filter/filter.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Filters
   3  *
   4  *      (c) 1999 Pavel Machek <pavel@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef _BIRD_FILT_H_
  10 #define _BIRD_FILT_H_
  11
  12 #include "lib/resource.h"
  13 #include "lib/ip.h"
  14 #include "nest/route.h"
  15 #include "nest/attrs.h"
  16
  17 struct f_inst {         /* Instruction */
  18   struct f_inst *next;  /* Structure is 16 bytes, anyway */
  19   u16 code;
  20   u16 aux;
  21   union {
  22     int i;
  23     void *p;
  24   } a1;
  25   union {
  26     int i;
  27     void *p;
  28   } a2;
  29   int lineno;
  30 };
  31
  32 #define arg1 a1.p
  33 #define arg2 a2.p
  34
  35 struct f_prefix {
  36   ip_addr ip;
  37   int len;
  38 #define LEN_MASK 0xff
  39 #define LEN_PLUS  0x1000000
  40 #define LEN_MINUS 0x2000000
  41 #define LEN_RANGE 0x4000000
  42   /* If range then prefix must be in range (len >> 16 & 0xff, len >> 8 & 0xff) */
  43 };
  44
  45 struct f_val {
  46   int type;
  47   union {
  48     int i;
  49     /*    ip_addr ip; Folded into prefix */
  50     struct f_prefix px;
  51     char *s;
  52     struct f_tree *t;
  53     struct f_trie *ti;
  54     struct adata *ad;
  55     struct f_path_mask *path_mask;
  56   } val;
  57 };
  58
  59 struct filter {
  60   char *name;
  61   struct f_inst *root;
  62 };
  63
  64 struct f_inst *f_new_inst(void);
  65 struct f_inst *f_new_dynamic_attr(int type, int f_type, int code);      /* Type as core knows it, type as filters know it, and code of dynamic attribute */
  66 struct f_tree *f_new_tree(void);
  67 struct f_inst *f_generate_complex(int operation, int operation_aux, struct f_inst *dyn, struct f_inst *argument);
  68
  69 struct f_tree *build_tree(struct f_tree *);
  70 struct f_tree *find_tree(struct f_tree *t, struct f_val val);
  71 int same_tree(struct f_tree *t1, struct f_tree *t2);
  72
  73 struct f_trie *f_new_trie(linpool *lp);
  74 void trie_add_prefix(struct f_trie *t, ip_addr px, int plen, int l, int h);
  75 int trie_match_prefix(struct f_trie *t, ip_addr px, int plen);
  76 int trie_same(struct f_trie *t1, struct f_trie *t2);
  77 int trie_print(struct f_trie *t, char *buf, int blen);
  78
  79 void fprefix_get_bounds(struct f_prefix *px, int *l, int *h);
  80
  81 static inline void
  82 trie_add_fprefix(struct f_trie *t, struct f_prefix *px)
  83 {
  84   int l, h;
  85   fprefix_get_bounds(px, &l, &h);
  86   trie_add_prefix(t, px->ip, px->len & LEN_MASK, l, h);
  87 }
  88
  89 static inline int
  90 trie_match_fprefix(struct f_trie *t, struct f_prefix *px)
  91 {
  92   return trie_match_prefix(t, px->ip, px->len & LEN_MASK);
  93 }
  94
  95
  96 struct ea_list;
  97 struct rte;
  98
  99 int f_run(struct filter *filter, struct rte **rte, struct ea_list **tmp_attrs, struct linpool *tmp_pool, int flags);
 100 int f_eval_int(struct f_inst *expr);
 101 u32 f_eval_asn(struct f_inst *expr);
 102
 103 char *filter_name(struct filter *filter);
 104 int filter_same(struct filter *new, struct filter *old);
 105
 106 int i_same(struct f_inst *f1, struct f_inst *f2);
 107
 108 int val_compare(struct f_val v1, struct f_val v2);
 109 int tree_compare(const void *p1, const void *p2);
 110 void val_print(struct f_val v);
 111
 112 #define F_NOP 0
 113 #define F_NONL 1
 114 #define F_ACCEPT 2      /* Need to preserve ordering: accepts < rejects! */
 115 #define F_REJECT 3
 116 #define F_ERROR 4
 117 #define F_QUITBIRD 5
 118
 119 #define FILTER_ACCEPT NULL
 120 #define FILTER_REJECT ((void *) 1)
 121
 122 /* Type numbers must be in 0..0xff range */
 123 #define T_MASK 0xff
 124
 125 /* Internal types */
 126 /* Do not use type of zero, that way we'll see errors easier. */
 127 #define T_VOID 1
 128
 129 /* User visible types, which fit in int */
 130 #define T_INT 0x10
 131 #define T_BOOL 0x11
 132 #define T_PAIR 0x12  /* Notice that pair is stored as integer: first << 16 | second */
 133 #define T_QUAD 0x13
 134
 135 /* Put enumerational types in 0x30..0x3f range */
 136 #define T_ENUM_LO 0x30
 137 #define T_ENUM_HI 0x3f
 138
 139 #define T_ENUM_RTS 0x30
 140 #define T_ENUM_BGP_ORIGIN 0x31
 141 #define T_ENUM_SCOPE 0x32
 142 #define T_ENUM_RTC 0x33
 143 #define T_ENUM_RTD 0x34
 144 /* new enums go here */
 145 #define T_ENUM_EMPTY 0x3f       /* Special hack for atomic_aggr */
 146
 147 #define T_ENUM T_ENUM_LO ... T_ENUM_HI
 148
 149 /* Bigger ones */
 150 #define T_IP 0x20
 151 #define T_PREFIX 0x21
 152 #define T_STRING 0x22
 153 #define T_PATH_MASK 0x23        /* mask for BGP path */
 154 #define T_PATH 0x24             /* BGP path */
 155 #define T_CLIST 0x25            /* Community list */
 156
 157 #define T_RETURN 0x40
 158 #define T_SET 0x80
 159 #define T_PREFIX_SET 0x81
 160
 161 struct f_tree {
 162   struct f_tree *left, *right;
 163   struct f_val from, to;
 164   void *data;
 165 };
 166
 167 struct f_trie_node
 168 {
 169   ip_addr addr, mask, accept;
 170   int plen;
 171   struct f_trie_node *c[2];
 172 };
 173
 174 struct f_trie
 175 {
 176   linpool *lp;
 177   int zero;
 178   struct f_trie_node root;
 179 };
 180
 181 #define NEW_F_VAL struct f_val * val; val = cfg_alloc(sizeof(struct f_val));
 182
 183 #define FF_FORCE_TMPATTR 1              /* Force all attributes to be temporary */
 184
 185 #endif