dhcpv6-ia: add full CONFIRM support

Add CONFIRM support as specified in RFC8415 paragraph 18.3.3

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

diff --git a/src/dhcpv6-ia.c b/src/dhcpv6-ia.c
index 8ac0a9efa5d1bc4841014af63e9cbe2bb12f6b43..b9120d33a6b214c1fefb184420d8d115c7e1746d 100644 (file)
--- a/src/dhcpv6-ia.c
+++ b/src/dhcpv6-ia.c
@@ -1117,16 +1117,16 @@ static void dhcpv6_log(uint8_t msgtype, struct interface *iface, time_t now,
 static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assignment *a,
                struct interface *iface)
 {
-       struct odhcpd_ipaddr *addrs = (a->managed) ? a->managed : iface->addr6;
-       size_t addrlen = (a->managed) ? (size_t)a->managed_size : iface->addr6_len;
+       struct odhcpd_ipaddr *addrs = (a && a->managed) ? a->managed : iface->addr6;
+       size_t addrlen = (a && a->managed) ? (size_t)a->managed_size : iface->addr6_len;
        time_t now = odhcpd_time();
        uint8_t *odata, *end = ((uint8_t*)ia) + htons(ia->len) + 4;
        uint16_t otype, olen;
        bool onlink = true;
 
        dhcpv6_for_each_option((uint8_t*)&ia[1], end, otype, olen, odata) {
-               struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix*)&odata[-4];
-               struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr*)&odata[-4];
+               struct dhcpv6_ia_prefix *p = (struct dhcpv6_ia_prefix *)&odata[-4];
+               struct dhcpv6_ia_addr *n = (struct dhcpv6_ia_addr *)&odata[-4];
 
                if ((otype != DHCPV6_OPT_IA_PREFIX || olen < sizeof(*p) - 4) &&
                                (otype != DHCPV6_OPT_IA_ADDR || olen < sizeof(*n) - 4))
@@ -1134,24 +1134,17 @@ static bool dhcpv6_ia_on_link(const struct dhcpv6_ia_hdr *ia, struct dhcpv6_assi
 
                onlink = false;
                for (size_t i = 0; i < addrlen; ++i) {
-                       struct in6_addr addr = addrs[i].addr.in6;
-
                        if (!valid_addr(&addrs[i], now))
                                continue;
 
                        if (ia->type == htons(DHCPV6_OPT_IA_PD)) {
-                               addr.s6_addr32[1] |= htonl(a->assigned);
-                               addr.s6_addr32[2] = addr.s6_addr32[3] = 0;
-
-                               if (memcmp(&p->addr, &addr, sizeof(addr)) ||
-                                               p->prefix != ((a->managed) ? addrs[i].prefix : a->length))
+                               if (p->prefix < addrs[i].prefix ||
+                                   odhcpd_bmemcmp(&p->addr, &addrs[i].addr.in6, addrs[i].prefix))
                                        continue;
-                       } else {
-                               addr.s6_addr32[3] = htonl(a->assigned);
 
-                               if (memcmp(&n->addr, &addr, sizeof(addr)))
-                                       continue;
-                       }
+                       } else if (odhcpd_bmemcmp(&n->addr, &addrs[i].addr.in6, addrs[i].prefix))
+                               continue;
+
                        onlink = true;
                }
 
@@ -1341,6 +1334,7 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                                        handshake_len += sizeof(auth);
                                }
 
+
                                buf += handshake_len;
                                buflen -= handshake_len;
                                response_len += handshake_len;
@@ -1413,11 +1407,16 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                                        a->valid_until = now + 3600; /* Block address for 1h */
                                }
                        }
-               } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM && ia_addr_present) {
-                       /* Send NOTONLINK for CONFIRM with addr present so that clients restart connection */
-                       status = DHCPV6_STATUS_NOTONLINK;
-                       ia_response_len = build_ia(buf, buflen, status, ia, a, iface, true);
-                       notonlink = true;
+               } else if (hdr->msg_type == DHCPV6_MSG_CONFIRM) {
+                       if (ia_addr_present && !dhcpv6_ia_on_link(ia, a, iface)) {
+                               notonlink = true;
+                               break;
+                       }
+
+                       if (!ia_addr_present || !a || !(a->flags & OAF_BOUND)) {
+                               response_len = 0;
+                               goto out;
+                       }
                }
 
                buf += ia_response_len;
@@ -1426,15 +1425,23 @@ ssize_t dhcpv6_handle_ia(uint8_t *buf, size_t buflen, struct interface *iface,
                dhcpv6_log(hdr->msg_type, iface, now, duidbuf, is_pd, a, status);
        }
 
-       if ((hdr->msg_type == DHCPV6_MSG_RELEASE || hdr->msg_type == DHCPV6_MSG_DECLINE || notonlink) &&
-                       response_len + 6 < buflen) {
-               buf[0] = 0;
-               buf[1] = DHCPV6_OPT_STATUS;
-               buf[2] = 0;
-               buf[3] = 2;
-               buf[4] = 0;
-               buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
-               response_len += 6;
+       switch (hdr->msg_type) {
+       case DHCPV6_MSG_RELEASE:
+       case DHCPV6_MSG_DECLINE:
+       case DHCPV6_MSG_CONFIRM:
+               if (response_len + 6 < buflen) {
+                       buf[0] = 0;
+                       buf[1] = DHCPV6_OPT_STATUS;
+                       buf[2] = 0;
+                       buf[3] = 2;
+                       buf[4] = 0;
+                       buf[5] = (notonlink) ? DHCPV6_STATUS_NOTONLINK : DHCPV6_STATUS_OK;
+                       response_len += 6;
+               }
+               break;
+
+       default:
+               break;
        }
 
        dhcpv6_write_statefile();