/* * 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. * * $FreeBSD$ */ #ifndef _IP_FW_H #define _IP_FW_H #include /* * This union structure identifies an interface, either explicitly * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME * and IP_FW_F_OIFNAME say how to interpret this structure. An * interface unit number of -1 matches any unit number, while an * IP address of 0.0.0.0 indicates matches any interface. * * The receive and transmit interfaces are only compared against the * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE) * is set. Note some packets lack a receive or transmit interface * (in which case the missing "interface" never matches). */ union ip_fw_if { struct in_addr fu_via_ip; /* Specified by IP address */ struct { /* Specified by interface name */ #define FW_IFNLEN 10 /* need room ! was IFNAMSIZ */ char name[FW_IFNLEN]; short unit; /* -1 means match any unit */ } fu_via_if; }; /* * Format of an IP firewall descriptor * * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order. * fw_flg and fw_n*p are stored in host byte order (of course). * Port numbers are stored in HOST byte order. */ /* * To match MAC headers: * 12 bytes at fw_mac_hdr contain the dst-src MAC address after masking. * 12 bytes at fw_mac_mask contain the mask to apply to dst-src * 2 bytes at fw_mac_type contain the mac type after mask (in net format) * 2 bytes at fw_mac_type_mask contain the mac type mask * If IP_FW_F_SRNG, the two contain the low-high of a range of types. * IP_FW_F_DRNG is used to indicare we want to match a vlan. */ #define fw_mac_hdr fw_src #define fw_mac_mask fw_uar #define fw_mac_type fw_iplen #define fw_mac_mask_type fw_ipid struct ip_fw { LIST_ENTRY(ip_fw) next; /* bidirectional list of rules */ u_int fw_flg; /* Operational Flags word */ u_int64_t fw_pcnt; /* Packet counters */ u_int64_t fw_bcnt; /* Byte counters */ struct in_addr fw_src; /* Source IP address */ struct in_addr fw_dst; /* Destination IP address */ struct in_addr fw_smsk; /* Mask for source IP address */ struct in_addr fw_dmsk; /* Mask for destination address */ u_short fw_number; /* Rule number */ u_char fw_prot; /* IP protocol */ #if 1 u_char fw_nports; /* # of src/dst port in array */ #define IP_FW_GETNSRCP(rule) ((rule)->fw_nports & 0x0f) #define IP_FW_SETNSRCP(rule, n) do { \ (rule)->fw_nports &= ~0x0f; \ (rule)->fw_nports |= (n); \ } while (0) #define IP_FW_GETNDSTP(rule) ((rule)->fw_nports >> 4) #define IP_FW_SETNDSTP(rule, n) do { \ (rule)->fw_nports &= ~0xf0; \ (rule)->fw_nports |= (n) << 4;\ } while (0) #define IP_FW_HAVEPORTS(rule) ((rule)->fw_nports != 0) #else u_char __pad[1]; u_int _nsrcp; u_int _ndstp; #define IP_FW_GETNSRCP(rule) (rule)->_nsrcp #define IP_FW_SETNSRCP(rule,n) (rule)->_nsrcp = n #define IP_FW_GETNDSTP(rule) (rule)->_ndstp #define IP_FW_SETNDSTP(rule,n) (rule)->_ndstp = n #define IP_FW_HAVEPORTS(rule) ((rule)->_ndstp + (rule)->_nsrcp != 0) #endif #define IP_FW_MAX_PORTS 10 /* A reasonable maximum */ union { u_short fw_pts[IP_FW_MAX_PORTS]; /* port numbers to match */ #define IP_FW_ICMPTYPES_MAX 128 #define IP_FW_ICMPTYPES_DIM (IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8)) unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /*ICMP types bitmap*/ } fw_uar; u_int fw_ipflg; /* IP flags word */ u_short fw_iplen; /* IP length */ u_short fw_ipid; /* Identification */ u_char fw_ipopt; /* IP options set */ u_char fw_ipnopt; /* IP options unset */ u_char fw_iptos; /* IP type of service set */ u_char fw_ipntos; /* IP type of service unset */ u_char fw_ipttl; /* IP time to live */ u_int fw_ipver:4; /* IP version */ u_char fw_tcpopt; /* TCP options set */ u_char fw_tcpnopt; /* TCP options unset */ u_char fw_tcpf; /* TCP flags set */ u_char fw_tcpnf; /* TCP flags unset */ u_short fw_tcpwin; /* TCP window size */ u_int32_t fw_tcpseq; /* TCP sequence */ u_int32_t fw_tcpack; /* TCP acknowledgement */ long timestamp; /* timestamp (tv_sec) of last match */ union ip_fw_if fw_in_if; /* Incoming interfaces */ union ip_fw_if fw_out_if; /* Outgoing interfaces */ union { u_short fu_divert_port; /* Divert/tee port (options IPDIVERT) */ u_short fu_pipe_nr; /* queue number (option DUMMYNET) */ u_short fu_skipto_rule; /* SKIPTO command rule number */ u_short fu_reject_code; /* REJECT response code */ struct sockaddr_in fu_fwd_ip; } fw_un; void *pipe_ptr; /* flow_set ptr for dummynet pipe */ void *next_rule_ptr; /* next rule in case of match */ uid_t fw_uid; /* uid to match */ gid_t fw_gid; /* gid to match */ int fw_logamount; /* amount to log */ u_int64_t fw_loghighest; /* highest number packet to log */ long dont_match_prob; /* 0x7fffffff means 1.0, always fail */ u_char dyn_type; /* type for dynamic rule */ #define DYN_KEEP_STATE 0 /* type for keep-state rules */ #define DYN_LIMIT 1 /* type for limit connection rules */ #define DYN_LIMIT_PARENT 2 /* parent entry for limit connection rules */ /* following two fields are used to limit number of connections * basing on either src, srcport, dst, dstport. */ u_char limit_mask; /* mask type for limit rule, can * have many. */ #define DYN_SRC_ADDR 0x1 #define DYN_SRC_PORT 0x2 #define DYN_DST_ADDR 0x4 #define DYN_DST_PORT 0x8 u_short conn_limit; /* # of connections for limit rule */ }; #define fw_divert_port fw_un.fu_divert_port #define fw_skipto_rule fw_un.fu_skipto_rule #define fw_reject_code fw_un.fu_reject_code #define fw_pipe_nr fw_un.fu_pipe_nr #define fw_fwd_ip fw_un.fu_fwd_ip /* * * rule_ptr -------------+ * V * [ next.le_next ]---->[ next.le_next ]---- [ next.le_next ]---> * [ next.le_prev ]<----[ next.le_prev ]<----[ next.le_prev ]<--- * [ body ] [ body ] [ body ] * */ /* * Flow mask/flow id for each queue. */ struct ipfw_flow_id { u_int32_t dst_ip; u_int32_t src_ip; u_int16_t dst_port; u_int16_t src_port; u_int8_t proto; u_int8_t flags; /* protocol-specific flags */ }; /* * dynamic ipfw rule */ struct ipfw_dyn_rule { struct ipfw_dyn_rule *next; struct ipfw_flow_id id; /* (masked) flow id */ struct ip_fw *rule; /* pointer to rule */ struct ipfw_dyn_rule *parent; /* pointer to parent rule */ u_int32_t expire; /* expire time */ u_int64_t pcnt; /* packet match counters */ u_int64_t bcnt; /* byte match counters */ u_int32_t bucket; /* which bucket in hash table */ u_int32_t state; /* state of this rule (typically a * combination of TCP flags) */ u_int16_t dyn_type; /* rule type */ u_int16_t count; /* refcount */ }; /* * Values for "flags" field . */ #define IP_FW_F_COMMAND 0x000000ff /* Mask for type of chain entry: */ #define IP_FW_F_DENY 0x00000000 /* This is a deny rule */ #define IP_FW_F_REJECT 0x00000001 /* Deny and send a response packet */ #define IP_FW_F_ACCEPT 0x00000002 /* This is an accept rule */ #define IP_FW_F_COUNT 0x00000003 /* This is a count rule */ #define IP_FW_F_DIVERT 0x00000004 /* This is a divert rule */ #define IP_FW_F_TEE 0x00000005 /* This is a tee rule */ #define IP_FW_F_SKIPTO 0x00000006 /* This is a skipto rule */ #define IP_FW_F_FWD 0x00000007 /* This is a "change forwarding * address" rule */ #define IP_FW_F_PIPE 0x00000008 /* This is a dummynet rule */ #define IP_FW_F_QUEUE 0x00000009 /* This is a dummynet queue */ #define IP_FW_F_IN 0x00000100 /* Check inbound packets */ #define IP_FW_F_OUT 0x00000200 /* Check outbound packets */ #define IP_FW_F_IIFACE 0x00000400 /* Apply inbound interface test */ #define IP_FW_F_OIFACE 0x00000800 /* Apply outbound interface test */ #define IP_FW_F_PRN 0x00001000 /* Print if this rule matches */ #define IP_FW_F_SRNG 0x00002000 /* The first two src ports are a min * and max range (stored in host byte * order). */ #define IP_FW_F_DRNG 0x00004000 /* The first two dst ports are a min * and max range (stored in host byte * order). */ #define IP_FW_F_FRAG 0x00008000 /* Fragment */ #define IP_FW_F_IIFNAME 0x00010000 /* In interface by name/unit (not IP) */ #define IP_FW_F_OIFNAME 0x00020000 /* Out interface by name/unit (not IP)*/ #define IP_FW_F_INVSRC 0x00040000 /* Invert sense of src check */ #define IP_FW_F_INVDST 0x00080000 /* Invert sense of dst check */ #define IP_FW_F_ICMPBIT 0x00100000 /* ICMP type bitmap is valid */ #define IP_FW_F_UID 0x00200000 /* filter by uid */ #define IP_FW_F_GID 0x00400000 /* filter by gid */ #define IP_FW_F_RND_MATCH 0x00800000 /* probabilistic rule match */ #define IP_FW_F_SMSK 0x01000000 /* src-port + mask */ #define IP_FW_F_DMSK 0x02000000 /* dst-port + mask */ #define IP_FW_BRIDGED 0x04000000 /* only match bridged packets */ #define IP_FW_F_KEEP_S 0x08000000 /* keep state */ #define IP_FW_F_CHECK_S 0x10000000 /* check state */ #define IP_FW_F_SME 0x20000000 /* source = me */ #define IP_FW_F_DME 0x40000000 /* destination = me */ #define IP_FW_F_MAC 0x80000000 /* match MAC header */ #define IP_FW_F_MASK 0xFFFFFFFF /* All possible flag bits mask */ /* * Flags for the 'fw_ipflg' field, for comparing values * of ip and its protocols. */ #define IP_FW_IF_TCPOPT 0x00000001 /* tcp options */ #define IP_FW_IF_TCPFLG 0x00000002 /* tcp flags */ #define IP_FW_IF_TCPSEQ 0x00000004 /* tcp sequence number */ #define IP_FW_IF_TCPACK 0x00000008 /* tcp acknowledgement number */ #define IP_FW_IF_TCPWIN 0x00000010 /* tcp window size */ #define IP_FW_IF_TCPEST 0x00000020 /* established TCP connection */ #define IP_FW_IF_TCPMSK 0x0000003f /* mask of all tcp values */ #define IP_FW_IF_IPOPT 0x00000100 /* ip options */ #define IP_FW_IF_IPLEN 0x00000200 /* ip length */ #define IP_FW_IF_IPID 0x00000400 /* ip identification */ #define IP_FW_IF_IPTOS 0x00000800 /* ip type of service */ #define IP_FW_IF_IPTTL 0x00001000 /* ip time to live */ #define IP_FW_IF_IPVER 0x00002000 /* ip version */ #define IP_FW_IF_IPPRE 0x00004000 /* ip precedence */ #define IP_FW_IF_IPMSK 0x00007f00 /* mask of all ip values */ #define IP_FW_IF_MSK 0x0000ffff /* All possible bits mask */ /* * For backwards compatibility with rules specifying "via iface" but * not restricted to only "in" or "out" packets, we define this combination * of bits to represent this configuration. */ #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE) /* * Definitions for REJECT response codes. * Values less than 256 correspond to ICMP unreachable codes. */ #define IP_FW_REJECT_RST 0x0100 /* TCP packets: send RST */ /* * Definitions for IP option names. */ #define IP_FW_IPOPT_LSRR 0x01 #define IP_FW_IPOPT_SSRR 0x02 #define IP_FW_IPOPT_RR 0x04 #define IP_FW_IPOPT_TS 0x08 /* * Definitions for TCP option names. */ #define IP_FW_TCPOPT_MSS 0x01 #define IP_FW_TCPOPT_WINDOW 0x02 #define IP_FW_TCPOPT_SACK 0x04 #define IP_FW_TCPOPT_TS 0x08 #define IP_FW_TCPOPT_CC 0x10 /* * Definitions for TCP flags. */ #define IP_FW_TCPF_FIN TH_FIN #define IP_FW_TCPF_SYN TH_SYN #define IP_FW_TCPF_RST TH_RST #define IP_FW_TCPF_PSH TH_PUSH #define IP_FW_TCPF_ACK TH_ACK #define IP_FW_TCPF_URG TH_URG /* * Main firewall chains definitions and global var's definitions. */ #ifdef _KERNEL #define IP_FW_PORT_DYNT_FLAG 0x10000 #define IP_FW_PORT_TEE_FLAG 0x20000 #define IP_FW_PORT_DENY_FLAG 0x40000 /* * Function definitions. */ void ip_fw_init(void); /* Firewall hooks */ struct ip; struct sockopt; typedef int ip_fw_chk_t (struct mbuf **m, struct ifnet *oif, u_int16_t *cookie, struct ip_fw **rule, struct sockaddr_in **next_hop); typedef int ip_fw_ctl_t (struct sockopt *); extern ip_fw_chk_t *ip_fw_chk_ptr; extern ip_fw_ctl_t *ip_fw_ctl_ptr; extern int fw_one_pass; extern int fw_enable; extern struct ipfw_flow_id last_pkt; #define IPFW_LOADED (ip_fw_chk_ptr != NULL) #endif /* _KERNEL */ #endif /* _IP_FW_H */