tc/pedit: p_tcp: introduce pedit tcp support

For example, forward tcp traffic destined to port 80 to veth0 and set
tcp port to 8080:
$ tc filter add dev enp0s9 protocol ip parent ffff: \
    flower \
      ip_proto tcp \
      dst_port 80 \
    action pedit ex munge \
      tcp dport set 8080 \
    action mirred egress \
      redirect dev veth0

Signed-off-by: Amir Vadai <amir@vadai.me>

diff --git a/man/man8/tc-pedit.8 b/man/man8/tc-pedit.8
index 8febdfe23f6e339d188f717ef527ab36a045b121..ad1929592660b22675d09a4f655b48c7e7d63919 100644 (file)
--- a/man/man8/tc-pedit.8
+++ b/man/man8/tc-pedit.8
@@ -32,6 +32,8 @@ pedit - generic packet editor action
 .BI ip " IPHDR_FIELD"
 |
 .BI ip " EX_IPHDR_FIELD"
+|
+.BI tcp " TCPHDR_FIELD"
 .RI } " CMD_SPEC"
 
 .ti -8
@@ -51,6 +53,10 @@ pedit - generic packet editor action
 .IR EX_IPHDR_FIELD " := { "
 .BR ttl " }"
 
+.ti -8
+.IR TCPHDR_FIELD " := { "
+.BR sport " | " dport " | " flags " }"
+
 .ti -8
 .IR CMD_SPEC " := {"
 .BR clear " | " invert " | " set
@@ -199,6 +205,20 @@ are:
 .B ttl
 .RE
 .TP
+.BI tcp " TCPHDR_FIELD"
+The supported keywords for
+.I TCPHDR_FIELD
+are:
+.RS
+.TP
+.B sport
+.TQ
+.B dport
+Source or destination TCP port number, a 16-bit value.
+.TP
+.B flags
+.RE
+.TP
 .B clear
 Clear the addressed data (i.e., set it to zero).
 .TP
@@ -293,6 +313,9 @@ tc filter add dev eth0 parent ffff: u32 \\
 tc filter add dev eth0 parent ffff: u32 \\
        match ip sport 22 0xffff \\
        action pedit ex munge eth dst set 11:22:33:44:55:66
+tc filter add dev eth0 parent ffff: u32 \\
+       match ip dport 23 0xffff \\
+       action pedit ex munge tcp dport set 22
 .EE
 .RE
 .SH SEE ALSO

diff --git a/tc/p_tcp.c b/tc/p_tcp.c
index 53ee9842160b6ddde5964c5db5c6bc18811a960a..cf14574c9c3ec7a28a4db17ebed2a6bb1997acda 100644 (file)
--- a/tc/p_tcp.c
+++ b/tc/p_tcp.c
@@ -28,6 +28,43 @@ parse_tcp(int *argc_p, char ***argv_p,
          struct m_pedit_sel *sel, struct m_pedit_key *tkey)
 {
        int res = -1;
+       int argc = *argc_p;
+       char **argv = *argv_p;
+
+       if (argc < 2)
+               return -1;
+
+       if (!sel->extended)
+               return -1;
+
+       tkey->htype = TCA_PEDIT_KEY_EX_HDR_TYPE_TCP;
+
+       if (strcmp(*argv, "sport") == 0) {
+               NEXT_ARG();
+               tkey->off = 0;
+               res = parse_cmd(&argc, &argv, 2, TU32, RU16, sel, tkey);
+               goto done;
+       }
+
+       if (strcmp(*argv, "dport") == 0) {
+               NEXT_ARG();
+               tkey->off = 2;
+               res = parse_cmd(&argc, &argv, 2, TU32, RU16, sel, tkey);
+               goto done;
+       }
+
+       if (strcmp(*argv, "flags") == 0) {
+               NEXT_ARG();
+               tkey->off = 13;
+               res = parse_cmd(&argc, &argv, 1, TU32, RU8, sel, tkey);
+               goto done;
+       }
+
+       return -1;
+
+done:
+       *argc_p = argc;
+       *argv_p = argv;
        return res;
 }
 struct m_pedit_util p_pedit_tcp = {