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bird/nest/iface.c
Ondrej Zajicek e4d179f2c2 Minor changes to default router ID calculation.
2013-11-24 12:50:53 +01:00

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/*
* BIRD -- Management of Interfaces and Neighbor Cache
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/**
* DOC: Interfaces
*
* The interface module keeps track of all network interfaces in the
* system and their addresses.
*
* Each interface is represented by an &iface structure which carries
* interface capability flags (%IF_MULTIACCESS, %IF_BROADCAST etc.),
* MTU, interface name and index and finally a linked list of network
* prefixes assigned to the interface, each one represented by
* struct &ifa.
*
* The interface module keeps a `soft-up' state for each &iface which
* is a conjunction of link being up, the interface being of a `sane'
* type and at least one IP address assigned to it.
*/
#undef LOCAL_DEBUG
#include "nest/bird.h"
#include "nest/iface.h"
#include "nest/protocol.h"
#include "nest/cli.h"
#include "lib/resource.h"
#include "lib/string.h"
#include "conf/conf.h"
static pool *if_pool;
list iface_list;
/**
* ifa_dump - dump interface address
* @a: interface address descriptor
*
* This function dumps contents of an &ifa to the debug output.
*/
void
ifa_dump(struct ifa *a)
{
debug("\t%I, net %I/%-2d bc %I -> %I%s%s%s\n", a->ip, a->prefix, a->pxlen, a->brd, a->opposite,
(a->flags & IF_UP) ? "" : " DOWN",
(a->flags & IA_PRIMARY) ? "" : " SEC",
(a->flags & IA_PEER) ? "PEER" : "");
}
/**
* if_dump - dump interface
* @i: interface to dump
*
* This function dumps all information associated with a given
* network interface to the debug output.
*/
void
if_dump(struct iface *i)
{
struct ifa *a;
debug("IF%d: %s", i->index, i->name);
if (i->flags & IF_SHUTDOWN)
debug(" SHUTDOWN");
if (i->flags & IF_UP)
debug(" UP");
else
debug(" DOWN");
if (i->flags & IF_ADMIN_UP)
debug(" LINK-UP");
if (i->flags & IF_MULTIACCESS)
debug(" MA");
if (i->flags & IF_BROADCAST)
debug(" BC");
if (i->flags & IF_MULTICAST)
debug(" MC");
if (i->flags & IF_LOOPBACK)
debug(" LOOP");
if (i->flags & IF_IGNORE)
debug(" IGN");
if (i->flags & IF_TMP_DOWN)
debug(" TDOWN");
debug(" MTU=%d\n", i->mtu);
WALK_LIST(a, i->addrs)
{
ifa_dump(a);
ASSERT((a != i->addr) == !(a->flags & IA_PRIMARY));
}
}
/**
* if_dump_all - dump all interfaces
*
* This function dumps information about all known network
* interfaces to the debug output.
*/
void
if_dump_all(void)
{
struct iface *i;
debug("Known network interfaces:\n");
WALK_LIST(i, iface_list)
if_dump(i);
debug("Router ID: %08x\n", config->router_id);
}
static inline unsigned
if_what_changed(struct iface *i, struct iface *j)
{
unsigned c;
if (((i->flags ^ j->flags) & ~(IF_UP | IF_SHUTDOWN | IF_UPDATED | IF_ADMIN_UP | IF_LINK_UP | IF_TMP_DOWN | IF_JUST_CREATED))
|| i->index != j->index)
return IF_CHANGE_TOO_MUCH;
c = 0;
if ((i->flags ^ j->flags) & IF_UP)
c |= (i->flags & IF_UP) ? IF_CHANGE_DOWN : IF_CHANGE_UP;
if ((i->flags ^ j->flags) & IF_LINK_UP)
c |= IF_CHANGE_LINK;
if (i->mtu != j->mtu)
c |= IF_CHANGE_MTU;
return c;
}
static inline void
if_copy(struct iface *to, struct iface *from)
{
to->flags = from->flags | (to->flags & IF_TMP_DOWN);
to->mtu = from->mtu;
}
static inline void
ifa_send_notify(struct proto *p, unsigned c, struct ifa *a)
{
if (p->ifa_notify)
{
if (p->debug & D_IFACES)
log(L_TRACE "%s < %s address %I/%d on interface %s %s",
p->name, (a->flags & IA_PRIMARY) ? "primary" : "secondary",
a->prefix, a->pxlen, a->iface->name,
(c & IF_CHANGE_UP) ? "added" : "removed");
p->ifa_notify(p, c, a);
}
}
static void
ifa_notify_change_dep(unsigned c, struct ifa *a)
{
struct proto *p;
DBG("IFA change notification (%x) for %s:%I\n", c, a->iface->name, a->ip);
WALK_LIST(p, active_proto_list)
ifa_send_notify(p, c, a);
}
static inline void
ifa_notify_change(unsigned c, struct ifa *a)
{
neigh_ifa_update(a);
ifa_notify_change_dep(c, a);
}
static inline void
if_send_notify(struct proto *p, unsigned c, struct iface *i)
{
if (p->if_notify)
{
if (p->debug & D_IFACES)
log(L_TRACE "%s < interface %s %s", p->name, i->name,
(c & IF_CHANGE_UP) ? "goes up" :
(c & IF_CHANGE_DOWN) ? "goes down" :
(c & IF_CHANGE_MTU) ? "changes MTU" :
(c & IF_CHANGE_LINK) ? "changes link" :
(c & IF_CHANGE_CREATE) ? "created" :
"sends unknown event");
p->if_notify(p, c, i);
}
}
static void
if_notify_change(unsigned c, struct iface *i)
{
struct proto *p;
struct ifa *a;
if (i->flags & IF_JUST_CREATED)
{
i->flags &= ~IF_JUST_CREATED;
c |= IF_CHANGE_CREATE | IF_CHANGE_MTU;
}
DBG("Interface change notification (%x) for %s\n", c, i->name);
#ifdef LOCAL_DEBUG
if_dump(i);
#endif
if (c & IF_CHANGE_UP)
neigh_if_up(i);
if (c & IF_CHANGE_DOWN)
WALK_LIST(a, i->addrs)
{
a->flags = (i->flags & ~IA_FLAGS) | (a->flags & IA_FLAGS);
ifa_notify_change_dep(IF_CHANGE_DOWN, a);
}
WALK_LIST(p, active_proto_list)
if_send_notify(p, c, i);
if (c & IF_CHANGE_UP)
WALK_LIST(a, i->addrs)
{
a->flags = (i->flags & ~IA_FLAGS) | (a->flags & IA_FLAGS);
ifa_notify_change_dep(IF_CHANGE_UP, a);
}
if ((c & (IF_CHANGE_UP | IF_CHANGE_DOWN | IF_CHANGE_LINK)) == IF_CHANGE_LINK)
neigh_if_link(i);
if (c & IF_CHANGE_DOWN)
neigh_if_down(i);
}
static unsigned
if_recalc_flags(struct iface *i, unsigned flags)
{
if ((flags & (IF_SHUTDOWN | IF_TMP_DOWN)) ||
!(flags & IF_ADMIN_UP) ||
!i->addr)
flags &= ~IF_UP;
else
flags |= IF_UP;
return flags;
}
static void
if_change_flags(struct iface *i, unsigned flags)
{
unsigned of = i->flags;
i->flags = if_recalc_flags(i, flags);
if ((i->flags ^ of) & IF_UP)
if_notify_change((i->flags & IF_UP) ? IF_CHANGE_UP : IF_CHANGE_DOWN, i);
}
/**
* if_delete - remove interface
* @old: interface
*
* This function is called by the low-level platform dependent code
* whenever it notices an interface disappears. It is just a shorthand
* for if_update().
*/
void
if_delete(struct iface *old)
{
struct iface f = {};
strncpy(f.name, old->name, sizeof(f.name)-1);
f.flags = IF_SHUTDOWN;
if_update(&f);
}
/**
* if_update - update interface status
* @new: new interface status
*
* if_update() is called by the low-level platform dependent code
* whenever it notices an interface change.
*
* There exist two types of interface updates -- synchronous and asynchronous
* ones. In the synchronous case, the low-level code calls if_start_update(),
* scans all interfaces reported by the OS, uses if_update() and ifa_update()
* to pass them to the core and then it finishes the update sequence by
* calling if_end_update(). When working asynchronously, the sysdep code
* calls if_update() and ifa_update() whenever it notices a change.
*
* if_update() will automatically notify all other modules about the change.
*/
struct iface *
if_update(struct iface *new)
{
struct iface *i;
unsigned c;
WALK_LIST(i, iface_list)
if (!strcmp(new->name, i->name))
{
new->addr = i->addr;
new->flags = if_recalc_flags(new, new->flags);
c = if_what_changed(i, new);
if (c & IF_CHANGE_TOO_MUCH) /* Changed a lot, convert it to down/up */
{
DBG("Interface %s changed too much -- forcing down/up transition\n", i->name);
if_change_flags(i, i->flags | IF_TMP_DOWN);
rem_node(&i->n);
new->addr = i->addr;
memcpy(&new->addrs, &i->addrs, sizeof(i->addrs));
memcpy(i, new, sizeof(*i));
i->flags &= ~IF_UP; /* IF_TMP_DOWN will be added later */
goto newif;
}
if_copy(i, new);
if (c)
if_notify_change(c, i);
i->flags |= IF_UPDATED;
return i;
}
i = mb_alloc(if_pool, sizeof(struct iface));
memcpy(i, new, sizeof(*i));
init_list(&i->addrs);
newif:
init_list(&i->neighbors);
i->flags |= IF_UPDATED | IF_TMP_DOWN; /* Tmp down as we don't have addresses yet */
add_tail(&iface_list, &i->n);
return i;
}
void
if_start_update(void)
{
struct iface *i;
struct ifa *a;
WALK_LIST(i, iface_list)
{
i->flags &= ~IF_UPDATED;
WALK_LIST(a, i->addrs)
a->flags &= ~IF_UPDATED;
}
}
void
if_end_partial_update(struct iface *i)
{
if (i->flags & IF_TMP_DOWN)
if_change_flags(i, i->flags & ~IF_TMP_DOWN);
}
void
if_end_update(void)
{
struct iface *i;
struct ifa *a, *b;
WALK_LIST(i, iface_list)
{
if (!(i->flags & IF_UPDATED))
if_change_flags(i, (i->flags & ~IF_ADMIN_UP) | IF_SHUTDOWN);
else
{
WALK_LIST_DELSAFE(a, b, i->addrs)
if (!(a->flags & IF_UPDATED))
ifa_delete(a);
if_end_partial_update(i);
}
}
}
void
if_flush_ifaces(struct proto *p)
{
if (p->debug & D_EVENTS)
log(L_TRACE "%s: Flushing interfaces", p->name);
if_start_update();
if_end_update();
}
/**
* if_feed_baby - advertise interfaces to a new protocol
* @p: protocol to feed
*
* When a new protocol starts, this function sends it a series
* of notifications about all existing interfaces.
*/
void
if_feed_baby(struct proto *p)
{
struct iface *i;
struct ifa *a;
if (!p->if_notify && !p->ifa_notify) /* shortcut */
return;
DBG("Announcing interfaces to new protocol %s\n", p->name);
WALK_LIST(i, iface_list)
{
if_send_notify(p, IF_CHANGE_CREATE | ((i->flags & IF_UP) ? IF_CHANGE_UP : 0), i);
if (i->flags & IF_UP)
WALK_LIST(a, i->addrs)
ifa_send_notify(p, IF_CHANGE_CREATE | IF_CHANGE_UP, a);
}
}
/**
* if_find_by_index - find interface by ifindex
* @idx: ifindex
*
* This function finds an &iface structure corresponding to an interface
* of the given index @idx. Returns a pointer to the structure or %NULL
* if no such structure exists.
*/
struct iface *
if_find_by_index(unsigned idx)
{
struct iface *i;
WALK_LIST(i, iface_list)
if (i->index == idx && !(i->flags & IF_SHUTDOWN))
return i;
return NULL;
}
/**
* if_find_by_name - find interface by name
* @name: interface name
*
* This function finds an &iface structure corresponding to an interface
* of the given name @name. Returns a pointer to the structure or %NULL
* if no such structure exists.
*/
struct iface *
if_find_by_name(char *name)
{
struct iface *i;
WALK_LIST(i, iface_list)
if (!strcmp(i->name, name))
return i;
return NULL;
}
struct iface *
if_get_by_name(char *name)
{
struct iface *i;
if (i = if_find_by_name(name))
return i;
/* No active iface, create a dummy */
i = mb_allocz(if_pool, sizeof(struct iface));
strncpy(i->name, name, sizeof(i->name)-1);
i->flags = IF_SHUTDOWN;
init_list(&i->addrs);
init_list(&i->neighbors);
add_tail(&iface_list, &i->n);
return i;
}
struct ifa *kif_choose_primary(struct iface *i);
static int
ifa_recalc_primary(struct iface *i)
{
struct ifa *a = kif_choose_primary(i);
if (a == i->addr)
return 0;
if (i->addr)
i->addr->flags &= ~IA_PRIMARY;
if (a)
{
a->flags |= IA_PRIMARY;
rem_node(&a->n);
add_head(&i->addrs, &a->n);
}
i->addr = a;
return 1;
}
void
ifa_recalc_all_primary_addresses(void)
{
struct iface *i;
WALK_LIST(i, iface_list)
{
if (ifa_recalc_primary(i))
if_change_flags(i, i->flags | IF_TMP_DOWN);
}
}
static inline int
ifa_same(struct ifa *a, struct ifa *b)
{
return ipa_equal(a->ip, b->ip) && ipa_equal(a->prefix, b->prefix) &&
a->pxlen == b->pxlen;
}
/**
* ifa_update - update interface address
* @a: new interface address
*
* This function adds address information to a network
* interface. It's called by the platform dependent code during
* the interface update process described under if_update().
*/
struct ifa *
ifa_update(struct ifa *a)
{
struct iface *i = a->iface;
struct ifa *b;
WALK_LIST(b, i->addrs)
if (ifa_same(b, a))
{
if (ipa_equal(b->brd, a->brd) &&
ipa_equal(b->opposite, a->opposite) &&
b->scope == a->scope &&
!((b->flags ^ a->flags) & IA_PEER))
{
b->flags |= IF_UPDATED;
return b;
}
ifa_delete(b);
break;
}
#ifndef IPV6
if ((i->flags & IF_BROADCAST) && !ipa_nonzero(a->brd))
log(L_ERR "Missing broadcast address for interface %s", i->name);
#endif
b = mb_alloc(if_pool, sizeof(struct ifa));
memcpy(b, a, sizeof(struct ifa));
add_tail(&i->addrs, &b->n);
b->flags = (i->flags & ~IA_FLAGS) | (a->flags & IA_FLAGS);
if (ifa_recalc_primary(i))
if_change_flags(i, i->flags | IF_TMP_DOWN);
if (b->flags & IF_UP)
ifa_notify_change(IF_CHANGE_CREATE | IF_CHANGE_UP, b);
return b;
}
/**
* ifa_delete - remove interface address
* @a: interface address
*
* This function removes address information from a network
* interface. It's called by the platform dependent code during
* the interface update process described under if_update().
*/
void
ifa_delete(struct ifa *a)
{
struct iface *i = a->iface;
struct ifa *b;
WALK_LIST(b, i->addrs)
if (ifa_same(b, a))
{
rem_node(&b->n);
if (b->flags & IF_UP)
{
b->flags &= ~IF_UP;
ifa_notify_change(IF_CHANGE_DOWN, b);
}
if (b->flags & IA_PRIMARY)
{
if_change_flags(i, i->flags | IF_TMP_DOWN);
ifa_recalc_primary(i);
}
mb_free(b);
return;
}
}
u32
if_choose_router_id(struct iface_patt *mask, u32 old_id)
{
#ifndef IPV6
struct iface *i;
struct ifa *a, *b;
b = NULL;
WALK_LIST(i, iface_list)
{
if (!(i->flags & IF_ADMIN_UP) ||
(i->flags & IF_SHUTDOWN))
continue;
WALK_LIST(a, i->addrs)
{
if (a->flags & IA_SECONDARY)
continue;
if (a->scope <= SCOPE_LINK)
continue;
/* Check pattern if specified */
if (mask && !iface_patt_match(mask, i, a))
continue;
/* No pattern or pattern matched */
if (!b || ipa_to_u32(a->ip) < ipa_to_u32(b->ip))
b = a;
}
}
if (!b)
return 0;
u32 id = ipa_to_u32(b->ip);
if (id != old_id)
log(L_INFO "Chosen router ID %R according to interface %s", id, b->iface->name);
return id;
#else
return 0;
#endif
}
/**
* if_init - initialize interface module
*
* This function is called during BIRD startup to initialize
* all data structures of the interface module.
*/
void
if_init(void)
{
if_pool = rp_new(&root_pool, "Interfaces");
init_list(&iface_list);
neigh_init(if_pool);
}
/*
* Interface Pattern Lists
*/
int
iface_patt_match(struct iface_patt *ifp, struct iface *i, struct ifa *a)
{
struct iface_patt_node *p;
WALK_LIST(p, ifp->ipn_list)
{
char *t = p->pattern;
int pos = p->positive;
if (t)
{
if (*t == '-')
{
t++;
pos = !pos;
}
if (!patmatch(t, i->name))
continue;
}
if (p->pxlen == 0)
return pos;
if (!a)
continue;
if (ipa_in_net(a->ip, p->prefix, p->pxlen))
return pos;
if ((a->flags & IA_PEER) &&
ipa_in_net(a->opposite, p->prefix, p->pxlen))
return pos;
continue;
}
return 0;
}
struct iface_patt *
iface_patt_find(list *l, struct iface *i, struct ifa *a)
{
struct iface_patt *p;
WALK_LIST(p, *l)
if (iface_patt_match(p, i, a))
return p;
return NULL;
}
static int
iface_plists_equal(struct iface_patt *pa, struct iface_patt *pb)
{
struct iface_patt_node *x, *y;
x = HEAD(pa->ipn_list);
y = HEAD(pb->ipn_list);
while (x->n.next && y->n.next)
{
if ((x->positive != y->positive) ||
(!x->pattern && y->pattern) || /* This nasty lines where written by me... :-( Feela */
(!y->pattern && x->pattern) ||
((x->pattern != y->pattern) && strcmp(x->pattern, y->pattern)) ||
!ipa_equal(x->prefix, y->prefix) ||
(x->pxlen != y->pxlen))
return 0;
x = (void *) x->n.next;
y = (void *) y->n.next;
}
return (!x->n.next && !y->n.next);
}
int
iface_patts_equal(list *a, list *b, int (*comp)(struct iface_patt *, struct iface_patt *))
{
struct iface_patt *x, *y;
x = HEAD(*a);
y = HEAD(*b);
while (x->n.next && y->n.next)
{
if (!iface_plists_equal(x, y) ||
(comp && !comp(x, y)))
return 0;
x = (void *) x->n.next;
y = (void *) y->n.next;
}
return (!x->n.next && !y->n.next);
}
/*
* CLI commands.
*/
static void
if_show_addr(struct ifa *a)
{
byte opp[STD_ADDRESS_P_LENGTH + 16];
if (ipa_nonzero(a->opposite))
bsprintf(opp, ", opposite %I", a->opposite);
else
opp[0] = 0;
cli_msg(-1003, "\t%I/%d (%s%s, scope %s)",
a->ip, a->pxlen,
(a->flags & IA_PRIMARY) ? "Primary" : (a->flags & IA_SECONDARY) ? "Secondary" : "Unselected",
opp, ip_scope_text(a->scope));
}
void
if_show(void)
{
struct iface *i;
struct ifa *a;
char *type;
WALK_LIST(i, iface_list)
{
if (i->flags & IF_SHUTDOWN)
continue;
cli_msg(-1001, "%s %s (index=%d)", i->name, (i->flags & IF_UP) ? "up" : "DOWN", i->index);
if (!(i->flags & IF_MULTIACCESS))
type = "PtP";
else
type = "MultiAccess";
cli_msg(-1004, "\t%s%s%s Admin%s Link%s%s%s MTU=%d",
type,
(i->flags & IF_BROADCAST) ? " Broadcast" : "",
(i->flags & IF_MULTICAST) ? " Multicast" : "",
(i->flags & IF_ADMIN_UP) ? "Up" : "Down",
(i->flags & IF_LINK_UP) ? "Up" : "Down",
(i->flags & IF_LOOPBACK) ? " Loopback" : "",
(i->flags & IF_IGNORE) ? " Ignored" : "",
i->mtu);
if (i->addr)
if_show_addr(i->addr);
WALK_LIST(a, i->addrs)
if (a != i->addr)
if_show_addr(a);
}
cli_msg(0, "");
}
void
if_show_summary(void)
{
struct iface *i;
byte addr[STD_ADDRESS_P_LENGTH + 16];
cli_msg(-2005, "interface state address");
WALK_LIST(i, iface_list)
{
if (i->addr)
bsprintf(addr, "%I/%d", i->addr->ip, i->addr->pxlen);
else
addr[0] = 0;
cli_msg(-1005, "%-9s %-5s %s", i->name, (i->flags & IF_UP) ? "up" : "DOWN", addr);
}
cli_msg(0, "");
}
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