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     TCPIP_APIMSG(&msg);
00079 
00080     if (conn->err != ERR_OK) {
00081       LWIP_ASSERT("freeing conn without freeing pcb", conn->pcb.tcp == NULL);
00082       LWIP_ASSERT("conn has no op_completed", conn->op_completed != SYS_SEM_NULL);
00083       LWIP_ASSERT("conn has no recvmbox", conn->recvmbox != SYS_MBOX_NULL);
00084       LWIP_ASSERT("conn->acceptmbox shouldn't exist", conn->acceptmbox == SYS_MBOX_NULL);
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   conn->pcb.tcp = NULL;
00117   netconn_free(conn);
00118 
00119   return ERR_OK;
00120 }
00121 
00122 /**
00123  * Get the type of a netconn (as enum netconn_type).
00124  *
00125  * @param conn the netconn of which to get the type
00126  * @return the netconn_type of conn
00127  */
00128 enum netconn_type
00129 netconn_type(struct netconn *conn)
00130 {
00131   LWIP_ERROR("netconn_type: invalid conn", (conn != NULL), return NETCONN_INVALID;);
00132   return conn->type;
00133 }
00134 
00135 /**
00136  * Get the local or remote IP address and port of a netconn.
00137  * For RAW netconns, this returns the protocol instead of a port!
00138  *
00139  * @param conn the netconn to query
00140  * @param addr a pointer to which to save the IP address
00141  * @param port a pointer to which to save the port (or protocol for RAW)
00142  * @param local 1 to get the local IP address, 0 to get the remote one
00143  * @return ERR_CONN for invalid connections
00144  *         ERR_OK if the information was retrieved
00145  */
00146 err_t
00147 netconn_getaddr(struct netconn *conn, struct ip_addr *addr, u16_t *port, u8_t local)
00148 {
00149   struct api_msg msg;
00150 
00151   LWIP_ERROR("netconn_getaddr: invalid conn", (conn != NULL), return ERR_ARG;);
00152   LWIP_ERROR("netconn_getaddr: invalid addr", (addr != NULL), return ERR_ARG;);
00153   LWIP_ERROR("netconn_getaddr: invalid port", (port != NULL), return ERR_ARG;);
00154 
00155   msg.function = do_getaddr;
00156   msg.msg.conn = conn;
00157   msg.msg.msg.ad.ipaddr = addr;
00158   msg.msg.msg.ad.port = port;
00159   msg.msg.msg.ad.local = local;
00160   TCPIP_APIMSG(&msg);
00161 
00162   return conn->err;
00163 }
00164 
00165 /**
00166  * Bind a netconn to a specific local IP address and port.
00167  * Binding one netconn twice might not always be checked correctly!
00168  *
00169  * @param conn the netconn to bind
00170  * @param addr the local IP address to bind the netconn to (use IP_ADDR_ANY
00171  *             to bind to all addresses)
00172  * @param port the local port to bind the netconn to (not used for RAW)
00173  * @return ERR_OK if bound, any other err_t on failure
00174  */
00175 err_t
00176 netconn_bind(struct netconn *conn, struct ip_addr *addr, u16_t port)
00177 {
00178   struct api_msg msg;
00179 
00180   LWIP_ERROR("netconn_bind: invalid conn", (conn != NULL), return ERR_ARG;);
00181 
00182   msg.function = do_bind;
00183   msg.msg.conn = conn;
00184   msg.msg.msg.bc.ipaddr = addr;
00185   msg.msg.msg.bc.port = port;
00186   TCPIP_APIMSG(&msg);
00187   return conn->err;
00188 }
00189 
00190 /**
00191  * Connect a netconn to a specific remote IP address and port.
00192  *
00193  * @param conn the netconn to connect
00194  * @param addr the remote IP address to connect to
00195  * @param port the remote port to connect to (no used for RAW)
00196  * @return ERR_OK if connected, return value of tcp_/udp_/raw_connect otherwise
00197  */
00198 err_t
00199 netconn_connect(struct netconn *conn, struct ip_addr *addr, u16_t port)
00200 {
00201   struct api_msg msg;
00202 
00203   LWIP_ERROR("netconn_connect: invalid conn", (conn != NULL), return ERR_ARG;);
00204 
00205   msg.function = do_connect;
00206   msg.msg.conn = conn;
00207   msg.msg.msg.bc.ipaddr = addr;
00208   msg.msg.msg.bc.port = port;
00209   /* This is the only function which need to not block tcpip_thread */
00210   tcpip_apimsg(&msg);
00211   return conn->err;
00212 }
00213 
00214 /**
00215  * Disconnect a netconn from its current peer (only valid for UDP netconns).
00216  *
00217  * @param conn the netconn to disconnect
00218  * @return TODO: return value is not set here...
00219  */
00220 err_t
00221 netconn_disconnect(struct netconn *conn)
00222 {
00223   struct api_msg msg;
00224 
00225   LWIP_ERROR("netconn_disconnect: invalid conn", (conn != NULL), return ERR_ARG;);
00226 
00227   msg.function = do_disconnect;
00228   msg.msg.conn = conn;
00229   TCPIP_APIMSG(&msg);
00230   return conn->err;
00231 }
00232 
00233 /**
00234  * Set a TCP netconn into listen mode
00235  *
00236  * @param conn the tcp netconn to set to listen mode
00237  * @param backlog the listen backlog, only used if TCP_LISTEN_BACKLOG==1
00238  * @return ERR_OK if the netconn was set to listen (UDP and RAW netconns
00239  *         don't return any error (yet?))
00240  */
00241 err_t
00242 netconn_listen_with_backlog(struct netconn *conn, u8_t backlog)
00243 {
00244   struct api_msg msg;
00245 
00246   /* This does no harm. If TCP_LISTEN_BACKLOG is off, backlog is unused. */
00247   LWIP_UNUSED_ARG(backlog);
00248 
00249   LWIP_ERROR("netconn_listen: invalid conn", (conn != NULL), return ERR_ARG;);
00250 
00251   msg.function = do_listen;
00252   msg.msg.conn = conn;
00253 #if TCP_LISTEN_BACKLOG
00254   msg.msg.msg.lb.backlog = backlog;
00255 #endif /* TCP_LISTEN_BACKLOG */
00256   TCPIP_APIMSG(&msg);
00257   return conn->err;
00258 }
00259 
00260 /**
00261  * Accept a new connection on a TCP listening netconn.
00262  *
00263  * @param conn the TCP listen netconn
00264  * @return the newly accepted netconn or NULL on timeout
00265  */
00266 struct netconn *
00267 netconn_accept(struct netconn *conn)
00268 {
00269   struct netconn *newconn;
00270 
00271   LWIP_ERROR("netconn_accept: invalid conn",       (conn != NULL),                      return NULL;);
00272   LWIP_ERROR("netconn_accept: invalid acceptmbox", (conn->acceptmbox != SYS_MBOX_NULL), return NULL;);
00273 
00274 #if LWIP_SO_RCVTIMEO
00275   if (sys_arch_mbox_fetch(conn->acceptmbox, (void *)&newconn, conn->recv_timeout) == SYS_ARCH_TIMEOUT) {
00276     newconn = NULL;
00277   } else
00278 #else
00279   sys_arch_mbox_fetch(conn->acceptmbox, (void *)&newconn, 0);
00280 #endif /* LWIP_SO_RCVTIMEO*/
00281   {
00282     /* Register event with callback */
00283     API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0);
00284 
00285 #if TCP_LISTEN_BACKLOG
00286     if (newconn != NULL) {
00287       /* Let the stack know that we have accepted the connection. */
00288       struct api_msg msg;
00289       msg.function = do_recv;
00290       msg.msg.conn = conn;
00291       TCPIP_APIMSG(&msg);
00292     }
00293 #endif /* TCP_LISTEN_BACKLOG */
00294   }
00295 
00296   return newconn;
00297 }
00298 
00299 /**
00300  * Receive data (in form of a netbuf containing a packet buffer) from a netconn
00301  *
00302  * @param conn the netconn from which to receive data
00303  * @return a new netbuf containing received data or NULL on memory error or timeout
00304  */
00305 struct netbuf *
00306 netconn_recv(struct netconn *conn)
00307 {
00308   struct api_msg msg;
00309   struct netbuf *buf = NULL;
00310   struct pbuf *p;
00311   u16_t len;
00312 
00313   LWIP_ERROR("netconn_recv: invalid conn",  (conn != NULL), return NULL;);
00314 
00315   if (conn->recvmbox == SYS_MBOX_NULL) {
00316     /* @todo: should calling netconn_recv on a TCP listen conn be fatal (ERR_CONN)?? */
00317     /* TCP listen conns don't have a recvmbox! */
00318     conn->err = ERR_CONN;
00319     return NULL;
00320   }
00321 
00322   if (ERR_IS_FATAL(conn->err)) {
00323     return NULL;
00324   }
00325 
00326   if (conn->type == NETCONN_TCP) {
00327 #if LWIP_TCP
00328     if (conn->state == NETCONN_LISTEN) {
00329       /* @todo: should calling netconn_recv on a TCP listen conn be fatal?? */
00330       conn->err = ERR_CONN;
00331       return NULL;
00332     }
00333 
00334     buf = memp_malloc(MEMP_NETBUF);
00335 
00336     if (buf == NULL) {
00337       conn->err = ERR_MEM;
00338       return NULL;
00339     }
00340 
00341 #if LWIP_SO_RCVTIMEO
00342     if (sys_arch_mbox_fetch(conn->recvmbox, (void *)&p, conn->recv_timeout)==SYS_ARCH_TIMEOUT) {
00343       conn->err = ERR_TIMEOUT;
00344       p = NULL;
00345     }
00346 #else
00347     sys_arch_mbox_fetch(conn->recvmbox, (void *)&p, 0);
00348 #endif /* LWIP_SO_RCVTIMEO*/
00349 
00350     if (p != NULL) {
00351       len = p->tot_len;
00352       SYS_ARCH_DEC(conn->recv_avail, len);
00353     } else {
00354       len = 0;
00355     }
00356 
00357     /* Register event with callback */
00358     API_EVENT(conn, NETCONN_EVT_RCVMINUS, len);
00359 
00360     /* If we are closed, we indicate that we no longer wish to use the socket */
00361     if (p == NULL) {
00362       memp_free(MEMP_NETBUF, buf);
00363       /* Avoid to lose any previous error code */
00364       if (conn->err == ERR_OK) {
00365         conn->err = ERR_CLSD;
00366       }
00367       return NULL;
00368     }
00369 
00370     buf->p = p;
00371     buf->ptr = p;
00372     buf->port = 0;
00373     buf->addr = NULL;
00374 
00375     /* Let the stack know that we have taken the data. */
00376     msg.function = do_recv;
00377     msg.msg.conn = conn;
00378     if (buf != NULL) {
00379       msg.msg.msg.r.len = buf->p->tot_len;
00380     } else {
00381       msg.msg.msg.r.len = 1;
00382     }
00383     TCPIP_APIMSG(&msg);
00384 #endif /* LWIP_TCP */
00385   } else {
00386 #if (LWIP_UDP || LWIP_RAW)
00387 #if LWIP_SO_RCVTIMEO
00388     if (sys_arch_mbox_fetch(conn->recvmbox, (void *)&buf, conn->recv_timeout)==SYS_ARCH_TIMEOUT) {
00389       buf = NULL;
00390     }
00391 #else
00392     sys_arch_mbox_fetch(conn->recvmbox, (void *)&buf, 0);
00393 #endif /* LWIP_SO_RCVTIMEO*/
00394     if (buf!=NULL) {
00395       SYS_ARCH_DEC(conn->recv_avail, buf->p->tot_len);
00396       /* Register event with callback */
00397       API_EVENT(conn, NETCONN_EVT_RCVMINUS, buf->p->tot_len);
00398     }
00399 #endif /* (LWIP_UDP || LWIP_RAW) */
00400   }
00401 
00402   LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_recv: received %p (err %d)\n", (void *)buf, conn->err));
00403 
00404   return buf;
00405 }
00406 
00407 /**
00408  * Send data (in form of a netbuf) to a specific remote IP address and port.
00409  * Only to be used for UDP and RAW netconns (not TCP).
00410  *
00411  * @param conn the netconn over which to send data
00412  * @param buf a netbuf containing the data to send
00413  * @param addr the remote IP address to which to send the data
00414  * @param port the remote port to which to send the data
00415  * @return ERR_OK if data was sent, any other err_t on error
00416  */
00417 err_t
00418 netconn_sendto(struct netconn *conn, struct netbuf *buf, struct ip_addr *addr, u16_t port)
00419 {
00420   if (buf != NULL) {
00421     buf->addr = addr;
00422     buf->port = port;
00423     return netconn_send(conn, buf);
00424   }
00425   return ERR_VAL;
00426 }
00427 
00428 /**
00429  * Send data over a UDP or RAW netconn (that is already connected).
00430  *
00431  * @param conn the UDP or RAW netconn over which to send data
00432  * @param buf a netbuf containing the data to send
00433  * @return ERR_OK if data was sent, any other err_t on error
00434  */
00435 err_t
00436 netconn_send(struct netconn *conn, struct netbuf *buf)
00437 {
00438   struct api_msg msg;
00439 
00440   LWIP_ERROR("netconn_send: invalid conn",  (conn != NULL), return ERR_ARG;);
00441 
00442   LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_send: sending %d bytes\n", buf->p->tot_len));
00443   msg.function = do_send;
00444   msg.msg.conn = conn;
00445   msg.msg.msg.b = buf;
00446   TCPIP_APIMSG(&msg);
00447   return conn->err;
00448 }
00449 
00450 /**
00451  * Send data over a TCP netconn.
00452  *
00453  * @param conn the TCP netconn over which to send data
00454  * @param dataptr pointer to the application buffer that contains the data to send
00455  * @param size size of the application data to send
00456  * @param apiflags combination of following flags :
00457  * - NETCONN_COPY (0x01) data will be copied into memory belonging to the stack
00458  * - NETCONN_MORE (0x02) for TCP connection, PSH flag will be set on last segment sent
00459  * @return ERR_OK if data was sent, any other err_t on error
00460  */
00461 err_t
00462 netconn_write(struct netconn *conn, const void *dataptr, int size, u8_t apiflags)
00463 {
00464   struct api_msg msg;
00465 
00466   LWIP_ERROR("netconn_write: invalid conn",  (conn != NULL), return ERR_ARG;);
00467   LWIP_ERROR("netconn_write: invalid conn->type",  (conn->type == NETCONN_TCP), return ERR_VAL;);
00468 
00469   msg.function = do_write;
00470   msg.msg.conn = conn;
00471   msg.msg.msg.w.dataptr = dataptr;
00472   msg.msg.msg.w.apiflags = apiflags;
00473   msg.msg.msg.w.len = size;
00474   /* For locking the core: this _can_ be delayed on low memory/low send buffer,
00475      but if it is, this is done inside api_msg.c:do_write(), so we can use the
00476      non-blocking version here. */
00477   TCPIP_APIMSG(&msg);
00478   return conn->err;
00479 }
00480 
00481 /**
00482  * Close a TCP netconn (doesn't delete it).
00483  *
00484  * @param conn the TCP netconn to close
00485  * @return ERR_OK if the netconn was closed, any other err_t on error
00486  */
00487 err_t
00488 netconn_close(struct netconn *conn)
00489 {
00490   struct api_msg msg;
00491 
00492   LWIP_ERROR("netconn_close: invalid conn",  (conn != NULL), return ERR_ARG;);
00493 
00494   msg.function = do_close;
00495   msg.msg.conn = conn;
00496   tcpip_apimsg(&msg);
00497   return conn->err;
00498 }
00499 
00500 #if LWIP_IGMP
00501 /**
00502  * Join multicast groups for UDP netconns.
00503  *
00504  * @param conn the UDP netconn for which to change multicast addresses
00505  * @param multiaddr IP address of the multicast group to join or leave
00506  * @param interface the IP address of the network interface on which to send
00507  *                  the igmp message
00508  * @param join_or_leave flag whether to send a join- or leave-message
00509  * @return ERR_OK if the action was taken, any err_t on error
00510  */
00511 err_t
00512 netconn_join_leave_group(struct netconn *conn,
00513                          struct ip_addr *multiaddr,
00514                          struct ip_addr *interface,
00515                          enum netconn_igmp join_or_leave)
00516 {
00517   struct api_msg msg;
00518 
00519   LWIP_ERROR("netconn_join_leave_group: invalid conn",  (conn != NULL), return ERR_ARG;);
00520 
00521   msg.function = do_join_leave_group;
00522   msg.msg.conn = conn;
00523   msg.msg.msg.jl.multiaddr = multiaddr;
00524   msg.msg.msg.jl.interface = interface;
00525   msg.msg.msg.jl.join_or_leave = join_or_leave;
00526   TCPIP_APIMSG(&msg);
00527   return conn->err;
00528 }
00529 #endif /* LWIP_IGMP */
00530 
00531 #if LWIP_DNS
00532 /**
00533  * Execute a DNS query, only one IP address is returned
00534  *
00535  * @param name a string representation of the DNS host name to query
00536  * @param addr a preallocated struct ip_addr where to store the resolved IP address
00537  * @return ERR_OK: resolving succeeded
00538  *         ERR_MEM: memory error, try again later
00539  *         ERR_ARG: dns client not initialized or invalid hostname
00540  *         ERR_VAL: dns server response was invalid
00541  */
00542 err_t
00543 netconn_gethostbyname(const char *name, struct ip_addr *addr)
00544 {
00545   struct dns_api_msg msg;
00546   err_t err;
00547   sys_sem_t sem;
00548 
00549   LWIP_ERROR("netconn_gethostbyname: invalid name", (name != NULL), return ERR_ARG;);
00550   LWIP_ERROR("netconn_gethostbyname: invalid addr", (addr != NULL), return ERR_ARG;);
00551 
00552   sem = sys_sem_new(0);
00553   if (sem == SYS_SEM_NULL) {
00554     return ERR_MEM;
00555   }
00556 
00557   msg.name = name;
00558   msg.addr = addr;
00559   msg.err = &err;
00560   msg.sem = sem;
00561 
00562   tcpip_callback(do_gethostbyname, &msg);
00563   sys_sem_wait(sem);
00564   sys_sem_free(sem);
00565 
00566   return err;
00567 }
00568 #endif /* LWIP_DNS*/
00569 
00570 #endif /* LWIP_NETCONN */