X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet.c;h=1e04bc9ae685a9c0c100a18d6ac9ac2477cb6183;hb=89d675c474a6717d9daa8b5d9ff2c0f2c03666f9;hp=2d16ae8363f571a72ccb585fa445f6f0d25cca6f;hpb=e4ff969a9868ecc25a85daab620f97227de8d493;p=meshlink diff --git a/src/net.c b/src/net.c index 2d16ae83..1e04bc9a 100644 --- a/src/net.c +++ b/src/net.c @@ -1,6 +1,6 @@ /* net.c -- most of the network code - Copyright (C) 1998,1999,2000 Ivo Timmermans + Copyright (C) 2014 Guus Sliepen 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 @@ -12,1125 +12,618 @@ 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 "utils.h" #include "conf.h" -#include "encr.h" +#include "connection.h" +#include "graph.h" +#include "logger.h" +#include "meshlink_internal.h" +#include "meta.h" #include "net.h" #include "netutl.h" #include "protocol.h" +#include "xalloc.h" -int tap_fd = -1; +#include -int total_tap_in = 0; -int total_tap_out = 0; -int total_socket_in = 0; -int total_socket_out = 0; - -/* The global list of existing connections */ -conn_list_t *conn_list = NULL; -conn_list_t *myself = NULL; - -/* - 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 !defined(min) +static const int min(int a, int b) { + return a < b ? a : b; } +#endif /* - reassemble MAC addresses + Terminate a connection: + - Mark it as inactive + - Remove the edge representing this connection + - Kill it with fire + - Check if we need to retry making an outgoing connection */ -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 -} +void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) { + logger(mesh, MESHLINK_INFO, "Closing connection with %s (%s)", c->name, c->hostname); -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; -} + c->status.active = false; -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(c->node && c->node->connection == c) + c->node->connection = NULL; -/* - add the given packet of size s to the - queue q, be it the send or receive queue -*/ -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 -} + if(c->edge) { + if(report) + send_del_edge(mesh, mesh->everyone, c->edge); -/* 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 -} + edge_del(mesh, c->edge); + c->edge = NULL; -/* - 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 -} + /* Run MST and SSSP algorithms */ -/* - flush the send&recv queues - void because nothing goes wrong here, packets - remain in the queue if something goes wrong -*/ -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 -} + graph(mesh); -/* - 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); -} + /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */ -/* - 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; -} + if(report && !c->node->status.reachable) { + edge_t *e; + e = lookup_edge(c->node, mesh->self); + if(e) { + send_del_edge(mesh, mesh->everyone, e); + edge_del(mesh, e); + } + } + } -/* - 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; -} + outgoing_t *outgoing = c->outgoing; + connection_del(mesh, c); -/* - 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; -} + /* Check if this was our outgoing connection */ -/* - 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(outgoing) + do_outgoing_connection(mesh, outgoing); -/* - 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; -} +#ifndef HAVE_MINGW + /* Clean up dead proxy processes */ -/* - 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; + while(waitpid(-1, NULL, WNOHANG) > 0); +#endif } /* - setup all initial network connections + Check if the other end is active. + If we have sent packets, but didn't receive any, + then possibly the other end is dead. We send a + PING request over the meta connection. If the other + end does not reply in time, we consider them dead + and close the connection. */ -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; -} +static void timeout_handler(event_loop_t *loop, void *data) { + meshlink_handle_t *mesh = loop->data; + logger(mesh, MESHLINK_DEBUG, "timeout_handler()"); + + for list_each(connection_t, c, mesh->connections) { + // Also make sure that if outstanding key requests for the UDP counterpart of a connection has timed out, we restart it. + if(c->node) { + if(c->node->status.waitingforkey && c->node->last_req_key + mesh->pingtimeout <= mesh->loop.now.tv_sec) + send_req_key(mesh, c->node); + } + if(c->last_ping_time + mesh->pingtimeout <= mesh->loop.now.tv_sec) { + if(c->status.active) { + if(c->status.pinged) { + logger(mesh, MESHLINK_INFO, "%s (%s) didn't respond to PING in %ld seconds", c->name, c->hostname, (long)mesh->loop.now.tv_sec - c->last_ping_time); + } else if(c->last_ping_time + mesh->pinginterval <= mesh->loop.now.tv_sec) { + send_ping(mesh, c); + continue; + } else { + continue; + } + } else { + if(c->status.connecting) + logger(mesh, MESHLINK_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname); + else + logger(mesh, MESHLINK_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname); + } + terminate_connection(mesh, c, c->status.active); + } + } -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 + timeout_set(&mesh->loop, data, &(struct timeval){mesh->pingtimeout, rand() % 100000}); } -/* - close all open network connections -*/ -void close_network_connections(void) +// devclass asc, last_successfull_connection desc +static int node_compare_devclass_asc_lsc_desc(const void *a, const void *b) { - 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(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; + const node_t *na = a, *nb = b; + + if(na->devclass < nb->devclass) + { return -1; } + + if(na->devclass > nb->devclass) + { return 1; } + + if(na->last_successfull_connection == nb->last_successfull_connection) + return 0; + + if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) + return -1; + + if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) + return 1; + + if(na < nb) + return -1; + + if(na > nb) + return 1; + + return 0; } -/* - create a data (udp) socket -*/ -int setup_vpn_connection(conn_list_t *cl) +// last_successfull_connection desc +static int node_compare_lsc_desc(const void *a, const void *b) { - 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, "Connecting to " IP_ADDR_S ":%d failed: %m", - IP_ADDR_V(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; + const node_t *na = a, *nb = b; + + if(na->last_successfull_connection == nb->last_successfull_connection) + return 0; + + if(na->last_successfull_connection == 0 || na->last_successfull_connection > nb->last_successfull_connection) + return -1; + + if(nb->last_successfull_connection == 0 || na->last_successfull_connection < nb->last_successfull_connection) + return 1; + + if(na < nb) + return -1; + + if(na > nb) + return 1; + + return 0; } -/* - handle an incoming tcp connect call and open - a connection to it. -*/ -conn_list_t *create_new_connection(int sfd) +// devclass desc +static int node_compare_devclass_desc(const void *a, const void *b) { - 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; + const node_t *na = a, *nb = b; + + if(na->devclass < nb->devclass) + { return -1; } + + if(na->devclass > nb->devclass) + { return 1; } + + if(na < nb) + return -1; + + if(na > nb) + return 1; + + return 0; } + /* - put all file descriptors in an fd_set array -*/ -void build_fdset(fd_set *fs) + +autoconnect() { - 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 + timeout = 5 + + // find the best one for initial connect + + if cur < min + newcon = + first from nodes + where dclass <= my.dclass and !connection and (timestamp - last_retry) > retry_timeout + order by dclass asc, last_connection desc + if newcon + timeout = 0 + goto connect + + + // find better nodes to connect to: in case we have less than min connections within [BACKBONE, i] and there are nodes which we are not connected to within the range + + if min <= cur < max + j = 0 + for i = BACKBONE to my.dclass + j += count(from connections where node.dclass = i) + if j < min + newcon = + first from nodes + where dclass = i and !connection and (timestamp - last_retry) > retry_timeout + order by last_connection desc + if newcon + goto connect + else + break + + + // heal partitions + + if min <= cur < max + newcon = + first from nodes + where dclass <= my.dclass and !reachable and (timestamp - last_retry) > retry_timeout + order by dclass asc, last_connection desc + if newcon + goto connect + + + // connect + +connect: + if newcon + connect newcon + + + // disconnect outgoing connections in case we have more than min connections within [BACKBONE, i] and there are nodes which we are connected to within the range [i, PORTABLE] + + if min < cur <= max + j = 0 + for i = BACKBONE to my.dclass + j += count(from connections where node.dclass = i) + if min < j + delcon = + first from nodes + where dclass >= i and outgoing_connection + order by dclass desc + if disconnect + goto disconnect + else + break + + + // disconnect connections in case we have more than enough connections + + if max < cur + delcon = + first from nodes + where outgoing_connection + order by dclass desc + goto disconnect + + // disconnect + +disconnect + if delcon + disconnect delcon + + + // next iteration + next (timeout, autoconnect) + } -/* - 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; - } - if(f->status.validkey) - xrecv(f, &rp); - else - { - add_queue(&(f->rq), &rp, rp.len); - if(!cl->status.waitingforkey) - send_key_request(rp.from); + +static void periodic_handler(event_loop_t *loop, void *data) { + meshlink_handle_t *mesh = loop->data; + + /* Check if there are too many contradicting ADD_EDGE and DEL_EDGE messages. + This usually only happens when another node has the same Name as this node. + If so, sleep for a short while to prevent a storm of contradicting messages. + */ + + if(mesh->contradicting_del_edge > 100 && mesh->contradicting_add_edge > 100) { + logger(mesh, MESHLINK_WARNING, "Possible node with same Name as us! Sleeping %d seconds.", mesh->sleeptime); + usleep(mesh->sleeptime * 1000000LL); + mesh->sleeptime *= 2; + if(mesh->sleeptime < 0) + mesh->sleeptime = 3600; + } else { + mesh->sleeptime /= 2; + if(mesh->sleeptime < 10) + mesh->sleeptime = 10; } - if(my_key_expiry <= time(NULL)) - regenerate_keys(); - } -cp - return 0; -} + mesh->contradicting_add_edge = 0; + mesh->contradicting_del_edge = 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) - { - signal(SIGALRM, sigalrm_handler); - alarm(5); - syslog(LOG_NOTICE, "Try to re-establish outgoing connection in 5 seconds."); - } - - cl->status.remove = 1; -cp -} + int timeout = 5; -/* - Check if the other end is active. - If we have sent packets, but didn't receive any, - then possibly the other end is dead. We send a - PING request over the meta connection. If the other - 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; - } - } + /* Check if we need to make or break connections. */ + + if(mesh->nodes->count > 1) { + + logger(mesh, MESHLINK_DEBUG, "--- autoconnect begin ---"); + + int retry_timeout = min(mesh->nodes->count * 5, 60); + + logger(mesh, MESHLINK_DEBUG, "* devclass = %d", mesh->devclass); + logger(mesh, MESHLINK_DEBUG, "* nodes = %d", mesh->nodes->count); + logger(mesh, MESHLINK_DEBUG, "* retry_timeout = %d", retry_timeout); + + + // connect disconnect nodes + + node_t* connect_to = NULL; + node_t* disconnect_from = NULL; + + + // get cur_connects + + int cur_connects = 0; + + for list_each(connection_t, c, mesh->connections) + { + if(c->status.active) + { + cur_connects += 1; + } + } + + logger(mesh, MESHLINK_DEBUG, "* cur_connects = %d", cur_connects); + logger(mesh, MESHLINK_DEBUG, "* outgoings = %d", mesh->outgoings->count); + + // get min_connects and max_connects + + assert(mesh->devclass >= 0 && mesh->devclass <= _DEV_CLASS_MAX); + + int min_connects = dev_class_traits[mesh->devclass].min_connects; + int max_connects = dev_class_traits[mesh->devclass].max_connects; + + logger(mesh, MESHLINK_DEBUG, "* min_connects = %d", min_connects); + logger(mesh, MESHLINK_DEBUG, "* max_connects = %d", max_connects); + + + // find the best one for initial connect + + if(cur_connects < min_connects) + { + splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL); + + for splay_each(node_t, n, mesh->nodes) + { + logger(mesh, MESHLINK_DEBUG, "* n->devclass = %d", n->devclass); + if(n != mesh->self && n->devclass <= mesh->devclass && !n->connection && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) + { splay_insert(nodes, n); } + } + + if(nodes->head) + { + logger(mesh, MESHLINK_DEBUG, "* found best one for initial connect"); + + //timeout = 0; + connect_to = (node_t*)nodes->head->data; + } + else + { logger(mesh, MESHLINK_DEBUG, "* could not find node for initial connect"); } + + splay_free_tree(nodes); + } + + + // find better nodes to connect to + + if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) + { + unsigned int connects = 0; + + for(int devclass = 0; devclass <= mesh->devclass; ++devclass) + { + for list_each(connection_t, c, mesh->connections) + { + if(c->status.active && c->node && c->node->devclass == devclass) + { connects += 1; } + } + + if( connects < min_connects ) + { + splay_tree_t *nodes = splay_alloc_tree(node_compare_lsc_desc, NULL); + + for splay_each(node_t, n, mesh->nodes) + { + if(n != mesh->self && n->devclass == devclass && !n->connection && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) + { splay_insert(nodes, n); } + } + + if(nodes->head) + { + logger(mesh, MESHLINK_DEBUG, "* found better node"); + connect_to = (node_t*)nodes->head->data; + + splay_free_tree(nodes); + break; + } + + splay_free_tree(nodes); + } + else + { break; } + } + + if(!connect_to) + { logger(mesh, MESHLINK_DEBUG, "* could not find better nodes"); } + } + + + // heal partitions + + if(!connect_to && min_connects <= cur_connects && cur_connects < max_connects) + { + splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_asc_lsc_desc, NULL); + + for splay_each(node_t, n, mesh->nodes) + { + if(n != mesh->self && n->devclass <= mesh->devclass && !n->status.reachable && (n->last_connect_try == 0 || (time(NULL) - n->last_connect_try) > retry_timeout)) + { splay_insert(nodes, n); } + } + + if(nodes->head) + { + logger(mesh, MESHLINK_DEBUG, "* try to heal partition"); + connect_to = (node_t*)nodes->head->data; + } + else + { logger(mesh, MESHLINK_DEBUG, "* could not find nodes for partition healing"); } + + splay_free_tree(nodes); + } + + + // perform connect + + if(connect_to && !connect_to->connection) + { + connect_to->last_connect_try = time(NULL); + + /* check if there is already a connection attempt to this node */ + bool found = false; + for list_each(outgoing_t, outgoing, mesh->outgoings) + { + if(!strcmp(outgoing->name, connect_to->name)) + { + found = true; + break; + } + } + + if(!found) + { + logger(mesh, MESHLINK_DEBUG, "Autoconnecting to %s", connect_to->name); + outgoing_t *outgoing = xzalloc(sizeof(outgoing_t)); + outgoing->mesh = mesh; + outgoing->name = xstrdup(connect_to->name); + list_insert_tail(mesh->outgoings, outgoing); + setup_outgoing_connection(mesh, outgoing); + } + else + { logger(mesh, MESHLINK_DEBUG, "* skip autoconnect since it is an outgoing connection already"); } + } + + + // disconnect suboptimal outgoing connections + + if(min_connects < cur_connects /*&& cur_connects <= max_connects*/) + { + unsigned int connects = 0; + + for(int devclass = 0; devclass <= mesh->devclass; ++devclass) + { + for list_each(connection_t, c, mesh->connections) + { + if(c->status.active && c->node && c->node->devclass == devclass) + { connects += 1; } + } + + if( min_connects < connects ) + { + splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL); + + for list_each(connection_t, c, mesh->connections) + { + if(c->outgoing && c->node && c->node->devclass >= devclass) + { splay_insert(nodes, c->node); } + } + + if(nodes->head) + { + logger(mesh, MESHLINK_DEBUG, "* disconnect suboptimal outgoing connection"); + disconnect_from = (node_t*)nodes->head->data; + } + + splay_free_tree(nodes); + break; + } + } + + if(!disconnect_from) + { logger(mesh, MESHLINK_DEBUG, "* no suboptimal outgoing connections"); } + } + + + // disconnect connections (too many connections) + + if(!disconnect_from && max_connects < cur_connects) + { + splay_tree_t *nodes = splay_alloc_tree(node_compare_devclass_desc, NULL); + + for list_each(connection_t, c, mesh->connections) + { + if(c->status.active && c->node) + { splay_insert(nodes, c->node); } + } + + if(nodes->head) + { + logger(mesh, MESHLINK_DEBUG, "* disconnect connection (too many connections)"); + + //timeout = 0; + disconnect_from = (node_t*)nodes->head->data; + } + else + { logger(mesh, MESHLINK_DEBUG, "* no node we want to disconnect, even though we have too many connections"); } + + splay_free_tree(nodes); + } + + + // perform disconnect + + if(disconnect_from && disconnect_from->connection) + { + logger(mesh, MESHLINK_DEBUG, "Autodisconnecting from %s", disconnect_from->connection->name); + list_delete(mesh->outgoings, disconnect_from->connection->outgoing); + disconnect_from->connection->outgoing = NULL; + terminate_connection(mesh, disconnect_from->connection, disconnect_from->connection->status.active); + } + + + // done! + + logger(mesh, MESHLINK_DEBUG, "--- autoconnect end ---"); } - } -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; + timeout_set(&mesh->loop, data, &(struct timeval){timeout, rand() % 100000}); } -/* - 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; +void handle_meta_connection_data(meshlink_handle_t *mesh, connection_t *c) { + if (!receive_meta(mesh, c)) { + terminate_connection(mesh, c, c->status.active); + return; + } } -/* - 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 -} +void retry(meshlink_handle_t *mesh) { + /* Reset the reconnection timers for all outgoing connections */ + for list_each(outgoing_t, outgoing, mesh->outgoings) { + outgoing->timeout = 0; + if(outgoing->ev.cb) + timeout_set(&mesh->loop, &outgoing->ev, &(struct timeval){0, 0}); + } -/* - 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 for outgoing connections that are in progress, and reset their ping timers */ + for list_each(connection_t, c, mesh->connections) { + if(c->outgoing && !c->node) + c->last_ping_time = 0; + } + + /* Kick the ping timeout handler */ + timeout_set(&mesh->loop, &mesh->pingtimer, &(struct timeval){0, 0}); } /* 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(meshlink_handle_t *mesh) { + timeout_add(&mesh->loop, &mesh->pingtimer, timeout_handler, &mesh->pingtimer, &(struct timeval){mesh->pingtimeout, rand() % 100000}); + timeout_add(&mesh->loop, &mesh->periodictimer, periodic_handler, &mesh->periodictimer, &(struct timeval){0, 0}); + + //Add signal handler + mesh->datafromapp.signum = 0; + signal_add(&(mesh->loop),&(mesh->datafromapp), (signal_cb_t)meshlink_send_from_queue,mesh, mesh->datafromapp.signum); + + if(!event_loop_run(&(mesh->loop), &(mesh->mesh_mutex))) { + logger(mesh, MESHLINK_ERROR, "Error while waiting for input: %s", strerror(errno)); + return 1; } - check_network_activity(&fset); + timeout_del(&mesh->loop, &mesh->periodictimer); + timeout_del(&mesh->loop, &mesh->pingtimer); - /* local tap data */ - if(FD_ISSET(tap_fd, &fset)) - handle_tap_input(); - } -cp + return 0; }