The document discusses network messaging over Bonjour connections. It identifies three ways to separate network messages from one another: 1) Making all messages the same length, 2) Appending a marker to each message, or 3) Sending a header with length information for each message. The document focuses on building a native iOS application that allows clients to publish and browse for servers over Bonjour, and exchange data between connected clients using stream sockets. Key classes discussed are Server, Connection, and ServerBrowser classes.

1. APPLE BONJOUR,
LET’S TALK!
Nicholas Valbusa - @squallstar
Intesys Web Agency
Thursday, May 24, 12

2. Thursday, May 24, 12

3. Few words about me
Thursday, May 24, 12

4. Few words about me
Nicholas Valbusa
@squallstar
Thursday, May 24, 12

5. Few words about me
Nicholas Valbusa
@squallstar
Web Developer since 2004
Thursday, May 24, 12

6. Few words about me
Nicholas Valbusa
@squallstar
Web Developer since 2004
Mobile Developer since 2010
Thursday, May 24, 12

7. Few words about me
Nicholas Valbusa
@squallstar
Web Developer since 2004
Mobile Developer since 2010
WHYMCA 2011: Webkit meets Native development
Thursday, May 24, 12

8. Thursday, May 24, 12

9. Intesys è una Web Agency Innovativa
nata nel 1995 a Verona
Thursday, May 24, 12

10. Intesys è una Web Agency Innovativa
nata nel 1995 a Verona
Un team di 90 specialisti divisi in 4 aree
Thursday, May 24, 12

11. Intesys è una Web Agency Innovativa
nata nel 1995 a Verona
Un team di 90 specialisti divisi in 4 aree
Thursday, May 24, 12

12. We’ll talk about
Thursday, May 24, 12

13. We’ll talk about
Thursday, May 24, 12

14. We’ll talk about
Thursday, May 24, 12

15. We’ll talk about
• TCP/IP
Thursday, May 24, 12

16. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
Thursday, May 24, 12

17. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
• Socket, Stream, Buffers
Thursday, May 24, 12

18. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
• Socket, Stream, Buffers
• Create and publish a server
Thursday, May 24, 12

19. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
• Socket, Stream, Buffers
• Create and publish a server
• Join a server
Thursday, May 24, 12

20. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
• Socket, Stream, Buffers
• Create and publish a server
• Join a server
• Network messages
Thursday, May 24, 12

21. We’ll talk about
• TCP/IP
• Apple Bonjour, uPNP
• Socket, Stream, Buffers
• Create and publish a server
• Join a server
• Network messages
• Other...
Thursday, May 24, 12

22. We’ll see
Thursday, May 24, 12

23. We’ll see
• A screencast native application
Thursday, May 24, 12

24. We’ll see
• A screencast native application
• Something like chats
Thursday, May 24, 12

25. We’ll see
• A screencast native application
• Something like chats
• Where server can send images and other things
Thursday, May 24, 12

26. We’ll see
• A screencast native application
• Something like chats
• Where server can send images and other things
Follow the talk from your iPad using the same app
that we’re going to make
iCast
Thursday, May 24, 12

27. iCast
Thursday, May 24, 12

28. iCast
Thursday, May 24, 12

29. iCast
Thursday, May 24, 12

30. Thursday, May 24, 12

31. “Once upon a time”
Thursday, May 24, 12

32. “Once upon a time”
Apple Talk
Thursday, May 24, 12

33. “Once upon a time”
Apple Talk
• Protocollo usato nelle reti Macintosh
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34. “Once upon a time”
Apple Talk
• Protocollo usato nelle reti Macintosh
• Condivisione di file e stampanti
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35. “Once upon a time”
Apple Talk
• Protocollo usato nelle reti Macintosh
• Condivisione di file e stampanti
• Uno dei primi sistemi plug-n-play
Thursday, May 24, 12

36. Thursday, May 24, 12

37. “things changes”
Thursday, May 24, 12

38. “things changes”
TCP/IP
Thursday, May 24, 12

39. “things changes”
TCP/IP
• Negli anni novanta, con la diffusione del TCP/IP
Apple dismesse AppleTalk
Thursday, May 24, 12

40. “things changes”
TCP/IP
• Negli anni novanta, con la diffusione del TCP/IP
Apple dismesse AppleTalk
• Finalmente i Mac potevano connettersi con
altri sistemi operativi
Thursday, May 24, 12

41. Thursday, May 24, 12

42. Zeroconf
DHCP DNS
Thursday, May 24, 12

43. Zeroconf
DHCP DNS
“A set of techniques that automatically
creates a usable IP network without manual
operator intervention”
Thursday, May 24, 12

44. Thursday, May 24, 12

45. Bonjour
Thursday, May 24, 12

46. Bonjour
L’implementazione Apple
di “Zero configuration network”
Thursday, May 24, 12

47. Bonjour
L’implementazione Apple
di “Zero configuration network”
“It just works”
Thursday, May 24, 12

48. Bonjour
L’implementazione Apple
di “Zero configuration network”
“It just works”
• mDNS + DNS Service discovery
Thursday, May 24, 12

49. Bonjour
L’implementazione Apple
di “Zero configuration network”
“It just works”
• mDNS + DNS Service discovery
• Address assignment
Thursday, May 24, 12

50. Bonjour
L’implementazione Apple
di “Zero configuration network”
“It just works”
• mDNS + DNS Service discovery
• Address assignment
• Name resolution
Thursday, May 24, 12

51. Bonjour
Thursday, May 24, 12

52. Bonjour
• Built-in con OSX e iOS.
Thursday, May 24, 12

53. Bonjour
• Built-in con OSX e iOS.
• Installabile su Windows
Thursday, May 24, 12

54. Bonjour
• Built-in con OSX e iOS.
• Installabile su Windows
• Incluso in Safari e iTunes.
Thursday, May 24, 12

55. Bonjour
• Built-in con OSX e iOS.
• Installabile su Windows
• Incluso in Safari e iTunes.
• Incluso nella Creative Suite 3 di Adobe
Thursday, May 24, 12

56. Thursday, May 24, 12

57. Who uses it
Thursday, May 24, 12

58. Who uses it
• iTunes finds shared music
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59. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
Thursday, May 24, 12

60. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
Thursday, May 24, 12

61. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
• Adobe Creative Suite 3+
Thursday, May 24, 12

62. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
• Adobe Creative Suite 3+
• Things, Omnifocus
Thursday, May 24, 12

63. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
• Adobe Creative Suite 3+
• Things, Omnifocus
• Cyberduck, Coda, SubEthaEdit
Thursday, May 24, 12

64. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
• Adobe Creative Suite 3+
• Things, Omnifocus
• Cyberduck, Coda, SubEthaEdit
• PostgreSQL
Thursday, May 24, 12

65. Who uses it
• iTunes finds shared music
• iPhotos finds shared photos
• iChat, Skype, Adium
• Adobe Creative Suite 3+
• Things, Omnifocus
• Cyberduck, Coda, SubEthaEdit
• PostgreSQL
• All uPNP-enabled devices
Thursday, May 24, 12

66. Thursday, May 24, 12

67. Who can also use it
Thursday, May 24, 12

68. Who can also use it
Thursday, May 24, 12

69. Who can also use it
Using “jmDNS”, a Java implementation
of multi-cast DNS for LAN service registration/discovery.
Thursday, May 24, 12

70. Thursday, May 24, 12

71. uPNP
Universal plug-n-play
Thursday, May 24, 12

72. uPNP
Universal plug-n-play
• It’s just another implementation of Zeroconf
Thursday, May 24, 12

73. uPNP
Universal plug-n-play
• It’s just another implementation of Zeroconf
• Media servers, Consoles, DLNA servers...
Thursday, May 24, 12

74. uPNP
Universal plug-n-play
• It’s just another implementation of Zeroconf
• Media servers, Consoles, DLNA servers...
• No authentication
Thursday, May 24, 12

75. uPNP
Universal plug-n-play
• It’s just another implementation of Zeroconf
• Media servers, Consoles, DLNA servers...
• No authentication
• No mDNS
Thursday, May 24, 12

76. Thursday, May 24, 12

77. Bonjour: Service Publication
Thursday, May 24, 12

78. Bonjour: Service Publication
Thursday, May 24, 12

79. Thursday, May 24, 12

80. Bonjour: Service Publication
Thursday, May 24, 12

81. Bonjour: Service Publication
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82. Thursday, May 24, 12

83. Bonjour: Query for services
Thursday, May 24, 12

84. Bonjour: Query for services
Thursday, May 24, 12

85. Thursday, May 24, 12

86. Bonjour: Connect
Thursday, May 24, 12

87. Bonjour: Connect
Thursday, May 24, 12

88. Thursday, May 24, 12

89. Sockets vs Streams
Thursday, May 24, 12

90. Sockets vs Streams
• Socket: unique communication
endpoint on the network
Thursday, May 24, 12

91. Sockets vs Streams
• Socket: unique communication
endpoint on the network
• Stream: one-way channel through
which data is transmitted serially
Thursday, May 24, 12

92. Thursday, May 24, 12

93. We will use
Thursday, May 24, 12

94. We will use
• Stream sockets that are paired up
to allow our app to send data over
network using TCP/IP
Thursday, May 24, 12

95. We will use
• Stream sockets that are paired up
to allow our app to send data over
network using TCP/IP
• Asynchronous, non-blocking
operations
Thursday, May 24, 12

96. Thursday, May 24, 12

97. 3 Networking Classes
Thursday, May 24, 12

98. 3 Networking Classes
Server class:
Thursday, May 24, 12

99. 3 Networking Classes
Server class:
• Creates a server
Thursday, May 24, 12

100. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Thursday, May 24, 12

101. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
Thursday, May 24, 12

102. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
• Resolves Bonjour Services
Thursday, May 24, 12

103. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
• Resolves Bonjour Services
• Establishes connections to other servers
Thursday, May 24, 12

104. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
• Resolves Bonjour Services
• Establishes connections to other servers
• Exchanges data via socket streams
Thursday, May 24, 12

105. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
• Resolves Bonjour Services
• Establishes connections to other servers
• Exchanges data via socket streams
Server Browser class:
Thursday, May 24, 12

106. 3 Networking Classes
Server class:
• Creates a server
• Announces the server via Bonjour
Connection class:
• Resolves Bonjour Services
• Establishes connections to other servers
• Exchanges data via socket streams
Server Browser class:
• Browses for other servers via Bonjour
Thursday, May 24, 12

107. Thursday, May 24, 12

108. Application layers
Thursday, May 24, 12

109. Application layers
Thursday, May 24, 12

110. Application layers
Thursday, May 24, 12

111. Application layers
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112. Thursday, May 24, 12

113. Down the Connection class
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114. Down the Connection class
2 stream sockets (one for writing, one for reading)
2 data buffers (one for each socket stream)
Thursday, May 24, 12

115. Thursday, May 24, 12

116. Network messages
Thursday, May 24, 12

117. Network messages
How do we separate network messages from one another?
Thursday, May 24, 12

118. Network messages
How do we separate network messages from one another?
3 different ways:
Thursday, May 24, 12

119. Network messages
How do we separate network messages from one another?
3 different ways:
1) Make all messages have the same length
Thursday, May 24, 12

120. Network messages
How do we separate network messages from one another?
3 different ways:
1) Make all messages have the same length
2) Append a marker to each message
Thursday, May 24, 12

121. Network messages
How do we separate network messages from one another?
3 different ways:
1) Make all messages have the same length
2) Append a marker to each message
3) Send some kind of header with some info about how long the
message is
Thursday, May 24, 12

122. Network messages
How do we separate network messages from one another?
3 different ways:
1) Make all messages have the same length
2) Append a marker to each message
3) Send some kind of header with some info about how long the
message is
Thursday, May 24, 12

123. Thursday, May 24, 12

124. 3) Send some kind of header...
Thursday, May 24, 12

125. 3) Send some kind of header...
Writing messages
Thursday, May 24, 12

126. 3) Send some kind of header...
Writing messages
• Convert an object into a byte array and measure its length
Thursday, May 24, 12

127. 3) Send some kind of header...
Writing messages
• Convert an object into a byte array and measure its length
• Write the integer (4 bytes) that represents the length of our byte
array to the stream
Thursday, May 24, 12

128. 3) Send some kind of header...
Writing messages
• Convert an object into a byte array and measure its length
• Write the integer (4 bytes) that represents the length of our byte
array to the stream
• Write the actual byte array to the stream
Thursday, May 24, 12

129. Reading messages
Thursday, May 24, 12

130. Reading messages
• Read first 4 bytes and interpret those as an integer called “x”
Thursday, May 24, 12

131. Reading messages
• Read first 4 bytes and interpret those as an integer called “x”
• Read “x” number of bytes.
(stop when enough data has been received)
Thursday, May 24, 12

132. Reading messages
• Read first 4 bytes and interpret those as an integer called “x”
• Read “x” number of bytes.
(stop when enough data has been received)
• Turn received sequence of bytes back into an object.
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133. Thursday, May 24, 12

134. It’s time!
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135. Thursday, May 24, 12

136. Frameworks
Thursday, May 24, 12

137. Frameworks
• Low level: BSD socket lib
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138. Frameworks
• Low level: BSD socket lib
Thursday, May 24, 12

139. Frameworks
• Low level: BSD socket lib
• High level: CFNetwork
Thursday, May 24, 12

140. Frameworks
• Low level: BSD socket lib
• High level: CFNetwork
• Bonjour iOS API: NSNetServices,
CFNetServices
Thursday, May 24, 12

141. Thursday, May 24, 12

142. Creating a server
Thursday, May 24, 12

143. Creating a server
We first create a stream
socket that will listen for
connections
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144. Creating a server
We first create a stream
socket that will listen for
connections
CFSocketRef listeningSocket;
Thursday, May 24, 12

145. Creating a server
We first create a stream
socket that will listen for
connections
CFSocketRef listeningSocket;
using port number 0
Thursday, May 24, 12

146. Creating a server
We first create a stream
socket that will listen for
connections
CFSocketRef listeningSocket;
using port number 0
zero???? O_o
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147. Thursday, May 24, 12

148. Let’s publish the service
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149. Let’s publish the service
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150. Thursday, May 24, 12

151. Services/Servers Browser
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152. Services/Servers Browser
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153. Thursday, May 24, 12

154. Found!
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155. Found!
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156. Thursday, May 24, 12

157. Displaying servers list
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158. Displaying servers list
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159. Thursday, May 24, 12

160. Please let me join
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161. Please let me join
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162. Please let me join
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163. Please let me join
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164. Please let me join
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165. Thursday, May 24, 12

166. The server receives the “request”
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167. The server receives the “request”
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168. Thursday, May 24, 12

169. The server welcomes you
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170. The server welcomes you
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171. The server welcomes you
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172. Thursday, May 24, 12

173. The client receives the stream
Thursday, May 24, 12

174. The client receives the stream
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175. Thursday, May 24, 12

176. Recap
Thursday, May 24, 12

177. Recap
• Apple Talk, TCP/IP
Thursday, May 24, 12

178. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
Thursday, May 24, 12

179. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
Thursday, May 24, 12

180. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
• Write/Read Network messages
Thursday, May 24, 12

181. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
• Write/Read Network messages
• Create and publish a server
Thursday, May 24, 12

182. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
• Write/Read Network messages
• Create and publish a server
• Join a server
Thursday, May 24, 12

183. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
• Write/Read Network messages
• Create and publish a server
• Join a server
• Interaction between the client and the server
Thursday, May 24, 12

184. Recap
• Apple Talk, TCP/IP
• Bonjour flow cycle, uPNP
• Application layers, Socket, Stream, Buffers
• Write/Read Network messages
• Create and publish a server
• Join a server
• Interaction between the client and the server
• One more thing: server broadcasts messages to connected clients
Thursday, May 24, 12

185. Thursday, May 24, 12

186. Thank you.
Any questions?
Nicholas Valbusa
@squallstar
Intesys - @Intesys_IT - www.intesys.it
Thursday, May 24, 12