Communications Programming Concepts

Chapter 13. Packet Capture Library

The Packet Capture Library information in this chapter is valid only for AIX 5.1 and later releases.

The operating system provides the Berkeley Packet Filter (BPF) as a means of packet capture. The Packet Capture Library (libpcap.a) provides a user-level interface to that packet capture facility.

The following code samples are only for illustrating the use of the Packet Capture Library APIs. It is recommended that you write your own applications for optimal function in a production environment.

This chapter discusses the following topics:

• Packet Capture Library Overview
• Packet Capture Library Subroutines
• Packet Capture Library Header Files
• Packet Capture Library Header Structures
• Packet Capture Library Filter Expressions
• Sample 1: Capturing Packet Data and Printing It in Binary Form to the Screen
• Sample 2: Capturing Packet Data and Saving It to a File for Processing Later
• Sample 3: Reading Previously Captured Packet Data from a Savefile and Processing It