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
  62   T_SET = 0x80,
  63   T_PREFIX_SET = 0x81,
  64 } PACKED;
  65
  66 /* Filter value; size of this affects filter memory consumption */
  67 struct f_val {
  68   enum f_type type;     /* T_*  */
  69   union {
  70     uint i;
  71     u64 ec;
  72     lcomm lc;
  73     ip_addr ip;
  74     const net_addr *net;
  75     const char *s;
  76     const struct f_tree *t;
  77     const struct f_trie *ti;
  78     const struct adata *ad;
  79     const struct f_path_mask *path_mask;
  80     struct f_path_mask_item pmi;
  81   } val;
  82 };
  83
  84 /* Dynamic attribute definition (eattrs) */
  85 struct f_dynamic_attr {
  86   u8 type;              /* EA type (EAF_*) */
  87   u8 bit;               /* For bitfield accessors */
  88   enum f_type f_type;   /* Filter type */
  89   uint ea_code;         /* EA code */
  90 };
  91
  92 enum f_sa_code {
  93   SA_FROM = 1,
  94   SA_GW,
  95   SA_NET,
  96   SA_PROTO,
  97   SA_SOURCE,
  98   SA_SCOPE,
  99   SA_DEST,
 100   SA_IFNAME,
 101   SA_IFINDEX,
 102   SA_WEIGHT,
 103   SA_PREF,
 104   SA_GW_MPLS,
 105   SA_ONLINK,
 106 } PACKED;
 107
 108 /* Static attribute definition (members of struct rta) */
 109 struct f_static_attr {
 110   enum f_type f_type;           /* Filter type */
 111   enum f_sa_code sa_code;       /* Static attribute id */
 112   int readonly:1;                       /* Don't allow writing */
 113 };
 114
 115 /* Filter l-value type */
 116 enum f_lval_type {
 117   F_LVAL_VARIABLE,
 118   F_LVAL_PREFERENCE,
 119   F_LVAL_SA,
 120   F_LVAL_EA,
 121 };
 122
 123 /* Filter l-value */
 124 struct f_lval {
 125   enum f_lval_type type;
 126   union {
 127     struct symbol *sym;
 128     struct f_dynamic_attr da;
 129     struct f_static_attr sa;
 130   };
 131 };
 132
 133 /* IP prefix range structure */
 134 struct f_prefix {
 135   net_addr net;         /* The matching prefix must match this net */
 136   u8 lo, hi;            /* And its length must fit between lo and hi */
 137 };
 138
 139 struct f_tree {
 140   struct f_tree *left, *right;
 141   struct f_val from, to;
 142   void *data;
 143 };
 144
 145 #ifdef ENABLE_COMPACT_TRIES
 146 /* Compact 4-way tries */
 147 #define TRIE_STEP               2
 148 #define TRIE_STACK_LENGTH       65
 149 #else
 150 /* Faster 16-way tries */
 151 #define TRIE_STEP               4
 152 #define TRIE_STACK_LENGTH       33
 153 #endif
 154
 155 struct f_trie_node4
 156 {
 157   ip4_addr addr, mask, accept;
 158   u16 plen;
 159   u16 local;
 160   struct f_trie_node4 *c[1 << TRIE_STEP];
 161 };
 162
 163 struct f_trie_node6
 164 {
 165   ip6_addr addr, mask, accept;
 166   u16 plen;
 167   u16 local;
 168   struct f_trie_node6 *c[1 << TRIE_STEP];
 169 };
 170
 171 struct f_trie_node
 172 {
 173   union {
 174     struct f_trie_node4 v4;
 175     struct f_trie_node6 v6;
 176   };
 177 };
 178
 179 struct f_trie
 180 {
 181   linpool *lp;
 182   u8 zero;
 183   s8 ipv4;                              /* -1 for undefined / empty */
 184   u16 data_size;                        /* Additional data for each trie node */
 185   u32 prefix_count;                     /* Works only for restricted tries (pxlen == l == h) */
 186   struct f_trie_node root;              /* Root trie node */
 187 };
 188
 189 struct f_trie_walk_state
 190 {
 191   u8 ipv4;
 192   u8 accept_length;                     /* Current inter-node prefix position */
 193   u8 start_pos;                         /* Initial prefix position in stack[0] */
 194   u8 local_pos;                         /* Current intra-node prefix position */
 195   u8 stack_pos;                         /* Current node in stack below */
 196   const struct f_trie_node *stack[TRIE_STACK_LENGTH];
 197 };
 198
 199 struct f_tree *f_new_tree(void);
 200 struct f_tree *build_tree(struct f_tree *);
 201 const struct f_tree *find_tree(const struct f_tree *t, const struct f_val *val);
 202 const struct f_tree *find_tree_linear(const struct f_tree *t, const struct f_val *val);
 203 int same_tree(const struct f_tree *t0, const struct f_tree *t2);
 204 int tree_node_count(const struct f_tree *t);
 205 void tree_format(const struct f_tree *t, buffer *buf);
 206 void tree_walk(const struct f_tree *t, void (*hook)(const struct f_tree *, void *), void *data);
 207
 208 struct f_trie *f_new_trie(linpool *lp, uint data_size);
 209 void *trie_add_prefix(struct f_trie *t, const net_addr *n, uint l, uint h);
 210 int trie_match_net(const struct f_trie *t, const net_addr *n);
 211 int trie_match_longest_ip4(const struct f_trie *t, const net_addr_ip4 *net, net_addr_ip4 *dst, ip4_addr *found0);
 212 int trie_match_longest_ip6(const struct f_trie *t, const net_addr_ip6 *net, net_addr_ip6 *dst, ip6_addr *found0);
 213 void trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_addr *from);
 214 int trie_walk_next(struct f_trie_walk_state *s, net_addr *net);
 215 int trie_same(const struct f_trie *t1, const struct f_trie *t2);
 216 void trie_format(const struct f_trie *t, buffer *buf);
 217
 218 static inline int
 219 trie_match_next_longest_ip4(net_addr_ip4 *n, ip4_addr *found)
 220 {
 221   while (n->pxlen)
 222   {
 223     n->pxlen--;
 224     ip4_clrbit(&n->prefix, n->pxlen);
 225
 226     if (ip4_getbit(*found, n->pxlen))
 227       return 1;
 228   }
 229
 230   return 0;
 231 }
 232
 233 static inline int
 234 trie_match_next_longest_ip6(net_addr_ip6 *n, ip6_addr *found)
 235 {
 236   while (n->pxlen)
 237   {
 238     n->pxlen--;
 239     ip6_clrbit(&n->prefix, n->pxlen);
 240
 241     if (ip6_getbit(*found, n->pxlen))
 242       return 1;
 243   }
 244
 245   return 0;
 246 }
 247
 248
 249 #define TRIE_WALK_TO_ROOT_IP4(trie, net, dst) ({                \
 250   net_addr_ip4 dst;                                             \
 251   ip4_addr _found;                                              \
 252   for (int _n = trie_match_longest_ip4(trie, net, &dst, &_found); \
 253        _n;                                                      \
 254        _n = trie_match_next_longest_ip4(&dst, &_found))
 255
 256 #define TRIE_WALK_TO_ROOT_IP6(trie, net, dst) ({                \
 257   net_addr_ip6 dst;                                             \
 258   ip6_addr _found;                                              \
 259   for (int _n = trie_match_longest_ip6(trie, net, &dst, &_found); \
 260        _n;                                                      \
 261        _n = trie_match_next_longest_ip6(&dst, &_found))
 262
 263 #define TRIE_WALK_TO_ROOT_END })
 264
 265
 266 #define TRIE_WALK(trie, net, from) ({                           \
 267   net_addr net;                                                 \
 268   struct f_trie_walk_state tws_;                                \
 269   trie_walk_init(&tws_, trie, from);                            \
 270   while (trie_walk_next(&tws_, &net))
 271
 272 #define TRIE_WALK_END })
 273
 274
 275 #define F_CMP_ERROR 999
 276
 277 const char *f_type_name(enum f_type t);
 278
 279 enum f_type f_type_element_type(enum f_type t);
 280
 281 int val_same(const struct f_val *v1, const struct f_val *v2);
 282 int val_compare(const struct f_val *v1, const struct f_val *v2);
 283 void val_format(const struct f_val *v, buffer *buf);
 284 char *val_format_str(struct linpool *lp, const struct f_val *v);
 285 const char *val_dump(const struct f_val *v);
 286
 287 static inline int val_is_ip4(const struct f_val *v)
 288 { return (v->type == T_IP) && ipa_is_ip4(v->val.ip); }
 289 int val_in_range(const struct f_val *v1, const struct f_val *v2);
 290
 291 int clist_set_type(const struct f_tree *set, struct f_val *v);
 292 static inline int eclist_set_type(const struct f_tree *set)
 293 { return !set || set->from.type == T_EC; }
 294 static inline int lclist_set_type(const struct f_tree *set)
 295 { return !set || set->from.type == T_LC; }
 296 static inline int path_set_type(const struct f_tree *set)
 297 { return !set || set->from.type == T_INT; }
 298
 299 int clist_match_set(const struct adata *clist, const struct f_tree *set);
 300 int eclist_match_set(const struct adata *list, const struct f_tree *set);
 301 int lclist_match_set(const struct adata *list, const struct f_tree *set);
 302
 303 const struct adata *clist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 304 const struct adata *eclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 305 const struct adata *lclist_filter(struct linpool *pool, const struct adata *list, const struct f_val *set, int pos);
 306
 307
 308 /* Special undef value for paths and clists */
 309 static inline int
 310 undef_value(struct f_val v)
 311 {
 312   return ((v.type == T_PATH) || (v.type == T_CLIST) ||
 313           (v.type == T_ECLIST) || (v.type == T_LCLIST)) &&
 314     (v.val.ad == &null_adata);
 315 }
 316
 317 extern const struct f_val f_const_empty_path, f_const_empty_clist, f_const_empty_eclist, f_const_empty_lclist, f_const_empty_prefix_set;
 318
 319 enum filter_return f_eval(const struct f_line *expr, struct linpool *tmp_pool, struct f_val *pres);
 320
 321 #endif