trunk/src/s_bsd.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 s_bsd.c
 * \brief Network functions.
 * \version $Id$
 */

#include "stdinc.h"
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include "list.h"
#include "fdlist.h"
#include "s_bsd.h"
#include "client.h"
#include "dbuf.h"
#include "event.h"
#include "irc_string.h"
#include "ircd.h"
#include "listener.h"
#include "numeric.h"
#include "packet.h"
#include "res.h"
#include "restart.h"
#include "conf.h"
#include "log.h"
#include "server.h"
#include "send.h"
#include "memory.h"
#include "user.h"


static const char *const comm_err_str[] =
{
  [COMM_OK] = "Comm OK",
  [COMM_ERR_BIND] = "Error during bind()",
  [COMM_ERR_DNS] = "Error during DNS lookup",
  [COMM_ERR_TIMEOUT] = "connect timeout",
  [COMM_ERR_CONNECT] = "Error during connect()",
  [COMM_ERROR] = "Comm Error"
};

static void comm_connect_callback(fde_t *, int);
static void comm_connect_timeout(fde_t *, void *);
static void comm_connect_dns_callback(void *, const struct irc_ssaddr *, const char *, size_t);
static void comm_connect_tryconnect(fde_t *, void *);


/* comm_get_sockerr - get the error value from the socket or the current errno
 *
 * Get the *real* error from the socket (well try to anyway..).
 * This may only work when SO_DEBUG is enabled but its worth the
 * gamble anyway.
 */
int
comm_get_sockerr(int fd)
{
  int errtmp = errno;
#ifdef SO_ERROR
  int err = 0;
  socklen_t len = sizeof(err);

  if (fd > -1 && !getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len))
  {
    if (err)
      errtmp = err;
  }
  errno = errtmp;
#endif
  return errtmp;
}

/*
 * report_error - report an error from an errno.
 * Record error to log and also send a copy to all *LOCAL* opers online.
 *
 *        text        is a *format* string for outputing error. It must
 *                contain only two '%s', the first will be replaced
 *                by the sockhost from the client_p, and the latter will
 *                be taken from sys_errlist[errno].
 *
 *        client_p        if not NULL, is the *LOCAL* client associated with
 *                the error.
 *
 * Cannot use perror() within daemon. stderr is closed in
 * ircd and cannot be used. And, worse yet, it might have
 * been reassigned to a normal connection...
 *
 * Actually stderr is still there IFF ircd was run with -s --Rodder
 */
void
report_error(int level, const char *text, const char *who, int error)
{
  who = (who) ? who : "";

  sendto_realops_flags(UMODE_DEBUG, level, SEND_NOTICE,
                       text, who, strerror(error));
  ilog(LOG_TYPE_IRCD, text, who, strerror(error));
}

/*
 * setup_socket()
 *
 * Set the socket non-blocking, and other wonderful bits.
 */
static void
setup_socket(int fd)
{
  int opt = 1;

  setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));

#ifdef IPTOS_LOWDELAY
  opt = IPTOS_LOWDELAY;
  setsockopt(fd, IPPROTO_IP, IP_TOS, &opt, sizeof(opt));
#endif

  fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
}

/*
 * ssl_handshake - let OpenSSL initialize the protocol. Register for
 * read/write events if necessary.
 */
static void
ssl_handshake(fde_t *F, void *data)
{
  struct Client *client_p = data;

  assert(client_p);
  assert(client_p->connection);
  assert(client_p->connection->fd);
  assert(client_p->connection->fd == F);

  tls_handshake_status_t ret = tls_handshake(&F->ssl, TLS_ROLE_SERVER, NULL);
  if (ret != TLS_HANDSHAKE_DONE)
  {
    if ((CurrentTime - client_p->connection->firsttime) > CONNECTTIMEOUT)
    {
      exit_client(client_p, "Timeout during TLS handshake");
      return;
    }

    switch (ret)
    {
      case TLS_HANDSHAKE_WANT_WRITE:
        comm_setselect(client_p->connection->fd, COMM_SELECT_WRITE,
                       ssl_handshake, client_p, CONNECTTIMEOUT);
        return;
      case TLS_HANDSHAKE_WANT_READ:
        comm_setselect(client_p->connection->fd, COMM_SELECT_READ,
                       ssl_handshake, client_p, CONNECTTIMEOUT);
        return;
      default:
        exit_client(client_p, "Error during TLS handshake");
        return;
    }
  }

  comm_settimeout(F, 0, NULL, NULL);

  if (!tls_verify_cert(&F->ssl, ConfigServerInfo.message_digest_algorithm, &client_p->certfp))
    ilog(LOG_TYPE_IRCD, "Client %s!%s@%s gave bad TLS client certificate",
         client_p->name, client_p->username, client_p->host);

  auth_start(client_p);
}

/*
 * add_connection - creates a client which has just connected to us on
 * the given fd. The sockhost field is initialized with the ip# of the host.
 * An unique id is calculated now, in case it is needed for auth.
 * The client is sent to the auth module for verification, and not put in
 * any client list yet.
 */
void
add_connection(struct Listener *listener, struct irc_ssaddr *irn, int fd)
{
  struct Client *client_p = client_make(NULL);

  client_p->connection->fd = fd_open(fd, 1, (listener->flags & LISTENER_SSL) ?
                                     "Incoming SSL connection" : "Incoming connection");

  /*
   * copy address to 'sockhost' as a string, copy it to host too
   * so we have something valid to put into error messages...
   */
  memcpy(&client_p->ip, irn, sizeof(client_p->ip));

  getnameinfo((const struct sockaddr *)&client_p->ip,
              client_p->ip.ss_len, client_p->sockhost,
              sizeof(client_p->sockhost), NULL, 0, NI_NUMERICHOST);

  if (client_p->sockhost[0] == ':')
  {
    client_p->sockhost[0] = '0';
    memmove(client_p->sockhost + 1, client_p->sockhost, sizeof(client_p->sockhost) - 1);
  }

  strlcpy(client_p->host, client_p->sockhost, sizeof(client_p->host));

  client_p->connection->listener = listener;
  ++listener->ref_count;

  if (listener->flags & LISTENER_SSL)
  {
    if (!tls_new(&client_p->connection->fd->ssl, fd, TLS_ROLE_SERVER))
    {
      SetDead(client_p);
      exit_client(client_p, "TLS context initialization failed");
      return;
    }

    AddFlag(client_p, FLAGS_SSL);
    ssl_handshake(client_p->connection->fd, client_p);
  }
  else
    auth_start(client_p);
}

/*
 * stolen from squid - its a neat (but overused! :) routine which we
 * can use to see whether we can ignore this errno or not. It is
 * generally useful for non-blocking network IO related errnos.
 *     -- adrian
 */
int
comm_ignore_errno(int ierrno)
{
  switch (ierrno)
  {
    case EINPROGRESS:
    case EWOULDBLOCK:
#if EAGAIN != EWOULDBLOCK
    case EAGAIN:
#endif
    case EALREADY:
    case EINTR:
#ifdef ERESTART
    case ERESTART:
#endif
        return 1;
    default:
        return 0;
  }
}

/*
 * comm_settimeout() - set the socket timeout
 *
 * Set the timeout for the fd
 */
void
comm_settimeout(fde_t *F, uintmax_t timeout, void (*callback)(fde_t *, void *), void *cbdata)
{
  assert(F->flags.open);

  F->timeout = CurrentTime + (timeout / 1000);
  F->timeout_handler = callback;
  F->timeout_data = cbdata;
}

/*
 * comm_setflush() - set a flush function
 *
 * A flush function is simply a function called if found during
 * comm_timeouts(). Its basically a second timeout, except in this case
 * I'm too lazy to implement multiple timeout functions! :-)
 * its kinda nice to have it separate, since this is designed for
 * flush functions, and when comm_close() is implemented correctly
 * with close functions, we _actually_ don't call comm_close() here ..
 * -- originally Adrian's notes
 * comm_close() is replaced with fd_close() in fdlist.c
 */
void
comm_setflush(fde_t *F, uintmax_t timeout, void (*callback)(fde_t *, void *), void *cbdata)
{
  assert(F->flags.open);

  F->flush_timeout = CurrentTime + (timeout / 1000);
  F->flush_handler = callback;
  F->flush_data = cbdata;
}

/*
 * comm_checktimeouts() - check the socket timeouts
 *
 * All this routine does is call the given callback/cbdata, without closing
 * down the file descriptor. When close handlers have been implemented,
 * this will happen.
 */
void
comm_checktimeouts(void *unused)
{
  void (*hdl)(fde_t *, void *);
  void *data;

  for (int fd = 0; fd <= highest_fd; ++fd)
  {
    fde_t *F = &fd_table[fd];

    if (F->flags.open == 0)
      continue;

    /* check flush functions */
    if (F->flush_handler && F->flush_timeout > 0 &&
        F->flush_timeout < CurrentTime)
    {
      hdl = F->flush_handler;
      data = F->flush_data;

      comm_setflush(F, 0, NULL, NULL);
      hdl(F, data);
    }

    /* check timeouts */
    if (F->timeout_handler && F->timeout > 0 &&
        F->timeout < CurrentTime)
    {
      /* Call timeout handler */
      hdl = F->timeout_handler;
      data = F->timeout_data;

      comm_settimeout(F, 0, NULL, NULL);
      hdl(F, data);
    }
  }
}

/*
 * void comm_connect_tcp(int fd, const char *host, unsigned short port,
 *                       struct sockaddr *clocal, int socklen,
 *                       CNCB *callback, void *data, int aftype, int timeout)
 * Input: An fd to connect with, a host and port to connect to,
 *        a local sockaddr to connect from + length(or NULL to use the
 *        default), a callback, the data to pass into the callback, the
 *        address family.
 * Output: None.
 * Side-effects: A non-blocking connection to the host is started, and
 *               if necessary, set up for selection. The callback given
 *               may be called now, or it may be called later.
 */
void
comm_connect_tcp(fde_t *F, const char *host, unsigned short port, struct sockaddr *clocal,
                 int socklen, void (*callback)(fde_t *, int, void *), void *data,
                 int aftype, uintmax_t timeout)
{
  struct addrinfo hints, *res;
  char portname[PORTNAMELEN + 1];

  assert(callback);
  F->connect.callback = callback;
  F->connect.data = data;

  F->connect.hostaddr.ss.ss_family = aftype;
  F->connect.hostaddr.ss_port = htons(port);

  /* Note that we're using a passed sockaddr here. This is because
   * generally you'll be bind()ing to a sockaddr grabbed from
   * getsockname(), so this makes things easier.
   * XXX If NULL is passed as local, we should later on bind() to the
   * virtual host IP, for completeness.
   *   -- adrian
   */
  if (clocal && bind(F->fd, clocal, socklen) < 0)
  {
    /* Failure, call the callback with COMM_ERR_BIND */
    comm_connect_callback(F, COMM_ERR_BIND);
    return;  /* ... and quit */
  }

  memset(&hints, 0, sizeof(hints));

  hints.ai_family = AF_UNSPEC;
  hints.ai_socktype = SOCK_STREAM;
  hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;

  snprintf(portname, sizeof(portname), "%d", port);

  /*
   * Next, if we have been given an IP address, get the address and skip the
   * DNS check (and head direct to comm_connect_tryconnect()).
   */
  if (getaddrinfo(host, portname, &hints, &res))
  {
    /* Send the DNS request, for the next level */
    if (aftype == AF_INET6)
      gethost_byname_type(comm_connect_dns_callback, F, host, T_AAAA);
    else
      gethost_byname_type(comm_connect_dns_callback, F, host, T_A);
  }
  else
  {
    /* We have a valid IP, so we just call tryconnect */
    /* Make sure we actually set the timeout here .. */
    assert(res);

    memcpy(&F->connect.hostaddr, res->ai_addr, res->ai_addrlen);
    F->connect.hostaddr.ss_len = res->ai_addrlen;
    F->connect.hostaddr.ss.ss_family = res->ai_family;

    freeaddrinfo(res);

    comm_settimeout(F, timeout * 1000, comm_connect_timeout, NULL);
    comm_connect_tryconnect(F, NULL);
  }
}

/*
 * comm_connect_callback() - call the callback, and continue with life
 */
static void
comm_connect_callback(fde_t *F, int status)
{
  void (*hdl)(fde_t *, int, void *);

  /* This check is gross..but probably necessary */
  if (F->connect.callback == NULL)
    return;

  /* Clear the connect flag + handler */
  hdl = F->connect.callback;
  F->connect.callback = NULL;

  /* Clear the timeout handler */
  comm_settimeout(F, 0, NULL, NULL);

  /* Call the handler */
  hdl(F, status, F->connect.data);
}

/*
 * comm_connect_timeout() - this gets called when the socket connection
 * times out. This *only* can be called once connect() is initially
 * called ..
 */
static void
comm_connect_timeout(fde_t *F, void *unused)
{
  /* error! */
  comm_connect_callback(F, COMM_ERR_TIMEOUT);
}

/*
 * comm_connect_dns_callback() - called at the completion of the DNS request
 *
 * The DNS request has completed, so if we've got an error, return it,
 * otherwise we initiate the connect()
 */
static void
comm_connect_dns_callback(void *vptr, const struct irc_ssaddr *addr, const char *name, size_t namelength)
{
  fde_t *const F = vptr;

  if (!addr)
  {
    comm_connect_callback(F, COMM_ERR_DNS);
    return;
  }

  /* No error, set a 30 second timeout */
  comm_settimeout(F, 30 * 1000, comm_connect_timeout, NULL);

  /* Copy over the DNS reply info so we can use it in the connect() */
  /*
   * Note we don't fudge the refcount here, because we aren't keeping
   * the DNS record around, and the DNS cache is gone anyway..
   *     -- adrian
   */
  memcpy(&F->connect.hostaddr, addr, addr->ss_len);

  /* The cast is hacky, but safe - port offset is same on v4 and v6 */
  ((struct sockaddr_in *)&F->connect.hostaddr)->sin_port = F->connect.hostaddr.ss_port;
  F->connect.hostaddr.ss_len = addr->ss_len;

  /* Now, call the tryconnect() routine to try a connect() */
  comm_connect_tryconnect(F, NULL);
}

/* static void comm_connect_tryconnect(fde_t *fd, void *unused)
 * Input: The fd, the handler data(unused).
 * Output: None.
 * Side-effects: Try and connect with pending connect data for the FD. If
 *               we succeed or get a fatal error, call the callback.
 *               Otherwise, it is still blocking or something, so register
 *               to select for a write event on this FD.
 */
static void
comm_connect_tryconnect(fde_t *F, void *unused)
{
  /* This check is needed or re-entrant s_bsd_* like sigio break it. */
  if (F->connect.callback == NULL)
    return;

  /* Try the connect() */
  int retval = connect(F->fd, (struct sockaddr *)&F->connect.hostaddr, F->connect.hostaddr.ss_len);

  /* Error? */
  if (retval < 0)
  {
    /*
     * If we get EISCONN, then we've already connect()ed the socket,
     * which is a good thing.
     *   -- adrian
     */
    if (errno == EISCONN)
      comm_connect_callback(F, COMM_OK);
    else if (comm_ignore_errno(errno))
      /* Ignore error? Reschedule */
      comm_setselect(F, COMM_SELECT_WRITE, comm_connect_tryconnect, NULL, 0);
    else
      /* Error? Fail with COMM_ERR_CONNECT */
      comm_connect_callback(F, COMM_ERR_CONNECT);
    return;
  }

  /* If we get here, we've suceeded, so call with COMM_OK */
  comm_connect_callback(F, COMM_OK);
}

/*
 * comm_errorstr() - return an error string for the given error condition
 */
const char *
comm_errstr(int error)
{
  if (error < 0 || error >= COMM_ERR_MAX)
    return "Invalid error number!";
  return comm_err_str[error];
}

/*
 * comm_open() - open a socket
 *
 * This is a highly highly cut down version of squid's comm_open() which
 * for the most part emulates socket(), *EXCEPT* it fails if we're about
 * to run out of file descriptors.
 */
int
comm_socket(int family, int sock_type, int proto)
{
  /* First, make sure we aren't going to run out of file descriptors */
  if (number_fd >= hard_fdlimit)
  {
    errno = ENFILE;
    return -1;
  }

  /*
   * Next, we try to open the socket. We *should* drop the reserved FD
   * limit if/when we get an error, but we can deal with that later.
   * XXX !!! -- adrian
   */
  int fd = socket(family, sock_type, proto);
  if (fd < 0)
    return -1; /* errno will be passed through, yay.. */

  setup_socket(fd);

  return fd;
}

/*
 * comm_accept() - accept an incoming connection
 *
 * This is a simple wrapper for accept() which enforces FD limits like
 * comm_open() does. Returned fd must be either closed or tagged with
 * fd_open (this function no longer does it).
 */
int
comm_accept(int fd, struct irc_ssaddr *addr)
{
  socklen_t addrlen = sizeof(struct irc_ssaddr);

  if (number_fd >= hard_fdlimit)
  {
    errno = ENFILE;
    return -1;
  }

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

  /*
   * Next, do the accept(). if we get an error, we should drop the
   * reserved fd limit, but we can deal with that when comm_open()
   * also does it. XXX -- adrian
   */
  int new_fd = accept(fd, (struct sockaddr *)addr, &addrlen);
  if (new_fd < 0)
    return -1;

  remove_ipv6_mapping(addr);

  setup_socket(new_fd);

  /* .. and return */
  return new_fd;
}

/*
 * remove_ipv6_mapping() - Removes IPv4-In-IPv6 mapping from an address
 * OSes with IPv6 mapping listening on both
 * AF_INET and AF_INET6 map AF_INET connections inside AF_INET6 structures
 *
 */
void
remove_ipv6_mapping(struct irc_ssaddr *addr)
{
  if (addr->ss.ss_family == AF_INET6)
  {
    if (IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)addr)->sin6_addr))
    {
      struct sockaddr_in6 v6;
      struct sockaddr_in *v4 = (struct sockaddr_in *)addr;

      memcpy(&v6, addr, sizeof(v6));
      memset(v4, 0, sizeof(struct sockaddr_in));
      memcpy(&v4->sin_addr, &v6.sin6_addr.s6_addr[12], sizeof(v4->sin_addr));

      addr->ss.ss_family = AF_INET;
      addr->ss_len = sizeof(struct sockaddr_in);
    }
    else
      addr->ss_len = sizeof(struct sockaddr_in6);
  }
  else
    addr->ss_len = sizeof(struct sockaddr_in);
}
Revision:	8500
Committed:	Thu Apr 5 13:00:49 2018 UTC (8 years, 5 months ago) by michael
Content type:	text/x-csrc
File size:	18103 byte(s)
Error occurred while calculating annotation data.
Log Message:	- Killed Connection::aftype. Use Client::ip.ss.ss_family instead.
#	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 s_bsd.c
23	* \brief Network functions.
24	* \version $Id$
25	*/
26
27	#include "stdinc.h"
28	#include <netinet/in_systm.h>
29	#include <netinet/ip.h>
30	#include <netinet/tcp.h>
31	#include "list.h"
32	#include "fdlist.h"
33	#include "s_bsd.h"
34	#include "client.h"
35	#include "dbuf.h"
36	#include "event.h"
37	#include "irc_string.h"
38	#include "ircd.h"
39	#include "listener.h"
40	#include "numeric.h"
41	#include "packet.h"
42	#include "res.h"
43	#include "restart.h"
44	#include "conf.h"
45	#include "log.h"
46	#include "server.h"
47	#include "send.h"
48	#include "memory.h"
49	#include "user.h"
50
51
52	static const char *const comm_err_str[] =
53	{
54	[COMM_OK] = "Comm OK",
55	[COMM_ERR_BIND] = "Error during bind()",
56	[COMM_ERR_DNS] = "Error during DNS lookup",
57	[COMM_ERR_TIMEOUT] = "connect timeout",
58	[COMM_ERR_CONNECT] = "Error during connect()",
59	[COMM_ERROR] = "Comm Error"
60	};
61
62	static void comm_connect_callback(fde_t *, int);
63	static void comm_connect_timeout(fde_t , void );
64	static void comm_connect_dns_callback(void , const struct irc_ssaddr , const char *, size_t);
65	static void comm_connect_tryconnect(fde_t , void );
66
67
68	/* comm_get_sockerr - get the error value from the socket or the current errno
69	*
70	* Get the real error from the socket (well try to anyway..).
71	* This may only work when SO_DEBUG is enabled but its worth the
72	* gamble anyway.
73	*/
74	int
75	comm_get_sockerr(int fd)
76	{
77	int errtmp = errno;
78	#ifdef SO_ERROR
79	int err = 0;
80	socklen_t len = sizeof(err);
81
82	if (fd > -1 && !getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &len))
83	{
84	if (err)
85	errtmp = err;
86	}
87	errno = errtmp;
88	#endif
89	return errtmp;
90	}
91
92	/*
93	* report_error - report an error from an errno.
94	* Record error to log and also send a copy to all LOCAL opers online.
95	*
96	* text is a format string for outputing error. It must
97	* contain only two '%s', the first will be replaced
98	* by the sockhost from the client_p, and the latter will
99	* be taken from sys_errlist[errno].
100	*
101	* client_p if not NULL, is the LOCAL client associated with
102	* the error.
103	*
104	* Cannot use perror() within daemon. stderr is closed in
105	* ircd and cannot be used. And, worse yet, it might have
106	* been reassigned to a normal connection...
107	*
108	* Actually stderr is still there IFF ircd was run with -s --Rodder
109	*/
110	void
111	report_error(int level, const char text, const char who, int error)
112	{
113	who = (who) ? who : "";
114
115	sendto_realops_flags(UMODE_DEBUG, level, SEND_NOTICE,
116	text, who, strerror(error));
117	ilog(LOG_TYPE_IRCD, text, who, strerror(error));
118	}
119
120	/*
121	* setup_socket()
122	*
123	* Set the socket non-blocking, and other wonderful bits.
124	*/
125	static void
126	setup_socket(int fd)
127	{
128	int opt = 1;
129
130	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));
131
132	#ifdef IPTOS_LOWDELAY
133	opt = IPTOS_LOWDELAY;
134	setsockopt(fd, IPPROTO_IP, IP_TOS, &opt, sizeof(opt));
135	#endif
136
137	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) \| O_NONBLOCK);
138	}
139
140	/*
141	* ssl_handshake - let OpenSSL initialize the protocol. Register for
142	* read/write events if necessary.
143	*/
144	static void
145	ssl_handshake(fde_t F, void data)
146	{
147	struct Client *client_p = data;
148
149	assert(client_p);
150	assert(client_p->connection);
151	assert(client_p->connection->fd);
152	assert(client_p->connection->fd == F);
153
154	tls_handshake_status_t ret = tls_handshake(&F->ssl, TLS_ROLE_SERVER, NULL);
155	if (ret != TLS_HANDSHAKE_DONE)
156	{
157	if ((CurrentTime - client_p->connection->firsttime) > CONNECTTIMEOUT)
158	{
159	exit_client(client_p, "Timeout during TLS handshake");
160	return;
161	}
162
163	switch (ret)
164	{
165	case TLS_HANDSHAKE_WANT_WRITE:
166	comm_setselect(client_p->connection->fd, COMM_SELECT_WRITE,
167	ssl_handshake, client_p, CONNECTTIMEOUT);
168	return;
169	case TLS_HANDSHAKE_WANT_READ:
170	comm_setselect(client_p->connection->fd, COMM_SELECT_READ,
171	ssl_handshake, client_p, CONNECTTIMEOUT);
172	return;
173	default:
174	exit_client(client_p, "Error during TLS handshake");
175	return;
176	}
177	}
178
179	comm_settimeout(F, 0, NULL, NULL);
180
181	if (!tls_verify_cert(&F->ssl, ConfigServerInfo.message_digest_algorithm, &client_p->certfp))
182	ilog(LOG_TYPE_IRCD, "Client %s!%s@%s gave bad TLS client certificate",
183	client_p->name, client_p->username, client_p->host);
184
185	auth_start(client_p);
186	}
187
188	/*
189	* add_connection - creates a client which has just connected to us on
190	* the given fd. The sockhost field is initialized with the ip# of the host.
191	* An unique id is calculated now, in case it is needed for auth.
192	* The client is sent to the auth module for verification, and not put in
193	* any client list yet.
194	*/
195	void
196	add_connection(struct Listener listener, struct irc_ssaddr irn, int fd)
197	{
198	struct Client *client_p = client_make(NULL);
199
200	client_p->connection->fd = fd_open(fd, 1, (listener->flags & LISTENER_SSL) ?
201	"Incoming SSL connection" : "Incoming connection");
202
203	/*
204	* copy address to 'sockhost' as a string, copy it to host too
205	* so we have something valid to put into error messages...
206	*/
207	memcpy(&client_p->ip, irn, sizeof(client_p->ip));
208
209	getnameinfo((const struct sockaddr *)&client_p->ip,
210	client_p->ip.ss_len, client_p->sockhost,
211	sizeof(client_p->sockhost), NULL, 0, NI_NUMERICHOST);
212
213	if (client_p->sockhost[0] == ':')
214	{
215	client_p->sockhost[0] = '0';
216	memmove(client_p->sockhost + 1, client_p->sockhost, sizeof(client_p->sockhost) - 1);
217	}
218
219	strlcpy(client_p->host, client_p->sockhost, sizeof(client_p->host));
220
221	client_p->connection->listener = listener;
222	++listener->ref_count;
223
224	if (listener->flags & LISTENER_SSL)
225	{
226	if (!tls_new(&client_p->connection->fd->ssl, fd, TLS_ROLE_SERVER))
227	{
228	SetDead(client_p);
229	exit_client(client_p, "TLS context initialization failed");
230	return;
231	}
232
233	AddFlag(client_p, FLAGS_SSL);
234	ssl_handshake(client_p->connection->fd, client_p);
235	}
236	else
237	auth_start(client_p);
238	}
239
240	/*
241	* stolen from squid - its a neat (but overused! :) routine which we
242	* can use to see whether we can ignore this errno or not. It is
243	* generally useful for non-blocking network IO related errnos.
244	* -- adrian
245	*/
246	int
247	comm_ignore_errno(int ierrno)
248	{
249	switch (ierrno)
250	{
251	case EINPROGRESS:
252	case EWOULDBLOCK:
253	#if EAGAIN != EWOULDBLOCK
254	case EAGAIN:
255	#endif
256	case EALREADY:
257	case EINTR:
258	#ifdef ERESTART
259	case ERESTART:
260	#endif
261	return 1;
262	default:
263	return 0;
264	}
265	}
266
267	/*
268	* comm_settimeout() - set the socket timeout
269	*
270	* Set the timeout for the fd
271	*/
272	void
273	comm_settimeout(fde_t F, uintmax_t timeout, void (callback)(fde_t , void ), void *cbdata)
274	{
275	assert(F->flags.open);
276
277	F->timeout = CurrentTime + (timeout / 1000);
278	F->timeout_handler = callback;
279	F->timeout_data = cbdata;
280	}
281
282	/*
283	* comm_setflush() - set a flush function
284	*
285	* A flush function is simply a function called if found during
286	* comm_timeouts(). Its basically a second timeout, except in this case
287	* I'm too lazy to implement multiple timeout functions! :-)
288	* its kinda nice to have it separate, since this is designed for
289	* flush functions, and when comm_close() is implemented correctly
290	* with close functions, we _actually_ don't call comm_close() here ..
291	* -- originally Adrian's notes
292	* comm_close() is replaced with fd_close() in fdlist.c
293	*/
294	void
295	comm_setflush(fde_t F, uintmax_t timeout, void (callback)(fde_t , void ), void *cbdata)
296	{
297	assert(F->flags.open);
298
299	F->flush_timeout = CurrentTime + (timeout / 1000);
300	F->flush_handler = callback;
301	F->flush_data = cbdata;
302	}
303
304	/*
305	* comm_checktimeouts() - check the socket timeouts
306	*
307	* All this routine does is call the given callback/cbdata, without closing
308	* down the file descriptor. When close handlers have been implemented,
309	* this will happen.
310	*/
311	void
312	comm_checktimeouts(void *unused)
313	{
314	void (hdl)(fde_t , void *);
315	void *data;
316
317	for (int fd = 0; fd <= highest_fd; ++fd)
318	{
319	fde_t *F = &fd_table[fd];
320
321	if (F->flags.open == 0)
322	continue;
323
324	/* check flush functions */
325	if (F->flush_handler && F->flush_timeout > 0 &&
326	F->flush_timeout < CurrentTime)
327	{
328	hdl = F->flush_handler;
329	data = F->flush_data;
330
331	comm_setflush(F, 0, NULL, NULL);
332	hdl(F, data);
333	}
334
335	/* check timeouts */
336	if (F->timeout_handler && F->timeout > 0 &&
337	F->timeout < CurrentTime)
338	{
339	/* Call timeout handler */
340	hdl = F->timeout_handler;
341	data = F->timeout_data;
342
343	comm_settimeout(F, 0, NULL, NULL);
344	hdl(F, data);
345	}
346	}
347	}
348
349	/*
350	* void comm_connect_tcp(int fd, const char *host, unsigned short port,
351	* struct sockaddr *clocal, int socklen,
352	* CNCB callback, void data, int aftype, int timeout)
353	* Input: An fd to connect with, a host and port to connect to,
354	* a local sockaddr to connect from + length(or NULL to use the
355	* default), a callback, the data to pass into the callback, the
356	* address family.
357	* Output: None.
358	* Side-effects: A non-blocking connection to the host is started, and
359	* if necessary, set up for selection. The callback given
360	* may be called now, or it may be called later.
361	*/
362	void
363	comm_connect_tcp(fde_t F, const char host, unsigned short port, struct sockaddr *clocal,
364	int socklen, void (callback)(fde_t , int, void ), void data,
365	int aftype, uintmax_t timeout)
366	{
367	struct addrinfo hints, *res;
368	char portname[PORTNAMELEN + 1];
369
370	assert(callback);
371	F->connect.callback = callback;
372	F->connect.data = data;
373
374	F->connect.hostaddr.ss.ss_family = aftype;
375	F->connect.hostaddr.ss_port = htons(port);
376
377	/* Note that we're using a passed sockaddr here. This is because
378	* generally you'll be bind()ing to a sockaddr grabbed from
379	* getsockname(), so this makes things easier.
380	* XXX If NULL is passed as local, we should later on bind() to the
381	* virtual host IP, for completeness.
382	* -- adrian
383	*/
384	if (clocal && bind(F->fd, clocal, socklen) < 0)
385	{
386	/* Failure, call the callback with COMM_ERR_BIND */
387	comm_connect_callback(F, COMM_ERR_BIND);
388	return; /* ... and quit */
389	}
390
391	memset(&hints, 0, sizeof(hints));
392
393	hints.ai_family = AF_UNSPEC;
394	hints.ai_socktype = SOCK_STREAM;
395	hints.ai_flags = AI_PASSIVE \| AI_NUMERICHOST;
396
397	snprintf(portname, sizeof(portname), "%d", port);
398
399	/*
400	* Next, if we have been given an IP address, get the address and skip the
401	* DNS check (and head direct to comm_connect_tryconnect()).
402	*/
403	if (getaddrinfo(host, portname, &hints, &res))
404	{
405	/* Send the DNS request, for the next level */
406	if (aftype == AF_INET6)
407	gethost_byname_type(comm_connect_dns_callback, F, host, T_AAAA);
408	else
409	gethost_byname_type(comm_connect_dns_callback, F, host, T_A);
410	}
411	else
412	{
413	/* We have a valid IP, so we just call tryconnect */
414	/* Make sure we actually set the timeout here .. */
415	assert(res);
416
417	memcpy(&F->connect.hostaddr, res->ai_addr, res->ai_addrlen);
418	F->connect.hostaddr.ss_len = res->ai_addrlen;
419	F->connect.hostaddr.ss.ss_family = res->ai_family;
420
421	freeaddrinfo(res);
422
423	comm_settimeout(F, timeout * 1000, comm_connect_timeout, NULL);
424	comm_connect_tryconnect(F, NULL);
425	}
426	}
427
428	/*
429	* comm_connect_callback() - call the callback, and continue with life
430	*/
431	static void
432	comm_connect_callback(fde_t *F, int status)
433	{
434	void (hdl)(fde_t , int, void *);
435
436	/* This check is gross..but probably necessary */
437	if (F->connect.callback == NULL)
438	return;
439
440	/* Clear the connect flag + handler */
441	hdl = F->connect.callback;
442	F->connect.callback = NULL;
443
444	/* Clear the timeout handler */
445	comm_settimeout(F, 0, NULL, NULL);
446
447	/* Call the handler */
448	hdl(F, status, F->connect.data);
449	}
450
451	/*
452	* comm_connect_timeout() - this gets called when the socket connection
453	* times out. This only can be called once connect() is initially
454	* called ..
455	*/
456	static void
457	comm_connect_timeout(fde_t F, void unused)
458	{
459	/* error! */
460	comm_connect_callback(F, COMM_ERR_TIMEOUT);
461	}
462
463	/*
464	* comm_connect_dns_callback() - called at the completion of the DNS request
465	*
466	* The DNS request has completed, so if we've got an error, return it,
467	* otherwise we initiate the connect()
468	*/
469	static void
470	comm_connect_dns_callback(void vptr, const struct irc_ssaddr addr, const char *name, size_t namelength)
471	{
472	fde_t *const F = vptr;
473
474	if (!addr)
475	{
476	comm_connect_callback(F, COMM_ERR_DNS);
477	return;
478	}
479
480	/* No error, set a 30 second timeout */
481	comm_settimeout(F, 30 * 1000, comm_connect_timeout, NULL);
482
483	/* Copy over the DNS reply info so we can use it in the connect() */
484	/*
485	* Note we don't fudge the refcount here, because we aren't keeping
486	* the DNS record around, and the DNS cache is gone anyway..
487	* -- adrian
488	*/
489	memcpy(&F->connect.hostaddr, addr, addr->ss_len);
490
491	/* The cast is hacky, but safe - port offset is same on v4 and v6 */
492	((struct sockaddr_in *)&F->connect.hostaddr)->sin_port = F->connect.hostaddr.ss_port;
493	F->connect.hostaddr.ss_len = addr->ss_len;
494
495	/* Now, call the tryconnect() routine to try a connect() */
496	comm_connect_tryconnect(F, NULL);
497	}
498
499	/* static void comm_connect_tryconnect(fde_t fd, void unused)
500	* Input: The fd, the handler data(unused).
501	* Output: None.
502	* Side-effects: Try and connect with pending connect data for the FD. If
503	* we succeed or get a fatal error, call the callback.
504	* Otherwise, it is still blocking or something, so register
505	* to select for a write event on this FD.
506	*/
507	static void
508	comm_connect_tryconnect(fde_t F, void unused)
509	{
510	/* This check is needed or re-entrant s_bsd_* like sigio break it. */
511	if (F->connect.callback == NULL)
512	return;
513
514	/* Try the connect() */
515	int retval = connect(F->fd, (struct sockaddr *)&F->connect.hostaddr, F->connect.hostaddr.ss_len);
516
517	/* Error? */
518	if (retval < 0)
519	{
520	/*
521	* If we get EISCONN, then we've already connect()ed the socket,
522	* which is a good thing.
523	* -- adrian
524	*/
525	if (errno == EISCONN)
526	comm_connect_callback(F, COMM_OK);
527	else if (comm_ignore_errno(errno))
528	/* Ignore error? Reschedule */
529	comm_setselect(F, COMM_SELECT_WRITE, comm_connect_tryconnect, NULL, 0);
530	else
531	/* Error? Fail with COMM_ERR_CONNECT */
532	comm_connect_callback(F, COMM_ERR_CONNECT);
533	return;
534	}
535
536	/* If we get here, we've suceeded, so call with COMM_OK */
537	comm_connect_callback(F, COMM_OK);
538	}
539
540	/*
541	* comm_errorstr() - return an error string for the given error condition
542	*/
543	const char *
544	comm_errstr(int error)
545	{
546	if (error < 0 \|\| error >= COMM_ERR_MAX)
547	return "Invalid error number!";
548	return comm_err_str[error];
549	}
550
551	/*
552	* comm_open() - open a socket
553	*
554	* This is a highly highly cut down version of squid's comm_open() which
555	* for the most part emulates socket(), EXCEPT it fails if we're about
556	* to run out of file descriptors.
557	*/
558	int
559	comm_socket(int family, int sock_type, int proto)
560	{
561	/* First, make sure we aren't going to run out of file descriptors */
562	if (number_fd >= hard_fdlimit)
563	{
564	errno = ENFILE;
565	return -1;
566	}
567
568	/*
569	* Next, we try to open the socket. We should drop the reserved FD
570	* limit if/when we get an error, but we can deal with that later.
571	* XXX !!! -- adrian
572	*/
573	int fd = socket(family, sock_type, proto);
574	if (fd < 0)
575	return -1; /* errno will be passed through, yay.. */
576
577	setup_socket(fd);
578
579	return fd;
580	}
581
582	/*
583	* comm_accept() - accept an incoming connection
584	*
585	* This is a simple wrapper for accept() which enforces FD limits like
586	* comm_open() does. Returned fd must be either closed or tagged with
587	* fd_open (this function no longer does it).
588	*/
589	int
590	comm_accept(int fd, struct irc_ssaddr *addr)
591	{
592	socklen_t addrlen = sizeof(struct irc_ssaddr);
593
594	if (number_fd >= hard_fdlimit)
595	{
596	errno = ENFILE;
597	return -1;
598	}
599
600	memset(addr, 0, sizeof(*addr));
601
602	/*
603	* Next, do the accept(). if we get an error, we should drop the
604	* reserved fd limit, but we can deal with that when comm_open()
605	* also does it. XXX -- adrian
606	*/
607	int new_fd = accept(fd, (struct sockaddr *)addr, &addrlen);
608	if (new_fd < 0)
609	return -1;
610
611	remove_ipv6_mapping(addr);
612
613	setup_socket(new_fd);
614
615	/* .. and return */
616	return new_fd;
617	}
618
619	/*
620	* remove_ipv6_mapping() - Removes IPv4-In-IPv6 mapping from an address
621	* OSes with IPv6 mapping listening on both
622	* AF_INET and AF_INET6 map AF_INET connections inside AF_INET6 structures
623	*
624	*/
625	void
626	remove_ipv6_mapping(struct irc_ssaddr *addr)
627	{
628	if (addr->ss.ss_family == AF_INET6)
629	{
630	if (IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)addr)->sin6_addr))
631	{
632	struct sockaddr_in6 v6;
633	struct sockaddr_in v4 = (struct sockaddr_in )addr;
634
635	memcpy(&v6, addr, sizeof(v6));
636	memset(v4, 0, sizeof(struct sockaddr_in));
637	memcpy(&v4->sin_addr, &v6.sin6_addr.s6_addr[12], sizeof(v4->sin_addr));
638
639	addr->ss.ss_family = AF_INET;
640	addr->ss_len = sizeof(struct sockaddr_in);
641	}
642	else
643	addr->ss_len = sizeof(struct sockaddr_in6);
644	}
645	else
646	addr->ss_len = sizeof(struct sockaddr_in);
647	}