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c10421d3d4
o Now compatible with filtering. o Learning of kernel routes supported only on CONFIG_SELF_CONSCIOUS systems (on the others it's impossible to get it semantically correct). o Learning now stores all of its routes in a separate fib and selects the ones the kernel really uses for forwarding packets. o Better treatment of CONFIG_AUTO_ROUTES ports. o Lots of internal changes.
306 lines
11 KiB
C
306 lines
11 KiB
C
/*
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* BIRD Internet Routing Daemon -- Routing Table
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*
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* (c) 1998 Martin Mares <mj@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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#ifndef _BIRD_ROUTE_H_
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#define _BIRD_ROUTE_H_
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#include "lib/resource.h"
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#include "lib/timer.h"
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struct protocol;
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struct proto;
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/*
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* Generic data structure for storing network prefixes. Also used
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* for the master routing table. Currently implemented as a hash
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* table.
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*
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* Available operations:
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* - insertion of new entry
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* - deletion of entry
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* - searching for entry by network prefix
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* - asynchronous retrieval of fib contents
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*/
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struct fib_node {
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struct fib_node *next; /* Next in hash chain */
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struct fib_iterator *readers; /* List of readers of this node */
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byte pxlen;
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byte flags; /* User-defined */
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byte x0, x1; /* User-defined */
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ip_addr prefix; /* In host order */
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};
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struct fib_iterator { /* See lib/slists.h for an explanation */
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struct fib_iterator *prev, *next; /* Must be synced with struct fib_node! */
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struct fib_node *node; /* Or NULL if freshly merged */
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byte efef; /* 0xff to distinguish between iterator and node */
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byte pad[3];
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unsigned int hash;
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};
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struct fib {
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pool *fib_pool; /* Pool holding all our data */
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slab *fib_slab; /* Slab holding all fib nodes */
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struct fib_node **hash_table; /* Node hash table */
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unsigned int hash_size; /* Number of hash table entries (a power of two) */
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unsigned int hash_order; /* Binary logarithm of hash_size */
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unsigned int hash_shift; /* 16 - hash_log */
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unsigned int entries; /* Number of entries */
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unsigned int entries_min, entries_max;/* Entry count limits (else start rehashing) */
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void (*init)(struct fib_node *); /* Constructor */
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};
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void fib_init(struct fib *, pool *, unsigned node_size, unsigned hash_order, void (*init)(struct fib_node *));
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void *fib_find(struct fib *, ip_addr *, int); /* Find or return NULL if doesn't exist */
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void *fib_get(struct fib *, ip_addr *, int); /* Find or create new if nonexistent */
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void fib_delete(struct fib *, void *); /* Remove fib entry */
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void fib_free(struct fib *); /* Destroy the fib */
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void fib_check(struct fib *); /* Consistency check for debugging */
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void fit_init(struct fib_iterator *, struct fib *); /* Internal functions, don't call */
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struct fib_node *fit_get(struct fib *, struct fib_iterator *);
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void fit_put(struct fib_iterator *, struct fib_node *);
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#define FIB_WALK(fib, z) do { \
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struct fib_node *z, **ff = (fib)->hash_table; \
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unsigned int count = (fib)->hash_size; \
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while (count--) \
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for(z = *ff++; z; z=z->next)
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#define FIB_WALK_END } while (0)
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#define FIB_ITERATE_INIT(it, fib) fit_init(it, fib)
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#define FIB_ITERATE_START(fib, it, z) do { \
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struct fib_node *z = fit_get(fib, it); \
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unsigned int count = (fib)->hash_size; \
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unsigned int hpos = (it)->hash; \
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for(;;) { \
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fis_again: if (!z) { \
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if (++hpos >= count) \
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break; \
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z = (fib)->hash_table[hpos]; \
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goto fis_again; \
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}
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#define FIB_ITERATE_END(z) z = z->next; } } while(0)
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#define FIB_ITERATE_PUT(it, z) fit_put(it, z)
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/*
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* Master Routing Tables. Generally speaking, each of them is a list
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* of FIB (one per TOS) with each entry pointing to a list of route entries
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* representing routes to given network.
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* Each of the RTE's contains variable data (the preference and protocol-dependent
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* metrics) and a pointer to a route attribute block common for many routes).
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* It's guaranteed that there is at most one RTE for every (prefix,proto,source) triplet.
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*/
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typedef struct rtable {
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struct rtable *sibling; /* Our sibling for different TOS */
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byte tos; /* TOS for this table */
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struct fib fib;
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char *name; /* Name of this table */
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} rtable;
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typedef struct network {
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struct fib_node n; /* FIB flags reserved for kernel syncer */
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struct rte *routes; /* Available routes for this network */
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} net;
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typedef struct rte {
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struct rte *next;
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net *net; /* Network this RTE belongs to */
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struct rta *attrs; /* Attributes of this route */
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byte flags; /* Flags (REF_...) */
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byte pflags; /* Protocol-specific flags */
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word pref; /* Route preference */
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bird_clock_t lastmod; /* Last modified */
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union { /* Protocol-dependent data (metrics etc.) */
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#ifdef CONFIG_RIP
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struct {
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node garbage; /* List for garbage collection */
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byte metric; /* RIP metric */
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u16 tag; /* External route tag */
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} rip;
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#endif
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#ifdef CONFIG_OSPF
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struct {
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u32 metric1, metric2; /* OSPF Type 1 and Type 2 metrics */
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u32 tag; /* External route tag */
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} ospf;
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#endif
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#ifdef CONFIG_BGP
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struct {
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} bgp;
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#endif
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struct { /* Routes generated by krt sync (both temporary and inherited ones) */
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s8 src; /* Alleged route source (see krt.h) */
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u8 proto; /* Kernel source protocol ID */
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u8 type; /* Kernel route type */
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u8 seen; /* Seen during last scan */
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u32 metric; /* Kernel metric */
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} krt;
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} u;
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} rte;
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extern rtable master_table;
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void rt_init(void);
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void rt_setup(pool *, rtable *, char *);
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net *net_find(rtable *tab, unsigned tos, ip_addr addr, unsigned len);
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net *net_get(rtable *tab, unsigned tos, ip_addr addr, unsigned len);
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rte *rte_find(net *net, struct proto *p);
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rte *rte_get_temp(struct rta *);
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void rte_update(net *net, struct proto *p, rte *new);
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void rte_discard(rte *old);
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void rte_dump(rte *);
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void rte_free(rte *);
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void rt_dump(rtable *);
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void rt_dump_all(void);
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void rt_feed_baby(struct proto *p);
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void rt_prune(rtable *tab);
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/*
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* Route Attributes
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*
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* Beware: All standard BGP attributes must be represented here instead
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* of making them local to the route. This is needed to ensure proper
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* construction of BGP route attribute lists.
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*/
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typedef struct rta {
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struct rta *next, *prev; /* Hash chain */
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struct rta *garbage; /* Garbage collector chain */
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struct proto *proto; /* Protocol instance */
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unsigned uc; /* Use count */
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byte source; /* Route source (RTS_...) */
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byte scope; /* Route scope (SCOPE_... -- see ip.h) */
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byte cast; /* Casting type (RTC_...) */
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byte dest; /* Route destination type (RTD_...) */
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byte tos; /* TOS of this route */
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byte flags; /* Route flags (RTF_...) */
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byte aflags; /* Attribute cache flags (RTAF_...) */
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byte rfu; /* Padding */
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ip_addr gw; /* Next hop */
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ip_addr from; /* Advertising router */
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struct iface *iface; /* Outgoing interface */
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struct ea_list *attrs; /* Extended Attribute chain */
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} rta;
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#define RTS_DUMMY 0 /* Dummy route to be removed soon */
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#define RTS_STATIC 1 /* Normal static route */
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#define RTS_INHERIT 2 /* Route inherited from kernel */
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#define RTS_DEVICE 3 /* Device route */
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#define RTS_STATIC_DEVICE 4 /* Static device route */
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#define RTS_REDIRECT 5 /* Learned via redirect */
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#define RTS_RIP 6 /* RIP route */
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#define RTS_RIP_EXT 7 /* RIP external route */
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#define RTS_OSPF 8 /* OSPF route */
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#define RTS_OSPF_EXT 9 /* OSPF external route */
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#define RTS_OSPF_IA 10 /* OSPF inter-area route */
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#define RTS_OSPF_BOUNDARY 11 /* OSPF route to boundary router (???) */
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#define RTS_BGP 12 /* BGP route */
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#define RTC_UNICAST 0
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#define RTC_BROADCAST 1
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#define RTC_MULTICAST 2
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#define RTC_ANYCAST 3 /* IPv6 Anycast */
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#define RTD_ROUTER 0 /* Next hop is neighbor router */
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#define RTD_DEVICE 1 /* Points to device */
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#define RTD_BLACKHOLE 2 /* Silently drop packets */
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#define RTD_UNREACHABLE 3 /* Reject as unreachable */
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#define RTD_PROHIBIT 4 /* Administratively prohibited */
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#define RTF_EXTERIOR 1 /* Learned via exterior protocol */
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#define RTF_TAGGED 2 /* Tagged external route learned via IGP */
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#define RTAF_CACHED 1 /* This is a cached rta */
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/*
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* Extended Route Attributes
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*/
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typedef struct eattr {
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word id; /* EA_CODE(EAP_..., protocol-dependent ID) */
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byte flags; /* Protocol-dependent flags */
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byte type; /* Attribute type and several flags (EAF_...) */
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union {
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u32 data;
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struct adata *ptr; /* Attribute data elsewhere */
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} u;
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} eattr;
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/* FIXME: Introduce real protocol numbers? */
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#define EAP_GENERIC 0 /* Generic attributes */
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#define EAP_BGP 1 /* BGP attributes */
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#define EA_CODE(proto,id) (((proto) << 8) | (id))
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#define EA_PROTO(ea) ((ea) >> 8)
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#define EA_ID(ea) ((ea) & 0xff)
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#define EAF_TYPE_MASK 0x0f /* Mask with this to get type */
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#define EAF_TYPE_INT 0x01 /* 32-bit signed integer number */
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#define EAF_TYPE_OPAQUE 0x02 /* Opaque byte string (not filterable) */
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#define EAF_TYPE_IP_ADDRESS 0x04 /* IP address [FIXME: embed at least for IPv4?] */
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#define EAF_TYPE_AS_PATH 0x06 /* BGP AS path [FIXME: define storage layout] */
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#define EAF_TYPE_INT_SET 0x0a /* Set of integers (e.g., a community list) */
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#define EAF_EMBEDDED 0x01 /* Data stored in eattr.u.data (part of type spec) */
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#define EAF_VAR_LENGTH 0x02 /* Attribute length is variable */
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#define EAF_INLINE 0x80 /* Copy of an attribute inlined in rte (temporary ea_lists only) */
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struct adata {
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unsigned int length;
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byte data[0];
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};
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typedef struct ea_list {
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struct ea_list *next; /* In case we have an override list */
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byte flags; /* Flags: EALF_... */
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byte rfu;
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word count; /* Number of attributes */
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eattr attrs[0]; /* Attribute definitions themselves */
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} ea_list;
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#define EALF_SORTED 1 /* Attributes are sorted by code */
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#define EALF_BISECT 2 /* Use interval bisection for searching */
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#define EALF_CACHED 4 /* Attributes belonging to cached rta */
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eattr *ea_find(ea_list *, unsigned ea);
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void ea_dump(ea_list *);
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void ea_sort(ea_list *); /* Sort entries in all sub-lists */
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unsigned ea_scan(ea_list *); /* How many bytes do we need for merged ea_list (0=merge not needed) */
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void ea_merge(ea_list *from, ea_list *to); /* Merge sub-lists to allocated buffer */
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void rta_init(void);
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rta *rta_lookup(rta *); /* Get rta equivalent to this one, uc++ */
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static inline rta *rta_clone(rta *r) { r->uc++; return r; }
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void rta__free(rta *r);
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static inline void rta_free(rta *r) { if (r && !--r->uc) rta__free(r); }
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void rta_dump(rta *);
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void rta_dump_all(void);
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static inline eattr * rta_find(rta *a, unsigned ea) { return ea_find(a->attrs, ea); }
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/*
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* Default protocol preferences
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*/
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#define DEF_PREF_DIRECT 240 /* Directly connected */
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#define DEF_PREF_STATIC 200 /* Static route */
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#define DEF_PREF_OSPF_INTERNAL 150 /* OSPF intra-area, inter-area and type 1 external routes */
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#define DEF_PREF_RIP 120 /* RIP */
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#define DEF_PREF_BGP 100 /* BGP */
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#define DEF_PREF_OSPF_EXTERNAL 80 /* OSPF external routes */
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#define DEF_PREF_RIP_EXTERNAL 70 /* RIP external routes */
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#define DEF_PREF_UKR 50 /* Unidentified Kernel Route */
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#define DEF_PREF_SINK 10 /* Sink route */
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#endif
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