trunk/src/auth.c

/*
 *  ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
 *
 *  Copyright (c) 1997-2018 ircd-hybrid development team
 *
 *  This program 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.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
 *  USA
 */

/*! \file auth.c
 * \brief Implementation of DNS and ident lookups.
 * \version $Id$
 */

/*
 * Changes:
 *   July 6, 1999 - Rewrote most of the code here. When a client connects
 *     to the server and passes initial socket validation checks, it
 *     is owned by this module (auth) which returns it to the rest of the
 *     server when dns and auth queries are finished. Until the client is
 *     released, the server does not know it exists and does not process
 *     any messages from it.
 *     --Bleep  Thomas Helvey <tomh@inxpress.net>
 */

#include "stdinc.h"
#include "list.h"
#include "ircd_defs.h"
#include "fdlist.h"
#include "auth.h"
#include "conf.h"
#include "client.h"
#include "event.h"
#include "irc_string.h"
#include "ircd.h"
#include "packet.h"
#include "res.h"
#include "s_bsd.h"
#include "log.h"
#include "send.h"
#include "memory.h"


enum
{
  REPORT_DO_DNS,
  REPORT_FIN_DNS,
  REPORT_FAIL_DNS,
  REPORT_DO_ID,
  REPORT_FIN_ID,
  REPORT_FAIL_ID,
  REPORT_IP_MISMATCH,
  REPORT_HOST_TOOLONG,
  REPORT_HOST_INVALID
};

static const char *const HeaderMessages[] =
{
  [REPORT_DO_DNS] = ":*** Looking up your hostname",
  [REPORT_FIN_DNS] = ":*** Found your hostname",
  [REPORT_FAIL_DNS] = ":*** Couldn't look up your hostname",
  [REPORT_DO_ID] = ":*** Checking Ident",
  [REPORT_FIN_ID] = ":*** Got Ident response",
  [REPORT_FAIL_ID] = ":*** No Ident response",
  [REPORT_IP_MISMATCH] = ":*** Your forward and reverse DNS do not match, ignoring hostname",
  [REPORT_HOST_TOOLONG] = ":*** Your hostname is too long, ignoring hostname",
  [REPORT_HOST_INVALID] = ":*** Your hostname contains illegal characters, ignoring hostname"
};

#define auth_sendheader(c, i) sendto_one_notice((c), &me, "%s", HeaderMessages[(i)])

static dlink_list auth_list;


/*! \brief Allocate a new auth request.
 * \param client The client being looked up.
 * \return The newly allocated auth request.
 */
static struct AuthRequest *
auth_make(struct Client *client)
{
  struct AuthRequest *auth = xcalloc(sizeof(*auth));

  auth->client = client;
  auth->client->connection->auth = auth;
  auth->timeout = CurrentTime + CONNECTTIMEOUT;

  return auth;
}

/*! \brief Unlink auth request from auth_list and free memory
 * \param auth The allocated auth request to cleanup.
 */
static void
auth_free(struct AuthRequest *auth)
{
  assert(dlinkFind(&auth_list, auth));
  dlinkDelete(&auth->node, &auth_list);
  assert(dlinkFind(&auth_list, auth) == NULL);

  xfree(auth);
}

/*! \brief Release auth client from auth system. This adds the client into the
 *         local client lists so it can be read by the main io processing loop.
 * \param auth Pointer to AuthRequest struct to release
 */
static void
auth_release_client(struct AuthRequest *auth)
{
  struct Client *client = auth->client;

  if (auth->ident_pending == true || auth->dns_pending == true)
    return;

  auth_free(auth);
  client->connection->auth = NULL;

  /*
   * When a client has auth'ed, we want to start reading what it sends
   * us. This is what read_packet() does.
   *     -- adrian
   */
  comm_setflush(client->connection->fd, 1000, flood_recalc, client);

  client->connection->since     = CurrentTime;
  client->connection->lasttime  = CurrentTime;
  client->connection->firsttime = CurrentTime;
  AddFlag(client, FLAGS_FINISHED_AUTH);

  strlcpy(client->realhost, client->host, sizeof(client->realhost));

  read_packet(client->connection->fd, client);
}

/*! Checks if a hostname is valid and doesn't contain illegal characters
 * \param hostname The string to verify
 * \return 1 if it is valid, 0 if it isn't
 */
static bool
auth_verify_hostname(const char *hostname)
{
  const char *p = hostname;

  assert(p);

  if (EmptyString(p) || *p == '.' || *p == ':')
    return false;

  for (; *p; ++p)
    if (!IsHostChar(*p))
      return false;

  return true;
}

/*! \brief Handle a complete DNS lookup. Send the client on its way to a connection
 *         completion, regardless of success or failure.
 * \param vptr The pending struct AuthRequest.
 * \param addr IP address being resolved.
 * \param name Resolved name, or NULL if lookup failed.
 * \param namelength String length of the resolved hostname pointed by 'name'
 */
static void
auth_dns_callback(void *vptr, const struct irc_ssaddr *addr, const char *name, size_t namelength)
{
  struct AuthRequest *const auth = vptr;

  auth->dns_pending = false;

  if (EmptyString(name))
    auth_sendheader(auth->client, REPORT_FAIL_DNS);
  else
  {
    if (auth->client->ip.ss.ss_family == AF_INET6)
    {
      const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)&auth->client->ip;
      const struct sockaddr_in6 *const v6dns = (const struct sockaddr_in6 *)addr;

      if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)))
      {
        auth_sendheader(auth->client, REPORT_IP_MISMATCH);
        auth_release_client(auth);
        return;
      }
    }
    else
    {
      const struct sockaddr_in *const v4 = (const struct sockaddr_in *)&auth->client->ip;
      const struct sockaddr_in *const v4dns = (const struct sockaddr_in *)addr;

      if (v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
      {
        auth_sendheader(auth->client, REPORT_IP_MISMATCH);
        auth_release_client(auth);
        return;
      }
    }

    if (namelength > HOSTLEN)
      auth_sendheader(auth->client, REPORT_HOST_TOOLONG);
    else if (auth_verify_hostname(name) == false)
      auth_sendheader(auth->client, REPORT_HOST_INVALID);
    else
    {
      strlcpy(auth->client->host, name, sizeof(auth->client->host));
      auth_sendheader(auth->client, REPORT_FIN_DNS);
    }
  }

  auth_release_client(auth);
}

/*
 * auth_error - handle auth send errors
 */
static void
auth_error(struct AuthRequest *auth)
{
  assert(auth);
  assert(auth->fd);

  ++ServerStats.is_abad;

  fd_close(auth->fd);
  auth->fd = NULL;
  auth->ident_pending = false;

  auth_sendheader(auth->client, REPORT_FAIL_ID);

  auth_release_client(auth);
}

/** Enum used to index ident reply fields in a human-readable way. */
enum IdentReplyFields
{
  IDENT_PORT_NUMBERS,
  IDENT_REPLY_TYPE,
  IDENT_OS_TYPE,
  IDENT_INFO,
  USERID_TOKEN_COUNT
};

/** Parse an ident reply line and extract the userid from it.
 * \param reply The ident reply line.
 * \return The userid, or NULL on parse failure.
 */
static const char *
auth_check_ident_reply(char *const reply)
{
  char *token = NULL, *end = NULL;
  char *vector[USERID_TOKEN_COUNT];
  const unsigned int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);

  if (USERID_TOKEN_COUNT != count)
    return NULL;

  /*
   * Second token is the reply type
   */
  token = vector[IDENT_REPLY_TYPE];

  if (EmptyString(token))
    return NULL;

  while (IsSpace(*token))
    ++token;

  if (strncmp(token, "USERID", 6))
    return NULL;

  /*
   * Third token is the os type
   */
  token = vector[IDENT_OS_TYPE];

  if (EmptyString(token))
    return NULL;

  while (IsSpace(*token))
   ++token;

  /*
   * Unless "OTHER" is specified as the operating system type, the server
   * is expected to return the "normal" user identification of the owner
   * of this connection. "Normal" in this context may be taken to mean a
   * string of characters which uniquely identifies the connection owner
   * such as a user identifier assigned by the system administrator and
   * used by such user as a mail identifier, or as the "user" part of a
   * user/password pair used to gain access to system resources. When an
   * operating system is specified (e.g., anything but "OTHER"), the user
   * identifier is expected to be in a more or less immediately useful
   * form - e.g., something that could be used as an argument to "finger"
   * or as a mail address.
   */
  if (strncmp(token, "OTHER", 5) == 0)
    return NULL;

  /*
   * Fourth token is the username
   */
  token = vector[IDENT_INFO];

  if (EmptyString(token))
    return NULL;

  while (IsSpace(*token))
    ++token;

  while (*token == '~' || *token == '^')
    ++token;

  /*
   * Look for the end of the username, terminators are '\0, @, <SPACE>, :'
   */
  for (end = token; *end; ++end)
    if (IsSpace(*end) || '@' == *end || ':' == *end)
      break;
  *end = '\0';

  return token;
}

/*! \brief Read the reply (if any) from the ident server we connected to. We
 *         only give it one shot, if the reply isn't good the first time fail
 *         the authentication entirely. --Bleep
 * \param F The socket/fd to read from.
 * \param data The request to read.
 */
static void
auth_read_reply(fde_t *F, void *data)
{
  struct AuthRequest *const auth = data;
  const char *username = NULL;
  ssize_t len = 0;
  char buf[RFC1413_BUFSIZ + 1];

  assert(auth->fd == F);

  if ((len = recv(auth->fd->fd, buf, RFC1413_BUFSIZ, 0)) > 0)
  {
    buf[len] = '\0';
    username = auth_check_ident_reply(buf);
  }

  fd_close(auth->fd);
  auth->fd = NULL;
  auth->ident_pending = false;

  if (EmptyString(username))
  {
    auth_sendheader(auth->client, REPORT_FAIL_ID);
    ++ServerStats.is_abad;
  }
  else
  {
    strlcpy(auth->client->username, username, sizeof(auth->client->username));
    auth_sendheader(auth->client, REPORT_FIN_ID);
    ++ServerStats.is_asuc;
    AddFlag(auth->client, FLAGS_GOTID);
  }

  auth_release_client(auth);
}

/*
 * auth_connect_callback() - deal with the result of comm_connect_tcp()
 *
 * If the connection failed, we simply close the auth fd and report
 * a failure. If the connection suceeded send the ident server a query
 * giving "theirport , ourport". The write is only attempted *once* so
 * it is deemed to be a fail if the entire write doesn't write all the
 * data given.  This shouldnt be a problem since the socket should have
 * a write buffer far greater than this message to store it in should
 * problems arise. -avalon
 */
static void
auth_connect_callback(fde_t *F, int error, void *data)
{
  struct AuthRequest *const auth = data;
  struct irc_ssaddr us;
  struct irc_ssaddr them;
  char authbuf[16];
  ssize_t len = 0;
  socklen_t ulen = sizeof(struct irc_ssaddr);
  socklen_t tlen = sizeof(struct irc_ssaddr);
  uint16_t uport, tport;
  struct sockaddr_in6 *v6;

  if (error != COMM_OK)
  {
    auth_error(auth);
    return;
  }

  assert(auth->fd == F);

  if (getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&us, &ulen) ||
      getpeername(auth->client->connection->fd->fd, (struct sockaddr *)&them, &tlen))
  {
    report_error(L_ALL, "auth get{sock,peer}name error %s:%s",
                 client_get_name(auth->client, SHOW_IP), errno);
    auth_error(auth);
    return;
  }

  v6 = (struct sockaddr_in6 *)&us;
  uport = ntohs(v6->sin6_port);
  v6 = (struct sockaddr_in6 *)&them;
  tport = ntohs(v6->sin6_port);

  len = snprintf(authbuf, sizeof(authbuf), "%u, %u\r\n", tport, uport);

  if (send(F->fd, authbuf, len, 0) != len)
  {
    auth_error(auth);
    return;
  }

  comm_setselect(F, COMM_SELECT_READ, auth_read_reply, auth, 0);
}

/*! \brief Flag the client to show an attempt to contact the ident server on
 *         the client's host. Should the connect or any later phase of the
 *         identifying process fail, it is aborted and the user is given a
 *         username of "unknown".
 * \param auth The request for which to start the ident lookup.
 */
static void
auth_start_query(struct AuthRequest *auth)
{
  struct irc_ssaddr localaddr;
  socklen_t locallen = sizeof(struct irc_ssaddr);
  struct sockaddr_in6 *v6;

  /* Open a socket of the same type as the client socket */
  int fd = comm_socket(auth->client->ip.ss.ss_family, SOCK_STREAM, 0);
  if (fd == -1)
  {
    report_error(L_ALL, "creating auth stream socket %s:%s",
                 client_get_name(auth->client, SHOW_IP), errno);
    ++ServerStats.is_abad;
    return;
  }

  auth->fd = fd_open(fd, true, "ident");
  auth->ident_pending = true;

  auth_sendheader(auth->client, REPORT_DO_ID);

  /*
   * Get the local address of the client and bind to that to
   * make the auth request.
   */
  memset(&localaddr, 0, locallen);
  getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&localaddr, &locallen);

  remove_ipv6_mapping(&localaddr);
  v6 = (struct sockaddr_in6 *)&localaddr;
  v6->sin6_port = htons(0);
  localaddr.ss_port = htons(0);

  comm_connect_tcp(auth->fd, auth->client->sockhost, RFC1413_PORT,
      (struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
      auth, auth->client->ip.ss.ss_family,
      GlobalSetOptions.ident_timeout);
}

/*
 * auth_start
 *
 * inputs       - pointer to client to auth
 * output       - NONE
 * side effects - starts auth (identd) and dns queries for a client
 */
void
auth_start(struct Client *client_p)
{
  struct AuthRequest *auth = auth_make(client_p);

  dlinkAddTail(auth, &auth->node, &auth_list);

  auth_sendheader(client_p, REPORT_DO_DNS);

  auth->dns_pending = true;

  if (ConfigGeneral.disable_auth == 0)
    auth_start_query(auth);

  gethost_byaddr(auth_dns_callback, auth, &client_p->ip);
}

/*
 * auth_delete()
 */
void
auth_delete(struct AuthRequest *auth)
{
  if (auth->ident_pending == true)
  {
    fd_close(auth->fd);
    auth->fd = NULL;
    auth->ident_pending = false;
  }

  if (auth->dns_pending == true)
  {
    delete_resolver_queries(auth);
    auth->dns_pending = false;
  }

  auth_free(auth);
}

/*
 * auth_timeout_queries - timeout resolver and identd requests
 * allow clients through if requests failed
 */
static void
auth_timeout_queries(void *notused)
{
  dlink_node *node, *node_next;

  DLINK_FOREACH_SAFE(node, node_next, auth_list.head)
  {
    struct AuthRequest *auth = node->data;

    if (auth->timeout > CurrentTime)
      break;

    if (auth->ident_pending == true)
    {
      ++ServerStats.is_abad;

      fd_close(auth->fd);
      auth->fd = NULL;
      auth->ident_pending = false;

      auth_sendheader(auth->client, REPORT_FAIL_ID);
    }

    if (auth->dns_pending == true)
    {
      delete_resolver_queries(auth);
      auth->dns_pending = false;

      auth_sendheader(auth->client, REPORT_FAIL_DNS);
    }

    auth_release_client(auth);
  }
}

/* auth_init
 *
 * Initialise the auth code
 */
void
auth_init(void)
{
  static struct event timeout_auth_queries =
  {
    .name = "auth_timeout_queries",
    .handler = auth_timeout_queries,
    .when = 1
  };

  event_add(&timeout_auth_queries, NULL);
}
Revision:	8721
Committed:	Tue Dec 11 20:54:22 2018 UTC (7 years, 9 months ago) by michael
Content type:	text/x-csrc
File size:	15261 byte(s)
Log Message:	- auth: replace AM_DOING_AUTH and AM_DNS_PENDING with dedicated variables
#	User	Rev	Content
1	adx	30	/*
2	michael	2916	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	adx	30	*
4	michael	8279	* Copyright (c) 1997-2018 ircd-hybrid development team
5	adx	30	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18	michael	4565	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	adx	30	* USA
20			*/
21
22	michael	3324	/*! \file auth.c
23	michael	8306	* \brief Implementation of DNS and ident lookups.
24	michael	2916	* \version $Id$
25			*/
26
27	adx	30	/*
28			* Changes:
29			* July 6, 1999 - Rewrote most of the code here. When a client connects
30			* to the server and passes initial socket validation checks, it
31			* is owned by this module (auth) which returns it to the rest of the
32			* server when dns and auth queries are finished. Until the client is
33			* released, the server does not know it exists and does not process
34			* any messages from it.
35			* --Bleep Thomas Helvey <tomh@inxpress.net>
36			*/
37	michael	1309
38	adx	30	#include "stdinc.h"
39			#include "list.h"
40	michael	1011	#include "ircd_defs.h"
41			#include "fdlist.h"
42	michael	3324	#include "auth.h"
43	michael	1309	#include "conf.h"
44	adx	30	#include "client.h"
45			#include "event.h"
46			#include "irc_string.h"
47			#include "ircd.h"
48			#include "packet.h"
49	michael	3322	#include "res.h"
50	adx	30	#include "s_bsd.h"
51	michael	1309	#include "log.h"
52	adx	30	#include "send.h"
53	michael	8385	#include "memory.h"
54	adx	30
55	michael	1011
56	michael	2916	enum
57			{
58	adx	30	REPORT_DO_DNS,
59			REPORT_FIN_DNS,
60			REPORT_FAIL_DNS,
61			REPORT_DO_ID,
62			REPORT_FIN_ID,
63			REPORT_FAIL_ID,
64			REPORT_IP_MISMATCH,
65	michael	8217	REPORT_HOST_TOOLONG,
66			REPORT_HOST_INVALID
67	adx	30	};
68
69	michael	5888	static const char *const HeaderMessages[] =
70			{
71			[REPORT_DO_DNS] = ":*** Looking up your hostname",
72			[REPORT_FIN_DNS] = ":*** Found your hostname",
73			[REPORT_FAIL_DNS] = ":*** Couldn't look up your hostname",
74			[REPORT_DO_ID] = ":*** Checking Ident",
75			[REPORT_FIN_ID] = ":*** Got Ident response",
76			[REPORT_FAIL_ID] = ":*** No Ident response",
77			[REPORT_IP_MISMATCH] = ":*** Your forward and reverse DNS do not match, ignoring hostname",
78	michael	8217	[REPORT_HOST_TOOLONG] = ":*** Your hostname is too long, ignoring hostname",
79			[REPORT_HOST_INVALID] = ":*** Your hostname contains illegal characters, ignoring hostname"
80	michael	5888	};
81
82	michael	8306	#define auth_sendheader(c, i) sendto_one_notice((c), &me, "%s", HeaderMessages[(i)])
83	adx	30
84	michael	6478	static dlink_list auth_list;
85	adx	30
86	michael	4094
87	michael	8349	/*! \brief Allocate a new auth request.
88			* \param client The client being looked up.
89			* \return The newly allocated auth request.
90	adx	30	*/
91			static struct AuthRequest *
92	michael	8339	auth_make(struct Client *client)
93	adx	30	{
94	michael	8385	struct AuthRequest auth = xcalloc(sizeof(auth));
95	adx	30
96	michael	6690	auth->client = client;
97	michael	8470	auth->client->connection->auth = auth;
98	michael	6690	auth->timeout = CurrentTime + CONNECTTIMEOUT;
99	michael	2181
100	michael	6690	return auth;
101	adx	30	}
102
103	michael	8470	/*! \brief Unlink auth request from auth_list and free memory
104			* \param auth The allocated auth request to cleanup.
105			*/
106			static void
107			auth_free(struct AuthRequest *auth)
108			{
109			assert(dlinkFind(&auth_list, auth));
110			dlinkDelete(&auth->node, &auth_list);
111			assert(dlinkFind(&auth_list, auth) == NULL);
112
113			xfree(auth);
114			}
115
116	michael	8306	/*! \brief Release auth client from auth system. This adds the client into the
117			* local client lists so it can be read by the main io processing loop.
118			* \param auth Pointer to AuthRequest struct to release
119	adx	30	*/
120	michael	8304	static void
121	michael	8306	auth_release_client(struct AuthRequest *auth)
122	adx	30	{
123	michael	8470	struct Client *client = auth->client;
124	michael	992
125	michael	8721	if (auth->ident_pending == true \|\| auth->dns_pending == true)
126	michael	992	return;
127
128	michael	8470	auth_free(auth);
129	michael	8339	client->connection->auth = NULL;
130
131	adx	30	/*
132			* When a client has auth'ed, we want to start reading what it sends
133			* us. This is what read_packet() does.
134			* -- adrian
135			*/
136	michael	8339	comm_setflush(client->connection->fd, 1000, flood_recalc, client);
137	michael	650
138	michael	4588	client->connection->since = CurrentTime;
139			client->connection->lasttime = CurrentTime;
140			client->connection->firsttime = CurrentTime;
141	michael	8298	AddFlag(client, FLAGS_FINISHED_AUTH);
142	michael	650
143	michael	8214	strlcpy(client->realhost, client->host, sizeof(client->realhost));
144
145	michael	8339	read_packet(client->connection->fd, client);
146	adx	30	}
147	michael	2916
148	michael	8218	/*! Checks if a hostname is valid and doesn't contain illegal characters
149			* \param hostname The string to verify
150			* \return 1 if it is valid, 0 if it isn't
151			*/
152	michael	8656	static bool
153	michael	8217	auth_verify_hostname(const char *hostname)
154			{
155			const char *p = hostname;
156
157			assert(p);
158
159			if (EmptyString(p) \|\| p == '.' \|\| p == ':')
160	michael	8656	return false;
161	michael	8217
162			for (; *p; ++p)
163			if (!IsHostChar(*p))
164	michael	8656	return false;
165	michael	8217
166	michael	8656	return true;
167	michael	8217	}
168
169	michael	8306	/*! \brief Handle a complete DNS lookup. Send the client on its way to a connection
170			* completion, regardless of success or failure.
171			* \param vptr The pending struct AuthRequest.
172			* \param addr IP address being resolved.
173			* \param name Resolved name, or NULL if lookup failed.
174			* \param namelength String length of the resolved hostname pointed by 'name'
175	adx	30	*/
176			static void
177	michael	4408	auth_dns_callback(void vptr, const struct irc_ssaddr addr, const char *name, size_t namelength)
178	adx	30	{
179	michael	4854	struct AuthRequest *const auth = vptr;
180	adx	30
181	michael	8721	auth->dns_pending = false;
182	adx	30
183	michael	8431	if (EmptyString(name))
184			auth_sendheader(auth->client, REPORT_FAIL_DNS);
185			else
186	adx	30	{
187	michael	8496	if (auth->client->ip.ss.ss_family == AF_INET6)
188	adx	30	{
189	michael	8496	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )&auth->client->ip;
190	michael	4858	const struct sockaddr_in6 const v6dns = (const struct sockaddr_in6 )addr;
191	michael	3250
192	michael	5902	if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)))
193	adx	30	{
194	michael	8306	auth_sendheader(auth->client, REPORT_IP_MISMATCH);
195			auth_release_client(auth);
196	michael	4408	return;
197	adx	30	}
198			}
199			else
200			{
201	michael	8496	const struct sockaddr_in const v4 = (const struct sockaddr_in )&auth->client->ip;
202	michael	4858	const struct sockaddr_in const v4dns = (const struct sockaddr_in )addr;
203	michael	3250
204			if (v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
205	adx	30	{
206	michael	8306	auth_sendheader(auth->client, REPORT_IP_MISMATCH);
207			auth_release_client(auth);
208	michael	4408	return;
209	adx	30	}
210			}
211	michael	3250
212	michael	4408	if (namelength > HOSTLEN)
213	michael	8306	auth_sendheader(auth->client, REPORT_HOST_TOOLONG);
214	michael	8656	else if (auth_verify_hostname(name) == false)
215	michael	8306	auth_sendheader(auth->client, REPORT_HOST_INVALID);
216	michael	4408	else
217	adx	30	{
218	michael	4408	strlcpy(auth->client->host, name, sizeof(auth->client->host));
219	michael	8306	auth_sendheader(auth->client, REPORT_FIN_DNS);
220	adx	30	}
221			}
222
223	michael	8306	auth_release_client(auth);
224	adx	30	}
225
226			/*
227	michael	8306	* auth_error - handle auth send errors
228	adx	30	*/
229			static void
230			auth_error(struct AuthRequest *auth)
231			{
232	michael	8524	assert(auth);
233			assert(auth->fd);
234
235	michael	896	++ServerStats.is_abad;
236	adx	30
237	michael	8339	fd_close(auth->fd);
238			auth->fd = NULL;
239	michael	8721	auth->ident_pending = false;
240	michael	8339
241	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_ID);
242	adx	30
243	michael	8306	auth_release_client(auth);
244	adx	30	}
245
246	michael	4309	/** Enum used to index ident reply fields in a human-readable way. */
247			enum IdentReplyFields
248			{
249			IDENT_PORT_NUMBERS,
250			IDENT_REPLY_TYPE,
251			IDENT_OS_TYPE,
252			IDENT_INFO,
253			USERID_TOKEN_COUNT
254			};
255
256			/** Parse an ident reply line and extract the userid from it.
257			* \param reply The ident reply line.
258			* \return The userid, or NULL on parse failure.
259			*/
260			static const char *
261	michael	8306	auth_check_ident_reply(char *const reply)
262	michael	4309	{
263			char token = NULL, end = NULL;
264			char *vector[USERID_TOKEN_COUNT];
265	michael	7584	const unsigned int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);
266	michael	4309
267			if (USERID_TOKEN_COUNT != count)
268			return NULL;
269
270			/*
271			* Second token is the reply type
272			*/
273			token = vector[IDENT_REPLY_TYPE];
274
275			if (EmptyString(token))
276			return NULL;
277
278			while (IsSpace(*token))
279			++token;
280
281			if (strncmp(token, "USERID", 6))
282			return NULL;
283
284			/*
285			* Third token is the os type
286			*/
287			token = vector[IDENT_OS_TYPE];
288
289			if (EmptyString(token))
290			return NULL;
291
292			while (IsSpace(*token))
293			++token;
294
295			/*
296			* Unless "OTHER" is specified as the operating system type, the server
297			* is expected to return the "normal" user identification of the owner
298			* of this connection. "Normal" in this context may be taken to mean a
299			* string of characters which uniquely identifies the connection owner
300			* such as a user identifier assigned by the system administrator and
301			* used by such user as a mail identifier, or as the "user" part of a
302			* user/password pair used to gain access to system resources. When an
303			* operating system is specified (e.g., anything but "OTHER"), the user
304			* identifier is expected to be in a more or less immediately useful
305			* form - e.g., something that could be used as an argument to "finger"
306			* or as a mail address.
307			*/
308	michael	8620	if (strncmp(token, "OTHER", 5) == 0)
309	michael	4309	return NULL;
310
311			/*
312			* Fourth token is the username
313			*/
314			token = vector[IDENT_INFO];
315
316			if (EmptyString(token))
317			return NULL;
318
319			while (IsSpace(*token))
320			++token;
321
322			while (token == '~' \|\| token == '^')
323			++token;
324
325			/*
326			* Look for the end of the username, terminators are '\0, @, <SPACE>, :'
327			*/
328			for (end = token; *end; ++end)
329			if (IsSpace(end) \|\| '@' == end \|\| ':' == *end)
330			break;
331			*end = '\0';
332
333			return token;
334			}
335
336	michael	8306	/*! \brief Read the reply (if any) from the ident server we connected to. We
337			* only give it one shot, if the reply isn't good the first time fail
338			* the authentication entirely. --Bleep
339	michael	8349	* \param F The socket/fd to read from.
340	michael	8306	* \param data The request to read.
341	adx	30	*/
342			static void
343	michael	8349	auth_read_reply(fde_t F, void data)
344	adx	30	{
345	michael	4854	struct AuthRequest *const auth = data;
346	michael	4309	const char *username = NULL;
347			ssize_t len = 0;
348			char buf[RFC1413_BUFSIZ + 1];
349	adx	30
350	michael	8349	assert(auth->fd == F);
351	michael	8339
352			if ((len = recv(auth->fd->fd, buf, RFC1413_BUFSIZ, 0)) > 0)
353	adx	30	{
354			buf[len] = '\0';
355	michael	8306	username = auth_check_ident_reply(buf);
356	adx	30	}
357
358	michael	8339	fd_close(auth->fd);
359			auth->fd = NULL;
360	michael	8721	auth->ident_pending = false;
361	michael	8339
362	michael	4309	if (EmptyString(username))
363	adx	30	{
364	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_ID);
365	michael	896	++ServerStats.is_abad;
366	adx	30	}
367			else
368			{
369	michael	4309	strlcpy(auth->client->username, username, sizeof(auth->client->username));
370	michael	8306	auth_sendheader(auth->client, REPORT_FIN_ID);
371	michael	896	++ServerStats.is_asuc;
372	michael	6313	AddFlag(auth->client, FLAGS_GOTID);
373	adx	30	}
374
375	michael	8306	auth_release_client(auth);
376	adx	30	}
377
378			/*
379	michael	8306	* auth_connect_callback() - deal with the result of comm_connect_tcp()
380			*
381			* If the connection failed, we simply close the auth fd and report
382			* a failure. If the connection suceeded send the ident server a query
383			* giving "theirport , ourport". The write is only attempted once so
384			* it is deemed to be a fail if the entire write doesn't write all the
385			* data given. This shouldnt be a problem since the socket should have
386			* a write buffer far greater than this message to store it in should
387			* problems arise. -avalon
388			*/
389			static void
390	michael	8349	auth_connect_callback(fde_t F, int error, void data)
391	michael	8306	{
392			struct AuthRequest *const auth = data;
393			struct irc_ssaddr us;
394			struct irc_ssaddr them;
395			char authbuf[16];
396			ssize_t len = 0;
397			socklen_t ulen = sizeof(struct irc_ssaddr);
398			socklen_t tlen = sizeof(struct irc_ssaddr);
399			uint16_t uport, tport;
400			struct sockaddr_in6 *v6;
401
402			if (error != COMM_OK)
403			{
404			auth_error(auth);
405			return;
406			}
407
408	michael	8349	assert(auth->fd == F);
409	michael	8339
410			if (getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&us, &ulen) \|\|
411			getpeername(auth->client->connection->fd->fd, (struct sockaddr *)&them, &tlen))
412	michael	8306	{
413			report_error(L_ALL, "auth get{sock,peer}name error %s:%s",
414			client_get_name(auth->client, SHOW_IP), errno);
415			auth_error(auth);
416			return;
417			}
418
419			v6 = (struct sockaddr_in6 *)&us;
420			uport = ntohs(v6->sin6_port);
421			v6 = (struct sockaddr_in6 *)&them;
422			tport = ntohs(v6->sin6_port);
423
424			len = snprintf(authbuf, sizeof(authbuf), "%u, %u\r\n", tport, uport);
425
426	michael	8349	if (send(F->fd, authbuf, len, 0) != len)
427	michael	8306	{
428			auth_error(auth);
429			return;
430			}
431
432	michael	8349	comm_setselect(F, COMM_SELECT_READ, auth_read_reply, auth, 0);
433	michael	8306	}
434
435			/*! \brief Flag the client to show an attempt to contact the ident server on
436			* the client's host. Should the connect or any later phase of the
437			* identifying process fail, it is aborted and the user is given a
438			* username of "unknown".
439			* \param auth The request for which to start the ident lookup.
440			*/
441			static void
442			auth_start_query(struct AuthRequest *auth)
443			{
444			struct irc_ssaddr localaddr;
445			socklen_t locallen = sizeof(struct irc_ssaddr);
446			struct sockaddr_in6 *v6;
447
448			/* Open a socket of the same type as the client socket */
449	michael	8496	int fd = comm_socket(auth->client->ip.ss.ss_family, SOCK_STREAM, 0);
450	michael	8339	if (fd == -1)
451	michael	8306	{
452			report_error(L_ALL, "creating auth stream socket %s:%s",
453			client_get_name(auth->client, SHOW_IP), errno);
454			++ServerStats.is_abad;
455			return;
456			}
457
458	michael	8658	auth->fd = fd_open(fd, true, "ident");
459	michael	8721	auth->ident_pending = true;
460	michael	8339
461	michael	8306	auth_sendheader(auth->client, REPORT_DO_ID);
462
463			/*
464			* Get the local address of the client and bind to that to
465			* make the auth request.
466			*/
467			memset(&localaddr, 0, locallen);
468	michael	8339	getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&localaddr, &locallen);
469	michael	8306
470			remove_ipv6_mapping(&localaddr);
471			v6 = (struct sockaddr_in6 *)&localaddr;
472			v6->sin6_port = htons(0);
473			localaddr.ss_port = htons(0);
474
475	michael	8339	comm_connect_tcp(auth->fd, auth->client->sockhost, RFC1413_PORT,
476	michael	8306	(struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
477	michael	8496	auth, auth->client->ip.ss.ss_family,
478	michael	8306	GlobalSetOptions.ident_timeout);
479			}
480
481			/*
482			* auth_start
483			*
484			* inputs - pointer to client to auth
485			* output - NONE
486			* side effects - starts auth (identd) and dns queries for a client
487			*/
488			void
489			auth_start(struct Client *client_p)
490			{
491	michael	8339	struct AuthRequest *auth = auth_make(client_p);
492	michael	8306
493			dlinkAddTail(auth, &auth->node, &auth_list);
494
495			auth_sendheader(client_p, REPORT_DO_DNS);
496
497	michael	8721	auth->dns_pending = true;
498	michael	8306
499			if (ConfigGeneral.disable_auth == 0)
500			auth_start_query(auth);
501
502	michael	8496	gethost_byaddr(auth_dns_callback, auth, &client_p->ip);
503	michael	8306	}
504
505			/*
506	michael	7955	* auth_delete()
507	adx	30	*/
508	michael	2916	void
509	michael	7955	auth_delete(struct AuthRequest *auth)
510	adx	30	{
511	michael	8721	if (auth->ident_pending == true)
512	michael	8306	{
513	michael	8339	fd_close(auth->fd);
514			auth->fd = NULL;
515	michael	8721	auth->ident_pending = false;
516	michael	8306	}
517
518	michael	8721	if (auth->dns_pending == true)
519	michael	8300	{
520	michael	992	delete_resolver_queries(auth);
521	michael	8721	auth->dns_pending = false;
522	michael	8300	}
523	adx	30
524	michael	8470	auth_free(auth);
525	adx	30	}
526	michael	4309
527	michael	8306	/*
528			* auth_timeout_queries - timeout resolver and identd requests
529			* allow clients through if requests failed
530			*/
531			static void
532			auth_timeout_queries(void *notused)
533			{
534			dlink_node node, node_next;
535
536			DLINK_FOREACH_SAFE(node, node_next, auth_list.head)
537			{
538			struct AuthRequest *auth = node->data;
539
540			if (auth->timeout > CurrentTime)
541			break;
542
543	michael	8721	if (auth->ident_pending == true)
544	michael	8306	{
545			++ServerStats.is_abad;
546	michael	8349
547	michael	8339	fd_close(auth->fd);
548			auth->fd = NULL;
549	michael	8721	auth->ident_pending = false;
550	michael	8339
551	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_ID);
552			}
553
554	michael	8721	if (auth->dns_pending == true)
555	michael	8306	{
556			delete_resolver_queries(auth);
557	michael	8721	auth->dns_pending = false;
558	michael	8306
559			auth_sendheader(auth->client, REPORT_FAIL_DNS);
560			}
561
562			auth_release_client(auth);
563			}
564			}
565
566	michael	4309	/* auth_init
567			*
568			* Initialise the auth code
569			*/
570			void
571			auth_init(void)
572			{
573			static struct event timeout_auth_queries =
574			{
575	michael	8306	.name = "auth_timeout_queries",
576			.handler = auth_timeout_queries,
577	michael	4309	.when = 1
578			};
579
580			event_add(&timeout_auth_queries, NULL);
581			}