bool flush_meta(connection_t *c) {
int result;
ifdebug(META) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s)",
c->outbuflen, c->name, c->hostname);
while(c->outbuflen) {
result = send(c->socket, c->outbuf + c->outbufstart, c->outbuflen, 0);
if(result <= 0) {
if(!errno || errno == EPIPE) {
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
c->name, c->hostname);
} else if(errno == EINTR) {
continue;
} else if(sockwouldblock(sockerrno)) {
ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Flushing %d bytes to %s (%s) would block",
c->outbuflen, c->name, c->hostname);
return true;
} else {
logger(LOG_ERR, "Flushing meta data to %s (%s) failed: %s", c->name,
c->hostname, sockstrerror(sockerrno));
}
return false;
}
c->outbufstart += result;
c->outbuflen -= result;
}
c->outbufstart = 0; /* avoid unnecessary memmoves */
return true;
}
/*
this is where it all happens...
*/
int main_loop(void) {
fd_set readset, writeset;
#ifdef HAVE_PSELECT
struct timespec tv;
sigset_t omask, block_mask;
time_t next_event;
#else
struct timeval tv;
#endif
int r, maxfd;
time_t last_ping_check, last_config_check, last_graph_dump;
event_t *event;
last_ping_check = now;
last_config_check = now;
last_graph_dump = now;
srand(now);
#ifdef HAVE_PSELECT
if(lookup_config(config_tree, "GraphDumpFile"))
graph_dump = true;
/* Block SIGHUP & SIGALRM */
sigemptyset(&block_mask);
sigaddset(&block_mask, SIGHUP);
sigaddset(&block_mask, SIGALRM);
sigprocmask(SIG_BLOCK, &block_mask, &omask);
#endif
running = true;
while(running) {
#ifdef HAVE_PSELECT
next_event = last_ping_check + pingtimeout;
if(graph_dump && next_event > last_graph_dump + 60)
next_event = last_graph_dump + 60;
if((event = peek_next_event()) && next_event > event->time)
next_event = event->time;
if(next_event <= now)
tv.tv_sec = 0;
else
tv.tv_sec = next_event - now;
tv.tv_nsec = 0;
#else
tv.tv_sec = 1;
tv.tv_usec = 0;
#endif
maxfd = build_fdset(&readset, &writeset);
#ifdef HAVE_MINGW
LeaveCriticalSection(&mutex);
#endif
#ifdef HAVE_PSELECT
r = pselect(maxfd + 1, &readset, &writeset, NULL, &tv, &omask);
#else
r = select(maxfd + 1, &readset, &writeset, NULL, &tv);
#endif
now = time(NULL);
#ifdef HAVE_MINGW
EnterCriticalSection(&mutex);
#endif
if(r < 0) {
if(!sockwouldblock(sockerrno)) {
logger(LOG_ERR, "Error while waiting for input: %s", sockstrerror(sockerrno));
dump_connections();
return 1;
}
}
if(r > 0)
check_network_activity(&readset, &writeset);
if(do_purge) {
purge();
do_purge = false;
}
/* Let's check if everybody is still alive */
if(last_ping_check + pingtimeout <= now) {
check_dead_connections();
last_ping_check = now;
if(routing_mode == RMODE_SWITCH)
age_subnets();
age_past_requests();
/* Should we regenerate our key? */
if(keyexpires <= now) {
avl_node_t *node;
node_t *n;
ifdebug(STATUS) logger(LOG_INFO, "Expiring symmetric keys");
for(node = node_tree->head; node; node = node->next) {
n = node->data;
if(n->inkey) {
free(n->inkey);
n->inkey = NULL;
}
}
send_key_changed();
keyexpires = now + keylifetime;
}
/* Detect ADD_EDGE/DEL_EDGE storms that are caused when
* two tinc daemons with the same name are on the VPN.
* If so, sleep a while. If this happens multiple times
* in a row, sleep longer. */
if(contradicting_del_edge > 100 && contradicting_add_edge > 100) {
logger(LOG_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", sleeptime);
usleep(sleeptime * 1000000LL);
sleeptime *= 2;
if(sleeptime < 0)
sleeptime = 3600;
} else {
sleeptime /= 2;
if(sleeptime < 10)
sleeptime = 10;
}
contradicting_add_edge = 0;
contradicting_del_edge = 0;
}
if(sigalrm) {
avl_node_t *node;
logger(LOG_INFO, "Flushing event queue");
expire_events();
for(node = connection_tree->head; node; node = node->next) {
connection_t *c = node->data;
if(c->status.active)
send_ping(c);
}
sigalrm = false;
}
while((event = get_expired_event())) {
event->handler(event->data);
free_event(event);
}
if(sighup) {
connection_t *c;
avl_node_t *node, *next;
char *fname;
struct stat s;
sighup = false;
reopenlogger();
/* Reread our own configuration file */
exit_configuration(&config_tree);
init_configuration(&config_tree);
if(!read_server_config()) {
logger(LOG_ERR, "Unable to reread configuration file, exitting.");
return 1;
}
/* Cancel non-active outgoing connections */
for(node = connection_tree->head; node; node = next) {
next = node->next;
c = node->data;
c->outgoing = NULL;
if(c->status.connecting) {
terminate_connection(c, false);
connection_del(c);
}
}
/* Wipe list of outgoing connections */
for(list_node_t *node = outgoing_list->head; node; node = node->next) {
outgoing_t *outgoing = node->data;
if(outgoing->event)
event_del(outgoing->event);
}
list_delete_list(outgoing_list);
/* Close connections to hosts that have a changed or deleted host config file */
for(node = connection_tree->head; node; node = node->next) {
c = node->data;
xasprintf(&fname, "%s/hosts/%s", confbase, c->name);
if(stat(fname, &s) || s.st_mtime > last_config_check)
terminate_connection(c, c->status.active);
free(fname);
}
last_config_check = now;
/* If StrictSubnet is set, expire deleted Subnets and read new ones in */
if(strictsubnets) {
subnet_t *subnet;
for(node = subnet_tree->head; node; node = node->next) {
subnet = node->data;
subnet->expires = 1;
}
load_all_subnets();
for(node = subnet_tree->head; node; node = next) {
next = node->next;
subnet = node->data;
if(subnet->expires == 1) {
send_del_subnet(everyone, subnet);
if(subnet->owner->status.reachable)
subnet_update(subnet->owner, subnet, false);
subnet_del(subnet->owner, subnet);
} else if(subnet->expires == -1) {
subnet->expires = 0;
} else {
send_add_subnet(everyone, subnet);
if(subnet->owner->status.reachable)
subnet_update(subnet->owner, subnet, true);
}
}
}
/* Try to make outgoing connections */
try_outgoing_connections();
}
/* Dump graph if wanted every 60 seconds*/
if(last_graph_dump + 60 <= now) {
dump_graph();
last_graph_dump = now;
}
}
#ifdef HAVE_PSELECT
/* Restore SIGHUP & SIGALARM mask */
sigprocmask(SIG_SETMASK, &omask, NULL);
#endif
return 0;
}
bool receive_meta(connection_t *c) {
int oldlen, i, result;
int lenin, lenout, reqlen;
bool decrypted = false;
char inbuf[MAXBUFSIZE];
/* Strategy:
- Read as much as possible from the TCP socket in one go.
- Decrypt it.
- Check if a full request is in the input buffer.
- If yes, process request and remove it from the buffer,
then check again.
- If not, keep stuff in buffer and exit.
*/
lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
if(lenin <= 0) {
if(!lenin || !errno) {
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
c->name, c->hostname);
} else if(sockwouldblock(sockerrno))
return true;
else
logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
c->name, c->hostname, sockstrerror(sockerrno));
return false;
}
oldlen = c->buflen;
c->buflen += lenin;
while(lenin > 0) {
/* Decrypt */
if(c->status.decryptin && !decrypted) {
result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
if(!result || lenout != lenin) {
logger(LOG_ERR, "Error while decrypting metadata from %s (%s): %s",
c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
memcpy(c->buffer + oldlen, inbuf, lenin);
decrypted = true;
}
/* Are we receiving a TCPpacket? */
if(c->tcplen) {
if(c->tcplen <= c->buflen) {
if(!c->node) {
if(c->outgoing && proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
if(c->buffer[0] == 0 && c->buffer[1] == 0x5a) {
ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Proxy request granted");
} else {
logger(LOG_ERR, "Proxy request rejected");
return false;
}
} else if(c->outgoing && proxytype == PROXY_SOCKS5 && c->allow_request == ID) {
if(c->buffer[0] != 5) {
logger(LOG_ERR, "Invalid response from proxy server");
return false;
}
if(c->buffer[1] == (char)0xff) {
logger(LOG_ERR, "Proxy request rejected: unsuitable authentication method");
return false;
}
if(c->buffer[2] != 5) {
logger(LOG_ERR, "Invalid response from proxy server");
return false;
}
if(c->buffer[3] == 0) {
ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Proxy request granted");
} else {
logger(LOG_ERR, "Proxy request rejected");
return false;
}
} else {
logger(LOG_ERR, "c->tcplen set but c->node is NULL!");
abort();
}
} else {
if(c->allow_request == ALL) {
receive_tcppacket(c, c->buffer, c->tcplen);
} else {
logger(LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname);
return false;
}
}
c->buflen -= c->tcplen;
lenin -= c->tcplen - oldlen;
memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
oldlen = 0;
c->tcplen = 0;
continue;
} else {
break;
}
}
/* Otherwise we are waiting for a request */
reqlen = 0;
for(i = oldlen; i < c->buflen; i++) {
if(c->buffer[i] == '\n') {
c->buffer[i] = '\0'; /* replace end-of-line by end-of-string so we can use sscanf */
reqlen = i + 1;
break;
}
}
if(reqlen) {
c->reqlen = reqlen;
if(!receive_request(c))
return false;
c->buflen -= reqlen;
lenin -= reqlen - oldlen;
memmove(c->buffer, c->buffer + reqlen, c->buflen);
oldlen = 0;
continue;
} else {
break;
}
}
if(c->buflen >= MAXBUFSIZE) {
logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
c->name, c->hostname);
return false;
}
return true;
}
bool receive_meta(connection_t *c) {
int oldlen, i, result;
int lenin, lenout, reqlen;
bool decrypted = false;
char inbuf[MAXBUFSIZE];
/* Strategy:
- Read as much as possible from the TCP socket in one go.
- Decrypt it.
- Check if a full request is in the input buffer.
- If yes, process request and remove it from the buffer,
then check again.
- If not, keep stuff in buffer and exit.
*/
lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
if(lenin <= 0) {
if(!lenin || !errno) {
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
c->name, c->hostname);
} else if(sockwouldblock(sockerrno))
return true;
else
logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
c->name, c->hostname, sockstrerror(sockerrno));
return false;
}
oldlen = c->buflen;
c->buflen += lenin;
while(lenin > 0) {
/* Decrypt */
if(c->status.decryptin && !decrypted) {
result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
if(!result || lenout != lenin) {
logger(LOG_ERR, "Error while decrypting metadata from %s (%s): %s",
c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
memcpy(c->buffer + oldlen, inbuf, lenin);
decrypted = true;
}
/* Are we receiving a TCPpacket? */
if(c->tcplen) {
if(c->tcplen <= c->buflen) {
receive_tcppacket(c, c->buffer, c->tcplen);
c->buflen -= c->tcplen;
lenin -= c->tcplen - oldlen;
memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
oldlen = 0;
c->tcplen = 0;
continue;
} else {
break;
}
}
/* Otherwise we are waiting for a request */
reqlen = 0;
for(i = oldlen; i < c->buflen; i++) {
if(c->buffer[i] == '\n') {
c->buffer[i] = '\0'; /* replace end-of-line by end-of-string so we can use sscanf */
reqlen = i + 1;
break;
}
}
if(reqlen) {
c->reqlen = reqlen;
if(!receive_request(c))
return false;
c->buflen -= reqlen;
lenin -= reqlen - oldlen;
memmove(c->buffer, c->buffer + reqlen, c->buflen);
oldlen = 0;
continue;
} else {
break;
}
}
if(c->buflen >= MAXBUFSIZE) {
logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
c->name, c->hostname);
return false;
}
return true;
}
