/*
 * 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_ */