pbrd, zebra, lib: DSCP / ECN-based PBR Matching

Extend PBR maps to discriminate by Differentiated Services Code Point and / or
Explicit Congestion Notification fields. These fields are used in the IP header
for classifying network traffic.

      0     1     2     3     4     5     6     7
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |          DS FIELD, DSCP           | ECN FIELD |
    +-----+-----+-----+-----+-----+-----+-----+-----+
      DSCP: differentiated services codepoint
      ECN:  Explicit Congestion Notification

Signed-off-by: Wesley Coakley <wcoakley@nvidia.com>
Signed-off-by: Saurav Kumar Paul <saurav@cumulusnetworks.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/pbr.h b/lib/pbr.h
index cf6ac41d32..fd183d7115 100644
--- a/lib/pbr.h
+++ b/lib/pbr.h
@@ -49,6 +49,10 @@ struct pbr_filter {
 #define PBR_FILTER_PROTO		(1 << 5)
 #define PBR_FILTER_SRC_PORT_RANGE	(1 << 6)
 #define PBR_FILTER_DST_PORT_RANGE	(1 << 7)
+#define PBR_FILTER_DSFIELD			(1 << 8)
+
+#define PBR_DSFIELD_DSCP (0xfc) /* Upper 6 bits of DS field: DSCP */
+#define PBR_DSFIELD_ECN (0x03)	/* Lower 2 bits of DS field: BCN */
 
 	/* Source and Destination IP address with masks. */
 	struct prefix src_ip;
@@ -58,6 +62,9 @@ struct pbr_filter {
 	uint16_t src_port;
 	uint16_t dst_port;
 
+	/* Filter by Differentiated Services field  */
+	uint8_t dsfield; /* DSCP (6 bits) & ECN (2 bits) */
+
 	/* Filter with fwmark */
 	uint32_t fwmark;
 };