wavecom/sysmocom: Directly send GPS/AIS via UDP to gpsd

This avoids having to have another client program which then passes
messages from gsmd into gpsd.  Rather, gpsd can directly receive the
messages via UDP.

1 files changed, 64 insertions, 2 deletions

diff --git a/src/gsmd/vendor_wavecom.c b/src/gsmd/vendor_wavecom.c
index 1331053..883ea39 100644
--- a/src/gsmd/vendor_wavecom.c
+++ b/src/gsmd/vendor_wavecom.c
@@ -26,6 +26,10 @@
 #include <errno.h>
 #include <stdint.h>
 
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
 #include "gsmd.h"
 
 #include <gsmd/gsmd.h>
@@ -37,6 +41,13 @@
 #include <gsmd/vendorplugin.h>
 #include <gsmd/unsolicited.h>
 
+#define AISGPS_UDP_HOST	"127.0.0.1"
+#define GPS_UDP_PORT	12345
+#define AIS_UDP_PORT	12346
+
+static int gps_udp_fd = -1;
+static int ais_udp_fd = -1;
+
 struct cell_info_fsq {
 	uint8_t cur;
 	uint8_t full;
@@ -144,11 +155,39 @@ struct gsmd_ucmd *usock_build_gps(uint8_t subtype, const char *data, uint16_t le
 	return ucmd;
 }
 
+const char *crlf = "\r\n";
+
+static int send_crlf(int fd, const char *buf, int len)
+{
+	struct iovec iov[2];
+	struct msghdr mh;
+
+	if (len <= strlen(AIS_PFX))
+		return 0;
+
+	len -= strlen(AIS_PFX);
+	buf += strlen(AIS_PFX);
+
+	iov[0].iov_base = (void *) buf;
+	iov[0].iov_len = len;
+	iov[1].iov_base = (void *) crlf;
+	iov[1].iov_len = strlen(crlf);
+
+	memset(&mh, 0, sizeof(mh));
+	mh.msg_iov = iov;
+	mh.msg_iovlen = ARRAY_SIZE(iov);
+
+	return sendmsg(fd, &mh, MSG_DONTWAIT);
+}
+
 static int sgps_parse(const char *buf, int len, const char *param,
 		     struct gsmd *gsmd)
 {
-	struct gsmd_ucmd *ucmd = usock_build_gps(GSMD_EVT_GPS, buf, len);
+	struct gsmd_ucmd *ucmd;
+
+	send_crlf(gps_udp_fd, buf, len);
 
+	ucmd = usock_build_gps(GSMD_EVT_GPS, buf, len);
 	if (!ucmd)
 		return -ENOMEM;
 
@@ -161,8 +200,11 @@ static int sais_parse(const char *buf, int len, const char *param,
 		     struct gsmd *gsmd)
 {
 
-	struct gsmd_ucmd *ucmd = usock_build_gps(GSMD_EVT_AIS, buf, len);
+	struct gsmd_ucmd *ucmd;
+
+	send_crlf(ais_udp_fd, buf, len);
 
+	ucmd = usock_build_gps(GSMD_EVT_AIS, buf, len);
 	if (!ucmd)
 		return -ENOMEM;
 
@@ -187,6 +229,26 @@ static int wavecom_initsettings(struct gsmd *g)
 {
 	int rc = 0;
 	struct gsmd_atcmd *cmd;
+	struct sockaddr_in sin;
+
+	gps_udp_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	ais_udp_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+	if (gps_udp_fd < 0 || ais_udp_fd < 0)
+		return -1;
+
+	memset(&sin, 0, sizeof(sin));
+	sin.sin_family = AF_INET;
+	inet_aton(AISGPS_UDP_HOST, &sin.sin_addr);
+
+	sin.sin_port = htons(GPS_UDP_PORT);
+	rc = connect(gps_udp_fd, (struct sockaddr *)&sin, sizeof(sin));
+	if (rc < 0)
+		return rc;
+
+	sin.sin_port = htons(AIS_UDP_PORT);
+	rc = connect(ais_udp_fd, (struct sockaddr *)&sin, sizeof(sin));
+	if (rc < 0)
+		return rc;
 
 	/* use +WREGC to enter "spy mode" (no transmit / registration) */
 	rc |= gsmd_simplecmd(g, "AT+WREGC=0");