New feature: Output in SBS format

README.md

@@ -152,6 +152,17 @@ Or alternatively to see what's happening on the screen:
 
 Then you can feed it from different data sources from the internet.
 
+Port 30003
+---
+
+Connected clients are served with messages in SBS1 (BaseStation) format, similar to:
+
+    MSG,4,,,738065,,,,,,,,420,179,,,0,,0,0,0,0
+    MSG,3,,,738065,,,,,,,35000,,,34.81609,34.07810,,,0,0,0,0
+
+This can be used to feed data to various sharing sites without the need to use another decoder.
+
+
 Antenna
 ---
 

TODO

@@ -8,10 +8,3 @@ TODO
   aircraft ICAO address, like: 30xxxx -> Italy.
 * Actually use the fancy --debug feature in order to improve the recognition
   algorithm if possibile.
-* Listen to port 30003 and provide output in the following format, to
-  connected clients:
-
-    Server: Welcome to the adsb-server
-    MSG,3,0,19,4841D9,19,2013/01/05,15:51:45.747,2013/01/05,15:51:45.747,,33700,,,51.8853,-6.2134,,,0,0,0,0
-    MSG,4,0,15,405638,15,2013/01/05,15:51:45.747,2013/01/05,15:51:45.747,,,415,188,,,0,,0,0,0,0
-    ...

dump1090.c

@@ -81,6 +81,7 @@
 #define MODES_INTERACTIVE_TTL 60                /* TTL before being removed */
 
 #define MODES_NET_MAX_FD 1024
+#define MODES_NET_OUTPUT_SBS_PORT 30003
 #define MODES_NET_OUTPUT_RAW_PORT 30002
 #define MODES_NET_INPUT_RAW_PORT 30001
 #define MODES_NET_HTTP_PORT 8080
@@ -144,6 +145,7 @@ struct {
     char aneterr[ANET_ERR_LEN];
     struct client *clients[MODES_NET_MAX_FD]; /* Our clients. */
     int maxfd;                      /* Greatest fd currently active. */
+    int sbsos;                      /* SBS output listening socket. */
     int ros;                        /* Raw output listening socket. */
     int ris;                        /* Raw input listening socket. */
     int https;                      /* HTTP listening socket. */
@@ -156,6 +158,7 @@ struct {
     int debug;                      /* Debugging mode. */
     int net;                        /* Enable networking. */
     int net_only;                   /* Enable just networking. */
+    int net_output_sbs_port;        /* SBS output TCP port. */
     int net_output_raw_port;        /* Raw output TCP port. */
     int net_input_raw_port;         /* Raw input TCP port. */
     int net_http_port;              /* HTTP port. */
@@ -180,6 +183,7 @@ struct {
     long long stat_single_bit_fix;
     long long stat_two_bits_fix;
     long long stat_http_requests;
+    long long stat_sbs_connections;
 } Modes;
 
 /* The struct we use to store information about a decoded message. */
@@ -227,8 +231,9 @@ struct modesMessage {
 };
 
 void interactiveShowData(void);
-void interactiveReceiveData(struct modesMessage *mm);
+struct aircraft* interactiveReceiveData(struct modesMessage *mm);
 void modesSendRawOutput(struct modesMessage *mm);
+void modesSendSBSOutput(struct modesMessage *mm, struct aircraft *a);
 void useModesMessage(struct modesMessage *mm);
 int fixSingleBitErrors(unsigned char *msg, int bits);
 int fixTwoBitsErrors(unsigned char *msg, int bits);
@@ -258,6 +263,7 @@ void modesInitConfig(void) {
     Modes.raw = 0;
     Modes.net = 0;
     Modes.net_only = 0;
+    Modes.net_output_sbs_port = MODES_NET_OUTPUT_SBS_PORT;
     Modes.net_output_raw_port = MODES_NET_OUTPUT_RAW_PORT;
     Modes.net_input_raw_port = MODES_NET_INPUT_RAW_PORT;
     Modes.net_http_port = MODES_NET_HTTP_PORT;
@@ -311,6 +317,7 @@ void modesInit(void) {
     Modes.stat_single_bit_fix = 0;
     Modes.stat_two_bits_fix = 0;
     Modes.stat_http_requests = 0;
+    Modes.stat_sbs_connections = 0;
     Modes.exit = 0;
 }
 
@@ -1369,8 +1376,9 @@ void useModesMessage(struct modesMessage *mm) {
     if (!Modes.stats && (Modes.check_crc == 0 || mm->crcok)) {
         /* Track aircrafts in interactive mode or if the HTTP
          * interface is enabled. */
-        if (Modes.interactive || Modes.stat_http_requests > 0) {
+        if (Modes.interactive || Modes.stat_http_requests > 0 || Modes.stat_sbs_connections > 0) {
-            interactiveReceiveData(mm);
+            struct aircraft *a = interactiveReceiveData(mm);
+            if (a && Modes.stat_sbs_connections > 0) modesSendSBSOutput(mm, a);  /* Feed SBS output clients. */
         }
         /* In non-interactive way, display messages on standard output. */
         if (!Modes.interactive) {
@@ -1552,11 +1560,11 @@ void decodeCPR(struct aircraft *a) {
 }
 
 /* Receive new messages and populate the interactive mode with more info. */
-void interactiveReceiveData(struct modesMessage *mm) {
+struct aircraft *interactiveReceiveData(struct modesMessage *mm) {
     uint32_t addr;
     struct aircraft *a, *aux;
 
-    if (Modes.check_crc && mm->crcok == 0) return;
+    if (Modes.check_crc && mm->crcok == 0) return NULL;
     addr = (mm->aa1 << 16) | (mm->aa2 << 8) | mm->aa3;
 
     /* Loookup our aircraft or create a new one. */
@@ -1615,6 +1623,7 @@ void interactiveReceiveData(struct modesMessage *mm) {
             }
         }
     }
+    return a;
 }
 
 /* Show the currently captured interactive data on screen. */
@@ -1715,17 +1724,18 @@ void modesInitNet(void) {
         char *descr;
         int *socket;
         int port;
-    } services[3] = {
+    } services[4] = {
         {"Raw TCP output", &Modes.ros, Modes.net_output_raw_port},
         {"Raw TCP input", &Modes.ris, Modes.net_input_raw_port},
-        {"HTTP server", &Modes.https, Modes.net_http_port}
+        {"HTTP server", &Modes.https, Modes.net_http_port},
+        {"Basestation TCP output", &Modes.sbsos, Modes.net_output_sbs_port}
     };
     int j;
 
     memset(Modes.clients,0,sizeof(Modes.clients));
     Modes.maxfd = -1;
 
-    for (j = 0; j < 3; j++) {
+    for (j = 0; j < 4; j++) {
         int s = anetTcpServer(Modes.aneterr, services[j].port, NULL);
         if (s == -1) {
             fprintf(stderr, "Error opening the listening port %d (%s): %s\n",
@@ -1746,11 +1756,12 @@ void modesAcceptClients(void) {
     int fd, port;
     unsigned int j;
     struct client *c;
-    int services[3];
+    int services[4];
 
     services[0] = Modes.ros;
     services[1] = Modes.ris;
     services[2] = Modes.https;
+    services[3] = Modes.sbsos;
 
     for (j = 0; j < sizeof(services)/sizeof(int); j++) {
         fd = anetTcpAccept(Modes.aneterr, services[j], NULL, &port);
@@ -1770,6 +1781,8 @@ void modesAcceptClients(void) {
         anetSetSendBuffer(Modes.aneterr,fd,MODES_NET_SNDBUF_SIZE);
 
         if (Modes.maxfd < fd) Modes.maxfd = fd;
+        if (services[j] == Modes.sbsos) Modes.stat_sbs_connections++;
+
         j--; /* Try again with the same listening port. */
 
         if (Modes.debug == MODES_DEBUG_NET)
@@ -1829,6 +1842,48 @@ void modesSendRawOutput(struct modesMessage *mm) {
     modesSendAllClients(Modes.ros, msg, p-msg);
 }
 
+
+/* Write SBS output to TCP clients. */
+void modesSendSBSOutput(struct modesMessage *mm, struct aircraft *a) {
+    char msg[256], *p = msg;
+    int emergency = 0, ground = 0, alert = 0, spi = 0;
+
+    if (mm->msgtype == 4 || mm->msgtype == 5 || mm->msgtype == 21) {
+            if (mm->identity == 7500 || mm->identity == 7600 || mm->identity == 7700) emergency = -1; /* identity is calculated/kept in base10 but is actually octal (07500 is represented as 7500) */
+            if (mm->fs == 1 || mm->fs == 3) ground = -1;
+            if (mm->fs == 2 || mm->fs == 3 || mm->fs == 4) alert = -1;
+            if (mm->fs == 4 || mm->fs == 5) spi = -1;
+        }
+
+    if (mm->msgtype == 0) {
+        p += sprintf(p, "MSG,5,,,%02X%02X%02X,,,,,,,%d,,,,,,,,,,", mm->aa1, mm->aa2, mm->aa3, mm->altitude);
+    } else if (mm->msgtype == 4) {
+        p += sprintf(p, "MSG,5,,,%02X%02X%02X,,,,,,,%d,,,,,,,%d,%d,%d,%d", mm->aa1, mm->aa2, mm->aa3, mm->altitude, alert, emergency, spi, ground);
+    } else if (mm->msgtype == 5) {
+        p += sprintf(p, "MSG,6,,,%02X%02X%02X,,,,,,,,,,,,,%d,%d,%d,%d,%d", mm->aa1, mm->aa2, mm->aa3, mm->identity, alert, emergency, spi, ground);
+    } else if (mm->msgtype == 11) {
+        p += sprintf(p, "MSG,8,,,%02X%02X%02X,,,,,,,,,,,,,,,,,", mm->aa1, mm->aa2, mm->aa3);
+    } else if (mm->msgtype == 17 && mm->metype == 4) {
+        p += sprintf(p, "MSG,1,,,%02X%02X%02X,,,,,,%s,,,,,,,,0,0,0,0", mm->aa1, mm->aa2, mm->aa3, mm->flight);
+    } else if (mm->msgtype == 17 && mm->metype >= 9 && mm->metype <= 18) {
+        if (a->lat == 0 && a->lon == 0)
+            p += sprintf(p, "MSG,3,,,%02X%02X%02X,,,,,,,%d,,,,,,,0,0,0,0", mm->aa1, mm->aa2, mm->aa3, mm->altitude);
+        else
+            p += sprintf(p, "MSG,3,,,%02X%02X%02X,,,,,,,%d,,,%1.5f,%1.5f,,,0,0,0,0", mm->aa1, mm->aa2, mm->aa3, mm->altitude, a->lat, a->lon);
+    } else if (mm->msgtype == 17 && mm->metype == 19 && mm->mesub == 1) {
+        int vr = (mm->vert_rate_sign==0?1:-1) * (mm->vert_rate-1) * 64;
+        p += sprintf(p, "MSG,4,,,%02X%02X%02X,,,,,,,,%d,%d,,,%i,,0,0,0,0", mm->aa1, mm->aa2, mm->aa3, a->speed, a->track, vr);
+    } else if (mm->msgtype == 21) {
+        p += sprintf(p, "MSG,6,,,%02X%02X%02X,,,,,,,,,,,,,%d,%d,%d,%d,%d", mm->aa1, mm->aa2, mm->aa3, mm->identity, alert, emergency, spi, ground);
+    }
+
+    if (msg == p) return; // empty string
+
+    *p++ = '\n';
+
+    modesSendAllClients(Modes.sbsos, msg, p-msg);
+}
+
 /* Turn an hex digit into its 4 bit decimal value.
  * Returns -1 if the digit is not in the 0-F range. */
 int hexDigitVal(int c) {
@@ -2130,6 +2185,7 @@ void showHelp(void) {
 "--net-ro-port <port>     TCP listening port for raw output (default: 30002).\n"
 "--net-ri-port <port>     TCP listening port for raw input (default: 30001).\n"
 "--net-http-port <port>   HTTP server port (default: 8080).\n"
+"--net-sbs-port <port>    TCP listening port for BaseStation format output (default: 30003).\n"
 "--no-fix                 Disable single-bits error correction using CRC.\n"
 "--no-crc-check           Disable messages with broken CRC (discouraged).\n"
 "--aggressive             More CPU for more messages (two bits fixes, ...).\n"
@@ -2199,6 +2255,8 @@ int main(int argc, char **argv) {
             Modes.net_input_raw_port = atoi(argv[++j]);
         } else if (!strcmp(argv[j],"--net-http-port") && more) {
             Modes.net_http_port = atoi(argv[++j]);
+        } else if (!strcmp(argv[j],"--net-sbs-port") && more) {
+            Modes.net_output_sbs_port = atoi(argv[++j]);
         } else if (!strcmp(argv[j],"--onlyaddr")) {
             Modes.onlyaddr = 1;
         } else if (!strcmp(argv[j],"--metric")) {