includes/tree.h

   1 /* tree.h
   2
   3    Definitions for address trees... */
   4
   5 /*
   6  * Copyright (c) 1996-1999 Internet Software Consortium.
   7  * Use is subject to license terms which appear in the file named
   8  * ISC-LICENSE that should have accompanied this file when you
   9  * received it.   If a file named ISC-LICENSE did not accompany this
  10  * file, or you are not sure the one you have is correct, you may
  11  * obtain an applicable copy of the license at:
  12  *
  13  *             http://www.isc.org/isc-license-1.0.html.
  14  *
  15  * This file is part of the ISC DHCP distribution.   The documentation
  16  * associated with this file is listed in the file DOCUMENTATION,
  17  * included in the top-level directory of this release.
  18  *
  19  * Support and other services are available for ISC products - see
  20  * http://www.isc.org for more information.
  21  */
  22
  23 /* A pair of pointers, suitable for making a linked list. */
  24 typedef struct _pair {
  25         caddr_t car;
  26         struct _pair *cdr;
  27 } *pair;
  28
  29 /* Tree node types... */
  30 #define TREE_CONCAT             1
  31 #define TREE_HOST_LOOKUP        2
  32 #define TREE_CONST              3
  33 #define TREE_LIMIT              4
  34 #define TREE_DATA_EXPR          5
  35
  36 /* A data buffer with a reference count. */
  37 struct buffer {
  38         int refcnt;
  39         unsigned char data [1];
  40 };
  41
  42 /* XXX The mechanism by which data strings are returned is currently
  43    XXX broken: rather than returning an ephemeral pointer, we create
  44    XXX a reference to the data in the caller's space, which the caller
  45    XXX then has to dereference - instead, the reference should be
  46    XXX ephemeral by default and be made a persistent reference explicitly. */
  47 /* XXX on the other hand, it seems to work pretty nicely, so maybe the
  48    XXX above comment is meshuggenah. */
  49
  50 /* A string of data bytes, possibly accompanied by a larger buffer. */
  51 struct data_string {
  52         struct buffer *buffer;
  53         const unsigned char *data;
  54         unsigned len;   /* Does not include NUL terminator, if any. */
  55         int terminated;
  56 };
  57
  58 enum expression_context {
  59         context_any, /* indefinite */
  60         context_boolean,
  61         context_data,
  62         context_numeric,
  63         context_dns,
  64         context_data_or_numeric, /* indefinite */
  65         context_function
  66 };
  67
  68 struct fundef {
  69         int refcnt;
  70         struct string_list *args;
  71         struct executable_statement *statements;
  72 };
  73
  74 struct binding_value {
  75         int refcnt;
  76         enum {
  77                 binding_boolean,
  78                 binding_data,
  79                 binding_numeric,
  80                 binding_dns,
  81                 binding_function
  82         } type;
  83         union value {
  84                 struct data_string data;
  85                 unsigned long intval;
  86                 int boolean;
  87 #if defined (NSUPDATE)
  88                 ns_updrec *dns;
  89 #endif
  90                 struct fundef *fundef;
  91                 struct binding_value *bv;
  92         } value;
  93 };
  94
  95 struct binding {
  96         struct binding *next;
  97         char *name;
  98         struct binding_value *value;
  99 };
 100
 101 struct binding_scope {
 102         struct binding_scope *outer;
 103         struct binding *bindings;
 104 };
 105
 106 /* Expression tree structure. */
 107
 108 enum expr_op {
 109         expr_none,
 110         expr_match,
 111         expr_check,
 112         expr_equal,
 113         expr_substring,
 114         expr_suffix,
 115         expr_concat,
 116         expr_host_lookup,
 117         expr_and,
 118         expr_or,
 119         expr_not,
 120         expr_option,
 121         expr_hardware,
 122         expr_packet,
 123         expr_const_data,
 124         expr_extract_int8,
 125         expr_extract_int16,
 126         expr_extract_int32,
 127         expr_encode_int8,
 128         expr_encode_int16,
 129         expr_encode_int32,
 130         expr_const_int,
 131         expr_exists,
 132         expr_encapsulate,
 133         expr_known,
 134         expr_reverse,
 135         expr_leased_address,
 136         expr_binary_to_ascii,
 137         expr_config_option,
 138         expr_host_decl_name,
 139         expr_pick_first_value,
 140         expr_lease_time,
 141         expr_dns_transaction,
 142         expr_static,
 143         expr_ns_add,
 144         expr_ns_delete,
 145         expr_ns_exists,
 146         expr_ns_not_exists,
 147         expr_not_equal,
 148         expr_null,
 149         expr_variable_exists,
 150         expr_variable_reference,
 151         expr_filename,
 152         expr_sname,
 153         expr_arg,
 154         expr_funcall,
 155         expr_function,
 156         expr_add,
 157         expr_subtract,
 158         expr_multiply,
 159         expr_divide,
 160         expr_remainder
 161 };
 162
 163 struct expression {
 164         int refcnt;
 165         enum expr_op op;
 166         union {
 167                 struct {
 168                         struct expression *expr;
 169                         struct expression *offset;
 170                         struct expression *len;
 171                 } substring;
 172                 struct expression *equal [2];
 173                 struct expression *and [2];
 174                 struct expression *or [2];
 175                 struct expression *not;
 176                 struct expression *add;
 177                 struct expression *subtract;
 178                 struct expression *multiply;
 179                 struct expression *divide;
 180                 struct expression *remainder;
 181                 struct collection *check;
 182                 struct {
 183                         struct expression *expr;
 184                         struct expression *len;
 185                 } suffix;
 186                 struct option *option;
 187                 struct option *config_option;
 188                 struct {
 189                         struct expression *offset;
 190                         struct expression *len;
 191                 } packet;
 192                 struct data_string const_data;
 193                 struct expression *extract_int;
 194                 struct expression *encode_int;
 195                 unsigned long const_int;
 196                 struct expression *concat [2];
 197                 struct dns_host_entry *host_lookup;
 198                 struct option *exists;
 199                 struct data_string encapsulate;
 200                 struct {
 201                         struct expression *base;
 202                         struct expression *width;
 203                         struct expression *seperator;
 204                         struct expression *buffer;
 205                 } b2a;
 206                 struct {
 207                         struct expression *width;
 208                         struct expression *buffer;
 209                 } reverse;
 210                 struct {
 211                         struct expression *car;
 212                         struct expression *cdr;
 213                 } pick_first_value;
 214                 struct {
 215                         struct expression *car;
 216                         struct expression *cdr;
 217                 } dns_transaction;
 218                 struct {
 219                         unsigned rrclass;
 220                         unsigned rrtype;
 221                         struct expression *rrname;
 222                         struct expression *rrdata;
 223                         struct expression *ttl;
 224                 } ns_add;
 225                 struct {
 226                         unsigned rrclass;
 227                         unsigned rrtype;
 228                         struct expression *rrname;
 229                         struct expression *rrdata;
 230                 } ns_delete, ns_exists, ns_not_exists;
 231                 char *variable;
 232                 struct {
 233                         struct expression *val;
 234                         struct expression *next;
 235                 } arg;
 236                 struct {
 237                         char *name;
 238                         struct expression *arglist;
 239                 } funcall;
 240                 struct fundef *func;
 241         } data;
 242         int flags;
 243 #       define EXPR_EPHEMERAL   1
 244 };
 245
 246 /* DNS host entry structure... */
 247 struct dns_host_entry {
 248         int refcnt;
 249         TIME timeout;
 250         struct data_string data;
 251         char hostname [1];
 252 };
 253
 254 struct option_cache; /* forward */
 255 struct packet; /* forward */
 256 struct option_state; /* forward */
 257 struct decoded_option_state; /* forward */
 258 struct lease; /* forward */
 259
 260 struct universe {
 261         const char *name;
 262         struct option_cache *(*lookup_func) PROTO ((struct universe *,
 263                                                     struct option_state *,
 264                                                     unsigned));
 265         void (*save_func) PROTO ((struct universe *, struct option_state *,
 266                                   struct option_cache *));
 267         int (*get_func) PROTO ((struct data_string *, struct universe *,
 268                                 struct packet *, struct lease *,
 269                                 struct option_state *, struct option_state *,
 270                                 struct option_state *, struct binding_scope *,
 271                                 unsigned));
 272         void (*set_func) PROTO ((struct universe *, struct option_state *,
 273                                  struct option_cache *, enum statement_op));
 274
 275         void (*delete_func) PROTO ((struct universe *universe,
 276                                     struct option_state *, int));
 277         int (*option_state_dereference) PROTO ((struct universe *,
 278                                                 struct option_state *,
 279                                                 const char *, int));
 280         int (*encapsulate) PROTO ((struct data_string *, struct packet *,
 281                                    struct lease *, struct option_state *,
 282                                    struct option_state *,
 283                                    struct binding_scope *, struct universe *));
 284         void (*store_tag) PROTO ((unsigned char *, u_int32_t));
 285         void (*store_length) PROTO ((unsigned char *, u_int32_t));
 286         int tag_size, length_size;
 287         struct hash_table *hash;
 288         struct option *options [256];
 289         int index;
 290 };
 291
 292 struct option {
 293         const char *name;
 294         const char *format;
 295         struct universe *universe;
 296         unsigned code;
 297 };