Wireguard: Add user space support

2 files changed, 263 insertions, 3 deletions

diff --git a/Makefile.in b/Makefile.in
index e0ff4a1d..f3b47053 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -163,6 +163,7 @@ $(objdir)/sysdep/paths.h: Makefile
 	echo  >$@ "/* Generated by Makefile, don't edit manually! */"
 	echo >>$@ "#define PATH_CONFIG_FILE \"@CONFIG_FILE@\""
 	echo >>$@ "#define PATH_CONTROL_SOCKET \"@CONTROL_SOCKET@\""
+	echo >>$@ "#define PATH_RUNSTATEDIR \"$(runstatedir)\""
 	if test -n "@iproutedir@" ; then echo >>$@ "#define PATH_IPROUTE_DIR \"@iproutedir@\"" ; fi
 
 # Unit tests rules
diff --git a/proto/wireguard/wireguard.c b/proto/wireguard/wireguard.c
index 970a383f..261c0e6e 100644
--- a/proto/wireguard/wireguard.c
+++ b/proto/wireguard/wireguard.c
@@ -2,12 +2,259 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include "lib/lists.h"
+#include "lib/socket.h"
 #include "nest/protocol.h"
 #include "nest/iface.h"
 #include "sysdep/linux/wireguard.h"
+#include "sysdep/unix/unix.h"
 #include "wireguard.h"
 #include "proto/bgp/bgp.h"
 
+#define SOCKET_PATH PATH_RUNSTATEDIR "/wireguard/"
+
+static
+char *get_socket_path(struct wg_proto *p, char *buf, uint size)
+{
+  struct wg_config *c = (struct wg_config *) p->p.cf;
+  bsnprintf(buf, size, SOCKET_PATH "%s.sock", c->ifname);
+  return buf;
+}
+
+static
+bool has_userspace(struct wg_proto *p)
+{
+  struct wg_config *c = (struct wg_config *) p->p.cf;
+  struct stat sb;
+  char tmp[sizeof(struct sockaddr_un)];
+
+  if (stat(get_socket_path(p, tmp, sizeof(tmp)), &sb) == 0)
+    return (sb.st_mode & S_IFMT) == S_IFSOCK;
+  else
+    {
+      log(L_TRACE "WG: no socket %s", tmp);
+      return false;
+    }
+}
+
+/* NULL=receiving turned off, returns 1 to clear rx buffer */
+static
+int user_rx_hook(struct birdsock *sk, uint size)
+{
+  log(L_TRACE "WG: RX %d", size);
+  return 1;
+}
+
+static
+void user_tx_hook(struct birdsock *bs)
+{
+  log(L_TRACE "WG: TX");
+}
+
+/* errno or zero if EOF */
+static
+void user_err_hook(struct birdsock *bs, int err)
+{
+  /* if (err == 0) */
+  /*   return; */
+
+  log(L_TRACE "WG: ERR %d %s", err, bs->err);
+  if (bs->fd >= 0)
+    close(bs->fd);
+  bs->fd = -1;
+}
+
+static void
+wg_puts(const char *str, byte **buf, uint *size)
+{
+  int len = strlen(str);
+  if (0 < len && len < (int)*size)
+    {
+      strcpy(*buf, str);
+      *size -= len;
+      *buf += len;
+    }
+  else
+    *size = 0;
+}
+
+static void
+wg_put_str(const char *key, const char *value, byte **buf, uint *size)
+{
+  char tmp[128];
+
+  int len = snprintf(tmp, sizeof(tmp), "%s=%s\n", key, value);
+  if (0 < len && len < (int)*size)
+    {
+      strcpy(*buf, tmp);
+      *size -= len;
+      *buf += len;
+    }
+  else
+    *size = 0;
+}
+
+static void
+wg_put_u16(const char *key, u16 value, byte **buf, uint *size)
+{
+  char tmp[64];
+
+  int len = snprintf(tmp, sizeof(tmp), "%u", value);
+  if (len > 0)
+    wg_put_str(key, tmp, buf, size);
+  else
+    *size = 0;
+}
+
+static void
+wg_put_bool(const char *key, bool value, byte **buf, uint *size)
+{
+  char tmp[64];
+
+  if (value)
+    wg_put_str(key, "true", buf, size);
+}
+
+static void
+wg_put_key(const char *key, wg_key value, byte **buf, uint *size)
+{
+  char tmp[128];
+
+  for (uint i=0; i < sizeof(wg_key); i++)
+    bsnprintf(tmp+2*i, sizeof(tmp)-2*i, "%02x", value[i]);
+
+  wg_put_str(key, tmp, buf, size);
+}
+
+static void
+wg_put_endpoint(const char *key, const wg_endpoint *endpoint, byte **buf, uint *size)
+{
+  char tmp[INET6_ADDRSTRLEN + 16];
+  ip_addr ip;
+  struct iface *ifa = NULL;
+  uint port = 0;
+
+  if (sockaddr_read((sockaddr*)&endpoint->addr, endpoint->addr.sa_family,
+		    &ip, &ifa, &port) == 0)
+    {
+      char *pos = NULL;
+
+      if (ipa_is_ip4(ip))
+	pos = ip4_ntop(ipa_to_ip4(ip), tmp);
+      else
+	{
+	  tmp[0] = '[';
+	  pos = ip6_ntop(ipa_to_ip6(ip), tmp + 1);
+	  if (ifa)
+	    pos += bsprintf(pos, "%%%u", ifa->index);
+	  *pos++ = ']';
+	}
+      bsprintf(pos, ":%u", port);
+      wg_put_str("endpoint", tmp, buf, size);
+    }
+}
+
+static void
+wg_put_allowedip(wg_allowedip *allowedip, byte **buf, uint *size)
+{
+  char tmp[INET6_ADDRSTRLEN + 10];
+  ip_addr ip = IP6_NONE;
+
+  switch (allowedip->family)
+    {
+    case AF_INET:
+      ip = ipa_from_in4(allowedip->ip4);
+      break;
+    case AF_INET6:
+      ip = ipa_from_in6(allowedip->ip6);
+      break;
+    default:
+      return;
+    }
+
+  int res = bsnprintf(tmp, sizeof(tmp), "%I/%u", ip, allowedip->cidr);
+
+  if (res < 0)
+    {
+      *size = 0;
+      return;
+    }
+
+  wg_put_str("allowed_ip", tmp, buf, size);
+}
+
+static int
+user_put_device(wg_device *dev, byte **buf, uint *size)
+{
+  wg_put_u16("set", 1, buf, size);
+  wg_put_key("private_key", dev->private_key, buf, size);
+  wg_put_u16("listen_port", dev->listen_port, buf, size);
+  wg_put_bool("replace_peers", dev->flags & WGDEVICE_REPLACE_PEERS, buf, size);
+
+  wg_peer *peer = NULL;
+  wg_for_each_peer(dev, peer)
+    {
+      wg_put_key("public_key", peer->public_key, buf, size);
+      wg_put_endpoint("endpoint", &peer->endpoint, buf, size);
+      wg_put_bool("replace_allowed_ips", peer->flags & WGPEER_REPLACE_ALLOWEDIPS, buf, size);
+
+      wg_allowedip *allowedip = NULL;
+      wg_for_each_allowedip(peer, allowedip)
+	{
+	  wg_put_allowedip(allowedip, buf, size);
+	}
+    }
+  wg_puts("\n", buf, size);
+
+  if (size > 0)
+    return 0;
+  else
+    return -1;
+}
+
+static int
+user_set_device(struct wg_proto *p)
+{
+  struct wg_config *c = (struct wg_config *) p->p.cf;
+  char path[sizeof(struct sockaddr_un)];
+
+  bsnprintf(path, sizeof(path), SOCKET_PATH "%s.sock", c->ifname);
+
+  struct birdsock *sock = sk_new(p->p.pool);
+  sock->rx_hook = user_rx_hook;
+  sock->tx_hook = user_tx_hook;
+  sock->err_hook = user_err_hook;
+  int res = sk_connect_unix(sock, path);
+  log(L_TRACE "WG: socket %d %d %s", res, sock->fd, path);
+  if (res < 0)
+    return -1;
+
+  uint tbsize = 8192;
+  sk_set_tbsize(sock, tbsize);
+  sk_set_rbsize(sock, 16);
+  byte *pos = sock->tbuf;
+  uint size = tbsize;
+  int len = user_put_device(p->dev, &pos, &size);
+
+  log(L_TRACE "WG: put %d %s", size, sock->tbuf);
+
+  if (len < 0)
+    {
+      /* FIXME close */
+      return -1;
+    }
+  res = sk_send(sock, tbsize - size);
+  /* Send data, <0=err, >0=ok, 0=sleep */
+  log(L_TRACE "WG: send %d", res);
+
+  /* abort(); */
+  return -1;
+}
+
 static
 int get_device(struct wg_proto *p, wg_device **pdev, const char *device_name)
 {
@@ -79,6 +326,18 @@ int get_device(struct wg_proto *p, wg_device **pdev, const char *device_name)
   return 0;
 }
 
+static int
+set_device(struct wg_proto *p)
+{
+  if (has_userspace(p))
+    return user_set_device(p);
+  else
+    {
+      log(L_TRACE "WG: wg_set_device");
+      return wg_set_device(p->dev);
+    }
+}
+
 static void
 wg_init_entry(void *e_)
 {
@@ -455,7 +714,7 @@ wg_rt_notify(struct proto *P, struct channel *CH, struct network *n,
 	  }
 
 	  if (dirty) {
-	    int res = wg_set_device(dev);
+	    int res = set_device(p);
 	    log(L_TRACE "WG: wg_set_device %d", res);
 	  }
 	}
@@ -597,7 +856,7 @@ wg_rt_notify(struct proto *P, struct channel *CH, struct network *n,
 	      }
 	      
 	      peer->flags |= WGPEER_REPLACE_ALLOWEDIPS;
-	      int res = wg_set_device(dev);
+	      int res = set_device(p);
 	      log(L_TRACE "WG: wg_set_device %d", res);
 	    }
 	  }
@@ -664,7 +923,7 @@ wg_start(struct proto *P)
 
   if (get_device(p, &p->dev, cf->ifname) >= 0)
     {
-      int res = wg_set_device(p->dev);
+      int res = set_device(p);
       log(L_TRACE "WG: wg_set_device %d", res);
     }