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sys/netlink/route/neigh.c

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/types.h>
#include <sys/malloc.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_llatbl.h>
#include <netlink/netlink.h>
#include <netlink/netlink_ctl.h>
#include <netlink/netlink_route.h>
#include <netlink/route/route_var.h>
#include <netinet6/in6_var.h> /* nd6.h requires this */
#include <netinet6/nd6.h> /* nd6 state machine */
#include <netinet6/scope6_var.h> /* scope deembedding */
#define DEBUG_MOD_NAME nl_neigh
#define DEBUG_MAX_LEVEL LOG_DEBUG3
#include <netlink/netlink_debug.h>
_DECLARE_DEBUG(LOG_DEBUG);
static int lle_families[] = { AF_INET, AF_INET6 };
static eventhandler_tag lle_event_p;
struct netlink_walkargs {
struct nlmsg_state *ns;
struct nlmsghdr hdr;
struct nlpcb *so;
struct ifnet *ifp;
int family;
int error;
int count;
int dumped;
};
static int
lle_state_to_nl_state(int family, struct llentry *lle)
{
int state = lle->ln_state;
switch (family) {
case AF_INET:
if (lle->la_flags & (LLE_STATIC | LLE_IFADDR))
state = 1;
switch (state) {
case 0: /* ARP_LLINFO_INCOMPLETE */
return (NUD_INCOMPLETE);
case 1: /* ARP_LLINFO_REACHABLE */
return (NUD_REACHABLE);
case 2: /* ARP_LLINFO_VERIFY */
return (NUD_PROBE);
}
break;
case AF_INET6:
switch (state) {
case ND6_LLINFO_INCOMPLETE:
return (NUD_INCOMPLETE);
case ND6_LLINFO_REACHABLE:
return (NUD_REACHABLE);
case ND6_LLINFO_STALE:
return (NUD_STALE);
case ND6_LLINFO_DELAY:
return (NUD_DELAY);
case ND6_LLINFO_PROBE:
return (NUD_PROBE);
}
break;
}
return (NUD_NONE);
}
static uint32_t
lle_flags_to_nl_flags(const struct llentry *lle)
{
uint32_t nl_flags = 0;
if (lle->la_flags & LLE_IFADDR)
nl_flags |= NTF_SELF;
if (lle->la_flags & LLE_PUB)
nl_flags |= NTF_PROXY;
if (lle->la_flags & LLE_STATIC)
nl_flags |= NTF_STICKY;
if (lle->ln_router != 0)
nl_flags |= NTF_ROUTER;
return (nl_flags);
}
static int
dump_lle_locked(struct lltable *llt, struct llentry *lle, void *arg)
{
struct netlink_walkargs *wa = (struct netlink_walkargs *)arg;
struct nlmsghdr *hdr = &wa->hdr;
struct nlmsg_state *ns = wa->ns;
struct ndmsg *ndm;
union {
struct in_addr in;
struct in6_addr in6;
} addr;
IF_DEBUG_LEVEL(LOG_DEBUG2) {
char llebuf[NHOP_PRINT_BUFSIZE];
llentry_print_buf_lltable(lle, llebuf, sizeof(llebuf));
NL_LOG(LOG_DEBUG2, "dumping %s", llebuf);
}
if (!nlmsg_reply(ns, hdr, sizeof(struct ndmsg)))
goto enomem;
ndm = nlmsg_reserve_object(ns, struct ndmsg);
ndm->ndm_family = wa->family;
ndm->ndm_ifindex = wa->ifp->if_index;
ndm->ndm_state = lle_state_to_nl_state(wa->family, lle);
ndm->ndm_flags = lle_flags_to_nl_flags(lle);
switch (wa->family) {
#ifdef INET
case AF_INET:
addr.in = lle->r_l3addr.addr4;
nlattr_add(ns, NDA_DST, 4, &addr);
break;
#endif
#ifdef INET6
case AF_INET6:
addr.in6 = lle->r_l3addr.addr6;
in6_clearscope(&addr.in6);
nlattr_add(ns, NDA_DST, 16, &addr);
break;
#endif
}
if (lle->r_flags & RLLE_VALID) {
/* Has L2 */
int addrlen = wa->ifp->if_addrlen;
nlattr_add(ns, NDA_LLADDR, addrlen, lle->ll_addr);
}
nlattr_add_u32(ns, NDA_PROBES, lle->la_asked);
struct nda_cacheinfo *cache;
cache = nlmsg_reserve_attr(ns, NDA_CACHEINFO, struct nda_cacheinfo);
if (cache == NULL)
goto enomem;
/* TODO: provide confirmed/updated */
cache->ndm_refcnt = lle->lle_refcnt;
if (nlmsg_end(ns))
return (0);
enomem:
NL_LOG(LOG_DEBUG, "unable to dump lle state (ENOMEM)");
nlmsg_abort(ns);
return (ENOMEM);
}
static int
dump_lle(struct lltable *llt, struct llentry *lle, void *arg)
{
int error;
LLE_RLOCK(lle);
error = dump_lle_locked(llt, lle, arg);
LLE_RUNLOCK(lle);
return (error);
}
static bool
dump_llt(struct lltable *llt, struct netlink_walkargs *wa)
{
lltable_foreach_lle(llt, dump_lle, wa);
return (true);
}
static int
dump_llts_iface(struct netlink_walkargs *wa, struct ifnet *ifp, int family)
{
int error = 0;
wa->ifp = ifp;
for (int i = 0; i < sizeof(lle_families) / sizeof(int); i++) {
int fam = lle_families[i];
struct lltable *llt = lltable_get(ifp, fam);
if (llt != NULL && (family == 0 || family == fam)) {
wa->count++;
wa->family = fam;
if (!dump_llt(llt, wa)) {
error = ENOMEM;
break;
}
wa->dumped++;
}
}
return (error);
}
static int
dump_llts(struct netlink_walkargs *wa, struct ifnet *ifp, int family)
{
NL_LOG(LOG_DEBUG, "Start dump ifp=%s family=%d", ifp ? if_name(ifp) : "NULL", family);
wa->hdr.nlmsg_flags |= NLM_F_MULTI;
if (ifp != NULL) {
dump_llts_iface(wa, ifp, family);
} else {
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
dump_llts_iface(wa, ifp, family);
}
}
NL_LOG(LOG_DEBUG, "End dump, iterated %d dumped %d", wa->count, wa->dumped);
if (!nlmsg_end_dump(wa->ns, wa->error, &wa->hdr)) {
NL_LOG(LOG_DEBUG, "Unable to add new message");
return (ENOMEM);
}
return (0);
}
static int
get_lle(struct netlink_walkargs *wa, struct ifnet *ifp, int family, struct sockaddr *dst)
{
struct lltable *llt = lltable_get(ifp, family);
if (llt == NULL)
return (ESRCH);
#ifdef INET6
if (dst->sa_family == AF_INET6) {
struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
if (IN6_IS_SCOPE_LINKLOCAL(&dst6->sin6_addr))
in6_set_unicast_scopeid(&dst6->sin6_addr, ifp->if_index);
}
#endif
struct llentry *lle = lla_lookup(llt, LLE_UNLOCKED, dst);
if (lle == NULL)
return (ESRCH);
wa->ifp = ifp;
wa->family = family;
return (dump_lle(llt, lle, wa));
}
struct nl_parsed_neigh {
struct sockaddr *nda_dst;
struct ifnet *nda_ifp;
struct nlattr *nda_lladdr;
uint32_t ndm_flags;
uint16_t ndm_state;
uint8_t ndm_family;
};
#define _OFF_S(_field) offsetof(struct nl_parsed_neigh, _field)
static struct nlattr_parser ps[] = {
{ .type = NDA_DST, .off = _OFF_S(nda_dst), .cb = nlattr_get_ip },
{ .type = NDA_LLADDR, .off = _OFF_S(nda_lladdr), .cb = nlattr_get_nla },
{ .type = NDA_IFINDEX, .off = _OFF_S(nda_ifp), .cb = nlattr_get_ifp },
{ .type = NDA_FLAGS_EXT, .off = _OFF_S(ndm_flags), .cb = nlattr_get_uint32 },
};
#undef _OFF_S
static int
nlf_get_u8_u32(void *src, struct netlink_parse_tracker *npt, void *target)
{
*((uint32_t *)target) = *((const uint8_t *)src);
return (0);
}
static int
nlf_get_u16(void *src, struct netlink_parse_tracker *npt, void *target)
{
*((uint16_t *)target) = *((const uint16_t *)src);
return (0);
}
#define _OFF_IN(_field) offsetof(struct ndmsg, _field)
#define _OFF_OUT(_field) offsetof(struct nl_parsed_neigh, _field)
static struct nlfield_parser fpneigh[] = {
{ .off_in = _OFF_IN(ndm_family), .off_out = _OFF_OUT(ndm_family), .cb = nlf_get_u8 },
{ .off_in = _OFF_IN(ndm_flags), .off_out = _OFF_OUT(ndm_flags), .cb = nlf_get_u8_u32 },
{ .off_in = _OFF_IN(ndm_state), .off_out = _OFF_OUT(ndm_state), .cb = nlf_get_u16 },
{ .off_in = _OFF_IN(ndm_ifindex), .off_out = _OFF_OUT(nda_ifp), .cb = nlf_get_ifpz },
};
#undef _OFF_IN
#undef _OFF_OUT
static struct nlhdr_parser ndmsg_parser = {
.hdr_off = sizeof(struct ndmsg),
.fp_size = sizeof(fpneigh) / sizeof(fpneigh[0]),
.np_size = sizeof(ps) / sizeof(ps[0]),
.fp = fpneigh,
.np = ps,
};
/*
* type=RTM_NEWNEIGH, flags=NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL|NLM_F_CREATE, seq=1661941473, pid=0},
* {ndm_family=AF_INET6, ndm_ifindex=if_nametoindex("enp0s31f6"), ndm_state=NUD_PERMANENT, ndm_flags=0, ndm_type=RTN_UNSPEC},
* [
* {{nla_len=20, nla_type=NDA_DST}, inet_pton(AF_INET6, "2a01:4f8:13a:70c::3")},
* {{nla_len=10, nla_type=NDA_LLADDR}, 20:4e:71:62:ae:f2}]}, iov_len=60}
*/
static int
rtnl_handle_newneigh(struct nlmsghdr *hdr, struct nlpcb *nlp, struct netlink_parse_tracker *npt)
{
int error;
error = nlp_has_priv_route(nlp);
if (error != 0)
return (error);
struct nl_parsed_neigh attrs = {};
error = nl_parse_nlmsg(hdr, &ndmsg_parser, npt, &attrs);
if (error != 0)
return (error);
if (attrs.nda_ifp == NULL || attrs.nda_dst == NULL || attrs.nda_lladdr == NULL) {
if (attrs.nda_ifp == NULL)
NLMSG_REPORT_ERR_MSG(npt, "NDA_IFINDEX / ndm_ifindex not set");
if (attrs.nda_dst == NULL)
NLMSG_REPORT_ERR_MSG(npt, "NDA_DST not set");
if (attrs.nda_lladdr == NULL)
NLMSG_REPORT_ERR_MSG(npt, "NDA_LLADDR not set");
return (EINVAL);
}
if (attrs.nda_dst->sa_family != attrs.ndm_family) {
NLMSG_REPORT_ERR_MSG(npt,
"NDA_DST family (%d) is different from ndm_family (%d)",
attrs.nda_dst->sa_family, attrs.ndm_family);
return (EINVAL);
}
int addrlen = attrs.nda_ifp->if_addrlen;
if (attrs.nda_lladdr->nla_len != sizeof(struct nlattr) + addrlen) {
NLMSG_REPORT_ERR_MSG(npt,
"NDA_LLADDR address length (%ld) is different from expected (%d)",
attrs.nda_lladdr->nla_len - sizeof(struct nlattr), addrlen);
return (EINVAL);
}
if (attrs.ndm_state != NUD_PERMANENT) {
NLMSG_REPORT_ERR_MSG(npt, "ndm_state %d not supported", attrs.ndm_state);
return (ENOTSUP);
}
const uint16_t supported_flags = NTF_PROXY | NTF_STICKY;
if ((attrs.ndm_flags & supported_flags) != attrs.ndm_flags) {
NLMSG_REPORT_ERR_MSG(npt, "ndm_flags %X not supported",
attrs.ndm_flags &~ supported_flags);
return (ENOTSUP);
}
/* Replacement requires new entry creation anyway */
if ((hdr->nlmsg_flags & (NLM_F_CREATE | NLM_F_REPLACE)) == 0)
return (ENOTSUP);
struct lltable *llt = lltable_get(attrs.nda_ifp, attrs.ndm_family);
if (llt == NULL)
return (EAFNOSUPPORT);
uint8_t linkhdr[LLE_MAX_LINKHDR];
size_t linkhdrsize = sizeof(linkhdr);
int lladdr_off = 0;
if (lltable_calc_llheader(attrs.nda_ifp, attrs.ndm_family,
(char *)(attrs.nda_lladdr + 1), linkhdr, &linkhdrsize, &lladdr_off) != 0) {
NLMSG_REPORT_ERR_MSG(npt, "unable to calculate lle prepend data");
return (EINVAL);
}
int lle_flags = LLE_STATIC | ((attrs.ndm_flags & NTF_PROXY) ? LLE_PUB : 0);
struct llentry *lle = lltable_alloc_entry(llt, lle_flags, attrs.nda_dst);
if (lle == NULL)
return (ENOMEM);
lltable_set_entry_addr(attrs.nda_ifp, lle, linkhdr, linkhdrsize, lladdr_off);
/* llentry created, try to insert or update :*/
IF_AFDATA_WLOCK(attrs.nda_ifp);
LLE_WLOCK(lle);
struct llentry *lle_tmp = lla_lookup(llt, LLE_EXCLUSIVE, attrs.nda_dst);
if (lle_tmp != NULL) {
if (hdr->nlmsg_flags & NLM_F_EXCL) {
LLE_WUNLOCK(lle_tmp);
lle_tmp = NULL;
error = EEXIST;
} else if (hdr->nlmsg_flags & NLM_F_REPLACE) {
lltable_unlink_entry(llt, lle_tmp);
lltable_link_entry(llt, lle);
} else
error = EEXIST;
} else {
if (hdr->nlmsg_flags & NLM_F_CREATE)
lltable_link_entry(llt, lle);
else
error = ENOENT;
}
IF_AFDATA_WUNLOCK(attrs.nda_ifp);
if (error != 0) {
if (lle != NULL)
llentry_free(lle);
return (error);
}
if (lle_tmp != NULL)
llentry_free(lle_tmp);
/* XXX: We're inside epoch */
EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_RESOLVED);
LLE_WUNLOCK(lle);
return (0);
}
static int
rtnl_handle_delneigh(struct nlmsghdr *hdr, struct nlpcb *nlp, struct netlink_parse_tracker *npt)
{
int error;
error = nlp_has_priv_route(nlp);
if (error != 0)
return (error);
struct nl_parsed_neigh attrs = {};
error = nl_parse_nlmsg(hdr, &ndmsg_parser, npt, &attrs);
if (error != 0)
return (error);
if (attrs.nda_dst == NULL) {
NLMSG_REPORT_ERR_MSG(npt, "NDA_DST not set");
return (EINVAL);
}
if (attrs.nda_ifp == NULL) {
NLMSG_REPORT_ERR_MSG(npt, "no ifindex provided");
return (EINVAL);
}
struct lltable *llt = lltable_get(attrs.nda_ifp, attrs.ndm_family);
if (llt == NULL)
return (EAFNOSUPPORT);
IF_AFDATA_WLOCK(attrs.nda_ifp);
struct llentry *lle = lla_lookup(llt, LLE_EXCLUSIVE, attrs.nda_dst);
if (lle != NULL) {
if ((lle->la_flags & LLE_IFADDR) != 0) {
LLE_WUNLOCK(lle);
lle = NULL;
error = EPERM;
} else
lltable_unlink_entry(llt, lle);
} else
error = ENOENT;
IF_AFDATA_WUNLOCK(attrs.nda_ifp);
if (error == 0 && lle != NULL)
EVENTHANDLER_INVOKE(lle_event, lle, LLENTRY_DELETED);
if (lle != NULL)
llentry_free(lle);
return (error);
}
static int
rtnl_handle_getneigh(struct nlmsghdr *hdr, struct nlpcb *nlp, struct netlink_parse_tracker *npt)
{
int error;
struct nl_parsed_neigh attrs = {};
error = nl_parse_nlmsg(hdr, &ndmsg_parser, npt, &attrs);
if (error != 0)
return (error);
if (attrs.nda_dst != NULL && attrs.nda_ifp == NULL) {
NLMSG_REPORT_ERR_MSG(npt, "has NDA_DST but no ifindex provided");
return (EINVAL);
}
struct netlink_walkargs wa = {
.so = nlp,
.ns = npt->ns,
.hdr.nlmsg_pid = hdr->nlmsg_pid,
.hdr.nlmsg_seq = hdr->nlmsg_seq,
.hdr.nlmsg_flags = hdr->nlmsg_flags,
.hdr.nlmsg_type = NL_RTM_NEWNEIGH,
};
if (attrs.nda_dst == NULL)
error = dump_llts(&wa, attrs.nda_ifp, attrs.ndm_family);
else
error = get_lle(&wa, attrs.nda_ifp, attrs.ndm_family, attrs.nda_dst);
return (error);
}
static struct rtnl_cmd_handler cmd_handlers[] = {
{ NL_RTM_NEWNEIGH, "RTM_NEWNEIGH", &rtnl_handle_newneigh, sizeof(struct ndmsg)},
{ NL_RTM_DELNEIGH, "RTM_DELNEIGH", &rtnl_handle_delneigh, sizeof(struct ndmsg)},
{ NL_RTM_GETNEIGH, "RTM_GETNEIGH", &rtnl_handle_getneigh, sizeof(struct ndmsg)},
};
static void
rtnl_lle_event(void *arg __unused, struct llentry *lle, int evt)
{
struct ifnet *ifp;
int family;
LLE_WLOCK_ASSERT(lle);
ifp = lltable_get_ifp(lle->lle_tbl);
family = lltable_get_af(lle->lle_tbl);
if (family != AF_INET && family != AF_INET6)
return;
int nlmsgs_type = evt == LLENTRY_RESOLVED ? NL_RTM_NEWNEIGH : NL_RTM_DELNEIGH;
struct nlmsg_state ns = {};
if (!nlmsg_get_group_writer(NLMSG_SMALL, NETLINK_ROUTE, RTNLGRP_NEIGH, &ns)) {
NL_LOG(LOG_DEBUG, "error allocating group writer");
return;
}
struct netlink_walkargs wa = {
.hdr.nlmsg_type = nlmsgs_type,
.ns = &ns,
.ifp = ifp,
.family = family,
};
dump_lle_locked(lle->lle_tbl, lle, &wa);
nlmsg_flush(&ns);
}
void
rtnl_neighs_init()
{
rtnl_register_messages(cmd_handlers, NL_ARRAY_LEN(cmd_handlers));
lle_event_p = EVENTHANDLER_REGISTER(lle_event, rtnl_lle_event, NULL,
EVENTHANDLER_PRI_ANY);
}