tc: m_mirred: Add support for ingress redirect/mirror

So far, only the 'egress' direction was implemented.

Allow specifying 'ingress' as the direction packet appears on the target
interface.

For example, this takes incoming 802.1q frames on veth0 and redirects
them for input on dummy0:

 # tc filter add dev veth0 parent ffff: pref 1 protocol 802.1q basic \
     action mirred ingress redirect dev dummy0

Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>

diff --git a/man/man8/tc-mirred.8 b/man/man8/tc-mirred.8
index bba96e0e5d8c0a92742a4250fe254a430e93d8e2..38833b452d92685747304337fcac443f31657881 100644 (file)
--- a/man/man8/tc-mirred.8
+++ b/man/man8/tc-mirred.8
@@ -30,9 +30,7 @@ receives. Mirroring is what is sometimes referred to as Switch Port Analyzer
 .TQ
 .B egress
 Specify the direction in which the packet shall appear on the destination
-interface. Currently only
-.B egress
-is implemented.
+interface.
 .TP
 .B mirror
 .TQ

diff --git a/tc/m_mirred.c b/tc/m_mirred.c
index 11f4c9b46fea9cf2c38e3d130714c2515894b6d1..01f916d55c4299349b9a6de24a325915f49cd64a 100644 (file)
--- a/tc/m_mirred.c
+++ b/tc/m_mirred.c
@@ -62,13 +62,13 @@ static const char *mirred_n2a(int action)
 }
 
 static int
-parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
-            int tca_id, struct nlmsghdr *n)
+parse_direction(struct action_util *a, int *argc_p, char ***argv_p,
+               int tca_id, struct nlmsghdr *n)
 {
 
        int argc = *argc_p;
        char **argv = *argv_p;
-       int ok = 0, iok = 0, mirror = 0, redir = 0;
+       int ok = 0, iok = 0, mirror = 0, redir = 0, ingress = 0, egress = 0;
        struct tc_mirred p = {};
        struct rtattr *tail;
        char d[16] = {};
@@ -77,7 +77,21 @@ parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
 
                if (matches(*argv, "action") == 0) {
                        break;
-               } else if (matches(*argv, "egress") == 0) {
+               } else if (!egress && matches(*argv, "egress") == 0) {
+                       egress = 1;
+                       if (ingress) {
+                               fprintf(stderr, "Can't have both egress and ingress\n");
+                               return -1;
+                       }
+                       NEXT_ARG();
+                       ok++;
+                       continue;
+               } else if (!ingress && matches(*argv, "ingress") == 0) {
+                       ingress = 1;
+                       if (egress) {
+                               fprintf(stderr, "Can't have both ingress and egress\n");
+                               return -1;
+                       }
                        NEXT_ARG();
                        ok++;
                        continue;
@@ -96,7 +110,7 @@ parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
                                        break;
                                }
                        } else if (!ok) {
-                               fprintf(stderr, "was expecting egress (%s)\n", *argv);
+                               fprintf(stderr, "was expecting egress or ingress (%s)\n", *argv);
                                break;
 
                        } else if (!mirror && matches(*argv, "mirror") == 0) {
@@ -105,7 +119,8 @@ parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
                                        fprintf(stderr, "Can't have both mirror and redir\n");
                                        return -1;
                                }
-                               p.eaction = TCA_EGRESS_MIRROR;
+                               p.eaction = egress ? TCA_EGRESS_MIRROR :
+                                           TCA_INGRESS_MIRROR;
                                p.action = TC_ACT_PIPE;
                                ok++;
                        } else if (!redir && matches(*argv, "redirect") == 0) {
@@ -114,7 +129,8 @@ parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
                                        fprintf(stderr, "Can't have both mirror and redir\n");
                                        return -1;
                                }
-                               p.eaction = TCA_EGRESS_REDIR;
+                               p.eaction = egress ? TCA_EGRESS_REDIR :
+                                           TCA_INGRESS_REDIR;
                                p.action = TC_ACT_STOLEN;
                                ok++;
                        } else if ((redir || mirror) && matches(*argv, "dev") == 0) {
@@ -154,7 +170,8 @@ parse_egress(struct action_util *a, int *argc_p, char ***argv_p,
        }
 
 
-       if (argc && p.eaction == TCA_EGRESS_MIRROR
+       if (argc &&
+           (p.eaction == TCA_EGRESS_MIRROR || p.eaction == TCA_INGRESS_MIRROR)
            && !action_a2n(*argv, &p.action, false))
                NEXT_ARG();
 
@@ -207,8 +224,9 @@ parse_mirred(struct action_util *a, int *argc_p, char ***argv_p,
        }
 
 
-       if (matches(*argv, "egress") == 0 || matches(*argv, "index") == 0) {
-               int ret = parse_egress(a, &argc, &argv, tca_id, n);
+       if (matches(*argv, "egress") == 0 || matches(*argv, "ingress") == 0 ||
+           matches(*argv, "index") == 0) {
+               int ret = parse_direction(a, &argc, &argv, tca_id, n);
 
                if (ret == 0) {
                        *argc_p = argc;
@@ -216,8 +234,6 @@ parse_mirred(struct action_util *a, int *argc_p, char ***argv_p,
                        return 0;
                }
 
-       } else if (matches(*argv, "ingress") == 0) {
-               fprintf(stderr, "mirred ingress not supported at the moment\n");
        } else if (matches(*argv, "help") == 0) {
                usage();
        } else {