xref: /freebsd/sys/netinet/tcp_lro.h (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2006, Myricom Inc.
5  * Copyright (c) 2008, Intel Corporation.
6  * Copyright (c) 2016-2021 Mellanox Technologies.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $FreeBSD$
31  */
32 
33 #ifndef _TCP_LRO_H_
34 #define _TCP_LRO_H_
35 
36 #include <sys/time.h>
37 #include <sys/param.h>
38 
39 #include <netinet/in.h>
40 
41 #ifndef TCP_LRO_ENTRIES
42 /* Define default number of LRO entries per RX queue */
43 #define	TCP_LRO_ENTRIES	8
44 #endif
45 
46 /*
47  * Flags for ACK entry for compression
48  * the bottom 12 bits has the th_x2|th_flags.
49  * LRO itself adds only the TSTMP flags
50  * to indicate if either of the types
51  * of timestamps are filled and the
52  * HAS_TSTMP option to indicate if the
53  * TCP timestamp option is valid.
54  *
55  * The other 1 flag bits are for processing
56  * by a stack.
57  *
58  */
59 #define TSTMP_LRO		0x1000
60 #define TSTMP_HDWR		0x2000
61 #define HAS_TSTMP		0x4000
62 /*
63  * Default number of interrupts on the same cpu in a row
64  * that will cause us to declare a "affinity cpu".
65  */
66 #define TCP_LRO_CPU_DECLARATION_THRESH 50
67 
68 struct inpcb;
69 
70 /* Precompute the LRO_RAW_ADDRESS_MAX value: */
71 #define	LRO_RAW_ADDRESS_MAX \
72 	howmany(12 + 2 * sizeof(struct in6_addr), sizeof(u_long))
73 
74 union lro_address {
75 	u_long raw[LRO_RAW_ADDRESS_MAX];
76 	struct {
77 		uint8_t lro_type;	/* internal */
78 #define	LRO_TYPE_NONE     0
79 #define	LRO_TYPE_IPV4_TCP 1
80 #define	LRO_TYPE_IPV6_TCP 2
81 #define	LRO_TYPE_IPV4_UDP 3
82 #define	LRO_TYPE_IPV6_UDP 4
83 		uint8_t lro_flags;
84 #define	LRO_FLAG_DECRYPTED 1
85 		uint16_t vlan_id;	/* VLAN identifier */
86 		uint16_t s_port;	/* source TCP/UDP port */
87 		uint16_t d_port;	/* destination TCP/UDP port */
88 		uint32_t vxlan_vni;	/* VXLAN virtual network identifier */
89 		union {
90 			struct in_addr v4;
91 			struct in6_addr v6;
92 		} s_addr;	/* source IPv4/IPv6 address */
93 		union {
94 			struct in_addr v4;
95 			struct in6_addr v6;
96 		} d_addr;	/* destination IPv4/IPv6 address */
97 	};
98 };
99 
100 _Static_assert(sizeof(union lro_address) == sizeof(u_long) * LRO_RAW_ADDRESS_MAX,
101     "The raw field in the lro_address union does not cover the whole structure.");
102 
103 /* Optimize address comparison by comparing one unsigned long at a time: */
104 
105 static inline bool
106 lro_address_compare(const union lro_address *pa, const union lro_address *pb)
107 {
108 	if (pa->lro_type == LRO_TYPE_NONE && pb->lro_type == LRO_TYPE_NONE) {
109 		return (true);
110 	} else for (unsigned i = 0; i < LRO_RAW_ADDRESS_MAX; i++) {
111 		if (pa->raw[i] != pb->raw[i])
112 			return (false);
113 	}
114 	return (true);
115 }
116 
117 struct lro_parser {
118 	union lro_address data;
119 	union {
120 		uint8_t *l3;
121 		struct ip *ip4;
122 		struct ip6_hdr *ip6;
123 	};
124 	union {
125 		uint8_t *l4;
126 		struct tcphdr *tcp;
127 		struct udphdr *udp;
128 	};
129 	uint16_t total_hdr_len;
130 };
131 
132 /* This structure is zeroed frequently, try to keep it small. */
133 struct lro_entry {
134 	LIST_ENTRY(lro_entry)	next;
135 	LIST_ENTRY(lro_entry)	hash_next;
136 	struct mbuf		*m_head;
137 	struct mbuf		*m_tail;
138 	struct mbuf		*m_last_mbuf;
139 	struct lro_parser	outer;
140 	struct lro_parser	inner;
141 	uint32_t		next_seq;	/* tcp_seq */
142 	uint32_t		ack_seq;	/* tcp_seq */
143 	uint32_t		tsval;
144 	uint32_t		tsecr;
145 	uint16_t		compressed;
146 	uint16_t		uncompressed;
147 	uint16_t		window;
148 	uint16_t		flags : 12,	/* 12 TCP header bits */
149 				timestamp : 1,
150 				needs_merge : 1,
151 				reserved : 2;	/* unused */
152 	struct bintime		alloc_time;	/* time when entry was allocated */
153 };
154 
155 LIST_HEAD(lro_head, lro_entry);
156 
157 struct lro_mbuf_sort {
158 	uint64_t seq;
159 	struct mbuf *mb;
160 };
161 
162 /* NB: This is part of driver structs. */
163 struct lro_ctrl {
164 	struct ifnet	*ifp;
165 	struct lro_mbuf_sort *lro_mbuf_data;
166 	struct bintime	lro_last_queue_time;	/* last time data was queued */
167 	uint64_t	lro_queued;
168 	uint64_t	lro_flushed;
169 	uint64_t	lro_bad_csum;
170 	unsigned	lro_cnt;
171 	unsigned	lro_mbuf_count;
172 	unsigned	lro_mbuf_max;
173 	unsigned short	lro_ackcnt_lim;		/* max # of aggregated ACKs */
174 	unsigned short	lro_cpu;		/* Guess at the cpu we have affinity too */
175 	unsigned 	lro_length_lim;		/* max len of aggregated data */
176 	u_long		lro_hashsz;
177 	uint32_t	lro_last_cpu;
178 	uint32_t 	lro_cnt_of_same_cpu;
179 	struct lro_head	*lro_hash;
180 	struct lro_head	lro_active;
181 	struct lro_head	lro_free;
182 	uint8_t		lro_cpu_is_set;		/* Flag to say its ok to set the CPU on the inp */
183 };
184 
185 struct tcp_ackent {
186 	uint64_t timestamp;	/* hardware or sofware timestamp, valid if TSTMP_LRO or TSTMP_HDRW set */
187 	uint32_t seq;		/* th_seq value */
188 	uint32_t ack;		/* th_ack value */
189 	uint32_t ts_value;	/* If ts option value, valid if HAS_TSTMP is set */
190 	uint32_t ts_echo;	/* If ts option echo, valid if HAS_TSTMP is set */
191 	uint16_t win;		/* TCP window */
192 	uint16_t flags;		/* Flags to say if TS is present and type of timestamp and th_flags */
193 	uint8_t  codepoint;	/* IP level codepoint including ECN bits */
194 	uint8_t  ack_val_set;	/* Classification of ack used by the stack */
195 	uint8_t  pad[2];	/* To 32 byte boundary */
196 };
197 
198 /* We use two M_PROTO on the mbuf */
199 #define M_ACKCMP	M_PROTO4   /* Indicates LRO is sending in a  Ack-compression mbuf */
200 #define M_LRO_EHDRSTRP	M_PROTO6   /* Indicates that LRO has stripped the etherenet header */
201 
202 #define	TCP_LRO_LENGTH_MAX	(65535 - 255)	/* safe value with room for outer headers */
203 #define	TCP_LRO_ACKCNT_MAX	65535		/* unlimited */
204 
205 int tcp_lro_init(struct lro_ctrl *);
206 int tcp_lro_init_args(struct lro_ctrl *, struct ifnet *, unsigned, unsigned);
207 void tcp_lro_free(struct lro_ctrl *);
208 void tcp_lro_flush_inactive(struct lro_ctrl *, const struct timeval *);
209 void tcp_lro_flush(struct lro_ctrl *, struct lro_entry *);
210 void tcp_lro_flush_all(struct lro_ctrl *);
211 int tcp_lro_rx(struct lro_ctrl *, struct mbuf *, uint32_t);
212 void tcp_lro_queue_mbuf(struct lro_ctrl *, struct mbuf *);
213 void tcp_lro_reg_mbufq(void);
214 void tcp_lro_dereg_mbufq(void);
215 
216 #define	TCP_LRO_NO_ENTRIES	-2
217 #define	TCP_LRO_CANNOT		-1
218 #define	TCP_LRO_NOT_SUPPORTED	1
219 
220 #endif /* _TCP_LRO_H_ */
221