core-lightning/lightningd/subd.h
Rusty Russell dd79813a75 common: add peer_error flag to treat this error as "soft".
The spec says to close the channel if they send us an error, but we
need to be more lenient to preserve channels with other
implementations.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-07-26 03:53:03 +00:00

219 lines
7.2 KiB
C

#ifndef LIGHTNING_LIGHTNINGD_SUBD_H
#define LIGHTNING_LIGHTNINGD_SUBD_H
#include "config.h"
#include <ccan/endian/endian.h>
#include <ccan/list/list.h>
#include <ccan/short_types/short_types.h>
#include <ccan/tal/tal.h>
#include <ccan/typesafe_cb/typesafe_cb.h>
#include <common/msg_queue.h>
#include <wire/wire.h>
struct crypto_state;
struct io_conn;
struct per_peer_state;
/* By convention, replies are requests + 100 */
#define SUBD_REPLY_OFFSET 100
/* And reply failures are requests + 200 */
#define SUBD_REPLYFAIL_OFFSET 200
/* One of our subds. */
struct subd {
/* Name, like John, or "lightning_hsmd" */
const char *name;
/* The Big Cheese. */
struct lightningd *ld;
/* pid, for waiting for status when it dies. */
int pid;
/* Connection. */
struct io_conn *conn;
/* If we are associated with a single channel, this points to it. */
void *channel;
/* For logging */
struct log *log;
/* Callback when non-reply message comes in (inside db transaction) */
unsigned (*msgcb)(struct subd *, const u8 *, const int *);
const char *(*msgname)(int msgtype);
/* If per_peer_state == NULL, it was a disconnect/crash. Otherwise,
* sufficient information to hand back to gossipd, including the
* error message we sent them if any. */
void (*errcb)(void *channel,
struct per_peer_state *pps,
const struct channel_id *channel_id,
const char *desc,
bool soft_error,
const u8 *err_for_them);
/* Callback to display information for listpeers RPC */
void (*billboardcb)(void *channel, bool perm, const char *happenings);
/* Buffer for input. */
u8 *msg_in;
/* While we're reading fds in. */
size_t num_fds_in_read;
int *fds_in;
/* For global daemons: we fail if they fail. */
bool must_not_exit;
/* Do we talk to a peer? ie. not onchaind */
bool talks_to_peer;
/* Messages queue up here. */
struct msg_queue *outq;
/* Callbacks for replies. */
struct list_head reqs;
};
/**
* new_global_subd - create a new global subdaemon.
* @ld: global state
* @name: basename of daemon
* @msgname: function to get name from messages
* @msgcb: function to call (inside db transaction) when non-fatal message received
* @...: NULL-terminated list of pointers to fds to hand as fd 3, 4...
* (can be take, if so, set to -1)
*
* @msgcb gets called with @fds set to NULL: if it returns a positive number,
* that many @fds are received before calling again. @msgcb can free subd
* to shut it down.
*/
struct subd *new_global_subd(struct lightningd *ld,
const char *name,
const char *(*msgname)(int msgtype),
unsigned int (*msgcb)(struct subd *, const u8 *,
const int *fds),
...);
/**
* new_channel_subd - create a new subdaemon for a specific channel.
* @ld: global state
* @name: basename of daemon
* @channel: channel to associate.
* @base_log: log to use (actually makes a copy so it has name in prefix)
* @msgname: function to get name from messages
* @msgcb: function to call (inside db transaction) when non-fatal message received (or NULL)
* @errcb: function to call on errors.
* @billboardcb: function to call for billboard updates.
* @...: NULL-terminated list of pointers to fds to hand as fd 3, 4...
* (can be take, if so, set to -1)
*
* @msgcb gets called with @fds set to NULL: if it returns a positive number,
* that many @fds are received before calling again. If it returns -1, the
* subdaemon is shutdown.
*/
struct subd *new_channel_subd_(struct lightningd *ld,
const char *name,
void *channel,
struct log *base_log,
bool talks_to_peer,
const char *(*msgname)(int msgtype),
unsigned int (*msgcb)(struct subd *, const u8 *,
const int *fds),
void (*errcb)(void *channel,
struct per_peer_state *pps,
const struct channel_id *channel_id,
const char *desc,
bool soft_error,
const u8 *err_for_them),
void (*billboardcb)(void *channel, bool perm,
const char *happenings),
...);
#define new_channel_subd(ld, name, channel, log, talks_to_peer, msgname, \
msgcb, errcb, billboardcb, ...) \
new_channel_subd_((ld), (name), (channel), (log), (talks_to_peer), \
(msgname), (msgcb), \
typesafe_cb_postargs(void, void *, (errcb), \
(channel), \
struct per_peer_state *, \
const struct channel_id *, \
const char *, bool, const u8 *), \
typesafe_cb_postargs(void, void *, (billboardcb), \
(channel), bool, \
const char *), \
__VA_ARGS__)
/**
* subd_send_msg - queue a message to the subdaemon.
* @sd: subdaemon to request
* @msg_out: message (can be take)
*/
void subd_send_msg(struct subd *sd, const u8 *msg_out);
/**
* subd_send_fd - queue a file descriptor to pass to the subdaemon.
* @sd: subdaemon to request
* @fd: the file descriptor (closed after passing).
*/
void subd_send_fd(struct subd *sd, int fd);
/**
* subd_req - queue a request to the subdaemon.
* @ctx: lifetime for the callback: if this is freed, don't call replycb.
* @sd: subdaemon to request
* @msg_out: request message (can be take)
* @fd_out: if >=0 fd to pass at the end of the message (closed after)
* @num_fds_in: how many fds to read in to hand to @replycb if it's a reply.
* @replycb: callback (inside db transaction) when reply comes in (can free subd)
* @replycb_data: final arg to hand to @replycb
*
* @replycb cannot free @sd, so it returns false to remove it.
* Note that @replycb is called for replies of type @msg_out + SUBD_REPLY_OFFSET
* with @num_fds_in fds, or type @msg_out + SUBD_REPLYFAIL_OFFSET with no fds.
*/
#define subd_req(ctx, sd, msg_out, fd_out, num_fds_in, replycb, replycb_data) \
subd_req_((ctx), (sd), (msg_out), (fd_out), (num_fds_in), \
typesafe_cb_preargs(void, void *, \
(replycb), (replycb_data), \
struct subd *, \
const u8 *, const int *), \
(replycb_data))
void subd_req_(const tal_t *ctx,
struct subd *sd,
const u8 *msg_out,
int fd_out, size_t num_fds_in,
void (*replycb)(struct subd *, const u8 *, const int *, void *),
void *replycb_data);
/**
* subd_release_channel - shut down a subdaemon which no longer owns the channel.
* @owner: subd which owned channel.
* @channel: channel to release.
*
* If the subdaemon is not already shutting down, and it is a per-channel
* subdaemon, this shuts it down.
*/
void subd_release_channel(struct subd *owner, void *channel);
/**
* subd_shutdown - try to politely shut down a subdaemon.
* @subd: subd to shutdown.
* @seconds: maximum seconds to wait for it to exit.
*
* This closes the fd to the subdaemon, and gives it a little while to exit.
* The @finished callback will never be called.
*
* Return value is null, so pattern should be:
*
* sd = subd_shutdown(sd, 10);
*/
struct subd *subd_shutdown(struct subd *subd, unsigned int seconds);
/* Ugly helper to get full pathname of the current binary. */
const char *find_my_abspath(const tal_t *ctx, const char *argv0);
#if DEVELOPER
char *opt_subd_dev_disconnect(const char *optarg, struct lightningd *ld);
bool dev_disconnect_permanent(struct lightningd *ld);
#endif /* DEVELOPER */
#endif /* LIGHTNING_LIGHTNINGD_SUBD_H */