Pull the DGPSIP code into its own module.

The DGPSIP socket is now part of the session context; it's guarded by
the same select as all other socket reads.  The latest RTCM104 report
from it is relayed to each attached GPS when appropriate.  (The old
code only passed a correction to the first GPS to be polled after the
report came in from the server.)

6 files changed, 123 insertions, 73 deletions

diff --git a/Makefile.am b/Makefile.am
index 7a322b94..c940f0c4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -80,6 +80,7 @@ libgps_c_sources = \
 	packet.c \
 	gpsutils.c \
 	geoid.c \
+	dgpsip.c \
 	sirf.c \
 	report.c \
 	bits.h \
diff --git a/dgpsip.c b/dgpsip.c
new file mode 100644
index 00000000..36164544
--- /dev/null
+++ b/dgpsip.c
@@ -0,0 +1,87 @@
+/* dgpsip.c -- gather and dispatch DGPS data from DGPSIP servers */
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include "gpsd.h"
+
+/*@ -branchstate */
+int dgpsip_open(struct gps_context_t *context, const char *dgpsserver)
+/* open a connection to a DGPSIP server */
+{
+    char hn[256], buf[BUFSIZ];
+    char *colon, *dgpsport = "rtcm-sc104";
+    int opts;
+
+    if ((colon = strchr(dgpsserver, ':'))) {
+	dgpsport = colon+1;
+	*colon = '\0';
+    }
+    if (!getservbyname(dgpsport, "tcp"))
+	dgpsport = "2101";
+
+    context->dsock = netlib_connectsock(dgpsserver, dgpsport, "tcp");
+    if (context->dsock >= 0) {
+	(void)gethostname(hn, sizeof(hn));
+	(void)snprintf(buf,sizeof(buf), "HELO %s gpsd %s\r\nR\r\n",hn,VERSION);
+	(void)write(context->dsock, buf, strlen(buf));
+    }
+    opts = fcntl(context->dsock, F_GETFL);
+
+    if (opts >= 0)
+	(void)fcntl(context->dsock, F_SETFL, opts | O_NONBLOCK);
+    return context->dsock;
+}
+/*@ +branchstate */
+
+void dgpsip_poll(struct gps_context_t *context)
+/* poll the DGPSIP server for a correction report */
+{
+    if (context->dsock > -1) {
+	context->rtcmbytes = read(context->dsock, context->rtcmbuf, sizeof(context->rtcmbuf));
+	if (context->rtcmbytes < 0 && errno != EAGAIN)
+	    gpsd_report(1, "Read from rtcm source failed\n");
+	else
+	    context->rtcmtime = timestamp();
+    }
+}
+
+void dgpsip_relay(struct gps_device_t *session)
+/* pass a DGPSIP connection report to a session */
+{
+    if (session->gpsdata.gps_fd !=-1 && session->context->rtcmbytes > -1
+			&& session->rtcmtime < session->context->rtcmtime) {
+	if (session->device_type->rtcm_writer(session, 
+					      session->context->rtcmbuf, 
+					      (size_t)session->context->rtcmbytes) == 0)
+	    gpsd_report(1, "Write to rtcm sink failed\n");
+	else { 
+	    session->rtcmtime = timestamp();
+	    gpsd_report(2, "<= DGPS: %d bytes of RTCM relayed.\n", session->context->rtcmbytes);
+	}
+    }
+}
+
+void dgpsip_report(struct gps_device_t *session)
+/* may be time to ship a usage report to the DGPSIP server */
+{
+    if (session->fixcnt > 10 && !session->sentdgps) {
+	session->sentdgps = true;
+	if (session->context->dsock > -1) {
+	    char buf[BUFSIZ];
+	    (void)snprintf(buf, sizeof(buf), "R %0.8f %0.8f %0.2f\r\n", 
+			   session->gpsdata.fix.latitude, 
+			   session->gpsdata.fix.longitude, 
+			   session->gpsdata.fix.altitude);
+	    (void)write(session->context->dsock, buf, strlen(buf));
+	    gpsd_report(2, "=> dgps %s", buf);
+	}
+    }
+}
+
diff --git a/gpsd.c b/gpsd.c
index cf64f4ab..0fda316b 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -59,7 +59,8 @@ static int debuglevel;
 static bool in_background = false;
 static jmp_buf restartbuf;
 /*@ -initallelements -nullassign -nullderef @*/
-static struct gps_context_t context = {0, LEAP_SECONDS, CENTURY_BASE,
+static struct gps_context_t context = {0, LEAP_SECONDS, CENTURY_BASE, 
+				       0, 0, {'\0'}, 0,
 #ifdef NTPSHM_ENABLE
 				       {0},
 				       {0},
@@ -936,7 +937,7 @@ int main(int argc, char *argv[])
 {
     static char *pid_file = NULL;
     static bool nowait = false;
-    static int st, dsock = -1, csock = -1;
+    static int st, csock = -1;
     static gps_mask_t changed;
     static char *dgpsserver = NULL;
     static char *service = NULL; 
@@ -1034,11 +1035,11 @@ int main(int argc, char *argv[])
     gpsd_report(1, "listening on port %s\n", service);
 
     if (dgpsserver) {
-	dsock = gpsd_open_dgps(dgpsserver);
-	if (dsock >= 0)
+        int dsock = dgpsip_open(&context, dgpsserver);
+	if (dsock >= 0) {
 	    FD_SET(dsock, &all_fds);
-	else
-	    gpsd_report(1, "Can't connect to DGPS server, netlib error %d\n",dsock);
+	} else
+	    gpsd_report(1, "Can't connect to DGPS server, netlib error %d\n", dsock);
     }
 
 #ifdef NTPSHM_ENABLE
@@ -1120,15 +1121,11 @@ int main(int argc, char *argv[])
 	device = open_device(argv[i], nowait);
 	if (!device) {
 	    gpsd_report(0, "GPS device %s nonexistent or can't be read\n", argv[i]);
-	} else if (dsock >= 0)
-	    device->dsock = dsock;
+	}
     }
 
     for (;;) {
         (void)memcpy((char *)&rfds, (char *)&all_fds, sizeof(rfds));
-	for (channel = channels; channel < channels + MAXDEVICES; channel++)
-	    if (allocated_channel(channel) && channel->dsock > -1)
-		FD_CLR(channel->dsock, &rfds);
 
 	/* 
 	 * Poll for user commands or GPS data.  The timeout doesn't
@@ -1193,6 +1190,11 @@ int main(int argc, char *argv[])
 	    FD_CLR(csock, &rfds);
 	}
 
+	/* be ready for DGPSIP reports */
+	if (FD_ISSET(context.dsock, &rfds)) {
+	    dgpsip_poll(&context);
+	}
+
 	/* read any commands that came in over control sockets */
 	for (cfd = 0; cfd < FD_SETSIZE; cfd++)
 	    if (FD_ISSET(cfd, &control_fds)) {
@@ -1212,6 +1214,7 @@ int main(int argc, char *argv[])
 
 	    if (!allocated_channel(channel))
 		continue;
+
 	    /* we may need to force the GPS open */
 	    if (nowait && channel->gpsdata.gps_fd == -1) {
 		gpsd_deactivate(channel);
@@ -1221,6 +1224,9 @@ int main(int argc, char *argv[])
 		}
 	    }
 
+	    /* pass the current DGPSIP coorection to the GPS if new */
+	    dgpsip_relay(channel);
+
 	    /* get data from the device */
 	    changed = 0;
 	    if (channel->gpsdata.gps_fd >= 0 && FD_ISSET(channel->gpsdata.gps_fd, &rfds))
diff --git a/gpsd.h b/gpsd.h
index feb0db7d..b1511b34 100644
--- a/gpsd.h
+++ b/gpsd.h
@@ -25,7 +25,7 @@
 /* only used if the GPS doesn't report estimated position error itself */
 #define UERE_NO_DGPS	8	/* meters */
 #define UERE_WITH_DGPS	2	/* meters */
-#define UERE(session)	((session->dsock==-1) ? UERE_NO_DGPS : UERE_WITH_DGPS)
+#define UERE(session)	((session->context->dsock==-1) ? UERE_NO_DGPS : UERE_WITH_DGPS)
 
 #define NTPSHMSEGS	4		/* number of NTP SHM segments */
 
@@ -34,6 +34,10 @@ struct gps_context_t {
 #define LEAP_SECOND_VALID	0x01	/* we have or don't need correction */
     int leap_seconds;
     int century;			/* for NMEA-only devices without ZDA */
+    int dsock;				/* socket to DGPS server */
+    ssize_t rtcmbytes;			/* byte count of last RTCM104 report */
+    char rtcmbuf[40];			/* last RTCM104 report */
+    double rtcmtime;			/* timestamp of last RTCM104 report */ 
 #ifdef NTPSHM_ENABLE
     /*@reldef@*/struct shmTime *shmTime[NTPSHMSEGS];
     bool shmTimeInuse[NTPSHMSEGS];
@@ -81,8 +85,8 @@ struct gps_device_t {
 /* session object, encapsulates all global state */
     struct gps_data_t gpsdata;
     /*@relnull@*/struct gps_type_t *device_type;
-    int dsock;		/* socket to DGPS server */
-    int sentdgps;	/* have we sent a DGPS correction? */
+    double rtcmtime;	/* timestamp of last RTCM104 correction to GPS */
+    bool sentdgps;	/* have we sent a DGPSIP usage report? */
     int fixcnt;		/* count of good fixes seen */
     struct termios ttyset, ttyset_old;
     /* packet-getter internals */
@@ -164,11 +168,16 @@ extern void nmea_add_checksum(char *);
 
 extern gps_mask_t sirf_parse(struct gps_device_t *, unsigned char *, size_t);
 
-extern void packet_reset(struct gps_device_t *session);
-extern void packet_pushback(struct gps_device_t *session);
+extern void packet_reset(struct gps_device_t *);
+extern void packet_pushback(struct gps_device_t *);
 extern ssize_t packet_get(struct gps_device_t *);
 extern int packet_sniff(struct gps_device_t *);
 
+extern int dgpsip_open(struct gps_context_t *, const char *);
+extern void dgpsip_poll(struct gps_context_t *);
+extern void dgpsip_relay(struct gps_device_t *);
+extern void dgpsip_report(struct gps_device_t *);
+
 extern int gpsd_open(struct gps_device_t *);
 extern bool gpsd_next_hunt_setting(struct gps_device_t *);
 extern int gpsd_switch_driver(struct gps_device_t *, char *);
@@ -191,7 +200,6 @@ extern void ecef_to_wgs84fix(struct gps_data_t *,
 extern gps_mask_t dop(struct gps_data_t *);
 
 /* External interface */
-extern int gpsd_open_dgps(char *);
 extern void gpsd_init(struct gps_device_t *, 
 			     struct gps_context_t *, char *device);
 extern int gpsd_activate(struct gps_device_t *);
diff --git a/libgpsd_core.c b/libgpsd_core.c
index 07715e9a..f9447c26 100644
--- a/libgpsd_core.c
+++ b/libgpsd_core.c
@@ -18,34 +18,6 @@
 
 #include "gpsd.h"
 
-/*@ -branchstate */
-int gpsd_open_dgps(char *dgpsserver)
-{
-    char hn[256], buf[BUFSIZ];
-    char *colon, *dgpsport = "rtcm-sc104";
-    int dsock, opts;
-
-    if ((colon = strchr(dgpsserver, ':'))) {
-	dgpsport = colon+1;
-	*colon = '\0';
-    }
-    if (!getservbyname(dgpsport, "tcp"))
-	dgpsport = "2101";
-
-    dsock = netlib_connectsock(dgpsserver, dgpsport, "tcp");
-    if (dsock >= 0) {
-	(void)gethostname(hn, sizeof(hn));
-	(void)snprintf(buf,sizeof(buf), "HELO %s gpsd %s\r\nR\r\n",hn,VERSION);
-	(void)write(dsock, buf, strlen(buf));
-    }
-    opts = fcntl(dsock, F_GETFL);
-
-    if (opts >= 0)
-	(void)fcntl(dsock, F_SETFL, opts | O_NONBLOCK);
-    return dsock;
-}
-/*@ +branchstate */
-
 int gpsd_switch_driver(struct gps_device_t *session, char* typename)
 {
     struct gps_type_t **dp;
@@ -70,7 +42,7 @@ void gpsd_init(struct gps_device_t *session, struct gps_context_t *context, char
     strncpy(session->gpsdata.gps_device, device, PATH_MAX);
     /*@ -mustfreeonly @*/
     session->device_type = NULL;	/* start by hunting packets */
-    session->dsock = -1;
+    session->rtcmtime = 0;
     /*@ -temptrans @*/
     session->context = context;
     /*@ +temptrans @*/
@@ -392,20 +364,6 @@ gps_mask_t gpsd_poll(struct gps_device_t *session)
 {
     ssize_t packet_length;
 
-    if (session->dsock > -1) {
-	char buf[BUFSIZ];
-	int rtcmbytes;
-
-	/* accept a DGPS correction if one is pending */
-	if ((rtcmbytes=(int)read(session->dsock,buf,sizeof(buf)))>0 && (session->gpsdata.gps_fd !=-1)) {
-	    if (session->device_type->rtcm_writer(session, buf, (size_t)rtcmbytes) == 0)
-		gpsd_report(1, "Write to rtcm sink failed\n");
-	    else
-		gpsd_report(2, "<= DGPS: %d bytes of RTCM relayed.\n", rtcmbytes);
-	} else if (errno != EAGAIN)
-	    gpsd_report(1, "Read from rtcm source failed\n");
-    }
-
     if (session->inbuflen==0)
 	session->gpsdata.d_xmit_time = timestamp();
 
@@ -578,19 +536,7 @@ gps_mask_t gpsd_poll(struct gps_device_t *session)
 	    }
 	}
 
-	/* may< be time to ship a DGPS correction to the GPS */
-	if (session->fixcnt > 10 && session->sentdgps==0) {
-	    session->sentdgps++;
-	    if (session->dsock > -1) {
-		char buf[BUFSIZ];
-		(void)snprintf(buf, sizeof(buf), "R %0.8f %0.8f %0.2f\r\n", 
-			       session->gpsdata.fix.latitude, 
-			       session->gpsdata.fix.longitude, 
-			       session->gpsdata.fix.altitude);
-		(void)write(session->dsock, buf, strlen(buf));
-		gpsd_report(2, "=> dgps %s", buf);
-	    }
-	}
+	dgpsip_report(session);
 
 	return session->gpsdata.set;
     }
diff --git a/serial.c b/serial.c
index 42d67a63..405f5b7f 100644
--- a/serial.c
+++ b/serial.c
@@ -128,8 +128,10 @@ int gpsd_open(struct gps_device_t *session)
 	 * Only block until we get at least one character, whatever the
 	 * third arg of read(2) says.
 	 */
+	/*@ ignore @*/
 	memset(session->ttyset.c_cc,0,sizeof(session->ttyset.c_cc));
 	session->ttyset.c_cc[VMIN] = 1;
+	/*@ end @*/
 	/*
 	 * Tip from Chris Kuethe: the FIDI chip used in the Trip-Nav
 	 * 200 (and possibly other USB GPSes) gets completely hosed