We're not using the change_outnum for withdraw tx's (and the way
we were calculating it was broken as of the addition of 'multiple
outputs'). This removes the change output knowhow from withdraw_tx
entirely, and pushes the responsibility up to the caller to
include the change output in the output set if desired.
Consequently, we also remove the change output knowhow from hsmd.
We erase peer data after the last channel close transaction for that
peer is 100 blocks deep. We were failing to finish the migration because
the peer_id lookup on these was failing.
Now we ignore any channel with a null peer_id.
Fixes#3768
Currently 'listfunds' lies, a teensy eeinsy bit, in that it doesn't list
all of the funds in a wallet (it omits reserved wallet UTXOs). This
change makes the reserved outputs visible by listing them in the
'outputs' section along with a new field, 'reserved', which denotes the
UTXO's state
Changelog-Changed: JSON-RPC: `listfunds` 'outputs' now includes reserved outputs, designated as 'reserved' = true
We update the `last_tx` in `channels` to be psbt format, instead
of a linearized transaction.
We need the amount of the input populated, which we have since
this is the 'funding' amount. Ideally we'd also populate the funding
scriptPubkey, but to do that we'd need to access the HSM module to fetch
our local funding pubkey, which isn't initialized at the time that the
database migrations are run.
Since the only field the HSM uses currently when signing these is the
amount field, it's ok to just leave it out.
needs a test!
when re-populating a channel's data from the database, since we don't
store the psbt data (with input scripts + amounts), we need to
re-populate it.
the right solution is to patch the psbt into the database; for now we
'monkey-patch' it in.
We did not take the value of --commit-fee into account : this removes
the unused option from lightningd and instead registers it in bcli,
where we set the actual feerate of commitment transactions. This also
corrects the documentation.
Changelog-Fixed: config: we now take the --commit-fee parameter into account.
Signed-off-by: Antoine Poinsot <darosior@protonmail.com>
Since we now over-write the wally malloc/free functions, we need to do
so for tests as well. Here we pull up all of the common setup/teardown
logic into a separate place, and update the tests that use libwally to
use the new common_setup core
Changelog-None
This moves the notification for our coin spends from when it's
successfully submited to the mempool to when they're confirmed in a
block.
We also add an 'informational' notice tagged as `spend_track` which
can be used to track which transaction a wallet output was spent in.
Previously we were annotating every movement with the blockheight of
lightningd at notification time. Which is lossy in terms of info, and
won't be helpful for reorg reconciliation. Here we switch over to
logging chain moves iff they've been confirmed.
Next PR will fix this up for withdrawals, which are currently tagged
with a blockheight of zero, since we log on successful send.
On node start we replay onchaind's transactions from the database/from
our loaded htlc table. To keep things tidy, we shouldn't notify the
ledger about these, so we wrap pretty much everything in a flag that
tells us whether or not this is a replay.
There's a very small corner case where dust transactions will get missed
if the node crashes after the htlc has been added to the database but
before we've successfully notified onchaind about it.
Notably, most of the obtrusive updates to onchaind wrappings are due to
the fact that we record dust (ignored outputs) before we receive
confirmation of its confirmation.
HTLCs trigger a coin movement only when their final form (state) is
reached. This prevents us from needing to concern ourselves with
retries, as well as being the absolutely most correct in terms of
answering the question 'when has the money irrevocably changed hands'.
All coin movements should pass this bar, for ultimate accounting
correctness
The current plan for coin movements involves tagging
origination/destination htlc's with a separate tag from 'routed' htlcs
(which pass through our node). In order to do this, we need a persistent flag on
incoming htlcs as to whether or not we are the final destination.
For sqlite3 versions < 3.14 (i.e. HAVE_SQLITE3_EXPANDED_SQL is not set),
tracing is used to dump statements. The function db_sqlite3_exec()
registers a tracing callback in the beginning and unregisters it at the
end to "avoid it accessing the potentially stale pointer to stmt".
However, the unregistering so far only happened in the success case,
i.e. if the prepare or step calls failed, the callback was still set!
Running the test wallet/test/db-run with sqlite 3.11 leads to a
segmentation fault in the last call to db_commit_transaction():
the tested transaction contains an invalid statement and the (still
registered) trace callback is triggered then by sqlite3_exec() in
db_sqlite3_commit_tx(), leading to a segfault in db_changes_add()
(according to gdb), where it tries to access "stmt->query->readonly".
Changelog-None
I noticed the following in logs for tests/test_connection.py::test_feerate_stress:
```
DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-chan#1: Failing HTLC 18446744073709551615 due to peer death
DEBUG 022d223620a359a47ff7f7ac447c85c46c923da53389221a0054c11c1e3ca31d59-chan#1: local_routing_failure: 8194 (WIRE_TEMPORARY_NODE_FAILURE)
```
This is because it reports the (transient) node_failure error, because
our channel_failure message is incomplete. Fix this wart up.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Previously we've used the term 'funder' to refer to the peer
paying the fees for a transaction; v2 of openchannel will make
this no longer true. Instead we rename this to 'opener', or the
peer sending the 'open_channel' message, since this will be universally
true in a dual-funding world.
One is called on every plugin return, and tells us whether to continue;
the other is only called if every plugin says ok.
This works for things like payload replacement, where we need to process
the results from each plugin, not just the final one!
We should probably turn everything into a chained callback next
release.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
They callback must take ownership of the payload (almost all do, but
now it's explicit).
And since the payload and cb_arg arguments to plugin_hook_call_() are
always identical, make them a single parameter.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Note that it's channeld which calculates the shared secret, too. This
minimizes the work that lightningd has to do, at cost of passing this
through.
We also don't yet save the blinding field(s) to the database.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This requires us to call ecdh() in the corner case where the blinding seed
is in the TLV itself (which is the case for the start of a blinded route).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Use `LC_ALL=C sort` instead of `sort` so that mocks get sorted in
the same way on all developers' environments.
Re-record the result of `make update-mocks`.
Changelog-None
This is useful in general, but in particular it allows fundchannel to avoid YA
query to figure out if it can wumbo.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-Added: JSON: `connect` returns `features` of the connected peer on success.
We kept track of an URGENT, a NORMAL, and a SLOW feerate. They were used
for opening (NORMAL), mutual (NORMAL), UNILATERAL (URGENT) transactions
as well as minimum and maximum estimations, and onchain resolution.
We now keep track of more fine-grained feerates:
- `opening` used for funding and also misc transactions
- `mutual_close` used for the mutual close transaction
- `unilateral_close` used for unilateral close (commitment transactions)
- `delayed_to_us` used for resolving our output from our unilateral close
- `htlc_resolution` used for resolving onchain HTLCs
- `penalty` used for resolving revoked transactions
We don't modify our requests to our Bitcoin backend, as the next commit
will batch them !
Changelog-deprecated: The "urgent", "slow", and "normal" field of the `feerates` command are now deprecated.
Changelog-added: The fields "opening", "mutual_close", "unilateral_close", "delayed_to_us", "htlc_resolution" and "penalty" have been added to the `feerates` command.
Postgres does not guarantee that the insertion order is the returned order,
which leads us to skip outputs that have already been stolen onto the selected
utxos set, but not added to it because it isn't confirmed. This may also
happen with sqlite3 though it's a lot rarer in that case.
For messages, we use the onion but payload lengths 0 and 1 aren't special.
Create a flag to disable that logic.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Even without optimization, it's faster to walk all the channels than
ping another daemon and wait for the response.
Changelog-Changed: Forwarding messages is now much faster (less inter-daemon traffic)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The idea is that gossipd can give us the cupdate we need for an error, and
we wire things up so that we ask for it (async) just before we send the
error to the subdaemon.
I tried many other things, but they were all too high-risk.
1. We need to ask gossipd every time, since it produces these lazily
(in particular, it doesn't actually generate an offline update unless
the channel is used).
2. We can't do async calls in random places, since we'll end up with
an HTLC in limbo. What if another path tries to fail it at the same time?
3. This allows us to use a temporary_node_failure error, and upgrade it
when gossipd replies. This doesn't change any existing assumptions.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a common thing to do, so create a macro.
Unfortunately, it still needs the type arg, because the paramter may
be const, and the return cannot be, and C doesn't have a general
"(-const)" cast.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This completes the conversion; any in-flight HTLC failures get turned into temporary_node_failures.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
At the moment, we store e.g. WIRE_TEMPORARY_CHANNEL_FAILURE, and then
lightningd has a large demux function which turns that into the correct
error message.
Such an enum demuxer is an anti-pattern.
Instead, store the message directly for output HTLCs; channeld now
sends us an error message rather than an error code.
For input HTLCs we will still need the failure code if the onion was
bad (since we need to prompt channeld to send a completely different
message than normal), though we can (and will!) eliminate its use in
non-BADONION failure cases.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We're going to change our internal structure next, so this is preparation.
We populate existing errors with temporary node failures, for simplicity.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Instead of making it ourselves, lightningd does it. Now we only have
two cases of failed htlcs: completely malformed (BADONION), and with
an already-wrapped onion reply to send.
This makes channeld's job much simpler.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I hadn't realized that lightningd asks gossipd every time we forward
a payment. But I'm going to abuse it here to get the latest channel_update,
otherwise (as lightningd takes over error message generation) lightningd
needs to do an async request at various painful points.
So have gossipd tell us the lastest update (stripped so compatible with
the strange in-onion-error format).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Turn it into temporary node failure: this only happens if we restart
with a failed htlc in, but it's clearer and more robust to handle it
generically.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Added in d901304120, this column is null in old dbs like mine:
2020-02-15T00:08:41.444Z **BROKEN** database: Accessing a null column 12 in query SELECT id, channel_htlc_id, msatoshi, cltv_expiry, hstate, payment_hash, payment_key, routing_onion, failuremsg, malformed_onion, origin_htlc, shared_secret, received_time FROM channel_htlcs WHERE direction= ? AND channel_id= ? AND hstate != ?
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the peer is not connected, or other error which means we don't
actually create an outgoing HTLC, we don't record the
short_channel_id. This is unhelpful!
Pass the scid down to the wallet code, and explicitly hand the
scid and amount down to the notification code rather than handing it
the htlc_out (which it doesn't need).
Changelog-Changed: JSON API: `listforwards` now shows `out_channel` even if we couldn't forward.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This sets the nLockTime to the tip (and accordingly each input's nSequence to
0xfffffffe) for withdrawal transactions.
Even if the anti fee-sniping argument might not be valid until some time yet,
this makes our regular wallet transactions far less distinguishable from
bitcoind's ones since it now defaults to using native Segwit transactions
(like us). Moreover other wallets are likely to implement this (if they
haven't already).
Changelog-Added: wallet: withdrawal transactions now sets nlocktime to the current tip.
Before this patch we used `int` for error codes. The problem with
`int` is that we try to pass it to/from wire and the size of `int` is
not defined by the standard. So a sender with 4-byte `int` would write
4 bytes to the wire and a receiver with 2-byte `int` (for example) would
read just 2 bytes from the wire.
To resolve this:
* Introduce an error code type with a known size:
`typedef s32 errcode_t`.
* Change all error code macros to constants of type `errcode_t`.
Constants also play better with gdb - it would visualize the name of
the constant instead of the numeric value.
* Change all functions that take error codes to take the new type
`errcode_t` instead of `int`.
* Introduce towire / fromwire functions to send / receive the newly added
type `errcode_t` and use it instead of `towire_int()`.
In addition:
* Remove the now unneeded `towire_int()`.
* Replace a hardcoded error code `-2` with a new constant
`INVOICE_EXPIRED_DURING_WAIT` (903).
Changelog-Changed: The waitinvoice command would now return error code 903 to designate that the invoice expired during wait, instead of the previous -2
This command injects a custom message into the encrypted transport stream to
the peer, allowing users to build custom protocols on top of c-lightning
without requiring any changes to c-lightning itself.
Generally I prefer structures over u8, since the size is enforced at
runtime; and in several places we were doing conversions as the code
using Sphinx does treat struct secret as type of the secret.
Note that passing an array is the same as passing the address, so
changing from 'u8 secret[32]' to 'struct secret secret' means various
'secret' parameters change to '&secret'. Technically, '&secret' also
would have worked before, since '&' is a noop on array, but that's
always seemed a bit weird.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes it clear we're dealing with a message which is a wrapped error
reply (needing unwrap_onionreply), not an already-wrapped one.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I really want a type which means "I am a wrapped onion reply" as separate
from "I am a normal wire msg". Currently both user u8 *, and I got very
confused trying to figure out where each one was an unwrapped error msg,
or where it still needed (un)wrapping.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
`wallet_payment_store` would free the `wallet_payment` instance which would
then cause us to reload it from the DB. Instead of doing the store->free->load
dance we now tell `wallet_payment_store` whether it should take ownership and
leave it alone if not.
Passing the payment around instead of referencing it through payment_hash and
partid is a nice side-effect.
The optimistic lock prevents multiple instances of c-lightning making
concurrent modifications to the database. That would be unsafe as it messes up
the state in the DB. The optimistic lock is implemented by checking whether a
gated update on the previous value of the `data_version` actually results in
an update. If that's not the case the DB has been changed under our feet.
The lock provides linearizability of DB modifications: if a database is
changed under the feet of a running process that process will `abort()`, which
from a global point of view is as if it had crashed right after the last
successful commit. Any process that also changed the DB must've started
between the last successful commit and the unsuccessful one since otherwise
its counters would not have matched (which would also have aborted that
transaction). So this reduces all the possible timelines to an equivalent
where the first process died, and the second process recovered from the DB.
This is not that interesting for `sqlite3` where we are also protected via the
PID file, but when running on multiple hosts against the same DB, e.g., with
`postgres`, this protection becomes important.
Changelog-Added: DB: Optimistic logging prevents instances from running concurrently against the same database, providing linear consistency to changes.
This increments the `data_version` upon committing dirty transactions, reads
the last data_version upon startup, and tracks the number in memory in
parallel to the DB (see next commit for rationale).
Changelog-Changed: JSON-RPC: Added a `data_version` field to the `db_write` hook which returns a numeric transaction counter.
This is the final step: we pass the complete fee_states to and from
channeld.
Changelog-Fixed: "Bad commitment signature" closing channels when we sent back-to-back update_fee messages across multiple reconnects.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The upgrade here is a bit tricky: we map the two values into the
feerate_state. This is trivial if they're both the same, but if
they're different we don't know exactly what state they're in (this
being the source of the bug!).
So, we assume that the have received the update and not acked it,
as that would be the normal case.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The invoice_try_pay code now takes a set, rather than a single htlc, but
it's basically the same thing.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a transient field, so rework things so we don't leave it in
struct htlc_out. Instead, load htlc_in first and connect htlc_out to
them as we go.
This also changes one place where we use it instead of the am_origin
flag.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is in preparation for partial payments. For existing payments,
partid is 0 (to match the corresponding payment).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is in preparation for partial payments. For existing payments,
partid is 0 (arbitrarity) and total_msat is msatoshi.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now "raw_payload" is always the complete string (including realm or length
bytes at the front).
This has several effects:
1. We can receive an decrypt an onion which is grossly malformed.
2. We can still hand this to the htlc_accepted hook.
3. We then fail it unless the htlc_accepted accepts it manually.
4. The createonion API now takes the raw payload, and does not know
anything about "style".
The only caveat is that the sphinx code needs to know the payload
length: we have a call for that, which simply tells it to copy the
entire onion (and treat us as the final node) if it's invalid.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we can't decode the onion, because the onion got corrupted or we used
`sendonion` without specifying the `shared_secrets` used, the best we can do
is tell the caller instead.
This means that c-lightning can now internally decrypt an eventual error
message, and not force the caller to implement the decryption. The main
difficulty was that we now have a new state (channels and nodes not specified,
while shared_secrets are specified) which needed to be handled.
We are breaking with a couple of assumptions, namely that we have the
`path_secrets` to decode the error onion. If this happens we just want it to
error out.
We don't set the secret to compulsory (yet!) but put code in for the
future. Meanwhile, if there is a secret, check it is correct.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In a future version, we will use features to insist that payers
provide the secret. In transition, we may have old invoices which
didn't insist on that, so we need to know this on a per-invoice basis.
Not sure if I got the right syntax for adding an empty blob though!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We have consolidated the two functions into a single `route_step_decode`
function, and made it static since we call it in the `process_onionpacket`
function. We remove the two exposed functions since they're no longer useful.
Since the parser itself just parses and doesn't include validation anymore we
need to put that functionality somewhere. The validation consists of enforcing
that the types are in monotonically increasing order without duplicates and
that for the even types we know how to handle it.
This allows finegrained logging control of particular subdaemons or
subsystems.
To do this, we defer setting the logging levels for each log object
until after early argument parsing (since e.g. "bitcoind" log object
is created early).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-changed: Options: log-level can now specify different levels for different subsystems.
1. Printed form is always "[<nodeid>-]<prefix>: <string>"
2. "jcon fd %i" becomes "jsonrpc #%i".
3. "jsonrpc" log is only used once, and is removed.
4. "database" log prefix is use for db accesses.
5. "lightningd(%i)" becomes simply "lightningd" without the pid.
6. The "lightningd_" prefix is stripped from subd log prefixes, and pid removed.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Changelog-changed: Logging: formatting made uniform: [NODEID-]SUBSYSTEM: MESSAGE
Changelog-removed: `lightning_` prefixes removed from subdaemon names, including in listpeers `owner` field.
We had a separate logbook for each peer, and copy log entries above
the printable log level into the master logbook. This didn't always
work well, since we didn't dump it on crash for example.
Keep a single global logbook instead, and remove this infrastructure.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
A log can have a default node_id, which can be overridden on a per-entry
basis. This changes the format of logging, so some tests need rework.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The case where this is needed is when the wallet had a forwarded payment
somewhere between commits 66a47d2 (which started tracking forwardings) and
d901304 (which added the `received_time` column). This just emulates the
behavior of sqlite3 for postgres as well.
Signed-off-by: Christian Decker <@cdecker>
Checking on whether we access a null field is ok, but should we crash right
away? Probably not. This reduces the access to a warning on sqlite3 and let's
it continue. We can look for occurences and fix them as they come up and then
re-arm the asserts once we addressed all cases.
We were implicitly relying on sqlite3 behavior that returns the zero-value for
nulled fields when accessing them. This adds the same behavior explicitly to
the DB abstraction in order to reduce `db_column_is_null` checks in the logic,
but still make it evident what is happening here.
Fixes https://github.com/fiatjaf/mcldsp/issues/1
Signed-off-by: Christian Decker <@cdecker>
I had a report of a 0.7.2 user whose node hadn't appeared on 1ml. Their
node_announcement wasn't visible to my node, either.
I suspect this is a consequence of recent version reducing the amount of
gossip they send, as well as large nodes increasingly turning off gossip
altogether from some peers (as we do). We should ignore timestamp filters
for our own channels: the easiest way to do this is to push them out
directly from gossipd (other messages are sent via the store).
We change channeld to wrap the local channel_announcements: previously
we just handed it to gossipd as for any other gossip message we received
from our peer. Now gossipd knows to push it out, as it's local.
This interferes with the logic in tests/test_misc.py::test_htlc_send_timeout
which expects the node_announcement message last, so we generalize
that too.
[ Thanks to @trueptolmy for bugfix! ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is mainly an internal-only change, especially since we don't
offer any globalfeatures.
However, LND (as of next release) will offer global features, and also
expect option_static_remotekey to be a *global* feature. So we send
our (merged) feature bitset as both global and local in init, and fold
those bitsets together when we get an init msg.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This patch adds a channel_id parameter to allow for specifying
channels that are lacking a short_channel_id.
Useful in the case where a peer has 1) multiple channels (ONCHAIN etc)
and 2) a channel where the funding transaction hasn't been
broadcast/mined.
Command format: close id [unilateraltimeout] [destination]
Close the channel with peer {id}, forcing a unilateral
close after {unilateraltimeout} seconds if non-zero, and
the to-local output will be sent to {destination}. If
{destination} isn't specified, the default is the address
of lightningd.
Also change the pylightning:
update the `close` API to support `destination` parameter
`shutdown_scriptpubkey[REMOTE]` is original remote_shutdown_scriptpubkey;
`shutdown_scriptpubkey[LOCAL]` is the script used for "to-local" output when `close`. Add the default is generated form `final_key_idx`;
Store `shutdown_scriptpubkey[LOCAL]` into wallet;
Our policy is generally to omit fields which aren't sensible.
Also, @niftynei points out the spacing in for loops.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This triple join should be efficient to read, and to process. We have a
one-to-many (tx-to-annotations), followed by a
one-to-one (annotation-to-channel) join, so we are limited to annotations x
transactions results.
We have split the iteration over the txs and the output in different
functions, so pushing the annotation down, while keeping the transaction
addition atop. This showcases the need to not have the txid reference the
transactions.id in the DB: we annotate in a function that doesn't have the tx
index context, but only add the TX after we have finished extracting.
Currently the only source for amount_asset is the value getter on a tx output,
and we don't hand it too far around (mainly ignoring it if it isn't the
chain's main currency). Eventually we could bubble them up to the wallet, use
them to select outputs or actually support assets in the channels.
Since we don't hand them around too widely I thought it was ok for them to be
pass-by-value rather than having to allocate them and pass them around by
reference. They're just 41 bytes currently so the overhead should be ok.
Signed-off-by: Christian Decker <@cdecker>
In elements we add an explicit fee output, if we don't consider it when
selecting coins, we end up underpaying the fees.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
Skipping coinbase transactions and ensuring that the transaction is serialized
correctly when sending it onwards.
Signed-off-by: Christian Decker <decker.christian@gmail.com>
With enable-autotor-v2 defined in cmdline the default behavior to create
v3 onions with the tor service call, is set to v2 onions.
Signed-off-by: Saibato <saibato.naga@pm.me>
niftynei
fiatjaf
Antoine Poinsot
Rusty Russell
Christian Decker
Sebastian Falbesoner
Vasil Dimov
Michael Schmoock
trueptolemy
Saibato