trafgen: parser: Add TCP header generation function

Add a function 'tcp()' to generate TCP headers from the trafgen
configuration language.

Fields supported:

    sp|sport     TCP source port (default 0)
    dp|dport     TCP destination port (default 0)
    seq          Sequence number (default: 0)
    aseq|ackseq  Acknowledgement number (default 0)
    doff|hlen    Header length/data offset (default: 5)
    cwr          Congestion Window Reduced flag (default: 0)
    ece|ecn      ECN-Echo flag (default: 0)
    urg          Urgent flag (default: 0)
    ack          Acknowledgement flag (default: 0)
    psh          Push flag (default: 0)
    rst          Reset flag (default: 0)
    syn          Synchronize flag (default: 0)
    fin          Finish flag (default: 0)
    win|window   Receive window size (default: 0)
    csum         Checksum field (calculated automatically)
    urgptr       Urgent pointer (default: 0)

Example (SYN on port 80/http):

    { tcp(dport=80, syn, window=5840) }

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 59 insertions, 0 deletions

diff --git a/trafgen.8 b/trafgen.8
index 48a252c..207cfc5 100644
--- a/trafgen.8
+++ b/trafgen.8
@@ -428,6 +428,65 @@ By default, if the lower level header is Ethernet, its EtherType field is set to
 By default, if the lower level header is IPv4, its protocol field is set to
 0x11 (UDP).
 
+.I TCP
+:
+.B tcp(sp=<number>, dp=<number>, seq=<number>, aseq|ackseq=<number>, doff|hlen=<number>,
+.B cwr, ece|ecn, urg, ack, psh, rst, syn, fin, win|window=<number>, csum=<number>,
+.B urgptr=<number>)
+.sp
+.in +4
+.B sp|sport
+- Source port (default: 0)
+.sp
+.B dp|dport
+- Destination port (default: 0)
+.sp
+.B seq
+- Sequence number (default: 0)
+.sp
+.B aseq|ackseq
+- Acknowledgement number (default: 0)
+.sp
+.B doff|hlen
+- Header size (data offset) in number of 32-bit words (default: 5)
+.sp
+.B cwr
+- Congestion Window Reduced (CWR) flag (default: 0)
+.sp
+.B ece|ecn
+- ECN-Echo (ECE) flag (default: 0)
+.sp
+.B urg
+- Urgent flag (default: 0)
+.sp
+.B ack
+- Acknowledgement flag (default: 0)
+.sp
+.B psh
+- Push flag (default: 0)
+.sp
+.B rst
+- Reset flag (default: 0)
+.sp
+.B syn
+- Synchronize flag (default: 0)
+.sp
+.B fin
+- Finish flag (default: 0)
+.sp
+.B win|window
+- Receive window size (default: 0)
+.sp
+.B csum
+- Checksum field over IPv4 pseudo header (calculated by default)
+.sp
+.B urgptr
+- Urgent pointer (default: 0)
+.sp
+.in -4
+By default, if the lower level header is IPv4, its protocol field is set to
+0x6 (TCP).
+
 Simple example of a UDP Echo packet:
 .PP
 .in +5