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334 lines
12 KiB
C
334 lines
12 KiB
C
/*
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* Copyright (c) 1993 Daniel Boulet
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* Copyright (c) 1994 Ugen J.S.Antsilevich
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*
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* Redistribution and use in source forms, with and without modification,
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* are permitted provided that this entire comment appears intact.
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*
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* Redistribution in binary form may occur without any restrictions.
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* Obviously, it would be nice if you gave credit where credit is due
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* but requiring it would be too onerous.
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*
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* This software is provided ``AS IS'' without any warranties of any kind.
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*
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* $FreeBSD$
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*/
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#ifndef _IP_FW_H
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#define _IP_FW_H
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#include <sys/queue.h>
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/*
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* This union structure identifies an interface, either explicitly
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* by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
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* and IP_FW_F_OIFNAME say how to interpret this structure. An
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* interface unit number of -1 matches any unit number, while an
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* IP address of 0.0.0.0 indicates matches any interface.
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*
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* The receive and transmit interfaces are only compared against the
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* the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
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* is set. Note some packets lack a receive or transmit interface
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* (in which case the missing "interface" never matches).
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*/
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union ip_fw_if {
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struct in_addr fu_via_ip; /* Specified by IP address */
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struct { /* Specified by interface name */
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#define FW_IFNLEN 10 /* need room ! was IFNAMSIZ */
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char name[FW_IFNLEN];
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short unit; /* -1 means match any unit */
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} fu_via_if;
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};
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/*
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* Format of an IP firewall descriptor
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*
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* fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
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* fw_flg and fw_n*p are stored in host byte order (of course).
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* Port numbers are stored in HOST byte order.
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*/
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struct ip_fw {
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LIST_ENTRY(ip_fw) next; /* bidirectional list of rules */
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u_int fw_flg; /* Operational Flags word */
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u_int64_t fw_pcnt; /* Packet counters */
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u_int64_t fw_bcnt; /* Byte counters */
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struct in_addr fw_src; /* Source IP address */
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struct in_addr fw_dst; /* Destination IP address */
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struct in_addr fw_smsk; /* Mask for source IP address */
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struct in_addr fw_dmsk; /* Mask for destination address */
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u_short fw_number; /* Rule number */
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u_char fw_prot; /* IP protocol */
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#if 1
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u_char fw_nports; /* # of src/dst port in array */
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#define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f)
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#define IP_FW_SETNSRCP(rule, n) do { \
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(rule)->fw_nports &= ~0x0f; \
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(rule)->fw_nports |= (n); \
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} while (0)
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#define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4)
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#define IP_FW_SETNDSTP(rule, n) do { \
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(rule)->fw_nports &= ~0xf0; \
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(rule)->fw_nports |= (n) << 4;\
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} while (0)
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#define IP_FW_HAVEPORTS(rule) ((rule)->fw_nports != 0)
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#else
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u_char __pad[1];
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u_int _nsrcp;
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u_int _ndstp;
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#define IP_FW_GETNSRCP(rule) (rule)->_nsrcp
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#define IP_FW_SETNSRCP(rule,n) (rule)->_nsrcp = n
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#define IP_FW_GETNDSTP(rule) (rule)->_ndstp
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#define IP_FW_SETNDSTP(rule,n) (rule)->_ndstp = n
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#define IP_FW_HAVEPORTS(rule) ((rule)->_ndstp + (rule)->_nsrcp != 0)
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#endif
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#define IP_FW_MAX_PORTS 10 /* A reasonable maximum */
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union {
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u_short fw_pts[IP_FW_MAX_PORTS]; /* port numbers to match */
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#define IP_FW_ICMPTYPES_MAX 128
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#define IP_FW_ICMPTYPES_DIM (IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
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unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /*ICMP types bitmap*/
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} fw_uar;
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u_int fw_ipflg; /* IP flags word */
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u_short fw_iplen; /* IP length */
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u_short fw_ipid; /* Identification */
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u_char fw_ipopt; /* IP options set */
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u_char fw_ipnopt; /* IP options unset */
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u_char fw_iptos; /* IP type of service set */
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u_char fw_ipntos; /* IP type of service unset */
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u_char fw_ipttl; /* IP time to live */
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u_int fw_ipver:4; /* IP version */
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u_char fw_tcpopt; /* TCP options set */
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u_char fw_tcpnopt; /* TCP options unset */
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u_char fw_tcpf; /* TCP flags set */
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u_char fw_tcpnf; /* TCP flags unset */
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u_short fw_tcpwin; /* TCP window size */
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u_int32_t fw_tcpseq; /* TCP sequence */
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u_int32_t fw_tcpack; /* TCP acknowledgement */
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long timestamp; /* timestamp (tv_sec) of last match */
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union ip_fw_if fw_in_if; /* Incoming interfaces */
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union ip_fw_if fw_out_if; /* Outgoing interfaces */
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union {
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u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */
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u_short fu_pipe_nr; /* queue number (option DUMMYNET) */
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u_short fu_skipto_rule; /* SKIPTO command rule number */
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u_short fu_reject_code; /* REJECT response code */
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struct sockaddr_in fu_fwd_ip;
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} fw_un;
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void *pipe_ptr; /* flow_set ptr for dummynet pipe */
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void *next_rule_ptr; /* next rule in case of match */
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uid_t fw_uid; /* uid to match */
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gid_t fw_gid; /* gid to match */
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int fw_logamount; /* amount to log */
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u_int64_t fw_loghighest; /* highest number packet to log */
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long dont_match_prob; /* 0x7fffffff means 1.0, always fail */
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u_char dyn_type; /* type for dynamic rule */
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#define DYN_KEEP_STATE 0 /* type for keep-state rules */
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#define DYN_LIMIT 1 /* type for limit connection rules */
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#define DYN_LIMIT_PARENT 2 /* parent entry for limit connection rules */
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/* following two fields are used to limit number of connections
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* basing on either src, srcport, dst, dstport.
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*/
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u_char limit_mask; /* mask type for limit rule, can
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* have many.
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*/
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#define DYN_SRC_ADDR 0x1
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#define DYN_SRC_PORT 0x2
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#define DYN_DST_ADDR 0x4
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#define DYN_DST_PORT 0x8
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u_short conn_limit; /* # of connections for limit rule */
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};
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#define fw_divert_port fw_un.fu_divert_port
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#define fw_skipto_rule fw_un.fu_skipto_rule
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#define fw_reject_code fw_un.fu_reject_code
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#define fw_pipe_nr fw_un.fu_pipe_nr
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#define fw_fwd_ip fw_un.fu_fwd_ip
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/*
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*
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* rule_ptr -------------+
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* V
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* [ next.le_next ]---->[ next.le_next ]---- [ next.le_next ]--->
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* [ next.le_prev ]<----[ next.le_prev ]<----[ next.le_prev ]<---
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* [ <ip_fw> body ] [ <ip_fw> body ] [ <ip_fw> body ]
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*
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*/
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/*
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* Flow mask/flow id for each queue.
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*/
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struct ipfw_flow_id {
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u_int32_t dst_ip;
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u_int32_t src_ip;
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u_int16_t dst_port;
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u_int16_t src_port;
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u_int8_t proto;
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u_int8_t flags; /* protocol-specific flags */
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};
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/*
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* dynamic ipfw rule
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*/
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struct ipfw_dyn_rule {
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struct ipfw_dyn_rule *next;
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struct ipfw_flow_id id; /* (masked) flow id */
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struct ip_fw *rule; /* pointer to rule */
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struct ipfw_dyn_rule *parent; /* pointer to parent rule */
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u_int32_t expire; /* expire time */
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u_int64_t pcnt; /* packet match counters */
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u_int64_t bcnt; /* byte match counters */
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u_int32_t bucket; /* which bucket in hash table */
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u_int32_t state; /* state of this rule (typically a
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* combination of TCP flags)
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*/
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u_int16_t dyn_type; /* rule type */
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u_int16_t count; /* refcount */
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};
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/*
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* Values for "flags" field .
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*/
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#define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */
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#define IP_FW_F_DENY 0x00000000 /* This is a deny rule */
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#define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */
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#define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */
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#define IP_FW_F_COUNT 0x00000003 /* This is a count rule */
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#define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */
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#define IP_FW_F_TEE 0x00000005 /* This is a tee rule */
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#define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */
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#define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding
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* address" rule
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*/
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#define IP_FW_F_PIPE 0x00000008 /* This is a dummynet rule */
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#define IP_FW_F_QUEUE 0x00000009 /* This is a dummynet queue */
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#define IP_FW_F_IN 0x00000100 /* Check inbound packets */
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#define IP_FW_F_OUT 0x00000200 /* Check outbound packets */
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#define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */
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#define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */
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#define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */
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#define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min
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* and max range (stored in host byte
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* order).
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*/
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#define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min
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* and max range (stored in host byte
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* order).
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*/
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#define IP_FW_F_FRAG 0x00008000 /* Fragment */
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#define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */
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#define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP)*/
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#define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */
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#define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */
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#define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */
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#define IP_FW_F_UID 0x00200000 /* filter by uid */
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#define IP_FW_F_GID 0x00400000 /* filter by gid */
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#define IP_FW_F_RND_MATCH 0x00800000 /* probabilistic rule match */
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#define IP_FW_F_SMSK 0x01000000 /* src-port + mask */
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#define IP_FW_F_DMSK 0x02000000 /* dst-port + mask */
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#define IP_FW_BRIDGED 0x04000000 /* only match bridged packets */
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#define IP_FW_F_KEEP_S 0x08000000 /* keep state */
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#define IP_FW_F_CHECK_S 0x10000000 /* check state */
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#define IP_FW_F_SME 0x20000000 /* source = me */
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#define IP_FW_F_DME 0x40000000 /* destination = me */
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#define IP_FW_F_MASK 0x7FFFFFFF /* All possible flag bits mask */
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/*
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* Flags for the 'fw_ipflg' field, for comparing values
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* of ip and its protocols.
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*/
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#define IP_FW_IF_TCPOPT 0x00000001 /* tcp options */
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#define IP_FW_IF_TCPFLG 0x00000002 /* tcp flags */
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#define IP_FW_IF_TCPSEQ 0x00000004 /* tcp sequence number */
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#define IP_FW_IF_TCPACK 0x00000008 /* tcp acknowledgement number */
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#define IP_FW_IF_TCPWIN 0x00000010 /* tcp window size */
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#define IP_FW_IF_TCPEST 0x00000020 /* established TCP connection */
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#define IP_FW_IF_TCPMSK 0x0000003f /* mask of all tcp values */
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#define IP_FW_IF_IPOPT 0x00000100 /* ip options */
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#define IP_FW_IF_IPLEN 0x00000200 /* ip length */
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#define IP_FW_IF_IPID 0x00000400 /* ip identification */
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#define IP_FW_IF_IPTOS 0x00000800 /* ip type of service */
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#define IP_FW_IF_IPTTL 0x00001000 /* ip time to live */
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#define IP_FW_IF_IPVER 0x00002000 /* ip version */
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#define IP_FW_IF_IPMSK 0x00003f00 /* mask of all ip values */
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#define IP_FW_IF_MSK 0x0000ffff /* All possible bits mask */
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/*
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* For backwards compatibility with rules specifying "via iface" but
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* not restricted to only "in" or "out" packets, we define this combination
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* of bits to represent this configuration.
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*/
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#define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)
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/*
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* Definitions for REJECT response codes.
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* Values less than 256 correspond to ICMP unreachable codes.
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*/
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#define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */
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/*
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* Definitions for IP option names.
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*/
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#define IP_FW_IPOPT_LSRR 0x01
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#define IP_FW_IPOPT_SSRR 0x02
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#define IP_FW_IPOPT_RR 0x04
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#define IP_FW_IPOPT_TS 0x08
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/*
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* Definitions for TCP option names.
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*/
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#define IP_FW_TCPOPT_MSS 0x01
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#define IP_FW_TCPOPT_WINDOW 0x02
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#define IP_FW_TCPOPT_SACK 0x04
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#define IP_FW_TCPOPT_TS 0x08
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#define IP_FW_TCPOPT_CC 0x10
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/*
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* Definitions for TCP flags.
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*/
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#define IP_FW_TCPF_FIN TH_FIN
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#define IP_FW_TCPF_SYN TH_SYN
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#define IP_FW_TCPF_RST TH_RST
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#define IP_FW_TCPF_PSH TH_PUSH
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#define IP_FW_TCPF_ACK TH_ACK
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#define IP_FW_TCPF_URG TH_URG
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/*
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* Main firewall chains definitions and global var's definitions.
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*/
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#ifdef _KERNEL
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#define IP_FW_PORT_DYNT_FLAG 0x10000
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#define IP_FW_PORT_TEE_FLAG 0x20000
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#define IP_FW_PORT_DENY_FLAG 0x40000
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/*
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* Function definitions.
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*/
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void ip_fw_init __P((void));
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/* Firewall hooks */
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struct ip;
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struct sockopt;
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typedef int ip_fw_chk_t (struct ip **, int, struct ifnet *, u_int16_t *,
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struct mbuf **, struct ip_fw **, struct sockaddr_in **);
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typedef int ip_fw_ctl_t (struct sockopt *);
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extern ip_fw_chk_t *ip_fw_chk_ptr;
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extern ip_fw_ctl_t *ip_fw_ctl_ptr;
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extern int fw_one_pass;
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extern int fw_enable;
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extern struct ipfw_flow_id last_pkt;
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#define IPFW_LOADED (ip_fw_chk_ptr != NULL)
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#endif /* _KERNEL */
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#endif /* _IP_FW_H */
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