/*
   * net/tipc/config.c: TIPC configuration management code
   *
   * Copyright (c) 2002-2006, Ericsson AB
   * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the names of the copyright holders nor the names of its
   *    contributors may be used to endorse or promote products derived from
   *    this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "core.h"
  #include "port.h"
  #include "name_table.h"
  #include "config.h"
  #include "server.h"
  
  #define REPLY_TRUNCATED "<truncated>
  "
  
  static DEFINE_MUTEX(config_mutex);
  static struct tipc_server cfgsrv;
  
  static const void *req_tlv_area;	/* request message TLV area */
  static int req_tlv_space;		/* request message TLV area size */
  static int rep_headroom;		/* reply message headroom to use */
  
  
  struct sk_buff *tipc_cfg_reply_alloc(int payload_size)
  {
  	struct sk_buff *buf;
  
  	buf = alloc_skb(rep_headroom + payload_size, GFP_ATOMIC);
  	if (buf)
  		skb_reserve(buf, rep_headroom);
  	return buf;
  }
  
  int tipc_cfg_append_tlv(struct sk_buff *buf, int tlv_type,
  			void *tlv_data, int tlv_data_size)
  {
  	struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(buf);
  	int new_tlv_space = TLV_SPACE(tlv_data_size);
  
  	if (skb_tailroom(buf) < new_tlv_space)
  		return 0;
  	skb_put(buf, new_tlv_space);
  	tlv->tlv_type = htons(tlv_type);
  	tlv->tlv_len  = htons(TLV_LENGTH(tlv_data_size));
  	if (tlv_data_size && tlv_data)
  		memcpy(TLV_DATA(tlv), tlv_data, tlv_data_size);
  	return 1;
  }
  
  static struct sk_buff *tipc_cfg_reply_unsigned_type(u16 tlv_type, u32 value)
  {
  	struct sk_buff *buf;
  	__be32 value_net;
  
  	buf = tipc_cfg_reply_alloc(TLV_SPACE(sizeof(value)));
  	if (buf) {
  		value_net = htonl(value);
  		tipc_cfg_append_tlv(buf, tlv_type, &value_net,
  				    sizeof(value_net));
  	}
  	return buf;
  }
  
  static struct sk_buff *tipc_cfg_reply_unsigned(u32 value)
  {
  	return tipc_cfg_reply_unsigned_type(TIPC_TLV_UNSIGNED, value);
  }
  
  struct sk_buff *tipc_cfg_reply_string_type(u16 tlv_type, char *string)
  {
  	struct sk_buff *buf;
  	int string_len = strlen(string) + 1;
  
  	buf = tipc_cfg_reply_alloc(TLV_SPACE(string_len));
  	if (buf)
  		tipc_cfg_append_tlv(buf, tlv_type, string, string_len);
  	return buf;
  }
  
  static struct sk_buff *tipc_show_stats(void)
  {
  	struct sk_buff *buf;
  	struct tlv_desc *rep_tlv;
  	char *pb;
  	int pb_len;
  	int str_len;
  	u32 value;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	value = ntohl(*(u32 *)TLV_DATA(req_tlv_area));
  	if (value != 0)
  		return tipc_cfg_reply_error_string("unsupported argument");
  
  	buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
  	if (buf == NULL)
  		return NULL;
  
  	rep_tlv = (struct tlv_desc *)buf->data;
  	pb = TLV_DATA(rep_tlv);
  	pb_len = ULTRA_STRING_MAX_LEN;
  
  	str_len = tipc_snprintf(pb, pb_len, "TIPC version " TIPC_MOD_VER "
  ");
  	str_len += 1;	/* for "\0" */
  	skb_put(buf, TLV_SPACE(str_len));
  	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
  
  	return buf;
  }
  
  static struct sk_buff *cfg_enable_bearer(void)
  {
  	struct tipc_bearer_config *args;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_CONFIG))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	args = (struct tipc_bearer_config *)TLV_DATA(req_tlv_area);
  	if (tipc_enable_bearer(args->name,
  			       ntohl(args->disc_domain),
  			       ntohl(args->priority)))
  		return tipc_cfg_reply_error_string("unable to enable bearer");
  
  	return tipc_cfg_reply_none();
  }
  
  static struct sk_buff *cfg_disable_bearer(void)
  {
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_NAME))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	if (tipc_disable_bearer((char *)TLV_DATA(req_tlv_area)))
  		return tipc_cfg_reply_error_string("unable to disable bearer");
  
  	return tipc_cfg_reply_none();
  }
  
  static struct sk_buff *cfg_set_own_addr(void)
  {
  	u32 addr;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	addr = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
  	if (addr == tipc_own_addr)
  		return tipc_cfg_reply_none();
  	if (!tipc_addr_node_valid(addr))
  		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
  						   " (node address)");
  	if (tipc_own_addr)
  		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  						   " (cannot change node address once assigned)");
  	tipc_net_start(addr);
  	return tipc_cfg_reply_none();
  }
  
  static struct sk_buff *cfg_set_remote_mng(void)
  {
  	u32 value;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  
  	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
  	tipc_remote_management = (value != 0);
  	return tipc_cfg_reply_none();
  }
  
  static struct sk_buff *cfg_set_max_ports(void)
  {
  	u32 value;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
  	if (value == tipc_max_ports)
  		return tipc_cfg_reply_none();
  	if (value < 127 || value > 65535)
  		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
  						   " (max ports must be 127-65535)");
  	return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  		" (cannot change max ports while TIPC is active)");
  }
  
  static struct sk_buff *cfg_set_netid(void)
  {
  	u32 value;
  
  	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
  		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
  	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
  	if (value == tipc_net_id)
  		return tipc_cfg_reply_none();
  	if (value < 1 || value > 9999)
  		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
  						   " (network id must be 1-9999)");
  	if (tipc_own_addr)
  		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  			" (cannot change network id once TIPC has joined a network)");
  	tipc_net_id = value;
  	return tipc_cfg_reply_none();
  }
  
  struct sk_buff *tipc_cfg_do_cmd(u32 orig_node, u16 cmd, const void *request_area,
  				int request_space, int reply_headroom)
  {
  	struct sk_buff *rep_tlv_buf;
  
  	mutex_lock(&config_mutex);
  
  	/* Save request and reply details in a well-known location */
  	req_tlv_area = request_area;
  	req_tlv_space = request_space;
  	rep_headroom = reply_headroom;
  
  	/* Check command authorization */
  	if (likely(in_own_node(orig_node))) {
  		/* command is permitted */
  	} else if (cmd >= 0x8000) {
  		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  							  " (cannot be done remotely)");
  		goto exit;
  	} else if (!tipc_remote_management) {
  		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NO_REMOTE);
  		goto exit;
  	} else if (cmd >= 0x4000) {
  		u32 domain = 0;
  
  		if ((tipc_nametbl_translate(TIPC_ZM_SRV, 0, &domain) == 0) ||
  		    (domain != orig_node)) {
  			rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_ZONE_MSTR);
  			goto exit;
  		}
  	}
  
  	/* Call appropriate processing routine */
  	switch (cmd) {
  	case TIPC_CMD_NOOP:
  		rep_tlv_buf = tipc_cfg_reply_none();
  		break;
  	case TIPC_CMD_GET_NODES:
  		rep_tlv_buf = tipc_node_get_nodes(req_tlv_area, req_tlv_space);
  		break;
  	case TIPC_CMD_GET_LINKS:
  		rep_tlv_buf = tipc_node_get_links(req_tlv_area, req_tlv_space);
  		break;
  	case TIPC_CMD_SHOW_LINK_STATS:
  		rep_tlv_buf = tipc_link_cmd_show_stats(req_tlv_area, req_tlv_space);
  		break;
  	case TIPC_CMD_RESET_LINK_STATS:
  		rep_tlv_buf = tipc_link_cmd_reset_stats(req_tlv_area, req_tlv_space);
  		break;
  	case TIPC_CMD_SHOW_NAME_TABLE:
  		rep_tlv_buf = tipc_nametbl_get(req_tlv_area, req_tlv_space);
  		break;
  	case TIPC_CMD_GET_BEARER_NAMES:
  		rep_tlv_buf = tipc_bearer_get_names();
  		break;
  	case TIPC_CMD_GET_MEDIA_NAMES:
  		rep_tlv_buf = tipc_media_get_names();
  		break;
  	case TIPC_CMD_SHOW_PORTS:
  		rep_tlv_buf = tipc_port_get_ports();
  		break;
  	case TIPC_CMD_SHOW_STATS:
  		rep_tlv_buf = tipc_show_stats();
  		break;
  	case TIPC_CMD_SET_LINK_TOL:
  	case TIPC_CMD_SET_LINK_PRI:
  	case TIPC_CMD_SET_LINK_WINDOW:
  		rep_tlv_buf = tipc_link_cmd_config(req_tlv_area, req_tlv_space, cmd);
  		break;
  	case TIPC_CMD_ENABLE_BEARER:
  		rep_tlv_buf = cfg_enable_bearer();
  		break;
  	case TIPC_CMD_DISABLE_BEARER:
  		rep_tlv_buf = cfg_disable_bearer();
  		break;
  	case TIPC_CMD_SET_NODE_ADDR:
  		rep_tlv_buf = cfg_set_own_addr();
  		break;
  	case TIPC_CMD_SET_REMOTE_MNG:
  		rep_tlv_buf = cfg_set_remote_mng();
  		break;
  	case TIPC_CMD_SET_MAX_PORTS:
  		rep_tlv_buf = cfg_set_max_ports();
  		break;
  	case TIPC_CMD_SET_NETID:
  		rep_tlv_buf = cfg_set_netid();
  		break;
  	case TIPC_CMD_GET_REMOTE_MNG:
  		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_remote_management);
  		break;
  	case TIPC_CMD_GET_MAX_PORTS:
  		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_ports);
  		break;
  	case TIPC_CMD_GET_NETID:
  		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_net_id);
  		break;
  	case TIPC_CMD_NOT_NET_ADMIN:
  		rep_tlv_buf =
  			tipc_cfg_reply_error_string(TIPC_CFG_NOT_NET_ADMIN);
  		break;
  	case TIPC_CMD_SET_MAX_ZONES:
  	case TIPC_CMD_GET_MAX_ZONES:
  	case TIPC_CMD_SET_MAX_SLAVES:
  	case TIPC_CMD_GET_MAX_SLAVES:
  	case TIPC_CMD_SET_MAX_CLUSTERS:
  	case TIPC_CMD_GET_MAX_CLUSTERS:
  	case TIPC_CMD_SET_MAX_NODES:
  	case TIPC_CMD_GET_MAX_NODES:
  	case TIPC_CMD_SET_MAX_SUBSCR:
  	case TIPC_CMD_GET_MAX_SUBSCR:
  	case TIPC_CMD_SET_MAX_PUBL:
  	case TIPC_CMD_GET_MAX_PUBL:
  	case TIPC_CMD_SET_LOG_SIZE:
  	case TIPC_CMD_DUMP_LOG:
  		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  							  " (obsolete command)");
  		break;
  	default:
  		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
  							  " (unknown command)");
  		break;
  	}
  
  	WARN_ON(rep_tlv_buf->len > TLV_SPACE(ULTRA_STRING_MAX_LEN));
  
  	/* Append an error message if we cannot return all requested data */
  	if (rep_tlv_buf->len == TLV_SPACE(ULTRA_STRING_MAX_LEN)) {
  		if (*(rep_tlv_buf->data + ULTRA_STRING_MAX_LEN) != '\0')
  			sprintf(rep_tlv_buf->data + rep_tlv_buf->len -
  				sizeof(REPLY_TRUNCATED) - 1, REPLY_TRUNCATED);
  	}
  
  	/* Return reply buffer */
  exit:
  	mutex_unlock(&config_mutex);
  	return rep_tlv_buf;
  }
  
  static void cfg_conn_msg_event(int conid, struct sockaddr_tipc *addr,
  			       void *usr_data, void *buf, size_t len)
  {
  	struct tipc_cfg_msg_hdr *req_hdr;
  	struct tipc_cfg_msg_hdr *rep_hdr;
  	struct sk_buff *rep_buf;
  
  	/* Validate configuration message header (ignore invalid message) */
  	req_hdr = (struct tipc_cfg_msg_hdr *)buf;
  	if ((len < sizeof(*req_hdr)) ||
  	    (len != TCM_ALIGN(ntohl(req_hdr->tcm_len))) ||
  	    (ntohs(req_hdr->tcm_flags) != TCM_F_REQUEST)) {
  		pr_warn("Invalid configuration message discarded
  ");
  		return;
  	}
  
  	/* Generate reply for request (if can't, return request) */
  	rep_buf = tipc_cfg_do_cmd(addr->addr.id.node, ntohs(req_hdr->tcm_type),
  				  buf + sizeof(*req_hdr),
  				  len - sizeof(*req_hdr),
  				  BUF_HEADROOM + MAX_H_SIZE + sizeof(*rep_hdr));
  	if (rep_buf) {
  		skb_push(rep_buf, sizeof(*rep_hdr));
  		rep_hdr = (struct tipc_cfg_msg_hdr *)rep_buf->data;
  		memcpy(rep_hdr, req_hdr, sizeof(*rep_hdr));
  		rep_hdr->tcm_len = htonl(rep_buf->len);
  		rep_hdr->tcm_flags &= htons(~TCM_F_REQUEST);
  		tipc_conn_sendmsg(&cfgsrv, conid, addr, rep_buf->data,
  				  rep_buf->len);
  		kfree_skb(rep_buf);
  	}
  }
  
  static struct sockaddr_tipc cfgsrv_addr __read_mostly = {
  	.family			= AF_TIPC,
  	.addrtype		= TIPC_ADDR_NAMESEQ,
  	.addr.nameseq.type	= TIPC_CFG_SRV,
  	.addr.nameseq.lower	= 0,
  	.addr.nameseq.upper	= 0,
  	.scope			= TIPC_ZONE_SCOPE
  };
  
  static struct tipc_server cfgsrv __read_mostly = {
  	.saddr			= &cfgsrv_addr,
  	.imp			= TIPC_CRITICAL_IMPORTANCE,
  	.type			= SOCK_RDM,
  	.max_rcvbuf_size	= 64 * 1024,
  	.name			= "cfg_server",
  	.tipc_conn_recvmsg	= cfg_conn_msg_event,
  	.tipc_conn_new		= NULL,
  	.tipc_conn_shutdown	= NULL
  };
  
  int tipc_cfg_init(void)
  {
  	return tipc_server_start(&cfgsrv);
  }
  
  void tipc_cfg_reinit(void)
  {
  	tipc_server_stop(&cfgsrv);
  
  	cfgsrv_addr.addr.nameseq.lower = tipc_own_addr;
  	cfgsrv_addr.addr.nameseq.upper = tipc_own_addr;
  	tipc_server_start(&cfgsrv);
  }
  
  void tipc_cfg_stop(void)
  {
  	tipc_server_stop(&cfgsrv);
  }