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 Functions for querying a users ident.
 * \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 sendheader(c, i) sendto_one_notice((c), &me, "%s", HeaderMessages[(i)])

static dlink_list auth_list;
static void auth_read_reply(fde_t *, void *);
static void auth_connect_callback(fde_t *, int, void *);


/*
 * make_auth_request - allocate a new auth request
 */
static struct AuthRequest *
make_auth_request(struct Client *client)
{
  struct AuthRequest *const auth = &client->connection->auth;

  memset(auth, 0, sizeof(*auth));

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

  return auth;
}

/*
 * release_auth_client - 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
 */
void
release_auth_client(struct AuthRequest *auth)
{
  struct Client *const client = auth->client;

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

  if (IsInAuth(auth))
  {
    dlinkDelete(&auth->node, &auth_list);
    ClearInAuth(auth);
  }

  /*
   * 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;
  client->flags |= 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;
}

/*
 * auth_dns_callback - called when resolver query finishes
 * if the query resulted in a successful search, name will contain
 * a non-NULL pointer, otherwise name will be NULL.
 * set the client on it's way to a connection completion, regardless
 * of success of failure
 */
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)))
      {
        sendheader(auth->client, REPORT_IP_MISMATCH);
        release_auth_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)
      {
        sendheader(auth->client, REPORT_IP_MISMATCH);
        release_auth_client(auth);
        return;
      }
    }

    if (namelength > HOSTLEN)
      sendheader(auth->client, REPORT_HOST_TOOLONG);
    else if (!auth_verify_hostname(name))
      sendheader(auth->client, REPORT_HOST_INVALID);
    else
    {
      strlcpy(auth->client->host, name, sizeof(auth->client->host));
      sendheader(auth->client, REPORT_FIN_DNS);
    }
  }
  else
    sendheader(auth->client, REPORT_FAIL_DNS);

  release_auth_client(auth);
}

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

  fd_close(&auth->fd);

  ClearAuth(auth);

  sendheader(auth->client, REPORT_FAIL_ID);

  release_auth_client(auth);
}

/*
 * start_auth_query - Flag the client to show that an attempt to
 * contact the ident server on
 * the client's host.  The connect and subsequently the socket are all put
 * into 'non-blocking' mode.  Should the connect or any later phase of the
 * identifing process fail, it is aborted and the user is given a username
 * of "unknown".
 */
static void
start_auth_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 */
  if (comm_open(&auth->fd, auth->client->connection->ip.ss.ss_family,
                SOCK_STREAM, 0, "ident") == -1)
  {
    report_error(L_ALL, "creating auth stream socket %s:%s",
                 client_get_name(auth->client, SHOW_IP), errno);
    ++ServerStats.is_abad;
    return;
  }

  SetDoingAuth(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 *const auth = make_auth_request(client_p);

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

  sendheader(client_p, REPORT_DO_DNS);

  SetDNSPending(auth);

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

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

/*
 * timeout_auth_queries - timeout resolver and identd requests
 * allow clients through if requests failed
 */
static void
timeout_auth_queries_event(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);
      ClearAuth(auth);
      sendheader(auth->client, REPORT_FAIL_ID);
    }

    if (IsDNSPending(auth))
    {
      delete_resolver_queries(auth);
      ClearDNSPending(auth);
      sendheader(auth->client, REPORT_FAIL_DNS);
    }

    release_auth_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;
  }

  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);
}

/** 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 *
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;
}

/*
 * auth_read_reply - 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
 */
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];

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

  fd_close(fd);

  ClearAuth(auth);

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

  release_auth_client(auth);
}

/*
 * auth_delete()
 */
void
auth_delete(struct AuthRequest *auth)
{
  if (IsDNSPending(auth))
    delete_resolver_queries(auth);

  if (IsDoingAuth(auth))
    fd_close(&auth->fd);

  if (IsInAuth(auth))
  {
    dlinkDelete(&auth->node, &auth_list);
    ClearInAuth(auth);
  }
}

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

  event_add(&timeout_auth_queries, NULL);
}
Revision:	8279
Committed:	Tue Feb 20 19:30:13 2018 UTC (7 years, 6 months ago) by michael
Content type:	text/x-csrc
File size:	14575 byte(s)
Log Message:	- Update copyright years
#	Content
1	/*
2	* ircd-hybrid: an advanced, lightweight Internet Relay Chat Daemon (ircd)
3	*
4	* Copyright (c) 1997-2018 ircd-hybrid development team
5	*
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	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
19	* USA
20	*/
21
22	/*! \file auth.c
23	* \brief Functions for querying a users ident.
24	* \version $Id$
25	*/
26
27	/*
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
38	#include "stdinc.h"
39	#include "list.h"
40	#include "ircd_defs.h"
41	#include "fdlist.h"
42	#include "auth.h"
43	#include "conf.h"
44	#include "client.h"
45	#include "event.h"
46	#include "irc_string.h"
47	#include "ircd.h"
48	#include "packet.h"
49	#include "res.h"
50	#include "s_bsd.h"
51	#include "log.h"
52	#include "send.h"
53	#include "mempool.h"
54
55
56	enum
57	{
58	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	REPORT_HOST_TOOLONG,
66	REPORT_HOST_INVALID
67	};
68
69	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	[REPORT_HOST_TOOLONG] = ":*** Your hostname is too long, ignoring hostname",
79	[REPORT_HOST_INVALID] = ":*** Your hostname contains illegal characters, ignoring hostname"
80	};
81
82	#define sendheader(c, i) sendto_one_notice((c), &me, "%s", HeaderMessages[(i)])
83
84	static dlink_list auth_list;
85	static void auth_read_reply(fde_t , void );
86	static void auth_connect_callback(fde_t , int, void );
87
88
89	/*
90	* make_auth_request - allocate a new auth request
91	*/
92	static struct AuthRequest *
93	make_auth_request(struct Client *client)
94	{
95	struct AuthRequest *const auth = &client->connection->auth;
96
97	memset(auth, 0, sizeof(*auth));
98
99	auth->client = client;
100	auth->timeout = CurrentTime + CONNECTTIMEOUT;
101
102	return auth;
103	}
104
105	/*
106	* release_auth_client - release auth client from auth system
107	* this adds the client into the local client lists so it can be read by
108	* the main io processing loop
109	*/
110	void
111	release_auth_client(struct AuthRequest *auth)
112	{
113	struct Client *const client = auth->client;
114
115	if (IsDoingAuth(auth) \|\| IsDNSPending(auth))
116	return;
117
118	if (IsInAuth(auth))
119	{
120	dlinkDelete(&auth->node, &auth_list);
121	ClearInAuth(auth);
122	}
123
124	/*
125	* When a client has auth'ed, we want to start reading what it sends
126	* us. This is what read_packet() does.
127	* -- adrian
128	*/
129	client->connection->allow_read = MAX_FLOOD;
130	comm_setflush(&client->connection->fd, 1000, flood_recalc, client);
131
132	client->connection->since = CurrentTime;
133	client->connection->lasttime = CurrentTime;
134	client->connection->firsttime = CurrentTime;
135	client->flags \|= FLAGS_FINISHED_AUTH;
136
137	strlcpy(client->realhost, client->host, sizeof(client->realhost));
138
139	read_packet(&client->connection->fd, client);
140	}
141
142	/*! Checks if a hostname is valid and doesn't contain illegal characters
143	* \param hostname The string to verify
144	* \return 1 if it is valid, 0 if it isn't
145	*/
146	static int
147	auth_verify_hostname(const char *hostname)
148	{
149	const char *p = hostname;
150
151	assert(p);
152
153	if (EmptyString(p) \|\| p == '.' \|\| p == ':')
154	return 0;
155
156	for (; *p; ++p)
157	if (!IsHostChar(*p))
158	return 0;
159
160	return 1;
161	}
162
163	/*
164	* auth_dns_callback - called when resolver query finishes
165	* if the query resulted in a successful search, name will contain
166	* a non-NULL pointer, otherwise name will be NULL.
167	* set the client on it's way to a connection completion, regardless
168	* of success of failure
169	*/
170	static void
171	auth_dns_callback(void vptr, const struct irc_ssaddr addr, const char *name, size_t namelength)
172	{
173	struct AuthRequest *const auth = vptr;
174
175	ClearDNSPending(auth);
176
177	if (!EmptyString(name))
178	{
179	if (auth->client->connection->ip.ss.ss_family == AF_INET6)
180	{
181	const struct sockaddr_in6 const v6 = (const struct sockaddr_in6 )&auth->client->connection->ip;
182	const struct sockaddr_in6 const v6dns = (const struct sockaddr_in6 )addr;
183
184	if (memcmp(&v6->sin6_addr, &v6dns->sin6_addr, sizeof(struct in6_addr)))
185	{
186	sendheader(auth->client, REPORT_IP_MISMATCH);
187	release_auth_client(auth);
188	return;
189	}
190	}
191	else
192	{
193	const struct sockaddr_in const v4 = (const struct sockaddr_in )&auth->client->connection->ip;
194	const struct sockaddr_in const v4dns = (const struct sockaddr_in )addr;
195
196	if (v4->sin_addr.s_addr != v4dns->sin_addr.s_addr)
197	{
198	sendheader(auth->client, REPORT_IP_MISMATCH);
199	release_auth_client(auth);
200	return;
201	}
202	}
203
204	if (namelength > HOSTLEN)
205	sendheader(auth->client, REPORT_HOST_TOOLONG);
206	else if (!auth_verify_hostname(name))
207	sendheader(auth->client, REPORT_HOST_INVALID);
208	else
209	{
210	strlcpy(auth->client->host, name, sizeof(auth->client->host));
211	sendheader(auth->client, REPORT_FIN_DNS);
212	}
213	}
214	else
215	sendheader(auth->client, REPORT_FAIL_DNS);
216
217	release_auth_client(auth);
218	}
219
220	/*
221	* authsenderr - handle auth send errors
222	*/
223	static void
224	auth_error(struct AuthRequest *auth)
225	{
226	++ServerStats.is_abad;
227
228	fd_close(&auth->fd);
229
230	ClearAuth(auth);
231
232	sendheader(auth->client, REPORT_FAIL_ID);
233
234	release_auth_client(auth);
235	}
236
237	/*
238	* start_auth_query - Flag the client to show that an attempt to
239	* contact the ident server on
240	* the client's host. The connect and subsequently the socket are all put
241	* into 'non-blocking' mode. Should the connect or any later phase of the
242	* identifing process fail, it is aborted and the user is given a username
243	* of "unknown".
244	*/
245	static void
246	start_auth_query(struct AuthRequest *auth)
247	{
248	struct irc_ssaddr localaddr;
249	socklen_t locallen = sizeof(struct irc_ssaddr);
250	struct sockaddr_in6 *v6;
251
252	/* open a socket of the same type as the client socket */
253	if (comm_open(&auth->fd, auth->client->connection->ip.ss.ss_family,
254	SOCK_STREAM, 0, "ident") == -1)
255	{
256	report_error(L_ALL, "creating auth stream socket %s:%s",
257	client_get_name(auth->client, SHOW_IP), errno);
258	++ServerStats.is_abad;
259	return;
260	}
261
262	SetDoingAuth(auth);
263	sendheader(auth->client, REPORT_DO_ID);
264
265	/*
266	* Get the local address of the client and bind to that to
267	* make the auth request.
268	*/
269	memset(&localaddr, 0, locallen);
270	getsockname(auth->client->connection->fd.fd, (struct sockaddr*)&localaddr,
271	&locallen);
272
273	remove_ipv6_mapping(&localaddr);
274	v6 = (struct sockaddr_in6 *)&localaddr;
275	v6->sin6_port = htons(0);
276	localaddr.ss_port = htons(0);
277
278	comm_connect_tcp(&auth->fd, auth->client->sockhost, RFC1413_PORT,
279	(struct sockaddr *)&localaddr, localaddr.ss_len, auth_connect_callback,
280	auth, auth->client->connection->ip.ss.ss_family,
281	GlobalSetOptions.ident_timeout);
282	}
283
284	/*
285	* auth_start
286	*
287	* inputs - pointer to client to auth
288	* output - NONE
289	* side effects - starts auth (identd) and dns queries for a client
290	*/
291	void
292	auth_start(struct Client *client_p)
293	{
294	struct AuthRequest *const auth = make_auth_request(client_p);
295
296	SetInAuth(auth);
297	dlinkAddTail(auth, &auth->node, &auth_list);
298
299	sendheader(client_p, REPORT_DO_DNS);
300
301	SetDNSPending(auth);
302
303	if (ConfigGeneral.disable_auth == 0)
304	start_auth_query(auth);
305
306	gethost_byaddr(auth_dns_callback, auth, &client_p->connection->ip);
307	}
308
309	/*
310	* timeout_auth_queries - timeout resolver and identd requests
311	* allow clients through if requests failed
312	*/
313	static void
314	timeout_auth_queries_event(void *notused)
315	{
316	dlink_node node, node_next;
317
318	DLINK_FOREACH_SAFE(node, node_next, auth_list.head)
319	{
320	struct AuthRequest *auth = node->data;
321
322	if (auth->timeout > CurrentTime)
323	break;
324
325	if (IsDoingAuth(auth))
326	{
327	++ServerStats.is_abad;
328	fd_close(&auth->fd);
329	ClearAuth(auth);
330	sendheader(auth->client, REPORT_FAIL_ID);
331	}
332
333	if (IsDNSPending(auth))
334	{
335	delete_resolver_queries(auth);
336	ClearDNSPending(auth);
337	sendheader(auth->client, REPORT_FAIL_DNS);
338	}
339
340	release_auth_client(auth);
341	}
342	}
343
344	/*
345	* auth_connect_callback() - deal with the result of comm_connect_tcp()
346	*
347	* If the connection failed, we simply close the auth fd and report
348	* a failure. If the connection suceeded send the ident server a query
349	* giving "theirport , ourport". The write is only attempted once so
350	* it is deemed to be a fail if the entire write doesn't write all the
351	* data given. This shouldnt be a problem since the socket should have
352	* a write buffer far greater than this message to store it in should
353	* problems arise. -avalon
354	*/
355	static void
356	auth_connect_callback(fde_t fd, int error, void data)
357	{
358	struct AuthRequest *const auth = data;
359	struct irc_ssaddr us;
360	struct irc_ssaddr them;
361	char authbuf[16];
362	ssize_t len = 0;
363	socklen_t ulen = sizeof(struct irc_ssaddr);
364	socklen_t tlen = sizeof(struct irc_ssaddr);
365	uint16_t uport, tport;
366	struct sockaddr_in6 *v6;
367
368	if (error != COMM_OK)
369	{
370	auth_error(auth);
371	return;
372	}
373
374	if (getsockname(auth->client->connection->fd.fd, (struct sockaddr *)&us, &ulen) \|\|
375	getpeername(auth->client->connection->fd.fd, (struct sockaddr *)&them, &tlen))
376	{
377	report_error(L_ALL, "auth get{sock,peer}name error %s:%s",
378	client_get_name(auth->client, SHOW_IP), errno);
379	auth_error(auth);
380	return;
381	}
382
383	v6 = (struct sockaddr_in6 *)&us;
384	uport = ntohs(v6->sin6_port);
385	v6 = (struct sockaddr_in6 *)&them;
386	tport = ntohs(v6->sin6_port);
387
388	len = snprintf(authbuf, sizeof(authbuf), "%u, %u\r\n", tport, uport);
389
390	if (send(fd->fd, authbuf, len, 0) != len)
391	{
392	auth_error(auth);
393	return;
394	}
395
396	comm_setselect(fd, COMM_SELECT_READ, auth_read_reply, auth, 0);
397	}
398
399	/** Enum used to index ident reply fields in a human-readable way. */
400	enum IdentReplyFields
401	{
402	IDENT_PORT_NUMBERS,
403	IDENT_REPLY_TYPE,
404	IDENT_OS_TYPE,
405	IDENT_INFO,
406	USERID_TOKEN_COUNT
407	};
408
409	/** Parse an ident reply line and extract the userid from it.
410	* \param reply The ident reply line.
411	* \return The userid, or NULL on parse failure.
412	*/
413	static const char *
414	check_ident_reply(char *const reply)
415	{
416	char token = NULL, end = NULL;
417	char *vector[USERID_TOKEN_COUNT];
418	const unsigned int count = token_vector(reply, ':', vector, USERID_TOKEN_COUNT);
419
420	if (USERID_TOKEN_COUNT != count)
421	return NULL;
422
423	/*
424	* Second token is the reply type
425	*/
426	token = vector[IDENT_REPLY_TYPE];
427
428	if (EmptyString(token))
429	return NULL;
430
431	while (IsSpace(*token))
432	++token;
433
434	if (strncmp(token, "USERID", 6))
435	return NULL;
436
437	/*
438	* Third token is the os type
439	*/
440	token = vector[IDENT_OS_TYPE];
441
442	if (EmptyString(token))
443	return NULL;
444
445	while (IsSpace(*token))
446	++token;
447
448	/*
449	* Unless "OTHER" is specified as the operating system type, the server
450	* is expected to return the "normal" user identification of the owner
451	* of this connection. "Normal" in this context may be taken to mean a
452	* string of characters which uniquely identifies the connection owner
453	* such as a user identifier assigned by the system administrator and
454	* used by such user as a mail identifier, or as the "user" part of a
455	* user/password pair used to gain access to system resources. When an
456	* operating system is specified (e.g., anything but "OTHER"), the user
457	* identifier is expected to be in a more or less immediately useful
458	* form - e.g., something that could be used as an argument to "finger"
459	* or as a mail address.
460	*/
461	if (!strncmp(token, "OTHER", 5))
462	return NULL;
463
464	/*
465	* Fourth token is the username
466	*/
467	token = vector[IDENT_INFO];
468
469	if (EmptyString(token))
470	return NULL;
471
472	while (IsSpace(*token))
473	++token;
474
475	while (token == '~' \|\| token == '^')
476	++token;
477
478	/*
479	* Look for the end of the username, terminators are '\0, @, <SPACE>, :'
480	*/
481	for (end = token; *end; ++end)
482	if (IsSpace(end) \|\| '@' == end \|\| ':' == *end)
483	break;
484	*end = '\0';
485
486	return token;
487	}
488
489	/*
490	* auth_read_reply - read the reply (if any) from the ident server
491	* we connected to.
492	* We only give it one shot, if the reply isn't good the first time
493	* fail the authentication entirely. --Bleep
494	*/
495	static void
496	auth_read_reply(fde_t fd, void data)
497	{
498	struct AuthRequest *const auth = data;
499	const char *username = NULL;
500	ssize_t len = 0;
501	char buf[RFC1413_BUFSIZ + 1];
502
503	if ((len = recv(fd->fd, buf, RFC1413_BUFSIZ, 0)) > 0)
504	{
505	buf[len] = '\0';
506	username = check_ident_reply(buf);
507	}
508
509	fd_close(fd);
510
511	ClearAuth(auth);
512
513	if (EmptyString(username))
514	{
515	sendheader(auth->client, REPORT_FAIL_ID);
516	++ServerStats.is_abad;
517	}
518	else
519	{
520	strlcpy(auth->client->username, username, sizeof(auth->client->username));
521	sendheader(auth->client, REPORT_FIN_ID);
522	++ServerStats.is_asuc;
523	AddFlag(auth->client, FLAGS_GOTID);
524	}
525
526	release_auth_client(auth);
527	}
528
529	/*
530	* auth_delete()
531	*/
532	void
533	auth_delete(struct AuthRequest *auth)
534	{
535	if (IsDNSPending(auth))
536	delete_resolver_queries(auth);
537
538	if (IsDoingAuth(auth))
539	fd_close(&auth->fd);
540
541	if (IsInAuth(auth))
542	{
543	dlinkDelete(&auth->node, &auth_list);
544	ClearInAuth(auth);
545	}
546	}
547
548	/* auth_init
549	*
550	* Initialise the auth code
551	*/
552	void
553	auth_init(void)
554	{
555	static struct event timeout_auth_queries =
556	{
557	.name = "timeout_auth_queries_event",
558	.handler = timeout_auth_queries_event,
559	.when = 1
560	};
561
562	event_add(&timeout_auth_queries, NULL);
563	}