core-lightning/connectd/connectd.c
Rusty Russell a62f5e5d82 connectd: hoist find_local_address so we can give more graceful Tor erros.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2022-03-05 15:48:03 +10:30

2137 lines
66 KiB
C

/*~ Welcome to the connect daemon: maintainer of connectivity!
*
* This is another separate daemon which is responsible for reaching out to
* other peers, and also accepting their incoming connections. It talks to
* them for just long enough to validate their identity using a cryptographic
* handshake, then receive and send supported feature sets; then it hands them
* up to lightningd which will fire up a specific per-peer daemon to talk to
* it.
*/
#include "config.h"
#include <ccan/array_size/array_size.h>
#include <ccan/asort/asort.h>
#include <ccan/fdpass/fdpass.h>
#include <ccan/noerr/noerr.h>
#include <ccan/tal/str/str.h>
#include <common/bech32.h>
#include <common/bech32_util.h>
#include <common/daemon_conn.h>
#include <common/dev_disconnect.h>
#include <common/ecdh_hsmd.h>
#include <common/gossip_rcvd_filter.h>
#include <common/gossip_store.h>
#include <common/jsonrpc_errors.h>
#include <common/memleak.h>
#include <common/status.h>
#include <common/subdaemon.h>
#include <common/timeout.h>
#include <common/type_to_string.h>
#include <common/wire_error.h>
#include <connectd/connectd.h>
#include <connectd/connectd_gossipd_wiregen.h>
#include <connectd/connectd_wiregen.h>
#include <connectd/handshake.h>
#include <connectd/multiplex.h>
#include <connectd/netaddress.h>
#include <connectd/onion_message.h>
#include <connectd/peer_exchange_initmsg.h>
#include <connectd/tor.h>
#include <connectd/tor_autoservice.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sodium.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <wire/wire_sync.h>
/*~ We are passed two file descriptors when exec'ed from `lightningd`: the
* first is a connection to `hsmd`, which we need for the cryptographic
* handshake, and the second is to `gossipd`: it gathers network gossip and
* thus may know how to reach certain peers. */
#define HSM_FD 3
#define GOSSIPCTL_FD 4
/*~ In C convention, constants are UPPERCASE macros. Not everything needs to
* be a constant, but it soothes the programmer's conscience to encapsulate
* arbitrary decisions like these in one place. */
#define MAX_CONNECT_ATTEMPTS 10
#define INITIAL_WAIT_SECONDS 1
#define MAX_WAIT_SECONDS 300
/* Peers we're trying to reach: we iterate through addrs until we succeed
* or fail. */
struct connecting {
/* daemon->connecting */
struct list_node list;
struct daemon *daemon;
struct io_conn *conn;
/* The ID of the peer (not necessarily unique, in transit!) */
struct node_id id;
/* We iterate through the tal_count(addrs) */
size_t addrnum;
struct wireaddr_internal *addrs;
/* NULL if there wasn't a hint. */
struct wireaddr_internal *addrhint;
/* How far did we get? */
const char *connstate;
/* Accumulated errors */
char *errors;
/* How many seconds did we wait this time? */
u32 seconds_waited;
};
/*~ C programs should generally be written bottom-to-top, with the root
* function at the bottom, and functions it calls above it. That avoids
* us having to pre-declare functions; but in the case of mutual recursion
* pre-declarations are necessary (also, sometimes we do it to avoid making
* a patch hard to review with gratuitous reorganizations). */
static void try_connect_one_addr(struct connecting *connect);
/*~ Some ISP resolvers will reply with a dummy IP to queries that would otherwise
* result in an NXDOMAIN reply. This just checks whether we have one such
* resolver upstream and remembers its reply so we can try to filter future
* dummies out.
*/
static bool broken_resolver(struct daemon *daemon)
{
struct addrinfo *addrinfo;
struct addrinfo hints;
const char *hostname = "nxdomain-test.doesntexist";
int err;
/* If they told us to never do DNS queries, don't even do this one and
* also not if we just say that we don't */
if (!daemon->use_dns || daemon->always_use_proxy) {
daemon->broken_resolver_response = NULL;
return false;
}
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
hints.ai_flags = AI_ADDRCONFIG;
err = getaddrinfo(hostname, tal_fmt(tmpctx, "%d", 42),
&hints, &addrinfo);
/*~ Note the use of tal_dup here: it is a memdup for tal, but it's
* type-aware so it's less error-prone. */
if (err == 0) {
daemon->broken_resolver_response
= tal_dup(daemon, struct sockaddr, addrinfo->ai_addr);
freeaddrinfo(addrinfo);
} else
daemon->broken_resolver_response = NULL;
return daemon->broken_resolver_response != NULL;
}
/*~ Here we see our first tal destructor: in this case the 'struct connect'
* simply removes itself from the list of all 'connect' structs. */
static void destroy_connecting(struct connecting *connect)
{
/*~ We don't *need* the list_head here; `list_del(&connect->list)`
* would work. But we have access to it, and `list_del_from()` is
* clearer for readers, and also does a very brief sanity check that
* the list isn't already empty which catches a surprising number of
* bugs! (If CCAN_LIST_DEBUG were defined, it would perform a
* complete list traverse to check it was in the list before
* deletion). */
list_del_from(&connect->daemon->connecting, &connect->list);
}
/*~ Most simple search functions start with find_; in this case, search
* for an existing attempt to connect the given peer id. */
static struct connecting *find_connecting(struct daemon *daemon,
const struct node_id *id)
{
struct connecting *i;
/*~ Note the node_id_eq function: this is generally preferred over
* doing a memcmp() manually, as it is both typesafe and can handle
* any padding which the C compiler is allowed to insert between
* members (unnecessary here, as there's no padding in a `struct
* node_id`). */
list_for_each(&daemon->connecting, i, list)
if (node_id_eq(id, &i->id))
return i;
return NULL;
}
/*~ Once we've connected out, we disable the callback which would cause us to
* to try the next address. */
static void connected_out_to_peer(struct daemon *daemon,
struct io_conn *conn,
const struct node_id *id)
{
struct connecting *connect = find_connecting(daemon, id);
/* We allocate 'conn' as a child of 'connect': we don't want to free
* it just yet though. tal_steal() it onto the permanent 'daemon'
* struct. */
tal_steal(daemon, conn);
/* We only allow one outgoing attempt at a time */
assert(connect->conn == conn);
/* Don't call destroy_io_conn, since we're done. */
io_set_finish(conn, NULL, NULL);
/* Now free the 'connecting' struct. */
tal_free(connect);
}
/*~ Once they've connected in, stop trying to connect out (if we were). */
static void peer_connected_in(struct daemon *daemon,
struct io_conn *conn,
const struct node_id *id)
{
struct connecting *connect = find_connecting(daemon, id);
if (!connect)
return;
/* Don't call destroy_io_conn, since we're done. */
io_set_finish(connect->conn, NULL, NULL);
/* Now free the 'connecting' struct since we succeeded. */
tal_free(connect);
}
/*~ This is an ad-hoc marshalling structure where we store arguments so we
* can call peer_connected again. */
struct peer_reconnected {
struct daemon *daemon;
struct node_id id;
struct wireaddr_internal addr;
const struct wireaddr *remote_addr;
struct crypto_state cs;
const u8 *their_features;
bool incoming;
};
/*~ For simplicity, lightningd only ever deals with a single connection per
* peer. So if we already know about a peer, we tell lightning to disconnect
* the old one and retry once it does. */
static struct io_plan *retry_peer_connected(struct io_conn *conn,
struct peer_reconnected *pr)
{
struct io_plan *plan;
/*~ As you can see, we've had issues with this code before :( */
status_peer_debug(&pr->id, "processing now old peer gone");
/*~ Usually the pattern is to return this directly, but we have to free
* our temporary structure. */
plan = peer_connected(conn, pr->daemon, &pr->id, &pr->addr,
pr->remote_addr,
&pr->cs, take(pr->their_features), pr->incoming);
tal_free(pr);
return plan;
}
/*~ If we already know about this peer, we tell lightningd and it disconnects
* the old one. We wait until it tells us that's happened. */
static struct io_plan *peer_reconnected(struct io_conn *conn,
struct daemon *daemon,
const struct node_id *id,
const struct wireaddr_internal *addr,
const struct wireaddr *remote_addr,
const struct crypto_state *cs,
const u8 *their_features TAKES,
bool incoming)
{
u8 *msg;
struct peer_reconnected *pr;
status_peer_debug(id, "reconnect");
/* Tell master to kill it: will send peer_disconnect */
msg = towire_connectd_reconnected(NULL, id);
daemon_conn_send(daemon->master, take(msg));
/* Save arguments for next time. */
pr = tal(daemon, struct peer_reconnected);
pr->daemon = daemon;
pr->id = *id;
pr->cs = *cs;
pr->addr = *addr;
pr->remote_addr = remote_addr;
pr->incoming = incoming;
/*~ Note that tal_dup_talarr() will do handle the take() of features
* (turning it into a simply tal_steal() in those cases). */
pr->their_features = tal_dup_talarr(pr, u8, their_features);
/*~ ccan/io supports waiting on an address: in this case, the key in
* the peer set. When someone calls `io_wake()` on that address, it
* will call retry_peer_connected above. */
return io_wait(conn, peer_htable_get(&daemon->peers, id),
/*~ The notleak() wrapper is a DEVELOPER-mode hack so
* that our memory leak detection doesn't consider 'pr'
* (which is not referenced from our code) to be a
* memory leak. */
retry_peer_connected, notleak(pr));
}
/*~ When we free a peer, we remove it from the daemon's hashtable */
static void destroy_peer(struct peer *peer, struct daemon *daemon)
{
peer_htable_del(&daemon->peers, peer);
}
/*~ This is where we create a new peer. */
static struct peer *new_peer(struct daemon *daemon,
const struct node_id *id,
const struct crypto_state *cs,
const u8 *their_features,
struct io_conn *conn STEALS,
int *fd_for_subd)
{
struct peer *peer = tal(daemon, struct peer);
peer->daemon = daemon;
peer->id = *id;
peer->cs = *cs;
peer->final_msg = NULL;
peer->subd_in = NULL;
peer->peer_in = NULL;
peer->sent_to_peer = NULL;
peer->urgent = false;
peer->told_to_close = false;
peer->peer_outq = msg_queue_new(peer, false);
peer->subd_outq = msg_queue_new(peer, false);
#if DEVELOPER
peer->dev_writes_enabled = NULL;
peer->dev_read_enabled = true;
#endif
peer->to_peer = conn;
/* Aim for connection to shuffle data back and forth: sets up
* peer->to_subd */
if (!multiplex_subd_setup(peer, fd_for_subd))
return tal_free(peer);
/* Now we own it */
tal_steal(peer, peer->to_peer);
peer_htable_add(&daemon->peers, peer);
tal_add_destructor2(peer, destroy_peer, daemon);
return peer;
}
/*~ Note the lack of static: this is called by peer_exchange_initmsg.c once the
* INIT messages are exchanged, and also by the retry code above. */
struct io_plan *peer_connected(struct io_conn *conn,
struct daemon *daemon,
const struct node_id *id,
const struct wireaddr_internal *addr,
const struct wireaddr *remote_addr,
struct crypto_state *cs,
const u8 *their_features TAKES,
bool incoming)
{
u8 *msg;
struct peer *peer;
int unsup;
size_t depender, missing;
int subd_fd;
bool option_gossip_queries;
peer = peer_htable_get(&daemon->peers, id);
if (peer)
return peer_reconnected(conn, daemon, id, addr, remote_addr, cs,
their_features, incoming);
/* We promised we'd take it by marking it TAKEN above; prepare to free it. */
if (taken(their_features))
tal_steal(tmpctx, their_features);
/* BOLT #1:
*
* The receiving node:
* ...
* - upon receiving unknown _odd_ feature bits that are non-zero:
* - MUST ignore the bit.
* - upon receiving unknown _even_ feature bits that are non-zero:
* - MUST fail the connection.
*/
unsup = features_unsupported(daemon->our_features, their_features,
INIT_FEATURE);
if (unsup != -1) {
status_peer_unusual(id, "Unsupported feature %u", unsup);
msg = towire_warningfmt(NULL, NULL, "Unsupported feature %u",
unsup);
msg = cryptomsg_encrypt_msg(tmpctx, cs, take(msg));
return io_write(conn, msg, tal_count(msg), io_close_cb, NULL);
}
if (!feature_check_depends(their_features, &depender, &missing)) {
status_peer_unusual(id, "Feature %zu requires feature %zu",
depender, missing);
msg = towire_warningfmt(NULL, NULL,
"Feature %zu requires feature %zu",
depender, missing);
msg = cryptomsg_encrypt_msg(tmpctx, cs, take(msg));
return io_write(conn, msg, tal_count(msg), io_close_cb, NULL);
}
/* We've successfully connected. */
if (incoming)
peer_connected_in(daemon, conn, id);
else
connected_out_to_peer(daemon, conn, id);
if (find_connecting(daemon, id))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"After %s connection on %p, still trying to connect conn %p?",
incoming ? "incoming" : "outgoing",
conn, find_connecting(daemon, id)->conn);
/* This contains the per-peer state info; gossipd fills in pps->gs */
peer = new_peer(daemon, id, cs, their_features, conn, &subd_fd);
/* Only takes over conn if it succeeds. */
if (!peer)
return io_close(conn);
/* Tell gossipd it can ask query this new peer for gossip */
option_gossip_queries = feature_negotiated(daemon->our_features,
their_features,
OPT_GOSSIP_QUERIES);
msg = towire_gossipd_new_peer(NULL, id, option_gossip_queries);
daemon_conn_send(daemon->gossipd, take(msg));
/* Get ready for streaming gossip from the store */
setup_peer_gossip_store(peer, daemon->our_features, their_features);
/* Create message to tell master peer has connected. */
msg = towire_connectd_peer_connected(NULL, id, addr, remote_addr,
incoming, their_features);
/*~ daemon_conn is a message queue for inter-daemon communication: we
* queue up the `connect_peer_connected` message to tell lightningd
* we have connected, and give the peer fd. */
daemon_conn_send(daemon->master, take(msg));
daemon_conn_send_fd(daemon->master, subd_fd);
/*~ Now we set up this connection to read/write from subd */
return multiplex_peer_setup(conn, peer);
}
/*~ handshake.c's handles setting up the crypto state once we get a connection
* in; we hand it straight to peer_exchange_initmsg() to send and receive INIT
* and call peer_connected(). */
static struct io_plan *handshake_in_success(struct io_conn *conn,
const struct pubkey *id_key,
const struct wireaddr_internal *addr,
struct crypto_state *cs,
struct oneshot *timeout,
struct daemon *daemon)
{
struct node_id id;
node_id_from_pubkey(&id, id_key);
status_peer_debug(&id, "Connect IN");
return peer_exchange_initmsg(conn, daemon, daemon->our_features,
cs, &id, addr, timeout, true);
}
/*~ If the timer goes off, we simply free everything, which hangs up. */
static void conn_timeout(struct io_conn *conn)
{
status_debug("conn timed out");
errno = ETIMEDOUT;
io_close(conn);
}
/*~ So, where are you from? */
static bool get_remote_address(struct io_conn *conn,
struct wireaddr_internal *addr)
{
struct sockaddr_storage s = {};
socklen_t len = sizeof(s);
/* The cast here is a weird Berkeley sockets API feature... */
if (getpeername(io_conn_fd(conn), (struct sockaddr *)&s, &len) != 0) {
status_debug("Failed to get peername for incoming conn: %s",
strerror(errno));
return false;
}
if (s.ss_family == AF_INET6) {
struct sockaddr_in6 *s6 = (void *)&s;
addr->itype = ADDR_INTERNAL_WIREADDR;
wireaddr_from_ipv6(&addr->u.wireaddr,
&s6->sin6_addr, ntohs(s6->sin6_port));
} else if (s.ss_family == AF_INET) {
struct sockaddr_in *s4 = (void *)&s;
addr->itype = ADDR_INTERNAL_WIREADDR;
wireaddr_from_ipv4(&addr->u.wireaddr,
&s4->sin_addr, ntohs(s4->sin_port));
} else if (s.ss_family == AF_UNIX) {
struct sockaddr_un *sun = (void *)&s;
addr->itype = ADDR_INTERNAL_SOCKNAME;
memcpy(addr->u.sockname, sun->sun_path, sizeof(sun->sun_path));
} else {
status_broken("Unknown socket type %i for incoming conn",
s.ss_family);
return false;
}
return true;
}
/*~ As so common in C, we need to bundle two args into a callback, so we
* allocate a temporary structure to hold them: */
struct conn_in {
struct wireaddr_internal addr;
struct daemon *daemon;
};
/*~ Once we've got a connection in, we set it up here (whether it's via the
* websocket proxy, or direct). */
static struct io_plan *conn_in(struct io_conn *conn,
struct conn_in *conn_in_arg)
{
struct daemon *daemon = conn_in_arg->daemon;
struct oneshot *timeout;
/* If they don't complete handshake in reasonable time, we hang up */
timeout = new_reltimer(&daemon->timers, conn,
time_from_sec(daemon->timeout_secs),
conn_timeout, conn);
/*~ The crypto handshake differs depending on whether you received or
* initiated the socket connection, so there are two entry points.
* Note, again, the notleak() to avoid our simplistic leak detection
* code from thinking `conn` (which we don't keep a pointer to) is
* leaked */
return responder_handshake(notleak(conn), &daemon->mykey,
&conn_in_arg->addr, timeout,
handshake_in_success, daemon);
}
/*~ When we get a direct connection in we set up its network address
* then call handshake.c to set up the crypto state. */
static struct io_plan *connection_in(struct io_conn *conn,
struct daemon *daemon)
{
struct conn_in conn_in_arg;
if (!get_remote_address(conn, &conn_in_arg.addr))
return io_close(conn);
conn_in_arg.daemon = daemon;
return conn_in(conn, &conn_in_arg);
}
/*~ <hello>I speak web socket</hello>.
*
* Actually that's dumb, websocket (aka rfc6455) looks nothing like that. */
static struct io_plan *websocket_connection_in(struct io_conn *conn,
struct daemon *daemon)
{
int childmsg[2], execfail[2];
pid_t childpid;
int err;
struct conn_in conn_in_arg;
if (!get_remote_address(conn, &conn_in_arg.addr))
return io_close(conn);
status_debug("Websocket connection in from %s",
type_to_string(tmpctx, struct wireaddr_internal,
&conn_in_arg.addr));
if (socketpair(AF_LOCAL, SOCK_STREAM, 0, childmsg) != 0)
goto fail;
if (pipe(execfail) != 0)
goto close_msgfd_fail;
if (fcntl(execfail[1], F_SETFD, fcntl(execfail[1], F_GETFD)
| FD_CLOEXEC) < 0)
goto close_execfail_fail;
childpid = fork();
if (childpid < 0)
goto close_execfail_fail;
if (childpid == 0) {
size_t max;
close(childmsg[0]);
close(execfail[0]);
/* Attach remote socket to stdin. */
if (dup2(io_conn_fd(conn), STDIN_FILENO) == -1)
goto child_errno_fail;
/* Attach our socket to stdout. */
if (dup2(childmsg[1], STDOUT_FILENO) == -1)
goto child_errno_fail;
/* Make (fairly!) sure all other fds are closed. */
max = sysconf(_SC_OPEN_MAX);
for (size_t i = STDERR_FILENO + 1; i < max; i++)
close(i);
/* Tell websocket helper what we read so far. */
execlp(daemon->websocket_helper, daemon->websocket_helper,
NULL);
child_errno_fail:
err = errno;
/* Gcc's warn-unused-result fail. */
if (write(execfail[1], &err, sizeof(err))) {
;
}
exit(127);
}
close(childmsg[1]);
close(execfail[1]);
/* Child will close this without writing on successful exec. */
if (read(execfail[0], &err, sizeof(err)) == sizeof(err)) {
close(execfail[0]);
waitpid(childpid, NULL, 0);
status_broken("Exec of helper %s failed: %s",
daemon->websocket_helper, strerror(err));
errno = err;
return io_close(conn);
}
close(execfail[0]);
/* New connection actually talks to proxy process. */
conn_in_arg.daemon = daemon;
io_new_conn(tal_parent(conn), childmsg[0], conn_in, &conn_in_arg);
/* Abandon original (doesn't close since child has dup'd fd) */
return io_close(conn);
close_execfail_fail:
close_noerr(execfail[0]);
close_noerr(execfail[1]);
close_msgfd_fail:
close_noerr(childmsg[0]);
close_noerr(childmsg[1]);
fail:
status_broken("Preparation of helper failed: %s",
strerror(errno));
return io_close(conn);
}
/*~ These are the mirror functions for the connecting-out case. */
static struct io_plan *handshake_out_success(struct io_conn *conn,
const struct pubkey *key,
const struct wireaddr_internal *addr,
struct crypto_state *cs,
struct oneshot *timeout,
struct connecting *connect)
{
struct node_id id;
node_id_from_pubkey(&id, key);
connect->connstate = "Exchanging init messages";
status_peer_debug(&id, "Connect OUT");
return peer_exchange_initmsg(conn, connect->daemon,
connect->daemon->our_features,
cs, &id, addr, timeout, false);
}
struct io_plan *connection_out(struct io_conn *conn, struct connecting *connect)
{
struct pubkey outkey;
struct oneshot *timeout;
/* This shouldn't happen: lightningd should not give invalid ids! */
if (!pubkey_from_node_id(&outkey, &connect->id)) {
status_broken("Connection out to invalid id %s",
type_to_string(tmpctx, struct node_id,
&connect->id));
return io_close(conn);
}
/* If they don't complete handshake in reasonable time, hang up */
timeout = new_reltimer(&connect->daemon->timers, conn,
time_from_sec(connect->daemon->timeout_secs),
conn_timeout, conn);
status_peer_debug(&connect->id, "Connected out, starting crypto");
connect->connstate = "Cryptographic handshake";
return initiator_handshake(conn, &connect->daemon->mykey, &outkey,
&connect->addrs[connect->addrnum],
timeout, handshake_out_success, connect);
}
/*~ When we've exhausted all addresses without success, we come here.
*
* Note that gcc gets upset if we put the PRINTF_FMT at the end like this if
* it's an actual function definition, but etags gets confused and ignores the
* rest of the file if we put PRINTF_FMT at the front. So we put it at the
* end, in a gratuitous declaration.
*/
static void connect_failed(struct daemon *daemon,
const struct node_id *id,
u32 seconds_waited,
const struct wireaddr_internal *addrhint,
errcode_t errcode,
const char *errfmt, ...)
PRINTF_FMT(6,7);
static void connect_failed(struct daemon *daemon,
const struct node_id *id,
u32 seconds_waited,
const struct wireaddr_internal *addrhint,
errcode_t errcode,
const char *errfmt, ...)
{
u8 *msg;
va_list ap;
char *errmsg;
u32 wait_seconds;
va_start(ap, errfmt);
errmsg = tal_vfmt(tmpctx, errfmt, ap);
va_end(ap);
/* Wait twice as long to reconnect, between min and max. */
wait_seconds = seconds_waited * 2;
if (wait_seconds > MAX_WAIT_SECONDS)
wait_seconds = MAX_WAIT_SECONDS;
if (wait_seconds < INITIAL_WAIT_SECONDS)
wait_seconds = INITIAL_WAIT_SECONDS;
/* lightningd may have a connect command waiting to know what
* happened. We leave it to lightningd to decide if it wants to try
* again, with the wait_seconds as a hint of how long before
* asking. */
msg = towire_connectd_connect_failed(NULL, id, errcode, errmsg,
wait_seconds, addrhint);
daemon_conn_send(daemon->master, take(msg));
status_peer_debug(id, "Failed connected out: %s", errmsg);
}
/* add errors to error list */
void add_errors_to_error_list(struct connecting *connect, const char *error)
{
tal_append_fmt(&connect->errors,
"%s. ", error);
}
/*~ This is the destructor for the (unsuccessful) outgoing connection. We accumulate
* the errors which occurred, so we can report to lightningd properly in case
* they all fail, and try the next address.
*
* This is a specialized form of destructor which takes an extra argument;
* it set up by either the creatively-named tal_add_destructor2(), or by
* the ccan/io's io_set_finish() on a connection. */
static void destroy_io_conn(struct io_conn *conn, struct connecting *connect)
{
/*~ tal_append_fmt appends to a tal string. It's terribly convenient */
const char *errstr = strerror(errno);
/* errno 0 means they hung up on us. */
if (errno == 0) {
errstr = "peer closed connection";
if (streq(connect->connstate, "Cryptographic handshake"))
errstr = "peer closed connection (wrong key?)";
}
add_errors_to_error_list(connect,
tal_fmt(tmpctx, "%s: %s: %s",
type_to_string(tmpctx, struct wireaddr_internal,
&connect->addrs[connect->addrnum]),
connect->connstate, errstr));
connect->addrnum++;
try_connect_one_addr(connect);
}
/* This initializes a fresh io_conn by setting it to io_connect to the
* destination */
static struct io_plan *conn_init(struct io_conn *conn,
struct connecting *connect)
{
/*~ I generally dislike the pattern of "set to NULL, assert if NULL at
* bottom". On -O2 and above the compiler will warn you at compile time
* if a there is a path by which the variable is not set, which is always
* preferable to a runtime assertion. In this case, it's the best way
* to use the "enum in a switch" trick to make sure we handle all enum
* cases, so I use it. */
struct addrinfo *ai = NULL;
const struct wireaddr_internal *addr = &connect->addrs[connect->addrnum];
switch (addr->itype) {
case ADDR_INTERNAL_SOCKNAME:
ai = wireaddr_internal_to_addrinfo(tmpctx, addr);
break;
case ADDR_INTERNAL_ALLPROTO:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect to all protocols");
break;
case ADDR_INTERNAL_AUTOTOR:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect to autotor address");
break;
case ADDR_INTERNAL_STATICTOR:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect to statictor address");
break;
case ADDR_INTERNAL_FORPROXY:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect to forproxy address");
break;
case ADDR_INTERNAL_WIREADDR:
/* DNS should have been resolved before */
assert(addr->u.wireaddr.type != ADDR_TYPE_DNS);
/* If it was a Tor address, we wouldn't be here. */
assert(!is_toraddr((char*)addr->u.wireaddr.addr));
ai = wireaddr_to_addrinfo(tmpctx, &addr->u.wireaddr);
break;
}
assert(ai);
io_set_finish(conn, destroy_io_conn, connect);
return io_connect(conn, ai, connection_out, connect);
}
/* This initializes a fresh io_conn by setting it to io_connect to the
* SOCKS proxy, as handled in tor.c. */
static struct io_plan *conn_proxy_init(struct io_conn *conn,
struct connecting *connect)
{
const char *host = NULL;
u16 port;
const struct wireaddr_internal *addr = &connect->addrs[connect->addrnum];
switch (addr->itype) {
case ADDR_INTERNAL_FORPROXY:
host = addr->u.unresolved.name;
port = addr->u.unresolved.port;
break;
case ADDR_INTERNAL_WIREADDR:
host = fmt_wireaddr_without_port(tmpctx, &addr->u.wireaddr);
port = addr->u.wireaddr.port;
break;
case ADDR_INTERNAL_SOCKNAME:
case ADDR_INTERNAL_ALLPROTO:
case ADDR_INTERNAL_AUTOTOR:
case ADDR_INTERNAL_STATICTOR:
break;
}
if (!host)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect to %u address", addr->itype);
io_set_finish(conn, destroy_io_conn, connect);
return io_tor_connect(conn, connect->daemon->proxyaddr, host, port,
connect);
}
/*~ This is the routine which tries to connect. */
static void try_connect_one_addr(struct connecting *connect)
{
int fd, af;
bool use_proxy = connect->daemon->always_use_proxy;
const struct wireaddr_internal *addr = &connect->addrs[connect->addrnum];
struct io_conn *conn;
#if EXPERIMENTAL_FEATURES /* BOLT7 DNS RFC #911 */
bool use_dns = connect->daemon->use_dns;
struct addrinfo hints, *ais, *aii;
struct wireaddr_internal addrhint;
int gai_err;
struct sockaddr_in *sa4;
struct sockaddr_in6 *sa6;
#endif
/* In case we fail without a connection, make destroy_io_conn happy */
connect->conn = NULL;
/* Out of addresses? */
if (connect->addrnum == tal_count(connect->addrs)) {
connect_failed(connect->daemon, &connect->id,
connect->seconds_waited,
connect->addrhint, CONNECT_ALL_ADDRESSES_FAILED,
"All addresses failed: %s",
connect->errors);
tal_free(connect);
return;
}
/* Might not even be able to create eg. IPv6 sockets */
af = -1;
switch (addr->itype) {
case ADDR_INTERNAL_SOCKNAME:
af = AF_LOCAL;
/* Local sockets don't use tor proxy */
use_proxy = false;
break;
case ADDR_INTERNAL_ALLPROTO:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect ALLPROTO");
case ADDR_INTERNAL_AUTOTOR:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect AUTOTOR");
case ADDR_INTERNAL_STATICTOR:
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Can't connect STATICTOR");
case ADDR_INTERNAL_FORPROXY:
use_proxy = true;
break;
case ADDR_INTERNAL_WIREADDR:
switch (addr->u.wireaddr.type) {
case ADDR_TYPE_TOR_V2_REMOVED:
af = -1;
break;
case ADDR_TYPE_TOR_V3:
use_proxy = true;
break;
case ADDR_TYPE_IPV4:
af = AF_INET;
break;
case ADDR_TYPE_IPV6:
af = AF_INET6;
break;
case ADDR_TYPE_DNS:
#if EXPERIMENTAL_FEATURES /* BOLT7 DNS RFC #911 */
if (use_proxy) /* hand it to the proxy */
break;
if (!use_dns) { /* ignore DNS when we can't use it */
tal_append_fmt(&connect->errors,
"%s: dns disabled. ",
type_to_string(tmpctx,
struct wireaddr_internal,
addr));
goto next;
}
/* Resolve with getaddrinfo */
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_STREAM;
hints.ai_family = AF_UNSPEC;
hints.ai_protocol = 0;
hints.ai_flags = AI_ADDRCONFIG;
gai_err = getaddrinfo((char *)addr->u.wireaddr.addr,
tal_fmt(tmpctx, "%d",
addr->u.wireaddr.port),
&hints, &ais);
if (gai_err != 0) {
tal_append_fmt(&connect->errors,
"%s: getaddrinfo error '%s'. ",
type_to_string(tmpctx,
struct wireaddr_internal,
addr),
gai_strerror(gai_err));
goto next;
}
/* create new addrhints on-the-fly per result ... */
for (aii = ais; aii; aii = aii->ai_next) {
addrhint.itype = ADDR_INTERNAL_WIREADDR;
if (aii->ai_family == AF_INET) {
sa4 = (struct sockaddr_in *) aii->ai_addr;
wireaddr_from_ipv4(&addrhint.u.wireaddr,
&sa4->sin_addr,
addr->u.wireaddr.port);
} else if (aii->ai_family == AF_INET6) {
sa6 = (struct sockaddr_in6 *) aii->ai_addr;
wireaddr_from_ipv6(&addrhint.u.wireaddr,
&sa6->sin6_addr,
addr->u.wireaddr.port);
} else {
/* skip unsupported ai_family */
continue;
}
tal_arr_expand(&connect->addrs, addrhint);
/* don't forget to update convenience pointer */
addr = &connect->addrs[connect->addrnum];
}
freeaddrinfo(ais);
#endif
tal_append_fmt(&connect->errors,
"%s: EXPERIMENTAL_FEATURES needed. ",
type_to_string(tmpctx,
struct wireaddr_internal,
addr));
goto next;
case ADDR_TYPE_WEBSOCKET:
af = -1;
break;
}
}
/* If we have to use proxy but we don't have one, we fail. */
if (use_proxy) {
if (!connect->daemon->proxyaddr) {
tal_append_fmt(&connect->errors,
"%s: need a proxy. ",
type_to_string(tmpctx,
struct wireaddr_internal,
addr));
goto next;
}
af = connect->daemon->proxyaddr->ai_family;
}
if (af == -1) {
tal_append_fmt(&connect->errors,
"%s: not supported. ",
type_to_string(tmpctx, struct wireaddr_internal,
addr));
goto next;
}
fd = socket(af, SOCK_STREAM, 0);
if (fd < 0) {
tal_append_fmt(&connect->errors,
"%s: opening %i socket gave %s. ",
type_to_string(tmpctx, struct wireaddr_internal,
addr),
af, strerror(errno));
goto next;
}
/* This creates the new connection using our fd, with the initialization
* function one of the above. */
if (use_proxy)
conn = io_new_conn(connect, fd, conn_proxy_init, connect);
else
conn = io_new_conn(connect, fd, conn_init, connect);
/* Careful! io_new_conn can fail (immediate connect() failure), and
* that frees connect. */
if (conn)
connect->conn = conn;
return;
next:
/* This causes very limited recursion. */
connect->addrnum++;
try_connect_one_addr(connect);
}
/*~ Sometimes it's nice to have an explicit enum instead of a bool to make
* arguments clearer: it kind of hacks around C's lack of naming formal
* arguments in callers (e.g. in Python we'd simply call func(websocket=False)).
*/
enum is_websocket {
NORMAL_SOCKET,
WEBSOCKET,
};
/*~ connectd is responsible for incoming connections, but it's the process of
* setting up the listening ports which gives us information we need for startup
* (such as our own address). So we perform setup in two phases: first we bind
* the sockets according to the command line arguments (if any), then we start
* listening for connections to them once lightningd is ready.
*
* This stores the fds we're going to listen on: */
struct listen_fd {
/* This is usually an IPv4/v6 address, but we also support local
* domain sockets (i.e. filesystem) */
struct wireaddr_internal wi;
/* The actual fd, ready to listen() on */
int fd;
/* If we bind() IPv6 then IPv4 to same port, we *may* fail to listen()
* on the IPv4 socket: under Linux, by default, the IPv6 listen()
* covers IPv4 too. Normally we'd consider failing to listen on a
* port to be fatal, so we note this when setting up addresses. */
bool mayfail;
/* Is this a websocket? */
enum is_websocket is_websocket;
};
static void add_listen_fd(struct daemon *daemon,
const struct wireaddr_internal *wi,
int fd, bool mayfail,
enum is_websocket is_websocket)
{
/*~ utils.h contains a convenience macro tal_arr_expand which
* reallocates a tal_arr to make it one longer, then returns a pointer
* to the (new) last element. */
struct listen_fd l;
l.wi = *wi;
l.fd = fd;
l.mayfail = mayfail;
l.is_websocket = is_websocket;
tal_arr_expand(&daemon->listen_fds, l);
}
/*~ Helper routine to create and bind a socket of a given type; like many
* daemons we set it SO_REUSEADDR so we won't have to wait 2 minutes to reuse
* it on restart.
*
* I generally avoid "return -1 on error", but for file-descriptors it's the
* UNIX standard, so it's not as offensive here as it would be in other
* contexts.
*
* Note that it's generally an antipattern to have a function which
* returns an allocated object (here, errstr) without an explicit tal ctx so the
* caller is aware.
*/
static int make_listen_fd(const tal_t *ctx,
struct daemon *daemon,
const struct wireaddr_internal *wi,
int domain, void *addr, socklen_t len,
char **errstr)
{
int fd = socket(domain, SOCK_STREAM, 0);
int on = 1;
if (fd < 0) {
if (errstr)
*errstr = tal_fmt(ctx, "Failed to create socket for %s: %s",
type_to_string(tmpctx, struct wireaddr_internal, wi),
strerror(errno));
status_debug("Failed to create %u socket: %s",
domain, strerror(errno));
return -1;
}
/* Re-use, please.. */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)))
status_unusual("Failed setting socket reuse: %s",
strerror(errno));
if (bind(fd, addr, len) != 0) {
if (errstr)
*errstr = tal_fmt(ctx, "Failed to bind socket for %s: %s",
type_to_string(tmpctx, struct wireaddr_internal, wi),
strerror(errno));
status_debug("Failed to create %u socket: %s",
domain, strerror(errno));
goto fail;
}
if (errstr)
*errstr = NULL;
return fd;
fail:
/*~ ccan/noerr contains convenient routines which don't clobber the
* errno global; in this case, the caller can report errno. */
close_noerr(fd);
return -1;
}
/* Return true if it created socket successfully. If errstr is non-NULL,
* allocate off ctx if return false, otherwise it implies it's OK to fail. */
static bool handle_wireaddr_listen(const tal_t *ctx,
struct daemon *daemon,
const struct wireaddr_internal *wi,
enum is_websocket is_websocket,
char **errstr)
{
int fd;
struct sockaddr_in addr;
struct sockaddr_in6 addr6;
const struct wireaddr *wireaddr;
assert(wi->itype == ADDR_INTERNAL_WIREADDR);
wireaddr = &wi->u.wireaddr;
/* Note the use of a switch() over enum here, even though it must be
* IPv4 or IPv6 here; that will catch future changes. */
switch (wireaddr->type) {
case ADDR_TYPE_IPV4:
wireaddr_to_ipv4(wireaddr, &addr);
/* We might fail if IPv6 bound to port first */
fd = make_listen_fd(ctx, daemon, wi, AF_INET, &addr, sizeof(addr), errstr);
if (fd >= 0) {
status_debug("Created IPv4 %slistener on port %u",
is_websocket ? "websocket ": "",
wireaddr->port);
add_listen_fd(daemon, wi, fd, errstr == NULL, is_websocket);
return true;
}
return false;
case ADDR_TYPE_IPV6:
wireaddr_to_ipv6(wireaddr, &addr6);
fd = make_listen_fd(ctx, daemon, wi, AF_INET6, &addr6, sizeof(addr6), errstr);
if (fd >= 0) {
status_debug("Created IPv6 %slistener on port %u",
is_websocket ? "websocket ": "",
wireaddr->port);
add_listen_fd(daemon, wi, fd, errstr == NULL, is_websocket);
return true;
}
return false;
/* Handle specially by callers. */
case ADDR_TYPE_WEBSOCKET:
case ADDR_TYPE_TOR_V2_REMOVED:
case ADDR_TYPE_TOR_V3:
case ADDR_TYPE_DNS:
break;
}
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid listener wireaddress type %u", wireaddr->type);
}
/* If it's a wildcard, turns it into a real address pointing to internet */
static bool public_address(struct daemon *daemon, struct wireaddr *wireaddr)
{
if (wireaddr_is_wildcard(wireaddr)) {
if (!guess_address(wireaddr))
return false;
}
/* --dev-allow-localhost treats the localhost as "public" for testing */
return address_routable(wireaddr, daemon->dev_allow_localhost);
}
static void add_announcable(struct wireaddr **announcable,
const struct wireaddr *addr)
{
tal_arr_expand(announcable, *addr);
}
static void add_binding(struct wireaddr_internal **binding,
const struct wireaddr_internal *addr)
{
tal_arr_expand(binding, *addr);
}
/*~ ccan/asort provides a type-safe sorting function; it requires a comparison
* function, which takes an optional extra argument which is usually unused as
* here, but deeply painful if you need it and don't have it! */
static int wireaddr_cmp_type(const struct wireaddr *a,
const struct wireaddr *b, void *unused)
{
/* This works, but of course it's inefficient. We don't
* really care, since it's called only once at startup. */
u8 *a_wire = tal_arr(tmpctx, u8, 0), *b_wire = tal_arr(tmpctx, u8, 0);
int cmp, minlen;
towire_wireaddr(&a_wire, a);
towire_wireaddr(&b_wire, b);
minlen = tal_bytelen(a_wire) < tal_bytelen(b_wire)
? tal_bytelen(a_wire) : tal_bytelen(b_wire);
cmp = memcmp(a_wire, b_wire, minlen);
/* On a tie, shorter one goes first. */
if (cmp == 0)
return tal_bytelen(a_wire) - tal_bytelen(b_wire);
return cmp;
}
/* We need to have a bound address we can tell Tor to connect to */
static const struct wireaddr *
find_local_address(const struct wireaddr_internal *bindings)
{
for (size_t i = 0; i < tal_count(bindings); i++) {
if (bindings[i].itype != ADDR_INTERNAL_WIREADDR)
continue;
if (bindings[i].u.wireaddr.type != ADDR_TYPE_IPV4
&& bindings[i].u.wireaddr.type != ADDR_TYPE_IPV6)
continue;
return &bindings[i].u.wireaddr;
}
return NULL;
}
static bool want_tor(const struct wireaddr_internal *proposed_wireaddr)
{
for (size_t i = 0; i < tal_count(proposed_wireaddr); i++) {
if (proposed_wireaddr[i].itype == ADDR_INTERNAL_STATICTOR
|| proposed_wireaddr[i].itype == ADDR_INTERNAL_AUTOTOR)
return true;
}
return false;
}
/*~ The user can specify three kinds of addresses: ones we bind to but don't
* announce, ones we announce but don't bind to, and ones we bind to and
* announce if they seem to be public addresses.
*
* This routine sorts out the mess: it populates the daemon->announcable array,
* and returns the addresses we bound to (by convention, return is allocated
* off `ctx` argument).
*/
static struct wireaddr_internal *setup_listeners(const tal_t *ctx,
struct daemon *daemon,
/* The proposed address. */
const struct wireaddr_internal *proposed_wireaddr,
/* For each one, listen,
announce or both */
const enum addr_listen_announce *proposed_listen_announce,
const char *tor_password,
struct wireaddr **announcable,
char **errstr)
{
struct sockaddr_un addrun;
int fd;
struct wireaddr_internal *binding;
const struct wireaddr *localaddr;
const char *blob = NULL;
struct secret random;
struct pubkey pb;
struct wireaddr *toraddr;
/* Start with empty arrays, for tal_arr_expand() */
binding = tal_arr(ctx, struct wireaddr_internal, 0);
*announcable = tal_arr(ctx, struct wireaddr, 0);
/* Add addresses we've explicitly been told to *first*: implicit
* addresses will be discarded then if we have multiple. */
for (size_t i = 0; i < tal_count(proposed_wireaddr); i++) {
struct wireaddr_internal wa = proposed_wireaddr[i];
/* We want announce-only addresses. */
if (proposed_listen_announce[i] & ADDR_LISTEN)
continue;
assert(proposed_listen_announce[i] & ADDR_ANNOUNCE);
/* You can only announce wiretypes, not internal formats! */
assert(proposed_wireaddr[i].itype
== ADDR_INTERNAL_WIREADDR);
add_announcable(announcable, &wa.u.wireaddr);
}
/* Now look for listening addresses. */
for (size_t i = 0; i < tal_count(proposed_wireaddr); i++) {
struct wireaddr_internal wa = proposed_wireaddr[i];
bool announce = (proposed_listen_announce[i] & ADDR_ANNOUNCE);
if (!(proposed_listen_announce[i] & ADDR_LISTEN))
continue;
switch (wa.itype) {
/* We support UNIX domain sockets, but can't announce */
case ADDR_INTERNAL_SOCKNAME:
addrun.sun_family = AF_UNIX;
memcpy(addrun.sun_path, wa.u.sockname,
sizeof(addrun.sun_path));
/* Remove any existing one. */
unlink(wa.u.sockname);
fd = make_listen_fd(ctx, daemon, &wa, AF_UNIX, &addrun, sizeof(addrun),
errstr);
/* Don't bother freeing here; we'll exit */
if (fd < 0)
return NULL;
status_debug("Created socket listener on file %s",
addrun.sun_path);
add_listen_fd(daemon, &wa, fd, false, NORMAL_SOCKET);
/* We don't announce socket names, though we allow
* them to lazily specify --addr=/socket. */
add_binding(&binding, &wa);
continue;
case ADDR_INTERNAL_AUTOTOR:
/* We handle these after we have all bindings. */
continue;
case ADDR_INTERNAL_STATICTOR:
/* We handle these after we have all bindings. */
continue;
/* Special case meaning IPv6 and IPv4 */
case ADDR_INTERNAL_ALLPROTO: {
bool ipv6_ok;
wa.itype = ADDR_INTERNAL_WIREADDR;
wa.u.wireaddr.port = wa.u.port;
/* First, create wildcard IPv6 address. */
wa.u.wireaddr.type = ADDR_TYPE_IPV6;
wa.u.wireaddr.addrlen = 16;
memset(wa.u.wireaddr.addr, 0,
sizeof(wa.u.wireaddr.addr));
ipv6_ok = handle_wireaddr_listen(ctx, daemon, &wa,
NORMAL_SOCKET, NULL);
if (ipv6_ok) {
add_binding(&binding, &wa);
if (announce
&& public_address(daemon, &wa.u.wireaddr))
add_announcable(announcable,
&wa.u.wireaddr);
}
/* Now, create wildcard IPv4 address. */
wa.u.wireaddr.type = ADDR_TYPE_IPV4;
wa.u.wireaddr.addrlen = 4;
memset(wa.u.wireaddr.addr, 0,
sizeof(wa.u.wireaddr.addr));
/* OK if this fails, as long as one succeeds! */
if (handle_wireaddr_listen(ctx, daemon, &wa,
NORMAL_SOCKET, ipv6_ok ? NULL : errstr)) {
add_binding(&binding, &wa);
if (announce
&& public_address(daemon, &wa.u.wireaddr))
add_announcable(announcable,
&wa.u.wireaddr);
} else if (!ipv6_ok) {
/* Both failed, return now, errstr set. */
return NULL;
}
continue;
}
/* This is a vanilla wireaddr as per BOLT #7 */
case ADDR_INTERNAL_WIREADDR:
if (!handle_wireaddr_listen(ctx, daemon, &wa,
NORMAL_SOCKET, errstr))
return NULL;
add_binding(&binding, &wa);
if (announce && public_address(daemon, &wa.u.wireaddr))
add_announcable(announcable, &wa.u.wireaddr);
continue;
case ADDR_INTERNAL_FORPROXY:
break;
}
/* Shouldn't happen. */
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid listener address type %u",
proposed_wireaddr[i].itype);
}
/* Make sure we have at least one non-websocket address to send to,
* for Tor */
localaddr = find_local_address(binding);
if (want_tor(proposed_wireaddr) && !localaddr) {
*errstr = "Need to bind at least one local address,"
" to send Tor connections to";
return NULL;
}
/* If we want websockets to match IPv4/v6, set it up now. */
if (daemon->websocket_port) {
bool announced_some = false;
struct wireaddr_internal addr;
/* If not overriden below, this is the default. */
*errstr = "Cannot advertize websocket: no IPv4/6 addresses advertized";
for (size_t i = 0; i < tal_count(binding); i++) {
/* Ignore UNIX sockets */
if (binding[i].itype != ADDR_INTERNAL_WIREADDR)
continue;
/* Override with websocket port */
addr = binding[i];
addr.u.wireaddr.port = daemon->websocket_port;
/* FIXME: catch errors here! */
if (handle_wireaddr_listen(ctx, daemon, &addr,
WEBSOCKET, NULL))
announced_some = true;
/* FIXME: We don't report these bindings to
* lightningd, so they don't appear in
* getinfo. */
}
/* We add the websocket port to the announcement if we made one
* *and* we have other announced addresses. */
/* BOLT-websocket #7:
* - MUST NOT add a `type 6` address unless there is also at
* least one address of different type.
*/
if (announced_some && tal_count(*announcable) != 0) {
wireaddr_from_websocket(&addr.u.wireaddr, daemon->websocket_port);
add_announcable(announcable, &addr.u.wireaddr);
} else
return NULL;
}
/* FIXME: Websocket over Tor (difficult for autotor, since we need
* to use the same onion addr!) */
/* Now we have bindings, set up any Tor auto addresses: we will point
* it at the first bound IPv4 or IPv6 address we have. */
for (size_t i = 0; i < tal_count(proposed_wireaddr); i++) {
if (!(proposed_listen_announce[i] & ADDR_LISTEN))
continue;
if (proposed_wireaddr[i].itype != ADDR_INTERNAL_AUTOTOR)
continue;
toraddr = tor_autoservice(tmpctx,
&proposed_wireaddr[i],
tor_password,
localaddr,
daemon->use_v3_autotor);
if (!(proposed_listen_announce[i] & ADDR_ANNOUNCE)) {
continue;
};
add_announcable(announcable, toraddr);
}
/* Now we have bindings, set up any Tor static addresses: we will point
* it at the first bound IPv4 or IPv6 address we have. */
for (size_t i = 0; i < tal_count(proposed_wireaddr); i++) {
if (!(proposed_listen_announce[i] & ADDR_LISTEN))
continue;
if (proposed_wireaddr[i].itype != ADDR_INTERNAL_STATICTOR)
continue;
blob = proposed_wireaddr[i].u.torservice.blob;
if (tal_strreg(tmpctx, (char *)proposed_wireaddr[i].u.torservice.blob, STATIC_TOR_MAGIC_STRING)) {
if (pubkey_from_node_id(&pb, &daemon->id)) {
if (sodium_mlock(&random, sizeof(random)) != 0)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not lock the random prf key memory.");
randombytes_buf((void * const)&random, 32);
/* generate static tor node address, take first 32 bytes from secret of node_id plus 32 random bytes from sodiom */
struct sha256 sha;
struct secret ss;
ecdh(&pb, &ss);
/* let's sha, that will clear ctx of hsm data */
sha256(&sha, &ss, 32);
/* even if it's a secret pub derived, tor shall see only the single sha */
memcpy((void *)&blob[0], &sha, 32);
memcpy((void *)&blob[32], &random, 32);
/* clear our temp buffer, don't leak by extern libs core-dumps, our blob we/tal handle later */
sodium_munlock(&random, sizeof(random));
} else status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Could not get the pub of our node id from hsm");
}
toraddr = tor_fixed_service(tmpctx,
&proposed_wireaddr[i],
tor_password,
blob,
localaddr,
0);
/* get rid of blob data on our side of tor and add jitter */
randombytes_buf((void * const)proposed_wireaddr[i].u.torservice.blob, TOR_V3_BLOBLEN);
if (!(proposed_listen_announce[i] & ADDR_ANNOUNCE)) {
continue;
};
add_announcable(announcable, toraddr);
}
/*~ The spec used to ban more than one address of each type, but
* nobody could remember exactly why, so now that's allowed. */
/* BOLT #7:
*
* The origin node:
*...
* - MUST place address descriptors in ascending order.
*/
asort(*announcable, tal_count(*announcable), wireaddr_cmp_type, NULL);
*errstr = NULL;
return binding;
}
/*~ Parse the incoming connect init message from lightningd ("master") and
* assign config variables to the daemon; it should be the first message we
* get. */
static void connect_init(struct daemon *daemon, const u8 *msg)
{
struct wireaddr *proxyaddr;
struct wireaddr_internal *binding;
struct wireaddr_internal *proposed_wireaddr;
enum addr_listen_announce *proposed_listen_announce;
struct wireaddr *announcable;
char *tor_password;
bool dev_fast_gossip;
bool dev_disconnect;
char *errstr;
/* Fields which require allocation are allocated off daemon */
if (!fromwire_connectd_init(
daemon, msg,
&chainparams,
&daemon->our_features,
&daemon->id,
&proposed_wireaddr,
&proposed_listen_announce,
&proxyaddr, &daemon->always_use_proxy,
&daemon->dev_allow_localhost, &daemon->use_dns,
&tor_password,
&daemon->use_v3_autotor,
&daemon->timeout_secs,
&daemon->websocket_helper,
&daemon->websocket_port,
&dev_fast_gossip,
&dev_disconnect)) {
/* This is a helper which prints the type expected and the actual
* message, then exits (it should never be called!). */
master_badmsg(WIRE_CONNECTD_INIT, msg);
}
#if DEVELOPER
/*~ Clearly mark this as a developer-only flag! */
daemon->dev_fast_gossip = dev_fast_gossip;
#endif
if (!pubkey_from_node_id(&daemon->mykey, &daemon->id))
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid id for me %s",
type_to_string(tmpctx, struct node_id,
&daemon->id));
/* Resolve Tor proxy address if any: we need an addrinfo to connect()
* to. */
if (proxyaddr) {
status_debug("Proxy address: %s",
fmt_wireaddr(tmpctx, proxyaddr));
daemon->proxyaddr = wireaddr_to_addrinfo(daemon, proxyaddr);
tal_free(proxyaddr);
} else
daemon->proxyaddr = NULL;
if (broken_resolver(daemon)) {
status_debug("Broken DNS resolver detected, will check for "
"dummy replies");
}
/* Figure out our addresses. */
binding = setup_listeners(tmpctx, daemon,
proposed_wireaddr,
proposed_listen_announce,
tor_password,
&announcable,
&errstr);
/* Free up old allocations */
tal_free(proposed_wireaddr);
tal_free(proposed_listen_announce);
tal_free(tor_password);
/* Tell it we're ready, handing it the addresses we have. */
daemon_conn_send(daemon->master,
take(towire_connectd_init_reply(NULL,
binding,
announcable,
errstr)));
#if DEVELOPER
if (dev_disconnect)
dev_disconnect_init(5);
#endif
}
/* Returning functions in C is ugly! */
static struct io_plan *(*get_in_cb(enum is_websocket is_websocket))(struct io_conn *, struct daemon *)
{
/*~ This switch and fall pattern serves a specific purpose:
* gcc will warn if we don't handle every case! */
switch (is_websocket) {
case WEBSOCKET:
return websocket_connection_in;
case NORMAL_SOCKET:
return connection_in;
}
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Invalid is_websocket %u", is_websocket);
}
/*~ lightningd tells us to go! */
static void connect_activate(struct daemon *daemon, const u8 *msg)
{
bool do_listen;
if (!fromwire_connectd_activate(msg, &do_listen))
master_badmsg(WIRE_CONNECTD_ACTIVATE, msg);
/* If we're --offline, lightningd tells us not to actually listen. */
if (do_listen) {
for (size_t i = 0; i < tal_count(daemon->listen_fds); i++) {
if (listen(daemon->listen_fds[i].fd, 64) != 0) {
if (daemon->listen_fds[i].mayfail)
continue;
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"Failed to listen on socket %s: %s",
type_to_string(tmpctx,
struct wireaddr_internal,
&daemon->listen_fds[i].wi),
strerror(errno));
}
notleak(io_new_listener(daemon,
daemon->listen_fds[i].fd,
get_in_cb(daemon->listen_fds[i]
.is_websocket),
daemon));
}
}
/* Free, with NULL assignment just as an extra sanity check. */
daemon->listen_fds = tal_free(daemon->listen_fds);
/* OK, we're ready! */
daemon_conn_send(daemon->master,
take(towire_connectd_activate_reply(NULL)));
}
/* BOLT #10:
*
* The DNS seed:
* ...
* - upon receiving a _node_ query:
* - MUST select the record matching the `node_id`, if any, AND return all
* addresses associated with that node.
*/
static const char **seednames(const tal_t *ctx, const struct node_id *id)
{
char bech32[100];
u5 *data = tal_arr(ctx, u5, 0);
const char **seednames = tal_arr(ctx, const char *, 0);
bech32_push_bits(&data, id->k, ARRAY_SIZE(id->k)*8);
bech32_encode(bech32, "ln", data, tal_count(data), sizeof(bech32),
BECH32_ENCODING_BECH32);
/* This is cdecker's seed */
tal_arr_expand(&seednames, tal_fmt(seednames, "%s.lseed.bitcoinstats.com", bech32));
/* This is darosior's seed */
tal_arr_expand(&seednames, tal_fmt(seednames, "%s.lseed.darosior.ninja", bech32));
return seednames;
}
/*~ As a last resort, we do a DNS lookup to the lightning DNS seed to
* resolve a node name when they say to connect to it. This is synchronous,
* so connectd blocks, but it's not very common so we haven't fixed it.
*
* This "seed by DNS" approach is similar to what bitcoind uses, and in fact
* has the nice property that DNS is cached, and the seed only sees a request
* from the ISP, not directly from the user. */
static void add_seed_addrs(struct wireaddr_internal **addrs,
const struct node_id *id,
struct sockaddr *broken_reply)
{
struct wireaddr *new_addrs;
const char **hostnames = seednames(tmpctx, id);
for (size_t i = 0; i < tal_count(hostnames); i++) {
status_peer_debug(id, "Resolving %s", hostnames[i]);
new_addrs = wireaddr_from_hostname(tmpctx, hostnames[i], DEFAULT_PORT,
NULL, broken_reply, NULL);
if (new_addrs) {
for (size_t j = 0; j < tal_count(new_addrs); j++) {
#if EXPERIMENTAL_FEATURES /* BOLT7 DNS RFC #911 */
if (new_addrs[j].type == ADDR_TYPE_DNS)
continue;
#endif
struct wireaddr_internal a;
a.itype = ADDR_INTERNAL_WIREADDR;
a.u.wireaddr = new_addrs[j];
status_peer_debug(id, "Resolved %s to %s", hostnames[i],
type_to_string(tmpctx, struct wireaddr,
&a.u.wireaddr));
tal_arr_expand(addrs, a);
}
/* Other seeds will likely have the same information. */
return;
} else
status_peer_debug(id, "Could not resolve %s", hostnames[i]);
}
}
static bool wireaddr_int_equals_wireaddr(const struct wireaddr_internal *addr_a,
const struct wireaddr *addr_b)
{
if (!addr_a || !addr_b)
return false;
return wireaddr_eq(&addr_a->u.wireaddr, addr_b);
}
/*~ Orders the addresses which lightningd gave us. */
static void add_gossip_addrs(struct wireaddr_internal **addrs,
const struct wireaddr *normal_addrs,
const struct wireaddr_internal *addrhint)
{
/* Wrap each one in a wireaddr_internal and add to addrs. */
for (size_t i = 0; i < tal_count(normal_addrs); i++) {
/* This is not supported, ignore. */
if (normal_addrs[i].type == ADDR_TYPE_TOR_V2_REMOVED)
continue;
/* add TOR addresses in a second loop */
if (normal_addrs[i].type == ADDR_TYPE_TOR_V3)
continue;
if (wireaddr_int_equals_wireaddr(addrhint, &normal_addrs[i]))
continue;
struct wireaddr_internal addr;
addr.itype = ADDR_INTERNAL_WIREADDR;
addr.u.wireaddr = normal_addrs[i];
tal_arr_expand(addrs, addr);
}
/* so connectd prefers direct connections if possible. */
for (size_t i = 0; i < tal_count(normal_addrs); i++) {
if (normal_addrs[i].type != ADDR_TYPE_TOR_V3)
continue;
if (wireaddr_int_equals_wireaddr(addrhint, &normal_addrs[i]))
continue;
struct wireaddr_internal addr;
addr.itype = ADDR_INTERNAL_WIREADDR;
addr.u.wireaddr = normal_addrs[i];
tal_arr_expand(addrs, addr);
}
}
/*~ Consumes addrhint if not NULL.
*
* That's a pretty ugly interface: we should use TAKEN, but we only have one
* caller so it's marginal. */
static void try_connect_peer(struct daemon *daemon,
const struct node_id *id,
u32 seconds_waited,
struct wireaddr *gossip_addrs,
struct wireaddr_internal *addrhint STEALS)
{
struct wireaddr_internal *addrs;
bool use_proxy = daemon->always_use_proxy;
struct connecting *connect;
struct peer *existing;
/* Already existing? */
existing = peer_htable_get(&daemon->peers, id);
if (existing) {
/* If it's exiting now, we've raced: reconnect after */
if (existing->to_subd
&& existing->to_peer
&& !existing->told_to_close)
return;
}
/* If we're trying to connect it right now, that's OK. */
if ((connect = find_connecting(daemon, id))) {
/* If we've been passed in new connection details
* for this connection, update our addrhint + add
* to addresses to check */
if (addrhint) {
connect->addrhint = tal_steal(connect, addrhint);
tal_arr_expand(&connect->addrs, *addrhint);
}
return;
}
/* Start an array of addresses to try. */
addrs = tal_arr(tmpctx, struct wireaddr_internal, 0);
/* They can supply an optional address for the connect RPC */
/* We add this first so its tried first by connectd */
if (addrhint)
tal_arr_expand(&addrs, *addrhint);
add_gossip_addrs(&addrs, gossip_addrs, addrhint);
if (tal_count(addrs) == 0) {
/* Don't resolve via DNS seed if we're supposed to use proxy. */
if (use_proxy) {
/* You're allowed to use names with proxies; in fact it's
* a good idea. */
struct wireaddr_internal unresolved;
const char **hostnames = seednames(tmpctx, id);
for (size_t i = 0; i < tal_count(hostnames); i++) {
wireaddr_from_unresolved(&unresolved,
hostnames[i],
DEFAULT_PORT);
tal_arr_expand(&addrs, unresolved);
}
} else if (daemon->use_dns) {
add_seed_addrs(&addrs, id,
daemon->broken_resolver_response);
}
}
/* Still no address? Fail immediately. Lightningd can still choose
* to retry; an address may get gossiped or appear on the DNS seed. */
if (tal_count(addrs) == 0) {
connect_failed(daemon, id, seconds_waited, addrhint,
CONNECT_NO_KNOWN_ADDRESS,
"Unable to connect, no address known for peer");
return;
}
/* Start connecting to it: since this is the only place we allocate
* a 'struct connecting' we don't write a separate new_connecting(). */
connect = tal(daemon, struct connecting);
connect->daemon = daemon;
connect->id = *id;
connect->addrs = tal_steal(connect, addrs);
connect->addrnum = 0;
/* connstate is supposed to be updated as we go, to give context for
* errors which occur. We miss it in a few places; would be nice to
* fix! */
connect->connstate = "Connection establishment";
connect->seconds_waited = seconds_waited;
connect->addrhint = tal_steal(connect, addrhint);
connect->errors = tal_strdup(connect, "");
list_add_tail(&daemon->connecting, &connect->list);
tal_add_destructor(connect, destroy_connecting);
/* Now we kick it off by recursively trying connect->addrs[connect->addrnum] */
if (!existing)
try_connect_one_addr(connect);
}
/* lightningd tells us to connect to a peer by id, with optional addr hint. */
static void connect_to_peer(struct daemon *daemon, const u8 *msg)
{
struct node_id id;
u32 seconds_waited;
struct wireaddr_internal *addrhint;
struct wireaddr *addrs;
if (!fromwire_connectd_connect_to_peer(tmpctx, msg,
&id, &seconds_waited,
&addrs, &addrhint))
master_badmsg(WIRE_CONNECTD_CONNECT_TO_PEER, msg);
try_connect_peer(daemon, &id, seconds_waited, addrs, addrhint);
}
void peer_conn_closed(struct peer *peer)
{
struct connecting *connect = find_connecting(peer->daemon, &peer->id);
/* These should be closed already! */
assert(!peer->to_subd);
assert(!peer->to_peer);
assert(peer->told_to_close);
/* Tell gossipd to stop asking this peer gossip queries */
daemon_conn_send(peer->daemon->gossipd,
take(towire_gossipd_peer_gone(NULL, &peer->id)));
/* Wake up in case there's a reconnecting peer waiting in io_wait. */
io_wake(peer);
/* Note: deleting from a htable (a-la node_set_del) does not free it:
* htable doesn't assume it's a tal object at all. That's why we have
* a destructor attached to peer (called destroy_peer by
* convention). */
tal_free(peer);
/* If we wanted to connect to it, but found it was exiting, try again */
if (connect)
try_connect_one_addr(connect);
}
/* A peer is gone: clean things up. */
static void cleanup_dead_peer(struct daemon *daemon, const struct node_id *id)
{
struct peer *peer;
/* We should stay in sync with lightningd at all times. */
peer = peer_htable_get(&daemon->peers, id);
if (!peer)
status_failed(STATUS_FAIL_INTERNAL_ERROR,
"peer_disconnected unknown peer: %s",
type_to_string(tmpctx, struct node_id, id));
status_peer_debug(id, "disconnect");
/* When it's finished, it will call peer_conn_closed() */
close_peer_conn(peer);
}
/* lightningd tells us a peer has disconnected. */
static void peer_disconnected(struct daemon *daemon, const u8 *msg)
{
struct node_id id;
if (!fromwire_connectd_peer_disconnected(msg, &id))
master_badmsg(WIRE_CONNECTD_PEER_DISCONNECTED, msg);
cleanup_dead_peer(daemon, &id);
}
/* lightningd tells us to send a msg and disconnect. */
static void peer_final_msg(struct io_conn *conn,
struct daemon *daemon, const u8 *msg)
{
struct peer *peer;
struct node_id id;
u8 *finalmsg;
if (!fromwire_connectd_peer_final_msg(tmpctx, msg, &id, &finalmsg))
master_badmsg(WIRE_CONNECTD_PEER_FINAL_MSG, msg);
/* This can happen if peer hung up on us. */
peer = peer_htable_get(&daemon->peers, &id);
if (peer) {
/* Log message for peer. */
status_peer_io(LOG_IO_OUT, &id, finalmsg);
multiplex_final_msg(peer, take(finalmsg));
}
}
#if DEVELOPER
static void dev_connect_memleak(struct daemon *daemon, const u8 *msg)
{
struct htable *memtable;
bool found_leak;
memtable = memleak_find_allocations(tmpctx, msg, msg);
/* Now delete daemon and those which it has pointers to. */
memleak_remove_region(memtable, daemon, sizeof(daemon));
memleak_remove_htable(memtable, &daemon->peers.raw);
found_leak = dump_memleak(memtable, memleak_status_broken);
daemon_conn_send(daemon->master,
take(towire_connectd_dev_memleak_reply(NULL,
found_leak)));
}
#endif /* DEVELOPER */
static struct io_plan *recv_req(struct io_conn *conn,
const u8 *msg,
struct daemon *daemon)
{
enum connectd_wire t = fromwire_peektype(msg);
/* Demux requests from lightningd: we expect INIT then ACTIVATE, then
* connect requests and disconnected messages. */
switch (t) {
case WIRE_CONNECTD_INIT:
connect_init(daemon, msg);
goto out;
case WIRE_CONNECTD_ACTIVATE:
connect_activate(daemon, msg);
goto out;
case WIRE_CONNECTD_CONNECT_TO_PEER:
connect_to_peer(daemon, msg);
goto out;
case WIRE_CONNECTD_PEER_DISCONNECTED:
peer_disconnected(daemon, msg);
goto out;
case WIRE_CONNECTD_PEER_FINAL_MSG:
peer_final_msg(conn, daemon, msg);
goto out;
case WIRE_CONNECTD_PING:
send_manual_ping(daemon, msg);
goto out;
case WIRE_CONNECTD_SEND_ONIONMSG:
onionmsg_req(daemon, msg);
goto out;
case WIRE_CONNECTD_CUSTOMMSG_OUT:
send_custommsg(daemon, msg);
goto out;
case WIRE_CONNECTD_DEV_MEMLEAK:
#if DEVELOPER
dev_connect_memleak(daemon, msg);
goto out;
#endif
/* We send these, we don't receive them */
case WIRE_CONNECTD_INIT_REPLY:
case WIRE_CONNECTD_ACTIVATE_REPLY:
case WIRE_CONNECTD_PEER_CONNECTED:
case WIRE_CONNECTD_RECONNECTED:
case WIRE_CONNECTD_CONNECT_FAILED:
case WIRE_CONNECTD_DEV_MEMLEAK_REPLY:
case WIRE_CONNECTD_PING_REPLY:
case WIRE_CONNECTD_GOT_ONIONMSG_TO_US:
case WIRE_CONNECTD_CUSTOMMSG_IN:
break;
}
/* Master shouldn't give bad requests. */
status_failed(STATUS_FAIL_MASTER_IO, "%i: %s",
t, tal_hex(tmpctx, msg));
out:
/* Read the next message. */
return daemon_conn_read_next(conn, daemon->master);
}
/*~ UNUSED is defined to an __attribute__ for GCC; at one stage we tried to use
* it ubiquitously to make us compile cleanly with -Wunused, but it's bitrotted
* and we'd need to start again.
*
* The C++ method of omitting unused parameter names is *much* neater, and I
* hope we'll eventually see it in a C standard. */
static void master_gone(struct daemon_conn *master UNUSED)
{
/* Can't tell master, it's gone. */
exit(2);
}
/*~ gossipd sends us gossip to send to the peers. */
static struct io_plan *recv_gossip(struct io_conn *conn,
const u8 *msg,
struct daemon *daemon)
{
struct node_id dst;
u8 *gossip_msg;
struct peer *peer;
if (!fromwire_gossipd_send_gossip(msg, msg, &dst, &gossip_msg))
status_failed(STATUS_FAIL_GOSSIP_IO, "Unknown msg %i",
fromwire_peektype(msg));
peer = peer_htable_get(&daemon->peers, &dst);
if (peer)
inject_peer_msg(peer, take(gossip_msg));
return daemon_conn_read_next(conn, daemon->gossipd);
}
/*~ This is a hook used by the memleak code (if DEVELOPER=1): it can't see
* pointers inside hash tables, so we give it a hint here. */
#if DEVELOPER
static void memleak_daemon_cb(struct htable *memtable, struct daemon *daemon)
{
memleak_remove_htable(memtable, &daemon->peers.raw);
}
#endif /* DEVELOPER */
int main(int argc, char *argv[])
{
setup_locale();
struct daemon *daemon;
/* Common subdaemon setup code. */
subdaemon_setup(argc, argv);
/* Allocate and set up our simple top-level structure. */
daemon = tal(NULL, struct daemon);
peer_htable_init(&daemon->peers);
memleak_add_helper(daemon, memleak_daemon_cb);
list_head_init(&daemon->connecting);
daemon->listen_fds = tal_arr(daemon, struct listen_fd, 0);
timers_init(&daemon->timers, time_mono());
daemon->gossip_store_fd = -1;
/* stdin == control */
daemon->master = daemon_conn_new(daemon, STDIN_FILENO, recv_req, NULL,
daemon);
tal_add_destructor(daemon->master, master_gone);
/* This tells the status_* subsystem to use this connection to send
* our status_ and failed messages. */
status_setup_async(daemon->master);
/* This streams gossip to and from gossipd */
daemon->gossipd = daemon_conn_new(daemon, GOSSIPCTL_FD,
recv_gossip, NULL,
daemon);
/* Set up ecdh() function so it uses our HSM fd, and calls
* status_failed on error. */
ecdh_hsmd_setup(HSM_FD, status_failed);
for (;;) {
struct timer *expired;
io_loop(&daemon->timers, &expired);
timer_expired(expired);
}
}
/*~ Getting bored? This was a pretty simple daemon!
*
* The good news is that the next daemon gossipd/gossipd.c is the most complex
* global daemon we have!
*/