Claudio Jeker(cje...@diehard.n-r-g.com) on 2023.10.16 09:23:12 +0200:
> This diff fixes a few more things when establishing connections with
> link-local IPv6 addresses. In get_alternate_addr() the interface scope
> of the connection is recovered and then passed to the RDE. The RDE can
> then use this scope id to insert link-local addresses with the correct
> scope.
looks good.
> I built a regress test for this which passes with this diff.
> Now probably more is needed because IPv6 link-local addresses are a gift
> that keep on giving. One thing to implement on top of this is template
> matching for link local -- which allows to auto-configure sessions more
> easily. This will probably follow soon.
it would be nice if that could match just on interfaces. As in "neighbor
<interface>", with some syntactic sugar so its clear this is for
link-local?
> --
> :wq Claudio
>
> Index: bgpd.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/bgpd.h,v
> retrieving revision 1.477
> diff -u -p -r1.477 bgpd.h
> --- bgpd.h 30 Aug 2023 08:16:28 -0000 1.477
> +++ bgpd.h 9 Oct 2023 13:50:36 -0000
> @@ -796,6 +796,7 @@ struct session_up {
> struct bgpd_addr remote_addr;
> struct capabilities capa;
> uint32_t remote_bgpid;
> + unsigned int if_scope;
> uint16_t short_as;
> };
>
> @@ -1439,6 +1440,7 @@ void kr_ifinfo(char *);
> void kr_net_reload(u_int, uint64_t, struct network_head *);
> int kr_reload(void);
> int get_mpe_config(const char *, u_int *, u_int *);
> +uint8_t mask2prefixlen(sa_family_t, struct sockaddr *);
>
> /* log.c */
> void log_peer_info(const struct peer_config *, const char *, ...)
> Index: kroute.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/kroute.c,v
> retrieving revision 1.305
> diff -u -p -r1.305 kroute.c
> --- kroute.c 1 Jun 2023 09:47:34 -0000 1.305
> +++ kroute.c 9 Oct 2023 13:54:25 -0000
> @@ -168,8 +168,6 @@ struct kroute6 *kroute6_match(struct kta
> void kroute_detach_nexthop(struct ktable *, struct knexthop *);
>
> uint8_t prefixlen_classful(in_addr_t);
> -uint8_t mask2prefixlen(in_addr_t);
> -uint8_t mask2prefixlen6(struct sockaddr_in6 *);
> uint64_t ift2ifm(uint8_t);
> const char *get_media_descr(uint64_t);
> const char *get_linkstate(uint8_t, int);
> @@ -2419,21 +2417,28 @@ prefixlen_classful(in_addr_t ina)
> return (8);
> }
>
> -uint8_t
> -mask2prefixlen(in_addr_t ina)
> +static uint8_t
> +mask2prefixlen4(struct sockaddr_in *sa_in)
> {
> + in_addr_t ina;
> +
> + if (sa_in->sin_len == 0)
> + return (0);
> + ina = sa_in->sin_addr.s_addr;
> if (ina == 0)
> return (0);
> else
> return (33 - ffs(ntohl(ina)));
> }
>
> -uint8_t
> +static uint8_t
> mask2prefixlen6(struct sockaddr_in6 *sa_in6)
> {
> uint8_t *ap, *ep;
> u_int l = 0;
>
> + if (sa_in6->sin6_len == 0)
> + return (0);
> /*
> * sin6_len is the size of the sockaddr so subtract the offset of
> * the possibly truncated sin6_addr struct.
> @@ -2480,6 +2485,19 @@ mask2prefixlen6(struct sockaddr_in6 *sa_
> return (l);
> }
>
> +uint8_t
> +mask2prefixlen(sa_family_t af, struct sockaddr *mask)
> +{
> + switch (af) {
> + case AF_INET:
> + return mask2prefixlen4((struct sockaddr_in *)mask);
> + case AF_INET6:
> + return mask2prefixlen6((struct sockaddr_in6 *)mask);
> + default:
> + fatalx("%s: unsupported af", __func__);
> + }
> +}
> +
> const struct if_status_description
> if_status_descriptions[] = LINK_STATE_DESCRIPTIONS;
> const struct ifmedia_description
> @@ -3079,9 +3097,7 @@ dispatch_rtmsg_addr(struct rt_msghdr *rt
> case AF_INET:
> sa_in = (struct sockaddr_in *)rti_info[RTAX_NETMASK];
> if (sa_in != NULL) {
> - if (sa_in->sin_len != 0)
> - kf->prefixlen =
> - mask2prefixlen(sa_in->sin_addr.s_addr);
> + kf->prefixlen = mask2prefixlen4(sa_in);
> } else if (rtm->rtm_flags & RTF_HOST)
> kf->prefixlen = 32;
> else
> @@ -3091,8 +3107,7 @@ dispatch_rtmsg_addr(struct rt_msghdr *rt
> case AF_INET6:
> sa_in6 = (struct sockaddr_in6 *)rti_info[RTAX_NETMASK];
> if (sa_in6 != NULL) {
> - if (sa_in6->sin6_len != 0)
> - kf->prefixlen = mask2prefixlen6(sa_in6);
> + kf->prefixlen = mask2prefixlen6(sa_in6);
> } else if (rtm->rtm_flags & RTF_HOST)
> kf->prefixlen = 128;
> else
> Index: logmsg.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/logmsg.c,v
> retrieving revision 1.9
> diff -u -p -r1.9 logmsg.c
> --- logmsg.c 24 Aug 2022 17:14:02 -0000 1.9
> +++ logmsg.c 14 Oct 2023 09:49:36 -0000
> @@ -60,55 +60,54 @@ log_fmt_peer(const struct peer_config *p
> void
> log_peer_info(const struct peer_config *peer, const char *emsg, ...)
> {
> - char *p, *nfmt;
> + char *p, *msg;
> va_list ap;
>
> p = log_fmt_peer(peer);
> - if (asprintf(&nfmt, "%s: %s", p, emsg) == -1)
> - fatal(NULL);
> va_start(ap, emsg);
> - vlog(LOG_INFO, nfmt, ap);
> + if (vasprintf(&msg, emsg, ap) == -1)
> + fatal(NULL);
> va_end(ap);
> + logit(LOG_INFO, "%s: %s", p, msg);
> + free(msg);
> free(p);
> - free(nfmt);
> }
>
> void
> log_peer_warn(const struct peer_config *peer, const char *emsg, ...)
> {
> - char *p, *nfmt;
> + char *p, *msg;
> va_list ap;
> + int saved_errno = errno;
>
> p = log_fmt_peer(peer);
> if (emsg == NULL) {
> - if (asprintf(&nfmt, "%s: %s", p, strerror(errno)) == -1)
> - fatal(NULL);
> + logit(LOG_ERR, "%s: %s", p, strerror(saved_errno));
> } else {
> - if (asprintf(&nfmt, "%s: %s: %s", p, emsg, strerror(errno)) ==
> - -1)
> + va_start(ap, emsg);
> + if (vasprintf(&msg, emsg, ap) == -1)
> fatal(NULL);
> + va_end(ap);
> + logit(LOG_ERR, "%s: %s: %s", p, msg, strerror(saved_errno));
> + free(msg);
> }
> - va_start(ap, emsg);
> - vlog(LOG_ERR, nfmt, ap);
> - va_end(ap);
> free(p);
> - free(nfmt);
> }
>
> void
> log_peer_warnx(const struct peer_config *peer, const char *emsg, ...)
> {
> - char *p, *nfmt;
> + char *p, *msg;
> va_list ap;
>
> p = log_fmt_peer(peer);
> - if (asprintf(&nfmt, "%s: %s", p, emsg) == -1)
> - fatal(NULL);
> va_start(ap, emsg);
> - vlog(LOG_ERR, nfmt, ap);
> + if (vasprintf(&msg, emsg, ap) == -1)
> + fatal(NULL);
> va_end(ap);
> + logit(LOG_ERR, "%s: %s", p, msg);
> + free(msg);
> free(p);
> - free(nfmt);
> }
>
> void
> Index: rde.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/rde.c,v
> retrieving revision 1.610
> diff -u -p -r1.610 rde.c
> --- rde.c 16 Aug 2023 08:26:35 -0000 1.610
> +++ rde.c 9 Oct 2023 14:16:23 -0000
> @@ -59,7 +59,7 @@ int rde_attr_parse(u_char *, uint16_t,
> int rde_attr_add(struct filterstate *, u_char *, uint16_t);
> uint8_t rde_attr_missing(struct rde_aspath *, int, uint16_t);
> int rde_get_mp_nexthop(u_char *, uint16_t, uint8_t,
> - struct filterstate *);
> + struct rde_peer *, struct filterstate *);
> void rde_as4byte_fixup(struct rde_peer *, struct rde_aspath *);
> uint8_t rde_aspa_validity(struct rde_peer *, struct rde_aspath
> *,
> uint8_t);
> @@ -1797,7 +1797,8 @@ rde_update_dispatch(struct rde_peer *pee
> /* unlock the previously locked nexthop, it is no longer used */
> nexthop_unref(state.nexthop);
> state.nexthop = NULL;
> - if ((pos = rde_get_mp_nexthop(mpp, mplen, aid, &state)) == -1) {
> + if ((pos = rde_get_mp_nexthop(mpp, mplen, aid, peer,
> + &state)) == -1) {
> log_peer_warnx(&peer->conf, "bad nlri nexthop");
> rde_update_err(peer, ERR_UPDATE, ERR_UPD_OPTATTR,
> mpa.reach, mpa.reach_len);
> @@ -2482,7 +2483,7 @@ rde_attr_missing(struct rde_aspath *a, i
>
> int
> rde_get_mp_nexthop(u_char *data, uint16_t len, uint8_t aid,
> - struct filterstate *state)
> + struct rde_peer *peer, struct filterstate *state)
> {
> struct bgpd_addr nexthop;
> uint8_t totlen, nhlen;
> @@ -2509,12 +2510,22 @@ rde_get_mp_nexthop(u_char *data, uint16_
> * traffic.
> */
> if (nhlen != 16 && nhlen != 32) {
> - log_warnx("bad %s nexthop, bad size %d", aid2str(aid),
> - nhlen);
> + log_peer_warnx(&peer->conf, "bad %s nexthop, "
> + "bad size %d", aid2str(aid), nhlen);
> return (-1);
> }
> memcpy(&nexthop.v6.s6_addr, data, 16);
> nexthop.aid = AID_INET6;
> + if (IN6_IS_ADDR_LINKLOCAL(&nexthop.v6)) {
> + if (peer->local_if_scope != 0) {
> + nexthop.scope_id = peer->local_if_scope;
> + } else {
> + log_peer_warnx(&peer->conf,
> + "unexpected link-local nexthop: %s",
> + log_addr(&nexthop));
> + return (-1);
> + }
> + }
> break;
> case AID_VPN_IPv4:
> /*
> @@ -2531,8 +2542,8 @@ rde_get_mp_nexthop(u_char *data, uint16_
> * AID_VPN_IPv4 in nexthop and kroute.
> */
> if (nhlen != 12) {
> - log_warnx("bad %s nexthop, bad size %d", aid2str(aid),
> - nhlen);
> + log_peer_warnx(&peer->conf, "bad %s nexthop, "
> + "bad size %d", aid2str(aid), nhlen);
> return (-1);
> }
> nexthop.aid = AID_INET;
> @@ -2541,26 +2552,37 @@ rde_get_mp_nexthop(u_char *data, uint16_
> break;
> case AID_VPN_IPv6:
> if (nhlen != 24) {
> - log_warnx("bad %s nexthop, bad size %d", aid2str(aid),
> - nhlen);
> + log_peer_warnx(&peer->conf, "bad %s nexthop, "
> + "bad size %d", aid2str(aid), nhlen);
> return (-1);
> }
> memcpy(&nexthop.v6, data + sizeof(uint64_t),
> sizeof(nexthop.v6));
> nexthop.aid = AID_INET6;
> + if (IN6_IS_ADDR_LINKLOCAL(&nexthop.v6)) {
> + if (peer->local_if_scope != 0) {
> + nexthop.scope_id = peer->local_if_scope;
> + } else {
> + log_peer_warnx(&peer->conf,
> + "unexpected link-local nexthop: %s",
> + log_addr(&nexthop));
> + return (-1);
> + }
> + }
> break;
> case AID_FLOWSPECv4:
> case AID_FLOWSPECv6:
> /* nexthop must be 0 and ignored for flowspec */
> if (nhlen != 0) {
> - log_warnx("bad %s nexthop, bad size %d", aid2str(aid),
> - nhlen);
> + log_peer_warnx(&peer->conf, "bad %s nexthop, "
> + "bad size %d", aid2str(aid), nhlen);
> return (-1);
> }
> /* also ignore reserved (old SNPA) field as per RFC4760 */
> return (totlen + 1);
> default:
> - log_warnx("bad multiprotocol nexthop, bad AID");
> + log_peer_warnx(&peer->conf, "bad multiprotocol nexthop, "
> + "bad AID");
> return (-1);
> }
>
> Index: rde.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/rde.h,v
> retrieving revision 1.296
> diff -u -p -r1.296 rde.h
> --- rde.h 16 Aug 2023 08:26:35 -0000 1.296
> +++ rde.h 9 Oct 2023 07:26:49 -0000
> @@ -92,6 +92,7 @@ struct rde_peer {
> time_t staletime[AID_MAX];
> uint32_t remote_bgpid; /* host byte order! */
> uint32_t path_id_tx;
> + unsigned int local_if_scope;
> enum peer_state state;
> enum export_type export_type;
> enum role role;
> Index: rde_peer.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/rde_peer.c,v
> retrieving revision 1.32
> diff -u -p -r1.32 rde_peer.c
> --- rde_peer.c 19 Apr 2023 13:23:33 -0000 1.32
> +++ rde_peer.c 26 Apr 2023 14:04:35 -0000
> @@ -430,6 +430,7 @@ peer_up(struct rde_peer *peer, struct se
> peer->remote_addr = sup->remote_addr;
> peer->local_v4_addr = sup->local_v4_addr;
> peer->local_v6_addr = sup->local_v6_addr;
> + peer->local_if_scope = sup->if_scope;
> memcpy(&peer->capa, &sup->capa, sizeof(peer->capa));
>
> /* clear eor markers depending on GR flags */
> Index: rde_rib.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/rde_rib.c,v
> retrieving revision 1.260
> diff -u -p -r1.260 rde_rib.c
> --- rde_rib.c 23 Apr 2023 11:39:10 -0000 1.260
> +++ rde_rib.c 9 Oct 2023 14:05:30 -0000
> @@ -1910,7 +1910,7 @@ nexthop_compare(struct nexthop *na, stru
> case AID_INET6:
> return (memcmp(&a->v6, &b->v6, sizeof(struct in6_addr)));
> default:
> - fatalx("nexthop_cmp: unknown af");
> + fatalx("nexthop_cmp: unknown aid %s", aid2str(a->aid));
> }
> return (-1);
> }
> Index: session.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/session.c,v
> retrieving revision 1.448
> diff -u -p -r1.448 session.c
> --- session.c 9 Oct 2023 07:11:20 -0000 1.448
> +++ session.c 16 Oct 2023 07:13:58 -0000
> @@ -1202,37 +1202,64 @@ session_setup_socket(struct peer *p)
> return (0);
> }
>
> -/* compare two sockaddrs by converting them into bgpd_addr */
> +/*
> + * compare the bgpd_addr with the sockaddr by converting the latter into
> + * a bgpd_addr. Return true if the two are equal, including any scope
> + */
> static int
> -sa_equal(struct sockaddr *a, struct sockaddr *b)
> +sa_equal(struct bgpd_addr *ba, struct sockaddr *b)
> {
> - struct bgpd_addr ba, bb;
> + struct bgpd_addr bb;
>
> - sa2addr(a, &ba, NULL);
> sa2addr(b, &bb, NULL);
> -
> - return (memcmp(&ba, &bb, sizeof(ba)) == 0);
> + return (memcmp(ba, &bb, sizeof(*ba)) == 0);
> }
>
> static void
> -get_alternate_addr(struct sockaddr *sa, struct bgpd_addr *alt)
> +get_alternate_addr(struct bgpd_addr *local, struct bgpd_addr *remote,
> + struct bgpd_addr *alt, unsigned int *scope)
> {
> struct ifaddrs *ifap, *ifa, *match;
> + int connected = 0;
> + u_int8_t plen;
>
> if (getifaddrs(&ifap) == -1)
> fatal("getifaddrs");
>
> - for (match = ifap; match != NULL; match = match->ifa_next)
> - if (match->ifa_addr != NULL && sa_equal(sa, match->ifa_addr))
> + for (match = ifap; match != NULL; match = match->ifa_next) {
> + if (match->ifa_addr == NULL)
> + continue;
> + if (match->ifa_addr->sa_family != AF_INET &&
> + match->ifa_addr->sa_family != AF_INET6)
> + continue;
> + if (sa_equal(local, match->ifa_addr)) {
> + if (match->ifa_flags & IFF_POINTOPOINT &&
> + match->ifa_dstaddr) {
> + if (sa_equal(remote, match->ifa_dstaddr))
> + connected = 1;
> + } else if (match->ifa_netmask) {
> + plen = mask2prefixlen(
> + match->ifa_addr->sa_family,
> + match->ifa_netmask);
> + if (plen != 0xff &&
> + prefix_compare(local, remote, plen) == 0)
> + connected = 1;
> + }
> break;
> + }
> + }
>
> if (match == NULL) {
> log_warnx("%s: local address not found", __func__);
> return;
> }
> + if (connected)
> + *scope = if_nametoindex(match->ifa_name);
> + else
> + *scope = 0;
>
> - switch (sa->sa_family) {
> - case AF_INET6:
> + switch (local->aid) {
> + case AID_INET6:
> for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
> if (ifa->ifa_addr != NULL &&
> ifa->ifa_addr->sa_family == AF_INET &&
> @@ -1242,7 +1269,7 @@ get_alternate_addr(struct sockaddr *sa,
> }
> }
> break;
> - case AF_INET:
> + case AID_INET:
> for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
> if (ifa->ifa_addr != NULL &&
> ifa->ifa_addr->sa_family == AF_INET6 &&
> @@ -1260,8 +1287,8 @@ get_alternate_addr(struct sockaddr *sa,
> }
> break;
> default:
> - log_warnx("%s: unsupported address family %d", __func__,
> - sa->sa_family);
> + log_warnx("%s: unsupported address family %s", __func__,
> + aid2str(local->aid));
> break;
> }
>
> @@ -1278,11 +1305,13 @@ session_tcp_established(struct peer *pee
> if (getsockname(peer->fd, (struct sockaddr *)&ss, &len) == -1)
> log_warn("getsockname");
> sa2addr((struct sockaddr *)&ss, &peer->local, &peer->local_port);
> - get_alternate_addr((struct sockaddr *)&ss, &peer->local_alt);
> len = sizeof(ss);
> if (getpeername(peer->fd, (struct sockaddr *)&ss, &len) == -1)
> log_warn("getpeername");
> sa2addr((struct sockaddr *)&ss, &peer->remote, &peer->remote_port);
> +
> + get_alternate_addr(&peer->local, &peer->remote, &peer->local_alt,
> + &peer->if_scope);
> }
>
> void
> @@ -3546,6 +3575,7 @@ session_up(struct peer *p)
> sup.local_v4_addr = p->local_alt;
> }
> sup.remote_addr = p->remote;
> + sup.if_scope = p->if_scope;
>
> sup.remote_bgpid = p->remote_bgpid;
> sup.short_as = p->short_as;
> Index: session.h
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/session.h,v
> retrieving revision 1.162
> diff -u -p -r1.162 session.h
> --- session.h 28 Mar 2023 12:15:23 -0000 1.162
> +++ session.h 30 Mar 2023 07:17:19 -0000
> @@ -240,6 +240,7 @@ struct peer {
> int lasterr;
> u_int errcnt;
> u_int IdleHoldTime;
> + unsigned int if_scope; /* interface scope for IPv6 */
> uint32_t remote_bgpid;
> enum session_state state;
> enum session_state prev_state;
>
