feat: add onion_seeds to seed creation; do seed creation (#5866)

## Issue being fixed or feature implemented
We did not previously ship any onion seeds. This results in people
needing to use `addnode` in order to actually get connected

## What was done?
Modified seed creation process to handle a list of onion seeds.

## How Has This Been Tested?
Running with and without onlynet=onion and with dnsseed=0 and deleting
peers.dat

## Breaking Changes
None

## Checklist:
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_

contrib/seeds/README.md

@@ -5,9 +5,20 @@ Utility to generate the seeds.txt list that is compiled into the client
 
 The seeds compiled into the release are created from the current protx list, like this:
 
-    dash-cli protx list valid 1 1716101 > protx_list.json
-    python3 makeseeds.py < protx_list.json > nodes_main.txt
-    python3 generate-seeds.py . > ../../src/chainparamsseeds.h
+```bash
+dash-cli protx list valid 1 2018966 > protx_list.json
+
+# Make sure the onion seeds still work!
+while IFS= read -r line
+do
+  address=$(echo $line | cut -d':' -f1)
+  port=$(echo $line | cut -d':' -f2)
+  nc -v -x 127.0.0.1:9050 -z $address $port
+done < "onion_seeds.txt"
+
+python3 makeseeds.py protx_list.json onion_seeds.txt > nodes_main.txt
+python3 generate-seeds.py . > ../../src/chainparamsseeds.h
+```
 
 Make sure to use a recent block height in the "protx list" call. After updating, create a PR and
 specify which block height you used so that reviewers can re-run the same commands and verify

contrib/seeds/makeseeds.py

@@ -4,6 +4,7 @@
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 #
 # Generate seeds.txt from "protx list valid 1"
+# then create onion_seeds.txt and add some active onion services to it; check tor.md for some
 #
 
 import re
@@ -25,16 +26,15 @@
 
 PATTERN_IPV4 = re.compile(r"^((\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})):(\d+)$")
 PATTERN_IPV6 = re.compile(r"^\[([0-9a-z:]+)\]:(\d+)$")
-PATTERN_ONION = re.compile(r"^([abcdefghijklmnopqrstuvwxyz234567]{16}\.onion):(\d+)$")
+PATTERN_ONION = re.compile(r"^([a-z2-7]{56}\.onion):(\d+)$")
 
-def parseip(ip):
-    m = PATTERN_IPV4.match(ip)
-    sortkey = None
+def parseip(ip_in):
+    m = PATTERN_IPV4.match(ip_in)
     ip = None
     if m is None:
-        m = PATTERN_IPV6.match(ip)
+        m = PATTERN_IPV6.match(ip_in)
         if m is None:
-            m = PATTERN_ONION.match(ip)
+            m = PATTERN_ONION.match(ip_in)
             if m is None:
                 return None
             else:
@@ -135,8 +135,8 @@ def filterbyasn(ips, max_per_asn, max_total):
                 continue
             asn_count[asn] += 1
             result.append(ip)
-        except:
-            sys.stderr.write('ERR: Could not resolve ASN for "' + ip['ip'] + '"\n')
+        except Exception as e:
+            sys.stderr.write(f'ERR: Could not resolve ASN for {ip["ip"]}: {e}\n')
 
     # Add back Onions
     result.extend(ips_onion)
@@ -150,6 +150,10 @@ def main():
     else:
         mns = json.load(sys.stdin)
 
+    if len(sys.argv) > 2:
+        with open(sys.argv[2], 'r', encoding="utf8") as f:
+            onions = f.read().split('\n')
+
     # Skip PoSe banned MNs
     mns = [mn for mn in mns if mn['state']['PoSeBanHeight'] == -1]
     # Skip MNs with < 10000 confirmations
@@ -160,10 +164,14 @@ def main():
     mns = filtermultipayoutaddress(mns)
     # Extract IPs
     ips = [parseip(mn['state']['service']) for mn in mns]
+    for onion in onions:
+        parsed = parseip(onion)
+        if parsed is not None:
+            ips.append(parsed)
     # Look up ASNs and limit results, both per ASN and globally.
     ips = filterbyasn(ips, MAX_SEEDS_PER_ASN, NSEEDS)
     # Sort the results by IP address (for deterministic output).
-    ips.sort(key=lambda x: (x['net'], x['sortkey']))
+    ips.sort(key=lambda x: (x['net'], x['sortkey']), reverse=True)
 
     for ip in ips:
         if ip['net'] == 'ipv6':