[ViewVC] Diff of: cvs/gvpe/src/vpn.C

Comparing gvpe/src/vpn.C (file contents):
Revision 1.56 by root, Tue Feb 8 23:11:36 2011 UTC vs.
Revision 1.71 by root, Thu Oct 6 03:25:54 2022 UTC

 /*
     vpn.C -- handle the protocol, encryption, handshaking etc.
-    Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de>
+    Copyright (C) 2003-2008,2010,2011,2013 Marc Lehmann <gvpe@schmorp.de>
     This file is part of GVPE.
     GVPE is free software; you can redistribute it and/or modify it
     under the terms of the GNU General Public License as published by the
 #include <cstdlib>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
+#include <sys/stat.h>
 #include <errno.h>
 #include <time.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/socket.h>
 #include "connection.h"
 #include "util.h"
 #include "vpn.h"
+using namespace std;
 vpn network; // THE vpn (bad design...)
+/////////////////////////////////////////////////////////////////////////////
+// hopefully temporary workaround for rare buffer full conditions
+// if it happens, usually instantly retrying or retrying ~5ms later
+// is good enough with current network technologies/kernels
+static ssize_t
+xsendto (int fd, const void *buf, size_t len, int flags,
+         const struct sockaddr *sa, socklen_t salen)
+{
+  ssize_t res;
+  for (int retry = 0; retry <= 13; ++retry) // ~100ms
+    {
+      res = sendto (fd, buf, len, flags, sa, salen);
+      if (res >= 0 || errno != ENOBUFS)
+        break;
+      struct timespec ts = { 0, 1000 * retry };
+      nanosleep (&ts, 0);
+    }
+  return res;
+}
 /////////////////////////////////////////////////////////////////////////////
 static void inline
 set_tos (int fd, int &tos_prev, int tos)
 {
   // the tunnel device mtu should be the physical mtu - overhead
   // the tricky part is rounding to the cipher key blocksize
   int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD;
   mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion
-  mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round
+  mtu -= mtu % BLOCK_SIZE (CIPHER); // round
   mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again
   char *env;
   asprintf (&env, "CONFBASE=%s", confbase); putenv (env);
   asprintf (&env, "IFNAME=%s", tap->interface ()); putenv (env);
 inline const char *
 vpn::script_if_up ()
 {
   script_init_env ();
-  char *filename;
+  return conf.config_filename (::conf.script_if_up, "if-up");
-  asprintf (&filename,
-            "%s/%s",
-            confbase,
-            ::conf.script_if_up ? ::conf.script_if_up : "if-up");
-  return filename;
 }
 int
 vpn::setup_socket (u8 prot, int family, int type, int proto)
 {
       icmpv4_fd = setup_socket (PROT_ICMPv4, PF_INET, SOCK_RAW, IPPROTO_ICMP);
       if (icmpv4_fd < 0)
         return -1;
+// no clue where trhis is actually defined
+#if !defined(ICMP_FILTER) && defined(__linux)
+  #define ICMP_FILTER 1
+#endif
 #ifdef ICMP_FILTER
       {
-        icmp_filter oval;
+        uint32_t oval;
-        oval.data = 0xffffffff;
+        oval = 0;
         if (::conf.icmp_type < 32)
-          oval.data &= ~(1 << ::conf.icmp_type);
+          oval |= 1 << ::conf.icmp_type;
+        oval = ~oval;
         setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval);
       }
 #endif
   return 0;
 }
 bool
+vpn::drop_privileges ()
+{
+  if (::conf.change_root)
+    {
+      if (!strcmp (::conf.change_root, "/"))
+        {
+          char dir [L_tmpnam];
+          if (!tmpnam (dir))
+            {
+              slog (L_CRIT, _("unable to create anonymous root path."));
+              return false;
+            }
+          if (mkdir (dir, 0700))
+            {
+              slog (L_CRIT, _("unable to create anonymous root directory."));
+              return false;
+            }
+          if (chdir (dir))
+            {
+              slog (L_CRIT, _("unable to change to anonymous root directory."));
+              return false;
+            }
+          if (rmdir (dir))
+            slog (L_ERR, _("unable to remove anonymous root directory, continuing."));
+        }
+      else
+        {
+          if (chdir (::conf.change_root))
+            {
+              slog (L_CRIT, _("%s: unable to change to specified root directory."), ::conf.change_root);
+              return false;
+            }
+        }
+      if (chroot ("."))
+        {
+          slog (L_CRIT, _("unable to set new root directory."));
+          return false;
+        }
+      if (chdir ("/"))
+        {
+          slog (L_CRIT, _("unable to set cwd to new root directory."));
+          return false;
+        }
+    }
+  if (::conf.change_gid)
+    if (setgid (::conf.change_gid))
+      {
+        slog (L_CRIT, _("unable to change group id to %d."), ::conf.change_gid);
+        return false;
+      }
+  if (::conf.change_uid)
+    if (setuid (::conf.change_uid))
+      {
+        slog (L_CRIT, _("unable to change user id to %d."), ::conf.change_uid);
+        return false;
+      }
+  return true;
+}
+bool
 vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
 {
   set_tos (ipv4_fd, ipv4_tos, tos);
-  sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
+  xsendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
   return true;
 }
 static u16
   hdr->code = 255;
   hdr->checksum = 0;
   hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len);
   set_tos (icmpv4_fd, icmpv4_tos, tos);
-  sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
+  xsendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
   return true;
 }
 #endif
 bool
 vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
 {
   set_tos (udpv4_fd, udpv4_tos, tos);
-  sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
+  xsendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ());
   return true;
 }
 void
         (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len);
   if (src == 0 || src > conns.size ()
       || dst > conns.size ()
       || pkt->typ () >= vpn_packet::PT_MAX)
-    slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)."),
-          (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
-  else if (dst > conns.size ())
     slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)."),
           (const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ());
   else
     {
       connection *c = conns[src - 1];
 vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos)
 {
   switch (si.prot)
     {
       case PROT_IPv4:
-        return send_ipv4_packet (pkt, si, tos);
+        return send_ipv4_packet   (pkt, si, tos);
       case PROT_UDPv4:
-        return send_udpv4_packet (pkt, si, tos);
+        return send_udpv4_packet  (pkt, si, tos);
 #if ENABLE_TCP
       case PROT_TCPv4:
-        return send_tcpv4_packet (pkt, si, tos);
+        return send_tcpv4_packet  (pkt, si, tos);
 #endif
 #if ENABLE_ICMP
       case PROT_ICMPv4:
         return send_icmpv4_packet (pkt, si, tos);
 #endif
 #if ENABLE_DNS
       case PROT_DNSv4:
-        return send_dnsv4_packet (pkt, si, tos);
+        return send_dnsv4_packet  (pkt, si, tos);
 #endif
       default:
         slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol."), (const char *)si);
     }
       if (len > 0)
         {
           pkt->len = len;
           // raw sockets deliver the ipv4 header, but don't expect it on sends
-          pkt->skip_hdr (IP_OVERHEAD);
+          pkt->skip_hdr (pkt->ipv4_hdr_len ());
           recv_vpn_packet (pkt, si);
         }
       else
         {
           if (hdr->type == ::conf.icmp_type
               && hdr->code == 255)
             {
               // raw sockets deliver the ipv4, but don't expect it on sends
               // this is slow, but...
-              pkt->skip_hdr (ICMP_OVERHEAD);
+              pkt->skip_hdr (pkt->ipv4_hdr_len () + (ICMP_OVERHEAD - IP_OVERHEAD));
               recv_vpn_packet (pkt, si);
             }
         }
       else
 {
   for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i)
     {
       connection *o = *i;
-      if (!o->is_direct
-          && o->si.valid ()
+      if (o->si.valid ()
           && c->si != o->si
-          && c == find_router_for (o))
+          && c == find_router_for (o)
+          && !can_direct (THISNODE, o->conf))
         {
           slog (L_DEBUG, _("%s: can now route packets via %s, re-keying connection."),
                 o->conf->nodename, c->conf->nodename);
           o->rekey ();
         }

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Comparing gvpe/src/vpn.C (file contents): Revision 1.56 by root, Tue Feb 8 23:11:36 2011 UTC vs. Revision 1.71 by root, Thu Oct 6 03:25:54 2022 UTC

Diff Legend

Comparing gvpe/src/vpn.C (file contents):
Revision 1.56 by root, Tue Feb 8 23:11:36 2011 UTC vs.
Revision 1.71 by root, Thu Oct 6 03:25:54 2022 UTC