Chelsio Communications Terminator 6, Инструкция по установке и эксплуатации, Страница: 325 / 432

Chapter XXIII. Traffic Management
Chelsio Unified Wire for Linux 325
Modifying the application
The application can also be modified to associate connections to scheduling classes. Follow the
steps mentioned below:
i. Determine the TCP socket file descriptor in the application through which data is sent.
ii. Declare and initialize a variable in the application:
int cl=1;
Here,
cl is the TCP traffic class(scheduler-class-index) that the user wishes to assign the data stream
to. This value needs to be in the range of 0 to 7.
The application will function as per the parameters set for that traffic class.
iii. Add socket option definitions:
In order to use setsockopt() to set the options to the TCP socket, the following two definitions
need to be made:
•
SOL_SCHEDCLASS used for setting TCP traffic class, which has the value 290.
•
IPPROTO_TCP used for setting the type of IP Protocol.
# define SOL_SCHEDCLASS 290
# define IPPROTO_TCP 6
iv. Use the setsockopt() function to set socket options:
The setsockopt() call must be mentioned after the connect() call.
//Get the TCP socket descriptor variable
setsockopt (sockfd , IPPROTO_TCP, SOL_SCHEDCLASS, &cl, sizeof(cl));
Here,
sockfd : The file descriptor of the TCP socket.
&cl : Pointer to the class variables.
sizeof(cl) : The size of the variable.
v. Now, compile the application.