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 /* eye catcher "SMCR" EBCDIC for CLC messages */
  26 static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
  27
  28 #define SMC_CLC_V1              0x1             /* SMC version                */
  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    0x02000000  /* timeout                        */
  32 #define SMC_CLC_DECL_CNFERR     0x03000000  /* configuration error            */
  33 #define SMC_CLC_DECL_IPSEC      0x03030000  /* IPsec usage                    */
  34 #define SMC_CLC_DECL_SYNCERR    0x04000000  /* synchronization error          */
  35 #define SMC_CLC_DECL_REPLY      0x06000000  /* reply to a received decline    */
  36 #define SMC_CLC_DECL_INTERR     0x99990000  /* internal error                 */
  37 #define SMC_CLC_DECL_TCL        0x02040000  /* timeout w4 QP confirm          */
  38 #define SMC_CLC_DECL_SEND       0x07000000  /* sending problem                */
  39
  40 struct smc_clc_msg_hdr {        /* header1 of clc messages */
  41         u8 eyecatcher[4];       /* eye catcher */
  42         u8 type;                /* proposal / accept / confirm / decline */
  43         __be16 length;
  44 #if defined(__BIG_ENDIAN_BITFIELD)
  45         u8 version : 4,
  46            flag    : 1,
  47            rsvd    : 3;
  48 #elif defined(__LITTLE_ENDIAN_BITFIELD)
  49         u8 rsvd    : 3,
  50            flag    : 1,
  51            version : 4;
  52 #endif
  53 } __packed;                     /* format defined in RFC7609 */
  54
  55 struct smc_clc_msg_trail {      /* trailer of clc messages */
  56         u8 eyecatcher[4];
  57 };
  58
  59 struct smc_clc_msg_local {      /* header2 of clc messages */
  60         u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
  61         u8 gid[16];             /* gid of ib_device port */
  62         u8 mac[6];              /* mac of ib_device port */
  63 };
  64
  65 struct smc_clc_ipv6_prefix {
  66         u8 prefix[4];
  67         u8 prefix_len;
  68 } __packed;
  69
  70 struct smc_clc_msg_proposal_prefix {    /* prefix part of clc proposal message*/
  71         __be32 outgoing_subnet; /* subnet mask */
  72         u8 prefix_len;          /* number of significant bits in mask */
  73         u8 reserved[2];
  74         u8 ipv6_prefixes_cnt;   /* number of IPv6 prefixes in prefix array */
  75 } __aligned(4);
  76
  77 struct smc_clc_msg_proposal {   /* clc proposal message sent by Linux */
  78         struct smc_clc_msg_hdr hdr;
  79         struct smc_clc_msg_local lcl;
  80         __be16 iparea_offset;   /* offset to IP address information area */
  81 } __aligned(4);
  82
  83 #define SMC_CLC_PROPOSAL_MAX_OFFSET     0x28
  84 #define SMC_CLC_PROPOSAL_MAX_PREFIX     (8 * sizeof(struct smc_clc_ipv6_prefix))
  85 #define SMC_CLC_MAX_LEN         (sizeof(struct smc_clc_msg_proposal) + \
  86                                  SMC_CLC_PROPOSAL_MAX_OFFSET + \
  87                                  SMC_CLC_PROPOSAL_MAX_PREFIX + \
  88                                  sizeof(struct smc_clc_msg_trail))
  89
  90 struct smc_clc_msg_accept_confirm {     /* clc accept / confirm message */
  91         struct smc_clc_msg_hdr hdr;
  92         struct smc_clc_msg_local lcl;
  93         u8 qpn[3];              /* QP number */
  94         __be32 rmb_rkey;        /* RMB rkey */
  95         u8 conn_idx;            /* Connection index, which RMBE in RMB */
  96         __be32 rmbe_alert_token;/* unique connection id */
  97 #if defined(__BIG_ENDIAN_BITFIELD)
  98         u8 rmbe_size : 4,       /* RMBE buf size (compressed notation) */
  99            qp_mtu   : 4;        /* QP mtu */
 100 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 101         u8 qp_mtu   : 4,
 102            rmbe_size : 4;
 103 #endif
 104         u8 reserved;
 105         __be64 rmb_dma_addr;    /* RMB virtual address */
 106         u8 reserved2;
 107         u8 psn[3];              /* initial packet sequence number */
 108         struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
 109 } __packed;                     /* format defined in RFC7609 */
 110
 111 struct smc_clc_msg_decline {    /* clc decline message */
 112         struct smc_clc_msg_hdr hdr;
 113         u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
 114         __be32 peer_diagnosis;  /* diagnosis information */
 115         u8 reserved2[4];
 116         struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
 117 } __aligned(4);
 118
 119 /* determine start of the prefix area within the proposal message */
 120 static inline struct smc_clc_msg_proposal_prefix *
 121 smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
 122 {
 123         return (struct smc_clc_msg_proposal_prefix *)
 124                ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
 125 }
 126
 127 struct smc_sock;
 128 struct smc_ib_device;
 129
 130 int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 131                      u8 expected_type);
 132 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
 133 int smc_clc_send_proposal(struct smc_sock *smc, struct smc_ib_device *smcibdev,
 134                           u8 ibport);
 135 int smc_clc_send_confirm(struct smc_sock *smc);
 136 int smc_clc_send_accept(struct smc_sock *smc, int srv_first_contact);
 137
 138 #endif