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1- You store a Future _spreeTask on the Player level (your impro variable should be named _impro, btw). 2 - You cancel it and relaunch it on every kill : if (_spreeTask != null) _spreeTask.cancel(false); _spreeTask = ThreadPool.schedule(() -> _impro = 0, 60000L); Basically, if you kill someone, it will cancel current task and reschedule it with a fresh timer. If you want to avoid to make one task per Player, you can also handled it using a Manager (similar to multiple other timed stuff : pvp, random animation timer, or even movement in default L2J...), where you register all Players on a 1sec task manager and test each of those every second. -
DESCRIPTION This topic is part of a multi-part series. We'll try to get everything straight to the point in this guide, without unnecessary over-explanation. PART 1 [CLICK HERE] Work faster with a better terminal emulator. Use a better editor. Basic L2J server setup. Manage and secure your MySQL server. [!] PART 2 [THIS GUIDE] Secure your Linux server. Tuning system profiles. [!] Network performance tuning. [!] How to build and manage a firewall using iptables and conntrack - simplified version. [!] PART 3 [COMING SOON] Understanding and managing the OVH Firewall. [!] How to build and manage a firewall using iptables, conntrack, ipset and synproxy - advanced version. [!] Mitigating most of the DDoS attacks. [!] PART 4 [COMING SOON] What is a TCP 3-way handshake? What is the only protocol used by Lineage II? Monitor, adapt and mitigate a DDoS attack. [!] Plan B, what if everything else fails? [!] PART 5 [COMING SOON] What is a proxy and types of proxy. How to create a proxy. How to build a better firewall behind a proxy. [!] SECURE YOUR LINUX SERVER Create a new user account. We should never log into our server as root: adduser trance Give your new user account sudo rights: usermod -a -G sudo trance SECURE SSH CONNECTION We could use a SSH key instead SSH password authentication. The keys are usually stored into user's directory/.ssh/authorized_keys You can google how to generated a SSH key or you can simply use MobaXterm's: Upload the SSH key: ssh-copy-id trance@<ip_address> WARNING - First double check if you can successfully login via the SSH key before disabling the SSH password authentication. Now since we all have the same favorite editor nano, let's use it it to disable the SSH password authentication. nano /etc/ssh/sshd_config Change the following options to: PasswordAuthentication no PermitRootLogin no TUNING SYSTEM PROFILES Optimize the performance of a system by adjusting various device settings based on a variety of use case workloads. Install and enable. yum install tuned systemctl enable --now tuned You can see all available profiles with the following: tuned-adm list Available profiles: balanced - Ideal for systems that require a compromise between power saving and performance. desktop - Derived from the balanced profile. Provides faster response of interactive applications. throughput-performance - Tunes the system for maximum throughput. latency-performance - Ideal for server systems that require low latency at the expense of power consumption. network-latency - Derived from the latency-performance profile. It enables additional network tuning parameters to provide low network latency. network-throughput - Derived from the throughput-performance profile. Additional network tuning parameters are applied for maximum network throughput. powersave - Tunes the system for maximum power saving. oracle - Optimized for Oracle database loads based on the throughput-performance profile. virtual-guest - Tunes the system for maximum performance if it runs on a virtual machine. virtual-host - Tunes the system for maximum performance if it acts as a host for virtual machines. See currently running profile: tuned-adm active I recommend latency-performance or network-latency. You can choose a profile just like this: tuned-adm recommend network-latency Turn off tuned tuning activity with tuned-adm off. tuned-adm off NETWORK PERFORMANCE TUNING We'll have to touch the HOT spot, the kernel. If you think an OS can handle it all by default, you're wrong! We can view all your current kernel settings via: sysctl -a We can add our custom settings to be saved in the following config: nano /etc/sysctl.conf I've put all this together myself. You can google everything one by one if you'd like to know for what it is. I've added some useful comments. These values are well calculated, not randomly added. # General kernel.randomize_va_space = 0 net.core.netdev_max_backlog = 25000 net.core.rmem_max = 4136960 net.core.wmem_max = 4136960 net.ipv4.tcp_congestion_control = cubic net.ipv4.tcp_fin_timeout = 1 net.ipv4.tcp_limit_output_bytes = 131072 net.ipv4.tcp_low_latency = 0 net.ipv4.tcp_max_tw_buckets = 45000 net.ipv4.tcp_rmem = 4096 87380 4136960 net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_wmem = 4096 16384 4136960 # Desactivate the automatic conntrack helper assignment. net.netfilter.nf_conntrack_helper = 0 # Enable the use of syncookies when the syn backlog queue is full. net.ipv4.tcp_syncookies = 1 # SYNPROXY - This is necessary to have ACK packets (from 3WHS) marked as INVALID state. # Disable picking up already established connections. net.netfilter.nf_conntrack_tcp_loose = 0 # SYNPROXY - TCP timestamps as SYN cookies utilize this TCP option field. # Tells the kernel to use timestamps as defined in RFC 1323. net.ipv4.tcp_timestamps = 1 # Default size is calculated by dividing total memory # by 16384 to determine the number of buckets but the hash table will # never have fewer than 32 and limited to 16384 buckets. For systems # with more than 4GB of memory it will be 65536 buckets. net.netfilter.nf_conntrack_buckets = 500000 # SYNPROXY - it's recommended to do some conntrack entry tuning to increase the default 64K conn limit. # nf_conntrack_buckets * 4 net.netfilter.nf_conntrack_max = 2000000 # nf_conntrack_max / 4 # as reference only: echo 500000 > /sys/module/nf_conntrack/parameters/hashsize net.netfilter.nf_conntrack_tcp_timeout_established = 1800 # default 432000 (5 days); 1800 = 30 minutes net.netfilter.nf_conntrack_tcp_timeout_close = 10 # default: 10 net.netfilter.nf_conntrack_tcp_timeout_close_wait = 20 # default: 60 net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 30 # default: 120 net.netfilter.nf_conntrack_tcp_timeout_last_ack = 30 # default: 30 net.netfilter.nf_conntrack_tcp_timeout_syn_recv = 30 # default: 60 net.netfilter.nf_conntrack_tcp_timeout_syn_sent = 30 # default: 120 net.netfilter.nf_conntrack_tcp_timeout_time_wait = 20 # default: 120 And then... Applying all of the above: sysctl -p Running the following as well have it all set: echo 2000000 > /sys/module/nf_conntrack/parameters/hashsize echo 0 > /proc/sys/net/netfilter/nf_conntrack_helper Our conntrack can handle so many connections now! IPTABLES AND CONNTRACK Conntrack allows us to use NEW, ESTABLISHED, RELATED states in ipables for the incoming connections. So we need to store all that info! We need to disable and replace the firewalld with iptables: sudo yum remove firewalld -y sudo yum install iptables-services -y sudo yum install conntrack-tools -y sudo yum install ipset -y sudo yum install ipset-service -y sudo systemctl start iptables sudo systemctl start ip6tables sudo systemctl enable iptables sudo systemctl enable ip6tables The following commands will be used to flush the entire iptables every time we f*ck it up. iptables -P INPUT ACCEPT iptables -P FORWARD ACCEPT iptables -P OUTPUT ACCEPT iptables -t nat -F iptables -t nat -X iptables -t mangle -F iptables -t mangle -X iptables -t raw -F iptables -t raw -X iptables -F iptables -X iptables -t filter -P INPUT ACCEPT iptables -t filter -P FORWARD ACCEPT iptables -t filter -P OUTPUT ACCEPT iptables -t filter -F iptables -t filter -X service iptables save IPTABLES' CHAINS Chains - A chain is a string of rules. When a packet is received, iptables finds the appropriate table, then runs it through the chain of rules until it finds a match. Rules - A rule is a statement that tells the system what to do with a packet. Rules can block one type of packet, or forward another type of packet. To make it easier for us to understand how the chains in iptables work: You’ll find that most if not all guides on how to block DDoS attacks using iptables use the filter table and the INPUT chain for anti-DDoS rules. The issue with this approach is that the INPUT chain is only processed after the PREROUTING and FORWARD chains and therefore only applies if the packet doesn’t match any of these two chains. This causes a delay in the filtering of the packet which consumes resources. In conclusion, to make our rules as effective as possible, we need to move our anti-DDoS rules as far up the chains as possible. The first chain that can apply to a packet is the PREROUTING chain, so ideally we’ll want to filter the bad packets in this chain already. THE ACTUAL BASIC RULES We can use the following command to see all rules in a particular table: iptables -t <table_name> -L Like iptables -t mangle -L or simply iptables -L for the default table a.k.a. the FILTER table. MANGLE TABLE PREROUTING Like it was described above, we need to save resources. So we'll have the following basic rules up in the mangle table. 1. Drop INVALID packets, which means the incoming connection is neither NEW, RELATED, or ESTABLISHED. iptables -t mangle -A PREROUTING -m conntrack --ctstate INVALID -j DROP 2. Drop the TCP packet if it's NEW and NOT a SYN. A TCP 3-way handshake should always start with a SYN. So the attacker can't exploit that. iptables -t mangle -A PREROUTING -p tcp ! --syn -m conntrack --ctstate NEW -j DROP 3. Drop SYN packets with weird MSS value iptables -t mangle -A PREROUTING -p tcp -m conntrack --ctstate NEW -m tcpmss ! --mss 536:65535 -j DROP 4. Block packets with bogus TCP flags - basically different set of unusual flags. iptables -t mangle -A PREROUTING -p tcp --tcp-flags ACK,FIN FIN -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ACK,PSH PSH -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ACK,URG URG -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags FIN,RST FIN,RST -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags SYN,RST SYN,RST -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ALL ALL -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ALL NONE -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ALL FIN,PSH,URG -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ALL SYN,FIN,PSH,URG -j DROP iptables -t mangle -A PREROUTING -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP 5. Block spoofed packets - no explanation is needed I guess. iptables -t mangle -A PREROUTING -s 224.0.0.0/3 -j DROP iptables -t mangle -A PREROUTING -s 169.254.0.0/16 -j DROP iptables -t mangle -A PREROUTING -s 172.16.0.0/12 -j DROP iptables -t mangle -A PREROUTING -s 192.0.2.0/24 -j DROP iptables -t mangle -A PREROUTING -s 192.168.0.0/16 -j DROP iptables -t mangle -A PREROUTING -s 10.0.0.0/8 -j DROP iptables -t mangle -A PREROUTING -s 0.0.0.0/8 -j DROP iptables -t mangle -A PREROUTING -s 240.0.0.0/5 -j DROP iptables -t mangle -A PREROUTING -s 127.0.0.0/8 ! -i lo -j DROP FILTER TABLE The next table we'll use is the one most people use. Like its name, we filter stuff in here. INPUT - incoming connections 1. Unlimited traffic on (local) loopback iptables -A INPUT -i lo -j ACCEPT 2. We no longer need to filter connections that are already ESTABLISHED. iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT 3. Allowing OVH's Gateway, DNS and NTP servers. So we avoid clock sync issues and such. iptables -A INPUT -s 198.244.200.254 -j ACCEPT iptables -A INPUT -s cdns.ovh.net -j ACCEPT iptables -A INPUT -s ntp0.ovh.net -j ACCEPT 4A. Next step we need to allow access to ourselves via SSH. Assuming my IP is 51.10.10.10. iptables -A INPUT -p tcp -m tcp -s 51.10.10.10 --dport 22 -m conntrack --ctstate NEW -j ACCEPT 4B. If my Home IP is changing dynamically, most of the time it stays in the same CIDR - 51.10.10.0/24 from 51.10.10.0 to 51.10.10.255 or 51.10.0.0/16 from 51.10.0.0 to 51.10.255.255. iptables -A INPUT -p tcp -m tcp -s 51.10.10.0/24 --dport 22 -m conntrack --ctstate NEW -j ACCEPT 4C. The best option is to have a VPN with a Dedicated IP (or a static IP at Home) and to allow that IP to access it all. iptables -A INPUT -p tcp -m tcp -s 51.10.10.10/32 -m conntrack --ctstate NEW -j ACCEPT 5A. Allow everyone to access the Login and Game servers on their specific ports. iptables -A INPUT -p tcp -m tcp --dport 2106 -m conntrack --ctstate NEW -j ACCEPT iptables -A INPUT -p tcp -m tcp --dport 7777 -m conntrack --ctstate NEW -j ACCEPT 5B. We can add multiple ports in a rule though. iptables -A INPUT -p tcp -m tcp -m multiport --dports 2106,7777 -m conntrack --ctstate NEW -j ACCEPT OUTPUT - from the machine outside 1. Unlimited traffic on (local) loopback iptables -A OUTPUT -o lo -j ACCEPT 2. We no longer need to filter connections that are already ESTABLISHED. iptables -A OUTPUT -m conntrack --ctstate ESTABLISHED -j ACCEPT 3. Allow the response to the SYN for the 3-way handshake before the connection is marked as ESTABLISHED. iptables -A OUTPUT -p tcp -m tcp --tcp-flags ALL ACK,SYN -j ACCEPT 3. Allowing OVH's Gateway, DNS and NTP servers. So we avoid clock sync issues and such. iptables -A OUTPUT -d 198.244.200.254 -j ACCEPT iptables -A OUTPUT -d cdns.ovh.net -j ACCEPT iptables -A OUTPUT -d ntp0.ovh.net -j ACCEPT 4. Allow OS updates and Vote reward. iptables -A OUTPUT -p tcp -m tcp -m multiport --dports 80,443 -m conntrack --ctstate NEW -j ACCEPT 5. Log output dropped packets; it's good for debugging to see why our server can't access something. You'll see it in the kernel logs. You can do the same for INPUT if you'd like to see what you do wrong - be aware of the spam! iptables -A OUTPUT -m limit --limit 1/second --limit-burst 5 -j LOG --log-prefix "output:drop: " --log-level 4 You can see kernel logs the same way you'd watch the Game Server console. tail -f /var/log/messages Tips and tricks: See the rules and their numbers on the mangle table: iptables -t mangle -L --line-number See the rules and their numbers on the filter table: iptables -t -L --line-number Delete a rule using the line number on the mangle table: iptables -t mangle -D PREROUTING 69 Delete a rule using the line number on the filter table: iptables -D INPUT 69 We'll get into more advanced and complicated firewall practices in the next part! SAVE ALL I'm pretty sure this is different on other distros. You may even create a list and always store all your rules in there, and then add that to the startup. service iptables save CREDITS Give me credits if you share it anywhere else, including my Discord and MxC topic's URL. Discord: Trance#0694 -
oke but how to make this 2 work auto spoil sweep if you kill a mob -
Akumu has a publicly available patcher that patches a lot on its own. So before ordering services, you need to try to patch it and not pay, which can be done for free, but the translation of labor cannot be done by yourself.Akumu has a publicly available patcher that patches a lot on its own. So before ordering services, you need to try to patch it and not pay, which can be done for free, but the translation of labor cannot be done by yourself. But finding the 162 protocol client itself is quite difficult. -
We have dates for Open Beta Testing and Official launch date set in stone! Open Beta Testing: 2023-02-17 GMT-3 19:00 OFFICIAL Launch: 2023-02-24 GMT-3 19:00 Until then we are going to be working on the server, balancing, checking a lot of stuff and making sure everything is perfectly well set for OBT and especially official launch. In upcoming days we will finalize marketing campaign that will take effect in facebook/google ads, forum banners, pinned topics and such. Website will be also reworked to make it a bit less complicated and with less information than it is now. Until OBT we will be sharing sneak peaks so the community can take a look at what they can expect, won't give the full picture as that wouldn't be interesting Thank you everyone for supporting the project and continuing to do so, we can promise that you won't bet bored as we will be bringing a lot of stuff weekly to the players! Little sneak peak of sophisticated quest system where you will be able to get rewards for completing tasks:
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