1 #include <bitcoin/chainparams.h>
2 #include <ccan/io/io.h>
3 #include <common/dev_disconnect.h>
4 #include <common/status.h>
5 #include <common/wire_error.h>
6 #include <connectd/connectd.h>
7 #include <connectd/connectd_wiregen.h>
8 #include <connectd/peer_exchange_initmsg.h>
9 #include <wire/peer_wire.h>
10
11 /* Temporary structure for us to read peer message in */
12 struct peer {
13 struct daemon *daemon;
14
15 /* The ID of the peer */
16 struct node_id id;
17
18 /* Where it's connected to/from. */
19 struct wireaddr_internal addr;
20
21 /* Crypto state for writing/reading peer initmsg */
22 struct crypto_state cs;
23
24 /* Buffer for reading/writing message. */
25 u8 *msg;
26
27 bool incoming;
28 };
29
contains_common_chain(struct bitcoin_blkid * chains)30 static bool contains_common_chain(struct bitcoin_blkid *chains)
31 {
32 for (size_t i = 0; i < tal_count(chains); i++) {
33 if (bitcoin_blkid_eq(&chains[i], &chainparams->genesis_blockhash))
34 return true;
35 }
36 return false;
37 }
38
39 /* Here in case we need to read another message. */
40 static struct io_plan *read_init(struct io_conn *conn, struct peer *peer);
41
peer_init_received(struct io_conn * conn,struct peer * peer)42 static struct io_plan *peer_init_received(struct io_conn *conn,
43 struct peer *peer)
44 {
45 u8 *msg = cryptomsg_decrypt_body(tmpctx, &peer->cs, peer->msg);
46 u8 *globalfeatures, *features;
47 struct tlv_init_tlvs *tlvs = tlv_init_tlvs_new(msg);
48
49 if (!msg)
50 return io_close(conn);
51
52 status_peer_io(LOG_IO_IN, &peer->id, msg);
53
54 /* BOLT #1:
55 *
56 * A receiving node:
57 * - upon receiving a message of _odd_, unknown type:
58 * - MUST ignore the received message.
59 */
60 if (unlikely(is_unknown_msg_discardable(msg)))
61 return read_init(conn, peer);
62
63 if (!fromwire_init(tmpctx, msg, &globalfeatures, &features, tlvs)) {
64 status_peer_debug(&peer->id,
65 "bad fromwire_init '%s', closing",
66 tal_hex(tmpctx, msg));
67 return io_close(conn);
68 }
69
70 /* BOLT #1:
71 * The receiving node:
72 * ...
73 * - upon receiving `networks` containing no common chains
74 * - MAY fail the connection.
75 */
76 if (tlvs->networks) {
77 if (!contains_common_chain(tlvs->networks)) {
78 status_peer_debug(&peer->id,
79 "No common chain with this peer '%s', closing",
80 tal_hex(tmpctx, msg));
81 msg = towire_warningfmt(NULL, NULL, "No common network");
82 msg = cryptomsg_encrypt_msg(NULL, &peer->cs, take(msg));
83 return io_write(conn, msg, tal_count(msg), io_close_cb, NULL);
84 }
85 }
86
87 /* The globalfeatures field is now unused, but there was a
88 * window where it was: combine the two. */
89 features = featurebits_or(tmpctx, take(features), globalfeatures);
90
91 /* Usually return io_close_taken_fd, but may wait for old peer to
92 * be disconnected if it's a reconnect. */
93 return peer_connected(conn, peer->daemon, &peer->id,
94 &peer->addr, &peer->cs,
95 take(features),
96 peer->incoming);
97 }
98
peer_init_hdr_received(struct io_conn * conn,struct peer * peer)99 static struct io_plan *peer_init_hdr_received(struct io_conn *conn,
100 struct peer *peer)
101 {
102 u16 len;
103
104 if (!cryptomsg_decrypt_header(&peer->cs, peer->msg, &len))
105 return io_close(conn);
106
107 tal_free(peer->msg);
108 peer->msg = tal_arr(peer, u8, (u32)len + CRYPTOMSG_BODY_OVERHEAD);
109 return io_read(conn, peer->msg, tal_count(peer->msg),
110 peer_init_received, peer);
111 }
112
read_init(struct io_conn * conn,struct peer * peer)113 static struct io_plan *read_init(struct io_conn *conn, struct peer *peer)
114 {
115 /* Free our sent init msg. */
116 tal_free(peer->msg);
117
118 /* BOLT #1:
119 *
120 * The receiving node:
121 * - MUST wait to receive `init` before sending any other messages.
122 */
123 peer->msg = tal_arr(peer, u8, CRYPTOMSG_HDR_SIZE);
124 return io_read(conn, peer->msg, tal_bytelen(peer->msg),
125 peer_init_hdr_received, peer);
126 }
127
128 #if DEVELOPER
peer_write_postclose(struct io_conn * conn,struct peer * peer)129 static struct io_plan *peer_write_postclose(struct io_conn *conn,
130 struct peer *peer)
131 {
132 dev_sabotage_fd(io_conn_fd(conn), true);
133 return read_init(conn, peer);
134 }
135
peer_write_post_sabotage(struct io_conn * conn,struct peer * peer)136 static struct io_plan *peer_write_post_sabotage(struct io_conn *conn,
137 struct peer *peer)
138 {
139 dev_sabotage_fd(io_conn_fd(conn), false);
140 return read_init(conn, peer);
141 }
142 #endif
143
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,bool incoming)144 struct io_plan *peer_exchange_initmsg(struct io_conn *conn,
145 struct daemon *daemon,
146 const struct feature_set *our_features,
147 const struct crypto_state *cs,
148 const struct node_id *id,
149 const struct wireaddr_internal *addr,
150 bool incoming)
151 {
152 /* If conn is closed, forget peer */
153 struct peer *peer = tal(conn, struct peer);
154 struct io_plan *(*next)(struct io_conn *, struct peer *);
155 struct tlv_init_tlvs *tlvs;
156
157 peer->daemon = daemon;
158 peer->id = *id;
159 peer->addr = *addr;
160 peer->cs = *cs;
161 peer->incoming = incoming;
162
163 /* BOLT #1:
164 *
165 * The sending node:
166 * - MUST send `init` as the first Lightning message for any
167 * connection.
168 * ...
169 * - SHOULD set `networks` to all chains it will gossip or open
170 * channels for.
171 */
172 tlvs = tlv_init_tlvs_new(tmpctx);
173 tlvs->networks = tal_dup_arr(tlvs, struct bitcoin_blkid,
174 &chainparams->genesis_blockhash, 1, 0);
175
176 /* Initially, there were two sets of feature bits: global and local.
177 * Local affected peer nodes only, global affected everyone. Both were
178 * sent in the `init` message, but node_announcement only advertized
179 * globals.
180 *
181 * But we didn't have any globals for a long time, and it turned out
182 * that people wanted us to broadcast local features so they could do
183 * peer selection. We agreed that the number spaces should be distinct,
184 * but debate still raged on how to handle them.
185 *
186 * Meanwhile, we finally added a global bit to the spec, so now it
187 * matters. And LND v0.8 decided to make option_static_remotekey a
188 * GLOBAL bit, not a local bit, so we need to send that as a global
189 * bit here.
190 *
191 * Finally, we agreed that bits below 13 could be put in both, but
192 * from now on they'll all go in initfeatures. */
193 peer->msg = towire_init(NULL,
194 our_features->bits[GLOBAL_INIT_FEATURE],
195 our_features->bits[INIT_FEATURE],
196 tlvs);
197 status_peer_io(LOG_IO_OUT, &peer->id, peer->msg);
198 peer->msg = cryptomsg_encrypt_msg(peer, &peer->cs, take(peer->msg));
199
200 next = read_init;
201 #if DEVELOPER
202 switch (dev_disconnect(WIRE_INIT)) {
203 case DEV_DISCONNECT_BEFORE:
204 dev_sabotage_fd(io_conn_fd(conn), true);
205 break;
206 case DEV_DISCONNECT_DROPPKT:
207 peer->msg = tal_free(peer->msg); /* FALL THRU */
208 case DEV_DISCONNECT_AFTER:
209 next = peer_write_postclose;
210 break;
211 case DEV_DISCONNECT_BLACKHOLE:
212 dev_blackhole_fd(io_conn_fd(conn));
213 break;
214 case DEV_DISCONNECT_NORMAL:
215 break;
216 case DEV_DISCONNECT_DISABLE_AFTER:
217 next = peer_write_post_sabotage;
218 break;
219 }
220 #endif /* DEVELOPER */
221
222 return io_write(conn, peer->msg, tal_bytelen(peer->msg), next, peer);
223 }
224