Add KPI that can be used by tunneling interfaces to handle IP addresses
appearing and disappearing on the host system. Such handling is need, because tunneling interfaces must use addresses, that are configured on the host as ingress addresses for tunnels. Otherwise the system can send spoofed packets with source address, that belongs to foreign host. The KPI uses ifaddr_event_ext event to implement addresses tracking. Tunneling interfaces register event handlers and then they are notified by the kernel, when an address disappears or appears. ifaddr_event_compat() handler from if.c replaced by srcaddr_change_event() in the ip_encap.c MFC after: 1 month Sponsored by: Yandex LLC Differential Revision: https://reviews.freebsd.org/D17134
This commit is contained in:
Andrey V. Elsukov
parent
6ab6e9d3f4
commit
8251c68d5c
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=339550
12
sys/net/if.c
12
sys/net/if.c
@ -328,18 +328,6 @@ static MALLOC_DEFINE(M_IFNET, "ifnet", "interface internals");
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MALLOC_DEFINE(M_IFADDR, "ifaddr", "interface address");
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MALLOC_DEFINE(M_IFMADDR, "ether_multi", "link-level multicast address");
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/*
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* Support for old ifaddr_event.
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*/
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static void
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ifaddr_event_compat(void *arg __unused, struct ifnet *ifp,
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struct ifaddr *ifa __unused, int event __unused)
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{
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EVENTHANDLER_INVOKE(ifaddr_event, ifp);
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}
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EVENTHANDLER_DEFINE(ifaddr_event_ext, ifaddr_event_compat, NULL, 0);
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struct ifnet *
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ifnet_byindex_locked(u_short idx)
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{
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@ -100,22 +100,139 @@ struct encaptab {
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encap_input_t input;
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};
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struct srcaddrtab {
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CK_LIST_ENTRY(srcaddrtab) chain;
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encap_srcaddr_t srcaddr;
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void *arg;
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};
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CK_LIST_HEAD(encaptab_head, encaptab);
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CK_LIST_HEAD(srcaddrtab_head, srcaddrtab);
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#ifdef INET
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static struct encaptab_head ipv4_encaptab = CK_LIST_HEAD_INITIALIZER();
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static struct srcaddrtab_head ipv4_srcaddrtab = CK_LIST_HEAD_INITIALIZER();
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#endif
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#ifdef INET6
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static struct encaptab_head ipv6_encaptab = CK_LIST_HEAD_INITIALIZER();
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static struct srcaddrtab_head ipv6_srcaddrtab = CK_LIST_HEAD_INITIALIZER();
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#endif
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static struct mtx encapmtx;
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static struct mtx encapmtx, srcaddrmtx;
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MTX_SYSINIT(encapmtx, &encapmtx, "encapmtx", MTX_DEF);
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MTX_SYSINIT(srcaddrmtx, &srcaddrmtx, "srcaddrmtx", MTX_DEF);
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#define ENCAP_WLOCK() mtx_lock(&encapmtx)
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#define ENCAP_WUNLOCK() mtx_unlock(&encapmtx)
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#define ENCAP_RLOCK() struct epoch_tracker encap_et; epoch_enter_preempt(net_epoch_preempt, &encap_et)
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#define ENCAP_RUNLOCK() epoch_exit_preempt(net_epoch_preempt, &encap_et)
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#define ENCAP_RLOCK_TRACKER struct epoch_tracker encap_et
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#define ENCAP_RLOCK() \
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epoch_enter_preempt(net_epoch_preempt, &encap_et)
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#define ENCAP_RUNLOCK() \
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epoch_exit_preempt(net_epoch_preempt, &encap_et)
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#define ENCAP_WAIT() epoch_wait_preempt(net_epoch_preempt)
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#define SRCADDR_WLOCK() mtx_lock(&srcaddrmtx)
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#define SRCADDR_WUNLOCK() mtx_unlock(&srcaddrmtx)
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#define SRCADDR_RLOCK_TRACKER struct epoch_tracker srcaddr_et
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#define SRCADDR_RLOCK() \
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epoch_enter_preempt(net_epoch_preempt, &srcaddr_et)
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#define SRCADDR_RUNLOCK() \
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epoch_exit_preempt(net_epoch_preempt, &srcaddr_et)
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#define SRCADDR_WAIT() epoch_wait_preempt(net_epoch_preempt)
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/*
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* ifaddr_event_ext handler.
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*
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* Tunnelling interfaces may request the kernel to notify when
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* some interface addresses appears or disappears. Usually tunnelling
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* interface must use an address configured on the local machine as
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* ingress address to be able receive datagramms and do not send
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* spoofed packets.
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*/
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static void
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srcaddr_change_event(void *arg __unused, struct ifnet *ifp,
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struct ifaddr *ifa, int event)
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{
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SRCADDR_RLOCK_TRACKER;
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struct srcaddrtab_head *head;
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struct srcaddrtab *p;
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/* Support for old ifaddr_event. */
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EVENTHANDLER_INVOKE(ifaddr_event, ifp);
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switch (ifa->ifa_addr->sa_family) {
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#ifdef INET
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case AF_INET:
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head = &ipv4_srcaddrtab;
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break;
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#endif
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#ifdef INET6
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case AF_INET6:
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head = &ipv6_srcaddrtab;
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break;
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#endif
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default:
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/* ignore event */
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return;
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}
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SRCADDR_RLOCK();
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CK_LIST_FOREACH(p, head, chain) {
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(*p->srcaddr)(p->arg, ifa->ifa_addr, event);
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}
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SRCADDR_RUNLOCK();
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}
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EVENTHANDLER_DEFINE(ifaddr_event_ext, srcaddr_change_event, NULL, 0);
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static struct srcaddrtab *
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encap_register_srcaddr(struct srcaddrtab_head *head, encap_srcaddr_t func,
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void *arg, int mflags)
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{
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struct srcaddrtab *p, *tmp;
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if (func == NULL)
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return (NULL);
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p = malloc(sizeof(*p), M_NETADDR, mflags);
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if (p == NULL)
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return (NULL);
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p->srcaddr = func;
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p->arg = arg;
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SRCADDR_WLOCK();
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CK_LIST_FOREACH(tmp, head, chain) {
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if (func == tmp->srcaddr && arg == tmp->arg)
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break;
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}
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if (tmp == NULL)
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CK_LIST_INSERT_HEAD(head, p, chain);
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SRCADDR_WUNLOCK();
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if (tmp != NULL) {
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free(p, M_NETADDR);
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p = tmp;
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}
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return (p);
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}
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static int
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encap_unregister_srcaddr(struct srcaddrtab_head *head,
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const struct srcaddrtab *cookie)
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{
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struct srcaddrtab *p;
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SRCADDR_WLOCK();
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CK_LIST_FOREACH(p, head, chain) {
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if (p == cookie) {
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CK_LIST_REMOVE(p, chain);
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SRCADDR_WUNLOCK();
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SRCADDR_WAIT();
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free(p, M_NETADDR);
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return (0);
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}
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}
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SRCADDR_WUNLOCK();
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return (EINVAL);
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}
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static struct encaptab *
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encap_attach(struct encaptab_head *head, const struct encap_config *cfg,
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void *arg, int mflags)
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@ -175,6 +292,7 @@ encap_detach(struct encaptab_head *head, const struct encaptab *cookie)
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static int
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encap_input(struct encaptab_head *head, struct mbuf *m, int off, int proto)
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{
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ENCAP_RLOCK_TRACKER;
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struct encaptab *ep, *match;
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void *arg;
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int matchprio, ret;
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@ -220,6 +338,20 @@ encap_input(struct encaptab_head *head, struct mbuf *m, int off, int proto)
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}
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#ifdef INET
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const struct srcaddrtab *
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ip_encap_register_srcaddr(encap_srcaddr_t func, void *arg, int mflags)
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{
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return (encap_register_srcaddr(&ipv4_srcaddrtab, func, arg, mflags));
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}
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int
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ip_encap_unregister_srcaddr(const struct srcaddrtab *cookie)
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{
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return (encap_unregister_srcaddr(&ipv4_srcaddrtab, cookie));
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}
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const struct encaptab *
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ip_encap_attach(const struct encap_config *cfg, void *arg, int mflags)
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{
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@ -245,6 +377,20 @@ encap4_input(struct mbuf **mp, int *offp, int proto)
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#endif /* INET */
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#ifdef INET6
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const struct srcaddrtab *
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ip6_encap_register_srcaddr(encap_srcaddr_t func, void *arg, int mflags)
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{
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return (encap_register_srcaddr(&ipv6_srcaddrtab, func, arg, mflags));
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}
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int
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ip6_encap_unregister_srcaddr(const struct srcaddrtab *cookie)
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{
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return (encap_unregister_srcaddr(&ipv6_srcaddrtab, cookie));
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}
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const struct encaptab *
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ip6_encap_attach(const struct encap_config *cfg, void *arg, int mflags)
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{
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@ -43,7 +43,8 @@ int encap6_input(struct mbuf **, int *, int);
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typedef int (*encap_lookup_t)(const struct mbuf *, int, int, void **);
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typedef int (*encap_check_t)(const struct mbuf *, int, int, void *);
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typedef int (*encap_input_t)(struct mbuf *, int , int, void *);
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typedef int (*encap_input_t)(struct mbuf *, int, int, void *);
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typedef void (*encap_srcaddr_t)(void *, const struct sockaddr *, int);
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struct encap_config {
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int proto; /* protocol */
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@ -60,12 +61,20 @@ struct encap_config {
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};
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struct encaptab;
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struct srcaddrtab;
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const struct encaptab *ip_encap_attach(const struct encap_config *,
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void *arg, int mflags);
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const struct encaptab *ip6_encap_attach(const struct encap_config *,
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void *arg, int mflags);
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const struct srcaddrtab *ip_encap_register_srcaddr(encap_srcaddr_t,
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void *arg, int mflags);
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const struct srcaddrtab *ip6_encap_register_srcaddr(encap_srcaddr_t,
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void *arg, int mflags);
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int ip_encap_unregister_srcaddr(const struct srcaddrtab *);
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int ip6_encap_unregister_srcaddr(const struct srcaddrtab *);
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int ip_encap_detach(const struct encaptab *);
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int ip6_encap_detach(const struct encaptab *);
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#endif
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