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Example: Use Socket Api in WAMR
The related code/working directory of this example resides in directory {WAMR_DIR}/samples/socket-api
This sample demonstrates how to use WAMR socket-api to develop wasm network applications. Two wasm applications are provided: tcp-server and tcp-client, and this sample demonstrates how they communicate with each other.
Please install WASI SDK, download the wasi-sdk release and extract the archive to default path
/opt/wasi-sdk. And install wabt, download the wabt release and extract the archive to default path /opt/wabtmkdir build
cd build
cmake ..
make
iwasm and the following Wasm modules (along with their corresponding native version) will be generated:addr_resolve.wasm,addr_resolvesend_recv.wasm,send_recvsocket_opts.wasm,socket_optstcp_client.wasm,tcp_clienttcp_server.wasm,tcp_serverudp_client.wasm,udp_clientudp_server.wasm,udp_server
Note that iwasm is built with libc-wasi and lib-pthread enabled.
Start the tcp server, which opens port 1234 and waits for clients to connect.
cd build
./iwasm --addr-pool=0.0.0.0/15 tcp_server.wasm
Start the tcp client, which connects the server and receives message.
cd build
./iwasm --addr-pool=127.0.0.1/15 tcp_client.wasm
The output of client is like:
[Client] Create socket
[Client] Connect socket
[Client] Client receive
[Client] 115 bytes received:
Buffer recieved:
Say Hi from the Server
Say Hi from the Server
Say Hi from the Server
Say Hi from the Server
Say Hi from the Server
[Client] BYE
send_recv.wasm contains a thread as a server and a thread as a client. They send and receive data via 127.0.0.1:1234.$ ./iwasm --addr-pool=127.0.0.1/0 ./send_recv.wasm
The output is:
Server is online ...
Client is running...
Start receiving.
Start sending.
Send 106 bytes successfully!
Receive 106 bytes successlly!
Data:
The stars shine down
It brings us light
Light comes down
To make us paths
It watches us
And mourns for us
socket_opts.wasm shows an example of getting and setting various supported socket options$ ./iwasm socket_opts.wasm
The output is:
[Client] Create TCP socket
[Client] Create UDP socket
[Client] Create UDP IPv6 socket
setsockopt SO_RCVTIMEO result is expected
getsockopt SO_RCVTIMEO result is expected
...
[Client] Close sockets
The
timeout_client.wasm and timeout_server.wasm examples demonstrate socket send and receive timeouts using the socket options. Start the server, then start the client.$ ./iwasm --addr-pool=0.0.0.0/15 timeout_server.wasm
The output is:
Wait for client to connect
Client connected, sleeping for 10s
Shuting down
$ ./iwasm --addr-pool=127.0.0.1/15 timeout_client.wasm
The output is:
Waiting on recv, which should timeout
Waiting on send, which should timeout
Success. Closing socket
The
multicast_client and multicast_server examples demonstrate receiving multicast packets in WASM. Start the client and then the server with a multicast IP address and port.$ ./iwasm --addr-pool=0.0.0.0/0,::/0 multicast_client.wasm <Multicast IP> <Port>
$ ./iwasm --addr-pool=0.0.0.0/0,::/0 multicast_client.wasm 224.0.0.1
$ ./iwasm --addr-pool=0.0.0.0/0,::/0 multicast_client.wasm FF02:113D:6FDD:2C17:A643:FFE2:1BD1:3CD2
The output should be
Joined multicast group. Waiting for datagram...
Reading datagram message...OK.
The message from multicast server is: "Test message"
$ ./multicast_server <Multicast IP> <Port>
$ ./multicast_server 224.0.0.1
$ ./multicast_server FF02:113D:6FDD:2C17:A643:FFE2:1BD1:3CD2
The output should be
Datagram sent
addr_resolve.wasm demonstrates the usage of resolving a domain name$ ./iwasm --allow-resolve=*.com addr_resolve.wasm github.com
The command displays the host name and its corresponding IP address:
Host: github.com
IPv4 address: 140.82.121.4 (TCP)
Start the UDP server, which opens port 1234 and waits for clients to send a message.
cd build
./iwasm --addr-pool=0.0.0.0/15 udp_server.wasm
Start the tcp client, which sends a message to the server and waits for the response.
cd build
./iwasm --addr-pool=127.0.0.1/15 udp_client.wasm
The output of client is like:
[Client] Create socket
[Client] Client send
[Client] Client receive
[Client] Buffer recieved: Hello from server
[Client] BYE
The output of the server is like:
[Server] Create socket
[Server] Bind socket
[Server] Wait for clients to connect ..
[Server] received 17 bytes from 127.0.0.1:60927: Hello from client
Last modified 7mo ago