#include "meshlink_internal.h"
#include "net.h"
#include "netutl.h"
+#include "pmtu.h"
#include "protocol.h"
#include "route.h"
#include "sptps.h"
#include "utils.h"
#include "xalloc.h"
-int keylifetime = 0;
-
-static void send_udppacket(meshlink_handle_t *mesh, node_t *, vpn_packet_t *);
-
-#define MAX_SEQNO 1073741824
-#define PROBE_OVERHEAD (SPTPS_DATAGRAM_OVERHEAD + 40)
-
-/* 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);
-
- n->out_meta += packet.len + PROBE_OVERHEAD;
- 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) {
- n->in_meta += len + PROBE_OVERHEAD;
-
- 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;
- logger(mesh, MESHLINK_DEBUG, "Sending MTU probe reply %d to %s", packet->len, n->name);
- n->out_meta += packet->len + PROBE_OVERHEAD;
- 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 */
+/* Packet I/O */
static void receive_packet(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *packet) {
logger(mesh, MESHLINK_DEBUG, "Received packet of %d bytes from %s", packet->len, 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) {
+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;
*sa = broadcast_sa;
}
-static void send_udppacket(meshlink_handle_t *mesh, node_t *n, vpn_packet_t *origpkt) {
+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;
}
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(sockmsgsize(sockerrno) && len > 21) {
+ if(to->maxmtu >= len - 21) {
+ to->maxmtu = len - 22;
}
- if(to->mtu >= len) {
- to->mtu = len - 1;
+ if(to->mtu >= len - 21) {
+ to->mtu = len - 22;
}
} else {
logger(mesh, MESHLINK_WARNING, "Error sending UDP SPTPS packet to %s: %s", to->name, sockstrerror(sockerrno));
inpkt.len = len;
inpkt.probe = true;
memcpy(inpkt.data, data, len);
- mtu_probe_h(mesh, from, &inpkt, len);
+ udp_probe_h(mesh, from, &inpkt, len);
return true;
} else {
inpkt.probe = false;
n->status.want_udp = true;
send_sptps_packet(mesh, n, packet);
+ keepalive(mesh, n, true);
return;
}
projects / meshlink / blobdiff