/*
 * Modified from NFSv4 project for Lustre
 *
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 *
 * Copyright (c) 2012, Intel Corporation.
 *
 * Author: Eric Mei <ericm@clusterfs.com>
 */

#ifndef __PTLRPC_GSS_GSS_INTERNAL_H_
#define __PTLRPC_GSS_GSS_INTERNAL_H_

#include <lustre_sec.h>

/*
 * rawobj stuff
 */
typedef struct netobj_s {
        __u32      len;
        __u8        data[0];
} netobj_t;

#define NETOBJ_EMPTY    ((netobj_t) { 0 })

typedef struct rawobj_s {
        __u32      len;
        __u8       *data;
} rawobj_t;

#define RAWOBJ_EMPTY    ((rawobj_t) { 0, NULL })

typedef struct rawobj_buf_s {
        __u32      dataoff;
        __u32      datalen;
        __u32      buflen;
        __u8       *buf;
} rawobj_buf_t;

int rawobj_empty(rawobj_t *obj);
int rawobj_alloc(rawobj_t *obj, char *buf, int len);
void rawobj_free(rawobj_t *obj);
int rawobj_equal(rawobj_t *a, rawobj_t *b);
int rawobj_dup(rawobj_t *dest, rawobj_t *src);
int rawobj_serialize(rawobj_t *obj, __u32 **buf, __u32 *buflen);
int rawobj_extract(rawobj_t *obj, __u32 **buf, __u32 *buflen);
int rawobj_extract_alloc(rawobj_t *obj, __u32 **buf, __u32 *buflen);
int rawobj_extract_local(rawobj_t *obj, __u32 **buf, __u32 *buflen);
int rawobj_extract_local_alloc(rawobj_t *obj, __u32 **buf, __u32 *buflen);
int rawobj_from_netobj(rawobj_t *rawobj, netobj_t *netobj);
int rawobj_from_netobj_alloc(rawobj_t *obj, netobj_t *netobj);

int buffer_extract_bytes(const void **buf, __u32 *buflen,
                         void *res, __u32 reslen);

/*
 * several timeout values. client refresh upcall timeout we using
 * default in pipefs implemnetation.
 */
#define __TIMEOUT_DELTA          (10)

#define GSS_SECINIT_RPC_TIMEOUT                                  \
        (obd_timeout < __TIMEOUT_DELTA ?                                \
         __TIMEOUT_DELTA : obd_timeout - __TIMEOUT_DELTA)

#define GSS_SECFINI_RPC_TIMEOUT  (__TIMEOUT_DELTA)
#define GSS_SECSVC_UPCALL_TIMEOUT       (GSS_SECINIT_RPC_TIMEOUT)

/*
 * default gc interval
 */
#define GSS_GC_INTERVAL          (60 * 60) /* 60 minutes */

static inline
unsigned long gss_round_ctx_expiry(unsigned long expiry,
                                   unsigned long sec_flags)
{
        if (sec_flags & PTLRPC_SEC_FL_REVERSE)
                return expiry;

        if (get_seconds() + __TIMEOUT_DELTA <= expiry)
                return expiry - __TIMEOUT_DELTA;

        return expiry;
}

/*
 * Max encryption element in block cipher algorithms.
 */
#define GSS_MAX_CIPHER_BLOCK           (16)

/*
 * XXX make it visible of kernel and lgssd/lsvcgssd
 */
#define GSSD_INTERFACE_VERSION    (1)

#define PTLRPC_GSS_VERSION            (1)


enum ptlrpc_gss_proc {
        PTLRPC_GSS_PROC_DATA        = 0,
        PTLRPC_GSS_PROC_INIT        = 1,
        PTLRPC_GSS_PROC_CONTINUE_INIT   = 2,
        PTLRPC_GSS_PROC_DESTROY  = 3,
        PTLRPC_GSS_PROC_ERR          = 4,
};

enum ptlrpc_gss_tgt {
        LUSTRE_GSS_TGT_MGS            = 0,
        LUSTRE_GSS_TGT_MDS            = 1,
        LUSTRE_GSS_TGT_OSS            = 2,
};

enum ptlrpc_gss_header_flags {
        LUSTRE_GSS_PACK_BULK        = 1,
        LUSTRE_GSS_PACK_USER        = 2,
};

static inline
__u32 import_to_gss_svc(struct obd_import *imp)
{
        const char *name = imp->imp_obd->obd_type->typ_name;

        if (!strcmp(name, LUSTRE_MGC_NAME))
                return LUSTRE_GSS_TGT_MGS;
        if (!strcmp(name, LUSTRE_MDC_NAME))
                return LUSTRE_GSS_TGT_MDS;
        if (!strcmp(name, LUSTRE_OSC_NAME))
                return LUSTRE_GSS_TGT_OSS;
        LBUG();
        return 0;
}

/*
 * following 3 header must have the same size and offset
 */
struct gss_header {
        __u8                gh_version;     /* gss version */
        __u8                gh_sp;        /* sec part */
        __u16              gh_pad0;
        __u32              gh_flags;       /* wrap flags */
        __u32              gh_proc;     /* proc */
        __u32              gh_seq;       /* sequence */
        __u32              gh_svc;       /* service */
        __u32              gh_pad1;
        __u32              gh_pad2;
        __u32              gh_pad3;
        netobj_t                gh_handle;      /* context handle */
};

struct gss_rep_header {
        __u8                gh_version;
        __u8                gh_sp;
        __u16              gh_pad0;
        __u32              gh_flags;
        __u32              gh_proc;
        __u32              gh_major;
        __u32              gh_minor;
        __u32              gh_seqwin;
        __u32              gh_pad2;
        __u32              gh_pad3;
        netobj_t                gh_handle;
};

struct gss_err_header {
        __u8                gh_version;
        __u8                gh_sp;
        __u16              gh_pad0;
        __u32              gh_flags;
        __u32              gh_proc;
        __u32              gh_major;
        __u32              gh_minor;
        __u32              gh_pad1;
        __u32              gh_pad2;
        __u32              gh_pad3;
        netobj_t                gh_handle;
};

/*
 * part of wire context information send from client which be saved and
 * used later by server.
 */
struct gss_wire_ctx {
        __u32              gw_flags;
        __u32              gw_proc;
        __u32              gw_seq;
        __u32              gw_svc;
        rawobj_t                gw_handle;
};

#define PTLRPC_GSS_MAX_HANDLE_SIZE      (8)
#define PTLRPC_GSS_HEADER_SIZE    (sizeof(struct gss_header) + \
                                         PTLRPC_GSS_MAX_HANDLE_SIZE)


static inline __u64 gss_handle_to_u64(rawobj_t *handle)
{
        if (handle->len != PTLRPC_GSS_MAX_HANDLE_SIZE)
                return -1;
        return *((__u64 *) handle->data);
}

#define GSS_SEQ_WIN                  (2048)
#define GSS_SEQ_WIN_MAIN                GSS_SEQ_WIN
#define GSS_SEQ_WIN_BACK                (128)
#define GSS_SEQ_REPACK_THRESHOLD        (GSS_SEQ_WIN_MAIN / 2 + \
                                         GSS_SEQ_WIN_MAIN / 4)

struct gss_svc_seq_data {
        spinlock_t              ssd_lock;
        /*
         * highest sequence number seen so far, for main and back window
         */
        __u32              ssd_max_main;
        __u32              ssd_max_back;
        /*
         * main and back window
         * for i such that ssd_max - GSS_SEQ_WIN < i <= ssd_max, the i-th bit
         * of ssd_win is nonzero iff sequence number i has been seen already.
         */
        unsigned long      ssd_win_main[GSS_SEQ_WIN_MAIN/BITS_PER_LONG];
        unsigned long      ssd_win_back[GSS_SEQ_WIN_BACK/BITS_PER_LONG];
};

struct gss_svc_ctx {
        struct gss_ctx   *gsc_mechctx;
        struct gss_svc_seq_data gsc_seqdata;
        rawobj_t                gsc_rvs_hdl;
        __u32              gsc_rvs_seq;
        uid_t              gsc_uid;
        gid_t              gsc_gid;
        uid_t              gsc_mapped_uid;
        unsigned int        gsc_usr_root:1,
                                gsc_usr_mds:1,
                                gsc_usr_oss:1,
                                gsc_remote:1,
                                gsc_reverse:1;
};

struct gss_svc_reqctx {
        struct ptlrpc_svc_ctx      src_base;
        /*
         * context
         */
        struct gss_wire_ctx          src_wirectx;
        struct gss_svc_ctx           *src_ctx;
        /*
         * record place of bulk_sec_desc in request/reply buffer
         */
        struct ptlrpc_bulk_sec_desc    *src_reqbsd;
        int                          src_reqbsd_size;
        struct ptlrpc_bulk_sec_desc    *src_repbsd;
        int                          src_repbsd_size;
        /*
         * flags
         */
        unsigned int                src_init:1,
                                        src_init_continue:1,
                                        src_err_notify:1;
        int                          src_reserve_len;
};

struct gss_cli_ctx {
        struct ptlrpc_cli_ctx   gc_base;
        __u32              gc_flavor;
        __u32              gc_proc;
        __u32              gc_win;
        atomic_t            gc_seq;
        rawobj_t                gc_handle;
        struct gss_ctx   *gc_mechctx;
        /* handle for the buddy svc ctx */
        rawobj_t                gc_svc_handle;
};

struct gss_cli_ctx_keyring {
        struct gss_cli_ctx      gck_base;
        struct key           *gck_key;
        struct timer_list      *gck_timer;
};

struct gss_sec {
        struct ptlrpc_sec       gs_base;
        struct gss_api_mech     *gs_mech;
        spinlock_t              gs_lock;
        __u64                   gs_rvs_hdl;
};

struct gss_sec_pipefs {
        struct gss_sec    gsp_base;
        int                  gsp_chash_size;  /* must be 2^n */
        struct hlist_head       gsp_chash[0];
};

/*
 * FIXME cleanup the keyring upcall mutexes
 */
#define HAVE_KEYRING_UPCALL_SERIALIZED  1

struct gss_sec_keyring {
        struct gss_sec    gsk_base;
        /*
         * all contexts listed here. access is protected by sec spinlock.
         */
        struct hlist_head       gsk_clist;
        /*
         * specially point to root ctx (only one at a time). access is
         * protected by sec spinlock.
         */
        struct ptlrpc_cli_ctx  *gsk_root_ctx;
        /*
         * specially serialize upcalls for root context.
         */
        struct mutex                    gsk_root_uc_lock;

#ifdef HAVE_KEYRING_UPCALL_SERIALIZED
        struct mutex            gsk_uc_lock;    /* serialize upcalls */
#endif
};

static inline struct gss_cli_ctx *ctx2gctx(struct ptlrpc_cli_ctx *ctx)
{
        return container_of(ctx, struct gss_cli_ctx, gc_base);
}

static inline
struct gss_cli_ctx_keyring *ctx2gctx_keyring(struct ptlrpc_cli_ctx *ctx)
{
        return container_of(ctx2gctx(ctx),
                            struct gss_cli_ctx_keyring, gck_base);
}

static inline struct gss_sec *sec2gsec(struct ptlrpc_sec *sec)
{
        return container_of(sec, struct gss_sec, gs_base);
}

static inline struct gss_sec_pipefs *sec2gsec_pipefs(struct ptlrpc_sec *sec)
{
        return container_of(sec2gsec(sec), struct gss_sec_pipefs, gsp_base);
}

static inline struct gss_sec_keyring *sec2gsec_keyring(struct ptlrpc_sec *sec)
{
        return container_of(sec2gsec(sec), struct gss_sec_keyring, gsk_base);
}


#define GSS_CTX_INIT_MAX_LEN        (1024)

/*
 * This only guaranteed be enough for current krb5 des-cbc-crc . We might
 * adjust this when new enc type or mech added in.
 */
#define GSS_PRIVBUF_PREFIX_LEN   (32)
#define GSS_PRIVBUF_SUFFIX_LEN   (32)

static inline
struct gss_svc_reqctx *gss_svc_ctx2reqctx(struct ptlrpc_svc_ctx *ctx)
{
        LASSERT(ctx);
        return container_of(ctx, struct gss_svc_reqctx, src_base);
}

static inline
struct gss_svc_ctx *gss_svc_ctx2gssctx(struct ptlrpc_svc_ctx *ctx)
{
        LASSERT(ctx);
        return gss_svc_ctx2reqctx(ctx)->src_ctx;
}

/* sec_gss.c */
int gss_cli_ctx_match(struct ptlrpc_cli_ctx *ctx, struct vfs_cred *vcred);
int gss_cli_ctx_display(struct ptlrpc_cli_ctx *ctx, char *buf, int bufsize);
int gss_cli_ctx_sign(struct ptlrpc_cli_ctx *ctx, struct ptlrpc_request *req);
int gss_cli_ctx_verify(struct ptlrpc_cli_ctx *ctx, struct ptlrpc_request *req);
int gss_cli_ctx_seal(struct ptlrpc_cli_ctx *ctx, struct ptlrpc_request *req);
int gss_cli_ctx_unseal(struct ptlrpc_cli_ctx *ctx, struct ptlrpc_request *req);

int  gss_sec_install_rctx(struct obd_import *imp, struct ptlrpc_sec *sec,
                          struct ptlrpc_cli_ctx *ctx);
int  gss_alloc_reqbuf(struct ptlrpc_sec *sec, struct ptlrpc_request *req,
                      int msgsize);
void gss_free_reqbuf(struct ptlrpc_sec *sec, struct ptlrpc_request *req);
int  gss_alloc_repbuf(struct ptlrpc_sec *sec, struct ptlrpc_request *req,
                      int msgsize);
void gss_free_repbuf(struct ptlrpc_sec *sec, struct ptlrpc_request *req);
int  gss_enlarge_reqbuf(struct ptlrpc_sec *sec, struct ptlrpc_request *req,
                        int segment, int newsize);

int  gss_svc_accept(struct ptlrpc_sec_policy *policy,
                    struct ptlrpc_request *req);
void gss_svc_invalidate_ctx(struct ptlrpc_svc_ctx *svc_ctx);
int  gss_svc_alloc_rs(struct ptlrpc_request *req, int msglen);
int  gss_svc_authorize(struct ptlrpc_request *req);
void gss_svc_free_rs(struct ptlrpc_reply_state *rs);
void gss_svc_free_ctx(struct ptlrpc_svc_ctx *ctx);

int cli_ctx_expire(struct ptlrpc_cli_ctx *ctx);
int cli_ctx_check_death(struct ptlrpc_cli_ctx *ctx);

int gss_copy_rvc_cli_ctx(struct ptlrpc_cli_ctx *cli_ctx,
                         struct ptlrpc_svc_ctx *svc_ctx);

struct gss_header *gss_swab_header(struct lustre_msg *msg, int segment,
                                   int swabbed);
netobj_t *gss_swab_netobj(struct lustre_msg *msg, int segment);

void gss_cli_ctx_uptodate(struct gss_cli_ctx *gctx);
int gss_pack_err_notify(struct ptlrpc_request *req, __u32 major, __u32 minor);
int gss_check_seq_num(struct gss_svc_seq_data *sd, __u32 seq_num, int set);

int gss_sec_create_common(struct gss_sec *gsec,
                          struct ptlrpc_sec_policy *policy,
                          struct obd_import *imp,
                          struct ptlrpc_svc_ctx *ctx,
                          struct sptlrpc_flavor *sf);
void gss_sec_destroy_common(struct gss_sec *gsec);
void gss_sec_kill(struct ptlrpc_sec *sec);

int gss_cli_ctx_init_common(struct ptlrpc_sec *sec,
                            struct ptlrpc_cli_ctx *ctx,
                            struct ptlrpc_ctx_ops *ctxops,
                            struct vfs_cred *vcred);
int gss_cli_ctx_fini_common(struct ptlrpc_sec *sec,
                            struct ptlrpc_cli_ctx *ctx);

void gss_cli_ctx_flags2str(unsigned long flags, char *buf, int bufsize);

/* gss_keyring.c */
int  __init gss_init_keyring(void);
void __exit gss_exit_keyring(void);

/* gss_pipefs.c */
int  __init gss_init_pipefs(void);
void __exit gss_exit_pipefs(void);

/* gss_bulk.c */
int gss_cli_prep_bulk(struct ptlrpc_request *req,
                      struct ptlrpc_bulk_desc *desc);
int gss_cli_ctx_wrap_bulk(struct ptlrpc_cli_ctx *ctx,
                          struct ptlrpc_request *req,
                          struct ptlrpc_bulk_desc *desc);
int gss_cli_ctx_unwrap_bulk(struct ptlrpc_cli_ctx *ctx,
                            struct ptlrpc_request *req,
                            struct ptlrpc_bulk_desc *desc);
int gss_svc_prep_bulk(struct ptlrpc_request *req,
                      struct ptlrpc_bulk_desc *desc);
int gss_svc_unwrap_bulk(struct ptlrpc_request *req,
                        struct ptlrpc_bulk_desc *desc);
int gss_svc_wrap_bulk(struct ptlrpc_request *req,
                      struct ptlrpc_bulk_desc *desc);

/* gss_mech_switch.c */
int init_kerberos_module(void);
void cleanup_kerberos_module(void);

/* gss_generic_token.c */
int g_token_size(rawobj_t *mech, unsigned int body_size);
void g_make_token_header(rawobj_t *mech, int body_size, unsigned char **buf);
__u32 g_verify_token_header(rawobj_t *mech, int *body_size,
                            unsigned char **buf_in, int toksize);


/* gss_cli_upcall.c */
int gss_do_ctx_init_rpc(char *buffer, unsigned long count);
int gss_do_ctx_fini_rpc(struct gss_cli_ctx *gctx);

int  __init gss_init_cli_upcall(void);
void __exit gss_exit_cli_upcall(void);

/* gss_svc_upcall.c */
__u64 gss_get_next_ctx_index(void);
int gss_svc_upcall_install_rvs_ctx(struct obd_import *imp,
                                   struct gss_sec *gsec,
                                   struct gss_cli_ctx *gctx);
int gss_svc_upcall_expire_rvs_ctx(rawobj_t *handle);
int gss_svc_upcall_dup_handle(rawobj_t *handle, struct gss_svc_ctx *ctx);
int gss_svc_upcall_update_sequence(rawobj_t *handle, __u32 seq);
int gss_svc_upcall_handle_init(struct ptlrpc_request *req,
                               struct gss_svc_reqctx *grctx,
                               struct gss_wire_ctx *gw,
                               struct obd_device *target,
                               __u32 lustre_svc,
                               rawobj_t *rvs_hdl,
                               rawobj_t *in_token);
struct gss_svc_ctx *gss_svc_upcall_get_ctx(struct ptlrpc_request *req,
                                           struct gss_wire_ctx *gw);
void gss_svc_upcall_put_ctx(struct gss_svc_ctx *ctx);
void gss_svc_upcall_destroy_ctx(struct gss_svc_ctx *ctx);

int  __init gss_init_svc_upcall(void);
void __exit gss_exit_svc_upcall(void);

/* lproc_gss.c */
void gss_stat_oos_record_cli(int behind);
void gss_stat_oos_record_svc(int phase, int replay);

int  __init gss_init_lproc(void);
void __exit gss_exit_lproc(void);

/* gss_krb5_mech.c */
int __init init_kerberos_module(void);
void __exit cleanup_kerberos_module(void);


/* debug */
static inline
void __dbg_memdump(char *name, void *ptr, int size)
{
        char *buf, *p = (char *) ptr;
        int bufsize = size * 2 + 1, i;

        OBD_ALLOC(buf, bufsize);
        if (!buf) {
                CDEBUG(D_ERROR, "DUMP ERROR: can't alloc %d bytes\n", bufsize);
                return;
        }

        for (i = 0; i < size; i++)
                sprintf(&buf[i+i], "%02x", (__u8) p[i]);
        buf[size + size] = '\0';
        LCONSOLE_INFO("DUMP %s@%p(%d): %s\n", name, ptr, size, buf);
        OBD_FREE(buf, bufsize);
}

#endif /* __PTLRPC_GSS_GSS_INTERNAL_H_ */