* p2p: add DialRatio for configuration of inbound vs. dialed connections
* p2p: add connection flags to PeerInfo
* p2p/netutil: add SameNet, DistinctNetSet
* p2p/discover: improve revalidation and seeding
This changes node revalidation to be periodic instead of on-demand. This
should prevent issues where dead nodes get stuck in closer buckets
because no other node will ever come along to replace them.
Every 5 seconds (on average), the last node in a random bucket is
checked and moved to the front of the bucket if it is still responding.
If revalidation fails, the last node is replaced by an entry of the
'replacement list' containing recently-seen nodes.
Most close buckets are removed because it's very unlikely we'll ever
encounter a node that would fall into any of those buckets.
Table seeding is also improved: we now require a few minutes of table
membership before considering a node as a potential seed node. This
should make it less likely to store short-lived nodes as potential
seeds.
* p2p/discover: fix nits in UDP transport
We would skip sending neighbors replies if there were fewer than
maxNeighbors results and CheckRelayIP returned an error for the last
one. While here, also resolve a TODO about pong reply tokens.
This commit introduces a network simulation framework which
can be used to run simulated networks of devp2p nodes. The
intention is to use this for testing protocols, performing
benchmarks and visualising emergent network behaviour.
* p2p/discover, p2p/discv5: add marshaling methods to Node
* p2p/netutil: make Netlist decodable from TOML
* common/math: encode nil HexOrDecimal256 as 0x0
* cmd/geth: add --config file flag
* cmd/geth: add missing license header
* eth: prettify Config again, fix tests
* eth: use gasprice.Config instead of duplicating its fields
* eth/gasprice: hide nil default from dumpconfig output
* cmd/geth: hide genesis block in dumpconfig output
* node: make tests compile
* console: fix tests
* cmd/geth: make TOML keys look exactly like Go struct fields
* p2p: use discovery by default
This makes the zero Config slightly more useful. It also fixes package
node tests because Node detects reuse of the datadir through the
NodeDatabase.
* cmd/geth: make ethstats URL settable through config file
* cmd/faucet: fix configuration
* cmd/geth: dedup attach tests
* eth: add comment for DefaultConfig
* eth: pass downloader.SyncMode in Config
This removes the FastSync, LightSync flags in favour of a more
general SyncMode flag.
* cmd/utils: remove jitvm flags
* cmd/utils: make mutually exclusive flag error prettier
It now reads:
Fatal: flags --dev, --testnet can't be used at the same time
* p2p: fix typo
* node: add DefaultConfig, use it for geth
* mobile: add missing NoDiscovery option
* cmd/utils: drop MakeNode
This exposed a couple of places that needed to be updated to use
node.DefaultConfig.
* node: fix typo
* eth: make fast sync the default mode
* cmd/utils: remove IPCApiFlag (unused)
* node: remove default IPC path
Set it in the frontends instead.
* cmd/geth: add --syncmode
* cmd/utils: make --ipcdisable and --ipcpath mutually exclusive
* cmd/utils: don't enable WS, HTTP when setting addr
* cmd/utils: fix --identity
PR #1621 changed Table locking so the mutex is not held while a
contested node is being pinged. If multiple nodes ping the local node
during this time window, multiple ping packets will be sent to the
contested node. The changes in this commit prevent multiple packets by
tracking whether the node is being replaced.
The previous metric was pubkey1^pubkey2, as specified in the Kademlia
paper. We missed that EC public keys are not uniformly distributed.
Using the hash of the public keys addresses that. It also makes it
a bit harder to generate node IDs that are close to a particular node.
This commit changes the discovery protocol to use the new "v4" endpoint
format, which allows for separate UDP and TCP ports and makes it
possible to discover the UDP address after NAT.
This a fix for an attack vector where the discovery protocol could be
used to amplify traffic in a DDOS attack. A malicious actor would send a
findnode request with the IP address and UDP port of the target as the
source address. The recipient of the findnode packet would then send a
neighbors packet (which is 16x the size of findnode) to the victim.
Our solution is to require a 'bond' with the sender of findnode. If no
bond exists, the findnode packet is not processed. A bond between nodes
α and β is created when α replies to a ping from β.
This (initial) version of the bonding implementation might still be
vulnerable against replay attacks during the expiration time window.
We will add stricter source address validation later.
