/* * 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; static void auto_router_id(void); 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_UNNUMBERED) ? " UNNUM" : ""); } /** * 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_ADMIN_DOWN) debug(" ADMIN-DOWN"); if (i->flags & IF_UP) debug(" UP"); else debug(" DOWN"); if (i->flags & IF_LINK_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_ADMIN_DOWN | IF_UPDATED | 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->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(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 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_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(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(IF_CHANGE_UP, a); } if (c & IF_CHANGE_DOWN) neigh_if_down(i); } static unsigned if_recalc_flags(struct iface *i, unsigned flags) { if ((flags & (IF_ADMIN_DOWN | IF_TMP_DOWN)) || !(flags & IF_LINK_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_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)); goto newif; } else if (c) { if_copy(i, new); 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; if (!config->router_id) auto_router_id(); WALK_LIST(i, iface_list) { if (!(i->flags & IF_UPDATED)) if_change_flags(i, (i->flags & ~IF_LINK_UP) | IF_ADMIN_DOWN); else { WALK_LIST_DELSAFE(a, b, i->addrs) if (!(a->flags & IF_UPDATED)) ifa_delete(a); if_end_partial_update(i); } } } /** * 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) 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; } static int ifa_recalc_primary(struct iface *i) { struct ifa *a, *b = NULL; int res; WALK_LIST(a, i->addrs) { if (!(a->flags & IA_SECONDARY) && (!b || a->scope > b->scope)) b = a; a->flags &= ~IA_PRIMARY; } res = (b != i->addr); i->addr = b; if (b) { b->flags |= IA_PRIMARY; rem_node(&b->n); add_head(&i->addrs, &b->n); } return res; } /** * 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 (ipa_equal(b->ip, a->ip)) { if (ipa_equal(b->prefix, a->prefix) && b->pxlen == a->pxlen && ipa_equal(b->brd, a->brd) && ipa_equal(b->opposite, a->opposite) && b->scope == a->scope && !((b->flags ^ a->flags) & IA_UNNUMBERED)) { b->flags |= IF_UPDATED; return b; } ifa_delete(b); break; } if (!(i->flags & IF_MULTIACCESS) && a->pxlen < BITS_PER_IP_ADDRESS - 2) log(L_WARN "Strange prefix length %d for point-to-point interface %s", a->pxlen, i->name); #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 ((!i->addr || i->addr->scope < b->scope) && 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 (ipa_equal(b->ip, a->ip)) { 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; } } static void auto_router_id(void) { #ifndef IPV6 struct iface *i, *j; j = NULL; WALK_LIST(i, iface_list) if ((i->flags & IF_LINK_UP) && !(i->flags & (IF_IGNORE | IF_ADMIN_DOWN)) && i->addr && !(i->addr->flags & IA_UNNUMBERED) && (!j || ipa_to_u32(i->addr->ip) < ipa_to_u32(j->addr->ip))) j = i; if (!j) die("Cannot determine router ID (no suitable network interface found), please configure it manually"); log(L_INFO "Guessed router ID %I according to interface %s", j->addr->ip, j->name); config->router_id = ipa_to_u32(j->addr->ip); #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 */ struct iface_patt * iface_patt_match(list *l, struct iface *i) { struct iface_patt *p; WALK_LIST(p, *l) { char *t = p->pattern; int ok = 1; if (t) { if (*t == '-') { t++; ok = 0; } if (!patmatch(t, i->name)) continue; } if (!i->addr || !ipa_in_net(i->addr->ip, p->prefix, p->pxlen)) continue; return ok ? p : NULL; } return NULL; } 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 (strcmp(x->pattern, y->pattern) || !ipa_equal(x->prefix, y->prefix) || x->pxlen != y->pxlen || 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 broad[STD_ADDRESS_P_LENGTH + 16]; byte opp[STD_ADDRESS_P_LENGTH + 16]; if (ipa_nonzero(a->brd)) bsprintf(broad, ", broadcast %I", a->brd); else broad[0] = 0; if (ipa_nonzero(a->opposite)) bsprintf(opp, ", opposite %I", a->opposite); else opp[0] = 0; cli_msg(-1003, "\t%I/%d (%s%s%s, scope %s%s)", a->ip, a->pxlen, (a->flags & IA_PRIMARY) ? "Primary" : (a->flags & IA_SECONDARY) ? "Secondary" : "???", broad, opp, ip_scope_text(a->scope), (a->flags & IA_UNNUMBERED) ? ", unnumbered" : ""); } void if_show(void) { struct iface *i; struct ifa *a; char *type; WALK_LIST(i, iface_list) { 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_DOWN) ? "Down" : "Up", (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, ""); }