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#include <bitcoin/chainparams.h>
#include <ccan/io/io.h>
#include <common/cryptomsg.h>
#include <common/dev_disconnect.h>
#include <common/features.h>
#include <common/per_peer_state.h>
#include <common/status.h>
#include <common/wire_error.h>
#include <connectd/connectd.h>
#include <connectd/connectd_wiregen.h>
#include <connectd/peer_exchange_initmsg.h>
#include <wire/peer_wire.h>
/* Temporary structure for us to read peer message in */
struct peer {
struct daemon *daemon;
/* The ID of the peer */
struct node_id id;
/* Where it's connected to/from. */
struct wireaddr_internal addr;
/* Crypto state for writing/reading peer initmsg */
struct crypto_state cs;
/* Buffer for reading/writing message. */
u8 *msg;
};
static bool contains_common_chain(struct bitcoin_blkid *chains)
{
for (size_t i = 0; i < tal_count(chains); i++) {
if (bitcoin_blkid_eq(&chains[i], &chainparams->genesis_blockhash))
return true;
}
return false;
}
/* Here in case we need to read another message. */
static struct io_plan *read_init(struct io_conn *conn, struct peer *peer);
static struct io_plan *peer_init_received(struct io_conn *conn,
struct peer *peer)
{
u8 *msg = cryptomsg_decrypt_body(tmpctx, &peer->cs, peer->msg);
u8 *globalfeatures, *features;
struct tlv_init_tlvs *tlvs = tlv_init_tlvs_new(msg);
if (!msg)
return io_close(conn);
status_peer_io(LOG_IO_IN, &peer->id, msg);
/* BOLT #1:
*
* A receiving node:
* - upon receiving a message of _odd_, unknown type:
* - MUST ignore the received message.
*/
if (unlikely(is_unknown_msg_discardable(msg)))
return read_init(conn, peer);
if (!fromwire_init(tmpctx, msg, &globalfeatures, &features, tlvs)) {
status_peer_debug(&peer->id,
"bad fromwire_init '%s', closing",
tal_hex(tmpctx, msg));
return io_close(conn);
}
/* BOLT #1:
* The receiving node:
* ...
* - upon receiving `networks` containing no common chains
* - MAY fail the connection.
*/
if (tlvs->networks) {
if (!contains_common_chain(tlvs->networks)) {
status_peer_debug(&peer->id,
"No common chain with this peer '%s', closing",
tal_hex(tmpctx, msg));
msg = towire_errorfmt(NULL, NULL, "No common network");
msg = cryptomsg_encrypt_msg(NULL, &peer->cs, take(msg));
return io_write(conn, msg, tal_count(msg), io_close_cb, NULL);
}
}
/* The globalfeatures field is now unused, but there was a
* window where it was: combine the two. */
features = featurebits_or(tmpctx, take(features), globalfeatures);
/* Usually return io_close_taken_fd, but may wait for old peer to
* be disconnected if it's a reconnect. */
return peer_connected(conn, peer->daemon, &peer->id,
&peer->addr, &peer->cs,
take(features));
}
static struct io_plan *peer_init_hdr_received(struct io_conn *conn,
struct peer *peer)
{
u16 len;
if (!cryptomsg_decrypt_header(&peer->cs, peer->msg, &len))
return io_close(conn);
tal_free(peer->msg);
peer->msg = tal_arr(peer, u8, (u32)len + CRYPTOMSG_BODY_OVERHEAD);
return io_read(conn, peer->msg, tal_count(peer->msg),
peer_init_received, peer);
}
static struct io_plan *read_init(struct io_conn *conn, struct peer *peer)
{
/* Free our sent init msg. */
tal_free(peer->msg);
/* BOLT #1:
*
* The receiving node:
* - MUST wait to receive `init` before sending any other messages.
*/
peer->msg = tal_arr(peer, u8, CRYPTOMSG_HDR_SIZE);
return io_read(conn, peer->msg, tal_bytelen(peer->msg),
peer_init_hdr_received, peer);
}
#if DEVELOPER
static struct io_plan *peer_write_postclose(struct io_conn *conn,
struct peer *peer)
{
dev_sabotage_fd(io_conn_fd(conn));
return read_init(conn, peer);
}
#endif
struct io_plan *peer_exchange_initmsg(struct io_conn *conn,
struct daemon *daemon,
const struct feature_set *our_features,
const struct crypto_state *cs,
const struct node_id *id,
const struct wireaddr_internal *addr)
{
/* If conn is closed, forget peer */
struct peer *peer = tal(conn, struct peer);
struct io_plan *(*next)(struct io_conn *, struct peer *);
struct tlv_init_tlvs *tlvs;
peer->daemon = daemon;
peer->id = *id;
peer->addr = *addr;
peer->cs = *cs;
/* BOLT #1:
*
* The sending node:
* - MUST send `init` as the first Lightning message for any
* connection.
* ...
* - SHOULD set `networks` to all chains it will gossip or open
* channels for.
*/
tlvs = tlv_init_tlvs_new(tmpctx);
tlvs->networks = tal_dup_arr(tlvs, struct bitcoin_blkid,
&chainparams->genesis_blockhash, 1, 0);
/* Initially, there were two sets of feature bits: global and local.
* Local affected peer nodes only, global affected everyone. Both were
* sent in the `init` message, but node_announcement only advertized
* globals.
*
* But we didn't have any globals for a long time, and it turned out
* that people wanted us to broadcast local features so they could do
* peer selection. We agreed that the number spaces should be distinct,
* but debate still raged on how to handle them.
*
* Meanwhile, we finally added a global bit to the spec, so now it
* matters. And LND v0.8 decided to make option_static_remotekey a
* GLOBAL bit, not a local bit, so we need to send that as a global
* bit here.
*
* Finally, we agreed that bits below 13 could be put in both, but
* from now on they'll all go in initfeatures. */
peer->msg = towire_init(NULL,
our_features->bits[GLOBAL_INIT_FEATURE],
our_features->bits[INIT_FEATURE],
tlvs);
status_peer_io(LOG_IO_OUT, &peer->id, peer->msg);
peer->msg = cryptomsg_encrypt_msg(peer, &peer->cs, take(peer->msg));
next = read_init;
#if DEVELOPER
switch (dev_disconnect(WIRE_INIT)) {
case DEV_DISCONNECT_BEFORE:
dev_sabotage_fd(io_conn_fd(conn));
break;
case DEV_DISCONNECT_DROPPKT:
peer->msg = tal_free(peer->msg); /* FALL THRU */
case DEV_DISCONNECT_AFTER:
next = peer_write_postclose;
break;
case DEV_DISCONNECT_BLACKHOLE:
dev_blackhole_fd(io_conn_fd(conn));
break;
case DEV_DISCONNECT_NORMAL:
break;
}
#endif /* DEVELOPER */
return io_write(conn, peer->msg, tal_bytelen(peer->msg), next, peer);
}