Trigger a USR1 if dco_update_keys fails

When dco_update_keys fails, we are in some weird state that we are
unlikely to recover since what userspace and kernel space think of
the keys is very likely to not in sync anymore. So abandon the
connection if this happens.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20221213225430.1892940-2-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25679.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/dco.c b/src/openvpn/dco.c
index c250826ca5710796702bd07517d99f4273d61e59..5804ce73e422ac6fb6a528f246d12b8cf3dac6eb 100644 (file)
--- a/src/openvpn/dco.c
+++ b/src/openvpn/dco.c
@@ -130,7 +130,7 @@ dco_get_secondary_key(struct tls_multi *multi, const struct key_state *primary)
     return NULL;
 }
 
-void
+bool
 dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
 {
     msg(D_DCO_DEBUG, "%s: peer_id=%d", __func__, multi->dco_peer_id);
@@ -140,7 +140,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
      */
     if (multi->dco_keys_installed == 0)
     {
-        return;
+        return true;
     }
 
     struct key_state *primary = tls_select_encryption_key(multi);
@@ -155,18 +155,18 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
         if (ret < 0)
         {
             msg(D_DCO, "Cannot delete primary key during wipe: %s (%d)", strerror(-ret), ret);
-            return;
+            return false;
         }
 
         ret = dco_del_key(dco, multi->dco_peer_id, OVPN_KEY_SLOT_SECONDARY);
         if (ret < 0)
         {
             msg(D_DCO, "Cannot delete secondary key during wipe: %s (%d)", strerror(-ret), ret);
-            return;
+            return false;
         }
 
         multi->dco_keys_installed = 0;
-        return;
+        return true;
     }
 
     /* if we have a primary key, it must have been installed already (keys
@@ -198,7 +198,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
         if (ret < 0)
         {
             msg(D_DCO, "Cannot swap keys: %s (%d)", strerror(-ret), ret);
-            return;
+            return false;
         }
 
         primary->dco_status = DCO_INSTALLED_PRIMARY;
@@ -216,7 +216,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
         if (ret < 0)
         {
             msg(D_DCO, "Cannot delete secondary key: %s (%d)", strerror(-ret), ret);
-            return;
+            return false;
         }
         multi->dco_keys_installed = 1;
     }
@@ -230,6 +230,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
             ks->dco_status = DCO_NOT_INSTALLED;
         }
     }
+    return true;
 }
 
 static bool

diff --git a/src/openvpn/dco.h b/src/openvpn/dco.h
index 941060e0449236b792dc15cc09134fa1176d8bfb..701bbea12939d9af1ca1117555e5d47fe78b3d32 100644 (file)
--- a/src/openvpn/dco.h
+++ b/src/openvpn/dco.h
@@ -164,9 +164,11 @@ int init_key_dco_bi(struct tls_multi *multi, struct key_state *ks,
  *
  * @param dco           DCO device context
  * @param multi         TLS multi instance
+ *
+ * @return              returns false if an error occurred that is not
+ *                      recoverable and should reset the connection
  */
-void dco_update_keys(dco_context_t *dco, struct tls_multi *multi);
-
+bool dco_update_keys(dco_context_t *dco, struct tls_multi *multi);
 /**
  * Install a new peer in DCO - to be called by a CLIENT (or P2P) instance
  *
@@ -312,10 +314,11 @@ init_key_dco_bi(struct tls_multi *multi, struct key_state *ks,
     return 0;
 }
 
-static inline void
+static inline bool
 dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
 {
     ASSERT(false);
+    return false;
 }
 
 static inline int

diff --git a/src/openvpn/forward.c b/src/openvpn/forward.c
index 5cd7eaa6e46bf779fd7cfd9a60e0d4c8bf8bf0c8..8c1e49a3472c689c0fac99813fe46177d9d13ae1 100644 (file)
--- a/src/openvpn/forward.c
+++ b/src/openvpn/forward.c
@@ -151,7 +151,12 @@ check_dco_key_status(struct context *c)
         return;
     }
 
-    dco_update_keys(&c->c1.tuntap->dco, c->c2.tls_multi);
+    if (!dco_update_keys(&c->c1.tuntap->dco, c->c2.tls_multi))
+    {
+        /* Something bad happened. Kill the connection to
+         * be able to recover. */
+        register_signal(c, SIGUSR1, "dco update keys error");
+    }
 }
 
 /*