nest/attrs.h

   1 /*
   2  *      BIRD Internet Routing Daemon -- Attribute Operations
   3  *
   4  *      (c) 2000 Martin Mares <mj@ucw.cz>
   5  *
   6  *      Can be freely distributed and used under the terms of the GNU GPL.
   7  */
   8
   9 #ifndef _BIRD_ATTRS_H_
  10 #define _BIRD_ATTRS_H_
  11
  12 #include <stdint.h>
  13 #include "lib/unaligned.h"
  14 #include "nest/route.h"
  15
  16
  17 /* a-path.c */
  18
  19 #define AS_PATH_SET             1       /* Types of path segments */
  20 #define AS_PATH_SEQUENCE        2
  21 #define AS_PATH_CONFED_SEQUENCE 3
  22 #define AS_PATH_CONFED_SET      4
  23
  24 #define AS_PATH_MAXLEN          10000
  25
  26 #define AS_TRANS                23456
  27 /* AS_TRANS is used when we need to store 32bit ASN larger than 0xFFFF
  28  * to 16bit slot (like in 16bit AS_PATH). See RFC 4893 for details
  29  */
  30
  31 struct f_tree;
  32
  33 int as_path_valid(byte *data, uint len, int bs, int confed, char *err, uint elen);
  34 int as_path_16to32(byte *dst, const byte *src, uint len);
  35 int as_path_32to16(byte *dst, const byte *src, uint len);
  36 int as_path_contains_as4(const struct adata *path);
  37 int as_path_contains_confed(const struct adata *path);
  38 struct adata *as_path_strip_confed(struct linpool *pool, const struct adata *op);
  39 struct adata *as_path_prepend2(struct linpool *pool, const struct adata *op, int seq, u32 as);
  40 struct adata *as_path_to_old(struct linpool *pool, const struct adata *path);
  41 struct adata *as_path_cut(struct linpool *pool, const struct adata *path, uint num);
  42 const struct adata *as_path_merge(struct linpool *pool, const struct adata *p1, const struct adata *p2);
  43 void as_path_format(const struct adata *path, byte *buf, uint size);
  44 int as_path_getlen(const struct adata *path);
  45 int as_path_getlen_int(const struct adata *path, int bs);
  46 int as_path_get_first(const struct adata *path, u32 *orig_as);
  47 int as_path_get_first_regular(const struct adata *path, u32 *last_as);
  48 int as_path_get_last(const struct adata *path, u32 *last_as);
  49 u32 as_path_get_last_nonaggregated(const struct adata *path);
  50 int as_path_contains(const struct adata *path, u32 as, int min);
  51 int as_path_match_set(const struct adata *path, const struct f_tree *set);
  52 const struct adata *as_path_filter(struct linpool *pool, const struct adata *path, const struct f_tree *set, u32 key, int pos);
  53
  54 static inline struct adata *as_path_prepend(struct linpool *pool, const struct adata *path, u32 as)
  55 { return as_path_prepend2(pool, path, AS_PATH_SEQUENCE, as); }
  56
  57
  58 #define PM_ASN          0
  59 #define PM_QUESTION     1
  60 #define PM_ASTERISK     2
  61 #define PM_ASN_EXPR     3
  62 #define PM_ASN_RANGE    4
  63 #define PM_ASN_SET      5
  64
  65 struct f_path_mask_item {
  66   union {
  67     u32 asn; /* PM_ASN */
  68     struct f_line *expr; /* PM_ASN_EXPR */
  69     struct f_tree *set; /* PM_ASN_SET */
  70     struct { /* PM_ASN_RANGE */
  71       u32 from;
  72       u32 to;
  73     };
  74   };
  75   int kind;
  76 };
  77
  78 struct f_path_mask {
  79   uint len;
  80   struct f_path_mask_item item[0];
  81 };
  82
  83 int as_path_match(const struct adata *path, const struct f_path_mask *mask);
  84
  85
  86 /* Counterparts to appropriate as_path_* functions */
  87
  88 static inline int
  89 aggregator_16to32(byte *dst, const byte *src)
  90 {
  91   put_u32(dst, get_u16(src));
  92   memcpy(dst+4, src+2, 4);
  93   return 8;
  94 }
  95
  96 static inline int
  97 aggregator_32to16(byte *dst, const byte *src)
  98 {
  99   put_u16(dst, get_u32(src));
 100   memcpy(dst+2, src+4, 4);
 101   return 6;
 102 }
 103
 104 static inline int
 105 aggregator_contains_as4(const struct adata *a)
 106 {
 107   return get_u32(a->data) > 0xFFFF;
 108 }
 109
 110 static inline struct adata *
 111 aggregator_to_old(struct linpool *pool, const struct adata *a)
 112 {
 113   struct adata *d = lp_alloc_adata(pool, 8);
 114   put_u32(d->data, 0xFFFF);
 115   memcpy(d->data + 4, a->data + 4, 4);
 116   return d;
 117 }
 118
 119
 120 /* a-set.c */
 121
 122
 123 /* Extended Community subtypes (kinds) */
 124 enum ec_subtype {
 125   EC_RT = 0x0002,
 126   EC_RO = 0x0003,
 127   EC_GENERIC = 0xFFFF,
 128 };
 129
 130 static inline const char *ec_subtype_str(const enum ec_subtype ecs) {
 131   switch (ecs) {
 132     case EC_RT: return "rt";
 133     case EC_RO: return "ro";
 134     default: return NULL;
 135   }
 136 }
 137
 138 /* Transitive bit (for first u32 half of EC) */
 139 #define EC_TBIT 0x40000000
 140
 141 #define ECOMM_LENGTH 8
 142
 143 static inline int int_set_get_size(const struct adata *list)
 144 { return list->length / 4; }
 145
 146 static inline int ec_set_get_size(const struct adata *list)
 147 { return list->length / 8; }
 148
 149 static inline int lc_set_get_size(const struct adata *list)
 150 { return list->length / 12; }
 151
 152 static inline u32 *int_set_get_data(const struct adata *list)
 153 { return (u32 *) list->data; }
 154
 155 static inline u32 ec_hi(u64 ec) { return ec >> 32; }
 156 static inline u32 ec_lo(u64 ec) { return ec; }
 157 static inline u64 ec_get(const u32 *l, int i)
 158 { return (((u64) l[i]) << 32) | l[i+1]; }
 159
 160 /* RFC 4360 3.1.  Two-Octet AS Specific Extended Community */
 161 static inline u64 ec_as2(enum ec_subtype kind, u64 key, u64 val)
 162 { return (((u64) kind | 0x0000) << 48) | (key << 32) | val; }
 163
 164 /* RFC 5668  4-Octet AS Specific BGP Extended Community */
 165 static inline u64 ec_as4(enum ec_subtype kind, u64 key, u64 val)
 166 { return (((u64) kind | 0x0200) << 48) | (key << 16) | val; }
 167
 168 /* RFC 4360 3.2.  IPv4 Address Specific Extended Community */
 169 static inline u64 ec_ip4(enum ec_subtype kind, u64 key, u64 val)
 170 { return (((u64) kind | 0x0100) << 48) | (key << 16) | val; }
 171
 172 static inline u64 ec_generic(u64 key, u64 val)
 173 { return (key << 32) | val; }
 174
 175 /* Large community value */
 176 typedef struct lcomm {
 177   u32 asn;
 178   u32 ldp1;
 179   u32 ldp2;
 180 } lcomm;
 181
 182 #define LCOMM_LENGTH 12
 183
 184 static inline lcomm lc_get(const u32 *l, int i)
 185 { return (lcomm) { l[i], l[i+1], l[i+2] }; }
 186
 187 static inline void lc_put(u32 *l, lcomm v)
 188 { l[0] = v.asn; l[1] = v.ldp1; l[2] = v.ldp2; }
 189
 190 static inline int lc_match(const u32 *l, int i, lcomm v)
 191 { return (l[i] == v.asn && l[i+1] == v.ldp1 && l[i+2] == v.ldp2); }
 192
 193 static inline u32 *lc_copy(u32 *dst, const u32 *src)
 194 { memcpy(dst, src, LCOMM_LENGTH); return dst + 3; }
 195
 196
 197 int int_set_format(const struct adata *set, int way, int from, byte *buf, uint size);
 198 int ec_format(byte *buf, u64 ec);
 199 int ec_set_format(const struct adata *set, int from, byte *buf, uint size);
 200 int lc_format(byte *buf, lcomm lc);
 201 int lc_set_format(const struct adata *set, int from, byte *buf, uint size);
 202 int int_set_contains(const struct adata *list, u32 val);
 203 int ec_set_contains(const struct adata *list, u64 val);
 204 int lc_set_contains(const struct adata *list, lcomm val);
 205 const struct adata *int_set_prepend(struct linpool *pool, const struct adata *list, u32 val);
 206 const struct adata *int_set_add(struct linpool *pool, const struct adata *list, u32 val);
 207 const struct adata *ec_set_add(struct linpool *pool, const struct adata *list, u64 val);
 208 const struct adata *lc_set_add(struct linpool *pool, const struct adata *list, lcomm val);
 209 const struct adata *int_set_del(struct linpool *pool, const struct adata *list, u32 val);
 210 const struct adata *ec_set_del(struct linpool *pool, const struct adata *list, u64 val);
 211 const struct adata *lc_set_del(struct linpool *pool, const struct adata *list, lcomm val);
 212 const struct adata *int_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
 213 const struct adata *ec_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
 214 const struct adata *lc_set_union(struct linpool *pool, const struct adata *l1, const struct adata *l2);
 215
 216 struct adata *ec_set_del_nontrans(struct linpool *pool, const struct adata *set);
 217 struct adata *int_set_sort(struct linpool *pool, const struct adata *src);
 218 struct adata *ec_set_sort(struct linpool *pool, const struct adata *src);
 219 struct adata *lc_set_sort(struct linpool *pool, const struct adata *src);
 220
 221 void ec_set_sort_x(struct adata *set); /* Sort in place */
 222
 223 #endif