--- /dev/null
+/*
+ * 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 */
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