core-lightning/gossipd
Rusty Russell 0ba547ee10 gossipd: handle overflowing query properly (avoid slow 100% CPU reports)
Don't do this:
  (gdb) bt
  #0  0x00007f37ae667c40 in ?? () from /lib/x86_64-linux-gnu/libz.so.1
  #1  0x00007f37ae668b38 in ?? () from /lib/x86_64-linux-gnu/libz.so.1
  #2  0x00007f37ae669907 in deflate () from /lib/x86_64-linux-gnu/libz.so.1
  #3  0x00007f37ae674c65 in compress2 () from /lib/x86_64-linux-gnu/libz.so.1
  #4  0x000000000040cfe3 in zencode_scids (ctx=0xc1f118, scids=0x2599bc49 "\a\325{", len=176320) at gossipd/gossipd.c:218
  #5  0x000000000040d0b3 in encode_short_channel_ids_end (encoded=0x7fff8f98d9f0, max_bytes=65490) at gossipd/gossipd.c:236
  #6  0x000000000040dd28 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290511, number_of_blocks=8) at gossipd/gossipd.c:576
  #7  0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290511, number_of_blocks=16) at gossipd/gossipd.c:595
  #8  0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290495, number_of_blocks=32) at gossipd/gossipd.c:596
  #9  0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290495, number_of_blocks=64) at gossipd/gossipd.c:595
  #10 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=128) at gossipd/gossipd.c:596
  #11 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=256) at gossipd/gossipd.c:595
  #12 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=512) at gossipd/gossipd.c:595
  #13 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17290431, number_of_blocks=1024) at gossipd/gossipd.c:595
  #14 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=2047) at gossipd/gossipd.c:596
  #15 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=4095) at gossipd/gossipd.c:595
  #16 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=8191) at gossipd/gossipd.c:595
  #17 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=16382) at gossipd/gossipd.c:595
  #18 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=32764) at gossipd/gossipd.c:595
  #19 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=65528) at gossipd/gossipd.c:595
  #20 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=131056) at gossipd/gossipd.c:595
  #21 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=262112) at gossipd/gossipd.c:595
  #22 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=524225) at gossipd/gossipd.c:595
  #23 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=1048450) at gossipd/gossipd.c:595
  #24 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=2096900) at gossipd/gossipd.c:595
  #25 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=4193801) at gossipd/gossipd.c:595
  #26 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=8387603) at gossipd/gossipd.c:595
  #27 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=17289408, number_of_blocks=16775207) at gossipd/gossipd.c:595
  #28 0x000000000040ddee in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=33550414) at gossipd/gossipd.c:596
  #29 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=67100829) at gossipd/gossipd.c:595
  #30 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=134201659) at gossipd/gossipd.c:595
  #31 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=268403318) at gossipd/gossipd.c:595
  #32 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=536806636) at gossipd/gossipd.c:595
  #33 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=1073613273) at gossipd/gossipd.c:595
  #34 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=2147226547) at gossipd/gossipd.c:595
  #35 0x000000000040ddc6 in queue_channel_ranges (peer=0x3868fc8, first_blocknum=514201, number_of_blocks=4294453094) at gossipd/gossipd.c:595
  #36 0x000000000040df26 in handle_query_channel_range (peer=0x3868fc8, msg=0x37e0678 "\001\ao\342\214\n\266\361\263r\301\246\242F\256c\367O\223\036\203e\341Z\b\234h\326\031") at gossipd/gossipd.c:625

The cause was that converting a block number to an scid truncates it
at 24 bits.  When we look through the index from (truncated number) to
(real end number) we get every channel, which is too large to encode,
so we iterate again.

This fixes both that problem, and also the issue that we'd end up
dividing into many empty sections until we get to the highest block
number.  Instead, we just tack the empty blocks on to then end of the
final query.

(My initial version requested 0xFFFFFFFE blocks, but the dev code
which records what blocks were returned can't make a bitmap that big
on 32 bit).

Reported-by: George Vaccaro
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-01-15 11:34:45 -08:00
..
test getroute: allow caller to specify maximum hops. 2019-01-15 12:01:38 +01:00
broadcast.c gossipd: wire up memleak detection. 2018-11-22 05:15:42 +00:00
broadcast.h gossipd: wire up memleak detection. 2018-11-22 05:15:42 +00:00
gossip_constants.h gossipd: split wire types into msgs from lightningd and msgs from per-peer daemons 2018-11-21 00:36:31 +00:00
gossip_peerd_wire.csv gossipd: split wire types into msgs from lightningd and msgs from per-peer daemons 2018-11-21 00:36:31 +00:00
gossip_store.c gossipd: split wire types into msgs from lightningd and msgs from per-peer daemons 2018-11-21 00:36:31 +00:00
gossip_store.csv gossip_store: Save local_add_channel messages and replay them 2018-04-22 12:50:34 +02:00
gossip_store.h gossipd: invalidate old gossip_stores. 2018-09-21 17:56:15 +02:00
gossip_wire.csv short_channel_id_dir: new primitive for one direction of short_channel_id 2019-01-15 12:01:38 +01:00
gossipd.c gossipd: handle overflowing query properly (avoid slow 100% CPU reports) 2019-01-15 11:34:45 -08:00
Makefile common: make funding_tx and withdraw_tx share UTXO code. 2018-12-06 23:11:51 +01:00
routing.c short_channel_id_dir: new primitive for one direction of short_channel_id 2019-01-15 12:01:38 +01:00
routing.h short_channel_id_dir: new primitive for one direction of short_channel_id 2019-01-15 12:01:38 +01:00