net/smc/smc_clc.h

   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 SMC_CLC_DECL_MEM        0x01010000  /* insufficient memory resources  */
  31 #define SMC_CLC_DECL_TIMEOUT_CL 0x02010000  /* timeout w4 QP confirm link     */
  32 #define SMC_CLC_DECL_TIMEOUT_AL 0x02020000  /* timeout w4 QP add link         */
  33 #define SMC_CLC_DECL_CNFERR     0x03000000  /* configuration error            */
  34 #define SMC_CLC_DECL_PEERNOSMC  0x03010000  /* peer did not indicate SMC      */
  35 #define SMC_CLC_DECL_IPSEC      0x03020000  /* IPsec usage                    */
  36 #define SMC_CLC_DECL_NOSMCDEV   0x03030000  /* no SMC device found            */
  37 #define SMC_CLC_DECL_MODEUNSUPP 0x03040000  /* smc modes do not match (R or D)*/
  38 #define SMC_CLC_DECL_RMBE_EC    0x03050000  /* peer has eyecatcher in RMBE    */
  39 #define SMC_CLC_DECL_OPTUNSUPP  0x03060000  /* fastopen sockopt not supported */
  40 #define SMC_CLC_DECL_SYNCERR    0x04000000  /* synchronization error          */
  41 #define SMC_CLC_DECL_PEERDECL   0x05000000  /* peer declined during handshake */
  42 #define SMC_CLC_DECL_INTERR     0x99990000  /* internal error                 */
  43 #define SMC_CLC_DECL_ERR_RTOK   0x99990001  /*   rtoken handling failed       */
  44 #define SMC_CLC_DECL_ERR_RDYLNK 0x99990002  /*   ib ready link failed         */
  45 #define SMC_CLC_DECL_ERR_REGRMB 0x99990003  /*   reg rmb failed               */
  46
  47 struct smc_clc_msg_hdr {        /* header1 of clc messages */
  48         u8 eyecatcher[4];       /* eye catcher */
  49         u8 type;                /* proposal / accept / confirm / decline */
  50         __be16 length;
  51 #if defined(__BIG_ENDIAN_BITFIELD)
  52         u8 version : 4,
  53            flag    : 1,
  54            rsvd    : 1,
  55            path    : 2;
  56 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  57         u8 path    : 2,
  58            rsvd    : 1,
  59            flag    : 1,
  60            version : 4;
  61 #endif
  62 } __packed;                     /* format defined in RFC7609 */
  63
  64 struct smc_clc_msg_trail {      /* trailer of clc messages */
  65         u8 eyecatcher[4];
  66 };
  67
  68 struct smc_clc_msg_local {      /* header2 of clc messages */
  69         u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
  70         u8 gid[16];             /* gid of ib_device port */
  71         u8 mac[6];              /* mac of ib_device port */
  72 };
  73
  74 #define SMC_CLC_MAX_V6_PREFIX   8
  75
  76 /* Struct would be 4 byte aligned, but it is used in an array that is sent
  77  * to peers and must conform to RFC7609, hence we need to use packed here.
  78  */
  79 struct smc_clc_ipv6_prefix {
  80         struct in6_addr prefix;
  81         u8 prefix_len;
  82 } __packed;                     /* format defined in RFC7609 */
  83
  84 struct smc_clc_msg_proposal_prefix {    /* prefix part of clc proposal message*/
  85         __be32 outgoing_subnet; /* subnet mask */
  86         u8 prefix_len;          /* number of significant bits in mask */
  87         u8 reserved[2];
  88         u8 ipv6_prefixes_cnt;   /* number of IPv6 prefixes in prefix array */
  89 } __aligned(4);
  90
  91 struct smc_clc_msg_smcd {       /* SMC-D GID information */
  92         u64 gid;                /* ISM GID of requestor */
  93         u8 res[32];
  94 };
  95
  96 struct smc_clc_msg_proposal {   /* clc proposal message sent by Linux */
  97         struct smc_clc_msg_hdr hdr;
  98         struct smc_clc_msg_local lcl;
  99         __be16 iparea_offset;   /* offset to IP address information area */
 100 } __aligned(4);
 101
 102 #define SMC_CLC_PROPOSAL_MAX_OFFSET     0x28
 103 #define SMC_CLC_PROPOSAL_MAX_PREFIX     (SMC_CLC_MAX_V6_PREFIX * \
 104                                          sizeof(struct smc_clc_ipv6_prefix))
 105 #define SMC_CLC_MAX_LEN         (sizeof(struct smc_clc_msg_proposal) + \
 106                                  SMC_CLC_PROPOSAL_MAX_OFFSET + \
 107                                  sizeof(struct smc_clc_msg_proposal_prefix) + \
 108                                  SMC_CLC_PROPOSAL_MAX_PREFIX + \
 109                                  sizeof(struct smc_clc_msg_trail))
 110
 111 struct smc_clc_msg_accept_confirm {     /* clc accept / confirm message */
 112         struct smc_clc_msg_hdr hdr;
 113         union {
 114                 struct { /* SMC-R */
 115                         struct smc_clc_msg_local lcl;
 116                         u8 qpn[3];              /* QP number */
 117                         __be32 rmb_rkey;        /* RMB rkey */
 118                         u8 rmbe_idx;            /* Index of RMBE in RMB */
 119                         __be32 rmbe_alert_token;/* unique connection id */
 120 #if defined(__BIG_ENDIAN_BITFIELD)
 121                         u8 rmbe_size : 4,       /* buf size (compressed) */
 122                            qp_mtu   : 4;        /* QP mtu */
 123 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 124                         u8 qp_mtu   : 4,
 125                            rmbe_size : 4;
 126 #endif
 127                         u8 reserved;
 128                         __be64 rmb_dma_addr;    /* RMB virtual address */
 129                         u8 reserved2;
 130                         u8 psn[3];              /* packet sequence number */
 131                         struct smc_clc_msg_trail smcr_trl;
 132                                                 /* eye catcher "SMCR" EBCDIC */
 133                 } __packed;
 134                 struct { /* SMC-D */
 135                         u64 gid;                /* Sender GID */
 136                         u64 token;              /* DMB token */
 137                         u8 dmbe_idx;            /* DMBE index */
 138 #if defined(__BIG_ENDIAN_BITFIELD)
 139                         u8 dmbe_size : 4,       /* buf size (compressed) */
 140                            reserved3 : 4;
 141 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 142                         u8 reserved3 : 4,
 143                            dmbe_size : 4;
 144 #endif
 145                         u16 reserved4;
 146                         u32 linkid;             /* Link identifier */
 147                         u32 reserved5[3];
 148                         struct smc_clc_msg_trail smcd_trl;
 149                                                 /* eye catcher "SMCD" EBCDIC */
 150                 } __packed;
 151         };
 152 } __packed;                     /* format defined in RFC7609 */
 153
 154 struct smc_clc_msg_decline {    /* clc decline message */
 155         struct smc_clc_msg_hdr hdr;
 156         u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
 157         __be32 peer_diagnosis;  /* diagnosis information */
 158         u8 reserved2[4];
 159         struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
 160 } __aligned(4);
 161
 162 /* determine start of the prefix area within the proposal message */
 163 static inline struct smc_clc_msg_proposal_prefix *
 164 smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
 165 {
 166         return (struct smc_clc_msg_proposal_prefix *)
 167                ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
 168 }
 169
 170 /* get SMC-D info from proposal message */
 171 static inline struct smc_clc_msg_smcd *
 172 smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
 173 {
 174         if (ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
 175                 return NULL;
 176
 177         return (struct smc_clc_msg_smcd *)(prop + 1);
 178 }
 179
 180 struct smcd_dev;
 181
 182 int smc_clc_prfx_match(struct socket *clcsock,
 183                        struct smc_clc_msg_proposal_prefix *prop);
 184 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 185                      u8 expected_type);
 186 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
 187 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
 188                           struct smc_ib_device *smcibdev, u8 ibport, u8 gid[],
 189                           struct smcd_dev *ismdev);
 190 int smc_clc_send_confirm(struct smc_sock *smc);
 191 int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
 192
 193 #endif