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 <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 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 166