Understanding Linux Network Internals

Functions and Variables Featured in This Chapter

Table 25-12 summarizes the main functions, variables, and data structures introduced in this chapter.

Table 25-12. Functions, variables, and data structures introduced in this chapter

Name	Description
Functions
icmp_init	Initializes the ICMPv4 protocol. See the section "Protocol Initialization."
icmp_rcv	Processes ingress ICMP messages. See the section "Receiving ICMP Messages."
icmp_send icmp_reply	Transmit an ICMP message. See the section "Transmitting ICMP Messages."
icmp_xmit_lock icmp_xmit_unlock	Get and release the per-CPU ICMP-socket's transmit lock.
icmpv4_xrlim_allow xrlim_allow	Rate limit ICMP message transmissions. See the section "Rate Limiting."
icmp_out_count	Updates SNMP counters for transmitted ICMP messages.
icmp_err_convert	Converts ICMP error codes to socket error codes. See the section "Passing Error Notifications to the Transport Layer."
ICMP_INC_STATS ICMP_INC_STATS_BH ICMP_INC_STATS_USER	Increment counters used to keep statistics on ICMP messages. See the section "ICMP Statistics."
Variables
icmp_statistics	SNMP counters. See the section "ICMP Statistics."
Data structures
struct icmphdr struct icmp_control struct icmp_bxm	Main data structures used by ICMPv4. See the section "Data Structures Featured in This Chapter."
icmp_mib	Array of counters. See the section "ICMP Statistics."