Merge #5375

5375: Paginate bans (partially fixes #3691) r=Learath2 a=def-

20 elements per page, we have too many bot bans
![Screenshot 2022-06-08 at 23 53 16](https://user-images.githubusercontent.com/2335377/172724048-70d99f57-4e3c-451a-ada3-96affdf7cd6c.png)

## Checklist

- [x] Tested the change ingame
- [x] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: Dennis Felsing <dennis@felsin9.de>

src/engine/client/client.cpp

@@ -4241,7 +4241,7 @@ void CClient::RegisterCommands()
 	m_pConsole->Register("kick", "i[id] ?r[reason]", CFGFLAG_SERVER, 0, 0, "Kick player with specified id for any reason");
 	m_pConsole->Register("ban", "s[ip|id] ?i[minutes] r[reason]", CFGFLAG_SERVER, 0, 0, "Ban player with ip/id for x minutes for any reason");
 	m_pConsole->Register("unban", "r[ip]", CFGFLAG_SERVER, 0, 0, "Unban ip");
-	m_pConsole->Register("bans", "", CFGFLAG_SERVER, 0, 0, "Show banlist");
+	m_pConsole->Register("bans", "?i[page]", CFGFLAG_SERVER, 0, 0, "Show banlist (page 0 by default, 20 entries per page)");
 	m_pConsole->Register("status", "?r[name]", CFGFLAG_SERVER, 0, 0, "List players containing name or all players");
 	m_pConsole->Register("shutdown", "", CFGFLAG_SERVER, 0, 0, "Shut down");
 	m_pConsole->Register("record", "r[file]", CFGFLAG_SERVER, 0, 0, "Record to a file");

src/engine/shared/netban.cpp

@@ -309,7 +309,7 @@ void CNetBan::Init(IConsole *pConsole, IStorage *pStorage)
 	Console()->Register("unban", "s[ip|entry]", CFGFLAG_SERVER | CFGFLAG_MASTER | CFGFLAG_STORE, ConUnban, this, "Unban ip/banlist entry");
 	Console()->Register("unban_range", "s[first ip] s[last ip]", CFGFLAG_SERVER | CFGFLAG_MASTER | CFGFLAG_STORE, ConUnbanRange, this, "Unban ip range");
 	Console()->Register("unban_all", "", CFGFLAG_SERVER | CFGFLAG_MASTER | CFGFLAG_STORE, ConUnbanAll, this, "Unban all entries");
-	Console()->Register("bans", "", CFGFLAG_SERVER | CFGFLAG_MASTER | CFGFLAG_STORE, ConBans, this, "Show banlist");
+	Console()->Register("bans", "?i[page]", CFGFLAG_SERVER | CFGFLAG_MASTER, ConBans, this, "Show banlist (page 0 by default, 20 entries per page)");
 	Console()->Register("bans_save", "s[file]", CFGFLAG_SERVER | CFGFLAG_MASTER | CFGFLAG_STORE, ConBansSave, this, "Save banlist in a file");
 }
 
@@ -503,16 +503,28 @@ void CNetBan::ConBans(IConsole::IResult *pResult, void *pUser)
 {
 	CNetBan *pThis = static_cast<CNetBan *>(pUser);
 
+	int Page = pResult->NumArguments() > 0 ? pResult->GetInteger(0) : 0;
+	static const int EntriesPerPage = 20;
+
 	int Count = 0;
 	char aBuf[256], aMsg[256];
-	for(CBanAddr *pBan = pThis->m_BanAddrPool.First(); pBan; pBan = pBan->m_pNext)
+	int i = 0;
+	for(CBanAddr *pBan = pThis->m_BanAddrPool.First(); pBan; pBan = pBan->m_pNext, i++)
 	{
+		if(i < Page * EntriesPerPage || i >= (Page + 1) * EntriesPerPage)
+		{
+			continue;
+		}
 		pThis->MakeBanInfo(pBan, aBuf, sizeof(aBuf), MSGTYPE_LIST);
 		str_format(aMsg, sizeof(aMsg), "#%i %s", Count++, aBuf);
 		pThis->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "net_ban", aMsg);
 	}
-	for(CBanRange *pBan = pThis->m_BanRangePool.First(); pBan; pBan = pBan->m_pNext)
+	for(CBanRange *pBan = pThis->m_BanRangePool.First(); pBan; pBan = pBan->m_pNext, i++)
 	{
+		if(i < Page * EntriesPerPage || i >= (Page + 1) * EntriesPerPage)
+		{
+			continue;
+		}
 		pThis->MakeBanInfo(pBan, aBuf, sizeof(aBuf), MSGTYPE_LIST);
 		str_format(aMsg, sizeof(aMsg), "#%i %s", Count++, aBuf);
 		pThis->Console()->Print(IConsole::OUTPUT_LEVEL_STANDARD, "net_ban", aMsg);