X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/b4e566689f469cc1cffe99e50e16a346d0f9832d..13a55605839046f6f42910de713f4a9b6c44dfd4:/peer.c

diff --git a/peer.c b/peer.c
index 87ea4e9e..50dec936 100644
--- a/peer.c
+++ b/peer.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: peer.c,v 1.11 2004/04/08 01:36:17 mdw Exp $
+ * $Id$
  *
  * Communication with the peer
  *
@@ -35,8 +35,94 @@
 static peer *peers = 0;
 static sel_file sock;
 
+/*----- Tunnel table ------------------------------------------------------*/
+
+const tunnel_ops *tunnels[] = {
+#ifdef TUN_LINUX
+  &tun_linux,
+#endif
+#ifdef TUN_BSD
+  &tun_bsd,
+#endif
+#ifdef TUN_UNET
+  &tun_unet,
+#endif
+  &tun_slip,
+  0
+}, *tun_default;
+
 /*----- Main code ---------------------------------------------------------*/
 
+/* --- @p_pingtype@ --- *
+ *
+ * Arguments:	@unsigned msg@ = message type
+ *
+ * Returns:	String to describe the message.
+ */
+
+static const char *p_pingtype(unsigned msg)
+{
+  switch (msg & MSG_TYPEMASK) {
+    case MISC_PING:
+    case MISC_PONG:
+      return "transport-ping";
+    case MISC_EPING:
+    case MISC_EPONG:
+      return "encrypted-ping";
+    default:
+      abort();
+  }
+}
+
+/* --- @p_ponged@ --- *
+ *
+ * Arguments:	@peer *p@ = peer packet arrived from
+ *		@unsigned msg@ = message type
+ *		@buf *b@ = buffer containing payload
+ *
+ * Returns:	---
+ *
+ * Use:		Processes a ping response.
+ */
+
+static void p_ponged(peer *p, unsigned msg, buf *b)
+{
+  uint32 id;
+  const octet *magic;
+  ping *pg;
+  
+  IF_TRACING(T_PEER, {
+    trace(T_PEER, "peer: received %s reply from %s",
+	  p_pingtype(msg), p->spec.name);
+    trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b));
+  })
+
+  if (buf_getu32(b, &id) ||
+      (magic = buf_get(b, sizeof(pg->magic))) == 0 ||
+      BLEFT(b)) {
+    a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END);
+    return;
+  }
+
+  for (pg = p->pings; pg; pg = pg->next) {
+    if (pg->id == id)
+      goto found;
+  }
+  a_warn("PEER",
+	 "?PEER", p,
+	 "unexpected-%s", p_pingtype(msg),
+	 "0x%08lx", (unsigned long)id,
+	 A_END);
+  return;
+
+found:
+  if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) {
+    a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END);
+    return;
+  }
+  p_pingdone(pg, PING_OK);
+}
+
 /* --- @p_read@ --- *
  *
  * Arguments:	@int fd@ = file descriptor to read from
@@ -50,7 +136,7 @@ static sel_file sock;
 
 static void p_read(int fd, unsigned mode, void *v)
 {
-  peer *p;
+  peer *p = 0;
   addr a;
   size_t sz;
   ssize_t n;
@@ -63,7 +149,29 @@ static void p_read(int fd, unsigned mode, void *v)
   sz = sizeof(addr);
   n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
   if (n < 0) {
-    a_warn("error reading socket: %s", strerror(errno));
+    a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
+    return;
+  }
+
+  /* --- If the packet is a greeting, don't check peers --- */
+
+  if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
+    IF_TRACING(T_PEER, {
+      trace(T_PEER, "peer: greeting received from INET %s %u",
+	    inet_ntoa(a.sin.sin_addr),
+	    (unsigned)ntohs(a.sin.sin_port));
+      trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
+    })
+    buf_init(&b, buf_i, n);
+    buf_getbyte(&b);
+    if (c_check(&b) || BLEFT(&b)) {
+      a_warn("PEER", "-", "invalid-greeting", A_END);
+      return;
+    }
+    a_notify("GREET",
+	     "?B64", buf_i + 1, (size_t)(n - 1),
+	     "?ADDR", &a,
+	     A_END);
     return;
   }
 
@@ -71,17 +179,18 @@ static void p_read(int fd, unsigned mode, void *v)
 
   assert(a.sa.sa_family == AF_INET);
   for (p = peers; p; p = p->next) {
-    if (p->peer.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
-	p->peer.sin.sin_port == a.sin.sin_port)
+    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("packet from unexpected peer: %s:%u",
-       inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port));
+  a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
   return;
 
 found:
-  T( trace(T_PEER, "peer: packet received from `%s'", p->name);
-     trace_block(T_PACKET, "peer: packet contents", buf_i, n); )
+  IF_TRACING(T_PEER, {
+    trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
+    trace_block(T_PACKET, "peer: packet contents", buf_i, n);
+  })
 
   /* --- Pick the packet apart --- */
 
@@ -90,37 +199,86 @@ found:
   p->st.sz_in += n;
   buf_init(&b, buf_i, n);
   if ((ch = buf_getbyte(&b)) < 0) {
-    a_warn("bad packet from `%s': no type byte", p->name);
+    a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
     return;
   }
   switch (ch & MSG_CATMASK) {
     case MSG_PACKET:
       if (ch & MSG_TYPEMASK) {
-	a_warn("unknown packet type from `%s'", p->name);
+	a_warn("PEER",
+	       "?PEER", p,
+	       "bad-packet",
+	       "unknown-type", "0x%02x", ch,
+	       A_END);
 	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("couldn't decrypt inbound packet from `%s'", p->name);
+	a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
 	return;
       }
       if (BOK(&bb)) {
 	p->st.n_ipin++;
 	p->st.sz_ipin += BSZ(&b);
-	tun_inject(&p->t, &bb);
+	p->t->ops->inject(p->t, &bb);
       } else {
 	p->st.n_reject++;
-	a_warn("packet build failed");
+	a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
       }
       break;
     case MSG_KEYEXCH:
       kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
       break;
+    case MSG_MISC:
+      switch (ch & MSG_TYPEMASK) {
+	case MISC_NOP:
+	  T( trace(T_PEER, "peer: received NOP packet"); )
+	  break;
+	case MISC_PING:
+	  buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
+	  p_txend(p);
+	  break;	
+	case MISC_PONG:
+	  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", "decrypt-failed", A_END);
+	    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_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);
+	    return;
+	  }
+	  if (BOK(&bb)) {
+	    buf_flip(&bb);
+	    p_ponged(p, MISC_EPONG, &bb);
+	  }
+	  break;
+      }
+      break;
     default:
       p->st.n_reject++;
-      a_warn("bad packet from `%s': unknown packet type", p->name);
+      a_warn("PEER",
+	     "?PEER", p,
+	     "bad-packet",
+	     "unknown-category" "0x%02x", ch,
+	     A_END);
       break;
   }
 }
@@ -152,23 +310,173 @@ buf *p_txstart(peer *p, unsigned msg)
  * Use:		Sends a packet to the peer.
  */
 
-void p_txend(peer *p)
+static void p_setkatimer(peer *);
+
+static int p_dotxend(peer *p)
 {
   if (!BOK(&p->b)) {
-    a_warn("packet build failed");
-    return;
+    a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
+    return (0);
   }
   IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
 				 BBASE(&p->b), BLEN(&p->b)); )
   if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
-	     0, &p->peer.sa, p->sasz) < 0)
-    a_warn("packet send to `%s' failed: %s", p->name, strerror(errno));
-  else {
+	     0, &p->spec.sa.sa, p->spec.sasz) < 0) {
+    a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
+    return (0);
+  } else {
     p->st.n_out++;
     p->st.sz_out += BLEN(&p->b);
+    return (1);
   }
 }
 
+void p_txend(peer *p)
+{
+  if (p_dotxend(p) && p->spec.t_ka) {
+    sel_rmtimer(&p->tka);
+    p_setkatimer(p);
+  }
+}
+
+/* --- @p_pingwrite@ --- *
+ *
+ * Arguments:	@ping *p@ = ping structure
+ *		@buf *b@ = buffer to write in
+ *
+ * Returns:	---
+ *
+ * Use:		Fills in a ping structure and writes the packet payload.
+ */
+
+static void p_pingwrite(ping *p, buf *b)
+{
+  static uint32 seq = 0;
+
+  p->id = U32(seq++);
+  GR_FILL(&rand_global, p->magic, sizeof(p->magic));
+  buf_putu32(b, p->id);
+  buf_put(b, p->magic, sizeof(p->magic));
+}
+
+/* --- @p_pingdone@ --- *
+ *
+ * Arguments:	@ping *p@ = ping structure
+ *		@int rc@ = return code to pass on
+ *
+ * Returns:	---
+ *
+ * Use:		Disposes of a ping structure, maybe sending a notification.
+ */
+
+void p_pingdone(ping *p, int rc)
+{
+  if (p->prev) p->prev->next = p->next;
+  else p->p->pings = p->next;
+  if (p->next) p->next->prev = p->prev;
+  if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
+  T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
+	   (unsigned long)p->id, rc); )
+  if (rc >= 0) p->func(rc, p->arg);
+}
+
+/* --- @p_pingtimeout@ --- *
+ *
+ * Arguments:	@struct timeval *now@ = the time now
+ *		@void *pv@ = pointer to ping block
+ *
+ * Returns:	---
+ *
+ * Use:		Called when a ping times out.
+ */
+
+static void p_pingtimeout(struct timeval *now, void *pv)
+{
+  ping *p = pv;
+
+  T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
+  p_pingdone(p, PING_TIMEOUT);
+}
+
+/* --- @p_pingsend@ --- *
+ *
+ * Arguments:	@peer *p@ = destination peer
+ *		@ping *pg@ = structure to fill in
+ *		@unsigned type@ = message type
+ *		@unsigned long timeout@ = how long to wait before giving up
+ *		@void (*func)(int, void *)@ = callback function
+ *		@void *arg@ = argument for callback
+ *
+ * Returns:	Zero if successful, nonzero if it failed.
+ *
+ * Use:		Sends a ping to a peer.  Call @func@ with a nonzero argument
+ *		if we get an answer within the timeout, or zero if no answer.
+ */
+
+int p_pingsend(peer *p, ping *pg, unsigned type,
+	       unsigned long timeout,
+	       void (*func)(int, void *), void *arg)
+{
+  buf *b, bb;
+  struct timeval tv;
+
+  switch (type) {
+    case MISC_PING:
+      pg->msg = MISC_PONG;
+      b = p_txstart(p, MSG_MISC | MISC_PING);
+      p_pingwrite(pg, b);
+      p_txend(p);
+      break;
+    case MISC_EPING:
+      pg->msg = MISC_EPONG;
+      b = p_txstart(p, MSG_MISC | MISC_EPING);
+      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);
+      if (!BOK(b))
+	return (-1);
+      p_txend(p);
+      break;
+    default:
+      abort();
+      break;
+  }
+
+  pg->next = p->pings;
+  pg->prev = 0;
+  pg->p = p;
+  pg->func = func;
+  pg->arg = arg;
+  if (p->pings) p->pings->prev = pg;
+  p->pings = pg;
+  gettimeofday(&tv, 0);
+  tv.tv_sec += timeout;
+  sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
+  T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
+	   p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
+  return (0);
+}
+
+/* --- @p_greet@ --- *
+ *
+ * Arguments:	@peer *p@ = peer to send to
+ *		@const void *c@ = pointer to challenge
+ *		@size_t sz@ = size of challenge
+ *
+ * Returns:	---
+ *
+ * Use:		Sends a greeting packet.
+ */
+
+void p_greet(peer *p, const void *c, size_t sz)
+{
+  buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
+  buf_put(b, c, sz);
+  p_txend(p);
+}
+
 /* --- @p_tun@ --- *
  *
  * Arguments:	@peer *p@ = pointer to peer block
@@ -185,7 +493,7 @@ void p_tun(peer *p, buf *b)
 
   TIMER;
   if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
-    kx_start(&p->kx);
+    kx_start(&p->kx, 0);
   if (BOK(bb) && BLEN(bb)) {
     p->st.n_ipout++;
     p->st.sz_ipout += BLEN(bb);
@@ -193,6 +501,25 @@ void p_tun(peer *p, buf *b)
   }
 }
 
+/* --- @p_keyreload@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Forces a check of the daemon's keyring files.
+ */
+
+void p_keyreload(void)
+{
+  peer *p;
+
+  if (km_reload()) {
+    for (p = peers; p; p = p->next)
+      kx_newkeys(&p->kx);
+  }
+}
+
 /* --- @p_interval@ --- *
  *
  * Arguments:	---
@@ -204,16 +531,11 @@ void p_tun(peer *p, buf *b)
 
 void p_interval(void)
 {
-  peer *p, *pp;
-  int reload;
+  peer *p;
 
-  reload = km_interval();
-  for (p = peers; p; p = pp) {
-    pp = p->next;
-    if (reload)
-      kx_newkeys(&p->kx);
+  p_keyreload();
+  for (p = peers; p; p = p->next)
     ksl_prune(&p->ks);
-  }
 }
 
 /* --- @p_stats@ --- *
@@ -232,7 +554,7 @@ stats *p_stats(peer *p) { return (&p->st); }
  * Returns:	A pointer to the peer's interface name.
  */
 
-const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); }
+const char *p_ifname(peer *p) { return (p->t->ops->ifname(p->t)); }
 
 /* --- @p_addr@ --- *
  *
@@ -241,7 +563,7 @@ const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); }
  * Returns:	A pointer to the peer's address.
  */
 
-const addr *p_addr(peer *p) { return (&p->peer); }
+const addr *p_addr(peer *p) { return (&p->spec.sa); }
 
 /* --- @p_init@ --- *
  *
@@ -304,11 +626,47 @@ unsigned p_port(void)
   return (ntohs(a.sin.sin_port));
 }
 
+/* --- @p_keepalive@ --- *
+ *
+ * Arguments:	@struct timeval *now@ = the current time
+ *		@void *pv@ = peer to wake up
+ *
+ * Returns:	---
+ *
+ * Use:		Sends a keepalive ping message to its peer.
+ */
+
+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);
+}
+
+/* --- @p_setkatimer@ --- *
+ *
+ * Arguments:	@peer *p@ = peer to set
+ *
+ * Returns:	---
+ *
+ * Use:		Resets the keepalive timer thing.
+ */
+
+static void p_setkatimer(peer *p)
+{
+  struct timeval tv;
+
+  if (!p->spec.t_ka)
+    return;
+  gettimeofday(&tv, 0);
+  tv.tv_sec += p->spec.t_ka;
+  sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
+}
+
 /* --- @p_create@ --- *
  *
- * Arguments:	@const char *name@ = name for this peer
- *		@struct sockaddr *sa@ = socket address of peer
- *		@size_t sz@ = size of socket address
+ * Arguments:	@peerspec *spec@ = information about this peer
  *
  * Returns:	Pointer to the peer block, or null if it failed.
  *
@@ -316,31 +674,42 @@ unsigned p_port(void)
  *		by this point.
  */
 
-peer *p_create(const char *name, struct sockaddr *sa, size_t sz)
+peer *p_create(peerspec *spec)
 {
   peer *p = CREATE(peer);
-  T( trace(T_PEER, "peer: creating new peer `%s'", name); )
-  p->name = xstrdup(name);
+
+  T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
+  p->spec = *spec;
+  p->spec.name = xstrdup(spec->name);
   p->ks = 0;
   p->prev = 0;
-  memcpy(&p->peer.sa, sa, sz);
-  p->sasz = sz;
+  p->pings = 0;
   memset(&p->st, 0, sizeof(stats));
   p->st.t_start = time(0);
-  if (kx_init(&p->kx, p, &p->ks))
+  if ((p->t = spec->tops->create(p)) == 0)
     goto tidy_0;
-  if (tun_create(&p->t, 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;
+  a_notify("ADD",
+	    "?PEER", p,
+	    "%s", p->t->ops->ifname(p->t),
+	    "?ADDR", &p->spec.sa,
+	    A_END);
+  a_notify("KXSTART", "?PEER", p, A_END);
+    /* Couldn't tell anyone before */
   return (p);
 
 tidy_1:
-  kx_free(&p->kx);
+  if (spec->t_ka)
+    sel_rmtimer(&p->tka);
+  p->t->ops->destroy(p->t);
 tidy_0:
-  xfree(p->name);
+  xfree(p->spec.name);
   DESTROY(p);
   return (0);
 }
@@ -352,7 +721,16 @@ tidy_0:
  * Returns:	A pointer to the peer's name.
  */
 
-const char *p_name(peer *p) { return (p->name); }
+const char *p_name(peer *p) { return (p->spec.name); }
+
+/* --- @p_spec@ --- *
+ *
+ * Arguments:	@peer *p@ = pointer to a peer block
+ *
+ * Returns:	Pointer to the peer's specification
+ */
+
+const peerspec *p_spec(peer *p) { return (&p->spec); }
 
 /* --- @p_find@ --- *
  *
@@ -367,7 +745,7 @@ peer *p_find(const char *name)
 {
   peer *p;
   for (p = peers; p; p = p->next) {
-    if (strcmp(name, p->name) == 0)
+    if (strcmp(name, p->spec.name) == 0)
       return (p);
   }
   return (0);  
@@ -384,11 +762,20 @@ peer *p_find(const char *name)
 
 void p_destroy(peer *p)
 {
-  T( trace(T_PEER, "peer: destroying peer `%s'", p->name); )
+  ping *pg, *ppg;
+
+  T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
+  a_notify("KILL", "%s", p->spec.name, A_END);
   ksl_free(&p->ks);
   kx_free(&p->kx);
-  tun_destroy(&p->t);
-  xfree(p->name);
+  p->t->ops->destroy(p->t);
+  if (p->spec.t_ka)
+    sel_rmtimer(&p->tka);
+  xfree(p->spec.name);
+  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)