#include <linux/ceph/ceph_debug.h>
  
  #include <linux/module.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  
  #include <linux/ceph/types.h>
  #include <linux/ceph/decode.h>
  #include <linux/ceph/libceph.h>
  #include <linux/ceph/messenger.h>
  #include "auth_none.h"
  #include "auth_x.h"
  
  
  /*
   * get protocol handler
   */
  static u32 supported_protocols[] = {
  	CEPH_AUTH_NONE,
  	CEPH_AUTH_CEPHX
  };
  
  static int ceph_auth_init_protocol(struct ceph_auth_client *ac, int protocol)
  {
  	switch (protocol) {
  	case CEPH_AUTH_NONE:
  		return ceph_auth_none_init(ac);
  	case CEPH_AUTH_CEPHX:
  		return ceph_x_init(ac);
  	default:
  		return -ENOENT;
  	}
  }
  
  /*
   * setup, teardown.
   */
  struct ceph_auth_client *ceph_auth_init(const char *name, const struct ceph_crypto_key *key)
  {
  	struct ceph_auth_client *ac;
  	int ret;
  
  	dout("auth_init name '%s'
  ", name);
  
  	ret = -ENOMEM;
  	ac = kzalloc(sizeof(*ac), GFP_NOFS);
  	if (!ac)
  		goto out;
  
  	mutex_init(&ac->mutex);
  	ac->negotiating = true;
  	if (name)
  		ac->name = name;
  	else
  		ac->name = CEPH_AUTH_NAME_DEFAULT;
  	dout("auth_init name %s
  ", ac->name);
  	ac->key = key;
  	return ac;
  
  out:
  	return ERR_PTR(ret);
  }
  
  void ceph_auth_destroy(struct ceph_auth_client *ac)
  {
  	dout("auth_destroy %p
  ", ac);
  	if (ac->ops)
  		ac->ops->destroy(ac);
  	kfree(ac);
  }
  
  /*
   * Reset occurs when reconnecting to the monitor.
   */
  void ceph_auth_reset(struct ceph_auth_client *ac)
  {
  	mutex_lock(&ac->mutex);
  	dout("auth_reset %p
  ", ac);
  	if (ac->ops && !ac->negotiating)
  		ac->ops->reset(ac);
  	ac->negotiating = true;
  	mutex_unlock(&ac->mutex);
  }
  
  int ceph_entity_name_encode(const char *name, void **p, void *end)
  {
  	int len = strlen(name);
  
  	if (*p + 2*sizeof(u32) + len > end)
  		return -ERANGE;
  	ceph_encode_32(p, CEPH_ENTITY_TYPE_CLIENT);
  	ceph_encode_32(p, len);
  	ceph_encode_copy(p, name, len);
  	return 0;
  }
  
  /*
   * Initiate protocol negotiation with monitor.  Include entity name
   * and list supported protocols.
   */
  int ceph_auth_build_hello(struct ceph_auth_client *ac, void *buf, size_t len)
  {
  	struct ceph_mon_request_header *monhdr = buf;
  	void *p = monhdr + 1, *end = buf + len, *lenp;
  	int i, num;
  	int ret;
  
  	mutex_lock(&ac->mutex);
  	dout("auth_build_hello
  ");
  	monhdr->have_version = 0;
  	monhdr->session_mon = cpu_to_le16(-1);
  	monhdr->session_mon_tid = 0;
  
  	ceph_encode_32(&p, 0);  /* no protocol, yet */
  
  	lenp = p;
  	p += sizeof(u32);
  
  	ceph_decode_need(&p, end, 1 + sizeof(u32), bad);
  	ceph_encode_8(&p, 1);
  	num = ARRAY_SIZE(supported_protocols);
  	ceph_encode_32(&p, num);
  	ceph_decode_need(&p, end, num * sizeof(u32), bad);
  	for (i = 0; i < num; i++)
  		ceph_encode_32(&p, supported_protocols[i]);
  
  	ret = ceph_entity_name_encode(ac->name, &p, end);
  	if (ret < 0)
  		goto out;
  	ceph_decode_need(&p, end, sizeof(u64), bad);
  	ceph_encode_64(&p, ac->global_id);
  
  	ceph_encode_32(&lenp, p - lenp - sizeof(u32));
  	ret = p - buf;
  out:
  	mutex_unlock(&ac->mutex);
  	return ret;
  
  bad:
  	ret = -ERANGE;
  	goto out;
  }
  
  static int ceph_build_auth_request(struct ceph_auth_client *ac,
  				   void *msg_buf, size_t msg_len)
  {
  	struct ceph_mon_request_header *monhdr = msg_buf;
  	void *p = monhdr + 1;
  	void *end = msg_buf + msg_len;
  	int ret;
  
  	monhdr->have_version = 0;
  	monhdr->session_mon = cpu_to_le16(-1);
  	monhdr->session_mon_tid = 0;
  
  	ceph_encode_32(&p, ac->protocol);
  
  	ret = ac->ops->build_request(ac, p + sizeof(u32), end);
  	if (ret < 0) {
  		pr_err("error %d building auth method %s request
  ", ret,
  		       ac->ops->name);
  		goto out;
  	}
  	dout(" built request %d bytes
  ", ret);
  	ceph_encode_32(&p, ret);
  	ret = p + ret - msg_buf;
  out:
  	return ret;
  }
  
  /*
   * Handle auth message from monitor.
   */
  int ceph_handle_auth_reply(struct ceph_auth_client *ac,
  			   void *buf, size_t len,
  			   void *reply_buf, size_t reply_len)
  {
  	void *p = buf;
  	void *end = buf + len;
  	int protocol;
  	s32 result;
  	u64 global_id;
  	void *payload, *payload_end;
  	int payload_len;
  	char *result_msg;
  	int result_msg_len;
  	int ret = -EINVAL;
  
  	mutex_lock(&ac->mutex);
  	dout("handle_auth_reply %p %p
  ", p, end);
  	ceph_decode_need(&p, end, sizeof(u32) * 3 + sizeof(u64), bad);
  	protocol = ceph_decode_32(&p);
  	result = ceph_decode_32(&p);
  	global_id = ceph_decode_64(&p);
  	payload_len = ceph_decode_32(&p);
  	payload = p;
  	p += payload_len;
  	ceph_decode_need(&p, end, sizeof(u32), bad);
  	result_msg_len = ceph_decode_32(&p);
  	result_msg = p;
  	p += result_msg_len;
  	if (p != end)
  		goto bad;
  
  	dout(" result %d '%.*s' gid %llu len %d
  ", result, result_msg_len,
  	     result_msg, global_id, payload_len);
  
  	payload_end = payload + payload_len;
  
  	if (global_id && ac->global_id != global_id) {
  		dout(" set global_id %lld -> %lld
  ", ac->global_id, global_id);
  		ac->global_id = global_id;
  	}
  
  	if (ac->negotiating) {
  		/* server does not support our protocols? */
  		if (!protocol && result < 0) {
  			ret = result;
  			goto out;
  		}
  		/* set up (new) protocol handler? */
  		if (ac->protocol && ac->protocol != protocol) {
  			ac->ops->destroy(ac);
  			ac->protocol = 0;
  			ac->ops = NULL;
  		}
  		if (ac->protocol != protocol) {
  			ret = ceph_auth_init_protocol(ac, protocol);
  			if (ret) {
  				pr_err("error %d on auth protocol %d init
  ",
  				       ret, protocol);
  				goto out;
  			}
  		}
  
  		ac->negotiating = false;
  	}
  
  	ret = ac->ops->handle_reply(ac, result, payload, payload_end);
  	if (ret == -EAGAIN) {
  		ret = ceph_build_auth_request(ac, reply_buf, reply_len);
  	} else if (ret) {
  		pr_err("auth method '%s' error %d
  ", ac->ops->name, ret);
  	}
  
  out:
  	mutex_unlock(&ac->mutex);
  	return ret;
  
  bad:
  	pr_err("failed to decode auth msg
  ");
  	ret = -EINVAL;
  	goto out;
  }
  
  int ceph_build_auth(struct ceph_auth_client *ac,
  		    void *msg_buf, size_t msg_len)
  {
  	int ret = 0;
  
  	mutex_lock(&ac->mutex);
  	if (!ac->protocol)
  		ret = ceph_auth_build_hello(ac, msg_buf, msg_len);
  	else if (ac->ops->should_authenticate(ac))
  		ret = ceph_build_auth_request(ac, msg_buf, msg_len);
  	mutex_unlock(&ac->mutex);
  	return ret;
  }
  
  int ceph_auth_is_authenticated(struct ceph_auth_client *ac)
  {
  	int ret = 0;
  
  	mutex_lock(&ac->mutex);
  	if (ac->ops)
  		ret = ac->ops->is_authenticated(ac);
  	mutex_unlock(&ac->mutex);
  	return ret;
  }
  EXPORT_SYMBOL(ceph_auth_is_authenticated);
  
  int ceph_auth_create_authorizer(struct ceph_auth_client *ac,
  				int peer_type,
  				struct ceph_auth_handshake *auth)
  {
  	int ret = 0;
  
  	mutex_lock(&ac->mutex);
  	if (ac->ops && ac->ops->create_authorizer)
  		ret = ac->ops->create_authorizer(ac, peer_type, auth);
  	mutex_unlock(&ac->mutex);
  	return ret;
  }
  EXPORT_SYMBOL(ceph_auth_create_authorizer);
  
  void ceph_auth_destroy_authorizer(struct ceph_auth_client *ac,
  				  struct ceph_authorizer *a)
  {
  	mutex_lock(&ac->mutex);
  	if (ac->ops && ac->ops->destroy_authorizer)
  		ac->ops->destroy_authorizer(ac, a);
  	mutex_unlock(&ac->mutex);
  }
  EXPORT_SYMBOL(ceph_auth_destroy_authorizer);
  
  int ceph_auth_update_authorizer(struct ceph_auth_client *ac,
  				int peer_type,
  				struct ceph_auth_handshake *a)
  {
  	int ret = 0;
  
  	mutex_lock(&ac->mutex);
  	if (ac->ops && ac->ops->update_authorizer)
  		ret = ac->ops->update_authorizer(ac, peer_type, a);
  	mutex_unlock(&ac->mutex);
  	return ret;
  }
  EXPORT_SYMBOL(ceph_auth_update_authorizer);
  
  int ceph_auth_verify_authorizer_reply(struct ceph_auth_client *ac,
  				      struct ceph_authorizer *a, size_t len)
  {
  	int ret = 0;
  
  	mutex_lock(&ac->mutex);
  	if (ac->ops && ac->ops->verify_authorizer_reply)
  		ret = ac->ops->verify_authorizer_reply(ac, a, len);
  	mutex_unlock(&ac->mutex);
  	return ret;
  }
  EXPORT_SYMBOL(ceph_auth_verify_authorizer_reply);
  
  void ceph_auth_invalidate_authorizer(struct ceph_auth_client *ac, int peer_type)
  {
  	mutex_lock(&ac->mutex);
  	if (ac->ops && ac->ops->invalidate_authorizer)
  		ac->ops->invalidate_authorizer(ac, peer_type);
  	mutex_unlock(&ac->mutex);
  }
  EXPORT_SYMBOL(ceph_auth_invalidate_authorizer);