xref: /linux/net/smc/smc_clc.h (revision 5bdd5fbb35ab0fe21bf2263106f51c5bee466a07)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
4  *
5  *  CLC (connection layer control) handshake over initial TCP socket to
6  *  prepare for RDMA traffic
7  *
8  *  Copyright IBM Corp. 2016
9  *
10  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
11  */
12 
13 #ifndef _SMC_CLC_H
14 #define _SMC_CLC_H
15 
16 #include <rdma/ib_verbs.h>
17 
18 #include "smc.h"
19 
20 #define SMC_CLC_PROPOSAL	0x01
21 #define SMC_CLC_ACCEPT		0x02
22 #define SMC_CLC_CONFIRM		0x03
23 #define SMC_CLC_DECLINE		0x04
24 
25 #define SMC_CLC_V1		0x1		/* SMC version                */
26 #define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
27 #define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
28 #define SMC_CLC_DECL_TIMEOUT	0x02000000  /* timeout                        */
29 #define SMC_CLC_DECL_CNFERR	0x03000000  /* configuration error            */
30 #define SMC_CLC_DECL_IPSEC	0x03030000  /* IPsec usage                    */
31 #define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
32 #define SMC_CLC_DECL_REPLY	0x06000000  /* reply to a received decline    */
33 #define SMC_CLC_DECL_INTERR	0x99990000  /* internal error                 */
34 #define SMC_CLC_DECL_TCL	0x02040000  /* timeout w4 QP confirm          */
35 #define SMC_CLC_DECL_SEND	0x07000000  /* sending problem                */
36 #define SMC_CLC_DECL_RMBE_EC	0x08000000  /* peer has eyecatcher in RMBE    */
37 
38 struct smc_clc_msg_hdr {	/* header1 of clc messages */
39 	u8 eyecatcher[4];	/* eye catcher */
40 	u8 type;		/* proposal / accept / confirm / decline */
41 	__be16 length;
42 #if defined(__BIG_ENDIAN_BITFIELD)
43 	u8 version : 4,
44 	   flag    : 1,
45 	   rsvd    : 3;
46 #elif defined(__LITTLE_ENDIAN_BITFIELD)
47 	u8 rsvd    : 3,
48 	   flag    : 1,
49 	   version : 4;
50 #endif
51 } __packed;			/* format defined in RFC7609 */
52 
53 struct smc_clc_msg_trail {	/* trailer of clc messages */
54 	u8 eyecatcher[4];
55 };
56 
57 struct smc_clc_msg_local {	/* header2 of clc messages */
58 	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
59 	u8 gid[16];		/* gid of ib_device port */
60 	u8 mac[6];		/* mac of ib_device port */
61 };
62 
63 #define SMC_CLC_MAX_V6_PREFIX	8
64 
65 /* Struct would be 4 byte aligned, but it is used in an array that is sent
66  * to peers and must conform to RFC7609, hence we need to use packed here.
67  */
68 struct smc_clc_ipv6_prefix {
69 	struct in6_addr prefix;
70 	u8 prefix_len;
71 } __packed;			/* format defined in RFC7609 */
72 
73 struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
74 	__be32 outgoing_subnet;	/* subnet mask */
75 	u8 prefix_len;		/* number of significant bits in mask */
76 	u8 reserved[2];
77 	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
78 } __aligned(4);
79 
80 struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
81 	struct smc_clc_msg_hdr hdr;
82 	struct smc_clc_msg_local lcl;
83 	__be16 iparea_offset;	/* offset to IP address information area */
84 } __aligned(4);
85 
86 #define SMC_CLC_PROPOSAL_MAX_OFFSET	0x28
87 #define SMC_CLC_PROPOSAL_MAX_PREFIX	(SMC_CLC_MAX_V6_PREFIX * \
88 					 sizeof(struct smc_clc_ipv6_prefix))
89 #define SMC_CLC_MAX_LEN		(sizeof(struct smc_clc_msg_proposal) + \
90 				 SMC_CLC_PROPOSAL_MAX_OFFSET + \
91 				 sizeof(struct smc_clc_msg_proposal_prefix) + \
92 				 SMC_CLC_PROPOSAL_MAX_PREFIX + \
93 				 sizeof(struct smc_clc_msg_trail))
94 
95 struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
96 	struct smc_clc_msg_hdr hdr;
97 	struct smc_clc_msg_local lcl;
98 	u8 qpn[3];		/* QP number */
99 	__be32 rmb_rkey;	/* RMB rkey */
100 	u8 rmbe_idx;		/* Index of RMBE in RMB */
101 	__be32 rmbe_alert_token;/* unique connection id */
102 #if defined(__BIG_ENDIAN_BITFIELD)
103 	u8 rmbe_size : 4,	/* RMBE buf size (compressed notation) */
104 	   qp_mtu   : 4;	/* QP mtu */
105 #elif defined(__LITTLE_ENDIAN_BITFIELD)
106 	u8 qp_mtu   : 4,
107 	   rmbe_size : 4;
108 #endif
109 	u8 reserved;
110 	__be64 rmb_dma_addr;	/* RMB virtual address */
111 	u8 reserved2;
112 	u8 psn[3];		/* initial packet sequence number */
113 	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
114 } __packed;			/* format defined in RFC7609 */
115 
116 struct smc_clc_msg_decline {	/* clc decline message */
117 	struct smc_clc_msg_hdr hdr;
118 	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
119 	__be32 peer_diagnosis;	/* diagnosis information */
120 	u8 reserved2[4];
121 	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
122 } __aligned(4);
123 
124 /* determine start of the prefix area within the proposal message */
125 static inline struct smc_clc_msg_proposal_prefix *
126 smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
127 {
128 	return (struct smc_clc_msg_proposal_prefix *)
129 	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
130 }
131 
132 int smc_clc_prfx_match(struct socket *clcsock,
133 		       struct smc_clc_msg_proposal_prefix *prop);
134 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
135 		     u8 expected_type);
136 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
137 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_ib_device *smcibdev,
138 			  u8 ibport);
139 int smc_clc_send_confirm(struct smc_sock *smc);
140 int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
141 
142 #endif
143