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#include <ccan/err/err.h>
#include <ccan/io/fdpass/fdpass.h>
#include <ccan/io/io.h>
#include <ccan/mem/mem.h>
#include <ccan/noerr/noerr.h>
#include <ccan/str/str.h>
#include <ccan/take/take.h>
#include <ccan/tal/path/path.h>
#include <ccan/tal/str/str.h>
#include <common/status.h>
#include <errno.h>
#include <fcntl.h>
#include <lightningd/lightningd.h>
#include <lightningd/log.h>
#include <lightningd/peer_control.h>
#include <lightningd/subd.h>
#include <signal.h>
#include <stdarg.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <wallet/db.h>
#include <wire/wire.h>
#include <wire/wire_io.h>
static bool move_fd(int from, int to)
{
if (dup2(from, to) == -1)
return false;
close(from);
return true;
}
struct subd_req {
struct list_node list;
/* Callback for a reply. */
int type;
void (*replycb)(struct subd *, const u8 *, const int *, void *);
void *replycb_data;
size_t num_reply_fds;
/* If non-NULL, this is here to disable replycb */
void *disabler;
};
static void free_subd_req(struct subd_req *sr)
{
list_del(&sr->list);
/* Don't disable once we're freed! */
if (sr->disabler)
tal_free(sr->disabler);
}
/* Called when the callback is disabled because caller was freed. */
static void ignore_reply(struct subd *sd, const u8 *msg, const int *fds,
void *arg)
{
size_t i;
log_debug(sd->log, "IGNORING REPLY");
for (i = 0; i < tal_count(fds); i++)
close(fds[i]);
}
static void disable_cb(void *disabler, struct subd_req *sr)
{
sr->replycb = ignore_reply;
sr->disabler = NULL;
}
static void add_req(const tal_t *ctx,
struct subd *sd, int type, size_t num_fds_in,
void (*replycb)(struct subd *, const u8 *, const int *,
void *),
void *replycb_data)
{
struct subd_req *sr = tal(sd, struct subd_req);
sr->type = type;
sr->replycb = replycb;
sr->replycb_data = replycb_data;
sr->num_reply_fds = num_fds_in;
/* We don't allocate sr off ctx, because we still have to handle the
* case where ctx is freed between request and reply. Hence this
* trick. */
if (ctx) {
sr->disabler = tal(ctx, char);
tal_add_destructor2(sr->disabler, disable_cb, sr);
} else
sr->disabler = NULL;
assert(strends(sd->msgname(sr->type + SUBD_REPLY_OFFSET), "_REPLY"));
/* Keep in FIFO order: we sent in order, so replies will be too. */
list_add_tail(&sd->reqs, &sr->list);
tal_add_destructor(sr, free_subd_req);
}
/* Caller must free. */
static struct subd_req *get_req(struct subd *sd, int reply_type)
{
struct subd_req *sr;
list_for_each(&sd->reqs, sr, list) {
if (sr->type + SUBD_REPLY_OFFSET == reply_type)
return sr;
/* If it's a fail, and that's a valid type. */
if (sr->type + SUBD_REPLYFAIL_OFFSET == reply_type
&& strends(sd->msgname(reply_type), "_REPLYFAIL")) {
sr->num_reply_fds = 0;
return sr;
}
}
return NULL;
}
static void close_taken_fds(va_list *ap)
{
int *fd;
while ((fd = va_arg(*ap, int *)) != NULL) {
if (taken(fd) && *fd >= 0) {
close(*fd);
*fd = -1;
}
}
}
/* We use sockets, not pipes, because fds are bidir. */
static int subd(const char *dir, const char *name, const char *debug_subdaemon,
int *msgfd, int dev_disconnect_fd, va_list *ap)
{
int childmsg[2], execfail[2];
pid_t childpid;
int err, *fd;
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) {
int fdnum = 3, i;
long max;
const char *debug_arg[2] = { NULL, NULL };
const char *path;
close(childmsg[0]);
close(execfail[0]);
// msg = STDIN
if (childmsg[1] != STDIN_FILENO) {
if (!move_fd(childmsg[1], STDIN_FILENO))
goto child_errno_fail;
}
// Move dev_disconnect_fd out the way.
if (dev_disconnect_fd != -1) {
if (!move_fd(dev_disconnect_fd, 101))
goto child_errno_fail;
dev_disconnect_fd = 101;
}
/* Dup any extra fds up first. */
if (ap) {
while ((fd = va_arg(*ap, int *)) != NULL) {
/* If this were stdin, dup2 closed! */
assert(*fd != STDIN_FILENO);
if (!move_fd(*fd, fdnum))
goto child_errno_fail;
fdnum++;
}
}
/* Make (fairly!) sure all other fds are closed. */
max = sysconf(_SC_OPEN_MAX);
for (i = fdnum; i < max; i++)
if (i != dev_disconnect_fd)
close(i);
#if DEVELOPER
if (dev_disconnect_fd != -1)
debug_arg[0] = tal_fmt(NULL, "--dev-disconnect=%i", dev_disconnect_fd);
if (debug_subdaemon && strends(name, debug_subdaemon))
debug_arg[debug_arg[0] ? 1 : 0] = "--debugger";
#endif
path = path_join(NULL, dir, name);
execl(path, path, debug_arg[0], debug_arg[1], 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]);
if (ap)
close_taken_fds(ap);
/* 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);
errno = err;
return -1;
}
close(execfail[0]);
*msgfd = childmsg[0];
return childpid;
close_execfail_fail:
close_noerr(execfail[0]);
close_noerr(execfail[1]);
close_msgfd_fail:
close_noerr(childmsg[0]);
close_noerr(childmsg[1]);
fail:
if (ap)
close_taken_fds(ap);
return -1;
}
int subd_raw(struct lightningd *ld, const char *name)
{
pid_t pid;
int msg_fd;
const char *debug_subd = NULL;
int disconnect_fd = -1;
#if DEVELOPER
debug_subd = ld->dev_debug_subdaemon;
disconnect_fd = ld->dev_disconnect_fd;
#endif /* DEVELOPER */
pid = subd(ld->daemon_dir, name, debug_subd, &msg_fd, disconnect_fd,
NULL);
if (pid == (pid_t)-1) {
log_unusual(ld->log, "subd %s failed: %s",
name, strerror(errno));
return -1;
}
return msg_fd;
}
static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd);
static void mark_freed(struct subd *unused, bool *freed)
{
*freed = true;
}
static struct io_plan *sd_msg_reply(struct io_conn *conn, struct subd *sd,
struct subd_req *sr)
{
int type = fromwire_peektype(sd->msg_in);
bool freed = false;
const tal_t *tmpctx = tal_tmpctx(conn);
int *fds_in;
log_debug(sd->log, "REPLY %s with %zu fds",
sd->msgname(type), tal_count(sd->fds_in));
/* Callback could free sd! Make sure destroy_subd() won't free conn */
sd->conn = NULL;
/* We want to free the msg_in, unless they tal_steal() it. */
tal_steal(tmpctx, sd->msg_in);
/* And we need to free sr after this too. */
tal_steal(tmpctx, sr);
/* In case they free sd, don't deref. */
list_del_init(&sr->list);
/* Free this array after, too. */
fds_in = tal_steal(tmpctx, sd->fds_in);
sd->fds_in = NULL;
/* Find out if they freed it. */
tal_add_destructor2(sd, mark_freed, &freed);
sr->replycb(sd, sd->msg_in, fds_in, sr->replycb_data);
tal_free(tmpctx);
if (freed)
return io_close(conn);
tal_del_destructor2(sd, mark_freed, &freed);
/* Restore conn ptr. */
sd->conn = conn;
return io_read_wire(conn, sd, &sd->msg_in, sd_msg_read, sd);
}
static struct io_plan *read_fds(struct io_conn *conn, struct subd *sd)
{
if (sd->num_fds_in_read == tal_count(sd->fds_in)) {
size_t i;
/* Don't trust subd to set it blocking. */
for (i = 0; i < tal_count(sd->fds_in); i++)
io_fd_block(sd->fds_in[i], true);
return sd_msg_read(conn, sd);
}
return io_recv_fd(conn, &sd->fds_in[sd->num_fds_in_read++],
read_fds, sd);
}
static struct io_plan *sd_collect_fds(struct io_conn *conn, struct subd *sd,
size_t num_fds)
{
assert(!sd->fds_in);
sd->fds_in = tal_arr(sd, int, num_fds);
sd->num_fds_in_read = 0;
return read_fds(conn, sd);
}
/* Don't trust, verify. Returns NULL if contains weird stuff. */
static const char *string_from_msg(const u8 *msg, int *str_len)
{
size_t len = tal_count(msg) - sizeof(be16), i;
for (i = 0; i < len; i++) {
if (!cisprint((char)msg[sizeof(be16) + i])) {
*str_len = 0;
return NULL;
}
}
*str_len = len;
return (const char *)(msg + sizeof(be16));
}
static void subdaemon_malformed_msg(struct subd *sd, const u8 *msg)
{
log_broken(sd->log, "%i: malformed string '%.s'",
fromwire_peektype(msg),
tal_hex(msg, msg));
#if DEVELOPER
if (sd->ld->dev_subdaemon_fail)
fatal("Subdaemon %s sent malformed message", sd->name);
#endif
}
/* Returns true if logged, false if malformed. */
static bool log_status_fail(struct subd *sd,
enum status_fail type, const char *str, int str_len)
{
const char *name;
/* No 'default:' here so gcc gives warning if a new type added */
switch (type) {
case STATUS_FAIL_MASTER_IO:
name = "STATUS_FAIL_MASTER_IO";
goto log_str_broken;
case STATUS_FAIL_HSM_IO:
name = "STATUS_FAIL_HSM_IO";
goto log_str_broken;
case STATUS_FAIL_GOSSIP_IO:
name = "STATUS_FAIL_GOSSIP_IO";
goto log_str_broken;
case STATUS_FAIL_INTERNAL_ERROR:
name = "STATUS_FAIL_INTERNAL_ERROR";
goto log_str_broken;
/*
* These errors happen when the other peer misbehaves:
*/
case STATUS_FAIL_PEER_IO:
name = "STATUS_FAIL_PEER_IO";
goto log_str_peer;
case STATUS_FAIL_PEER_BAD:
name = "STATUS_FAIL_PEER_BAD";
goto log_str_peer;
}
return false;
/* Peers misbehaving is expected. */
log_str_peer:
log_info(sd->log, "%s: %.*s", name, str_len, str);
return true;
/* Shouldn't happen. */
log_str_broken:
log_broken(sd->log, "%s: %.*s", name, str_len, str);
#if DEVELOPER
if (sd->ld->dev_subdaemon_fail)
fatal("Subdaemon %s hit error", sd->name);
#endif
return true;
}
static struct io_plan *sd_msg_read(struct io_conn *conn, struct subd *sd)
{
int type = fromwire_peektype(sd->msg_in);
const tal_t *tmpctx;
struct subd_req *sr;
struct db *db = sd->ld->wallet->db;
struct io_plan *plan;
/* Everything we do, we wrap in a database transaction */
db_begin_transaction(db);
if (type == -1)
goto malformed;
/* First, check for replies. */
sr = get_req(sd, type);
if (sr) {
if (sr->num_reply_fds && sd->fds_in == NULL) {
plan = sd_collect_fds(conn, sd, sr->num_reply_fds);
goto out;
}
assert(sr->num_reply_fds == tal_count(sd->fds_in));
plan = sd_msg_reply(conn, sd, sr);
goto out;
}
/* If not stolen, we'll free this below. */
tmpctx = tal_tmpctx(sd);
tal_steal(tmpctx, sd->msg_in);
if (type == STATUS_TRACE) {
int str_len;
const char *str = string_from_msg(sd->msg_in, &str_len);
if (!str)
goto malformed;
log_debug(sd->log, "TRACE: %.*s", str_len, str);
goto next;
} else if (type & STATUS_FAIL) {
int str_len;
const char *str = string_from_msg(sd->msg_in, &str_len);
if (!str)
goto malformed;
if (!log_status_fail(sd, type, str, str_len))
goto malformed;
/* If they care, tell them about invalid peer behavior */
if (sd->peer && type == STATUS_FAIL_PEER_BAD) {
/* Don't free ourselves; we're about to do that. */
struct peer *peer = sd->peer;
sd->peer = NULL;
peer_fail_permanent(peer, "%s: %.*s", sd->name, str_len, str);
}
goto close;
}
log_debug(sd->log, "UPDATE %s", sd->msgname(type));
if (sd->msgcb) {
unsigned int i;
bool freed = false;
/* Might free sd (if returns negative); save/restore sd->conn */
sd->conn = NULL;
tal_add_destructor2(sd, mark_freed, &freed);
i = sd->msgcb(sd, sd->msg_in, sd->fds_in);
if (freed)
goto close;
tal_del_destructor2(sd, mark_freed, &freed);
sd->conn = conn;
if (i != 0) {
/* Don't ask for fds twice! */
assert(!sd->fds_in);
/* Don't free msg_in: we go around again. */
tal_steal(sd, sd->msg_in);
tal_free(tmpctx);
plan = sd_collect_fds(conn, sd, i);
goto out;
}
}
next:
sd->msg_in = NULL;
sd->fds_in = tal_free(sd->fds_in);
tal_free(tmpctx);
plan = io_read_wire(conn, sd, &sd->msg_in, sd_msg_read, sd);
goto out;
malformed:
subdaemon_malformed_msg(sd, sd->msg_in);
close:
plan = io_close(conn);
out:
db_commit_transaction(db);
return plan;
}
static void destroy_subd(struct subd *sd)
{
int status;
bool fail_if_subd_fails = false;
#if DEVELOPER
fail_if_subd_fails = sd->ld->dev_subdaemon_fail;
#endif
switch (waitpid(sd->pid, &status, WNOHANG)) {
case 0:
/* If it's an essential daemon, don't kill: we want the
* exit status */
if (!sd->must_not_exit) {
log_debug(sd->log,
"Status closed, but not exited. Killing");
kill(sd->pid, SIGKILL);
}
waitpid(sd->pid, &status, 0);
fail_if_subd_fails = false;
break;
case -1:
log_unusual(sd->log, "Status closed, but waitpid %i says %s",
sd->pid, strerror(errno));
status = -1;
break;
}
if (fail_if_subd_fails && WIFSIGNALED(status))
fatal("Subdaemon %s killed with signal %i",
sd->name, WTERMSIG(status));
/* In case we're freed manually, such as peer_fail_permanent */
if (sd->conn)
sd->conn = tal_free(sd->conn);
/* Peer still attached? */
if (sd->peer) {
/* Don't loop back when we fail it. */
struct peer *peer = sd->peer;
struct db *db = sd->ld->wallet->db;
bool outer_transaction;
sd->peer = NULL;
/* We can be freed both inside msg handling, or spontaneously. */
outer_transaction = db->in_transaction;
if (!outer_transaction)
db_begin_transaction(db);
peer_fail_transient(peer,
"Owning subdaemon %s died (%i)",
sd->name, status);
if (!outer_transaction)
db_commit_transaction(db);
}
if (sd->must_not_exit) {
if (WIFEXITED(status))
errx(1, "%s failed (exit status %i), exiting.",
sd->name, WEXITSTATUS(status));
errx(1, "%s failed (signal %u), exiting.",
sd->name, WTERMSIG(status));
}
}
static struct io_plan *msg_send_next(struct io_conn *conn, struct subd *sd)
{
const u8 *msg = msg_dequeue(&sd->outq);
int fd;
/* Nothing to do? Wait for msg_enqueue. */
if (!msg)
return msg_queue_wait(conn, &sd->outq, msg_send_next, sd);
fd = msg_extract_fd(msg);
if (fd >= 0) {
tal_free(msg);
return io_send_fd(conn, fd, true, msg_send_next, sd);
}
return io_write_wire(conn, take(msg), msg_send_next, sd);
}
static struct io_plan *msg_setup(struct io_conn *conn, struct subd *sd)
{
return io_duplex(conn,
io_read_wire(conn, sd, &sd->msg_in, sd_msg_read, sd),
msg_send_next(conn, sd));
}
static struct subd *new_subd(struct lightningd *ld,
const char *name,
struct peer *peer,
const char *(*msgname)(int msgtype),
unsigned int (*msgcb)(struct subd *,
const u8 *, const int *fds),
va_list *ap)
{
struct subd *sd = tal(ld, struct subd);
int msg_fd;
const char *debug_subd = NULL;
int disconnect_fd = -1;
#if DEVELOPER
debug_subd = ld->dev_debug_subdaemon;
disconnect_fd = ld->dev_disconnect_fd;
#endif /* DEVELOPER */
sd->pid = subd(ld->daemon_dir, name, debug_subd, &msg_fd, disconnect_fd,
ap);
if (sd->pid == (pid_t)-1) {
log_unusual(ld->log, "subd %s failed: %s",
name, strerror(errno));
return tal_free(sd);
}
sd->ld = ld;
if (peer) {
/* FIXME: Use minimal unique pubkey prefix for logs! */
const char *idstr = type_to_string(peer, struct pubkey,
&peer->id);
sd->log = new_log(sd, peer->log_book, "%s(%s):", name, idstr);
tal_free(idstr);
} else {
sd->log = new_log(sd, ld->log_book, "%s(%u):", name, sd->pid);
}
sd->name = name;
sd->must_not_exit = false;
sd->msgname = msgname;
sd->msgcb = msgcb;
sd->fds_in = NULL;
msg_queue_init(&sd->outq, sd);
tal_add_destructor(sd, destroy_subd);
list_head_init(&sd->reqs);
sd->peer = peer;
/* conn actually owns daemon: we die when it does. */
sd->conn = io_new_conn(ld, msg_fd, msg_setup, sd);
tal_steal(sd->conn, sd);
log_debug(sd->log, "pid %u, msgfd %i", sd->pid, msg_fd);
return sd;
}
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),
...)
{
va_list ap;
struct subd *sd;
va_start(ap, msgcb);
sd = new_subd(ld, name, NULL, msgname, msgcb, &ap);
va_end(ap);
sd->must_not_exit = true;
return sd;
}
struct subd *new_peer_subd(struct lightningd *ld,
const char *name,
struct peer *peer,
const char *(*msgname)(int msgtype),
unsigned int (*msgcb)(struct subd *, const u8 *,
const int *fds), ...)
{
va_list ap;
struct subd *sd;
va_start(ap, msgcb);
sd = new_subd(ld, name, peer, msgname, msgcb, &ap);
va_end(ap);
return sd;
}
void subd_send_msg(struct subd *sd, const u8 *msg_out)
{
/* FIXME: We should use unique upper bits for each daemon, then
* have generate-wire.py add them, just assert here. */
assert(!strstarts(sd->msgname(fromwire_peektype(msg_out)), "INVALID"));
msg_enqueue(&sd->outq, msg_out);
}
void subd_send_fd(struct subd *sd, int fd)
{
msg_enqueue_fd(&sd->outq, fd);
}
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)
{
/* Grab type now in case msg_out is taken() */
int type = fromwire_peektype(msg_out);
subd_send_msg(sd, msg_out);
if (fd_out >= 0)
subd_send_fd(sd, fd_out);
add_req(ctx, sd, type, num_fds_in, replycb, replycb_data);
}
void subd_shutdown(struct subd *sd, unsigned int seconds)
{
log_debug(sd->log, "Shutting down");
tal_del_destructor(sd, destroy_subd);
/* This should make it exit; steal so it stays around. */
tal_steal(sd->ld, sd);
sd->conn = tal_free(sd->conn);
/* Wait for a while. */
while (seconds) {
if (waitpid(sd->pid, NULL, WNOHANG) > 0) {
return;
}
sleep(1);
seconds--;
}
/* Didn't die? This will kill it harder */
sd->must_not_exit = false;
destroy_subd(sd);
tal_free(sd);
}
void subd_release_peer(struct subd *owner, struct peer *peer)
{
/* If owner is a per-peer-daemon, and not already freeing itself... */
if (owner->peer) {
assert(owner->peer == peer);
owner->peer = NULL;
tal_free(owner);
}
}
#if DEVELOPER
char *opt_subd_debug(const char *optarg, struct lightningd *ld)
{
ld->dev_debug_subdaemon = optarg;
return NULL;
}
char *opt_subd_dev_disconnect(const char *optarg, struct lightningd *ld)
{
ld->dev_disconnect_fd = open(optarg, O_RDONLY);
if (ld->dev_disconnect_fd < 0)
return tal_fmt(ld, "Could not open --dev-disconnect=%s: %s",
optarg, strerror(errno));
return NULL;
}
/* If test specified that this disconnection should cause permanent failure */
bool dev_disconnect_permanent(struct lightningd *ld)
{
char permfail[strlen("PERMFAIL")];
int r;
if (ld->dev_disconnect_fd == -1)
return false;
r = read(ld->dev_disconnect_fd, permfail, sizeof(permfail));
if (r < 0)
fatal("Reading dev_disconnect file: %s", strerror(errno));
if (memeq(permfail, r, "permfail", strlen("permfail")))
return true;
/* Nope, restore. */
if (lseek(ld->dev_disconnect_fd, -r, SEEK_CUR) < 0) {
fatal("lseek failure");
}
return false;
}
#endif /* DEVELOPER */