tc: m_tunnel_key: support code for "nofrag" tunnels

add control plane for setting TCA_TUNNEL_KEY_NO_FRAG flag on
act_tunnel_key actions.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/man/man8/tc-tunnel_key.8 b/man/man8/tc-tunnel_key.8
index f639f4333540d2e16d306ac3bfc29c69abd0d4e2..b987cd0d95a1f35817704548978f9f07b08a61b0 100644 (file)
--- a/man/man8/tc-tunnel_key.8
+++ b/man/man8/tc-tunnel_key.8
@@ -131,6 +131,9 @@ If using
 .B nocsum
 with IPv6, be sure you know what you are doing. Zero UDP checksums provide
 weaker protection against corrupted packets. See RFC6935 for details.
+.TP
+.B nofrag
+disallow IP fragmentation.
 .RE
 .SH EXAMPLES
 The following example encapsulates incoming ICMP packets on eth0 into a vxlan

diff --git a/tc/m_tunnel_key.c b/tc/m_tunnel_key.c
index 1b4c8bd640ebfa9d47be446814182310d51d86f0..ff699cc8917d45f8999f45013e5e1c8003d249ad 100644 (file)
--- a/tc/m_tunnel_key.c
+++ b/tc/m_tunnel_key.c
@@ -26,7 +26,8 @@ static void explain(void)
                "dst_ip <IP> (mandatory)\n"
                "dst_port <UDP_PORT>\n"
                "geneve_opts | vxlan_opts | erspan_opts <OPTIONS>\n"
-               "csum | nocsum (default is \"csum\")\n");
+               "csum | nocsum (default is \"csum\")\n"
+               "nofrag\n");
 }
 
 static void usage(void)
@@ -321,7 +322,7 @@ static int parse_tunnel_key(struct action_util *a, int *argc_p, char ***argv_p,
        int ret;
        int has_src_ip = 0;
        int has_dst_ip = 0;
-       int csum = 1;
+       int csum = 1, nofrag = 0;
 
        if (matches(*argv, "tunnel_key") != 0)
                return -1;
@@ -425,6 +426,8 @@ static int parse_tunnel_key(struct action_util *a, int *argc_p, char ***argv_p,
                        csum = 1;
                } else if (matches(*argv, "nocsum") == 0) {
                        csum = 0;
+               } else if (strcmp(*argv, "nofrag") == 0) {
+                       nofrag = 1;
                } else if (matches(*argv, "help") == 0) {
                        usage();
                } else {
@@ -435,6 +438,9 @@ static int parse_tunnel_key(struct action_util *a, int *argc_p, char ***argv_p,
 
        addattr8(n, MAX_MSG, TCA_TUNNEL_KEY_NO_CSUM, !csum);
 
+       if (nofrag)
+               addattr(n, MAX_MSG, TCA_TUNNEL_KEY_NO_FRAG);
+
        parse_action_control_dflt(&argc, &argv, &parm.action,
                                  false, TC_ACT_PIPE);
 
@@ -513,15 +519,36 @@ static void tunnel_key_print_dst_port(FILE *f, char *name,
                   rta_getattr_be16(attr));
 }
 
-static void tunnel_key_print_flag(FILE *f, const char *name_on,
-                                 const char *name_off,
-                                 struct rtattr *attr)
+static const struct {
+       const char *name;
+       unsigned int nl_flag;
+} tunnel_key_flag_names[] = {
+       { "",       TCA_TUNNEL_KEY_NO_CSUM }, /* special handling, not bool */
+       { "nofrag", TCA_TUNNEL_KEY_NO_FRAG },
+};
+
+static void tunnel_key_print_flags(struct rtattr *tb[])
 {
-       if (!attr)
-               return;
+       unsigned int i, nl_flag;
+
        print_nl();
-       print_string(PRINT_ANY, "flag", "\t%s",
-                    rta_getattr_u8(attr) ? name_on : name_off);
+       for (i = 0; i < ARRAY_SIZE(tunnel_key_flag_names); i++) {
+               nl_flag = tunnel_key_flag_names[i].nl_flag;
+               if (nl_flag == TCA_TUNNEL_KEY_NO_CSUM) {
+                       /* special handling to preserve csum/nocsum design */
+                       if (!tb[nl_flag])
+                               continue;
+                       print_string(PRINT_ANY, "flag", "\t%s",
+                                    rta_getattr_u8(tb[nl_flag]) ?
+                                       "nocsum" : "csum" );
+               } else {
+                       if (tb[nl_flag])
+                               print_string(PRINT_FP, NULL, "\t%s",
+                                            tunnel_key_flag_names[i].name);
+                       print_bool(PRINT_JSON, tunnel_key_flag_names[i].name,
+                                  NULL, !!tb[nl_flag]);
+               }
+       }
 }
 
 static void tunnel_key_print_geneve_options(struct rtattr *attr)
@@ -697,8 +724,7 @@ static int print_tunnel_key(struct action_util *au, FILE *f, struct rtattr *arg)
                tunnel_key_print_dst_port(f, "dst_port",
                                          tb[TCA_TUNNEL_KEY_ENC_DST_PORT]);
                tunnel_key_print_key_opt(tb[TCA_TUNNEL_KEY_ENC_OPTS]);
-               tunnel_key_print_flag(f, "nocsum", "csum",
-                                     tb[TCA_TUNNEL_KEY_NO_CSUM]);
+               tunnel_key_print_flags(tb);
                tunnel_key_print_tos_ttl(f, "tos",
                                          tb[TCA_TUNNEL_KEY_ENC_TOS]);
                tunnel_key_print_tos_ttl(f, "ttl",