filter/data.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Dynamic data structures
   3  *
   4  *      (c) 1999 Pavel Machek <pavel@ucw.cz>
   5  *      (c) 2018--2019 Maria Matejka <mq@jmq.cz>
   6  *
   7  *      Can be freely distributed and used under the terms of the GNU GPL.
   8  */
   9
  10 #ifndef _BIRD_FILTER_DATA_H_
  11 #define _BIRD_FILTER_DATA_H_
  12
  13 #include "nest/bird.h"
  14
  15 /* Type numbers must be in 0..0xff range */
  16 #define T_MASK 0xff
  17
  18 /* Internal types */
  19 enum f_type {
  20 /* Nothing. Simply nothing. */
  21   T_VOID = 0,
  22
  23 /* User visible types, which fit in int */
  24   T_INT = 0x10,
  25   T_BOOL = 0x11,
  26   T_PAIR = 0x12,  /*    Notice that pair is stored as integer: first << 16 | second */
  27   T_QUAD = 0x13,
  28
  29 /* Put enumerational types in 0x30..0x3f range */
  30   T_ENUM_LO = 0x30,
  31   T_ENUM_HI = 0x3f,
  32
  33   T_ENUM_RTS = 0x30,
  34   T_ENUM_BGP_ORIGIN = 0x31,
  35   T_ENUM_SCOPE = 0x32,
  36   T_ENUM_RTC = 0x33,
  37   T_ENUM_RTD = 0x34,
  38   T_ENUM_ROA = 0x35,
  39   T_ENUM_NETTYPE = 0x36,
  40   T_ENUM_RA_PREFERENCE = 0x37,
  41   T_ENUM_AF = 0x38,
  42
  43 /* new enums go here */
  44   T_ENUM_EMPTY = 0x3f,  /* Special hack for atomic_aggr */
  45
  46 #define T_ENUM T_ENUM_LO ... T_ENUM_HI
  47
  48 /* Bigger ones */
  49   T_IP = 0x20,
  50   T_NET = 0x21,
  51   T_STRING = 0x22,
  52   T_PATH_MASK = 0x23,   /* mask for BGP path */
  53   T_PATH = 0x24,                /* BGP path */
  54   T_CLIST = 0x25,               /* Community list */
  55   T_EC = 0x26,          /* Extended community value, u64 */
  56   T_ECLIST = 0x27,              /* Extended community list */
  57   T_LC = 0x28,          /* Large community value, lcomm */
  58   T_LCLIST = 0x29,              /* Large community list */
  59   T_RD = 0x2a,          /* Route distinguisher for VPN addresses */
  60   T_PATH_MASK_ITEM = 0x2b,      /* Path mask item for path mask constructors */
  61   T_BYTESTRING = 0x2c,
  62
  63   T_SET = 0x80,
  64   T_PREFIX_SET = 0x81,
  65 } PACKED;
  66
  67 struct f_method {
  68   struct symbol *sym;
  69   struct f_inst *(*new_inst)(struct f_inst *obj, struct f_inst *args);
  70   const struct f_method *next;
  71   uint arg_num;
  72   enum f_type args_type[];
  73 };
  74
  75 /* Filter value; size of this affects filter memory consumption */
  76 struct f_val {
  77   enum f_type type;     /* T_*  */
  78   union {
  79     uint i;
  80     u64 ec;
  81     lcomm lc;
  82     ip_addr ip;
  83     const net_addr *net;
  84     const char *s;
  85     const struct bytestring *bs;
  86     const struct f_tree *t;
  87     const struct f_trie *ti;
  88     const struct adata *ad;
  89     const struct f_path_mask *path_mask;
  90     struct f_path_mask_item pmi;
  91   } val;
  92 };
  93
  94 /* Dynamic attribute definition (eattrs) */
  95 struct f_dynamic_attr {
  96   u8 type;              /* EA type (EAF_*) */
  97   u8 bit;               /* For bitfield accessors */
  98   enum f_type f_type;   /* Filter type */
  99   uint ea_code;         /* EA code */
 100 };
 101
 102 enum f_sa_code {
 103   SA_FROM = 1,
 104   SA_GW,
 105   SA_NET,
 106   SA_PROTO,
 107   SA_SOURCE,
 108   SA_SCOPE,
 109   SA_DEST,
 110   SA_IFNAME,
 111   SA_IFINDEX,
 112   SA_WEIGHT,
 113   SA_PREF,
 114   SA_GW_MPLS,
 115   SA_ONLINK,
 116 } PACKED;
 117
 118 /* Static attribute definition (members of struct rta) */
 119 struct f_static_attr {
 120   enum f_type f_type;           /* Filter type */
 121   enum f_sa_code sa_code;       /* Static attribute id */
 122   int readonly:1;                       /* Don't allow writing */
 123 };
 124
 125 /* Filter l-value type */
 126 enum f_lval_type {
 127   F_LVAL_VARIABLE,
 128   F_LVAL_PREFERENCE,
 129   F_LVAL_SA,
 130   F_LVAL_EA,
 131 };
 132
 133 /* Filter l-value */
 134 struct f_lval {
 135   enum f_lval_type type;
 136   union {
 137     struct symbol *sym;
 138     struct f_dynamic_attr da;
 139     struct f_static_attr sa;
 140   };
 141 };
 142
 143 /* IP prefix range structure */
 144 struct f_prefix {
 145   net_addr net;         /* The matching prefix must match this net */
 146   u8 lo, hi;            /* And its length must fit between lo and hi */
 147 };
 148
 149 struct f_tree {
 150   struct f_tree *left, *right;
 151   struct f_val from, to;
 152   void *data;
 153 };
 154
 155 #ifdef ENABLE_COMPACT_TRIES
 156 /* Compact 4-way tries */
 157 #define TRIE_STEP               2
 158 #define TRIE_STACK_LENGTH       65
 159 #else
 160 /* Faster 16-way tries */
 161 #define TRIE_STEP               4
 162 #define TRIE_STACK_LENGTH       33
 163 #endif
 164
 165 struct f_trie_node4
 166 {
 167   ip4_addr addr, mask, accept;
 168   u16 plen;
 169   u16 local;
 170   struct f_trie_node4 *c[1 << TRIE_STEP];
 171 };
 172
 173 struct f_trie_node6
 174 {
 175   ip6_addr addr, mask, accept;
 176   u16 plen;
 177   u16 local;
 178   struct f_trie_node6 *c[1 << TRIE_STEP];
 179 };
 180
 181 struct f_trie_node
 182 {
 183   union {
 184     struct f_trie_node4 v4;
 185     struct f_trie_node6 v6;
 186   };
 187 };
 188
 189 struct f_trie
 190 {
 191   linpool *lp;
 192   u8 zero;
 193   s8 ipv4;                              /* -1 for undefined / empty */
 194   u16 data_size;                        /* Additional data for each trie node */
 195   u32 prefix_count;                     /* Works only for restricted tries (pxlen == l == h) */
 196   struct f_trie_node root;              /* Root trie node */
 197 };
 198
 199 struct f_trie_walk_state
 200 {
 201   u8 ipv4;
 202   u8 accept_length;                     /* Current inter-node prefix position */
 203   u8 start_pos;                         /* Initial prefix position in stack[0] */
 204   u8 local_pos;                         /* Current intra-node prefix position */
 205   u8 stack_pos;                         /* Current node in stack below */
 206   const struct f_trie_node *stack[TRIE_STACK_LENGTH];
 207 };
 208
 209 struct f_tree *f_new_tree(void);
 210 struct f_tree *build_tree(struct f_tree *);
 211 const struct f_tree *find_tree(const struct f_tree *t, const struct f_val *val);
 212 const struct f_tree *find_tree_linear(const struct f_tree *t, const struct f_val *val);
 213 int same_tree(const struct f_tree *t0, const struct f_tree *t2);
 214 int tree_node_count(const struct f_tree *t);
 215 void tree_format(const struct f_tree *t, buffer *buf);
 216 void tree_walk(const struct f_tree *t, void (*hook)(const struct f_tree *, void *), void *data);
 217
 218 struct f_trie *f_new_trie(linpool *lp, uint data_size);
 219 void *trie_add_prefix(struct f_trie *t, const net_addr *n, uint l, uint h);
 220 int trie_match_net(const struct f_trie *t, const net_addr *n);
 221 int trie_match_longest_ip4(const struct f_trie *t, const net_addr_ip4 *net, net_addr_ip4 *dst, ip4_addr *found0);
 222 int trie_match_longest_ip6(const struct f_trie *t, const net_addr_ip6 *net, net_addr_ip6 *dst, ip6_addr *found0);
 223 void trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_addr *from);
 224 int trie_walk_next(struct f_trie_walk_state *s, net_addr *net);
 225 int trie_same(const struct f_trie *t1, const struct f_trie *t2);
 226 void trie_format(const struct f_trie *t, buffer *buf);
 227
 228 static inline int
 229 trie_match_next_longest_ip4(net_addr_ip4 *n, ip4_addr *found)
 230 {
 231   while (n->pxlen)
 232   {
 233     n->pxlen--;
 234     ip4_clrbit(&n->prefix, n->pxlen);
 235
 236     if (ip4_getbit(*found, n->pxlen))
 237       return 1;
 238   }
 239
 240   return 0;
 241 }
 242
 243 static inline int
 244 trie_match_next_longest_ip6(net_addr_ip6 *n, ip6_addr *found)
 245 {
 246   while (n->pxlen)
 247   {
 248     n->pxlen--;
 249     ip6_clrbit(&n->prefix, n->pxlen);
 250
 251     if (ip6_getbit(*found, n->pxlen))
 252       return 1;
 253   }
 254
 255   return 0;
 256 }
 257
 258
 259 #define TRIE_WALK_TO_ROOT_IP4(trie, net, dst) ({                \
 260   net_addr_ip4 dst;                                             \
 261   ip4_addr _found;                                              \
 262   for (int _n = trie_match_longest_ip4(trie, net, &dst, &_found); \
 263        _n;                                                      \
 264        _n = trie_match_next_longest_ip4(&dst, &_found))
 265
 266 #define TRIE_WALK_TO_ROOT_IP6(trie, net, dst) ({                \
 267   net_addr_ip6 dst;                                             \
 268   ip6_addr _found;                                              \
 269   for (int _n = trie_match_longest_ip6(trie, net, &dst, &_found); \
 270        _n;                                                      \
 271        _n = trie_match_next_longest_ip6(&dst, &_found))
 272
 273 #define TRIE_WALK_TO_ROOT_END })
 274
 275
 276 #define TRIE_WALK(trie, net, from) ({                           \
 277   net_addr net;                                                 \
 278   struct f_trie_walk_state tws_;                                \
 279   trie_walk_init(&tws_, trie, from);                            \
 280   while (trie_walk_next(&tws_, &net))
 281
 282 #define TRIE_WALK_END })
 283
 284
 285 #define F_CMP_ERROR 999
 286
 287 const char *f_type_name(enum f_type t);
 288 enum f_type f_type_element_type(enum f_type t);
 289 struct sym_scope *f_type_method_scope(enum f_type t);
 290
 291 int val_same(const struct f_val *v1, const struct f_val *v2);
 292 int val_compare(const struct f_val *v1, const struct f_val *v2);
 293 void val_format(const struct f_val *v, buffer *buf);
 294 char *val_format_str(struct linpool *lp, const struct f_val *v);
 295 const char *val_dump(const struct f_val *v);
 296
 297 static inline int val_is_ip4(const struct f_val *v)
 298 { return (v->type == T_IP) && ipa_is_ip4(v->val.ip); }
 299 int val_in_range(const struct f_val *v1, const struct f_val *v2);
 300
 301 int clist_set_type(const struct f_tree *set, struct f_val *v);
 302 static inline int eclist_set_type(const struct f_tree *set)
 303 { return !set || set->from.type == T_EC; }
 304 static inline int lclist_set_type(const struct f_tree *set)
 305 { return !set || set->from.type == T_LC; }
 306 static inline int path_set_type(const struct f_tree *set)
 307 { return !set || set->from.type == T_INT; }
 308
 309 int clist_match_set(const struct adata *clist, const struct f_tree *set);
 310 int eclist_match_set(const struct adata *list, const struct f_tree *set);
 311 int lclist_match_set(const struct adata *list, const struct f_tree *set);
 312
 313 const struct adata *clist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 314 const struct adata *eclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 315 const struct adata *lclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 316
 317
 318 /* Special undef value for paths and clists */
 319 static inline int
 320 undef_value(struct f_val v)
 321 {
 322   return ((v.type == T_PATH) || (v.type == T_CLIST) ||
 323           (v.type == T_ECLIST) || (v.type == T_LCLIST)) &&
 324     (v.val.ad == &null_adata);
 325 }
 326
 327 extern const struct f_val f_const_empty_prefix_set;
 328
 329 enum filter_return f_eval(const struct f_line *expr, struct linpool *tmp_pool, struct f_val *pres);
 330
 331 #endif