Fix server candidate selection logic

Flush all server candidates for unbound client in stateless mode
Fix initial server candidate promotion condition

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index e44be4831fcaca3cfd8635a9f7d3d01ce1d54640..cd8e43800dca33315047cd000262a5697c985be5 100644 (file)
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -60,6 +60,7 @@ static void dhcpv6_handle_ia_status_code(const enum dhcpv6_msg orig,
                bool handled_status_codes[_DHCPV6_Status_Max],
                int *ret);
 static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand);
+static void dhcpv6_clear_all_server_cand(void);
 
 static reply_handler dhcpv6_handle_reply;
 static reply_handler dhcpv6_handle_advert;
@@ -941,8 +942,13 @@ static int dhcpv6_handle_reply(enum dhcpv6_msg orig, _unused const int rc,
                        }
                }
        }
-       else if (ret > 0)
+       else if (ret > 0) {
+               // All server candidates can be cleared if not yet bound
+               if (!odhcp6c_is_bound())
+                       dhcpv6_clear_all_server_cand();
+
                t1 = refresh;
+       }
 
        return ret;
 }
@@ -1243,6 +1249,21 @@ static void dhcpv6_add_server_cand(const struct dhcpv6_server_cand *cand)
        odhcp6c_insert_state(STATE_SERVER_CAND, i * sizeof(*c), cand, sizeof(*cand));
 }
 
+static void dhcpv6_clear_all_server_cand(void)
+{
+       size_t cand_len, i;
+       struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
+
+       // Server candidates need deep delete for IA_NA/IA_PD
+       for (i = 0; i < cand_len / sizeof(*c); ++i) {
+               if (c[i].ia_na)
+                       free(c[i].ia_na);
+               if (c[i].ia_pd)
+                       free(c[i].ia_pd);
+       }
+       odhcp6c_clear_state(STATE_SERVER_CAND);
+}
+
 int dhcpv6_promote_server_cand(void)
 {
        size_t cand_len;
@@ -1255,7 +1276,7 @@ int dhcpv6_promote_server_cand(void)
        odhcp6c_clear_state(STATE_IA_NA);
        odhcp6c_clear_state(STATE_IA_PD);
 
-       if (!cand)
+       if (!cand_len)
                return -1;
 
        if (cand->has_noaddravail && na_mode == IA_MODE_TRY) {
@@ -1285,18 +1306,3 @@ int dhcpv6_promote_server_cand(void)
 
        return ret;
 }
-
-void dhcpv6_clear_all_server_cand(void)
-{
-       size_t cand_len, i;
-       struct dhcpv6_server_cand *c = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
-
-       // Server candidates need deep delete for IA_NA/IA_PD
-       for (i = 0; i < cand_len / sizeof(*c); ++i) {
-               if (c[i].ia_na)
-                       free(c[i].ia_na);
-               if (c[i].ia_pd)
-                       free(c[i].ia_pd);
-       }
-       odhcp6c_clear_state(STATE_SERVER_CAND);
-}

diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index 2c28c807d335e239e7e932a1219a78dd3b7eed51..15be59ae4de59ec94c2e91fc869f7a88f2af85b1 100644 (file)
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -233,7 +233,6 @@ void dhcpv6_set_ia_mode(enum odhcp6c_ia_mode na, enum odhcp6c_ia_mode pd);
 int dhcpv6_request(enum dhcpv6_msg type);
 int dhcpv6_poll_reconfigure(void);
 int dhcpv6_promote_server_cand(void);
-void dhcpv6_clear_all_server_cand(void);
 
 int init_rtnetlink(void);
 int set_rtnetlink_addr(int ifindex, const struct in6_addr *addr,