* use dialPeer function in a seed mode

Fixes #3532

by storing a number of attempts we've tried to connect in-memory and
removing the address from addrbook when number of attempts > 16

A prior change to address accidental DNS lookups introduced the
SocketAddr on peer, which was then used to add it to the addressbook.
Which in turn swallowed the self reported port of the peer, which is
important on a reconnect. This change revives the NetAddress on NodeInfo
which the Peer carries, but now returns an error to avoid nil
dereferencing another issue observed in the past. Additionally we could
potentially address #3532, yet the original problem statemenf of that
issue stands.

As a drive-by optimisation `MarkAsGood` now takes only a `p2p.ID` which
makes it interface a bit stricter and leaner.

* add actionable advice for ErrAddrBookNonRoutable err

Should replace https://github.com/tendermint/tendermint/pull/3463

* reorder checks in addrbook#addAddress so

ErrAddrBookPrivate is returned first

and do not log error in DialPeersAsync if the address is private
because it's not an error

ListOfKnownAddresses is removed
panic if addrbook size is less than zero
CrawlPeers does not attempt to connect to existing or peers we're currently dialing
various perf. fixes
improved tests (though not complete)
move IsDialingOrExistingAddress check into DialPeerWithAddress (Fixes #2716)


* addrbook: preallocate memory when saving addrbook to file

* addrbook: remove oldestFirst struct and check for ID

* oldestFirst replaced with sort.Slice
* ID is now mandatory, so no need to check

* addrbook: remove ListOfKnownAddresses

GetSelection is used instead in seed mode.

* addrbook: panic if size is less than 0

* rewrite addrbook#saveToFile to not use a counter

* test AttemptDisconnects func

* move IsDialingOrExistingAddress check into DialPeerWithAddress

* save and cleanup crawl peer data

* get rid of DefaultSeedDisconnectWaitPeriod

* make linter happy

* fix TestPEXReactorSeedMode

* fix comment

* add a changelog entry

* Apply suggestions from code review

Co-Authored-By: melekes <anton.kalyaev@gmail.com>

* rename ErrDialingOrExistingAddress to ErrCurrentlyDialingOrExistingAddress

* lowercase errors

* do not persist seed data

pros:
- no extra files
- less IO

cons:
- if the node crashes, seed might crawl a peer too soon

* fixes after Ethan's review

* add a changelog entry

* we should only consult Switch about peers

checking addrbook size does not make sense since only PEX reactor uses
it for dialing peers!

https://github.com/tendermint/tendermint/pull/3011#discussion_r270948875

* OriginalAddr -> SocketAddr

OriginalAddr records the originally dialed address for outbound peers,
rather than the peer's self reported address. For inbound peers, it was
nil. Here, we rename it to SocketAddr and for inbound peers, set it to
the RemoteAddr of the connection.

* use SocketAddr

Numerous places in the code call peer.NodeInfo().NetAddress().
However, this call to NetAddress() may perform a DNS lookup if the
reported NodeInfo.ListenAddr includes a name. Failure of this lookup
returns a nil address, which can lead to panics in the code.

Instead, call peer.SocketAddr() to return the static address of the
connection.

* remove nodeInfo.NetAddress()

Expose `transport.NetAddress()`, a static result determined
when the transport is created. Removing NetAddress() from the nodeInfo
prevents accidental DNS lookups.

* fixes from review

* linter

* fixes from review

* mempool: add a safety check, write tests for mempoolIDs

and document 65536 limit in the mempool reactor spec

follow-up to https://github.com/tendermint/tendermint/pull/2778

* rename the test

* fixes after Ismail's review

Why submit this pr:

    we have suffered from infinite loop in addrbook bug which takes us a long time to find out why process become a zombie peer. It have been fixed in #3232. But the ADDRS_LOOP is still there, risk of infinite loop is still exist.
    The algorithm that to random pick a bucket is not stable, which means the peer may unluckily always choose the wrong bucket for a long time, the time and cpu cost is meaningless.

A simple improvement:
shuffle bucketsNew and bucketsOld, and pick necessary number of address from them. A stable
algorithm.

Fixes https://circleci.com/gh/tendermint/tendermint/44901

* failing test

* fix infinite loop in addrbook

There are cases where we only have a small number of addresses marked
good ("old"), but the selection mechanism keeps trying to select more of these
addresses, and hence ends up in an infinite loop. Here we fix this to
only try and select such "old" addresses if we have enough of them. Note this
means, if we don't have enough of them, we may return more "new"
addresses than otherwise expected by the newSelectionBias.

This whole GetSelectionWithBias method probably needs to be rewritten,
but this is a quick fix for the issue.

* changelog

* fix infinite loop if not enough new addrs

* fix another potential infinite loop

if a.nNew == 0 -> pickFromOldBucket=true, but we don't have enough items
  (a.nOld > len(oldBucketToAddrsMap) false)

* Revert "fix another potential infinite loop"

This reverts commit 146540c112.

* check num addresses instead of buckets, new test

* fixed the int division

* add slack to bias % in test, lint fixes

* Added checks for selection content in test

* test cleanup

* Apply suggestions from code review

Co-Authored-By: ebuchman <ethan@coinculture.info>

* address review comments

* change after  Anton's review comments

* use the same docker image we use for testing

when building a binary for localnet

* switch back to circleci classic

* more review comments

* more review comments

* refactor addrbook_test

* build linux binary inside docker

in attempt to fix

```
--> Running dep
+ make build-linux
GOOS=linux GOARCH=amd64 make build
make[1]: Entering directory `/home/circleci/.go_workspace/src/github.com/tendermint/tendermint'
CGO_ENABLED=0 go build -ldflags "-X github.com/tendermint/tendermint/version.GitCommit=`git rev-parse --short=8 HEAD`" -tags 'tendermint' -o build/tendermint ./cmd/tendermint/
p2p/pex/addrbook.go:373:13: undefined: math.Round
```

* change dir from /usr to /go

* use concrete Go version for localnet binary

* check for nil addresses just to be sure

* p2p/pex: failing test

* p2p/conn: add stopMtx for FlushStop and OnStop

* changelog

As per conversation here: https://github.com/tendermint/tendermint/pull/3218#discussion_r251364041

This is the result of running the following code on the repo:

```bash
find . -name '*.go' | grep -v 'vendor/' | xargs -n 1 goimports -w
```

Closes #3037

* close peer's connection to avoid fd leak

Fixes #2967

* rename peer#Addr to RemoteAddr

* fix test

* fixes after Ethan's review

* bring back the check

* changelog entry

* write a test for switch#acceptRoutine

* increase timeouts? :(

* remove extra assertNPeersWithTimeout

* simplify test

* assert number of peers (just to be safe)

* Cleanup in OnStop

* run tests with verbose flag on CircleCI

* spawn a reading routine to prevent connection from closing

* get port from the listener

random port is faster, but often results in

```
panic: listen tcp 127.0.0.1:44068: bind: address already in use [recovered]
        panic: listen tcp 127.0.0.1:44068: bind: address already in use

goroutine 79 [running]:
testing.tRunner.func1(0xc0001bd600)
        /usr/local/go/src/testing/testing.go:792 +0x387
panic(0x974d20, 0xc0001b0500)
        /usr/local/go/src/runtime/panic.go:513 +0x1b9
github.com/tendermint/tendermint/p2p.MakeSwitch(0xc0000f42a0, 0x0, 0x9fb9cc, 0x9, 0x9fc346, 0xb, 0xb42128, 0x0, 0x0, 0x0, ...)
        /home/vagrant/go/src/github.com/tendermint/tendermint/p2p/test_util.go:182 +0xa28
github.com/tendermint/tendermint/p2p.MakeConnectedSwitches(0xc0000f42a0, 0x2, 0xb42128, 0xb41eb8, 0x4f1205, 0xc0001bed80, 0x4f16ed)
        /home/vagrant/go/src/github.com/tendermint/tendermint/p2p/test_util.go:75 +0xf9
github.com/tendermint/tendermint/p2p.MakeSwitchPair(0xbb8d20, 0xc0001bd600, 0xb42128, 0x2f7, 0x4f16c0)
        /home/vagrant/go/src/github.com/tendermint/tendermint/p2p/switch_test.go:94 +0x4c
github.com/tendermint/tendermint/p2p.TestSwitches(0xc0001bd600)
        /home/vagrant/go/src/github.com/tendermint/tendermint/p2p/switch_test.go:117 +0x58
testing.tRunner(0xc0001bd600, 0xb42038)
        /usr/local/go/src/testing/testing.go:827 +0xbf
created by testing.(*T).Run
        /usr/local/go/src/testing/testing.go:878 +0x353
exit status 2
FAIL    github.com/tendermint/tendermint/p2p    0.350s
```

* Revert to using defers in addrbook.  ValidateBasic->Validate since it requires DNS

* Update CHANGELOG_PENDING

* p2p/conn: FlushStop. Use in pex. Closes #2092

In seed mode, we call StopPeer immediately after Send.
Since flushing msgs to the peer happens in the background,
the peer connection is often closed before the messages are
actually sent out. The new FlushStop method allows all msgs
to first be written and flushed out on the conn before it is closed.

* fix dummy peer

* typo

* fixes from review

* more comments

* ensure pex doesn't call FlushStop more than once

FlushStop is not safe to call more than once,
but we call it from Receive in a go-routine so Receive
doesn't block.

To ensure we only call it once, we use the lastReceivedRequests
map - if an entry already exists, then FlushStop should already have
been called and we can return.

* use READ lock/unlock in ConsensusState#GetLastHeight

Refs #2721

* do not use defers when there's no need

* fix peer formatting (output its address instead of the pointer)

```
[54310]: E[11-02|11:59:39.851] Connection failed @ sendRoutine              module=p2p peer=0xb78f00 conn=MConn{74.207.236.148:26656} err="pong timeout"
```

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435326581

* panic if peer has no state

https://github.com/tendermint/tendermint/issues/2721#issuecomment-435347165

It's confusing that sometimes we check if peer has a state, but most of
the times we expect it to be there

1. add79700b5/mempool/reactor.go (L138)
2. add79700b5/rpc/core/consensus.go (L196) (edited)

I will change everything to always assume peer has a state and panic
otherwise

that should help identify issues earlier

* abci/localclient: extend lock on app callback

App callback should be protected by lock as well (note this was already
done for InitChainAsync, why not for others???). Otherwise, when we
execute the block, tx might come in and call the callback in the same
time we're updating it in execBlockOnProxyApp => DATA RACE

Fixes #2721

Consensus state is locked

```
goroutine 113333 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00180009c, 0xc0000c7e00)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*RWMutex).RLock(0xc001800090)
        /usr/local/go/src/sync/rwmutex.go:50 +0x4e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).GetRoundState(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:218 +0x46
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).queryMaj23Routine(0xc0017def80, 0x11104a0, 0xc0072488f0, 0xc007248
9c0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:735 +0x16d
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusReactor).AddPeer
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/reactor.go:172 +0x236
```

because localClient is locked

```
goroutine 1899 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0xc0000cb500)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).SetResponseCallback(0xc0001fb560, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:32 +0x33
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnConsensus).SetResponseCallback(0xc00002f750, 0xc007868540)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:57 +0x40
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.execBlockOnProxyApp(0x1104e20, 0xc002ca0ba0, 0x11092a0, 0xc00002f750, 0xc0001fe960, 0xc000bfc660, 0x110cfe0, 0xc000090330, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:230 +0x1fd
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state.(*BlockExecutor).ApplyBlock(0xc002c2a230, 0x7, 0x0, 0xc000eae880, 0x6, 0xc002e52c60, 0x16, 0x1f927, 0xc9d12, 0xc000d9d5a0, ...)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/state/execution.go:96 +0x142
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).finalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1339 +0xa3e
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryFinalizeCommit(0xc001800000, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1270 +0x451
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit.func1(0xc001800000, 0x0, 0x1f928)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1218 +0x90
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).enterCommit(0xc001800000, 0x1f928, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1247 +0x6b8
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).addVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xc003bc7ad0, 0xc003bc7b10)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1659 +0xbad
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).tryAddVote(0xc001800000, 0xc003d8dea0, 0xc000cf4cc0, 0x28, 0xf1, 0xf1, 0xf1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:1517 +0x59
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).handleMsg(0xc001800000, 0xd98200, 0xc0070dbed0, 0xc000cf4cc0, 0x28)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:660 +0x64b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).receiveRoutine(0xc001800000, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:617 +0x670
created by github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus.(*ConsensusState).OnStart
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/consensus/state.go:311 +0x132
```

tx comes in and CheckTx is executed right when we execute the block

```
goroutine 111044 [semacquire, 309 minutes]:
sync.runtime_SemacquireMutex(0xc00003363c, 0x0)
        /usr/local/go/src/runtime/sema.go:71 +0x3d
sync.(*Mutex).Lock(0xc000033638)
        /usr/local/go/src/sync/mutex.go:134 +0xff
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client.(*localClient).CheckTxAsync(0xc0001fb0e0, 0xc002d94500, 0x13f, 0x280, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/abci/client/local_client.go:85 +0x47
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy.(*appConnMempool).CheckTxAsync(0xc00002f720, 0xc002d94500, 0x13f, 0x280, 0x1)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/proxy/app_conn.go:114 +0x51
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool.(*Mempool).CheckTx(0xc002d3a320, 0xc002d94500, 0x13f, 0x280, 0xc0072355f0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/mempool/mempool.go:316 +0x17b
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core.BroadcastTxSync(0xc002d94500, 0x13f, 0x280, 0x0, 0x0, 0x0)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/core/mempool.go:93 +0xb8
reflect.Value.call(0xd85560, 0x10326c0, 0x13, 0xec7b8b, 0x4, 0xc00663f180, 0x1, 0x1, 0xc00663f180, 0xc00663f188, ...)
        /usr/local/go/src/reflect/value.go:447 +0x449
reflect.Value.Call(0xd85560, 0x10326c0, 0x13, 0xc00663f180, 0x1, 0x1, 0x0, 0x0, 0xc005cc9344)
        /usr/local/go/src/reflect/value.go:308 +0xa4
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.makeHTTPHandler.func2(0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/handlers.go:269 +0x188
net/http.HandlerFunc.ServeHTTP(0xc002c81f20, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.(*ServeMux).ServeHTTP(0xc002c81b60, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2361 +0x127
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.maxBytesHandler.ServeHTTP(0x10f8a40, 0xc002c81b60, 0xf4240, 0x1102060, 0xc00663f100, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:219 +0xcf
github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server.RecoverAndLogHandler.func1(0x1103220, 0xc00121e620, 0xc0082d7900)
        /root/go/src/github.com/MinterTeam/minter-go-node/vendor/github.com/tendermint/tendermint/rpc/lib/server/http_server.go:192 +0x394
net/http.HandlerFunc.ServeHTTP(0xc002c06ea0, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:1964 +0x44
net/http.serverHandler.ServeHTTP(0xc001a1aa90, 0x1103220, 0xc00121e620, 0xc0082d7900)
        /usr/local/go/src/net/http/server.go:2741 +0xab
net/http.(*conn).serve(0xc00785a3c0, 0x11041a0, 0xc000f844c0)
        /usr/local/go/src/net/http/server.go:1847 +0x646
created by net/http.(*Server).Serve
        /usr/local/go/src/net/http/server.go:2851 +0x2f5
```

* consensus: use read lock in Receive#VoteMessage

* use defer to unlock mutex because application might panic

* use defer in every method of the localClient

* add a changelog entry

* drain channels before Unsubscribe(All)

Read 55362ed766/libs/pubsub/pubsub.go (L13)
for the detailed explanation of the issue.

We'll need to fix it someday. Make sure to keep an eye on
https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-033-pubsub.md

* retry instead of panic when peer has no state in reactors other than consensus

in /dump_consensus_state RPC endpoint, skip a peer with no state

* rpc/core/mempool: simplify error messages

* rpc/core/mempool: use time.After instead of timer

also, do not log DeliverTx result (to be consistent with other memthods)

* unlock before calling the callback in reqRes#SetCallback

* Require addressbook to only store addresses with valid ID

* Do not shut down peer immediately after sending pex addrs in SeedMode

* p2p: fix #2773

* seed mode: use go-routine to sleep before stopping peer

* validate reactor messages

Refs #2683

* validate blockchain messages

Refs #2683

* validate evidence messages

Refs #2683

* todo

* check ProposalPOL and signature sizes

* add a changelog entry

* check addr is valid when we add it to the addrbook

* validate incoming netAddr (not just nil check!)

* fixes after Bucky's review

* check timestamps

* beef up block#ValidateBasic

* move some checks into bcBlockResponseMessage

* update Gopkg.lock

Fix

```
grouped write of manifest, lock and vendor: failed to export github.com/tendermint/go-amino: fatal: failed to unpack tree object 6dcc6ddc14
```

by running `dep ensure -update`

* bump year since now we check it

* generate test/p2p/data on the fly using tendermint testnet

* allow sync chains older than 1 year

* use full path when creating a testnet

* move testnet gen to test/docker/Dockerfile

* relax LastCommitRound check

Refs #2737

* fix conflicts after merge

* add small comment

* some ValidateBasic updates

* fixes

* AppHash length is not fixed

* p2p: bring back OriginalAddr

* p2p: set OriginalAddr

* update changelog

* p2p: NodeInfo is an interface

* (squash) fixes from review

* (squash) more fixes from review

* p2p: remove peerConn.HandshakeTimeout

* p2p: NodeInfo is two interfaces. Remove String()

* fixes from review

* remove test code from peer.RemoteIP()

* p2p: remove peer.OriginalAddr(). See #2618

* use a mockPeer in peer_set_test.go

* p2p: fix testNodeInfo naming

* p2p: remove unused var

* remove testRandNodeInfo

* fix linter

* fix retry dialing self

* fix rpc

We are swapping the exisiting listener implementation with the newly
introduced Transport and its default implementation MultiplexTransport,
removing a large chunk of old connection setup and handling scattered
over the Peer and Switch code. The Switch requires a Transport now and
handles externally passed Peer filters.

* ignore existing peers in DialPeersAsync

Fixes #2253

* rename HasPeerWithAddress to IsDialingOrExistingAddress

[breaking] remove Switch#IsDialing

* check if addrBook is nil

to be consistent with other usages of addrBook across Switch

* different log messages for 2 use-cases

* [p2p/pex] connect to more than 10 peers

also, remove DefaultMinNumOutboundPeers because a) I am not sure it's
needed b) it's super confusing

look closely

```
maxPeers := sw.config.MaxNumPeers - DefaultMinNumOutboundPeers
if maxPeers <= sw.peers.Size() {
  sw.Logger.Info("Ignoring inbound connection: already have enough peers", "address", inConn.RemoteAddr().String(), "numPeers", sw.peers.Size(), "max", maxPeers)
```

we print maxPeers = config.MaxPeers - DefaultMinNumOutboundPeers. So we
may not have enough peers even though we say we have enough.

Refs #2130

* update spec

* replace MaxNumPeers with MaxNumInboundPeers/MaxNumOutboundPeers

Refs #2130

* update changelog

* make max rpc conns formula visible to users

* update spec

* docs: note max outbound peers excludes persistent

* libs: Remove usage of custom Fmt, in favor of fmt.Sprintf

Closes #2193

* Fix bug that was masked by custom Fmt!

* p2p/pex: Allow configured seed nodes to be offline

Previously you couldn't startup tendermint if a seed node was offline.
This now allows you to startup tendermint, as long as all seed node addresses
are formatted correctly. In the event that all seed nodes are down,
and the address book is empty, then it crashes with an informative error msg.
(This case doesn't occur if no seeds were specified)

Closes #1716

* (Squash this) Address melekes' comments

* (squash this) fix package imports

* (squash this) fix pex_reactor comment

* (squash this) add a test case

also, remove excessive log message

Refs #2072

This is to reduce wait times when initially connecting. This still runs checks
such as whether you still want additional peers.

A test case has been created, which fails if this change is not included.

* Removed unnecessary onStart & onStop calls in reactor

* Refactor OnStart & OnStop in reactor

* Removed redundant OnStart func in reactor

Refs #1706

Currently the top level directory contains basically all of the code
for the crypto package. This PR moves the crypto code into submodules
in a similar manner to what `golang/x/crypto` does. This improves code
organization.

Ref discussion: https://github.com/tendermint/tendermint/pull/1966

Closes #1956

Refs #1720

* Add private peer ID tracking to AddrBook

* Remove private peer tracking/blocking from pex

* debug level msg when we fail to add private address

This commit switches all usage of math/rand to cmn's rand. The only
exceptions are within the random file itself, the tools package, and the
crypto package. In tools you don't want it to lock between the go-routines.
The crypto package doesn't use it so the crypto package have no other
dependencies within tendermint/tendermint for easier portability.

Crypto/rand usage is unadjusted.

Closes #1343

This reverts commit d02c5d1e30.

Refs #646

Refs #646

* new config option for external address to advertise
* if blank, defaults to best guess from listener
* if laddr ip address is also blank, default to IPv4

Fixes #1830

remember that PeerSet#Get can return nil

* config: rename skip_upnp to upnp

Change default option to enable upnp.

Closes #1806

* doc updates

- fix comment and set UPNP to false in TestP2PConfig
- add UPNP to config template
- update changelog

This reverts commit 96a3502

As both configs are concerned with the p2p packaage and PeerConfig is
only used inside of the package there is no good reason to keep the
couple of fields separate, therefore it is collapsed into the more
general P2PConifg. This is a stepping stone towards a setup where the
components inside of p2p do not have any knowledge about the config.

follow-up to #1325