From ef3c5632c100fda0fa463a3ed56ff926f3f86b20 Mon Sep 17 00:00:00 2001 From: Hans Dedecker Date: Fri, 6 Jan 2017 15:26:17 +0100 Subject: [PATCH] dhcpv6-ia: filter out prefixes having invalid length Function append_reply filters out addresses having invalid prefix length when constructing prefixes being delegated to a client. Now also filter out addresses with an invalid prefix length when writing the delegated prefixes in the statefile and during logging of the delegated prefixes. Signed-off-by: Hans Dedecker --- src/dhcpv6-ia.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c index 4c077db..88686c9 100644 --- a/src/dhcpv6-ia.c +++ b/src/dhcpv6-ia.c @@ -146,6 +146,11 @@ static void free_dhcpv6_assignment(struct dhcpv6_assignment *c) free(c); } +static inline bool valid_prefix_length(const struct dhcpv6_assignment *a, const uint8_t prefix_length) +{ + return (a->managed_size || a->length > prefix_length); +} + static inline bool valid_addr(const struct odhcpd_ipaddr *addr, time_t now) { return (addr->prefix <= 96 && addr->preferred > (uint32_t)now); @@ -280,15 +285,22 @@ void dhcpv6_write_statefile(void) for (size_t i = 0; i < addrlen; ++i) { if (!valid_addr(&addrs[i], now) || - (!INFINITE_VALID(c->valid_until) && c->valid_until <= now) || - !ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs)) + (!INFINITE_VALID(c->valid_until) && c->valid_until <= now)) continue; addr = addrs[i].addr; - if (c->length == 128) + if (c->length == 128) { + if (!ADDR_ENTRY_VALID_IA_ADDR(iface, i, m, addrs)) + continue; + addr.s6_addr32[3] = htonl(c->assigned); - else + } + else { + if (!valid_prefix_length(c, addrs[i].prefix)) + continue; + addr.s6_addr32[1] |= htonl(c->assigned); + } inet_ntop(AF_INET6, &addr, ipbuf, sizeof(ipbuf) - 1); @@ -746,7 +758,7 @@ static size_t append_reply(uint8_t *buf, size_t buflen, uint16_t status, if (datalen + entrlen + 4 > buflen || (a->assigned == 0 && a->managed_size == 0) || - (!a->managed_size && a->length <= addrs[i].prefix)) + !valid_prefix_length(a, addrs[i].prefix)) continue; memcpy(buf + datalen, &p, sizeof(p)); @@ -944,8 +956,12 @@ static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now, addr.s6_addr32[3] = htonl(a->assigned); } - else + else { + if (!valid_prefix_length(a, addrs[i].prefix)) + continue; + addr.s6_addr32[1] |= htonl(a->assigned); + } inet_ntop(AF_INET6, &addr, addrbuf, sizeof(addrbuf)); lbsize += snprintf(leasebuf + lbsize, sizeof(leasebuf) - lbsize, "%s/%d ", addrbuf, prefix); -- 2.25.1