact index 1
>
>... send some traffic..
>$ ping 127.0.0.1 -c 3
>PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
>64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.020 ms
>64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.027 ms
>64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.038 ms
>
>--- 127.0.0.1 ping statistics ---
>3 packets transmitted, 3 received, 0% packet loss, time 2109ms
>rtt min/avg/max/mdev = 0.020/0.028/0.038/0.008 ms 1
>
>... show some stats
>$ sudo $TC -s actions get action gact index 1
>
>       action order 1: gact action pass
>        random type none pass val 0
>        index 1 ref 2 bind 1 installed 204 sec used 5 sec
>       Action statistics:
>        Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0)
>       backlog 0b 0p requeues 0
>       cookie a1b2c3d4
>
>.. try longer cookie...
>$ sudo $TC actions replace action ok index 1 cookie 1234567890abcdef
>.. dump..
>$ sudo $TC -s actions ls action gact
>
>       action order 1: gact action pass
>        random type none pass val 0
>        index 1 ref 2 bind 1 installed 204 sec used 5 sec
>       Action statistics:
>        Sent 12168 bytes 164 pkt (dropped 0, overlimits 0 requeues 0)
>       backlog 0b 0p requeues 0
>       cookie 1234567890abcdef
>
>Signed-off-by: Jamal Hadi Salim <j...@mojatatu.com>
>---
> include/net/act_api.h        |  1 +
> include/net/pkt_cls.h        | 19 +++++++++++++------
> include/uapi/linux/pkt_cls.h |  3 +++
> net/sched/act_api.c          | 29 +++++++++++++++++++++++++++--
> 4 files changed, 44 insertions(+), 8 deletions(-)
>
>diff --git a/include/net/act_api.h b/include/net/act_api.h
>index 1d71644..0692458 100644
>--- a/include/net/act_api.h
>+++ b/include/net/act_api.h
>@@ -41,6 +41,7 @@ struct tc_action {
>       struct rcu_head                 tcfa_rcu;
>       struct gnet_stats_basic_cpu __percpu *cpu_bstats;
>       struct gnet_stats_queue __percpu *cpu_qstats;
>+      struct tc_cookie        *act_ck;
> };
> #define tcf_head      common.tcfa_head
> #define tcf_index     common.tcfa_index
>diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
>index f0a0514..f2fafeb 100644
>--- a/include/net/pkt_cls.h
>+++ b/include/net/pkt_cls.h
>@@ -24,15 +24,15 @@ struct tcf_walker {
> }
> 
> static inline unsigned long
>-cls_set_class(struct tcf_proto *tp, unsigned long *clp, 
>+cls_set_class(struct tcf_proto *tp, unsigned long *clp,

??

>       unsigned long cl)
> {
>       unsigned long old_cl;
>-      
>+

??

>       tcf_tree_lock(tp);
>       old_cl = __cls_set_class(clp, cl);
>       tcf_tree_unlock(tp);
>- 
>+

??

>       return old_cl;
> }
> 
>@@ -237,7 +237,7 @@ static inline int tcf_em_early_end(struct tcf_ematch *em, 
>int result)
> 
>       return 0;
> }
>-      
>+

??


> /**
>  * struct tcf_ematch_tree - ematch tree handle
>  *
>@@ -246,8 +246,7 @@ static inline int tcf_em_early_end(struct tcf_ematch *em, 
>int result)
>  */
> struct tcf_ematch_tree {
>       struct tcf_ematch_tree_hdr hdr;
>-      struct tcf_ematch *     matches;
>-      
>+      struct tcf_ematch *matches;

??

> };
> 
> /**
>@@ -515,4 +514,12 @@ struct tc_cls_bpf_offload {
>       u32 gen_flags;
> };
> 
>+
>+/* This structure holds cookie structure that is passed from user
>+ * to the kernel for actions and classifiers

You can add "." to the end of the sentence in V4.


>+ */
>+struct tc_cookie {
>+      unsigned char ck[TC_COOKIE_MAX_SIZE];
>+      unsigned char ck_len;
>+};
> #endif
>diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
>index 1e5e1dd..2d2414e 100644
>--- a/include/uapi/linux/pkt_cls.h
>+++ b/include/uapi/linux/pkt_cls.h
>@@ -4,6 +4,8 @@
> #include <linux/types.h>
> #include <linux/pkt_sched.h>
> 
>+#define TC_COOKIE_MAX_SIZE 16
>+
> /* Action attributes */
> enum {
>       TCA_ACT_UNSPEC,
>@@ -12,6 +14,7 @@ enum {
>       TCA_ACT_INDEX,
>       TCA_ACT_STATS,
>       TCA_ACT_PAD,
>+      TCA_ACT_COOKIE,
>       __TCA_ACT_MAX
> };
> 
>diff --git a/net/sched/act_api.c b/net/sched/act_api.c
>index f04715a..9d05b70 100644
>--- a/net/sched/act_api.c
>+++ b/net/sched/act_api.c
>@@ -24,6 +24,7 @@
> #include <net/net_namespace.h>
> #include <net/sock.h>
> #include <net/sch_generic.h>
>+#include <net/pkt_cls.h>
> #include <net/act_api.h>
> #include <net/netlink.h>
> 
>@@ -33,6 +34,7 @@ static void free_tcf(struct rcu_head *head)
> 
>       free_percpu(p->cpu_bstats);
>       free_percpu(p->cpu_qstats);
>+      kfree(p->act_ck);
>       kfree(p);
> }
> 
>@@ -464,8 +466,8 @@ int tcf_action_destroy(struct list_head *actions, int bind)
>       return a->ops->dump(skb, a, bind, ref);
> }
> 
>-int
>-tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
>+int tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind,
>+                    int ref)

??

Otherwise, this looks good. Thanks.



> {
>       int err = -EINVAL;
>       unsigned char *b = skb_tail_pointer(skb);
>@@ -475,6 +477,12 @@ int tcf_action_destroy(struct list_head *actions, int 
>bind)
>               goto nla_put_failure;
>       if (tcf_action_copy_stats(skb, a, 0))
>               goto nla_put_failure;
>+      if (a->act_ck) {
>+              if (nla_put(skb, TCA_ACT_COOKIE, a->act_ck->ck_len,
>+                          a->act_ck))
>+                      goto nla_put_failure;
>+      }
>+
>       nest = nla_nest_start(skb, TCA_OPTIONS);
>       if (nest == NULL)
>               goto nla_put_failure;
>@@ -575,6 +583,23 @@ struct tc_action *tcf_action_init_1(struct net *net, 
>struct nlattr *nla,
>       if (err < 0)
>               goto err_mod;
> 
>+      if (tb[TCA_ACT_COOKIE]) {
>+              if (nla_len(tb[TCA_ACT_COOKIE]) > TC_COOKIE_MAX_SIZE) {
>+                      err = -EINVAL;
>+                      goto err_mod;
>+              }
>+
>+              a->act_ck = kzalloc(sizeof(*a->act_ck), GFP_KERNEL);
>+              if (unlikely(!a->act_ck)) {
>+                      err = -ENOMEM;
>+                      goto err_mod;
>+              }
>+
>+              memcpy(a->act_ck->ck, nla_data(tb[TCA_ACT_COOKIE]),
>+                     nla_len(tb[TCA_ACT_COOKIE]));
>+              a->act_ck->ck_len = nla_len(tb[TCA_ACT_COOKIE]);
>+      }
>+
>       /* module count goes up only when brand new policy is created
>        * if it exists and is only bound to in a_o->init() then
>        * ACT_P_CREATED is not returned (a zero is).
>-- 
>1.9.1
>

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