bsd/netinet/ip_fw.h

   1 /*
   2  * Copyright (c) 2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1993 Daniel Boulet
  24  * Copyright (c) 1994 Ugen J.S.Antsilevich
  25  *
  26  * Redistribution and use in source forms, with and without modification,
  27  * are permitted provided that this entire comment appears intact.
  28  *
  29  * Redistribution in binary form may occur without any restrictions.
  30  * Obviously, it would be nice if you gave credit where credit is due
  31  * but requiring it would be too onerous.
  32  *
  33  * This software is provided ``AS IS'' without any warranties of any kind.
  34  *
  35  */
  36
  37 #ifndef _IP_FW_H
  38 #define _IP_FW_H
  39 #include <sys/appleapiopts.h>
  40
  41 #ifdef IPFW2
  42 #include <netinet/ip_fw2.h>
  43 #else /* !IPFW2, good old ipfw */
  44
  45 #include <sys/queue.h>
  46
  47
  48 #define IP_FW_CURRENT_API_VERSION 20    /* Version of this API */
  49
  50
  51 /*
  52  * This union structure identifies an interface, either explicitly
  53  * by name or implicitly by IP address. The flags IP_FW_F_IIFNAME
  54  * and IP_FW_F_OIFNAME say how to interpret this structure. An
  55  * interface unit number of -1 matches any unit number, while an
  56  * IP address of 0.0.0.0 indicates matches any interface.
  57  *
  58  * The receive and transmit interfaces are only compared against the
  59  * the packet if the corresponding bit (IP_FW_F_IIFACE or IP_FW_F_OIFACE)
  60  * is set. Note some packets lack a receive or transmit interface
  61  * (in which case the missing "interface" never matches).
  62  */
  63
  64 union ip_fw_if {
  65     struct in_addr fu_via_ip;   /* Specified by IP address */
  66     struct {                    /* Specified by interface name */
  67 #define FW_IFNLEN     10 /* need room ! was IFNAMSIZ */
  68             char  name[FW_IFNLEN];
  69             short unit;         /* -1 means match any unit */
  70     } fu_via_if;
  71 };
  72
  73 /*
  74  * Format of an IP firewall descriptor
  75  *
  76  * fw_src, fw_dst, fw_smsk, fw_dmsk are always stored in network byte order.
  77  * fw_flg and fw_n*p are stored in host byte order (of course).
  78  * Port numbers are stored in HOST byte order.
  79  */
  80
  81 struct ip_fw {
  82         u_int32_t version;              /* Version of this structure.  Should always be */
  83                                                         /* set to IP_FW_CURRENT_API_VERSION by clients. */
  84         void *context;                  /* Context that is usable by user processes to */
  85                                                         /* identify this rule. */
  86     u_int64_t fw_pcnt,fw_bcnt;          /* Packet and byte counters */
  87     struct in_addr fw_src, fw_dst;      /* Source and destination IP addr */
  88     struct in_addr fw_smsk, fw_dmsk;    /* Mask for src and dest IP addr */
  89     u_short fw_number;                  /* Rule number */
  90     u_int fw_flg;                       /* Flags word */
  91 #define IP_FW_MAX_PORTS 10              /* A reasonable maximum */
  92         union {
  93         u_short fw_pts[IP_FW_MAX_PORTS];        /* Array of port numbers to match */
  94 #define IP_FW_ICMPTYPES_MAX     128
  95 #define IP_FW_ICMPTYPES_DIM     (IP_FW_ICMPTYPES_MAX / (sizeof(unsigned) * 8))
  96         unsigned fw_icmptypes[IP_FW_ICMPTYPES_DIM]; /* ICMP types bitmap */
  97         } fw_uar;
  98     u_int fw_ipflg;                     /* IP flags word */
  99     u_char fw_ipopt,fw_ipnopt;          /* IP options set/unset */
 100     u_char fw_tcpopt,fw_tcpnopt;        /* TCP options set/unset */
 101     u_char fw_tcpf,fw_tcpnf;            /* TCP flags set/unset */
 102     long timestamp;                     /* timestamp (tv_sec) of last match */
 103     union ip_fw_if fw_in_if, fw_out_if; /* Incoming and outgoing interfaces */
 104     union {
 105         u_short fu_divert_port;         /* Divert/tee port (options IPDIVERT) */
 106         u_short fu_pipe_nr;             /* queue number (option DUMMYNET) */
 107         u_short fu_skipto_rule;         /* SKIPTO command rule number */
 108         u_short fu_reject_code;         /* REJECT response code */
 109         struct sockaddr_in fu_fwd_ip;
 110     } fw_un;
 111     u_char fw_prot;                     /* IP protocol */
 112         /*
 113          * N'of src ports and # of dst ports in ports array (dst ports
 114          * follow src ports; max of 10 ports in all; count of 0 means
 115          * match all ports)
 116          */
 117     u_char fw_nports;
 118     void *pipe_ptr;                    /* flow_set ptr for dummynet pipe */
 119     void *next_rule_ptr ;              /* next rule in case of match */
 120     uid_t fw_uid;                       /* uid to match */
 121     int fw_logamount;                   /* amount to log */
 122     u_int64_t fw_loghighest;            /* highest number packet to log */
 123 };
 124
 125 /*
 126  * extended ipfw structure... some fields in the original struct
 127  * can be used to pass parameters up/down, namely pointers
 128  *     void *pipe_ptr
 129  *     void *next_rule_ptr
 130  * some others can be used to pass parameters down, namely counters etc.
 131  *     u_int64_t fw_pcnt,fw_bcnt;
 132  *     long timestamp;
 133  */
 134
 135 struct ip_fw_ext {             /* extended structure */
 136     struct ip_fw rule;      /* must be at offset 0 */
 137     long    dont_match_prob;        /* 0x7fffffff means 1.0, always fail */
 138     u_int   dyn_type;  /* type for dynamic rule */
 139 };
 140
 141 #define IP_FW_GETNSRCP(rule)            ((rule)->fw_nports & 0x0f)
 142 #define IP_FW_SETNSRCP(rule, n)         do {                            \
 143                                           (rule)->fw_nports &= ~0x0f;   \
 144                                           (rule)->fw_nports |= (n);     \
 145                                         } while (0)
 146 #define IP_FW_GETNDSTP(rule)            ((rule)->fw_nports >> 4)
 147 #define IP_FW_SETNDSTP(rule, n)         do {                            \
 148                                           (rule)->fw_nports &= ~0xf0;   \
 149                                           (rule)->fw_nports |= (n) << 4;\
 150                                         } while (0)
 151
 152 #define fw_divert_port  fw_un.fu_divert_port
 153 #define fw_skipto_rule  fw_un.fu_skipto_rule
 154 #define fw_reject_code  fw_un.fu_reject_code
 155 #define fw_pipe_nr      fw_un.fu_pipe_nr
 156 #define fw_fwd_ip       fw_un.fu_fwd_ip
 157
 158 struct ip_fw_chain {
 159         LIST_ENTRY(ip_fw_chain) next;
 160         struct ip_fw *rule;
 161 };
 162
 163 /*
 164  * Flow mask/flow id for each queue.
 165  */
 166 struct ipfw_flow_id {
 167     u_int32_t dst_ip, src_ip ;
 168     u_int16_t dst_port, src_port ;
 169     u_int8_t proto ;
 170     u_int8_t flags ;    /* protocol-specific flags */
 171 } ;
 172
 173 /*
 174  * dynamic ipfw rule
 175  */
 176 struct ipfw_dyn_rule {
 177     struct ipfw_dyn_rule *next ;
 178
 179     struct ipfw_flow_id id ;
 180     struct ipfw_flow_id mask ;
 181     struct ip_fw_chain *chain ;         /* pointer to parent rule       */
 182     u_int32_t type ;                    /* rule type                    */
 183     u_int32_t expire ;                  /* expire time                  */
 184     u_int64_t pcnt, bcnt;               /* match counters               */
 185     u_int32_t bucket ;                  /* which bucket in hash table   */
 186     u_int32_t state ;                   /* state of this rule (typ. a   */
 187                                         /* combination of TCP flags)    */
 188 } ;
 189
 190 /*
 191  * Values for "flags" field .
 192  */
 193 #define IP_FW_F_COMMAND 0x000000ff      /* Mask for type of chain entry:        */
 194 #define IP_FW_F_DENY    0x00000000      /* This is a deny rule                  */
 195 #define IP_FW_F_REJECT  0x00000001      /* Deny and send a response packet      */
 196 #define IP_FW_F_ACCEPT  0x00000002      /* This is an accept rule               */
 197 #define IP_FW_F_COUNT   0x00000003      /* This is a count rule                 */
 198 #define IP_FW_F_DIVERT  0x00000004      /* This is a divert rule                */
 199 #define IP_FW_F_TEE     0x00000005      /* This is a tee rule                   */
 200 #define IP_FW_F_SKIPTO  0x00000006      /* This is a skipto rule                */
 201 #define IP_FW_F_FWD     0x00000007      /* This is a "change forwarding address" rule */
 202 #define IP_FW_F_PIPE    0x00000008      /* This is a dummynet rule */
 203 #define IP_FW_F_QUEUE   0x00000009      /* This is a dummynet queue */
 204
 205 #define IP_FW_F_IN      0x00000100      /* Check inbound packets                */
 206 #define IP_FW_F_OUT     0x00000200      /* Check outbound packets               */
 207 #define IP_FW_F_IIFACE  0x00000400      /* Apply inbound interface test         */
 208 #define IP_FW_F_OIFACE  0x00000800      /* Apply outbound interface test        */
 209
 210 #define IP_FW_F_PRN     0x00001000      /* Print if this rule matches           */
 211
 212 #define IP_FW_F_SRNG    0x00002000      /* The first two src ports are a min    *
 213                                          * and max range (stored in host byte   *
 214                                          * order).                              */
 215
 216 #define IP_FW_F_DRNG    0x00004000      /* The first two dst ports are a min    *
 217                                          * and max range (stored in host byte   *
 218                                          * order).                              */
 219
 220 #define IP_FW_F_FRAG    0x00008000      /* Fragment                             */
 221
 222 #define IP_FW_F_IIFNAME 0x00010000      /* In interface by name/unit (not IP)   */
 223 #define IP_FW_F_OIFNAME 0x00020000      /* Out interface by name/unit (not IP)  */
 224
 225 #define IP_FW_F_INVSRC  0x00040000      /* Invert sense of src check            */
 226 #define IP_FW_F_INVDST  0x00080000      /* Invert sense of dst check            */
 227
 228 #define IP_FW_F_ICMPBIT 0x00100000      /* ICMP type bitmap is valid            */
 229
 230 #define IP_FW_F_UID     0x00200000      /* filter by uid                        */
 231
 232 #define IP_FW_F_RND_MATCH 0x00800000    /* probabilistic rule match             */
 233 #define IP_FW_F_SMSK    0x01000000      /* src-port + mask                      */
 234 #define IP_FW_F_DMSK    0x02000000      /* dst-port + mask                      */
 235 #define IP_FW_BRIDGED   0x04000000      /* only match bridged packets           */
 236 #define IP_FW_F_KEEP_S  0x08000000      /* keep state                           */
 237 #define IP_FW_F_CHECK_S 0x10000000      /* check state                          */
 238
 239 #define IP_FW_F_SME     0x20000000      /* source = me                          */
 240 #define IP_FW_F_DME     0x40000000      /* destination = me                     */
 241
 242 #define IP_FW_F_MASK    0x7FFFFFFF      /* All possible flag bits mask          */
 243
 244 /*
 245  * Flags for the 'fw_ipflg' field, for comparing values of ip and its protocols.
 246  */
 247 #define IP_FW_IF_TCPEST 0x00000020      /* established TCP connection */
 248 #define IP_FW_IF_TCPMSK 0x00000020      /* mask of all TCP values */
 249
 250 /*
 251  * For backwards compatibility with rules specifying "via iface" but
 252  * not restricted to only "in" or "out" packets, we define this combination
 253  * of bits to represent this configuration.
 254  */
 255
 256 #define IF_FW_F_VIAHACK (IP_FW_F_IN|IP_FW_F_OUT|IP_FW_F_IIFACE|IP_FW_F_OIFACE)
 257
 258 /*
 259  * Definitions for REJECT response codes.
 260  * Values less than 256 correspond to ICMP unreachable codes.
 261  */
 262 #define IP_FW_REJECT_RST        0x0100          /* TCP packets: send RST */
 263
 264 /*
 265  * Definitions for IP option names.
 266  */
 267 #define IP_FW_IPOPT_LSRR        0x01
 268 #define IP_FW_IPOPT_SSRR        0x02
 269 #define IP_FW_IPOPT_RR          0x04
 270 #define IP_FW_IPOPT_TS          0x08
 271
 272 /*
 273  * Definitions for TCP option names.
 274  */
 275 #define IP_FW_TCPOPT_MSS        0x01
 276 #define IP_FW_TCPOPT_WINDOW     0x02
 277 #define IP_FW_TCPOPT_SACK       0x04
 278 #define IP_FW_TCPOPT_TS         0x08
 279 #define IP_FW_TCPOPT_CC         0x10
 280
 281 /*
 282  * Definitions for TCP flags.
 283  */
 284 #define IP_FW_TCPF_FIN          TH_FIN
 285 #define IP_FW_TCPF_SYN          TH_SYN
 286 #define IP_FW_TCPF_RST          TH_RST
 287 #define IP_FW_TCPF_PSH          TH_PUSH
 288 #define IP_FW_TCPF_ACK          TH_ACK
 289 #define IP_FW_TCPF_URG          TH_URG
 290
 291 /*
 292  * Main firewall chains definitions and global var's definitions.
 293  */
 294 #ifdef KERNEL_PRIVATE
 295
 296 #define IP_FW_PORT_DYNT_FLAG    0x10000
 297 #define IP_FW_PORT_TEE_FLAG     0x20000
 298 #define IP_FW_PORT_DENY_FLAG    0x40000
 299
 300 /*
 301  * Function definitions.
 302  */
 303 void ip_fw_init(void);
 304
 305 /* Firewall hooks */
 306 struct ip;
 307 struct sockopt;
 308 typedef int ip_fw_chk_t(struct ip **, int, struct ifnet *, u_int16_t *,
 309              struct mbuf **, struct ip_fw_chain **, struct sockaddr_in **);
 310 typedef int ip_fw_ctl_t(struct sockopt *);
 311 extern  ip_fw_chk_t *ip_fw_chk_ptr;
 312 extern  ip_fw_ctl_t *ip_fw_ctl_ptr;
 313 extern int fw_one_pass;
 314 extern int fw_enable;
 315 extern struct ipfw_flow_id last_pkt ;
 316 #endif KERNEL_PRIVATE
 317
 318 #endif !IPFW2
 319 #endif /* _IP_FW_H */