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 /**
  * @file
  * netconn API (to be used from non-TCPIP threads)
  */
 
 /*
  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
  * 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. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
  *
  * This file is part of the lwIP TCP/IP stack.
  *
  * Author: Adam Dunkels <adam@sics.se>
  *
  */
 #ifndef LWIP_HDR_API_H
 #define LWIP_HDR_API_H
 
 #include "lwip/opt.h"
 
 #if LWIP_NETCONN || LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */
 /* Note: Netconn API is always available when sockets are enabled -
  * sockets are implemented on top of them */
 
 #include "lwip/arch.h"
 #include "lwip/netbuf.h"
 #include "lwip/sys.h"
 #include "lwip/ip_addr.h"
 #include "lwip/err.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 /* Throughout this file, IP addresses and port numbers are expected to be in
  * the same byte order as in the corresponding pcb.
  */
 
 /* Flags for netconn_write (u8_t) */
 #define NETCONN_NOFLAG      0x00
 #define NETCONN_NOCOPY      0x00 /* Only for source code compatibility */
 #define NETCONN_COPY        0x01
 #define NETCONN_MORE        0x02
 #define NETCONN_DONTBLOCK   0x04
 #define NETCONN_NOAUTORCVD  0x08 /* prevent netconn_recv_data_tcp() from updating the tcp window - must be done manually via netconn_tcp_recvd() */
 #define NETCONN_NOFIN       0x10 /* upper layer already received data, leave FIN in queue until called again */
 
 /* Flags for struct netconn.flags (u8_t) */
 /** This netconn had an error, don't block on recvmbox/acceptmbox any more */
 #define NETCONN_FLAG_MBOXCLOSED               0x01
 /** Should this netconn avoid blocking? */
 #define NETCONN_FLAG_NON_BLOCKING             0x02
 /** Was the last connect action a non-blocking one? */
 #define NETCONN_FLAG_IN_NONBLOCKING_CONNECT   0x04
 #if LWIP_NETCONN_FULLDUPLEX
   /** The mbox of this netconn is being deallocated, don't use it anymore */
 #define NETCONN_FLAG_MBOXINVALID              0x08
 #endif /* LWIP_NETCONN_FULLDUPLEX */
 /** If a nonblocking write has been rejected before, poll_tcp needs to
     check if the netconn is writable again */
 #define NETCONN_FLAG_CHECK_WRITESPACE         0x10
 #if LWIP_IPV6
 /** If this flag is set then only IPv6 communication is allowed on the
     netconn. As per RFC#3493 this features defaults to OFF allowing
     dual-stack usage by default. */
 #define NETCONN_FLAG_IPV6_V6ONLY              0x20
 #endif /* LWIP_IPV6 */
 #if LWIP_NETBUF_RECVINFO
 /** Received packet info will be recorded for this netconn */
 #define NETCONN_FLAG_PKTINFO                  0x40
 #endif /* LWIP_NETBUF_RECVINFO */
 /** A FIN has been received but not passed to the application yet */
 #define NETCONN_FIN_RX_PENDING                0x80
 
 /* Helpers to process several netconn_types by the same code */
 #define NETCONNTYPE_GROUP(t)         ((t)&0xF0)
 #define NETCONNTYPE_DATAGRAM(t)      ((t)&0xE0)
 #if LWIP_IPV6
 #define NETCONN_TYPE_IPV6            0x08
 #define NETCONNTYPE_ISIPV6(t)        (((t)&NETCONN_TYPE_IPV6) != 0)
 #define NETCONNTYPE_ISUDPLITE(t)     (((t)&0xF3) == NETCONN_UDPLITE)
 #define NETCONNTYPE_ISUDPNOCHKSUM(t) (((t)&0xF3) == NETCONN_UDPNOCHKSUM)
 #else /* LWIP_IPV6 */
 #define NETCONNTYPE_ISIPV6(t)        (0)
 #define NETCONNTYPE_ISUDPLITE(t)     ((t) == NETCONN_UDPLITE)
 #define NETCONNTYPE_ISUDPNOCHKSUM(t) ((t) == NETCONN_UDPNOCHKSUM)
 #endif /* LWIP_IPV6 */
 
 /** @ingroup netconn_common
  * Protocol family and type of the netconn
  */
 enum netconn_type {
   NETCONN_INVALID     = 0,
   /** TCP IPv4 */
   NETCONN_TCP         = 0x10,
 #if LWIP_IPV6
   /** TCP IPv6 */
   NETCONN_TCP_IPV6    = NETCONN_TCP | NETCONN_TYPE_IPV6 /* 0x18 */,
 #endif /* LWIP_IPV6 */
   /** UDP IPv4 */
   NETCONN_UDP         = 0x20,
   /** UDP IPv4 lite */
   NETCONN_UDPLITE     = 0x21,
   /** UDP IPv4 no checksum */
   NETCONN_UDPNOCHKSUM = 0x22,
 
 #if LWIP_IPV6
   /** UDP IPv6 (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
   NETCONN_UDP_IPV6         = NETCONN_UDP | NETCONN_TYPE_IPV6 /* 0x28 */,
   /** UDP IPv6 lite (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
   NETCONN_UDPLITE_IPV6     = NETCONN_UDPLITE | NETCONN_TYPE_IPV6 /* 0x29 */,
   /** UDP IPv6 no checksum (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
   NETCONN_UDPNOCHKSUM_IPV6 = NETCONN_UDPNOCHKSUM | NETCONN_TYPE_IPV6 /* 0x2a */,
 #endif /* LWIP_IPV6 */
 
   /** Raw connection IPv4 */
   NETCONN_RAW         = 0x40
 #if LWIP_IPV6
   /** Raw connection IPv6 (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
   , NETCONN_RAW_IPV6    = NETCONN_RAW | NETCONN_TYPE_IPV6 /* 0x48 */
 #endif /* LWIP_IPV6 */
 };
 
 /** Current state of the netconn. Non-TCP netconns are always
  * in state NETCONN_NONE! */
 enum netconn_state {
   NETCONN_NONE,
   NETCONN_WRITE,
   NETCONN_LISTEN,
   NETCONN_CONNECT,
   NETCONN_CLOSE
 };
 
 /** Used to inform the callback function about changes
  * 
  * Event explanation:
  * 
  * In the netconn implementation, there are three ways to block a client:
  * 
  * - accept mbox (sys_arch_mbox_fetch(&conn->acceptmbox, &accept_ptr, 0); in netconn_accept())
  * - receive mbox (sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0); in netconn_recv_data())
  * - send queue is full (sys_arch_sem_wait(LWIP_API_MSG_SEM(msg), 0); in lwip_netconn_do_write())
  * 
  * The events have to be seen as events signaling the state of these mboxes/semaphores. For non-blocking
  * connections, you need to know in advance whether a call to a netconn function call would block or not,
  * and these events tell you about that.
  * 
  * RCVPLUS events say: Safe to perform a potentially blocking call call once more. 
  * They are counted in sockets - three RCVPLUS events for accept mbox means you are safe
  * to call netconn_accept 3 times without being blocked.
  * Same thing for receive mbox.
  * 
  * RCVMINUS events say: Your call to to a possibly blocking function is "acknowledged".
  * Socket implementation decrements the counter.
  * 
  * For TX, there is no need to count, its merely a flag. SENDPLUS means you may send something.
  * SENDPLUS occurs when enough data was delivered to peer so netconn_send() can be called again.
  * A SENDMINUS event occurs when the next call to a netconn_send() would be blocking.
  */
 enum netconn_evt {
   NETCONN_EVT_RCVPLUS,
   NETCONN_EVT_RCVMINUS,
   NETCONN_EVT_SENDPLUS,
   NETCONN_EVT_SENDMINUS,
   NETCONN_EVT_ERROR
 };
 
 #if LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD)
 /** Used for netconn_join_leave_group() */
 enum netconn_igmp {
   NETCONN_JOIN,
   NETCONN_LEAVE
 };
 #endif /* LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD) */
 
 #if LWIP_DNS
 /* Used for netconn_gethostbyname_addrtype(), these should match the DNS_ADDRTYPE defines in dns.h */
 #define NETCONN_DNS_DEFAULT   NETCONN_DNS_IPV4_IPV6
 #define NETCONN_DNS_IPV4      0
 #define NETCONN_DNS_IPV6      1
 #define NETCONN_DNS_IPV4_IPV6 2 /* try to resolve IPv4 first, try IPv6 if IPv4 fails only */
 #define NETCONN_DNS_IPV6_IPV4 3 /* try to resolve IPv6 first, try IPv4 if IPv6 fails only */
 #endif /* LWIP_DNS */
 
 /* forward-declare some structs to avoid to include their headers */
 struct ip_pcb;
 struct tcp_pcb;
 struct udp_pcb;
 struct raw_pcb;
 struct netconn;
 struct api_msg;
 
 /** A callback prototype to inform about events for a netconn */
 typedef void (* netconn_callback)(struct netconn *, enum netconn_evt, u16_t len);
 
 /** A netconn descriptor */
 struct netconn {
   /** type of the netconn (TCP, UDP or RAW) */
   enum netconn_type type;
   /** current state of the netconn */
   enum netconn_state state;
   /** the lwIP internal protocol control block */
   union {
     struct ip_pcb  *ip;
     struct tcp_pcb *tcp;
     struct udp_pcb *udp;
     struct raw_pcb *raw;
   } pcb;
   /** the last asynchronous unreported error this netconn had */
   err_t pending_err;
 #if !LWIP_NETCONN_SEM_PER_THREAD
   /** sem that is used to synchronously execute functions in the core context */
   sys_sem_t op_completed;
 #endif
   /** mbox where received packets are stored until they are fetched
       by the netconn application thread (can grow quite big) */
   sys_mbox_t recvmbox;
 #if LWIP_TCP
   /** mbox where new connections are stored until processed
       by the application thread */
   sys_mbox_t acceptmbox;
 #endif /* LWIP_TCP */
 #if LWIP_NETCONN_FULLDUPLEX
   /** number of threads waiting on an mbox. This is required to unblock
       all threads when closing while threads are waiting. */
   int mbox_threads_waiting;
 #endif
   /** only used for socket layer */
 #if LWIP_SOCKET
   int socket;
 #endif /* LWIP_SOCKET */
 #if LWIP_SO_SNDTIMEO
   /** timeout to wait for sending data (which means enqueueing data for sending
       in internal buffers) in milliseconds */
   s32_t send_timeout;
 #endif /* LWIP_SO_RCVTIMEO */
 #if LWIP_SO_RCVTIMEO
   /** timeout in milliseconds to wait for new data to be received
       (or connections to arrive for listening netconns) */
   u32_t recv_timeout;
 #endif /* LWIP_SO_RCVTIMEO */
 #if LWIP_SO_RCVBUF
   /** maximum amount of bytes queued in recvmbox
       not used for TCP: adjust TCP_WND instead! */
   int recv_bufsize;
   /** number of bytes currently in recvmbox to be received,
       tested against recv_bufsize to limit bytes on recvmbox
       for UDP and RAW, used for FIONREAD */
   int recv_avail;
 #endif /* LWIP_SO_RCVBUF */
 #if LWIP_SO_LINGER
    /** values <0 mean linger is disabled, values > 0 are seconds to linger */
   s16_t linger;
 #endif /* LWIP_SO_LINGER */
   /** flags holding more netconn-internal state, see NETCONN_FLAG_* defines */
   u8_t flags;
 #if LWIP_TCP
   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
       this temporarily stores the message.
       Also used during connect and close. */
   struct api_msg *current_msg;
 #endif /* LWIP_TCP */
   /** A callback function that is informed about events for this netconn */
   netconn_callback callback;
 };
 
 /** This vector type is passed to @ref netconn_write_vectors_partly to send
  * multiple buffers at once.
  * ATTENTION: This type has to directly map struct iovec since one is casted
  *            into the other!
  */
 struct netvector {
   /** pointer to the application buffer that contains the data to send */
   const void *ptr;
   /** size of the application data to send */
   size_t len;
 };
 
 /** Register an Network connection event */
 #define API_EVENT(c,e,l) if (c->callback) {         \
                            (*c->callback)(c, e, l); \
                          }
 
 /* Network connection functions: */
 
 /** @ingroup netconn_common
  * Create new netconn connection
  * @param t @ref netconn_type */
 #define netconn_new(t)                  netconn_new_with_proto_and_callback(t, 0, NULL)
 #define netconn_new_with_callback(t, c) netconn_new_with_proto_and_callback(t, 0, c)
 struct netconn *netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto,
                                              netconn_callback callback);
 err_t   netconn_prepare_delete(struct netconn *conn);
 err_t   netconn_delete(struct netconn *conn);
 /** Get the type of a netconn (as enum netconn_type). */
 #define netconn_type(conn) (conn->type)
 
 err_t   netconn_getaddr(struct netconn *conn, ip_addr_t *addr,
                         u16_t *port, u8_t local);
 /** @ingroup netconn_common */
 #define netconn_peer(c,i,p) netconn_getaddr(c,i,p,0)
 /** @ingroup netconn_common */
 #define netconn_addr(c,i,p) netconn_getaddr(c,i,p,1)
 
 err_t   netconn_bind(struct netconn *conn, const ip_addr_t *addr, u16_t port);
 err_t   netconn_bind_if(struct netconn *conn, u8_t if_idx);
 err_t   netconn_connect(struct netconn *conn, const ip_addr_t *addr, u16_t port);
 err_t   netconn_disconnect (struct netconn *conn);
 err_t   netconn_listen_with_backlog(struct netconn *conn, u8_t backlog);
 /** @ingroup netconn_tcp */
 #define netconn_listen(conn) netconn_listen_with_backlog(conn, TCP_DEFAULT_LISTEN_BACKLOG)
 err_t   netconn_accept(struct netconn *conn, struct netconn **new_conn);
 err_t   netconn_recv(struct netconn *conn, struct netbuf **new_buf);
 err_t   netconn_recv_udp_raw_netbuf(struct netconn *conn, struct netbuf **new_buf);
 err_t   netconn_recv_udp_raw_netbuf_flags(struct netconn *conn, struct netbuf **new_buf, u8_t apiflags);
 err_t   netconn_recv_tcp_pbuf(struct netconn *conn, struct pbuf **new_buf);
 err_t   netconn_recv_tcp_pbuf_flags(struct netconn *conn, struct pbuf **new_buf, u8_t apiflags);
 err_t   netconn_tcp_recvd(struct netconn *conn, size_t len);
 err_t   netconn_sendto(struct netconn *conn, struct netbuf *buf,
                              const ip_addr_t *addr, u16_t port);
 err_t   netconn_send(struct netconn *conn, struct netbuf *buf);
 err_t   netconn_write_partly(struct netconn *conn, const void *dataptr, size_t size,
                              u8_t apiflags, size_t *bytes_written);
 err_t   netconn_write_vectors_partly(struct netconn *conn, struct netvector *vectors, u16_t vectorcnt,
                                      u8_t apiflags, size_t *bytes_written);
 /** @ingroup netconn_tcp */
 #define netconn_write(conn, dataptr, size, apiflags) \
           netconn_write_partly(conn, dataptr, size, apiflags, NULL)
 err_t   netconn_close(struct netconn *conn);
 err_t   netconn_shutdown(struct netconn *conn, u8_t shut_rx, u8_t shut_tx);
 
 #if LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD)
 err_t   netconn_join_leave_group(struct netconn *conn, const ip_addr_t *multiaddr,
                              const ip_addr_t *netif_addr, enum netconn_igmp join_or_leave);
 err_t   netconn_join_leave_group_netif(struct netconn *conn, const ip_addr_t *multiaddr,
                              u8_t if_idx, enum netconn_igmp join_or_leave);
 #endif /* LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD) */
 #if LWIP_DNS
 #if LWIP_IPV4 && LWIP_IPV6
 err_t   netconn_gethostbyname_addrtype(const char *name, ip_addr_t *addr, u8_t dns_addrtype);
 #define netconn_gethostbyname(name, addr) netconn_gethostbyname_addrtype(name, addr, NETCONN_DNS_DEFAULT)
 #else /* LWIP_IPV4 && LWIP_IPV6 */
 err_t   netconn_gethostbyname(const char *name, ip_addr_t *addr);
 #define netconn_gethostbyname_addrtype(name, addr, dns_addrtype) netconn_gethostbyname(name, addr)
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
 #endif /* LWIP_DNS */
 
 err_t   netconn_err(struct netconn *conn);
 #define netconn_recv_bufsize(conn)      ((conn)->recv_bufsize)
 
 #define netconn_set_flags(conn, set_flags)     do { (conn)->flags = (u8_t)((conn)->flags |  (set_flags)); } while(0)
 #define netconn_clear_flags(conn, clr_flags)   do { (conn)->flags = (u8_t)((conn)->flags & (u8_t)(~(clr_flags) & 0xff)); } while(0)
 #define netconn_is_flag_set(conn, flag)        (((conn)->flags & (flag)) != 0)
 
 /** Set the blocking status of netconn calls (@todo: write/send is missing) */
 #define netconn_set_nonblocking(conn, val)  do { if(val) { \
   netconn_set_flags(conn, NETCONN_FLAG_NON_BLOCKING); \
 } else { \
   netconn_clear_flags(conn, NETCONN_FLAG_NON_BLOCKING); }} while(0)
 /** Get the blocking status of netconn calls (@todo: write/send is missing) */
 #define netconn_is_nonblocking(conn)        (((conn)->flags & NETCONN_FLAG_NON_BLOCKING) != 0)
 
 #if LWIP_IPV6
 /** @ingroup netconn_common
  * TCP: Set the IPv6 ONLY status of netconn calls (see NETCONN_FLAG_IPV6_V6ONLY)
  */
 #define netconn_set_ipv6only(conn, val)  do { if(val) { \
   netconn_set_flags(conn, NETCONN_FLAG_IPV6_V6ONLY); \
 } else { \
   netconn_clear_flags(conn, NETCONN_FLAG_IPV6_V6ONLY); }} while(0)
 /** @ingroup netconn_common
  * TCP: Get the IPv6 ONLY status of netconn calls (see NETCONN_FLAG_IPV6_V6ONLY)
  */
 #define netconn_get_ipv6only(conn)        (((conn)->flags & NETCONN_FLAG_IPV6_V6ONLY) != 0)
 #endif /* LWIP_IPV6 */
 
 #if LWIP_SO_SNDTIMEO
 /** Set the send timeout in milliseconds */
 #define netconn_set_sendtimeout(conn, timeout)      ((conn)->send_timeout = (timeout))
 /** Get the send timeout in milliseconds */
 #define netconn_get_sendtimeout(conn)               ((conn)->send_timeout)
 #endif /* LWIP_SO_SNDTIMEO */
 #if LWIP_SO_RCVTIMEO
 /** Set the receive timeout in milliseconds */
 #define netconn_set_recvtimeout(conn, timeout)      ((conn)->recv_timeout = (timeout))
 /** Get the receive timeout in milliseconds */
 #define netconn_get_recvtimeout(conn)               ((conn)->recv_timeout)
 #endif /* LWIP_SO_RCVTIMEO */
 #if LWIP_SO_RCVBUF
 /** Set the receive buffer in bytes */
 #define netconn_set_recvbufsize(conn, recvbufsize)  ((conn)->recv_bufsize = (recvbufsize))
 /** Get the receive buffer in bytes */
 #define netconn_get_recvbufsize(conn)               ((conn)->recv_bufsize)
 #endif /* LWIP_SO_RCVBUF*/
 
 #if LWIP_NETCONN_SEM_PER_THREAD
 void netconn_thread_init(void);
 void netconn_thread_cleanup(void);
 #else /* LWIP_NETCONN_SEM_PER_THREAD */
 #define netconn_thread_init()
 #define netconn_thread_cleanup()
 #endif /* LWIP_NETCONN_SEM_PER_THREAD */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif /* LWIP_NETCONN || LWIP_SOCKET */
 
 #endif /* LWIP_HDR_API_H */
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