X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/d98625f4404ba4fca4f395bc72f15d68043d75b4..136f3f44e25317d5423b4bc0b075b297e6d00c93:/server/peer.c

diff --git a/server/peer.c b/server/peer.c
index ea6e09bb..dab3bfcf 100644
--- a/server/peer.c
+++ b/server/peer.c
@@ -29,29 +29,18 @@
 
 /*----- Global state ------------------------------------------------------*/
 
-sel_file udpsock[NADDRFAM];
+udpsocket udpsock[NADDRFAM];
 
 /*----- Static variables --------------------------------------------------*/
 
 static sym_table byname;
 static addrmap byaddr;
 static unsigned nmobile;
-
-/*----- 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;
+static struct tunnel_node {
+  struct tunnel_node *next;
+  const tunnel_ops *tops;
+} *tunnels, **tunnels_tail = &tunnels;
+const tunnel_ops *dflttun;
 
 /*----- Main code ---------------------------------------------------------*/
 
@@ -336,6 +325,10 @@ static void p_read(int fd, unsigned mode, void *v)
   ssize_t n;
   int ch;
   buf b, bb;
+#ifndef NTRACE
+  int ix = -1;
+  char name[NI_MAXHOST], svc[NI_MAXSERV];
+#endif
 
   /* --- Read the data --- */
 
@@ -346,19 +339,23 @@ static void p_read(int fd, unsigned mode, void *v)
     a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
     return;
   }
+  IF_TRACING(T_PEER, {
+    ix = afix(a.sa.sa_family);
+    getnameinfo(&a.sa, sz, name, sizeof(name), svc, sizeof(svc),
+		NI_NUMERICHOST | NI_NUMERICSERV);
+  })
 
   /* --- 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(T_PEER, "peer: greeting received from %s %s %s",
+	    aftab[ix].name, name, svc);
       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)) {
+    if (c_check(0, 0, &b) || BLEFT(&b)) {
       a_warn("PEER", "-", "invalid-greeting", A_END);
       return;
     }
@@ -379,11 +376,11 @@ static void p_read(int fd, unsigned mode, void *v)
   IF_TRACING(T_PEER, {
     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));
+	    "peer: packet received from `%s' from address %s %s %s",
+	    p_name(p), aftab[ix].name, name, svc);
     } 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(T_PEER, "peer: packet received from unknown address %s %s %s",
+	    aftab[ix].name, name, svc);
     }
     trace_block(T_PACKET, "peer: packet contents", buf_i, n);
   })
@@ -419,9 +416,8 @@ static void p_read(int fd, unsigned mode, void *v)
       }
       break;
     case MSG_KEYEXCH:
-      if (!p) goto unexp;
-      p_rxupdstats(p, n);
-      kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
+      if (p) p_rxupdstats(p, n);
+      if (kx_message(p ? &p->kx : 0, &a, ch & MSG_TYPEMASK, &b)) goto unexp;
       break;
     case MSG_MISC:
       switch (ch & MSG_TYPEMASK) {
@@ -461,6 +457,16 @@ static void p_read(int fd, unsigned mode, void *v)
 	    p_ponged(p, MISC_EPONG, &bb);
 	  }
 	  break;
+	case MISC_BYE:
+	  buf_init(&bb, buf_t, sizeof(buf_t));
+	  if (p_decrypt(&p, &a, n, ch, &b, &bb)) return;
+	  if (!(p->spec.f&PSF_EPHEM)) return;
+	  if (BOK(&bb)) {
+	    buf_flip(&bb);
+	    if (BSZ(&bb)) return;
+	    p_destroy(p, 0);
+	  }
+	  break;
       }
       break;
     default:
@@ -495,6 +501,35 @@ buf *p_txstart(peer *p, unsigned msg)
   return (&p->b);
 }
 
+/* --- @p_txaddr@ --- *
+ *
+ * Arguments:	@const addr *a@ = recipient address
+ *		@const void *p@ = pointer to packet to send
+ *		@size_t sz@ = length of packet
+ *
+ * Returns:	Zero if successful, nonzero on error.
+ *
+ * Use:		Sends a packet to an address which (possibly) isn't a current
+ *		peer.
+ */
+
+int p_txaddr(const addr *a, const void *p, size_t sz)
+{
+  socklen_t sasz = addrsz(a);
+  int i;
+
+  if ((i = afix(a->sa.sa_family)) < 0) {
+    a_warn("PEER", "?ADDR", a, "disabled-address-family", A_END);
+    return (-1);
+  }
+  IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet", p, sz); )
+  if (sendto(udpsock[i].sf.fd, p, sz, 0, &a->sa, sasz) < 0) {
+    a_warn("PEER", "?ADDR", a, "socket-write-error", "?ERRNO", A_END);
+    return (-1);
+  }
+  return (0);
+}
+
 /* --- @p_txend@ --- *
  *
  * Arguments:	@peer *p@ = pointer to peer block
@@ -516,7 +551,7 @@ static int p_dotxend(peer *p)
   }
   IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
 				 BBASE(&p->b), BLEN(&p->b)); )
-  if (sendto(udpsock[p->afix].fd, BBASE(&p->b), BLEN(&p->b),
+  if (sendto(udpsock[p->afix].sf.fd, BBASE(&p->b), BLEN(&p->b),
 	     0, &p->spec.sa.sa, sasz) < 0) {
     a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
     return (0);
@@ -770,67 +805,226 @@ void p_setifname(peer *p, const char *name)
 
 const addr *p_addr(peer *p) { return (&p->spec.sa); }
 
-/* --- @p_init@ --- *
+/* --- @p_bind@ --- *
  *
- * Arguments:	@struct in_addr addr@ = address to bind to
- *		@unsigned port@ = port number to listen to
+ * Arguments:	@struct addrinfo *ailist@ = addresses to bind to
  *
- * Returns:	---
+ * Returns:	Zero on success, @-1@ on failure.
  *
- * Use:		Initializes the peer system; creates the socket.
+ * Use:		Binds to the main UDP sockets.
  */
 
-void p_init(struct in_addr addr, unsigned port)
+int p_bind(struct addrinfo *ailist)
 {
-  int fd;
-  struct sockaddr_in sin;
+  int fd = -1;
   int len = PKBUFSZ;
+  int yes = 1;
+  int i;
+  struct addrinfo *ai;
+  unsigned port, lastport = 0;
+  addr a;
+  socklen_t sz;
 
-  /* --- Note on socket buffer sizes --- *
-   *
-   * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
-   * sizes I pass to @setsockopt@.  I'm not putting special-case code here
-   * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
-   * guessing me.
-   */
+  for (i = 0; i < NADDRFAM; i++) udpsock[i].sf.fd = -1;
+
+  for (ai = ailist; ai; ai = ai->ai_next) {
+    if ((i = afix(ai->ai_family)) < 0) continue;
+    if (udpsock[i].sf.fd != -1) continue;
+
+    /* --- Note on socket buffer sizes --- *
+     *
+     * For some bizarre reason, Linux 2.2 (at least) doubles the socket
+     * buffer sizes I pass to @setsockopt@.  I'm not putting special-case
+     * code here for Linux: BSD (at least TCPv2) does what I tell it rather
+     * than second-guessing me.
+     */
 
-  if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
-    die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
-  BURN(sin);
-  sin.sin_family = AF_INET;
-  sin.sin_addr = addr;
-  sin.sin_port = htons(port);
-  if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
-    die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
-  if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
-      setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
-    die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
-	strerror(errno));
+    if ((fd = socket(ai->ai_family, SOCK_DGRAM, 0)) < 0) {
+      a_warn("PEER", "-", "udp-socket", "%s", aftab[i].name,
+	     "create-failed", "?ERRNO", A_END);
+      goto fail;
+    }
+    if (i == AFIX_INET6 &&
+	setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes))) {
+      a_warn("PEER", "-", "udp-socket", "%s", aftab[i].name,
+	     "set-v6only-failed", "?ERRNO", A_END);
+      goto fail;
+    }
+    assert(ai->ai_addrlen <= sizeof(a));
+    memcpy(&a, ai->ai_addr, ai->ai_addrlen);
+    if ((port = getport(&a)) == 0 && lastport) setport(&a, lastport);
+    if (bind(fd, &a.sa, addrsz(&a))) {
+      a_warn("PEER", "-", "udp-socket", "%s", aftab[i].name,
+	     "bind-failed", "?ERRNO", A_END);
+      goto fail;
+    }
+    if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
+	setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
+      a_warn("PEER", "-", "udp-socket", "%s", aftab[i].name,
+	     "set-buffers-failed", "?ERRNO", A_END);
+      goto fail;
+    }
+    fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+    if (port)
+      udpsock[i].port = port;
+    else {
+      sz = sizeof(a);
+      if (getsockname(fd, &a.sa, &sz)) {
+	a_warn("PEER", "-", "udp-socket", "%s", aftab[i].name,
+	       "read-local-address-failed", "?ERRNO", A_END);
+	goto fail;
+      }
+      udpsock[i].port = lastport = getport(&a);
+    }
+    T( trace(T_PEER, "peer: created %s socket", aftab[i].name); )
+    sel_initfile(&sel, &udpsock[i].sf, fd, SEL_READ, p_read, 0);
+    sel_addfile(&udpsock[i].sf);
+    fd = -1;
   }
-  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
-  sel_initfile(&sel, &udpsock[AFIX_INET], fd, SEL_READ, p_read, 0);
-  sel_addfile(&udpsock[AFIX_INET]);
-  T( trace(T_PEER, "peer: created socket"); )
 
+  return (0);
+
+fail:
+  if (fd != -1) close(fd);
+  p_unbind();
+  return (-1);
+}
+
+/* --- @p_unbind@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Unbinds the UDP sockets.  There must not be any active peers,
+ *		and none can be created until the sockets are rebound.
+ */
+
+void p_unbind(void)
+{
+  int i;
+
+#ifndef NDEBUG
+  { peer_iter it; p_mkiter(&it); assert(!p_next(&it)); }
+#endif
+
+  for (i = 0; i < NADDRFAM; i++) {
+    if (udpsock[i].sf.fd == -1) continue;
+    sel_rmfile(&udpsock[i].sf);
+    close(udpsock[i].sf.fd);
+    udpsock[i].sf.fd = -1;
+  }
+}
+
+/* --- @p_init@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes the peer system.
+ */
+
+void p_init(void)
+{
   sym_create(&byname);
   am_create(&byaddr);
 }
 
-/* --- @p_port@ --- *
+/* --- @p_addtun@ --- *
  *
- * Arguments:	@int i@ = address family index to retrieve
+ * Arguments:	@const tunnel_ops *tops@ = tunnel ops to add
  *
- * Returns:	Port number used for socket.
+ * Returns:	Zero on success, @-1@ on failure.
+ *
+ * Use:		Adds a tunnel class to the list of known classes, if it
+ *		initializes properly.  If there is no current default tunnel,
+ *		then this one is made the default.
+ *
+ *		Does nothing if the tunnel class is already known.  So adding
+ *		a bunch of tunnels takes quadratic time, but there will be
+ *		too few to care about.
  */
 
-unsigned p_port(int i)
+int p_addtun(const tunnel_ops *tops)
 {
-  addr a;
-  socklen_t sz = sizeof(addr);
+  struct tunnel_node *tn;
+
+  for (tn = tunnels; tn; tn = tn->next)
+    if (tn->tops == tops) return (0);
+  if (tops->init()) return (-1);
+  tn = CREATE(struct tunnel_node);
+  tn->next = 0; tn->tops = tops;
+  *tunnels_tail = tn; tunnels_tail = &tn->next;
+  if (!dflttun) dflttun = tops;
+  return (0);
+}
+
+/* --- @p_setdflttun@ --- *
+ *
+ * Arguments:	@const tunnel_ops *tops@ = tunnel ops to set
+ *
+ * Returns:	---
+ *
+ * Use:		Sets the default tunnel.  It must already be registered.  The
+ *		old default is forgotten.
+ */
+
+void p_setdflttun(const tunnel_ops *tops)
+  { dflttun = tops; }
+
+/* --- @p_dflttun@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	A pointer to the current default tunnel operations, or null
+ *		if no tunnels are defined.
+ */
+
+const tunnel_ops *p_dflttun(void) { return (dflttun); }
+
+/* --- @p_findtun@ --- *
+ *
+ * Arguments:	@const char *name@ = tunnel name
+ *
+ * Returns:	Pointer to the tunnel operations, or null.
+ *
+ * Use:		Finds the operations for a named tunnel class.
+ */
 
-  if (getsockname(udpsock[i].fd, &a.sa, &sz))
-    die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
-  return (getport(&a));
+const tunnel_ops *p_findtun(const char *name)
+{
+  const struct tunnel_node *tn;
+
+  for (tn = tunnels; tn; tn = tn->next)
+    if (mystrieq(tn->tops->name, name) == 0) return (tn->tops);
+  return (0);
+}
+
+/* --- @p_mktuniter@ --- *
+ *
+ * Arguments:	@tuniter *i@ = pointer to iterator to initialize
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes a tunnel iterator.
+ */
+
+void p_mktuniter(tun_iter *i) { i->next = tunnels; }
+
+/* --- @p_nexttun@ --- *
+ *
+ * Arguments:	@tuniter *i@ = pointer to iterator
+ *
+ * Returns:	Pointer to the next tunnel's operations, or null.
+ */
+
+const tunnel_ops *p_nexttun(tun_iter *i)
+{
+  const struct tunnel_node *tn = i->next;
+
+  if (!tn) return (0);
+  else { i->next = tn->next; return (tn->tops); }
 }
 
 /* --- @p_keepalive@ --- *
@@ -900,6 +1094,7 @@ peer *p_create(peerspec *spec)
   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);
+  if (spec->knock) p->spec.knock = xstrdup(spec->knock);
   p->ks = 0;
   p->pings = 0;
   p->ifname = 0;
@@ -915,7 +1110,8 @@ peer *p_create(peerspec *spec)
   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, p->spec.f & PSF_KXMASK))
+  iv_addreason();
+  if (kx_setup(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK))
     goto tidy_4;
   a_notify("ADD",
 	   "?PEER", p,
@@ -933,6 +1129,7 @@ tidy_4:
   if (spec->t_ka) sel_rmtimer(&p->tka);
   xfree(p->ifname);
   p->t->ops->destroy(p->t);
+  iv_rmreason();
 tidy_3:
   if (fd >= 0) close(fd);
 tidy_2:
@@ -1026,17 +1223,28 @@ peer *p_find(const char *name)
 /* --- @p_destroy@ --- *
  *
  * Arguments:	@peer *p@ = pointer to a peer
+ *		@int bye@ = say goodbye to the peer?
  *
  * Returns:	---
  *
  * Use:		Destroys a peer.
  */
 
-void p_destroy(peer *p)
+void p_destroy(peer *p, int bye)
 {
   ping *pg, *ppg;
+  buf *b, bb;
 
   T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
+
+  if (bye) {
+    b = p_txstart(p, MSG_MISC | MISC_BYE);
+    buf_init(&bb, buf_t, sizeof(buf_t));
+    assert(BOK(&bb)); buf_flip(&bb);
+    p_encrypt(p, MSG_MISC | MISC_BYE, &bb, b);
+    p_txend(p);
+  }
+
   a_notify("KILL", "%s", p->spec.name, A_END);
   ksl_free(&p->ks);
   kx_free(&p->kx);
@@ -1044,6 +1252,7 @@ void p_destroy(peer *p)
   if (p->ifname) xfree(p->ifname);
   if (p->spec.tag) xfree(p->spec.tag);
   if (p->spec.privtag) xfree(p->spec.privtag);
+  if (p->spec.knock) xfree(p->spec.knock);
   p->t->ops->destroy(p->t);
   if (p->spec.t_ka) sel_rmtimer(&p->tka);
   for (pg = p->pings; pg; pg = ppg) {
@@ -1052,9 +1261,21 @@ void p_destroy(peer *p)
   }
   sym_remove(&byname, p->byname);
   am_remove(&byaddr, p->byaddr);
+  iv_rmreason();
   DESTROY(p);
 }
 
+/* --- @p_destroyall@ --- *
+ *
+ * Arguments:	---
+ *
+ * Returns:	---
+ *
+ * Use:		Destroys all of the peers, saying goodbye.
+ */
+
+void p_destroyall(void) { FOREACH_PEER(p, { p_destroy(p, 1); }); }
+
 /* --- @p_mkiter@ --- *
  *
  * Arguments:	@peer_iter *i@ = pointer to an iterator