Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
inet_lro.h
Go to the documentation of this file.
1 /*
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 <[email protected]>
10  * Christoph Raisch <[email protected]>
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 
38 struct 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  */
47 struct 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;
53  __wsum data_csum;
54  __be32 tcp_rcv_tsecr;
55  __be32 tcp_rcv_tsval;
56  __be32 tcp_ack;
57  u32 tcp_next_seq;
58  u32 skb_tot_frags_len;
59  u16 ip_tot_len;
60  u16 tcp_saw_tstamp; /* timestamps enabled */
61  __be16 tcp_window;
62  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 
74 struct 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 
85  /*
86  * Set for generated SKBs that are not added to
87  * the frag list in fragmented mode
88  */
89  u32 ip_summed;
90  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 
96  int frag_align_pad; /* Padding required to properly align layer 3
97  * headers in generated skb when using frags */
98 
99  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 
133 void lro_receive_skb(struct net_lro_mgr *lro_mgr,
134  struct sk_buff *skb,
135  void *priv);
136 
137 /*
138  * 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 
152 void 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 
156 /*
157  * Forward all aggregated SKBs held by lro_mgr to network stack
158  */
159 
160 void lro_flush_all(struct net_lro_mgr *lro_mgr);
161 
162 void lro_flush_pkt(struct net_lro_mgr *lro_mgr,
163  struct iphdr *iph, struct tcphdr *tcph);
164 
165 #endif
Generated on Thu Jan 10 2013 14:51:36 for Linux Kernel by   doxygen 1.8.2