doc: add missing network layers in API index

Add missing files in doxy-api-index.md and add a short description
for files that hadn't one.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

doc/api/doxy-api-index.md

@@ -107,14 +107,18 @@ The public API headers are grouped by topics:
   [IPsec SA]           (@ref rte_ipsec_sa.h),
   [IPsec SAD]          (@ref rte_ipsec_sad.h),
   [IP]                 (@ref rte_ip.h),
+  [frag/reass]         (@ref rte_ip_frag.h),
   [SCTP]               (@ref rte_sctp.h),
   [TCP]                (@ref rte_tcp.h),
   [UDP]                (@ref rte_udp.h),
   [GTP]                (@ref rte_gtp.h),
   [GRO]                (@ref rte_gro.h),
   [GSO]                (@ref rte_gso.h),
-  [frag/reass]         (@ref rte_ip_frag.h),
-  [VXLAN]              (@ref rte_vxlan.h)
+  [GRE]                (@ref rte_gre.h),
+  [MPLS]               (@ref rte_mpls.h),
+  [VXLAN]              (@ref rte_vxlan.h),
+  [Geneve]             (@ref rte_geneve.h),
+  [eCPRI]              (@ref rte_ecpri.h)
 
 - **QoS**:
   [metering]           (@ref rte_meter.h),

lib/librte_net/rte_ecpri.h

@@ -5,6 +5,15 @@
 #ifndef _RTE_ECPRI_H_
 #define _RTE_ECPRI_H_
 
+/**
+ * @file
+ *
+ * eCPRI headers definition.
+ *
+ * eCPRI (Common Public Radio Interface) is used in internal interfaces
+ * of radio base station in a 5G infrastructure.
+ */
+
 #include <stdint.h>
 #include <rte_byteorder.h>
 

lib/librte_net/rte_gre.h

@@ -8,6 +8,17 @@
 #include <stdint.h>
 #include <rte_byteorder.h>
 
+/**
+ * @file
+ *
+ * GRE headers definition.
+ *
+ * Generic Routing Encapsulation (GRE) is a tunneling protocol
+ * that can encapsulate a wide variety of network layer protocols
+ * inside virtual point-to-point links or point-to-multipoint links
+ * over an Internet Protocol network.
+ */
+
 #ifdef __cplusplus
 extern "C" {
 #endif

lib/librte_net/rte_higig.h

@@ -1,4 +1,3 @@
-
 /* SPDX-License-Identifier: BSD-3-Clause
  * Copyright(C) 2019 Marvell International Ltd.
  */
@@ -6,6 +5,14 @@
 #ifndef _RTE_HIGIG_H_
 #define _RTE_HIGIG_H_
 
+/**
+ * @file
+ *
+ * HIGIG2 headers definition.
+ *
+ * It is a layer 2.5 protocol and used in Broadcom switches.
+ */
+
 #include <stdint.h>
 #include <rte_byteorder.h>