Bug: WARP WireGuard fails on IPv4-only VPS — IPv6 address removal sed rule doesn't work #5416

Bug Description

On IPv4-only VPS (no IPv6 address, net.ipv6.conf.all.disable_ipv6 = 1), the WARP WireGuard tunnel (wg-quick@warp) fails to start with:

RTNETLINK answers: Permission denied

This causes the entire WARP interface to be torn down, making WARP completely non-functional.

Root Cause

File: other/warp/wireguard/run.sh.j2, line 43

The generate_warp_config() function has logic to detect IPv6-disabled systems and strip IPv6 addresses from wgcf-profile.conf. However, the sed rule is incorrect:

# Current (broken)
sed -i '/Address = [0-9a-fA-F:]\{4,\}/s/^/# /' wgcf-profile.conf

This rule is designed to comment out lines containing IPv6 addresses, but wgcf generate produces output where IPv4 and IPv6 are on the same line:

Address = 172.16.0.2/32, 2606:4700:110:8961:16c9:4520:593:6a9e/128

The sed pattern only matches lines where the Address value starts with an IPv6-looking pattern. Since the line starts with 172.16.0.2 (IPv4), the rule doesn't match, and the IPv6 address remains in the config.

When wg-quick@warp tries to bring up the interface, it attempts ip -6 address add 2606:4700:.../128 dev warp, which fails because IPv6 is disabled at the kernel level. wg-quick then tears down the entire interface as a cleanup step.

Reproduction

1. Deploy Hiddify Manager on an IPv4-only VPS (e.g., RackNerd KVM with IPv6 disabled via sysctl)
2. Enable WARP in Hiddify panel (warp_mode != "disable")
3. Run install.sh or wait for daily auto-update
4. wg-quick@warp fails to start

Environment

• Hiddify Manager v12.3.0
• Ubuntu 22.04, kernel 5.15.0-46-generic
• VPS: IPv4-only (no IPv6 assigned), net.ipv6.conf.all.disable_ipv6 = 1
• wgcf generates configs with both IPv4 and IPv6 addresses

Suggested Fix

Replace the sed rule in other/warp/wireguard/run.sh.j2 line 43 to strip the IPv6 portion from the combined Address line:

# Replace this:
sed -i '/Address = [0-9a-fA-F:]\{4,\}/s/^/# /' wgcf-profile.conf

# With this:
sed -i 's/, [0-9a-fA-F:]*\/[0-9]*//' wgcf-profile.conf

This removes the , <ipv6-address>/<prefix> portion from the Address line, leaving only the IPv4 address:

# Before:
Address = 172.16.0.2/32, 2606:4700:110:8961:16c9:4520:593:6a9e/128

# After:
Address = 172.16.0.2/32

Workaround

Manually edit /etc/wireguard/warp.conf to remove the IPv6 address:

sed -i 's/, 2606:[^ ]*//' /etc/wireguard/warp.conf
systemctl restart wg-quick@warp

Note: This workaround will be overwritten on the next Hiddify auto-update that regenerates WARP config.