NAME `Linux::SocketFilter' - interface to Linux's socket packet filtering DESCRIPTION This module contains the constants and structure definitions to use Linux's socket packet filtering mechanism. CONSTANTS The following constants are exported: Socket Options SO_ATTACH_FILTER SO_DETACH_FILTER BPF Instructions BPF_LD BPF_LDX BPF_ST BPF_STX BPF_ALU BPF_JMP BPF_RET BPF_MISC BPF_W BPF_H BPF_B BPF_IMM BPF_ABS BPF_IND BPF_MEM PBF_LEN BPF_MSH BPF_ADD BPF_SUB BPF_MUL BPF_DIV BPF_OR BPF_AND BPF_LSH BPF_RSH BPF_NEG BPF_JA BPF_JEQ BPF_JGT BPF_JGE BPF_JSET BPF_K BPF_X BPF_A BPF_TAX BPF_TXA This entire set of constants is also exported under the tag name `:bpf'. Linux BPF Extension Packet Addresses SKF_AD_OFF SKF_AD_PROTOCOL SKF_AD_PKTTYPE SKF_AD_IFINDEX SKF_NET_OFF SKF_LL_OFF STRUCTURE FUNCTIONS $buffer = pack_sock_filter( $code, $jt, $jf, $k ) ( $code, $jt, $jf, $k ) = unpack_sock_filter( $buffer ) Pack or unpack a single BPF instruction. SOCKET FUNCTIONS attach_filter( $sock, $filter ) Attaches the given filter program to the given socket. The program should be a string formed by concatenating multiple calls to `pack_sock_filter()' to build the filter program. detach_filter( $sock ) Detaches the current filter from the socket, returning it to accepting all packets. AUTHOR Paul Evans