X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/f4c9c08fb4a558d880d183b65a12de3770c3860b..7737eb87d283d46b7a90caba20ac75c3214451d3:/server/peer.c

diff --git a/server/peer.c b/server/peer.c
index 57891e7b..27ac4a78 100644
--- a/server/peer.c
+++ b/server/peer.c
@@ -9,30 +9,32 @@
  *
  * This file is part of Trivial IP Encryption (TrIPE).
  *
- * TrIPE is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * TrIPE is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
  *
- * TrIPE is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * TrIPE is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with TrIPE; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 /*----- Header files ------------------------------------------------------*/
 
 #include "tripe.h"
 
+/*----- Global state ------------------------------------------------------*/
+
+udpsocket udpsock[NADDRFAM];
+
 /*----- Static variables --------------------------------------------------*/
 
 static sym_table byname;
 static addrmap byaddr;
-static sel_file sock;
 static unsigned nmobile;
 
 /*----- Tunnel table ------------------------------------------------------*/
@@ -167,6 +169,54 @@ static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
   return (err);
 }
 
+/* --- @p_updateaddr@ --- *
+ *
+ * Arguments:	@peer *p@ = pointer to peer block
+ *		@const addr *a@ = address to associate with this peer
+ *
+ * Returns:	Zero if the address was changed; @+1@ if it was already
+ *		right.
+ *
+ * Use:		Updates our idea of @p@'s address.
+ */
+
+int p_updateaddr(peer *p, const addr *a)
+{
+  peer *q;
+  peer_byaddr *pa, *qa;
+  int ix;
+  unsigned f;
+
+  /* --- Figure out how to proceed --- *
+   *
+   * If this address already belongs to a different peer, then swap the
+   * addresses over.  This doesn't leave the displaced peer in an especially
+   * good state, but it ought to get sorted out soon enough.
+   */
+
+  pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f);
+  if (f && pa->p == p)
+    return (+1);
+  else if (!f) {
+    T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); )
+    am_remove(&byaddr, p->byaddr);
+    p->byaddr = pa; p->spec.sa = *a; pa->p = p;
+    p->afix = afix(p->spec.sa.sa.sa_family); assert(p->afix >= 0);
+    a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
+    return (0);
+  } else {
+    q = pa->p; qa = p->byaddr;
+    T( trace(T_PEER, "peer: swapping addresses for `%s' and `%s'",
+	     p_name(p), p_name(q)); )
+    q->byaddr = qa; qa->p = q; q->spec.sa = p->spec.sa;
+    p->byaddr = pa; pa->p = p; p->spec.sa = *a;
+    ix = p->afix; p->afix = q->afix; q->afix = ix;
+    a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
+    a_notify("NEWADDR", "?PEER", q, "?ADDR", &q->spec.sa, A_END);
+    return (0);
+  }
+}
+
 /* --- @p_decrypt@ --- *
  *
  * Arguments:	@peer **pp@ = pointer to peer to decrypt message from
@@ -189,9 +239,7 @@ 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 --- */
 
@@ -249,33 +297,11 @@ searched:
     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.
-   */
+  /* --- We found one that accepted, so update the peer's address --- */
 
   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);
-    }
+    p_updateaddr(p, a);
   }
 
 match:
@@ -310,6 +336,10 @@ 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 --- */
 
@@ -320,19 +350,23 @@ 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;
     }
@@ -353,11 +387,11 @@ 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);
   })
@@ -393,9 +427,8 @@ 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) {
@@ -435,6 +468,16 @@ 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:
@@ -469,6 +512,35 @@ 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
@@ -482,14 +554,16 @@ static void p_setkatimer(peer *);
 
 static int p_dotxend(peer *p)
 {
+  socklen_t sasz = addrsz(&p->spec.sa);
+
   if (!BOK(&p->b)) {
     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->spec.sa.sa, p->spec.sasz) < 0) {
+  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);
   } else {
@@ -742,68 +816,88 @@ 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:	---
  *
  * Use:		Initializes the peer system; creates the socket.
  */
 
-void p_init(struct in_addr addr, unsigned port)
+void p_bind(struct addrinfo *ailist)
 {
   int fd;
-  struct sockaddr_in sin;
   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.
-   */
-
-  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));
+  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(ai->ai_family, SOCK_DGRAM, 0)) < 0)
+      die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
+    if (i == AFIX_INET6 &&
+	setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes))) {
+      die(EXIT_FAILURE, "failed to set IPv6-only state: %s",
+	  strerror(errno));
+    }
+    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)))
+      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));
+    }
+    fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+    sel_initfile(&sel, &udpsock[i].sf, fd, SEL_READ, p_read, 0);
+    sel_addfile(&udpsock[i].sf);
+    T( trace(T_PEER, "peer: created %s socket", aftab[i].name); )
+    if (port)
+      udpsock[i].port = port;
+    else {
+      sz = sizeof(a);
+      if (getsockname(fd, &a.sa, &sz)) {
+	die(EXIT_FAILURE, "failed to read local socket address: %s",
+	    strerror(errno));
+      }
+      udpsock[i].port = lastport = getport(&a);
+    }
   }
-  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
-  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@ --- *
+/* --- @p_init@ --- *
  *
  * Arguments:	---
  *
- * Returns:	Port number used for socket.
+ * Returns:	---
+ *
+ * Use:		Initializes the peer system.
  */
 
-unsigned p_port(void)
+void p_init(void)
 {
-  addr a;
-  socklen_t sz = sizeof(addr);
-
-  if (getsockname(sock.fd, &a.sa, &sz))
-    die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
-  assert(a.sa.sa_family == AF_INET);
-  return (ntohs(a.sin.sin_port));
+  sym_create(&byname);
+  am_create(&byaddr);
 }
 
 /* --- @p_keepalive@ --- *
@@ -873,9 +967,11 @@ 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;
+  p->afix = afix(p->spec.sa.sa.sa_family); assert(p->afix >= 0);
   memset(&p->st, 0, sizeof(stats));
   p->st.t_start = time(0);
   if (!(tops->flags & TUNF_PRIVOPEN))
@@ -887,7 +983,7 @@ 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))
+  if (kx_setup(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK))
     goto tidy_4;
   a_notify("ADD",
 	   "?PEER", p,
@@ -998,17 +1094,28 @@ 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 && (p->spec.f&PSF_EPHEM)) {
+    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);
@@ -1016,6 +1123,7 @@ 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) {