[Swan] Problem with SAupdate when SA does not exist in the kernel

[Mattias Walström]

Hi!
I have discovered a problem with a non-clean restart of the responder, I 
have 14 tunnels configured between one initiator and one responder. When 
I do a "killall -9 pluto" on the responder, it will force pluto to exit, 
without closing the connection. When pluto starts again I will get an 
error on the initiator for some of the tunnels (one to three tunnels 
will not come back up at all):

Jan  5 16:46:50 i pluto[2593]: | setup_half_ipsec_sa() hit fail:
Jan  5 16:46:50 i pluto[2593]: "ipsec7" #23: ERROR: netlink response for 
Add SA esp.17d54247 at 198.18.106.2 included errno 3: No such process

To solve this I have made sure that update will not fail even if there 
has been a problem adding the SA, but I am unsure if this is a proper 
solution.

I have seen the same problem for both libreswan 3.5 and openswan 2.6.38, 
but I have only tested to patch for openswan.

Regards
Mattias

Index: openswan-2.6.38/programs/pluto/kernel_netlink.c
===================================================================
--- openswan-2.6.38.orig/programs/pluto/kernel_netlink.c 2013-09-12 
11:35:45.853061103 +0200
+++ openswan-2.6.38/programs/pluto/kernel_netlink.c    2013-09-12 
12:09:50.948600196 +0200
@@ -393,6 +393,7 @@
          , description, text_said
          , -rsp.e.error
          , strerror(-rsp.e.error));
+    errno = -rsp.e.error;
      return FALSE;
      }

@@ -794,6 +795,7 @@
      } req;
      struct rtattr *attr;
      struct aead_alg *aead;
+    int ret;

      memset(&req, 0, sizeof(req));
      req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
@@ -990,8 +992,11 @@
          attr = (struct rtattr *)((char *)attr + attr->rta_len);
     }
  #endif
+    ret = send_netlink_msg(&req.n, NULL, 0, "Add SA", sa->text_said);
+    if (ret == FALSE && errno == ESRCH && req.n.nlmsg_type == 
XFRM_MSG_UPDSA)
+        return netlink_add_sa(sa, 0);

-    return send_netlink_msg(&req.n, NULL, 0, "Add SA", sa->text_said);
+    return ret;
  }

  /** netlink_del_sa - Delete an SA from the Kernel