X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fnet.c;h=9799feabdf73952f3dc709434210f6014dee31d4;hb=c6b1643c2bcc727db4aed69bc58eb1f31903fdcf;hp=6de95b5f0c87ebb1ed7778c42856fa0c7499f302;hpb=9d023b1f2e7750f4a0e506c0f61498a44c0b95a8;p=tinc diff --git a/src/net.c b/src/net.c index 6de95b5f..9799feab 100644 --- a/src/net.c +++ b/src/net.c @@ -1,6 +1,9 @@ /* net.c -- most of the network code - Copyright (C) 1998,1999,2000 Ivo Timmermans + Copyright (C) 1998-2005 Ivo Timmermans, + 2000-2012 Guus Sliepen + 2006 Scott Lamb + 2011 Loïc Grenié This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -12,822 +15,203 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "config.h" - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include +#include "system.h" +#include + +#include "utils.h" +#include "avl_tree.h" #include "conf.h" -#include "encr.h" +#include "connection.h" +#include "device.h" +#include "event.h" +#include "graph.h" +#include "logger.h" +#include "meta.h" #include "net.h" #include "netutl.h" +#include "process.h" #include "protocol.h" +#include "route.h" +#include "subnet.h" +#include "xalloc.h" + +bool do_purge = false; +volatile bool running = false; +#ifdef HAVE_PSELECT +bool graph_dump = false; +#endif + +time_t now = 0; +int contradicting_add_edge = 0; +int contradicting_del_edge = 0; +static int sleeptime = 10; + +/* Purge edges and subnets of unreachable nodes. Use carefully. */ + +static void purge(void) { + avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext; + node_t *n; + edge_t *e; + subnet_t *s; + + ifdebug(PROTOCOL) logger(LOG_DEBUG, "Purging unreachable nodes"); + + /* Remove all edges and subnets owned by unreachable nodes. */ + + for(nnode = node_tree->head; nnode; nnode = nnext) { + nnext = nnode->next; + n = nnode->data; + + if(!n->status.reachable) { + ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Purging node %s (%s)", n->name, + n->hostname); + + for(snode = n->subnet_tree->head; snode; snode = snext) { + snext = snode->next; + s = snode->data; + send_del_subnet(everyone, s); + if(!strictsubnets) + subnet_del(n, s); + } + + for(enode = n->edge_tree->head; enode; enode = enext) { + enext = enode->next; + e = enode->data; + if(!tunnelserver) + send_del_edge(everyone, e); + edge_del(e); + } + } + } -int tap_fd = -1; - -int total_tap_in = 0; -int total_tap_out = 0; -int total_socket_in = 0; -int total_socket_out = 0; + /* Check if anyone else claims to have an edge to an unreachable node. If not, delete node. */ -/* The global list of existing connections */ -conn_list_t *conn_list = NULL; -conn_list_t *myself = NULL; + for(nnode = node_tree->head; nnode; nnode = nnext) { + nnext = nnode->next; + n = nnode->data; -/* - strip off the MAC adresses of an ethernet frame -*/ -void strip_mac_addresses(vpn_packet_t *p) -{ - unsigned char tmp[MAXSIZE]; -cp - memcpy(tmp, p->data, p->len); - p->len -= 12; - memcpy(p->data, &tmp[12], p->len); -cp -} + if(!n->status.reachable) { + for(enode = edge_weight_tree->head; enode; enode = enext) { + enext = enode->next; + e = enode->data; -/* - reassemble MAC addresses -*/ -void add_mac_addresses(vpn_packet_t *p) -{ - unsigned char tmp[MAXSIZE]; -cp - memcpy(&tmp[12], p->data, p->len); - p->len += 12; - tmp[0] = tmp[6] = 0xfe; - tmp[1] = tmp[7] = 0xfd; - *((ip_t*)(&tmp[2])) = (ip_t)(htonl(myself->vpn_ip)); - *((ip_t*)(&tmp[8])) = *((ip_t*)(&tmp[26])); - memcpy(p->data, &tmp[0], p->len); -cp -} - -int xsend(conn_list_t *cl, void *packet) -{ - int r; - real_packet_t rp; -cp - do_encrypt((vpn_packet_t*)packet, &rp, cl->key); - rp.from = htonl(myself->vpn_ip); - rp.data.len = htons(rp.data.len); - rp.len = htons(rp.len); - - if(debug_lvl > 3) - syslog(LOG_ERR, "Sent %d bytes to %lx", ntohs(rp.len), cl->vpn_ip); - - if((r = send(cl->socket, (char*)&rp, ntohs(rp.len), 0)) < 0) - { - syslog(LOG_ERR, "Error sending data: %m"); - return -1; - } - - total_socket_out += r; - - cl->want_ping = 1; -cp - return 0; -} + if(e->to == n) + break; + } -int xrecv(conn_list_t *cl, void *packet) -{ - vpn_packet_t vp; - int lenin; -cp - do_decrypt((real_packet_t*)packet, &vp, cl->key); - add_mac_addresses(&vp); - - if((lenin = write(tap_fd, &vp, vp.len + sizeof(vp.len))) < 0) - syslog(LOG_ERR, "Can't write to tap device: %m"); - else - total_tap_out += lenin; - - cl->want_ping = 0; - cl->last_ping_time = time(NULL); -cp - return 0; + if(!enode && (!strictsubnets || !n->subnet_tree->head)) + /* in strictsubnets mode do not delete nodes with subnets */ + node_del(n); + } + } } /* - add the given packet of size s to the - queue q, be it the send or receive queue + put all file descriptors in an fd_set array + While we're at it, purge stuff that needs to be removed. */ -void add_queue(packet_queue_t **q, void *packet, size_t s) -{ - queue_element_t *e; -cp - if(debug_lvl > 3) - syslog(LOG_DEBUG, "packet to queue: %d", s); - - e = xmalloc(sizeof(*e)); - e->packet = xmalloc(s); - memcpy(e->packet, packet, s); - - if(!*q) - { - *q = xmalloc(sizeof(**q)); - (*q)->head = (*q)->tail = NULL; - } - - e->next = NULL; /* We insert at the tail */ - - if((*q)->tail) /* Do we have a tail? */ - { - (*q)->tail->next = e; - e->prev = (*q)->tail; - } - else /* No tail -> no head too */ - { - (*q)->head = e; - e->prev = NULL; - } - - (*q)->tail = e; -cp -} +static int build_fdset(fd_set *readset, fd_set *writeset) { + avl_node_t *node, *next; + connection_t *c; + int i, max = 0; + + FD_ZERO(readset); + FD_ZERO(writeset); + + for(node = connection_tree->head; node; node = next) { + next = node->next; + c = node->data; + + if(c->status.remove) { + connection_del(c); + if(!connection_tree->head) + purge(); + } else { + FD_SET(c->socket, readset); + if(c->outbuflen > 0) + FD_SET(c->socket, writeset); + if(c->socket > max) + max = c->socket; + } + } -/* Remove a queue element */ -void del_queue(packet_queue_t **q, queue_element_t *e) -{ -cp - free(e->packet); - - if(e->next) /* There is a successor, so we are not tail */ - { - if(e->prev) /* There is a predecessor, so we are not head */ - { - e->next->prev = e->prev; - e->prev->next = e->next; - } - else /* We are head */ - { - e->next->prev = NULL; - (*q)->head = e->next; - } - } - else /* We are tail (or all alone!) */ - { - if(e->prev) /* We are not alone :) */ - { - e->prev->next = NULL; - (*q)->tail = e->prev; - } - else /* Adieu */ - { - free(*q); - *q = NULL; - } - } - - free(e); -cp -} + for(i = 0; i < listen_sockets; i++) { + FD_SET(listen_socket[i].tcp, readset); + if(listen_socket[i].tcp > max) + max = listen_socket[i].tcp; + FD_SET(listen_socket[i].udp, readset); + if(listen_socket[i].udp > max) + max = listen_socket[i].udp; + } -/* - flush a queue by calling function for - each packet, and removing it when that - returned a zero exit code -*/ -void flush_queue(conn_list_t *cl, packet_queue_t **pq, - int (*function)(conn_list_t*,void*)) -{ - queue_element_t *p, *next = NULL; -cp - for(p = (*pq)->head; p != NULL; ) - { - next = p->next; - - if(!function(cl, p->packet)) - del_queue(pq, p); - - p = next; - } - - if(debug_lvl > 3) - syslog(LOG_DEBUG, "queue flushed"); -cp + if(device_fd >= 0) + FD_SET(device_fd, readset); + if(device_fd > max) + max = device_fd; + + return max; } /* - flush the send&recv queues - void because nothing goes wrong here, packets - remain in the queue if something goes wrong + Terminate a connection: + - Close the socket + - Remove associated edge and tell other connections about it if report = true + - Check if we need to retry making an outgoing connection + - Deactivate the host */ -void flush_queues(conn_list_t *cl) -{ -cp - if(cl->sq) - { - if(debug_lvl > 1) - syslog(LOG_DEBUG, "Flushing send queue for " IP_ADDR_S, - IP_ADDR_V(cl->vpn_ip)); - flush_queue(cl, &(cl->sq), xsend); - } - - if(cl->rq) - { - if(debug_lvl > 1) - syslog(LOG_DEBUG, "Flushing receive queue for " IP_ADDR_S, - IP_ADDR_V(cl->vpn_ip)); - flush_queue(cl, &(cl->rq), xrecv); - } -cp -} +void terminate_connection(connection_t *c, bool report) { + if(c->status.remove) + return; -/* - send a packet to the given vpn ip. -*/ -int send_packet(ip_t to, vpn_packet_t *packet) -{ - conn_list_t *cl; -cp - if((cl = lookup_conn(to)) == NULL) - { - if(debug_lvl > 2) - { - syslog(LOG_NOTICE, "trying to look up " IP_ADDR_S " in connection list failed.", - IP_ADDR_V(to)); - } - for(cl = conn_list; cl != NULL && !cl->status.outgoing; cl = cl->next); - if(!cl) - { /* No open outgoing connection has been found. */ - if(debug_lvl > 2) - syslog(LOG_NOTICE, "There is no remote host I can send this packet to."); - return -1; - } - } - - if(my_key_expiry <= time(NULL)) - regenerate_keys(); - - if(!cl->status.dataopen) - if(setup_vpn_connection(cl) < 0) - return -1; - - if(!cl->status.validkey) - { - add_queue(&(cl->sq), packet, packet->len + 2); - if(!cl->status.waitingforkey) - send_key_request(cl->vpn_ip); /* Keys should be sent to the host running the tincd */ - return 0; - } - - if(!cl->status.active) - { - add_queue(&(cl->sq), packet, packet->len + 2); - if(debug_lvl > 1) - syslog(LOG_INFO, IP_ADDR_S " is not ready, queueing packet.", IP_ADDR_V(cl->vpn_ip)); - return 0; /* We don't want to mess up, do we? */ - } - - /* can we send it? can we? can we? huh? */ -cp - return xsend(cl, packet); -} + ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Closing connection with %s (%s)", + c->name, c->hostname); -/* - open the local ethertap device -*/ -int setup_tap_fd(void) -{ - int nfd; - const char *tapfname; - config_t const *cfg; -cp - if((cfg = get_config_val(tapdevice)) == NULL) - tapfname = "/dev/tap0"; - else - tapfname = cfg->data.ptr; - - if((nfd = open(tapfname, O_RDWR | O_NONBLOCK)) < 0) - { - syslog(LOG_ERR, "Could not open %s: %m", tapfname); - return -1; - } - - tap_fd = nfd; -cp - return 0; -} + c->status.remove = true; + c->status.active = false; -/* - set up the socket that we listen on for incoming - (tcp) connections -*/ -int setup_listen_meta_socket(int port) -{ - int nfd, flags; - struct sockaddr_in a; - const int one = 1; -cp - if((nfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) - { - syslog(LOG_ERR, "Creating metasocket failed: %m"); - return -1; - } - - if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one))) - { - syslog(LOG_ERR, "setsockopt: %m"); - return -1; - } - - flags = fcntl(nfd, F_GETFL); - if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) - { - syslog(LOG_ERR, "fcntl: %m"); - return -1; - } - - memset(&a, 0, sizeof(a)); - a.sin_family = AF_INET; - a.sin_port = htons(port); - a.sin_addr.s_addr = htonl(INADDR_ANY); - - if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr))) - { - syslog(LOG_ERR, "Can't bind to port %hd/tcp: %m", port); - return -1; - } - - if(listen(nfd, 3)) - { - syslog(LOG_ERR, "listen: %m"); - return -1; - } -cp - return nfd; -} + if(c->node) + c->node->connection = NULL; -/* - setup the socket for incoming encrypted - data (the udp part) -*/ -int setup_vpn_in_socket(int port) -{ - int nfd, flags; - struct sockaddr_in a; - const int one = 1; -cp - if((nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) - { - syslog(LOG_ERR, "Creating socket failed: %m"); - return -1; - } - - if(setsockopt(nfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one))) - { - syslog(LOG_ERR, "setsockopt: %m"); - return -1; - } - - flags = fcntl(nfd, F_GETFL); - if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) - { - syslog(LOG_ERR, "fcntl: %m"); - return -1; - } - - memset(&a, 0, sizeof(a)); - a.sin_family = AF_INET; - a.sin_port = htons(port); - a.sin_addr.s_addr = htonl(INADDR_ANY); - - if(bind(nfd, (struct sockaddr *)&a, sizeof(struct sockaddr))) - { - syslog(LOG_ERR, "Can't bind to port %hd/udp: %m", port); - return -1; - } -cp - return nfd; -} + if(c->socket) + closesocket(c->socket); -/* - setup an outgoing meta (tcp) socket -*/ -int setup_outgoing_meta_socket(conn_list_t *cl) -{ - int flags; - struct sockaddr_in a; - config_t const *cfg; -cp - if((cfg = get_config_val(upstreamport)) == NULL) - cl->port = 655; - else - cl->port = cfg->data.val; - - cl->meta_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); - if(cl->meta_socket == -1) - { - syslog(LOG_ERR, "Creating socket failed: %m"); - return -1; - } - - a.sin_family = AF_INET; - a.sin_port = htons(cl->port); - a.sin_addr.s_addr = htonl(cl->real_ip); - - if(connect(cl->meta_socket, (struct sockaddr *)&a, sizeof(a)) == -1) - { - syslog(LOG_ERR, IP_ADDR_S ":%d: %m", IP_ADDR_V(cl->real_ip), cl->port); - return -1; - } - - flags = fcntl(cl->meta_socket, F_GETFL); - if(fcntl(cl->meta_socket, F_SETFL, flags | O_NONBLOCK) < 0) - { - syslog(LOG_ERR, "fcntl: %m"); - return -1; - } - - cl->hostname = hostlookup(htonl(cl->real_ip)); - - syslog(LOG_INFO, "Connected to %s:%hd" , cl->hostname, cl->port); -cp - return 0; -} + if(c->edge) { + if(report && !tunnelserver) + send_del_edge(everyone, c->edge); -/* - setup an outgoing connection. It's not - necessary to also open an udp socket as - well, because the other host will initiate - an authentication sequence during which - we will do just that. -*/ -int setup_outgoing_connection(ip_t ip) -{ - conn_list_t *ncn; -cp - ncn = new_conn_list(); - ncn->real_ip = ip; - - if(setup_outgoing_meta_socket(ncn) < 0) - { - syslog(LOG_ERR, "Could not set up a meta connection."); - free_conn_element(ncn); - return -1; - } - - ncn->status.meta = 1; - ncn->status.outgoing = 1; - ncn->next = conn_list; - conn_list = ncn; -cp - return 0; -} + edge_del(c->edge); -/* - set up the local sockets (listen only) -*/ -int setup_myself(void) -{ - config_t const *cfg; -cp - myself = new_conn_list(); - - if(!(cfg = get_config_val(myvpnip))) - { - syslog(LOG_ERR, "No value for my VPN IP given"); - return -1; - } - - myself->vpn_ip = cfg->data.ip->ip; - myself->vpn_mask = cfg->data.ip->mask; - - if(!(cfg = get_config_val(listenport))) - myself->port = 655; - else - myself->port = cfg->data.val; - - if((myself->meta_socket = setup_listen_meta_socket(myself->port)) < 0) - { - syslog(LOG_ERR, "Unable to set up a listening socket"); - return -1; - } - - if((myself->socket = setup_vpn_in_socket(myself->port)) < 0) - { - syslog(LOG_ERR, "Unable to set up an incoming vpn data socket"); - close(myself->meta_socket); - return -1; - } - - myself->status.active = 1; - - syslog(LOG_NOTICE, "Ready: listening on port %d.", myself->port); -cp - return 0; -} + /* Run MST and SSSP algorithms */ -/* - setup all initial network connections -*/ -int setup_network_connections(void) -{ - config_t const *cfg; -cp - if((cfg = get_config_val(pingtimeout)) == NULL) - timeout = 5; - else - timeout = cfg->data.val; - - if(setup_tap_fd() < 0) - return -1; - - if(setup_myself() < 0) - return -1; - - if((cfg = get_config_val(upstreamip)) == NULL) - /* No upstream IP given, we're listen only. */ - return 0; - - if(setup_outgoing_connection(cfg->data.ip->ip)) - return -1; -cp - return 0; -} + graph(); -RETSIGTYPE -sigalrm_handler(int a) -{ - config_t const *cfg; - static int seconds_till_retry; -cp - cfg = get_config_val(upstreamip); - - if(!setup_outgoing_connection(cfg->data.ip->ip)) - { - signal(SIGALRM, SIG_IGN); - seconds_till_retry = 5; - } - else - { - signal(SIGALRM, sigalrm_handler); - seconds_till_retry += 5; - alarm(seconds_till_retry); - syslog(LOG_ERR, "Still failed to connect to other. Will retry in %d seconds.", - seconds_till_retry); - } -cp -} + /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */ -/* - close all open network connections -*/ -void close_network_connections(void) -{ - conn_list_t *p; -cp - for(p = conn_list; p != NULL; p = p->next) - { - if(p->status.dataopen) - { - shutdown(p->socket, 0); /* No more receptions */ - close(p->socket); + if(report && !c->node->status.reachable) { + edge_t *e; + e = lookup_edge(c->node, myself); + if(e) { + if(!tunnelserver) + send_del_edge(everyone, e); + edge_del(e); + } + } } - if(p->status.meta) - { - send_termreq(p); - shutdown(p->meta_socket, 0); /* No more receptions */ - close(p->meta_socket); - } - } - - if(myself) - if(myself->status.active) - { - close(myself->meta_socket); - close(myself->socket); - } - - close(tap_fd); - destroy_conn_list(); - - syslog(LOG_NOTICE, "Terminating."); -cp - return; -} -/* - create a data (udp) socket -*/ -int setup_vpn_connection(conn_list_t *cl) -{ - int nfd, flags; - struct sockaddr_in a; -cp - if(debug_lvl > 1) - syslog(LOG_DEBUG, "Opening UDP socket to " IP_ADDR_S, IP_ADDR_V(cl->real_ip)); - - nfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); - if(nfd == -1) - { - syslog(LOG_ERR, "Creating data socket failed: %m"); - return -1; - } - - a.sin_family = AF_INET; - a.sin_port = htons(cl->port); - a.sin_addr.s_addr = htonl(cl->real_ip); - - if(connect(nfd, (struct sockaddr *)&a, sizeof(a)) == -1) - { - syslog(LOG_ERR, "Create connection to %08lx:%d failed: %m", ntohs(cl->real_ip), - cl->port); - return -1; - } - - flags = fcntl(nfd, F_GETFL); - if(fcntl(nfd, F_SETFL, flags | O_NONBLOCK) < 0) - { - syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, nfd); - return -1; - } - - cl->socket = nfd; - cl->status.dataopen = 1; -cp - return 0; -} + free_connection_partially(c); -/* - handle an incoming tcp connect call and open - a connection to it. -*/ -conn_list_t *create_new_connection(int sfd) -{ - conn_list_t *p; - struct sockaddr_in ci; - int len = sizeof(ci); -cp - p = new_conn_list(); - - if(getpeername(sfd, &ci, &len) < 0) - { - syslog(LOG_ERR, "Error: getpeername: %m"); - return NULL; - } - - p->hostname = hostlookup(ci.sin_addr.s_addr); - p->real_ip = ntohl(ci.sin_addr.s_addr); - p->meta_socket = sfd; - p->status.meta = 1; - p->buflen = 0; - p->last_ping_time = time(NULL); - p->want_ping = 0; - - syslog(LOG_NOTICE, "Connection from %s:%d", p->hostname, htons(ci.sin_port)); - - if(send_basic_info(p) < 0) - { - free(p); - return NULL; - } -cp - return p; -} - -/* - put all file descriptors in an fd_set array -*/ -void build_fdset(fd_set *fs) -{ - conn_list_t *p; -cp - FD_ZERO(fs); - - for(p = conn_list; p != NULL; p = p->next) - { - if(p->status.meta) - FD_SET(p->meta_socket, fs); - if(p->status.dataopen) - FD_SET(p->socket, fs); - } - - FD_SET(myself->meta_socket, fs); - FD_SET(myself->socket, fs); - FD_SET(tap_fd, fs); -cp -} - -/* - receive incoming data from the listening - udp socket and write it to the ethertap - device after being decrypted -*/ -int handle_incoming_vpn_data(conn_list_t *cl) -{ - real_packet_t rp; - int lenin; - int x, l = sizeof(x); - conn_list_t *f; -cp - if(getsockopt(cl->socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0) - { - syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, cl->socket); - return -1; - } - if(x) - { - syslog(LOG_ERR, "Incoming data socket error: %s", sys_errlist[x]); - return -1; - } - - rp.len = -1; - lenin = recvfrom(cl->socket, &rp, MTU, 0, NULL, NULL); - if(lenin <= 0) - { - syslog(LOG_ERR, "Receiving data failed: %m"); - return -1; - } - total_socket_in += lenin; - - rp.data.len = ntohs(rp.data.len); - rp.len = ntohs(rp.len); - rp.from = ntohl(rp.from); - - if(rp.len >= 0) - { - f = lookup_conn(rp.from); - if(debug_lvl > 3) - syslog(LOG_DEBUG, "packet from " IP_ADDR_S " (len %d)", - IP_ADDR_V(rp.from), rp.len); - if(!f) - { - syslog(LOG_ERR, "Got packet from unknown source " IP_ADDR_S, - IP_ADDR_V(rp.from)); - return -1; - } + /* Check if this was our outgoing connection */ - if(f->status.validkey) - xrecv(f, &rp); - else - { - add_queue(&(f->rq), &rp, rp.len); - if(!cl->status.waitingforkey) - send_key_request(rp.from); + if(c->outgoing) { + c->status.remove = false; + do_outgoing_connection(c); } - - if(my_key_expiry <= time(NULL)) - regenerate_keys(); - } -cp - return 0; -} - -/* - terminate a connection and notify the other - end before closing the sockets -*/ -void terminate_connection(conn_list_t *cl) -{ -cp - if(cl->status.remove) - return; - - if(debug_lvl > 0) - syslog(LOG_NOTICE, "Closing connection with %s.", cl->hostname); - - if(cl->status.timeout) - send_timeout(cl); - else if(!cl->status.termreq) - send_termreq(cl); - - close(cl->socket); - if(cl->status.meta) - close(cl->meta_socket); - - if(cl->status.outgoing) - { - alarm(5); - signal(SIGALRM, sigalrm_handler); - syslog(LOG_NOTICE, "Try to re-establish outgoing connection in 5 seconds."); - } - - cl->status.remove = 1; -cp } /* @@ -838,299 +222,389 @@ cp end does not reply in time, we consider them dead and close the connection. */ -int check_dead_connections(void) -{ - conn_list_t *p; - time_t now; -cp - now = time(NULL); - for(p = conn_list; p != NULL; p = p->next) - { - if(p->status.remove) - continue; - if(p->status.active && p->status.meta) - { - if(p->last_ping_time + timeout < now) - { - if(p->status.pinged && !p->status.got_pong) - { - syslog(LOG_INFO, "%s (" IP_ADDR_S ") didn't respond to ping", - p->hostname, IP_ADDR_V(p->vpn_ip)); - p->status.timeout = 1; - terminate_connection(p); - } - else if(p->want_ping) - { - send_ping(p); - p->last_ping_time = now; - p->status.pinged = 1; - p->status.got_pong = 0; - } - } +static void check_dead_connections(void) { + avl_node_t *node, *next; + connection_t *c; + + for(node = connection_tree->head; node; node = next) { + next = node->next; + c = node->data; + + if(c->last_ping_time + pingtimeout <= now) { + if(c->status.active) { + if(c->status.pinged) { + ifdebug(CONNECTIONS) logger(LOG_INFO, "%s (%s) didn't respond to PING in %ld seconds", + c->name, c->hostname, (long)now - c->last_ping_time); + c->status.timeout = true; + terminate_connection(c, true); + } else if(c->last_ping_time + pinginterval <= now) { + send_ping(c); + } + } else { + if(c->status.remove) { + logger(LOG_WARNING, "Old connection_t for %s (%s) status %04x still lingering, deleting...", + c->name, c->hostname, bitfield_to_int(&c->status, sizeof c->status)); + connection_del(c); + continue; + } + ifdebug(CONNECTIONS) logger(LOG_WARNING, "Timeout from %s (%s) during authentication", + c->name, c->hostname); + if(c->status.connecting) { + c->status.connecting = false; + closesocket(c->socket); + do_outgoing_connection(c); + } else { + terminate_connection(c, false); + } + } + } + + if(c->outbuflen > 0 && c->last_flushed_time + pingtimeout <= now) { + if(c->status.active) { + ifdebug(CONNECTIONS) logger(LOG_INFO, + "%s (%s) could not flush for %ld seconds (%d bytes remaining)", + c->name, c->hostname, (long)now - c->last_flushed_time, c->outbuflen); + c->status.timeout = true; + terminate_connection(c, true); + } + } } - } -cp - return 0; -} - -/* - accept a new tcp connect and create a - new connection -*/ -int handle_new_meta_connection(conn_list_t *cl) -{ - conn_list_t *ncn; - struct sockaddr client; - int nfd, len = sizeof(client); -cp - if((nfd = accept(cl->meta_socket, &client, &len)) < 0) - { - syslog(LOG_ERR, "Accepting a new connection failed: %m"); - return -1; - } - - if((ncn = create_new_connection(nfd)) == NULL) - { - shutdown(nfd, 2); - close(nfd); - syslog(LOG_NOTICE, "Closed attempted connection."); - return 0; - } - - ncn->status.meta = 1; - ncn->next = conn_list; - conn_list = ncn; -cp - return 0; -} - -/* - dispatch any incoming meta requests -*/ -int handle_incoming_meta_data(conn_list_t *cl) -{ - int x, l = sizeof(x); - int request, oldlen, i; - int lenin = 0; -cp - if(getsockopt(cl->meta_socket, SOL_SOCKET, SO_ERROR, &x, &l) < 0) - { - syslog(LOG_ERR, "This is a bug: %s:%d: %d:%m", __FILE__, __LINE__, cl->meta_socket); - return -1; - } - if(x) - { - syslog(LOG_ERR, "Metadata socket error: %s", sys_errlist[x]); - return -1; - } - - if(cl->buflen >= MAXBUFSIZE) - { - syslog(LOG_ERR, "Metadata read buffer full! Discarding contents."); - cl->buflen = 0; - } - - lenin = read(cl->meta_socket, cl->buffer, MAXBUFSIZE-cl->buflen); - - if(lenin<=0) - { - syslog(LOG_ERR, "Metadata socket read error: %m"); - return -1; - } - - oldlen = cl->buflen; - cl->buflen += lenin; - - for(;;) - { - cl->reqlen = 0; - - for(i = oldlen; i < cl->buflen; i++) - { - if(cl->buffer[i] == '\n') - { - cl->buffer[i] = 0; /* replace end-of-line by end-of-string so we can use sscanf */ - cl->reqlen = i + 1; - break; - } - } - - if(cl->reqlen) - { - if(sscanf(cl->buffer, "%d", &request) == 1) - { - if(request_handlers[request] == NULL) - { - syslog(LOG_ERR, "Unknown request: %s", cl->buffer); - return 0; - } - - if(debug_lvl > 3) - syslog(LOG_DEBUG, "Got request: %s", cl->buffer); - - request_handlers[request](cl); - } - else - { - syslog(LOG_ERR, "Bogus data received: %s", cl->buffer); - } - - cl->buflen -= cl->reqlen; - memmove(cl->buffer, cl->buffer + cl->reqlen, cl->buflen); - oldlen = 0; - } - else - { - break; - } - } - - cl->last_ping_time = time(NULL); - cl->want_ping = 0; -cp - return 0; } /* check all connections to see if anything happened on their sockets */ -void check_network_activity(fd_set *f) -{ - conn_list_t *p; - int x, l = sizeof(x); -cp - for(p = conn_list; p != NULL; p = p->next) - { - if(p->status.remove) - continue; - - if(p->status.dataopen) - if(FD_ISSET(p->socket, f)) - { - /* - The only thing that can happen to get us here is apparently an - error on this outgoing(!) UDP socket that isn't immediate (i.e. - something that will not trigger an error directly on send()). - I've once got here when it said `No route to host'. - */ - getsockopt(p->socket, SOL_SOCKET, SO_ERROR, &x, &l); - syslog(LOG_ERR, "Outgoing data socket error: %s", sys_errlist[x]); - terminate_connection(p); - return; - } - - if(p->status.meta) - if(FD_ISSET(p->meta_socket, f)) - if(handle_incoming_meta_data(p) < 0) - { - terminate_connection(p); - return; - } - } - - if(FD_ISSET(myself->socket, f)) - handle_incoming_vpn_data(myself); - - if(FD_ISSET(myself->meta_socket, f)) - handle_new_meta_connection(myself); -cp -} +static void check_network_activity(fd_set * readset, fd_set * writeset) { + connection_t *c; + avl_node_t *node; + int result, i; + socklen_t len = sizeof(result); + vpn_packet_t packet; + static int errors = 0; + + /* check input from kernel */ + if(device_fd >= 0 && FD_ISSET(device_fd, readset)) { + if(devops.read(&packet)) { + if(packet.len) { + errors = 0; + packet.priority = 0; + route(myself, &packet); + } + } else { + usleep(errors * 50000); + errors++; + if(errors > 10) { + logger(LOG_ERR, "Too many errors from %s, exiting!", device); + running = false; + } + } + } -/* - read, encrypt and send data that is - available through the ethertap device -*/ -void handle_tap_input(void) -{ - vpn_packet_t vp; - ip_t from, to; - int ether_type, lenin; -cp - memset(&vp, 0, sizeof(vp)); - if((lenin = read(tap_fd, &vp, MTU)) <= 0) - { - syslog(LOG_ERR, "Error while reading from tapdevice: %m"); - return; - } - - total_tap_in += lenin; - - ether_type = ntohs(*((unsigned short*)(&vp.data[12]))); - if(ether_type != 0x0800) - { - if(debug_lvl > 0) - syslog(LOG_INFO, "Non-IP ethernet frame %04x from " MAC_ADDR_S, - ether_type, MAC_ADDR_V(vp.data[6])); - return; - } - - if(lenin < 32) - { - if(debug_lvl > 0) - syslog(LOG_INFO, "Dropping short packet"); - return; - } - - from = ntohl(*((unsigned long*)(&vp.data[26]))); - to = ntohl(*((unsigned long*)(&vp.data[30]))); - - if(debug_lvl > 3) - syslog(LOG_DEBUG, "An IP packet (%04x) for " IP_ADDR_S " from " IP_ADDR_S, - ether_type, IP_ADDR_V(to), IP_ADDR_V(from)); - if(debug_lvl > 4) - syslog(LOG_DEBUG, MAC_ADDR_S " to " MAC_ADDR_S, - MAC_ADDR_V(vp.data[0]), MAC_ADDR_V(vp.data[6])); - - vp.len = (length_t)lenin - 2; - - strip_mac_addresses(&vp); - - send_packet(to, &vp); -cp + /* check meta connections */ + for(node = connection_tree->head; node; node = node->next) { + c = node->data; + + if(c->status.remove) + continue; + + if(FD_ISSET(c->socket, readset)) { + if(c->status.connecting) { + c->status.connecting = false; + getsockopt(c->socket, SOL_SOCKET, SO_ERROR, (void *)&result, &len); + + if(!result) + finish_connecting(c); + else { + ifdebug(CONNECTIONS) logger(LOG_DEBUG, + "Error while connecting to %s (%s): %s", + c->name, c->hostname, sockstrerror(result)); + closesocket(c->socket); + do_outgoing_connection(c); + continue; + } + } + + if(!receive_meta(c)) { + terminate_connection(c, c->status.active); + continue; + } + } + + if(FD_ISSET(c->socket, writeset)) { + if(!flush_meta(c)) { + terminate_connection(c, c->status.active); + continue; + } + } + } + + for(i = 0; i < listen_sockets; i++) { + if(FD_ISSET(listen_socket[i].udp, readset)) + handle_incoming_vpn_data(i); + + if(FD_ISSET(listen_socket[i].tcp, readset)) + handle_new_meta_connection(listen_socket[i].tcp); + } } /* this is where it all happens... */ -void main_loop(void) -{ - fd_set fset; - struct timeval tv; - int r; - time_t last_ping_check; -cp - last_ping_check = time(NULL); - - for(;;) - { - tv.tv_sec = timeout; - tv.tv_usec = 0; - - prune_conn_list(); - build_fdset(&fset); - - if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0) - { - if(errno == EINTR) /* because of alarm */ - continue; - syslog(LOG_ERR, "Error while waiting for input: %m"); - return; - } - - if(last_ping_check + timeout < time(NULL)) - /* Let's check if everybody is still alive */ - { - check_dead_connections(); - last_ping_check = time(NULL); - continue; +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; + 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; + } } - check_network_activity(&fset); +#ifdef HAVE_PSELECT + /* Restore SIGHUP & SIGALARM mask */ + sigprocmask(SIG_SETMASK, &omask, NULL); +#endif - /* local tap data */ - if(FD_ISSET(tap_fd, &fset)) - handle_tap_input(); - } -cp + return 0; }