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Jan-Bernd Themann71c87e02007-08-08 22:38:05 -07001/*
2 * linux/include/linux/inet_lro.h
3 *
4 * Large Receive Offload (ipv4 / tcp)
5 *
6 * (C) Copyright IBM Corp. 2007
7 *
8 * Authors:
9 * Jan-Bernd Themann <themann@de.ibm.com>
10 * Christoph Raisch <raisch@de.ibm.com>
11 *
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 */
27
28#ifndef __INET_LRO_H_
29#define __INET_LRO_H_
30
31#include <net/ip.h>
32#include <net/tcp.h>
33
34/*
35 * LRO statistics
36 */
37
38struct net_lro_stats {
39 unsigned long aggregated;
40 unsigned long flushed;
41 unsigned long no_desc;
42};
43
44/*
45 * LRO descriptor for a tcp session
46 */
47struct net_lro_desc {
48 struct sk_buff *parent;
49 struct sk_buff *last_skb;
50 struct skb_frag_struct *next_frag;
51 struct iphdr *iph;
52 struct tcphdr *tcph;
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -070053 __wsum data_csum;
Al Viro9df7c982007-10-14 19:40:59 +010054 __be32 tcp_rcv_tsecr;
55 __be32 tcp_rcv_tsval;
Al Virof53f4132007-10-14 19:41:09 +010056 __be32 tcp_ack;
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -070057 u32 tcp_next_seq;
58 u32 skb_tot_frags_len;
59 u16 ip_tot_len;
60 u16 tcp_saw_tstamp; /* timestamps enabled */
Al Viro9df7c982007-10-14 19:40:59 +010061 __be16 tcp_window;
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -070062 int pkt_aggr_cnt; /* counts aggregated packets */
63 int vlan_packet;
64 int mss;
65 int active;
66};
67
68/*
69 * Large Receive Offload (LRO) Manager
70 *
71 * Fields must be set by driver
72 */
73
74struct net_lro_mgr {
75 struct net_device *dev;
76 struct net_lro_stats stats;
77
78 /* LRO features */
79 unsigned long features;
80#define LRO_F_NAPI 1 /* Pass packets to stack via NAPI */
81#define LRO_F_EXTRACT_VLAN_ID 2 /* Set flag if VLAN IDs are extracted
82 from received packets and eth protocol
83 is still ETH_P_8021Q */
84
Eli Cohen251a4b32008-06-27 20:09:00 -070085 /*
86 * Set for generated SKBs that are not added to
87 * the frag list in fragmented mode
88 */
89 u32 ip_summed;
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -070090 u32 ip_summed_aggr; /* Set in aggregated SKBs: CHECKSUM_UNNECESSARY
91 * or CHECKSUM_NONE */
92
93 int max_desc; /* Max number of LRO descriptors */
94 int max_aggr; /* Max number of LRO packets to be aggregated */
95
Andrew Gallatin621544e2007-12-05 02:31:42 -080096 int frag_align_pad; /* Padding required to properly align layer 3
97 * headers in generated skb when using frags */
98
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -070099 struct net_lro_desc *lro_arr; /* Array of LRO descriptors */
100
101 /*
102 * Optimized driver functions
103 *
104 * get_skb_header: returns tcp and ip header for packet in SKB
105 */
106 int (*get_skb_header)(struct sk_buff *skb, void **ip_hdr,
107 void **tcpudp_hdr, u64 *hdr_flags, void *priv);
108
109 /* hdr_flags: */
110#define LRO_IPV4 1 /* ip_hdr is IPv4 header */
111#define LRO_TCP 2 /* tcpudp_hdr is TCP header */
112
113 /*
114 * get_frag_header: returns mac, tcp and ip header for packet in SKB
115 *
116 * @hdr_flags: Indicate what kind of LRO has to be done
117 * (IPv4/IPv6/TCP/UDP)
118 */
119 int (*get_frag_header)(struct skb_frag_struct *frag, void **mac_hdr,
120 void **ip_hdr, void **tcpudp_hdr, u64 *hdr_flags,
121 void *priv);
122};
123
124/*
125 * Processes a SKB
126 *
127 * @lro_mgr: LRO manager to use
128 * @skb: SKB to aggregate
129 * @priv: Private data that may be used by driver functions
130 * (for example get_tcp_ip_hdr)
131 */
132
133void lro_receive_skb(struct net_lro_mgr *lro_mgr,
134 struct sk_buff *skb,
135 void *priv);
136
137/*
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -0700138 * Processes a fragment list
139 *
140 * This functions aggregate fragments and generate SKBs do pass
141 * the packets to the stack.
142 *
143 * @lro_mgr: LRO manager to use
144 * @frags: Fragment to be processed. Must contain entire header in first
145 * element.
146 * @len: Length of received data
147 * @true_size: Actual size of memory the fragment is consuming
148 * @priv: Private data that may be used by driver functions
149 * (for example get_tcp_ip_hdr)
150 */
151
152void lro_receive_frags(struct net_lro_mgr *lro_mgr,
153 struct skb_frag_struct *frags,
154 int len, int true_size, void *priv, __wsum sum);
155
Jan-Bernd Themann71c87e02007-08-08 22:38:05 -0700156/*
157 * Forward all aggregated SKBs held by lro_mgr to network stack
158 */
159
160void lro_flush_all(struct net_lro_mgr *lro_mgr);
161
162void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
163 struct iphdr *iph, struct tcphdr *tcph);
164
165#endif