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libtdevnc/x11vnc/avahi.c

368 lines
8.2 KiB

/* -- avahi.c -- */
#include "x11vnc.h"
void avahi_initialise(void);
void avahi_advertise(const char *name, const char *host, const uint16_t port);
void avahi_reset(void);
void avahi_cleanup(void);
static pid_t avahi_pid = 0;
static void kill_avahi_pid(void) {
if (avahi_pid != 0) {
kill(avahi_pid, SIGTERM);
avahi_pid = 0;
}
}
static int try_avahi_helper(const char *name, const char *host, const uint16_t port) {
#if LIBVNCSERVER_HAVE_FORK
char *cmd, *p, *path = getenv("PATH"), portstr[32];
int i;
/* avahi-publish */
if (no_external_cmds || !cmd_ok("zeroconf")) {
return 0;
}
if (!path) {
return 0;
}
path = strdup(path);
cmd = (char *) malloc(strlen(path) + 100);
sprintf(portstr, "%d", (int) port);
p = strtok(path, ":");
while (p) {
struct stat sbuf;
sprintf(cmd, "%s/avahi-publish", p);
if (stat(cmd, &sbuf) == 0) {
break;
}
sprintf(cmd, "%s/dns-sd", p);
if (stat(cmd, &sbuf) == 0) {
break;
}
sprintf(cmd, "%s/mDNS", p);
if (stat(cmd, &sbuf) == 0) {
break;
}
cmd[0] = '\0';
p = strtok(NULL, ":");
}
free(path);
if (!strcmp(cmd, "")) {
free(cmd);
rfbLog("Could not find an external avahi/zeroconf helper program.\n");
return 0;
}
avahi_pid = fork();
if (avahi_pid < 0) {
rfbLogPerror("fork");
avahi_pid = 0;
free(cmd);
return 0;
}
if (avahi_pid != 0) {
int status;
usleep(500 * 1000);
waitpid(avahi_pid, &status, WNOHANG);
if (kill(avahi_pid, 0) != 0) {
waitpid(avahi_pid, &status, WNOHANG);
avahi_pid = 0;
free(cmd);
return 0;
}
if (! quiet) {
rfbLog("%s helper pid is: %d\n", cmd, (int) avahi_pid);
}
free(cmd);
return 1;
}
for (i=3; i<256; i++) {
close(i);
}
if (strstr(cmd, "/avahi-publish")) {
execlp(cmd, cmd, "-s", name, "_rfb._tcp", portstr, (char *) NULL);
} else {
execlp(cmd, cmd, "-R", name, "_rfb._tcp", ".", portstr, (char *) NULL);
}
exit(1);
#else
if (!name || !host || !port) {}
return 0;
#endif
}
#if !defined(LIBVNCSERVER_HAVE_AVAHI) || !defined(LIBVNCSERVER_HAVE_LIBPTHREAD)
void avahi_initialise(void) {
rfbLog("avahi_initialise: no Avahi support at buildtime.\n");
}
void avahi_advertise(const char *name, const char *host, const uint16_t port) {
if (!try_avahi_helper(name, host, port)) {
rfbLog("avahi_advertise: no Avahi support at buildtime.\n");
avahi = 0;
}
}
void avahi_reset(void) {
kill_avahi_pid();
rfbLog("avahi_reset: no Avahi support at buildtime.\n");
}
void avahi_cleanup(void) {
kill_avahi_pid();
rfbLog("avahi_cleanup: no Avahi support at buildtime.\n");
}
#else
#include <avahi-common/thread-watch.h>
#include <avahi-common/alternative.h>
#include <avahi-client/client.h>
#include <avahi-client/publish.h>
static AvahiThreadedPoll *_poll = NULL;
static AvahiClient *_client = NULL;
static AvahiEntryGroup *_group = NULL;
static int db = 0;
typedef struct {
const char *name;
const char *host;
uint16_t port;
} avahi_service_t;
typedef struct {
char *name;
char *host;
uint16_t port;
} avahi_reg_t;
#define NREG 16
static avahi_reg_t registered[NREG];
void avahi_initialise(void) {
int ret;
static int first = 1;
if (getenv("AVAHI_DEBUG")) {
db = 1;
}
if (first) {
int i;
for (i=0; i<NREG; i++) {
registered[i].name = NULL;
registered[i].host = NULL;
}
first = 0;
}
if (db) fprintf(stderr, "in avahi_initialise\n");
if (_poll) {
if (db) fprintf(stderr, " avahi_initialise: poll not null\n");
return;
}
if (! (_poll = avahi_threaded_poll_new()) ) {
rfbLog("warning: unable to open Avahi poll.\n");
return;
}
_client = avahi_client_new(avahi_threaded_poll_get(_poll),
0, NULL, NULL, &ret);
if (! _client) {
rfbLog("warning: unable to open Avahi client: %s\n",
avahi_strerror(ret));
avahi_threaded_poll_free(_poll);
_poll = NULL;
return;
}
if (avahi_threaded_poll_start(_poll) < 0) {
rfbLog("warning: unable to start Avahi poll.\n");
avahi_client_free(_client);
_client = NULL;
avahi_threaded_poll_free(_poll);
_poll = NULL;
return;
}
if (db) fprintf(stderr, "out avahi_initialise\n");
}
static void _avahi_create_services(const char *name, const char *host,
const uint16_t port);
static void _avahi_entry_group_callback(AvahiEntryGroup *g,
AvahiEntryGroupState state, void *userdata) {
char *new_name;
avahi_service_t *svc = (avahi_service_t *)userdata;
if (db) fprintf(stderr, "in _avahi_entry_group_callback %d 0x%p\n", state, svc);
if (g != _group && _group != NULL) {
rfbLog("avahi_entry_group_callback fatal error (group).\n");
clean_up_exit(1);
}
if (userdata == NULL) {
rfbLog("avahi_entry_group_callback fatal error (userdata).\n");
clean_up_exit(1);
}
switch(state) {
case AVAHI_ENTRY_GROUP_ESTABLISHED:
rfbLog("Avahi group %s established.\n", svc->name);
#if 0 /* is this the segv problem? */
free(svc);
#endif
break;
case AVAHI_ENTRY_GROUP_COLLISION:
new_name = avahi_alternative_service_name(svc->name);
_avahi_create_services(new_name, svc->host, svc->port);
rfbLog("Avahi Entry group collision\n");
avahi_free(new_name);
break;
case AVAHI_ENTRY_GROUP_FAILURE:
rfbLog("Avahi Entry group failure: %s\n",
avahi_strerror(avahi_client_errno(
avahi_entry_group_get_client(g))));
break;
}
if (db) fprintf(stderr, "out _avahi_entry_group_callback\n");
}
static void _avahi_create_services(const char *name, const char *host,
const uint16_t port) {
avahi_service_t *svc = (avahi_service_t *)malloc(sizeof(avahi_service_t));
int ret = 0;
if (db) fprintf(stderr, "in _avahi_create_services %s %s %d\n", name, host, port);
svc->name = name;
svc->host = host;
svc->port = port;
if (!_group) {
if (db) fprintf(stderr, " _avahi_create_services create group\n");
_group = avahi_entry_group_new(_client,
_avahi_entry_group_callback, svc);
}
if (!_group) {
rfbLog("avahi_entry_group_new() failed: %s\n",
avahi_strerror(avahi_client_errno(_client)));
return;
}
ret = avahi_entry_group_add_service(_group, AVAHI_IF_UNSPEC,
AVAHI_PROTO_UNSPEC, 0, name, "_rfb._tcp", NULL, NULL, port, NULL);
if (ret < 0) {
rfbLog("Failed to add _rfb._tcp service: %s\n",
avahi_strerror(ret));
return;
}
ret = avahi_entry_group_commit(_group);
if (ret < 0) {
rfbLog("Failed to commit entry_group:: %s\n",
avahi_strerror(ret));
return;
}
if (db) fprintf(stderr, "out _avahi_create_services\n");
}
void avahi_advertise(const char *name, const char *host, const uint16_t port) {
int i;
if (db) fprintf(stderr, "in avahi_advertise: %s %s %d\n", name, host, port);
if (!_client) {
if (db) fprintf(stderr, " avahi_advertise client null\n");
return;
}
if (_poll == NULL) {
rfbLog("Avahi poll not initialized.\n");
return;
}
/* well, we just track it ourselves... */
for (i=0; i<NREG; i++) {
if (!registered[i].name) {
continue;
}
if (strcmp(registered[i].name, name)) {
continue;
}
if (strcmp(registered[i].host, host)) {
continue;
}
if (registered[i].port != port) {
continue;
}
if (db) fprintf(stderr, " avahi_advertise already did this one\n");
return;
}
for (i=0; i<NREG; i++) {
if (!registered[i].name) {
registered[i].name = strdup(name);
registered[i].host = strdup(host);
registered[i].port = port;
break;
}
}
avahi_threaded_poll_lock(_poll);
_avahi_create_services(name, host, port >= 5900 ? port : 5900+port);
avahi_threaded_poll_unlock(_poll);
if (db) fprintf(stderr, "out avahi_advertise\n");
}
void avahi_reset(void) {
int i;
if (db) fprintf(stderr, "in avahi_reset\n");
for (i=0; i<NREG; i++) {
if (registered[i].name) {
free(registered[i].name);
registered[i].name = NULL;
}
if (registered[i].host) {
free(registered[i].host);
registered[i].host = NULL;
}
}
if (!_client || !_group) {
if (db) fprintf(stderr, " avahi_reset client/group null\n");
return;
}
avahi_entry_group_reset(_group);
rfbLog("Avahi resetting group.\n");
if (db) fprintf(stderr, "out avahi_reset\n");
}
void avahi_cleanup(void) {
if (db) fprintf(stderr, "in avahi_cleanup\n");
if (!_client) {
if (db) fprintf(stderr, " avahi_cleanup client null\n");
return;
}
avahi_threaded_poll_lock(_poll);
avahi_threaded_poll_stop(_poll);
avahi_client_free(_client);
_client = NULL;
avahi_threaded_poll_free(_poll);
_poll = NULL;
if (db) fprintf(stderr, "out avahi_cleanup\n");
}
#endif