sctp sk_reuseport allows multiple socks to listen on the same port and addresses, as long as these socks have the same uid. This works pretty much as TCP/UDP does, the only difference is that sctp is multi-homing and all the bind_addrs in these socks will have to completely matched, otherwise listen() will return err.
The below is when 5 sockets are listening on 172.16.254.254:6400 on a server, 26 sockets on a client connect to 172.16.254.254:6400 and each may be processed by a different socket on the server which is selected by hash(lport, pport, paddr) in reuseport_select_sock(): # ss --sctp -nn State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 10 172.16.254.254:6400 *:* `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.2.1:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.2.4:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.3.3:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.3.4:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.5.2:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.5.3:1234 LISTEN 0 10 172.16.254.254:6400 *:* `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.1.3:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.1.4:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.3.2:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.4.1:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.4.2:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.4.3:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.4.4:1234 LISTEN 0 10 172.16.254.254:6400 *:* `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.1.2:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.3.5:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.4.5:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.253.253:1234 LISTEN 0 10 172.16.254.254:6400 *:* `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.2.2:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.2.3:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.5.4:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.5.5:1234 LISTEN 0 10 172.16.254.254:6400 *:* `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.1.1:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.1.5:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.2.5:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.3.1:1234 `- ESTAB 0 0 172.16.254.254%eth1:6400 172.16.5.1:1234 Xin Long (3): sctp: do reuseport_select_sock in __sctp_rcv_lookup_endpoint sctp: add sock_reuseport for the sock in __sctp_hash_endpoint sctp: process sk_reuseport in sctp_get_port_local include/net/sctp/sctp.h | 2 +- include/net/sctp/structs.h | 6 ++- net/core/sock_reuseport.c | 1 + net/sctp/bind_addr.c | 28 ++++++++++ net/sctp/input.c | 129 ++++++++++++++++++++++++++++++++------------- net/sctp/socket.c | 49 +++++++++++------ 6 files changed, 162 insertions(+), 53 deletions(-) -- 2.1.0
