pg: set vnet buffer flags in pg streams

See .../extras/pg/checksum_offload.pg for a nontrivial example, which
deliberately sets bogus ip and udp checksums in the generated packets,
then fixes the mess with (software emulated) hardware checksum
offload.

Validated via "pcap dispatch trace on max 1000 buffer-trace pg-input 100".
Packets stuffed into loop1-output have the configured bogus ip and udp
checksums. vnet_calc_checksums_inline(...) fixes the checksums, which
are correct when packets visit loop1-tx.

The packet generator is a dumb robot in this regard. If you ask for a
ridiculous flag combination - example: ip4 and ip6 - your mileage may
vary.

Type: feature

Signed-off-by: Dave Barach <dave@barachs.net>
Change-Id: I6d9e790f373bcd9e445a89113ca8e4c8f9aa9419

1 files changed, 26 insertions, 0 deletions

diff --git a/extras/pg/checksum_offload.pg b/extras/pg/checksum_offload.pg
new file mode 100644
index 00000000000..a2e3205a21e
--- /dev/null
+++ b/extras/pg/checksum_offload.pg
@@ -0,0 +1,26 @@
+set term pag off
+loop cre
+set int ip address loop0 11.22.33.1/24
+set int state loop0 up
+loop cre
+set int ip address loop1 11.22.34.1/24
+set int state loop1 up
+
+set ip neighbor loop1 11.22.34.44 03:00:11:22:34:44
+
+packet-generator new {
+    name s0
+    limit 10000
+    size 128-128
+    interface loop0
+    tx-interface loop1
+    node loop1-output
+    buffer-flags ip4 offload-ip-cksum offload-udp-cksum
+    data { IP4: 1.2.3 -> 4.5.6
+           UDP: 11.22.33.44 -> 11.22.34.44
+                ttl 2 checksum 13
+           UDP: 1234 -> 2345
+                checksum 11
+           incrementing 114
+    }
+}