#include "net.h"
#include "netutl.h"
#include "protocol.h"
-#include "process.h"
#include "route.h"
#include "utils.h"
#include "xalloc.h"
static void send_udppacket(node_t *, vpn_packet_t *);
unsigned replaywin = 16;
-bool localdiscovery = false;
-sockaddr_t localdiscovery_address;
+bool localdiscovery = true;
#define MAX_SEQNO 1073741824
memset(packet.data, 0, 14);
randomize(packet.data + 14, len - 14);
packet.len = len;
- if(i >= 4 && n->mtuprobes <= 10)
- packet.priority = -1;
- else
- packet.priority = 0;
+ packet.priority = 0;
+ n->status.send_locally = i >= 4 && n->mtuprobes <= 10 && n->prevedge;
logger(DEBUG_TRAFFIC, LOG_INFO, "Sending MTU probe length %d to %s (%s)", len, n->name, n->hostname);
send_udppacket(n, &packet);
}
+ n->status.send_locally = false;
n->probe_counter = 0;
gettimeofday(&n->probe_time, NULL);
/* It's a probe request, send back a reply */
/* Type 2 probe replies were introduced in protocol 17.3 */
- if ((n->options >> 24) == 3) {
+ if ((n->options >> 24) >= 3) {
uint8_t* data = packet->data;
*data++ = 2;
uint16_t len16 = htons(len); memcpy(data, &len16, 2); data += 2;
static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
if(n->status.sptps)
- return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
+ return sptps_verify_datagram(&n->sptps, ((sptps_packet_t *)inpkt)->data, inpkt->len);
if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest))
return false;
- return digest_verify(n->indigest, &inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
+ return digest_verify(n->indigest, (const char *)&inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
}
-static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
+static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
vpn_packet_t pkt1, pkt2;
vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
int nextpkt = 0;
- vpn_packet_t *outpkt = pkt[0];
size_t outlen;
if(n->status.sptps) {
} else {
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
}
- return;
+ return false;
}
- sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len);
- return;
+ if(!sptps_receive_data(&n->sptps, ((sptps_packet_t *)&inpkt)->data, inpkt->len)) {
+ logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname);
+ return false;
+ }
+ return true;
}
- if(!cipher_active(n->incipher)) {
+ if(!n->status.validkey) {
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got packet from %s (%s) but he hasn't got our key yet", n->name, n->hostname);
- return;
+ return false;
}
/* Check packet length */
if(inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) {
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got too short packet from %s (%s)",
n->name, n->hostname);
- return;
+ return false;
}
/* Check the message authentication code */
inpkt->len -= digest_length(n->indigest);
if(!digest_verify(n->indigest, &inpkt->seqno, inpkt->len, (const char *)&inpkt->seqno + inpkt->len)) {
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Got unauthenticated packet from %s (%s)", n->name, n->hostname);
- return;
+ return false;
}
}
/* Decrypt the packet */
if(cipher_active(n->incipher)) {
- outpkt = pkt[nextpkt++];
+ vpn_packet_t *outpkt = pkt[nextpkt++];
outlen = MAXSIZE;
if(!cipher_decrypt(n->incipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Error decrypting packet from %s (%s)", n->name, n->hostname);
- return;
+ return false;
}
outpkt->len = outlen;
/* Check the sequence number */
inpkt->len -= sizeof inpkt->seqno;
- inpkt->seqno = ntohl(inpkt->seqno);
+ uint32_t seqno = ntohl(inpkt->seqno);
if(replaywin) {
- if(inpkt->seqno != n->received_seqno + 1) {
- if(inpkt->seqno >= n->received_seqno + replaywin * 8) {
+ if(seqno != n->received_seqno + 1) {
+ if(seqno >= n->received_seqno + replaywin * 8) {
if(n->farfuture++ < replaywin >> 2) {
logger(DEBUG_ALWAYS, LOG_WARNING, "Packet from %s (%s) is %d seqs in the future, dropped (%u)",
- n->name, n->hostname, inpkt->seqno - n->received_seqno - 1, n->farfuture);
- return;
+ n->name, n->hostname, seqno - n->received_seqno - 1, n->farfuture);
+ return false;
}
logger(DEBUG_ALWAYS, LOG_WARNING, "Lost %d packets from %s (%s)",
- inpkt->seqno - n->received_seqno - 1, n->name, n->hostname);
+ seqno - n->received_seqno - 1, n->name, n->hostname);
memset(n->late, 0, replaywin);
- } else if (inpkt->seqno <= n->received_seqno) {
- if((n->received_seqno >= replaywin * 8 && inpkt->seqno <= n->received_seqno - replaywin * 8) || !(n->late[(inpkt->seqno / 8) % replaywin] & (1 << inpkt->seqno % 8))) {
+ } else if (seqno <= n->received_seqno) {
+ if((n->received_seqno >= replaywin * 8 && seqno <= n->received_seqno - replaywin * 8) || !(n->late[(seqno / 8) % replaywin] & (1 << seqno % 8))) {
logger(DEBUG_ALWAYS, LOG_WARNING, "Got late or replayed packet from %s (%s), seqno %d, last received %d",
- n->name, n->hostname, inpkt->seqno, n->received_seqno);
- return;
+ n->name, n->hostname, seqno, n->received_seqno);
+ return false;
}
} else {
- for(int i = n->received_seqno + 1; i < inpkt->seqno; i++)
+ for(int i = n->received_seqno + 1; i < seqno; i++)
n->late[(i / 8) % replaywin] |= 1 << i % 8;
}
}
n->farfuture = 0;
- n->late[(inpkt->seqno / 8) % replaywin] &= ~(1 << inpkt->seqno % 8);
+ n->late[(seqno / 8) % replaywin] &= ~(1 << seqno % 8);
}
- if(inpkt->seqno > n->received_seqno)
- n->received_seqno = inpkt->seqno;
+ if(seqno > n->received_seqno)
+ n->received_seqno = seqno;
n->received++;
length_t origlen = inpkt->len;
if(n->incompression) {
- outpkt = pkt[nextpkt++];
+ vpn_packet_t *outpkt = pkt[nextpkt++];
if((outpkt->len = uncompress_packet(outpkt->data, inpkt->data, inpkt->len, n->incompression)) < 0) {
logger(DEBUG_TRAFFIC, LOG_ERR, "Error while uncompressing packet from %s (%s)",
n->name, n->hostname);
- return;
+ return false;
}
inpkt = outpkt;
mtu_probe_h(n, inpkt, origlen);
else
receive_packet(n, inpkt);
+ return true;
}
void receive_tcppacket(connection_t *c, const char *buffer, int len) {
receive_packet(c->node, &outpkt);
}
+static bool try_sptps(node_t *n) {
+ if(n->status.validkey)
+ return true;
+
+ logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
+
+ if(!n->status.waitingforkey)
+ send_req_key(n);
+ else if(n->last_req_key + 10 < now.tv_sec) {
+ logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
+ sptps_stop(&n->sptps);
+ n->status.waitingforkey = false;
+ send_req_key(n);
+ }
+
+ return false;
+}
+
static void send_sptps_packet(node_t *n, vpn_packet_t *origpkt) {
- if(!n->status.validkey) {
- logger(DEBUG_TRAFFIC, LOG_INFO, "No valid key known yet for %s (%s)", n->name, n->hostname);
- if(!n->status.waitingforkey)
- send_req_key(n);
- else if(n->last_req_key + 10 < now.tv_sec) {
- logger(DEBUG_ALWAYS, LOG_DEBUG, "No key from %s after 10 seconds, restarting SPTPS", n->name);
- sptps_stop(&n->sptps);
- n->status.waitingforkey = false;
- send_req_key(n);
- }
+ if (!try_sptps(n))
return;
- }
uint8_t type = 0;
int offset = 0;
return;
}
+static void adapt_socket(const sockaddr_t *sa, int *sock) {
+ /* Make sure we have a suitable socket for the chosen address */
+ if(listen_socket[*sock].sa.sa.sa_family != sa->sa.sa_family) {
+ for(int i = 0; i < listen_sockets; i++) {
+ if(listen_socket[i].sa.sa.sa_family == sa->sa.sa_family) {
+ *sock = i;
+ break;
+ }
+ }
+ }
+}
+
static void choose_udp_address(const node_t *n, const sockaddr_t **sa, int *sock) {
/* Latest guess */
*sa = &n->address;
*sock = rand() % listen_sockets;
}
- /* Make sure we have a suitable socket for the chosen address */
- if(listen_socket[*sock].sa.sa.sa_family != (*sa)->sa.sa_family) {
- for(int i = 0; i < listen_sockets; i++) {
- if(listen_socket[i].sa.sa.sa_family == (*sa)->sa.sa_family) {
- *sock = i;
- break;
- }
- }
- }
+ adapt_socket(*sa, sock);
}
-static void choose_broadcast_address(const node_t *n, const sockaddr_t **sa, int *sock) {
- static sockaddr_t broadcast_ipv4 = {
- .in = {
- .sin_family = AF_INET,
- .sin_addr.s_addr = -1,
- }
- };
-
- static sockaddr_t broadcast_ipv6 = {
- .in6 = {
- .sin6_family = AF_INET6,
- .sin6_addr.s6_addr[0x0] = 0xff,
- .sin6_addr.s6_addr[0x1] = 0x02,
- .sin6_addr.s6_addr[0xf] = 0x01,
- }
- };
+static void choose_local_address(const node_t *n, const sockaddr_t **sa, int *sock) {
+ *sa = NULL;
- *sock = rand() % listen_sockets;
+ /* Pick one of the edges from this node at random, then use its local address. */
- if(listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
- if(localdiscovery_address.sa.sa_family == AF_INET6) {
- localdiscovery_address.in6.sin6_port = n->prevedge->address.in.sin_port;
- *sa = &localdiscovery_address;
- } else {
- broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
- broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
- *sa = &broadcast_ipv6;
- }
- } else {
- if(localdiscovery_address.sa.sa_family == AF_INET) {
- localdiscovery_address.in.sin_port = n->prevedge->address.in.sin_port;
- *sa = &localdiscovery_address;
- } else {
- broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
- *sa = &broadcast_ipv4;
+ int i = 0;
+ int j = rand() % n->edge_tree->count;
+ edge_t *candidate = NULL;
+
+ for splay_each(edge_t, e, n->edge_tree) {
+ if(i++ == j) {
+ candidate = e;
+ break;
}
}
+
+ if (candidate && candidate->local_address.sa.sa_family) {
+ *sa = &candidate->local_address;
+ *sock = rand() % listen_sockets;
+ adapt_socket(*sa, sock);
+ }
}
static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
size_t outlen;
#if defined(SOL_IP) && defined(IP_TOS)
static int priority = 0;
-#endif
int origpriority = origpkt->priority;
+#endif
if(!n->status.reachable) {
logger(DEBUG_TRAFFIC, LOG_INFO, "Trying to send UDP packet to unreachable node %s (%s)", n->name, n->hostname);
/* Add the message authentication code */
if(digest_active(n->outdigest)) {
- if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, (char *)&inpkt->seqno + inpkt->len)) {
+ if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
goto end;
}
/* Send the packet */
- const sockaddr_t *sa;
+ const sockaddr_t *sa = NULL;
int sock;
- /* Overloaded use of priority field: -1 means local broadcast */
-
- if(origpriority == -1 && n->prevedge)
- choose_broadcast_address(n, &sa, &sock);
- else
+ if(n->status.send_locally)
+ choose_local_address(n, &sa, &sock);
+ if(!sa)
choose_udp_address(n, &sa, &sock);
#if defined(SOL_IP) && defined(IP_TOS)
priority = origpriority;
logger(DEBUG_TRAFFIC, LOG_DEBUG, "Setting outgoing packet priority to %d", priority);
if(setsockopt(listen_socket[n->sock].udp.fd, SOL_IP, IP_TOS, &priority, sizeof(priority))) /* SO_PRIORITY doesn't seem to work */
- logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", strerror(errno));
+ logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "setsockopt", sockstrerror(sockerrno));
}
#endif
- if(sendto(listen_socket[sock].udp.fd, (char *) &inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
+ if(sendto(listen_socket[sock].udp.fd, &inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
if(sockmsgsize(sockerrno)) {
if(n->maxmtu >= origlen)
n->maxmtu = origlen - 1;
origpkt->len = origlen;
}
-bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
- node_t *to = handle;
+static bool send_sptps_data_priv(node_t *to, node_t *from, int type, const void *data, size_t len) {
+ node_t *relay = (to->via != myself && (type == PKT_PROBE || (len - SPTPS_DATAGRAM_OVERHEAD) <= to->via->minmtu)) ? to->via : to->nexthop;
+ bool direct = from == myself && to == relay;
+ bool relay_supported = (relay->options >> 24) >= 4;
+ bool tcponly = (myself->options | relay->options) & OPTION_TCPONLY;
+
+ /* We don't really need the relay's key, but we need to establish a UDP tunnel with it and discover its MTU. */
+ if (!direct && relay_supported && !tcponly)
+ try_sptps(relay);
- /* Send it via TCP if it is a handshake packet, TCPOnly is in use, or this packet is larger than the MTU. */
+ /* Send it via TCP if it is a handshake packet, TCPOnly is in use, this is a relay packet that the other node cannot understand, or this packet is larger than the MTU.
+ TODO: When relaying, the original sender does not know the end-to-end PMTU (it only knows the PMTU of the first hop).
+ This can lead to scenarios where large packets are sent over UDP to relay, but then relay has no choice but fall back to TCP. */
- if(type >= SPTPS_HANDSHAKE || ((myself->options | to->options) & OPTION_TCPONLY) || (type != PKT_PROBE && len > to->minmtu)) {
+ if(type == SPTPS_HANDSHAKE || tcponly || (!direct && !relay_supported) || (type != PKT_PROBE && (len - SPTPS_DATAGRAM_OVERHEAD) > relay->minmtu)) {
char buf[len * 4 / 3 + 5];
b64encode(data, buf, len);
/* 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(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, myself->name, to->name, buf, myself->incompression);
- else
- return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_SPTPS, buf);
+ if(from == myself && !to->status.validkey) {
+ to->incompression = myself->incompression;
+ return send_request(to->nexthop->connection, "%d %s %s %s -1 -1 -1 %d", ANS_KEY, from->name, to->name, buf, to->incompression);
+ } else {
+ return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, from->name, to->name, REQ_SPTPS, buf);
+ }
}
- /* Otherwise, send the packet via UDP */
-
- const sockaddr_t *sa;
- int sock;
+ size_t overhead = 0;
+ if(relay_supported) overhead += sizeof to->id + sizeof from->id;
+ char buf[len + overhead]; char* buf_ptr = buf;
+ if(relay_supported) {
+ if(direct) {
+ /* Inform the recipient that this packet was sent directly. */
+ node_id_t nullid = {};
+ memcpy(buf_ptr, &nullid, sizeof nullid); buf_ptr += sizeof nullid;
+ } else {
+ memcpy(buf_ptr, &to->id, sizeof to->id); buf_ptr += sizeof to->id;
+ }
+ memcpy(buf_ptr, &from->id, sizeof from->id); buf_ptr += sizeof from->id;
- choose_udp_address(to, &sa, &sock);
+ }
+ /* TODO: if this copy turns out to be a performance concern, change sptps_send_record() to add some "pre-padding" to the buffer and use that instead */
+ memcpy(buf_ptr, data, len); buf_ptr += len;
- if(sendto(listen_socket[sock].udp.fd, data, len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
+ const sockaddr_t *sa = NULL;
+ int sock;
+ if(relay->status.send_locally)
+ choose_local_address(relay, &sa, &sock);
+ if(!sa)
+ choose_udp_address(relay, &sa, &sock);
+ logger(DEBUG_TRAFFIC, LOG_INFO, "Sending packet from %s (%s) to %s (%s) via %s (%s)", from->name, from->hostname, to->name, to->hostname, relay->name, relay->hostname);
+ if(sendto(listen_socket[sock].udp.fd, buf, buf_ptr - buf, 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;
+ // Compensate for SPTPS overhead
+ len -= SPTPS_DATAGRAM_OVERHEAD;
+ if(relay->maxmtu >= len)
+ relay->maxmtu = len - 1;
+ if(relay->mtu >= len)
+ relay->mtu = len - 1;
} else {
- logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", to->name, to->hostname, sockstrerror(sockerrno));
+ logger(DEBUG_TRAFFIC, LOG_WARNING, "Error sending UDP SPTPS packet to %s (%s): %s", relay->name, relay->hostname, sockstrerror(sockerrno));
return false;
}
}
return true;
}
+bool send_sptps_data(void *handle, uint8_t type, const char *data, size_t len) {
+ return send_sptps_data_priv(handle, myself, type, data, len);
+}
+
bool receive_sptps_record(void *handle, uint8_t type, const char *data, uint16_t len) {
node_t *from = handle;
// usually distributes the sending of broadcast packets over all nodes.
case BMODE_MST:
for list_each(connection_t, c, connection_list)
- if(c->status.active && c->status.mst && c != from->nexthop->connection)
+ if(c->edge && c->status.mst && c != from->nexthop->connection)
send_packet(c->node, packet);
break;
break;
for splay_each(node_t, n, node_tree)
- if(n->status.reachable && ((n->via == myself && n->nexthop == n) || n->via == n))
+ if(n->status.reachable && n != myself && ((n->via == myself && n->nexthop == n) || n->via == n))
send_packet(n, packet);
break;
void handle_incoming_vpn_data(void *data, int flags) {
listen_socket_t *ls = data;
vpn_packet_t pkt;
+ sptps_packet_t *spkt = (sptps_packet_t *)&pkt;
char *hostname;
- sockaddr_t from = {{0}};
- socklen_t fromlen = sizeof from;
- node_t *n;
- int len;
+ node_id_t nullid = {};
+ sockaddr_t addr = {};
+ socklen_t addrlen = sizeof addr;
+ node_t *from, *to;
+ bool direct = false;
- len = recvfrom(ls->udp.fd, (char *) &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
+ int len = recvfrom(ls->udp.fd, &pkt.seqno, MAXSIZE, 0, &addr.sa, &addrlen);
if(len <= 0 || len > MAXSIZE) {
if(!sockwouldblock(sockerrno))
pkt.len = len;
- sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
+ sockaddrunmap(&addr); /* Some braindead IPv6 implementations do stupid things. */
+
+ // Try to figure out who sent this packet.
- n = lookup_node_udp(&from);
+ node_t *n = lookup_node_udp(&addr);
if(!n) {
- n = try_harder(&from, &pkt);
- if(n)
- update_node_udp(n, &from);
- else if(debug_level >= DEBUG_PROTOCOL) {
- hostname = sockaddr2hostname(&from);
+ // It might be from a 1.1 node, which might have a source ID in the packet.
+ from = lookup_node_id(&spkt->srcid);
+ if(from && !memcmp(&spkt->dstid, &nullid, sizeof nullid) && from->status.sptps) {
+ if(sptps_verify_datagram(&from->sptps, spkt->data, spkt->len - sizeof(spkt->srcid) - sizeof(spkt->dstid)))
+ n = from;
+ else
+ goto skip_harder;
+ }
+ }
+
+ if(!n)
+ n = try_harder(&addr, &pkt);
+
+skip_harder:
+ if(!n) {
+ if(debug_level >= DEBUG_PROTOCOL) {
+ hostname = sockaddr2hostname(&addr);
logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from unknown source %s", hostname);
free(hostname);
+ }
+ return;
+ }
+
+ if(n->status.sptps) {
+ if(memcmp(&spkt->dstid, &nullid, sizeof nullid)) {
+ direct = true;
+ from = n;
+ to = myself;
+ } else {
+ from = lookup_node_id(&spkt->srcid);
+ to = lookup_node_id(&spkt->dstid);
+ }
+ if(!from || !to) {
+ logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet from %s (%s) with unknown source and/or destination ID", n->name, n->hostname);
return;
}
- else
+
+ spkt->len -= sizeof spkt->dstid + sizeof spkt->srcid;
+ if(to != myself) {
+ send_sptps_data_priv(to, n, 0, spkt->data, spkt->len);
return;
+ }
+ } else {
+ direct = true;
+ from = n;
}
- n->sock = ls - listen_socket;
+ if(!receive_udppacket(from, &pkt))
+ return;
- receive_udppacket(n, &pkt);
+ n->sock = ls - listen_socket;
+ if(direct && sockaddrcmp(&addr, &n->address))
+ update_node_udp(n, &addr);
}
void handle_device_data(void *data, int flags) {
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