sendmmsg: address family not supported by protocol

[sp41mer]

I've tried to deploy swgp-go and encountered the following issue:

WARN Failed to write swgpPacket to proxyConn {"client": "client", "listenAddress": ":20222", "clientAddress": "<home ip v4>:51820", "proxyAddress": "<remote ip v4>:20220", "error": "sendmmsg: address family not supported by protocol"}

My client config is:

{
"clients": [
        {
            "name": "client",
            "wgListenNetwork": "",
            "wgListen": ":20222",
            "wgFwmark": 0,
            "wgTrafficClass": 0,
            "proxyEndpointNetwork": "",
            "proxyEndpoint": "<remote-ip-v4>:20220",
            "proxyConnListenNetwork": "",
            "proxyConnListenAddress": "",
            "proxyMode": "zero-overhead",
            "proxyPSK": "sAe5RvzLJ3Q0Ll88QRM1N01dYk83Q4y0rXMP1i4rDmI=",
            "proxyFwmark": 0,
            "proxyTrafficClass": 0,
            "mtu": 1500,
            "batchMode": "",
            "relayBatchSize": 0,
            "mainRecvBatchSize": 0,
            "sendChannelCapacity": 0
        }
    ]
}

My server config is:

{
  "servers": [
      {
          "proxyListen": ":20220",
          "proxyMode": "zero-overhead",
          "proxyPSK": "sAe5RvzLJ3Q0Ll88QRM1N01dYk83Q4y0rXMP1i4rDmI=",
          "wgEndpoint": "<remote-ip-v4>:51820",
          "wgFwmark": 0,
          "mtu": 1500,
          "proxyFwmark": 0
      }
  ]
}

[database64128]

1. What's the version of your Linux kernel?
2. What's the net.ipv6.bindv6only sysctl value on your system?
3. Does changing "proxyConnListenNetwork" to "udp4" fix the issue for you?

[sp41mer]

1. What's the version of your Linux kernel?

I have Ubuntu 22.04 x64 with 5.15.0-60-generic kernel version

~/wgp# uname -r
5.15.0-60-generic

I've also tried the same for Debian 12 x64 with 6.1.0-9-amd64 kernel version

2. What's the net.ipv6.bindv6only sysctl value on your system?

I couldn't find this value, there is the only thing related to IPv6 I was able to find on my machine:

CONFIG_IPV6=y
CONFIG_IPV6_ROUTER_PREF=y
CONFIG_IPV6_ROUTE_INFO=y
# CONFIG_IPV6_OPTIMISTIC_DAD is not set
CONFIG_IPV6_MIP6=m
CONFIG_IPV6_ILA=m
CONFIG_IPV6_VTI=m
CONFIG_IPV6_SIT=m
CONFIG_IPV6_SIT_6RD=y
CONFIG_IPV6_NDISC_NODETYPE=y
CONFIG_IPV6_TUNNEL=m
CONFIG_IPV6_GRE=m
CONFIG_IPV6_FOU=m
CONFIG_IPV6_FOU_TUNNEL=m
CONFIG_IPV6_MULTIPLE_TABLES=y
CONFIG_IPV6_SUBTREES=y
CONFIG_IPV6_MROUTE=y
CONFIG_IPV6_MROUTE_MULTIPLE_TABLES=y
CONFIG_IPV6_PIMSM_V2=y
CONFIG_IPV6_SEG6_LWTUNNEL=y
CONFIG_IPV6_SEG6_HMAC=y
CONFIG_IPV6_SEG6_BPF=y
# CONFIG_IPV6_RPL_LWTUNNEL is not set
CONFIG_IPV6_IOAM6_LWTUNNEL=y
CONFIG_MPTCP_IPV6=y
CONFIG_IP_VS_IPV6=y
CONFIG_NF_SOCKET_IPV6=m
CONFIG_NF_TPROXY_IPV6=m
CONFIG_NF_TABLES_IPV6=y
CONFIG_NFT_REJECT_IPV6=m
CONFIG_NFT_DUP_IPV6=m
CONFIG_NFT_FIB_IPV6=m
CONFIG_NF_FLOW_TABLE_IPV6=m
CONFIG_NF_DUP_IPV6=m
CONFIG_NF_REJECT_IPV6=m
CONFIG_NF_LOG_IPV6=m
CONFIG_IP6_NF_MATCH_IPV6HEADER=m
CONFIG_NF_DEFRAG_IPV6=m
CONFIG_6LOWPAN_NHC_IPV6=m
CONFIG_AF_RXRPC_IPV6=y

3. Does changing "proxyConnListenNetwork" to "udp4" fix the issue for you?

Nope, it didn't work for me

[database64128]

Interesting. I tried to mimic your config as much as possible, and it just won't reproduce. My kernel version is 6.9.9-arch1-1.

Did you build from the latest commit on the master branch? Can you try changing "batchMode" to "no"?

I couldn't find this value

Run sysctl net.ipv6.bindv6only. On my system, it returns:

net.ipv6.bindv6only = 0

[sp41mer]

Thank you! Setting "batchMode" to "no" resolved the issue

[database64128]

Glad to hear it helped, but I wouldn't say it's "resolved". The sendmmsg path, which is the default batchMode on Linux, currently does not work on systems with dual-stack IPv6 sockets disabled. That's why I asked you to check the sysctl value. IPv4-mapped IPv6 is enabled by default on Linux, and there really isn't any reason to disable it.

[database64128]

This should no longer be an issue after 26aed422a7ed9682787174023c2242ccc82a39e6. Can you update to the latest commit and see if it works for you without "batchMode": "no"?