Windows 8.1 Sockets

Consulting/Training
Windows 8.1 Sockets

Consulting/Training
consulting
Wintellect helps you build better software,
faster, tackling the tough projects and solving
the software and technology questions that
help you transform your business.
 Architecture, Analysis and Design
 Full lifecycle software development
 Debugging and Performance tuning
 Database design and development
training
Wintellect's courses are written and taught by
some of the biggest and most respected names
in the Microsoft programming industry.
 Learn from the best. Access the same
training Microsoft’s developers enjoy
 Real world knowledge and solutions on
both current and cutting edge
technologies
 Flexibility in training options – onsite,
virtual, on demand
Founded by top experts on Microsoft – Jeffrey Richter, Jeff Prosise, and John Robbins – we pull
out all the stops to help our customers achieve their goals through advanced software-based
consulting and training solutions.
who we are
About Wintellect

Consulting/Training
 Sockets, Simplified
 WebSockets
 UDP and TCP Sockets
 Proximity / NFC “Tap to Connect”
 Bluetooth and Wi-Fi Direct
 Recap
Agenda

Consulting/Training
 Covers full WinRT API
 Over 80 example
projects
 This presentation is
based on Chapter 10
 Full source online at
http://winrtexamples
.codeplex.com/
 Book available at
http://bit.ly/winrtxmpl
WinRT by Example

Consulting/Training
Sockets, Simplified
Byte

Consulting/Training
Sockets, Simplified
Byte Array

Consulting/Training
Sockets, Simplified
Stream
 Length (maybe)
 Position
 Read
 Write
 Seek

Consulting/Training
Sockets Are Specialized Streams

Consulting/Training
 Berkeley sockets released with Unix in 1983 (owned by
AT&T at the time) for “IPC” while I was writing my first
Commodore 64 programs in 6502 assembly
 Open licensing in 1989 (I had finally moved to IBM PC and
MS-DOS)
 POSIX API (Portable Operating System Interface) released
in 1988
 Windows Sockets API (WSA or Winsock) released in 1992 (I
graduated high school and discovered the Internet in
college) and later implemented for Windows
 Another F Ancillary Function Driver (AFD.sys) still exists to
this day
Sockets: A Brief History

Consulting/Training
 A way to communicate between end points
 Usually operate on streams, which are
abstractions over buffers that contain bytes
 But can be a datagram that has no connection
 A socket connection has two distinct end points
 An end point is a combination of an address and
a port
 End points can be hosted on the same machine,
or different machines
Sockets Recap

Consulting/Training
int main(void)
{
struct sockaddr_in stSockAddr;
int Res;
int SocketFD = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
if (-1 == SocketFD)
{
perror("cannot create socket");
exit(EXIT_FAILURE);
}
memset(&stSockAddr, 0, sizeof(stSockAddr));
stSockAddr.sin_family = AF_INET;
stSockAddr.sin_port = htons(1100);
Res = inet_pton(AF_INET, "192.168.1.1", &stSockAddr.sin_addr);
(void) shutdown(SocketFD, SHUT_RDWR);
close(SocketFD);
return EXIT_SUCCESS;
}
“The Old Days” (still valid 30 yrs. later)

Consulting/Training
 Sit on top of TCP (you’ll learn more about TCP
later)
 Operate over ports 80/443 by default (keeps
firewalls happy)
 Use HTTP for the initial “handshake”
 Provide full-duplex communications
 WinRT implementation allows for message-
based or stream-based
WebSockets

Consulting/Training
GET /info HTTP/1.1
HOST: 1.2.3.4
Upgrade: websocket
Connection: Upgrade
Origin: http://jeremylikness.com/
HTTP/1.1 101 Switching Protocols
Upgrade: websocket
Connection: Upgrade
WebSocket Handshake
Placing my call …
Accepting ….
Now it’s streams from here on out….

Consulting/Training
(a prime example… source code: http://bit.ly/1i5vB9p)
WebSockets

Consulting/Training
 Both are communication protocols for delivering
octet streams (bytes!)
 UDP is fire-and-forget (connectionless)
 Individual messages sent, i.e. “datagrams”
 Fast, lots of questions: DNS, DHCP, SNMP
 TCP is connection-oriented
 TCP is stream-based
 Slower, but reliable: HTTP, FTP, SMTP, Telnet
UDP and TCP

Consulting/Training
this.serverSocket = new StreamSocketListener();
this.serverSocket.ConnectionReceived +=
this.ServerSocketConnectionReceived;
await this.serverSocket.BindServiceNameAsync(ServiceName);
// can both read and write messages (full-duplex)
if (serverWriter == null)
{
serverWriter = new DataWriter(args.Socket.OutputStream);
serverReader = new DataReader(args.Socket.InputStream);
}
Server Listens for Connections

Consulting/Training
var hostName = new HostName("localhost");
this.clientSocket = new StreamSocket();
await this.clientSocket.ConnectAsync(hostName, ServiceName);
clientWriter = new DataWriter(this.clientSocket.OutputStream);
clientReader = new DataReader(this.clientSocket.InputStream);
// both client and server require long-running tasks to wait for
// messages and send them as needed
while (true)
{
var data = await GetStringFromReader(clientReader);
// do something with the data
}
Client “Dials In” to Chat

Consulting/Training
(a true adventure… source code: http://bit.ly/1j77rP3)
TCP Sockets

Consulting/Training
 Near Field Communications (NFC) is a standard for extremely low powered
communications typically very slow and over a very small distance, between devices
and/or smart tags
 NFC is capable of sending small bursts of information. However, “tap to connect” is a
powerful mechanism for establishing a hand-shake to open a stream over other,
longer range and faster protocols like Bluetooth and Wi-Fi Direct
 Windows Runtime exposes the Proximity APIs that provide a unified way to discover
nearby devices and a protocol-agnostic mechanism to connect
 Literally you can discover, handshake, etc. and WinRT will “hand-off” a socket that is
ready to use (you won’t even know if it is over Wi-Fi Direct or Bluetooth)
 Bluetooth = short wavelength wireless technology
 Wi-Fi Direct = peer to peer over Wi-Fi (wireless cards without requiring a wireless
access point or router)
NFC and Proximity

Consulting/Training
this.proximityDevice = ProximityDevice.GetDefault();
this.proximityDevice.DeviceArrived +=
this.ProximityDeviceDeviceArrived;
this.proximityDevice.DeviceDeparted +=
this.ProximityDeviceDeviceDeparted;
PeerFinder.ConnectionRequested +=
this.PeerFinderConnectionRequested;
PeerFinder.Role = PeerRole.Peer;
PeerFinder.Start();
var peers = await PeerFinder.FindAllPeersAsync();
var socket = await
PeerFinder.ConnectAsync(this.SelectedPeer.Information);
Proximity APIs
NFC device and events
Peer Finder (listen and browse)
Browse for peers
Connect to peer

Consulting/Training
1. Try to get Proximity Device (NFC)
2. If exists, register to enter/leave events (NFC)
3. If it supports triggers (i.e. tap) register for connection
state change event (NFC)
4. Otherwise browse for peers (Wi-Fi Direct, Bluetooth)
5. When a peer is found, send a connection request
6. Peer must accept the connection request
7. In any scenario, once the connection exists you are
passed a stream socket and are free to communicate
Steps for Proximity

Consulting/Training
Source code: http://bit.ly/1jlnGbB
Proximity

Consulting/Training
 WebSockets API for simplified WebSockets
 Sockets API for TCP, UDP, Bluetooth, Wi-Fi Direct
 Windows 8.1 is capable of dialing out to any
address and port
 As a server, most practical example is listening
for Bluetooth connections
 The security sandbox prevents using sockets for
inter-app communications
Recap

Consulting/Training
Subscribers Enjoy
 Expert Instructors
 Quality Content
 Practical Application
 All Devices
Wintellect’s On-Demand
Video Training Solution
Individuals | Businesses | Enterprise Organizations
WintellectNOW.com
Authors Enjoy
 Royalty Income
 Personal Branding
 Free Library Access
 Cross-Sell
Opportunities
Try It Free!
Use Promo Code:
LIKNESS-13

Consulting/Training
http://winrtexamples.codeplex.com/
http://bit.ly/winrtxmpl
Questions?

Windows 8.1 Sockets

Related slideshows

More Related Content

Windows 8.1 Sockets