/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2021 Ng Peng Nam Sean * Copyright (c) 2022 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 #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 #define DEBUG_MOD_NAME nl_route #define DEBUG_MAX_LEVEL LOG_DEBUG3 #include _DECLARE_DEBUG(LOG_INFO); static unsigned char get_rtm_type(const struct nhop_object *nh) { int nh_flags = nh->nh_flags; /* Use the fact that nhg runtime flags are only NHF_MULTIPATH */ if (nh_flags & NHF_BLACKHOLE) return (RTN_BLACKHOLE); else if (nh_flags & NHF_REJECT) return (RTN_PROHIBIT); return (RTN_UNICAST); } static uint8_t nl_get_rtm_protocol(const struct nhop_object *nh) { #ifdef ROUTE_MPATH if (NH_IS_NHGRP(nh)) { const struct nhgrp_object *nhg = (const struct nhgrp_object *)nh; uint8_t origin = nhgrp_get_origin(nhg); if (origin != RTPROT_UNSPEC) return (origin); nh = nhg->nhops[0]; } #endif uint8_t origin = nhop_get_origin(nh); if (origin != RTPROT_UNSPEC) return (origin); /* TODO: remove guesswork once all kernel users fill in origin */ int rt_flags = nhop_get_rtflags(nh); if (rt_flags & RTF_PROTO1) return (RTPROT_ZEBRA); if (rt_flags & RTF_STATIC) return (RTPROT_STATIC); return (RTPROT_KERNEL); } static int get_rtmsg_type_from_rtsock(int cmd) { switch (cmd) { case RTM_ADD: case RTM_CHANGE: case RTM_GET: return NL_RTM_NEWROUTE; case RTM_DELETE: return NL_RTM_DELROUTE; } return (0); } /* * fibnum heuristics * * if (dump && rtm_table == 0 && !rta_table) RT_ALL_FIBS * msg rtm_table RTA_TABLE result * RTM_GETROUTE/dump 0 - RT_ALL_FIBS * RTM_GETROUTE/dump 1 - 1 * RTM_GETROUTE/get 0 - 0 * */ static struct nhop_object * rc_get_nhop(const struct rib_cmd_info *rc) { return ((rc->rc_cmd == RTM_DELETE) ? rc->rc_nh_old : rc->rc_nh_new); } static void dump_rc_nhop_gw(struct nl_writer *nw, const struct nhop_object *nh) { #ifdef INET6 int upper_family; #endif switch (nhop_get_neigh_family(nh)) { case AF_LINK: /* onlink prefix, skip */ break; case AF_INET: nlattr_add(nw, NL_RTA_GATEWAY, 4, &nh->gw4_sa.sin_addr); break; #ifdef INET6 case AF_INET6: upper_family = nhop_get_upper_family(nh); if (upper_family == AF_INET6) { struct in6_addr gw6 = nh->gw6_sa.sin6_addr; in6_clearscope(&gw6); nlattr_add(nw, NL_RTA_GATEWAY, 16, &gw6); } else if (upper_family == AF_INET) { /* IPv4 over IPv6 */ struct in6_addr gw6 = nh->gw6_sa.sin6_addr; in6_clearscope(&gw6); char buf[20]; struct rtvia *via = (struct rtvia *)&buf[0]; via->rtvia_family = AF_INET6; memcpy(via->rtvia_addr, &gw6, 16); nlattr_add(nw, NL_RTA_VIA, 17, via); } break; #endif } } static void dump_rc_nhop_mtu(struct nl_writer *nw, const struct nhop_object *nh) { int nla_len = sizeof(struct nlattr) * 2 + sizeof(uint32_t); struct nlattr *nla = nlmsg_reserve_data(nw, nla_len, struct nlattr); if (nla == NULL) return; nla->nla_type = NL_RTA_METRICS; nla->nla_len = nla_len; nla++; nla->nla_type = NL_RTAX_MTU; nla->nla_len = sizeof(struct nlattr) + sizeof(uint32_t); *((uint32_t *)(nla + 1)) = nh->nh_mtu; } #ifdef ROUTE_MPATH static void dump_rc_nhg(struct nl_writer *nw, const struct nhgrp_object *nhg, struct rtmsg *rtm) { uint32_t uidx = nhgrp_get_uidx(nhg); uint32_t num_nhops; const struct weightened_nhop *wn = nhgrp_get_nhops(nhg, &num_nhops); uint32_t base_rtflags = nhop_get_rtflags(wn[0].nh); if (uidx != 0) nlattr_add_u32(nw, NL_RTA_NH_ID, uidx); nlattr_add_u32(nw, NL_RTA_KNH_ID, nhgrp_get_idx(nhg)); nlattr_add_u32(nw, NL_RTA_RTFLAGS, base_rtflags); int off = nlattr_add_nested(nw, NL_RTA_MULTIPATH); if (off == 0) return; for (int i = 0; i < num_nhops; i++) { int nh_off = nlattr_save_offset(nw); struct rtnexthop *rtnh = nlmsg_reserve_object(nw, struct rtnexthop); if (rtnh == NULL) return; rtnh->rtnh_flags = 0; rtnh->rtnh_ifindex = if_getindex(wn[i].nh->nh_ifp); rtnh->rtnh_hops = wn[i].weight; dump_rc_nhop_gw(nw, wn[i].nh); uint32_t rtflags = nhop_get_rtflags(wn[i].nh); if (rtflags != base_rtflags) nlattr_add_u32(nw, NL_RTA_RTFLAGS, rtflags); if (rtflags & RTF_FIXEDMTU) dump_rc_nhop_mtu(nw, wn[i].nh); rtnh = nlattr_restore_offset(nw, nh_off, struct rtnexthop); /* * nlattr_add() allocates 4-byte aligned storage, no need to aligh * length here * */ rtnh->rtnh_len = nlattr_save_offset(nw) - nh_off; } nlattr_set_len(nw, off); } #endif static void dump_rc_nhop(struct nl_writer *nw, const struct route_nhop_data *rnd, struct rtmsg *rtm) { #ifdef ROUTE_MPATH if (NH_IS_NHGRP(rnd->rnd_nhop)) { dump_rc_nhg(nw, rnd->rnd_nhgrp, rtm); return; } #endif const struct nhop_object *nh = rnd->rnd_nhop; uint32_t rtflags = nhop_get_rtflags(nh); /* * IPv4 over IPv6 * ('RTA_VIA', {'family': 10, 'addr': 'fe80::20c:29ff:fe67:2dd'}), ('RTA_OIF', 2), * IPv4 w/ gw * ('RTA_GATEWAY', '172.16.107.131'), ('RTA_OIF', 2)], * Direct route: * ('RTA_OIF', 2) */ if (nh->nh_flags & NHF_GATEWAY) dump_rc_nhop_gw(nw, nh); uint32_t uidx = nhop_get_uidx(nh); if (uidx != 0) nlattr_add_u32(nw, NL_RTA_NH_ID, uidx); nlattr_add_u32(nw, NL_RTA_KNH_ID, nhop_get_idx(nh)); nlattr_add_u32(nw, NL_RTA_RTFLAGS, rtflags); if (rtflags & RTF_FIXEDMTU) dump_rc_nhop_mtu(nw, nh); uint32_t nh_expire = nhop_get_expire(nh); if (nh_expire > 0) nlattr_add_u32(nw, NL_RTA_EXPIRES, nh_expire - time_uptime); /* In any case, fill outgoing interface */ nlattr_add_u32(nw, NL_RTA_OIF, if_getindex(nh->nh_ifp)); if (rnd->rnd_weight != RT_DEFAULT_WEIGHT) nlattr_add_u32(nw, NL_RTA_WEIGHT, rnd->rnd_weight); } /* * Dumps output from a rib command into an rtmsg */ static int dump_px(uint32_t fibnum, const struct nlmsghdr *hdr, const struct rtentry *rt, struct route_nhop_data *rnd, struct nl_writer *nw) { struct rtmsg *rtm; int error = 0; NET_EPOCH_ASSERT(); if (!nlmsg_reply(nw, hdr, sizeof(struct rtmsg))) goto enomem; int family = rt_get_family(rt); int rtm_off = nlattr_save_offset(nw); rtm = nlmsg_reserve_object(nw, struct rtmsg); rtm->rtm_family = family; rtm->rtm_dst_len = 0; rtm->rtm_src_len = 0; rtm->rtm_tos = 0; if (fibnum < 255) rtm->rtm_table = (unsigned char)fibnum; rtm->rtm_scope = RT_SCOPE_UNIVERSE; rtm->rtm_protocol = nl_get_rtm_protocol(rnd->rnd_nhop); rtm->rtm_type = get_rtm_type(rnd->rnd_nhop); nlattr_add_u32(nw, NL_RTA_TABLE, fibnum); int plen = 0; #if defined(INET) || defined(INET6) uint32_t scopeid; #endif switch (family) { #ifdef INET case AF_INET: { struct in_addr addr; rt_get_inet_prefix_plen(rt, &addr, &plen, &scopeid); nlattr_add(nw, NL_RTA_DST, 4, &addr); break; } #endif #ifdef INET6 case AF_INET6: { struct in6_addr addr; rt_get_inet6_prefix_plen(rt, &addr, &plen, &scopeid); nlattr_add(nw, NL_RTA_DST, 16, &addr); break; } #endif default: FIB_LOG(LOG_NOTICE, fibnum, family, "unsupported rt family: %d", family); error = EAFNOSUPPORT; goto flush; } rtm = nlattr_restore_offset(nw, rtm_off, struct rtmsg); if (plen > 0) rtm->rtm_dst_len = plen; dump_rc_nhop(nw, rnd, rtm); if (nlmsg_end(nw)) return (0); enomem: error = ENOMEM; flush: nlmsg_abort(nw); return (error); } static int family_to_group(int family) { switch (family) { case AF_INET: return (RTNLGRP_IPV4_ROUTE); case AF_INET6: return (RTNLGRP_IPV6_ROUTE); } return (0); } static void report_operation(uint32_t fibnum, struct rib_cmd_info *rc, struct nlpcb *nlp, struct nlmsghdr *hdr) { struct nl_writer nw; uint32_t group_id = family_to_group(rt_get_family(rc->rc_rt)); if (nl_writer_group(&nw, NLMSG_SMALL, NETLINK_ROUTE, group_id, false)) { struct route_nhop_data rnd = { .rnd_nhop = rc_get_nhop(rc), .rnd_weight = rc->rc_nh_weight, }; hdr->nlmsg_flags &= ~(NLM_F_REPLACE | NLM_F_CREATE); hdr->nlmsg_flags &= ~(NLM_F_EXCL | NLM_F_APPEND); switch (rc->rc_cmd) { case RTM_ADD: hdr->nlmsg_type = NL_RTM_NEWROUTE; hdr->nlmsg_flags |= NLM_F_CREATE | NLM_F_EXCL; break; case RTM_CHANGE: hdr->nlmsg_type = NL_RTM_NEWROUTE; hdr->nlmsg_flags |= NLM_F_REPLACE; break; case RTM_DELETE: hdr->nlmsg_type = NL_RTM_DELROUTE; break; } dump_px(fibnum, hdr, rc->rc_rt, &rnd, &nw); nlmsg_flush(&nw); } rtsock_callback_p->route_f(fibnum, rc); } static void set_scope6(struct sockaddr *sa, struct ifnet *ifp) { #ifdef INET6 if (sa != NULL && sa->sa_family == AF_INET6 && ifp != NULL) { struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr)) in6_set_unicast_scopeid(&sa6->sin6_addr, if_getindex(ifp)); } #endif } struct rta_mpath_nh { struct sockaddr *gw; struct ifnet *ifp; uint8_t rtnh_flags; uint8_t rtnh_weight; }; #define _IN(_field) offsetof(struct rtnexthop, _field) #define _OUT(_field) offsetof(struct rta_mpath_nh, _field) const static struct nlattr_parser nla_p_rtnh[] = { { .type = NL_RTA_GATEWAY, .off = _OUT(gw), .cb = nlattr_get_ip }, { .type = NL_RTA_VIA, .off = _OUT(gw), .cb = nlattr_get_ipvia }, }; const static struct nlfield_parser nlf_p_rtnh[] = { { .off_in = _IN(rtnh_flags), .off_out = _OUT(rtnh_flags), .cb = nlf_get_u8 }, { .off_in = _IN(rtnh_hops), .off_out = _OUT(rtnh_weight), .cb = nlf_get_u8 }, { .off_in = _IN(rtnh_ifindex), .off_out = _OUT(ifp), .cb = nlf_get_ifpz }, }; #undef _IN #undef _OUT static bool post_p_rtnh(void *_attrs, struct nl_pstate *npt __unused) { struct rta_mpath_nh *attrs = (struct rta_mpath_nh *)_attrs; set_scope6(attrs->gw, attrs->ifp); return (true); } NL_DECLARE_PARSER_EXT(mpath_parser, struct rtnexthop, NULL, nlf_p_rtnh, nla_p_rtnh, post_p_rtnh); struct rta_mpath { int num_nhops; struct rta_mpath_nh nhops[0]; }; static int nlattr_get_multipath(struct nlattr *nla, struct nl_pstate *npt, const void *arg, void *target) { int data_len = nla->nla_len - sizeof(struct nlattr); struct rtnexthop *rtnh; int max_nhops = data_len / sizeof(struct rtnexthop); struct rta_mpath *mp = npt_alloc(npt, (max_nhops + 2) * sizeof(struct rta_mpath_nh)); mp->num_nhops = 0; for (rtnh = (struct rtnexthop *)(nla + 1); data_len > 0; ) { struct rta_mpath_nh *mpnh = &mp->nhops[mp->num_nhops++]; int error = nl_parse_header(rtnh, rtnh->rtnh_len, &mpath_parser, npt, mpnh); if (error != 0) { NLMSG_REPORT_ERR_MSG(npt, "RTA_MULTIPATH: nexhop %d: parse failed", mp->num_nhops - 1); return (error); } int len = NL_ITEM_ALIGN(rtnh->rtnh_len); data_len -= len; rtnh = (struct rtnexthop *)((char *)rtnh + len); } if (data_len != 0 || mp->num_nhops == 0) { NLMSG_REPORT_ERR_MSG(npt, "invalid RTA_MULTIPATH attr"); return (EINVAL); } *((struct rta_mpath **)target) = mp; return (0); } struct nl_parsed_route { struct sockaddr *rta_dst; struct sockaddr *rta_gw; struct ifnet *rta_oif; struct rta_mpath *rta_multipath; uint32_t rta_table; uint32_t rta_rtflags; uint32_t rta_nh_id; uint32_t rta_weight; uint32_t rtax_mtu; uint8_t rtm_table; uint8_t rtm_family; uint8_t rtm_dst_len; uint8_t rtm_protocol; uint8_t rtm_type; uint32_t rtm_flags; }; #define _IN(_field) offsetof(struct rtmsg, _field) #define _OUT(_field) offsetof(struct nl_parsed_route, _field) static struct nlattr_parser nla_p_rtmetrics[] = { { .type = NL_RTAX_MTU, .off = _OUT(rtax_mtu), .cb = nlattr_get_uint32 }, }; NL_DECLARE_ATTR_PARSER(metrics_parser, nla_p_rtmetrics); static const struct nlattr_parser nla_p_rtmsg[] = { { .type = NL_RTA_DST, .off = _OUT(rta_dst), .cb = nlattr_get_ip }, { .type = NL_RTA_OIF, .off = _OUT(rta_oif), .cb = nlattr_get_ifp }, { .type = NL_RTA_GATEWAY, .off = _OUT(rta_gw), .cb = nlattr_get_ip }, { .type = NL_RTA_METRICS, .arg = &metrics_parser, .cb = nlattr_get_nested }, { .type = NL_RTA_MULTIPATH, .off = _OUT(rta_multipath), .cb = nlattr_get_multipath }, { .type = NL_RTA_WEIGHT, .off = _OUT(rta_weight), .cb = nlattr_get_uint32 }, { .type = NL_RTA_RTFLAGS, .off = _OUT(rta_rtflags), .cb = nlattr_get_uint32 }, { .type = NL_RTA_TABLE, .off = _OUT(rta_table), .cb = nlattr_get_uint32 }, { .type = NL_RTA_VIA, .off = _OUT(rta_gw), .cb = nlattr_get_ipvia }, { .type = NL_RTA_NH_ID, .off = _OUT(rta_nh_id), .cb = nlattr_get_uint32 }, }; static const struct nlfield_parser nlf_p_rtmsg[] = { { .off_in = _IN(rtm_family), .off_out = _OUT(rtm_family), .cb = nlf_get_u8 }, { .off_in = _IN(rtm_dst_len), .off_out = _OUT(rtm_dst_len), .cb = nlf_get_u8 }, { .off_in = _IN(rtm_protocol), .off_out = _OUT(rtm_protocol), .cb = nlf_get_u8 }, { .off_in = _IN(rtm_type), .off_out = _OUT(rtm_type), .cb = nlf_get_u8 }, { .off_in = _IN(rtm_table), .off_out = _OUT(rtm_table), .cb = nlf_get_u8 }, { .off_in = _IN(rtm_flags), .off_out = _OUT(rtm_flags), .cb = nlf_get_u32 }, }; #undef _IN #undef _OUT static bool post_p_rtmsg(void *_attrs, struct nl_pstate *npt __unused) { struct nl_parsed_route *attrs = (struct nl_parsed_route *)_attrs; set_scope6(attrs->rta_dst, attrs->rta_oif); set_scope6(attrs->rta_gw, attrs->rta_oif); return (true); } NL_DECLARE_PARSER_EXT(rtm_parser, struct rtmsg, NULL, nlf_p_rtmsg, nla_p_rtmsg, post_p_rtmsg); struct netlink_walkargs { struct nl_writer *nw; struct route_nhop_data rnd; struct nlmsghdr hdr; struct nlpcb *nlp; uint32_t fibnum; int family; int error; int count; int dumped; int dumped_tables; }; static int dump_rtentry(struct rtentry *rt, void *_arg) { struct netlink_walkargs *wa = (struct netlink_walkargs *)_arg; int error; wa->count++; if (wa->error != 0) return (0); if (!rt_is_exportable(rt, nlp_get_cred(wa->nlp))) return (0); wa->dumped++; rt_get_rnd(rt, &wa->rnd); error = dump_px(wa->fibnum, &wa->hdr, rt, &wa->rnd, wa->nw); IF_DEBUG_LEVEL(LOG_DEBUG3) { char rtbuf[INET6_ADDRSTRLEN + 5]; FIB_LOG(LOG_DEBUG3, wa->fibnum, wa->family, "Dump %s, error %d", rt_print_buf(rt, rtbuf, sizeof(rtbuf)), error); } wa->error = error; return (0); } static void dump_rtable_one(struct netlink_walkargs *wa, uint32_t fibnum, int family) { FIB_LOG(LOG_DEBUG2, fibnum, family, "Start dump"); wa->count = 0; wa->dumped = 0; rib_walk(fibnum, family, false, dump_rtentry, wa); wa->dumped_tables++; FIB_LOG(LOG_DEBUG2, fibnum, family, "End dump, iterated %d dumped %d", wa->count, wa->dumped); } static int dump_rtable_fib(struct netlink_walkargs *wa, uint32_t fibnum, int family) { wa->fibnum = fibnum; if (family == AF_UNSPEC) { for (int i = 0; i < AF_MAX; i++) { if (rt_tables_get_rnh(fibnum, i) != 0) { wa->family = i; dump_rtable_one(wa, fibnum, i); if (wa->error != 0) break; } } } else { if (rt_tables_get_rnh(fibnum, family) != 0) { wa->family = family; dump_rtable_one(wa, fibnum, family); } } return (wa->error); } static int handle_rtm_getroute(struct nlpcb *nlp, struct nl_parsed_route *attrs, struct nlmsghdr *hdr, struct nl_pstate *npt) { RIB_RLOCK_TRACKER; struct rib_head *rnh; const struct rtentry *rt; struct route_nhop_data rnd; uint32_t fibnum = attrs->rta_table; sa_family_t family = attrs->rtm_family; if (attrs->rta_dst == NULL) { NLMSG_REPORT_ERR_MSG(npt, "No RTA_DST supplied"); return (EINVAL); } rnh = rt_tables_get_rnh(fibnum, family); if (rnh == NULL) return (EAFNOSUPPORT); RIB_RLOCK(rnh); struct sockaddr *dst = attrs->rta_dst; if (attrs->rtm_flags & RTM_F_PREFIX) rt = rib_lookup_prefix_plen(rnh, dst, attrs->rtm_dst_len, &rnd); else rt = (const struct rtentry *)rnh->rnh_matchaddr(dst, &rnh->head); if (rt == NULL) { RIB_RUNLOCK(rnh); return (ESRCH); } rt_get_rnd(rt, &rnd); rnd.rnd_nhop = nhop_select_func(rnd.rnd_nhop, 0); RIB_RUNLOCK(rnh); if (!rt_is_exportable(rt, nlp_get_cred(nlp))) return (ESRCH); IF_DEBUG_LEVEL(LOG_DEBUG2) { char rtbuf[NHOP_PRINT_BUFSIZE] __unused, nhbuf[NHOP_PRINT_BUFSIZE] __unused; FIB_LOG(LOG_DEBUG2, fibnum, family, "getroute completed: got %s for %s", nhop_print_buf_any(rnd.rnd_nhop, nhbuf, sizeof(nhbuf)), rt_print_buf(rt, rtbuf, sizeof(rtbuf))); } hdr->nlmsg_type = NL_RTM_NEWROUTE; dump_px(fibnum, hdr, rt, &rnd, npt->nw); return (0); } static int handle_rtm_dump(struct nlpcb *nlp, uint32_t fibnum, int family, struct nlmsghdr *hdr, struct nl_writer *nw) { struct netlink_walkargs wa = { .nlp = nlp, .nw = nw, .hdr.nlmsg_pid = hdr->nlmsg_pid, .hdr.nlmsg_seq = hdr->nlmsg_seq, .hdr.nlmsg_type = NL_RTM_NEWROUTE, .hdr.nlmsg_flags = hdr->nlmsg_flags | NLM_F_MULTI, }; if (fibnum == RT_TABLE_UNSPEC) { for (int i = 0; i < V_rt_numfibs; i++) { dump_rtable_fib(&wa, fibnum, family); if (wa.error != 0) break; } } else dump_rtable_fib(&wa, fibnum, family); if (wa.error == 0 && wa.dumped_tables == 0) { FIB_LOG(LOG_DEBUG, fibnum, family, "incorrect fibnum/family"); wa.error = ESRCH; // How do we propagate it? } if (!nlmsg_end_dump(wa.nw, wa.error, &wa.hdr)) { NL_LOG(LOG_DEBUG, "Unable to finalize the dump"); return (ENOMEM); } return (wa.error); } static struct nhop_object * finalize_nhop(struct nhop_object *nh, const struct sockaddr *dst, int *perror) { /* * The following MUST be filled: * nh_ifp, nh_ifa, nh_gw */ if (nh->gw_sa.sa_family == 0) { /* * Empty gateway. Can be direct route with RTA_OIF set. */ if (nh->nh_ifp != NULL) nhop_set_direct_gw(nh, nh->nh_ifp); else { NL_LOG(LOG_DEBUG, "empty gateway and interface, skipping"); *perror = EINVAL; return (NULL); } /* Both nh_ifp and gateway are set */ } else { /* Gateway is set up, we can derive ifp if not set */ if (nh->nh_ifp == NULL) { uint32_t fibnum = nhop_get_fibnum(nh); uint32_t flags = 0; if (nh->nh_flags & NHF_GATEWAY) flags = RTF_GATEWAY; else if (nh->nh_flags & NHF_HOST) flags = RTF_HOST; struct ifaddr *ifa = ifa_ifwithroute(flags, dst, &nh->gw_sa, fibnum); if (ifa == NULL) { NL_LOG(LOG_DEBUG, "Unable to determine ifp, skipping"); *perror = EINVAL; return (NULL); } nhop_set_transmit_ifp(nh, ifa->ifa_ifp); } } /* Both nh_ifp and gateway are set */ if (nh->nh_ifa == NULL) { const struct sockaddr *gw_sa = &nh->gw_sa; if (gw_sa->sa_family != dst->sa_family) { /* * Use dst as the target for determining the default * preferred ifa IF * 1) the gateway is link-level (e.g. direct route) * 2) the gateway family is different (e.g. IPv4 over IPv6). */ gw_sa = dst; } struct ifaddr *ifa = ifaof_ifpforaddr(gw_sa, nh->nh_ifp); if (ifa == NULL) { /* Try link-level ifa. */ gw_sa = &nh->gw_sa; ifa = ifaof_ifpforaddr(gw_sa, nh->nh_ifp); if (ifa == NULL) { NL_LOG(LOG_DEBUG, "Unable to determine ifa, skipping"); *perror = EINVAL; return (NULL); } } nhop_set_src(nh, ifa); } return (nhop_get_nhop(nh, perror)); } static int get_pxflag(const struct nl_parsed_route *attrs) { int pxflag = 0; switch (attrs->rtm_family) { case AF_INET: if (attrs->rtm_dst_len == 32) pxflag = NHF_HOST; else if (attrs->rtm_dst_len == 0) pxflag = NHF_DEFAULT; break; case AF_INET6: if (attrs->rtm_dst_len == 128) pxflag = NHF_HOST; else if (attrs->rtm_dst_len == 0) pxflag = NHF_DEFAULT; break; } return (pxflag); } static int get_op_flags(int nlm_flags) { int op_flags = 0; op_flags |= (nlm_flags & NLM_F_REPLACE) ? RTM_F_REPLACE : 0; op_flags |= (nlm_flags & NLM_F_EXCL) ? RTM_F_EXCL : 0; op_flags |= (nlm_flags & NLM_F_CREATE) ? RTM_F_CREATE : 0; op_flags |= (nlm_flags & NLM_F_APPEND) ? RTM_F_APPEND : 0; return (op_flags); } #ifdef ROUTE_MPATH static int create_nexthop_one(struct nl_parsed_route *attrs, struct rta_mpath_nh *mpnh, struct nl_pstate *npt, struct nhop_object **pnh) { int error; if (mpnh->gw == NULL) return (EINVAL); struct nhop_object *nh = nhop_alloc(attrs->rta_table, attrs->rtm_family); if (nh == NULL) return (ENOMEM); error = nl_set_nexthop_gw(nh, mpnh->gw, mpnh->ifp, npt); if (error != 0) { nhop_free(nh); return (error); } if (mpnh->ifp != NULL) nhop_set_transmit_ifp(nh, mpnh->ifp); nhop_set_pxtype_flag(nh, get_pxflag(attrs)); nhop_set_rtflags(nh, attrs->rta_rtflags); if (attrs->rtm_protocol > RTPROT_STATIC) nhop_set_origin(nh, attrs->rtm_protocol); *pnh = finalize_nhop(nh, attrs->rta_dst, &error); return (error); } #endif static struct nhop_object * create_nexthop_from_attrs(struct nl_parsed_route *attrs, struct nl_pstate *npt, int *perror) { struct nhop_object *nh = NULL; int error = 0; if (attrs->rta_multipath != NULL) { #ifdef ROUTE_MPATH /* Multipath w/o explicit nexthops */ int num_nhops = attrs->rta_multipath->num_nhops; struct weightened_nhop *wn = npt_alloc(npt, sizeof(*wn) * num_nhops); for (int i = 0; i < num_nhops; i++) { struct rta_mpath_nh *mpnh = &attrs->rta_multipath->nhops[i]; error = create_nexthop_one(attrs, mpnh, npt, &wn[i].nh); if (error != 0) { for (int j = 0; j < i; j++) nhop_free(wn[j].nh); break; } wn[i].weight = mpnh->rtnh_weight > 0 ? mpnh->rtnh_weight : 1; } if (error == 0) { struct rib_head *rh = nhop_get_rh(wn[0].nh); struct nhgrp_object *nhg; nhg = nhgrp_alloc(rh->rib_fibnum, rh->rib_family, wn, num_nhops, perror); if (nhg != NULL) { if (attrs->rtm_protocol > RTPROT_STATIC) nhgrp_set_origin(nhg, attrs->rtm_protocol); nhg = nhgrp_get_nhgrp(nhg, perror); } for (int i = 0; i < num_nhops; i++) nhop_free(wn[i].nh); if (nhg != NULL) return ((struct nhop_object *)nhg); error = *perror; } #else error = ENOTSUP; #endif *perror = error; } else { nh = nhop_alloc(attrs->rta_table, attrs->rtm_family); if (nh == NULL) { *perror = ENOMEM; return (NULL); } if (attrs->rta_gw != NULL) { *perror = nl_set_nexthop_gw(nh, attrs->rta_gw, attrs->rta_oif, npt); if (*perror != 0) { nhop_free(nh); return (NULL); } } if (attrs->rta_oif != NULL) nhop_set_transmit_ifp(nh, attrs->rta_oif); if (attrs->rtax_mtu != 0) nhop_set_mtu(nh, attrs->rtax_mtu, true); if (attrs->rta_rtflags & RTF_BROADCAST) nhop_set_broadcast(nh, true); if (attrs->rtm_protocol > RTPROT_STATIC) nhop_set_origin(nh, attrs->rtm_protocol); nhop_set_pxtype_flag(nh, get_pxflag(attrs)); nhop_set_rtflags(nh, attrs->rta_rtflags); switch (attrs->rtm_type) { case RTN_UNICAST: break; case RTN_BLACKHOLE: nhop_set_blackhole(nh, RTF_BLACKHOLE); break; case RTN_PROHIBIT: case RTN_UNREACHABLE: nhop_set_blackhole(nh, RTF_REJECT); break; /* TODO: return ENOTSUP for other types if strict option is set */ } nh = finalize_nhop(nh, attrs->rta_dst, perror); } return (nh); } static int rtnl_handle_newroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt) { struct rib_cmd_info rc = {}; struct nhop_object *nh = NULL; int error; struct nl_parsed_route attrs = {}; error = nl_parse_nlmsg(hdr, &rtm_parser, npt, &attrs); if (error != 0) return (error); /* Check if we have enough data */ if (attrs.rta_dst == NULL) { NL_LOG(LOG_DEBUG, "missing RTA_DST"); return (EINVAL); } if (attrs.rtm_table > 0 && attrs.rta_table == 0) { /* pre-2.6.19 Linux API compatibility */ attrs.rta_table = attrs.rtm_table; } else if (attrs.rta_table >= V_rt_numfibs) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL); } if (attrs.rta_nh_id != 0) { /* Referenced uindex */ int pxflag = get_pxflag(&attrs); nh = nl_find_nhop(attrs.rta_table, attrs.rtm_family, attrs.rta_nh_id, pxflag, &error); if (error != 0) return (error); } else { nh = create_nexthop_from_attrs(&attrs, npt, &error); if (error != 0) { NL_LOG(LOG_DEBUG, "Error creating nexthop"); return (error); } } if (!NH_IS_NHGRP(nh) && attrs.rta_weight == 0) attrs.rta_weight = RT_DEFAULT_WEIGHT; struct route_nhop_data rnd = { .rnd_nhop = nh, .rnd_weight = attrs.rta_weight }; int op_flags = get_op_flags(hdr->nlmsg_flags); error = rib_add_route_px(attrs.rta_table, attrs.rta_dst, attrs.rtm_dst_len, &rnd, op_flags, &rc); if (error == 0) report_operation(attrs.rta_table, &rc, nlp, hdr); return (error); } static int path_match_func(const struct rtentry *rt, const struct nhop_object *nh, void *_data) { struct nl_parsed_route *attrs = (struct nl_parsed_route *)_data; if ((attrs->rta_gw != NULL) && !rib_match_gw(rt, nh, attrs->rta_gw)) return (0); if ((attrs->rta_oif != NULL) && (attrs->rta_oif != nh->nh_ifp)) return (0); return (1); } static int rtnl_handle_delroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt) { struct rib_cmd_info rc; int error; struct nl_parsed_route attrs = {}; error = nl_parse_nlmsg(hdr, &rtm_parser, npt, &attrs); if (error != 0) return (error); if (attrs.rta_dst == NULL) { NLMSG_REPORT_ERR_MSG(npt, "RTA_DST is not set"); return (ESRCH); } if (attrs.rta_table >= V_rt_numfibs) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL); } error = rib_del_route_px(attrs.rta_table, attrs.rta_dst, attrs.rtm_dst_len, path_match_func, &attrs, 0, &rc); if (error == 0) report_operation(attrs.rta_table, &rc, nlp, hdr); return (error); } static int rtnl_handle_getroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *npt) { int error; struct nl_parsed_route attrs = {}; error = nl_parse_nlmsg(hdr, &rtm_parser, npt, &attrs); if (error != 0) return (error); if (attrs.rta_table >= V_rt_numfibs) { NLMSG_REPORT_ERR_MSG(npt, "invalid fib"); return (EINVAL); } if (hdr->nlmsg_flags & NLM_F_DUMP) error = handle_rtm_dump(nlp, attrs.rta_table, attrs.rtm_family, hdr, npt->nw); else error = handle_rtm_getroute(nlp, &attrs, hdr, npt); return (error); } void rtnl_handle_route_event(uint32_t fibnum, const struct rib_cmd_info *rc) { struct nl_writer nw; int family, nlm_flags = 0; family = rt_get_family(rc->rc_rt); /* XXX: check if there are active listeners first */ /* TODO: consider passing PID/type/seq */ switch (rc->rc_cmd) { case RTM_ADD: nlm_flags = NLM_F_EXCL | NLM_F_CREATE; break; case RTM_CHANGE: nlm_flags = NLM_F_REPLACE; break; case RTM_DELETE: nlm_flags = 0; break; } IF_DEBUG_LEVEL(LOG_DEBUG2) { char rtbuf[NHOP_PRINT_BUFSIZE] __unused; FIB_LOG(LOG_DEBUG2, fibnum, family, "received event %s for %s / nlm_flags=%X", rib_print_cmd(rc->rc_cmd), rt_print_buf(rc->rc_rt, rtbuf, sizeof(rtbuf)), nlm_flags); } struct nlmsghdr hdr = { .nlmsg_flags = nlm_flags, .nlmsg_type = get_rtmsg_type_from_rtsock(rc->rc_cmd), }; struct route_nhop_data rnd = { .rnd_nhop = rc_get_nhop(rc), .rnd_weight = rc->rc_nh_weight, }; uint32_t group_id = family_to_group(family); if (!nl_writer_group(&nw, NLMSG_SMALL, NETLINK_ROUTE, group_id, false)) { NL_LOG(LOG_DEBUG, "error allocating event buffer"); return; } dump_px(fibnum, &hdr, rc->rc_rt, &rnd, &nw); nlmsg_flush(&nw); } static const struct rtnl_cmd_handler cmd_handlers[] = { { .cmd = NL_RTM_GETROUTE, .name = "RTM_GETROUTE", .cb = &rtnl_handle_getroute, .flags = RTNL_F_ALLOW_NONVNET_JAIL, }, { .cmd = NL_RTM_DELROUTE, .name = "RTM_DELROUTE", .cb = &rtnl_handle_delroute, .priv = PRIV_NET_ROUTE, }, { .cmd = NL_RTM_NEWROUTE, .name = "RTM_NEWROUTE", .cb = &rtnl_handle_newroute, .priv = PRIV_NET_ROUTE, } }; static const struct nlhdr_parser *all_parsers[] = {&mpath_parser, &metrics_parser, &rtm_parser}; void rtnl_routes_init(void) { NL_VERIFY_PARSERS(all_parsers); rtnl_register_messages(cmd_handlers, nitems(cmd_handlers)); }