Splitting route data structures out to lib

1 files changed, 332 insertions, 0 deletions

diff --git a/lib/route.h b/lib/route.h
new file mode 100644
index 00000000..47355abc
--- /dev/null
+++ b/lib/route.h
@@ -0,0 +1,332 @@
+/*
+ *	BIRD Internet Routing Daemon -- Routing data structures
+ *
+ *	(c) 1998--2000 Martin Mares <mj@ucw.cz>
+ *	(c) 2022 Maria Matejka <mq@jmq.cz>
+ *
+ *	Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#ifndef _BIRD_LIB_ROUTE_H_
+#define _BIRD_LIB_ROUTE_H_
+
+struct network;
+struct proto;
+struct cli;
+
+typedef struct rte {
+  struct rte *next;
+  struct network *net;			/* Network this RTE belongs to */
+  struct rte_src *src;			/* Route source that created the route */
+  struct channel *sender;		/* Channel used to send the route to the routing table */
+  struct rta *attrs;			/* Attributes of this route */
+  u32 id;				/* Table specific route id */
+  byte flags;				/* Flags (REF_...) */
+  byte pflags;				/* Protocol-specific flags */
+  btime lastmod;			/* Last modified */
+} rte;
+
+#define REF_COW		1		/* Copy this rte on write */
+#define REF_FILTERED	2		/* Route is rejected by import filter */
+#define REF_STALE	4		/* Route is stale in a refresh cycle */
+#define REF_DISCARD	8		/* Route is scheduled for discard */
+#define REF_MODIFY	16		/* Route is scheduled for modify */
+
+/* Route is valid for propagation (may depend on other flags in the future), accepts NULL */
+static inline int rte_is_valid(rte *r) { return r && !(r->flags & REF_FILTERED); }
+
+/* Route just has REF_FILTERED flag */
+static inline int rte_is_filtered(rte *r) { return !!(r->flags & REF_FILTERED); }
+
+struct rte_src {
+  struct rte_src *next;			/* Hash chain */
+  struct proto *proto;			/* Protocol the source is based on */
+  u32 private_id;			/* Private ID, assigned by the protocol */
+  u32 global_id;			/* Globally unique ID of the source */
+  unsigned uc;				/* Use count */
+};
+
+
+struct rte_src *rt_find_source(struct proto *p, u32 id);
+struct rte_src *rt_get_source(struct proto *p, u32 id);
+static inline void rt_lock_source(struct rte_src *src) { src->uc++; }
+static inline void rt_unlock_source(struct rte_src *src) { src->uc--; }
+void rt_prune_sources(void);
+
+/*
+ *	Route Attributes
+ *
+ *	Beware: All standard BGP attributes must be represented here instead
+ *	of making them local to the route. This is needed to ensure proper
+ *	construction of BGP route attribute lists.
+ */
+
+/* Nexthop structure */
+struct nexthop {
+  ip_addr gw;				/* Next hop */
+  struct iface *iface;			/* Outgoing interface */
+  struct nexthop *next;
+  byte flags;
+  byte weight;
+  byte labels_orig;			/* Number of labels before hostentry was applied */
+  byte labels;				/* Number of all labels */
+  u32 label[0];
+};
+
+#define RNF_ONLINK		0x1	/* Gateway is onlink regardless of IP ranges */
+
+
+typedef struct rta {
+  struct rta *next, **pprev;		/* Hash chain */
+  u32 uc;				/* Use count */
+  u32 hash_key;				/* Hash over important fields */
+  struct ea_list *eattrs;		/* Extended Attribute chain */
+  struct hostentry *hostentry;		/* Hostentry for recursive next-hops */
+  ip_addr from;				/* Advertising router */
+  u32 igp_metric;			/* IGP metric to next hop (for iBGP routes) */
+  u16 cached:1;				/* Are attributes cached? */
+  u16 source:7;				/* Route source (RTS_...) */
+  u16 scope:4;				/* Route scope (SCOPE_... -- see ip.h) */
+  u16 dest:4;				/* Route destination type (RTD_...) */
+  word pref;
+  struct nexthop nh;			/* Next hop */
+} rta;
+
+#define RTS_STATIC 1			/* Normal static route */
+#define RTS_INHERIT 2			/* Route inherited from kernel */
+#define RTS_DEVICE 3			/* Device route */
+#define RTS_STATIC_DEVICE 4		/* Static device route */
+#define RTS_REDIRECT 5			/* Learned via redirect */
+#define RTS_RIP 6			/* RIP route */
+#define RTS_OSPF 7			/* OSPF route */
+#define RTS_OSPF_IA 8			/* OSPF inter-area route */
+#define RTS_OSPF_EXT1 9			/* OSPF external route type 1 */
+#define RTS_OSPF_EXT2 10		/* OSPF external route type 2 */
+#define RTS_BGP 11			/* BGP route */
+#define RTS_PIPE 12			/* Inter-table wormhole */
+#define RTS_BABEL 13			/* Babel route */
+#define RTS_RPKI 14			/* Route Origin Authorization */
+#define RTS_PERF 15			/* Perf checker */
+#define RTS_MAX 16
+
+#define RTD_NONE 0			/* Undefined next hop */
+#define RTD_UNICAST 1			/* Next hop is neighbor router */
+#define RTD_BLACKHOLE 2			/* Silently drop packets */
+#define RTD_UNREACHABLE 3		/* Reject as unreachable */
+#define RTD_PROHIBIT 4			/* Administratively prohibited */
+#define RTD_MAX 5
+
+#define IGP_METRIC_UNKNOWN 0x80000000	/* Default igp_metric used when no other
+					   protocol-specific metric is availabe */
+
+
+extern const char * rta_dest_names[RTD_MAX];
+
+static inline const char *rta_dest_name(uint n)
+{ return (n < RTD_MAX) ? rta_dest_names[n] : "???"; }
+
+/* Route has regular, reachable nexthop (i.e. not RTD_UNREACHABLE and like) */
+static inline int rte_is_reachable(rte *r)
+{ return r->attrs->dest == RTD_UNICAST; }
+
+
+/*
+ *	Extended Route Attributes
+ */
+
+typedef struct eattr {
+  word id;				/* EA_CODE(PROTOCOL_..., protocol-dependent ID) */
+  byte flags;				/* Protocol-dependent flags */
+  byte type:5;				/* Attribute type */
+  byte originated:1;			/* The attribute has originated locally */
+  byte fresh:1;				/* An uncached attribute (e.g. modified in export filter) */
+  byte undef:1;				/* Explicitly undefined */
+
+  union bval u;
+} eattr;
+
+
+#define EA_CODE(proto,id) (((proto) << 8) | (id))
+#define EA_ID(ea) ((ea) & 0xff)
+#define EA_PROTO(ea) ((ea) >> 8)
+#define EA_CUSTOM(id) ((id) | EA_CUSTOM_BIT)
+#define EA_IS_CUSTOM(ea) ((ea) & EA_CUSTOM_BIT)
+#define EA_CUSTOM_ID(ea) ((ea) & ~EA_CUSTOM_BIT)
+
+const char *ea_custom_name(uint ea);
+
+#define EA_GEN_IGP_METRIC EA_CODE(PROTOCOL_NONE, 0)
+
+#define EA_CODE_MASK 0xffff
+#define EA_CUSTOM_BIT 0x8000
+#define EA_ALLOW_UNDEF 0x10000		/* ea_find: allow EAF_TYPE_UNDEF */
+#define EA_BIT(n) ((n) << 24)		/* Used in bitfield accessors */
+#define EA_BIT_GET(ea) ((ea) >> 24)
+
+typedef struct adata {
+  uint length;				/* Length of data */
+  byte data[0];
+} adata;
+
+extern const adata null_adata;		/* adata of length 0 */
+
+static inline struct adata *
+lp_alloc_adata(struct linpool *pool, uint len)
+{
+  struct adata *ad = lp_alloc(pool, sizeof(struct adata) + len);
+  ad->length = len;
+  return ad;
+}
+
+static inline int adata_same(const struct adata *a, const struct adata *b)
+{ return (a->length == b->length && !memcmp(a->data, b->data, a->length)); }
+
+
+typedef struct ea_list {
+  struct ea_list *next;			/* In case we have an override list */
+  byte flags;				/* Flags: EALF_... */
+  byte rfu;
+  word count;				/* Number of attributes */
+  eattr attrs[0];			/* Attribute definitions themselves */
+} ea_list;
+
+#define EALF_SORTED 1			/* Attributes are sorted by code */
+#define EALF_BISECT 2			/* Use interval bisection for searching */
+#define EALF_CACHED 4			/* Attributes belonging to cached rta */
+
+struct ea_walk_state {
+  ea_list *eattrs;			/* Ccurrent ea_list, initially set by caller */
+  eattr *ea;				/* Current eattr, initially NULL */
+  u32 visited[4];			/* Bitfield, limiting max to 128 */
+};
+
+eattr *ea_find(ea_list *, unsigned ea);
+eattr *ea_walk(struct ea_walk_state *s, uint id, uint max);
+
+/**
+ * ea_get_int - fetch an integer attribute
+ * @e: attribute list
+ * @id: attribute ID
+ * @def: default value
+ *
+ * This function is a shortcut for retrieving a value of an integer attribute
+ * by calling ea_find() to find the attribute, extracting its value or returning
+ * a provided default if no such attribute is present.
+ */
+static inline u32
+ea_get_int(ea_list *e, unsigned id, u32 def)
+{
+  eattr *a = ea_find(e, id);
+  return a ? a->u.data : def;
+}
+
+void ea_dump(ea_list *);
+void ea_sort(ea_list *);		/* Sort entries in all sub-lists */
+unsigned ea_scan(ea_list *);		/* How many bytes do we need for merged ea_list */
+void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
+int ea_same(ea_list *x, ea_list *y);	/* Test whether two ea_lists are identical */
+uint ea_hash(ea_list *e);	/* Calculate 16-bit hash value */
+ea_list *ea_append(ea_list *to, ea_list *what);
+void ea_format_bitfield(const struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max);
+
+#define ea_normalize(ea) do { \
+  if (ea->next) { \
+    ea_list *t = alloca(ea_scan(ea)); \
+    ea_merge(ea, t); \
+    ea = t; \
+  } \
+  ea_sort(ea); \
+  if (ea->count == 0) \
+    ea = NULL; \
+} while(0) \
+
+struct ea_one_attr_list {
+  ea_list l;
+  eattr a;
+};
+
+static inline eattr *
+ea_set_attr(ea_list **to, struct linpool *pool, uint id, uint flags, uint type, union bval val)
+{
+  struct ea_one_attr_list *ea = lp_alloc(pool, sizeof(*ea));
+  *ea = (struct ea_one_attr_list) {
+    .l.flags = EALF_SORTED,
+    .l.count = 1,
+    .l.next = *to,
+
+    .a.id = id,
+    .a.type = type,
+    .a.flags = flags,
+  };
+
+  ea->a.u = val;
+  *to = &ea->l;
+
+  return &ea->a;
+}
+
+static inline void
+ea_unset_attr(ea_list **to, struct linpool *pool, _Bool local, uint code)
+{
+  struct ea_one_attr_list *ea = lp_alloc(pool, sizeof(*ea));
+  *ea = (struct ea_one_attr_list) {
+    .l.flags = EALF_SORTED,
+    .l.count = 1,
+    .l.next = *to,
+    .a.id = code,
+    .a.fresh = local,
+    .a.originated = local,
+    .a.undef = 1,
+  };
+
+  *to = &ea->l;
+}
+
+static inline void
+ea_set_attr_u32(ea_list **to, struct linpool *pool, uint id, uint flags, uint type, u32 data)
+{
+  union bval bv = { .data = data };
+  ea_set_attr(to, pool, id, flags, type, bv);
+}
+
+static inline void
+ea_set_attr_data(ea_list **to, struct linpool *pool, uint id, uint flags, uint type, void *data, uint len)
+{
+  struct adata *a = lp_alloc_adata(pool, len);
+  memcpy(a->data, data, len);
+  union bval bv = { .ptr = a, };
+  ea_set_attr(to, pool, id, flags, type, bv);
+}
+
+
+#define NEXTHOP_MAX_SIZE (sizeof(struct nexthop) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+
+static inline size_t nexthop_size(const struct nexthop *nh)
+{ return sizeof(struct nexthop) + sizeof(u32)*nh->labels; }
+int nexthop__same(struct nexthop *x, struct nexthop *y); /* Compare multipath nexthops */
+static inline int nexthop_same(struct nexthop *x, struct nexthop *y)
+{ return (x == y) || nexthop__same(x, y); }
+struct nexthop *nexthop_merge(struct nexthop *x, struct nexthop *y, int rx, int ry, int max, linpool *lp);
+struct nexthop *nexthop_sort(struct nexthop *x);
+static inline void nexthop_link(struct rta *a, struct nexthop *from)
+{ memcpy(&a->nh, from, nexthop_size(from)); }
+void nexthop_insert(struct nexthop **n, struct nexthop *y);
+int nexthop_is_sorted(struct nexthop *x);
+
+void rta_init(void);
+static inline size_t rta_size(const rta *a) { return sizeof(rta) + sizeof(u32)*a->nh.labels; }
+#define RTA_MAX_SIZE (sizeof(rta) + sizeof(u32)*MPLS_MAX_LABEL_STACK)
+rta *rta_lookup(rta *);			/* Get rta equivalent to this one, uc++ */
+static inline int rta_is_cached(rta *r) { return r->cached; }
+static inline rta *rta_clone(rta *r) { r->uc++; return r; }
+void rta__free(rta *r);
+static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }
+rta *rta_do_cow(rta *o, linpool *lp);
+static inline rta * rta_cow(rta *r, linpool *lp) { return rta_is_cached(r) ? rta_do_cow(r, lp) : r; }
+void rta_dump(rta *);
+void rta_dump_all(void);
+void rta_show(struct cli *, rta *);
+
+u32 rt_get_igp_metric(rte *rt);
+
+#endif