diff options
Diffstat (limited to 'dhcpv6.c')
| -rw-r--r-- | dhcpv6.c | 20 |
1 files changed, 15 insertions, 5 deletions
@@ -318,7 +318,7 @@ static bool dhcpv6_opt(struct iov_tail *data, uint16_t type) * false otherwise and @data is unmodified */ static bool dhcpv6_ia_notonlink(struct iov_tail *data, - struct in6_addr *la) + const struct in6_addr *la) { int ia_types[2] = { OPT_IA_NA, OPT_IA_TA }; struct opt_ia_addr opt_addr_storage; @@ -567,6 +567,7 @@ int dhcpv6(struct ctx *c, struct iov_tail *data, struct opt_hdr client_id_storage; /* cppcheck-suppress [variableScope,unmatchedSuppression] */ struct opt_ia_na ia_storage; + const struct guest_addr *a; const struct in6_addr *src; struct msg_hdr mh_storage; const struct msg_hdr *mh; @@ -584,6 +585,15 @@ int dhcpv6(struct ctx *c, struct iov_tail *data, if (c->no_dhcpv6) return 1; + /* If no address is available, drop all messages rather than sending a + * bogus address. Information-request messages could ideally still be + * answered, but since we unconditionally include an IA_NA option in all + * replies (RFC 9915, Appendix B.), dropping them is safer. + */ + a = fwd_get_addr(c, AF_INET6, true, CONF_ADDR_ANY); + if (!a) + return 1; + if (!IN6_IS_ADDR_MULTICAST(daddr)) return -1; @@ -627,7 +637,7 @@ int dhcpv6(struct ctx *c, struct iov_tail *data, if (mh->type == TYPE_CONFIRM && server_id) return -1; - if (dhcpv6_ia_notonlink(data, &c->ip6.addr)) { + if (dhcpv6_ia_notonlink(data, &a->addr.a6)) { dhcpv6_send_ia_notonlink(c, saddr, data, &client_id_base, @@ -667,6 +677,7 @@ int dhcpv6(struct ctx *c, struct iov_tail *data, default: return -1; } + if (ia) resp.ia_na.iaid = ((struct opt_ia_na *)ia)->iaid; @@ -681,8 +692,9 @@ int dhcpv6(struct ctx *c, struct iov_tail *data, resp.hdr.xid = mh->xid; + resp.ia_addr.addr = a->addr.a6; tap_udp6_send(c, src, 547, saddr, 546, mh->xid, &resp, n); - c->ip6.addr_seen = c->ip6.addr; + c->ip6.addr_seen = a->addr.a6; return 1; } @@ -705,6 +717,4 @@ void dhcpv6_init(const struct ctx *c) c->our_tap_mac, sizeof(c->our_tap_mac)); memcpy(resp_not_on_link.server_id.duid_lladdr, c->our_tap_mac, sizeof(c->our_tap_mac)); - - resp.ia_addr.addr = c->ip6.addr; } |