/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */

/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright (C) 2008 Red Hat, Inc.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library 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

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General

 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "config.h"

#include <glib.h>

#include "glibintl.h"

#include <stdlib.h>

#include "gnetworkaddress.h"

#include "gasyncresult.h"

#include "ginetaddress.h"

#include "ginetsocketaddress.h"

#include "gnetworkingprivate.h"

#include "gproxyaddressenumerator.h"

#include "gresolver.h"

#include "gtask.h"

#include "gsocketaddressenumerator.h"

#include "gioerror.h"

#include "gsocketconnectable.h"

#include <string.h>

/**

 * SECTION:gnetworkaddress

 * @short_description: A GSocketConnectable for resolving hostnames

 * @include: gio/gio.h

 *

 * #GNetworkAddress provides an easy way to resolve a hostname and

 * then attempt to connect to that host, handling the possibility of

 * multiple IP addresses and multiple address families.

 *

 * See #GSocketConnectable for and example of using the connectable

 * interface.

 */

/**

 * GNetworkAddress:

 *

 * A #GSocketConnectable for resolving a hostname and connecting to

 * that host.

 */

struct _GNetworkAddressPrivate {

  gchar *hostname;

  guint16 port;

  GList *sockaddrs;

  gchar *scheme;

  gint64 resolver_serial;

};

enum {

  PROP_0,

  PROP_HOSTNAME,

  PROP_PORT,

  PROP_SCHEME,

};

static void g_network_address_set_property (GObject      *object,

                                            guint         prop_id,

                                            const GValue *value,

                                            GParamSpec   *pspec);

static void g_network_address_get_property (GObject      *object,

                                            guint         prop_id,

                                            GValue       *value,

                                            GParamSpec   *pspec);

static void                      g_network_address_connectable_iface_init       (GSocketConnectableIface *iface);

static GSocketAddressEnumerator *g_network_address_connectable_enumerate        (GSocketConnectable      *connectable);

static GSocketAddressEnumerator	*g_network_address_connectable_proxy_enumerate  (GSocketConnectable      *connectable);

static gchar                    *g_network_address_connectable_to_string        (GSocketConnectable      *connectable);

G_DEFINE_TYPE_WITH_CODE (GNetworkAddress, g_network_address, G_TYPE_OBJECT,

                         G_ADD_PRIVATE (GNetworkAddress)

                         G_IMPLEMENT_INTERFACE (G_TYPE_SOCKET_CONNECTABLE,

                                                g_network_address_connectable_iface_init))

static void

g_network_address_finalize (GObject *object)

{

  GNetworkAddress *addr = G_NETWORK_ADDRESS (object);

  g_free (addr->priv->hostname);

  g_free (addr->priv->scheme);

  g_list_free_full (addr->priv->sockaddrs, g_object_unref);

  G_OBJECT_CLASS (g_network_address_parent_class)->finalize (object);

}

static void

g_network_address_class_init (GNetworkAddressClass *klass)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->set_property = g_network_address_set_property;

  gobject_class->get_property = g_network_address_get_property;

  gobject_class->finalize = g_network_address_finalize;

  g_object_class_install_property (gobject_class, PROP_HOSTNAME,

                                   g_param_spec_string ("hostname",

                                                        P_("Hostname"),

                                                        P_("Hostname to resolve"),

                                                        NULL,

                                                        G_PARAM_READWRITE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_PORT,

                                   g_param_spec_uint ("port",

                                                      P_("Port"),

                                                      P_("Network port"),

                                                      0, 65535, 0,

                                                      G_PARAM_READWRITE |

                                                      G_PARAM_CONSTRUCT_ONLY |

                                                      G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_SCHEME,

                                   g_param_spec_string ("scheme",

                                                        P_("Scheme"),

                                                        P_("URI Scheme"),

                                                        NULL,

                                                        G_PARAM_READWRITE |

                                                        G_PARAM_CONSTRUCT_ONLY |

                                                        G_PARAM_STATIC_STRINGS));

}

static void

g_network_address_connectable_iface_init (GSocketConnectableIface *connectable_iface)

{

  connectable_iface->enumerate  = g_network_address_connectable_enumerate;

  connectable_iface->proxy_enumerate = g_network_address_connectable_proxy_enumerate;

  connectable_iface->to_string = g_network_address_connectable_to_string;

}

static void

g_network_address_init (GNetworkAddress *addr)

{

  addr->priv = g_network_address_get_instance_private (addr);

}

static void

g_network_address_set_property (GObject      *object,

                                guint         prop_id,

                                const GValue *value,

                                GParamSpec   *pspec)

{

  GNetworkAddress *addr = G_NETWORK_ADDRESS (object);

  switch (prop_id)

    {

    case PROP_HOSTNAME:

      g_free (addr->priv->hostname);

      addr->priv->hostname = g_value_dup_string (value);

      break;

    case PROP_PORT:

      addr->priv->port = g_value_get_uint (value);

      break;

    case PROP_SCHEME:

      g_free (addr->priv->scheme);

      addr->priv->scheme = g_value_dup_string (value);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

static void

g_network_address_get_property (GObject    *object,

                                guint       prop_id,

                                GValue     *value,

                                GParamSpec *pspec)

{

  GNetworkAddress *addr = G_NETWORK_ADDRESS (object);

  switch (prop_id)

    {

    case PROP_HOSTNAME:

      g_value_set_string (value, addr->priv->hostname);

      break;

    case PROP_PORT:

      g_value_set_uint (value, addr->priv->port);

      break;

    case PROP_SCHEME:

      g_value_set_string (value, addr->priv->scheme);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

    }

}

static void

g_network_address_set_addresses (GNetworkAddress *addr,

                                 GList           *addresses,

                                 guint64          resolver_serial)

{

  GList *a;

  GSocketAddress *sockaddr;

  g_return_if_fail (addresses != NULL && addr->priv->sockaddrs == NULL);

  for (a = addresses; a; a = a->next)

    {

      sockaddr = g_inet_socket_address_new (a->data, addr->priv->port);

      addr->priv->sockaddrs = g_list_prepend (addr->priv->sockaddrs, sockaddr);

      g_object_unref (a->data);

    }

  g_list_free (addresses);

  addr->priv->sockaddrs = g_list_reverse (addr->priv->sockaddrs);

  addr->priv->resolver_serial = resolver_serial;

}

static gboolean

g_network_address_parse_sockaddr (GNetworkAddress *addr)

{

  GSocketAddress *sockaddr;

  sockaddr = g_inet_socket_address_new_from_string (addr->priv->hostname,

                                                    addr->priv->port);

  if (sockaddr)

    {

      addr->priv->sockaddrs = g_list_prepend (addr->priv->sockaddrs, sockaddr);

      return TRUE;

    }

  else

    return FALSE;

}

/**

 * g_network_address_new:

 * @hostname: the hostname

 * @port: the port

 *

 * Creates a new #GSocketConnectable for connecting to the given

 * @hostname and @port.

 *

 * Note that depending on the configuration of the machine, a

 * @hostname of `localhost` may refer to the IPv4 loopback address

 * only, or to both IPv4 and IPv6; use

 * g_network_address_new_loopback() to create a #GNetworkAddress that

 * is guaranteed to resolve to both addresses.

 *

 * Returns: (transfer full) (type GNetworkAddress): the new #GNetworkAddress

 *

 * Since: 2.22

 */

GSocketConnectable *

g_network_address_new (const gchar *hostname,

                       guint16      port)

{

  return g_object_new (G_TYPE_NETWORK_ADDRESS,

                       "hostname", hostname,

                       "port", port,

                       NULL);

}

/**

 * g_network_address_new_loopback:

 * @port: the port

 *

 * Creates a new #GSocketConnectable for connecting to the local host

 * over a loopback connection to the given @port. This is intended for

 * use in connecting to local services which may be running on IPv4 or

 * IPv6.

 *

 * The connectable will return IPv4 and IPv6 loopback addresses,

 * regardless of how the host resolves `localhost`. By contrast,

 * g_network_address_new() will often only return an IPv4 address when

 * resolving `localhost`, and an IPv6 address for `localhost6`.

 *

 * g_network_address_get_hostname() will always return `localhost` for

 * #GNetworkAddresses created with this constructor.

 *

 * Returns: (transfer full) (type GNetworkAddress): the new #GNetworkAddress

 *

 * Since: 2.44

 */

GSocketConnectable *

g_network_address_new_loopback (guint16 port)

{

  GNetworkAddress *addr;

  GList *addrs = NULL;

  addr = g_object_new (G_TYPE_NETWORK_ADDRESS,

                       "hostname", "localhost",

                       "port", port,

                       NULL);

  addrs = g_list_append (addrs, g_inet_address_new_loopback (AF_INET6));

  addrs = g_list_append (addrs, g_inet_address_new_loopback (AF_INET));

  g_network_address_set_addresses (addr, addrs, 0);

  return G_SOCKET_CONNECTABLE (addr);

}

/**

 * g_network_address_parse:

 * @host_and_port: the hostname and optionally a port

 * @default_port: the default port if not in @host_and_port

 * @error: a pointer to a #GError, or %NULL

 *

 * Creates a new #GSocketConnectable for connecting to the given

 * @hostname and @port. May fail and return %NULL in case

 * parsing @host_and_port fails.

 *

 * @host_and_port may be in any of a number of recognised formats; an IPv6

 * address, an IPv4 address, or a domain name (in which case a DNS

 * lookup is performed). Quoting with [] is supported for all address

 * types. A port override may be specified in the usual way with a

 * colon.

 *

 * If no port is specified in @host_and_port then @default_port will be

 * used as the port number to connect to.

 *

 * In general, @host_and_port is expected to be provided by the user

 * (allowing them to give the hostname, and a port override if necessary)

 * and @default_port is expected to be provided by the application.

 *

 * (The port component of @host_and_port can also be specified as a

 * service name rather than as a numeric port, but this functionality

 * is deprecated, because it depends on the contents of /etc/services,

 * which is generally quite sparse on platforms other than Linux.)

 *

 * Returns: (transfer full) (type GNetworkAddress): the new

 *   #GNetworkAddress, or %NULL on error

 *

 * Since: 2.22

 */

GSocketConnectable *

g_network_address_parse (const gchar  *host_and_port,

                         guint16       default_port,

                         GError      **error)

{

  GSocketConnectable *connectable;

  const gchar *port;

  guint16 portnum;

  gchar *name;

  g_return_val_if_fail (host_and_port != NULL, NULL);

  port = NULL;

  if (host_and_port[0] == '[')

    /* escaped host part (to allow, eg. "[2001:db8::1]:888") */

    {

      const gchar *end;

      end = strchr (host_and_port, ']');

      if (end == NULL)

        {

          g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                       _("Hostname “%s” contains “[” but not “]”"), host_and_port);

          return NULL;

        }

      if (end[1] == '\0')

        port = NULL;

      else if (end[1] == ':')

        port = &end[2];

      else

        {

          g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                       "The ']' character (in hostname '%s') must come at the"

                       " end or be immediately followed by ':' and a port",

                       host_and_port);

          return NULL;

        }

      name = g_strndup (host_and_port + 1, end - host_and_port - 1);

    }

  else if ((port = strchr (host_and_port, ':')))

    /* string has a ':' in it */

    {

      /* skip ':' */

      port++;

      if (strchr (port, ':'))

        /* more than one ':' in string */

        {

          /* this is actually an unescaped IPv6 address */

          name = g_strdup (host_and_port);

          port = NULL;

        }

      else

        name = g_strndup (host_and_port, port - host_and_port - 1);

    }

  else

    /* plain hostname, no port */

    name = g_strdup (host_and_port);

  if (port != NULL)

    {

      if (port[0] == '\0')

        {

          g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                       "If a ':' character is given, it must be followed by a "

                       "port (in hostname '%s').", host_and_port);

          g_free (name);

          return NULL;

        }

      else if ('0' <= port[0] && port[0] <= '9')

        {

          char *end;

          long value;

          value = strtol (port, &end, 10);

          if (*end != '\0' || value < 0 || value > G_MAXUINT16)

            {

              g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                           "Invalid numeric port '%s' specified in hostname '%s'",

                           port, host_and_port);

              g_free (name);

              return NULL;

            }

          portnum = value;

        }

      else

        {

          struct servent *entry;

          entry = getservbyname (port, "tcp");

          if (entry == NULL)

            {

              g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

                           "Unknown service '%s' specified in hostname '%s'",

                           port, host_and_port);

#ifdef HAVE_ENDSERVENT

              endservent ();

#endif

              g_free (name);

              return NULL;

            }

          portnum = g_ntohs (entry->s_port);

#ifdef HAVE_ENDSERVENT

          endservent ();

#endif

        }

    }

  else

    {

      /* No port in host_and_port */

      portnum = default_port;

    }

  connectable = g_network_address_new (name, portnum);

  g_free (name);

  return connectable;

}

/* Allowed characters outside alphanumeric for unreserved. */

#define G_URI_OTHER_UNRESERVED "-._~"

/* This or something equivalent will eventually go into glib/guri.h */

gboolean

_g_uri_parse_authority (const char  *uri,

		        char       **host,

		        guint16     *port,

		        char       **userinfo,

		        GError     **error)

{

  char *ascii_uri, *tmp_str;

  const char *start, *p, *at, *delim;

  char c;

  g_return_val_if_fail (uri != NULL, FALSE);

  if (host)

    *host = NULL;

  if (port)

    *port = 0;

  if (userinfo)

    *userinfo = NULL;

  /* Catch broken URIs early by trying to convert to ASCII. */

  ascii_uri = g_hostname_to_ascii (uri);

  if (!ascii_uri)

    goto error;

  /* From RFC 3986 Decodes:

   * URI          = scheme ":" hier-part [ "?" query ] [ "#" fragment ]

   * hier-part    = "//" authority path-abempty

   * path-abempty = *( "/" segment )

   * authority    = [ userinfo "@" ] host [ ":" port ]

   */

  /* Check we have a valid scheme */

  tmp_str = g_uri_parse_scheme (ascii_uri);

  if (tmp_str == NULL)

    goto error;

  g_free (tmp_str);

  /* Decode hier-part:

   *  hier-part   = "//" authority path-abempty

   */

  p = ascii_uri;

  start = strstr (p, "//");

  if (start == NULL)

    goto error;

  start += 2;

  /* check if the @ sign is part of the authority before attempting to

   * decode the userinfo */

  delim = strpbrk (start, "/?#[]");

  at = strchr (start, '@');

  if (at && delim && at > delim)

    at = NULL;

  if (at != NULL)

    {

      /* Decode userinfo:

       * userinfo      = *( unreserved / pct-encoded / sub-delims / ":" )

       * unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"

       * pct-encoded   = "%" HEXDIG HEXDIG

       */

      p = start;

      while (1)

	{

	  c = *p++;

	  if (c == '@')

	    break;

	  /* pct-encoded */

	  if (c == '%')

	    {

	      if (!(g_ascii_isxdigit (p[0]) ||

		    g_ascii_isxdigit (p[1])))

          goto error;

	      p++;

	      continue;

	    }

	  /* unreserved /  sub-delims / : */

	  if (!(g_ascii_isalnum (c) ||

		strchr (G_URI_OTHER_UNRESERVED, c) ||

		strchr (G_URI_RESERVED_CHARS_SUBCOMPONENT_DELIMITERS, c) ||

		c == ':'))

      goto error;

	}

      if (userinfo)

	*userinfo = g_strndup (start, p - start - 1);

      start = p;

    }

  else

    {

      p = start;

    }

  /* decode host:

   * host          = IP-literal / IPv4address / reg-name

   * reg-name      = *( unreserved / pct-encoded / sub-delims )

   */

  /* If IPv6 or IPvFuture */

  if (*p == '[')

    {

      gboolean has_scope_id = FALSE, has_bad_scope_id = FALSE;

      start++;

      p++;

      while (1)

	{

	  c = *p++;

	  if (c == ']')

	    break;

          if (c == '%' && !has_scope_id)

            {

              has_scope_id = TRUE;

              if (p[0] != '2' || p[1] != '5')

                has_bad_scope_id = TRUE;

              continue;

            }

	  /* unreserved /  sub-delims */

	  if (!(g_ascii_isalnum (c) ||

		strchr (G_URI_OTHER_UNRESERVED, c) ||

		strchr (G_URI_RESERVED_CHARS_SUBCOMPONENT_DELIMITERS, c) ||

		c == ':' ||

		c == '.'))

      goto error;

	}

      if (host)

        {

          if (has_bad_scope_id)

            *host = g_strndup (start, p - start - 1);

          else

            *host = g_uri_unescape_segment (start, p - 1, NULL);

        }

      c = *p++;

    }

  else

    {

      while (1)

	{

	  c = *p++;

	  if (c == ':' ||

	      c == '/' ||

	      c == '?' ||

	      c == '#' ||

	      c == '\0')

	    break;

	  /* pct-encoded */

	  if (c == '%')

	    {

	      if (!(g_ascii_isxdigit (p[0]) ||

		    g_ascii_isxdigit (p[1])))

          goto error;

	      p++;

	      continue;

	    }

	  /* unreserved /  sub-delims */

	  if (!(g_ascii_isalnum (c) ||

		strchr (G_URI_OTHER_UNRESERVED, c) ||

		strchr (G_URI_RESERVED_CHARS_SUBCOMPONENT_DELIMITERS, c)))

      goto error;

	}

      if (host)

        *host = g_uri_unescape_segment (start, p - 1, NULL);

    }

  if (c == ':')

    {

      /* Decode port:

       *  port          = *DIGIT

       */

      guint tmp = 0;

      while (1)

	{

	  c = *p++;

	  if (c == '/' ||

	      c == '?' ||

	      c == '#' ||

	      c == '\0')

	    break;

	  if (!g_ascii_isdigit (c))

      goto error;

	  tmp = (tmp * 10) + (c - '0');

	  if (tmp > 65535)

	    goto error;

	}

      if (port)

	*port = (guint16) tmp;

    }

  g_free (ascii_uri);

  return TRUE;

error:

  g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,

               "Invalid URI ‘%s’", uri);

  if (host && *host)

    {

      g_free (*host);

      *host = NULL;

    }

  if (userinfo && *userinfo)

    {

      g_free (*userinfo);

      *userinfo = NULL;

    }

  g_free (ascii_uri);

  return FALSE;

}

gchar *

_g_uri_from_authority (const gchar *protocol,

                       const gchar *host,

                       guint        port,

                       const gchar *userinfo)

{

  GString *uri;

  uri = g_string_new (protocol);

  g_string_append (uri, "://");

  if (userinfo)

    {

      g_string_append_uri_escaped (uri, userinfo, G_URI_RESERVED_CHARS_ALLOWED_IN_USERINFO, FALSE);

      g_string_append_c (uri, '@');

    }

  if (g_hostname_is_non_ascii (host))

    {

      gchar *ace_encoded = g_hostname_to_ascii (host);

      if (!ace_encoded)

        {

          g_string_free (uri, TRUE);

          return NULL;

        }

      g_string_append (uri, ace_encoded);

      g_free (ace_encoded);

    }

  else if (strchr (host, ':'))

    g_string_append_printf (uri, "[%s]", host);

  else

    g_string_append (uri, host);

  if (port != 0)

    g_string_append_printf (uri, ":%u", port);

  return g_string_free (uri, FALSE);

}

/**

 * g_network_address_parse_uri:

 * @uri: the hostname and optionally a port

 * @default_port: The default port if none is found in the URI

 * @error: a pointer to a #GError, or %NULL

 *

 * Creates a new #GSocketConnectable for connecting to the given

 * @uri. May fail and return %NULL in case parsing @uri fails.

 *

 * Using this rather than g_network_address_new() or

 * g_network_address_parse() allows #GSocketClient to determine

 * when to use application-specific proxy protocols.

 *

 * Returns: (transfer full) (type GNetworkAddress): the new

 *   #GNetworkAddress, or %NULL on error

 *

 * Since: 2.26

 */

GSocketConnectable *

g_network_address_parse_uri (const gchar  *uri,

    			     guint16       default_port,

			     GError      **error)

{

  GSocketConnectable *conn;

  gchar *scheme;

  gchar *hostname;

  guint16 port;

  if (!_g_uri_parse_authority (uri, &hostname, &port, NULL, error))

    return NULL;

  if (port == 0)

    port = default_port;

  scheme = g_uri_parse_scheme (uri);

  conn = g_object_new (G_TYPE_NETWORK_ADDRESS,

                       "hostname", hostname,

                       "port", port,

                       "scheme", scheme,

                       NULL);

  g_free (scheme);

  g_free (hostname);

  return conn;

}

/**

 * g_network_address_get_hostname:

 * @addr: a #GNetworkAddress

 *

 * Gets @addr's hostname. This might be either UTF-8 or ASCII-encoded,

 * depending on what @addr was created with.

 *

 * Returns: @addr's hostname

 *

 * Since: 2.22

 */

const gchar *

g_network_address_get_hostname (GNetworkAddress *addr)

{

  g_return_val_if_fail (G_IS_NETWORK_ADDRESS (addr), NULL);

  return addr->priv->hostname;

}

/**

 * g_network_address_get_port:

 * @addr: a #GNetworkAddress

 *

 * Gets @addr's port number

 *

 * Returns: @addr's port (which may be 0)

 *

 * Since: 2.22

 */

guint16

g_network_address_get_port (GNetworkAddress *addr)

{

  g_return_val_if_fail (G_IS_NETWORK_ADDRESS (addr), 0);

  return addr->priv->port;

}

/**

 * g_network_address_get_scheme:

 * @addr: a #GNetworkAddress

 *

 * Gets @addr's scheme

 *

 * Returns: @addr's scheme (%NULL if not built from URI)

 *

 * Since: 2.26

 */

const gchar *

g_network_address_get_scheme (GNetworkAddress *addr)

{

  g_return_val_if_fail (G_IS_NETWORK_ADDRESS (addr), NULL);

  return addr->priv->scheme;

}

#define G_TYPE_NETWORK_ADDRESS_ADDRESS_ENUMERATOR (_g_network_address_address_enumerator_get_type ())

#define G_NETWORK_ADDRESS_ADDRESS_ENUMERATOR(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_NETWORK_ADDRESS_ADDRESS_ENUMERATOR, GNetworkAddressAddressEnumerator))

typedef struct {

  GSocketAddressEnumerator parent_instance;

  GNetworkAddress *addr;

  GList *addresses;