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
 38struct 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
 53struct smc_clc_msg_trail {	/* trailer of clc messages */
 54	u8 eyecatcher[4];
 55};
 56
 57struct 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 */
 68struct smc_clc_ipv6_prefix {
 69	struct in6_addr prefix;
 70	u8 prefix_len;
 71} __packed;			/* format defined in RFC7609 */
 72
 73struct 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
 80struct 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
 95struct 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 conn_idx;		/* Connection index, which 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
116struct 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 */
125static inline struct smc_clc_msg_proposal_prefix *
126smc_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
132int smc_clc_prfx_match(struct socket *clcsock,
133		       struct smc_clc_msg_proposal_prefix *prop);
134int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
135		     u8 expected_type);
136int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
137int smc_clc_send_proposal(struct smc_sock *smc, struct smc_ib_device *smcibdev,
138			  u8 ibport);
139int smc_clc_send_confirm(struct smc_sock *smc);
140int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
141
142#endif