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Add handling for appearing/disappearing of ingress addresses to if_me(4).

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* register handler for ingress address appearing/disappearing;
* add new srcaddr hash table for fast softc lookup by srcaddr;
* when srcaddr disappears, clear IFF_DRV_RUNNING flag from interface,
  and set it otherwise;

MFC after:	1 month
Sponsored by:	Yandex LLC
This commit is contained in:
Andrey V. Elsukov 2018-10-21 18:18:37 +00:00
parent 19873f4780
commit df49ca9fd3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=339553
1 changed files with 59 additions and 4 deletions
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63
sys/net/if_me.c
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@ -83,11 +83,13 @@ struct me_softc {
struct in_addr me_dst;
CK_LIST_ENTRY(me_softc) chain;
CK_LIST_ENTRY(me_softc) srchash;
};
CK_LIST_HEAD(me_list, me_softc);
#define ME2IFP(sc) ((sc)->me_ifp)
#define ME_READY(sc) ((sc)->me_src.s_addr != 0)
#define ME_RLOCK() struct epoch_tracker me_et; epoch_enter_preempt(net_epoch_preempt, &me_et)
#define ME_RLOCK_TRACKER struct epoch_tracker me_et
#define ME_RLOCK() epoch_enter_preempt(net_epoch_preempt, &me_et)
#define ME_RUNLOCK() epoch_exit_preempt(net_epoch_preempt, &me_et)
#define ME_WAIT() epoch_wait_preempt(net_epoch_preempt)
@ -95,9 +97,13 @@ CK_LIST_HEAD(me_list, me_softc);
#define ME_HASH_SIZE (1 << 4)
#endif
VNET_DEFINE_STATIC(struct me_list *, me_hashtbl) = NULL;
VNET_DEFINE_STATIC(struct me_list *, me_srchashtbl) = NULL;
#define V_me_hashtbl VNET(me_hashtbl)
#define V_me_srchashtbl VNET(me_srchashtbl)
#define ME_HASH(src, dst) (V_me_hashtbl[\
me_hashval((src), (dst)) & (ME_HASH_SIZE - 1)])
#define ME_SRCHASH(src) (V_me_srchashtbl[\
fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (ME_HASH_SIZE - 1)])
static struct sx me_ioctl_sx;
SX_SYSINIT(me_ioctl_sx, &me_ioctl_sx, "me_ioctl");
@ -165,8 +171,10 @@ static void
vnet_me_uninit(const void *unused __unused)
{
if (V_me_hashtbl != NULL)
if (V_me_hashtbl != NULL) {
free(V_me_hashtbl, M_IFME);
free(V_me_srchashtbl, M_IFME);
}
if_clone_detach(V_me_cloner);
}
VNET_SYSUNINIT(vnet_me_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
@ -330,6 +338,43 @@ me_lookup(const struct mbuf *m, int off, int proto, void **arg)
return (0);
}
/*
* Check that ingress address belongs to local host.
*/
static void
me_set_running(struct me_softc *sc)
{
if (in_localip(sc->me_src))
ME2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
else
ME2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
}
/*
* ifaddr_event handler.
* Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent
* source address spoofing.
*/
static void
me_srcaddr(void *arg __unused, const struct sockaddr *sa,
int event __unused)
{
const struct sockaddr_in *sin;
struct me_softc *sc;
if (V_me_srchashtbl == NULL)
return;
MPASS(in_epoch(net_epoch_preempt));
sin = (const struct sockaddr_in *)sa;
CK_LIST_FOREACH(sc, &ME_SRCHASH(sin->sin_addr.s_addr), srchash) {
if (sc->me_src.s_addr != sin->sin_addr.s_addr)
continue;
me_set_running(sc);
}
}
static int
me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
{
@ -337,8 +382,10 @@ me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
sx_assert(&me_ioctl_sx, SA_XLOCKED);
if (V_me_hashtbl == NULL)
if (V_me_hashtbl == NULL) {
V_me_hashtbl = me_hashinit();
V_me_srchashtbl = me_hashinit();
}
if (sc->me_src.s_addr == src && sc->me_dst.s_addr == dst)
return (0);
@ -355,8 +402,9 @@ me_set_tunnel(struct me_softc *sc, in_addr_t src, in_addr_t dst)
sc->me_dst.s_addr = dst;
sc->me_src.s_addr = src;
CK_LIST_INSERT_HEAD(&ME_HASH(src, dst), sc, chain);
CK_LIST_INSERT_HEAD(&ME_SRCHASH(src), sc, srchash);
ME2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING;
me_set_running(sc);
if_link_state_change(ME2IFP(sc), LINK_STATE_UP);
return (0);
}
@ -368,6 +416,7 @@ me_delete_tunnel(struct me_softc *sc)
sx_assert(&me_ioctl_sx, SA_XLOCKED);
if (ME_READY(sc)) {
CK_LIST_REMOVE(sc, chain);
CK_LIST_REMOVE(sc, srchash);
ME_WAIT();
sc->me_src.s_addr = 0;
@ -473,6 +522,7 @@ me_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
static int
me_transmit(struct ifnet *ifp, struct mbuf *m)
{
ME_RLOCK_TRACKER;
struct mobhdr mh;
struct me_softc *sc;
struct ip *ip;
@ -490,6 +540,7 @@ me_transmit(struct ifnet *ifp, struct mbuf *m)
if (sc == NULL || !ME_READY(sc) ||
(ifp->if_flags & IFF_MONITOR) != 0 ||
(ifp->if_flags & IFF_UP) == 0 ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
(error = if_tunnel_check_nesting(ifp, m, MTAG_ME,
V_max_me_nesting)) != 0) {
m_freem(m);
@ -567,6 +618,7 @@ me_qflush(struct ifnet *ifp __unused)
}
static const struct srcaddrtab *me_srcaddrtab = NULL;
static const struct encaptab *ecookie = NULL;
static const struct encap_config me_encap_cfg = {
.proto = IPPROTO_MOBILE,
@ -583,10 +635,13 @@ memodevent(module_t mod, int type, void *data)
switch (type) {
case MOD_LOAD:
me_srcaddrtab = ip_encap_register_srcaddr(me_srcaddr,
NULL, M_WAITOK);
ecookie = ip_encap_attach(&me_encap_cfg, NULL, M_WAITOK);
break;
case MOD_UNLOAD:
ip_encap_detach(ecookie);
ip_encap_unregister_srcaddr(me_srcaddrtab);
break;
default:
return (EOPNOTSUPP);