moving basic logic for launching nat-server helper to new NAT service

4 files changed, 422 insertions, 1 deletions

diff --git a/src/nat/Makefile.am b/src/nat/Makefile.am
index 6e96c41ff..0ca6dc1d2 100644
--- a/src/nat/Makefile.am
+++ b/src/nat/Makefile.am
@@ -96,7 +96,8 @@ libgnunetnatnew_la_LDFLAGS = \
 
 gnunet_service_nat_SOURCES = \
  gnunet-service-nat.c \
- gnunet-service-nat_stun.c gnunet-service-nat_stun.h
+ gnunet-service-nat_stun.c gnunet-service-nat_stun.h \
+ gnunet-service-nat_helper.c gnunet-service-nat_helper.h
 gnunet_service_nat_LDADD = \
   $(top_builddir)/src/util/libgnunetutil.la \
   $(top_builddir)/src/statistics/libgnunetstatistics.la \
diff --git a/src/nat/gnunet-service-nat.c b/src/nat/gnunet-service-nat.c
index 8499a9724..ffee6374e 100644
--- a/src/nat/gnunet-service-nat.c
+++ b/src/nat/gnunet-service-nat.c
@@ -35,6 +35,7 @@
 #include "gnunet_statistics_service.h"
 #include "gnunet_nat_service.h"
 #include "gnunet-service-nat_stun.h"
+#include "gnunet-service-nat_helper.h"
 #include "nat.h"
 #include <gcrypt.h>
 
diff --git a/src/nat/gnunet-service-nat_helper.c b/src/nat/gnunet-service-nat_helper.c
new file mode 100644
index 000000000..4867f5675
--- /dev/null
+++ b/src/nat/gnunet-service-nat_helper.c
@@ -0,0 +1,345 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009, 2010, 2011, 2016 GNUnet e.V.
+
+     GNUnet 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, or (at your
+     option) any later version.
+
+     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+
+/**
+ * @file nat/gnunet-service-nat_helper.c
+ * @brief runs the gnunet-helper-nat-server
+ * @author Milan Bouchet-Valat
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet-service-nat_helper.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "nat", __VA_ARGS__)
+
+/**
+ * Information we keep per NAT helper process.
+ */
+struct HelperContext
+{
+
+  /**
+   * IP address we pass to the NAT helper.
+   */
+  const char *internal_address;
+
+  /**
+   * Function to call if we receive a reversal request.
+   */
+  GN_ReversalCallback cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+  
+  /**
+   * How long do we wait for restarting a crashed gnunet-helper-nat-server?
+   */
+  struct GNUNET_TIME_Relative server_retry_delay;
+
+  /**
+   * ID of select gnunet-helper-nat-server stdout read task
+   */
+  struct GNUNET_SCHEDULER_Task *server_read_task;
+
+  /**
+   * The process id of the server process (if behind NAT)
+   */
+  struct GNUNET_OS_Process *server_proc;
+
+  /**
+   * stdout pipe handle for the gnunet-helper-nat-server process
+   */
+  struct GNUNET_DISK_PipeHandle *server_stdout;
+
+  /**
+   * stdout file handle (for reading) for the gnunet-helper-nat-server process
+   */
+  const struct GNUNET_DISK_FileHandle *server_stdout_handle;
+};
+
+
+/**
+ * Task that restarts the gnunet-helper-nat-server process after a crash
+ * after a certain delay.
+ *
+ * @param cls a `struct HelperContext`
+ */
+static void
+restart_nat_server (void *cls);
+
+
+/**
+ * Try again starting the helper later
+ *
+ * @param h context of the helper
+ */
+static void
+try_again (struct HelperContext *h)
+{
+  GNUNET_assert (NULL == h->server_read_task);
+  h->server_retry_delay
+    = GNUNET_TIME_STD_BACKOFF (h->server_retry_delay);
+  h->server_read_task
+    = GNUNET_SCHEDULER_add_delayed (h->server_retry_delay,
+                                    &restart_nat_server,
+                                    h);
+}
+
+
+/**
+ * We have been notified that gnunet-helper-nat-server has written
+ * something to stdout.  Handle the output, then reschedule this
+ * function to be called again once more is available.
+ *
+ * @param cls the `struct HelperContext`
+ */
+static void
+nat_server_read (void *cls)
+{
+  struct HelperContext *h = cls;
+  char mybuf[40];
+  ssize_t bytes;
+  int port;
+  const char *port_start;
+  struct sockaddr_in sin_addr;
+
+  h->server_read_task = NULL;
+  memset (mybuf,
+          0,
+          sizeof (mybuf));
+  bytes 
+    = GNUNET_DISK_file_read (h->server_stdout_handle,
+                             mybuf,
+                             sizeof (mybuf));
+  if (bytes < 1)
+  {
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Finished reading from server stdout with code: %d\n",
+         bytes);
+    if (0 != GNUNET_OS_process_kill (h->server_proc,
+-                                    GNUNET_TERM_SIG))
+      GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING,
+                                "nat",
+                                "kill");
+    GNUNET_OS_process_wait (h->server_proc);
+    GNUNET_OS_process_destroy (h->server_proc);
+    h->server_proc = NULL;
+    GNUNET_DISK_pipe_close (h->server_stdout);
+    h->server_stdout = NULL;
+    h->server_stdout_handle = NULL;
+    try_again (h);
+    return;
+  }
+
+  port_start = NULL;
+  for (size_t i = 0; i < sizeof (mybuf); i++)
+  {
+    if (mybuf[i] == '\n')
+    {
+      mybuf[i] = '\0';
+      break;
+    }
+    if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf)))
+    {
+      mybuf[i] = '\0';
+      port_start = &mybuf[i + 1];
+    }
+  }
+
+  /* construct socket address of sender */
+  memset (&sin_addr,
+          0,
+          sizeof (sin_addr));
+  sin_addr.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+  sin_addr.sin_len = sizeof (sin_addr);
+#endif
+  if ( (NULL == port_start) ||
+       (1 != SSCANF (port_start,
+                     "%d",
+                     &port)) ||
+       (-1 == inet_pton (AF_INET,
+                         mybuf,
+                         &sin_addr.sin_addr)))
+  {
+    /* should we restart gnunet-helper-nat-server? */
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         "nat",
+         _("gnunet-helper-nat-server generated malformed address `%s'\n"),
+         mybuf);
+    h->server_read_task 
+      = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
+                                        h->server_stdout_handle,
+                                        &nat_server_read,
+                                        h);
+    return;
+  }
+  sin_addr.sin_port = htons ((uint16_t) port);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "gnunet-helper-nat-server read: %s:%d\n",
+       mybuf,
+       port);
+  h->cb (h->cb_cls,
+         &sin_addr);
+  h->server_read_task 
+    = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
+                                      h->server_stdout_handle,
+                                      &nat_server_read,
+                                      h);
+}
+
+
+/**
+ * Task that restarts the gnunet-helper-nat-server process after a crash
+ * after a certain delay.
+ *
+ * @param cls a `struct HelperContext`
+ */
+static void
+restart_nat_server (void *cls)
+{
+  struct HelperContext *h = cls;
+  char *binary;
+  
+  h->server_read_task = NULL;
+  h->server_stdout 
+    = GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES,
+                        GNUNET_NO, GNUNET_YES);
+  if (NULL == h->server_stdout)
+  {
+    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
+                         "pipe");
+    try_again (h);
+    return;
+  }
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Starting `%s' at `%s'\n",
+       "gnunet-helper-nat-server",
+       h->internal_address);
+  /* Start the server process */
+  binary
+    = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
+  h->server_proc 
+    = GNUNET_OS_start_process (GNUNET_NO,
+                               0,
+                               NULL,
+                               h->server_stdout,
+                               NULL,
+                               binary,
+                               "gnunet-helper-nat-server",
+                               h->internal_address,
+                               NULL);
+  GNUNET_free (binary);
+  if (NULL == h->server_proc)
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         "nat",
+         _("Failed to start %s\n"),
+         "gnunet-helper-nat-server");
+    GNUNET_DISK_pipe_close (h->server_stdout);
+    h->server_stdout = NULL;
+    try_again (h);
+    return;
+  }
+  /* Close the write end of the read pipe */
+  GNUNET_DISK_pipe_close_end (h->server_stdout,
+                              GNUNET_DISK_PIPE_END_WRITE);
+  h->server_stdout_handle 
+    = GNUNET_DISK_pipe_handle (h->server_stdout,
+                               GNUNET_DISK_PIPE_END_READ);
+  h->server_read_task 
+    = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
+                                      h->server_stdout_handle,
+                                      &nat_server_read,
+                                      h);
+}
+
+
+/**
+ * Start the gnunet-helper-nat-server and process incoming
+ * requests.
+ *
+ * @param internal_address
+ * @param cb function to call if we receive a request
+ * @param cb_cls closure for @a cb
+ * @return NULL on error
+ */
+struct HelperContext *
+GN_start_gnunet_nat_server_ (const char *internal_address,
+                             GN_ReversalCallback cb,
+                             void *cb_cls)
+{
+  struct HelperContext *h;
+
+  h = GNUNET_new (struct HelperContext);
+  h->cb = cb;
+  h->cb_cls = cb_cls;
+  h->internal_address
+    = internal_address;
+  if (NULL == h->server_stdout)
+  {
+    GN_stop_gnunet_nat_server_ (h);
+    return NULL;
+  }
+  return h;
+}
+
+
+/**
+ * Start the gnunet-helper-nat-server and process incoming
+ * requests.
+ *
+ * @param h helper context to stop
+ */
+void
+GN_stop_gnunet_nat_server_ (struct HelperContext *h)
+{  
+  if (NULL != h->server_read_task)
+  {
+    GNUNET_SCHEDULER_cancel (h->server_read_task);
+    h->server_read_task = NULL;
+  }
+    if (NULL != h->server_proc)
+  {
+    if (0 != GNUNET_OS_process_kill (h->server_proc,
+                                     GNUNET_TERM_SIG))
+      GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING,
+                                "nat",
+                                "kill");
+    GNUNET_OS_process_wait (h->server_proc);
+    GNUNET_OS_process_destroy (h->server_proc);
+    h->server_proc = NULL;
+    GNUNET_DISK_pipe_close (h->server_stdout);
+    h->server_stdout = NULL;
+    h->server_stdout_handle = NULL;
+  }
+  if (NULL != h->server_stdout)
+  {
+    GNUNET_DISK_pipe_close (h->server_stdout);
+    h->server_stdout = NULL;
+    h->server_stdout_handle = NULL;
+  }
+  GNUNET_free (h);
+}
+
+/* end of gnunet-service-nat_helper.c */
diff --git a/src/nat/gnunet-service-nat_helper.h b/src/nat/gnunet-service-nat_helper.h
new file mode 100644
index 000000000..c3074d9ad
--- /dev/null
+++ b/src/nat/gnunet-service-nat_helper.h
@@ -0,0 +1,74 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2009, 2010, 2011, 2016 GNUnet e.V.
+
+     GNUnet 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, or (at your
+     option) any later version.
+
+     GNUnet 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 GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+     Boston, MA 02110-1301, USA.
+*/
+
+/**
+ * @file nat/gnunet-service-nat_helper.h
+ * @brief runs the gnunet-helper-nat-server
+ * @author Milan Bouchet-Valat
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+
+
+/**
+ * Information we keep per NAT helper process.
+ */
+struct HelperContext;
+
+
+/**
+ * Function called whenever we get a connection reversal
+ * request from another peer.
+ *
+ * @param cls closure
+ * @param ra IP address of the peer who wants us to connect to it 
+ */
+typedef void
+(*GN_ReversalCallback) (void *cls,
+                        const struct sockaddr_in *ra);
+
+
+/**
+ * Start the gnunet-helper-nat-server and process incoming
+ * requests.
+ *
+ * @param internal_address
+ * @param cb function to call if we receive a request
+ * @param cb_cls closure for @a cb
+ * @return NULL on error
+ */
+struct HelperContext *
+GN_start_gnunet_nat_server_ (const char *internal_address,
+                             GN_ReversalCallback cb,
+                             void *cb_cls);
+
+                        
+/**
+ * Start the gnunet-helper-nat-server and process incoming
+ * requests.
+ *
+ * @param h helper context to stop
+ */
+void
+GN_stop_gnunet_nat_server_ (struct HelperContext *h);
+
+
+/* end of gnunet-service-nat_helper.h */