mirror of
https://gitlab.labs.nic.cz/labs/bird.git
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beb5f78ada
Passing protocol to preexport was in fact a historical relic from the old times when channels weren't a thing. Refactoring that to match current extensibility needs.
2486 lines
65 KiB
C
2486 lines
65 KiB
C
/*
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* BIRD -- The Babel protocol
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*
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* Copyright (c) 2015--2016 Toke Hoiland-Jorgensen
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* (c) 2016--2017 Ondrej Zajicek <santiago@crfreenet.org>
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* (c) 2016--2017 CZ.NIC z.s.p.o.
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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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* This file contains the main routines for handling and sending TLVs, as
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* well as timers and interaction with the nest.
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*/
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/**
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* DOC: The Babel protocol
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*
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* Babel (RFC6126) is a loop-avoiding distance-vector routing protocol that is
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* robust and efficient both in ordinary wired networks and in wireless mesh
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* networks.
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*
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* The Babel protocol keeps state for each neighbour in a &babel_neighbor
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* struct, tracking received Hello and I Heard You (IHU) messages. A
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* &babel_interface struct keeps hello and update times for each interface, and
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* a separate hello seqno is maintained for each interface.
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*
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* For each prefix, Babel keeps track of both the possible routes (with next hop
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* and router IDs), as well as the feasibility distance for each prefix and
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* router id. The prefix itself is tracked in a &babel_entry struct, while the
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* possible routes for the prefix are tracked as &babel_route entries and the
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* feasibility distance is maintained through &babel_source structures.
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*
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* The main route selection is done in babel_select_route(). This is called when
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* an entry is updated by receiving updates from the network or when modified by
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* internal timers. The function selects from feasible and reachable routes the
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* one with the lowest metric to be announced to the core.
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*/
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#include <stdlib.h>
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#include "babel.h"
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#define LOG_PKT_AUTH(msg, args...) \
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log_rl(&p->log_pkt_tbf, L_AUTH "%s: " msg, p->p.name, args)
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/*
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* Is one number greater or equal than another mod 2^16? This is based on the
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* definition of serial number space in RFC 1982. Note that arguments are of
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* uint type to avoid integer promotion to signed integer.
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*/
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static inline int ge_mod64k(uint a, uint b)
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{ return (u16)(a - b) < 0x8000; }
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static void babel_expire_requests(struct babel_proto *p, struct babel_entry *e);
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static void babel_select_route(struct babel_proto *p, struct babel_entry *e, struct babel_route *mod);
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static inline void babel_announce_retraction(struct babel_proto *p, struct babel_entry *e);
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static void babel_send_route_request(struct babel_proto *p, struct babel_entry *e, struct babel_neighbor *n);
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static void babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e, struct babel_seqno_request *sr);
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static void babel_update_cost(struct babel_neighbor *n);
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static inline void babel_kick_timer(struct babel_proto *p);
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static inline void babel_iface_kick_timer(struct babel_iface *ifa);
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/*
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* Functions to maintain data structures
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*/
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static void
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babel_init_entry(struct fib *f UNUSED, void *E)
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{
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struct babel_entry *e = E;
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e->updated = current_time();
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init_list(&e->requests);
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init_list(&e->sources);
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init_list(&e->routes);
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}
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static inline struct babel_entry *
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babel_find_entry(struct babel_proto *p, const net_addr *n)
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{
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struct fib *rtable = (n->type == NET_IP4) ? &p->ip4_rtable : &p->ip6_rtable;
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return fib_find(rtable, n);
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}
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static struct babel_entry *
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babel_get_entry(struct babel_proto *p, const net_addr *n)
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{
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struct fib *rtable = (n->type == NET_IP4) ? &p->ip4_rtable : &p->ip6_rtable;
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struct babel_entry *e = fib_get(rtable, n);
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return e;
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}
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static struct babel_source *
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babel_find_source(struct babel_entry *e, u64 router_id)
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{
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struct babel_source *s;
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WALK_LIST(s, e->sources)
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if (s->router_id == router_id)
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return s;
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return NULL;
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}
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static struct babel_source *
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babel_get_source(struct babel_proto *p, struct babel_entry *e, u64 router_id)
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{
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struct babel_source *s = babel_find_source(e, router_id);
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if (s)
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return s;
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s = sl_allocz(p->source_slab);
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s->router_id = router_id;
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s->expires = current_time() + BABEL_GARBAGE_INTERVAL;
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s->seqno = 0;
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s->metric = BABEL_INFINITY;
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add_tail(&e->sources, NODE s);
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return s;
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}
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static void
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babel_expire_sources(struct babel_proto *p, struct babel_entry *e)
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{
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struct babel_source *n, *nx;
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btime now_ = current_time();
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WALK_LIST_DELSAFE(n, nx, e->sources)
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{
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if (n->expires && n->expires <= now_)
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{
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rem_node(NODE n);
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sl_free(p->source_slab, n);
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}
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}
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}
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static struct babel_route *
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babel_find_route(struct babel_entry *e, struct babel_neighbor *n)
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{
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struct babel_route *r;
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WALK_LIST(r, e->routes)
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if (r->neigh == n)
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return r;
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return NULL;
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}
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static struct babel_route *
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babel_get_route(struct babel_proto *p, struct babel_entry *e, struct babel_neighbor *nbr)
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{
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struct babel_route *r = babel_find_route(e, nbr);
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if (r)
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return r;
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r = sl_allocz(p->route_slab);
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r->e = e;
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r->neigh = nbr;
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add_tail(&e->routes, NODE r);
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add_tail(&nbr->routes, NODE &r->neigh_route);
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return r;
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}
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static inline void
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babel_retract_route(struct babel_proto *p, struct babel_route *r)
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{
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r->metric = r->advert_metric = BABEL_INFINITY;
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if (r == r->e->selected)
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babel_select_route(p, r->e, r);
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}
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static void
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babel_flush_route(struct babel_proto *p, struct babel_route *r)
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{
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DBG("Babel: Flush route %N router_id %lR neigh %I\n",
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r->e->n.addr, r->router_id, r->neigh->addr);
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rem_node(NODE r);
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rem_node(&r->neigh_route);
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if (r->e->selected == r)
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r->e->selected = NULL;
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sl_free(p->route_slab, r);
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}
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static void
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babel_expire_route(struct babel_proto *p, struct babel_route *r)
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{
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struct babel_config *cf = (void *) p->p.cf;
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TRACE(D_EVENTS, "Route expiry timer for %N router-id %lR fired",
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r->e->n.addr, r->router_id);
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if (r->metric < BABEL_INFINITY)
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{
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r->metric = r->advert_metric = BABEL_INFINITY;
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r->expires = current_time() + cf->hold_time;
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}
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else
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{
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babel_flush_route(p, r);
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}
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}
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static void
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babel_refresh_route(struct babel_proto *p, struct babel_route *r)
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{
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if (r == r->e->selected)
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babel_send_route_request(p, r->e, r->neigh);
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r->refresh_time = 0;
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}
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static void
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babel_expire_routes_(struct babel_proto *p, struct fib *rtable)
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{
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struct babel_config *cf = (void *) p->p.cf;
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struct babel_route *r, *rx;
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struct fib_iterator fit;
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btime now_ = current_time();
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FIB_ITERATE_INIT(&fit, rtable);
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loop:
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FIB_ITERATE_START(rtable, &fit, struct babel_entry, e)
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{
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int changed = 0;
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WALK_LIST_DELSAFE(r, rx, e->routes)
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{
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if (r->refresh_time && r->refresh_time <= now_)
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babel_refresh_route(p, r);
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if (r->expires && r->expires <= now_)
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{
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changed = changed || (r == e->selected);
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babel_expire_route(p, r);
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}
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}
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if (changed)
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{
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/*
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* We have to restart the iteration because there may be a cascade of
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* synchronous events babel_select_route() -> nest table change ->
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* babel_rt_notify() -> rtable change, invalidating hidden variables.
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*/
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FIB_ITERATE_PUT(&fit);
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babel_select_route(p, e, NULL);
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goto loop;
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}
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/* Clean up stale entries */
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if ((e->valid == BABEL_ENTRY_STALE) && ((e->updated + cf->hold_time) <= now_))
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e->valid = BABEL_ENTRY_DUMMY;
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/* Clean up unreachable route */
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if (e->unreachable && (!e->valid || (e->router_id == p->router_id)))
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{
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FIB_ITERATE_PUT(&fit);
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babel_announce_retraction(p, e);
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goto loop;
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}
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babel_expire_sources(p, e);
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babel_expire_requests(p, e);
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/* Remove empty entries */
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if (!e->valid && EMPTY_LIST(e->routes) && EMPTY_LIST(e->sources) && EMPTY_LIST(e->requests))
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{
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FIB_ITERATE_PUT(&fit);
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fib_delete(rtable, e);
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goto loop;
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}
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}
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FIB_ITERATE_END;
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}
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static void
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babel_expire_routes(struct babel_proto *p)
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{
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babel_expire_routes_(p, &p->ip4_rtable);
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babel_expire_routes_(p, &p->ip6_rtable);
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}
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static inline int seqno_request_valid(struct babel_seqno_request *sr)
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{ return !sr->nbr || sr->nbr->ifa; }
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/*
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* Add seqno request to the table of pending requests (RFC 6216 3.2.6) and send
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* it to network. Do nothing if it is already in the table.
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*/
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static void
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babel_add_seqno_request(struct babel_proto *p, struct babel_entry *e,
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u64 router_id, u16 seqno, u8 hop_count,
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struct babel_neighbor *nbr)
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{
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struct babel_seqno_request *sr;
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WALK_LIST(sr, e->requests)
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if (sr->router_id == router_id)
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{
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/* Found matching or newer */
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if (ge_mod64k(sr->seqno, seqno) && seqno_request_valid(sr))
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return;
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/* Found older */
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rem_node(NODE sr);
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if (sr->nbr)
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rem_node(&sr->nbr_node);
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goto found;
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}
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/* No entries found */
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sr = sl_allocz(p->seqno_slab);
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found:
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sr->router_id = router_id;
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sr->seqno = seqno;
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sr->hop_count = hop_count;
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sr->count = 0;
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sr->expires = current_time() + BABEL_SEQNO_REQUEST_EXPIRY;
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if (sr->nbr = nbr)
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add_tail(&nbr->requests, &sr->nbr_node);
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add_tail(&e->requests, NODE sr);
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babel_send_seqno_request(p, e, sr);
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}
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static void
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babel_remove_seqno_request(struct babel_proto *p, struct babel_seqno_request *sr)
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{
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if (sr->nbr)
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rem_node(&sr->nbr_node);
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rem_node(NODE sr);
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sl_free(p->seqno_slab, sr);
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}
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static int
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babel_satisfy_seqno_request(struct babel_proto *p, struct babel_entry *e,
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u64 router_id, u16 seqno)
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{
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struct babel_seqno_request *sr;
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WALK_LIST(sr, e->requests)
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if ((sr->router_id == router_id) && ge_mod64k(seqno, sr->seqno))
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{
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/* Found the request, remove it */
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babel_remove_seqno_request(p, sr);
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return 1;
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}
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return 0;
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}
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static void
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babel_expire_requests(struct babel_proto *p, struct babel_entry *e)
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{
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struct babel_seqno_request *sr, *srx;
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btime now_ = current_time();
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WALK_LIST_DELSAFE(sr, srx, e->requests)
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{
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/* Remove seqno requests sent to dead neighbors */
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if (!seqno_request_valid(sr))
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{
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babel_remove_seqno_request(p, sr);
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continue;
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}
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/* Handle expired requests - resend or remove */
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if (sr->expires && sr->expires <= now_)
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{
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if (sr->count < BABEL_SEQNO_REQUEST_RETRY)
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{
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sr->count++;
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sr->expires += (BABEL_SEQNO_REQUEST_EXPIRY << sr->count);
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babel_send_seqno_request(p, e, sr);
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}
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else
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{
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TRACE(D_EVENTS, "Seqno request for %N router-id %lR expired",
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e->n.addr, sr->router_id);
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babel_remove_seqno_request(p, sr);
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continue;
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}
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}
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}
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}
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|
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static struct babel_neighbor *
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babel_find_neighbor(struct babel_iface *ifa, ip_addr addr)
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{
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struct babel_neighbor *nbr;
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|
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WALK_LIST(nbr, ifa->neigh_list)
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if (ipa_equal(nbr->addr, addr))
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return nbr;
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return NULL;
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}
|
|
|
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static struct babel_neighbor *
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babel_get_neighbor(struct babel_iface *ifa, ip_addr addr)
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{
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struct babel_proto *p = ifa->proto;
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struct babel_neighbor *nbr = babel_find_neighbor(ifa, addr);
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|
|
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if (nbr)
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return nbr;
|
|
|
|
TRACE(D_EVENTS, "New neighbor %I on %s", addr, ifa->iface->name);
|
|
|
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nbr = mb_allocz(ifa->pool, sizeof(struct babel_neighbor));
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nbr->ifa = ifa;
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nbr->addr = addr;
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nbr->rxcost = BABEL_INFINITY;
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nbr->txcost = BABEL_INFINITY;
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nbr->cost = BABEL_INFINITY;
|
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nbr->init_expiry = current_time() + BABEL_INITIAL_NEIGHBOR_TIMEOUT;
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init_list(&nbr->routes);
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init_list(&nbr->requests);
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add_tail(&ifa->neigh_list, NODE nbr);
|
|
|
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return nbr;
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}
|
|
|
|
static void
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babel_flush_neighbor(struct babel_proto *p, struct babel_neighbor *nbr)
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{
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struct babel_route *r;
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node *n;
|
|
|
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TRACE(D_EVENTS, "Removing neighbor %I on %s", nbr->addr, nbr->ifa->iface->name);
|
|
|
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WALK_LIST_FIRST(n, nbr->routes)
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{
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r = SKIP_BACK(struct babel_route, neigh_route, n);
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babel_retract_route(p, r);
|
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babel_flush_route(p, r);
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}
|
|
|
|
struct babel_seqno_request *sr;
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WALK_LIST_FIRST2(sr, nbr_node, nbr->requests)
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babel_remove_seqno_request(p, sr);
|
|
|
|
nbr->ifa = NULL;
|
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rem_node(NODE nbr);
|
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mb_free(nbr);
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}
|
|
|
|
static void
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babel_expire_ihu(struct babel_proto *p, struct babel_neighbor *nbr)
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{
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TRACE(D_EVENTS, "IHU from nbr %I on %s expired", nbr->addr, nbr->ifa->iface->name);
|
|
|
|
nbr->txcost = BABEL_INFINITY;
|
|
nbr->ihu_expiry = 0;
|
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babel_update_cost(nbr);
|
|
}
|
|
|
|
static void
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|
babel_expire_hello(struct babel_proto *p, struct babel_neighbor *nbr, btime now_)
|
|
{
|
|
again:
|
|
nbr->hello_map <<= 1;
|
|
|
|
if (nbr->hello_cnt < 16)
|
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nbr->hello_cnt++;
|
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|
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nbr->hello_expiry += nbr->last_hello_int;
|
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|
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/* We may expire multiple hellos if last_hello_int is too short */
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if (nbr->hello_map && nbr->hello_expiry <= now_)
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goto again;
|
|
|
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TRACE(D_EVENTS, "Hello from nbr %I on %s expired, %d left",
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nbr->addr, nbr->ifa->iface->name, u32_popcount(nbr->hello_map));
|
|
|
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if (nbr->hello_map)
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babel_update_cost(nbr);
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else
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babel_flush_neighbor(p, nbr);
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|
}
|
|
|
|
static void
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|
babel_expire_neighbors(struct babel_proto *p)
|
|
{
|
|
struct babel_iface *ifa;
|
|
struct babel_neighbor *nbr, *nbx;
|
|
btime now_ = current_time();
|
|
|
|
WALK_LIST(ifa, p->interfaces)
|
|
{
|
|
WALK_LIST_DELSAFE(nbr, nbx, ifa->neigh_list)
|
|
{
|
|
if (nbr->ihu_expiry && nbr->ihu_expiry <= now_)
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|
babel_expire_ihu(p, nbr);
|
|
|
|
if (nbr->init_expiry && nbr->init_expiry <= now_)
|
|
{ babel_flush_neighbor(p, nbr); continue; }
|
|
|
|
if (nbr->hello_expiry && nbr->hello_expiry <= now_)
|
|
{ babel_expire_hello(p, nbr, now_); continue; }
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Best route selection
|
|
*/
|
|
|
|
/*
|
|
* From the RFC (section 3.5.1):
|
|
*
|
|
* a route advertisement carrying the quintuple (prefix, plen, router-id, seqno,
|
|
* metric) is feasible if one of the following conditions holds:
|
|
*
|
|
* - metric is infinite; or
|
|
*
|
|
* - no entry exists in the source table indexed by (id, prefix, plen); or
|
|
*
|
|
* - an entry (prefix, plen, router-id, seqno', metric') exists in the source
|
|
* table, and either
|
|
* - seqno' < seqno or
|
|
* - seqno = seqno' and metric < metric'.
|
|
*/
|
|
static inline int
|
|
babel_is_feasible(struct babel_source *s, u16 seqno, u16 metric)
|
|
{
|
|
return !s ||
|
|
(metric == BABEL_INFINITY) ||
|
|
(seqno > s->seqno) ||
|
|
((seqno == s->seqno) && (metric < s->metric));
|
|
}
|
|
|
|
/* Simple additive metric - Appendix 3.1 in the RFC */
|
|
static inline u16
|
|
babel_compute_metric(struct babel_neighbor *n, uint metric)
|
|
{
|
|
return MIN(metric + n->cost, BABEL_INFINITY);
|
|
}
|
|
|
|
static void
|
|
babel_update_cost(struct babel_neighbor *nbr)
|
|
{
|
|
struct babel_proto *p = nbr->ifa->proto;
|
|
struct babel_iface_config *cf = nbr->ifa->cf;
|
|
uint rcv = u32_popcount(nbr->hello_map); // number of bits set
|
|
uint max = nbr->hello_cnt;
|
|
uint rxcost = BABEL_INFINITY; /* Cost to announce in IHU */
|
|
uint txcost = BABEL_INFINITY; /* Effective cost for route selection */
|
|
|
|
if (!rcv || !nbr->ifa->up)
|
|
goto done;
|
|
|
|
switch (cf->type)
|
|
{
|
|
case BABEL_IFACE_TYPE_WIRED:
|
|
/* k-out-of-j selection - Appendix 2.1 in the RFC. */
|
|
|
|
/* Link is bad if less than cf->limit/16 of expected hellos were received */
|
|
if (rcv * 16 < cf->limit * max)
|
|
break;
|
|
|
|
rxcost = cf->rxcost;
|
|
txcost = nbr->txcost;
|
|
break;
|
|
|
|
case BABEL_IFACE_TYPE_WIRELESS:
|
|
/*
|
|
* ETX - Appendix 2.2 in the RFC.
|
|
*
|
|
* alpha = prob. of successful transmission estimated by the neighbor
|
|
* beta = prob. of successful transmission estimated by the router
|
|
* rxcost = nominal rxcost of the router / beta
|
|
* txcost = nominal rxcost of the neighbor / (alpha * beta)
|
|
* = received txcost / beta
|
|
*
|
|
* Note that received txcost is just neighbor's rxcost. Beta is rcv/max,
|
|
* we use inverse values of beta (i.e. max/rcv) to stay in integers.
|
|
*/
|
|
rxcost = MIN( cf->rxcost * max / rcv, BABEL_INFINITY);
|
|
txcost = MIN(nbr->txcost * max / rcv, BABEL_INFINITY);
|
|
break;
|
|
}
|
|
|
|
done:
|
|
/* If RX cost changed, send IHU with next Hello */
|
|
if (rxcost != nbr->rxcost)
|
|
{
|
|
nbr->rxcost = rxcost;
|
|
nbr->ihu_cnt = 0;
|
|
}
|
|
|
|
/* If link cost changed, run route selection */
|
|
if (txcost != nbr->cost)
|
|
{
|
|
TRACE(D_EVENTS, "Cost of nbr %I on %s changed from %u to %u",
|
|
nbr->addr, nbr->ifa->iface->name, nbr->cost, txcost);
|
|
|
|
nbr->cost = txcost;
|
|
|
|
struct babel_route *r; node *n;
|
|
WALK_LIST2(r, n, nbr->routes, neigh_route)
|
|
{
|
|
r->metric = babel_compute_metric(nbr, r->advert_metric);
|
|
babel_select_route(p, r->e, r);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* babel_announce_rte - announce selected route to the core
|
|
* @p: Babel protocol instance
|
|
* @e: Babel route entry to announce
|
|
*
|
|
* This function announces a Babel entry to the core if it has a selected
|
|
* incoming path, and retracts it otherwise. If there is no selected route but
|
|
* the entry is valid and ours, the unreachable route is announced instead.
|
|
*/
|
|
static void
|
|
babel_announce_rte(struct babel_proto *p, struct babel_entry *e)
|
|
{
|
|
struct babel_route *r = e->selected;
|
|
struct channel *c = (e->n.addr->type == NET_IP4) ? p->ip4_channel : p->ip6_channel;
|
|
|
|
if (r)
|
|
{
|
|
rta a0 = {
|
|
.src = p->p.main_source,
|
|
.source = RTS_BABEL,
|
|
.scope = SCOPE_UNIVERSE,
|
|
.dest = RTD_UNICAST,
|
|
.from = r->neigh->addr,
|
|
.nh.gw = r->next_hop,
|
|
.nh.iface = r->neigh->ifa->iface,
|
|
};
|
|
|
|
/*
|
|
* If we cannot find a reachable neighbour, set the entry to be onlink. This
|
|
* makes it possible to, e.g., assign /32 addresses on a mesh interface and
|
|
* have routing work.
|
|
*/
|
|
if (!neigh_find(&p->p, r->next_hop, r->neigh->ifa->iface, 0))
|
|
a0.nh.flags = RNF_ONLINK;
|
|
|
|
rta *a = rta_lookup(&a0);
|
|
rte *rte = rte_get_temp(a);
|
|
rte->u.babel.seqno = r->seqno;
|
|
rte->u.babel.metric = r->metric;
|
|
rte->u.babel.router_id = r->router_id;
|
|
rte->pflags = EA_ID_FLAG(EA_BABEL_METRIC) | EA_ID_FLAG(EA_BABEL_ROUTER_ID);
|
|
|
|
e->unreachable = 0;
|
|
rte_update2(c, e->n.addr, rte, p->p.main_source);
|
|
}
|
|
else if (e->valid && (e->router_id != p->router_id))
|
|
{
|
|
/* Unreachable */
|
|
rta a0 = {
|
|
.src = p->p.main_source,
|
|
.source = RTS_BABEL,
|
|
.scope = SCOPE_UNIVERSE,
|
|
.dest = RTD_UNREACHABLE,
|
|
};
|
|
|
|
rta *a = rta_lookup(&a0);
|
|
rte *rte = rte_get_temp(a);
|
|
memset(&rte->u.babel, 0, sizeof(rte->u.babel));
|
|
rte->pflags = 0;
|
|
rte->pref = 1;
|
|
|
|
e->unreachable = 1;
|
|
rte_update2(c, e->n.addr, rte, p->p.main_source);
|
|
}
|
|
else
|
|
{
|
|
/* Retraction */
|
|
e->unreachable = 0;
|
|
rte_update2(c, e->n.addr, NULL, p->p.main_source);
|
|
}
|
|
}
|
|
|
|
/* Special case of babel_announce_rte() just for retraction */
|
|
static inline void
|
|
babel_announce_retraction(struct babel_proto *p, struct babel_entry *e)
|
|
{
|
|
struct channel *c = (e->n.addr->type == NET_IP4) ? p->ip4_channel : p->ip6_channel;
|
|
e->unreachable = 0;
|
|
rte_update2(c, e->n.addr, NULL, p->p.main_source);
|
|
}
|
|
|
|
|
|
/**
|
|
* babel_select_route - select best route for given route entry
|
|
* @p: Babel protocol instance
|
|
* @e: Babel entry to select the best route for
|
|
* @mod: Babel route that was modified or NULL if unspecified
|
|
*
|
|
* Select the best reachable and feasible route for a given prefix among the
|
|
* routes received from peers, and propagate it to the nest. This just selects
|
|
* the reachable and feasible route with the lowest metric, but keeps selected
|
|
* the old one in case of tie.
|
|
*
|
|
* If no feasible route is available for a prefix that previously had a route
|
|
* selected, a seqno request is sent to try to get a valid route. If the entry
|
|
* is valid and not owned by us, the unreachable route is announced to the nest
|
|
* (to blackhole packets going to it, as per section 2.8). It is later removed
|
|
* by babel_expire_routes(). Otherwise, the route is just removed from the nest.
|
|
*
|
|
* Argument @mod is used to optimize best route calculation. When specified, the
|
|
* function can assume that only the @mod route was modified to avoid full best
|
|
* route selection and announcement when non-best route was modified in minor
|
|
* way. The caller is advised to not call babel_select_route() when no change is
|
|
* done (e.g. periodic route updates) to avoid unnecessary announcements of the
|
|
* same best route. The caller is not required to call the function in case of a
|
|
* retraction of a non-best route.
|
|
*
|
|
* Note that the function does not active triggered updates. That is done by
|
|
* babel_rt_notify() when the change is propagated back to Babel.
|
|
*/
|
|
static void
|
|
babel_select_route(struct babel_proto *p, struct babel_entry *e, struct babel_route *mod)
|
|
{
|
|
struct babel_route *r, *best = e->selected;
|
|
|
|
/* Shortcut if only non-best was modified */
|
|
if (mod && (mod != best))
|
|
{
|
|
/* Either select modified route, or keep old best route */
|
|
if ((mod->metric < (best ? best->metric : BABEL_INFINITY)) && mod->feasible)
|
|
best = mod;
|
|
else
|
|
return;
|
|
}
|
|
else
|
|
{
|
|
/* Selected route may be modified and no longer admissible */
|
|
if (!best || (best->metric == BABEL_INFINITY) || !best->feasible)
|
|
best = NULL;
|
|
|
|
/* Find the best feasible route from all routes */
|
|
WALK_LIST(r, e->routes)
|
|
if ((r->metric < (best ? best->metric : BABEL_INFINITY)) && r->feasible)
|
|
best = r;
|
|
}
|
|
|
|
if (best)
|
|
{
|
|
if (best != e->selected)
|
|
TRACE(D_EVENTS, "Picked new route for prefix %N: router-id %lR metric %d",
|
|
e->n.addr, best->router_id, best->metric);
|
|
}
|
|
else if (e->selected)
|
|
{
|
|
/*
|
|
* We have lost all feasible routes. We have to broadcast seqno request
|
|
* (Section 3.8.2.1) and keep unreachable route for a while (section 2.8).
|
|
* The later is done automatically by babel_announce_rte().
|
|
*/
|
|
|
|
TRACE(D_EVENTS, "Lost feasible route for prefix %N", e->n.addr);
|
|
if (e->valid && (e->selected->router_id == e->router_id))
|
|
babel_add_seqno_request(p, e, e->selected->router_id, e->selected->seqno + 1, 0, NULL);
|
|
}
|
|
else
|
|
return;
|
|
|
|
e->selected = best;
|
|
babel_announce_rte(p, e);
|
|
}
|
|
|
|
/*
|
|
* Functions to send replies
|
|
*/
|
|
|
|
static void
|
|
babel_send_ack(struct babel_iface *ifa, ip_addr dest, u16 nonce)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending ACK to %I with nonce %d", dest, nonce);
|
|
|
|
msg.type = BABEL_TLV_ACK;
|
|
msg.ack.nonce = nonce;
|
|
|
|
babel_send_unicast(&msg, ifa, dest);
|
|
}
|
|
|
|
static void
|
|
babel_build_ihu(union babel_msg *msg, struct babel_iface *ifa, struct babel_neighbor *n)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
msg->type = BABEL_TLV_IHU;
|
|
msg->ihu.addr = n->addr;
|
|
msg->ihu.rxcost = n->rxcost;
|
|
msg->ihu.interval = ifa->cf->ihu_interval;
|
|
|
|
TRACE(D_PACKETS, "Sending IHU for %I with rxcost %d interval %t",
|
|
msg->ihu.addr, msg->ihu.rxcost, (btime) msg->ihu.interval);
|
|
}
|
|
|
|
static void
|
|
babel_send_ihu(struct babel_iface *ifa, struct babel_neighbor *n)
|
|
{
|
|
union babel_msg msg = {};
|
|
babel_build_ihu(&msg, ifa, n);
|
|
babel_send_unicast(&msg, ifa, n->addr);
|
|
n->ihu_cnt = BABEL_IHU_INTERVAL_FACTOR;
|
|
}
|
|
|
|
static void
|
|
babel_send_ihus(struct babel_iface *ifa)
|
|
{
|
|
struct babel_neighbor *n;
|
|
WALK_LIST(n, ifa->neigh_list)
|
|
{
|
|
if (n->hello_cnt && (--n->ihu_cnt <= 0))
|
|
{
|
|
union babel_msg msg = {};
|
|
babel_build_ihu(&msg, ifa, n);
|
|
babel_enqueue(&msg, ifa);
|
|
n->ihu_cnt = BABEL_IHU_INTERVAL_FACTOR;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
babel_send_hello(struct babel_iface *ifa, uint interval)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
msg.type = BABEL_TLV_HELLO;
|
|
msg.hello.seqno = ifa->hello_seqno++;
|
|
msg.hello.interval = interval ?: ifa->cf->hello_interval;
|
|
|
|
TRACE(D_PACKETS, "Sending hello on %s with seqno %d interval %t",
|
|
ifa->ifname, msg.hello.seqno, (btime) msg.hello.interval);
|
|
|
|
babel_enqueue(&msg, ifa);
|
|
|
|
babel_send_ihus(ifa);
|
|
}
|
|
|
|
static void
|
|
babel_send_route_request(struct babel_proto *p, struct babel_entry *e, struct babel_neighbor *n)
|
|
{
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending route request for %N to %I", e->n.addr, n->addr);
|
|
|
|
msg.type = BABEL_TLV_ROUTE_REQUEST;
|
|
net_copy(&msg.route_request.net, e->n.addr);
|
|
|
|
babel_send_unicast(&msg, n->ifa, n->addr);
|
|
}
|
|
|
|
static void
|
|
babel_send_wildcard_request(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending wildcard route request on %s", ifa->ifname);
|
|
|
|
msg.type = BABEL_TLV_ROUTE_REQUEST;
|
|
msg.route_request.full = 1;
|
|
|
|
babel_enqueue(&msg, ifa);
|
|
}
|
|
|
|
static void
|
|
babel_send_seqno_request(struct babel_proto *p, struct babel_entry *e, struct babel_seqno_request *sr)
|
|
{
|
|
union babel_msg msg = {};
|
|
|
|
msg.type = BABEL_TLV_SEQNO_REQUEST;
|
|
msg.seqno_request.hop_count = sr->hop_count ?: BABEL_INITIAL_HOP_COUNT;
|
|
msg.seqno_request.seqno = sr->seqno;
|
|
msg.seqno_request.router_id = sr->router_id;
|
|
net_copy(&msg.seqno_request.net, e->n.addr);
|
|
|
|
if (sr->nbr)
|
|
{
|
|
TRACE(D_PACKETS, "Sending seqno request for %N router-id %lR seqno %d to %I on %s",
|
|
e->n.addr, sr->router_id, sr->seqno, sr->nbr->addr, sr->nbr->ifa->ifname);
|
|
|
|
babel_send_unicast(&msg, sr->nbr->ifa, sr->nbr->addr);
|
|
}
|
|
else
|
|
{
|
|
TRACE(D_PACKETS, "Sending broadcast seqno request for %N router-id %lR seqno %d",
|
|
e->n.addr, sr->router_id, sr->seqno);
|
|
|
|
struct babel_iface *ifa;
|
|
WALK_LIST(ifa, p->interfaces)
|
|
babel_enqueue(&msg, ifa);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* babel_send_update - send route table updates
|
|
* @ifa: Interface to transmit on
|
|
* @changed: Only send entries changed since this time
|
|
*
|
|
* This function produces update TLVs for all entries changed since the time
|
|
* indicated by the &changed parameter and queues them for transmission on the
|
|
* selected interface. During the process, the feasibility distance for each
|
|
* transmitted entry is updated.
|
|
*/
|
|
static void
|
|
babel_send_update_(struct babel_iface *ifa, btime changed, struct fib *rtable)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
/* Update increase was requested */
|
|
if (p->update_seqno_inc)
|
|
{
|
|
p->update_seqno++;
|
|
p->update_seqno_inc = 0;
|
|
}
|
|
|
|
FIB_WALK(rtable, struct babel_entry, e)
|
|
{
|
|
if (!e->valid)
|
|
continue;
|
|
|
|
/* Our own seqno might have changed, in which case we update the routes we
|
|
originate. */
|
|
if ((e->router_id == p->router_id) && (e->seqno < p->update_seqno))
|
|
{
|
|
e->seqno = p->update_seqno;
|
|
e->updated = current_time();
|
|
}
|
|
|
|
/* Skip routes that weren't updated since 'changed' time */
|
|
if (e->updated < changed)
|
|
continue;
|
|
|
|
TRACE(D_PACKETS, "Sending update for %N router-id %lR seqno %d metric %d",
|
|
e->n.addr, e->router_id, e->seqno, e->metric);
|
|
|
|
union babel_msg msg = {};
|
|
msg.type = BABEL_TLV_UPDATE;
|
|
msg.update.interval = ifa->cf->update_interval;
|
|
msg.update.seqno = e->seqno;
|
|
msg.update.metric = e->metric;
|
|
msg.update.router_id = e->router_id;
|
|
net_copy(&msg.update.net, e->n.addr);
|
|
|
|
msg.update.next_hop = ((e->n.addr->type == NET_IP4) ?
|
|
ifa->next_hop_ip4 : ifa->next_hop_ip6);
|
|
|
|
/* Do not send route if next hop is unknown, e.g. no configured IPv4 address */
|
|
if (ipa_zero(msg.update.next_hop))
|
|
continue;
|
|
|
|
babel_enqueue(&msg, ifa);
|
|
|
|
/* Update feasibility distance for redistributed routes */
|
|
if (e->router_id != p->router_id)
|
|
{
|
|
struct babel_source *s = babel_get_source(p, e, e->router_id);
|
|
s->expires = current_time() + BABEL_GARBAGE_INTERVAL;
|
|
|
|
if ((msg.update.seqno > s->seqno) ||
|
|
((msg.update.seqno == s->seqno) && (msg.update.metric < s->metric)))
|
|
{
|
|
s->seqno = msg.update.seqno;
|
|
s->metric = msg.update.metric;
|
|
}
|
|
}
|
|
}
|
|
FIB_WALK_END;
|
|
}
|
|
|
|
static void
|
|
babel_send_update(struct babel_iface *ifa, btime changed)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
babel_send_update_(ifa, changed, &p->ip4_rtable);
|
|
babel_send_update_(ifa, changed, &p->ip6_rtable);
|
|
}
|
|
|
|
static void
|
|
babel_trigger_iface_update(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
/* Interface not active or already scheduled */
|
|
if (!ifa->up || ifa->want_triggered)
|
|
return;
|
|
|
|
TRACE(D_EVENTS, "Scheduling triggered updates for %s seqno %d",
|
|
ifa->iface->name, p->update_seqno);
|
|
|
|
ifa->want_triggered = current_time();
|
|
babel_iface_kick_timer(ifa);
|
|
}
|
|
|
|
/* Sends and update on all interfaces. */
|
|
static void
|
|
babel_trigger_update(struct babel_proto *p)
|
|
{
|
|
if (p->triggered)
|
|
return;
|
|
|
|
struct babel_iface *ifa;
|
|
WALK_LIST(ifa, p->interfaces)
|
|
babel_trigger_iface_update(ifa);
|
|
|
|
p->triggered = 1;
|
|
}
|
|
|
|
/* A retraction is an update with an infinite metric */
|
|
static void
|
|
babel_send_retraction(struct babel_iface *ifa, net_addr *n)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending retraction for %N seqno %d", n, p->update_seqno);
|
|
|
|
msg.type = BABEL_TLV_UPDATE;
|
|
msg.update.interval = ifa->cf->update_interval;
|
|
msg.update.seqno = p->update_seqno;
|
|
msg.update.metric = BABEL_INFINITY;
|
|
msg.update.net = *n;
|
|
|
|
babel_enqueue(&msg, ifa);
|
|
}
|
|
|
|
static void
|
|
babel_send_wildcard_retraction(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending wildcard retraction on %s", ifa->ifname);
|
|
|
|
msg.type = BABEL_TLV_UPDATE;
|
|
msg.update.wildcard = 1;
|
|
msg.update.interval = ifa->cf->update_interval;
|
|
msg.update.seqno = p->update_seqno;
|
|
msg.update.metric = BABEL_INFINITY;
|
|
|
|
babel_enqueue(&msg, ifa);
|
|
}
|
|
|
|
|
|
/*
|
|
* TLV handler helpers
|
|
*/
|
|
|
|
/* Update hello history according to Appendix A1 of the RFC */
|
|
static void
|
|
babel_update_hello_history(struct babel_neighbor *n, u16 seqno, uint interval)
|
|
{
|
|
/*
|
|
* Compute the difference between expected and received seqno (modulo 2^16).
|
|
* If the expected and received seqnos are within 16 of each other, the modular
|
|
* difference is going to be less than 16 for one of the directions. Otherwise,
|
|
* the values differ too much, so just reset the state.
|
|
*/
|
|
|
|
u16 delta = ((uint) seqno - (uint) n->next_hello_seqno);
|
|
|
|
if ((delta == 0) || (n->hello_cnt == 0))
|
|
{
|
|
/* Do nothing */
|
|
}
|
|
else if (delta <= 16)
|
|
{
|
|
/* Sending node decreased interval; fast-forward */
|
|
n->hello_map <<= delta;
|
|
n->hello_cnt = MIN(n->hello_cnt + delta, 16);
|
|
}
|
|
else if (delta >= 0xfff0)
|
|
{
|
|
u8 diff = (0xffff - delta);
|
|
/* Sending node increased interval; undo history */
|
|
n->hello_map >>= diff;
|
|
n->hello_cnt = (diff < n->hello_cnt) ? n->hello_cnt - diff : 0;
|
|
}
|
|
else
|
|
{
|
|
/* Note state reset - flush entries */
|
|
n->hello_map = n->hello_cnt = 0;
|
|
}
|
|
|
|
/* Current entry */
|
|
n->hello_map = (n->hello_map << 1) | 1;
|
|
n->next_hello_seqno = seqno+1;
|
|
if (n->hello_cnt < 16) n->hello_cnt++;
|
|
|
|
/* Update expiration */
|
|
n->hello_expiry = current_time() + BABEL_HELLO_EXPIRY_FACTOR(interval);
|
|
n->last_hello_int = interval;
|
|
|
|
/* Disable initial timeout */
|
|
n->init_expiry = 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* TLV handlers
|
|
*/
|
|
|
|
void
|
|
babel_handle_ack_req(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_ack_req *msg = &m->ack_req;
|
|
|
|
TRACE(D_PACKETS, "Handling ACK request nonce %d interval %t",
|
|
msg->nonce, (btime) msg->interval);
|
|
|
|
babel_send_ack(ifa, msg->sender, msg->nonce);
|
|
}
|
|
|
|
void
|
|
babel_handle_hello(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_hello *msg = &m->hello;
|
|
|
|
TRACE(D_PACKETS, "Handling hello seqno %d interval %t",
|
|
msg->seqno, (btime) msg->interval);
|
|
|
|
struct babel_neighbor *n = babel_get_neighbor(ifa, msg->sender);
|
|
int first_hello = !n->hello_cnt;
|
|
|
|
babel_update_hello_history(n, msg->seqno, msg->interval);
|
|
babel_update_cost(n);
|
|
|
|
/* Speed up session establishment by sending IHU immediately */
|
|
if (first_hello)
|
|
babel_send_ihu(ifa, n);
|
|
}
|
|
|
|
void
|
|
babel_handle_ihu(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_ihu *msg = &m->ihu;
|
|
|
|
/* Ignore IHUs that are not about us */
|
|
if ((msg->ae != BABEL_AE_WILDCARD) && !ipa_equal(msg->addr, ifa->addr))
|
|
return;
|
|
|
|
TRACE(D_PACKETS, "Handling IHU rxcost %d interval %t",
|
|
msg->rxcost, (btime) msg->interval);
|
|
|
|
struct babel_neighbor *n = babel_get_neighbor(ifa, msg->sender);
|
|
n->txcost = msg->rxcost;
|
|
n->ihu_expiry = current_time() + BABEL_IHU_EXPIRY_FACTOR(msg->interval);
|
|
babel_update_cost(n);
|
|
}
|
|
|
|
/**
|
|
* babel_handle_update - handle incoming route updates
|
|
* @m: Incoming update TLV
|
|
* @ifa: Interface the update was received on
|
|
*
|
|
* This function is called as a handler for update TLVs and handles the updating
|
|
* and maintenance of route entries in Babel's internal routing cache. The
|
|
* handling follows the actions described in the Babel RFC, and at the end of
|
|
* each update handling, babel_select_route() is called on the affected entry to
|
|
* optionally update the selected routes and propagate them to the core.
|
|
*/
|
|
void
|
|
babel_handle_update(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_update *msg = &m->update;
|
|
|
|
struct babel_neighbor *nbr;
|
|
struct babel_entry *e;
|
|
struct babel_source *s;
|
|
struct babel_route *r, *best;
|
|
node *n;
|
|
int feasible, metric;
|
|
|
|
if (msg->wildcard)
|
|
TRACE(D_PACKETS, "Handling wildcard retraction", msg->seqno);
|
|
else
|
|
TRACE(D_PACKETS, "Handling update for %N with seqno %d metric %d",
|
|
&msg->net, msg->seqno, msg->metric);
|
|
|
|
nbr = babel_find_neighbor(ifa, msg->sender);
|
|
if (!nbr)
|
|
{
|
|
DBG("Babel: Haven't heard from neighbor %I; ignoring update.\n", msg->sender);
|
|
return;
|
|
}
|
|
|
|
if (msg->router_id == p->router_id)
|
|
{
|
|
DBG("Babel: Ignoring update for our own router ID.\n");
|
|
return;
|
|
}
|
|
|
|
struct channel *c = (msg->net.type == NET_IP4) ? p->ip4_channel : p->ip6_channel;
|
|
if (!c || (c->channel_state != CS_UP))
|
|
{
|
|
DBG("Babel: Ignoring update for inactive address family.\n");
|
|
return;
|
|
}
|
|
|
|
/* Retraction */
|
|
if (msg->metric == BABEL_INFINITY)
|
|
{
|
|
if (msg->wildcard)
|
|
{
|
|
/*
|
|
* Special case: This is a retraction of all prefixes announced by this
|
|
* neighbour (see second-to-last paragraph of section 4.4.9 in the RFC).
|
|
*/
|
|
WALK_LIST(n, nbr->routes)
|
|
{
|
|
r = SKIP_BACK(struct babel_route, neigh_route, n);
|
|
babel_retract_route(p, r);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
e = babel_find_entry(p, &msg->net);
|
|
|
|
if (!e)
|
|
return;
|
|
|
|
/* The route entry indexed by neighbour */
|
|
r = babel_find_route(e, nbr);
|
|
|
|
if (!r)
|
|
return;
|
|
|
|
/* Router-id, next-hop and seqno are ignored for retractions */
|
|
babel_retract_route(p, r);
|
|
}
|
|
|
|
/* Done with retractions */
|
|
return;
|
|
}
|
|
|
|
/* Regular update */
|
|
e = babel_get_entry(p, &msg->net);
|
|
r = babel_get_route(p, e, nbr); /* the route entry indexed by neighbour */
|
|
s = babel_find_source(e, msg->router_id); /* for feasibility */
|
|
feasible = babel_is_feasible(s, msg->seqno, msg->metric);
|
|
metric = babel_compute_metric(nbr, msg->metric);
|
|
best = e->selected;
|
|
|
|
/* RFC section 3.8.2.2 - Dealing with unfeasible updates */
|
|
if (!feasible && (metric != BABEL_INFINITY) &&
|
|
(!best || (r == best) || (metric < best->metric)))
|
|
babel_add_seqno_request(p, e, s->router_id, s->seqno + 1, 0, nbr);
|
|
|
|
/* Special case - ignore unfeasible update to best route */
|
|
if (r == best && !feasible && (msg->router_id == r->router_id))
|
|
return;
|
|
|
|
r->expires = current_time() + BABEL_ROUTE_EXPIRY_FACTOR(msg->interval);
|
|
r->refresh_time = current_time() + BABEL_ROUTE_REFRESH_FACTOR(msg->interval);
|
|
|
|
/* No further processing if there is no change */
|
|
if ((r->feasible == feasible) && (r->seqno == msg->seqno) &&
|
|
(r->metric == metric) && (r->advert_metric == msg->metric) &&
|
|
(r->router_id == msg->router_id) && ipa_equal(r->next_hop, msg->next_hop))
|
|
return;
|
|
|
|
/* Last paragraph above - update the entry */
|
|
r->feasible = feasible;
|
|
r->seqno = msg->seqno;
|
|
r->metric = metric;
|
|
r->advert_metric = msg->metric;
|
|
r->router_id = msg->router_id;
|
|
r->next_hop = msg->next_hop;
|
|
|
|
/* If received update satisfies seqno request, we send triggered updates */
|
|
if (babel_satisfy_seqno_request(p, e, msg->router_id, msg->seqno))
|
|
{
|
|
babel_trigger_update(p);
|
|
e->updated = current_time();
|
|
}
|
|
|
|
babel_select_route(p, e, r);
|
|
}
|
|
|
|
void
|
|
babel_handle_route_request(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_route_request *msg = &m->route_request;
|
|
|
|
/* RFC 6126 3.8.1.1 */
|
|
|
|
/* Wildcard request - full update on the interface */
|
|
if (msg->full)
|
|
{
|
|
TRACE(D_PACKETS, "Handling wildcard route request");
|
|
ifa->want_triggered = 1;
|
|
return;
|
|
}
|
|
|
|
TRACE(D_PACKETS, "Handling route request for %N", &msg->net);
|
|
|
|
/* Non-wildcard request - see if we have an entry for the route.
|
|
If not, send a retraction, otherwise send an update. */
|
|
struct babel_entry *e = babel_find_entry(p, &msg->net);
|
|
if (!e)
|
|
{
|
|
babel_send_retraction(ifa, &msg->net);
|
|
}
|
|
else
|
|
{
|
|
babel_trigger_iface_update(ifa);
|
|
e->updated = current_time();
|
|
}
|
|
}
|
|
|
|
void
|
|
babel_handle_seqno_request(union babel_msg *m, struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_msg_seqno_request *msg = &m->seqno_request;
|
|
|
|
/* RFC 6126 3.8.1.2 */
|
|
|
|
TRACE(D_PACKETS, "Handling seqno request for %N router-id %lR seqno %d hop count %d",
|
|
&msg->net, msg->router_id, msg->seqno, msg->hop_count);
|
|
|
|
/* Ignore if we have no such entry or entry has infinite metric */
|
|
struct babel_entry *e = babel_find_entry(p, &msg->net);
|
|
if (!e || !e->valid || (e->metric == BABEL_INFINITY))
|
|
return;
|
|
|
|
/* Trigger update on incoming interface if we have a selected route with
|
|
different router id or seqno no smaller than requested */
|
|
if ((e->router_id != msg->router_id) || ge_mod64k(e->seqno, msg->seqno))
|
|
{
|
|
babel_trigger_iface_update(ifa);
|
|
e->updated = current_time();
|
|
return;
|
|
}
|
|
|
|
/* Seqno is larger; check if we own the router id */
|
|
if (msg->router_id == p->router_id)
|
|
{
|
|
/* Ours; seqno increase and trigger global update */
|
|
p->update_seqno_inc = 1;
|
|
babel_trigger_update(p);
|
|
}
|
|
else if (msg->hop_count > 1)
|
|
{
|
|
/* Not ours; forward if TTL allows it */
|
|
|
|
/* Find best admissible route */
|
|
struct babel_route *r, *best1 = NULL, *best2 = NULL;
|
|
WALK_LIST(r, e->routes)
|
|
if ((r->router_id == msg->router_id) && !ipa_equal(r->neigh->addr, msg->sender))
|
|
{
|
|
/* Find best feasible route */
|
|
if ((!best1 || r->metric < best1->metric) && r->feasible)
|
|
best1 = r;
|
|
|
|
/* Find best not necessary feasible route */
|
|
if (!best2 || r->metric < best2->metric)
|
|
best2 = r;
|
|
}
|
|
|
|
/* If no route is found, do nothing */
|
|
r = best1 ?: best2;
|
|
if (!r)
|
|
return;
|
|
|
|
babel_add_seqno_request(p, e, msg->router_id, msg->seqno, msg->hop_count-1, r->neigh);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Authentication functions
|
|
*/
|
|
|
|
/**
|
|
* babel_auth_reset_index - Reset authentication index on interface
|
|
* @ifa: Interface to reset
|
|
*
|
|
* This function resets the authentication index and packet counter for an
|
|
* interface, and should be called on interface configuration, or when the
|
|
* packet counter overflows.
|
|
*/
|
|
void
|
|
babel_auth_reset_index(struct babel_iface *ifa)
|
|
{
|
|
random_bytes(ifa->auth_index, BABEL_AUTH_INDEX_LEN);
|
|
ifa->auth_pc = 1;
|
|
}
|
|
|
|
static void
|
|
babel_auth_send_challenge_request(struct babel_iface *ifa, struct babel_neighbor *n)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending challenge request to %I on %s",
|
|
n->addr, ifa->ifname);
|
|
|
|
random_bytes(n->auth_nonce, BABEL_AUTH_NONCE_LEN);
|
|
n->auth_nonce_expiry = current_time() + BABEL_AUTH_CHALLENGE_TIMEOUT;
|
|
n->auth_next_challenge = current_time() + BABEL_AUTH_CHALLENGE_INTERVAL;
|
|
|
|
msg.type = BABEL_TLV_CHALLENGE_REQUEST;
|
|
msg.challenge.nonce_len = BABEL_AUTH_NONCE_LEN;
|
|
msg.challenge.nonce = n->auth_nonce;
|
|
|
|
babel_send_unicast(&msg, ifa, n->addr);
|
|
}
|
|
|
|
static void
|
|
babel_auth_send_challenge_reply(struct babel_iface *ifa, struct babel_neighbor *n, struct babel_msg_auth *rcv)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
union babel_msg msg = {};
|
|
|
|
TRACE(D_PACKETS, "Sending challenge reply to %I on %s",
|
|
n->addr, ifa->ifname);
|
|
|
|
n->auth_next_challenge_reply = current_time() + BABEL_AUTH_CHALLENGE_INTERVAL;
|
|
|
|
msg.type = BABEL_TLV_CHALLENGE_REPLY;
|
|
msg.challenge.nonce_len = rcv->challenge_len;
|
|
msg.challenge.nonce = rcv->challenge;
|
|
|
|
babel_send_unicast(&msg, ifa, n->addr);
|
|
}
|
|
|
|
int
|
|
babel_auth_check_pc(struct babel_iface *ifa, struct babel_msg_auth *msg)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_neighbor *n;
|
|
|
|
/*
|
|
* We create the neighbour entry at this point because it makes it easier to
|
|
* rate limit challenge replies; this is explicitly allowed by the spec (see
|
|
* Section 4.3).
|
|
*/
|
|
n = babel_get_neighbor(ifa, msg->sender);
|
|
|
|
/* (3b) Handle challenge request */
|
|
if (msg->challenge_seen && (n->auth_next_challenge_reply <= current_time()))
|
|
babel_auth_send_challenge_reply(ifa, n, msg);
|
|
|
|
/* (4a) If PC TLV is missing, drop the packet */
|
|
if (!msg->pc_seen)
|
|
{
|
|
LOG_PKT_AUTH("Authentication failed for %I on %s - missing or invalid PC",
|
|
msg->sender, ifa->ifname);
|
|
return 0;
|
|
}
|
|
|
|
/* (4b) On successful challenge, update PC and index to current values */
|
|
if (msg->challenge_reply_seen &&
|
|
(n->auth_nonce_expiry > current_time()) &&
|
|
!memcmp(msg->challenge_reply, n->auth_nonce, BABEL_AUTH_NONCE_LEN))
|
|
{
|
|
n->auth_index_len = msg->index_len;
|
|
memcpy(n->auth_index, msg->index, msg->index_len);
|
|
|
|
n->auth_pc = msg->pc;
|
|
n->auth_passed = 1;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* (5) If index differs, send challenge and drop the packet */
|
|
if ((n->auth_index_len != msg->index_len) ||
|
|
memcmp(n->auth_index, msg->index, msg->index_len))
|
|
{
|
|
TRACE(D_PACKETS, "Index mismatch for packet from %I via %s",
|
|
msg->sender, ifa->ifname);
|
|
|
|
if (n->auth_next_challenge <= current_time())
|
|
babel_auth_send_challenge_request(ifa, n);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* (6) Index matches; only accept if PC is greater than last */
|
|
if (n->auth_pc >= msg->pc)
|
|
{
|
|
LOG_PKT_AUTH("Authentication failed for %I on %s - "
|
|
"lower packet counter (rcv %u, old %u)",
|
|
msg->sender, ifa->ifname, msg->pc, n->auth_pc);
|
|
return 0;
|
|
}
|
|
|
|
n->auth_pc = msg->pc;
|
|
n->auth_passed = 1;
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* Babel interfaces
|
|
*/
|
|
|
|
/**
|
|
* babel_iface_timer - Babel interface timer handler
|
|
* @t: Timer
|
|
*
|
|
* This function is called by the per-interface timer and triggers sending of
|
|
* periodic Hello's and both triggered and periodic updates. Periodic Hello's
|
|
* and updates are simply handled by setting the next_{hello,regular} variables
|
|
* on the interface, and triggering an update (and resetting the variable)
|
|
* whenever 'now' exceeds that value.
|
|
*
|
|
* For triggered updates, babel_trigger_iface_update() will set the
|
|
* want_triggered field on the interface to a timestamp value. If this is set
|
|
* (and the next_triggered time has passed; this is a rate limiting mechanism),
|
|
* babel_send_update() will be called with this timestamp as the second
|
|
* parameter. This causes updates to be send consisting of only the routes that
|
|
* have changed since the time saved in want_triggered.
|
|
*
|
|
* Mostly when an update is triggered, the route being modified will be set to
|
|
* the value of 'now' at the time of the trigger; the >= comparison for
|
|
* selecting which routes to send in the update will make sure this is included.
|
|
*/
|
|
static void
|
|
babel_iface_timer(timer *t)
|
|
{
|
|
struct babel_iface *ifa = t->data;
|
|
struct babel_proto *p = ifa->proto;
|
|
btime hello_period = ifa->cf->hello_interval;
|
|
btime update_period = ifa->cf->update_interval;
|
|
btime now_ = current_time();
|
|
|
|
if (now_ >= ifa->next_hello)
|
|
{
|
|
babel_send_hello(ifa, 0);
|
|
ifa->next_hello += hello_period * (1 + (now_ - ifa->next_hello) / hello_period);
|
|
}
|
|
|
|
if (now_ >= ifa->next_regular)
|
|
{
|
|
TRACE(D_EVENTS, "Sending regular updates on %s", ifa->ifname);
|
|
babel_send_update(ifa, 0);
|
|
ifa->next_regular += update_period * (1 + (now_ - ifa->next_regular) / update_period);
|
|
ifa->want_triggered = 0;
|
|
p->triggered = 0;
|
|
}
|
|
else if (ifa->want_triggered && (now_ >= ifa->next_triggered))
|
|
{
|
|
TRACE(D_EVENTS, "Sending triggered updates on %s", ifa->ifname);
|
|
babel_send_update(ifa, ifa->want_triggered);
|
|
ifa->next_triggered = now_ + MIN(1 S, update_period / 2);
|
|
ifa->want_triggered = 0;
|
|
p->triggered = 0;
|
|
}
|
|
|
|
btime next_event = MIN(ifa->next_hello, ifa->next_regular);
|
|
if (ifa->want_triggered) next_event = MIN(next_event, ifa->next_triggered);
|
|
tm_set(ifa->timer, next_event);
|
|
}
|
|
|
|
static inline void
|
|
babel_iface_kick_timer(struct babel_iface *ifa)
|
|
{
|
|
if (ifa->timer->expires > (current_time() + 100 MS))
|
|
tm_start(ifa->timer, 100 MS);
|
|
}
|
|
|
|
static void
|
|
babel_iface_start(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
TRACE(D_EVENTS, "Starting interface %s", ifa->ifname);
|
|
|
|
ifa->next_hello = current_time() + (random() % ifa->cf->hello_interval);
|
|
ifa->next_regular = current_time() + (random() % ifa->cf->update_interval);
|
|
ifa->next_triggered = current_time() + MIN(1 S, ifa->cf->update_interval / 2);
|
|
ifa->want_triggered = 0; /* We send an immediate update (below) */
|
|
tm_start(ifa->timer, 100 MS);
|
|
ifa->up = 1;
|
|
|
|
babel_send_hello(ifa, 0);
|
|
babel_send_wildcard_retraction(ifa);
|
|
babel_send_wildcard_request(ifa);
|
|
babel_send_update(ifa, 0); /* Full update */
|
|
}
|
|
|
|
static void
|
|
babel_iface_stop(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
struct babel_neighbor *nbr;
|
|
struct babel_route *r;
|
|
node *n;
|
|
|
|
TRACE(D_EVENTS, "Stopping interface %s", ifa->ifname);
|
|
|
|
/*
|
|
* Rather than just flushing the neighbours, we set the metric of their routes
|
|
* to infinity. This allows us to keep the neighbour hello state for when the
|
|
* interface comes back up. The routes will also be kept until they expire.
|
|
*/
|
|
WALK_LIST(nbr, ifa->neigh_list)
|
|
{
|
|
WALK_LIST(n, nbr->routes)
|
|
{
|
|
r = SKIP_BACK(struct babel_route, neigh_route, n);
|
|
babel_retract_route(p, r);
|
|
}
|
|
}
|
|
|
|
tm_stop(ifa->timer);
|
|
ifa->up = 0;
|
|
}
|
|
|
|
static inline int
|
|
babel_iface_link_up(struct babel_iface *ifa)
|
|
{
|
|
return !ifa->cf->check_link || (ifa->iface->flags & IF_LINK_UP);
|
|
}
|
|
|
|
static void
|
|
babel_iface_update_state(struct babel_iface *ifa)
|
|
{
|
|
int up = ifa->sk && babel_iface_link_up(ifa);
|
|
|
|
if (up == ifa->up)
|
|
return;
|
|
|
|
if (up)
|
|
babel_iface_start(ifa);
|
|
else
|
|
babel_iface_stop(ifa);
|
|
}
|
|
|
|
static void
|
|
babel_iface_update_addr4(struct babel_iface *ifa)
|
|
{
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
ip_addr addr4 = ifa->iface->addr4 ? ifa->iface->addr4->ip : IPA_NONE;
|
|
ifa->next_hop_ip4 = ipa_nonzero(ifa->cf->next_hop_ip4) ? ifa->cf->next_hop_ip4 : addr4;
|
|
|
|
if (ipa_zero(ifa->next_hop_ip4) && p->ip4_channel)
|
|
log(L_WARN "%s: Missing IPv4 next hop address for %s", p->p.name, ifa->ifname);
|
|
|
|
if (ifa->up)
|
|
babel_iface_kick_timer(ifa);
|
|
}
|
|
|
|
static void
|
|
babel_iface_update_buffers(struct babel_iface *ifa)
|
|
{
|
|
if (!ifa->sk)
|
|
return;
|
|
|
|
uint mtu = MAX(BABEL_MIN_MTU, ifa->iface->mtu);
|
|
uint rbsize = ifa->cf->rx_buffer ?: mtu;
|
|
uint tbsize = ifa->cf->tx_length ?: mtu;
|
|
rbsize = MAX(rbsize, tbsize);
|
|
|
|
sk_set_rbsize(ifa->sk, rbsize);
|
|
sk_set_tbsize(ifa->sk, tbsize);
|
|
|
|
ifa->tx_length = tbsize - BABEL_OVERHEAD;
|
|
|
|
babel_auth_set_tx_overhead(ifa);
|
|
}
|
|
|
|
static struct babel_iface*
|
|
babel_find_iface(struct babel_proto *p, struct iface *what)
|
|
{
|
|
struct babel_iface *ifa;
|
|
|
|
WALK_LIST (ifa, p->interfaces)
|
|
if (ifa->iface == what)
|
|
return ifa;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
babel_iface_locked(struct object_lock *lock)
|
|
{
|
|
struct babel_iface *ifa = lock->data;
|
|
struct babel_proto *p = ifa->proto;
|
|
|
|
if (!babel_open_socket(ifa))
|
|
{
|
|
log(L_ERR "%s: Cannot open socket for %s", p->p.name, ifa->iface->name);
|
|
return;
|
|
}
|
|
|
|
babel_iface_update_buffers(ifa);
|
|
babel_iface_update_state(ifa);
|
|
}
|
|
|
|
static void
|
|
babel_add_iface(struct babel_proto *p, struct iface *new, struct babel_iface_config *ic)
|
|
{
|
|
struct babel_iface *ifa;
|
|
|
|
TRACE(D_EVENTS, "Adding interface %s", new->name);
|
|
|
|
pool *pool = rp_new(p->p.pool, new->name);
|
|
|
|
ifa = mb_allocz(pool, sizeof(struct babel_iface));
|
|
ifa->proto = p;
|
|
ifa->iface = new;
|
|
ifa->cf = ic;
|
|
ifa->pool = pool;
|
|
ifa->ifname = new->name;
|
|
ifa->addr = new->llv6->ip;
|
|
|
|
add_tail(&p->interfaces, NODE ifa);
|
|
|
|
ip_addr addr4 = new->addr4 ? new->addr4->ip : IPA_NONE;
|
|
ifa->next_hop_ip4 = ipa_nonzero(ic->next_hop_ip4) ? ic->next_hop_ip4 : addr4;
|
|
ifa->next_hop_ip6 = ipa_nonzero(ic->next_hop_ip6) ? ic->next_hop_ip6 : ifa->addr;
|
|
|
|
if (ipa_zero(ifa->next_hop_ip4) && p->ip4_channel)
|
|
log(L_WARN "%s: Missing IPv4 next hop address for %s", p->p.name, new->name);
|
|
|
|
init_list(&ifa->neigh_list);
|
|
ifa->hello_seqno = 1;
|
|
|
|
if (ic->auth_type != BABEL_AUTH_NONE)
|
|
babel_auth_reset_index(ifa);
|
|
|
|
ifa->timer = tm_new_init(ifa->pool, babel_iface_timer, ifa, 0, 0);
|
|
|
|
init_list(&ifa->msg_queue);
|
|
ifa->send_event = ev_new_init(ifa->pool, babel_send_queue, ifa);
|
|
|
|
struct object_lock *lock = olock_new(ifa->pool);
|
|
lock->type = OBJLOCK_UDP;
|
|
lock->addr = IP6_BABEL_ROUTERS;
|
|
lock->port = ifa->cf->port;
|
|
lock->iface = ifa->iface;
|
|
lock->hook = babel_iface_locked;
|
|
lock->data = ifa;
|
|
|
|
olock_acquire(lock);
|
|
}
|
|
|
|
static void
|
|
babel_remove_iface(struct babel_proto *p, struct babel_iface *ifa)
|
|
{
|
|
TRACE(D_EVENTS, "Removing interface %s", ifa->iface->name);
|
|
|
|
struct babel_neighbor *n;
|
|
WALK_LIST_FIRST(n, ifa->neigh_list)
|
|
babel_flush_neighbor(p, n);
|
|
|
|
rem_node(NODE ifa);
|
|
|
|
rfree(ifa->pool); /* contains ifa itself, locks, socket, etc */
|
|
}
|
|
|
|
static int
|
|
iface_is_valid(struct babel_proto *p, struct iface *iface)
|
|
{
|
|
if (!(iface->flags & IF_MULTICAST))
|
|
{
|
|
log(L_ERR "%s: Interface %s does not support multicast",
|
|
p->p.name, iface->name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
babel_if_notify(struct proto *P, unsigned flags, struct iface *iface)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_config *cf = (void *) P->cf;
|
|
struct babel_iface *ifa = babel_find_iface(p, iface);
|
|
|
|
if (iface->flags & IF_IGNORE)
|
|
return;
|
|
|
|
/* Add, remove or restart interface */
|
|
if (flags & (IF_CHANGE_UPDOWN | IF_CHANGE_LLV6))
|
|
{
|
|
if (ifa)
|
|
babel_remove_iface(p, ifa);
|
|
|
|
if (!(iface->flags & IF_UP))
|
|
return;
|
|
|
|
/* Ignore ifaces without link-local address */
|
|
if (!iface->llv6)
|
|
return;
|
|
|
|
struct babel_iface_config *ic = (void *) iface_patt_find(&cf->iface_list, iface, NULL);
|
|
|
|
if (ic && iface_is_valid(p, iface))
|
|
babel_add_iface(p, iface, ic);
|
|
|
|
return;
|
|
}
|
|
|
|
if (!ifa)
|
|
return;
|
|
|
|
if (flags & IF_CHANGE_ADDR4)
|
|
babel_iface_update_addr4(ifa);
|
|
|
|
if (flags & IF_CHANGE_MTU)
|
|
babel_iface_update_buffers(ifa);
|
|
|
|
if (flags & IF_CHANGE_LINK)
|
|
babel_iface_update_state(ifa);
|
|
}
|
|
|
|
static int
|
|
babel_reconfigure_iface(struct babel_proto *p, struct babel_iface *ifa, struct babel_iface_config *new)
|
|
{
|
|
struct babel_iface_config *old = ifa->cf;
|
|
|
|
/* Change of these options would require to reset the iface socket */
|
|
if ((new->port != old->port) ||
|
|
(new->tx_tos != old->tx_tos) ||
|
|
(new->tx_priority != old->tx_priority))
|
|
return 0;
|
|
|
|
TRACE(D_EVENTS, "Reconfiguring interface %s", ifa->iface->name);
|
|
|
|
ifa->cf = new;
|
|
|
|
ip_addr addr4 = ifa->iface->addr4 ? ifa->iface->addr4->ip : IPA_NONE;
|
|
ifa->next_hop_ip4 = ipa_nonzero(new->next_hop_ip4) ? new->next_hop_ip4 : addr4;
|
|
ifa->next_hop_ip6 = ipa_nonzero(new->next_hop_ip6) ? new->next_hop_ip6 : ifa->addr;
|
|
|
|
babel_iface_update_buffers(ifa);
|
|
|
|
if ((new->auth_type != BABEL_AUTH_NONE) && (new->auth_type != old->auth_type))
|
|
babel_auth_reset_index(ifa);
|
|
|
|
if (ipa_zero(ifa->next_hop_ip4) && p->ip4_channel)
|
|
log(L_WARN "%s: Missing IPv4 next hop address for %s", p->p.name, ifa->ifname);
|
|
|
|
if (ifa->next_hello > (current_time() + new->hello_interval))
|
|
ifa->next_hello = current_time() + (random() % new->hello_interval);
|
|
|
|
if (ifa->next_regular > (current_time() + new->update_interval))
|
|
ifa->next_regular = current_time() + (random() % new->update_interval);
|
|
|
|
if (new->check_link != old->check_link)
|
|
babel_iface_update_state(ifa);
|
|
|
|
if (ifa->up)
|
|
babel_iface_kick_timer(ifa);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
babel_reconfigure_ifaces(struct babel_proto *p, struct babel_config *cf)
|
|
{
|
|
struct iface *iface;
|
|
|
|
WALK_LIST(iface, iface_list)
|
|
{
|
|
if (!(iface->flags & IF_UP))
|
|
continue;
|
|
|
|
/* Ignore ifaces without link-local address */
|
|
if (!iface->llv6)
|
|
continue;
|
|
|
|
struct babel_iface *ifa = babel_find_iface(p, iface);
|
|
struct babel_iface_config *ic = (void *) iface_patt_find(&cf->iface_list, iface, NULL);
|
|
|
|
if (ic && !iface_is_valid(p, iface))
|
|
ic = NULL;
|
|
|
|
if (ifa && ic)
|
|
{
|
|
if (babel_reconfigure_iface(p, ifa, ic))
|
|
continue;
|
|
|
|
/* Hard restart */
|
|
log(L_INFO "%s: Restarting interface %s", p->p.name, ifa->iface->name);
|
|
babel_remove_iface(p, ifa);
|
|
babel_add_iface(p, iface, ic);
|
|
}
|
|
|
|
if (ifa && !ic)
|
|
babel_remove_iface(p, ifa);
|
|
|
|
if (!ifa && ic)
|
|
babel_add_iface(p, iface, ic);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Debugging and info output functions
|
|
*/
|
|
|
|
static void
|
|
babel_dump_source(struct babel_source *s)
|
|
{
|
|
debug("Source router_id %lR seqno %d metric %d expires %t\n",
|
|
s->router_id, s->seqno, s->metric,
|
|
s->expires ? s->expires - current_time() : 0);
|
|
}
|
|
|
|
static void
|
|
babel_dump_route(struct babel_route *r)
|
|
{
|
|
debug("Route neigh %I if %s seqno %d metric %d/%d router_id %lR expires %t\n",
|
|
r->neigh->addr, r->neigh->ifa->ifname, r->seqno, r->advert_metric, r->metric,
|
|
r->router_id, r->expires ? r->expires - current_time() : 0);
|
|
}
|
|
|
|
static void
|
|
babel_dump_entry(struct babel_entry *e)
|
|
{
|
|
struct babel_source *s;
|
|
struct babel_route *r;
|
|
|
|
debug("Babel: Entry %N:\n", e->n.addr);
|
|
|
|
WALK_LIST(s,e->sources)
|
|
{ debug(" "); babel_dump_source(s); }
|
|
|
|
WALK_LIST(r,e->routes)
|
|
{
|
|
debug(" ");
|
|
if (r == e->selected) debug("*");
|
|
babel_dump_route(r);
|
|
}
|
|
}
|
|
|
|
static void
|
|
babel_dump_neighbor(struct babel_neighbor *n)
|
|
{
|
|
debug("Neighbor %I txcost %d hello_map %x next seqno %d expires %t/%t\n",
|
|
n->addr, n->txcost, n->hello_map, n->next_hello_seqno,
|
|
n->hello_expiry ? n->hello_expiry - current_time() : 0,
|
|
n->ihu_expiry ? n->ihu_expiry - current_time() : 0);
|
|
}
|
|
|
|
static void
|
|
babel_dump_iface(struct babel_iface *ifa)
|
|
{
|
|
struct babel_neighbor *n;
|
|
|
|
debug("Babel: Interface %s addr %I rxcost %d type %d hello seqno %d intervals %t %t",
|
|
ifa->ifname, ifa->addr, ifa->cf->rxcost, ifa->cf->type, ifa->hello_seqno,
|
|
ifa->cf->hello_interval, ifa->cf->update_interval);
|
|
debug(" next hop v4 %I next hop v6 %I\n", ifa->next_hop_ip4, ifa->next_hop_ip6);
|
|
|
|
WALK_LIST(n, ifa->neigh_list)
|
|
{ debug(" "); babel_dump_neighbor(n); }
|
|
}
|
|
|
|
static void
|
|
babel_dump(struct proto *P)
|
|
{
|
|
struct babel_proto *p = (struct babel_proto *) P;
|
|
struct babel_iface *ifa;
|
|
|
|
debug("Babel: router id %lR update seqno %d\n", p->router_id, p->update_seqno);
|
|
|
|
WALK_LIST(ifa, p->interfaces)
|
|
babel_dump_iface(ifa);
|
|
|
|
FIB_WALK(&p->ip4_rtable, struct babel_entry, e)
|
|
{
|
|
babel_dump_entry(e);
|
|
}
|
|
FIB_WALK_END;
|
|
FIB_WALK(&p->ip6_rtable, struct babel_entry, e)
|
|
{
|
|
babel_dump_entry(e);
|
|
}
|
|
FIB_WALK_END;
|
|
}
|
|
|
|
static void
|
|
babel_get_route_info(rte *rte, byte *buf)
|
|
{
|
|
buf += bsprintf(buf, " (%d/%d) [%lR]", rte->pref, rte->u.babel.metric, rte->u.babel.router_id);
|
|
}
|
|
|
|
static int
|
|
babel_get_attr(const eattr *a, byte *buf, int buflen UNUSED)
|
|
{
|
|
switch (a->id)
|
|
{
|
|
case EA_BABEL_METRIC:
|
|
bsprintf(buf, "metric: %d", a->u.data);
|
|
return GA_FULL;
|
|
|
|
case EA_BABEL_ROUTER_ID:
|
|
{
|
|
u64 rid = 0;
|
|
memcpy(&rid, a->u.ptr->data, sizeof(u64));
|
|
bsprintf(buf, "router_id: %lR", rid);
|
|
return GA_FULL;
|
|
}
|
|
|
|
default:
|
|
return GA_UNKNOWN;
|
|
}
|
|
}
|
|
|
|
void
|
|
babel_show_interfaces(struct proto *P, const char *iff)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_iface *ifa = NULL;
|
|
struct babel_neighbor *nbr = NULL;
|
|
|
|
if (p->p.proto_state != PS_UP)
|
|
{
|
|
cli_msg(-1023, "%s: is not up", p->p.name);
|
|
return;
|
|
}
|
|
|
|
cli_msg(-1023, "%s:", p->p.name);
|
|
cli_msg(-1023, "%-10s %-6s %-5s %7s %6s %7s %-15s %s",
|
|
"Interface", "State", "Auth", "RX cost", "Nbrs", "Timer",
|
|
"Next hop (v4)", "Next hop (v6)");
|
|
|
|
WALK_LIST(ifa, p->interfaces)
|
|
{
|
|
if (iff && !patmatch(iff, ifa->iface->name))
|
|
continue;
|
|
|
|
int nbrs = 0;
|
|
WALK_LIST(nbr, ifa->neigh_list)
|
|
nbrs++;
|
|
|
|
btime timer = MIN(ifa->next_regular, ifa->next_hello) - current_time();
|
|
cli_msg(-1023, "%-10s %-6s %-5s %7u %6u %7t %-15I %I",
|
|
ifa->iface->name, (ifa->up ? "Up" : "Down"),
|
|
(ifa->cf->auth_type == BABEL_AUTH_MAC ?
|
|
(ifa->cf->auth_permissive ? "Perm" : "Yes") : "No"),
|
|
ifa->cf->rxcost, nbrs, MAX(timer, 0),
|
|
ifa->next_hop_ip4, ifa->next_hop_ip6);
|
|
}
|
|
}
|
|
|
|
void
|
|
babel_show_neighbors(struct proto *P, const char *iff)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_iface *ifa = NULL;
|
|
struct babel_neighbor *n = NULL;
|
|
struct babel_route *r = NULL;
|
|
|
|
if (p->p.proto_state != PS_UP)
|
|
{
|
|
cli_msg(-1024, "%s: is not up", p->p.name);
|
|
return;
|
|
}
|
|
|
|
cli_msg(-1024, "%s:", p->p.name);
|
|
cli_msg(-1024, "%-25s %-10s %6s %6s %6s %7s %4s",
|
|
"IP address", "Interface", "Metric", "Routes", "Hellos", "Expires", "Auth");
|
|
|
|
WALK_LIST(ifa, p->interfaces)
|
|
{
|
|
if (iff && !patmatch(iff, ifa->iface->name))
|
|
continue;
|
|
|
|
WALK_LIST(n, ifa->neigh_list)
|
|
{
|
|
int rts = 0;
|
|
WALK_LIST(r, n->routes)
|
|
rts++;
|
|
|
|
uint hellos = u32_popcount(n->hello_map);
|
|
btime timer = (n->hello_expiry ?: n->init_expiry) - current_time();
|
|
cli_msg(-1024, "%-25I %-10s %6u %6u %6u %7t %-4s",
|
|
n->addr, ifa->iface->name, n->cost, rts, hellos, MAX(timer, 0),
|
|
n->auth_passed ? "Yes" : "No");
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
babel_show_entries_(struct babel_proto *p, struct fib *rtable)
|
|
{
|
|
int width = babel_sadr_enabled(p) ? -54 : -24;
|
|
|
|
FIB_WALK(rtable, struct babel_entry, e)
|
|
{
|
|
struct babel_route *r = NULL;
|
|
uint rts = 0, srcs = 0;
|
|
node *n;
|
|
|
|
WALK_LIST(n, e->routes)
|
|
rts++;
|
|
|
|
WALK_LIST(n, e->sources)
|
|
srcs++;
|
|
|
|
if (e->valid)
|
|
cli_msg(-1025, "%-*N %-23lR %6u %5u %7u %7u", width,
|
|
e->n.addr, e->router_id, e->metric, e->seqno, rts, srcs);
|
|
else if (r = e->selected)
|
|
cli_msg(-1025, "%-*N %-23lR %6u %5u %7u %7u", width,
|
|
e->n.addr, r->router_id, r->metric, r->seqno, rts, srcs);
|
|
else
|
|
cli_msg(-1025, "%-*N %-23s %6s %5s %7u %7u", width,
|
|
e->n.addr, "<none>", "-", "-", rts, srcs);
|
|
}
|
|
FIB_WALK_END;
|
|
}
|
|
|
|
void
|
|
babel_show_entries(struct proto *P)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
int width = babel_sadr_enabled(p) ? -54 : -24;
|
|
|
|
if (p->p.proto_state != PS_UP)
|
|
{
|
|
cli_msg(-1025, "%s: is not up", p->p.name);
|
|
return;
|
|
}
|
|
|
|
cli_msg(-1025, "%s:", p->p.name);
|
|
cli_msg(-1025, "%-*s %-23s %6s %5s %7s %7s", width,
|
|
"Prefix", "Router ID", "Metric", "Seqno", "Routes", "Sources");
|
|
|
|
babel_show_entries_(p, &p->ip4_rtable);
|
|
babel_show_entries_(p, &p->ip6_rtable);
|
|
}
|
|
|
|
static void
|
|
babel_show_routes_(struct babel_proto *p, struct fib *rtable)
|
|
{
|
|
int width = babel_sadr_enabled(p) ? -54 : -24;
|
|
|
|
FIB_WALK(rtable, struct babel_entry, e)
|
|
{
|
|
struct babel_route *r;
|
|
WALK_LIST(r, e->routes)
|
|
{
|
|
char c = (r == e->selected) ? '*' : (r->feasible ? '+' : ' ');
|
|
btime time = r->expires ? r->expires - current_time() : 0;
|
|
cli_msg(-1025, "%-*N %-25I %-10s %5u %c %5u %7t", width,
|
|
e->n.addr, r->next_hop, r->neigh->ifa->ifname,
|
|
r->metric, c, r->seqno, MAX(time, 0));
|
|
}
|
|
}
|
|
FIB_WALK_END;
|
|
}
|
|
|
|
void
|
|
babel_show_routes(struct proto *P)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
int width = babel_sadr_enabled(p) ? -54 : -24;
|
|
|
|
if (p->p.proto_state != PS_UP)
|
|
{
|
|
cli_msg(-1025, "%s: is not up", p->p.name);
|
|
return;
|
|
}
|
|
|
|
cli_msg(-1025, "%s:", p->p.name);
|
|
cli_msg(-1025, "%-*s %-25s %-9s %6s F %5s %7s", width,
|
|
"Prefix", "Nexthop", "Interface", "Metric", "Seqno", "Expires");
|
|
|
|
babel_show_routes_(p, &p->ip4_rtable);
|
|
babel_show_routes_(p, &p->ip6_rtable);
|
|
}
|
|
|
|
|
|
/*
|
|
* Babel protocol glue
|
|
*/
|
|
|
|
/**
|
|
* babel_timer - global timer hook
|
|
* @t: Timer
|
|
*
|
|
* This function is called by the global protocol instance timer and handles
|
|
* expiration of routes and neighbours as well as pruning of the seqno request
|
|
* cache.
|
|
*/
|
|
static void
|
|
babel_timer(timer *t)
|
|
{
|
|
struct babel_proto *p = t->data;
|
|
|
|
babel_expire_routes(p);
|
|
babel_expire_neighbors(p);
|
|
}
|
|
|
|
static inline void
|
|
babel_kick_timer(struct babel_proto *p)
|
|
{
|
|
if (p->timer->expires > (current_time() + 100 MS))
|
|
tm_start(p->timer, 100 MS);
|
|
}
|
|
|
|
|
|
static int
|
|
babel_preexport(struct channel *C, struct rte **new, struct linpool *pool UNUSED)
|
|
{
|
|
struct rta *a = (*new)->attrs;
|
|
|
|
/* Reject our own unreachable routes */
|
|
if ((a->dest == RTD_UNREACHABLE) && (a->src->proto == C->proto))
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void
|
|
babel_make_tmp_attrs(struct rte *rt, struct linpool *pool)
|
|
{
|
|
struct adata *id = lp_alloc_adata(pool, sizeof(u64));
|
|
memcpy(id->data, &rt->u.babel.router_id, sizeof(u64));
|
|
|
|
rte_init_tmp_attrs(rt, pool, 2);
|
|
rte_make_tmp_attr(rt, EA_BABEL_METRIC, EAF_TYPE_INT, rt->u.babel.metric);
|
|
rte_make_tmp_attr(rt, EA_BABEL_ROUTER_ID, EAF_TYPE_OPAQUE, (uintptr_t) id);
|
|
}
|
|
|
|
static void
|
|
babel_store_tmp_attrs(struct rte *rt, struct linpool *pool)
|
|
{
|
|
rte_init_tmp_attrs(rt, pool, 2);
|
|
rt->u.babel.metric = rte_store_tmp_attr(rt, EA_BABEL_METRIC);
|
|
|
|
/* EA_BABEL_ROUTER_ID is read-only, we do not really save the value */
|
|
rte_store_tmp_attr(rt, EA_BABEL_ROUTER_ID);
|
|
}
|
|
|
|
/*
|
|
* babel_rt_notify - core tells us about new route (possibly our own),
|
|
* so store it into our data structures.
|
|
*/
|
|
static void
|
|
babel_rt_notify(struct proto *P, struct channel *c UNUSED, struct network *net,
|
|
struct rte *new, struct rte *old UNUSED)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_entry *e;
|
|
|
|
if (new)
|
|
{
|
|
/* Update */
|
|
uint internal = (new->attrs->src->proto == P);
|
|
uint rt_seqno = internal ? new->u.babel.seqno : p->update_seqno;
|
|
uint rt_metric = ea_get_int(new->attrs->eattrs, EA_BABEL_METRIC, 0);
|
|
u64 rt_router_id = internal ? new->u.babel.router_id : p->router_id;
|
|
|
|
if (rt_metric > BABEL_INFINITY)
|
|
{
|
|
log(L_WARN "%s: Invalid babel_metric value %u for route %N",
|
|
p->p.name, rt_metric, net->n.addr);
|
|
rt_metric = BABEL_INFINITY;
|
|
}
|
|
|
|
e = babel_get_entry(p, net->n.addr);
|
|
|
|
/* Activate triggered updates */
|
|
if ((e->valid != BABEL_ENTRY_VALID) ||
|
|
(e->router_id != rt_router_id))
|
|
{
|
|
babel_trigger_update(p);
|
|
e->updated = current_time();
|
|
}
|
|
|
|
e->valid = BABEL_ENTRY_VALID;
|
|
e->seqno = rt_seqno;
|
|
e->metric = rt_metric;
|
|
e->router_id = rt_router_id;
|
|
}
|
|
else
|
|
{
|
|
/* Withdraw */
|
|
e = babel_find_entry(p, net->n.addr);
|
|
|
|
if (!e || e->valid != BABEL_ENTRY_VALID)
|
|
return;
|
|
|
|
e->valid = BABEL_ENTRY_STALE;
|
|
e->metric = BABEL_INFINITY;
|
|
|
|
babel_trigger_update(p);
|
|
e->updated = current_time();
|
|
}
|
|
}
|
|
|
|
static int
|
|
babel_rte_better(struct rte *new, struct rte *old)
|
|
{
|
|
return new->u.babel.metric < old->u.babel.metric;
|
|
}
|
|
|
|
static int
|
|
babel_rte_same(struct rte *new, struct rte *old)
|
|
{
|
|
return ((new->u.babel.seqno == old->u.babel.seqno) &&
|
|
(new->u.babel.metric == old->u.babel.metric) &&
|
|
(new->u.babel.router_id == old->u.babel.router_id));
|
|
}
|
|
|
|
|
|
static void
|
|
babel_postconfig(struct proto_config *CF)
|
|
{
|
|
struct babel_config *cf = (void *) CF;
|
|
struct channel_config *ip4, *ip6, *ip6_sadr;
|
|
|
|
ip4 = proto_cf_find_channel(CF, NET_IP4);
|
|
ip6 = proto_cf_find_channel(CF, NET_IP6);
|
|
ip6_sadr = proto_cf_find_channel(CF, NET_IP6_SADR);
|
|
|
|
if (ip6 && ip6_sadr)
|
|
cf_error("Both ipv6 and ipv6-sadr channels");
|
|
|
|
cf->ip4_channel = ip4;
|
|
cf->ip6_channel = ip6 ?: ip6_sadr;
|
|
}
|
|
|
|
static struct proto *
|
|
babel_init(struct proto_config *CF)
|
|
{
|
|
struct proto *P = proto_new(CF);
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_config *cf = (void *) CF;
|
|
|
|
proto_configure_channel(P, &p->ip4_channel, cf->ip4_channel);
|
|
proto_configure_channel(P, &p->ip6_channel, cf->ip6_channel);
|
|
|
|
P->if_notify = babel_if_notify;
|
|
P->rt_notify = babel_rt_notify;
|
|
P->preexport = babel_preexport;
|
|
P->make_tmp_attrs = babel_make_tmp_attrs;
|
|
P->store_tmp_attrs = babel_store_tmp_attrs;
|
|
P->rte_better = babel_rte_better;
|
|
P->rte_same = babel_rte_same;
|
|
|
|
return P;
|
|
}
|
|
|
|
static inline void
|
|
babel_randomize_router_id(struct babel_proto *p)
|
|
{
|
|
p->router_id &= (u64) 0xffffffff;
|
|
p->router_id |= ((u64) random()) << 32;
|
|
TRACE(D_EVENTS, "Randomized router ID to %lR", p->router_id);
|
|
}
|
|
|
|
static int
|
|
babel_start(struct proto *P)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_config *cf = (void *) P->cf;
|
|
u8 ip6_type = cf->ip6_channel ? cf->ip6_channel->net_type : NET_IP6;
|
|
|
|
fib_init(&p->ip4_rtable, P->pool, NET_IP4, sizeof(struct babel_entry),
|
|
OFFSETOF(struct babel_entry, n), 0, babel_init_entry);
|
|
fib_init(&p->ip6_rtable, P->pool, ip6_type, sizeof(struct babel_entry),
|
|
OFFSETOF(struct babel_entry, n), 0, babel_init_entry);
|
|
|
|
init_list(&p->interfaces);
|
|
p->timer = tm_new_init(P->pool, babel_timer, p, 1 S, 0);
|
|
tm_start(p->timer, 1 S);
|
|
p->update_seqno = 1;
|
|
p->router_id = proto_get_router_id(&cf->c);
|
|
|
|
if (cf->randomize_router_id)
|
|
babel_randomize_router_id(p);
|
|
|
|
p->route_slab = sl_new(P->pool, sizeof(struct babel_route));
|
|
p->source_slab = sl_new(P->pool, sizeof(struct babel_source));
|
|
p->msg_slab = sl_new(P->pool, sizeof(struct babel_msg_node));
|
|
p->seqno_slab = sl_new(P->pool, sizeof(struct babel_seqno_request));
|
|
|
|
p->log_pkt_tbf = (struct tbf){ .rate = 1, .burst = 5 };
|
|
|
|
return PS_UP;
|
|
}
|
|
|
|
static inline void
|
|
babel_iface_shutdown(struct babel_iface *ifa)
|
|
{
|
|
if (ifa->sk)
|
|
{
|
|
/*
|
|
* Retract all our routes and lower the hello interval so peers' neighbour
|
|
* state expires quickly
|
|
*/
|
|
babel_send_hello(ifa, BABEL_MIN_INTERVAL);
|
|
babel_send_wildcard_retraction(ifa);
|
|
babel_send_queue(ifa);
|
|
}
|
|
}
|
|
|
|
static int
|
|
babel_shutdown(struct proto *P)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_iface *ifa;
|
|
|
|
TRACE(D_EVENTS, "Shutdown requested");
|
|
|
|
WALK_LIST(ifa, p->interfaces)
|
|
babel_iface_shutdown(ifa);
|
|
|
|
return PS_DOWN;
|
|
}
|
|
|
|
static int
|
|
babel_reconfigure(struct proto *P, struct proto_config *CF)
|
|
{
|
|
struct babel_proto *p = (void *) P;
|
|
struct babel_config *new = (void *) CF;
|
|
u8 ip6_type = new->ip6_channel ? new->ip6_channel->net_type : NET_IP6;
|
|
|
|
TRACE(D_EVENTS, "Reconfiguring");
|
|
|
|
if (p->ip6_rtable.addr_type != ip6_type)
|
|
return 0;
|
|
|
|
if (!proto_configure_channel(P, &p->ip4_channel, new->ip4_channel) ||
|
|
!proto_configure_channel(P, &p->ip6_channel, new->ip6_channel))
|
|
return 0;
|
|
|
|
p->p.cf = CF;
|
|
babel_reconfigure_ifaces(p, new);
|
|
|
|
babel_trigger_update(p);
|
|
babel_kick_timer(p);
|
|
|
|
return 1;
|
|
}
|
|
|
|
|
|
struct protocol proto_babel = {
|
|
.name = "Babel",
|
|
.template = "babel%d",
|
|
.class = PROTOCOL_BABEL,
|
|
.preference = DEF_PREF_BABEL,
|
|
.channel_mask = NB_IP | NB_IP6_SADR,
|
|
.proto_size = sizeof(struct babel_proto),
|
|
.config_size = sizeof(struct babel_config),
|
|
.postconfig = babel_postconfig,
|
|
.init = babel_init,
|
|
.dump = babel_dump,
|
|
.start = babel_start,
|
|
.shutdown = babel_shutdown,
|
|
.reconfigure = babel_reconfigure,
|
|
.get_route_info = babel_get_route_info,
|
|
.get_attr = babel_get_attr
|
|
};
|