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 SMC_TYPE_R		0		/* SMC-R only		      */
 27#define SMC_TYPE_D		1		/* SMC-D only		      */
 28#define SMC_TYPE_N		2		/* neither SMC-R nor SMC-D    */
 29#define SMC_TYPE_B		3		/* SMC-R and SMC-D	      */
 30#define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
 31#define CLC_WAIT_TIME_SHORT	HZ		/* short wait time on clcsock */
 32#define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
 33#define SMC_CLC_DECL_TIMEOUT_CL	0x02010000  /* timeout w4 QP confirm link     */
 34#define SMC_CLC_DECL_TIMEOUT_AL	0x02020000  /* timeout w4 QP add link	      */
 35#define SMC_CLC_DECL_CNFERR	0x03000000  /* configuration error            */
 36#define SMC_CLC_DECL_PEERNOSMC	0x03010000  /* peer did not indicate SMC      */
 37#define SMC_CLC_DECL_IPSEC	0x03020000  /* IPsec usage		      */
 38#define SMC_CLC_DECL_NOSMCDEV	0x03030000  /* no SMC device found (R or D)   */
 39#define SMC_CLC_DECL_NOSMCDDEV	0x03030001  /* no SMC-D device found	      */
 40#define SMC_CLC_DECL_NOSMCRDEV	0x03030002  /* no SMC-R device found	      */
 41#define SMC_CLC_DECL_SMCDNOTALK	0x03030003  /* SMC-D dev can't talk to peer   */
 42#define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 43#define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 44#define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
 45#define SMC_CLC_DECL_DIFFPREFIX	0x03070000  /* IP prefix / subnet mismatch    */
 46#define SMC_CLC_DECL_GETVLANERR	0x03080000  /* err to get vlan id of ip device*/
 47#define SMC_CLC_DECL_ISMVLANERR	0x03090000  /* err to reg vlan id on ism dev  */
 48#define SMC_CLC_DECL_NOACTLINK	0x030a0000  /* no active smc-r link in lgr    */
 49#define SMC_CLC_DECL_NOSRVLINK	0x030b0000  /* SMC-R link from srv not found  */
 50#define SMC_CLC_DECL_VERSMISMAT	0x030c0000  /* SMC version mismatch	      */
 51#define SMC_CLC_DECL_MAX_DMB	0x030d0000  /* SMC-D DMB limit exceeded       */
 52#define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
 53#define SMC_CLC_DECL_PEERDECL	0x05000000  /* peer declined during handshake */
 54#define SMC_CLC_DECL_INTERR	0x09990000  /* internal error		      */
 55#define SMC_CLC_DECL_ERR_RTOK	0x09990001  /*	 rtoken handling failed       */
 56#define SMC_CLC_DECL_ERR_RDYLNK	0x09990002  /*	 ib ready link failed	      */
 57#define SMC_CLC_DECL_ERR_REGRMB	0x09990003  /*	 reg rmb failed		      */
 58
 59struct smc_clc_msg_hdr {	/* header1 of clc messages */
 60	u8 eyecatcher[4];	/* eye catcher */
 61	u8 type;		/* proposal / accept / confirm / decline */
 62	__be16 length;
 63#if defined(__BIG_ENDIAN_BITFIELD)
 64	u8 version : 4,
 65	   flag    : 1,
 66	   rsvd	   : 1,
 67	   path	   : 2;
 68#elif defined(__LITTLE_ENDIAN_BITFIELD)
 69	u8 path    : 2,
 70	   rsvd    : 1,
 71	   flag    : 1,
 72	   version : 4;
 73#endif
 74} __packed;			/* format defined in RFC7609 */
 75
 76struct smc_clc_msg_trail {	/* trailer of clc messages */
 77	u8 eyecatcher[4];
 78};
 79
 80struct smc_clc_msg_local {	/* header2 of clc messages */
 81	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
 82	u8 gid[16];		/* gid of ib_device port */
 83	u8 mac[6];		/* mac of ib_device port */
 84};
 85
 86#define SMC_CLC_MAX_V6_PREFIX	8
 87
 88/* Struct would be 4 byte aligned, but it is used in an array that is sent
 89 * to peers and must conform to RFC7609, hence we need to use packed here.
 90 */
 91struct smc_clc_ipv6_prefix {
 92	struct in6_addr prefix;
 93	u8 prefix_len;
 94} __packed;			/* format defined in RFC7609 */
 95
 96struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
 97	__be32 outgoing_subnet;	/* subnet mask */
 98	u8 prefix_len;		/* number of significant bits in mask */
 99	u8 reserved[2];
100	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
101} __aligned(4);
102
103struct smc_clc_msg_smcd {	/* SMC-D GID information */
104	u64 gid;		/* ISM GID of requestor */
105	u8 res[32];
106};
107
108struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
109	struct smc_clc_msg_hdr hdr;
110	struct smc_clc_msg_local lcl;
111	__be16 iparea_offset;	/* offset to IP address information area */
112} __aligned(4);
113
114#define SMC_CLC_PROPOSAL_MAX_OFFSET	0x28
115#define SMC_CLC_PROPOSAL_MAX_PREFIX	(SMC_CLC_MAX_V6_PREFIX * \
116					 sizeof(struct smc_clc_ipv6_prefix))
117#define SMC_CLC_MAX_LEN		(sizeof(struct smc_clc_msg_proposal) + \
118				 SMC_CLC_PROPOSAL_MAX_OFFSET + \
119				 sizeof(struct smc_clc_msg_proposal_prefix) + \
120				 SMC_CLC_PROPOSAL_MAX_PREFIX + \
121				 sizeof(struct smc_clc_msg_trail))
122
123struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
124	struct smc_clc_msg_hdr hdr;
125	union {
126		struct { /* SMC-R */
127			struct smc_clc_msg_local lcl;
128			u8 qpn[3];		/* QP number */
129			__be32 rmb_rkey;	/* RMB rkey */
130			u8 rmbe_idx;		/* Index of RMBE in RMB */
131			__be32 rmbe_alert_token;/* unique connection id */
132#if defined(__BIG_ENDIAN_BITFIELD)
133			u8 rmbe_size : 4,	/* buf size (compressed) */
134			   qp_mtu   : 4;	/* QP mtu */
135#elif defined(__LITTLE_ENDIAN_BITFIELD)
136			u8 qp_mtu   : 4,
137			   rmbe_size : 4;
138#endif
139			u8 reserved;
140			__be64 rmb_dma_addr;	/* RMB virtual address */
141			u8 reserved2;
142			u8 psn[3];		/* packet sequence number */
143			struct smc_clc_msg_trail smcr_trl;
144						/* eye catcher "SMCR" EBCDIC */
145		} __packed;
146		struct { /* SMC-D */
147			u64 gid;		/* Sender GID */
148			u64 token;		/* DMB token */
149			u8 dmbe_idx;		/* DMBE index */
150#if defined(__BIG_ENDIAN_BITFIELD)
151			u8 dmbe_size : 4,	/* buf size (compressed) */
152			   reserved3 : 4;
153#elif defined(__LITTLE_ENDIAN_BITFIELD)
154			u8 reserved3 : 4,
155			   dmbe_size : 4;
156#endif
157			u16 reserved4;
158			u32 linkid;		/* Link identifier */
159			u32 reserved5[3];
160			struct smc_clc_msg_trail smcd_trl;
161						/* eye catcher "SMCD" EBCDIC */
162		} __packed;
163	};
164} __packed;			/* format defined in RFC7609 */
165
166struct smc_clc_msg_decline {	/* clc decline message */
167	struct smc_clc_msg_hdr hdr;
168	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
169	__be32 peer_diagnosis;	/* diagnosis information */
170	u8 reserved2[4];
171	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
172} __aligned(4);
173
174/* determine start of the prefix area within the proposal message */
175static inline struct smc_clc_msg_proposal_prefix *
176smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
177{
178	return (struct smc_clc_msg_proposal_prefix *)
179	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
180}
181
182/* get SMC-D info from proposal message */
183static inline struct smc_clc_msg_smcd *
184smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
185{
186	if (ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
187		return NULL;
188
189	return (struct smc_clc_msg_smcd *)(prop + 1);
190}
191
192struct smcd_dev;
193struct smc_init_info;
194
195int smc_clc_prfx_match(struct socket *clcsock,
196		       struct smc_clc_msg_proposal_prefix *prop);
197int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
198		     u8 expected_type, unsigned long timeout);
199int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
200int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
201			  struct smc_init_info *ini);
202int smc_clc_send_confirm(struct smc_sock *smc);
203int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
204
205#endif