api_lib.c

00001 /**
00002  * @file
00003  * Sequential API External module
00004  *
00005  */
00006 
00007 /*
00008  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00009  * All rights reserved.
00010  *
00011  * Redistribution and use in source and binary forms, with or without modification,
00012  * are permitted provided that the following conditions are met:
00013  *
00014  * 1. Redistributions of source code must retain the above copyright notice,
00015  *    this list of conditions and the following disclaimer.
00016  * 2. Redistributions in binary form must reproduce the above copyright notice,
00017  *    this list of conditions and the following disclaimer in the documentation
00018  *    and/or other materials provided with the distribution.
00019  * 3. The name of the author may not be used to endorse or promote products
00020  *    derived from this software without specific prior written permission.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00023  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00024  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00025  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00026  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00027  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00028  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00029  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00030  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00031  * OF SUCH DAMAGE.
00032  *
00033  * This file is part of the lwIP TCP/IP stack.
00034  *
00035  * Author: Adam Dunkels <adam@sics.se>
00036  *
00037  */
00038 
00039 /* This is the part of the API that is linked with
00040    the application */
00041 
00042 #include "lwip/opt.h"
00043 
00044 #if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */
00045 
00046 #include "lwip/api.h"
00047 #include "lwip/tcpip.h"
00048 #include "lwip/memp.h"
00049 
00050 #include "lwip/ip.h"
00051 #include "lwip/raw.h"
00052 #include "lwip/udp.h"
00053 #include "lwip/tcp.h"
00054 
00055 #include <string.h>
00056 
00057 /**
00058  * Create a new netconn (of a specific type) that has a callback function.
00059  * The corresponding pcb is also created.
00060  *
00061  * @param t the type of 'connection' to create (@see enum netconn_type)
00062  * @param proto the IP protocol for RAW IP pcbs
00063  * @param callback a function to call on status changes (RX available, TX'ed)
00064  * @return a newly allocated struct netconn or
00065  *         NULL on memory error
00066  */
00067 struct netconn*
00068 netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto, netconn_callback callback)
00069 {
00070   struct netconn *conn;
00071   struct api_msg msg;
00072 
00073   conn = netconn_alloc(t, callback);
00074   if (conn != NULL) {
00075     msg.function = do_newconn;
00076     msg.msg.msg.n.proto = proto;
00077     msg.msg.conn = conn;
00078     if (TCPIP_APIMSG(&msg) != ERR_OK) {
00079       LWIP_ASSERT("freeing conn without freeing pcb", conn->pcb.tcp == NULL);
00080       LWIP_ASSERT("conn has no op_completed", sys_sem_valid(&conn->op_completed));
00081       LWIP_ASSERT("conn has no recvmbox", sys_mbox_valid(&conn->recvmbox));
00082 #if LWIP_TCP
00083       LWIP_ASSERT("conn->acceptmbox shouldn't exist", !sys_mbox_valid(&conn->acceptmbox));
00084 #endif /* LWIP_TCP */
00085       sys_sem_free(&conn->op_completed);
00086       sys_mbox_free(&conn->recvmbox);
00087       memp_free(MEMP_NETCONN, conn);
00088       return NULL;
00089     }
00090   }
00091   return conn;
00092 }
00093 
00094 /**
00095  * Close a netconn 'connection' and free its resources.
00096  * UDP and RAW connection are completely closed, TCP pcbs might still be in a waitstate
00097  * after this returns.
00098  *
00099  * @param conn the netconn to delete
00100  * @return ERR_OK if the connection was deleted
00101  */
00102 err_t
00103 netconn_delete(struct netconn *conn)
00104 {
00105   struct api_msg msg;
00106 
00107   /* No ASSERT here because possible to get a (conn == NULL) if we got an accept error */
00108   if (conn == NULL) {
00109     return ERR_OK;
00110   }
00111 
00112   msg.function = do_delconn;
00113   msg.msg.conn = conn;
00114   tcpip_apimsg(&msg);
00115 
00116   netconn_free(conn);
00117 
00118   /* don't care for return value of do_delconn since it only calls void functions */
00119 
00120   return ERR_OK;
00121 }
00122 
00123 /**
00124  * Get the local or remote IP address and port of a netconn.
00125  * For RAW netconns, this returns the protocol instead of a port!
00126  *
00127  * @param conn the netconn to query
00128  * @param addr a pointer to which to save the IP address
00129  * @param port a pointer to which to save the port (or protocol for RAW)
00130  * @param local 1 to get the local IP address, 0 to get the remote one
00131  * @return ERR_CONN for invalid connections
00132  *         ERR_OK if the information was retrieved
00133  */
00134 err_t
00135 netconn_getaddr(struct netconn *conn, ip_addr_t *addr, u16_t *port, u8_t local)
00136 {
00137   struct api_msg msg;
00138   err_t err;
00139 
00140   LWIP_ERROR("netconn_getaddr: invalid conn", (conn != NULL), return ERR_ARG;);
00141   LWIP_ERROR("netconn_getaddr: invalid addr", (addr != NULL), return ERR_ARG;);
00142   LWIP_ERROR("netconn_getaddr: invalid port", (port != NULL), return ERR_ARG;);
00143 
00144   msg.function = do_getaddr;
00145   msg.msg.conn = conn;
00146   msg.msg.msg.ad.ipaddr = addr;
00147   msg.msg.msg.ad.port = port;
00148   msg.msg.msg.ad.local = local;
00149   err = TCPIP_APIMSG(&msg);
00150 
00151   NETCONN_SET_SAFE_ERR(conn, err);
00152   return err;
00153 }
00154 
00155 /**
00156  * Bind a netconn to a specific local IP address and port.
00157  * Binding one netconn twice might not always be checked correctly!
00158  *
00159  * @param conn the netconn to bind
00160  * @param addr the local IP address to bind the netconn to (use IP_ADDR_ANY
00161  *             to bind to all addresses)
00162  * @param port the local port to bind the netconn to (not used for RAW)
00163  * @return ERR_OK if bound, any other err_t on failure
00164  */
00165 err_t
00166 netconn_bind(struct netconn *conn, ip_addr_t *addr, u16_t port)
00167 {
00168   struct api_msg msg;
00169   err_t err;
00170 
00171   LWIP_ERROR("netconn_bind: invalid conn", (conn != NULL), return ERR_ARG;);
00172 
00173   msg.function = do_bind;
00174   msg.msg.conn = conn;
00175   msg.msg.msg.bc.ipaddr = addr;
00176   msg.msg.msg.bc.port = port;
00177   err = TCPIP_APIMSG(&msg);
00178 
00179   NETCONN_SET_SAFE_ERR(conn, err);
00180   return err;
00181 }
00182 
00183 /**
00184  * Connect a netconn to a specific remote IP address and port.
00185  *
00186  * @param conn the netconn to connect
00187  * @param addr the remote IP address to connect to
00188  * @param port the remote port to connect to (no used for RAW)
00189  * @return ERR_OK if connected, return value of tcp_/udp_/raw_connect otherwise
00190  */
00191 err_t
00192 netconn_connect(struct netconn *conn, ip_addr_t *addr, u16_t port)
00193 {
00194   struct api_msg msg;
00195   err_t err;
00196 
00197   LWIP_ERROR("netconn_connect: invalid conn", (conn != NULL), return ERR_ARG;);
00198 
00199   msg.function = do_connect;
00200   msg.msg.conn = conn;
00201   msg.msg.msg.bc.ipaddr = addr;
00202   msg.msg.msg.bc.port = port;
00203   /* This is the only function which need to not block tcpip_thread */
00204   err = tcpip_apimsg(&msg);
00205 
00206   NETCONN_SET_SAFE_ERR(conn, err);
00207   return err;
00208 }
00209 
00210 /**
00211  * Disconnect a netconn from its current peer (only valid for UDP netconns).
00212  *
00213  * @param conn the netconn to disconnect
00214  * @return TODO: return value is not set here...
00215  */
00216 err_t
00217 netconn_disconnect(struct netconn *conn)
00218 {
00219   struct api_msg msg;
00220   err_t err;
00221 
00222   LWIP_ERROR("netconn_disconnect: invalid conn", (conn != NULL), return ERR_ARG;);
00223 
00224   msg.function = do_disconnect;
00225   msg.msg.conn = conn;
00226   err = TCPIP_APIMSG(&msg);
00227 
00228   NETCONN_SET_SAFE_ERR(conn, err);
00229   return err;
00230 }
00231 
00232 /**
00233  * Set a TCP netconn into listen mode
00234  *
00235  * @param conn the tcp netconn to set to listen mode
00236  * @param backlog the listen backlog, only used if TCP_LISTEN_BACKLOG==1
00237  * @return ERR_OK if the netconn was set to listen (UDP and RAW netconns
00238  *         don't return any error (yet?))
00239  */
00240 err_t
00241 netconn_listen_with_backlog(struct netconn *conn, u8_t backlog)
00242 {
00243 #if LWIP_TCP
00244   struct api_msg msg;
00245   err_t err;
00246 
00247   /* This does no harm. If TCP_LISTEN_BACKLOG is off, backlog is unused. */
00248   LWIP_UNUSED_ARG(backlog);
00249 
00250   LWIP_ERROR("netconn_listen: invalid conn", (conn != NULL), return ERR_ARG;);
00251 
00252   msg.function = do_listen;
00253   msg.msg.conn = conn;
00254 #if TCP_LISTEN_BACKLOG
00255   msg.msg.msg.lb.backlog = backlog;
00256 #endif /* TCP_LISTEN_BACKLOG */
00257   err = TCPIP_APIMSG(&msg);
00258 
00259   NETCONN_SET_SAFE_ERR(conn, err);
00260   return err;
00261 #else /* LWIP_TCP */
00262   LWIP_UNUSED_ARG(conn);
00263   LWIP_UNUSED_ARG(backlog);
00264   return ERR_ARG;
00265 #endif /* LWIP_TCP */
00266 }
00267 
00268 /**
00269  * Accept a new connection on a TCP listening netconn.
00270  *
00271  * @param conn the TCP listen netconn
00272  * @param new_conn pointer where the new connection is stored
00273  * @return ERR_OK if a new connection has been received or an error
00274  *                code otherwise
00275  */
00276 err_t
00277 netconn_accept(struct netconn *conn, struct netconn **new_conn)
00278 {
00279 #if LWIP_TCP
00280   struct netconn *newconn;
00281   err_t err;
00282 #if TCP_LISTEN_BACKLOG
00283   struct api_msg msg;
00284 #endif /* TCP_LISTEN_BACKLOG */
00285 
00286   LWIP_ERROR("netconn_accept: invalid pointer",    (new_conn != NULL),                  return ERR_ARG;);
00287   *new_conn = NULL;
00288   LWIP_ERROR("netconn_accept: invalid conn",       (conn != NULL),                      return ERR_ARG;);
00289   LWIP_ERROR("netconn_accept: invalid acceptmbox", sys_mbox_valid(&conn->acceptmbox),   return ERR_ARG;);
00290 
00291   err = conn->last_err;
00292   if (ERR_IS_FATAL(err)) {
00293     /* don't recv on fatal errors: this might block the application task
00294        waiting on acceptmbox forever! */
00295     return err;
00296   }
00297 
00298 #if LWIP_SO_RCVTIMEO
00299   if (sys_arch_mbox_fetch(&conn->acceptmbox, (void **)&newconn, conn->recv_timeout) == SYS_ARCH_TIMEOUT) {
00300     NETCONN_SET_SAFE_ERR(conn, ERR_TIMEOUT);
00301     return ERR_TIMEOUT;
00302   }
00303 #else
00304   sys_arch_mbox_fetch(&conn->acceptmbox, (void **)&newconn, 0);
00305 #endif /* LWIP_SO_RCVTIMEO*/
00306   /* Register event with callback */
00307   API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0);
00308 
00309   if (newconn == NULL) {
00310     /* connection has been aborted */
00311     NETCONN_SET_SAFE_ERR(conn, ERR_ABRT);
00312     return ERR_ABRT;
00313   }
00314 #if TCP_LISTEN_BACKLOG
00315   /* Let the stack know that we have accepted the connection. */
00316   msg.function = do_recv;
00317   msg.msg.conn = conn;
00318   /* don't care for the return value of do_recv */
00319   TCPIP_APIMSG(&msg);
00320 #endif /* TCP_LISTEN_BACKLOG */
00321 
00322   *new_conn = newconn;
00323   /* don't set conn->last_err: it's only ERR_OK, anyway */
00324   return ERR_OK;
00325 #else /* LWIP_TCP */
00326   LWIP_UNUSED_ARG(conn);
00327   LWIP_UNUSED_ARG(new_conn);
00328   return ERR_ARG;
00329 #endif /* LWIP_TCP */
00330 }
00331 
00332 /**
00333  * Receive data: actual implementation that doesn't care whether pbuf or netbuf
00334  * is received
00335  *
00336  * @param conn the netconn from which to receive data
00337  * @param new_buf pointer where a new pbuf/netbuf is stored when received data
00338  * @return ERR_OK if data has been received, an error code otherwise (timeout,
00339  *                memory error or another error)
00340  */
00341 static err_t
00342 netconn_recv_data(struct netconn *conn, void **new_buf)
00343 {
00344   void *buf = NULL;
00345   u16_t len;
00346   err_t err;
00347 #if LWIP_TCP
00348   struct api_msg msg;
00349 #endif /* LWIP_TCP */
00350   LWIP_DEBUGF(API_LIB_DEBUG, ("~netconn_recv_data: new_buf=0x%x\r\n",new_buf));
00351   LWIP_DEBUGF(API_LIB_DEBUG, ("~~netconn_recv_data: conn mailbox=0x%x\r\n",&conn->recvmbox));
00352   LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;);
00353   *new_buf = NULL;
00354   LWIP_ERROR("netconn_recv: invalid conn",    (conn != NULL),    return ERR_ARG;);
00355   LWIP_ERROR("netconn_accept: invalid recvmbox", sys_mbox_valid(&conn->recvmbox), return ERR_CONN;);
00356   LWIP_DEBUGF(API_LIB_DEBUG, ("~~netconn_recv_data: err=0x%x\r\n",conn->last_err));
00357   err = conn->last_err;
00358   if (err < ERR_ISCONN) {
00359     /* don't recv on fatal errors: this might block the application task
00360        waiting on recvmbox forever! */
00361     /* @todo: this does not allow us to fetch data that has been put into recvmbox
00362        before the fatal error occurred - is that a problem? */
00363     return err;
00364   }
00365 
00366 #if LWIP_SO_RCVTIMEO
00367    LWIP_DEBUGF(API_LIB_DEBUG, ("~~~netconn_recv_data: fetch with timeout id %d\r\n",conn->recvmbox.id));
00368   if (sys_arch_mbox_fetch(&conn->recvmbox, &buf, conn->recv_timeout) == SYS_ARCH_TIMEOUT) {
00369     NETCONN_SET_SAFE_ERR(conn, ERR_TIMEOUT);
00370     return ERR_TIMEOUT;
00371   }
00372 #else
00373   LWIP_DEBUGF(API_LIB_DEBUG, ("~~~netconn_recv_data: fetch id %d \r\n",conn->recvmbox.id));
00374   sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0);
00375 #endif /* LWIP_SO_RCVTIMEO*/
00376 
00377 #if LWIP_TCP
00378 #if (LWIP_UDP || LWIP_RAW)
00379   if (conn->type == NETCONN_TCP)
00380 #endif /* (LWIP_UDP || LWIP_RAW) */
00381   {
00382     if (!netconn_get_noautorecved(conn) || (buf == NULL)) {
00383       /* Let the stack know that we have taken the data. */
00384       /* TODO: Speedup: Don't block and wait for the answer here
00385          (to prevent multiple thread-switches). */
00386       msg.function = do_recv;
00387       msg.msg.conn = conn;
00388       if (buf != NULL) {
00389         msg.msg.msg.r.len = ((struct pbuf *)buf)->tot_len;
00390       } else {
00391         msg.msg.msg.r.len = 1;
00392       }
00393       /* don't care for the return value of do_recv */
00394       TCPIP_APIMSG(&msg);
00395     }
00396 
00397     /* If we are closed, we indicate that we no longer wish to use the socket */
00398     if (buf == NULL) {
00399       API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0);
00400       /* Avoid to lose any previous error code */
00401       NETCONN_SET_SAFE_ERR(conn, ERR_CLSD);
00402       return ERR_CLSD;
00403     }
00404     len = ((struct pbuf *)buf)->tot_len;
00405   }
00406 #endif /* LWIP_TCP */
00407 #if LWIP_TCP && (LWIP_UDP || LWIP_RAW)
00408   else
00409 #endif /* LWIP_TCP && (LWIP_UDP || LWIP_RAW) */
00410 #if (LWIP_UDP || LWIP_RAW)
00411   {
00412     LWIP_ASSERT("buf != NULL", buf != NULL);
00413     len = netbuf_len((struct netbuf *)buf);
00414   }
00415 #endif /* (LWIP_UDP || LWIP_RAW) */
00416 
00417 #if LWIP_SO_RCVBUF
00418   SYS_ARCH_DEC(conn->recv_avail, len);
00419 #endif /* LWIP_SO_RCVBUF */
00420   /* Register event with callback */
00421   API_EVENT(conn, NETCONN_EVT_RCVMINUS, len);
00422 
00423   LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_recv_data: received %p, len=%"U16_F"\n", buf, len));
00424 
00425   *new_buf = buf;
00426   /* don't set conn->last_err: it's only ERR_OK, anyway */
00427   return ERR_OK;
00428 }
00429 
00430 /**
00431  * Receive data (in form of a pbuf) from a TCP netconn
00432  *
00433  * @param conn the netconn from which to receive data
00434  * @param new_buf pointer where a new pbuf is stored when received data
00435  * @return ERR_OK if data has been received, an error code otherwise (timeout,
00436  *                memory error or another error)
00437  *         ERR_ARG if conn is not a TCP netconn
00438  */
00439 err_t
00440 netconn_recv_tcp_pbuf(struct netconn *conn, struct pbuf **new_buf)
00441 {
00442   LWIP_ERROR("netconn_recv: invalid conn", (conn != NULL) &&
00443              netconn_type(conn) == NETCONN_TCP, return ERR_ARG;);
00444   LWIP_DEBUGF(API_LIB_DEBUG, ("+++netconn_recv_data: tcp \n"));
00445   return netconn_recv_data(conn, (void **)new_buf);
00446 }
00447 
00448 /**
00449  * Receive data (in form of a netbuf containing a packet buffer) from a netconn
00450  *
00451  * @param conn the netconn from which to receive data
00452  * @param new_buf pointer where a new netbuf is stored when received data
00453  * @return ERR_OK if data has been received, an error code otherwise (timeout,
00454  *                memory error or another error)
00455  */
00456 err_t
00457 netconn_recv(struct netconn *conn, struct netbuf **new_buf)
00458 {
00459 #if LWIP_TCP
00460   struct netbuf *buf = NULL;
00461   err_t err;
00462 #endif /* LWIP_TCP */
00463 
00464   LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;);
00465   *new_buf = NULL;
00466   LWIP_ERROR("netconn_recv: invalid conn",    (conn != NULL),    return ERR_ARG;);
00467   LWIP_ERROR("netconn_accept: invalid recvmbox", sys_mbox_valid(&conn->recvmbox), return ERR_CONN;);
00468 
00469 #if LWIP_TCP
00470 #if (LWIP_UDP || LWIP_RAW)
00471   if (conn->type == NETCONN_TCP)
00472 #endif /* (LWIP_UDP || LWIP_RAW) */
00473   {
00474     struct pbuf *p = NULL;
00475     /* This is not a listening netconn, since recvmbox is set */
00476 
00477     buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
00478     if (buf == NULL) {
00479       NETCONN_SET_SAFE_ERR(conn, ERR_MEM);
00480       return ERR_MEM;
00481     }
00482 
00483     err = netconn_recv_data(conn, (void **)&p);
00484     if (err != ERR_OK) {
00485       memp_free(MEMP_NETBUF, buf);
00486       return err;
00487     }
00488     LWIP_ASSERT("p != NULL", p != NULL);
00489 
00490     buf->p = p;
00491     buf->ptr = p;
00492     buf->port = 0;
00493     ip_addr_set_any(&buf->addr);
00494     *new_buf = buf;
00495     /* don't set conn->last_err: it's only ERR_OK, anyway */
00496     return ERR_OK;
00497   }
00498 #endif /* LWIP_TCP */
00499 #if LWIP_TCP && (LWIP_UDP || LWIP_RAW)
00500   else
00501 #endif /* LWIP_TCP && (LWIP_UDP || LWIP_RAW) */
00502   {
00503 #if (LWIP_UDP || LWIP_RAW)
00504     return netconn_recv_data(conn, (void **)new_buf);
00505 #endif /* (LWIP_UDP || LWIP_RAW) */
00506   }
00507 }
00508 
00509 /**
00510  * TCP: update the receive window: by calling this, the application
00511  * tells the stack that it has processed data and is able to accept
00512  * new data.
00513  * ATTENTION: use with care, this is mainly used for sockets!
00514  * Can only be used when calling netconn_set_noautorecved(conn, 1) before.
00515  *
00516  * @param conn the netconn for which to update the receive window
00517  * @param length amount of data processed (ATTENTION: this must be accurate!)
00518  */
00519 void
00520 netconn_recved(struct netconn *conn, u32_t length)
00521 {
00522 #if LWIP_TCP
00523   if ((conn != NULL) && (conn->type == NETCONN_TCP) &&
00524       (netconn_get_noautorecved(conn))) {
00525     struct api_msg msg;
00526     /* Let the stack know that we have taken the data. */
00527     /* TODO: Speedup: Don't block and wait for the answer here
00528        (to prevent multiple thread-switches). */
00529     msg.function = do_recv;
00530     msg.msg.conn = conn;
00531     msg.msg.msg.r.len = length;
00532     /* don't care for the return value of do_recv */
00533     TCPIP_APIMSG(&msg);
00534   }
00535 #else /* LWIP_TCP */
00536   LWIP_UNUSED_ARG(conn);
00537   LWIP_UNUSED_ARG(length);
00538 #endif /* LWIP_TCP */
00539 }
00540 
00541 /**
00542  * Send data (in form of a netbuf) to a specific remote IP address and port.
00543  * Only to be used for UDP and RAW netconns (not TCP).
00544  *
00545  * @param conn the netconn over which to send data
00546  * @param buf a netbuf containing the data to send
00547  * @param addr the remote IP address to which to send the data
00548  * @param port the remote port to which to send the data
00549  * @return ERR_OK if data was sent, any other err_t on error
00550  */
00551 err_t
00552 netconn_sendto(struct netconn *conn, struct netbuf *buf, ip_addr_t *addr, u16_t port)
00553 {
00554   if (buf != NULL) {
00555     ip_addr_set(&buf->addr, addr);
00556     buf->port = port;
00557     return netconn_send(conn, buf);
00558   }
00559   return ERR_VAL;
00560 }
00561 
00562 /**
00563  * Send data over a UDP or RAW netconn (that is already connected).
00564  *
00565  * @param conn the UDP or RAW netconn over which to send data
00566  * @param buf a netbuf containing the data to send
00567  * @return ERR_OK if data was sent, any other err_t on error
00568  */
00569 err_t
00570 netconn_send(struct netconn *conn, struct netbuf *buf)
00571 {
00572   struct api_msg msg;
00573   err_t err;
00574 
00575   LWIP_ERROR("netconn_send: invalid conn",  (conn != NULL), return ERR_ARG;);
00576 
00577   LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_send: sending %"U16_F" bytes\n", buf->p->tot_len));
00578   msg.function = do_send;
00579   msg.msg.conn = conn;
00580   msg.msg.msg.b = buf;
00581   err = TCPIP_APIMSG(&msg);
00582 
00583   NETCONN_SET_SAFE_ERR(conn, err);
00584   return err;
00585 }
00586 
00587 /**
00588  * Send data over a TCP netconn.
00589  *
00590  * @param conn the TCP netconn over which to send data
00591  * @param dataptr pointer to the application buffer that contains the data to send
00592  * @param size size of the application data to send
00593  * @param apiflags combination of following flags :
00594  * - NETCONN_COPY: data will be copied into memory belonging to the stack
00595  * - NETCONN_MORE: for TCP connection, PSH flag will be set on last segment sent
00596  * - NETCONN_DONTBLOCK: only write the data if all dat can be written at once
00597  * @param bytes_written pointer to a location that receives the number of written bytes
00598  * @return ERR_OK if data was sent, any other err_t on error
00599  */
00600 err_t
00601 netconn_write_partly(struct netconn *conn, const void *dataptr, size_t size,
00602                      u8_t apiflags, size_t *bytes_written)
00603 {
00604   struct api_msg msg;
00605   err_t err;
00606   u8_t dontblock;
00607 
00608   LWIP_ERROR("netconn_write: invalid conn",  (conn != NULL), return ERR_ARG;);
00609   LWIP_ERROR("netconn_write: invalid conn->type",  (conn->type == NETCONN_TCP), return ERR_VAL;);
00610   if (size == 0) {
00611     return ERR_OK;
00612   }
00613   dontblock = netconn_is_nonblocking(conn) || (apiflags & NETCONN_DONTBLOCK);
00614   if (dontblock && !bytes_written) {
00615     /* This implies netconn_write() cannot be used for non-blocking send, since
00616        it has no way to return the number of bytes written. */
00617     return ERR_VAL;
00618   }
00619 
00620   /* non-blocking write sends as much  */
00621   msg.function = do_write;
00622   msg.msg.conn = conn;
00623   msg.msg.msg.w.dataptr = dataptr;
00624   msg.msg.msg.w.apiflags = apiflags;
00625   msg.msg.msg.w.len = size;
00626 #if LWIP_SO_SNDTIMEO
00627   if (conn->send_timeout != 0) {
00628     /* get the time we started, which is later compared to
00629         sys_now() + conn->send_timeout */
00630     msg.msg.msg.w.time_started = sys_now();
00631   } else {
00632     msg.msg.msg.w.time_started = 0;
00633   }
00634 #endif /* LWIP_SO_SNDTIMEO */
00635 
00636   /* For locking the core: this _can_ be delayed on low memory/low send buffer,
00637      but if it is, this is done inside api_msg.c:do_write(), so we can use the
00638      non-blocking version here. */
00639   err = TCPIP_APIMSG(&msg);
00640   if ((err == ERR_OK) && (bytes_written != NULL)) {
00641     if (dontblock
00642 #if LWIP_SO_SNDTIMEO
00643         || (conn->send_timeout != 0)
00644 #endif /* LWIP_SO_SNDTIMEO */
00645        ) {
00646       /* nonblocking write: maybe the data has been sent partly */
00647       *bytes_written = msg.msg.msg.w.len;
00648     } else {
00649       /* blocking call succeeded: all data has been sent if it */
00650       *bytes_written = size;
00651     }
00652   }
00653 
00654   NETCONN_SET_SAFE_ERR(conn, err);
00655   return err;
00656 }
00657 
00658 /**
00659  * Close ot shutdown a TCP netconn (doesn't delete it).
00660  *
00661  * @param conn the TCP netconn to close or shutdown
00662  * @param how fully close or only shutdown one side?
00663  * @return ERR_OK if the netconn was closed, any other err_t on error
00664  */
00665 static err_t
00666 netconn_close_shutdown(struct netconn *conn, u8_t how)
00667 {
00668   struct api_msg msg;
00669   err_t err;
00670 
00671   LWIP_ERROR("netconn_close: invalid conn",  (conn != NULL), return ERR_ARG;);
00672 
00673   msg.function = do_close;
00674   msg.msg.conn = conn;
00675   /* shutting down both ends is the same as closing */
00676   msg.msg.msg.sd.shut = how;
00677   /* because of the LWIP_TCPIP_CORE_LOCKING implementation of do_close,
00678      don't use TCPIP_APIMSG here */
00679   err = tcpip_apimsg(&msg);
00680 
00681   NETCONN_SET_SAFE_ERR(conn, err);
00682   return err;
00683 }
00684 
00685 /**
00686  * Close a TCP netconn (doesn't delete it).
00687  *
00688  * @param conn the TCP netconn to close
00689  * @return ERR_OK if the netconn was closed, any other err_t on error
00690  */
00691 err_t
00692 netconn_close(struct netconn *conn)
00693 {
00694   /* shutting down both ends is the same as closing */
00695   return netconn_close_shutdown(conn, NETCONN_SHUT_RDWR);
00696 }
00697 
00698 /**
00699  * Shut down one or both sides of a TCP netconn (doesn't delete it).
00700  *
00701  * @param conn the TCP netconn to shut down
00702  * @return ERR_OK if the netconn was closed, any other err_t on error
00703  */
00704 err_t
00705 netconn_shutdown(struct netconn *conn, u8_t shut_rx, u8_t shut_tx)
00706 {
00707   return netconn_close_shutdown(conn, (shut_rx ? NETCONN_SHUT_RD : 0) | (shut_tx ? NETCONN_SHUT_WR : 0));
00708 }
00709 
00710 #if LWIP_IGMP
00711 /**
00712  * Join multicast groups for UDP netconns.
00713  *
00714  * @param conn the UDP netconn for which to change multicast addresses
00715  * @param multiaddr IP address of the multicast group to join or leave
00716  * @param netif_addr the IP address of the network interface on which to send
00717  *                  the igmp message
00718  * @param join_or_leave flag whether to send a join- or leave-message
00719  * @return ERR_OK if the action was taken, any err_t on error
00720  */
00721 err_t
00722 netconn_join_leave_group(struct netconn *conn,
00723                          ip_addr_t *multiaddr,
00724                          ip_addr_t *netif_addr,
00725                          enum netconn_igmp join_or_leave)
00726 {
00727   struct api_msg msg;
00728   err_t err;
00729 
00730   LWIP_ERROR("netconn_join_leave_group: invalid conn",  (conn != NULL), return ERR_ARG;);
00731 
00732   msg.function = do_join_leave_group;
00733   msg.msg.conn = conn;
00734   msg.msg.msg.jl.multiaddr = multiaddr;
00735   msg.msg.msg.jl.netif_addr = netif_addr;
00736   msg.msg.msg.jl.join_or_leave = join_or_leave;
00737   err = TCPIP_APIMSG(&msg);
00738 
00739   NETCONN_SET_SAFE_ERR(conn, err);
00740   return err;
00741 }
00742 #endif /* LWIP_IGMP */
00743 
00744 #if LWIP_DNS
00745 /**
00746  * Execute a DNS query, only one IP address is returned
00747  *
00748  * @param name a string representation of the DNS host name to query
00749  * @param addr a preallocated ip_addr_t where to store the resolved IP address
00750  * @return ERR_OK: resolving succeeded
00751  *         ERR_MEM: memory error, try again later
00752  *         ERR_ARG: dns client not initialized or invalid hostname
00753  *         ERR_VAL: dns server response was invalid
00754  */
00755 err_t
00756 netconn_gethostbyname(const char *name, ip_addr_t *addr)
00757 {
00758   struct dns_api_msg msg;
00759   err_t err;
00760   sys_sem_t sem;
00761 
00762   LWIP_ERROR("netconn_gethostbyname: invalid name", (name != NULL), return ERR_ARG;);
00763   LWIP_ERROR("netconn_gethostbyname: invalid addr", (addr != NULL), return ERR_ARG;);
00764 
00765   err = sys_sem_new(&sem, 0);
00766   if (err != ERR_OK) {
00767     return err;
00768   }
00769 
00770   msg.name = name;
00771   msg.addr = addr;
00772   msg.err = &err;
00773   msg.sem = &sem;
00774 
00775   tcpip_callback(do_gethostbyname, &msg);
00776   sys_sem_wait(&sem);
00777   sys_sem_free(&sem);
00778 
00779   return err;
00780 }
00781 #endif /* LWIP_DNS*/
00782 
00783 #endif /* LWIP_NETCONN */