wip
Dependents: EthernetInterface_vz
Fork of lwip by
Diff: api/api_lib.c
- Revision:
- 0:51ac1d130fd4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/api/api_lib.c Fri Jun 22 09:25:39 2012 +0000 @@ -0,0 +1,740 @@ +/** + * @file + * Sequential API External module + * + */ + +/* + * 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> + * + */ + +/* This is the part of the API that is linked with + the application */ + +#include "lwip/opt.h" + +#if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */ + +#include "lwip/api.h" +#include "lwip/tcpip.h" +#include "lwip/memp.h" + +#include "lwip/ip.h" +#include "lwip/raw.h" +#include "lwip/udp.h" +#include "lwip/tcp.h" + +#include <string.h> + +/** + * Create a new netconn (of a specific type) that has a callback function. + * The corresponding pcb is also created. + * + * @param t the type of 'connection' to create (@see enum netconn_type) + * @param proto the IP protocol for RAW IP pcbs + * @param callback a function to call on status changes (RX available, TX'ed) + * @return a newly allocated struct netconn or + * NULL on memory error + */ +struct netconn* +netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto, netconn_callback callback) +{ + struct netconn *conn; + struct api_msg msg; + + conn = netconn_alloc(t, callback); + if (conn != NULL) { + msg.function = do_newconn; + msg.msg.msg.n.proto = proto; + msg.msg.conn = conn; + if (TCPIP_APIMSG(&msg) != ERR_OK) { + LWIP_ASSERT("freeing conn without freeing pcb", conn->pcb.tcp == NULL); + LWIP_ASSERT("conn has no op_completed", sys_sem_valid(&conn->op_completed)); + LWIP_ASSERT("conn has no recvmbox", sys_mbox_valid(&conn->recvmbox)); +#if LWIP_TCP + LWIP_ASSERT("conn->acceptmbox shouldn't exist", !sys_mbox_valid(&conn->acceptmbox)); +#endif /* LWIP_TCP */ + sys_sem_free(&conn->op_completed); + sys_mbox_free(&conn->recvmbox); + memp_free(MEMP_NETCONN, conn); + return NULL; + } + } + return conn; +} + +/** + * Close a netconn 'connection' and free its resources. + * UDP and RAW connection are completely closed, TCP pcbs might still be in a waitstate + * after this returns. + * + * @param conn the netconn to delete + * @return ERR_OK if the connection was deleted + */ +err_t +netconn_delete(struct netconn *conn) +{ + struct api_msg msg; + + /* No ASSERT here because possible to get a (conn == NULL) if we got an accept error */ + if (conn == NULL) { + return ERR_OK; + } + + msg.function = do_delconn; + msg.msg.conn = conn; + tcpip_apimsg(&msg); + + netconn_free(conn); + + /* don't care for return value of do_delconn since it only calls void functions */ + + return ERR_OK; +} + +/** + * Get the local or remote IP address and port of a netconn. + * For RAW netconns, this returns the protocol instead of a port! + * + * @param conn the netconn to query + * @param addr a pointer to which to save the IP address + * @param port a pointer to which to save the port (or protocol for RAW) + * @param local 1 to get the local IP address, 0 to get the remote one + * @return ERR_CONN for invalid connections + * ERR_OK if the information was retrieved + */ +err_t +netconn_getaddr(struct netconn *conn, ip_addr_t *addr, u16_t *port, u8_t local) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_getaddr: invalid conn", (conn != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_getaddr: invalid addr", (addr != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_getaddr: invalid port", (port != NULL), return ERR_ARG;); + + msg.function = do_getaddr; + msg.msg.conn = conn; + msg.msg.msg.ad.ipaddr = addr; + msg.msg.msg.ad.port = port; + msg.msg.msg.ad.local = local; + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Bind a netconn to a specific local IP address and port. + * Binding one netconn twice might not always be checked correctly! + * + * @param conn the netconn to bind + * @param addr the local IP address to bind the netconn to (use IP_ADDR_ANY + * to bind to all addresses) + * @param port the local port to bind the netconn to (not used for RAW) + * @return ERR_OK if bound, any other err_t on failure + */ +err_t +netconn_bind(struct netconn *conn, ip_addr_t *addr, u16_t port) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_bind: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_bind; + msg.msg.conn = conn; + msg.msg.msg.bc.ipaddr = addr; + msg.msg.msg.bc.port = port; + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Connect a netconn to a specific remote IP address and port. + * + * @param conn the netconn to connect + * @param addr the remote IP address to connect to + * @param port the remote port to connect to (no used for RAW) + * @return ERR_OK if connected, return value of tcp_/udp_/raw_connect otherwise + */ +err_t +netconn_connect(struct netconn *conn, ip_addr_t *addr, u16_t port) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_connect: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_connect; + msg.msg.conn = conn; + msg.msg.msg.bc.ipaddr = addr; + msg.msg.msg.bc.port = port; + /* This is the only function which need to not block tcpip_thread */ + err = tcpip_apimsg(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Disconnect a netconn from its current peer (only valid for UDP netconns). + * + * @param conn the netconn to disconnect + * @return TODO: return value is not set here... + */ +err_t +netconn_disconnect(struct netconn *conn) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_disconnect: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_disconnect; + msg.msg.conn = conn; + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Set a TCP netconn into listen mode + * + * @param conn the tcp netconn to set to listen mode + * @param backlog the listen backlog, only used if TCP_LISTEN_BACKLOG==1 + * @return ERR_OK if the netconn was set to listen (UDP and RAW netconns + * don't return any error (yet?)) + */ +err_t +netconn_listen_with_backlog(struct netconn *conn, u8_t backlog) +{ +#if LWIP_TCP + struct api_msg msg; + err_t err; + + /* This does no harm. If TCP_LISTEN_BACKLOG is off, backlog is unused. */ + LWIP_UNUSED_ARG(backlog); + + LWIP_ERROR("netconn_listen: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_listen; + msg.msg.conn = conn; +#if TCP_LISTEN_BACKLOG + msg.msg.msg.lb.backlog = backlog; +#endif /* TCP_LISTEN_BACKLOG */ + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +#else /* LWIP_TCP */ + LWIP_UNUSED_ARG(conn); + LWIP_UNUSED_ARG(backlog); + return ERR_ARG; +#endif /* LWIP_TCP */ +} + +/** + * Accept a new connection on a TCP listening netconn. + * + * @param conn the TCP listen netconn + * @param new_conn pointer where the new connection is stored + * @return ERR_OK if a new connection has been received or an error + * code otherwise + */ +err_t +netconn_accept(struct netconn *conn, struct netconn **new_conn) +{ +#if LWIP_TCP + struct netconn *newconn; + err_t err; +#if TCP_LISTEN_BACKLOG + struct api_msg msg; +#endif /* TCP_LISTEN_BACKLOG */ + + LWIP_ERROR("netconn_accept: invalid pointer", (new_conn != NULL), return ERR_ARG;); + *new_conn = NULL; + LWIP_ERROR("netconn_accept: invalid conn", (conn != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_accept: invalid acceptmbox", sys_mbox_valid(&conn->acceptmbox), return ERR_ARG;); + + err = conn->last_err; + if (ERR_IS_FATAL(err)) { + /* don't recv on fatal errors: this might block the application task + waiting on acceptmbox forever! */ + return err; + } + +#if LWIP_SO_RCVTIMEO + if (sys_arch_mbox_fetch(&conn->acceptmbox, (void **)&newconn, conn->recv_timeout) == SYS_ARCH_TIMEOUT) { + NETCONN_SET_SAFE_ERR(conn, ERR_TIMEOUT); + return ERR_TIMEOUT; + } +#else + sys_arch_mbox_fetch(&conn->acceptmbox, (void **)&newconn, 0); +#endif /* LWIP_SO_RCVTIMEO*/ + /* Register event with callback */ + API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0); + + if (newconn == NULL) { + /* connection has been aborted */ + NETCONN_SET_SAFE_ERR(conn, ERR_ABRT); + return ERR_ABRT; + } +#if TCP_LISTEN_BACKLOG + /* Let the stack know that we have accepted the connection. */ + msg.function = do_recv; + msg.msg.conn = conn; + /* don't care for the return value of do_recv */ + TCPIP_APIMSG(&msg); +#endif /* TCP_LISTEN_BACKLOG */ + + *new_conn = newconn; + /* don't set conn->last_err: it's only ERR_OK, anyway */ + return ERR_OK; +#else /* LWIP_TCP */ + LWIP_UNUSED_ARG(conn); + LWIP_UNUSED_ARG(new_conn); + return ERR_ARG; +#endif /* LWIP_TCP */ +} + +/** + * Receive data: actual implementation that doesn't care whether pbuf or netbuf + * is received + * + * @param conn the netconn from which to receive data + * @param new_buf pointer where a new pbuf/netbuf is stored when received data + * @return ERR_OK if data has been received, an error code otherwise (timeout, + * memory error or another error) + */ +static err_t +netconn_recv_data(struct netconn *conn, void **new_buf) +{ + void *buf = NULL; + u16_t len; + err_t err; +#if LWIP_TCP + struct api_msg msg; +#endif /* LWIP_TCP */ + + LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;); + *new_buf = NULL; + LWIP_ERROR("netconn_recv: invalid conn", (conn != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_accept: invalid recvmbox", sys_mbox_valid(&conn->recvmbox), return ERR_CONN;); + + err = conn->last_err; + if (ERR_IS_FATAL(err)) { + /* don't recv on fatal errors: this might block the application task + waiting on recvmbox forever! */ + /* @todo: this does not allow us to fetch data that has been put into recvmbox + before the fatal error occurred - is that a problem? */ + return err; + } + +#if LWIP_SO_RCVTIMEO + if (sys_arch_mbox_fetch(&conn->recvmbox, &buf, conn->recv_timeout) == SYS_ARCH_TIMEOUT) { + NETCONN_SET_SAFE_ERR(conn, ERR_TIMEOUT); + return ERR_TIMEOUT; + } +#else + sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0); +#endif /* LWIP_SO_RCVTIMEO*/ + +#if LWIP_TCP + if (conn->type == NETCONN_TCP) { + if (!netconn_get_noautorecved(conn) || (buf == NULL)) { + /* Let the stack know that we have taken the data. */ + /* TODO: Speedup: Don't block and wait for the answer here + (to prevent multiple thread-switches). */ + msg.function = do_recv; + msg.msg.conn = conn; + if (buf != NULL) { + msg.msg.msg.r.len = ((struct pbuf *)buf)->tot_len; + } else { + msg.msg.msg.r.len = 1; + } + /* don't care for the return value of do_recv */ + TCPIP_APIMSG(&msg); + } + + /* If we are closed, we indicate that we no longer wish to use the socket */ + if (buf == NULL) { + API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0); + /* Avoid to lose any previous error code */ + NETCONN_SET_SAFE_ERR(conn, ERR_CLSD); + return ERR_CLSD; + } + len = ((struct pbuf *)buf)->tot_len; + } +#endif /* LWIP_TCP */ +#if LWIP_TCP && (LWIP_UDP || LWIP_RAW) + else +#endif /* LWIP_TCP && (LWIP_UDP || LWIP_RAW) */ +#if (LWIP_UDP || LWIP_RAW) + { + LWIP_ASSERT("buf != NULL", buf != NULL); + len = netbuf_len((struct netbuf *)buf); + } +#endif /* (LWIP_UDP || LWIP_RAW) */ + +#if LWIP_SO_RCVBUF + SYS_ARCH_DEC(conn->recv_avail, len); +#endif /* LWIP_SO_RCVBUF */ + /* Register event with callback */ + API_EVENT(conn, NETCONN_EVT_RCVMINUS, len); + + LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_recv_data: received %p, len=%"U16_F"\n", buf, len)); + + *new_buf = buf; + /* don't set conn->last_err: it's only ERR_OK, anyway */ + return ERR_OK; +} + +/** + * Receive data (in form of a pbuf) from a TCP netconn + * + * @param conn the netconn from which to receive data + * @param new_buf pointer where a new pbuf is stored when received data + * @return ERR_OK if data has been received, an error code otherwise (timeout, + * memory error or another error) + * ERR_ARG if conn is not a TCP netconn + */ +err_t +netconn_recv_tcp_pbuf(struct netconn *conn, struct pbuf **new_buf) +{ + LWIP_ERROR("netconn_recv: invalid conn", (conn != NULL) && + netconn_type(conn) == NETCONN_TCP, return ERR_ARG;); + + return netconn_recv_data(conn, (void **)new_buf); +} + +/** + * Receive data (in form of a netbuf containing a packet buffer) from a netconn + * + * @param conn the netconn from which to receive data + * @param new_buf pointer where a new netbuf is stored when received data + * @return ERR_OK if data has been received, an error code otherwise (timeout, + * memory error or another error) + */ +err_t +netconn_recv(struct netconn *conn, struct netbuf **new_buf) +{ +#if LWIP_TCP + struct netbuf *buf = NULL; + err_t err; +#endif /* LWIP_TCP */ + + LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;); + *new_buf = NULL; + LWIP_ERROR("netconn_recv: invalid conn", (conn != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_accept: invalid recvmbox", sys_mbox_valid(&conn->recvmbox), return ERR_CONN;); + +#if LWIP_TCP + if (conn->type == NETCONN_TCP) { + struct pbuf *p = NULL; + /* This is not a listening netconn, since recvmbox is set */ + + buf = (struct netbuf *)memp_malloc(MEMP_NETBUF); + if (buf == NULL) { + NETCONN_SET_SAFE_ERR(conn, ERR_MEM); + return ERR_MEM; + } + + err = netconn_recv_data(conn, (void **)&p); + if (err != ERR_OK) { + memp_free(MEMP_NETBUF, buf); + return err; + } + LWIP_ASSERT("p != NULL", p != NULL); + + buf->p = p; + buf->ptr = p; + buf->port = 0; + ip_addr_set_any(&buf->addr); + *new_buf = buf; + /* don't set conn->last_err: it's only ERR_OK, anyway */ + return ERR_OK; + } else +#endif /* LWIP_TCP */ + { +#if (LWIP_UDP || LWIP_RAW) + return netconn_recv_data(conn, (void **)new_buf); +#endif /* (LWIP_UDP || LWIP_RAW) */ + } +} + +/** + * TCP: update the receive window: by calling this, the application + * tells the stack that it has processed data and is able to accept + * new data. + * ATTENTION: use with care, this is mainly used for sockets! + * Can only be used when calling netconn_set_noautorecved(conn, 1) before. + * + * @param conn the netconn for which to update the receive window + * @param length amount of data processed (ATTENTION: this must be accurate!) + */ +void +netconn_recved(struct netconn *conn, u32_t length) +{ +#if LWIP_TCP + if ((conn != NULL) && (conn->type == NETCONN_TCP) && + (netconn_get_noautorecved(conn))) { + struct api_msg msg; + /* Let the stack know that we have taken the data. */ + /* TODO: Speedup: Don't block and wait for the answer here + (to prevent multiple thread-switches). */ + msg.function = do_recv; + msg.msg.conn = conn; + msg.msg.msg.r.len = length; + /* don't care for the return value of do_recv */ + TCPIP_APIMSG(&msg); + } +#else /* LWIP_TCP */ + LWIP_UNUSED_ARG(conn); + LWIP_UNUSED_ARG(length); +#endif /* LWIP_TCP */ +} + +/** + * Send data (in form of a netbuf) to a specific remote IP address and port. + * Only to be used for UDP and RAW netconns (not TCP). + * + * @param conn the netconn over which to send data + * @param buf a netbuf containing the data to send + * @param addr the remote IP address to which to send the data + * @param port the remote port to which to send the data + * @return ERR_OK if data was sent, any other err_t on error + */ +err_t +netconn_sendto(struct netconn *conn, struct netbuf *buf, ip_addr_t *addr, u16_t port) +{ + if (buf != NULL) { + ip_addr_set(&buf->addr, addr); + buf->port = port; + return netconn_send(conn, buf); + } + return ERR_VAL; +} + +/** + * Send data over a UDP or RAW netconn (that is already connected). + * + * @param conn the UDP or RAW netconn over which to send data + * @param buf a netbuf containing the data to send + * @return ERR_OK if data was sent, any other err_t on error + */ +err_t +netconn_send(struct netconn *conn, struct netbuf *buf) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_send: invalid conn", (conn != NULL), return ERR_ARG;); + + LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_send: sending %"U16_F" bytes\n", buf->p->tot_len)); + msg.function = do_send; + msg.msg.conn = conn; + msg.msg.msg.b = buf; + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Send data over a TCP netconn. + * + * @param conn the TCP netconn over which to send data + * @param dataptr pointer to the application buffer that contains the data to send + * @param size size of the application data to send + * @param apiflags combination of following flags : + * - NETCONN_COPY: data will be copied into memory belonging to the stack + * - NETCONN_MORE: for TCP connection, PSH flag will be set on last segment sent + * - NETCONN_DONTBLOCK: only write the data if all dat can be written at once + * @return ERR_OK if data was sent, any other err_t on error + */ +err_t +netconn_write(struct netconn *conn, const void *dataptr, size_t size, u8_t apiflags) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_write: invalid conn", (conn != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_write: invalid conn->type", (conn->type == NETCONN_TCP), return ERR_VAL;); + if (size == 0) { + return ERR_OK; + } + + /* @todo: for non-blocking write, check if 'size' would ever fit into + snd_queue or snd_buf */ + msg.function = do_write; + msg.msg.conn = conn; + msg.msg.msg.w.dataptr = dataptr; + msg.msg.msg.w.apiflags = apiflags; + msg.msg.msg.w.len = size; + /* For locking the core: this _can_ be delayed on low memory/low send buffer, + but if it is, this is done inside api_msg.c:do_write(), so we can use the + non-blocking version here. */ + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Close ot shutdown a TCP netconn (doesn't delete it). + * + * @param conn the TCP netconn to close or shutdown + * @param how fully close or only shutdown one side? + * @return ERR_OK if the netconn was closed, any other err_t on error + */ +static err_t +netconn_close_shutdown(struct netconn *conn, u8_t how) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_close: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_close; + msg.msg.conn = conn; + /* shutting down both ends is the same as closing */ + msg.msg.msg.sd.shut = how; + /* because of the LWIP_TCPIP_CORE_LOCKING implementation of do_close, + don't use TCPIP_APIMSG here */ + err = tcpip_apimsg(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} + +/** + * Close a TCP netconn (doesn't delete it). + * + * @param conn the TCP netconn to close + * @return ERR_OK if the netconn was closed, any other err_t on error + */ +err_t +netconn_close(struct netconn *conn) +{ + /* shutting down both ends is the same as closing */ + return netconn_close_shutdown(conn, NETCONN_SHUT_RDWR); +} + +/** + * Shut down one or both sides of a TCP netconn (doesn't delete it). + * + * @param conn the TCP netconn to shut down + * @return ERR_OK if the netconn was closed, any other err_t on error + */ +err_t +netconn_shutdown(struct netconn *conn, u8_t shut_rx, u8_t shut_tx) +{ + return netconn_close_shutdown(conn, (shut_rx ? NETCONN_SHUT_RD : 0) | (shut_tx ? NETCONN_SHUT_WR : 0)); +} + +#if LWIP_IGMP +/** + * Join multicast groups for UDP netconns. + * + * @param conn the UDP netconn for which to change multicast addresses + * @param multiaddr IP address of the multicast group to join or leave + * @param netif_addr the IP address of the network interface on which to send + * the igmp message + * @param join_or_leave flag whether to send a join- or leave-message + * @return ERR_OK if the action was taken, any err_t on error + */ +err_t +netconn_join_leave_group(struct netconn *conn, + ip_addr_t *multiaddr, + ip_addr_t *netif_addr, + enum netconn_igmp join_or_leave) +{ + struct api_msg msg; + err_t err; + + LWIP_ERROR("netconn_join_leave_group: invalid conn", (conn != NULL), return ERR_ARG;); + + msg.function = do_join_leave_group; + msg.msg.conn = conn; + msg.msg.msg.jl.multiaddr = multiaddr; + msg.msg.msg.jl.netif_addr = netif_addr; + msg.msg.msg.jl.join_or_leave = join_or_leave; + err = TCPIP_APIMSG(&msg); + + NETCONN_SET_SAFE_ERR(conn, err); + return err; +} +#endif /* LWIP_IGMP */ + +#if LWIP_DNS +/** + * Execute a DNS query, only one IP address is returned + * + * @param name a string representation of the DNS host name to query + * @param addr a preallocated ip_addr_t where to store the resolved IP address + * @return ERR_OK: resolving succeeded + * ERR_MEM: memory error, try again later + * ERR_ARG: dns client not initialized or invalid hostname + * ERR_VAL: dns server response was invalid + */ +err_t +netconn_gethostbyname(const char *name, ip_addr_t *addr) +{ + struct dns_api_msg msg; + err_t err; + sys_sem_t sem; + + LWIP_ERROR("netconn_gethostbyname: invalid name", (name != NULL), return ERR_ARG;); + LWIP_ERROR("netconn_gethostbyname: invalid addr", (addr != NULL), return ERR_ARG;); + + err = sys_sem_new(&sem, 0); + if (err != ERR_OK) { + return err; + } + + msg.name = name; + msg.addr = addr; + msg.err = &err; + msg.sem = &sem; + + tcpip_callback(do_gethostbyname, &msg); + sys_sem_wait(&sem); + sys_sem_free(&sem); + + return err; +} +#endif /* LWIP_DNS*/ + +#endif /* LWIP_NETCONN */