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866 lines
32 KiB
866 lines
32 KiB
/*~ Welcome, wonderful reader!
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*
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* This is the core of c-lightning: the main file of the master daemon
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* `lightningd`. It's mainly cluttered with the miscellany of setup,
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* and a few startup sanity checks.
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*
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* The role of this daemon is to start the subdaemons, shuffle peers
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* between them, handle the JSON RPC requests, bitcoind, the database
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* and centralize logging. In theory, it doesn't trust the other
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* daemons, though we expect `hsmd` (which holds secret keys) to be
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* responsive.
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*
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* Comments beginning with a ~ (like this one!) are part of our shared
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* adventure through the source, so they're more meta than normal code
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* comments, and meant to be read in a certain order.
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*/
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/*~ Notice how includes are in ASCII order: this is actually enforced by
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* the build system under `make check-source`. It avoids merge conflicts
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* and keeps things consistent. */
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#include "gossip_control.h"
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#include "hsm_control.h"
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#include "lightningd.h"
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#include "peer_control.h"
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#include "subd.h"
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/*~ This is Ian Lance Taylor's libbacktrace. It turns out that it's
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* horrifically difficult to obtain a decent backtrace in C; the standard
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* backtrace function is useless in most programs. */
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#include <backtrace.h>
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/*~ These headers are from CCAN: http://ccodearchive.net.
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*
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* It's another one of Rusty's projects, and we copy and paste it
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* automatically into the source tree here, so you should never edit
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* it. There's a Makefile target update-ccan to update it (and add modules
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* if CCAN_NEW is specified).
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*
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* The most used of these are `ccan/tal` and `ccan/take`, which we'll describe
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* in detail below.
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*/
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#include <ccan/array_size/array_size.h>
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#include <ccan/cast/cast.h>
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#include <ccan/crypto/hkdf_sha256/hkdf_sha256.h>
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#include <ccan/daemonize/daemonize.h>
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#include <ccan/err/err.h>
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#include <ccan/io/fdpass/fdpass.h>
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#include <ccan/io/io.h>
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#include <ccan/noerr/noerr.h>
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#include <ccan/pipecmd/pipecmd.h>
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#include <ccan/read_write_all/read_write_all.h>
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#include <ccan/take/take.h>
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#include <ccan/tal/grab_file/grab_file.h>
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#include <ccan/tal/path/path.h>
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#include <ccan/tal/str/str.h>
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/*~ This is common code: routines shared by one or more executables
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* (separate daemons, or the lightning-cli program). */
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#include <common/daemon.h>
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#include <common/json_escaped.h>
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#include <common/timeout.h>
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#include <common/utils.h>
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#include <common/version.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <gen_header_versions.h>
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#include <lightningd/bitcoind.h>
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#include <lightningd/chaintopology.h>
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#include <lightningd/channel_control.h>
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#include <lightningd/connect_control.h>
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#include <lightningd/invoice.h>
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#include <lightningd/jsonrpc.h>
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#include <lightningd/log.h>
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#include <lightningd/onchain_control.h>
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#include <lightningd/options.h>
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#include <onchaind/onchain_wire.h>
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#include <signal.h>
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#include <sys/types.h>
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#include <unistd.h>
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/*~ The core lightning object: it's passed everywhere, and is basically a
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* global variable. This new_xxx pattern is something we'll see often:
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* it allocates and initializes a new structure, using *tal*, the hierarchical
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* allocator. */
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static struct lightningd *new_lightningd(const tal_t *ctx)
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{
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/*~ tal: each allocation is a child of an existing object (or NULL,
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* the top-level object). When an object is freed, all the objects
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* `tallocated` off it are also freed. We use it in place of malloc
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* and free. For the technically inclined: tal allocations usually
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* build a tree, and tal_freeing any node in the tree will result in
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* the entire subtree rooted at that node to be freed.
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*
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* It's incredibly useful for grouping object lifetimes, as we'll see.
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* For example, a `struct bitcoin_tx` has a pointer to an array of
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* `struct bitcoin_tx_input`; they are allocated off the `struct
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* bitcoind_tx`, so freeing the `struct bitcoind_tx` frees them all.
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*
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* In this case, freeing `ctx` will free `ld`:
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*/
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struct lightningd *ld = tal(ctx, struct lightningd);
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/*~ Style note: `ctx` is declared `const`, yet we can `tallocate` from
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* it. Adding/removing children is not considered to change an
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* object; nor, in fact, is freeing it with tal_free(). This allows
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* us to use const more liberally: the style rule here is that you
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* should use 'const' on pointers if you can. */
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/*~ Note that we generally EXPLICITLY #if-wrap DEVELOPER code. This
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* is a nod to keeping it minimal and explicit: we need this code for
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* testing, but its existence means we're not actually testing the
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* same exact code users will be running. */
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ld->dev_debug_subprocess = NULL;
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#if DEVELOPER
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ld->dev_disconnect_fd = -1;
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ld->dev_subdaemon_fail = false;
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ld->dev_allow_localhost = false;
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#endif
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/*~ These are CCAN lists: an embedded double-linked list. It's not
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* really typesafe, but relies on convention to access the contents.
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* It's inspired by the closely-related Linux kernel list.h.
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*
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* You declare them as a `struct list_head` (or use the LIST_HEAD()
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* macro which doesn't work on dynamically-allocated objects like `ld`
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* here). The item which will go into the list must declared a
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* `struct list_node` for each list it can be in.
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*
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* The most common operations are list_head_init(), list_add(),
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* list_del() and list_for_each().
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*
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* This method of manually declaring the list hooks avoids dynamic
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* allocations to put things into a list. */
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list_head_init(&ld->peers);
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/*~ These are hash tables of incoming and outgoing HTLCs (contracts),
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* defined as `struct htlc_in` and `struct htlc_out`in htlc_end.h.
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* The hash tables are declared there using the very ugly
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* HTABLE_DEFINE_TYPE macro. The key is the channel the HTLC is in
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* and the 64-bit htlc-id which is unique for that channel and
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* direction. That htlc-id is used in the inter-peer wire protocol,
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* so it is the logical key.
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*
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* There aren't usually many HTLCs, so we could have just used a linked
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* list attached to the channel structure itself, or even left them in
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* the database rather than making an in-memory version. Obviously
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* I was in a premature optimization mood when I wrote this: */
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htlc_in_map_init(&ld->htlcs_in);
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htlc_out_map_init(&ld->htlcs_out);
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/*~ We have a two-level log-book infrastructure: we define a 20MB log
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* book to hold all the entries (and trims as necessary), and multiple
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* log objects which each can write into it, each with a unique
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* prefix. */
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ld->log_book = new_log_book(20*1024*1024, LOG_INFORM);
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/*~ Note the tal context arg (by convention, the first argument to any
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* allocation function): ld->log will be implicitly freed when ld
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* is. */
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ld->log = new_log(ld, ld->log_book, "lightningd(%u):", (int)getpid());
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ld->logfile = NULL;
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/*~ We explicitly set these to NULL: if they're still NULL after option
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* parsing, we know they're to be set to the defaults. */
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ld->alias = NULL;
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ld->rgb = NULL;
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list_head_init(&ld->connects);
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list_head_init(&ld->waitsendpay_commands);
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list_head_init(&ld->sendpay_commands);
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list_head_init(&ld->close_commands);
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list_head_init(&ld->ping_commands);
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/*~ Tal also explicitly supports arrays: it stores the number of
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* elements, which can be accessed with tal_count() (or tal_bytelen()
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* for raw bytecount). It's common for simple arrays to use
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* tal_resize() (or tal_arr_expand) to expand, which does not work on
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* NULL. So we start with an zero-length array. */
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ld->proposed_wireaddr = tal_arr(ld, struct wireaddr_internal, 0);
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ld->proposed_listen_announce = tal_arr(ld, enum addr_listen_announce, 0);
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ld->portnum = DEFAULT_PORT;
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ld->listen = true;
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ld->autolisten = true;
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ld->reconnect = true;
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/*~ This is from ccan/timer: it is efficient for the case where timers
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* are deleted before expiry (as is common with timeouts) using an
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* ingenious bucket system which more precisely sorts timers as they
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* approach expiry. It's a fascinating implementation you should read
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* if you have a spare few hours. */
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timers_init(&ld->timers, time_mono());
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/*~ This is detailed in chaintopology.c */
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ld->topology = new_topology(ld, ld->log);
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ld->daemon = false;
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ld->config_filename = NULL;
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ld->pidfile = NULL;
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ld->ini_autocleaninvoice_cycle = 0;
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ld->ini_autocleaninvoice_expiredby = 86400;
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ld->proxyaddr = NULL;
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ld->use_proxy_always = false;
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ld->pure_tor_setup = false;
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ld->tor_service_password = NULL;
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ld->max_funding_unconfirmed = 2016;
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/*~ In the next step we will initialize the plugins. This will
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* also populate the JSON-RPC with passthrough methods, hence
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* lightningd needs to have something to put those in. This
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* is that :-)
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*/
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jsonrpc_setup(ld);
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/*~ We run a number of plugins (subprocesses that we talk JSON-RPC with)
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*alongside this process. This allows us to have an easy way for users
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*to add their own tools without having to modify the c-lightning source
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*code. Here we initialize the context that will keep track and control
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*the plugins.
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*/
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ld->plugins = plugins_new(ld, ld->log_book, ld);
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return ld;
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}
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/*~ We list our daemons here so on startup we can test they're the
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* correct versions and that they exist. */
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static const char *subdaemons[] = {
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"lightning_channeld",
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"lightning_closingd",
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"lightning_connectd",
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"lightning_gossipd",
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"lightning_hsmd",
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"lightning_onchaind",
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"lightning_openingd"
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};
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/*~ Check we can run them, and check their versions */
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void test_subdaemons(const struct lightningd *ld)
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{
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size_t i;
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/*~ CCAN's ARRAY_SIZE() should always be used on defined arrays like
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* the subdaemons array above. You can calculate the number of
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* elements it has using `sizeof(subdaemons)/sizeof(subdaemons[0])`
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* but if `subdaemons` were refactored into a pointer (eg. to make
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* it a dynamic array) that would erroneously evaluate to `1`.
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*
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* ARRAY_SIZE will cause a compiler error if the argument is actually
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* a pointer, not an array. */
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for (i = 0; i < ARRAY_SIZE(subdaemons); i++) {
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int outfd;
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/*~ CCAN's path module uses tal, so wants a context to
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* allocate from. We have a magic convenience context
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* `tmpctx` for temporary allocations like this.
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*
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* Because all our daemons at their core are of form `while
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* (!stopped) handle_events();` (an event loop pattern), we
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* can free `tmpctx` in that top-level loop after each event
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* is handled.
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*/
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const char *dpath = path_join(tmpctx, ld->daemon_dir, subdaemons[i]);
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const char *verstring;
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/*~ CCAN's pipecmd module is like popen for grownups: it
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* takes pointers to fill in stdin, stdout and stderr file
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* descriptors if desired, and the remainder of arguments
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* are the command and its argument. */
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pid_t pid = pipecmd(NULL, &outfd, &outfd,
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dpath, "--version", NULL);
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/*~ Our logging system: spam goes in at log_debug level, but
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* logging is mainly added by developer necessity and removed
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* by developer/user complaints . The only strong convention
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* is that log_broken() is used for "should never happen".
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*
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* Note, however, that logging takes care to preserve the
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* global `errno` which is set above. */
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log_debug(ld->log, "testing %s", dpath);
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/*~ ccan/err is a wrapper around BSD's err.h, which defines
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* the convenience functions err() (error with message
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* followed by a string based on errno) and errx() (same,
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* but no errno string). */
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if (pid == -1)
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err(1, "Could not run %s", dpath);
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/*~ CCAN's grab_file module contains a routine to read into a
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* tallocated buffer until EOF */
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verstring = grab_fd(tmpctx, outfd);
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/*~ Like many CCAN modules, it set errno on failure, which
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* err (ccan/err, but usually just the BSD <err.h>) prints */
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if (!verstring)
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err(1, "Could not get output from %s", dpath);
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/*~ strstarts is from CCAN/str. */
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if (!strstarts(verstring, version())
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|| verstring[strlen(version())] != '\n')
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errx(1, "%s: bad version '%s'",
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subdaemons[i], verstring);
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/*~ finally reap the child process, freeing all OS
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* resources that go with it */
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waitpid(pid, NULL, 0);
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}
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}
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/* Check if all subdaemons exist in specified directory. */
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static bool has_all_subdaemons(const char *daemon_dir)
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{
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size_t i;
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bool missing_daemon = false;
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for (i = 0; i < ARRAY_SIZE(subdaemons); ++i) {
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if (!path_is_file(path_join(tmpctx, daemon_dir, subdaemons[i]))) {
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missing_daemon = true;
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break;
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}
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}
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return !missing_daemon;
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}
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/* Returns the directory this executable is running from */
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static const char *find_my_directory(const tal_t *ctx, const char *argv0)
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{
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/* find_my_abspath simply exits on failure, so never returns NULL. */
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const char *me = find_my_abspath(NULL, argv0);
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/*~ The caller just wants the directory we're in.
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*
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* Note the magic `take()` macro here: it annotates a pointer as "to
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* be taken", and the recipient is expected to take ownership of the
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* pointer. This improves efficiency because the recipient might
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* choose to use or even keep it rather than make a copy (or it
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* might just free it).
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*
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* Many CCAN and our own routines support this, but if you hand a
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* `take()` to a routine which *doesn't* expect it, unfortunately you
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* don't get a compile error (we have runtime detection for this
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* case, however).
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*/
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return path_dirname(ctx, take(me));
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}
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/*~ This returns the PKGLIBEXEC path which is where binaries get installed.
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* Note the `TAKES` annotation which indicates that the `my_path` parameter
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* can be take(); in which case, this function will handle freeing it.
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*
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* TAKES is only a convention unfortunately, and ignored by the compiler.
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*/
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static const char *find_my_pkglibexec_path(struct lightningd *ld,
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const char *my_path TAKES)
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{
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const char *pkglibexecdir;
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/*~`path_join` is declared in ccan/path/path.h as:
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*
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* char *path_join(const tal_t *ctx,
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* const char *base TAKES, const char *a TAKES);
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*
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* So, as we promised with 'TAKES' in our own declaration, if the
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* caller has called `take()` the `my_path` parameter, path_join()
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* will free it. */
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pkglibexecdir = path_join(NULL, my_path, BINTOPKGLIBEXECDIR);
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/*~ The plugin dir is in ../libexec/c-lightning/plugins, which (unlike
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* those given on the command line) does not need to exist. */
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add_plugin_dir(ld->plugins,
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path_join(tmpctx, pkglibexecdir, "plugins"),
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true);
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/*~ Sometimes take() can be more efficient, since the routine can
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* manipulate the string in place. This is the case here. */
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return path_simplify(ld, take(pkglibexecdir));
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}
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/* Determine the correct daemon dir. */
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static const char *find_daemon_dir(struct lightningd *ld, const char *argv0)
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{
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const char *my_path = find_my_directory(ld, argv0);
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/* If we're running in-tree, all the subdaemons are with lightningd. */
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if (has_all_subdaemons(my_path)) {
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/* In this case, look in ../plugins */
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add_plugin_dir(ld->plugins,
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path_join(tmpctx, my_path, "../plugins"),
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true);
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return my_path;
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}
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/* Otherwise we assume they're in the installed dir. */
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return find_my_pkglibexec_path(ld, take(my_path));
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}
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/*~ We like to free everything on exit, so valgrind doesn't complain (valgrind
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* is an awesome runtime memory usage detector for C and C++ programs). In
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* some ways it would be neater not to do this, but it turns out some
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* transient objects still need cleaning. */
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static void shutdown_subdaemons(struct lightningd *ld)
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{
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struct peer *p;
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/*~ tal supports *destructors* using `tal_add_destructor()`; the most
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* common use is for an object to delete itself from a linked list
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* when it's freed.
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*
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* As a result, freeing an object (which frees any tal objects
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* allocated off it, and any allocated off them, etc) may cause
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* callbacks; in this case, some objects freed here can cause database
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* writes, which must be inside a transaction. */
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db_begin_transaction(ld->wallet->db);
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/* Let everyone shutdown cleanly. */
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close(ld->hsm_fd);
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/*~ The three "global" daemons, which we shutdown explicitly: we
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* give them 10 seconds to exit gracefully before killing them. */
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subd_shutdown(ld->connectd, 10);
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subd_shutdown(ld->gossip, 10);
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subd_shutdown(ld->hsm, 10);
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/* Now we free all the HTLCs */
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free_htlcs(ld, NULL);
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/*~ For every peer, we free every channel. On allocation the peer was
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* given a destructor (`destroy_peer`) which removes itself from the
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* list. Thus we use list_top() not list_pop() here. */
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while ((p = list_top(&ld->peers, struct peer, list)) != NULL) {
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struct channel *c;
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/*~ A peer can have multiple channels; we only allow one to be
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* open at any time, but we remember old ones for 100 blocks,
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* after all the outputs we care about are spent. */
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while ((c = list_top(&p->channels, struct channel, list))
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!= NULL) {
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/* Removes itself from list as we free it */
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tal_free(c);
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}
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/* A peer may have a channel in the process of opening. */
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if (p->uncommitted_channel) {
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struct uncommitted_channel *uc = p->uncommitted_channel;
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/* Setting to NULL stops destroy_uncommitted_channel
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|
* from trying to remove peer from db! */
|
|
p->uncommitted_channel = NULL;
|
|
tal_free(uc);
|
|
}
|
|
/* Removes itself from list as we free it */
|
|
tal_free(p);
|
|
}
|
|
|
|
/*~ Commit the transaction. Note that the db is actually
|
|
* single-threaded, so commits never fail and we don't need
|
|
* spin-and-retry logic everywhere. */
|
|
db_commit_transaction(ld->wallet->db);
|
|
}
|
|
|
|
/*~ Chainparams are the parameters for eg. testnet vs mainnet. This wrapper
|
|
* saves lots of struggles with our 80-column guideline! */
|
|
const struct chainparams *get_chainparams(const struct lightningd *ld)
|
|
{
|
|
/* "The lightningd is connected to the blockchain."
|
|
* "The blockchain is connected to the bitcoind API."
|
|
* "The bitcoind API is connected chain parameters."
|
|
* -- Worst childhood song ever. */
|
|
return ld->topology->bitcoind->chainparams;
|
|
}
|
|
|
|
/*~ Our wallet logic needs to know what outputs we might be interested in. We
|
|
* use BIP32 (a.k.a. "HD wallet") to generate keys from a single seed, so we
|
|
* keep the maximum-ever-used key index in the db, and add them all to the
|
|
* filter here. */
|
|
static void init_txfilter(struct wallet *w, struct txfilter *filter)
|
|
{
|
|
/*~ This is defined in libwally, so we didn't have to reimplement */
|
|
struct ext_key ext;
|
|
/*~ Note the use of ccan/short_types u64 rather than uint64_t.
|
|
* Thank me later. */
|
|
u64 bip32_max_index;
|
|
|
|
bip32_max_index = db_get_intvar(w->db, "bip32_max_index", 0);
|
|
/*~ One of the C99 things I unequivocally approve: for-loop scope. */
|
|
for (u64 i = 0; i <= bip32_max_index; i++) {
|
|
if (bip32_key_from_parent(w->bip32_base, i, BIP32_FLAG_KEY_PUBLIC, &ext) != WALLY_OK) {
|
|
abort();
|
|
}
|
|
txfilter_add_derkey(filter, ext.pub_key);
|
|
}
|
|
}
|
|
|
|
/*~ The normal advice for daemons is to move into the root directory, so you
|
|
* don't prevent unmounting whatever filesystem you happen to start in.
|
|
*
|
|
* But we define every path relative to our (~/.lightning) data dir, so we
|
|
* make sure we stay there.
|
|
*/
|
|
static void daemonize_but_keep_dir(struct lightningd *ld)
|
|
{
|
|
/* daemonize moves us into /, but we want to be here */
|
|
const char *cwd = path_cwd(NULL);
|
|
|
|
/*~ SQLite3 does NOT like being open across fork(), a.k.a. daemonize() */
|
|
db_close_for_fork(ld->wallet->db);
|
|
if (!cwd)
|
|
fatal("Could not get current directory: %s", strerror(errno));
|
|
if (!daemonize())
|
|
fatal("Could not become a daemon: %s", strerror(errno));
|
|
|
|
/*~ Move back: important, since lightning dir may be relative! */
|
|
if (chdir(cwd) != 0)
|
|
fatal("Could not return to directory %s: %s",
|
|
cwd, strerror(errno));
|
|
|
|
db_reopen_after_fork(ld->wallet->db);
|
|
|
|
/*~ Why not allocate cwd off tmpctx? Probably because this code predates
|
|
* tmpctx. So we free manually here. */
|
|
tal_free(cwd);
|
|
}
|
|
|
|
/*~ It's pretty standard behaviour (especially for daemons) to create and
|
|
* file-lock a pidfile. This not only prevents accidentally running multiple
|
|
* daemons on the same database at once, but lets nosy sysadmins see what pid
|
|
* the currently-running daemon is supposed to be. */
|
|
static int pidfile_create(const struct lightningd *ld)
|
|
{
|
|
int pid_fd;
|
|
|
|
/* Create PID file */
|
|
pid_fd = open(ld->pidfile, O_WRONLY|O_CREAT, 0640);
|
|
if (pid_fd < 0)
|
|
err(1, "Failed to open PID file");
|
|
|
|
/* Lock PID file, so future lockf will fail. */
|
|
if (lockf(pid_fd, F_TLOCK, 0) < 0)
|
|
/* Problem locking file */
|
|
err(1, "lightningd already running? Error locking PID file");
|
|
|
|
/*~ As closing the file will remove the lock, we need to keep it open;
|
|
* the OS will close it implicitly when we exit for any reason. */
|
|
return pid_fd;
|
|
}
|
|
|
|
/*~ Writing the pid into the lockfile provides a useful clue to users as to
|
|
* what created it; however, we can't do that until we've got a stable process
|
|
* id, and if --daemon is specified, that's quite late. */
|
|
static void pidfile_write(const struct lightningd *ld, int pid_fd)
|
|
{
|
|
char *pid;
|
|
|
|
/*~ Note that tal_fmt() is what asprintf() dreams of being. */
|
|
pid = tal_fmt(tmpctx, "%d\n", getpid());
|
|
/*~ CCAN's write_all writes to a file descriptor, looping if necessary
|
|
* (which, on a file unlike a socket, is never, for historical UNIX
|
|
* reasons). It also isn't declared with GCC's warn_unused_result
|
|
* which write() is when FORTIFY_SOURCE is defined, so we're allowed
|
|
* to ignore the result without jumping through hoops. */
|
|
write_all(pid_fd, pid, strlen(pid));
|
|
}
|
|
|
|
/*~ ccan/io allows overriding the poll() function that is the very core
|
|
* of the event loop it runs for us. We override it so that we can do
|
|
* extra sanity checks, and it's also a good point to free the tmpctx. */
|
|
static int io_poll_lightningd(struct pollfd *fds, nfds_t nfds, int timeout)
|
|
{
|
|
/*~ In particular, we should *not* have left a database transaction
|
|
* open! */
|
|
db_assert_no_outstanding_statements();
|
|
|
|
/* The other checks and freeing tmpctx are common to all daemons. */
|
|
return daemon_poll(fds, nfds, timeout);
|
|
}
|
|
|
|
/*~ Ever had one of those functions which doesn't quite fit anywhere? Me too.
|
|
* Implementing a generic notifier framework is overkill in a static codebase
|
|
* like this, and it's always better to have compile-time calls than runtime,
|
|
* as it makes the code more explicit. But pasting in direct calls is also an
|
|
* abstraction violation, so we use this middleman function. */
|
|
void notify_new_block(struct lightningd *ld, u32 block_height)
|
|
{
|
|
/* Inform our subcomponents individually. */
|
|
htlcs_notify_new_block(ld, block_height);
|
|
channel_notify_new_block(ld, block_height);
|
|
}
|
|
|
|
static void on_sigint(int _ UNUSED)
|
|
{
|
|
static const char *msg = "lightningd: SIGINT caught, exiting.\n";
|
|
write_all(STDERR_FILENO, msg, strlen(msg));
|
|
_exit(1);
|
|
}
|
|
|
|
static void on_sigterm(int _ UNUSED)
|
|
{
|
|
static const char *msg = "lightningd: SIGTERM caught, exiting.\n";
|
|
write_all(STDERR_FILENO, msg, strlen(msg));
|
|
_exit(1);
|
|
}
|
|
|
|
/*~ We only need to handle SIGTERM and SIGINT for the case we are PID 1 of
|
|
* docker container since Linux makes special this PID and requires that
|
|
* some handler exist. */
|
|
static void setup_sig_handlers(void)
|
|
{
|
|
struct sigaction sigint, sigterm;
|
|
memset(&sigint, 0, sizeof(struct sigaction));
|
|
memset(&sigterm, 0, sizeof(struct sigaction));
|
|
|
|
sigint.sa_handler = on_sigint;
|
|
sigterm.sa_handler = on_sigterm;
|
|
|
|
if (1 == getpid()) {
|
|
sigaction(SIGINT, &sigint, NULL);
|
|
sigaction(SIGTERM, &sigterm, NULL);
|
|
}
|
|
}
|
|
|
|
int main(int argc, char *argv[])
|
|
{
|
|
struct lightningd *ld;
|
|
u32 min_blockheight, max_blockheight;
|
|
int connectd_gossipd_fd, pid_fd;
|
|
|
|
/*~ What happens in strange locales should stay there. */
|
|
setup_locale();
|
|
|
|
setup_sig_handlers();
|
|
|
|
/*~ This checks that the system-installed libraries (usually
|
|
* dynamically linked) actually are compatible with the ones we
|
|
* compiled with.
|
|
*
|
|
* The header itself is auto-generated every time the version of the
|
|
* installed libraries changes, as we had an sqlite3 version update
|
|
* which broke people, and "make" didn't think there was any work to
|
|
* do, so rebuilding didn't fix it. */
|
|
check_linked_library_versions();
|
|
|
|
/*~ Every daemon calls this in some form: the hooks are for dumping
|
|
* backtraces when we crash (if supported on this platform). */
|
|
daemon_setup(argv[0], log_backtrace_print, log_backtrace_exit);
|
|
|
|
/*~ There's always a battle between what a constructor like this
|
|
* should do, and what should be added later by the caller. In
|
|
* general, because we use valgrind heavily for testing, we prefer not
|
|
* to initialize unused fields which we expect the caller to set:
|
|
* valgrind will warn us if we make decisions based on uninitialized
|
|
* variables. */
|
|
ld = new_lightningd(NULL);
|
|
|
|
/* Figure out where our daemons are first. */
|
|
ld->daemon_dir = find_daemon_dir(ld, argv[0]);
|
|
if (!ld->daemon_dir)
|
|
errx(1, "Could not find daemons");
|
|
|
|
/*~ The ccan/opt code requires registration then parsing; we
|
|
* mimic this API here, even though they're on separate lines.*/
|
|
register_opts(ld);
|
|
|
|
/*~ Handle early options, but don't move to --lightning-dir
|
|
* just yet. Plugins may add new options, which is why we are
|
|
* splitting between early args (including --plugin
|
|
* registration) and non-early opts. */
|
|
handle_early_opts(ld, argc, argv);
|
|
|
|
/*~ Initialize all the plugins we just registered, so they can
|
|
* do their thing and tell us about themselves (including
|
|
* options registration). */
|
|
plugins_init(ld->plugins, ld->dev_debug_subprocess);
|
|
|
|
/*~ Handle options and config; move to .lightningd (--lightning-dir) */
|
|
handle_opts(ld, argc, argv);
|
|
|
|
/*~ Make sure we can reach the subdaemons, and versions match. */
|
|
test_subdaemons(ld);
|
|
|
|
/*~ Our "wallet" code really wraps the db, which is more than a simple
|
|
* bitcoin wallet (though it's that too). It also stores channel
|
|
* states, invoices, payments, blocks and bitcoin transactions. */
|
|
ld->wallet = wallet_new(ld, ld->log, &ld->timers);
|
|
|
|
/*~ We keep a filter of scriptpubkeys we're interested in. */
|
|
ld->owned_txfilter = txfilter_new(ld);
|
|
|
|
/*~ This is the ccan/io central poll override from above. */
|
|
io_poll_override(io_poll_lightningd);
|
|
|
|
/*~ Set up the HSM daemon, which knows our node secret key, so tells
|
|
* us who we are.
|
|
*
|
|
* HSM stands for Hardware Security Module, which is the industry
|
|
* standard of key storage; ours is in software for now, so the name
|
|
* doesn't really make sense, but we can't call it the Badly-named
|
|
* Daemon Software Module. */
|
|
hsm_init(ld);
|
|
|
|
/*~ Our default color and alias are derived from our node id, so we
|
|
* can only set those now (if not set by config options). */
|
|
setup_color_and_alias(ld);
|
|
|
|
/*~ Set up connect daemon: this manages receiving and making
|
|
* TCP connections. It needs to talk to the gossip daemon
|
|
* which knows (via node_announcement messages) the public
|
|
* addresses of nodes, so connectd_init hands it one end of a
|
|
* socket pair, and gives us the other */
|
|
connectd_gossipd_fd = connectd_init(ld);
|
|
|
|
/*~ The gossip daemon looks after the routing gossip;
|
|
* channel_announcement, channel_update, node_announcement and gossip
|
|
* queries. */
|
|
gossip_init(ld, connectd_gossipd_fd);
|
|
|
|
/*~ We do every database operation within a transaction; usually this
|
|
* is covered by the infrastructure (eg. opening a transaction before
|
|
* handling a message or expiring a timer), but for startup we do this
|
|
* explicitly. */
|
|
db_begin_transaction(ld->wallet->db);
|
|
|
|
/*~ Our default names, eg. for the database file, are not dependent on
|
|
* the network. Instead, the db knows what chain it belongs to, and we
|
|
* simple barf here if it's wrong. */
|
|
if (!wallet_network_check(ld->wallet, get_chainparams(ld)))
|
|
errx(1, "Wallet network check failed.");
|
|
|
|
/*~ Initialize the transaction filter with our pubkeys. */
|
|
init_txfilter(ld->wallet, ld->owned_txfilter);
|
|
|
|
/*~ Set up invoice autoclean. */
|
|
wallet_invoice_autoclean(ld->wallet,
|
|
ld->ini_autocleaninvoice_cycle,
|
|
ld->ini_autocleaninvoice_expiredby);
|
|
|
|
/*~ Pull peers, channels and HTLCs from db. */
|
|
load_channels_from_wallet(ld);
|
|
|
|
/*~ Get the blockheight we are currently at, UINT32_MAX is used to signal
|
|
* an uninitialized wallet and that we should start off of bitcoind's
|
|
* current height */
|
|
wallet_blocks_heights(ld->wallet, UINT32_MAX,
|
|
&min_blockheight, &max_blockheight);
|
|
|
|
/*~ If we were asked to rescan from an absolute height (--rescan < 0)
|
|
* then just go there. Otherwise compute the diff to our current height,
|
|
* lowerbounded by 0. */
|
|
if (ld->config.rescan < 0)
|
|
max_blockheight = -ld->config.rescan;
|
|
else if (max_blockheight < (u32)ld->config.rescan)
|
|
max_blockheight = 0;
|
|
else if (max_blockheight != UINT32_MAX)
|
|
max_blockheight -= ld->config.rescan;
|
|
|
|
/*~ That's all of the wallet db operations for now. */
|
|
db_commit_transaction(ld->wallet->db);
|
|
|
|
/*~ Initialize block topology. This does its own io_loop to
|
|
* talk to bitcoind, so does its own db transactions. */
|
|
setup_topology(ld->topology, &ld->timers,
|
|
min_blockheight, max_blockheight);
|
|
|
|
/*~ Now create the PID file: this errors out if there's already a
|
|
* daemon running, so we call before trying to create an RPC socket. */
|
|
pid_fd = pidfile_create(ld);
|
|
|
|
/*~ Create RPC socket: now lightning-cli can send us JSON RPC commands
|
|
* over a UNIX domain socket specified by `ld->rpc_filename`. */
|
|
jsonrpc_listen(ld->jsonrpc, ld);
|
|
|
|
/*~ Now that the rpc path exists, we can start the plugins and they
|
|
* can start talking to us. */
|
|
plugins_config(ld->plugins);
|
|
|
|
/*~ Setting this (global) activates the crash log: we don't usually need
|
|
* a backtrace if we fail during startup. We do this before daemonize,
|
|
* in case that runs into trouble. */
|
|
crashlog = ld->log;
|
|
|
|
/*~ We defer --daemon until we've completed most initialization: that
|
|
* way we'll exit with an error rather than silently exiting 0, then
|
|
* realizing we can't start and forcing the confused user to read the
|
|
* logs. */
|
|
if (ld->daemon)
|
|
daemonize_but_keep_dir(ld);
|
|
|
|
/*~ We have to do this after daemonize, since that changes our pid! */
|
|
pidfile_write(ld, pid_fd);
|
|
|
|
/*~ Activate connect daemon. Needs to be after the initialization of
|
|
* chaintopology, otherwise peers may connect and ask for
|
|
* uninitialized data. */
|
|
connectd_activate(ld);
|
|
|
|
/*~ "onchaind" is a dumb daemon which tries to get our funds back: it
|
|
* doesn't handle reorganizations, but it's idempotent, so we can
|
|
* simply just restart it if the chain moves. Similarly, we replay it
|
|
* chain events from the database on restart, beginning with the
|
|
* "funding transaction spent" event which creates it. */
|
|
onchaind_replay_channels(ld);
|
|
|
|
/*~ Mark ourselves live.
|
|
*
|
|
* Note the use of type_to_string() here: it's a typesafe formatter,
|
|
* often handed 'tmpctx' like here to allocate a throwaway string for
|
|
* formatting. json_escape() avoids printing weird characters in our
|
|
* log. And tal_hex() is a helper from utils which returns a hex string;
|
|
* it's assumed that the argument was allocated with tal or tal_arr
|
|
* so it can use tal_bytelen() to get the length. */
|
|
log_info(ld->log, "Server started with public key %s, alias %s (color #%s) and lightningd %s",
|
|
type_to_string(tmpctx, struct pubkey, &ld->id),
|
|
json_escape(tmpctx, (const char *)ld->alias)->s,
|
|
tal_hex(tmpctx, ld->rgb), version());
|
|
|
|
/*~ This is where we ask connectd to reconnect to any peers who have
|
|
* live channels with us, and makes sure we're watching the funding
|
|
* tx. */
|
|
activate_peers(ld);
|
|
|
|
/*~ Now that all the notifications for transactions are in place, we
|
|
* can start the poll loop which queries bitcoind for new blocks. */
|
|
begin_topology(ld->topology);
|
|
|
|
/*~ The root of every backtrace (almost). This is our main event
|
|
* loop. */
|
|
for (;;) {
|
|
/* ~ccan/io's io_loop() continuously calls
|
|
* io_poll_lightningd() for all file descriptors registered
|
|
* with it, then calls their callbacks or closes them if they
|
|
* fail, as appropriate.
|
|
*
|
|
* It will only exit if there's an expired timer, *or* someone
|
|
* calls io_break, or if there are no more file descriptors
|
|
* (which never happens in our code). */
|
|
struct timer *expired;
|
|
void *v = io_loop(&ld->timers, &expired);
|
|
|
|
/*~ We use io_break(ld) to shut down. */
|
|
if (v == ld)
|
|
break;
|
|
|
|
/*~ Notice that timers are called here in the event loop like
|
|
* anything else, so there are no weird concurrency issues. */
|
|
if (expired) {
|
|
db_begin_transaction(ld->wallet->db);
|
|
timer_expired(ld, expired);
|
|
db_commit_transaction(ld->wallet->db);
|
|
}
|
|
}
|
|
|
|
shutdown_subdaemons(ld);
|
|
|
|
tal_free(ld->plugins);
|
|
|
|
/* Clean up the JSON-RPC. This needs to happen in a DB transaction since
|
|
* it might actually be touching the DB in some destructors, e.g.,
|
|
* unreserving UTXOs (see #1737) */
|
|
db_begin_transaction(ld->wallet->db);
|
|
tal_free(ld->jsonrpc);
|
|
db_commit_transaction(ld->wallet->db);
|
|
|
|
remove(ld->pidfile);
|
|
|
|
/* FIXME: pay can have children off tmpctx which unlink from
|
|
* ld->payments, so clean that up. */
|
|
clean_tmpctx();
|
|
tal_free(ld);
|
|
opt_free_table();
|
|
|
|
daemon_shutdown();
|
|
|
|
/*~ Farewell. Next stop: hsmd/hsmd.c. */
|
|
return 0;
|
|
}
|
|
|