This patch provides generic Large Receive Offload (LRO) functionality
for IPv4/TCP traffic.
LRO combines received tcp packets to a single larger tcp packet and
passes them then to the network stack in order to increase performance
(throughput). The interface supports two modes: Drivers can either pass
SKBs or fragment lists to the LRO engine.
Signed-off-by: Jan-Bernd Themann [EMAIL PROTECTED]
---
include/linux/inet_lro.h | 177 ++
net/ipv4/Kconfig |8 +
net/ipv4/Makefile|1 +
net/ipv4/inet_lro.c | 600 ++
4 files changed, 786 insertions(+), 0 deletions(-)
create mode 100644 include/linux/inet_lro.h
create mode 100644 net/ipv4/inet_lro.c
diff --git a/include/linux/inet_lro.h b/include/linux/inet_lro.h
new file mode 100644
index 000..e1fc1d1
--- /dev/null
+++ b/include/linux/inet_lro.h
@@ -0,0 +1,177 @@
+/*
+ * linux/include/linux/inet_lro.h
+ *
+ * Large Receive Offload (ipv4 / tcp)
+ *
+ * (C) Copyright IBM Corp. 2007
+ *
+ * Authors:
+ * Jan-Bernd Themann [EMAIL PROTECTED]
+ * Christoph Raisch [EMAIL PROTECTED]
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __INET_LRO_H_
+#define __INET_LRO_H_
+
+#include net/ip.h
+#include net/tcp.h
+
+/*
+ * LRO statistics
+ */
+
+struct net_lro_stats {
+ unsigned long aggregated;
+ unsigned long flushed;
+ unsigned long no_desc;
+};
+
+/*
+ * LRO descriptor for a tcp session
+ */
+struct net_lro_desc {
+ struct sk_buff *parent;
+ struct sk_buff *last_skb;
+ struct skb_frag_struct *next_frag;
+ struct iphdr *iph;
+ struct tcphdr *tcph;
+ struct vlan_group *vgrp;
+ __wsum data_csum;
+ u32 tcp_rcv_tsecr;
+ u32 tcp_rcv_tsval;
+ u32 tcp_ack;
+ u32 tcp_next_seq;
+ u32 skb_tot_frags_len;
+ u16 ip_tot_len;
+ u16 tcp_saw_tstamp; /* timestamps enabled */
+ u16 tcp_window;
+ u16 vlan_tag;
+ int pkt_aggr_cnt; /* counts aggregated packets */
+ int vlan_packet;
+ int mss;
+ int active;
+};
+
+/*
+ * Large Receive Offload (LRO) Manager
+ *
+ * Fields must be set by driver
+ */
+
+struct net_lro_mgr {
+ struct net_device *dev;
+ struct net_lro_stats stats;
+
+ /* LRO features */
+ unsigned long features;
+#define LRO_F_NAPI1 /* Pass packets to stack via NAPI */
+#define LRO_F_EXTRACT_VLAN_ID 2 /* Set flag if VLAN IDs are extracted
+ from received packets and eth protocol
+ is still ETH_P_8021Q */
+
+ u32 ip_summed; /* Set in non generated SKBs in page mode */
+ u32 ip_summed_aggr; /* Set in aggregated SKBs: CHECKSUM_UNNECESSARY
+* or CHECKSUM_NONE */
+
+ int max_desc; /* Max number of LRO descriptors */
+ int max_aggr; /* Max number of LRO packets to be aggregated */
+
+ struct net_lro_desc *lro_arr; /* Array of LRO descriptors */
+
+ /*
+* Optimized driver functions
+*
+* get_skb_header: returns tcp and ip header for packet in SKB
+*/
+ int (*get_skb_header)(struct sk_buff *skb, void **ip_hdr,
+ void **tcpudp_hdr, u64 *hdr_flags, void *priv);
+
+ /* hdr_flags: */
+#define LRO_IPV4 1 /* ip_hdr is IPv4 header */
+#define LRO_TCP 2 /* tcpudp_hdr is TCP header */
+
+ /*
+* get_frag_header: returns mac, tcp and ip header for packet in SKB
+*
+* @hdr_flags: Indicate what kind of LRO has to be done
+* (IPv4/IPv6/TCP/UDP)
+*/
+ int (*get_frag_header)(struct skb_frag_struct *frag, void **mac_hdr,
+ void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags,
+ void *priv);
+};
+
+/*
+ * Processes a SKB
+ *
+ * @lro_mgr: LRO manager to use
+ * @skb: SKB to aggregate
+ * @priv: Private data that may be used by driver functions
+ *(for example get_tcp_ip_hdr)
+ */
+
+void lro_receive_skb(struct net_lro_mgr *lro_mgr,
+struct sk_buff *skb,
+void *priv);
+
+/*
+ * Processes a SKB with VLAN HW acceleration support
+ */
+
+void lro_vlan_hwaccel_receive_skb(struct
