Experimental code for sending hexified binary over the control channel.

6 files changed, 33 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 83e982c9..4e21c040 100644
--- a/NEWS
+++ b/NEWS
@@ -8,7 +8,8 @@
   gpsd_hexdump to save CPU. Lots of little fixes to various packet
   parsers. Always keep the device open: "-n" is not optional any
   more. xgpsspeed no longer depends on Motif.  gpsctl can now ship
-  arbitrary payloads to a device.
+  arbitrary payloads to a device. It's possible to send binary through the
+  control channel with the new & command.
 
 * Sun Feb 17 2008 Chris Kuethe <ckuethe@mail.berlios.de> - 2.37
   The C++ bindings, Garmin USB support, and multiple instances of ntp
diff --git a/gpsd.c b/gpsd.c
index 94311a9a..4a739dbd 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -1266,6 +1266,27 @@ static void handle_control(int sfd, char *buf)
 		assert(write(sfd, "ERROR\n", 6) != -1);
 	    }
 	}
+    } else if (buf[0] == '&') {
+	size_t len;
+	p = snarfline(buf+1, &stash);
+	eq = strchr(stash, '=');
+	if (eq == NULL) {
+	    gpsd_report(LOG_WARN,"<= control(%d): ill-formed command \n", sfd);
+	    assert(write(sfd, "ERROR\n", 6) != -1);
+	} else {
+	    *eq++ = '\0';
+	    len = strlen(eq)+5;
+	    if ((chp = find_device(stash)) != NULL) {
+		gpsd_report(LOG_INF,"<= control(%d): writing fromhex(%s) to %s\n", sfd, eq, stash);
+		/* NOTE: this destroys the original buffer contents */
+		len = gpsd_hexpack(eq, eq, len);
+		assert(write(chp->gpsdata.gps_fd, eq, len) != 1);
+		assert(write(sfd, "OK\n", 3) != -1);
+	    } else {
+		gpsd_report(LOG_INF,"<= control(%d): %s not active \n", sfd, stash);
+		assert(write(sfd, "ERROR\n", 6) != -1);
+	    }
+	}
     }
     /*@ +sefparams @*/
 }
diff --git a/gpsd.h-tail b/gpsd.h-tail
index 2653ea83..21183c3b 100644
--- a/gpsd.h-tail
+++ b/gpsd.h-tail
@@ -393,7 +393,7 @@ extern void gpsd_zero_satellites(/*@out@*/struct gps_data_t *sp)/*@modifies sp@*
 extern void gpsd_interpret_subframe(struct gps_device_t *, unsigned int[]);
 extern /*@ observer @*/ char *gpsd_hexdump(/*@null@*/const void *, size_t);
 extern /*@ observer @*/ char *gpsd_hexdump_wrapper(/*@null@*/const void *, size_t, int);
-extern int gpsd_hexpack(char *, char *, int);
+extern int gpsd_hexpack(char *, char *, size_t);
 extern int hex2bin(char *);
 extern void ntpd_link_activate(struct gps_device_t *session);
 extern char /*@observer@*/ *gpsd_id(/*@in@*/struct gps_device_t *);
diff --git a/gpsd.hotplug b/gpsd.hotplug
index eac47675..a70d66a4 100755
--- a/gpsd.hotplug
+++ b/gpsd.hotplug
@@ -52,6 +52,9 @@ def gpsd_control(action, argument):
     elif action == 'remove':
         connect.sendall("-%s\r\n" % argument)
         connect.recv(12)
+    elif action == 'send':
+        connect.sendall("%s\r\n" % argument)
+        connect.recv(12)
     connect.close()
     #syslog.syslog("gpsd_control ends")
     return action
diff --git a/gpsd.xml b/gpsd.xml
index c7b7a558..dbbd3b50 100644
--- a/gpsd.xml
+++ b/gpsd.xml
@@ -709,6 +709,10 @@ list. send "-/dev/foo\n".</para>
 control socket a '!', followed by the device name, followed by '=',
 followed by the control string.</para>
 
+<para>To send a binary control string to a specified device, write to the
+control socket a '&', followed by the device name, followed by '=',
+followed by the control string in paired hex digits.</para>
+
 <para>Your client may await a response, which will be a line beginning
 with either "OK" or "ERROR".  An ERROR reponse to an add command means
 the device did not emit data recognizable as GPS packets; an ERROR
diff --git a/hex.c b/hex.c
index 19e08cbf..d4d52980 100644
--- a/hex.c
+++ b/hex.c
@@ -52,7 +52,8 @@ char /*@ observer @*/ *gpsd_hexdump(const void *binbuf, size_t binbuflen)
     return hexbuf;
 }
 
-int gpsd_hexpack(char *src, char *dst, int len){
+int gpsd_hexpack(char *src, char *dst, size_t len){
+/* hex2bin source string to destination - destination can be same as source */ 
     int i, k, l;
 
     l = (int)(strlen(src) / 2);