All driver method tables are now const.

This required moving one field, the modifiable cycle time, into the
session structure; the driver type field is now the default value set
on switching to that driver, if the field has not already been set
during a previous activation.

16 files changed, 52 insertions, 49 deletions

diff --git a/driver_proto.c b/driver_proto.c
index f83639ea..20cdbbb8 100644
--- a/driver_proto.c
+++ b/driver_proto.c
@@ -369,7 +369,7 @@ static void _proto__wrapup(struct gps_device_t *session)
 /* any driver must use to compile.                   */
 
 /* This is everything we export */
-struct gps_type_t _proto__binary = {
+const struct gps_type_t _proto__binary = {
     /* Full name of type */
     .type_name        = "_proto_ binary",
     /* associated lexer packet type */
diff --git a/drivers.c b/drivers.c
index 6258f0fd..698d2a8f 100644
--- a/drivers.c
+++ b/drivers.c
@@ -14,8 +14,8 @@
 #include "gpsd.h"
 #include "bits.h"	/* for getbeuw(), to extract big-endiamn words */
 
-extern struct gps_type_t zodiac_binary;
-extern struct gps_type_t ubx_binary;
+extern const struct gps_type_t zodiac_binary;
+extern const struct gps_type_t ubx_binary;
 
 ssize_t generic_get(struct gps_device_t *session)
 {
@@ -105,7 +105,7 @@ gps_mask_t nmea_parse_input(struct gps_device_t *session)
 
 	if ((st=nmea_parse((char *)session->packet.outbuffer, session))==0) {
 #ifdef NON_NMEA_ENABLE
-	    struct gps_type_t **dp;
+	    const struct gps_type_t **dp;
 
 	    /* maybe this is a trigger string for a driver we know about? */
 #ifdef UBX_ENABLE
@@ -239,7 +239,7 @@ static void nmea_probe_subtype(struct gps_device_t *session, unsigned int seq)
     }
 }
 
-static struct gps_type_t nmea = {
+static const struct gps_type_t nmea = {
     .type_name      = "Generic NMEA",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = NULL,		/* it's the default */
@@ -329,7 +329,7 @@ static void garmin_nmea_configurator(struct gps_device_t *session, unsigned int
 }
 #endif /* ALLOW_RECONFIGURE */
 
-static struct gps_type_t garmin = {
+static const struct gps_type_t garmin = {
     .type_name      = "Garmin Serial",	/* full name of type */
     .packet_type    = GARMIN_PACKET,	/* associated lexer packet type */
     .trigger	    = "$PGRMC,",	/* Garmin private */
@@ -392,7 +392,7 @@ static void ashtech_ping(struct gps_device_t *session)
 	(void)nmea_send(session, "$PASHQ,RID");
 }
 
-static struct gps_type_t ashtech = {
+static const struct gps_type_t ashtech = {
     .type_name      = "Ashtech",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = "$PASHR,RID,",	/* Ashtech receivers respond thus */
@@ -439,7 +439,7 @@ static void fv18_configure(struct gps_device_t *session, unsigned int seq)
 }
 #endif /* ALLOW_RECONFIGURE */
 
-static struct gps_type_t fv18 = {
+static const struct gps_type_t fv18 = {
     .type_name      = "San Jose Navigation FV18",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = "$PFEC,GPint,",	/* FV18s should echo the probe */
@@ -489,7 +489,7 @@ static void gpsclock_probe_subtype(struct gps_device_t *session, unsigned int se
     }
 }
 
-static struct gps_type_t gpsclock = {
+static const struct gps_type_t gpsclock = {
     .type_name      = "Furuno Electric GH-79L4",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = "$PFEC,GPssd",	/* GPSclock should return this */
@@ -547,7 +547,7 @@ static void tripmate_configurator(struct gps_device_t *session, unsigned int seq
 }
 #endif /* ALLOW_RECONFIGURE */
 
-static struct gps_type_t tripmate = {
+static const struct gps_type_t tripmate = {
     .type_name     = "Delorme TripMate",	/* full name of type */
     .packet_type   = NMEA_PACKET,		/* lexer packet type */
     .trigger       ="ASTRAL",			/* tells us to switch */
@@ -590,12 +590,12 @@ static void earthmate_probe_subtype(struct gps_device_t *session, unsigned int s
     if (seq == 0) {
 	(void)gpsd_write(session, "EARTHA\r\n", 8);
 	(void)usleep(10000);
-	gpsd_switch_driver(session, "Zodiac Binary");
+	(void)gpsd_switch_driver(session, "Zodiac Binary");
     }
 }
 
 /*@ -redef @*/
-static struct gps_type_t earthmate = {
+static const struct gps_type_t earthmate = {
     .type_name     = "Delorme EarthMate (pre-2003, Zodiac chipset)",
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger       = "EARTHA",			/* Earthmate trigger string */
@@ -770,7 +770,7 @@ static bool tnt_probe(struct gps_device_t *session)
   return false;
 }
 
-static struct gps_type_t trueNorth = {
+static const struct gps_type_t trueNorth = {
     .type_name      = "True North",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = " TNT1500",
@@ -844,7 +844,7 @@ static void oceanserver_configure(struct gps_device_t *session, unsigned int seq
 }
 #endif /* ALLOW_RECONFIGURE */
 
-static struct gps_type_t oceanServer = {
+static const struct gps_type_t oceanServer = {
     .type_name      = "OceanServer Digital Compass OS5000", /* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = "$C,",
@@ -888,7 +888,7 @@ static gps_mask_t rtcm104v2_analyze(struct gps_device_t *session)
     return RTCM2_SET;
 }
 
-static struct gps_type_t rtcm104v2 = {
+static const struct gps_type_t rtcm104v2 = {
     .type_name     = "RTCM104V2",	/* full name of type */
     .packet_type   = RTCM2_PACKET,	/* associated lexer packet type */
     .trigger       = NULL,		/* no recognition string */
@@ -932,7 +932,7 @@ static gps_mask_t rtcm104v3_analyze(struct gps_device_t *session)
     return RTCM3_SET;
 }
 
-static struct gps_type_t rtcm104v3 = {
+static const struct gps_type_t rtcm104v3 = {
     .type_name     = "RTCM104V3",	/* full name of type */
     .packet_type   = RTCM3_PACKET,	/* associated lexer packet type */
     .trigger       = NULL,		/* no recognition string */
@@ -973,7 +973,7 @@ static gps_mask_t garmintxt_parse_input(struct gps_device_t *session)
 }
 
 
-static struct gps_type_t garmintxt = {
+static const struct gps_type_t garmintxt = {
     .type_name     = "Garmin Simple Text",		/* full name of type */
     .packet_type   = RTCM2_PACKET;	/* associated lexer packet type */
     .trigger       = NULL,		/* no recognition string */
@@ -1068,7 +1068,7 @@ static void mkt3301_configure(struct gps_device_t *session, unsigned int seq)
 }
 #endif /* ALLOW_RECONFIGURE */
 
-static struct gps_type_t mkt3301 = {
+static const struct gps_type_t mkt3301 = {
     .type_name      = "MKT-3301",	/* full name of type */
     .packet_type    = NMEA_PACKET,	/* associated lexer packet type */
     .trigger	    = "$PMTK705,",	/* MKT-3301s send firmware release name and version */
@@ -1095,14 +1095,14 @@ static struct gps_type_t mkt3301 = {
 };
 #endif /* MKT3301_ENABLE */
 
-extern struct gps_type_t garmin_usb_binary, garmin_ser_binary;
-extern struct gps_type_t sirf_binary, tsip_binary;
-extern struct gps_type_t evermore_binary, italk_binary;
-extern struct gps_type_t navcom_binary, superstar2_binary;
+extern const struct gps_type_t garmin_usb_binary, garmin_ser_binary;
+extern const struct gps_type_t sirf_binary, tsip_binary;
+extern const struct gps_type_t evermore_binary, italk_binary;
+extern const struct gps_type_t navcom_binary, superstar2_binary;
 
 /*@ -nullassign @*/
 /* the point of this rigamarole is to not have to export a table size */
-static struct gps_type_t *gpsd_driver_array[] = {
+static const struct gps_type_t *gpsd_driver_array[] = {
 #ifdef NMEA_ENABLE
     &nmea,
 #ifdef ASHTECH_ENABLE
@@ -1176,4 +1176,4 @@ static struct gps_type_t *gpsd_driver_array[] = {
     NULL,
 };
 /*@ +nullassign @*/
-struct gps_type_t **gpsd_drivers = &gpsd_driver_array[0];
+const struct gps_type_t **gpsd_drivers = &gpsd_driver_array[0];
diff --git a/evermore.c b/evermore.c
index da1524fd..0f4c713b 100644
--- a/evermore.c
+++ b/evermore.c
@@ -488,7 +488,7 @@ static void evermore_wrap(struct gps_device_t *session)
 
 
 /* this is everything we export */
-struct gps_type_t evermore_binary =
+const struct gps_type_t evermore_binary =
 {
     .type_name      = "EverMore binary",	/* full name of type */
     .packet_type    = NMEA_PACKET,		/* lexer packet type */
diff --git a/garmin.c b/garmin.c
index 4a44e2cc..54d84b7d 100644
--- a/garmin.c
+++ b/garmin.c
@@ -1156,7 +1156,7 @@ static ssize_t garmin_get_packet(struct gps_device_t *session)
     return (ssize_t)( 0 == GetPacket( session ) ? 1 : 0);
 }
 
-struct gps_type_t garmin_usb_binary_old =
+const struct gps_type_t garmin_usb_binary_old =
 {
     .type_name      = "Garmin USB binary",	/* full name of type */
     .packet_type    = GARMIN_PACKET;	/* associated lexer packet type */
@@ -1184,7 +1184,7 @@ struct gps_type_t garmin_usb_binary_old =
 };
 #endif /* __UNUSED__ */
 
-struct gps_type_t garmin_usb_binary =
+const struct gps_type_t garmin_usb_binary =
 {
     .type_name      = "Garmin USB binary",	/* full name of type */
     .packet_type    = GARMIN_PACKET,	/* associated lexer packet type */
@@ -1211,7 +1211,7 @@ struct gps_type_t garmin_usb_binary =
     .cycle          = 1,		/* updates every second */
 };
 
-struct gps_type_t garmin_ser_binary =
+const struct gps_type_t garmin_ser_binary =
 {
     .type_name      = "Garmin Serial binary",	/* full name of type */
     .packet_type    = GARMIN_PACKET,	/* associated lexer packet type */
diff --git a/gpsctl.c b/gpsctl.c
index 32c48520..e2033647 100644
--- a/gpsctl.c
+++ b/gpsctl.c
@@ -78,8 +78,8 @@ int main(int argc, char **argv)
     bool to_binary = false, to_nmea = false, reset = false; 
     bool lowlevel=false, echo=false;
     struct gps_data_t *gpsdata = NULL;
-    struct gps_type_t *forcetype = NULL;
-    struct gps_type_t **dp;
+    const struct gps_type_t *forcetype = NULL;
+    const struct gps_type_t **dp;
     char cooked[BUFSIZ];
     ssize_t cooklen = 0;
     unsigned int timeout = 4;
@@ -458,7 +458,7 @@ int main(int argc, char **argv)
 	     * length.  This means they don't fit well in the model 
 	     * assumed by the driver interface.
 	     */
-	    extern struct gps_type_t ubx_binary;
+	    extern const struct gps_type_t ubx_binary;
 	    /*@ -usedef @*/
 	    if (session.device_type == &ubx_binary) {
 		if (!ubx_write(session.gpsdata.gps_fd,
diff --git a/gpsd.c b/gpsd.c
index 5aec95db..90a85a34 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -211,7 +211,7 @@ void gpsd_report(int errlevel, const char *fmt, ... )
 
 static void usage(void)
 {
-    struct gps_type_t **dp;
+    const struct gps_type_t **dp;
 
     (void)printf("usage: gpsd [-b] [-n] [-N] [-D n] [-F sockfile] [-P pidfile] [-S port] [-h] device...\n\
   Options include: \n\
@@ -762,21 +762,21 @@ static int handle_gpsd_request(struct subscriber_t* sub, char *buf, int buflen)
 	    if (!assign_channel(sub) || sub->device->device_type==NULL)
 		(void)strlcpy(phrase, ",C=?", BUFSIZ);
 	    else {
-		struct gps_type_t *dev = sub->device->device_type;
+		const struct gps_type_t *dev = sub->device->device_type;
 		double mincycle = (dev->cycle_chars * 10.0) / sub->device->gpsdata.baudrate;
 		if (*p == '=' && privileged_user(sub)) {
 		    double cycle = strtod(++p, &p);
 		    if (cycle >= mincycle)
 			if (dev->rate_switcher != NULL)
 			    if (dev->rate_switcher(sub->device, cycle))
-				dev->cycle = cycle;
+				sub->device->cycle = cycle;
 		}
 		if (dev->rate_switcher == NULL)
 		    (void)snprintf(phrase, sizeof(phrase),
-				   ",C=%.2f", dev->cycle);
+				   ",C=%.2f", sub->device->cycle);
 		else
 		    (void)snprintf(phrase, sizeof(phrase),
-				   ",C=%.2f %.2f", dev->cycle, mincycle);
+				   ",C=%.2f %.2f", sub->device->cycle, mincycle);
 	    }
 	    break;
 	case 'D':
diff --git a/gpsd.h-tail b/gpsd.h-tail
index 923f9b10..96fc5670 100644
--- a/gpsd.h-tail
+++ b/gpsd.h-tail
@@ -210,7 +210,7 @@ struct gps_type_t {
 struct gps_device_t {
 /* session object, encapsulates all global state */
     struct gps_data_t gpsdata;
-    /*@relnull@*/struct gps_type_t *device_type;
+    /*@relnull@*/const struct gps_type_t *device_type;
     struct gps_context_t	*context;
 #ifdef ALLOW_RECONFIGURE
     bool enable_reconfigure;		/* OK to hack GPS settings? */ 
@@ -219,6 +219,7 @@ struct gps_device_t {
     struct termios ttyset, ttyset_old;
     unsigned int baudindex;
     int saved_baud;
+    double cycle;
     struct gps_packet_t packet;
     char subtype[64];			/* firmware version or subtype ID */
     double poll_times[FD_SETSIZE];	/* last daemon poll time */
@@ -353,7 +354,7 @@ struct gps_device_t {
 #define IS_HIGHEST_BIT(v,m)	(v & ~((m<<1)-1))==0
 
 /* here are the available GPS drivers */
-extern struct gps_type_t **gpsd_drivers;
+extern const struct gps_type_t **gpsd_drivers;
 
 /* gpsd library internal prototypes */
 extern gps_mask_t nmea_parse_input(struct gps_device_t *);
diff --git a/italk.c b/italk.c
index 52c0c6f9..d615484e 100644
--- a/italk.c
+++ b/italk.c
@@ -343,7 +343,7 @@ static void italk_ping(struct gps_device_t *session)
 #endif /* __not_yet__ */
 
 /* this is everything we export */
-struct gps_type_t italk_binary =
+const struct gps_type_t italk_binary =
 {
     .type_name      = "iTalk binary",	/* full name of type */
     .packet_type    = ITALK_PACKET,	/* associated lexer packet type */
diff --git a/libgpsd_core.c b/libgpsd_core.c
index 6c485784..8b4e144c 100644
--- a/libgpsd_core.c
+++ b/libgpsd_core.c
@@ -27,7 +27,7 @@
 
 int gpsd_switch_driver(struct gps_device_t *session, char* type_name)
 {
-    struct gps_type_t **dp;
+    const struct gps_type_t **dp;
 
     gpsd_report(LOG_PROG, "switch_driver(%s) called...\n", type_name);
     if (session->device_type != NULL &&
@@ -47,6 +47,8 @@ int gpsd_switch_driver(struct gps_device_t *session, char* type_name)
 	    gpsd_report(LOG_PROG, "selecting %s driver...\n", (*dp)->type_name);
 	    gpsd_assert_sync(session);
 	    /*@i@*/session->device_type = *dp;
+	    if (session->cycle <= 0)
+		session->cycle = (*dp)->cycle;
 	    if (!session->context->readonly && session->device_type->probe_subtype != NULL)
 		session->device_type->probe_subtype(session, session->packet.counter = 0);
 #ifdef ALLOW_RECONFIGURE
@@ -247,7 +249,7 @@ int gpsd_activate(struct gps_device_t *session, bool reconfigurable)
 	return -1;
     else {
 #ifdef NON_NMEA_ENABLE
-	struct gps_type_t **dp;
+	const struct gps_type_t **dp;
 
 	/*@ -mustfreeonly @*/
 	for (dp = gpsd_drivers; *dp; dp++) {
diff --git a/navcom.c b/navcom.c
index e1e1f2bf..ae2b262a 100644
--- a/navcom.c
+++ b/navcom.c
@@ -1238,7 +1238,7 @@ static gps_mask_t navcom_parse_input(struct gps_device_t *session)
 
 
 /* this is everything we export */
-struct gps_type_t navcom_binary =
+const struct gps_type_t navcom_binary =
 {
     .type_name      = "Navcom binary",  	/* full name of type */
     .packet_type    = NAVCOM_PACKET,		/* lexer packet type */
diff --git a/serial.c b/serial.c
index 831fbd39..8f896b52 100644
--- a/serial.c
+++ b/serial.c
@@ -193,7 +193,7 @@ void gpsd_set_speed(struct gps_device_t *session,
 	 * in hopes it will respond.
 	 */
 	if (isatty(session->gpsdata.gps_fd)!=0 && !session->context->readonly) {
-	    struct gps_type_t **dp;
+	    const struct gps_type_t **dp;
 	    if (session->device_type == NULL) {
 		for (dp = gpsd_drivers; *dp; dp++)
 		    if ((*dp)->probe_wakeup != NULL)
diff --git a/sirf.c b/sirf.c
index ef6c58f7..9e5e7684 100644
--- a/sirf.c
+++ b/sirf.c
@@ -988,7 +988,7 @@ static bool sirfbin_speed(struct gps_device_t *session, speed_t speed)
 }
 
 /* this is everything we export */
-struct gps_type_t sirf_binary =
+const struct gps_type_t sirf_binary =
 {
     .type_name      = "SiRF binary",	/* full name of type */
     .packet_type    = SIRF_PACKET,	/* associated lexer packet type */
diff --git a/superstar2.c b/superstar2.c
index ec48844e..5a8284e8 100644
--- a/superstar2.c
+++ b/superstar2.c
@@ -480,7 +480,7 @@ static void superstar2_set_mode(struct gps_device_t *session, int mode)
     }
 }
 
-struct gps_type_t superstar2_binary = {
+const struct gps_type_t superstar2_binary = {
     /* Full name of type */
     .type_name		= "SuperStarII binary",
     /* associated lexer packet type */
diff --git a/tsip.c b/tsip.c
index 54372d22..58088ecd 100644
--- a/tsip.c
+++ b/tsip.c
@@ -822,7 +822,7 @@ static gps_mask_t tsip_parse_input(struct gps_device_t *session)
 }
 
 /* this is everything we export */
-struct gps_type_t tsip_binary =
+const struct gps_type_t tsip_binary =
 {
     .type_name      = "Trimble TSIP",	/* full name of type */
     .packet_type    = TSIP_PACKET,	/* associated lexer packet type */
diff --git a/ubx.c b/ubx.c
index 6b16b5d0..1b3f9535 100644
--- a/ubx.c
+++ b/ubx.c
@@ -632,7 +632,7 @@ static bool ubx_speed(struct gps_device_t *session, speed_t speed)
 }
 
 /* This is everything we export */
-struct gps_type_t ubx_binary = {
+const struct gps_type_t ubx_binary = {
     .type_name        = "uBlox UBX binary",    /* Full name of type */
     .packet_type    = UBX_PACKET,	/* associated lexer packet type */
     .trigger          = NULL,           /* Response string that identifies device (not active) */
diff --git a/zodiac.c b/zodiac.c
index da6e4c53..845e046f 100644
--- a/zodiac.c
+++ b/zodiac.c
@@ -382,7 +382,7 @@ static gps_mask_t zodiac_analyze(struct gps_device_t *session)
     unsigned int id = (unsigned int)((session->packet.outbuffer[3]<<8) | session->packet.outbuffer[2]);
 
     if (session->packet.type != ZODIAC_PACKET) {
-	struct gps_type_t **dp;
+	const struct gps_type_t **dp;
 	gpsd_report(LOG_PROG, "zodiac_analyze packet type %d\n",session->packet.type);
 	// Wrong packet type ? 
 	// Maybe find a trigger just in case it's an Earthmate
@@ -437,7 +437,7 @@ static gps_mask_t zodiac_analyze(struct gps_device_t *session)
 /* caller needs to specify a wrapup function */
 
 /* this is everything we export */
-struct gps_type_t zodiac_binary =
+const struct gps_type_t zodiac_binary =
 {
     .type_name      = "Zodiac binary",	/* full name of type */
     .packet_type    = ZODIAC_PACKET,	/* associated lexer packet type */