X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/88622d1dc9b1c03e95552817151047e574b312d4..61682d3405e6b7c72ec8295fec1467333e336b65:/server/peer.c

diff --git a/server/peer.c b/server/peer.c
index a62b20a8..308ab1d1 100644
--- a/server/peer.c
+++ b/server/peer.c
@@ -188,45 +188,79 @@ static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
 static int p_decrypt(peer **pp, addr *a, size_t n,
 		     int ty, buf *bin, buf *bout)
 {
-  peer *p;
-  peer_byaddr *pa;
+  peer *p, *q;
+  peer_byaddr *pa, *qa;
   int err = KSERR_DECRYPT;
   unsigned f;
 
-  if (*pp) {
-    p = *pp;
+  /* --- If we have a match on the source address then try that first --- */
+
+  q = *pp;
+  if (q) {
     T( trace(T_PEER, "peer: decrypting packet from known peer `%s'",
-	     p_name(p)); )
-    err = ksl_decrypt(&p->ks, ty, bin, bout);
-  } else {
+	     p_name(q)); )
+    if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) != KSERR_DECRYPT ||
+	!(q->spec.f & PSF_MOBILE) || nmobile == 1) {
+      p = q;
+      goto match;
+    }
+    T( trace(T_PEER, "peer: failed to decrypt: try other mobile peers...",
+	     p_name(q)); )
+  } else if (nmobile)
+    T( trace(T_PEER, "peer: unknown source: trying mobile peers..."); )
+  else {
     p = 0;
-    if (nmobile) {
-      T( trace(T_PEER, "peer: unknown source: trying mobile peers..."); )
-      FOREACH_PEER(q, {
-	if (!(q->spec.f & PSF_MOBILE)) continue;
-	if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) == KSERR_DECRYPT) {
-	  T( trace(T_PEER, "peer: peer `%s' failed to decrypt",
-		   p_name(q)); )
-	  continue;
-	} else {
-	  p = *pp = q;
-	  IF_TRACING(T_PEER, {
-	    if (!err)
-	      trace(T_PEER, "peer: peer `%s' reports success", p_name(p));
-	    else {
-	      trace(T_PEER, "peer: peer `%s' reports decryption error %d",
-		    p_name(p), err);
-	    }
-	  })
-	  break;
+    goto searched;
+  }
+
+  /* --- See whether any mobile peer is interested --- */
+
+  p = 0;
+  FOREACH_PEER(qq, {
+    if (qq == q || !(qq->spec.f & PSF_MOBILE)) continue;
+    if ((err = ksl_decrypt(&qq->ks, ty, bin, bout)) == KSERR_DECRYPT) {
+      T( trace(T_PEER, "peer: peer `%s' failed to decrypt",
+	       p_name(qq)); )
+	continue;
+    } else {
+      p = qq;
+      IF_TRACING(T_PEER, {
+	if (!err)
+	  trace(T_PEER, "peer: peer `%s' reports success", p_name(qq));
+	else {
+	  trace(T_PEER, "peer: peer `%s' reports decryption error %d",
+		p_name(qq), err);
 	}
-      });
+      })
+      break;
     }
-    if (!p) {
+  });
+
+  /* --- We've searched the mobile peers --- */
+
+searched:
+  if (!p) {
+    if (!q)
       a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END);
-      return (-1);
+    else {
+      a_warn("PEER", "?PEER", p, "decrypt-failed",
+	     "error-code", "%d", err, A_END);
+      p_rxupdstats(q, n);
     }
-    if (!err) {
+    return (-1);
+  }
+
+  /* --- We found one that accepted, so update the peer's address --- *
+   *
+   * If we had an initial guess of which peer this packet came from -- i.e.,
+   * @q@ is not null -- then swap the addresses over.  This doesn't leave the
+   * evicted peer in an especially good state, but it ought to get sorted out
+   * soon enough.
+   */
+
+  if (!err) {
+    *pp = p;
+    if (!q) {
       T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); )
       pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f); assert(!f);
       am_remove(&byaddr, p->byaddr);
@@ -234,8 +268,18 @@ static int p_decrypt(peer **pp, addr *a, size_t n,
       pa->p = p;
       p->spec.sa = *a;
       a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
+    } else {
+      T( trace(T_PEER, "peer: swapping addresses for `%s' and `%s'",
+	       p_name(p), p_name(q)); )
+      pa = p->byaddr; qa = q->byaddr;
+      pa->p = q; q->byaddr = pa; q->spec.sa = p->spec.sa;
+      qa->p = p; p->byaddr = qa; p->spec.sa = *a;
+      a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
+      a_notify("NEWADDR", "?PEER", q, "?ADDR", &q->spec.sa, A_END);
     }
   }
+
+match:
   p_rxupdstats(p, n);
   if (err) {
     if (p) p->st.n_reject++;