Add UDP audio output for Linux

src/audio.c

@@ -75,6 +75,7 @@
 #include <sys/socket.h>
 #include <arpa/inet.h>
 #include <netinet/in.h>
+#include <netdb.h>
 #include <errno.h>
 
 
@@ -131,7 +132,9 @@ static struct adev_s {
 	enum audio_in_type_e g_audio_in_type;
 	enum audio_out_type_e g_audio_out_type;
 
-	int udp_sock;			/* UDP socket for receiving data */
+	int udp_in_sock;			/* UDP socket for receiving data */
+	int udp_out_sock;			/* UDP socket for sending data */
+	struct sockaddr_storage udp_dest_addr;	/* Destination address for UDP socket sending */
 
 } adev[MAX_ADEVS];
 
@@ -239,7 +242,7 @@ int audio_open (struct audio_s *pa)
 #else
 	  adev[a].oss_audio_device_fd = -1;
 #endif
-	  adev[a].udp_sock = -1;
+	  adev[a].udp_in_sock = -1;
 	}
 
 
@@ -413,7 +416,7 @@ int audio_open (struct audio_s *pa)
 	          //int data_size = 0;
 
 	          //Create UDP Socket
-	          if ((adev[a].udp_sock=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1) {
+	          if ((adev[a].udp_in_sock=socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP))==-1) {
 	            text_color_set(DW_COLOR_ERROR);
 	            dw_printf ("Couldn't create socket, errno %d\n", errno);
 	            return -1;
@@ -425,7 +428,7 @@ int audio_open (struct audio_s *pa)
 	          si_me.sin_addr.s_addr = htonl(INADDR_ANY);
 
 	          //Bind to the socket
-	          if (bind(adev[a].udp_sock, (const struct sockaddr *) &si_me, sizeof(si_me))==-1) {
+	          if (bind(adev[a].udp_in_sock, (const struct sockaddr *) &si_me, sizeof(si_me))==-1) {
 	            text_color_set(DW_COLOR_ERROR);
 	            dw_printf ("Couldn't bind socket, errno %d\n", errno);
 	            return -1;
@@ -454,7 +457,7 @@ int audio_open (struct audio_s *pa)
   	    }
 
 /*
- * Output device.  Only "soundcard" and "stdout" are supported at this time.
+ * Output device.  Soundcard, stdout, and UDP are supported at this time.
  */
 	    if (strcasecmp(pa->adev[a].adevice_out, "stdout") == 0 || strcmp(pa->adev[a].adevice_out, "-") == 0) {
 	      adev[a].g_audio_out_type = AUDIO_OUT_TYPE_STDOUT;
@@ -463,6 +466,16 @@ int audio_open (struct audio_s *pa)
 	        dw_printf ("stdout must only be used with the -O option\n");
 	        return (-1);
 	      }
+	    } else if (strncasecmp(pa->adev[a].adevice_out, "udp:", 4) == 0) {
+	      adev[a].g_audio_out_type = AUDIO_OUT_TYPE_SDR_UDP;
+	      /* User must supply address and port */
+	      if (strcasecmp(pa->adev[a].adevice_out,"udp:") == 0 ||
+	          strlen(pa->adev[a].adevice_out) < 7 ||
+	          strstr(pa->adev[a].adevice_out+5, ":") == 0) {
+	        text_color_set (DW_COLOR_ERROR);
+	        dw_printf ("Destination address and port must be supplied for UDP output\n");
+	        return (-1);
+	      }
 	    } else {
 	      adev[a].g_audio_out_type = AUDIO_OUT_TYPE_SOUNDCARD;
 	    }
@@ -514,7 +527,63 @@ int audio_open (struct audio_s *pa)
 	          audio_out_name);
 	          return (-1);
 	        }
+		break;
 #endif
+
+	      case AUDIO_OUT_TYPE_SDR_UDP:;
+
+	        struct addrinfo ai_out;
+	        struct addrinfo *ai_res;
+	        char udp_outhost[256];
+	        char *udp_outport;
+	        int res;
+
+	        // Initialize structure for addrinfo restrictions
+	        memset((char *) &ai_out, 0, sizeof(ai_out));
+	        ai_out.ai_socktype = SOCK_DGRAM;
+	        ai_out.ai_protocol = IPPROTO_UDP;
+
+	        // Separate out the host and port strings
+	        strncpy(udp_outhost, pa->adev[a].adevice_out+4, 255);
+	        udp_outhost[255] = 0;
+	        udp_outport = strstr(udp_outhost,":");
+	        *udp_outport++ = 0;
+
+	        if (strlen(udp_outport) == 0) {
+	          text_color_set(DW_COLOR_ERROR);
+	          dw_printf ("UDP output destination port must be supplied\n");
+	          return -1;
+	        }
+
+	        // Get the sockaddr to represent the host/port provided
+	        res = getaddrinfo(udp_outhost, udp_outport, &ai_out, &ai_res);
+	        if (res != 0) {
+	          text_color_set(DW_COLOR_ERROR);
+	          dw_printf ("Error parsing/resolving UDP output address\n");
+	          return -1;
+	        }
+
+	        // IPv4 and IPv6 structs are different sizes
+	        if (ai_res->ai_family == AF_INET6) {
+	          res = sizeof(struct sockaddr_in6);
+	        } else {
+	           res = sizeof(struct sockaddr_in);
+	        }
+
+	        //Create UDP Socket for the right address family
+	        if ((adev[a].udp_out_sock=socket(ai_res->ai_family, SOCK_DGRAM, IPPROTO_UDP))==-1) {
+	          text_color_set(DW_COLOR_ERROR);
+	          dw_printf ("Couldn't create socket, errno %d\n", errno);
+	          return -1;
+	        }
+
+	        // Save sockaddr needed later to send the data and set buffer size
+	        memcpy(&adev[a].udp_dest_addr, ai_res->ai_addr, res);
+	        adev[a].outbuf_size_in_bytes = SDR_UDP_BUF_MAXLEN;
+	        freeaddrinfo(ai_res);
+
+	        break;
+
 	    }
 /*
  * Finally allocate buffer for each direction.
@@ -1222,8 +1291,8 @@ int audio_get (int a)
 	    while (adev[a].inbuf_next >= adev[a].inbuf_len) {
 	      int res;
 
-              assert (adev[a].udp_sock > 0);
-	      res = recv(adev[a].udp_sock, adev[a].inbuf_ptr, adev[a].inbuf_size_in_bytes, 0);
+              assert (adev[a].udp_in_sock > 0);
+	      res = recv(adev[a].udp_in_sock, adev[a].inbuf_ptr, adev[a].inbuf_size_in_bytes, 0);
 	      if (res < 0) {
 	        text_color_set(DW_COLOR_ERROR);
 	        dw_printf ("Can't read from udp socket, res=%d", res);
@@ -1350,11 +1419,12 @@ int audio_put (int a, int c)
 
 int audio_flush (int a)
 {
+	int res;
+	unsigned char *ptr;
+	int len;
+
 	switch (adev[a].g_audio_out_type) {
 	  case AUDIO_OUT_TYPE_STDOUT:;
-	    int res;
-	    unsigned char *ptr;
-	    int len;
 
 	    ptr = adev[a].outbuf_ptr;
 	    len = adev[a].outbuf_len;
@@ -1544,6 +1614,32 @@ int audio_flush (int a)
 	    adev[a].outbuf_len = 0;
 	    return (0);
 #endif
+
+	  case AUDIO_OUT_TYPE_SDR_UDP:;
+
+	    ptr = adev[a].outbuf_ptr;
+	    len = adev[a].outbuf_len;
+
+	    while (len > 0) {
+
+	      assert (adev[a].udp_out_sock > 0);
+
+	      res = sendto(adev[a].udp_out_sock, adev[a].outbuf_ptr, len, 0, (struct sockaddr *)&adev[a].udp_dest_addr, sizeof(struct sockaddr_storage));
+
+	      if (res <= 0) {
+	        text_color_set(DW_COLOR_INFO);
+	        dw_printf ("\nError %d writing to UDP socket.  Exiting.\n", errno);
+	        exit (0);
+	      }
+
+	      ptr += res;
+	      len -= res;
+
+	    }
+
+	    adev[a].outbuf_len = 0;
+	    return 0;
+
 	}
 	return (0);
 } /* end audio_flush */
@@ -1589,7 +1685,7 @@ void audio_wait (int a)
 {	
 	audio_flush (a);
 
-	if (adev[a].g_audio_out_type == AUDIO_OUT_TYPE_STDOUT) {
+	if (adev[a].g_audio_out_type != AUDIO_OUT_TYPE_SOUNDCARD) {
 	  return;
 	}
 

src/audio.h

@@ -45,6 +45,7 @@ enum audio_in_type_e {
 
 enum audio_out_type_e {
 	AUDIO_OUT_TYPE_SOUNDCARD,
+	AUDIO_OUT_TYPE_SDR_UDP,
 	AUDIO_OUT_TYPE_STDOUT };
 
 /* For option to try fixing frames with bad CRC. */