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 "mempool.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 mp_pool_t *auth_pool;
static dlink_list auth_list;


/*
 * auth_make_request - allocate a new auth request
 */
static struct AuthRequest *
auth_make(struct Client *client)
{
  struct AuthRequest *auth = mp_pool_get(auth_pool);;

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

  return 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 *const client = auth->client;

  if (IsDoingAuth(auth) || IsDNSPending(auth))
    return;

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

  mp_pool_release(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
   */
  client->connection->allow_read = MAX_FLOOD;
  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 int
auth_verify_hostname(const char *hostname)
{
  const char *p = hostname;

  assert(p);

  if (EmptyString(p) || *p == '.' || *p == ':')
    return 0;

  for (; *p; ++p)
    if (!IsHostChar(*p))
      return 0;

  return 1;
}

/*! \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;

  ClearDNSPending(auth);

  if (!EmptyString(name))
  {
    if (auth->client->connection->ip.ss.ss_family == AF_INET6)
    {
      const struct sockaddr_in6 *const v6 = (const struct sockaddr_in6 *)&auth->client->connection->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->connection->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))
      auth_sendheader(auth->client, REPORT_HOST_INVALID);
    else
    {
      strlcpy(auth->client->host, name, sizeof(auth->client->host));
      auth_sendheader(auth->client, REPORT_FIN_DNS);
    }
  }
  else
    auth_sendheader(auth->client, REPORT_FAIL_DNS);

  auth_release_client(auth);
}

/*
 * auth_error - handle auth send errors
 */
static void
auth_error(struct AuthRequest *auth)
{
  ++ServerStats.is_abad;

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

  ClearAuth(auth);

  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))
    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 fd The socket/fd to read from.
 * \param data The request to read.
 */
static void
auth_read_reply(fde_t *fd, void *data)
{
  struct AuthRequest *const auth = data;
  const char *username = NULL;
  ssize_t len = 0;
  char buf[RFC1413_BUFSIZ + 1];

  assert(fd == auth->fd);

  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;

  ClearAuth(auth);

  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 *fd, 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(fd == auth->fd);

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

  comm_setselect(fd, 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->connection->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, 1, "ident");

  SetDoingAuth(auth);
  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->connection->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);

  SetDNSPending(auth);

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

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

/*
 * auth_delete()
 */
void
auth_delete(struct AuthRequest *auth)
{
  if (IsDoingAuth(auth))
  {
    fd_close(auth->fd);
    auth->fd = NULL;
    ClearAuth(auth);
  }

  if (IsDNSPending(auth))
  {
    delete_resolver_queries(auth);
    ClearDNSPending(auth);
  }

  dlinkDelete(&auth->node, &auth_list);
  mp_pool_release(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 (IsDoingAuth(auth))
    {
      ++ServerStats.is_abad;
      fd_close(auth->fd);
      auth->fd = NULL;

      ClearAuth(auth);

      auth_sendheader(auth->client, REPORT_FAIL_ID);
    }

    if (IsDNSPending(auth))
    {
      delete_resolver_queries(auth);
      ClearDNSPending(auth);

      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
  };

  auth_pool = mp_pool_new(sizeof(struct AuthRequest), MP_CHUNK_SIZE_AUTH);
  event_add(&timeout_auth_queries, NULL);
}
Revision:	8339
Committed:	Sat Mar 3 22:47:06 2018 UTC (8 years, 7 months ago) by michael
Content type:	text/x-csrc
File size:	14974 byte(s)
Log Message:	- Restore fd_table. No longer allocate fde_t items from within any other structures like the AuthRequest, or Connection structure - struct AuthRequest once again is no longer allocated from within the Connection structure
#	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	1654	#include "mempool.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	8339	static mp_pool_t *auth_pool;
85	michael	6478	static dlink_list auth_list;
86	adx	30
87	michael	4094
88	adx	30	/*
89	michael	8306	* auth_make_request - allocate a new auth request
90	adx	30	*/
91			static struct AuthRequest *
92	michael	8339	auth_make(struct Client *client)
93	adx	30	{
94	michael	8339	struct AuthRequest *auth = mp_pool_get(auth_pool);;
95	adx	30
96	michael	6690	auth->client = client;
97			auth->timeout = CurrentTime + CONNECTTIMEOUT;
98	michael	2181
99	michael	6690	return auth;
100	adx	30	}
101
102	michael	8306	/*! \brief Release auth client from auth system. This adds the client into the
103			* local client lists so it can be read by the main io processing loop.
104			* \param auth Pointer to AuthRequest struct to release
105	adx	30	*/
106	michael	8304	static void
107	michael	8306	auth_release_client(struct AuthRequest *auth)
108	adx	30	{
109	michael	4854	struct Client *const client = auth->client;
110	michael	992
111			if (IsDoingAuth(auth) \|\| IsDNSPending(auth))
112			return;
113
114	michael	8339	dlinkDelete(&auth->node, &auth_list);
115	michael	992
116	michael	8339	mp_pool_release(auth);
117			client->connection->auth = NULL;
118
119	adx	30	/*
120			* When a client has auth'ed, we want to start reading what it sends
121			* us. This is what read_packet() does.
122			* -- adrian
123			*/
124	michael	4588	client->connection->allow_read = MAX_FLOOD;
125	michael	8339	comm_setflush(client->connection->fd, 1000, flood_recalc, client);
126	michael	650
127	michael	4588	client->connection->since = CurrentTime;
128			client->connection->lasttime = CurrentTime;
129			client->connection->firsttime = CurrentTime;
130	michael	8298	AddFlag(client, FLAGS_FINISHED_AUTH);
131	michael	650
132	michael	8214	strlcpy(client->realhost, client->host, sizeof(client->realhost));
133
134	michael	8339	read_packet(client->connection->fd, client);
135	adx	30	}
136	michael	2916
137	michael	8218	/*! Checks if a hostname is valid and doesn't contain illegal characters
138			* \param hostname The string to verify
139			* \return 1 if it is valid, 0 if it isn't
140			*/
141	michael	8217	static int
142			auth_verify_hostname(const char *hostname)
143			{
144			const char *p = hostname;
145
146			assert(p);
147
148			if (EmptyString(p) \|\| p == '.' \|\| p == ':')
149			return 0;
150
151			for (; *p; ++p)
152			if (!IsHostChar(*p))
153			return 0;
154
155			return 1;
156			}
157
158	michael	8306	/*! \brief Handle a complete DNS lookup. Send the client on its way to a connection
159			* completion, regardless of success or failure.
160			* \param vptr The pending struct AuthRequest.
161			* \param addr IP address being resolved.
162			* \param name Resolved name, or NULL if lookup failed.
163			* \param namelength String length of the resolved hostname pointed by 'name'
164	adx	30	*/
165			static void
166	michael	4408	auth_dns_callback(void vptr, const struct irc_ssaddr addr, const char *name, size_t namelength)
167	adx	30	{
168	michael	4854	struct AuthRequest *const auth = vptr;
169	adx	30
170			ClearDNSPending(auth);
171
172	michael	4408	if (!EmptyString(name))
173	adx	30	{
174	michael	4588	if (auth->client->connection->ip.ss.ss_family == AF_INET6)
175	adx	30	{
176	michael	4858	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )&auth->client->connection->ip;
177			const struct sockaddr_in6 const v6dns = (const struct sockaddr_in6 )addr;
178	michael	3250
179	michael	5902	if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)))
180	adx	30	{
181	michael	8306	auth_sendheader(auth->client, REPORT_IP_MISMATCH);
182			auth_release_client(auth);
183	michael	4408	return;
184	adx	30	}
185			}
186			else
187			{
188	michael	4858	const struct sockaddr_in const v4 = (const struct sockaddr_in )&auth->client->connection->ip;
189			const struct sockaddr_in const v4dns = (const struct sockaddr_in )addr;
190	michael	3250
191			if (v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
192	adx	30	{
193	michael	8306	auth_sendheader(auth->client, REPORT_IP_MISMATCH);
194			auth_release_client(auth);
195	michael	4408	return;
196	adx	30	}
197			}
198	michael	3250
199	michael	4408	if (namelength > HOSTLEN)
200	michael	8306	auth_sendheader(auth->client, REPORT_HOST_TOOLONG);
201	michael	8217	else if (!auth_verify_hostname(name))
202	michael	8306	auth_sendheader(auth->client, REPORT_HOST_INVALID);
203	michael	4408	else
204	adx	30	{
205	michael	4408	strlcpy(auth->client->host, name, sizeof(auth->client->host));
206	michael	8306	auth_sendheader(auth->client, REPORT_FIN_DNS);
207	adx	30	}
208			}
209			else
210	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_DNS);
211	adx	30
212	michael	8306	auth_release_client(auth);
213	adx	30	}
214
215			/*
216	michael	8306	* auth_error - handle auth send errors
217	adx	30	*/
218			static void
219			auth_error(struct AuthRequest *auth)
220			{
221	michael	896	++ServerStats.is_abad;
222	adx	30
223	michael	8339	fd_close(auth->fd);
224			auth->fd = NULL;
225
226	adx	30	ClearAuth(auth);
227
228	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_ID);
229	adx	30
230	michael	8306	auth_release_client(auth);
231	adx	30	}
232
233	michael	4309	/** Enum used to index ident reply fields in a human-readable way. */
234			enum IdentReplyFields
235			{
236			IDENT_PORT_NUMBERS,
237			IDENT_REPLY_TYPE,
238			IDENT_OS_TYPE,
239			IDENT_INFO,
240			USERID_TOKEN_COUNT
241			};
242
243			/** Parse an ident reply line and extract the userid from it.
244			* \param reply The ident reply line.
245			* \return The userid, or NULL on parse failure.
246			*/
247			static const char *
248	michael	8306	auth_check_ident_reply(char *const reply)
249	michael	4309	{
250			char token = NULL, end = NULL;
251			char *vector[USERID_TOKEN_COUNT];
252	michael	7584	const unsigned int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);
253	michael	4309
254			if (USERID_TOKEN_COUNT != count)
255			return NULL;
256
257			/*
258			* Second token is the reply type
259			*/
260			token = vector[IDENT_REPLY_TYPE];
261
262			if (EmptyString(token))
263			return NULL;
264
265			while (IsSpace(*token))
266			++token;
267
268			if (strncmp(token, "USERID", 6))
269			return NULL;
270
271			/*
272			* Third token is the os type
273			*/
274			token = vector[IDENT_OS_TYPE];
275
276			if (EmptyString(token))
277			return NULL;
278
279			while (IsSpace(*token))
280			++token;
281
282			/*
283			* Unless "OTHER" is specified as the operating system type, the server
284			* is expected to return the "normal" user identification of the owner
285			* of this connection. "Normal" in this context may be taken to mean a
286			* string of characters which uniquely identifies the connection owner
287			* such as a user identifier assigned by the system administrator and
288			* used by such user as a mail identifier, or as the "user" part of a
289			* user/password pair used to gain access to system resources. When an
290			* operating system is specified (e.g., anything but "OTHER"), the user
291			* identifier is expected to be in a more or less immediately useful
292			* form - e.g., something that could be used as an argument to "finger"
293			* or as a mail address.
294			*/
295			if (!strncmp(token, "OTHER", 5))
296			return NULL;
297
298			/*
299			* Fourth token is the username
300			*/
301			token = vector[IDENT_INFO];
302
303			if (EmptyString(token))
304			return NULL;
305
306			while (IsSpace(*token))
307			++token;
308
309			while (token == '~' \|\| token == '^')
310			++token;
311
312			/*
313			* Look for the end of the username, terminators are '\0, @, <SPACE>, :'
314			*/
315			for (end = token; *end; ++end)
316			if (IsSpace(end) \|\| '@' == end \|\| ':' == *end)
317			break;
318			*end = '\0';
319
320			return token;
321			}
322
323	michael	8306	/*! \brief Read the reply (if any) from the ident server we connected to. We
324			* only give it one shot, if the reply isn't good the first time fail
325			* the authentication entirely. --Bleep
326			* \param fd The socket/fd to read from.
327			* \param data The request to read.
328	adx	30	*/
329			static void
330	michael	7955	auth_read_reply(fde_t fd, void data)
331	adx	30	{
332	michael	4854	struct AuthRequest *const auth = data;
333	michael	4309	const char *username = NULL;
334			ssize_t len = 0;
335			char buf[RFC1413_BUFSIZ + 1];
336	adx	30
337	michael	8339	assert(fd == auth->fd);
338
339			if ((len = recv(auth->fd->fd, buf, RFC1413_BUFSIZ, 0)) > 0)
340	adx	30	{
341			buf[len] = '\0';
342	michael	8306	username = auth_check_ident_reply(buf);
343	adx	30	}
344
345	michael	8339	fd_close(auth->fd);
346			auth->fd = NULL;
347
348	adx	30	ClearAuth(auth);
349
350	michael	4309	if (EmptyString(username))
351	adx	30	{
352	michael	8306	auth_sendheader(auth->client, REPORT_FAIL_ID);
353	michael	896	++ServerStats.is_abad;
354	adx	30	}
355			else
356			{
357	michael	4309	strlcpy(auth->client->username, username, sizeof(auth->client->username));
358	michael	8306	auth_sendheader(auth->client, REPORT_FIN_ID);
359	michael	896	++ServerStats.is_asuc;
360	michael	6313	AddFlag(auth->client, FLAGS_GOTID);
361	adx	30	}
362
363	michael	8306	auth_release_client(auth);
364	adx	30	}
365
366			/*
367	michael	8306	* auth_connect_callback() - deal with the result of comm_connect_tcp()
368			*
369			* If the connection failed, we simply close the auth fd and report
370			* a failure. If the connection suceeded send the ident server a query
371			* giving "theirport , ourport". The write is only attempted once so
372			* it is deemed to be a fail if the entire write doesn't write all the
373			* data given. This shouldnt be a problem since the socket should have
374			* a write buffer far greater than this message to store it in should
375			* problems arise. -avalon
376			*/
377			static void
378			auth_connect_callback(fde_t fd, int error, void data)
379			{
380			struct AuthRequest *const auth = data;
381			struct irc_ssaddr us;
382			struct irc_ssaddr them;
383			char authbuf[16];
384			ssize_t len = 0;
385			socklen_t ulen = sizeof(struct irc_ssaddr);
386			socklen_t tlen = sizeof(struct irc_ssaddr);
387			uint16_t uport, tport;
388			struct sockaddr_in6 *v6;
389
390			if (error != COMM_OK)
391			{
392			auth_error(auth);
393			return;
394			}
395
396	michael	8339	assert(fd == auth->fd);
397
398			if (getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&us, &ulen) \|\|
399			getpeername(auth->client->connection->fd->fd, (struct sockaddr *)&them, &tlen))
400	michael	8306	{
401			report_error(L_ALL, "auth get{sock,peer}name error %s:%s",
402			client_get_name(auth->client, SHOW_IP), errno);
403			auth_error(auth);
404			return;
405			}
406
407			v6 = (struct sockaddr_in6 *)&us;
408			uport = ntohs(v6->sin6_port);
409			v6 = (struct sockaddr_in6 *)&them;
410			tport = ntohs(v6->sin6_port);
411
412			len = snprintf(authbuf, sizeof(authbuf), "%u, %u\r\n", tport, uport);
413
414			if (send(fd->fd, authbuf, len, 0) != len)
415			{
416			auth_error(auth);
417			return;
418			}
419
420			comm_setselect(fd, COMM_SELECT_READ, auth_read_reply, auth, 0);
421			}
422
423			/*! \brief Flag the client to show an attempt to contact the ident server on
424			* the client's host. Should the connect or any later phase of the
425			* identifying process fail, it is aborted and the user is given a
426			* username of "unknown".
427			* \param auth The request for which to start the ident lookup.
428			*/
429			static void
430			auth_start_query(struct AuthRequest *auth)
431			{
432			struct irc_ssaddr localaddr;
433			socklen_t locallen = sizeof(struct irc_ssaddr);
434			struct sockaddr_in6 *v6;
435
436			/* Open a socket of the same type as the client socket */
437	michael	8339	int fd = comm_socket(auth->client->connection->ip.ss.ss_family, SOCK_STREAM, 0);
438			if (fd == -1)
439	michael	8306	{
440			report_error(L_ALL, "creating auth stream socket %s:%s",
441			client_get_name(auth->client, SHOW_IP), errno);
442			++ServerStats.is_abad;
443			return;
444			}
445
446	michael	8339	auth->fd = fd_open(fd, 1, "ident");
447
448	michael	8306	SetDoingAuth(auth);
449			auth_sendheader(auth->client, REPORT_DO_ID);
450
451			/*
452			* Get the local address of the client and bind to that to
453			* make the auth request.
454			*/
455			memset(&localaddr, 0, locallen);
456	michael	8339	getsockname(auth->client->connection->fd->fd, (struct sockaddr *)&localaddr, &locallen);
457	michael	8306
458			remove_ipv6_mapping(&localaddr);
459			v6 = (struct sockaddr_in6 *)&localaddr;
460			v6->sin6_port = htons(0);
461			localaddr.ss_port = htons(0);
462
463	michael	8339	comm_connect_tcp(auth->fd, auth->client->sockhost, RFC1413_PORT,
464	michael	8306	(struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
465			auth, auth->client->connection->ip.ss.ss_family,
466			GlobalSetOptions.ident_timeout);
467			}
468
469			/*
470			* auth_start
471			*
472			* inputs - pointer to client to auth
473			* output - NONE
474			* side effects - starts auth (identd) and dns queries for a client
475			*/
476			void
477			auth_start(struct Client *client_p)
478			{
479	michael	8339	struct AuthRequest *auth = auth_make(client_p);
480	michael	8306
481			dlinkAddTail(auth, &auth->node, &auth_list);
482
483			auth_sendheader(client_p, REPORT_DO_DNS);
484
485			SetDNSPending(auth);
486
487			if (ConfigGeneral.disable_auth == 0)
488			auth_start_query(auth);
489
490			gethost_byaddr(auth_dns_callback, auth, &client_p->connection->ip);
491			}
492
493			/*
494	michael	7955	* auth_delete()
495	adx	30	*/
496	michael	2916	void
497	michael	7955	auth_delete(struct AuthRequest *auth)
498	adx	30	{
499	michael	8306	if (IsDoingAuth(auth))
500			{
501	michael	8339	fd_close(auth->fd);
502			auth->fd = NULL;
503	michael	8306	ClearAuth(auth);
504			}
505
506	michael	992	if (IsDNSPending(auth))
507	michael	8300	{
508	michael	992	delete_resolver_queries(auth);
509	michael	8300	ClearDNSPending(auth);
510			}
511	adx	30
512	michael	8339	dlinkDelete(&auth->node, &auth_list);
513			mp_pool_release(auth);
514	adx	30	}
515	michael	4309
516	michael	8306	/*
517			* auth_timeout_queries - timeout resolver and identd requests
518			* allow clients through if requests failed
519			*/
520			static void
521			auth_timeout_queries(void *notused)
522			{
523			dlink_node node, node_next;
524
525			DLINK_FOREACH_SAFE(node, node_next, auth_list.head)
526			{
527			struct AuthRequest *auth = node->data;
528
529			if (auth->timeout > CurrentTime)
530			break;
531
532			if (IsDoingAuth(auth))
533			{
534			++ServerStats.is_abad;
535	michael	8339	fd_close(auth->fd);
536			auth->fd = NULL;
537
538	michael	8306	ClearAuth(auth);
539
540			auth_sendheader(auth->client, REPORT_FAIL_ID);
541			}
542
543			if (IsDNSPending(auth))
544			{
545			delete_resolver_queries(auth);
546			ClearDNSPending(auth);
547
548			auth_sendheader(auth->client, REPORT_FAIL_DNS);
549			}
550
551			auth_release_client(auth);
552			}
553			}
554
555	michael	4309	/* auth_init
556			*
557			* Initialise the auth code
558			*/
559			void
560			auth_init(void)
561			{
562			static struct event timeout_auth_queries =
563			{
564	michael	8306	.name = "auth_timeout_queries",
565			.handler = auth_timeout_queries,
566	michael	4309	.when = 1
567			};
568
569	michael	8339	auth_pool = mp_pool_new(sizeof(struct AuthRequest), MP_CHUNK_SIZE_AUTH);
570	michael	4309	event_add(&timeout_auth_queries, NULL);
571			}