/*- * Copyright (c) 2002-2009 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. * * $FreeBSD$ */ #ifndef _IPFW2_H #define _IPFW2_H /* * The default rule number. By the design of ip_fw, the default rule * is the last one, so its number can also serve as the highest number * allowed for a rule. The ip_fw code relies on both meanings of this * constant. */ #define IPFW_DEFAULT_RULE 65535 /* * The number of ipfw tables. The maximum allowed table number is the * (IPFW_TABLES_MAX - 1). */ #define IPFW_TABLES_MAX 128 /* * Most commands (queue, pipe, tag, untag, limit...) can have a 16-bit * argument between 1 and 65534. The value 0 is unused, the value * 65535 (IP_FW_TABLEARG) is used to represent 'tablearg', i.e. the * can be 1..65534, or 65535 to indicate the use of a 'tablearg' * result of the most recent table() lookup. * Note that 16bit is only a historical limit, resulting from * the use of a 16-bit fields for that value. In reality, we can have * 2^32 pipes, queues, tag values and so on, and use 0 as a tablearg. */ #define IPFW_ARG_MIN 1 #define IPFW_ARG_MAX 65534 #define IP_FW_TABLEARG 65535 /* XXX should use 0 */ /* * 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. When adding new opcodes, they should * be appended to the end of the opcode list before O_LAST_OPCODE, * this will prevent the ABI from being broken, otherwise users * will have to recompile ipfw(8) when they update the kernel. */ 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_VERSRCREACH, /* 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 */ O_NAT, /* nope */ O_REASS, /* none */ /* * More opcodes. */ O_IPSEC, /* has ipsec history */ O_IP_SRC_LOOKUP, /* arg1=table number, u32=value */ O_IP_DST_LOOKUP, /* arg1=table number, u32=value */ O_ANTISPOOF, /* none */ O_JAIL, /* u32 = id */ O_ALTQ, /* u32 = altq classif. qid */ O_DIVERTED, /* arg1=bitmap (1:loop, 2:out) */ O_TCPDATALEN, /* arg1 = tcp data len */ O_IP6_SRC, /* address without mask */ O_IP6_SRC_ME, /* my addresses */ O_IP6_SRC_MASK, /* address with the mask */ O_IP6_DST, O_IP6_DST_ME, O_IP6_DST_MASK, O_FLOW6ID, /* for flow id tag in the ipv6 pkt */ O_ICMP6TYPE, /* icmp6 packet type filtering */ O_EXT_HDR, /* filtering for ipv6 extension header */ O_IP6, /* * actions for ng_ipfw */ O_NETGRAPH, /* send to ng_ipfw */ O_NGTEE, /* copy to ng_ipfw */ O_IP4, O_UNREACH6, /* arg1=icmpv6 code arg (deny) */ O_TAG, /* arg1=tag number */ O_TAGGED, /* arg1=tag number */ O_SETFIB, /* arg1=FIB number */ O_FIB, /* arg1=FIB desired fib number */ O_LAST_OPCODE /* not an opcode! */ }; /* * The extension header are filtered only for presence using a bit * vector with a flag for each header. */ #define EXT_FRAGMENT 0x1 #define EXT_HOPOPTS 0x2 #define EXT_ROUTING 0x4 #define EXT_AH 0x8 #define EXT_ESP 0x10 #define EXT_DSTOPTS 0x20 #define EXT_RTHDR0 0x40 #define EXT_RTHDR2 0x80 /* * 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; /* number of 32-bit 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; int glob; } p; char name[IFNAMSIZ]; } ipfw_insn_if; /* * This is used for storing an altq queue id number. */ typedef struct _ipfw_insn_altq { ipfw_insn o; u_int32_t qid; } ipfw_insn_altq; /* * 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; /* * Data structures required by both ipfw(8) and ipfw(4) but not part of the * management API are protected by IPFW_INTERNAL. */ #ifdef IPFW_INTERNAL /* Server pool support (LSNAT). */ struct cfg_spool { LIST_ENTRY(cfg_spool) _next; /* chain of spool instances */ struct in_addr addr; u_short port; }; #endif /* Redirect modes id. */ #define REDIR_ADDR 0x01 #define REDIR_PORT 0x02 #define REDIR_PROTO 0x04 #ifdef IPFW_INTERNAL /* Nat redirect configuration. */ struct cfg_redir { LIST_ENTRY(cfg_redir) _next; /* chain of redir instances */ u_int16_t mode; /* type of redirect mode */ struct in_addr laddr; /* local ip address */ struct in_addr paddr; /* public ip address */ struct in_addr raddr; /* remote ip address */ u_short lport; /* local port */ u_short pport; /* public port */ u_short rport; /* remote port */ u_short pport_cnt; /* number of public ports */ u_short rport_cnt; /* number of remote ports */ int proto; /* protocol: tcp/udp */ struct alias_link **alink; /* num of entry in spool chain */ u_int16_t spool_cnt; /* chain of spool instances */ LIST_HEAD(spool_chain, cfg_spool) spool_chain; }; #endif #define NAT_BUF_LEN 1024 #ifdef IPFW_INTERNAL /* Nat configuration data struct. */ struct cfg_nat { /* chain of nat instances */ LIST_ENTRY(cfg_nat) _next; int id; /* nat id */ struct in_addr ip; /* nat ip address */ char if_name[IF_NAMESIZE]; /* interface name */ int mode; /* aliasing mode */ struct libalias *lib; /* libalias instance */ /* number of entry in spool chain */ int redir_cnt; /* chain of redir instances */ LIST_HEAD(redir_chain, cfg_redir) redir_chain; }; #endif #define SOF_NAT sizeof(struct cfg_nat) #define SOF_REDIR sizeof(struct cfg_redir) #define SOF_SPOOL sizeof(struct cfg_spool) /* Nat command. */ typedef struct _ipfw_insn_nat { ipfw_insn o; struct cfg_nat *nat; } ipfw_insn_nat; /* Apply ipv6 mask on ipv6 addr */ #define APPLY_MASK(addr,mask) \ (addr)->__u6_addr.__u6_addr32[0] &= (mask)->__u6_addr.__u6_addr32[0]; \ (addr)->__u6_addr.__u6_addr32[1] &= (mask)->__u6_addr.__u6_addr32[1]; \ (addr)->__u6_addr.__u6_addr32[2] &= (mask)->__u6_addr.__u6_addr32[2]; \ (addr)->__u6_addr.__u6_addr32[3] &= (mask)->__u6_addr.__u6_addr32[3]; /* Structure for ipv6 */ typedef struct _ipfw_insn_ip6 { ipfw_insn o; struct in6_addr addr6; struct in6_addr mask6; } ipfw_insn_ip6; /* Used to support icmp6 types */ typedef struct _ipfw_insn_icmp6 { ipfw_insn o; uint32_t d[7]; /* XXX This number si related to the netinet/icmp6.h * define ICMP6_MAXTYPE * as follows: n = ICMP6_MAXTYPE/32 + 1 * Actually is 203 */ } ipfw_insn_icmp6; /* * 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 * + if a rule has an "altq" option, it comes after "log" * + if a rule has an O_TAG option, it comes after "log" and "altq" * * 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 */ /* 'next_rule' is used to pass up 'set_disable' status */ 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) */ #define RESVD_SET 31 /* set for default and persistent rules */ uint8_t _pad; /* padding */ uint32_t id; /* rule id */ /* 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 */ 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 fib; u_int8_t proto; u_int8_t flags; /* protocol-specific flags */ uint8_t addr_type; /* 4 = ipv4, 6 = ipv6, 1=ether ? */ struct in6_addr dst_ip6; /* could also store MAC addr! */ struct in6_addr src_ip6; u_int32_t flow_id6; u_int32_t frag_id6; }; #define IS_IP6_FLOW_ID(id) ((id)->addr_type == 6) /* * 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) */ #define ICMP6_UNREACH_RST 0x100 /* fake ICMPv6 code (send a TCP RST) */ /* * These are used for lookup tables. */ typedef struct _ipfw_table_entry { in_addr_t addr; /* network address */ u_int32_t value; /* value */ u_int16_t tbl; /* table number */ u_int8_t masklen; /* mask length */ } ipfw_table_entry; typedef struct _ipfw_table { u_int32_t size; /* size of entries in bytes */ u_int32_t cnt; /* # of entries */ u_int16_t tbl; /* table number */ ipfw_table_entry ent[0]; /* entries */ } ipfw_table; /* * Main firewall chains definitions and global var's definitions. */ #ifdef _KERNEL #define MTAG_IPFW 1148380143 /* IPFW-tagged cookie */ /* Return values from ipfw_chk() */ enum { IP_FW_PASS = 0, IP_FW_DENY, IP_FW_DIVERT, IP_FW_TEE, IP_FW_DUMMYNET, IP_FW_NETGRAPH, IP_FW_NGTEE, IP_FW_NAT, IP_FW_REASS, }; /* flags for divert mtag */ #define IP_FW_DIVERT_LOOPBACK_FLAG 0x00080000 #define IP_FW_DIVERT_OUTPUT_FLAG 0x00100000 /* * Structure for collecting parameters to dummynet for ip6_output forwarding */ struct _ip6dn_args { struct ip6_pktopts *opt_or; struct route_in6 ro_or; int flags_or; struct ip6_moptions *im6o_or; struct ifnet *origifp_or; struct ifnet *ifp_or; struct sockaddr_in6 dst_or; u_long mtu_or; struct route_in6 ro_pmtu_or; }; /* * 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 */ uint32_t rule_id; /* matching rule id */ uint32_t chain_id; /* ruleset id */ struct ether_header *eh; /* for bridged packets */ struct ipfw_flow_id f_id; /* grabbed from IP header */ uint32_t cookie; /* a cookie depending on rule action */ struct inpcb *inp; struct _ip6dn_args dummypar; /* dummynet->ip6_output */ struct sockaddr_in hopstore; /* store here if cannot use a pointer */ }; /* * Function definitions. */ /* Firewall hooks */ struct sockopt; struct dn_flow_set; int ipfw_check_in(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp); int ipfw_check_out(void *, struct mbuf **, struct ifnet *, int, struct inpcb *inp); int ipfw_chk(struct ip_fw_args *); int ipfw_init(void); void ipfw_destroy(void); #ifdef NOTYET void ipfw_nat_destroy(void); #endif VNET_DECLARE(int, fw_one_pass); VNET_DECLARE(int, fw_enable); #define V_fw_one_pass VNET_GET(fw_one_pass) #define V_fw_enable VNET_GET(fw_enable) #ifdef INET6 VNET_DECLARE(int, fw6_enable); #define V_fw6_enable VNET_GET(fw6_enable) #endif struct ip_fw_chain { struct ip_fw *rules; /* list of rules */ struct ip_fw *reap; /* list of rules to reap */ LIST_HEAD(, cfg_nat) nat; /* list of nat entries */ struct radix_node_head *tables[IPFW_TABLES_MAX]; struct rwlock rwmtx; uint32_t id; /* ruleset id */ }; #ifdef IPFW_INTERNAL #define IPFW_LOCK_INIT(_chain) \ rw_init(&(_chain)->rwmtx, "IPFW static rules") #define IPFW_LOCK_DESTROY(_chain) rw_destroy(&(_chain)->rwmtx) #define IPFW_WLOCK_ASSERT(_chain) rw_assert(&(_chain)->rwmtx, RA_WLOCKED) #define IPFW_RLOCK(p) rw_rlock(&(p)->rwmtx) #define IPFW_RUNLOCK(p) rw_runlock(&(p)->rwmtx) #define IPFW_WLOCK(p) rw_wlock(&(p)->rwmtx) #define IPFW_WUNLOCK(p) rw_wunlock(&(p)->rwmtx) #define LOOKUP_NAT(l, i, p) do { \ LIST_FOREACH((p), &(l.nat), _next) { \ if ((p)->id == (i)) { \ break; \ } \ } \ } while (0) typedef int ipfw_nat_t(struct ip_fw_args *, struct cfg_nat *, struct mbuf *); typedef int ipfw_nat_cfg_t(struct sockopt *); #endif VNET_DECLARE(struct ip_fw_chain, layer3_chain); #define V_layer3_chain VNET_GET(layer3_chain) #endif /* _KERNEL */ #endif /* _IPFW2_H */