crypto/zuc: support IPsec Multi-buffer lib v0.54

[dpdk.git] / doc / guides / prog_guide / generic_receive_offload_lib.rst

diff --git a/doc/guides/prog_guide/generic_receive_offload_lib.rst b/doc/guides/prog_guide/generic_receive_offload_lib.rst
index 1652e64..5b3fb91 100644 (file)
--- a/doc/guides/prog_guide/generic_receive_offload_lib.rst
+++ b/doc/guides/prog_guide/generic_receive_offload_lib.rst
@@ -1,32 +1,5 @@
-..  BSD LICENSE
-    Copyright(c) 2017 Intel Corporation. All rights reserved.
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
-    are met:
-
-    * Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in
-    the documentation and/or other materials provided with the
-    distribution.
-    * Neither the name of Intel Corporation nor the names of its
-    contributors may be used to endorse or promote products derived
-    from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2017 Intel Corporation.

 
 Generic Receive Offload Library
 ===============================
 
 Generic Receive Offload Library
 ===============================


@@ -54,10 +27,12 @@ corresponding GRO functions by MBUF->packet_type.
 The GRO library doesn't check if input packets have correct checksums and
 doesn't re-calculate checksums for merged packets. The GRO library
 assumes the packets are complete (i.e., MF==0 && frag_off==0), when IP
 The GRO library doesn't check if input packets have correct checksums and
 doesn't re-calculate checksums for merged packets. The GRO library
 assumes the packets are complete (i.e., MF==0 && frag_off==0), when IP

-fragmentation is possible (i.e., DF==0). Additionally, it requires IPv4
-ID to be increased by one.
+fragmentation is possible (i.e., DF==0). Additionally, it complies RFC
+6864 to process the IPv4 ID field.

 
 

-Currently, the GRO library provides GRO supports for TCP/IPv4 packets.
+Currently, the GRO library provides GRO supports for TCP/IPv4 packets and
+VxLAN packets which contain an outer IPv4 header and an inner TCP/IPv4
+packet.

 
 Two Sets of API
 ---------------
 
 Two Sets of API
 ---------------


@@ -108,7 +83,8 @@ Reassembly Algorithm
 
 The reassembly algorithm is used for reassembling packets. In the GRO
 library, different GRO types can use different algorithms. In this
 
 The reassembly algorithm is used for reassembling packets. In the GRO
 library, different GRO types can use different algorithms. In this

-section, we will introduce an algorithm, which is used by TCP/IPv4 GRO.
+section, we will introduce an algorithm, which is used by TCP/IPv4 GRO
+and VxLAN GRO.

 
 Challenges
 ~~~~~~~~~~
 
 Challenges
 ~~~~~~~~~~


@@ -182,4 +158,55 @@ Header fields deciding if two packets are neighbors include:
 
 - TCP sequence number
 
 
 - TCP sequence number
 

-- IPv4 ID. The IPv4 ID fields of the packets should be increased by 1.
+- IPv4 ID. The IPv4 ID fields of the packets, whose DF bit is 0, should
+  be increased by 1.
+
+VxLAN GRO
+---------
+
+The table structure used by VxLAN GRO, which is in charge of processing
+VxLAN packets with an outer IPv4 header and inner TCP/IPv4 packet, is
+similar with that of TCP/IPv4 GRO. Differently, the header fields used
+to define a VxLAN flow include:
+
+- outer source and destination: Ethernet and IP address, UDP port
+
+- VxLAN header (VNI and flag)
+
+- inner source and destination: Ethernet and IP address, TCP port
+
+Header fields deciding if packets are neighbors include:
+
+- outer IPv4 ID. The IPv4 ID fields of the packets, whose DF bit in the
+  outer IPv4 header is 0, should be increased by 1.
+
+- inner TCP sequence number
+
+- inner IPv4 ID. The IPv4 ID fields of the packets, whose DF bit in the
+  inner IPv4 header is 0, should be increased by 1.
+
+.. note::
+        We comply RFC 6864 to process the IPv4 ID field. Specifically,
+        we check IPv4 ID fields for the packets whose DF bit is 0 and
+        ignore IPv4 ID fields for the packets whose DF bit is 1.
+        Additionally, packets which have different value of DF bit can't
+        be merged.
+
+GRO Library Limitations
+-----------------------
+
+- GRO library uses MBUF->l2_len/l3_len/l4_len/outer_l2_len/
+  outer_l3_len/packet_type to get protocol headers for the
+  input packet, rather than parsing the packet header. Therefore,
+  before call GRO APIs to merge packets, user applications
+  must set MBUF->l2_len/l3_len/l4_len/outer_l2_len/outer_l3_len/
+  packet_type to the same values as the protocol headers of the
+  packet.
+
+- GRO library doesn't support to process the packets with IPv4
+  Options or VLAN tagged.
+
+- GRO library just supports to process the packet organized
+  in a single MBUF. If the input packet consists of multiple
+  MBUFs (i.e. chained MBUFs), GRO reassembly behaviors are
+  unknown.