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/*
* IP firewalling code. This is taken from 4.4BSD. Please note the
* copyright message below. As per the GPL it must be maintained
* and the licenses thus do not conflict. While this port is subject
* to the GPL I also place my modifications under the original
* license in recognition of the original copyright.
*
* Ported from BSD to Linux,
* Alan Cox 22/Nov/1994.
* Merged and included the FreeBSD-Current changes at Ugen's request
* (but hey it's a lot cleaner now). Ugen would prefer in some ways
* we waited for his final product but since Linux 1.2.0 is about to
* appear it's not practical - Read: It works, it's not clean but please
* don't consider it to be his standard of finished work.
* Alan.
*
* Fixes:
* Pauline Middelink : Added masquerading.
* Jos Vos : Separate input and output firewall
* chains, new "insert" and "append"
* commands to replace "add" commands,
* add ICMP header to struct ip_fwpkt.
* Jos Vos : Add support for matching device names.
* Willy Konynenberg : Add transparent proxying support.
* Jos Vos : Add options for input/output accounting.
*
* All the real work was done by .....
*/
/*
* Copyright (c) 1993 Daniel Boulet
* Copyright (c) 1994 Ugen J.S.Antsilevich
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*/
/*
* Format of an IP firewall descriptor
*
* src, dst, src_mask, dst_mask are always stored in network byte order.
* flags and num_*_ports are stored in host byte order (of course).
* Port numbers are stored in HOST byte order.
*/
#ifndef _IP_FW_H
#define _IP_FW_H
#include <linux/icmp.h>
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/udp.h>
struct ip_fw
{
struct ip_fw *fw_next; /* Next firewall on chain */
struct in_addr fw_src, fw_dst; /* Source and destination IP addr */
struct in_addr fw_smsk, fw_dmsk; /* Mask for src and dest IP addr */
struct in_addr fw_via; /* IP address of interface "via" */
struct device *fw_viadev; /* device of interface "via" */
__u16 fw_flg; /* Flags word */
__u16 fw_nsp, fw_ndp; /* N'of src ports and # of dst ports */
/* in ports array (dst ports follow */
/* src ports; max of 10 ports in all; */
/* count of 0 means match all ports) */
#define IP_FW_MAX_PORTS 10 /* A reasonable maximum */
__u16 fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */
unsigned long fw_pcnt,fw_bcnt; /* Packet and byte counters */
__u8 fw_tosand, fw_tosxor; /* Revised packet priority */
char fw_vianame[IFNAMSIZ]; /* name of interface "via" */
};
/*
* Values for "flags" field .
*/
#define IP_FW_F_ALL 0x0000 /* This is a universal packet firewall*/
#define IP_FW_F_TCP 0x0001 /* This is a TCP packet firewall */
#define IP_FW_F_UDP 0x0002 /* This is a UDP packet firewall */
#define IP_FW_F_ICMP 0x0003 /* This is a ICMP packet firewall */
#define IP_FW_F_KIND 0x0003 /* Mask to isolate firewall kind */
#define IP_FW_F_ACCEPT 0x0004 /* This is an accept firewall (as *
* opposed to a deny firewall)*
* */
#define IP_FW_F_SRNG 0x0008 /* The first two src ports are a min *
* and max range (stored in host byte *
* order). *
* */
#define IP_FW_F_DRNG 0x0010 /* The first two dst ports are a min *
* and max range (stored in host byte *
* order). *
* (ports[0] <= port <= ports[1]) *
* */
#define IP_FW_F_PRN 0x0020 /* In verbose mode print this firewall*/
#define IP_FW_F_BIDIR 0x0040 /* For bidirectional firewalls */
#define IP_FW_F_TCPSYN 0x0080 /* For tcp packets-check SYN only */
#define IP_FW_F_ICMPRPL 0x0100 /* Send back icmp unreachable packet */
#define IP_FW_F_MASQ 0x0200 /* Masquerading */
#define IP_FW_F_TCPACK 0x0400 /* For tcp-packets match if ACK is set*/
#define IP_FW_F_REDIR 0x0800 /* Redirect to local port fw_pts[n] */
#define IP_FW_F_ACCTIN 0x1000 /* Account incoming packets only. */
#define IP_FW_F_ACCTOUT 0x2000 /* Account outgoing packets only. */
#define IP_FW_F_MASK 0x3FFF /* All possible flag bits mask */
/*
* New IP firewall options for [gs]etsockopt at the RAW IP level.
* Unlike BSD Linux inherits IP options so you don't have to use
* a raw socket for this. Instead we check rights in the calls.
*/
#define IP_FW_BASE_CTL 64 /* base for firewall socket options */
#define IP_FW_COMMAND 0x00FF /* mask for command without chain */
#define IP_FW_TYPE 0x0300 /* mask for type (chain) */
#define IP_FW_SHIFT 8 /* shift count for type (chain) */
#define IP_FW_FWD 0
#define IP_FW_IN 1
#define IP_FW_OUT 2
#define IP_FW_ACCT 3
#define IP_FW_CHAINS 4 /* total number of ip_fw chains */
#define IP_FW_INSERT (IP_FW_BASE_CTL)
#define IP_FW_APPEND (IP_FW_BASE_CTL+1)
#define IP_FW_DELETE (IP_FW_BASE_CTL+2)
#define IP_FW_FLUSH (IP_FW_BASE_CTL+3)
#define IP_FW_ZERO (IP_FW_BASE_CTL+4)
#define IP_FW_POLICY (IP_FW_BASE_CTL+5)
#define IP_FW_CHECK (IP_FW_BASE_CTL+6)
#define IP_FW_MASQ_TIMEOUTS (IP_FW_BASE_CTL+7)
#define IP_FW_INSERT_FWD (IP_FW_INSERT | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_APPEND_FWD (IP_FW_APPEND | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_DELETE_FWD (IP_FW_DELETE | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_FLUSH_FWD (IP_FW_FLUSH | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_ZERO_FWD (IP_FW_ZERO | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_POLICY_FWD (IP_FW_POLICY | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_CHECK_FWD (IP_FW_CHECK | (IP_FW_FWD << IP_FW_SHIFT))
#define IP_FW_INSERT_IN (IP_FW_INSERT | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_APPEND_IN (IP_FW_APPEND | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_DELETE_IN (IP_FW_DELETE | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_FLUSH_IN (IP_FW_FLUSH | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_ZERO_IN (IP_FW_ZERO | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_POLICY_IN (IP_FW_POLICY | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_CHECK_IN (IP_FW_CHECK | (IP_FW_IN << IP_FW_SHIFT))
#define IP_FW_INSERT_OUT (IP_FW_INSERT | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_APPEND_OUT (IP_FW_APPEND | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_DELETE_OUT (IP_FW_DELETE | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_FLUSH_OUT (IP_FW_FLUSH | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_ZERO_OUT (IP_FW_ZERO | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_POLICY_OUT (IP_FW_POLICY | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_FW_CHECK_OUT (IP_FW_CHECK | (IP_FW_OUT << IP_FW_SHIFT))
#define IP_ACCT_INSERT (IP_FW_INSERT | (IP_FW_ACCT << IP_FW_SHIFT))
#define IP_ACCT_APPEND (IP_FW_APPEND | (IP_FW_ACCT << IP_FW_SHIFT))
#define IP_ACCT_DELETE (IP_FW_DELETE | (IP_FW_ACCT << IP_FW_SHIFT))
#define IP_ACCT_FLUSH (IP_FW_FLUSH | (IP_FW_ACCT << IP_FW_SHIFT))
#define IP_ACCT_ZERO (IP_FW_ZERO | (IP_FW_ACCT << IP_FW_SHIFT))
struct ip_fwpkt
{
struct iphdr fwp_iph; /* IP header */
union {
struct tcphdr fwp_tcph; /* TCP header or */
struct udphdr fwp_udph; /* UDP header */
struct icmphdr fwp_icmph; /* ICMP header */
} fwp_protoh;
struct in_addr fwp_via; /* interface address */
char fwp_vianame[IFNAMSIZ]; /* interface name */
};
/*
* timeouts for ip masquerading
*/
struct ip_fw_masq;
/*
* Main firewall chains definitions and global var's definitions.
*/
#ifdef __KERNEL__
/* Modes used in the ip_fw_chk() routine. */
#define IP_FW_MODE_FW 0x00 /* kernel firewall check */
#define IP_FW_MODE_ACCT_IN 0x01 /* accounting (incoming) */
#define IP_FW_MODE_ACCT_OUT 0x02 /* accounting (outgoing) */
#define IP_FW_MODE_CHK 0x04 /* check requested by user */
#include <linux/config.h>
#ifdef CONFIG_IP_FIREWALL
extern struct ip_fw *ip_fw_in_chain;
extern struct ip_fw *ip_fw_out_chain;
extern struct ip_fw *ip_fw_fwd_chain;
extern int ip_fw_in_policy;
extern int ip_fw_out_policy;
extern int ip_fw_fwd_policy;
extern int ip_fw_ctl(int, void *, int);
#endif
#ifdef CONFIG_IP_ACCT
extern struct ip_fw *ip_acct_chain;
extern int ip_acct_ctl(int, void *, int);
#endif
extern int ip_fw_chk(struct iphdr *, struct device *, __u16 *, struct ip_fw *, int, int);
extern void ip_fw_init(void);
#endif /* KERNEL */
#endif /* _IP_FW_H */
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