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gpsd.c
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gpsd.c
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/*
* This is the main sequence of the gpsd daemon. The IO dispatcher, main
* select loop, and user command handling lives here.
*
* This file is Copyright (c) 2010 by the GPSD project
* BSD terms apply: see the file COPYING in the distribution root for details.
*/
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h> /* for select() */
#include <sys/select.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdarg.h>
#include <ctype.h>
#include <setjmp.h>
#include <assert.h>
#include <pwd.h>
#include <grp.h>
#include <math.h>
#include <syslog.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <pthread.h>
#ifndef S_SPLINT_S
#include <netdb.h>
#ifndef AF_UNSPEC
#include <sys/socket.h>
#endif /* AF_UNSPEC */
#ifndef INADDR_ANY
#include <netinet/in.h>
#endif /* INADDR_ANY */
#include <sys/un.h>
#include <arpa/inet.h> /* for htons() and friends */
#endif /* S_SPLINT_S */
#ifndef S_SPLINT_S
#include <unistd.h>
#endif /* S_SPLINT_S */
#include "gpsd_config.h"
#include "gpsd.h"
#include "sockaddr.h"
#include "gps_json.h"
#include "revision.h"
#if defined(SYSTEMD_ENABLE)
#include "sd_socket.h"
#endif
/*
* The name of a tty device from which to pick up whatever the local
* owning group for tty devices is. Used when we drop privileges.
*/
#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
#define PROTO_TTY "/dev/tty00" /* correct for *BSD */
#else
#define PROTO_TTY "/dev/ttyS0" /* correct for Linux */
#endif
/*
* Timeout policy. We can't rely on clients closing connections
* correctly, so we need timeouts to tell us when it's OK to
* reclaim client fds. COMMAND_TIMEOUT fends off programs
* that open connections and just sit there, not issuing a WATCH or
* doing anything else that triggers a device assignment. Clients
* in watcher or raw mode that don't read their data will get dropped
* when throttled_write() fills up the outbound buffers and the
* NOREAD_TIMEOUT expires.
*
* RELEASE_TIMEOUT sets the amount of time we hold a device
* open after the last subscriber closes it; this is nonzero so a
* client that does open/query/close will have time to come back and
* do another single-shot query, if it wants to, before the device is
* actually closed. The reason this matters is because some Bluetooth
* GPSes not only shut down the GPS receiver on close to save battery
* power, they actually shut down the Bluetooth RF stage as well and
* only re-wake it periodically to see if an attempt to raise the
* device is in progress. The result is that if you close the device
* when it's powered up, a re-open can fail with EIO and needs to be
* tried repeatedly. Better to avoid this...
*
* DEVICE_REAWAKE says how long to wait before repolling after a zero-length
* read. It's there so we avoid spinning forever on an EOF condition.
*
* DEVICE_RECONNECT sets interval on retries when (re)connecting to
* a device.
*/
#define COMMAND_TIMEOUT 60*15
#define NOREAD_TIMEOUT 60*3
#define RELEASE_TIMEOUT 60
#define DEVICE_REAWAKE 0.01
#define DEVICE_RECONNECT 2
#define QLEN 5
/*
* If ntpshm is enabled, we renice the process to this priority level.
* For precise timekeeping increase priority.
*/
#define NICEVAL -10
#if defined(FIXED_PORT_SPEED) || !defined(SOCKET_EXPORT_ENABLE)
/*
* Force nowait in two circumstances:
*
* (1) If we're running with FIXED_PORT_SPEED we're some sort
* of embedded configuration where we don't want to wait for connect
*
* (2) Socket export has been disabled. In this case we have no
* way to know when client apps are watching the export channels,
* so we need to be running all the time.
*/
#define FORCE_NOWAIT
#endif /* defined(FIXED_PORT_SPEED) || !defined(SOCKET_EXPORT_ENABLE) */
/* IP version used by the program */
/* AF_UNSPEC: all
* AF_INET: IPv4 only
* AF_INET6: IPv6 only
*/
#ifdef IPV6_ENABLE
static const int af = AF_UNSPEC;
#else
static const int af = AF_INET;
#endif
#define AFCOUNT 2
static fd_set all_fds;
static int maxfd;
#ifndef FORCE_GLOBAL_ENABLE
static bool listen_global = false;
#endif /* FORCE_GLOBAL_ENABLE */
#ifndef FORCE_NOWAIT
#define NOWAIT nowait
static bool nowait = false;
#else /* FORCE_NOWAIT */
#define NOWAIT true
#endif /* FORCE_NOWAIT */
static jmp_buf restartbuf;
static struct gps_context_t context;
#if defined(SYSTEMD_ENABLE)
static int sd_socket_count = 0;
#endif
/* work around the unfinished ipv6 implementation on hurd */
#ifdef __GNU__
#ifndef IPV6_TCLASS
#define IPV6_TCLASS 61
#endif
#endif
#define UNALLOCATED_FD -1
static volatile sig_atomic_t signalled;
static void onsig(int sig)
{
/* just set a variable, and deal with it in the main loop */
signalled = (sig_atomic_t) sig;
}
static void typelist(void)
/* list installed drivers and enabled features */
{
const struct gps_type_t **dp;
for (dp = gpsd_drivers; *dp; dp++) {
if ((*dp)->packet_type == COMMENT_PACKET)
continue;
#ifdef RECONFIGURE_ENABLE
if ((*dp)->mode_switcher != NULL)
(void)fputs("n\t", stdout);
else
(void)fputc('\t', stdout);
if ((*dp)->speed_switcher != NULL)
(void)fputs("b\t", stdout);
else
(void)fputc('\t', stdout);
if ((*dp)->rate_switcher != NULL)
(void)fputs("c\t", stdout);
else
(void)fputc('\t', stdout);
if ((*dp)->packet_type > NMEA_PACKET)
(void)fputs("*\t", stdout);
else
(void)fputc('\t', stdout);
#endif /* RECONFIGURE_ENABLE */
(void)puts((*dp)->type_name);
}
(void)printf("# n: mode switch, b: speed switch, "
"c: rate switch, *: non-NMEA packet type.\n");
#if defined(SOCKET_EXPORT_ENABLE)
(void)printf("# Socket export enabled.\n");
#endif
#if defined(SHM_EXPORT_ENABLE)
(void)printf("# Shared memory export enabled.\n");
#endif
#if defined(DBUS_EXPORT_ENABLE)
(void)printf("# DBUS export enabled\n");
#endif
#if defined(TIMEHINT_ENABLE)
(void)printf("# Time service features enabled.\n");
#endif
#if defined(PPS_ENABLE)
(void)printf("# PPS enabled.\n");
#endif
exit(EXIT_SUCCESS);
}
static void usage(void)
{
(void)printf("usage: gpsd [-b] [-n] [-N] [-D n] [-F sockfile] [-G] [-P pidfile] [-S port] [-h] device...\n\
Options include: \n\
-b = bluetooth-safe: open data sources read-only\n\
-n = don't wait for client connects to poll GPS\n\
-N = don't go into background\n\
-F sockfile = specify control socket location\n"
#ifndef FORCE_GLOBAL_ENABLE
" -G = make gpsd listen on INADDR_ANY\n"
#endif /* FORCE_GLOBAL_ENABLE */
" -P pidfile = set file to record process ID \n\
-D integer (default 0) = set debug level \n\
-S integer (default %s) = set port for daemon \n\
-h = help message \n\
-V = emit version and exit.\n\
A device may be a local serial device for GPS input, or a URL in one \n\
of the following forms:\n\
tcp://host[:port]\n\
udp://host[:port]\n\
{dgpsip|ntrip}://[user:passwd@]host[:port][/stream]\n\
gpsd://host[:port][/device][?protocol]\n\
in which case it specifies an input source for device, DGPS or ntrip data.\n\
\n\
The following driver types are compiled into this gpsd instance:\n",
DEFAULT_GPSD_PORT);
typelist();
}
#ifdef CONTROL_SOCKET_ENABLE
static socket_t filesock(char *filename)
{
struct sockaddr_un addr;
socket_t sock;
/*@ -mayaliasunique -usedef @*/
if (BAD_SOCKET(sock = socket(AF_UNIX, SOCK_STREAM, 0))) {
gpsd_report(&context.errout, LOG_ERROR, "Can't create device-control socket\n");
return -1;
}
(void)strlcpy(addr.sun_path, filename, sizeof(addr.sun_path));
addr.sun_family = (sa_family_t)AF_UNIX;
if (bind(sock, (struct sockaddr *)&addr, (int)sizeof(addr)) < 0) {
gpsd_report(&context.errout, LOG_ERROR, "can't bind to local socket %s\n", filename);
(void)close(sock);
return -1;
}
if (listen(sock, QLEN) == -1) {
gpsd_report(&context.errout, LOG_ERROR, "can't listen on local socket %s\n", filename);
(void)close(sock);
return -1;
}
/*@ +mayaliasunique +usedef @*/
/* coverity[leaked_handle] This is an intentional allocation */
return sock;
}
#endif /* CONTROL_SOCKET_ENABLE */
/*
* This hackery is intended to support SBCs that are resource-limited
* and only need to support one or a few devices each. It avoids the
* space overhead of allocating thousands of unused device structures.
* This array fills from the bottom, so as an extreme case you could
* reduce LIMITED_MAX_DEVICES to 1.
*/
#ifdef LIMITED_MAX_DEVICES
#define MAXDEVICES LIMITED_MAX_DEVICES
#else
/* we used to make this FD_SETSIZE, but that cost 14MB of wasted core! */
#define MAXDEVICES 4
#endif
#define sub_index(s) (int)((s) - subscribers)
#define allocated_device(devp) ((devp)->gpsdata.dev.path[0] != '\0')
#define free_device(devp) (devp)->gpsdata.dev.path[0] = '\0'
#define initialized_device(devp) ((devp)->context != NULL)
static struct gps_device_t devices[MAXDEVICES];
static void adjust_max_fd(int fd, bool on)
/* track the largest fd currently in use */
{
if (on) {
if (fd > maxfd)
maxfd = fd;
}
#if !defined(LIMITED_MAX_DEVICES) && !defined(LIMITED_MAX_CLIENT_FD)
/*
* I suspect there could be some weird interactions here if
* either of these were set lower than FD_SETSIZE. We'll avoid
* potential bugs by not scavenging in this case at all -- should
* be OK, as the use case for limiting is SBCs where the limits
* will be very low (typically 1) and the maximum size of fd
* set to scan through correspondingly small.
*/
else {
if (fd == maxfd) {
int tfd;
for (maxfd = tfd = 0; tfd < FD_SETSIZE; tfd++)
if (FD_ISSET(tfd, &all_fds))
maxfd = tfd;
}
}
#endif /* !defined(LIMITED_MAX_DEVICES) && !defined(LIMITED_MAX_CLIENT_FD) */
}
#ifdef SOCKET_EXPORT_ENABLE
#ifndef IPTOS_LOWDELAY
#define IPTOS_LOWDELAY 0x10
#endif
static socket_t passivesock_af(int af, char *service, char *tcp_or_udp, int qlen)
/* bind a passive command socket for the daemon */
{
volatile socket_t s;
/*
* af = address family,
* service = IANA protocol name or number.
* tcp_or_udp = TCP or UDP
* qlen = maximum wait-queue length for connections
*/
struct servent *pse;
struct protoent *ppe; /* splint has a bug here */
sockaddr_t sat;
int sin_len = 0;
int type, proto, one = 1;
in_port_t port;
char *af_str = "";
const int dscp = IPTOS_LOWDELAY; /* Prioritize packet */
INVALIDATE_SOCKET(s);
if ((pse = getservbyname(service, tcp_or_udp)))
port = ntohs((in_port_t) pse->s_port);
// cppcheck-suppress unreadVariable
else if ((port = (in_port_t) atoi(service)) == 0) {
gpsd_report(&context.errout, LOG_ERROR,
"can't get \"%s\" service entry.\n", service);
return -1;
}
ppe = getprotobyname(tcp_or_udp);
if (strcmp(tcp_or_udp, "udp") == 0) {
type = SOCK_DGRAM;
/*@i@*/ proto = (ppe) ? ppe->p_proto : IPPROTO_UDP;
} else {
type = SOCK_STREAM;
/*@i@*/ proto = (ppe) ? ppe->p_proto : IPPROTO_TCP;
}
/*@ -mustfreefresh +matchanyintegral @*/
switch (af) {
case AF_INET:
sin_len = sizeof(sat.sa_in);
memset((char *)&sat.sa_in, 0, sin_len);
sat.sa_in.sin_family = (sa_family_t) AF_INET;
#ifndef S_SPLINT_S
#ifndef FORCE_GLOBAL_ENABLE
if (!listen_global)
sat.sa_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
else
#endif /* FORCE_GLOBAL_ENABLE */
sat.sa_in.sin_addr.s_addr = htonl(INADDR_ANY);
sat.sa_in.sin_port = htons(port);
#endif /* S_SPLINT_S */
af_str = "IPv4";
/* see PF_INET6 case below */
s = socket(PF_INET, type, proto);
if (s > -1 ) {
/*@-unrecog@*/
/* Set packet priority */
if (setsockopt(s, IPPROTO_IP, IP_TOS, &dscp, sizeof(dscp)) == -1)
gpsd_report(&context.errout, LOG_WARN,
"Warning: SETSOCKOPT TOS failed\n");
}
/*@+unrecog@*/
break;
#ifdef IPV6_ENABLE
case AF_INET6:
#ifndef S_SPLINT_S
sin_len = sizeof(sat.sa_in6);
memset((char *)&sat.sa_in6, 0, sin_len);
sat.sa_in6.sin6_family = (sa_family_t) AF_INET6;
#ifndef FORCE_GLOBAL_ENABLE
if (!listen_global)
sat.sa_in6.sin6_addr = in6addr_loopback;
else
#endif /* FORCE_GLOBAL_ENABLE */
sat.sa_in6.sin6_addr = in6addr_any;
sat.sa_in6.sin6_port = htons(port);
/*
* Traditionally BSD uses "communication domains", named by
* constants starting with PF_ as the first argument for
* select. In practice PF_INET has the same value as AF_INET
* (on BSD and Linux, and probably everywhere else). POSIX
* leaves much of this unspecified, but requires that AF_INET
* be recognized. We follow tradition here.
*/
af_str = "IPv6";
s = socket(PF_INET6, type, proto);
/*
* On some network stacks, including Linux's, an IPv6 socket
* defaults to listening on IPv4 as well. Unless we disable
* this, trying to listen on in6addr_any will fail with the
* address-in-use error condition.
*/
if (s > -1) {
int on = 1;
if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) {
gpsd_report(&context.errout, LOG_ERROR,
"Error: SETSOCKOPT IPV6_V6ONLY\n");
(void)close(s);
return -1;
}
/* Set packet priority */
if (setsockopt(s, IPPROTO_IPV6, IPV6_TCLASS, &dscp, sizeof(dscp)) == -1)
gpsd_report(&context.errout, LOG_WARN,
"Warning: SETSOCKOPT TOS failed\n");
}
#endif /* S_SPLINT_S */
break;
#endif /* IPV6_ENABLE */
default:
gpsd_report(&context.errout, LOG_ERROR,
"unhandled address family %d\n", af);
return -1;
}
gpsd_report(&context.errout, LOG_IO,
"opening %s socket\n", af_str);
if (BAD_SOCKET(s)) {
gpsd_report(&context.errout, LOG_ERROR,
"can't create %s socket\n", af_str);
return -1;
}
if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&one,
(int)sizeof(one)) == -1) {
gpsd_report(&context.errout, LOG_ERROR,
"Error: SETSOCKOPT SO_REUSEADDR\n");
(void)close(s);
return -1;
}
if (bind(s, &sat.sa, sin_len) < 0) {
gpsd_report(&context.errout, LOG_ERROR,
"can't bind to %s port %s, %s\n", af_str,
service, strerror(errno));
if (errno == EADDRINUSE) {
gpsd_report(&context.errout, LOG_ERROR,
"maybe gpsd is already running!\n");
}
(void)close(s);
return -1;
}
if (type == SOCK_STREAM && listen(s, qlen) == -1) {
gpsd_report(&context.errout, LOG_ERROR, "can't listen on port %s\n", service);
(void)close(s);
return -1;
}
gpsd_report(&context.errout, LOG_SPIN, "passivesock_af() -> %d\n", s);
return s;
/*@ +mustfreefresh -matchanyintegral @*/
}
/* *INDENT-OFF* */
static int passivesocks(char *service, char *tcp_or_udp,
int qlen, /*@out@*/socket_t socks[])
{
int numsocks = AFCOUNT;
int i;
for (i = 0; i < AFCOUNT; i++)
INVALIDATE_SOCKET(socks[i]);
#if defined(SYSTEMD_ENABLE)
if (sd_socket_count > 0) {
for (i = 0; i < AFCOUNT && i < sd_socket_count - 1; i++) {
socks[i] = SD_SOCKET_FDS_START + i + 1;
}
return sd_socket_count - 1;
}
#endif
if (AF_UNSPEC == af || (AF_INET == af))
socks[0] = passivesock_af(AF_INET, service, tcp_or_udp, qlen);
if (AF_UNSPEC == af || (AF_INET6 == af))
socks[1] = passivesock_af(AF_INET6, service, tcp_or_udp, qlen);
for (i = 0; i < AFCOUNT; i++)
if (socks[i] < 0)
numsocks--;
/* Return the number of succesfully opened sockets
* The failed ones are identified by negative values */
return numsocks;
}
/* *INDENT-ON* */
struct subscriber_t
{
int fd; /* client file descriptor. -1 if unused */
timestamp_t active; /* when subscriber last polled for data */
struct policy_t policy; /* configurable bits */
pthread_mutex_t mutex; /* serialize access to fd */
};
#ifdef LIMITED_MAX_CLIENTS
#define MAXSUBSCRIBERS LIMITED_MAX_CLIENTS
#else
/* subscriber structure is small enough that there's no need to limit this */
#define MAXSUBSCRIBERS FD_SETSIZE
#endif
#define subscribed(sub, devp) (sub->policy.watcher && (sub->policy.devpath[0]=='\0' || strcmp(sub->policy.devpath, devp->gpsdata.dev.path)==0))
static struct subscriber_t subscribers[MAXSUBSCRIBERS]; /* indexed by client file descriptor */
static void lock_subscriber(struct subscriber_t *sub)
{
(void)pthread_mutex_lock(&sub->mutex);
}
static void unlock_subscriber(struct subscriber_t *sub)
{
(void)pthread_mutex_unlock(&sub->mutex);
}
static /*@null@*//*@observer@ */ struct subscriber_t *allocate_client(void)
/* return the address of a subscriber structure allocated for a new session */
{
int si;
#if UNALLOCATED_FD == 0
#error client allocation code will fail horribly
#endif
for (si = 0; si < NITEMS(subscribers); si++) {
if (subscribers[si].fd == UNALLOCATED_FD) {
subscribers[si].fd = 0; /* mark subscriber as allocated */
return &subscribers[si];
}
}
return NULL;
}
static void detach_client(struct subscriber_t *sub)
/* detach a client and terminate the session */
{
char *c_ip;
lock_subscriber(sub);
if (sub->fd == UNALLOCATED_FD) {
unlock_subscriber(sub);
return;
}
c_ip = netlib_sock2ip(sub->fd);
(void)shutdown(sub->fd, SHUT_RDWR);
gpsd_report(&context.errout, LOG_SPIN,
"close(%d) in detach_client()\n",
sub->fd);
(void)close(sub->fd);
gpsd_report(&context.errout, LOG_INF,
"detaching %s (sub %d, fd %d) in detach_client\n",
c_ip, sub_index(sub), sub->fd);
FD_CLR(sub->fd, &all_fds);
adjust_max_fd(sub->fd, false);
sub->active = (timestamp_t)0;
sub->policy.watcher = false;
sub->policy.json = false;
sub->policy.nmea = false;
sub->policy.raw = 0;
sub->policy.scaled = false;
sub->policy.timing = false;
sub->policy.split24 = false;
sub->policy.devpath[0] = '\0';
sub->fd = UNALLOCATED_FD;
unlock_subscriber(sub);
/*@+mustfreeonly@*/
}
static ssize_t throttled_write(struct subscriber_t *sub, char *buf,
size_t len)
/* write to client -- throttle if it's gone or we're close to buffer overrun */
{
ssize_t status;
if (context.errout.debug >= LOG_CLIENT) {
if (isprint((unsigned char) buf[0]))
gpsd_report(&context.errout, LOG_CLIENT,
"=> client(%d): %s\n", sub_index(sub), buf);
else {
char *cp, buf2[MAX_PACKET_LENGTH * 3];
buf2[0] = '\0';
for (cp = buf; cp < buf + len; cp++)
(void)snprintf(buf2 + strlen(buf2),
sizeof(buf2) - strlen(buf2),
"%02x", (unsigned int)(*cp & 0xff));
gpsd_report(&context.errout, LOG_CLIENT,
"=> client(%d): =%s\n", sub_index(sub), buf2);
}
}
#if defined(PPS_ENABLE)
gpsd_acquire_reporting_lock();
#endif /* PPS_ENABLE */
status = send(sub->fd, buf, len, 0);
#if defined(PPS_ENABLE)
gpsd_release_reporting_lock();
#endif /* PPS_ENABLE */
if (status == (ssize_t) len)
return status;
else if (status > -1) {
gpsd_report(&context.errout, LOG_INF,
"short write disconnecting client(%d)\n",
sub_index(sub));
detach_client(sub);
return 0;
} else if (errno == EAGAIN || errno == EINTR)
return 0; /* no data written, and errno says to retry */
else if (errno == EBADF)
gpsd_report(&context.errout, LOG_WARN, "client(%d) has vanished.\n", sub_index(sub));
else if (errno == EWOULDBLOCK
&& timestamp() - sub->active > NOREAD_TIMEOUT)
gpsd_report(&context.errout, LOG_INF,
"client(%d) timed out.\n", sub_index(sub));
else
gpsd_report(&context.errout, LOG_INF,
"client(%d) write: %s\n",
sub_index(sub), strerror(errno));
detach_client(sub);
return status;
}
static void notify_watchers(struct gps_device_t *device,
const char *sentence, ...)
/* notify all JSON-watching clients of a given device about an event */
{
va_list ap;
char buf[BUFSIZ];
struct subscriber_t *sub;
va_start(ap, sentence);
(void)vsnprintf(buf, sizeof(buf), sentence, ap);
va_end(ap);
for (sub = subscribers; sub < subscribers + MAXSUBSCRIBERS; sub++)
if (sub->active != 0 && subscribed(sub, device)) {
if (sub->policy.json)
(void)throttled_write(sub, buf, strlen(buf));
}
}
#endif /* SOCKET_EXPORT_ENABLE */
static void deactivate_device(struct gps_device_t *device)
/* deactivate device, but leave it in the pool (do not free it) */
{
#ifdef SOCKET_EXPORT_ENABLE
notify_watchers(device,
"{\"class\":\"DEVICE\",\"path\":\"%s\",\"activated\":0}\r\n",
device->gpsdata.dev.path);
#endif /* SOCKET_EXPORT_ENABLE */
if (!BAD_SOCKET(device->gpsdata.gps_fd)) {
FD_CLR(device->gpsdata.gps_fd, &all_fds);
adjust_max_fd(device->gpsdata.gps_fd, false);
#if defined(PPS_ENABLE) && defined(TIOCMIWAIT)
#endif /* defined(PPS_ENABLE) && defined(TIOCMIWAIT) */
#ifdef NTPSHM_ENABLE
ntpshm_link_deactivate(device);
#endif /* NTPSHM_ENABLE */
gpsd_deactivate(device);
}
}
#if defined(SOCKET_EXPORT_ENABLE) || defined(CONTROL_SOCKET_ENABLE)
/* *INDENT-OFF* */
/*@null@*//*@observer@*/ static struct gps_device_t *find_device(/*@null@*/const char
*device_name)
/* find the device block for an existing device name */
{
struct gps_device_t *devp;
for (devp = devices; devp < devices + MAXDEVICES; devp++)
{
if (allocated_device(devp) && NULL != device_name &&
strcmp(devp->gpsdata.dev.path, device_name) == 0)
return devp;
}
return NULL;
}
/* *INDENT-ON* */
#endif /* defined(SOCKET_EXPORT_ENABLE) || defined(CONTROL_SOCKET_ENABLE) */
static bool open_device( /*@null@*/struct gps_device_t *device)
{
if (NULL == device || gpsd_activate(device, O_OPTIMIZE) < 0) {
return false;
}
#ifdef NTPSHM_ENABLE
/*
* Now is the right time to grab the shared memory segment(s)
* to communicate the navigation message derived and (possibly)
* 1PPS derived time data to ntpd/chrony.
*/
ntpshm_link_activate(device);
gpsd_report(&context.errout, LOG_INF,
"NTPD ntpshm_link_activate: %d\n",
(int)device->shmIndex >= 0);
#endif /* NTPSHM_ENABLE */
gpsd_report(&context.errout, LOG_INF,
"device %s activated\n", device->gpsdata.dev.path);
FD_SET(device->gpsdata.gps_fd, &all_fds);
adjust_max_fd(device->gpsdata.gps_fd, true);
return true;
}
bool gpsd_add_device(const char *device_name, bool flag_nowait)
/* add a device to the pool; open it right away if in nowait mode */
{
struct gps_device_t *devp;
bool ret = false;
/* we can't handle paths longer than GPS_PATH_MAX, so don't try */
if (strlen(device_name) >= GPS_PATH_MAX) {
gpsd_report(&context.errout, LOG_ERROR,
"ignoring device %s: path length exceeds maximum %d\n",
device_name, GPS_PATH_MAX);
return false;
}
/* stash devicename away for probing when the first client connects */
for (devp = devices; devp < devices + MAXDEVICES; devp++)
if (!allocated_device(devp)) {
gpsd_init(devp, &context, device_name);
#ifdef NTPSHM_ENABLE
ntpshm_session_init(devp);
#endif /* NTPSHM_ENABLE */
gpsd_report(&context.errout, LOG_INF,
"stashing device %s at slot %d\n",
device_name, (int)(devp - devices));
if (!flag_nowait) {
devp->gpsdata.gps_fd = UNALLOCATED_FD;
ret = true;
} else {
ret = open_device(devp);
}
#ifdef SOCKET_EXPORT_ENABLE
notify_watchers(devp,
"{\"class\":\"DEVICE\",\"path\":\"%s\",\"activated\":%lf}\r\n",
devp->gpsdata.dev.path, timestamp());
#endif /* SOCKET_EXPORT_ENABLE */
break;
}
return ret;
}
#ifdef CONTROL_SOCKET_ENABLE
/*@ observer @*/ static char *snarfline(char *p, /*@out@*/ char **out)
/* copy the rest of the command line, before CR-LF */
{
char *q;
static char stash[BUFSIZ];
/*@ -temptrans -mayaliasunique @*/
for (q = p; isprint((unsigned char) *p) && !isspace((unsigned char) *p) && /*@i@*/ (p - q < BUFSIZ - 1);
p++)
continue;
(void)memcpy(stash, q, (size_t) (p - q));
stash[p - q] = '\0';
*out = stash;
return p;
/*@ +temptrans +mayaliasunique @*/
}
static void handle_control(int sfd, char *buf)
/* handle privileged commands coming through the control socket */
{
char *stash;
struct gps_device_t *devp;
/*
* The only other place in the code that knows about the format
* of the + and - commands is the gpsd_control() function in
* gpsdctl.c. Be careful about keeping them in sync, or
* hotplugging will have mysterious failures.
*/
/*@ -sefparams @*/
if (buf[0] == '-') {
/* remove device named after - */
(void)snarfline(buf + 1, &stash);
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): removing %s\n", sfd, stash);
if ((devp = find_device(stash))) {
deactivate_device(devp);
free_device(devp);
ignore_return(write(sfd, "OK\n", 3));
} else
ignore_return(write(sfd, "ERROR\n", 6));
} else if (buf[0] == '+') {
/* add device named after + */
(void)snarfline(buf + 1, &stash);
if (find_device(stash)) {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): %s already active \n", sfd,
stash);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): adding %s\n", sfd, stash);
if (gpsd_add_device(stash, NOWAIT))
ignore_return(write(sfd, "OK\n", 3));
else
ignore_return(write(sfd, "ERROR\n", 6));
}
} else if (buf[0] == '!') {
/* split line after ! into device=string, send string to device */
char *eq;
(void)snarfline(buf + 1, &stash);
eq = strchr(stash, '=');
if (eq == NULL) {
gpsd_report(&context.errout, LOG_WARN,
"<= control(%d): ill-formed command \n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
*eq++ = '\0';
if ((devp = find_device(stash))) {
if (devp->context->readonly || (devp->sourcetype <= source_blockdev)) {
gpsd_report(&context.errout, LOG_WARN,
"<= control(%d): attempted to write to a read-only device\n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): writing to %s \n", sfd,
stash);
if (write(devp->gpsdata.gps_fd, eq, strlen(eq)) <= 0) {
gpsd_report(&context.errout, LOG_WARN, "<= control(%d): write to device failed\n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
ignore_return(write(sfd, "OK\n", 3));
}
}
} else {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): %s not active \n", sfd,
stash);
ignore_return(write(sfd, "ERROR\n", 6));
}
}
} else if (buf[0] == '&') {
/* split line after & into dev=hexdata, send unpacked hexdata to dev */
char *eq;
(void)snarfline(buf + 1, &stash);
eq = strchr(stash, '=');
if (eq == NULL) {
gpsd_report(&context.errout, LOG_WARN,
"<= control(%d): ill-formed command\n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
size_t len;
*eq++ = '\0';
len = strlen(eq) + 5;
if ((devp = find_device(stash)) != NULL) {
if (devp->context->readonly || (devp->sourcetype <= source_blockdev)) {
gpsd_report(&context.errout, LOG_WARN,
"<= control(%d): attempted to write to a read-only device\n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
int st;
/* NOTE: this destroys the original buffer contents */
st = gpsd_hexpack(eq, eq, len);
if (st <= 0) {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): invalid hex string (error %d).\n",
sfd, st);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): writing %d bytes fromhex(%s) to %s\n",
sfd, st, eq, stash);
if (write(devp->gpsdata.gps_fd, eq, (size_t) st) <= 0) {
gpsd_report(&context.errout, LOG_WARN,
"<= control(%d): write to device failed\n",
sfd);
ignore_return(write(sfd, "ERROR\n", 6));
} else {
ignore_return(write(sfd, "OK\n", 3));
}
}
}
} else {
gpsd_report(&context.errout, LOG_INF,
"<= control(%d): %s not active\n", sfd,
stash);
ignore_return(write(sfd, "ERROR\n", 6));
}
}
} else if (strstr(buf, "?devices")==buf) {
/* write back devices list followed by OK */
for (devp = devices; devp < devices + MAXDEVICES; devp++) {
char *path = devp->gpsdata.dev.path;
ignore_return(write(sfd, path, strlen(path)));
ignore_return(write(sfd, "\n", 1));
}
ignore_return(write(sfd, "OK\n", 3));
} else {
/* unknown command */
ignore_return(write(sfd, "ERROR\n", 6));
}
/*@ +sefparams @*/
}
#endif /* CONTROL_SOCKET_ENABLE */
#ifdef SOCKET_EXPORT_ENABLE
static bool awaken(struct gps_device_t *device)
/* awaken a device and notify all watchers*/
{
/* open that device */
if (!initialized_device(device)) {
if (!open_device(device)) {
gpsd_report(&context.errout, LOG_WARN,
"%s: open failed\n",
device->gpsdata.dev.path);
free_device(device);
return false;
}
}
if (!BAD_SOCKET(device->gpsdata.gps_fd)) {
gpsd_report(&context.errout, LOG_PROG,
"device %d (fd=%d, path %s) already active.\n",
(int)(device - devices),
device->gpsdata.gps_fd, device->gpsdata.dev.path);
return true;
} else {
if (gpsd_activate(device, O_OPTIMIZE) < 0) {
gpsd_report(&context.errout, LOG_ERROR,
"%s: device activation failed.\n",
device->gpsdata.dev.path);
return false;
} else {
gpsd_report(&context.errout, LOG_RAW,
"flagging descriptor %d in assign_channel()\n",
device->gpsdata.gps_fd);
FD_SET(device->gpsdata.gps_fd, &all_fds);
adjust_max_fd(device->gpsdata.gps_fd, true);
return true;
}
}
}
#ifdef RECONFIGURE_ENABLE
static bool privileged_user(struct gps_device_t *device)
/* is this channel privileged to change a device's behavior? */
{
/* grant user privilege if he's the only one listening to the device */
struct subscriber_t *sub;
int subcount = 0;
for (sub = subscribers; sub < subscribers + MAXSUBSCRIBERS; sub++) {
if (subscribed(sub, device))
subcount++;
}
/*
* Yes, zero subscribers is possible. For example, gpsctl talking
* to the daemon connects but doesn't necessarily issue a ?WATCH
* before shipping a request, which means it isn't marked as a
* subscribers,
*/
return subcount <= 1;
}
static void set_serial(struct gps_device_t *device,
speed_t speed, char *modestring)
/* set serial parameters for a device from a speed and modestring */
{
unsigned int stopbits = device->gpsdata.dev.stopbits;