1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/* $Id$ */
/* dgpsip.c -- gather and dispatch DGPS data from DGPSIP servers */
#include <sys/types.h>
#ifndef S_SPLINT_S
#include <sys/socket.h>
#endif /* S_SPLINT_S */
#include <sys/time.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <netdb.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include "gpsd_config.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, ':')) != NULL) {
dgpsport = colon+1;
*colon = '\0';
}
if (!getservbyname(dgpsport, "tcp"))
dgpsport = DEFAULT_RTCM_PORT;
context->dsock = netlib_connectsock(dgpsserver, dgpsport, "tcp");
if (context->dsock >= 0) {
gpsd_report(LOG_PROG,"connection to DGPS server %s established.\n",dgpsserver);
(void)gethostname(hn, sizeof(hn));
/* greeting required by some RTCM104 servers; others will ignore it */
(void)snprintf(buf,sizeof(buf), "HELO %s gpsd %s\r\nR\r\n",hn,VERSION);
if (write(context->dsock, buf, strlen(buf)) == (ssize_t)strlen(buf))
context->dgnss_service = dgnss_dgpsip;
else
gpsd_report(LOG_ERROR, "hello to DGPS server %s failed\n", dgpsserver);
} else
gpsd_report(LOG_ERROR, "can't connect to DGPS server %s, netlib error %d.\n", dgpsserver, context->dsock);
opts = fcntl(context->dsock, F_GETFL);
if (opts >= 0)
(void)fcntl(context->dsock, F_SETFL, opts | O_NONBLOCK);
return context->dsock;
}
/*@ +branchstate */
void dgpsip_report(struct gps_device_t *session)
/* may be time to ship a usage report to the DGPSIP server */
{
/*
* 10 is an arbitrary number, the point is to have gotten several good
* fixes before reporting usage to our DGPSIP server.
*/
if (session->context->fixcnt > 10 && !session->context->sentdgps) {
session->context->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);
if (write(session->context->dsock, buf, strlen(buf)) == (ssize_t)strlen(buf))
gpsd_report(LOG_IO, "=> dgps %s", buf);
else
gpsd_report(LOG_IO, "write to dgps FAILED");
}
}
}
#define DGPS_THRESHOLD 1600000 /* max. useful dist. from DGPS server (m) */
#define SERVER_SAMPLE 12 /* # of servers within threshold to check */
struct dgps_server_t {
double lat, lon;
char server[257];
double dist;
};
static int srvcmp(const void *s, const void *t)
{
return (int)(((const struct dgps_server_t *)s)->dist - ((const struct dgps_server_t *)t)->dist); /* fixes: warning: cast discards qualifiers from pointer target type */
}
void dgpsip_autoconnect(struct gps_context_t *context,
double lat, double lon,
const char *serverlist)
/* tell the library to talk to the nearest DGPSIP server */
{
struct dgps_server_t keep[SERVER_SAMPLE], hold, *sp, *tp;
char buf[BUFSIZ];
FILE *sfp = fopen(serverlist, "r");
if (sfp == NULL) {
gpsd_report(LOG_ERROR, "no DGPS server list found.\n");
context->dsock = -2; /* don't try this again */
return;
}
for (sp = keep; sp < keep + SERVER_SAMPLE; sp++) {
sp->dist = DGPS_THRESHOLD;
sp->server[0] = '\0';
}
/*@ -usedef @*/
while (fgets(buf, (int)sizeof(buf), sfp)) {
char *cp = strchr(buf, '#');
if (cp != NULL)
*cp = '\0';
if (sscanf(buf,"%lf %lf %256s",&hold.lat, &hold.lon, hold.server)==3) {
hold.dist = earth_distance(lat, lon, hold.lat, hold.lon);
tp = NULL;
/*
* The idea here is to look for a server in the sample array
* that is (a) closer than the one we're checking, and (b)
* furtherest away of all those that are closer. Replace it.
* In this way we end up with the closest possible set.
*/
for (sp = keep; sp < keep + SERVER_SAMPLE; sp++)
if (hold.dist < sp->dist && (tp==NULL || hold.dist > tp->dist))
tp = sp;
if (tp != NULL)
memcpy(tp, &hold, sizeof(struct dgps_server_t));
}
}
(void)fclose(sfp);
if (keep[0].server[0] == '\0') {
gpsd_report(LOG_ERROR, "no DGPS servers within %dm.\n", (int)(DGPS_THRESHOLD/1000));
context->dsock = -2; /* don't try this again */
return;
}
/*@ +usedef @*/
/* sort them and try the closest first */
qsort((void *)keep, SERVER_SAMPLE, sizeof(struct dgps_server_t), srvcmp);
for (sp = keep; sp < keep + SERVER_SAMPLE; sp++) {
if (sp->server[0] != '\0') {
gpsd_report(LOG_INF,"%s is %dkm away.\n",sp->server,(int)(sp->dist/1000));
if (dgpsip_open(context, sp->server) >= 0)
break;
}
}
}
|
