/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  CLC (connection layer control) handshake over initial TCP socket to
 *  prepare for RDMA traffic
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#ifndef _SMC_CLC_H
#define _SMC_CLC_H

#include <rdma/ib_verbs.h>
#include <linux/smc.h>

#include "smc.h"
#include "smc_netlink.h"

#define SMC_CLC_PROPOSAL        0x01
#define SMC_CLC_ACCEPT          0x02
#define SMC_CLC_CONFIRM         0x03
#define SMC_CLC_DECLINE         0x04

#define SMC_TYPE_R              0               /* SMC-R only                 */
#define SMC_TYPE_D              1               /* SMC-D only                 */
#define SMC_TYPE_N              2               /* neither SMC-R nor SMC-D    */
#define SMC_TYPE_B              3               /* SMC-R and SMC-D            */
#define CLC_WAIT_TIME           (6 * HZ)        /* max. wait time on clcsock  */
#define CLC_WAIT_TIME_SHORT     HZ              /* short wait time on clcsock */
#define SMC_CLC_DECL_MEM        0x01010000  /* insufficient memory resources  */
#define SMC_CLC_DECL_TIMEOUT_CL 0x02010000  /* timeout w4 QP confirm link     */
#define SMC_CLC_DECL_TIMEOUT_AL 0x02020000  /* timeout w4 QP add link         */
#define SMC_CLC_DECL_CNFERR     0x03000000  /* configuration error            */
#define SMC_CLC_DECL_PEERNOSMC  0x03010000  /* peer did not indicate SMC      */
#define SMC_CLC_DECL_IPSEC      0x03020000  /* IPsec usage                    */
#define SMC_CLC_DECL_NOSMCDEV   0x03030000  /* no SMC device found (R or D)   */
#define SMC_CLC_DECL_NOSMCDDEV  0x03030001  /* no SMC-D device found          */
#define SMC_CLC_DECL_NOSMCRDEV  0x03030002  /* no SMC-R device found          */
#define SMC_CLC_DECL_NOISM2SUPP 0x03030003  /* hardware has no ISMv2 support  */
#define SMC_CLC_DECL_NOV2EXT    0x03030004  /* peer sent no clc v2 extension  */
#define SMC_CLC_DECL_NOV2DEXT   0x03030005  /* peer sent no clc SMC-Dv2 ext.  */
#define SMC_CLC_DECL_NOSEID     0x03030006  /* peer sent no SEID              */
#define SMC_CLC_DECL_NOSMCD2DEV 0x03030007  /* no SMC-Dv2 device found        */
#define SMC_CLC_DECL_NOUEID     0x03030008  /* peer sent no UEID              */
#define SMC_CLC_DECL_RELEASEERR 0x03030009  /* release version negotiate failed */
#define SMC_CLC_DECL_MAXCONNERR 0x0303000a  /* max connections negotiate failed */
#define SMC_CLC_DECL_MAXLINKERR 0x0303000b  /* max links negotiate failed */
#define SMC_CLC_DECL_MODEUNSUPP 0x03040000  /* smc modes do not match (R or D)*/
#define SMC_CLC_DECL_RMBE_EC    0x03050000  /* peer has eyecatcher in RMBE    */
#define SMC_CLC_DECL_OPTUNSUPP  0x03060000  /* fastopen sockopt not supported */
#define SMC_CLC_DECL_DIFFPREFIX 0x03070000  /* IP prefix / subnet mismatch    */
#define SMC_CLC_DECL_GETVLANERR 0x03080000  /* err to get vlan id of ip device*/
#define SMC_CLC_DECL_ISMVLANERR 0x03090000  /* err to reg vlan id on ism dev  */
#define SMC_CLC_DECL_NOACTLINK  0x030a0000  /* no active smc-r link in lgr    */
#define SMC_CLC_DECL_NOSRVLINK  0x030b0000  /* SMC-R link from srv not found  */
#define SMC_CLC_DECL_VERSMISMAT 0x030c0000  /* SMC version mismatch           */
#define SMC_CLC_DECL_MAX_DMB    0x030d0000  /* SMC-D DMB limit exceeded       */
#define SMC_CLC_DECL_NOROUTE    0x030e0000  /* SMC-Rv2 conn. no route to peer */
#define SMC_CLC_DECL_NOINDIRECT 0x030f0000  /* SMC-Rv2 conn. indirect mismatch*/
#define SMC_CLC_DECL_SYNCERR    0x04000000  /* synchronization error          */
#define SMC_CLC_DECL_PEERDECL   0x05000000  /* peer declined during handshake */
#define SMC_CLC_DECL_INTERR     0x09990000  /* internal error                 */
#define SMC_CLC_DECL_ERR_RTOK   0x09990001  /*   rtoken handling failed       */
#define SMC_CLC_DECL_ERR_RDYLNK 0x09990002  /*   ib ready link failed         */
#define SMC_CLC_DECL_ERR_REGBUF 0x09990003  /*   reg rdma bufs failed         */

#define SMC_FIRST_CONTACT_MASK  0b10    /* first contact bit within typev2 */

struct smc_clc_msg_hdr {        /* header1 of clc messages */
        u8 eyecatcher[4];       /* eye catcher */
        u8 type;                /* proposal / accept / confirm / decline */
        __be16 length;
#if defined(__BIG_ENDIAN_BITFIELD)
        u8 version : 4,
           typev2  : 2,
           typev1  : 2;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 typev1  : 2,
           typev2  : 2,
           version : 4;
#endif
} __packed;                     /* format defined in RFC7609 */

struct smc_clc_msg_trail {      /* trailer of clc messages */
        u8 eyecatcher[4];
};

struct smc_clc_msg_local {      /* header2 of clc messages */
        u8 id_for_peer[SMC_SYSTEMID_LEN]; /* unique system id */
        u8 gid[16];             /* gid of ib_device port */
        u8 mac[6];              /* mac of ib_device port */
};

/* Struct would be 4 byte aligned, but it is used in an array that is sent
 * to peers and must conform to RFC7609, hence we need to use packed here.
 */
struct smc_clc_ipv6_prefix {
        struct in6_addr prefix;
        u8 prefix_len;
} __packed;                     /* format defined in RFC7609 */

#if defined(__BIG_ENDIAN_BITFIELD)
struct smc_clc_v2_flag {
        u8 release : 4,
           rsvd    : 3,
           seid    : 1;
};
#elif defined(__LITTLE_ENDIAN_BITFIELD)
struct smc_clc_v2_flag {
        u8 seid   : 1,
        rsvd      : 3,
        release   : 4;
};
#endif

struct smc_clnt_opts_area_hdr {
        u8 eid_cnt;             /* number of user defined EIDs */
        u8 ism_gid_cnt;         /* number of ISMv2 GIDs */
        u8 reserved1;
        struct smc_clc_v2_flag flag;
        u8 reserved2[2];
        __be16 smcd_v2_ext_offset; /* SMC-Dv2 Extension Offset */
};

struct smc_clc_smcd_gid_chid {
        __be64 gid;             /* ISM GID */
        __be16 chid;            /* ISMv2 CHID */
} __packed;             /* format defined in
                         * IBM Shared Memory Communications Version 2
                         * (https://www.ibm.com/support/pages/node/6326337)
                         */

struct smc_clc_v2_extension {
        /* New members must be added within the struct_group() macro below. */
        struct_group_tagged(smc_clc_v2_extension_fixed, fixed,
                struct smc_clnt_opts_area_hdr hdr;
                u8 roce[16];            /* RoCEv2 GID */
                u8 max_conns;
                u8 max_links;
                __be16 feature_mask;
                u8 reserved[12];
        );
        u8 user_eids[][SMC_MAX_EID_LEN];
};
static_assert(offsetof(struct smc_clc_v2_extension, user_eids) == sizeof(struct smc_clc_v2_extension_fixed),
              "struct member likely outside of struct_group_tagged()");

struct smc_clc_msg_proposal_prefix {    /* prefix part of clc proposal message*/
        __be32 outgoing_subnet; /* subnet mask */
        u8 prefix_len;          /* number of significant bits in mask */
        u8 reserved[2];
        u8 ipv6_prefixes_cnt;   /* number of IPv6 prefixes in prefix array */
} __aligned(4);

struct smc_clc_msg_smcd {       /* SMC-D GID information */
        struct smc_clc_smcd_gid_chid ism; /* ISM native GID+CHID of requester */
        __be16 v2_ext_offset;   /* SMC Version 2 Extension Offset */
        u8 vendor_oui[3];       /* vendor organizationally unique identifier */
        u8 vendor_exp_options[5];
        u8 reserved[20];
};

struct smc_clc_smcd_v2_extension {
        /* New members must be added within the struct_group() macro below. */
        struct_group_tagged(smc_clc_smcd_v2_extension_fixed, fixed,
                u8 system_eid[SMC_MAX_EID_LEN];
                u8 reserved[16];
        );
        struct smc_clc_smcd_gid_chid gidchid[];
};
static_assert(offsetof(struct smc_clc_smcd_v2_extension, gidchid) == sizeof(struct smc_clc_smcd_v2_extension_fixed),
              "struct member likely outside of struct_group_tagged()");

struct smc_clc_msg_proposal {   /* clc proposal message sent by Linux */
        struct smc_clc_msg_hdr hdr;
        struct smc_clc_msg_local lcl;
        __be16 iparea_offset;   /* offset to IP address information area */
} __aligned(4);

#define SMC_CLC_MAX_V6_PREFIX           8
#define SMC_CLC_MAX_UEID                8
#define SMCD_CLC_MAX_V2_GID_ENTRIES     8 /* max # of CHID-GID entries in CLC
                                           * proposal SMC-Dv2 extension.
                                           * each ISM device takes one entry and
                                           * each Emulated-ISM takes two entries
                                           */

struct smc_clc_msg_proposal_area {
        struct smc_clc_msg_proposal             pclc_base;
        struct smc_clc_msg_smcd                 pclc_smcd;
        struct smc_clc_msg_proposal_prefix      pclc_prfx;
        struct smc_clc_ipv6_prefix      pclc_prfx_ipv6[SMC_CLC_MAX_V6_PREFIX];
        struct smc_clc_v2_extension_fixed       pclc_v2_ext;
        u8                      user_eids[SMC_CLC_MAX_UEID][SMC_MAX_EID_LEN];
        struct smc_clc_smcd_v2_extension_fixed  pclc_smcd_v2_ext;
        struct smc_clc_smcd_gid_chid
                                pclc_gidchids[SMCD_CLC_MAX_V2_GID_ENTRIES];
        struct smc_clc_msg_trail                pclc_trl;
};

struct smcr_clc_msg_accept_confirm {    /* SMCR accept/confirm */
        struct smc_clc_msg_local lcl;
        u8 qpn[3];                      /* QP number */
        __be32 rmb_rkey;                /* RMB rkey */
        u8 rmbe_idx;                    /* Index of RMBE in RMB */
        __be32 rmbe_alert_token;        /* unique connection id */
 #if defined(__BIG_ENDIAN_BITFIELD)
        u8 rmbe_size : 4,               /* buf size (compressed) */
           qp_mtu   : 4;                /* QP mtu */
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 qp_mtu   : 4,
           rmbe_size : 4;
#endif
        u8 reserved;
        __be64 rmb_dma_addr;    /* RMB virtual address */
        u8 reserved2;
        u8 psn[3];              /* packet sequence number */
} __packed;

struct smcd_clc_msg_accept_confirm_common {     /* SMCD accept/confirm */
        __be64 gid;             /* Sender GID */
        __be64 token;           /* DMB token */
        u8 dmbe_idx;            /* DMBE index */
#if defined(__BIG_ENDIAN_BITFIELD)
        u8 dmbe_size : 4,       /* buf size (compressed) */
           reserved3 : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 reserved3 : 4,
           dmbe_size : 4;
#endif
        u16 reserved4;
        __be32 linkid;          /* Link identifier */
} __packed;

#define SMC_CLC_OS_ZOS          1
#define SMC_CLC_OS_LINUX        2
#define SMC_CLC_OS_AIX          3

struct smc_clc_first_contact_ext {
#if defined(__BIG_ENDIAN_BITFIELD)
        u8 v2_direct : 1,
           reserved  : 7;
        u8 os_type : 4,
           release : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 reserved  : 7,
           v2_direct : 1;
        u8 release : 4,
           os_type : 4;
#endif
        u8 reserved2[2];
        u8 hostname[SMC_MAX_HOSTNAME_LEN];
};

struct smc_clc_first_contact_ext_v2x {
        struct smc_clc_first_contact_ext fce_v2_base;
        union {
                struct {
                        u8 max_conns; /* for SMC-R only */
                        u8 max_links; /* for SMC-R only */
                };
                u8 reserved3[2];        /* for SMC-D only */
        };
        __be16 feature_mask;
        __be32 vendor_exp_options;
        u8 reserved4[8];
} __packed;             /* format defined in
                         * IBM Shared Memory Communications Version 2 (Third Edition)
                         * (https://www.ibm.com/support/pages/node/7009315)
                         */

struct smc_clc_fce_gid_ext {
        u8 gid_cnt;
        u8 reserved2[3];
        u8 gid[][SMC_GID_SIZE];
};

struct smc_clc_msg_accept_confirm {     /* clc accept / confirm message */
        struct smc_clc_msg_hdr hdr;
        union {
                struct { /* SMC-R */
                        struct smcr_clc_msg_accept_confirm r0;
                        struct { /* v2 only */
                                u8 eid[SMC_MAX_EID_LEN];
                                u8 reserved6[8];
                        } __packed r1;
                };
                struct { /* SMC-D */
                        struct smcd_clc_msg_accept_confirm_common d0;
                        struct { /* v2 only, but 12 bytes reserved in v1 */
                                __be16 chid;
                                u8 eid[SMC_MAX_EID_LEN];
                                __be64 gid_ext;
                        } __packed d1;
                };
        };
};

struct smc_clc_msg_decline {    /* clc decline message */
        struct smc_clc_msg_hdr hdr;
        u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
        __be32 peer_diagnosis;  /* diagnosis information */
#if defined(__BIG_ENDIAN_BITFIELD)
        u8 os_type  : 4,
           reserved : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 reserved : 4,
           os_type  : 4;
#endif
        u8 reserved2[3];
        struct smc_clc_msg_trail trl; /* eye catcher "SMCD" or "SMCR" EBCDIC */
} __aligned(4);

#define SMC_DECL_DIAG_COUNT_V2  4 /* no. of additional peer diagnosis codes */

struct smc_clc_msg_decline_v2 { /* clc decline message */
        struct smc_clc_msg_hdr hdr;
        u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
        __be32 peer_diagnosis;  /* diagnosis information */
#if defined(__BIG_ENDIAN_BITFIELD)
        u8 os_type  : 4,
           reserved : 4;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
        u8 reserved : 4,
           os_type  : 4;
#endif
        u8 reserved2[3];
        __be32 peer_diagnosis_v2[SMC_DECL_DIAG_COUNT_V2];
        struct smc_clc_msg_trail trl; /* eye catcher "SMCD" or "SMCR" EBCDIC */
} __aligned(4);

/* determine start of the prefix area within the proposal message */
static inline struct smc_clc_msg_proposal_prefix *
smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
{
        u16 offset = ntohs(pclc->iparea_offset);

        if (offset > sizeof(struct smc_clc_msg_smcd))
                return NULL;
        return (struct smc_clc_msg_proposal_prefix *)
               ((u8 *)pclc + sizeof(*pclc) + offset);
}

static inline bool smcr_indicated(int smc_type)
{
        return smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B;
}

static inline bool smcd_indicated(int smc_type)
{
        return smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B;
}

static inline u8 smc_indicated_type(int is_smcd, int is_smcr)
{
        if (is_smcd && is_smcr)
                return SMC_TYPE_B;
        if (is_smcd)
                return SMC_TYPE_D;
        if (is_smcr)
                return SMC_TYPE_R;
        return SMC_TYPE_N;
}

/* get SMC-D info from proposal message */
static inline struct smc_clc_msg_smcd *
smc_get_clc_msg_smcd(struct smc_clc_msg_proposal *prop)
{
        if (smcd_indicated(prop->hdr.typev1) &&
            ntohs(prop->iparea_offset) != sizeof(struct smc_clc_msg_smcd))
                return NULL;

        return (struct smc_clc_msg_smcd *)(prop + 1);
}

static inline struct smc_clc_v2_extension *
smc_get_clc_v2_ext(struct smc_clc_msg_proposal *prop)
{
        struct smc_clc_msg_smcd *prop_smcd = smc_get_clc_msg_smcd(prop);
        u16 max_offset;

        max_offset = offsetof(struct smc_clc_msg_proposal_area, pclc_v2_ext) -
                     offsetof(struct smc_clc_msg_proposal_area, pclc_smcd) -
                     offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);

        if (!prop_smcd || !ntohs(prop_smcd->v2_ext_offset) ||
            ntohs(prop_smcd->v2_ext_offset) > max_offset)
                return NULL;

        return (struct smc_clc_v2_extension *)
               ((u8 *)prop_smcd +
               offsetof(struct smc_clc_msg_smcd, v2_ext_offset) +
               sizeof(prop_smcd->v2_ext_offset) +
               ntohs(prop_smcd->v2_ext_offset));
}

static inline struct smc_clc_smcd_v2_extension *
smc_get_clc_smcd_v2_ext(struct smc_clc_v2_extension *prop_v2ext)
{
        u16 max_offset = offsetof(struct smc_clc_msg_proposal_area, pclc_smcd_v2_ext) -
                offsetof(struct smc_clc_msg_proposal_area, pclc_v2_ext) -
                offsetof(struct smc_clc_v2_extension, hdr) -
                offsetofend(struct smc_clnt_opts_area_hdr, smcd_v2_ext_offset);

        if (!prop_v2ext)
                return NULL;
        if (!ntohs(prop_v2ext->hdr.smcd_v2_ext_offset) ||
            ntohs(prop_v2ext->hdr.smcd_v2_ext_offset) > max_offset)
                return NULL;

        return (struct smc_clc_smcd_v2_extension *)
                ((u8 *)prop_v2ext +
                 offsetof(struct smc_clc_v2_extension, hdr) +
                 offsetof(struct smc_clnt_opts_area_hdr, smcd_v2_ext_offset) +
                 sizeof(prop_v2ext->hdr.smcd_v2_ext_offset) +
                 ntohs(prop_v2ext->hdr.smcd_v2_ext_offset));
}

static inline struct smc_clc_first_contact_ext *
smc_get_clc_first_contact_ext(struct smc_clc_msg_accept_confirm *clc,
                              bool is_smcd)
{
        int clc_v2_len;

        if (clc->hdr.version == SMC_V1 ||
            !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
                return NULL;

        if (is_smcd)
                clc_v2_len =
                        offsetofend(struct smc_clc_msg_accept_confirm, d1);
        else
                clc_v2_len =
                        offsetofend(struct smc_clc_msg_accept_confirm, r1);

        return (struct smc_clc_first_contact_ext *)(((u8 *)clc) + clc_v2_len);
}

struct smcd_dev;
struct smc_init_info;

int smc_clc_prfx_match(struct socket *clcsock,
                       struct smc_clc_msg_proposal_prefix *prop);
int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
                     u8 expected_type, unsigned long timeout);
int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version);
int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini);
int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
                         u8 version, u8 *eid, struct smc_init_info *ini);
int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
                        u8 version, u8 *negotiated_eid, struct smc_init_info *ini);
int smc_clc_srv_v2x_features_validate(struct smc_sock *smc,
                                      struct smc_clc_msg_proposal *pclc,
                                      struct smc_init_info *ini);
int smc_clc_clnt_v2x_features_validate(struct smc_clc_first_contact_ext *fce,
                                       struct smc_init_info *ini);
int smc_clc_v2x_features_confirm_check(struct smc_clc_msg_accept_confirm *cclc,
                                       struct smc_init_info *ini);
void smc_clc_init(void) __init;
void smc_clc_exit(void);
void smc_clc_get_hostname(u8 **host);
bool smc_clc_match_eid(u8 *negotiated_eid,
                       struct smc_clc_v2_extension *smc_v2_ext,
                       u8 *peer_eid, u8 *local_eid);
int smc_clc_ueid_count(void);
int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb);
int smc_nl_add_ueid(struct sk_buff *skb, struct genl_info *info);
int smc_nl_remove_ueid(struct sk_buff *skb, struct genl_info *info);
int smc_nl_flush_ueid(struct sk_buff *skb, struct genl_info *info);
int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb);
int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info);
int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info);

#endif