X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fnet.c;h=7d8c58c0f4ec66a9a9d1a215f7e83677ee6fcc41;hb=6d1ac53f5c34ece4c7a82efb432a8e1d81fcff0d;hp=e42ccf4a7df0a827ce88502f6fbab6bf0b3accd6;hpb=76f01453dfa157b0070751b1025e55a1e36ebdca;p=meshlink diff --git a/src/net.c b/src/net.c index e42ccf4a..b368e505 100644 --- a/src/net.c +++ b/src/net.c @@ -1,7 +1,6 @@ /* net.c -- most of the network code - Copyright (C) 1998-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + 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 @@ -13,205 +12,80 @@ 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. - - $Id: net.c,v 1.35.4.157 2002/02/20 16:04:07 guus Exp $ + 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 -#ifdef HAVE_LINUX - #include - #include -#endif -#include -#include -#include -#include -#include -#include -#include -#include -#include -/* SunOS really wants sys/socket.h BEFORE net/if.h, - and FreeBSD wants these lines below the rest. */ -#include -#include -#include - -#include - -#include -#include -#include -#include +#include "system.h" +#include "utils.h" #include "conf.h" #include "connection.h" +#include "graph.h" +#include "logger.h" +#include "meshlink_internal.h" #include "meta.h" #include "net.h" #include "netutl.h" -#include "process.h" #include "protocol.h" -#include "subnet.h" -#include "graph.h" -#include "process.h" -#include "route.h" -#include "device.h" -#include "event.h" - -#include "system.h" - -int do_prune = 0; -int do_purge = 0; -int sighup = 0; -int sigalrm = 0; - -/* - put all file descriptors in an fd_set array -*/ -void build_fdset(fd_set *fs) -{ - avl_node_t *node; - connection_t *c; -cp - FD_ZERO(fs); - - for(node = connection_tree->head; node; node = node->next) - { - c = (connection_t *)node->data; - FD_SET(c->socket, fs); - } - - FD_SET(tcp_socket, fs); - FD_SET(udp_socket, fs); - FD_SET(device_fd, fs); -cp -} +#include "xalloc.h" -/* Purge edges and subnets of unreachable nodes. Use carefully. */ - -void purge(void) -{ - avl_node_t *nnode, *nnext, *enode, *enext, *snode, *snext, *cnode; - node_t *n; - edge_t *e; - subnet_t *s; - connection_t *c; -cp - if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_DEBUG, _("Purging unreachable nodes")); - - for(nnode = node_tree->head; nnode; nnode = nnext) - { - nnext = nnode->next; - n = (node_t *)nnode->data; - - if(!n->status.reachable) - { - if(debug_lvl >= DEBUG_SCARY_THINGS) - syslog(LOG_DEBUG, _("Purging node %s (%s)"), n->name, n->hostname); - - for(snode = n->subnet_tree->head; snode; snode = snext) - { - snext = snode->next; - s = (subnet_t *)snode->data; - - for(cnode = connection_tree->head; cnode; cnode = cnode->next) - { - c = (connection_t *)cnode->data; - if(c->status.active) - send_del_subnet(c, s); - } - - subnet_del(n, s); - } - - for(enode = n->edge_tree->head; enode; enode = enext) - { - enext = enode->next; - e = (edge_t *)enode->data; - - for(cnode = connection_tree->head; cnode; cnode = cnode->next) - { - c = (connection_t *)cnode->data; - if(c->status.active) - send_del_edge(c, e); - } - - edge_del(e); - } - - node_del(n); - } - } -cp +static const int min(int a, int b) { + return a < b ? a : b; } /* Terminate a connection: - - Close the socket - - Remove associated edge and tell other connections about it if report = 1 + - Mark it as inactive + - Remove the edge representing this connection + - Kill it with fire - Check if we need to retry making an outgoing connection - - Deactivate the host */ -void terminate_connection(connection_t *c, int report) -{ - avl_node_t *node; - connection_t *other; -cp - if(c->status.remove) - return; - - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Closing connection with %s (%s)"), - c->name, c->hostname); - - c->status.remove = 1; - - if(c->socket) - close(c->socket); - - if(c->edge) - { - if(report) - { - for(node = connection_tree->head; node; node = node->next) - { - other = (connection_t *)node->data; - if(other->status.active && other != c) - send_del_edge(other, c->edge); - } - } - - edge_del(c->edge); - } - - /* Run MST and SSSP algorithms */ - - graph(); - - /* Check if this was our outgoing connection */ - - if(c->outgoing) - { - retry_outgoing(c->outgoing); - c->outgoing = NULL; - } - - /* Deactivate */ - - c->status.active = 0; - if(c->node) - c->node->connection = NULL; - do_prune = 1; -cp +void terminate_connection(meshlink_handle_t *mesh, connection_t *c, bool report) { + logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Closing connection with %s (%s)", c->name, c->hostname); + + c->status.active = false; + + if(c->node && c->node->connection == c) + c->node->connection = NULL; + + if(c->edge) { + if(report) + send_del_edge(mesh, mesh->everyone, c->edge); + + edge_del(mesh, c->edge); + c->edge = NULL; + + /* Run MST and SSSP algorithms */ + + graph(mesh); + + /* If the node is not reachable anymore but we remember it had an edge to us, clean it up */ + + 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); + } + } + } + + outgoing_t *outgoing = c->outgoing; + connection_del(mesh, c); + + /* Check if this was our outgoing connection */ + + if(outgoing) + do_outgoing_connection(mesh, outgoing); + +#ifndef HAVE_MINGW + /* Clean up dead proxy processes */ + + while(waitpid(-1, NULL, WNOHANG) > 0); +#endif } /* @@ -222,235 +96,266 @@ cp end does not reply in time, we consider them dead and close the connection. */ -void check_dead_connections(void) -{ - time_t now; - avl_node_t *node, *next; - connection_t *c; -cp - now = time(NULL); - - for(node = connection_tree->head; node; node = next) - { - next = node->next; - c = (connection_t *)node->data; - if(c->last_ping_time + pingtimeout < now) - { - if(c->status.active) - { - if(c->status.pinged) - { - if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_INFO, _("%s (%s) didn't respond to PING"), - c->name, c->hostname); - c->status.timeout = 1; - terminate_connection(c, 1); - } - else - { - send_ping(c); - } - } - else - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_WARNING, _("Timeout from %s (%s) during authentication"), - c->name, c->hostname); - terminate_connection(c, 0); - } - } - } -cp +static void timeout_handler(event_loop_t *loop, void *data) { + meshlink_handle_t *mesh = loop->data; + + for list_each(connection_t, c, mesh->connections) { + if(c->last_ping_time + mesh->pingtimeout <= mesh->loop.now.tv_sec) { + if(c->status.active) { + if(c->status.pinged) { + logger(DEBUG_CONNECTIONS, LOG_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(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout while connecting to %s (%s)", c->name, c->hostname); + else + logger(DEBUG_CONNECTIONS, LOG_WARNING, "Timeout from %s (%s) during authentication", c->name, c->hostname); + } + terminate_connection(mesh, c, c->status.active); + } + } + + timeout_set(&mesh->loop, data, &(struct timeval){mesh->pingtimeout, rand() % 100000}); } -/* - check all connections to see if anything - happened on their sockets -*/ -void check_network_activity(fd_set *f) -{ - connection_t *c; - avl_node_t *node; - int result; - int len = sizeof(result); - vpn_packet_t packet; -cp - if(FD_ISSET(device_fd, f)) - { - if(!read_packet(&packet)) - route_outgoing(&packet); - } - - if(FD_ISSET(udp_socket, f)) - handle_incoming_vpn_data(); - - for(node = connection_tree->head; node; node = node->next) - { - c = (connection_t *)node->data; - - if(c->status.remove) - return; - - if(FD_ISSET(c->socket, f)) - { - if(c->status.connecting) - { - c->status.connecting = 0; - getsockopt(c->socket, SOL_SOCKET, SO_ERROR, &result, &len); - if(!result) - finish_connecting(c); - else - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_DEBUG, _("Error while connecting to %s (%s): %s"), c->name, c->hostname, strerror(result)); - close(c->socket); - do_outgoing_connection(c); - continue; - } - } - if(receive_meta(c) < 0) - { - terminate_connection(c, c->status.active); - return; - } - } - } - - if(FD_ISSET(tcp_socket, f)) - handle_new_meta_connection(); -cp +/// Utility function to establish connections based on condition check +/** The function iterates over all nodes, but skips those that do + * not pass the condition check. + * + * The condition check function is passed + * a pointer to a random number r between 0 and rand_modulo, a pointer to the + * current node index i, and the node pointer n. This function should return true + * if a connection attempt to the node should be made. + * + * @param mesh A pointer to the mesh structure + * @param rand_modulo Random index is selected between 0 and rand_modulo + * @cond_check A function pointer. This function should return true + * if a connection attempt to the node should be made + */ +static void cond_add_connection(meshlink_handle_t *mesh, int rand_modulo, bool (*cond_check)(int*, int*, node_t*)) { + int r = rand() % rand_modulo; + int i = 0; + + for splay_each(node_t, n, mesh->nodes) { + /* skip nodes that do not pass condition check */ + if(!(*cond_check)(&i, &r, n)) + continue; + + /* 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, n->name)) { + found = true; + break; + } + } + + if(!found) { + //TODO: if the node is blacklisted the connection will not happen, but + //the user will read this debug message "Autoconnecting to %s" that is misleading + logger(DEBUG_CONNECTIONS, LOG_INFO, "Autoconnecting to %s", n->name); + outgoing_t *outgoing = xzalloc(sizeof *outgoing); + outgoing->mesh = mesh; + outgoing->name = xstrdup(n->name); + list_insert_tail(mesh->outgoings, outgoing); + setup_outgoing_connection(mesh, outgoing); + } + break; + } +} + +static bool found_random_node(int *i, int *r, node_t *n) { + if((*i)++ != *r) + return false; + + if(n->connection) + return false; + + return true; +} + +static bool found_random_unreachable_node(int *i, int *r, node_t *n) { + if(n->status.reachable) + return false; + + if((*i)++ != *r) + return false; + + if(n->connection) + return false; + + return true; } -void prune_connections(void) -{ - connection_t *c; - avl_node_t *node, *next; -cp - for(node = connection_tree->head; node; node = next) - { - next = node->next; - c = (connection_t *)node->data; - - if(c->status.remove) - connection_del(c); - } - - if(!connection_tree->head) - purge(); -cp +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(DEBUG_ALWAYS, LOG_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; + } + + mesh->contradicting_add_edge = 0; + mesh->contradicting_del_edge = 0; + + int timeout = 5; + + /* If AutoConnect is set, check if we need to make or break connections. */ + + if(autoconnect && mesh->nodes->count > 1) { + /* Count number of active connections */ + int nc = 0; + for list_each(connection_t, c, mesh->connections) { + if(c->status.active) + nc++; + } + + /* Count number of unreachable nodes */ + int num_unreachable = 0; + for splay_each(node_t, n, mesh->nodes) { + if(!n->status.reachable) + num_unreachable++; + } + + if(nc < autoconnect) { + /* Not enough active connections, try to add one. + Choose a random node, if we don't have a connection to it, + and we are not already trying to make one, create an + outgoing connection to this node. + */ + cond_add_connection(mesh, mesh->nodes->count, &found_random_node); + } else if(num_unreachable > 0) { + /* Min number of connections established. Now try + to connect to some unreachable nodes to attempt + to heal possible partitions. + */ + cond_add_connection(mesh, num_unreachable, &found_random_unreachable_node); + } + + if(nc > autoconnect) { + /* Too many active connections, try to remove one. + Choose a random outgoing connection to a node + that has at least one other connection. + */ + int r = rand() % nc; + int i = 0; + + for list_each(connection_t, c, mesh->connections) { + if(!c->status.active) + continue; + + if(i++ != r) + continue; + + if(!c->outgoing || !c->node || c->node->edge_tree->count < 2) + break; + + logger(DEBUG_CONNECTIONS, LOG_INFO, "Autodisconnecting from %s", c->name); + list_delete(mesh->outgoings, c->outgoing); + c->outgoing = NULL; + terminate_connection(mesh, c, c->status.active); + break; + } + } + + if(nc >= autoconnect) { + /* If we have enough active connections, + remove any pending outgoing connections. + Do not remove pending connections to unreachable + nodes. + */ + node_t *o_node = NULL; + for list_each(outgoing_t, o, mesh->outgoings) { + o_node = lookup_node(mesh, o->name); + /* o_node is NULL if it is not part of the graph yet */ + if(!o_node || !o_node->status.reachable) + continue; + + bool found = false; + for list_each(connection_t, c, mesh->connections) { + if(c->outgoing == o) { + found = true; + break; + } + } + if(!found) { + logger(DEBUG_CONNECTIONS, LOG_INFO, "Cancelled outgoing connection to %s", o->name); + /* The node variable is leaked in from using the list_each macro. + The o variable could be used, but using node directly + is more efficient. + */ + list_delete_node(mesh->outgoings, node); + } + } + } + + if (nc + mesh->outgoings->count < min(autoconnect, mesh->nodes->count - 1)) + timeout = 0; + } + + timeout_set(&mesh->loop, data, &(struct timeval){timeout, rand() % 100000}); +} + +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; + } +} + +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}); + } + + /* 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; - int t; - event_t *event; -cp - last_ping_check = time(NULL); - - srand(time(NULL)); - - for(;;) - { - tv.tv_sec = 1 + (rand() & 7); /* Approx. 5 seconds, randomized to prevent global synchronisation effects */ - tv.tv_usec = 0; - - build_fdset(&fset); - - if((r = select(FD_SETSIZE, &fset, NULL, NULL, &tv)) < 0) - { - if(errno != EINTR) /* because of a signal */ - { - syslog(LOG_ERR, _("Error while waiting for input: %s"), strerror(errno)); - return; - } - } - - if(r > 0) - check_network_activity(&fset); - - if(do_prune) - { - prune_connections(); - do_prune = 0; - } - - if(do_purge) - { - purge(); - do_purge = 0; - } - - t = time(NULL); - - /* Let's check if everybody is still alive */ - - if(last_ping_check + pingtimeout < t) - { - check_dead_connections(); - last_ping_check = time(NULL); - - /* Should we regenerate our key? */ - - if(keyexpires < t) - { - if(debug_lvl >= DEBUG_STATUS) - syslog(LOG_INFO, _("Regenerating symmetric key")); - - RAND_pseudo_bytes(myself->key, myself->keylength); - send_key_changed(myself->connection, myself); - keyexpires = time(NULL) + keylifetime; - } - } - - - while((event = get_expired_event())) - { - event->handler(event->data); - free(event); - } - - if(sigalrm) - { - syslog(LOG_INFO, _("Flushing event queue")); - - while(event_tree->head) - { - event = (event_t *)event_tree->head->data; - event->handler(event->data); - event_del(event); - } - sigalrm = 0; - } - - if(sighup) - { - sighup = 0; - close_network_connections(); - exit_configuration(&config_tree); - - syslog(LOG_INFO, _("Rereading configuration file and restarting in 5 seconds")); - sleep(5); - - init_configuration(&config_tree); - - if(read_server_config()) - { - syslog(LOG_ERR, _("Unable to reread configuration file, exiting")); - exit(1); - } - - if(setup_network_connections()) - return; - - continue; - } - } -cp +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)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error while waiting for input: %s", strerror(errno)); + return 1; + } + + timeout_del(&mesh->loop, &mesh->periodictimer); + timeout_del(&mesh->loop, &mesh->pingtimer); + + return 0; }