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(F, COMM_SELECT_WRITE, ssl_handshake, client_p, CONNECTTIMEOUT);
        return;
      case TLS_HANDSHAKE_WANT_READ:
        comm_setselect(F, 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) == false)
    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, true, (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) == false)
    {
      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
 */
bool
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 true;
    default:
      return false;
  }
}

/*
 * 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);
  assert(F->flags.open == true);

  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);
  assert(F->flags.open == true);

  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 == false)
      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 == NULL)
  {
    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:	8717
Committed:	Mon Dec 10 16:53:51 2018 UTC (6 years, 8 months ago) by michael
Content type:	text/x-csrc
File size:	18088 byte(s)
Log Message:	- Sprinkle some assert()
#	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
88	errno = errtmp;
89	#endif
90	return errtmp;
91	}
92
93	/*
94	* report_error - report an error from an errno.
95	* Record error to log and also send a copy to all LOCAL opers online.
96	*
97	* text is a format string for outputing error. It must
98	* contain only two '%s', the first will be replaced
99	* by the sockhost from the client_p, and the latter will
100	* be taken from sys_errlist[errno].
101	*
102	* client_p if not NULL, is the LOCAL client associated with
103	* the error.
104	*
105	* Cannot use perror() within daemon. stderr is closed in
106	* ircd and cannot be used. And, worse yet, it might have
107	* been reassigned to a normal connection...
108	*
109	* Actually stderr is still there IFF ircd was run with -s --Rodder
110	*/
111	void
112	report_error(int level, const char text, const char who, int error)
113	{
114	who = (who) ? who : "";
115
116	sendto_realops_flags(UMODE_DEBUG, level, SEND_NOTICE,
117	text, who, strerror(error));
118	ilog(LOG_TYPE_IRCD, text, who, strerror(error));
119	}
120
121	/*
122	* setup_socket()
123	*
124	* Set the socket non-blocking, and other wonderful bits.
125	*/
126	static void
127	setup_socket(int fd)
128	{
129	int opt = 1;
130
131	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt));
132
133	#ifdef IPTOS_LOWDELAY
134	opt = IPTOS_LOWDELAY;
135	setsockopt(fd, IPPROTO_IP, IP_TOS, &opt, sizeof(opt));
136	#endif
137
138	fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) \| O_NONBLOCK);
139	}
140
141	/*
142	* ssl_handshake - let OpenSSL initialize the protocol. Register for
143	* read/write events if necessary.
144	*/
145	static void
146	ssl_handshake(fde_t F, void data)
147	{
148	struct Client *client_p = data;
149
150	assert(client_p);
151	assert(client_p->connection);
152	assert(client_p->connection->fd);
153	assert(client_p->connection->fd == F);
154
155	tls_handshake_status_t ret = tls_handshake(&F->ssl, TLS_ROLE_SERVER, NULL);
156	if (ret != TLS_HANDSHAKE_DONE)
157	{
158	if ((CurrentTime - client_p->connection->firsttime) > CONNECTTIMEOUT)
159	{
160	exit_client(client_p, "Timeout during TLS handshake");
161	return;
162	}
163
164	switch (ret)
165	{
166	case TLS_HANDSHAKE_WANT_WRITE:
167	comm_setselect(F, COMM_SELECT_WRITE, ssl_handshake, client_p, CONNECTTIMEOUT);
168	return;
169	case TLS_HANDSHAKE_WANT_READ:
170	comm_setselect(F, COMM_SELECT_READ, ssl_handshake, client_p, CONNECTTIMEOUT);
171	return;
172	default:
173	exit_client(client_p, "Error during TLS handshake");
174	return;
175	}
176	}
177
178	comm_settimeout(F, 0, NULL, NULL);
179
180	if (tls_verify_cert(&F->ssl, ConfigServerInfo.message_digest_algorithm, &client_p->certfp) == false)
181	ilog(LOG_TYPE_IRCD, "Client %s!%s@%s gave bad TLS client certificate",
182	client_p->name, client_p->username, client_p->host);
183
184	auth_start(client_p);
185	}
186
187	/*
188	* add_connection - creates a client which has just connected to us on
189	* the given fd. The sockhost field is initialized with the ip# of the host.
190	* An unique id is calculated now, in case it is needed for auth.
191	* The client is sent to the auth module for verification, and not put in
192	* any client list yet.
193	*/
194	void
195	add_connection(struct Listener listener, struct irc_ssaddr irn, int fd)
196	{
197	struct Client *client_p = client_make(NULL);
198
199	client_p->connection->fd = fd_open(fd, true, (listener->flags & LISTENER_SSL) ?
200	"Incoming SSL connection" : "Incoming connection");
201
202	/*
203	* copy address to 'sockhost' as a string, copy it to host too
204	* so we have something valid to put into error messages...
205	*/
206	memcpy(&client_p->ip, irn, sizeof(client_p->ip));
207
208	getnameinfo((const struct sockaddr *)&client_p->ip,
209	client_p->ip.ss_len, client_p->sockhost,
210	sizeof(client_p->sockhost), NULL, 0, NI_NUMERICHOST);
211
212	if (client_p->sockhost[0] == ':')
213	{
214	client_p->sockhost[0] = '0';
215	memmove(client_p->sockhost + 1, client_p->sockhost, sizeof(client_p->sockhost) - 1);
216	}
217
218	strlcpy(client_p->host, client_p->sockhost, sizeof(client_p->host));
219
220	client_p->connection->listener = listener;
221	++listener->ref_count;
222
223	if (listener->flags & LISTENER_SSL)
224	{
225	if (tls_new(&client_p->connection->fd->ssl, fd, TLS_ROLE_SERVER) == false)
226	{
227	SetDead(client_p);
228	exit_client(client_p, "TLS context initialization failed");
229	return;
230	}
231
232	AddFlag(client_p, FLAGS_SSL);
233	ssl_handshake(client_p->connection->fd, client_p);
234	}
235	else
236	auth_start(client_p);
237	}
238
239	/*
240	* stolen from squid - its a neat (but overused! :) routine which we
241	* can use to see whether we can ignore this errno or not. It is
242	* generally useful for non-blocking network IO related errnos.
243	* -- adrian
244	*/
245	bool
246	comm_ignore_errno(int ierrno)
247	{
248	switch (ierrno)
249	{
250	case EINPROGRESS:
251	case EWOULDBLOCK:
252	#if EAGAIN != EWOULDBLOCK
253	case EAGAIN:
254	#endif
255	case EALREADY:
256	case EINTR:
257	#ifdef ERESTART
258	case ERESTART:
259	#endif
260	return true;
261	default:
262	return false;
263	}
264	}
265
266	/*
267	* comm_settimeout() - set the socket timeout
268	*
269	* Set the timeout for the fd
270	*/
271	void
272	comm_settimeout(fde_t F, uintmax_t timeout, void (callback)(fde_t , void ), void *cbdata)
273	{
274	assert(F);
275	assert(F->flags.open == true);
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);
298	assert(F->flags.open == true);
299
300	F->flush_timeout = CurrentTime + (timeout / 1000);
301	F->flush_handler = callback;
302	F->flush_data = cbdata;
303	}
304
305	/*
306	* comm_checktimeouts() - check the socket timeouts
307	*
308	* All this routine does is call the given callback/cbdata, without closing
309	* down the file descriptor. When close handlers have been implemented,
310	* this will happen.
311	*/
312	void
313	comm_checktimeouts(void *unused)
314	{
315	void (hdl)(fde_t , void *);
316	void *data;
317
318	for (int fd = 0; fd <= highest_fd; ++fd)
319	{
320	fde_t *F = &fd_table[fd];
321
322	if (F->flags.open == false)
323	continue;
324
325	/* check flush functions */
326	if (F->flush_handler && F->flush_timeout > 0 &&
327	F->flush_timeout < CurrentTime)
328	{
329	hdl = F->flush_handler;
330	data = F->flush_data;
331
332	comm_setflush(F, 0, NULL, NULL);
333	hdl(F, data);
334	}
335
336	/* check timeouts */
337	if (F->timeout_handler && F->timeout > 0 &&
338	F->timeout < CurrentTime)
339	{
340	/* Call timeout handler */
341	hdl = F->timeout_handler;
342	data = F->timeout_data;
343
344	comm_settimeout(F, 0, NULL, NULL);
345	hdl(F, data);
346	}
347	}
348	}
349
350	/*
351	* void comm_connect_tcp(int fd, const char *host, unsigned short port,
352	* struct sockaddr *clocal, int socklen,
353	* CNCB callback, void data, int aftype, int timeout)
354	* Input: An fd to connect with, a host and port to connect to,
355	* a local sockaddr to connect from + length(or NULL to use the
356	* default), a callback, the data to pass into the callback, the
357	* address family.
358	* Output: None.
359	* Side-effects: A non-blocking connection to the host is started, and
360	* if necessary, set up for selection. The callback given
361	* may be called now, or it may be called later.
362	*/
363	void
364	comm_connect_tcp(fde_t F, const char host, unsigned short port, struct sockaddr *clocal,
365	int socklen, void (callback)(fde_t , int, void ), void data,
366	int aftype, uintmax_t timeout)
367	{
368	struct addrinfo hints, *res;
369	char portname[PORTNAMELEN + 1];
370
371	assert(callback);
372	F->connect.callback = callback;
373	F->connect.data = data;
374
375	F->connect.hostaddr.ss.ss_family = aftype;
376	F->connect.hostaddr.ss_port = htons(port);
377
378	/* Note that we're using a passed sockaddr here. This is because
379	* generally you'll be bind()ing to a sockaddr grabbed from
380	* getsockname(), so this makes things easier.
381	* XXX If NULL is passed as local, we should later on bind() to the
382	* virtual host IP, for completeness.
383	* -- adrian
384	*/
385	if (clocal && bind(F->fd, clocal, socklen) < 0)
386	{
387	/* Failure, call the callback with COMM_ERR_BIND */
388	comm_connect_callback(F, COMM_ERR_BIND);
389	return; /* ... and quit */
390	}
391
392	memset(&hints, 0, sizeof(hints));
393
394	hints.ai_family = AF_UNSPEC;
395	hints.ai_socktype = SOCK_STREAM;
396	hints.ai_flags = AI_PASSIVE \| AI_NUMERICHOST;
397
398	snprintf(portname, sizeof(portname), "%d", port);
399
400	/*
401	* Next, if we have been given an IP address, get the address and skip the
402	* DNS check (and head direct to comm_connect_tryconnect()).
403	*/
404	if (getaddrinfo(host, portname, &hints, &res))
405	{
406	/* Send the DNS request, for the next level */
407	if (aftype == AF_INET6)
408	gethost_byname_type(comm_connect_dns_callback, F, host, T_AAAA);
409	else
410	gethost_byname_type(comm_connect_dns_callback, F, host, T_A);
411	}
412	else
413	{
414	/* We have a valid IP, so we just call tryconnect */
415	/* Make sure we actually set the timeout here .. */
416	assert(res);
417
418	memcpy(&F->connect.hostaddr, res->ai_addr, res->ai_addrlen);
419	F->connect.hostaddr.ss_len = res->ai_addrlen;
420	F->connect.hostaddr.ss.ss_family = res->ai_family;
421
422	freeaddrinfo(res);
423
424	comm_settimeout(F, timeout * 1000, comm_connect_timeout, NULL);
425	comm_connect_tryconnect(F, NULL);
426	}
427	}
428
429	/*
430	* comm_connect_callback() - call the callback, and continue with life
431	*/
432	static void
433	comm_connect_callback(fde_t *F, int status)
434	{
435	void (hdl)(fde_t , int, void *);
436
437	/* This check is gross..but probably necessary */
438	if (F->connect.callback == NULL)
439	return;
440
441	/* Clear the connect flag + handler */
442	hdl = F->connect.callback;
443	F->connect.callback = NULL;
444
445	/* Clear the timeout handler */
446	comm_settimeout(F, 0, NULL, NULL);
447
448	/* Call the handler */
449	hdl(F, status, F->connect.data);
450	}
451
452	/*
453	* comm_connect_timeout() - this gets called when the socket connection
454	* times out. This only can be called once connect() is initially
455	* called ..
456	*/
457	static void
458	comm_connect_timeout(fde_t F, void unused)
459	{
460	/* error! */
461	comm_connect_callback(F, COMM_ERR_TIMEOUT);
462	}
463
464	/*
465	* comm_connect_dns_callback() - called at the completion of the DNS request
466	*
467	* The DNS request has completed, so if we've got an error, return it,
468	* otherwise we initiate the connect()
469	*/
470	static void
471	comm_connect_dns_callback(void vptr, const struct irc_ssaddr addr, const char *name, size_t namelength)
472	{
473	fde_t *const F = vptr;
474
475	if (addr == NULL)
476	{
477	comm_connect_callback(F, COMM_ERR_DNS);
478	return;
479	}
480
481	/* No error, set a 30 second timeout */
482	comm_settimeout(F, 30 * 1000, comm_connect_timeout, NULL);
483
484	/* Copy over the DNS reply info so we can use it in the connect() */
485	/*
486	* Note we don't fudge the refcount here, because we aren't keeping
487	* the DNS record around, and the DNS cache is gone anyway..
488	* -- adrian
489	*/
490	memcpy(&F->connect.hostaddr, addr, addr->ss_len);
491
492	/* The cast is hacky, but safe - port offset is same on v4 and v6 */
493	((struct sockaddr_in *)&F->connect.hostaddr)->sin_port = F->connect.hostaddr.ss_port;
494	F->connect.hostaddr.ss_len = addr->ss_len;
495
496	/* Now, call the tryconnect() routine to try a connect() */
497	comm_connect_tryconnect(F, NULL);
498	}
499
500	/* static void comm_connect_tryconnect(fde_t fd, void unused)
501	* Input: The fd, the handler data(unused).
502	* Output: None.
503	* Side-effects: Try and connect with pending connect data for the FD. If
504	* we succeed or get a fatal error, call the callback.
505	* Otherwise, it is still blocking or something, so register
506	* to select for a write event on this FD.
507	*/
508	static void
509	comm_connect_tryconnect(fde_t F, void unused)
510	{
511	/* This check is needed or re-entrant s_bsd_* like sigio break it. */
512	if (F->connect.callback == NULL)
513	return;
514
515	/* Try the connect() */
516	int retval = connect(F->fd, (struct sockaddr *)&F->connect.hostaddr, F->connect.hostaddr.ss_len);
517
518	/* Error? */
519	if (retval < 0)
520	{
521	/*
522	* If we get EISCONN, then we've already connect()ed the socket,
523	* which is a good thing.
524	* -- adrian
525	*/
526	if (errno == EISCONN)
527	comm_connect_callback(F, COMM_OK);
528	else if (comm_ignore_errno(errno))
529	/* Ignore error? Reschedule */
530	comm_setselect(F, COMM_SELECT_WRITE, comm_connect_tryconnect, NULL, 0);
531	else
532	/* Error? Fail with COMM_ERR_CONNECT */
533	comm_connect_callback(F, COMM_ERR_CONNECT);
534	return;
535	}
536
537	/* If we get here, we've suceeded, so call with COMM_OK */
538	comm_connect_callback(F, COMM_OK);
539	}
540
541	/*
542	* comm_errorstr() - return an error string for the given error condition
543	*/
544	const char *
545	comm_errstr(int error)
546	{
547	if (error < 0 \|\| error >= COMM_ERR_MAX)
548	return "Invalid error number!";
549	return comm_err_str[error];
550	}
551
552	/*
553	* comm_open() - open a socket
554	*
555	* This is a highly highly cut down version of squid's comm_open() which
556	* for the most part emulates socket(), EXCEPT it fails if we're about
557	* to run out of file descriptors.
558	*/
559	int
560	comm_socket(int family, int sock_type, int proto)
561	{
562	/* First, make sure we aren't going to run out of file descriptors */
563	if (number_fd >= hard_fdlimit)
564	{
565	errno = ENFILE;
566	return -1;
567	}
568
569	/*
570	* Next, we try to open the socket. We should drop the reserved FD
571	* limit if/when we get an error, but we can deal with that later.
572	* XXX !!! -- adrian
573	*/
574	int fd = socket(family, sock_type, proto);
575	if (fd < 0)
576	return -1; /* errno will be passed through, yay.. */
577
578	setup_socket(fd);
579
580	return fd;
581	}
582
583	/*
584	* comm_accept() - accept an incoming connection
585	*
586	* This is a simple wrapper for accept() which enforces FD limits like
587	* comm_open() does. Returned fd must be either closed or tagged with
588	* fd_open (this function no longer does it).
589	*/
590	int
591	comm_accept(int fd, struct irc_ssaddr *addr)
592	{
593	socklen_t addrlen = sizeof(struct irc_ssaddr);
594
595	if (number_fd >= hard_fdlimit)
596	{
597	errno = ENFILE;
598	return -1;
599	}
600
601	memset(addr, 0, sizeof(*addr));
602
603	/*
604	* Next, do the accept(). if we get an error, we should drop the
605	* reserved fd limit, but we can deal with that when comm_open()
606	* also does it. XXX -- adrian
607	*/
608	int new_fd = accept(fd, (struct sockaddr *)addr, &addrlen);
609	if (new_fd < 0)
610	return -1;
611
612	remove_ipv6_mapping(addr);
613
614	setup_socket(new_fd);
615
616	/* .. and return */
617	return new_fd;
618	}
619
620	/*
621	* remove_ipv6_mapping() - Removes IPv4-In-IPv6 mapping from an address
622	* OSes with IPv6 mapping listening on both
623	* AF_INET and AF_INET6 map AF_INET connections inside AF_INET6 structures
624	*
625	*/
626	void
627	remove_ipv6_mapping(struct irc_ssaddr *addr)
628	{
629	if (addr->ss.ss_family == AF_INET6)
630	{
631	if (IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)addr)->sin6_addr))
632	{
633	struct sockaddr_in6 v6;
634	struct sockaddr_in v4 = (struct sockaddr_in )addr;
635
636	memcpy(&v6, addr, sizeof(v6));
637	memset(v4, 0, sizeof(struct sockaddr_in));
638	memcpy(&v4->sin_addr, &v6.sin6_addr.s6_addr[12], sizeof(v4->sin_addr));
639
640	addr->ss.ss_family = AF_INET;
641	addr->ss_len = sizeof(struct sockaddr_in);
642	}
643	else
644	addr->ss_len = sizeof(struct sockaddr_in6);
645	}
646	else
647	addr->ss_len = sizeof(struct sockaddr_in);
648	}