1. openvpn
  2. Commit 238ac1785f08e4cde4c095629c94f2b9bcc977fa
Browse code

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>
(cherry picked from commit 419051c96e9fb1f3202fd67733aa3b6a4bbc3181)

Arne Schwabe authored on 2022/12/14 07:54:29
Showing 3 changed files
src/openvpn/dco.c
History View file @ 238ac17
... ... 
@@ -130,7 +130,7 @@ dco_get_secondary_key(struct tls_multi *multi, const struct key_state *primary)
130 130 
     return NULL;
131 131 
 }
132 132
133 
-void
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+bool
134 134 
 dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
135 135 
 {
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     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)
140 140 
      */
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     if (multi->dco_keys_installed == 0)
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     {
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-        return;
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+        return true;
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     }
145 145
146 146 
     struct key_state *primary = tls_select_encryption_key(multi);
... ... 
@@ -155,18 +155,18 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
155 155 
         if (ret < 0)
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         {
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             msg(D_DCO, "Cannot delete primary key during wipe: %s (%d)", strerror(-ret), ret);
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-            return;
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+            return false;
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         }
160 160
161 161 
         ret = dco_del_key(dco, multi->dco_peer_id, OVPN_KEY_SLOT_SECONDARY);
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         if (ret < 0)
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         {
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             msg(D_DCO, "Cannot delete secondary key during wipe: %s (%d)", strerror(-ret), ret);
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-            return;
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+            return false;
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         }
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         multi->dco_keys_installed = 0;
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-        return;
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+        return true;
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     }
171 171
172 172 
     /* 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)
198 198 
         if (ret < 0)
199 199 
         {
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             msg(D_DCO, "Cannot swap keys: %s (%d)", strerror(-ret), ret);
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-            return;
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+            return false;
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         }
203 203
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         primary->dco_status = DCO_INSTALLED_PRIMARY;
... ... 
@@ -216,7 +216,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
216 216 
         if (ret < 0)
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         {
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             msg(D_DCO, "Cannot delete secondary key: %s (%d)", strerror(-ret), ret);
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-            return;
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+            return false;
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         }
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         multi->dco_keys_installed = 1;
222 222 
     }
... ... 
@@ -230,6 +230,7 @@ dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
230 230 
             ks->dco_status = DCO_NOT_INSTALLED;
231 231 
         }
232 232 
     }
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+    return true;
233 234 
 }
234 235
235 236 
 static bool
src/openvpn/dco.h
History View file @ 238ac17
... ... 
@@ -164,9 +164,11 @@ int init_key_dco_bi(struct tls_multi *multi, struct key_state *ks,
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  *
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  * @param dco           DCO device context
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  * @param multi         TLS multi instance
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+ *
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+ * @return              returns false if an error occurred that is not
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+ *                      recoverable and should reset the connection
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  */
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-void dco_update_keys(dco_context_t *dco, struct tls_multi *multi);
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-
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+bool dco_update_keys(dco_context_t *dco, struct tls_multi *multi);
170 172 
 /**
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  * Install a new peer in DCO - to be called by a CLIENT (or P2P) instance
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  *
... ... 
@@ -312,10 +314,11 @@ init_key_dco_bi(struct tls_multi *multi, struct key_state *ks,
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     return 0;
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 }
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-static inline void
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+static inline bool
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 dco_update_keys(dco_context_t *dco, struct tls_multi *multi)
317 317 
 {
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     ASSERT(false);
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+    return false;
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 }
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321 322 
 static inline int
src/openvpn/forward.c
History View file @ 238ac17
... ... 
@@ -151,7 +151,12 @@ check_dco_key_status(struct context *c)
151 151 
         return;
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     }
153 153
154 
-    dco_update_keys(&c->c1.tuntap->dco, c->c2.tls_multi);
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+    if (!dco_update_keys(&c->c1.tuntap->dco, c->c2.tls_multi))
155 
+    {
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+        /* Something bad happened. Kill the connection to
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+         * be able to recover. */
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+        register_signal(c, SIGUSR1, "dco update keys error");
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+    }
155 160 
 }
156 161
157 162 
 /*