Fix fatal error at switching remotes (#629)

If remote server has been resolved to multiple addresses, at
least one connection attempt has been made and connection to
the last address was skipped by management - resolved earlier
link socket addrinfo objects will not be cleared neither on
instance close nor in the next connection entry loop.
This causes fatal error assert:

    >REMOTE:openvpn.net,1194,udp
    remote ACCEPT
    SUCCESS: remote command succeeded
    >REMOTE:openvpn.net,1194,udp
    remote SKIP
    SUCCESS: remote command succeeded
    >FATAL:Assertion failed at init.c:504
(c->c1.link_socket_addr.current_remote == NULL)

Fix this behaviour by cleaning stale addrinfo objects.

v2: better comment placement and too long length fix

Signed-off-by: Vladislav Grishenko <themiron@yandex-team.ru>
Acked-by: Lev Stipakov <lstipakov@gmail.com>
Message-Id: <20200916141755.1923-1-themiron@yandex-team.ru>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21019.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/init.c b/src/openvpn/init.c
index a785934a69b95013485a0a9c795267468de20a82..d1ad5c8f7560d5890eacf58224925179b876adc7 100644 (file)
--- a/src/openvpn/init.c
+++ b/src/openvpn/init.c
@@ -500,6 +500,17 @@ next_connection_entry(struct context *c)
                  */
                 if (!c->options.persist_remote_ip)
                 {
+                    /* Connection entry addrinfo objects might have been
+                     * resolved earlier but the entry itself might have been
+                     * skipped by management on the previous loop.
+                     * If so, clear the addrinfo objects as close_instance does
+                     */
+                    if (c->c1.link_socket_addr.remote_list)
+                    {
+                        clear_remote_addrlist(&c->c1.link_socket_addr,
+                                              !c->options.resolve_in_advance);
+                    }
+
                     /* close_instance should have cleared the addrinfo objects */
                     ASSERT(c->c1.link_socket_addr.current_remote == NULL);
                     ASSERT(c->c1.link_socket_addr.remote_list == NULL);