net.cc

cygwin, 著名的在win32下模拟unix操作系统的东东

/* net.cc: network-related routines.

   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

This file is part of Cygwin.

This software is a copyrighted work licensed under the terms of the
Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
details. */

/* #define DEBUG_NEST_ON 1 */

#define  __INSIDE_CYGWIN_NET__

#include "winsup.h"
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <iphlpapi.h>

#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>
#define USE_SYS_TYPES_FD_SET
#include <winsock2.h>
#include "cygerrno.h"
#include "security.h"
#include "fhandler.h"
#include "path.h"
#include "dtable.h"
#include "cygheap.h"
#include "sigproc.h"
#include "pinfo.h"
#include "registry.h"
#include "wsock_event.h"

extern "C"
{
  int h_errno;

  int __stdcall rcmd (char **ahost, unsigned short inport, char *locuser,
		      char *remuser, char *cmd, SOCKET * fd2p);
  int __stdcall rexec (char **ahost, unsigned short inport, char *locuser,
		       char *password, char *cmd, SOCKET * fd2p);
  int __stdcall rresvport (int *);
  int sscanf (const char *, const char *, ...);
}				/* End of "C" section */

LPWSAOVERLAPPED
wsock_event::prepare ()
{
  LPWSAOVERLAPPED ret = NULL;

  SetLastError (0);
  if ((event = WSACreateEvent ()) != WSA_INVALID_EVENT)
    {
      memset (&ovr, 0, sizeof ovr);
      ovr.hEvent = event;
      ret = &ovr;
    }
  else if (GetLastError () == ERROR_PROC_NOT_FOUND) /* winsock2 not available */
    WSASetLastError (0);

  debug_printf ("%d = wsock_event::prepare ()", ret);
  return ret;
}

int
wsock_event::wait (int socket, LPDWORD flags)
{
  int ret = -1;
  WSAEVENT ev[2] = { event, signal_arrived };

  switch (WSAWaitForMultipleEvents (2, ev, FALSE, WSA_INFINITE, FALSE))
    {
      case WSA_WAIT_EVENT_0:
	DWORD len;
	if (WSAGetOverlappedResult (socket, &ovr, &len, FALSE, flags))
	  ret = (int) len;
	break;
      case WSA_WAIT_EVENT_0 + 1:
	if (!CancelIo ((HANDLE) socket))
	  {
	    debug_printf ("CancelIo() %E, fallback to blocking io");
	    WSAGetOverlappedResult (socket, &ovr, &len, TRUE, flags);
	  }
	else
	  WSASetLastError (WSAEINTR);
	break;
      case WSA_WAIT_FAILED:
	break;
      default:			/* Should be impossible. *LOL* */
	WSASetLastError (WSAEFAULT);
	break;
    }
  WSACloseEvent (event);
  event = NULL;
  return ret;
}

WSADATA wsadata;

static fhandler_socket *
get (const int fd)
{
  cygheap_fdget cfd (fd);

  if (cfd < 0)
    return 0;

  fhandler_socket *const fh = cfd->is_socket ();

  if (!fh)
    set_errno (ENOTSOCK);

  return fh;
}

static SOCKET __stdcall
set_socket_inheritance (SOCKET sock)
{
  SOCKET osock = sock;

  if (!DuplicateHandle (hMainProc, (HANDLE) sock, hMainProc, (HANDLE *) &sock,
                        0, TRUE, DUPLICATE_SAME_ACCESS | DUPLICATE_CLOSE_SOURCE))
    system_printf ("DuplicateHandle failed %E");
  else
    debug_printf ("DuplicateHandle succeeded osock %p, sock %p", osock, sock);
  return sock;
}

/* htonl: standards? */
extern "C" unsigned long int
htonl (unsigned long int x)
{
  return ((((x & 0x000000ffU) << 24) |
	   ((x & 0x0000ff00U) << 8) |
	   ((x & 0x00ff0000U) >> 8) |
	   ((x & 0xff000000U) >> 24)));
}

/* ntohl: standards? */
extern "C" unsigned long int
ntohl (unsigned long int x)
{
  return htonl (x);
}

/* htons: standards? */
extern "C" unsigned short
htons (unsigned short x)
{
  return ((((x & 0x000000ffU) << 8) |
           ((x & 0x0000ff00U) >> 8)));
}

/* ntohs: standards? */
extern "C" unsigned short
ntohs (unsigned short x)
{
  return htons (x);
}

static void
dump_protoent (struct protoent *p)
{
  if (p)
    debug_printf ("protoent %s %x %x", p->p_name, p->p_aliases, p->p_proto);
}

/* exported as inet_ntoa: BSD 4.3 */
extern "C" char *
cygwin_inet_ntoa (struct in_addr in)
{
#ifdef _MT_SAFE
#define ntoa_buf  _reent_winsup ()->_ntoa_buf
#else
  static char *ntoa_buf = NULL;
#endif

  char *res = inet_ntoa (in);

  if (ntoa_buf)
    {
      free (ntoa_buf);
      ntoa_buf = NULL;
    }
  if (res)
    ntoa_buf = strdup (res);
  return ntoa_buf;
}

/* exported as inet_addr: BSD 4.3 */
extern "C" unsigned long
cygwin_inet_addr (const char *cp)
{
  if (check_null_str_errno (cp))
    return INADDR_NONE;
  unsigned long res = inet_addr (cp);

  return res;
}

/* exported as inet_aton: BSD 4.3
   inet_aton is not exported by wsock32 and ws2_32,
   so it has to be implemented here. */
extern "C" int
cygwin_inet_aton (const char *cp, struct in_addr *inp)
{
  if (check_null_str_errno (cp) || check_null_invalid_struct_errno (inp))
    return 0;

  unsigned long res = inet_addr (cp);

  if (res == INADDR_NONE && strcmp (cp, "255.255.255.255"))
    return 0;
  if (inp)
    inp->s_addr = res;
  return 1;
}

/* undocumented in wsock32.dll */
extern "C" unsigned int WINAPI inet_network (const char *);

extern "C" unsigned int
cygwin_inet_network (const char *cp)
{
  if (check_null_str_errno (cp))
    return INADDR_NONE;
  unsigned int res = inet_network (cp);

  return res;
}

/* inet_netof is in the standard BSD sockets library.  It is useless
   for modern networks, since it assumes network values which are no
   longer meaningful, but some existing code calls it.  */

extern "C" unsigned long
inet_netof (struct in_addr in)
{
  unsigned long i, res;

  i = ntohl (in.s_addr);
  if (IN_CLASSA (i))
    res = (i & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT;
  else if (IN_CLASSB (i))
    res = (i & IN_CLASSB_NET) >> IN_CLASSB_NSHIFT;
  else
    res = (i & IN_CLASSC_NET) >> IN_CLASSC_NSHIFT;


  return res;
}

/* inet_makeaddr is in the standard BSD sockets library.  It is
   useless for modern networks, since it assumes network values which
   are no longer meaningful, but some existing code calls it.  */

extern "C" struct in_addr
inet_makeaddr (int net, int lna)
{
  unsigned long i;
  struct in_addr in;

  if (net < IN_CLASSA_MAX)
    i = (net << IN_CLASSA_NSHIFT) | (lna & IN_CLASSA_HOST);
  else if (net < IN_CLASSB_MAX)
    i = (net << IN_CLASSB_NSHIFT) | (lna & IN_CLASSB_HOST);
  else if (net < 0x1000000)
    i = (net << IN_CLASSC_NSHIFT) | (lna & IN_CLASSC_HOST);
  else
    i = net | lna;

  in.s_addr = htonl (i);


  return in;
}

struct tl
{
  int w;
  const char *s;
  int e;
};

static NO_COPY struct tl errmap[] = {
  {WSAEINTR, "WSAEINTR", EINTR},
  {WSAEWOULDBLOCK, "WSAEWOULDBLOCK", EWOULDBLOCK},
  {WSAEINPROGRESS, "WSAEINPROGRESS", EINPROGRESS},
  {WSAEALREADY, "WSAEALREADY", EALREADY},
  {WSAENOTSOCK, "WSAENOTSOCK", ENOTSOCK},
  {WSAEDESTADDRREQ, "WSAEDESTADDRREQ", EDESTADDRREQ},
  {WSAEMSGSIZE, "WSAEMSGSIZE", EMSGSIZE},
  {WSAEPROTOTYPE, "WSAEPROTOTYPE", EPROTOTYPE},
  {WSAENOPROTOOPT, "WSAENOPROTOOPT", ENOPROTOOPT},
  {WSAEPROTONOSUPPORT, "WSAEPROTONOSUPPORT", EPROTONOSUPPORT},
  {WSAESOCKTNOSUPPORT, "WSAESOCKTNOSUPPORT", ESOCKTNOSUPPORT},
  {WSAEOPNOTSUPP, "WSAEOPNOTSUPP", EOPNOTSUPP},
  {WSAEPFNOSUPPORT, "WSAEPFNOSUPPORT", EPFNOSUPPORT},
  {WSAEAFNOSUPPORT, "WSAEAFNOSUPPORT", EAFNOSUPPORT},
  {WSAEADDRINUSE, "WSAEADDRINUSE", EADDRINUSE},
  {WSAEADDRNOTAVAIL, "WSAEADDRNOTAVAIL", EADDRNOTAVAIL},
  {WSAENETDOWN, "WSAENETDOWN", ENETDOWN},
  {WSAENETUNREACH, "WSAENETUNREACH", ENETUNREACH},
  {WSAENETRESET, "WSAENETRESET", ENETRESET},
  {WSAECONNABORTED, "WSAECONNABORTED", ECONNABORTED},
  {WSAECONNRESET, "WSAECONNRESET", ECONNRESET},
  {WSAENOBUFS, "WSAENOBUFS", ENOBUFS},
  {WSAEISCONN, "WSAEISCONN", EISCONN},
  {WSAENOTCONN, "WSAENOTCONN", ENOTCONN},
  {WSAESHUTDOWN, "WSAESHUTDOWN", ESHUTDOWN},
  {WSAETOOMANYREFS, "WSAETOOMANYREFS", ETOOMANYREFS},
  {WSAETIMEDOUT, "WSAETIMEDOUT", ETIMEDOUT},
  {WSAECONNREFUSED, "WSAECONNREFUSED", ECONNREFUSED},
  {WSAELOOP, "WSAELOOP", ELOOP},
  {WSAENAMETOOLONG, "WSAENAMETOOLONG", ENAMETOOLONG},
  {WSAEHOSTDOWN, "WSAEHOSTDOWN", EHOSTDOWN},
  {WSAEHOSTUNREACH, "WSAEHOSTUNREACH", EHOSTUNREACH},
  {WSAENOTEMPTY, "WSAENOTEMPTY", ENOTEMPTY},
  {WSAEPROCLIM, "WSAEPROCLIM", EPROCLIM},
  {WSAEUSERS, "WSAEUSERS", EUSERS},
  {WSAEDQUOT, "WSAEDQUOT", EDQUOT},
  {WSAESTALE, "WSAESTALE", ESTALE},
  {WSAEREMOTE, "WSAEREMOTE", EREMOTE},
  {WSAEINVAL, "WSAEINVAL", EINVAL},
  {WSAEFAULT, "WSAEFAULT", EFAULT},
  {0, "NOERROR", 0},
  {0, NULL, 0}
};

static int
find_winsock_errno (int why)
{
  for (int i = 0; errmap[i].s != NULL; ++i)
    if (why == errmap[i].w)
      return errmap[i].e;

  return EPERM;
}

void
__set_winsock_errno (const char *fn, int ln)
{
  DWORD werr = WSAGetLastError ();
  int err = find_winsock_errno (werr);

  set_errno (err);
  syscall_printf ("%s:%d - winsock error %d -> errno %d", fn, ln, werr, err);
}

/*
 * Since the member `s' isn't used for debug output we can use it
 * for the error text returned by herror and hstrerror.
 */
static NO_COPY struct tl host_errmap[] = {
  {WSAHOST_NOT_FOUND, "Unknown host", HOST_NOT_FOUND},
  {WSATRY_AGAIN, "Host name lookup failure", TRY_AGAIN},
  {WSANO_RECOVERY, "Unknown server error", NO_RECOVERY},
  {WSANO_DATA, "No address associated with name", NO_DATA},
  {0, NULL, 0}
};

static void
set_host_errno ()
{
  int i;

  int why = WSAGetLastError ();

  for (i = 0; host_errmap[i].w != 0; ++i)
    if (why == host_errmap[i].w)
      break;

  if (host_errmap[i].w != 0)
    h_errno = host_errmap[i].e;
  else
    h_errno = NETDB_INTERNAL;
}

static void
free_char_list (char **clist)
{
  if (clist)
    {
      for (char **cl = clist; *cl; ++cl)
	free (*cl);
      free (clist);
    }
}

static char **
dup_char_list (char **src)
{
  char **dst;
  int cnt = 0;

  for (char **cl = src; *cl; ++cl)
    ++cnt;
  if (!(dst = (char **) calloc (cnt + 1, sizeof *dst)))
    return NULL;
  while (cnt-- > 0)
    if (!(dst[cnt] = strdup (src[cnt])))
      return NULL;
  return dst;
}

#define free_addr_list(addr_list)	free_char_list (addr_list)

static char **
dup_addr_list (char **src, unsigned int size)
{
  char **dst;
  int cnt = 0;

  for (char **cl = src; *cl; ++cl)
    ++cnt;
  if (!(dst = (char **) calloc (cnt + 1, sizeof *dst)))
    return NULL;
  while (cnt-- > 0)
    {
      if (!(dst[cnt] = (char *) malloc (size)))
	return NULL;
      memcpy (dst[cnt], src[cnt], size);
    }
  return dst;
}

static void
free_protoent_ptr (struct protoent *&p)
{
  if (p)
    {
      debug_printf ("protoent: %s", p->p_name);

      if (p->p_name)
	free (p->p_name);
      free_char_list (p->p_aliases);
      p = NULL;
    }
}

static struct protoent *
dup_protoent_ptr (struct protoent *src)
{
  if (!src)
    return NULL;

  struct protoent *dst = (struct protoent *) calloc (1, sizeof *dst);

  if (!dst)
    return NULL;

  debug_printf ("protoent: %s", src->p_name);

  dst->p_proto = src->p_proto;
  if (src->p_name && !(dst->p_name = strdup (src->p_name)))
    goto out;
  if (src->p_aliases && !(dst->p_aliases = dup_char_list (src->p_aliases)))
    goto out;

  debug_printf ("protoent: copied %s", dst->p_name);

  return dst;

out:
  free_protoent_ptr (dst);
  return NULL;
}

#ifdef _MT_SAFE
#define protoent_buf  _reent_winsup ()->_protoent_buf
#else
static struct protoent *protoent_buf = NULL;
#endif

/* exported as getprotobyname: standards? */
extern "C" struct protoent *
cygwin_getprotobyname (const char *p)
{
  if (check_null_str_errno (p))
    return NULL;
  free_protoent_ptr (protoent_buf);
  protoent_buf = dup_protoent_ptr (getprotobyname (p));
  if (!protoent_buf)
    set_winsock_errno ();

  dump_protoent (protoent_buf);
  return protoent_buf;
}

/* exported as getprotobynumber: standards? */
extern "C" struct protoent *
cygwin_getprotobynumber (int number)
{
  free_protoent_ptr (protoent_buf);
  protoent_buf = dup_protoent_ptr (getprotobynumber (number));
  if (!protoent_buf)
    set_winsock_errno ();

  dump_protoent (protoent_buf);
  return protoent_buf;
}

fhandler_socket *
fdsock (int &fd, const char *name, SOCKET soc)
{
  if (!winsock2_active)
    soc = set_socket_inheritance (soc);
  else if (wincap.has_set_handle_information ())
    {
      /* NT systems apparently set sockets to inheritable by default */
      SetHandleInformation ((HANDLE) soc, HANDLE_FLAG_INHERIT, 0);
      debug_printf ("reset socket inheritance since winsock2_active %d",
		    winsock2_active);
    }
  else
    debug_printf ("not setting socket inheritance since winsock2_active %d",
		  winsock2_active);
  fhandler_socket *fh =
    (fhandler_socket *) cygheap->fdtab.build_fhandler (fd, FH_SOCKET, name);
  fh->set_io_handle ((HANDLE) soc);
  fh->set_flags (O_RDWR | O_BINARY);
  fh->set_r_no_interrupt (winsock2_active);
  debug_printf ("fd %d, name '%s', soc %p", fd, name, soc);
  return fh;
}

/* exported as socket: standards? */
extern "C" int
cygwin_socket (int af, int type, int protocol)
{
  int res = -1;
  SOCKET soc = 0;
  fhandler_socket *fh = NULL;

  cygheap_fdnew fd;

  if (fd >= 0)
    {
      debug_printf ("socket (%d, %d, %d)", af, type, protocol);

      soc = socket (AF_INET, type, af == AF_LOCAL ? 0 : protocol);

      if (soc == INVALID_SOCKET)
	{
	  set_winsock_errno ();
	  goto done;
	}

      const char *name;

      if (af == AF_INET)
	name = (type == SOCK_STREAM ? "/dev/tcp" : "/dev/udp");
      else
	name = (type == SOCK_STREAM ? "/dev/streamsocket" : "/dev/dgsocket");

      fh = fdsock (fd, name, soc);
      if (fh)
	{
	  fh->set_addr_family (af);
	  fh->set_socket_type (type);
	}
      res = fd;
    }