The UDP socket API code

core/net/ip/udp-socket.c

@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2012-2014, Thingsquare, http://www.thingsquare.com/.
+ * 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. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``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
+ * COPYRIGHT HOLDER OR CONTRIBUTORS 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.
+ *
+ */
+
+#include "contiki-net.h"
+#include "udp-socket.h"
+
+#include <string.h>
+
+PROCESS(udp_socket_process, "UDP socket process");
+
+static uint8_t buf[UIP_BUFSIZE];
+
+#define UIP_IP_BUF   ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
+
+
+/*---------------------------------------------------------------------------*/
+static void
+init(void)
+{
+  static uint8_t inited = 0;
+  if(!inited) {
+    inited = 1;
+    process_start(&udp_socket_process, NULL);
+  }
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_register(struct udp_socket *c,
+                    void *ptr,
+                    udp_socket_input_callback_t input_callback)
+{
+  init();
+
+  if(c == NULL) {
+    return -1;
+  }
+  c->ptr = ptr;
+  c->input_callback = input_callback;
+
+  c->p = PROCESS_CURRENT();
+  PROCESS_CONTEXT_BEGIN(&udp_socket_process);
+  c->udp_conn = udp_new(NULL, 0, c);
+  PROCESS_CONTEXT_END();
+
+  if(c->udp_conn == NULL) {
+    return -1;
+  }
+  return 1;
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_close(struct udp_socket *c)
+{
+  if(c == NULL) {
+    return -1;
+  }
+  if(c->udp_conn != NULL) {
+    uip_udp_remove(c->udp_conn);
+    return 1;
+  }
+  return -1;
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_bind(struct udp_socket *c,
+                uint16_t local_port)
+{
+  if(c == NULL || c->udp_conn == NULL) {
+    return -1;
+  }
+  udp_bind(c->udp_conn, UIP_HTONS(local_port));
+
+  return 1;
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_connect(struct udp_socket *c,
+                   uip_ipaddr_t *remote_addr,
+                   uint16_t remote_port)
+{
+  if(c == NULL || c->udp_conn == NULL) {
+    return -1;
+  }
+
+  if(remote_addr != NULL) {
+    uip_ipaddr_copy(&c->udp_conn->ripaddr, remote_addr);
+  }
+  c->udp_conn->rport = UIP_HTONS(remote_port);
+  return 1;
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_send(struct udp_socket *c,
+                const void *data, uint16_t datalen)
+{
+  if(c == NULL || c->udp_conn == NULL) {
+    return -1;
+  }
+
+  uip_udp_packet_send(c->udp_conn, data, datalen);
+  return datalen;
+}
+/*---------------------------------------------------------------------------*/
+int
+udp_socket_sendto(struct udp_socket *c,
+                  const void *data, uint16_t datalen,
+                  const uip_ipaddr_t *to,
+                  uint16_t port)
+{
+  if(c == NULL || c->udp_conn == NULL) {
+    return -1;
+  }
+
+  if(c->udp_conn != NULL) {
+    uip_udp_packet_sendto(c->udp_conn, data, datalen,
+                          to, UIP_HTONS(port));
+    return datalen;
+  }
+  return -1;
+}
+/*---------------------------------------------------------------------------*/
+PROCESS_THREAD(udp_socket_process, ev, data)
+{
+  struct udp_socket *c;
+  PROCESS_BEGIN();
+
+  while(1) {
+    PROCESS_WAIT_EVENT();
+    if(ev == tcpip_event) {
+
+      /* An appstate pointer is passed to use from the IP stack
+         through the 'data' pointer. We registered this appstate when
+         we did the udp_new() call in udp_socket_register() as the
+         struct udp_socket pointer. So we extract this
+         pointer and use it when calling the reception callback. */
+      c = (struct udp_socket *)data;
+
+      /* Defensive coding: although the appstate *should* be non-null
+         here, we make sure to avoid the program crashing on us. */
+      if(c != NULL) {
+
+        /* If we were called because of incoming data, we should call
+           the reception callback. */
+        if(uip_newdata()) {
+          /* Copy the data from the uIP data buffer into our own
+             buffer to avoid the uIP buffer being messed with by the
+             callee. */
+          memcpy(buf, uip_appdata, uip_datalen());
+
+          /* Call the client process. We use the PROCESS_CONTEXT
+             mechanism to temporarily switch process context to the
+             client process. */
+          if(c->input_callback != NULL) {
+            PROCESS_CONTEXT_BEGIN(c->p);
+            c->input_callback(c, c->ptr,
+                              &(UIP_IP_BUF->srcipaddr),
+                              UIP_HTONS(UIP_IP_BUF->srcport),
+                              &(UIP_IP_BUF->destipaddr),
+                              UIP_HTONS(UIP_IP_BUF->destport),
+                              buf, uip_datalen());
+            PROCESS_CONTEXT_END();
+          }
+        }
+      }
+    }
+  }
+
+  PROCESS_END();
+}
+/*---------------------------------------------------------------------------*/
+/** @} */