[PATCH RFC, iproute2] tc/mirred: Extend the mirred/redirect action to accept additional traffic class parameter

[Amritha Nambiar]

The Mirred/redirect action is extended to accept a traffic
class on the device in addition to the device's ifindex.

Usage: mirred <DIRECTION> <ACTION> <dev DEVICENAME> <tc TC_INDEX>

Example:
# tc qdisc add dev eth0 ingress

# tc filter add dev eth0 protocol ip parent ffff: prio 1 flower\
  dst_ip 192.168.1.1/32 ip_proto udp dst_port 22\
  indev eth0 action mirred ingress redirect dev eth0 tc 1

Signed-off-by: Amritha Nambiar <amritha.namb...@intel.com>
---
 tc/m_mirred.c |   26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/include/linux/tc_act/tc_mirred.h b/include/linux/tc_act/tc_mirred.h
index 3d7a2b3..9a3aa61 100644
--- a/include/linux/tc_act/tc_mirred.h
+++ b/include/linux/tc_act/tc_mirred.h
@@ -9,6 +9,9 @@
 #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 */
+
+#define MIRRED_F_TC_MAP                0x1
+#define MIRRED_TC_MAP_MAX      0x10
                                                                                
 
 struct tc_mirred {
        tc_gen;
@@ -21,6 +24,7 @@ enum {
        TCA_MIRRED_TM,
        TCA_MIRRED_PARMS,
        TCA_MIRRED_PAD,
+       TCA_MIRRED_TC_MAP,
        __TCA_MIRRED_MAX
 };
 #define TCA_MIRRED_MAX (__TCA_MIRRED_MAX - 1)
diff --git a/tc/m_mirred.c b/tc/m_mirred.c
index 2384bda..1a18c6b 100644
--- a/tc/m_mirred.c
+++ b/tc/m_mirred.c
@@ -29,12 +29,13 @@
 static void
 explain(void)
 {
-       fprintf(stderr, "Usage: mirred <DIRECTION> <ACTION> [index INDEX] <dev 
DEVICENAME>\n");
+       fprintf(stderr, "Usage: mirred <DIRECTION> <ACTION> [index INDEX] <dev 
DEVICENAME> [tc TCINDEX]\n");
        fprintf(stderr, "where:\n");
        fprintf(stderr, "\tDIRECTION := <ingress | egress>\n");
        fprintf(stderr, "\tACTION := <mirror | redirect>\n");
        fprintf(stderr, "\tINDEX  is the specific policy instance id\n");
        fprintf(stderr, "\tDEVICENAME is the devicename\n");
+       fprintf(stderr, "\tTCINDEX is the traffic class index\n");
 
 }
 
@@ -72,6 +73,8 @@ parse_direction(struct action_util *a, int *argc_p, char 
***argv_p,
        struct tc_mirred p = {};
        struct rtattr *tail;
        char d[16] = {};
+       __u32 flags = 0;
+       __u8 tc;
 
        while (argc > 0) {
 
@@ -142,6 +145,18 @@ parse_direction(struct action_util *a, int *argc_p, char 
***argv_p,
                                argc--;
                                argv++;
 
+                               if ((argc > 0) && (matches(*argv, "tc") == 0)) {
+                                       NEXT_ARG();
+                                       tc = atoi(*argv);
+                                       if (tc >= MIRRED_TC_MAP_MAX) {
+                                               fprintf(stderr, "Invalid TC 
index\n");
+                                               return -1;
+                                       }
+                                       flags |= MIRRED_F_TC_MAP;
+                                       ok++;
+                                       argc--;
+                                       argv++;
+                               }
                                break;
 
                        }
@@ -193,6 +208,9 @@ parse_direction(struct action_util *a, int *argc_p, char 
***argv_p,
        tail = NLMSG_TAIL(n);
        addattr_l(n, MAX_MSG, tca_id, NULL, 0);
        addattr_l(n, MAX_MSG, TCA_MIRRED_PARMS, &p, sizeof(p));
+       if (flags & MIRRED_F_TC_MAP)
+               addattr_l(n, MAX_MSG, TCA_MIRRED_TC_MAP,
+                         &tc, sizeof(tc));
        tail->rta_len = (void *) NLMSG_TAIL(n) - (void *) tail;
 
        *argc_p = argc;
@@ -248,6 +266,7 @@ print_mirred(struct action_util *au, FILE * f, struct 
rtattr *arg)
        struct tc_mirred *p;
        struct rtattr *tb[TCA_MIRRED_MAX + 1];
        const char *dev;
+       __u8 *tc;
 
        if (arg == NULL)
                return -1;
@@ -273,6 +292,11 @@ print_mirred(struct action_util *au, FILE * f, struct 
rtattr *arg)
        fprintf(f, "mirred (%s to device %s)", mirred_n2a(p->eaction), dev);
        print_action_control(f, " ", p->action, "");
 
+       if (tb[TCA_MIRRED_TC_MAP]) {
+               tc = RTA_DATA(tb[TCA_MIRRED_TC_MAP]);
+               fprintf(f, " tc %d", *tc);
+       }
+
        fprintf(f, "\n ");
        fprintf(f, "\tindex %u ref %d bind %d", p->index, p->refcnt,
                p->bindcnt);