X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_misc.c;h=95bd322e72487e3ea506f670d64d22f7f11d0a05;hp=713dacf19a800a2a4c357da55f79056840060d74;hb=d4410d0cce40929db9a0ce7042ef962f1867234d;hpb=04fc19112da5e7fcefefcf6e490987cdcfb6f620 diff --git a/src/protocol_misc.c b/src/protocol_misc.c index 713dacf1..95bd322e 100644 --- a/src/protocol_misc.c +++ b/src/protocol_misc.c @@ -28,8 +28,15 @@ #include "netutl.h" #include "protocol.h" #include "utils.h" +#include "xalloc.h" + +#ifndef MIN +#define MIN(x, y) (((x)<(y))?(x):(y)) +#endif int maxoutbufsize = 0; +int mtu_info_interval = 5; +int udp_info_interval = 5; /* Status and error notification routines */ @@ -149,3 +156,229 @@ bool tcppacket_h(connection_t *c, const char *request) { return true; } + +bool send_sptps_tcppacket(connection_t *c, const char* packet, int len) { + /* If there already is a lot of data in the outbuf buffer, discard this packet. + We use a very simple Random Early Drop algorithm. */ + + if(2.0 * c->outbuf.len / (float)maxoutbufsize - 1 > (float)rand()/(float)RAND_MAX) + return true; + + if(!send_request(c, "%d %d", SPTPS_PACKET, len)) + return false; + + send_meta_raw(c, packet, len); + return true; +} + +bool sptps_tcppacket_h(connection_t *c, const char* request) { + short int len; + + if(sscanf(request, "%*d %hd", &len) != 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "SPTPS_PACKET", c->name, + c->hostname); + return false; + } + + /* Set sptpslen to len, this will tell receive_meta() that a SPTPS packet is coming. */ + + c->sptpslen = len; + + return true; +} + +/* Transmitting UDP information */ + +bool send_udp_info(node_t *from, node_t *to) { + /* If there's a static relay in the path, there's no point in sending the message + farther than the static relay. */ + to = (to->via == myself) ? to->nexthop : to->via; + + /* Skip cases where sending UDP info messages doesn't make sense. + This is done here in order to avoid repeating the same logic in multiple callsites. */ + + if(to == myself) + return true; + + if(!to->status.reachable) + return true; + + if(from == myself) { + if(to->connection) + return true; + + struct timeval elapsed; + timersub(&now, &to->udp_info_sent, &elapsed); + if(elapsed.tv_sec < udp_info_interval) + return true; + } + + if((myself->options | from->options | to->options) & OPTION_TCPONLY) + return true; + + if((to->nexthop->options >> 24) < 5) + return true; + + char *from_address, *from_port; + /* If we're the originator, the address we use is irrelevant + because the first intermediate node will ignore it. + We use our local address as it somewhat makes sense + and it's simpler than introducing an encoding for "null" addresses anyway. */ + sockaddr2str((from != myself) ? &from->address : &to->nexthop->connection->edge->local_address, &from_address, &from_port); + + bool x = send_request(to->nexthop->connection, "%d %s %s %s %s", UDP_INFO, from->name, to->name, from_address, from_port); + + free(from_address); + free(from_port); + + if(from == myself) + to->udp_info_sent = now; + + return x; +} + +bool udp_info_h(connection_t *c, const char* request) { + char from_name[MAX_STRING_SIZE]; + char to_name[MAX_STRING_SIZE]; + char from_address[MAX_STRING_SIZE]; + char from_port[MAX_STRING_SIZE]; + + if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" "MAX_STRING, from_name, to_name, from_address, from_port) != 4) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "UDP_INFO", c->name, c->hostname); + return false; + } + + if(!check_id(from_name) || !check_id(to_name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "UDP_INFO", c->name, c->hostname, "invalid name"); + return false; + } + + node_t *from = lookup_node(from_name); + if(!from) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list", "UDP_INFO", c->name, c->hostname, from_name); + return true; + } + + if(from != from->via) { + /* Not supposed to happen, as it means the message wandered past a static relay */ + logger(DEBUG_PROTOCOL, LOG_WARNING, "Got UDP info message from %s (%s) which we can't reach directly", from->name, from->hostname); + return true; + } + + /* If we have a direct edge to "from", we are in a better position + to guess its address than it is itself. */ + if(!from->connection && !from->status.udp_confirmed) { + sockaddr_t from_addr = str2sockaddr(from_address, from_port); + if(sockaddrcmp(&from_addr, &from->address)) + update_node_udp(from, &from_addr); + } + + node_t *to = lookup_node(to_name); + if(!to) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list", "UDP_INFO", c->name, c->hostname, to_name); + return true; + } + + /* Send our own data (which could be what we just received) up the chain. */ + + return send_udp_info(from, to); +} + +/* Transmitting MTU information */ + +bool send_mtu_info(node_t *from, node_t *to, int mtu) { + /* Skip cases where sending MTU info messages doesn't make sense. + This is done here in order to avoid repeating the same logic in multiple callsites. */ + + if(to == myself) + return true; + + if(!to->status.reachable) + return true; + + if(from == myself) { + if(to->connection) + return true; + + struct timeval elapsed; + timersub(&now, &to->mtu_info_sent, &elapsed); + if(elapsed.tv_sec < mtu_info_interval) + return true; + } + + if((to->nexthop->options >> 24) < 6) + return true; + + /* We will send the passed-in MTU value, unless we believe ours is better. */ + + node_t *via = (from->via == myself) ? from->nexthop : from->via; + if(from->minmtu == from->maxmtu && from->via == myself) { + /* We have a direct measurement. Override the value entirely. + Note that we only do that if we are sitting as a static relay in the path; + otherwise, we can't guarantee packets will flow through us, and increasing + MTU could therefore end up being too optimistic. */ + mtu = from->minmtu; + } else if(via->minmtu == via->maxmtu) { + /* Static relay. Ensure packets will make it through the entire relay path. */ + mtu = MIN(mtu, via->minmtu); + } else if(via->nexthop->minmtu == via->nexthop->maxmtu) { + /* Dynamic relay. Ensure packets will make it through the entire relay path. */ + mtu = MIN(mtu, via->nexthop->minmtu); + } + + if(from == myself) + to->mtu_info_sent = now; + + /* If none of the conditions above match in the steady state, it means we're using TCP, + so the MTU is irrelevant. That said, it is still important to honor the MTU that was passed in, + because other parts of the relay path might be able to use UDP, which means they care about the MTU. */ + + return send_request(to->nexthop->connection, "%d %s %s %d", MTU_INFO, from->name, to->name, mtu); +} + +bool mtu_info_h(connection_t *c, const char* request) { + char from_name[MAX_STRING_SIZE]; + char to_name[MAX_STRING_SIZE]; + int mtu; + + if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" %d", from_name, to_name, &mtu) != 3) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "MTU_INFO", c->name, c->hostname); + return false; + } + + if(mtu < 512) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid MTU"); + return false; + } + + mtu = MIN(mtu, MTU); + + if(!check_id(from_name) || !check_id(to_name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "MTU_INFO", c->name, c->hostname, "invalid name"); + return false; + } + + node_t *from = lookup_node(from_name); + if(!from) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list", "MTU_INFO", c->name, c->hostname, from_name); + return true; + } + + /* If we don't know the current MTU for that node, use the one we received. + Even if we're about to make our own measurements, the value we got from downstream nodes should be pretty close + so it's a good idea to use it in the mean time. */ + if(from->mtu != mtu && from->minmtu != from->maxmtu) { + logger(DEBUG_TRAFFIC, LOG_INFO, "Using provisional MTU %d for node %s (%s)", mtu, from->name, from->hostname); + from->mtu = mtu; + } + + node_t *to = lookup_node(to_name); + if(!to) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list", "MTU_INFO", c->name, c->hostname, to_name); + return true; + } + + /* Continue passing the MTU value (or a better one if we have it) up the chain. */ + + return send_mtu_info(from, to, mtu); +}