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Diffstat (limited to 'include/linux/ip_fw.h')
| -rw-r--r-- | include/linux/ip_fw.h | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/include/linux/ip_fw.h b/include/linux/ip_fw.h new file mode 100644 index 000000000..29bafa34f --- /dev/null +++ b/include/linux/ip_fw.h @@ -0,0 +1,183 @@ +/* + * 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. + * + * 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 + +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" */ + unsigned short fw_flg; /* Flags word */ + unsigned short 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 */ + unsigned short fw_pts[IP_FW_MAX_PORTS]; /* Array of port numbers to match */ + unsigned long fw_pcnt,fw_bcnt; /* Packet and byte counters */ +}; + +/* + * Values for "flags" field . + */ + +#define IP_FW_F_ALL 0x000 /* This is a universal packet firewall*/ +#define IP_FW_F_TCP 0x001 /* This is a TCP packet firewall */ +#define IP_FW_F_UDP 0x002 /* This is a UDP packet firewall */ +#define IP_FW_F_ICMP 0x003 /* This is a ICMP packet firewall */ +#define IP_FW_F_KIND 0x003 /* Mask to isolate firewall kind */ +#define IP_FW_F_ACCEPT 0x004 /* This is an accept firewall (as * + * opposed to a deny firewall)* + * */ +#define IP_FW_F_SRNG 0x008 /* The first two src ports are a min * + * and max range (stored in host byte * + * order). * + * */ +#define IP_FW_F_DRNG 0x010 /* 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 0x020 /* In verbose mode print this firewall*/ +#define IP_FW_F_BIDIR 0x040 /* For bidirectional firewalls */ +#define IP_FW_F_TCPSYN 0x080 /* For tcp packets-check SYN only */ +#define IP_FW_F_ICMPRPL 0x100 /* Send back icmp unreachable packet */ +#define IP_FW_F_MASQ 0x200 /* Masquerading */ +#define IP_FW_F_MASK 0x3FF /* 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 + +#define IP_FW_ADD_BLK (IP_FW_BASE_CTL) +#define IP_FW_ADD_FWD (IP_FW_BASE_CTL+1) +#define IP_FW_CHK_BLK (IP_FW_BASE_CTL+2) +#define IP_FW_CHK_FWD (IP_FW_BASE_CTL+3) +#define IP_FW_DEL_BLK (IP_FW_BASE_CTL+4) +#define IP_FW_DEL_FWD (IP_FW_BASE_CTL+5) +#define IP_FW_FLUSH_BLK (IP_FW_BASE_CTL+6) +#define IP_FW_FLUSH_FWD (IP_FW_BASE_CTL+7) +#define IP_FW_ZERO_BLK (IP_FW_BASE_CTL+8) +#define IP_FW_ZERO_FWD (IP_FW_BASE_CTL+9) +#define IP_FW_POLICY_BLK (IP_FW_BASE_CTL+10) +#define IP_FW_POLICY_FWD (IP_FW_BASE_CTL+11) + +#define IP_ACCT_ADD (IP_FW_BASE_CTL+16) +#define IP_ACCT_DEL (IP_FW_BASE_CTL+17) +#define IP_ACCT_FLUSH (IP_FW_BASE_CTL+18) +#define IP_ACCT_ZERO (IP_FW_BASE_CTL+19) + +struct ip_fwpkt +{ + struct iphdr fwp_iph; /* IP header */ + union { + struct tcphdr fwp_tcph; /* TCP header or */ + struct udphdr fwp_udph; /* UDP header */ + } fwp_protoh; + struct in_addr fwp_via; /* interface address */ +}; + +/* + * Main firewall chains definitions and global var's definitions. + */ + +#ifdef __KERNEL__ + +#include <linux/config.h> + +#ifdef CONFIG_IP_MASQUERADE +struct ip_masq { + struct ip_masq *next; /* next member in list */ + struct timer_list timer; /* Expiration timer */ + __u16 protocol; /* Which protocol are we talking? */ + __u32 src, dst; /* Source and destination IP addresses */ + __u16 sport,dport; /* Source and destoination ports */ + __u16 mport; /* Masquaraded port */ + __u32 init_seq; /* Add delta from this seq. on */ + short delta; /* Delta in sequence numbers */ + char sawfin; /* Did we saw an FIN packet? */ +}; +extern struct ip_masq *ip_msq_hosts; +extern void ip_fw_masquerade(struct sk_buff **, struct device *); +extern int ip_fw_demasquerade(struct sk_buff *); +#endif +#ifdef CONFIG_IP_FIREWALL +extern struct ip_fw *ip_fw_blk_chain; +extern struct ip_fw *ip_fw_fwd_chain; +extern int ip_fw_blk_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 void ip_acct_cnt(struct iphdr *, struct device *, struct ip_fw *); +extern int ip_acct_ctl(int, void *, int); +#endif +extern int ip_fw_chk(struct iphdr *, struct device *rif,struct ip_fw *, int, int); +#endif /* KERNEL */ + +#ifdef CONFIG_IP_MASQUERADE + +#undef DEBUG_MASQ + +#define MASQUERADE_EXPIRE_TCP 15*60*HZ +#define MASQUERADE_EXPIRE_TCP_FIN 2*60*HZ +#define MASQUERADE_EXPIRE_UDP 5*60*HZ + +/* + * Linux ports don't normally get allocated above 32K. I used an extra 4K port-space + */ + +#define PORT_MASQ_BEGIN 60000 +#define PORT_MASQ_END (PORT_MASQ_BEGIN+4096) +#endif + +#endif /* _IP_FW_H */ |