api.h

00001 /**
00002  * @file
00003  * netconn API (to be used from non-TCPIP threads)
00004  */
00005 
00006 /*
00007  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * This file is part of the lwIP TCP/IP stack.
00033  *
00034  * Author: Adam Dunkels <adam@sics.se>
00035  *
00036  */
00037 #ifndef LWIP_HDR_API_H
00038 #define LWIP_HDR_API_H
00039 
00040 #include "lwip/opt.h"
00041 
00042 #if LWIP_NETCONN || LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */
00043 /* Note: Netconn API is always available when sockets are enabled -
00044  * sockets are implemented on top of them */
00045 
00046 #include "lwip/arch.h"
00047 #include "lwip/netbuf.h"
00048 #include "lwip/sys.h"
00049 #include "lwip/ip_addr.h"
00050 #include "lwip/err.h"
00051 
00052 #ifdef __cplusplus
00053 extern "C" {
00054 #endif
00055 
00056 /* Throughout this file, IP addresses and port numbers are expected to be in
00057  * the same byte order as in the corresponding pcb.
00058  */
00059 
00060 /* Flags for netconn_write (u8_t) */
00061 #define NETCONN_NOFLAG    0x00
00062 #define NETCONN_NOCOPY    0x00 /* Only for source code compatibility */
00063 #define NETCONN_COPY      0x01
00064 #define NETCONN_MORE      0x02
00065 #define NETCONN_DONTBLOCK 0x04
00066 
00067 /* Flags for struct netconn.flags (u8_t) */
00068 /** Should this netconn avoid blocking? */
00069 #define NETCONN_FLAG_NON_BLOCKING             0x02
00070 /** Was the last connect action a non-blocking one? */
00071 #define NETCONN_FLAG_IN_NONBLOCKING_CONNECT   0x04
00072 /** If a nonblocking write has been rejected before, poll_tcp needs to
00073     check if the netconn is writable again */
00074 #define NETCONN_FLAG_CHECK_WRITESPACE         0x10
00075 #if LWIP_IPV6
00076 /** If this flag is set then only IPv6 communication is allowed on the
00077     netconn. As per RFC#3493 this features defaults to OFF allowing
00078     dual-stack usage by default. */
00079 #define NETCONN_FLAG_IPV6_V6ONLY              0x20
00080 #endif /* LWIP_IPV6 */
00081 
00082 
00083 /* Helpers to process several netconn_types by the same code */
00084 #define NETCONNTYPE_GROUP(t)         ((t)&0xF0)
00085 #define NETCONNTYPE_DATAGRAM(t)      ((t)&0xE0)
00086 #if LWIP_IPV6
00087 #define NETCONN_TYPE_IPV6            0x08
00088 #define NETCONNTYPE_ISIPV6(t)        (((t)&NETCONN_TYPE_IPV6) != 0)
00089 #define NETCONNTYPE_ISUDPLITE(t)     (((t)&0xF3) == NETCONN_UDPLITE)
00090 #define NETCONNTYPE_ISUDPNOCHKSUM(t) (((t)&0xF3) == NETCONN_UDPNOCHKSUM)
00091 #else /* LWIP_IPV6 */
00092 #define NETCONNTYPE_ISIPV6(t)        (0)
00093 #define NETCONNTYPE_ISUDPLITE(t)     ((t) == NETCONN_UDPLITE)
00094 #define NETCONNTYPE_ISUDPNOCHKSUM(t) ((t) == NETCONN_UDPNOCHKSUM)
00095 #endif /* LWIP_IPV6 */
00096 
00097 /** @ingroup netconn_common
00098  * Protocol family and type of the netconn
00099  */
00100 enum netconn_type {
00101   NETCONN_INVALID     = 0,
00102   /** TCP IPv4 */
00103   NETCONN_TCP         = 0x10,
00104 #if LWIP_IPV6
00105   /** TCP IPv6 */
00106   NETCONN_TCP_IPV6    = NETCONN_TCP | NETCONN_TYPE_IPV6 /* 0x18 */,
00107 #endif /* LWIP_IPV6 */
00108   /** UDP IPv4 */
00109   NETCONN_UDP         = 0x20,
00110   /** UDP IPv4 lite */
00111   NETCONN_UDPLITE     = 0x21,
00112   /** UDP IPv4 no checksum */
00113   NETCONN_UDPNOCHKSUM = 0x22,
00114 
00115 #if LWIP_IPV6
00116   /** UDP IPv6 (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
00117   NETCONN_UDP_IPV6         = NETCONN_UDP | NETCONN_TYPE_IPV6 /* 0x28 */,
00118   /** UDP IPv6 lite (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
00119   NETCONN_UDPLITE_IPV6     = NETCONN_UDPLITE | NETCONN_TYPE_IPV6 /* 0x29 */,
00120   /** UDP IPv6 no checksum (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
00121   NETCONN_UDPNOCHKSUM_IPV6 = NETCONN_UDPNOCHKSUM | NETCONN_TYPE_IPV6 /* 0x2a */,
00122 #endif /* LWIP_IPV6 */
00123 
00124   /** Raw connection IPv4 */
00125   NETCONN_RAW         = 0x40
00126 #if LWIP_IPV6
00127   /** Raw connection IPv6 (dual-stack by default, unless you call @ref netconn_set_ipv6only) */
00128   , NETCONN_RAW_IPV6    = NETCONN_RAW | NETCONN_TYPE_IPV6 /* 0x48 */
00129 #endif /* LWIP_IPV6 */
00130 };
00131 
00132 /** Current state of the netconn. Non-TCP netconns are always
00133  * in state NETCONN_NONE! */
00134 enum netconn_state {
00135   NETCONN_NONE,
00136   NETCONN_WRITE,
00137   NETCONN_LISTEN,
00138   NETCONN_CONNECT,
00139   NETCONN_CLOSE
00140 };
00141 
00142 /** Used to inform the callback function about changes
00143  * 
00144  * Event explanation:
00145  * 
00146  * In the netconn implementation, there are three ways to block a client:
00147  * 
00148  * - accept mbox (sys_arch_mbox_fetch(&conn->acceptmbox, &accept_ptr, 0); in netconn_accept())
00149  * - receive mbox (sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0); in netconn_recv_data())
00150  * - send queue is full (sys_arch_sem_wait(LWIP_API_MSG_SEM(msg), 0); in lwip_netconn_do_write())
00151  * 
00152  * The events have to be seen as events signaling the state of these mboxes/semaphores. For non-blocking
00153  * connections, you need to know in advance whether a call to a netconn function call would block or not,
00154  * and these events tell you about that.
00155  * 
00156  * RCVPLUS events say: Safe to perform a potentially blocking call call once more. 
00157  * They are counted in sockets - three RCVPLUS events for accept mbox means you are safe
00158  * to call netconn_accept 3 times without being blocked.
00159  * Same thing for receive mbox.
00160  * 
00161  * RCVMINUS events say: Your call to to a possibly blocking function is "acknowledged".
00162  * Socket implementation decrements the counter.
00163  * 
00164  * For TX, there is no need to count, its merely a flag. SENDPLUS means you may send something.
00165  * SENDPLUS occurs when enough data was delivered to peer so netconn_send() can be called again.
00166  * A SENDMINUS event occurs when the next call to a netconn_send() would be blocking.
00167  */
00168 enum netconn_evt {
00169   NETCONN_EVT_RCVPLUS,
00170   NETCONN_EVT_RCVMINUS,
00171   NETCONN_EVT_SENDPLUS,
00172   NETCONN_EVT_SENDMINUS,
00173   NETCONN_EVT_ERROR
00174 };
00175 
00176 #if LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD)
00177 /** Used for netconn_join_leave_group() */
00178 enum netconn_igmp {
00179   NETCONN_JOIN,
00180   NETCONN_LEAVE
00181 };
00182 #endif /* LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD) */
00183 
00184 #if LWIP_DNS
00185 /* Used for netconn_gethostbyname_addrtype(), these should match the DNS_ADDRTYPE defines in dns.h */
00186 #define NETCONN_DNS_DEFAULT   NETCONN_DNS_IPV4_IPV6
00187 #define NETCONN_DNS_IPV4      0
00188 #define NETCONN_DNS_IPV6      1
00189 #define NETCONN_DNS_IPV4_IPV6 2 /* try to resolve IPv4 first, try IPv6 if IPv4 fails only */
00190 #define NETCONN_DNS_IPV6_IPV4 3 /* try to resolve IPv6 first, try IPv4 if IPv6 fails only */
00191 #endif /* LWIP_DNS */
00192 
00193 /* forward-declare some structs to avoid to include their headers */
00194 struct ip_pcb;
00195 struct tcp_pcb;
00196 struct udp_pcb;
00197 struct raw_pcb;
00198 struct netconn;
00199 struct api_msg;
00200 
00201 /** A callback prototype to inform about events for a netconn */
00202 typedef void (* netconn_callback)(struct netconn *, enum netconn_evt, u16_t len);
00203 
00204 /** A netconn descriptor */
00205 struct netconn {
00206   /** type of the netconn (TCP, UDP or RAW) */
00207   enum netconn_type type;
00208   /** current state of the netconn */
00209   enum netconn_state state;
00210   /** the lwIP internal protocol control block */
00211   union {
00212     struct ip_pcb  *ip;
00213     struct tcp_pcb *tcp;
00214     struct udp_pcb *udp;
00215     struct raw_pcb *raw;
00216   } pcb;
00217   /** the last error this netconn had */
00218   err_t last_err;
00219 #if !LWIP_NETCONN_SEM_PER_THREAD
00220   /** sem that is used to synchronously execute functions in the core context */
00221   sys_sem_t op_completed;
00222 #endif
00223   /** mbox where received packets are stored until they are fetched
00224       by the netconn application thread (can grow quite big) */
00225   sys_mbox_t recvmbox;
00226 #if LWIP_TCP
00227   /** mbox where new connections are stored until processed
00228       by the application thread */
00229   sys_mbox_t acceptmbox;
00230 #endif /* LWIP_TCP */
00231   /** only used for socket layer */
00232 #if LWIP_SOCKET
00233   int socket;
00234 #endif /* LWIP_SOCKET */
00235 #if LWIP_SO_SNDTIMEO
00236   /** timeout to wait for sending data (which means enqueueing data for sending
00237       in internal buffers) in milliseconds */
00238   s32_t send_timeout;
00239 #endif /* LWIP_SO_RCVTIMEO */
00240 #if LWIP_SO_RCVTIMEO
00241   /** timeout in milliseconds to wait for new data to be received
00242       (or connections to arrive for listening netconns) */
00243   int recv_timeout;
00244 #endif /* LWIP_SO_RCVTIMEO */
00245 #if LWIP_SO_RCVBUF
00246   /** maximum amount of bytes queued in recvmbox
00247       not used for TCP: adjust TCP_WND instead! */
00248   int recv_bufsize;
00249   /** number of bytes currently in recvmbox to be received,
00250       tested against recv_bufsize to limit bytes on recvmbox
00251       for UDP and RAW, used for FIONREAD */
00252   int recv_avail;
00253 #endif /* LWIP_SO_RCVBUF */
00254 #if LWIP_SO_LINGER
00255    /** values <0 mean linger is disabled, values > 0 are seconds to linger */
00256   s16_t linger;
00257 #endif /* LWIP_SO_LINGER */
00258   /** flags holding more netconn-internal state, see NETCONN_FLAG_* defines */
00259   u8_t flags;
00260 #if LWIP_TCP
00261   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
00262       this temporarily stores how much is already sent. */
00263   size_t write_offset;
00264   /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
00265       this temporarily stores the message.
00266       Also used during connect and close. */
00267   struct api_msg *current_msg;
00268 #endif /* LWIP_TCP */
00269   /** A callback function that is informed about events for this netconn */
00270   netconn_callback callback;
00271 };
00272 
00273 /** Register an Network connection event */
00274 #define API_EVENT(c,e,l) if (c->callback) {         \
00275                            (*c->callback)(c, e, l); \
00276                          }
00277 
00278 /** Set conn->last_err to err but don't overwrite fatal errors */
00279 #define NETCONN_SET_SAFE_ERR(conn, err) do { if ((conn) != NULL) { \
00280   SYS_ARCH_DECL_PROTECT(netconn_set_safe_err_lev); \
00281   SYS_ARCH_PROTECT(netconn_set_safe_err_lev); \
00282   if (!ERR_IS_FATAL((conn)->last_err)) { \
00283     (conn)->last_err = err; \
00284   } \
00285   SYS_ARCH_UNPROTECT(netconn_set_safe_err_lev); \
00286 }} while(0);
00287 
00288 /* Network connection functions: */
00289 
00290 /** @ingroup netconn_common
00291  * Create new netconn connection
00292  * @param t @ref netconn_type */
00293 #define netconn_new(t)                  netconn_new_with_proto_and_callback(t, 0, NULL)
00294 #define netconn_new_with_callback(t, c) netconn_new_with_proto_and_callback(t, 0, c)
00295 struct netconn *netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto,
00296                                              netconn_callback callback);
00297 err_t   netconn_delete(struct netconn *conn);
00298 /** Get the type of a netconn (as enum netconn_type). */
00299 #define netconn_type(conn) (conn->type)
00300 
00301 err_t   netconn_getaddr(struct netconn *conn, ip_addr_t *addr,
00302                         u16_t *port, u8_t local);
00303 /** @ingroup netconn_common */
00304 #define netconn_peer(c,i,p) netconn_getaddr(c,i,p,0)
00305 /** @ingroup netconn_common */
00306 #define netconn_addr(c,i,p) netconn_getaddr(c,i,p,1)
00307 
00308 err_t   netconn_bind(struct netconn *conn, const ip_addr_t *addr, u16_t port);
00309 err_t   netconn_connect(struct netconn *conn, const ip_addr_t *addr, u16_t port);
00310 err_t   netconn_disconnect (struct netconn *conn);
00311 err_t   netconn_listen_with_backlog(struct netconn *conn, u8_t backlog);
00312 /** @ingroup netconn_tcp */
00313 #define netconn_listen(conn) netconn_listen_with_backlog(conn, TCP_DEFAULT_LISTEN_BACKLOG)
00314 err_t   netconn_accept(struct netconn *conn, struct netconn **new_conn);
00315 err_t   netconn_recv(struct netconn *conn, struct netbuf **new_buf);
00316 err_t   netconn_recv_tcp_pbuf(struct netconn *conn, struct pbuf **new_buf);
00317 err_t   netconn_sendto(struct netconn *conn, struct netbuf *buf,
00318                              const ip_addr_t *addr, u16_t port);
00319 err_t   netconn_send(struct netconn *conn, struct netbuf *buf);
00320 err_t   netconn_write_partly(struct netconn *conn, const void *dataptr, size_t size,
00321                              u8_t apiflags, size_t *bytes_written);
00322 /** @ingroup netconn_tcp */
00323 #define netconn_write(conn, dataptr, size, apiflags) \
00324           netconn_write_partly(conn, dataptr, size, apiflags, NULL)
00325 err_t   netconn_close(struct netconn *conn);
00326 err_t   netconn_shutdown(struct netconn *conn, u8_t shut_rx, u8_t shut_tx);
00327 
00328 #if LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD)
00329 err_t   netconn_join_leave_group(struct netconn *conn, const ip_addr_t *multiaddr,
00330                              const ip_addr_t *netif_addr, enum netconn_igmp join_or_leave);
00331 #endif /* LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD) */
00332 #if LWIP_DNS
00333 #if LWIP_IPV4 && LWIP_IPV6
00334 err_t   netconn_gethostbyname_addrtype(const char *name, ip_addr_t *addr, u8_t dns_addrtype);
00335 #define netconn_gethostbyname(name, addr) netconn_gethostbyname_addrtype(name, addr, NETCONN_DNS_DEFAULT)
00336 #else /* LWIP_IPV4 && LWIP_IPV6 */
00337 err_t   netconn_gethostbyname(const char *name, ip_addr_t *addr);
00338 #define netconn_gethostbyname_addrtype(name, addr, dns_addrtype) netconn_gethostbyname(name, addr)
00339 #endif /* LWIP_IPV4 && LWIP_IPV6 */
00340 #endif /* LWIP_DNS */
00341 
00342 #define netconn_err(conn)               ((conn)->last_err)
00343 #define netconn_recv_bufsize(conn)      ((conn)->recv_bufsize)
00344 
00345 /** Set the blocking status of netconn calls (@todo: write/send is missing) */
00346 #define netconn_set_nonblocking(conn, val)  do { if(val) { \
00347   (conn)->flags |= NETCONN_FLAG_NON_BLOCKING; \
00348 } else { \
00349   (conn)->flags &= ~ NETCONN_FLAG_NON_BLOCKING; }} while(0)
00350 /** Get the blocking status of netconn calls (@todo: write/send is missing) */
00351 #define netconn_is_nonblocking(conn)        (((conn)->flags & NETCONN_FLAG_NON_BLOCKING) != 0)
00352 
00353 #if LWIP_IPV6
00354 /** @ingroup netconn_common
00355  * TCP: Set the IPv6 ONLY status of netconn calls (see NETCONN_FLAG_IPV6_V6ONLY)
00356  */
00357 #define netconn_set_ipv6only(conn, val)  do { if(val) { \
00358   (conn)->flags |= NETCONN_FLAG_IPV6_V6ONLY; \
00359 } else { \
00360   (conn)->flags &= ~ NETCONN_FLAG_IPV6_V6ONLY; }} while(0)
00361 /** @ingroup netconn_common
00362  * TCP: Get the IPv6 ONLY status of netconn calls (see NETCONN_FLAG_IPV6_V6ONLY)
00363  */
00364 #define netconn_get_ipv6only(conn)        (((conn)->flags & NETCONN_FLAG_IPV6_V6ONLY) != 0)
00365 #endif /* LWIP_IPV6 */
00366 
00367 #if LWIP_SO_SNDTIMEO
00368 /** Set the send timeout in milliseconds */
00369 #define netconn_set_sendtimeout(conn, timeout)      ((conn)->send_timeout = (timeout))
00370 /** Get the send timeout in milliseconds */
00371 #define netconn_get_sendtimeout(conn)               ((conn)->send_timeout)
00372 #endif /* LWIP_SO_SNDTIMEO */
00373 #if LWIP_SO_RCVTIMEO
00374 /** Set the receive timeout in milliseconds */
00375 #define netconn_set_recvtimeout(conn, timeout)      ((conn)->recv_timeout = (timeout))
00376 /** Get the receive timeout in milliseconds */
00377 #define netconn_get_recvtimeout(conn)               ((conn)->recv_timeout)
00378 #endif /* LWIP_SO_RCVTIMEO */
00379 #if LWIP_SO_RCVBUF
00380 /** Set the receive buffer in bytes */
00381 #define netconn_set_recvbufsize(conn, recvbufsize)  ((conn)->recv_bufsize = (recvbufsize))
00382 /** Get the receive buffer in bytes */
00383 #define netconn_get_recvbufsize(conn)               ((conn)->recv_bufsize)
00384 #endif /* LWIP_SO_RCVBUF*/
00385 
00386 #if LWIP_NETCONN_SEM_PER_THREAD
00387 void netconn_thread_init(void);
00388 void netconn_thread_cleanup(void);
00389 #else /* LWIP_NETCONN_SEM_PER_THREAD */
00390 #define netconn_thread_init()
00391 #define netconn_thread_cleanup()
00392 #endif /* LWIP_NETCONN_SEM_PER_THREAD */
00393 
00394 #ifdef __cplusplus
00395 }
00396 #endif
00397 
00398 #endif /* LWIP_NETCONN || LWIP_SOCKET */
00399 
00400 #endif /* LWIP_HDR_API_H */