chaincfg: introduce Seeder

Seeder identifies the hostname as a seeder.

chaincfg/mainnetparams.go

@@ -347,5 +347,10 @@ func MainNetParams() *Params {
 		OrganizationPkScript:        hexDecode("a914f5916158e3e2c4551c1796708db8367207ed13bb87"),
 		OrganizationPkScriptVersion: 0,
 		BlockOneLedger:              tokenPayouts_MainNetParams(),
+
+		seeders: []string{
+			"mainnet-seed-1.decred.org",
+			"mainnet-seed-2.decred.org",
+		},
 	}
 }

chaincfg/params.go

@@ -454,6 +454,10 @@ type Params struct {
 	// block height 1. If there are no payouts to be given, set this
 	// to an empty slice.
 	BlockOneLedger []TokenPayout
+
+	// seeders defines a list of seeders for the network that are used
+	// as one method to discover peers.
+	seeders []string
 }
 
 // HDPrivKeyVersion returns the hierarchical deterministic extended private key
@@ -656,3 +660,8 @@ func (p *Params) LatestCheckpointHeight() int64 {
 	}
 	return p.Checkpoints[len(p.Checkpoints)-1].Height
 }
+
+// Seeders returns the list of HTTP seeders.
+func (p *Params) Seeders() []string {
+	return p.seeders
+}

chaincfg/regnetparams.go

@@ -353,5 +353,7 @@ func RegNetParams() *Params {
 		OrganizationPkScript:        hexDecode("a9146913bcc838bd0087fb3f6b3c868423d5e300078d87"),
 		OrganizationPkScriptVersion: 0,
 		BlockOneLedger:              tokenPayouts_RegNetParams(),
+
+		seeders: nil, // NOTE: There must NOT be any seeds.
 	}
 }

chaincfg/simnetparams.go

@@ -210,5 +210,7 @@ func SimNetParams() *Params {
 		OrganizationPkScript:        hexDecode("a914cbb08d6ca783b533b2c7d24a51fbca92d937bf9987"),
 		OrganizationPkScriptVersion: 0,
 		BlockOneLedger:              tokenPayouts_SimNetParams(),
+
+		seeders: nil, // NOTE: There must NOT be any seeds.
 	}
 }

chaincfg/testnetparams.go

@@ -242,5 +242,10 @@ func TestNet3Params() *Params {
 		OrganizationPkScript:        hexDecode("a914d585cd7426d25b4ea5faf1e6987aacfeda3db94287"),
 		OrganizationPkScriptVersion: 0,
 		BlockOneLedger:              tokenPayouts_TestNet3Params(),
+
+		seeders: []string{
+			"testnet-seed-1.decred.org",
+			"testnet-seed-2.decred.org",
+		},
 	}
 }