diff options
| -rw-r--r-- | TODO | 4 | ||||
| -rw-r--r-- | nest/iface.c | 256 | ||||
| -rw-r--r-- | nest/iface.h | 57 | ||||
| -rw-r--r-- | nest/protocol.h | 2 | ||||
| -rw-r--r-- | nest/route.h | 20 |
5 files changed, 244 insertions, 95 deletions
@@ -1,15 +1,17 @@ Core ~~~~ +* router id + - fake multipath? - config file: symbolic constants? - counters (according to SNMP MIB?) - generation of subnet mask ICMP's for v6? -- neighbor cache: local broadcast address? - ipv4: recognize site scope addresses? - ifdef out some debugging code? - better memory allocators - default preferences of protocols: prefer BGP over OSPF/RIP external routes? - all internal tables are in host order +- secondary addresses -> subinterfaces - filter: logging of dropped routes (?) - limitation of memory consumption: per-process and total (?) diff --git a/nest/iface.c b/nest/iface.c index 79a7b7d..5342f12 100644 --- a/nest/iface.c +++ b/nest/iface.c @@ -1,24 +1,168 @@ /* - * BIRD -- Management of Interfaces + * BIRD -- Management of Interfaces and Neighbor Cache * * (c) 1998 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ +#define LOCAL_DEBUG + #include "nest/bird.h" #include "nest/iface.h" +#include "nest/protocol.h" #include "lib/resource.h" -list iface_list; - static pool *if_pool; +/* + * Neighbor Cache + * + * FIXME: Use hashing to get some real speed. + * FIXME: Cleanup when a protocol goes down. + */ + +static slab *neigh_slab; +static list neigh_list; + +static int +if_connected(ip_addr *a, struct iface *i) /* -1=error, 1=match, 0=no match */ +{ + if (i->flags & (IF_ADMIN_DOWN | IF_IGNORE)) + return 0; + if ((i->flags & IF_UNNUMBERED) && ipa_equal(*a, i->opposite)) + return 1; + if (!ipa_in_net(*a, i->prefix, i->pxlen)) + return 0; + if (ipa_equal(*a, i->prefix) || /* Network address */ + ipa_equal(*a, i->brd) || /* Broadcast */ + ipa_equal(*a, i->ip)) /* Our own address */ + return -1; + if (!(i->flags & IF_UP)) + return 0; + return 1; +} + +neighbor * +neigh_find(struct proto *p, ip_addr *a, unsigned flags) +{ + neighbor *n; + int class; + struct iface *i, *j; + + WALK_LIST(n, neigh_list) + if (n->proto == p && ipa_equal(*a, n->addr)) + return n; + + class = ipa_classify(*a); + if (class < 0) /* Invalid address */ + return NULL; + if ((class & IADDR_SCOPE_MASK) < SCOPE_SITE || + !(class & IADDR_HOST)) + return NULL; /* Bad scope or a somecast */ + + j = NULL; + WALK_LIST(i, iface_list) + switch (if_connected(a, i)) + { + case -1: + return NULL; + case 1: + if (!j || j->pxlen > i->pxlen) + j = i; + /* Fall-thru */ + } + if (!j && !(flags & NEF_STICKY)) + return NULL; + + n = sl_alloc(neigh_slab); + n->addr = *a; + n->iface = j; + add_tail(&neigh_list, &n->n); + if (j) + { + n->sibling = j->neigh; + j->neigh = n; + } + else + n->sibling = NULL; + n->proto = p; + n->data = NULL; + n->flags = flags; + return n; +} + void -if_dump(struct iface *i) +neigh_dump(neighbor *n) +{ + debug("%p %08x ", n, _I(n->addr)); + if (n->iface) + debug("%s ", n->iface->name); + else + debug("[] "); + debug("%s %p", n->proto->name, n->data); + if (n->flags & NEF_STICKY) + debug("STICKY"); + debug("\n"); +} + +void +neigh_dump_all(void) +{ + neighbor *n; + + debug("Known neighbors:\n"); + WALK_LIST(n, neigh_list) + neigh_dump(n); + debug("\n"); +} + +static void +neigh_if_up(struct iface *i) +{ + neighbor *n; + + WALK_LIST(n, neigh_list) + if (!n->iface && + if_connected(&n->addr, i) > 0) + { + n->iface = i; + n->sibling = i->neigh; + i->neigh = n; + DBG("Waking up sticky neighbor %08x\n", _I(n->addr)); + n->proto->neigh_notify(n); + } +} + +static void +neigh_if_down(struct iface *i) { - struct ifa *a; + neighbor *n, *m; + for(m=i->neigh; n = m;) + { + m = n->sibling; + DBG("Flushing neighbor %08x on %s\n", _I(n->addr), n->iface->name); + n->iface = NULL; + n->proto->neigh_notify(n); + if (!(n->flags & NEF_STICKY)) + { + rem_node(&n->n); + sl_free(neigh_slab, n); + } + i->neigh = NULL; + } +} + +/* + * The Interface List + */ + +list iface_list; + +void +if_dump(struct iface *i) +{ debug("IF%d: %s", i->index, i->name); if (i->flags & IF_ADMIN_DOWN) debug(" ADMIN-DOWN"); @@ -39,8 +183,7 @@ if_dump(struct iface *i) if (i->flags & IF_IGNORE) debug(" IGN"); debug(" MTU=%d\n", i->mtu); - for(a=i->ifa; a; a=a->next) - debug("\t%08x, net %08x/%-2d bc %08x -> %08x\n", _I(a->ip), _I(a->prefix), a->pxlen, _I(a->brd), _I(a->opposite)); + debug("\t%08x, net %08x/%-2d bc %08x -> %08x\n", _I(i->ip), _I(i->prefix), i->pxlen, _I(i->brd), _I(i->opposite)); } void @@ -54,64 +197,36 @@ if_dump_all(void) debug("\n"); } -struct if_with_a { - struct iface i; - struct ifa a[0]; -}; - -static struct iface * -if_copy(struct iface *j) +static inline int +if_change_too_big_p(struct iface *i, struct iface *j) { - int len; - struct if_with_a *w; - struct iface *i; - struct ifa *a, **b, *c; - - len = 0; - for(a=j->ifa; a; a=a->next) - len++; - w = mb_alloc(if_pool, sizeof(struct if_with_a) + len*sizeof(struct ifa)); - i = &w->i; - c = w->a; - memcpy(i, j, sizeof(struct iface)); - b = &i->ifa; - a = j->ifa; - while (a) - { - *b = c; - memcpy(c, a, sizeof(struct ifa)); - b = &c->next; - a = a->next; - c++; - } - *b = NULL; - return i; + if (!ipa_equal(i->ip, j->ip) || + !ipa_equal(i->prefix, j->prefix) || + i->pxlen != j->pxlen || + !ipa_equal(i->brd, j->brd) || + !ipa_equal(i->opposite, j->opposite)) + return 1; /* Changed addresses */ + if ((i->flags ^ j->flags) & ~(IF_UP | IF_ADMIN_DOWN | IF_UPDATED)) + return 1; + return 0; } static inline void -if_free(struct iface *i) +if_copy(struct iface *to, struct iface *from) { - mb_free(i); + to->flags = from->flags; + to->mtu = from->mtu; + to->index = from->index; } static unsigned if_changed(struct iface *i, struct iface *j) { unsigned f = 0; - struct ifa *x, *y; - x = i->ifa; - y = j->ifa; - while (x && y) - { - x = x->next; - y = y->next; - } - if (x || y) - f |= IF_CHANGE_ADDR; if (i->mtu != j->mtu) f |= IF_CHANGE_MTU; - if (i->flags != j->flags) + if ((i->flags ^ j->flags) & ~IF_UPDATED) { f |= IF_CHANGE_FLAGS; if ((i->flags ^ j->flags) & IF_UP) @@ -127,30 +242,51 @@ static void if_notify_change(unsigned c, struct iface *old, struct iface *new) { debug("Interface change notification (%x) for %s\n", c, new->name); + if (old) + if_dump(old); + if (new) + if_dump(new); + + if (c & IF_CHANGE_UP) + neigh_if_up(new); + + /* FIXME: Notify protocols here */ + + if (c & IF_CHANGE_DOWN) + neigh_if_down(old); } void if_update(struct iface *new) { struct iface *i; + unsigned c; WALK_LIST(i, iface_list) if (!strcmp(new->name, i->name)) { - unsigned c = if_changed(i, new); - if (c) + if (if_change_too_big_p(i, new)) /* Changed a lot, convert it to down/up */ { - struct iface *j = if_copy(new); - if_notify_change(c, i, j); - insert_node(&j->n, &i->n); + DBG("Interface %s changed too much -- forcing down/up transition\n", i->name); + i->flags &= ~IF_UP; + if_notify_change(IF_CHANGE_DOWN | IF_CHANGE_FLAGS, i, NULL); rem_node(&i->n); - if_free(i); + goto newif; } + c = if_changed(i, new); + if_copy(i, new); /* Even if c==0 as we might need to update i->index et al. */ + i->flags |= IF_UPDATED; + if (c) + if_notify_change(c, i, new); return; } - i = if_copy(new); + + i = mb_alloc(if_pool, sizeof(struct iface)); +newif: + memcpy(i, new, sizeof(*i)); + i->flags |= IF_UPDATED; add_tail(&iface_list, &i->n); - if_notify_change(IF_CHANGE_UP | IF_CHANGE_FLAGS | IF_CHANGE_MTU | IF_CHANGE_ADDR, NULL, i); + if_notify_change(IF_CHANGE_UP | IF_CHANGE_FLAGS | IF_CHANGE_MTU, NULL, i); } void @@ -174,4 +310,6 @@ if_init(void) { if_pool = rp_new(&root_pool, "Interfaces"); init_list(&iface_list); + neigh_slab = sl_new(if_pool, sizeof(neighbor)); + init_list(&neigh_list); } diff --git a/nest/iface.h b/nest/iface.h index 4df9873..c359449 100644 --- a/nest/iface.h +++ b/nest/iface.h @@ -18,8 +18,13 @@ struct iface { char name[16]; unsigned flags; unsigned mtu; - struct ifa *ifa; /* First address is primary */ unsigned index; /* OS-dependent interface index */ + ip_addr ip; /* IP address of this host */ + ip_addr prefix; /* Network prefix */ + unsigned pxlen; /* Prefix length */ + ip_addr brd; /* Broadcast address */ + ip_addr opposite; /* Opposite end of a point-to-point link */ + struct neighbor *neigh; /* List of neighbors on this interface */ }; #define IF_UP 1 @@ -33,25 +38,12 @@ struct iface { #define IF_IGNORE 256 #define IF_UPDATED 0x1000 /* Touched in last scan */ -/* Interface address */ - -struct ifa { - struct ifa *next; - ip_addr ip; /* IP address of this host */ - ip_addr prefix; /* Network prefix */ - unsigned pxlen; /* Prefix length */ - ip_addr brd; /* Broadcast address */ - ip_addr opposite; /* Opposite end of a point-to-point link */ - struct neighbor *neigh; /* List of neighbors on this interface */ -}; - /* Interface change events */ #define IF_CHANGE_UP 1 #define IF_CHANGE_DOWN 2 -#define IF_CHANGE_FLAGS 4 +#define IF_CHANGE_FLAGS 4 /* Can be converted to down/up internally */ #define IF_CHANGE_MTU 8 -#define IF_CHANGE_ADDR 16 void if_init(void); void if_dump(struct iface *); @@ -59,4 +51,39 @@ void if_dump_all(void); void if_update(struct iface *); void if_end_update(void); +/* + * Neighbor Cache. We hold (direct neighbor, protocol) pairs we've seen + * along with pointer to protocol-specific data. + * + * The primary goal of this cache is to quickly validate all incoming + * packets if their have been sent by our neighbors and to notify + * protocols about lost neighbors when an interface goes down. + * + * Anyway, it can also contain `sticky' entries for currently unreachable + * addresses which cause notification when the address becomes a neighbor. + */ + +typedef struct neighbor { + node n; /* Node in global neighbor list */ + ip_addr addr; /* Address of the neighbor */ + struct iface *iface; /* Interface address it's connected to */ + struct neighbor *sibling; /* Next in per-device chain */ + struct proto *proto; /* Protocol this belongs to */ + void *data; /* Protocol-specific data */ + unsigned flags; +} neighbor; + +#define NEF_STICKY 1 + +/* + * Find neighbor or return NULL if it doesn't exist. + * If you specify flags == NEF_STICKY, a sticky entry is created if the + * address is not a neighbor, but NULL can still be returned if the address + * given is invalid. + */ +neighbor *neigh_find(struct proto *, ip_addr *, unsigned flags); + +void neigh_dump(neighbor *); +void neigh_dump_all(void); + #endif diff --git a/nest/protocol.h b/nest/protocol.h index 26db248..45776ec 100644 --- a/nest/protocol.h +++ b/nest/protocol.h @@ -55,7 +55,7 @@ struct proto { void (*if_notify)(struct proto *, struct iface *new, struct iface *old); void (*rt_notify)(struct proto *, struct rte *new, struct rte *old); - void (*neigh_lost_notify)(struct proto *, struct neighbor *neigh); + void (*neigh_notify)(struct neighbor *neigh); void (*dump)(struct proto *); /* Debugging dump */ void (*start)(struct proto *); /* Start the instance */ void (*shutdown)(struct proto *, int time); /* Stop the instance */ diff --git a/nest/route.h b/nest/route.h index 255d31a..f00dded 100644 --- a/nest/route.h +++ b/nest/route.h @@ -13,6 +13,7 @@ #include "lib/timer.h" struct protocol; +struct proto; /* * Generic data structure for storing network prefixes. Also used @@ -61,25 +62,6 @@ void fib_free(struct fib *); /* Destroy the fib */ } while (0) /* - * Neighbor Cache. We hold (direct neighbor, protocol) pairs we've seen - * along with pointer to protocol-specific data. - * - * The primary goal of this cache is to quickly validate all incoming - * packets if their have been sent by our neighbors and to notify - * protocols about lost neighbors when an interface goes down. - */ - -typedef struct neighbor { - ip_addr addr; /* Address of the neighbor */ - struct next *next; /* Next in hashed chain */ - struct next *sibling; /* Next in per-device chain */ - struct proto *proto; /* Protocol this belongs to */ - void *data; /* Protocol-specific data */ -} neighbor; - -neighbor *neigh_find(ip_addr *); /* NULL if not a neighbor */ - -/* * Master Routing Tables. Generally speaking, each of them is a list * of FIB (one per TOS) with each entry pointing to a list of route entries * representing routes to given network. |