How to connect to sctp server running in docker container from the sctp client on host machine?

General
1

My host machine application is trying to establish a SCTP connection at port 38412 to a docker container which is running SCTP server at port 38412. I am mapping and publishing the ports but getting an error. My host application is timing out at the following check:

if (connect(fd, (struct sockaddr*)&myaddr,sizeof(myaddr))== -1){
	higLog("SCTP CLIENT connect failed, port %d, Error %s",
		port, strerror(errno));
	return -1;
}

Error Connection timed out

My DockerFile looks something like this.

FROM ubuntu:focal

ARG DEBIAN_FRONTEND=noninteractive

RUN apt-get update && \
	apt-get install -y \
    dialog \
    apt-utils \
    iputils-ping \
    inetutils-traceroute \
    iproute2 \
    curl \
    dnsutils \
    nano \
    build-essential \
    libcpprest-dev \
    libboost-all-dev \
    libssl-dev \
    cmake \
    libyaml-cpp-dev \
    libsctp1 \
    libsctp-dev \
    tre-agrep \
    libtre5 \
    libtre-dev \
    libhiredis-dev \
    gcovr \
    lcov \
    curl \
    make \
    binutils \
    libcurlpp-dev \
    libcurlpp0 \
    libjsoncpp-dev

COPY . $HOME/src/D1/Func
RUN cd src
RUN mkdir utility_library
RUN cd ..
RUN mv src/D1/Func/utility_library src/utility_library
WORKDIR "$HOME/src/D1/Func"
EXPOSE 80
CMD ["/bin/bash", "-c", "cmake .;make -j16;./build/bin/Func eth0"]

And running this container using the following docker-run command:

docker run --name con1 --net Network1 --ip 10.0.0.21 -p 127.0.0.1:38412:38412/sctp sourav/image1:1.0.0

Can I get some ideas on how to solve it ?

2

did you get any success? im in the same situation (opposite direction, server is in the network and i need to connect to the server from a container)

4

Same port no. mapping doesn’t work with sctp. Try different port no. for the container and host for the mapping. This change helped in solving my issue.

1 Like
5

faced with a similar situation and trying to ask for help - I realized that I really have no idea how docker interacts with iptables to do its’ magic. Unable to explain the problem - I spoke to my coach who recommended I build an isolated test case to demonstrate the issue.

+ cat /etc/docker/daemon.json
{ "userland-proxy": true }
++ docker ps -q
+ for i in $(docker ps -q)
+ docker rm -f 8ba2df66cf92
8ba2df66cf92
+ docker network prune -f
Deleted Networks:
mybr0

+ docker network create --driver=bridge --subnet=172.28.0.0/16 --ip-range=172.28.5.0/24 --gateway=172.28.5.254 mybr0
787b9bde508dba2261d74e5b9372bd35eb9ff7cfae89f436141feb309fb5ee78
+ tshark -i any -q sctp
+ sleep 1
+ docker run --rm --network mybr0 --ip 172.28.5.1 --publish 1234:1234/sctp -v /usr/lib64:/usr/lib64 -v /usr/bin/sctp_test:/usr/bin/sctp_test registry.access.redhat.com/ubi9/ubi sctp_test -H 172.28.5.1 -P 1234 -l -d 2
Running as user "root" and group "root". This could be dangerous.
Capturing on 'any'
local:addr=172.28.5.1, port=search-agent, family=2
seed = 1733813572

Starting tests...
	socket(SOCK_SEQPACKET, IPPROTO_SCTP)  ->  sk=3
	bind(sk=3, [a:172.28.5.1,p:search-agent])  --  attempt 1/10
	listen(sk=3,backlog=100)
Server: Receiving packets.
	recvmsg(sk=3) + netstat -laSnp
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
sctp                :::1234                                         LISTEN      57759/docker-proxy  
sctp                0.0.0.0:1234                                    LISTEN      57752/docker-proxy  
+ sctp_test -H 192.168.122.43 -P 4321 -h 192.168.122.43 -p 1234 -s -x 1 -d 2
remote:addr=192.168.122.43, port=search-agent, family=2
local:addr=192.168.122.43, port=rwhois, family=2
seed = 1733813573

Starting tests...
	socket(SOCK_SEQPACKET, IPPROTO_SCTP)  ->  sk=3
	bind(sk=3, [a:192.168.122.43,p:rwhois])  --  attempt 1/10
Client: Sending packets.(1/1)
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=371520400
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=1901294125
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=1788810168
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=933540669
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=386168570
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCVNotification: SCTP_ASSOC_CHANGE(COMMUNICATION_UP)
		(assoc_change: state=0, error=0, instr=10 outstr=10)
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563197 flags=0x1 ppid=1901294125
cumtsn=1341563197
	recvmsg(sk=3) (stream=0 flags=0x1 ppid=1460147230
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=209436834
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=405171373
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=1479754597
	sendmsg(sk=3, assoc=0)    1 bytes.
	  SNDRCV(stream=0 flags=0x1 ppid=936625727
	close(sk=3)
Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563198 flags=0x1 ppid=1788810168
cumtsn=1341563198
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563199 flags=0x1 ppid=933540669
cumtsn=1341563199
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563200 flags=0x1 ppid=386168570
cumtsn=1341563200
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563201 flags=0x1 ppid=1460147230
cumtsn=1341563201
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563202 flags=0x1 ppid=209436834
cumtsn=1341563202
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563203 flags=0x1 ppid=405171373
cumtsn=1341563203
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563204 flags=0x1 ppid=1479754597
cumtsn=1341563204
	recvmsg(sk=3) Data 1 bytes. First 1 bytes: <empty> text[0]=0
	  SNDRCV(stream=0 ssn=0 tsn=1341563205 flags=0x1 ppid=936625727
cumtsn=1341563205
	recvmsg(sk=3) Notification: SCTP_ASSOC_CHANGE(SHUTDOWN_COMPLETE)
		(assoc_change: state=3, error=0, instr=0 outstr=0)
	recvmsg(sk=3) 8.5.1   SCTP 208 DATA DATA DATA DATA DATA DATA DATA DATA 
   52 184.296948061 192.168.122.43 → 172.28.5.1   SCTP 208 DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) 
   53 184.296960905   172.28.5.1 → 192.168.122.43 SCTP 64 SACK 
   54 184.296960905   172.28.5.1 → 192.168.122.43 SCTP 64 SACK 
   55 184.296992493 192.168.122.43 → 172.28.5.1   SCTP 56 SHUTDOWN 
   56 184.296994564 192.168.122.43 → 172.28.5.1   SCTP 56 SHUTDOWN 
   57 184.297000952   172.28.5.1 → 192.168.122.43 SCTP 52 SHUTDOWN_ACK 
   58 184.297000952   172.28.5.1 → 192.168.122.43 SCTP 52 SHUTDOWN_ACK 
   59 184.297010138 192.168.122.43 → 172.28.5.1   SCTP 52 SHUTDOWN_COMPLETE 
   60 184.297022829 192.168.122.43 → 172.28.5.1   SCTP 52 SHUTDOWN_COMPLETE 
   61 229.266328325 192.168.122.43 → 172.28.5.1   SCTP 84 INIT 
   62 229.266335197 192.168.122.43 → 172.28.5.1   SCTP 84 INIT 
   63 229.266379559   172.28.5.1 → 192.168.122.43 SCTP 308 INIT_ACK 
   64 229.266379559   172.28.5.1 → 192.168.122.43 SCTP 308 INIT_ACK 
   65 229.266399935 192.168.122.43 → 172.28.5.1   SCTP 300 COOKIE_ECHO DATA 
   66 229.266402789 192.168.122.43 → 172.28.5.1   SCTP 300 COOKIE_ECHO DATA (retransmission) 
   67 229.266446197   172.28.5.1 → 192.168.122.43 SCTP 68 COOKIE_ACK SACK 
   68 229.266446197   172.28.5.1 → 192.168.122.43 SCTP 68 COOKIE_ACK SACK 
   69 229.266474789 192.168.122.43 → 172.28.5.1   SCTP 68 DATA 
   70 229.266477903 192.168.122.43 → 172.28.5.1   SCTP 68 DATA (retransmission) 
   71 229.266532280 192.168.122.43 → 172.28.5.1   SCTP 208 DATA DATA DATA DATA DATA DATA DATA DATA 
   72 229.266535147 192.168.122.43 → 172.28.5.1   SCTP 208 DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) DATA (retransmission) 
   73 229.266544529   172.28.5.1 → 192.168.122.43 SCTP 64 SACK 
   74 229.266544529   172.28.5.1 → 192.168.122.43 SCTP 64 SACK 
   75 229.266557710 192.168.122.43 → 172.28.5.1   SCTP 56 SHUTDOWN 
   76 229.266560039 192.168.122.43 → 172.28.5.1   SCTP 56 SHUTDOWN 
   77 229.266566416   172.28.5.1 → 192.168.122.43 SCTP 52 SHUTDOWN_ACK 
   78 229.266566416   172.28.5.1 → 192.168.122.43 SCTP 52 SHUTDOWN_ACK 
   79 229.266576215 192.168.122.43 → 172.28.5.1   SCTP 52 SHUTDOWN_COMPLETE 
   80 229.266583435 192.168.122.43 → 172.28.5.1   SCTP 52 SHUTDOWN_COMPLETE