/* * 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 1.1.2.4 2003/07/17 06:03:39 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 metadata) 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). * Note that the code is written so that individual instructions * have a size which is a multiple of 32 bits. This means that, if * such structures contain pointers or other 64-bit entities, * (there is just one instance now) they may end up unaligned on * 64-bit architectures, so the must be handled with care. * * "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, /* u32 = icmp bitmap */ O_TCPOPTS, /* arg1 = 2*u8 bitmap */ O_VERREVPATH, /* none */ O_PROBE_STATE, /* none */ O_KEEP_STATE, /* none */ O_LIMIT, /* ipfw_insn_limit */ O_LIMIT_PARENT, /* dyn_type, not an opcode. */ /* * These are really '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 */ /* * More opcodes. */ O_IPSEC, /* has ipsec history */ O_LAST_OPCODE /* not an opcode! */ }; /* * 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(u_int32_t) * this needs to be fixed. * */ typedef struct _ipfw_insn { /* template for instructions */ enum ipfw_opcodes opcode:8; u_int8_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) u_int16_t arg1; } ipfw_insn; /* * The F_INSN_SIZE(type) computes the size, in 4-byte words, of * a given type. */ #define F_INSN_SIZE(t) ((sizeof (t))/sizeof(u_int32_t)) /* * This is used to store an array of 16-bit entries (ports etc.) */ typedef struct _ipfw_insn_u16 { ipfw_insn o; u_int16_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; u_int32_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; int32_t unit; } 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. * Note that, because of previous instructions, pipe_ptr might * be unaligned in the overall structure, so it needs to be * manipulated with care. */ typedef struct _ipfw_insn_pipe { ipfw_insn o; void *pipe_ptr; /* XXX */ } ipfw_insn_pipe; /* * This is used for limit rules. */ typedef struct _ipfw_insn_limit { ipfw_insn o; u_int8_t _pad; u_int8_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 u_int16_t conn_limit; } ipfw_insn_limit; /* * This is used for log instructions. */ typedef struct _ipfw_insn_log { ipfw_insn o; u_int32_t max_log; /* how many do we log -- 0 = all */ u_int32_t log_left; /* how many left to log */ } ipfw_insn_log; /* Version of this API */ #define IP_FW_VERSION_NONE 0 #define IP_FW_VERSION_0 10 /* old ipfw */ #define IP_FW_VERSION_1 20 /* ipfw in Jaguar/Panther */ #define IP_FW_VERSION_2 30 /* ipfw2 */ #define IP_FW_CURRENT_API_VERSION IP_FW_VERSION_2 /* * 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 { u_int32_t version; /* Version of this structure. MUST be set */ /* by clients. Should always be */ /* set to IP_FW_CURRENT_API_VERSION. */ void *context; /* Context that is usable by user processes to */ /* identify this rule. */ struct ip_fw *next; /* linked list of rules */ struct ip_fw *next_rule; /* ptr to next [skipto] rule */ /* 'next_rule' is used to pass up 'set_disable' status */ u_int16_t act_ofs; /* offset of action in 32-bit units */ u_int16_t cmd_len; /* # of 32-bit words in cmd */ u_int16_t rulenum; /* rule number */ u_int8_t set; /* rule set (0..31) */ u_int32_t set_masks[2]; /* masks for manipulating sets atomically */ #define RESVD_SET 31 /* set for default and persistent rules */ u_int8_t _pad; /* padding */ /* These fields are present in all rules. */ u_int64_t pcnt; /* Packet counter */ u_int64_t bcnt; /* Byte counter */ u_int32_t timestamp; /* tv_sec of last match */ u_int32_t reserved_1; /* reserved - set to 0 */ u_int32_t reserved_2; /* reserved - set to 0 */ ipfw_insn cmd[1]; /* storage for commands */ }; #define ACTION_PTR(rule) \ (ipfw_insn *)( (u_int32_t *)((rule)->cmd) + ((rule)->act_ofs) ) #define RULESIZE(rule) (sizeof(struct ip_fw) + \ ((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 { 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. */ typedef struct _ipfw_dyn_rule ipfw_dyn_rule; struct _ipfw_dyn_rule { ipfw_dyn_rule *next; /* linked list of rules. */ struct ip_fw *rule; /* pointer to rule */ /* 'rule' is used to pass up the rule number (from the parent) */ ipfw_dyn_rule *parent; /* pointer to parent rule */ u_int64_t pcnt; /* packet match counter */ u_int64_t bcnt; /* byte match counter */ struct ipfw_flow_id id; /* (masked) flow id */ u_int32_t expire; /* expire time */ u_int32_t bucket; /* which bucket in hash table */ u_int32_t state; /* state of this rule (typically a * combination of TCP flags) */ u_int32_t ack_fwd; /* most recent ACKs in forward */ u_int32_t ack_rev; /* and reverse directions (used */ /* to generate keepalives) */ u_int16_t dyn_type; /* rule type */ u_int16_t count; /* refcount */ }; /* * 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) */ /* * 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 /* * 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 sockaddr_in *next_hop; /* forward address */ struct ip_fw *rule; /* matching rule */ struct ether_header *eh; /* for bridged packets */ struct route *ro; /* for dummynet */ struct sockaddr_in *dst; /* for dummynet */ int flags; /* for dummynet */ struct ipfw_flow_id f_id; /* grabbed from IP header */ u_int16_t divert_rule; /* divert cookie */ u_int32_t retval; }; /* * Function definitions. */ /* Firewall hooks */ struct sockopt; struct dn_flow_set; void flush_pipe_ptrs(struct dn_flow_set *match); /* used by dummynet */ void ipfw_init(void); /* called from raw_ip.c: load_ipfw() */ typedef int ip_fw_chk_t (struct ip_fw_args *args); 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; #define IPFW_LOADED (ip_fw_chk_ptr != NULL) #endif /* KERNEL */ #endif /* _IPFW2_H */