lib/nexthop.h

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Nexthop structure definition.
   4  * Copyright (C) 1997, 98, 99, 2001 Kunihiro Ishiguro
   5  * Copyright (C) 2013 Cumulus Networks, Inc.
   6  */
   7
   8 #ifndef _LIB_NEXTHOP_H
   9 #define _LIB_NEXTHOP_H
  10
  11 #include "prefix.h"
  12 #include "mpls.h"
  13 #include "vxlan.h"
  14 #include "srv6.h"
  15
  16 #ifdef __cplusplus
  17 extern "C" {
  18 #endif
  19
  20 /* Maximum next hop string length - gateway + ifindex */
  21 #define NEXTHOP_STRLEN (INET6_ADDRSTRLEN + 30)
  22
  23 union g_addr {
  24         struct in_addr ipv4;
  25         struct in6_addr ipv6;
  26 };
  27
  28 enum nexthop_types_t {
  29         NEXTHOP_TYPE_IFINDEX = 1,  /* Directly connected.  */
  30         NEXTHOP_TYPE_IPV4,       /* IPv4 nexthop.  */
  31         NEXTHOP_TYPE_IPV4_IFINDEX, /* IPv4 nexthop with ifindex.  */
  32         NEXTHOP_TYPE_IPV6,       /* IPv6 nexthop.  */
  33         NEXTHOP_TYPE_IPV6_IFINDEX, /* IPv6 nexthop with ifindex.  */
  34         NEXTHOP_TYPE_BLACKHOLE,    /* Null0 nexthop.  */
  35 };
  36
  37 enum blackhole_type {
  38         BLACKHOLE_UNSPEC = 0,
  39         BLACKHOLE_NULL,
  40         BLACKHOLE_REJECT,
  41         BLACKHOLE_ADMINPROHIB,
  42 };
  43
  44 enum nh_encap_type {
  45         NET_VXLAN = 100, /* value copied from FPM_NH_ENCAP_VXLAN. */
  46 };
  47
  48 /* Fixed limit on the number of backup nexthops per primary nexthop */
  49 #define NEXTHOP_MAX_BACKUPS  8
  50
  51 /* Backup index value is limited */
  52 #define NEXTHOP_BACKUP_IDX_MAX 255
  53
  54 /* Nexthop structure. */
  55 struct nexthop {
  56         struct nexthop *next;
  57         struct nexthop *prev;
  58
  59         /*
  60          * What vrf is this nexthop associated with?
  61          */
  62         vrf_id_t vrf_id;
  63
  64         /* Interface index. */
  65         ifindex_t ifindex;
  66
  67         enum nexthop_types_t type;
  68
  69         uint16_t flags;
  70 #define NEXTHOP_FLAG_ACTIVE     (1 << 0) /* This nexthop is alive. */
  71 #define NEXTHOP_FLAG_FIB        (1 << 1) /* FIB nexthop. */
  72 #define NEXTHOP_FLAG_RECURSIVE  (1 << 2) /* Recursive nexthop. */
  73 #define NEXTHOP_FLAG_ONLINK     (1 << 3) /* Nexthop should be installed
  74                                           * onlink.
  75                                           */
  76 #define NEXTHOP_FLAG_DUPLICATE  (1 << 4) /* nexthop duplicates another
  77                                           * active one
  78                                           */
  79 #define NEXTHOP_FLAG_RNH_FILTERED  (1 << 5) /* rmap filtered, used by rnh */
  80 #define NEXTHOP_FLAG_HAS_BACKUP (1 << 6)    /* Backup nexthop index is set */
  81 #define NEXTHOP_FLAG_SRTE       (1 << 7) /* SR-TE color used for BGP traffic */
  82 #define NEXTHOP_FLAG_EVPN       (1 << 8) /* nexthop is EVPN */
  83 #define NEXTHOP_FLAG_LINKDOWN   (1 << 9) /* is not removed on link down */
  84
  85 #define NEXTHOP_IS_ACTIVE(flags)                                               \
  86         (CHECK_FLAG(flags, NEXTHOP_FLAG_ACTIVE)                                \
  87          && !CHECK_FLAG(flags, NEXTHOP_FLAG_DUPLICATE))
  88
  89         /* Nexthop address */
  90         union {
  91                 union g_addr gate;
  92                 enum blackhole_type bh_type;
  93         };
  94         union g_addr src;
  95         union g_addr rmap_src; /* Src is set via routemap */
  96
  97         /* Nexthops obtained by recursive resolution.
  98          *
  99          * If the nexthop struct needs to be resolved recursively,
 100          * NEXTHOP_FLAG_RECURSIVE will be set in flags and the nexthops
 101          * obtained by recursive resolution will be added to `resolved'.
 102          */
 103         struct nexthop *resolved;
 104         /* Recursive parent */
 105         struct nexthop *rparent;
 106
 107         /* Type of label(s), if any */
 108         enum lsp_types_t nh_label_type;
 109
 110         /* Label(s) associated with this nexthop. */
 111         struct mpls_label_stack *nh_label;
 112
 113         /* Weight of the nexthop ( for unequal cost ECMP ) */
 114         uint8_t weight;
 115
 116         /* Count and index of corresponding backup nexthop(s) in a backup list;
 117          * only meaningful if the HAS_BACKUP flag is set.
 118          */
 119         uint8_t backup_num;
 120         uint8_t backup_idx[NEXTHOP_MAX_BACKUPS];
 121
 122         /* Encapsulation information. */
 123         enum nh_encap_type nh_encap_type;
 124         union {
 125                 vni_t vni;
 126         } nh_encap;
 127
 128         /* SR-TE color used for matching SR-TE policies */
 129         uint32_t srte_color;
 130
 131         /* SRv6 information */
 132         struct nexthop_srv6 *nh_srv6;
 133 };
 134
 135 /* Utility to append one nexthop to another. */
 136 #define NEXTHOP_APPEND(to, new)           \
 137         do {                              \
 138                 (to)->next = (new);       \
 139                 (new)->prev = (to);       \
 140                 (new)->next = NULL;       \
 141         } while (0)
 142
 143 struct nexthop *nexthop_new(void);
 144
 145 void nexthop_free(struct nexthop *nexthop);
 146 void nexthops_free(struct nexthop *nexthop);
 147
 148 void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t ltype,
 149                         uint8_t num_labels, const mpls_label_t *labels);
 150 void nexthop_del_labels(struct nexthop *);
 151 void nexthop_add_srv6_seg6local(struct nexthop *nexthop, uint32_t action,
 152                                 const struct seg6local_context *ctx);
 153 void nexthop_del_srv6_seg6local(struct nexthop *nexthop);
 154 void nexthop_add_srv6_seg6(struct nexthop *nexthop,
 155                            const struct in6_addr *segs);
 156 void nexthop_del_srv6_seg6(struct nexthop *nexthop);
 157
 158 /*
 159  * Allocate a new nexthop object and initialize it from various args.
 160  */
 161 struct nexthop *nexthop_from_ifindex(ifindex_t ifindex, vrf_id_t vrf_id);
 162 struct nexthop *nexthop_from_ipv4(const struct in_addr *ipv4,
 163                                   const struct in_addr *src,
 164                                   vrf_id_t vrf_id);
 165 struct nexthop *nexthop_from_ipv4_ifindex(const struct in_addr *ipv4,
 166                                           const struct in_addr *src,
 167                                           ifindex_t ifindex, vrf_id_t vrf_id);
 168 struct nexthop *nexthop_from_ipv6(const struct in6_addr *ipv6,
 169                                   vrf_id_t vrf_id);
 170 struct nexthop *nexthop_from_ipv6_ifindex(const struct in6_addr *ipv6,
 171                                           ifindex_t ifindex, vrf_id_t vrf_id);
 172 struct nexthop *nexthop_from_blackhole(enum blackhole_type bh_type,
 173                                        vrf_id_t nh_vrf_id);
 174
 175 /*
 176  * Hash a nexthop. Suitable for use with hash tables.
 177  *
 178  * This function uses the following values when computing the hash:
 179  * - vrf_id
 180  * - ifindex
 181  * - type
 182  * - gate
 183  *
 184  * nexthop
 185  *    The nexthop to hash
 186  *
 187  * Returns:
 188  *    32-bit hash of nexthop
 189  */
 190 uint32_t nexthop_hash(const struct nexthop *nexthop);
 191 /*
 192  * Hash a nexthop only on word-sized attributes:
 193  * - vrf_id
 194  * - ifindex
 195  * - type
 196  * - (some) flags
 197  */
 198 uint32_t nexthop_hash_quick(const struct nexthop *nexthop);
 199
 200 extern bool nexthop_same(const struct nexthop *nh1, const struct nexthop *nh2);
 201 extern bool nexthop_same_no_labels(const struct nexthop *nh1,
 202                                    const struct nexthop *nh2);
 203 extern int nexthop_cmp(const struct nexthop *nh1, const struct nexthop *nh2);
 204 extern int nexthop_g_addr_cmp(enum nexthop_types_t type,
 205                               const union g_addr *addr1,
 206                               const union g_addr *addr2);
 207
 208 /* More-limited comparison function used to detect duplicate nexthops.
 209  * Returns -1, 0, 1
 210  */
 211 int nexthop_cmp_basic(const struct nexthop *nh1, const struct nexthop *nh2);
 212
 213 extern const char *nexthop_type_to_str(enum nexthop_types_t nh_type);
 214 extern bool nexthop_labels_match(const struct nexthop *nh1,
 215                                  const struct nexthop *nh2);
 216
 217 extern const char *nexthop2str(const struct nexthop *nexthop,
 218                                char *str, int size);
 219 extern struct nexthop *nexthop_next(const struct nexthop *nexthop);
 220 extern struct nexthop *
 221 nexthop_next_active_resolved(const struct nexthop *nexthop);
 222 extern unsigned int nexthop_level(const struct nexthop *nexthop);
 223 /* Copies to an already allocated nexthop struct */
 224 extern void nexthop_copy(struct nexthop *copy, const struct nexthop *nexthop,
 225                          struct nexthop *rparent);
 226 /* Copies to an already allocated nexthop struct, not including recurse info */
 227 extern void nexthop_copy_no_recurse(struct nexthop *copy,
 228                                     const struct nexthop *nexthop,
 229                                     struct nexthop *rparent);
 230 /* Duplicates a nexthop and returns the newly allocated nexthop */
 231 extern struct nexthop *nexthop_dup(const struct nexthop *nexthop,
 232                                    struct nexthop *rparent);
 233 /* Duplicates a nexthop and returns the newly allocated nexthop */
 234 extern struct nexthop *nexthop_dup_no_recurse(const struct nexthop *nexthop,
 235                                               struct nexthop *rparent);
 236
 237 /* Check nexthop of IFINDEX type */
 238 extern bool nexthop_is_ifindex_type(const struct nexthop *nh);
 239
 240 /*
 241  * Parse one or more backup index values, as comma-separated numbers,
 242  * into caller's array of uint8_ts. The array must be NEXTHOP_MAX_BACKUPS
 243  * in size. Mails back the number of values converted, and returns 0 on
 244  * success, <0 if an error in parsing.
 245  */
 246 int nexthop_str2backups(const char *str, int *num_backups,
 247                         uint8_t *backups);
 248
 249 #ifdef _FRR_ATTRIBUTE_PRINTFRR
 250 #pragma FRR printfrr_ext "%pNH"  (struct nexthop *)
 251 #endif
 252
 253 ssize_t printfrr_nhs(struct fbuf *buf, const struct nexthop *nh);
 254 #ifdef __cplusplus
 255 }
 256 #endif
 257
 258 #endif /*_LIB_NEXTHOP_H */