#include "conf.h"
#include "connection.h"
#include "crypto.h"
-#include "graph.h"
#include "logger.h"
#include "meshlink_internal.h"
#include "net.h"
int keylifetime = 0;
-static void send_udppacket(meshlink_handle_t *mesh, node_t *, vpn_packet_t *);
-
-#define MAX_SEQNO 1073741824
-
-/* mtuprobes == 1..30: initial discovery, send bursts with 1 second interval
- mtuprobes == 31: sleep pinginterval seconds
- mtuprobes == 32: send 1 burst, sleep pingtimeout second
- mtuprobes == 33: no response from other side, restart PMTU discovery process
-
- Probes are sent in batches of at least three, with random sizes between the
- lower and upper boundaries for the MTU thus far discovered.
-
- After the initial discovery, a fourth packet is added to each batch with a
- size larger than the currently known PMTU, to test if the PMTU has increased.
-
- In case local discovery is enabled, another packet is added to each batch,
- which will be broadcast to the local network.
-
-*/
-
-static void send_mtu_probe_handler(event_loop_t *loop, void *data) {
- meshlink_handle_t *mesh = loop->data;
- node_t *n = data;
- int timeout = 1;
-
- n->mtuprobes++;
-
- if(!n->status.reachable || !n->status.validkey) {
- logger(mesh, MESHLINK_INFO, "Trying to send MTU probe to unreachable or rekeying node %s", n->name);
- n->mtuprobes = 0;
- return;
- }
-
- if(n->mtuprobes > 32) {
- if(!n->minmtu) {
- n->mtuprobes = 31;
- timeout = mesh->dev_class_traits[n->devclass].pinginterval;
- goto end;
- }
-
- logger(mesh, MESHLINK_INFO, "%s did not respond to UDP ping, restarting PMTU discovery", n->name);
- n->status.udp_confirmed = false;
- n->mtuprobes = 1;
- n->minmtu = 0;
- n->maxmtu = MTU;
-
- update_node_pmtu(mesh, n);
- }
-
- if(n->mtuprobes >= 10 && n->mtuprobes < 32 && !n->minmtu) {
- logger(mesh, MESHLINK_INFO, "No response to MTU probes from %s", n->name);
- n->mtuprobes = 31;
- }
-
- if(n->mtuprobes == 30 || (n->mtuprobes < 30 && n->minmtu >= n->maxmtu)) {
- if(n->minmtu > n->maxmtu) {
- n->minmtu = n->maxmtu;
- update_node_pmtu(mesh, n);
- } else {
- n->maxmtu = n->minmtu;
- }
-
- n->mtu = n->minmtu;
- logger(mesh, MESHLINK_INFO, "Fixing MTU of %s to %d after %d probes", n->name, n->mtu, n->mtuprobes);
- n->mtuprobes = 31;
- }
-
- if(n->mtuprobes == 31) {
- if(!n->minmtu && n->status.want_udp && n->nexthop && n->nexthop->connection) {
- /* Send a dummy ANS_KEY to try to update the reflexive UDP address */
- send_request(mesh, n->nexthop->connection, NULL, "%d %s %s . -1 -1 -1 0", ANS_KEY, mesh->self->name, n->name);
- n->status.want_udp = false;
- }
-
- timeout = mesh->dev_class_traits[n->devclass].pinginterval;
- goto end;
- } else if(n->mtuprobes == 32) {
- timeout = mesh->dev_class_traits[n->devclass].pingtimeout;
- }
-
- for(int i = 0; i < 5; i++) {
- int len;
-
- if(i == 0) {
- if(n->mtuprobes < 30 || n->maxmtu + 8 >= MTU) {
- continue;
- }
-
- len = n->maxmtu + 8;
- } else if(n->maxmtu <= n->minmtu) {
- len = n->maxmtu;
- } else {
- len = n->minmtu + 1 + prng(mesh, n->maxmtu - n->minmtu);
- }
-
- if(len < 64) {
- len = 64;
- }
-
- vpn_packet_t packet;
- packet.probe = true;
- memset(packet.data, 0, 14);
- randomize(packet.data + 14, len - 14);
- packet.len = len;
- n->status.broadcast = i >= 4 && n->mtuprobes <= 10 && n->prevedge;
-
- logger(mesh, MESHLINK_DEBUG, "Sending MTU probe length %d to %s", len, n->name);
-
- send_udppacket(mesh, n, &packet);
- }
-
- n->status.broadcast = false;
-
-end:
- timeout_set(&mesh->loop, &n->mtutimeout, &(struct timespec) {
- timeout, prng(mesh, TIMER_FUDGE)
- });
-}
-
-void send_mtu_probe(meshlink_handle_t *mesh, node_t *n) {
- timeout_add(&mesh->loop, &n->mtutimeout, send_mtu_probe_handler, n, &(struct timespec) {
- 1, 0
- });
- send_mtu_probe_handler(&mesh->loop, n);
-}
-
-static void mtu_probe_h(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet, uint16_t len) {
- if(len < 64) {
- logger(mesh, MESHLINK_WARNING, "Got too short MTU probe length %d from %s", packet->len, n->name);
- return;
- }
-
- logger(mesh, MESHLINK_DEBUG, "Got MTU probe length %d from %s", packet->len, n->name);
-
- if(!packet->data[0]) {
- /* It's a probe request, send back a reply */
-
- packet->data[0] = 1;
-
- /* Temporarily set udp_confirmed, so that the reply is sent
- back exactly the way it came in. */
-
- bool udp_confirmed = n->status.udp_confirmed;
- n->status.udp_confirmed = true;
- send_udppacket(mesh, n, packet);
- n->status.udp_confirmed = udp_confirmed;
- } else {
- /* It's a valid reply: now we know bidirectional communication
- is possible using the address and socket that the reply
- packet used. */
-
- if(!n->status.udp_confirmed) {
- char *address, *port;
- sockaddr2str(&n->address, &address, &port);
-
- if(n->nexthop && n->nexthop->connection) {
- send_request(mesh, n->nexthop->connection, NULL, "%d %s %s . -1 -1 -1 0 %s %s", ANS_KEY, n->name, n->name, address, port);
- } else {
- logger(mesh, MESHLINK_WARNING, "Cannot send reflexive address to %s via %s", n->name, n->nexthop ? n->nexthop->name : n->name);
- }
-
- free(address);
- free(port);
- n->status.udp_confirmed = true;
- }
-
- /* If we haven't established the PMTU yet, restart the discovery process. */
-
- if(n->mtuprobes > 30) {
- if(len == n->maxmtu + 8) {
- logger(mesh, MESHLINK_INFO, "Increase in PMTU to %s detected, restarting PMTU discovery", n->name);
- n->maxmtu = MTU;
- n->mtuprobes = 10;
- return;
- }
-
- if(n->minmtu) {
- n->mtuprobes = 30;
- } else {
- n->mtuprobes = 1;
- }
- }
-
- /* If applicable, raise the minimum supported MTU */
-
- if(len > n->maxmtu) {
- len = n->maxmtu;
- }
-
- if(n->minmtu < len) {
- n->minmtu = len;
- update_node_pmtu(mesh, n);
- }
- }
-}
-
/* VPN packet I/O */
static void receive_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet) {
}
}
-static bool try_mac(meshlink_handle_t *mesh, node_t *n, const vpn_packet_t *inpkt) {
- (void)mesh;
- return sptps_verify_datagram(&n->sptps, inpkt->data, inpkt->len);
-}
-
-static void receive_udppacket(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *inpkt) {
- if(!n->status.reachable) {
- logger(mesh, MESHLINK_ERROR, "Got SPTPS data from unreachable node %s", n->name);
- return;
- }
-
- if(!n->sptps.state) {
- if(!n->status.waitingforkey) {
- logger(mesh, MESHLINK_DEBUG, "Got packet from %s but we haven't exchanged keys yet", n->name);
- send_req_key(mesh, n);
- } else {
- logger(mesh, MESHLINK_DEBUG, "Got packet from %s but he hasn't got our key yet", n->name);
- }
-
- return;
- }
-
- if(!sptps_receive_data(&n->sptps, inpkt->data, inpkt->len)) {
- logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", n->name, strerror(errno));
- }
-}
-
static void send_sptps_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
if(!n->status.reachable) {
logger(mesh, MESHLINK_ERROR, "Trying to send SPTPS data to unreachable node %s", n->name);
return;
}
-static void choose_udp_address(meshlink_handle_t *mesh, const node_t *n, const sockaddr_t **sa, int *sock, sockaddr_t *sa_buf) {
- /* Latest guess */
- *sa = &n->address;
- *sock = n->sock;
-
- /* If the UDP address is confirmed, use it. */
- if(n->status.udp_confirmed) {
- return;
- }
-
- /* Send every third packet to n->address; that could be set
- to the node's reflexive UDP address discovered during key
- exchange. */
-
- if(++mesh->udp_choice >= 3) {
- mesh->udp_choice = 0;
- return;
- }
-
- /* If we have learned an address via Catta, try this once every batch */
- if(mesh->udp_choice == 1 && n->catta_address.sa.sa_family != AF_UNSPEC) {
- *sa = &n->catta_address;
- goto check_socket;
- }
-
- /* Else, if we have a canonical address, try this once every batch */
- if(mesh->udp_choice == 1 && n->canonical_address) {
- char *host = xstrdup(n->canonical_address);
- char *port = strchr(host, ' ');
-
- if(port) {
- *port++ = 0;
- *sa_buf = str2sockaddr_random(mesh, host, port);
- *sa = sa_buf;
-
- if(sa_buf->sa.sa_family != AF_UNKNOWN) {
- free(host);
- goto check_socket;
- }
- }
-
- free(host);
- }
-
- /* Otherwise, address are found in edges to this node.
- So we pick a random edge and a random socket. */
-
- edge_t *candidate = NULL;
-
- {
- int i = 0;
- int j = prng(mesh, n->edge_tree->count);
-
- for splay_each(edge_t, e, n->edge_tree) {
- if(i++ == j) {
- candidate = e->reverse;
- break;
- }
- }
- }
-
- if(candidate) {
- *sa = &candidate->address;
- *sock = prng(mesh, mesh->listen_sockets);
- }
-
-check_socket:
-
- /* Make sure we have a suitable socket for the chosen address */
- if(mesh->listen_socket[*sock].sa.sa.sa_family != (*sa)->sa.sa_family) {
- for(int i = 0; i < mesh->listen_sockets; i++) {
- if(mesh->listen_socket[i].sa.sa.sa_family == (*sa)->sa.sa_family) {
- *sock = i;
- break;
- }
- }
- }
-}
-
-static void choose_broadcast_address(meshlink_handle_t *mesh, const node_t *n, const sockaddr_t **sa, int *sock) {
- *sock = prng(mesh, mesh->listen_sockets);
- sockaddr_t *broadcast_sa = &mesh->listen_socket[*sock].broadcast_sa;
-
- if(broadcast_sa->sa.sa_family == AF_INET6) {
- broadcast_sa->in6.sin6_port = n->prevedge->address.in.sin_port;
- } else {
- broadcast_sa->in.sin_port = n->prevedge->address.in.sin_port;
- }
-
- *sa = broadcast_sa;
-}
-
-static void send_udppacket(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
- if(!n->status.reachable) {
- logger(mesh, MESHLINK_INFO, "Trying to send UDP packet to unreachable node %s", n->name);
- return;
- }
-
- send_sptps_packet(mesh, n, origpkt);
-}
-
bool send_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
assert(handle);
assert(data);
return false;
}
- /* Send it via TCP if it is a handshake packet, TCPOnly is in use, or this packet is larger than the MTU. */
-
- if(type >= SPTPS_HANDSHAKE || (type != PKT_PROBE && (len - 21) > to->minmtu)) {
- char buf[len * 4 / 3 + 5];
- b64encode(data, buf, len);
- if(!to->nexthop || !to->nexthop->connection) {
- logger(mesh, MESHLINK_WARNING, "Unable to forward SPTPS packet to %s via %s", to->name, to->nexthop ? to->nexthop->name : to->name);
- return false;
- }
-
- /* If no valid key is known yet, send the packets using ANS_KEY requests,
- to ensure we get to learn the reflexive UDP address. */
- if(!to->status.validkey) {
- return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, mesh->self->name, to->name, buf, 0);
- } else {
- return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_SPTPS, buf);
- }
+ if(type == PKT_PROBE) {
+ /* Probe packets are not supported. */
+ return false;
}
- /* Otherwise, send the packet via UDP */
+ /* Send it via TCP. */
- sockaddr_t sa_buf;
- const sockaddr_t *sa;
- int sock;
+ char buf[len * 4 / 3 + 5];
+ b64encode(data, buf, len);
- if(to->status.broadcast) {
- choose_broadcast_address(mesh, to, &sa, &sock);
- } else {
- choose_udp_address(mesh, to, &sa, &sock, &sa_buf);
+ if(!to->nexthop || !to->nexthop->connection) {
+ logger(mesh, MESHLINK_WARNING, "Unable to forward SPTPS packet to %s via %s", to->name, to->nexthop ? to->nexthop->name : to->name);
+ return false;
}
- if(sendto(mesh->listen_socket[sock].udp.fd, data, len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
- if(sockmsgsize(sockerrno)) {
- if(to->maxmtu >= len) {
- to->maxmtu = len - 1;
- }
-
- if(to->mtu >= len) {
- to->mtu = len - 1;
- }
- } else {
- logger(mesh, MESHLINK_WARNING, "Error sending UDP SPTPS packet to %s: %s", to->name, sockstrerror(sockerrno));
- return false;
- }
+ /* If no valid key is known yet, send the packets using ANS_KEY requests,
+ to ensure we get to learn the reflexive UDP address. */
+ if(!to->status.validkey) {
+ return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, mesh->self->name, to->name, buf, 0);
+ } else {
+ return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_SPTPS, buf);
}
-
- return true;
}
bool receive_sptps_record(void *handle, uint8_t type, const void *data, uint16_t len) {
vpn_packet_t inpkt;
if(type == PKT_PROBE) {
- inpkt.len = len;
- inpkt.probe = true;
- memcpy(inpkt.data, data, len);
- mtu_probe_h(mesh, from, &inpkt, len);
- return true;
+ /* We shouldn't receive any UDP probe packets. */
+ return false;
} else {
inpkt.probe = false;
}
send_sptps_packet(mesh, n, packet);
return;
}
-
-static node_t *try_harder(meshlink_handle_t *mesh, const sockaddr_t *from, const vpn_packet_t *pkt) {
- node_t *n = NULL;
- bool hard = false;
-
- for splay_each(edge_t, e, mesh->edges) {
- if(!e->to->status.reachable || e->to == mesh->self) {
- continue;
- }
-
- if(sockaddrcmp_noport(from, &e->address)) {
- if(mesh->last_hard_try == mesh->loop.now.tv_sec) {
- continue;
- }
-
- hard = true;
- }
-
- if(!try_mac(mesh, e->to, pkt)) {
- continue;
- }
-
- n = e->to;
- break;
- }
-
- if(hard) {
- mesh->last_hard_try = mesh->loop.now.tv_sec;
- }
-
- return n;
-}
-
-void handle_incoming_vpn_data(event_loop_t *loop, void *data, int flags) {
- (void)flags;
- meshlink_handle_t *mesh = loop->data;
- listen_socket_t *ls = data;
- vpn_packet_t pkt;
- char *hostname;
- sockaddr_t from;
- socklen_t fromlen = sizeof(from);
- node_t *n;
- int len;
-
- memset(&from, 0, sizeof(from));
-
- len = recvfrom(ls->udp.fd, pkt.data, MAXSIZE, 0, &from.sa, &fromlen);
-
- if(len <= 0 || len > MAXSIZE) {
- if(!sockwouldblock(sockerrno)) {
- logger(mesh, MESHLINK_ERROR, "Receiving packet failed: %s", sockstrerror(sockerrno));
- }
-
- return;
- }
-
- pkt.len = len;
-
- sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
-
- n = lookup_node_udp(mesh, &from);
-
- if(!n) {
- n = try_harder(mesh, &from, &pkt);
-
- if(n) {
- update_node_udp(mesh, n, &from);
- } else if(mesh->log_level <= MESHLINK_WARNING) {
- hostname = sockaddr2hostname(&from);
- logger(mesh, MESHLINK_WARNING, "Received UDP packet from unknown source %s", hostname);
- free(hostname);
- return;
- } else {
- return;
- }
- }
-
- if(n->status.blacklisted) {
- logger(mesh, MESHLINK_WARNING, "Dropping packet from blacklisted node %s", n->name);
- return;
- }
-
- n->sock = ls - mesh->listen_socket;
-
- receive_udppacket(mesh, n, &pkt);
-}
projects / meshlink-tiny / blobdiff