dhcp ip: DSCP settings for transmitted DHCP packets

Type: feature

- Define the ip_dscp_t and use in the IP headers
- Add DSCP setting to the DHCP client for use with packet TX

Change-Id: If220dde0017ea78793747d65f53e11daf23a28fa
Signed-off-by: Neale Ranns <nranns@cisco.com>

12 files changed, 117 insertions, 18 deletions

diff --git a/src/vnet/dhcp/client.c b/src/vnet/dhcp/client.c
index 472de5253ef..aaeda96327d 100644
--- a/src/vnet/dhcp/client.c
+++ b/src/vnet/dhcp/client.c
@@ -17,6 +17,7 @@
 #include <vnet/dhcp/client.h>
 #include <vnet/dhcp/dhcp_proxy.h>
 #include <vnet/fib/fib_table.h>
+#include <vnet/qos/qos_types.h>
 
 dhcp_client_main_t dhcp_client_main;
 static u8 *format_dhcp_client_state (u8 * s, va_list * va);
@@ -434,6 +435,19 @@ send_dhcp_pkt (dhcp_client_main_t * dcm, dhcp_client_t * c,
   ip->ttl = 128;
   ip->protocol = IP_PROTOCOL_UDP;
 
+  ip->tos = c->dscp;
+
+  if (ip->tos)
+    {
+      /*
+       * Setup the buffer's QoS settings so any QoS marker on the egress
+       * interface, that might set VLAN CoS bits, based on this DSCP setting
+       */
+      vnet_buffer2 (b)->qos.source = QOS_SOURCE_IP;
+      vnet_buffer2 (b)->qos.bits = ip->tos;
+      b->flags |= VNET_BUFFER_F_QOS_DATA_VALID;
+    }
+
   if (is_broadcast)
     {
       /* src = 0.0.0.0, dst = 255.255.255.255 */
@@ -825,6 +839,9 @@ format_dhcp_client (u8 * s, va_list * va)
 	      format_vnet_sw_if_index_name, dcm->vnet_main, c->sw_if_index,
 	      format_dhcp_client_state, c->state);
 
+  if (0 != c->dscp)
+    s = format (s, "dscp %d ", c->dscp);
+
   if (c->leased_address.as_u32)
     {
       s = format (s, "addr %U/%d gw %U",
@@ -942,6 +959,7 @@ dhcp_client_add_del (dhcp_client_add_del_args_t * a)
       c->hostname = a->hostname;
       c->client_identifier = a->client_identifier;
       c->set_broadcast_flag = a->set_broadcast_flag;
+      c->dscp = a->dscp;
       c->ai_ucast = ADJ_INDEX_INVALID;
       c->ai_bcast = adj_nbr_add_or_lock (FIB_PROTOCOL_IP4,
 					 VNET_LINK_IP4,
@@ -1011,7 +1029,7 @@ dhcp_client_config (u32 is_add,
 		    u8 * hostname,
 		    u8 * client_id,
 		    dhcp_event_cb_t event_callback,
-		    u8 set_broadcast_flag, u32 pid)
+		    u8 set_broadcast_flag, ip_dscp_t dscp, u32 pid)
 {
   dhcp_client_add_del_args_t _a, *a = &_a;
   int rv;
@@ -1023,6 +1041,7 @@ dhcp_client_config (u32 is_add,
   a->pid = pid;
   a->event_callback = event_callback;
   a->set_broadcast_flag = set_broadcast_flag;
+  a->dscp = dscp;
   vec_validate (a->hostname, strlen ((char *) hostname) - 1);
   strncpy ((char *) a->hostname, (char *) hostname, vec_len (a->hostname));
   vec_validate (a->client_identifier, strlen ((char *) client_id) - 1);
diff --git a/src/vnet/dhcp/client.h b/src/vnet/dhcp/client.h
index a79d6e59715..5191fcf0fa8 100644
--- a/src/vnet/dhcp/client.h
+++ b/src/vnet/dhcp/client.h
@@ -89,6 +89,8 @@ typedef struct dhcp_client_t_
   adj_index_t ai_ucast;
   /* the broadcast adjacency on the link */
   adj_index_t ai_bcast;
+  /* IP DSCP to set in sent packets */
+  ip_dscp_t dscp;
 
   dhcp_event_cb_t event_callback;
 } dhcp_client_t;
@@ -121,6 +123,7 @@ typedef struct
   /* Information used for event callback */
   u32 client_index;
   u32 pid;
+  ip_dscp_t dscp;
   dhcp_event_cb_t event_callback;
 } dhcp_client_add_del_args_t;
 
@@ -143,7 +146,8 @@ extern int dhcp_client_config (u32 is_add,
 			       u8 * hostname,
 			       u8 * client_id,
 			       dhcp_event_cb_t event_callback,
-			       u8 set_broadcast_flag, u32 pid);
+			       u8 set_broadcast_flag,
+			       ip_dscp_t dscp, u32 pid);
 
 /**
  * callback function for clients walking the DHCP client configurations
diff --git a/src/vnet/dhcp/dhcp.api b/src/vnet/dhcp/dhcp.api
index 033c7a34fed..6db9033a7f4 100644
--- a/src/vnet/dhcp/dhcp.api
+++ b/src/vnet/dhcp/dhcp.api
@@ -15,6 +15,8 @@
 
 option version = "2.0.1";
 
+import "vnet/ip/ip_types.api";
+
 /** \brief DHCP Proxy config add / del request
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
@@ -70,6 +72,7 @@ autoreply define dhcp_proxy_set_vss
            via dhcp_compl_event API message if non-zero
     @param set_broadcast_flag - in the DHCP Discover to control
                                 how the resulting OFFER is addressed.
+    @param dscp - DSCP value set in IP packets sent by the client
     @param pid - sender's pid
 */
 typeonly define dhcp_client
@@ -79,6 +82,7 @@ typeonly define dhcp_client
   u8 id[64];
   u8 want_dhcp_event;
   u8 set_broadcast_flag;
+  vl_api_ip_dscp_t dscp;
   u32 pid;
 };
 
diff --git a/src/vnet/dhcp/dhcp_api.c b/src/vnet/dhcp/dhcp_api.c
index 7eb2bf46a06..7935ad8ba01 100644
--- a/src/vnet/dhcp/dhcp_api.c
+++ b/src/vnet/dhcp/dhcp_api.c
@@ -28,6 +28,7 @@
 #include <vnet/dhcp/dhcp6_ia_na_client_dp.h>
 #include <vnet/dhcp/dhcp6_client_common_dp.h>
 #include <vnet/fib/fib_table.h>
+#include <vnet/ip/ip_types_api.h>
 
 #include <vnet/vnet_msg_enum.h>
 
@@ -263,6 +264,7 @@ dhcp_client_data_encode (vl_api_dhcp_client_t * vclient,
   else
     vclient->want_dhcp_event = 0;
   vclient->set_broadcast_flag = client->set_broadcast_flag;
+  vclient->dscp = ip_dscp_encode (client->dscp);
   vclient->pid = client->pid;
 }
 
@@ -292,14 +294,13 @@ static void vl_api_dhcp_client_config_t_handler
   vlib_main_t *vm = vlib_get_main ();
   vl_api_dhcp_client_config_reply_t *rmp;
   u32 sw_if_index;
+  ip_dscp_t dscp;
   int rv = 0;
 
+  VALIDATE_SW_IF_INDEX (&(mp->client));
+
   sw_if_index = ntohl (mp->client.sw_if_index);
-  if (!vnet_sw_if_index_is_api_valid (sw_if_index))
-    {
-      rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;
-      goto bad_sw_if_index;
-    }
+  dscp = ip_dscp_decode (mp->client.dscp);
 
   rv = dhcp_client_config (mp->is_add,
 			   mp->client_index,
@@ -310,10 +311,10 @@ static void vl_api_dhcp_client_config_t_handler
 			   (mp->client.want_dhcp_event ?
 			    dhcp_compl_event_callback :
 			    NULL),
-			   mp->client.set_broadcast_flag, mp->client.pid);
+			   mp->client.set_broadcast_flag,
+			   dscp, mp->client.pid);
 
   BAD_SW_IF_INDEX_LABEL;
-
   REPLY_MACRO (VL_API_DHCP_CLIENT_CONFIG_REPLY);
 }
 
diff --git a/src/vnet/ip/ip.c b/src/vnet/ip/ip.c
index 6e8ac7c437d..133767bd06c 100644
--- a/src/vnet/ip/ip.c
+++ b/src/vnet/ip/ip.c
@@ -294,6 +294,23 @@ format_ip_address_family (u8 * s, va_list * args)
   return (format (s, "unknown"));
 }
 
+u8 *
+format_ip_dscp (u8 * s, va_list * va)
+{
+  ip_dscp_t dscp = va_arg (*va, u32);	// int promotion of u8
+
+  switch (dscp)
+    {
+#define _(n,v)                                                  \
+    case IP_DSCP_##v:                                           \
+      return (format (s, "%s", #v));
+      foreach_ip_dscp
+#undef _
+    }
+
+  return (format (s, "unknon"));
+}
+
 /*
  * fd.io coding-style-patch-verification: ON
  *
diff --git a/src/vnet/ip/ip4_packet.h b/src/vnet/ip/ip4_packet.h
index 2ce6763f8d7..c1852fc3ff2 100644
--- a/src/vnet/ip/ip4_packet.h
+++ b/src/vnet/ip/ip4_packet.h
@@ -138,7 +138,7 @@ typedef union
     u8 ip_version_and_header_length;
 
     /* Type of service. */
-    u8 tos;
+    ip_dscp_t tos;
 
     /* Total layer 3 packet length including this header. */
     u16 length;
diff --git a/src/vnet/ip/ip6_packet.h b/src/vnet/ip/ip6_packet.h
index c8bc4c817e8..c1bd2aa3bf7 100644
--- a/src/vnet/ip/ip6_packet.h
+++ b/src/vnet/ip/ip6_packet.h
@@ -383,13 +383,13 @@ typedef struct
   ip6_address_t src_address, dst_address;
 } ip6_header_t;
 
-always_inline u8
+always_inline ip_dscp_t
 ip6_traffic_class (const ip6_header_t * i)
 {
   return (i->ip_version_traffic_class_and_flow_label & 0x0FF00000) >> 20;
 }
 
-static_always_inline u8
+static_always_inline ip_dscp_t
 ip6_traffic_class_network_order (const ip6_header_t * ip6)
 {
   return (clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label)
@@ -397,7 +397,7 @@ ip6_traffic_class_network_order (const ip6_header_t * ip6)
 }
 
 static_always_inline void
-ip6_set_traffic_class_network_order (ip6_header_t * ip6, u8 dscp)
+ip6_set_traffic_class_network_order (ip6_header_t * ip6, ip_dscp_t dscp)
 {
   u32 tmp =
     clib_net_to_host_u32 (ip6->ip_version_traffic_class_and_flow_label);
diff --git a/src/vnet/ip/ip_packet.h b/src/vnet/ip/ip_packet.h
index c4990976188..97b3c96b2ce 100644
--- a/src/vnet/ip/ip_packet.h
+++ b/src/vnet/ip/ip_packet.h
@@ -84,6 +84,44 @@ typedef enum
 #undef _
 } ip_multicast_group_t;
 
+
+/**
+ * The set of RFC defined DSCP values.
+ */
+#define foreach_ip_dscp                       \
+  _(0, CS0)                                   \
+  _(8, CS1)                                   \
+  _(10, AF11)                                 \
+  _(12, AF12)                                 \
+  _(14, AF13)                                 \
+  _(16, CS2)                                  \
+  _(18, AF21)                                 \
+  _(20, AF22)                                 \
+  _(22, AF23)                                 \
+  _(24, CS3)                                  \
+  _(26, AF31)                                 \
+  _(28, AF32)                                 \
+  _(30, AF33)                                 \
+  _(32, CS4)                                  \
+  _(34, AF41)                                 \
+  _(36, AF42)                                 \
+  _(38, AF43)                                 \
+  _(40, CS5)                                  \
+  _(46, EF)                                   \
+  _(48, CS6)                                  \
+  _(50, CS7)
+
+typedef enum ip_dscp_t_
+{
+#define _(n,f) IP_DSCP_##f = n,
+  foreach_ip_dscp
+#undef _
+} __clib_packed ip_dscp_t;
+
+STATIC_ASSERT_SIZEOF (ip_dscp_t, 1);
+
+extern u8 *format_ip_dscp (u8 * s, va_list * va);
+
 /* IP checksum support. */
 
 static_always_inline u16
diff --git a/src/vnet/ip/ip_types.api b/src/vnet/ip/ip_types.api
index 8b46a1d44fe..13c6a4aab28 100644
--- a/src/vnet/ip/ip_types.api
+++ b/src/vnet/ip/ip_types.api
@@ -34,8 +34,8 @@ enum ip_ecn : u8 {
 
 /* DSCP code points - RFC 2474
    https://tools.ietf.org/html/rfc2474
+   Values other than these RFC defined values are accepted.
 */
-
 enum ip_dscp : u8 {
   IP_API_DSCP_CS0 =  0,
   IP_API_DSCP_CS1 = 8,
diff --git a/src/vnet/ip/ip_types_api.c b/src/vnet/ip/ip_types_api.c
index 0343d2001ad..ca26731a30a 100644
--- a/src/vnet/ip/ip_types_api.c
+++ b/src/vnet/ip/ip_types_api.c
@@ -95,6 +95,18 @@ ip_proto_encode (ip_protocol_t ipp)
   return (clib_host_to_net_u32 (IP_API_PROTO_TCP));
 }
 
+ip_dscp_t
+ip_dscp_decode (u8 in)
+{
+  return ((ip_dscp_t) in);
+}
+
+u8
+ip_dscp_encode (ip_dscp_t dscp)
+{
+  return (dscp);
+}
+
 void
 ip6_address_encode (const ip6_address_t * in, vl_api_ip6_address_t out)
 {
diff --git a/src/vnet/ip/ip_types_api.h b/src/vnet/ip/ip_types_api.h
index 4c79bf138e3..fc7a416a06d 100644
--- a/src/vnet/ip/ip_types_api.h
+++ b/src/vnet/ip/ip_types_api.h
@@ -41,6 +41,8 @@ extern int ip_address_family_decode (int _af, ip_address_family_t * out);
 extern int ip_address_family_encode (ip_address_family_t af);
 extern int ip_proto_decode (int _af, ip_protocol_t * out);
 extern int ip_proto_encode (ip_protocol_t af);
+extern ip_dscp_t ip_dscp_decode (u8 _dscp);
+extern u8 ip_dscp_encode (ip_dscp_t dscp);
 
 /**
  * Decode/Encode for struct/union types
diff --git a/src/vnet/mpls/packet.h b/src/vnet/mpls/packet.h
index ca6ac407686..8573bc3bef5 100644
--- a/src/vnet/mpls/packet.h
+++ b/src/vnet/mpls/packet.h
@@ -1,6 +1,3 @@
-#ifndef included_vnet_mpls_packet_h
-#define included_vnet_mpls_packet_h
-
 /*
  * MPLS packet format
  *
@@ -18,6 +15,11 @@
  * limitations under the License.
  */
 
+#ifndef included_vnet_mpls_packet_h
+#define included_vnet_mpls_packet_h
+
+#include <vnet/ip/ip_packet.h>
+
 /**
  * A label value only, i.e. 20bits.
  */
@@ -55,7 +57,7 @@ typedef enum mpls_eos_bit_t_
 /**
  * When in uniform mode convert an IPv[46] DSCP value to an MPLS EXP value
  */
-static inline u8 ip_dscp_to_mpls_exp (u8 tos)
+static inline u8 ip_dscp_to_mpls_exp (ip_dscp_t tos)
 {
     return (tos >> 5);
 }