Fix rt_ifa selection during loopback route insertion process.
Currently such routes are added with a link-level IFA, which is plain wrong. Only after the insertion they get fixed by the special link_rtrequest() ifa handler. This behaviour complicates routing code and makes ifa selection more complex. Streamline this process by explicitly moving link_rtrequest() logic to the pre-insertion rt_getifa_fib() ifa selector. Avoid calling all this logic in the loopback route case by explicitly specifying proper rt_ifa inside the ifa_maintain_loopback_route().§ MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D20076
This commit is contained in:
Alexander V. Chernikov
parent
980bde5834
commit
2ad7ed6e4a
46
sys/net/if.c
46
sys/net/if.c
@ -264,7 +264,6 @@ static void if_route(struct ifnet *, int flag, int fam);
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static int if_setflag(struct ifnet *, int, int, int *, int);
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static int if_transmit(struct ifnet *ifp, struct mbuf *m);
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static void if_unroute(struct ifnet *, int flag, int fam);
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static void link_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
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static int if_delmulti_locked(struct ifnet *, struct ifmultiaddr *, int);
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static void do_link_state_change(void *, int);
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static int if_getgroup(struct ifgroupreq *, struct ifnet *);
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@ -862,7 +861,6 @@ if_attach_internal(struct ifnet *ifp, int vmove, struct if_clone *ifc)
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sdl->sdl_type = ifp->if_type;
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ifp->if_addr = ifa;
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ifa->ifa_ifp = ifp;
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ifa->ifa_rtrequest = link_rtrequest;
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ifa->ifa_addr = (struct sockaddr *)sdl;
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sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
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ifa->ifa_netmask = (struct sockaddr *)sdl;
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@ -1892,6 +1890,7 @@ static int
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ifa_maintain_loopback_route(int cmd, const char *otype, struct ifaddr *ifa,
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struct sockaddr *ia)
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{
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struct epoch_tracker et;
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int error;
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struct rt_addrinfo info;
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struct sockaddr_dl null_sdl;
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@ -1902,6 +1901,16 @@ ifa_maintain_loopback_route(int cmd, const char *otype, struct ifaddr *ifa,
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bzero(&info, sizeof(info));
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if (cmd != RTM_DELETE)
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info.rti_ifp = V_loif;
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if (cmd == RTM_ADD) {
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/* explicitly specify (loopback) ifa */
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if (info.rti_ifp != NULL) {
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NET_EPOCH_ENTER(et);
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info.rti_ifa = ifaof_ifpforaddr(ifa->ifa_addr, info.rti_ifp);
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if (info.rti_ifa != NULL)
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ifa_ref(info.rti_ifa);
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NET_EPOCH_EXIT(et);
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}
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}
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info.rti_flags = ifa->ifa_flags | RTF_HOST | RTF_STATIC | RTF_PINNED;
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info.rti_info[RTAX_DST] = ia;
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info.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&null_sdl;
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@ -2210,39 +2219,6 @@ ifa_preferred(struct ifaddr *cur, struct ifaddr *next)
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((*carp_master_p)(next) && !(*carp_master_p)(cur))));
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}
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#include <net/if_llatbl.h>
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/*
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* Default action when installing a route with a Link Level gateway.
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* Lookup an appropriate real ifa to point to.
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* This should be moved to /sys/net/link.c eventually.
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*/
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static void
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link_rtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
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{
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struct epoch_tracker et;
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struct ifaddr *ifa, *oifa;
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struct sockaddr *dst;
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struct ifnet *ifp;
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if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == NULL) ||
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((ifp = ifa->ifa_ifp) == NULL) || ((dst = rt_key(rt)) == NULL))
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return;
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NET_EPOCH_ENTER(et);
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ifa = ifaof_ifpforaddr(dst, ifp);
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if (ifa) {
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oifa = rt->rt_ifa;
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if (oifa != ifa) {
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ifa_free(oifa);
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ifa_ref(ifa);
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}
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rt->rt_ifa = ifa;
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if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
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ifa->ifa_rtrequest(cmd, rt, info);
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}
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NET_EPOCH_EXIT(et);
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}
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struct sockaddr_dl *
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link_alloc_sdl(size_t size, int flags)
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{
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@ -1276,12 +1276,14 @@ rt_notifydelete(struct rtentry *rt, struct rt_addrinfo *info)
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/*
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* Look up rt_addrinfo for a specific fib. Note that if rti_ifa is defined,
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* it will be referenced so the caller must free it.
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*
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* Assume basic consistency checks are executed by callers:
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* RTAX_DST exists, if RTF_GATEWAY is set, RTAX_GATEWAY exists as well.
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*/
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int
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rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum)
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{
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struct epoch_tracker et;
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struct ifaddr *ifa;
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int needref, error;
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/*
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@ -1291,21 +1293,54 @@ rt_getifa_fib(struct rt_addrinfo *info, u_int fibnum)
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error = 0;
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needref = (info->rti_ifa == NULL);
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NET_EPOCH_ENTER(et);
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/* If we have interface specified by the ifindex in the address, use it */
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if (info->rti_ifp == NULL && ifpaddr != NULL &&
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ifpaddr->sa_family == AF_LINK &&
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(ifa = ifa_ifwithnet(ifpaddr, 0, fibnum)) != NULL) {
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info->rti_ifp = ifa->ifa_ifp;
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ifpaddr->sa_family == AF_LINK) {
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const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)ifpaddr;
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if (sdl->sdl_index != 0)
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info->rti_ifp = ifnet_byindex_locked(sdl->sdl_index);
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}
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/*
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* If we have source address specified, try to find it
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* TODO: avoid enumerating all ifas on all interfaces.
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*/
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if (info->rti_ifa == NULL && ifaaddr != NULL)
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info->rti_ifa = ifa_ifwithaddr(ifaaddr);
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if (info->rti_ifa == NULL) {
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struct sockaddr *sa;
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sa = ifaaddr != NULL ? ifaaddr :
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(gateway != NULL ? gateway : dst);
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if (sa != NULL && info->rti_ifp != NULL)
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/*
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* Most common use case for the userland-supplied routes.
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*
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* Choose sockaddr to select ifa.
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* -- if ifp is set --
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* Order of preference:
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* 1) IFA address
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* 2) gateway address
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* Note: for interface routes link-level gateway address
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* is specified to indicate the interface index without
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* specifying RTF_GATEWAY. In this case, ignore gateway
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* Note: gateway AF may be different from dst AF. In this case,
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* ignore gateway
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* 3) final destination.
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* 4) if all of these fails, try to get at least link-level ifa.
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* -- else --
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* try to lookup gateway or dst in the routing table to get ifa
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*/
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if (info->rti_info[RTAX_IFA] != NULL)
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sa = info->rti_info[RTAX_IFA];
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else if ((info->rti_flags & RTF_GATEWAY) != 0 &&
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gateway->sa_family == dst->sa_family)
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sa = gateway;
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else
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sa = dst;
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if (info->rti_ifp != NULL) {
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info->rti_ifa = ifaof_ifpforaddr(sa, info->rti_ifp);
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else if (dst != NULL && gateway != NULL)
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/* Case 4 */
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if (info->rti_ifa == NULL && gateway != NULL)
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info->rti_ifa = ifaof_ifpforaddr(gateway, info->rti_ifp);
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} else if (dst != NULL && gateway != NULL)
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info->rti_ifa = ifa_ifwithroute(flags, dst, gateway,
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fibnum);
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else if (sa != NULL)
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