/* * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/netinet/ip_fw2.h,v 1.1.2.2 2002/08/16 11:03:11 luigi Exp $ */ #ifndef _IPFW2_H #define _IPFW2_H /* * The kernel representation of ipfw rules is made of a list of * 'instructions' (for all practical purposes equivalent to BPF * instructions), which specify which fields of the packet * (or its metatada) should be analysed. * * Each instruction is stored in a structure which begins with * "ipfw_insn", and can contain extra fields depending on the * instruction type (listed below). * * "enum ipfw_opcodes" are the opcodes supported. We can have up * to 256 different opcodes. */ enum ipfw_opcodes { /* arguments (4 byte each) */ O_NOP, O_IP_SRC, /* u32 = IP */ O_IP_SRC_MASK, /* ip = IP/mask */ O_IP_SRC_ME, /* none */ O_IP_SRC_SET, /* u32=base, arg1=len, bitmap */ O_IP_DST, /* u32 = IP */ O_IP_DST_MASK, /* ip = IP/mask */ O_IP_DST_ME, /* none */ O_IP_DST_SET, /* u32=base, arg1=len, bitmap */ O_IP_SRCPORT, /* (n)port list:mask 4 byte ea */ O_IP_DSTPORT, /* (n)port list:mask 4 byte ea */ O_PROTO, /* arg1=protocol */ O_MACADDR2, /* 2 mac addr:mask */ O_MAC_TYPE, /* same as srcport */ O_LAYER2, /* none */ O_IN, /* none */ O_FRAG, /* none */ O_RECV, /* none */ O_XMIT, /* none */ O_VIA, /* none */ O_IPOPT, /* arg1 = 2*u8 bitmap */ O_IPLEN, /* arg1 = len */ O_IPID, /* arg1 = id */ O_IPTOS, /* arg1 = id */ O_IPPRECEDENCE, /* arg1 = precedence << 5 */ O_IPTTL, /* arg1 = TTL */ O_IPVER, /* arg1 = version */ O_UID, /* u32 = id */ O_GID, /* u32 = id */ O_ESTAB, /* none (tcp established) */ O_TCPFLAGS, /* arg1 = 2*u8 bitmap */ O_TCPWIN, /* arg1 = desired win */ O_TCPSEQ, /* u32 = desired seq. */ O_TCPACK, /* u32 = desired seq. */ O_ICMPTYPE, /* 1*u32 = icmp type bitmap */ O_TCPOPTS, /* arg1 = 2*u8 bitmap */ /* States. */ O_PROBE_STATE, /* none */ O_KEEP_STATE, /* none */ O_LIMIT, /* ipfw_insn_limit */ O_LIMIT_PARENT, /* dyn_type, not an opcode. */ /* Actions. */ O_LOG, /* ipfw_insn_log */ O_PROB, /* u32 = match probability */ O_CHECK_STATE, /* none */ O_ACCEPT, /* none */ O_DENY, /* none */ O_REJECT, /* arg1=icmp arg (same as deny) */ O_COUNT, /* none */ O_SKIPTO, /* arg1=next rule number */ O_PIPE, /* arg1=pipe number */ O_QUEUE, /* arg1=queue number */ O_DIVERT, /* arg1=port number */ O_TEE, /* arg1=port number */ O_FORWARD_IP, /* fwd sockaddr */ O_FORWARD_MAC, /* fwd mac */ /* Table based filters. */ O_IP_SRC_TABLE, /* arg1 = tableid */ O_IP_DST_TABLE, /* arg1 = tableid */ /* Action. */ O_DEFRAG, /* none */ /* Filters. */ O_IPFRAG, /* none */ O_IP_SRC_IFIP, /* ipfw_insn_ifip */ O_IP_DST_IFIP, /* ipfw_insn_ifip */ /* Translates. */ O_REDIRECT, /* ipfw_insn_rdr */ O_RESERVED1, /* reserved for NAT */ O_ICMPCODE, /* 1*u32 = icmp code bitmap */ O_LAST_OPCODE /* not an opcode! */ }; #ifdef _KERNEL CTASSERT(O_LAST_OPCODE <= 256); #endif /* * Template for instructions. * * ipfw_insn is used for all instructions which require no operands, * a single 16-bit value (arg1), or a couple of 8-bit values. * * For other instructions which require different/larger arguments * we have derived structures, ipfw_insn_*. * * The size of the instruction (in 32-bit words) is in the low * 6 bits of "len". The 2 remaining bits are used to implement * NOT and OR on individual instructions. Given a type, you can * compute the length to be put in "len" using F_INSN_SIZE(t) * * F_NOT negates the match result of the instruction. * * F_OR is used to build or blocks. By default, instructions * are evaluated as part of a logical AND. An "or" block * { X or Y or Z } contains F_OR set in all but the last * instruction of the block. A match will cause the code * to skip past the last instruction of the block. * * NOTA BENE: in a couple of places we assume that * sizeof(ipfw_insn) == sizeof(uint32_t) * this needs to be fixed. * */ typedef struct _ipfw_insn { /* template for instructions */ enum ipfw_opcodes opcode:8; uint8_t len; /* numer of 32-byte words */ #define F_NOT 0x80 #define F_OR 0x40 #define F_LEN_MASK 0x3f #define F_LEN(cmd) ((cmd)->len & F_LEN_MASK) uint16_t arg1; } ipfw_insn; #define IPFW_INSN_SIZE_MAX 63 /* unit: uint32_t */ /* * The F_INSN_SIZE(type) computes the size, in 4-byte words, of * a given type. */ #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(uint32_t)) /* * This is used to store an array of 16-bit entries (ports etc.) */ typedef struct _ipfw_insn_u16 { ipfw_insn o; uint16_t ports[2]; /* there may be more */ } ipfw_insn_u16; /* * This is used to store an array of 32-bit entries * (uid, single IPv4 addresses etc.) */ typedef struct _ipfw_insn_u32 { ipfw_insn o; uint32_t d[1]; /* one or more */ } ipfw_insn_u32; /* * This is used to store IP addr-mask pairs. */ typedef struct _ipfw_insn_ip { ipfw_insn o; struct in_addr addr; struct in_addr mask; } ipfw_insn_ip; /* * This is used to forward to a given address (ip) */ typedef struct _ipfw_insn_sa { ipfw_insn o; struct sockaddr_in sa; } ipfw_insn_sa; /* * This is used for MAC addr-mask pairs. */ typedef struct _ipfw_insn_mac { ipfw_insn o; u_char addr[12]; /* dst[6] + src[6] */ u_char mask[12]; /* dst[6] + src[6] */ } ipfw_insn_mac; /* * This is used for interface match rules (recv xx, xmit xx) */ typedef struct _ipfw_insn_if { ipfw_insn o; union { struct in_addr ip; int glob; } p; char name[IFNAMSIZ]; } ipfw_insn_if; /* * This is used for pipe and queue actions, which need to store * a single pointer (which can have different size on different * architectures. */ typedef struct _ipfw_insn_pipe { ipfw_insn o; void *pipe_ptr; } ipfw_insn_pipe; /* * This is used for limit rules. */ typedef struct _ipfw_insn_limit { ipfw_insn o; uint8_t _pad; uint8_t limit_mask; /* combination of DYN_* below */ #define DYN_SRC_ADDR 0x1 #define DYN_SRC_PORT 0x2 #define DYN_DST_ADDR 0x4 #define DYN_DST_PORT 0x8 uint16_t conn_limit; } ipfw_insn_limit; /* * This is used for log instructions */ typedef struct _ipfw_insn_log { ipfw_insn o; uint32_t max_log; /* how many do we log -- 0 = all */ uint32_t log_left; /* how many left to log */ } ipfw_insn_log; /* * This is used by O_IP_{SRC,DST}_IFIP. */ typedef struct _ipfw_insn_ifip { ipfw_insn o; /* arg1 & 0x1, addr is valid */ #define IPFW_IFIP_VALID 0x0001 #define IPFW_IFIP_NET 0x0002 #define IPFW_IFIP_SETTINGS IPFW_IFIP_NET char ifname[IFNAMSIZ]; struct in_addr addr; struct in_addr mask; } ipfw_insn_ifip; /* * This is used by O_REDIRECT. */ typedef struct _ipfw_insn_rdr { ipfw_insn o; struct in_addr addr; uint16_t port; /* network byte order, 0 = same port */ uint16_t set; /* reserved for set, 0xffff */ } ipfw_insn_rdr; #ifdef _KERNEL /* * Here we have the structure representing an ipfw rule. * * It starts with a general area (with link fields and counters) * followed by an array of one or more instructions, which the code * accesses as an array of 32-bit values. * * Given a rule pointer r: * * r->cmd is the start of the first instruction. * ACTION_PTR(r) is the start of the first action (things to do * once a rule matched). * * When assembling instruction, remember the following: * * + if a rule has a "keep-state" (or "limit") option, then the * first instruction (at r->cmd) MUST BE an O_PROBE_STATE * + if a rule has a "log" option, then the first action * (at ACTION_PTR(r)) MUST be O_LOG * * NOTE: we use a simple linked list of rules because we never need * to delete a rule without scanning the list. We do not use * queue(3) macros for portability and readability. */ struct ip_fw { struct ip_fw *next; /* linked list of rules */ struct ip_fw *next_rule; /* ptr to next [skipto] rule */ uint16_t act_ofs; /* offset of action in 32-bit units */ uint16_t cmd_len; /* # of 32-bit words in cmd */ uint16_t rulenum; /* rule number */ uint8_t set; /* rule set (0..31) */ uint8_t usr_flags; /* IPFW_USR_F_ */ /* These fields are present in all rules. */ uint64_t pcnt; /* Packet counter */ uint64_t bcnt; /* Byte counter */ uint32_t timestamp; /* tv_sec of last match */ int cpuid; /* owner cpu */ struct ip_fw *sibling; /* clone on next cpu */ struct ip_fw **cross_rules; /* cross referenced rules */ volatile uint64_t cross_refs; /* cross references */ uint32_t refcnt; /* Ref count for transit pkts */ uint32_t rule_flags; /* IPFW_RULE_F_ */ uintptr_t track_ruleid; /* ruleid for src/dst tracks */ ipfw_insn cmd[1]; /* storage for commands */ }; #define IPFW_RULE_F_INVALID 0x1 /* unused 0x2 */ #define IPFW_RULE_F_GENSTATE 0x4 #define IPFW_RULE_F_GENTRACK 0x8 #define IPFW_RULE_F_CROSSREF 0x10 #define IPFW_RULE_F_DYNIFADDR 0x20 #define RULESIZE(rule) (sizeof(struct ip_fw) + (rule)->cmd_len * 4 - 4) /* * This structure is used as a flow mask and a flow id for various * parts of the code. */ struct ipfw_flow_id { uint32_t dst_ip; /* host byte order */ uint32_t src_ip; /* host byte order */ uint16_t dst_port; /* host byte order */ uint16_t src_port; /* host byte order */ uint8_t proto; uint8_t flags; /* protocol-specific flags */ }; /* * Main firewall chains definitions and global var's definitions. */ /* ipfw_chk/ip_fw_chk_ptr return values */ #define IP_FW_PASS 0 #define IP_FW_DENY 1 #define IP_FW_DIVERT 2 #define IP_FW_TEE 3 #define IP_FW_DUMMYNET 4 #define IP_FW_REDISPATCH 6 /* * arguments for calling ipfw_chk() and dummynet_io(). We put them * all into a structure because this way it is easier and more * efficient to pass variables around and extend the interface. */ struct ip_fw_args { struct mbuf *m; /* the mbuf chain */ struct ifnet *oif; /* output interface */ struct ip_fw *rule; /* matching rule */ struct ipfw_xlat *xlat; /* matching xlate */ struct ether_header *eh; /* for bridged packets */ struct ipfw_flow_id f_id; /* grabbed from IP header */ uint8_t flags; #define IP_FWARG_F_CONT 0x01 #define IP_FWARG_F_XLATINS 0x02 #define IP_FWARG_F_XLATFWD 0x04 /* * Depend on the return value of ipfw_chk/ip_fw_chk_ptr * 'cookie' field may save following information: * * IP_FW_TEE or IP_FW_DIVERT * The divert port number * * IP_FW_DUMMYNET * The pipe or queue number */ uint32_t cookie; }; /* * Function definitions. */ int ip_fw_sockopt(struct sockopt *); /* Firewall hooks */ struct sockopt; struct dn_flow_set; typedef int ip_fw_chk_t(struct ip_fw_args *); typedef int ip_fw_ctl_t(struct sockopt *); typedef struct mbuf *ip_fw_dn_io_t(struct mbuf *, int, int, struct ip_fw_args *); extern ip_fw_chk_t *ip_fw_chk_ptr; extern ip_fw_ctl_t *ip_fw_ctl_ptr; extern ip_fw_dn_io_t *ip_fw_dn_io_ptr; extern int fw_one_pass; extern int fw_enable; extern int ip_fw_loaded; #define IPFW_LOADED (ip_fw_loaded) #endif /* _KERNEL */ #define ACTION_PTR(rule) \ (ipfw_insn *)((uint32_t *)((rule)->cmd) + ((rule)->act_ofs)) struct ipfw_ioc_rule { uint16_t act_ofs; /* offset of action in 32-bit units */ uint16_t cmd_len; /* # of 32-bit words in cmd */ uint16_t rulenum; /* rule number */ uint8_t set; /* rule set (0..31) */ uint8_t usr_flags; /* IPFW_USR_F_ */ /* Rule set information */ uint32_t set_disable; /* disabled rule sets */ uint32_t static_count; /* # of static rules */ uint32_t static_len; /* total length of static rules */ /* Statistics */ uint64_t pcnt; /* Packet counter */ uint64_t bcnt; /* Byte counter */ uint32_t timestamp; /* tv_sec of last match */ uint8_t reserved[16]; ipfw_insn cmd[1]; /* storage for commands */ }; #define IPFW_USR_F_NORULE 0x01 #define IPFW_RULE_SIZE_MAX 255 /* unit: uint32_t */ #define IOC_RULESIZE(rule) \ (sizeof(struct ipfw_ioc_rule) + (rule)->cmd_len * 4 - 4) struct ipfw_ioc_flowid { uint16_t type; /* ETHERTYPE_ */ uint16_t pad; union { struct { uint32_t dst_ip; /* host byte order */ uint32_t src_ip; /* host byte order */ uint16_t dst_port; /* host byte order */ uint16_t src_port; /* host byte order */ uint8_t proto; } ip; uint8_t pad[64]; } u; }; struct ipfw_ioc_state { uint32_t expire; /* expire time */ uint64_t pcnt; /* packet match counter */ uint64_t bcnt; /* byte match counter */ uint16_t dyn_type; /* rule type */ uint16_t count; /* refcount */ uint16_t rulenum; /* rule number */ uint16_t xlat_port; /* xlate port, host byte order */ uint32_t xlat_addr; /* xlate addr, host byte order */ struct ipfw_ioc_flowid id; /* (masked) flow id */ uint8_t reserved[16]; }; /* * 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 #define ICMP_REJECT_RST 0x100 /* fake ICMP code (send a TCP RST) */ /* * IP_FW_TBL_CREATE, tableid >= 0. * IP_FW_TBL_FLUSH, tableid >= 0. * IP_FW_TBL_FLUSH, tableid < 0, flush all tables. * IP_FW_TBL_DESTROY, tableid >= 0. * IP_FW_TBL_ZERO, tableid >= 0. * IP_FW_TBL_ZERO, tableid < 0, zero all tables' counters. */ struct ipfw_ioc_table { int tableid; }; struct ipfw_ioc_tblent { struct sockaddr_in key; struct sockaddr_in netmask; u_long use; time_t last_used; long unused[2]; }; /* * IP_FW_TBL_GET, tableid < 0, list of all tables. */ struct ipfw_ioc_tbllist { int tableid; /* MUST be the first field */ int tablecnt; uint16_t tables[]; }; /* * IP_FW_TBL_GET, tableid >= 0, entries in the table. * IP_FW_TBL_ADD, tableid >= 0, entcnt == 1. * IP_FW_TBL_DEL, tableid >= 0, entcnt == 1. */ struct ipfw_ioc_tblcont { int tableid; /* MUST be the first field */ int entcnt; struct ipfw_ioc_tblent ent[1]; }; /* * IP_FW_TBL_EXPIRE, tableid < 0, expire all tables. * IP_FW_TBL_EXPIRE, tableid >= 0. */ struct ipfw_ioc_tblexp { int tableid; int expcnt; time_t expire; u_long unused1[2]; }; #endif /* _IPFW2_H */
