/*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2020 Alexander V. Chernikov * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include "opt_route.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * This file contains control plane routing tables functions. * * All functions assumes they are called in net epoch. */ struct rib_subscription { CK_STAILQ_ENTRY(rib_subscription) next; rib_subscription_cb_t *func; void *arg; struct rib_head *rnh; enum rib_subscription_type type; struct epoch_context epoch_ctx; }; static int add_route(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc); static int add_route_nhop(struct rib_head *rnh, struct rtentry *rt, struct rt_addrinfo *info, struct route_nhop_data *rnd, struct rib_cmd_info *rc); static int del_route(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc); static int change_route(struct rib_head *rnh, struct rt_addrinfo *info, struct route_nhop_data *nhd_orig, struct rib_cmd_info *rc); static int rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc); static void rib_notify(struct rib_head *rnh, enum rib_subscription_type type, struct rib_cmd_info *rc); static void destroy_subscription_epoch(epoch_context_t ctx); #ifdef ROUTE_MPATH static bool rib_can_multipath(struct rib_head *rh); #endif /* Per-vnet multipath routing configuration */ SYSCTL_DECL(_net_route); #define V_rib_route_multipath VNET(rib_route_multipath) #ifdef ROUTE_MPATH #define _MP_FLAGS CTLFLAG_RW #else #define _MP_FLAGS CTLFLAG_RD #endif VNET_DEFINE(u_int, rib_route_multipath) = 0; SYSCTL_UINT(_net_route, OID_AUTO, multipath, _MP_FLAGS | CTLFLAG_VNET, &VNET_NAME(rib_route_multipath), 0, "Enable route multipath"); #undef _MP_FLAGS /* Routing table UMA zone */ VNET_DEFINE_STATIC(uma_zone_t, rtzone); #define V_rtzone VNET(rtzone) void vnet_rtzone_init() { V_rtzone = uma_zcreate("rtentry", sizeof(struct rtentry), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); } #ifdef VIMAGE void vnet_rtzone_destroy() { uma_zdestroy(V_rtzone); } #endif static void destroy_rtentry(struct rtentry *rt) { /* * At this moment rnh, nh_control may be already freed. * nhop interface may have been migrated to a different vnet. * Use vnet stored in the nexthop to delete the entry. */ CURVNET_SET(nhop_get_vnet(rt->rt_nhop)); /* Unreference nexthop */ nhop_free_any(rt->rt_nhop); uma_zfree(V_rtzone, rt); CURVNET_RESTORE(); } /* * Epoch callback indicating rtentry is safe to destroy */ static void destroy_rtentry_epoch(epoch_context_t ctx) { struct rtentry *rt; rt = __containerof(ctx, struct rtentry, rt_epoch_ctx); destroy_rtentry(rt); } /* * Schedule rtentry deletion */ static void rtfree(struct rtentry *rt) { KASSERT(rt != NULL, ("%s: NULL rt", __func__)); epoch_call(net_epoch_preempt, destroy_rtentry_epoch, &rt->rt_epoch_ctx); } static struct rib_head * get_rnh(uint32_t fibnum, const struct rt_addrinfo *info) { struct rib_head *rnh; struct sockaddr *dst; KASSERT((fibnum < rt_numfibs), ("rib_add_route: bad fibnum")); dst = info->rti_info[RTAX_DST]; rnh = rt_tables_get_rnh(fibnum, dst->sa_family); return (rnh); } #ifdef ROUTE_MPATH static bool rib_can_multipath(struct rib_head *rh) { int result; CURVNET_SET(rh->rib_vnet); result = !!V_rib_route_multipath; CURVNET_RESTORE(); return (result); } /* * Check is nhop is multipath-eligible. * Avoid nhops without gateways and redirects. * * Returns 1 for multipath-eligible nexthop, * 0 otherwise. */ bool nhop_can_multipath(const struct nhop_object *nh) { if ((nh->nh_flags & NHF_MULTIPATH) != 0) return (1); if ((nh->nh_flags & NHF_GATEWAY) == 0) return (0); if ((nh->nh_flags & NHF_REDIRECT) != 0) return (0); return (1); } #endif static int get_info_weight(const struct rt_addrinfo *info, uint32_t default_weight) { uint32_t weight; if (info->rti_mflags & RTV_WEIGHT) weight = info->rti_rmx->rmx_weight; else weight = default_weight; /* Keep upper 1 byte for adm distance purposes */ if (weight > RT_MAX_WEIGHT) weight = RT_MAX_WEIGHT; return (weight); } bool rt_is_host(const struct rtentry *rt) { return (rt->rte_flags & RTF_HOST); } sa_family_t rt_get_family(const struct rtentry *rt) { const struct sockaddr *dst; dst = (const struct sockaddr *)rt_key_const(rt); return (dst->sa_family); } /* * Returns pointer to nexthop or nexthop group * associated with @rt */ struct nhop_object * rt_get_raw_nhop(const struct rtentry *rt) { return (rt->rt_nhop); } #ifdef INET /* * Stores IPv4 address and prefix length of @rt inside * @paddr and @plen. * @pscopeid is currently always set to 0. */ void rt_get_inet_prefix_plen(const struct rtentry *rt, struct in_addr *paddr, int *plen, uint32_t *pscopeid) { const struct sockaddr_in *dst; dst = (const struct sockaddr_in *)rt_key_const(rt); KASSERT((dst->sin_family == AF_INET), ("rt family is %d, not inet", dst->sin_family)); *paddr = dst->sin_addr; dst = (const struct sockaddr_in *)rt_mask_const(rt); if (dst == NULL) *plen = 32; else *plen = bitcount32(dst->sin_addr.s_addr); *pscopeid = 0; } /* * Stores IPv4 address and prefix mask of @rt inside * @paddr and @pmask. Sets mask to INADDR_ANY for host routes. * @pscopeid is currently always set to 0. */ void rt_get_inet_prefix_pmask(const struct rtentry *rt, struct in_addr *paddr, struct in_addr *pmask, uint32_t *pscopeid) { const struct sockaddr_in *dst; dst = (const struct sockaddr_in *)rt_key_const(rt); KASSERT((dst->sin_family == AF_INET), ("rt family is %d, not inet", dst->sin_family)); *paddr = dst->sin_addr; dst = (const struct sockaddr_in *)rt_mask_const(rt); if (dst == NULL) pmask->s_addr = INADDR_BROADCAST; else *pmask = dst->sin_addr; *pscopeid = 0; } #endif #ifdef INET6 static int inet6_get_plen(const struct in6_addr *addr) { return (bitcount32(addr->s6_addr32[0]) + bitcount32(addr->s6_addr32[1]) + bitcount32(addr->s6_addr32[2]) + bitcount32(addr->s6_addr32[3])); } /* * Stores IPv6 address and prefix length of @rt inside * @paddr and @plen. Addresses are returned in de-embedded form. * Scopeid is set to 0 for non-LL addresses. */ void rt_get_inet6_prefix_plen(const struct rtentry *rt, struct in6_addr *paddr, int *plen, uint32_t *pscopeid) { const struct sockaddr_in6 *dst; dst = (const struct sockaddr_in6 *)rt_key_const(rt); KASSERT((dst->sin6_family == AF_INET6), ("rt family is %d, not inet6", dst->sin6_family)); if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) in6_splitscope(&dst->sin6_addr, paddr, pscopeid); else *paddr = dst->sin6_addr; dst = (const struct sockaddr_in6 *)rt_mask_const(rt); if (dst == NULL) *plen = 128; else *plen = inet6_get_plen(&dst->sin6_addr); } /* * Stores IPv6 address and prefix mask of @rt inside * @paddr and @pmask. Addresses are returned in de-embedded form. * Scopeid is set to 0 for non-LL addresses. */ void rt_get_inet6_prefix_pmask(const struct rtentry *rt, struct in6_addr *paddr, struct in6_addr *pmask, uint32_t *pscopeid) { const struct sockaddr_in6 *dst; dst = (const struct sockaddr_in6 *)rt_key_const(rt); KASSERT((dst->sin6_family == AF_INET6), ("rt family is %d, not inet", dst->sin6_family)); if (IN6_IS_SCOPE_LINKLOCAL(&dst->sin6_addr)) in6_splitscope(&dst->sin6_addr, paddr, pscopeid); else *paddr = dst->sin6_addr; dst = (const struct sockaddr_in6 *)rt_mask_const(rt); if (dst == NULL) memset(pmask, 0xFF, sizeof(struct in6_addr)); else *pmask = dst->sin6_addr; } #endif static void rt_set_expire_info(struct rtentry *rt, const struct rt_addrinfo *info) { /* Kernel -> userland timebase conversion. */ if (info->rti_mflags & RTV_EXPIRE) rt->rt_expire = info->rti_rmx->rmx_expire ? info->rti_rmx->rmx_expire - time_second + time_uptime : 0; } /* * Check if specified @gw matches gw data in the nexthop @nh. * * Returns true if matches, false otherwise. */ bool match_nhop_gw(const struct nhop_object *nh, const struct sockaddr *gw) { if (nh->gw_sa.sa_family != gw->sa_family) return (false); switch (gw->sa_family) { case AF_INET: return (nh->gw4_sa.sin_addr.s_addr == ((const struct sockaddr_in *)gw)->sin_addr.s_addr); case AF_INET6: { const struct sockaddr_in6 *gw6; gw6 = (const struct sockaddr_in6 *)gw; /* * Currently (2020-09) IPv6 gws in kernel have their * scope embedded. Once this becomes false, this code * has to be revisited. */ if (IN6_ARE_ADDR_EQUAL(&nh->gw6_sa.sin6_addr, &gw6->sin6_addr)) return (true); return (false); } case AF_LINK: { const struct sockaddr_dl *sdl; sdl = (const struct sockaddr_dl *)gw; return (nh->gwl_sa.sdl_index == sdl->sdl_index); } default: return (memcmp(&nh->gw_sa, gw, nh->gw_sa.sa_len) == 0); } /* NOTREACHED */ return (false); } /* * Checks if data in @info matches nexhop @nh. * * Returns 0 on success, * ESRCH if not matched, * ENOENT if filter function returned false */ int check_info_match_nhop(const struct rt_addrinfo *info, const struct rtentry *rt, const struct nhop_object *nh) { const struct sockaddr *gw = info->rti_info[RTAX_GATEWAY]; if (info->rti_filter != NULL) { if (info->rti_filter(rt, nh, info->rti_filterdata) == 0) return (ENOENT); else return (0); } if ((gw != NULL) && !match_nhop_gw(nh, gw)) return (ESRCH); return (0); } /* * Checks if nexhop @nh can be rewritten by data in @info because * of higher "priority". Currently the only case for such scenario * is kernel installing interface routes, marked by RTF_PINNED flag. * * Returns: * 1 if @info data has higher priority * 0 if priority is the same * -1 if priority is lower */ int can_override_nhop(const struct rt_addrinfo *info, const struct nhop_object *nh) { if (info->rti_flags & RTF_PINNED) { return (NH_IS_PINNED(nh)) ? 0 : 1; } else { return (NH_IS_PINNED(nh)) ? -1 : 0; } } /* * Runs exact prefix match based on @dst and @netmask. * Returns matched @rtentry if found or NULL. * If rtentry was found, saves nexthop / weight value into @rnd. */ static struct rtentry * lookup_prefix_bysa(struct rib_head *rnh, const struct sockaddr *dst, const struct sockaddr *netmask, struct route_nhop_data *rnd) { struct rtentry *rt; RIB_LOCK_ASSERT(rnh); rt = (struct rtentry *)rnh->rnh_lookup(__DECONST(void *, dst), __DECONST(void *, netmask), &rnh->head); if (rt != NULL) { rnd->rnd_nhop = rt->rt_nhop; rnd->rnd_weight = rt->rt_weight; } else { rnd->rnd_nhop = NULL; rnd->rnd_weight = 0; } return (rt); } /* * Runs exact prefix match based on dst/netmask from @info. * Assumes RIB lock is held. * Returns matched @rtentry if found or NULL. * If rtentry was found, saves nexthop / weight value into @rnd. */ struct rtentry * lookup_prefix(struct rib_head *rnh, const struct rt_addrinfo *info, struct route_nhop_data *rnd) { struct rtentry *rt; rt = lookup_prefix_bysa(rnh, info->rti_info[RTAX_DST], info->rti_info[RTAX_NETMASK], rnd); return (rt); } /* * Adds route defined by @info into the kernel table specified by @fibnum and * sa_family in @info->rti_info[RTAX_DST]. * * Returns 0 on success and fills in operation metadata into @rc. */ int rib_add_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc) { struct rib_head *rnh; int error; NET_EPOCH_ASSERT(); rnh = get_rnh(fibnum, info); if (rnh == NULL) return (EAFNOSUPPORT); /* * Check consistency between RTF_HOST flag and netmask * existence. */ if (info->rti_flags & RTF_HOST) info->rti_info[RTAX_NETMASK] = NULL; else if (info->rti_info[RTAX_NETMASK] == NULL) return (EINVAL); bzero(rc, sizeof(struct rib_cmd_info)); rc->rc_cmd = RTM_ADD; error = add_route(rnh, info, rc); if (error == 0) rib_notify(rnh, RIB_NOTIFY_DELAYED, rc); return (error); } /* * Creates rtentry and nexthop based on @info data. * Return 0 and fills in rtentry into @prt on success, * return errno otherwise. */ static int create_rtentry(struct rib_head *rnh, struct rt_addrinfo *info, struct rtentry **prt) { struct sockaddr *dst, *ndst, *gateway, *netmask; struct rtentry *rt; struct nhop_object *nh; struct ifaddr *ifa; int error, flags; dst = info->rti_info[RTAX_DST]; gateway = info->rti_info[RTAX_GATEWAY]; netmask = info->rti_info[RTAX_NETMASK]; flags = info->rti_flags; if ((flags & RTF_GATEWAY) && !gateway) return (EINVAL); if (dst && gateway && (dst->sa_family != gateway->sa_family) && (gateway->sa_family != AF_UNSPEC) && (gateway->sa_family != AF_LINK)) return (EINVAL); if (dst->sa_len > sizeof(((struct rtentry *)NULL)->rt_dstb)) return (EINVAL); if (info->rti_ifa == NULL) { error = rt_getifa_fib(info, rnh->rib_fibnum); if (error) return (error); } else { ifa_ref(info->rti_ifa); } error = nhop_create_from_info(rnh, info, &nh); if (error != 0) { ifa_free(info->rti_ifa); return (error); } rt = uma_zalloc(V_rtzone, M_NOWAIT | M_ZERO); if (rt == NULL) { ifa_free(info->rti_ifa); nhop_free(nh); return (ENOBUFS); } rt->rte_flags = (RTF_UP | flags) & RTE_RT_FLAG_MASK; rt->rt_nhop = nh; /* Fill in dst */ memcpy(&rt->rt_dst, dst, dst->sa_len); rt_key(rt) = &rt->rt_dst; /* * point to the (possibly newly malloc'd) dest address. */ ndst = (struct sockaddr *)rt_key(rt); /* * make sure it contains the value we want (masked if needed). */ if (netmask) { rt_maskedcopy(dst, ndst, netmask); } else bcopy(dst, ndst, dst->sa_len); /* * We use the ifa reference returned by rt_getifa_fib(). * This moved from below so that rnh->rnh_addaddr() can * examine the ifa and ifa->ifa_ifp if it so desires. */ ifa = info->rti_ifa; rt->rt_weight = get_info_weight(info, RT_DEFAULT_WEIGHT); rt_set_expire_info(rt, info); *prt = rt; return (0); } static int add_route(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc) { struct nhop_object *nh_orig; struct route_nhop_data rnd_orig, rnd_add; struct nhop_object *nh; struct rtentry *rt, *rt_orig; int error; error = create_rtentry(rnh, info, &rt); if (error != 0) return (error); rnd_add.rnd_nhop = rt->rt_nhop; rnd_add.rnd_weight = rt->rt_weight; nh = rt->rt_nhop; RIB_WLOCK(rnh); error = add_route_nhop(rnh, rt, info, &rnd_add, rc); if (error == 0) { RIB_WUNLOCK(rnh); return (0); } /* addition failed. Lookup prefix in the rib to determine the cause */ rt_orig = lookup_prefix(rnh, info, &rnd_orig); if (rt_orig == NULL) { /* No prefix -> rnh_addaddr() failed to allocate memory */ RIB_WUNLOCK(rnh); nhop_free(nh); uma_zfree(V_rtzone, rt); return (ENOMEM); } /* We have existing route in the RIB. */ nh_orig = rnd_orig.rnd_nhop; /* Check if new route has higher preference */ if (can_override_nhop(info, nh_orig) > 0) { /* Update nexthop to the new route */ change_route_nhop(rnh, rt_orig, info, &rnd_add, rc); RIB_WUNLOCK(rnh); uma_zfree(V_rtzone, rt); nhop_free(nh_orig); return (0); } RIB_WUNLOCK(rnh); #ifdef ROUTE_MPATH if (rib_can_multipath(rnh) && nhop_can_multipath(rnd_add.rnd_nhop) && nhop_can_multipath(rnd_orig.rnd_nhop)) error = add_route_mpath(rnh, info, rt, &rnd_add, &rnd_orig, rc); else #endif /* Unable to add - another route with the same preference exists */ error = EEXIST; /* * ROUTE_MPATH disabled: failed to add route, free both nhop and rt. * ROUTE_MPATH enabled: original nhop reference is unused in any case, * free rt only if not _adding_ new route to rib (e.g. the case * when initial lookup returned existing route, but then it got * deleted prior to multipath group insertion, leading to a simple * non-multipath add as a result). */ nhop_free(nh); if ((error != 0) || rc->rc_cmd != RTM_ADD) uma_zfree(V_rtzone, rt); return (error); } /* * Removes route defined by @info from the kernel table specified by @fibnum and * sa_family in @info->rti_info[RTAX_DST]. * * Returns 0 on success and fills in operation metadata into @rc. */ int rib_del_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc) { struct rib_head *rnh; struct sockaddr *dst_orig, *netmask; struct sockaddr_storage mdst; int error; NET_EPOCH_ASSERT(); rnh = get_rnh(fibnum, info); if (rnh == NULL) return (EAFNOSUPPORT); bzero(rc, sizeof(struct rib_cmd_info)); rc->rc_cmd = RTM_DELETE; dst_orig = info->rti_info[RTAX_DST]; netmask = info->rti_info[RTAX_NETMASK]; if (netmask != NULL) { /* Ensure @dst is always properly masked */ if (dst_orig->sa_len > sizeof(mdst)) return (EINVAL); rt_maskedcopy(dst_orig, (struct sockaddr *)&mdst, netmask); info->rti_info[RTAX_DST] = (struct sockaddr *)&mdst; } error = del_route(rnh, info, rc); info->rti_info[RTAX_DST] = dst_orig; return (error); } /* * Conditionally unlinks rtentry matching data inside @info from @rnh. * Returns 0 on success with operation result stored in @rc. * On error, returns: * ESRCH - if prefix was not found, * EADDRINUSE - if trying to delete higher priority route. * ENOENT - if supplied filter function returned 0 (not matched). */ static int rt_unlinkrte(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc) { struct rtentry *rt; struct nhop_object *nh; struct radix_node *rn; struct route_nhop_data rnd; int error; rt = lookup_prefix(rnh, info, &rnd); if (rt == NULL) return (ESRCH); nh = rt->rt_nhop; #ifdef ROUTE_MPATH if (NH_IS_NHGRP(nh)) { error = del_route_mpath(rnh, info, rt, (struct nhgrp_object *)nh, rc); return (error); } #endif error = check_info_match_nhop(info, rt, nh); if (error != 0) return (error); if (can_override_nhop(info, nh) < 0) return (EADDRINUSE); /* * Remove the item from the tree and return it. * Complain if it is not there and do no more processing. */ rn = rnh->rnh_deladdr(info->rti_info[RTAX_DST], info->rti_info[RTAX_NETMASK], &rnh->head); if (rn == NULL) return (ESRCH); if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) panic ("rtrequest delete"); rt = RNTORT(rn); rt->rte_flags &= ~RTF_UP; /* Finalize notification */ rnh->rnh_gen++; rnh->rnh_prefixes--; rc->rc_cmd = RTM_DELETE; rc->rc_rt = rt; rc->rc_nh_old = rt->rt_nhop; rc->rc_nh_weight = rt->rt_weight; rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc); return (0); } static int del_route(struct rib_head *rnh, struct rt_addrinfo *info, struct rib_cmd_info *rc) { int error; RIB_WLOCK(rnh); error = rt_unlinkrte(rnh, info, rc); RIB_WUNLOCK(rnh); if (error != 0) return (error); rib_notify(rnh, RIB_NOTIFY_DELAYED, rc); /* * If the caller wants it, then it can have it, * the entry will be deleted after the end of the current epoch. */ if (rc->rc_cmd == RTM_DELETE) rtfree(rc->rc_rt); #ifdef ROUTE_MPATH else { /* * Deleting 1 path may result in RTM_CHANGE to * a different mpath group/nhop. * Free old mpath group. */ nhop_free_any(rc->rc_nh_old); } #endif return (0); } int rib_change_route(uint32_t fibnum, struct rt_addrinfo *info, struct rib_cmd_info *rc) { RIB_RLOCK_TRACKER; struct route_nhop_data rnd_orig; struct rib_head *rnh; struct rtentry *rt; int error; NET_EPOCH_ASSERT(); rnh = get_rnh(fibnum, info); if (rnh == NULL) return (EAFNOSUPPORT); bzero(rc, sizeof(struct rib_cmd_info)); rc->rc_cmd = RTM_CHANGE; /* Check if updated gateway exists */ if ((info->rti_flags & RTF_GATEWAY) && (info->rti_info[RTAX_GATEWAY] == NULL)) { /* * route(8) adds RTF_GATEWAY flag if -interface is not set. * Remove RTF_GATEWAY to enforce consistency and maintain * compatibility.. */ info->rti_flags &= ~RTF_GATEWAY; } /* * route change is done in multiple steps, with dropping and * reacquiring lock. In the situations with multiple processes * changes the same route in can lead to the case when route * is changed between the steps. Address it by retrying the operation * multiple times before failing. */ RIB_RLOCK(rnh); rt = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST], info->rti_info[RTAX_NETMASK], &rnh->head); if (rt == NULL) { RIB_RUNLOCK(rnh); return (ESRCH); } rnd_orig.rnd_nhop = rt->rt_nhop; rnd_orig.rnd_weight = rt->rt_weight; RIB_RUNLOCK(rnh); for (int i = 0; i < RIB_MAX_RETRIES; i++) { error = change_route(rnh, info, &rnd_orig, rc); if (error != EAGAIN) break; } return (error); } static int change_nhop(struct rib_head *rnh, struct rt_addrinfo *info, struct nhop_object *nh_orig, struct nhop_object **nh_new) { int free_ifa = 0; int error; /* * New gateway could require new ifaddr, ifp; * flags may also be different; ifp may be specified * by ll sockaddr when protocol address is ambiguous */ if (((nh_orig->nh_flags & NHF_GATEWAY) && info->rti_info[RTAX_GATEWAY] != NULL) || info->rti_info[RTAX_IFP] != NULL || (info->rti_info[RTAX_IFA] != NULL && !sa_equal(info->rti_info[RTAX_IFA], nh_orig->nh_ifa->ifa_addr))) { error = rt_getifa_fib(info, rnh->rib_fibnum); if (info->rti_ifa != NULL) free_ifa = 1; if (error != 0) { if (free_ifa) { ifa_free(info->rti_ifa); info->rti_ifa = NULL; } return (error); } } error = nhop_create_from_nhop(rnh, nh_orig, info, nh_new); if (free_ifa) { ifa_free(info->rti_ifa); info->rti_ifa = NULL; } return (error); } #ifdef ROUTE_MPATH static int change_mpath_route(struct rib_head *rnh, struct rt_addrinfo *info, struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc) { int error = 0; struct nhop_object *nh, *nh_orig, *nh_new; struct route_nhop_data rnd_new; nh = NULL; nh_orig = rnd_orig->rnd_nhop; struct weightened_nhop *wn = NULL, *wn_new; uint32_t num_nhops; wn = nhgrp_get_nhops((struct nhgrp_object *)nh_orig, &num_nhops); nh_orig = NULL; for (int i = 0; i < num_nhops; i++) { if (check_info_match_nhop(info, NULL, wn[i].nh)) { nh_orig = wn[i].nh; break; } } if (nh_orig == NULL) return (ESRCH); error = change_nhop(rnh, info, nh_orig, &nh_new); if (error != 0) return (error); wn_new = mallocarray(num_nhops, sizeof(struct weightened_nhop), M_TEMP, M_NOWAIT | M_ZERO); if (wn_new == NULL) { nhop_free(nh_new); return (EAGAIN); } memcpy(wn_new, wn, num_nhops * sizeof(struct weightened_nhop)); for (int i = 0; i < num_nhops; i++) { if (wn[i].nh == nh_orig) { wn[i].nh = nh_new; wn[i].weight = get_info_weight(info, rnd_orig->rnd_weight); break; } } error = nhgrp_get_group(rnh, wn_new, num_nhops, &rnd_new); nhop_free(nh_new); free(wn_new, M_TEMP); if (error != 0) return (error); error = change_route_conditional(rnh, NULL, info, rnd_orig, &rnd_new, rc); return (error); } #endif static int change_route(struct rib_head *rnh, struct rt_addrinfo *info, struct route_nhop_data *rnd_orig, struct rib_cmd_info *rc) { int error = 0; struct nhop_object *nh, *nh_orig; struct route_nhop_data rnd_new; nh = NULL; nh_orig = rnd_orig->rnd_nhop; if (nh_orig == NULL) return (ESRCH); #ifdef ROUTE_MPATH if (NH_IS_NHGRP(nh_orig)) return (change_mpath_route(rnh, info, rnd_orig, rc)); #endif rnd_new.rnd_weight = get_info_weight(info, rnd_orig->rnd_weight); error = change_nhop(rnh, info, nh_orig, &rnd_new.rnd_nhop); if (error != 0) return (error); error = change_route_conditional(rnh, NULL, info, rnd_orig, &rnd_new, rc); return (error); } /* * Insert @rt with nhop data from @rnd_new to @rnh. * Returns 0 on success and stores operation results in @rc. */ static int add_route_nhop(struct rib_head *rnh, struct rtentry *rt, struct rt_addrinfo *info, struct route_nhop_data *rnd, struct rib_cmd_info *rc) { struct sockaddr *ndst, *netmask; struct radix_node *rn; int error = 0; RIB_WLOCK_ASSERT(rnh); ndst = (struct sockaddr *)rt_key(rt); netmask = info->rti_info[RTAX_NETMASK]; rt->rt_nhop = rnd->rnd_nhop; rt->rt_weight = rnd->rnd_weight; rn = rnh->rnh_addaddr(ndst, netmask, &rnh->head, rt->rt_nodes); if (rn != NULL) { if (rt->rt_expire > 0) tmproutes_update(rnh, rt); /* Finalize notification */ rnh->rnh_gen++; rnh->rnh_prefixes++; rc->rc_cmd = RTM_ADD; rc->rc_rt = rt; rc->rc_nh_old = NULL; rc->rc_nh_new = rnd->rnd_nhop; rc->rc_nh_weight = rnd->rnd_weight; rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc); } else { /* Existing route or memory allocation failure */ error = EEXIST; } return (error); } /* * Switch @rt nhop/weigh to the ones specified in @rnd. * Conditionally set rt_expire if set in @info. * Returns 0 on success. */ int change_route_nhop(struct rib_head *rnh, struct rtentry *rt, struct rt_addrinfo *info, struct route_nhop_data *rnd, struct rib_cmd_info *rc) { struct nhop_object *nh_orig; RIB_WLOCK_ASSERT(rnh); nh_orig = rt->rt_nhop; if (rnd->rnd_nhop != NULL) { /* Changing expiration & nexthop & weight to a new one */ rt_set_expire_info(rt, info); rt->rt_nhop = rnd->rnd_nhop; rt->rt_weight = rnd->rnd_weight; if (rt->rt_expire > 0) tmproutes_update(rnh, rt); } else { /* Route deletion requested. */ struct sockaddr *ndst, *netmask; struct radix_node *rn; ndst = (struct sockaddr *)rt_key(rt); netmask = info->rti_info[RTAX_NETMASK]; rn = rnh->rnh_deladdr(ndst, netmask, &rnh->head); if (rn == NULL) return (ESRCH); rt = RNTORT(rn); rt->rte_flags &= ~RTF_UP; } /* Finalize notification */ rnh->rnh_gen++; if (rnd->rnd_nhop == NULL) rnh->rnh_prefixes--; rc->rc_cmd = (rnd->rnd_nhop != NULL) ? RTM_CHANGE : RTM_DELETE; rc->rc_rt = rt; rc->rc_nh_old = nh_orig; rc->rc_nh_new = rnd->rnd_nhop; rc->rc_nh_weight = rnd->rnd_weight; rib_notify(rnh, RIB_NOTIFY_IMMEDIATE, rc); return (0); } /* * Conditionally update route nhop/weight IFF data in @nhd_orig is * consistent with the current route data. * Nexthop in @nhd_new is consumed. */ int change_route_conditional(struct rib_head *rnh, struct rtentry *rt, struct rt_addrinfo *info, struct route_nhop_data *rnd_orig, struct route_nhop_data *rnd_new, struct rib_cmd_info *rc) { struct rtentry *rt_new; int error = 0; RIB_WLOCK(rnh); rt_new = (struct rtentry *)rnh->rnh_lookup(info->rti_info[RTAX_DST], info->rti_info[RTAX_NETMASK], &rnh->head); if (rt_new == NULL) { if (rnd_orig->rnd_nhop == NULL) error = add_route_nhop(rnh, rt, info, rnd_new, rc); else { /* * Prefix does not exist, which was not our assumption. * Update @rnd_orig with the new data and return */ rnd_orig->rnd_nhop = NULL; rnd_orig->rnd_weight = 0; error = EAGAIN; } } else { /* Prefix exists, try to update */ if (rnd_orig->rnd_nhop == rt_new->rt_nhop) { /* * Nhop/mpath group hasn't changed. Flip * to the new precalculated one and return */ error = change_route_nhop(rnh, rt_new, info, rnd_new, rc); } else { /* Update and retry */ rnd_orig->rnd_nhop = rt_new->rt_nhop; rnd_orig->rnd_weight = rt_new->rt_weight; error = EAGAIN; } } RIB_WUNLOCK(rnh); if (error == 0) { rib_notify(rnh, RIB_NOTIFY_DELAYED, rc); if (rnd_orig->rnd_nhop != NULL) nhop_free_any(rnd_orig->rnd_nhop); } else { if (rnd_new->rnd_nhop != NULL) nhop_free_any(rnd_new->rnd_nhop); } return (error); } /* * Performs modification of routing table specificed by @action. * Table is specified by @fibnum and sa_family in @info->rti_info[RTAX_DST]. * Needs to be run in network epoch. * * Returns 0 on success and fills in @rc with action result. */ int rib_action(uint32_t fibnum, int action, struct rt_addrinfo *info, struct rib_cmd_info *rc) { int error; switch (action) { case RTM_ADD: error = rib_add_route(fibnum, info, rc); break; case RTM_DELETE: error = rib_del_route(fibnum, info, rc); break; case RTM_CHANGE: error = rib_change_route(fibnum, info, rc); break; default: error = ENOTSUP; } return (error); } struct rt_delinfo { struct rt_addrinfo info; struct rib_head *rnh; struct rtentry *head; struct rib_cmd_info rc; }; /* * Conditionally unlinks @rn from radix tree based * on info data passed in @arg. */ static int rt_checkdelroute(struct radix_node *rn, void *arg) { struct rt_delinfo *di; struct rt_addrinfo *info; struct rtentry *rt; int error; di = (struct rt_delinfo *)arg; rt = (struct rtentry *)rn; info = &di->info; info->rti_info[RTAX_DST] = rt_key(rt); info->rti_info[RTAX_NETMASK] = rt_mask(rt); error = rt_unlinkrte(di->rnh, info, &di->rc); /* * Add deleted rtentries to the list to GC them * after dropping the lock. * * XXX: Delayed notifications not implemented * for nexthop updates. */ if ((error == 0) && (di->rc.rc_cmd == RTM_DELETE)) { /* Add to the list and return */ rt->rt_chain = di->head; di->head = rt; } return (0); } /* * Iterates over a routing table specified by @fibnum and @family and * deletes elements marked by @filter_f. * @fibnum: rtable id * @family: AF_ address family * @filter_f: function returning non-zero value for items to delete * @arg: data to pass to the @filter_f function * @report: true if rtsock notification is needed. */ void rib_walk_del(u_int fibnum, int family, rib_filter_f_t *filter_f, void *arg, bool report) { struct rib_head *rnh; struct rt_delinfo di; struct rtentry *rt; struct nhop_object *nh; struct epoch_tracker et; rnh = rt_tables_get_rnh(fibnum, family); if (rnh == NULL) return; bzero(&di, sizeof(di)); di.info.rti_filter = filter_f; di.info.rti_filterdata = arg; di.rnh = rnh; di.rc.rc_cmd = RTM_DELETE; NET_EPOCH_ENTER(et); RIB_WLOCK(rnh); rnh->rnh_walktree(&rnh->head, rt_checkdelroute, &di); RIB_WUNLOCK(rnh); /* We might have something to reclaim. */ bzero(&di.rc, sizeof(di.rc)); di.rc.rc_cmd = RTM_DELETE; while (di.head != NULL) { rt = di.head; di.head = rt->rt_chain; rt->rt_chain = NULL; nh = rt->rt_nhop; di.rc.rc_rt = rt; di.rc.rc_nh_old = nh; rib_notify(rnh, RIB_NOTIFY_DELAYED, &di.rc); /* TODO std rt -> rt_addrinfo export */ di.info.rti_info[RTAX_DST] = rt_key(rt); di.info.rti_info[RTAX_NETMASK] = rt_mask(rt); if (report) { #ifdef ROUTE_MPATH struct nhgrp_object *nhg; struct weightened_nhop *wn; uint32_t num_nhops; if (NH_IS_NHGRP(nh)) { nhg = (struct nhgrp_object *)nh; wn = nhgrp_get_nhops(nhg, &num_nhops); for (int i = 0; i < num_nhops; i++) rt_routemsg(RTM_DELETE, rt, wn[i].nh, fibnum); } else #endif rt_routemsg(RTM_DELETE, rt, nh, fibnum); } rtfree(rt); } NET_EPOCH_EXIT(et); } static void rib_notify(struct rib_head *rnh, enum rib_subscription_type type, struct rib_cmd_info *rc) { struct rib_subscription *rs; CK_STAILQ_FOREACH(rs, &rnh->rnh_subscribers, next) { if (rs->type == type) rs->func(rnh, rc, rs->arg); } } static struct rib_subscription * allocate_subscription(rib_subscription_cb_t *f, void *arg, enum rib_subscription_type type, bool waitok) { struct rib_subscription *rs; int flags = M_ZERO | (waitok ? M_WAITOK : M_NOWAIT); rs = malloc(sizeof(struct rib_subscription), M_RTABLE, flags); if (rs == NULL) return (NULL); rs->func = f; rs->arg = arg; rs->type = type; return (rs); } /* * Subscribe for the changes in the routing table specified by @fibnum and * @family. * * Returns pointer to the subscription structure on success. */ struct rib_subscription * rib_subscribe(uint32_t fibnum, int family, rib_subscription_cb_t *f, void *arg, enum rib_subscription_type type, bool waitok) { struct rib_head *rnh; struct epoch_tracker et; NET_EPOCH_ENTER(et); KASSERT((fibnum < rt_numfibs), ("%s: bad fibnum", __func__)); rnh = rt_tables_get_rnh(fibnum, family); NET_EPOCH_EXIT(et); return (rib_subscribe_internal(rnh, f, arg, type, waitok)); } struct rib_subscription * rib_subscribe_internal(struct rib_head *rnh, rib_subscription_cb_t *f, void *arg, enum rib_subscription_type type, bool waitok) { struct rib_subscription *rs; struct epoch_tracker et; if ((rs = allocate_subscription(f, arg, type, waitok)) == NULL) return (NULL); rs->rnh = rnh; NET_EPOCH_ENTER(et); RIB_WLOCK(rnh); CK_STAILQ_INSERT_TAIL(&rnh->rnh_subscribers, rs, next); RIB_WUNLOCK(rnh); NET_EPOCH_EXIT(et); return (rs); } /* * Remove rtable subscription @rs from the routing table. * Needs to be run in network epoch. */ void rib_unsibscribe(struct rib_subscription *rs) { struct rib_head *rnh = rs->rnh; NET_EPOCH_ASSERT(); RIB_WLOCK(rnh); CK_STAILQ_REMOVE(&rnh->rnh_subscribers, rs, rib_subscription, next); RIB_WUNLOCK(rnh); epoch_call(net_epoch_preempt, destroy_subscription_epoch, &rs->epoch_ctx); } /* * Epoch callback indicating subscription is safe to destroy */ static void destroy_subscription_epoch(epoch_context_t ctx) { struct rib_subscription *rs; rs = __containerof(ctx, struct rib_subscription, epoch_ctx); free(rs, M_RTABLE); } void rib_init_subscriptions(struct rib_head *rnh) { CK_STAILQ_INIT(&rnh->rnh_subscribers); } void rib_destroy_subscriptions(struct rib_head *rnh) { struct rib_subscription *rs; struct epoch_tracker et; NET_EPOCH_ENTER(et); RIB_WLOCK(rnh); while ((rs = CK_STAILQ_FIRST(&rnh->rnh_subscribers)) != NULL) { CK_STAILQ_REMOVE_HEAD(&rnh->rnh_subscribers, next); epoch_call(net_epoch_preempt, destroy_subscription_epoch, &rs->epoch_ctx); } RIB_WUNLOCK(rnh); NET_EPOCH_EXIT(et); }