Let's say an attacker wants to use/exhaust the network's bandwidth, and
has the choice between renting resources from a commercial provider and
getting the network to "spam" itself it by sending unconfirmed
transactions. We'd like the latter to be more expensive than the former.
The bandwidth for relaying a transaction across the network is roughly
its serialized size (plus relay overhead) x number of nodes. A 1000vB
transaction is 1000-4000B serialized. With 100k nodes, that's 0.1-0.4GB
If the going rate for commercial services is 10c/GB, that's like 1-4c per kvB
of transaction data, so a 1000vB transaction should pay at least $0.04.
At a price of 120k USD/BTC, 100sat is about $0.12. This price allows us
to tolerate a large decrease in the conversion rate or increase in the
number of nodes.
p2p_ibd_txrelay expects no GETDATA to have been received by a peer after
announcing a transaction. The reason is that the node is doing IBD, so
transaction requests are not replied to. However, the way this is checked
is wrong, and the check will pass even if the node **was not** in IBD.
This is due to the mocktime not being properly initialized, so the check
is always performed earlier than it should, making it impossible for the
request to be there
6aed8b7e9b [test] tx processing before and after ibd (glozow)
b9e105b664 [net_processing] ignore all transactions during ibd (glozow)
Pull request description:
This is basically a mini, IBD-only version of #21224
Incoming transactions aren't really relevant until we're caught up. That's why we send a giant feefilter and don't send tx getdatas, but we also shouldn't process them if peers send them anyway. Simply ignore them.
ACKs for top commit:
jnewbery:
reACK 6aed8b7e9b
laanwj:
Code review ACK 6aed8b7e9b
Tree-SHA512: 8e1616bf355f9d0b180bdbc5461f24c757dc5d7bc7bf651470f3b0bffcca5d5e68287106255b5cede2d96b42bce448a0f8c0649de35a530c5e079f7c89c70a35
The previous diff touched most files in ./test/, so bump the headers to
avoid having to touch them again for a bump later.
-BEGIN VERIFY SCRIPT-
./contrib/devtools/copyright_header.py update ./test/
-END VERIFY SCRIPT-
