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_B		3		/* SMC-R and SMC-D	      */
 29#define CLC_WAIT_TIME		(6 * HZ)	/* max. wait time on clcsock  */
 30#define CLC_WAIT_TIME_SHORT	HZ		/* short wait time on clcsock */
 31#define SMC_CLC_DECL_MEM	0x01010000  /* insufficient memory resources  */
 32#define SMC_CLC_DECL_TIMEOUT_CL	0x02010000  /* timeout w4 QP confirm link     */
 33#define SMC_CLC_DECL_TIMEOUT_AL	0x02020000  /* timeout w4 QP add link	      */
 34#define SMC_CLC_DECL_CNFERR	0x03000000  /* configuration error            */
 35#define SMC_CLC_DECL_PEERNOSMC	0x03010000  /* peer did not indicate SMC      */
 36#define SMC_CLC_DECL_IPSEC	0x03020000  /* IPsec usage		      */
 37#define SMC_CLC_DECL_NOSMCDEV	0x03030000  /* no SMC device found (R or D)   */
 38#define SMC_CLC_DECL_NOSMCDDEV	0x03030001  /* no SMC-D device found	      */
 39#define SMC_CLC_DECL_NOSMCRDEV	0x03030002  /* no SMC-R device found	      */
 40#define SMC_CLC_DECL_SMCDNOTALK	0x03030003  /* SMC-D dev can't talk to peer   */
 41#define SMC_CLC_DECL_MODEUNSUPP	0x03040000  /* smc modes do not match (R or D)*/
 42#define SMC_CLC_DECL_RMBE_EC	0x03050000  /* peer has eyecatcher in RMBE    */
 43#define SMC_CLC_DECL_OPTUNSUPP	0x03060000  /* fastopen sockopt not supported */
 44#define SMC_CLC_DECL_DIFFPREFIX	0x03070000  /* IP prefix / subnet mismatch    */
 45#define SMC_CLC_DECL_GETVLANERR	0x03080000  /* err to get vlan id of ip device*/
 46#define SMC_CLC_DECL_ISMVLANERR	0x03090000  /* err to reg vlan id on ism dev  */
 47#define SMC_CLC_DECL_SYNCERR	0x04000000  /* synchronization error          */
 48#define SMC_CLC_DECL_PEERDECL	0x05000000  /* peer declined during handshake */
 49#define SMC_CLC_DECL_INTERR	0x09990000  /* internal error		      */
 50#define SMC_CLC_DECL_ERR_RTOK	0x09990001  /*	 rtoken handling failed       */
 51#define SMC_CLC_DECL_ERR_RDYLNK	0x09990002  /*	 ib ready link failed	      */
 52#define SMC_CLC_DECL_ERR_REGRMB	0x09990003  /*	 reg rmb failed		      */
 53
 54struct smc_clc_msg_hdr {	/* header1 of clc messages */
 55	u8 eyecatcher[4];	/* eye catcher */
 56	u8 type;		/* proposal / accept / confirm / decline */
 57	__be16 length;
 58#if defined(__BIG_ENDIAN_BITFIELD)
 59	u8 version : 4,
 60	   flag    : 1,
 61	   rsvd	   : 1,
 62	   path	   : 2;
 63#elif defined(__LITTLE_ENDIAN_BITFIELD)
 64	u8 path    : 2,
 65	   rsvd    : 1,
 66	   flag    : 1,
 67	   version : 4;
 68#endif
 69} __packed;			/* format defined in RFC7609 */
 70
 71struct smc_clc_msg_trail {	/* trailer of clc messages */
 72	u8 eyecatcher[4];
 73};
 74
 75struct smc_clc_msg_local {	/* header2 of clc messages */
 76	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
 77	u8 gid[16];		/* gid of ib_device port */
 78	u8 mac[6];		/* mac of ib_device port */
 79};
 80
 81#define SMC_CLC_MAX_V6_PREFIX	8
 82
 83/* Struct would be 4 byte aligned, but it is used in an array that is sent
 84 * to peers and must conform to RFC7609, hence we need to use packed here.
 85 */
 86struct smc_clc_ipv6_prefix {
 87	struct in6_addr prefix;
 88	u8 prefix_len;
 89} __packed;			/* format defined in RFC7609 */
 90
 91struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
 92	__be32 outgoing_subnet;	/* subnet mask */
 93	u8 prefix_len;		/* number of significant bits in mask */
 94	u8 reserved[2];
 95	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
 96} __aligned(4);
 97
 98struct smc_clc_msg_smcd {	/* SMC-D GID information */
 99	u64 gid;		/* ISM GID of requestor */
100	u8 res[32];
101};
102
103struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
104	struct smc_clc_msg_hdr hdr;
105	struct smc_clc_msg_local lcl;
106	__be16 iparea_offset;	/* offset to IP address information area */
107} __aligned(4);
108
109#define SMC_CLC_PROPOSAL_MAX_OFFSET	0x28
110#define SMC_CLC_PROPOSAL_MAX_PREFIX	(SMC_CLC_MAX_V6_PREFIX * \
111					 sizeof(struct smc_clc_ipv6_prefix))
112#define SMC_CLC_MAX_LEN		(sizeof(struct smc_clc_msg_proposal) + \
113				 SMC_CLC_PROPOSAL_MAX_OFFSET + \
114				 sizeof(struct smc_clc_msg_proposal_prefix) + \
115				 SMC_CLC_PROPOSAL_MAX_PREFIX + \
116				 sizeof(struct smc_clc_msg_trail))
117
118struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
119	struct smc_clc_msg_hdr hdr;
120	union {
121		struct { /* SMC-R */
122			struct smc_clc_msg_local lcl;
123			u8 qpn[3];		/* QP number */
124			__be32 rmb_rkey;	/* RMB rkey */
125			u8 rmbe_idx;		/* Index of RMBE in RMB */
126			__be32 rmbe_alert_token;/* unique connection id */
127#if defined(__BIG_ENDIAN_BITFIELD)
128			u8 rmbe_size : 4,	/* buf size (compressed) */
129			   qp_mtu   : 4;	/* QP mtu */
130#elif defined(__LITTLE_ENDIAN_BITFIELD)
131			u8 qp_mtu   : 4,
132			   rmbe_size : 4;
133#endif
134			u8 reserved;
135			__be64 rmb_dma_addr;	/* RMB virtual address */
136			u8 reserved2;
137			u8 psn[3];		/* packet sequence number */
138			struct smc_clc_msg_trail smcr_trl;
139						/* eye catcher "SMCR" EBCDIC */
140		} __packed;
141		struct { /* SMC-D */
142			u64 gid;		/* Sender GID */
143			u64 token;		/* DMB token */
144			u8 dmbe_idx;		/* DMBE index */
145#if defined(__BIG_ENDIAN_BITFIELD)
146			u8 dmbe_size : 4,	/* buf size (compressed) */
147			   reserved3 : 4;
148#elif defined(__LITTLE_ENDIAN_BITFIELD)
149			u8 reserved3 : 4,
150			   dmbe_size : 4;
151#endif
152			u16 reserved4;
153			u32 linkid;		/* Link identifier */
154			u32 reserved5[3];
155			struct smc_clc_msg_trail smcd_trl;
156						/* eye catcher "SMCD" EBCDIC */
157		} __packed;
158	};
159} __packed;			/* format defined in RFC7609 */
160
161struct smc_clc_msg_decline {	/* clc decline message */
162	struct smc_clc_msg_hdr hdr;
163	u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
164	__be32 peer_diagnosis;	/* diagnosis information */
165	u8 reserved2[4];
166	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
167} __aligned(4);
168
169/* determine start of the prefix area within the proposal message */
170static inline struct smc_clc_msg_proposal_prefix *
171smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
172{
173	return (struct smc_clc_msg_proposal_prefix *)
174	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
175}
176
177/* get SMC-D info from proposal message */
178static inline struct smc_clc_msg_smcd *
179smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
180{
181	if (ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
182		return NULL;
183
184	return (struct smc_clc_msg_smcd *)(prop + 1);
185}
186
187struct smcd_dev;
188struct smc_init_info;
189
190int smc_clc_prfx_match(struct socket *clcsock,
191		       struct smc_clc_msg_proposal_prefix *prop);
192int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
193		     u8 expected_type, unsigned long timeout);
194int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
195int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
196			  struct smc_init_info *ini);
197int smc_clc_send_confirm(struct smc_sock *smc);
198int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
199
200#endif