/*
   * NetLabel Management Support
   *
   * This file defines the management functions for the NetLabel system.  The
   * NetLabel system manages static and dynamic label mappings for network
   * protocols such as CIPSO and RIPSO.
   *
   * Author: Paul Moore <paul.moore@hp.com>
   *
   */
  
  /*
   * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
   *
   * This program is free software;  you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY;  without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   * the GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program;  if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   */
  
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/string.h>
  #include <linux/skbuff.h>
  #include <net/sock.h>
  #include <net/netlink.h>
  #include <net/genetlink.h>
  #include <net/netlabel.h>
  #include <net/cipso_ipv4.h>
  
  #include "netlabel_domainhash.h"
  #include "netlabel_user.h"
  #include "netlabel_mgmt.h"

  /* NetLabel configured protocol count */
  static DEFINE_SPINLOCK(netlabel_mgmt_protocount_lock);
  static u32 netlabel_mgmt_protocount = 0;

  /* Argument struct for netlbl_domhsh_walk() */
  struct netlbl_domhsh_walk_arg {
  	struct netlink_callback *nl_cb;
  	struct sk_buff *skb;
  	u32 seq;
  };

  /* NetLabel Generic NETLINK CIPSOv4 family */
  static struct genl_family netlbl_mgmt_gnl_family = {
  	.id = GENL_ID_GENERATE,
  	.hdrsize = 0,
  	.name = NETLBL_NLTYPE_MGMT_NAME,
  	.version = NETLBL_PROTO_VERSION,

  	.maxattr = NLBL_MGMT_A_MAX,

  };

  /* NetLabel Netlink attribute policy */

  static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {

  	[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
  	[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
  	[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
  	[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
  };

  
  /*

   * NetLabel Misc Managment Functions
   */
  
  /**
   * netlbl_mgmt_protocount_inc - Increment the configured labeled protocol count
   *
   * Description:
   * Increment the number of labeled protocol configurations in the current
   * NetLabel configuration.  Keep track of this for use in determining if
   * NetLabel label enforcement should be active/enabled or not in the LSM.
   *
   */
  void netlbl_mgmt_protocount_inc(void)
  {
  	rcu_read_lock();
  	spin_lock(&netlabel_mgmt_protocount_lock);
  	netlabel_mgmt_protocount++;
  	spin_unlock(&netlabel_mgmt_protocount_lock);
  	rcu_read_unlock();
  }
  
  /**
   * netlbl_mgmt_protocount_dec - Decrement the configured labeled protocol count
   *
   * Description:
   * Decrement the number of labeled protocol configurations in the current
   * NetLabel configuration.  Keep track of this for use in determining if
   * NetLabel label enforcement should be active/enabled or not in the LSM.
   *
   */
  void netlbl_mgmt_protocount_dec(void)
  {
  	rcu_read_lock();
  	spin_lock(&netlabel_mgmt_protocount_lock);
  	if (netlabel_mgmt_protocount > 0)
  		netlabel_mgmt_protocount--;
  	spin_unlock(&netlabel_mgmt_protocount_lock);
  	rcu_read_unlock();
  }
  
  /**
   * netlbl_mgmt_protocount_value - Return the number of configured protocols
   *
   * Description:
   * Return the number of labeled protocols in the current NetLabel
   * configuration.  This value is useful in  determining if NetLabel label
   * enforcement should be active/enabled or not in the LSM.
   *
   */
  u32 netlbl_mgmt_protocount_value(void)
  {
  	u32 val;
  
  	rcu_read_lock();
  	val = netlabel_mgmt_protocount;
  	rcu_read_unlock();
  
  	return val;
  }
  
  /*

   * NetLabel Command Handlers
   */
  
  /**
   * netlbl_mgmt_add - Handle an ADD message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated ADD message and add the domains from the message
   * to the hash table.  See netlabel.h for a description of the message format.
   * Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
  {
  	int ret_val = -EINVAL;

  	struct netlbl_dom_map *entry = NULL;

  	size_t tmp_size;

  	u32 tmp_val;

  	struct netlbl_audit audit_info;

  	if (!info->attrs[NLBL_MGMT_A_DOMAIN] ||
  	    !info->attrs[NLBL_MGMT_A_PROTOCOL])

  		goto add_failure;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	if (entry == NULL) {
  		ret_val = -ENOMEM;
  		goto add_failure;
  	}
  	tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
  	entry->domain = kmalloc(tmp_size, GFP_KERNEL);
  	if (entry->domain == NULL) {
  		ret_val = -ENOMEM;

  		goto add_failure;

  	}
  	entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
  	nla_strlcpy(entry->domain, info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);

  	switch (entry->type) {
  	case NETLBL_NLTYPE_UNLABELED:

  		ret_val = netlbl_domhsh_add(entry, &audit_info);

  		break;
  	case NETLBL_NLTYPE_CIPSOV4:
  		if (!info->attrs[NLBL_MGMT_A_CV4DOI])

  			goto add_failure;

  		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
  		/* We should be holding a rcu_read_lock() here while we hold
  		 * the result but since the entry will always be deleted when
  		 * the CIPSO DOI is deleted we aren't going to keep the
  		 * lock. */
  		rcu_read_lock();
  		entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
  		if (entry->type_def.cipsov4 == NULL) {

  			rcu_read_unlock();

  			goto add_failure;

  		}

  		ret_val = netlbl_domhsh_add(entry, &audit_info);

  		rcu_read_unlock();
  		break;
  	default:
  		goto add_failure;

  	}

  	if (ret_val != 0)
  		goto add_failure;

  	return 0;
  
  add_failure:
  	if (entry)
  		kfree(entry->domain);
  	kfree(entry);

  	return ret_val;
  }
  
  /**
   * netlbl_mgmt_remove - Handle a REMOVE message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated REMOVE message and remove the specified domain
   * mappings.  Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
  {

  	char *domain;

  	struct netlbl_audit audit_info;

  	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
  		return -EINVAL;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);

  	return netlbl_domhsh_remove(domain, &audit_info);

  }
  
  /**
   * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
   * @entry: the domain mapping hash table entry
   * @arg: the netlbl_domhsh_walk_arg structure
   *
   * Description:
   * This function is designed to be used as a callback to the
   * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
   * message.  Returns the size of the message on success, negative values on
   * failure.
   *
   */
  static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
  {
  	int ret_val = -ENOMEM;
  	struct netlbl_domhsh_walk_arg *cb_arg = arg;
  	void *data;

  	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
  			   cb_arg->seq, &netlbl_mgmt_gnl_family,
  			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);

  	if (data == NULL)
  		goto listall_cb_failure;
  
  	ret_val = nla_put_string(cb_arg->skb,
  				 NLBL_MGMT_A_DOMAIN,
  				 entry->domain);
  	if (ret_val != 0)
  		goto listall_cb_failure;
  	ret_val = nla_put_u32(cb_arg->skb, NLBL_MGMT_A_PROTOCOL, entry->type);
  	if (ret_val != 0)
  		goto listall_cb_failure;
  	switch (entry->type) {
  	case NETLBL_NLTYPE_CIPSOV4:
  		ret_val = nla_put_u32(cb_arg->skb,
  				      NLBL_MGMT_A_CV4DOI,
  				      entry->type_def.cipsov4->doi);

  		if (ret_val != 0)

  			goto listall_cb_failure;
  		break;

  	}

  	cb_arg->seq++;
  	return genlmsg_end(cb_arg->skb, data);

  listall_cb_failure:
  	genlmsg_cancel(cb_arg->skb, data);

  	return ret_val;
  }
  
  /**

   * netlbl_mgmt_listall - Handle a LISTALL message

   * @skb: the NETLINK buffer

   * @cb: the NETLINK callback

   *
   * Description:

   * Process a user generated LISTALL message and dumps the domain hash table in
   * a form suitable for use in a kernel generated LISTALL message.  Returns zero
   * on success, negative values on failure.

   *
   */

  static int netlbl_mgmt_listall(struct sk_buff *skb,
  			       struct netlink_callback *cb)

  {

  	struct netlbl_domhsh_walk_arg cb_arg;
  	u32 skip_bkt = cb->args[0];
  	u32 skip_chain = cb->args[1];
  
  	cb_arg.nl_cb = cb;
  	cb_arg.skb = skb;
  	cb_arg.seq = cb->nlh->nlmsg_seq;
  
  	netlbl_domhsh_walk(&skip_bkt,
  			   &skip_chain,
  			   netlbl_mgmt_listall_cb,
  			   &cb_arg);
  
  	cb->args[0] = skip_bkt;
  	cb->args[1] = skip_chain;
  	return skb->len;

  }
  
  /**
   * netlbl_mgmt_adddef - Handle an ADDDEF message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated ADDDEF message and respond accordingly.  Returns
   * zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
  {
  	int ret_val = -EINVAL;

  	struct netlbl_dom_map *entry = NULL;
  	u32 tmp_val;

  	struct netlbl_audit audit_info;

  	if (!info->attrs[NLBL_MGMT_A_PROTOCOL])

  		goto adddef_failure;

  	netlbl_netlink_auditinfo(skb, &audit_info);

  	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
  	if (entry == NULL) {
  		ret_val = -ENOMEM;
  		goto adddef_failure;
  	}

  	entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);

  	switch (entry->type) {
  	case NETLBL_NLTYPE_UNLABELED:

  		ret_val = netlbl_domhsh_add_default(entry, &audit_info);

  		break;
  	case NETLBL_NLTYPE_CIPSOV4:

  		if (!info->attrs[NLBL_MGMT_A_CV4DOI])

  			goto adddef_failure;

  
  		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
  		/* We should be holding a rcu_read_lock() here while we hold
  		 * the result but since the entry will always be deleted when
  		 * the CIPSO DOI is deleted we aren't going to keep the
  		 * lock. */

  		rcu_read_lock();
  		entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
  		if (entry->type_def.cipsov4 == NULL) {
  			rcu_read_unlock();

  			goto adddef_failure;
  		}

  		ret_val = netlbl_domhsh_add_default(entry, &audit_info);

  		rcu_read_unlock();
  		break;
  	default:

  		goto adddef_failure;

  	}
  	if (ret_val != 0)
  		goto adddef_failure;

  	return 0;
  
  adddef_failure:
  	kfree(entry);

  	return ret_val;
  }
  
  /**
   * netlbl_mgmt_removedef - Handle a REMOVEDEF message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated REMOVEDEF message and remove the default domain
   * mapping.  Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
  {

  	struct netlbl_audit audit_info;
  
  	netlbl_netlink_auditinfo(skb, &audit_info);
  
  	return netlbl_domhsh_remove_default(&audit_info);

  }
  
  /**
   * netlbl_mgmt_listdef - Handle a LISTDEF message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated LISTDEF message and dumps the default domain
   * mapping in a form suitable for use in a kernel generated LISTDEF message.
   * Returns zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
  {
  	int ret_val = -ENOMEM;

  	struct sk_buff *ans_skb = NULL;
  	void *data;
  	struct netlbl_dom_map *entry;

  	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

  	if (ans_skb == NULL)

  		return -ENOMEM;

  	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
  				 0, NLBL_MGMT_C_LISTDEF);

  	if (data == NULL)

  		goto listdef_failure;

  	rcu_read_lock();
  	entry = netlbl_domhsh_getentry(NULL);
  	if (entry == NULL) {
  		ret_val = -ENOENT;
  		goto listdef_failure_lock;
  	}
  	ret_val = nla_put_u32(ans_skb, NLBL_MGMT_A_PROTOCOL, entry->type);

  	if (ret_val != 0)

  		goto listdef_failure_lock;
  	switch (entry->type) {
  	case NETLBL_NLTYPE_CIPSOV4:
  		ret_val = nla_put_u32(ans_skb,
  				      NLBL_MGMT_A_CV4DOI,
  				      entry->type_def.cipsov4->doi);
  		if (ret_val != 0)
  			goto listdef_failure_lock;
  		break;
  	}
  	rcu_read_unlock();

  	genlmsg_end(ans_skb, data);

  	ret_val = genlmsg_reply(ans_skb, info);

  	if (ret_val != 0)
  		goto listdef_failure;

  	return 0;

  listdef_failure_lock:
  	rcu_read_unlock();

  listdef_failure:

  	kfree_skb(ans_skb);

  	return ret_val;
  }
  
  /**

   * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
   * @skb: the skb to write to
   * @seq: the NETLINK sequence number
   * @cb: the NETLINK callback
   * @protocol: the NetLabel protocol to use in the message

   *
   * Description:

   * This function is to be used in conjunction with netlbl_mgmt_protocols() to
   * answer a application's PROTOCOLS message.  Returns the size of the message
   * on success, negative values on failure.

   *
   */

  static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
  				    struct netlink_callback *cb,
  				    u32 protocol)

  {
  	int ret_val = -ENOMEM;

  	void *data;

  	data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
  			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
  			   NLBL_MGMT_C_PROTOCOLS);

  	if (data == NULL)
  		goto protocols_cb_failure;
  
  	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);

  	if (ret_val != 0)

  		goto protocols_cb_failure;

  	return genlmsg_end(skb, data);

  protocols_cb_failure:
  	genlmsg_cancel(skb, data);

  	return ret_val;
  }
  
  /**

   * netlbl_mgmt_protocols - Handle a PROTOCOLS message
   * @skb: the NETLINK buffer
   * @cb: the NETLINK callback
   *
   * Description:
   * Process a user generated PROTOCOLS message and respond accordingly.
   *
   */
  static int netlbl_mgmt_protocols(struct sk_buff *skb,
  				 struct netlink_callback *cb)
  {
  	u32 protos_sent = cb->args[0];
  
  	if (protos_sent == 0) {
  		if (netlbl_mgmt_protocols_cb(skb,
  					     cb,
  					     NETLBL_NLTYPE_UNLABELED) < 0)
  			goto protocols_return;
  		protos_sent++;
  	}
  	if (protos_sent == 1) {
  		if (netlbl_mgmt_protocols_cb(skb,
  					     cb,
  					     NETLBL_NLTYPE_CIPSOV4) < 0)
  			goto protocols_return;
  		protos_sent++;
  	}
  
  protocols_return:
  	cb->args[0] = protos_sent;
  	return skb->len;
  }
  
  /**

   * netlbl_mgmt_version - Handle a VERSION message
   * @skb: the NETLINK buffer
   * @info: the Generic NETLINK info block
   *
   * Description:
   * Process a user generated VERSION message and respond accordingly.  Returns
   * zero on success, negative values on failure.
   *
   */
  static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
  {
  	int ret_val = -ENOMEM;
  	struct sk_buff *ans_skb = NULL;

  	void *data;

  	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

  	if (ans_skb == NULL)

  		return -ENOMEM;

  	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
  				 0, NLBL_MGMT_C_VERSION);

  	if (data == NULL)

  		goto version_failure;

  	ret_val = nla_put_u32(ans_skb,
  			      NLBL_MGMT_A_VERSION,
  			      NETLBL_PROTO_VERSION);

  	if (ret_val != 0)
  		goto version_failure;

  	genlmsg_end(ans_skb, data);

  	ret_val = genlmsg_reply(ans_skb, info);

  	if (ret_val != 0)
  		goto version_failure;

  	return 0;
  
  version_failure:
  	kfree_skb(ans_skb);

  	return ret_val;
  }
  
  
  /*
   * NetLabel Generic NETLINK Command Definitions
   */
  
  static struct genl_ops netlbl_mgmt_genl_c_add = {
  	.cmd = NLBL_MGMT_C_ADD,

  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_add,
  	.dumpit = NULL,
  };
  
  static struct genl_ops netlbl_mgmt_genl_c_remove = {
  	.cmd = NLBL_MGMT_C_REMOVE,

  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_remove,
  	.dumpit = NULL,
  };

  static struct genl_ops netlbl_mgmt_genl_c_listall = {
  	.cmd = NLBL_MGMT_C_LISTALL,

  	.flags = 0,

  	.policy = netlbl_mgmt_genl_policy,
  	.doit = NULL,
  	.dumpit = netlbl_mgmt_listall,

  };
  
  static struct genl_ops netlbl_mgmt_genl_c_adddef = {
  	.cmd = NLBL_MGMT_C_ADDDEF,

  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_adddef,
  	.dumpit = NULL,
  };
  
  static struct genl_ops netlbl_mgmt_genl_c_removedef = {
  	.cmd = NLBL_MGMT_C_REMOVEDEF,

  	.flags = GENL_ADMIN_PERM,
  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_removedef,
  	.dumpit = NULL,
  };
  
  static struct genl_ops netlbl_mgmt_genl_c_listdef = {
  	.cmd = NLBL_MGMT_C_LISTDEF,
  	.flags = 0,

  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_listdef,
  	.dumpit = NULL,
  };

  static struct genl_ops netlbl_mgmt_genl_c_protocols = {
  	.cmd = NLBL_MGMT_C_PROTOCOLS,

  	.flags = 0,

  	.policy = netlbl_mgmt_genl_policy,
  	.doit = NULL,
  	.dumpit = netlbl_mgmt_protocols,

  };
  
  static struct genl_ops netlbl_mgmt_genl_c_version = {
  	.cmd = NLBL_MGMT_C_VERSION,
  	.flags = 0,

  	.policy = netlbl_mgmt_genl_policy,

  	.doit = netlbl_mgmt_version,
  	.dumpit = NULL,
  };
  
  /*
   * NetLabel Generic NETLINK Protocol Functions
   */
  
  /**
   * netlbl_mgmt_genl_init - Register the NetLabel management component
   *
   * Description:
   * Register the NetLabel management component with the Generic NETLINK
   * mechanism.  Returns zero on success, negative values on failure.
   *
   */
  int netlbl_mgmt_genl_init(void)
  {
  	int ret_val;
  
  	ret_val = genl_register_family(&netlbl_mgmt_gnl_family);
  	if (ret_val != 0)
  		return ret_val;
  
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_add);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_remove);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,

  				    &netlbl_mgmt_genl_c_listall);

  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_adddef);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_removedef);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_listdef);
  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,

  				    &netlbl_mgmt_genl_c_protocols);

  	if (ret_val != 0)
  		return ret_val;
  	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
  				    &netlbl_mgmt_genl_c_version);
  	if (ret_val != 0)
  		return ret_val;
  
  	return 0;
  }