- main reason being it's a burden to always define sentinel errors at global scope, wrap them with `%w` instead of using a string directly
- only use sentinel errors when it has to be checked using `errors.Is`
- replace all usage of these sentinel errors in `fmt.Errorf` with direct strings that were in the sentinel error
- exclude the sentinel error definition requirement from .golangci.yml
- update unit tests to use ContainersError instead of ErrorIs so it stays as a "not a change detector test" without requiring a sentinel error
- add option `IPV6_CHECK_ADDRESSESES=[2001:4860:4860::8888]:53,[2606:4700:4700::1111]:53`
- gluetun needs access to the addresses above through the host firewall, to test ipv6 support before setting up the vpn
- firewall log level is still fully controlled by `LOG_LEVEL`
- iptables log level defaults to `info` even if global log level is `debug` to minimize the amount of debug logs
- iptables log level is only set to debug if retro-compatible `FIREWALL_DEBUG=on` or if `FIREWALL_IPTABLES_LOG_LEVEL=debug`
- Fix#3179
- I believe specifying tcp4, tcp6 or tcp-client does not change anything versus tcp + remote ip address
- I believe specifying udp4 or udp6 does not change anything versus tcp + remote ip address
- Simplify firewall code to not account for tcp-client etc.
- restore if IPv4 set all policies fails
- fix deadlock when using iptables custom rules
- fix setting ipv6 rules when running runMixedIptablesInstruction
- all operations rollback on failure
- disabling the firewall means rolling back to its state before enabling it
- aligns with nftables atomicity feature
- this makes PMTUD TCP reliable
- this only works on kernels with the mark module
- on kernels without the mark module, the icmp pmtud mtu found is used
- Existing option `WIREGUARD_MTU` , if set, disables PMTUD and is used
- New option `PMTUD_ICMP_ADDRESSES=1.1.1.1,8.8.8.8` and `PMTUD_TCP_ADDRESSES=1.1.1.1:443,8.8.8.8:443`
- ICMP PMTUD now targets external-by-default IP addresses
- New TCP PMTUD (binary search only) as a second MTU confirmation and fallback mechanism.
- Force set TCP MSS to MTU - IP header - TCP base header - "magic 20 bytes" 🎆
- Fix#3108
- Alpine / iptables-legacy bug introduced in Alpine 3.22
- Alpine: what the hell? Stop introducing breaking changes in iptables on every god damn release!
Quentin McGaw