Validate lease before setting state to REQUEST when REPLY is recieved in

DISCOVER.

diff --git a/dhcp6.c b/dhcp6.c
index 4f6637004e5b131213f8beaac88d61b4cde38e3c..6e35a9fc399a5933a392e62cbaae7d08286c0e5c 100644 (file)
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -2715,7 +2715,7 @@ dhcp6_handledata(void *arg)
        const struct dhcp_opt *opt;
        const struct if_options *ifo;
        struct ipv6_addr *ap;
-       uint8_t has_new;
+       bool valid_op, has_new;
        uint32_t u32;
 
        dctx = arg;
@@ -2879,6 +2879,7 @@ dhcp6_handledata(void *arg)
 #endif
 
        op = dhcp6_get_op(r->type);
+       valid_op = op != NULL;
        switch(r->type) {
        case DHCP6_REPLY:
                switch(state->state) {
@@ -2906,12 +2907,16 @@ dhcp6_handledata(void *arg)
                        }
                        break;
                case DH6S_DISCOVER:
-                       if (has_option_mask(ifo->requestmask6,
-                           D6_OPTION_RAPID_COMMIT) &&
-                           dhcp6_getmoption(D6_OPTION_RAPID_COMMIT, r, len))
-                               state->state = DH6S_REQUEST;
-                       else
-                               op = NULL;
+                       /* Only accept REPLY in DISCOVER for RAPID_COMMIT.
+                        * Normally we get an ADVERTISE for a DISCOVER. */
+                       if (!has_option_mask(ifo->requestmask6,
+                           D6_OPTION_RAPID_COMMIT) ||
+                           !dhcp6_getmoption(D6_OPTION_RAPID_COMMIT, r, len))
+                       {
+                               valid_op = false;
+                               break;
+                       }
+                       /* Validate lease before setting state to REQUEST. */
                        /* FALLTHROUGH */
                case DH6S_REQUEST: /* FALLTHROUGH */
                case DH6S_RENEW: /* FALLTHROUGH */
@@ -2929,14 +2934,17 @@ dhcp6_handledata(void *arg)
 #endif
                                return;
                        }
+                       if (state->state == DH6S_DISCOVER)
+                               state->state = DH6S_REQUEST;
                        break;
                default:
-                       op = NULL;
+                       valid_op = false;
+                       break;
                }
                break;
        case DHCP6_ADVERTISE:
                if (state->state != DH6S_DISCOVER) {
-                       op = NULL;
+                       valid_op = false;
                        break;
                }
                /* RFC7083 */
@@ -3027,7 +3035,7 @@ dhcp6_handledata(void *arg)
                    ifp->name, op, r->type);
                return;
        }
-       if (op == NULL) {
+       if (!valid_op) {
                logger(ifp->ctx, LOG_WARNING,
                    "%s: invalid state for DHCP6 type %s (%d)",
                    ifp->name, op, r->type);
@@ -3064,10 +3072,10 @@ dhcp6_handledata(void *arg)
                return;
        }
 
-       has_new = 0;
+       has_new = false;
        TAILQ_FOREACH(ap, &state->addrs, next) {
                if (ap->flags & IPV6_AF_NEW) {
-                       has_new = 1;
+                       has_new = true;
                        break;
                }
        }