Commit 4cc78c50 authored by Martin Mareš's avatar Martin Mareš

- Rewrote whole interface logic. Removed support for multiple addresses per

  interface since it makes much trouble everywhere. Instead, we understand
  secondary addresses as subinterfaces.

- In case interface addresses or basic flags change, we simply convert it
  to a down/up sequence.

- Implemented the universal neighbour cache. (Just forget what did previous
  includes say of neighbour caching, this one is brand new.)
parent 0fe3b28b
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 (?)
......
/*
* 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);
}
......@@ -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
......@@ -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 */
......
......@@ -13,6 +13,7 @@
#include "lib/timer.h"
struct protocol;
struct proto;
/*
* Generic data structure for storing network prefixes. Also used
......@@ -60,25 +61,6 @@ 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
......
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