X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/e04c2d50fd96f3f31bc96851c55c6efecc10469c..add23883a6378567be6b7866bc2ff2c32400a346:/server/peer.c

diff --git a/server/peer.c b/server/peer.c
index 25354f1a..f4d80665 100644
--- a/server/peer.c
+++ b/server/peer.c
@@ -1,6 +1,4 @@
 /* -*-c-*-
- *
- * $Id$
  *
  * Communication with the peer
  *
@@ -32,8 +30,10 @@
 
 /*----- Static variables --------------------------------------------------*/
 
-static peer *peers = 0;
+static sym_table byname;
+static addrmap byaddr;
 static sel_file sock;
+static unsigned nmobile;
 
 /*----- Tunnel table ------------------------------------------------------*/
 
@@ -123,6 +123,174 @@ found:
   p_pingdone(pg, PING_OK);
 }
 
+/* --- @p_rxupdstats@ --- *
+ *
+ * Arguments:	@peer *p@ = peer to update
+ *		@size_t n@ = size of incoming packet
+ *
+ * Returns:	---
+ *
+ * Use:		Updates the peer's incoming packet statistics.
+ */
+
+static void p_rxupdstats(peer *p, size_t n)
+{
+  p->st.t_last = time(0);
+  p->st.n_in++;
+  p->st.sz_in += n;
+}
+
+/* --- @p_encrypt@ --- *
+ *
+ * Arguments:	@peer *p@ = peer to encrypt message to
+ *		@int ty@ message type to send
+ *		@buf *bin, *bout@ = input and output buffers
+ *
+ * Returns:	---
+ *
+ * Use:		Convenience function for packet encryption.  Forces
+ *		renegotiation when necessary.  Check for the output buffer
+ *		being broken to find out whether the encryption was
+ *		successful.
+ */
+
+static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
+{
+  int err = ksl_encrypt(&p->ks, ty, bin, bout);
+
+  if (err == KSERR_REGEN) {
+    kx_start(&p->kx, 1);
+    err = 0;
+  }
+  if (!BOK(bout))
+    err = -1;
+  return (err);
+}
+
+/* --- @p_decrypt@ --- *
+ *
+ * Arguments:	@peer **pp@ = pointer to peer to decrypt message from
+ *		@addr *a@ = address the packet arrived on
+ *		@size_t n@ = size of original incoming packet
+ *		@int ty@ = message type to expect
+ *		@buf *bin, *bout@ = input and output buffers
+ *
+ * Returns:	Zero on success; nonzero on error.
+ *
+ * Use:		Convenience function for packet decryption.  Reports errors
+ *		and updates statistics appropriately.
+ *
+ *		If @*pp@ is null on entry and there are mobile peers then we
+ *		see if any of them can decrypt the packet.  If so, we record
+ *		@*a@ as the peer's new address and send a notification.
+ */
+
+static int p_decrypt(peer **pp, addr *a, size_t n,
+		     int ty, buf *bin, buf *bout)
+{
+  peer *p, *q;
+  peer_byaddr *pa, *qa;
+  int err = KSERR_DECRYPT;
+  unsigned f;
+
+  /* --- 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(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..."); )
+  } else if (nmobile)
+    T( trace(T_PEER, "peer: unknown source: trying mobile peers...") );
+  else {
+    p = 0;
+    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;
+    }
+  });
+
+  /* --- We've searched the mobile peers --- */
+
+searched:
+  if (!p) {
+    if (!q)
+      a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END);
+    else {
+      a_warn("PEER", "?PEER", p, "decrypt-failed",
+	     "error-code", "%d", err, A_END);
+      p_rxupdstats(q, n);
+    }
+    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);
+      p->byaddr = pa;
+      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++;
+    a_warn("PEER", "?PEER", p, "decrypt-failed",
+	   "error-code", "%d", err, A_END);
+    return (-1);
+  }
+  if (!BOK(bout))
+    return (-1);
+  return (0);
+}
+
 /* --- @p_read@ --- *
  *
  * Arguments:	@int fd@ = file descriptor to read from
@@ -175,28 +343,27 @@ static void p_read(int fd, unsigned mode, void *v)
     return;
   }
 
-  /* --- Find the appropriate peer --- */
+  /* --- Find the appropriate peer --- *
+   *
+   * At this stage, don't worry too much about whether we actually found it.
+   */
 
-  assert(a.sa.sa_family == AF_INET);
-  for (p = peers; p; p = p->next) {
-    if (p->spec.sa.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
-	p->spec.sa.sin.sin_port == a.sin.sin_port)
-      goto found;
-  }
-  a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
-  return;
+  p = p_findbyaddr(&a);
 
-found:
   IF_TRACING(T_PEER, {
-    trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
+    if (p) {
+      trace(T_PEER,
+	    "peer: packet received from `%s' from address INET %s %d",
+	    p_name(p), inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port));
+    } else {
+      trace(T_PEER, "peer: packet received from unknown address INET %s %d",
+	    inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port));
+    }
     trace_block(T_PACKET, "peer: packet contents", buf_i, n);
   })
 
   /* --- Pick the packet apart --- */
 
-  p->st.t_last = time(0);
-  p->st.n_in++;
-  p->st.sz_in += n;
   buf_init(&b, buf_i, n);
   if ((ch = buf_getbyte(&b)) < 0) {
     a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
@@ -210,15 +377,12 @@ found:
 	       "bad-packet",
 	       "unknown-type", "0x%02x", ch,
 	       A_END);
-	p->st.n_reject++;
+	if (p) p->st.n_reject++;
 	return;
       }
       buf_init(&bb, buf_o, sizeof(buf_o));
-      if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) {
-	p->st.n_reject++;
-	a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
+      if (p_decrypt(&p, &a, n, MSG_PACKET, &b, &bb))
 	return;
-      }
       if (BOK(&bb)) {
 	p->st.n_ipin++;
 	p->st.sz_ipin += BSZ(&b);
@@ -229,42 +393,43 @@ found:
       }
       break;
     case MSG_KEYEXCH:
+      if (!p) goto unexp;
+      p_rxupdstats(p, n);
       kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
       break;
     case MSG_MISC:
       switch (ch & MSG_TYPEMASK) {
 	case MISC_NOP:
+	  if (!p) goto unexp;
+	  p_rxupdstats(p, n);
 	  T( trace(T_PEER, "peer: received NOP packet"); )
 	  break;
 	case MISC_PING:
+	  if (!p) goto unexp;
+	  p_rxupdstats(p, n);
 	  buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
 	  p_txend(p);
 	  break;
 	case MISC_PONG:
+	  if (!p) goto unexp;
+	  p_rxupdstats(p, n);
 	  p_ponged(p, MISC_PONG, &b);
 	  break;
 	case MISC_EPING:
 	  buf_init(&bb, buf_t, sizeof(buf_t));
-	  if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
-	    p->st.n_reject++;
-	    a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
+	  if (p_decrypt(&p, &a, n, ch, &b, &bb))
 	    return;
-	  }
 	  if (BOK(&bb)) {
 	    buf_flip(&bb);
-	    if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPONG, &bb,
-			    p_txstart(p, MSG_MISC | MISC_EPONG)))
-	      kx_start(&p->kx, 0);
+	    p_encrypt(p, MSG_MISC | MISC_EPONG, &bb,
+		      p_txstart(p, MSG_MISC | MISC_EPONG));
 	    p_txend(p);
 	  }
 	  break;
 	case MISC_EPONG:
 	  buf_init(&bb, buf_t, sizeof(buf_t));
-	  if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
-	    p->st.n_reject++;
-	    a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
+	  if (p_decrypt(&p, &a, n, ch, &b, &bb))
 	    return;
-	  }
 	  if (BOK(&bb)) {
 	    buf_flip(&bb);
 	    p_ponged(p, MISC_EPONG, &bb);
@@ -273,13 +438,16 @@ found:
       }
       break;
     default:
-      p->st.n_reject++;
+      if (p) p->st.n_reject++;
       a_warn("PEER",
 	     "?PEER", p,
 	     "bad-packet",
-	     "unknown-category" "0x%02x", ch,
+	     "unknown-category", "0x%02x", ch,
 	     A_END);
       break;
+    unexp:
+      a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
+      break;
   }
 }
 
@@ -433,8 +601,7 @@ int p_pingsend(peer *p, ping *pg, unsigned type,
       buf_init(&bb, buf_t, sizeof(buf_t));
       p_pingwrite(pg, &bb);
       buf_flip(&bb);
-      if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPING, &bb, b))
-	kx_start(&p->kx, 0);
+      p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b);
       if (!BOK(b))
 	return (-1);
       p_txend(p);
@@ -492,8 +659,7 @@ void p_tun(peer *p, buf *b)
   buf *bb = p_txstart(p, MSG_PACKET);
 
   TIMER;
-  if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
-    kx_start(&p->kx, 0);
+  p_encrypt(p, MSG_PACKET, b, bb);
   if (BOK(bb) && BLEN(bb)) {
     p->st.n_ipout++;
     p->st.sz_ipout += BLEN(bb);
@@ -512,12 +678,8 @@ void p_tun(peer *p, buf *b)
 
 void p_keyreload(void)
 {
-  peer *p;
-
-  if (km_reload()) {
-    for (p = peers; p; p = p->next)
-      kx_newkeys(&p->kx);
-  }
+  if (km_reload())
+    FOREACH_PEER(p, { kx_newkeys(&p->kx); });
 }
 
 /* --- @p_interval@ --- *
@@ -531,11 +693,8 @@ void p_keyreload(void)
 
 void p_interval(void)
 {
-  peer *p;
-
   p_keyreload();
-  for (p = peers; p; p = p->next)
-    ksl_prune(&p->ks);
+  FOREACH_PEER(p, { ksl_prune(&p->ks); });
 }
 
 /* --- @p_stats@ --- *
@@ -624,6 +783,9 @@ void p_init(struct in_addr addr, unsigned port)
   sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
   sel_addfile(&sock);
   T( trace(T_PEER, "peer: created socket"); )
+
+  sym_create(&byname);
+  am_create(&byaddr);
 }
 
 /* --- @p_port@ --- *
@@ -657,6 +819,7 @@ unsigned p_port(void)
 static void p_keepalive(struct timeval *now, void *pv)
 {
   peer *p = pv;
+
   p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
   T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
   p_setkatimer(p);
@@ -695,41 +858,62 @@ static void p_setkatimer(peer *p)
 peer *p_create(peerspec *spec)
 {
   peer *p = CREATE(peer);
+  const tunnel_ops *tops = spec->tops;
+  int fd;
+  unsigned f;
+
+  p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f);
+  if (f) goto tidy_0;
+  p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f);
+  if (f) goto tidy_1;
+  p->byname->p = p->byaddr->p = p;
 
   T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
   p->spec = *spec;
-  p->spec.name = xstrdup(spec->name);
+  p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname);
+  if (spec->tag) p->spec.tag = xstrdup(spec->tag);
+  if (spec->privtag) p->spec.privtag = xstrdup(spec->privtag);
   p->ks = 0;
-  p->prev = 0;
   p->pings = 0;
   p->ifname = 0;
   memset(&p->st, 0, sizeof(stats));
   p->st.t_start = time(0);
-  if ((p->t = spec->tops->create(p, &p->ifname)) == 0)
-    goto tidy_0;
+  if (!(tops->flags & TUNF_PRIVOPEN))
+    fd = -1;
+  else if ((fd = ps_tunfd(tops, &p->ifname)) < 0)
+    goto tidy_2;
+  if ((p->t = tops->create(p, fd, &p->ifname)) == 0)
+    goto tidy_3;
+  T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'",
+	   p->ifname, p_name(p)); )
   p_setkatimer(p);
-  if (kx_init(&p->kx, p, &p->ks))
-    goto tidy_1;
-  p->next = peers;
-  if (peers)
-    peers->prev = p;
-  peers = p;
+  if (kx_init(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK))
+    goto tidy_4;
   a_notify("ADD",
-	    "?PEER", p,
-	    "%s", p->ifname,
-	    "?ADDR", &p->spec.sa,
-	    A_END);
-  a_notify("KXSTART", "?PEER", p, A_END);
+	   "?PEER", p,
+	   "%s", p->ifname,
+	   "?ADDR", &p->spec.sa,
+	   A_END);
+  if (!(p->spec.f & KXF_CORK)) {
+    a_notify("KXSTART", "?PEER", p, A_END);
     /* Couldn't tell anyone before */
+  }
+  if (p->spec.f & PSF_MOBILE) nmobile++;
   return (p);
 
-tidy_1:
-  if (spec->t_ka)
-    sel_rmtimer(&p->tka);
+tidy_4:
+  if (spec->t_ka) sel_rmtimer(&p->tka);
   xfree(p->ifname);
   p->t->ops->destroy(p->t);
+tidy_3:
+  if (fd >= 0) close(fd);
+tidy_2:
+  am_remove(&byaddr, p->byaddr);
+  if (p->spec.tag) xfree(p->spec.tag);
+  if (p->spec.privtag) xfree(p->spec.privtag);
+tidy_1:
+  sym_remove(&byname, p->byname);
 tidy_0:
-  xfree(p->spec.name);
   DESTROY(p);
   return (0);
 }
@@ -741,7 +925,28 @@ tidy_0:
  * Returns:	A pointer to the peer's name.
  */
 
-const char *p_name(peer *p) { return (p->spec.name); }
+const char *p_name(peer *p)
+  { if (p) return (p->spec.name); else return ("-"); }
+
+/* --- @p_tag@ --- *
+ *
+ * Arguments:	@peer *p@ = pointer to a peer block
+ *
+ * Returns:	A pointer to the peer's public key tag.
+ */
+
+const char *p_tag(peer *p)
+  { return (p->spec.tag ? p->spec.tag : p->spec.name); }
+
+/* --- @p_privtag@ --- *
+ *
+ * Arguments:	@peer *p@ = pointer to a peer block
+ *
+ * Returns:	A pointer to the peer's private key tag.
+ */
+
+const char *p_privtag(peer *p)
+  { return (p->spec.privtag ? p->spec.privtag : tag_priv); }
 
 /* --- @p_spec@ --- *
  *
@@ -752,6 +957,26 @@ const char *p_name(peer *p) { return (p->spec.name); }
 
 const peerspec *p_spec(peer *p) { return (&p->spec); }
 
+/* --- @p_findbyaddr@ --- *
+ *
+ * Arguments:	@const addr *a@ = address to look up
+ *
+ * Returns:	Pointer to the peer block, or null if not found.
+ *
+ * Use:		Finds a peer by address.
+ */
+
+peer *p_findbyaddr(const addr *a)
+{
+  peer_byaddr *pa;
+
+  if ((pa = am_find(&byaddr, a, 0, 0)) != 0) {
+    assert(pa->p);
+    return (pa->p);
+  }
+  return (0);
+}
+
 /* --- @p_find@ --- *
  *
  * Arguments:	@const char *name@ = name to look up
@@ -763,11 +988,10 @@ const peerspec *p_spec(peer *p) { return (&p->spec); }
 
 peer *p_find(const char *name)
 {
-  peer *p;
-  for (p = peers; p; p = p->next) {
-    if (strcmp(name, p->spec.name) == 0)
-      return (p);
-  }
+  peer_byname *pn;
+
+  if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0)
+    return (pn->p);
   return (0);
 }
 
@@ -788,34 +1012,48 @@ void p_destroy(peer *p)
   a_notify("KILL", "%s", p->spec.name, A_END);
   ksl_free(&p->ks);
   kx_free(&p->kx);
-  if (p->ifname)
-    xfree(p->ifname);
+  if (p->spec.f & PSF_MOBILE) nmobile--;
+  if (p->ifname) xfree(p->ifname);
+  if (p->spec.tag) xfree(p->spec.tag);
+  if (p->spec.privtag) xfree(p->spec.privtag);
   p->t->ops->destroy(p->t);
-  if (p->spec.t_ka)
-    sel_rmtimer(&p->tka);
+  if (p->spec.t_ka) sel_rmtimer(&p->tka);
   for (pg = p->pings; pg; pg = ppg) {
     ppg = pg->next;
     p_pingdone(pg, PING_PEERDIED);
   }
-  if (p->next)
-    p->next->prev = p->prev;
-  if (p->prev)
-    p->prev->next = p->next;
-  else
-    peers = p->next;
+  sym_remove(&byname, p->byname);
+  am_remove(&byaddr, p->byaddr);
   DESTROY(p);
 }
 
-/* --- @p_first@, @p_next@ --- *
+/* --- @p_mkiter@ --- *
+ *
+ * Arguments:	@peer_iter *i@ = pointer to an iterator
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes the iterator.
+ */
+
+void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); }
+
+/* --- @p_next@ --- *
  *
- * Arguments:	@peer *p@ = a peer block
+ * Arguments:	@peer_iter *i@ = pointer to an iterator
  *
- * Returns:	@peer_first@ returns the first peer in some ordering;
- *		@peer_next@ returns the peer following a given one in the
- *		same ordering.  Null is returned for the end of the list.
+ * Returns:	Next peer, or null if at the end.
+ *
+ * Use:		Returns the next peer.
  */
 
-peer *p_first(void) { return (peers); }
-peer *p_next(peer *p) { return (p->next); }
+peer *p_next(peer_iter *i)
+{
+  peer_byname *pn;
+
+  if ((pn = sym_next(&i->i)) == 0)
+    return (0);
+  return (pn->p);
+}
 
 /*----- That's all, folks -------------------------------------------------*/