Initial Alpine Version

1 files changed, 916 insertions, 0 deletions

diff --git a/imap/src/osdep/nt/tcp_nt.c b/imap/src/osdep/nt/tcp_nt.c
new file mode 100644
index 00000000..a6d735dc
--- /dev/null
+++ b/imap/src/osdep/nt/tcp_nt.c
@@ -0,0 +1,916 @@
+/* ========================================================================
+ * Copyright 1988-2007 University of Washington
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 
+ * ========================================================================
+ */
+
+/*
+ * Program:	Winsock TCP/IP routines
+ *
+ * Author:	Mark Crispin from Mike Seibel's Winsock code
+ *		Networks and Distributed Computing
+ *		Computing & Communications
+ *		University of Washington
+ *		Administration Building, AG-44
+ *		Seattle, WA  98195
+ *		Internet: MRC@CAC.Washington.EDU
+ *
+ * Date:	11 April 1989
+ * Last Edited: 13 January 2007
+ */
+
+#include "ip_nt.c"
+
+
+#define TCPMAXSEND 32768
+
+/* Private functions */
+
+int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
+		     char *tmp,char *hst);
+static char *tcp_getline_work (TCPSTREAM *stream,unsigned long *size,
+			       long *contd);
+long tcp_abort (TCPSTREAM *stream);
+long tcp_close_socket (SOCKET *sock);
+char *tcp_name (struct sockaddr *sadr,long flag);
+char *tcp_name_valid (char *s);
+
+
+/* Private data */
+
+int wsa_initted = 0;		/* init ? */
+static int wsa_sock_open = 0;	/* keep track of open sockets */
+static tcptimeout_t tmoh = NIL;	/* TCP timeout handler routine */
+static long ttmo_open = 0;	/* TCP timeouts, in seconds */
+static long ttmo_read = 0;
+static long ttmo_write = 0;
+static long allowreversedns = T;/* allow reverse DNS lookup */
+static long tcpdebug = NIL;	/* extra TCP debugging telemetry */
+static char *myClientAddr = NIL;/* client host address */
+static char *myClientHost = NIL;/* client host name */
+static long myClientPort = -1;	/* client port */
+static char *myServerAddr = NIL;/* server host address */
+static char *myServerHost = NIL;/* server host name */
+static long myServerPort = -1;	/* server port */
+
+extern long maxposint;		/* get this from write.c */
+
+/* TCP/IP manipulate parameters
+ * Accepts: function code
+ *	    function-dependent value
+ * Returns: function-dependent return value
+ */
+
+void *tcp_parameters (long function,void *value)
+{
+  void *ret = NIL;
+  switch ((int) function) {
+  case SET_TIMEOUT:
+    tmoh = (tcptimeout_t) value;
+  case GET_TIMEOUT:
+    ret = (void *) tmoh;
+    break;
+  case SET_OPENTIMEOUT:
+    ttmo_open = (long) value ? (long) value : (long) WSA_INFINITE;
+  case GET_OPENTIMEOUT:
+    ret = (void *) ttmo_open;
+    break;
+  case SET_READTIMEOUT:
+    ttmo_read = (long) value;
+  case GET_READTIMEOUT:
+    ret = (void *) ttmo_read;
+    break;
+  case SET_WRITETIMEOUT:
+    ttmo_write = (long) value;
+  case GET_WRITETIMEOUT:
+    ret = (void *) ttmo_write;
+    break;
+  case SET_ALLOWREVERSEDNS:
+    allowreversedns = (long) value;
+  case GET_ALLOWREVERSEDNS:
+    ret = (void *) allowreversedns;
+    break;
+  case SET_TCPDEBUG:
+    tcpdebug = (long) value;
+  case GET_TCPDEBUG:
+    ret = (void *) tcpdebug;
+    break;
+  }
+  return ret;
+}
+
+/* TCP/IP open
+ * Accepts: host name
+ *	    contact service name
+ *	    contact port number and optional silent flag
+ * Returns: TCP/IP stream if success else NIL
+ */
+
+TCPSTREAM *tcp_open (char *host,char *service,unsigned long port)
+{
+  TCPSTREAM *stream = NIL;
+  int i,family;
+  SOCKET sock = INVALID_SOCKET;
+  int silent = (port & NET_SILENT) ? T : NIL;
+  char *s,*hostname,tmp[MAILTMPLEN];
+  void *adr,*next;
+  size_t adrlen;
+  struct servent *sv = NIL;
+  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+  if (!wsa_initted++) {		/* init Windows Sockets */
+    WSADATA wsock;
+    if (i = (int) WSAStartup (WINSOCK_VERSION,&wsock)) {
+      wsa_initted = 0;		/* in case we try again */
+      sprintf (tmp,"Unable to start Windows Sockets (%d)",i);
+      mm_log (tmp,ERROR);
+      return NIL;
+    }
+  }
+  port &= 0xffff;		/* erase flags */
+				/* lookup service */
+  if (service && (sv = getservbyname (service,"tcp")))
+    port = ntohs (sv->s_port);
+  /* The domain literal form is used (rather than simply the dotted decimal
+     as with other Windows programs) because it has to be a valid "host name"
+     in mailsystem terminology. */
+				/* look like domain literal? */
+  if (host[0] == '[' && host[(strlen (host))-1] == ']') {
+    strcpy (tmp,host+1);	/* yes, copy number part */
+    tmp[strlen (tmp)-1] = '\0';
+    if (adr = ip_stringtoaddr (tmp,&adrlen,&family)) {
+      (*bn) (BLOCK_TCPOPEN,NIL);
+      sock = tcp_socket_open (family,adr,adrlen,(unsigned short) port,tmp,
+			      hostname = host);
+      (*bn) (BLOCK_NONE,NIL);
+      fs_give ((void **) &adr);
+    }
+    else sprintf (tmp,"Bad format domain-literal: %.80s",host);
+  }
+
+  else {			/* lookup host name */
+    if (tcpdebug) {
+      sprintf (tmp,"DNS resolution %.80s",host);
+      mm_log (tmp,TCPDEBUG);
+    }
+    (*bn) (BLOCK_DNSLOOKUP,NIL);/* look up name */
+    if (!(s = ip_nametoaddr (host,&adrlen,&family,&hostname,&next)))
+      sprintf (tmp,"Host not found (#%d): %s",WSAGetLastError (),host);
+    (*bn) (BLOCK_NONE,NIL);
+    if (s) {			/* DNS resolution won? */
+      if (tcpdebug) mm_log ("DNS resolution done",TCPDEBUG);
+      wsa_sock_open++;		/* prevent tcp_close_socket() from freeing in
+				   loop */
+      do {
+	(*bn) (BLOCK_TCPOPEN,NIL);
+	if (((sock = tcp_socket_open (family,s,adrlen,(unsigned short) port,
+				      tmp,hostname)) == INVALID_SOCKET) &&
+	    (s = ip_nametoaddr (NIL,&adrlen,&family,&hostname,&next)) &&
+	    !silent) mm_log (tmp,WARN);
+	(*bn) (BLOCK_NONE,NIL);
+      } while ((sock == INVALID_SOCKET) && s);
+      wsa_sock_open--;		/* undo protection */
+    }
+  }
+  if (sock == INVALID_SOCKET) {	/* do possible cleanup action */
+    if (!silent) mm_log (tmp,ERROR);
+    tcp_close_socket (&sock);	
+  }
+  else {			/* got a socket, create TCP/IP stream */
+    stream = (TCPSTREAM *) memset (fs_get (sizeof (TCPSTREAM)),0,
+				   sizeof (TCPSTREAM));
+    stream->port = port;	/* port number */
+				/* init socket */
+    stream->tcpsi = stream->tcpso = sock;
+    stream->ictr = 0;		/* init input counter */
+				/* copy official host name */
+    stream->host = cpystr (hostname);
+    if (tcpdebug) mm_log ("Stream open and ready for read",TCPDEBUG);
+  }
+  return stream;		/* return success */
+}
+
+/* Open a TCP socket
+ * Accepts: protocol family
+ *	    address to connect to
+ *	    address length
+ *	    port
+ *	    scratch buffer
+ *	    host name
+ * Returns: socket if success, else SOCKET_ERROR with error string in scratch
+ */
+
+int tcp_socket_open (int family,void *adr,size_t adrlen,unsigned short port,
+		     char *tmp,char *hst)
+{
+  int sock,err;
+  char *s,errmsg[100];
+  size_t len;
+  DWORD eo;
+  WSAEVENT event;
+  WSANETWORKEVENTS events;
+  unsigned long cmd = 0;
+  struct protoent *pt = getprotobyname ("tcp");
+  struct sockaddr *sadr = ip_sockaddr (family,adr,adrlen,port,&len);
+  sprintf (tmp,"Trying IP address [%s]",ip_sockaddrtostring (sadr));
+  mm_log (tmp,NIL);
+				/* get a TCP stream */
+  if ((sock = socket (sadr->sa_family,SOCK_STREAM,pt ? pt->p_proto : 0)) ==
+      INVALID_SOCKET)
+    sprintf (tmp,"Unable to create TCP socket (%d)",WSAGetLastError ());
+  else {
+    /* On Windows, FD_SETSIZE is the number of descriptors which can be
+     * held in an fd_set, as opposed to the maximum descriptor value on UNIX.
+     * Similarly, an fd_set in Windows is a vector of descriptor values, as
+     * opposed to a bitmask of set fds on UNIX.  Thus, an fd_set can hold up
+     * to FD_SETSIZE values which can be larger than FD_SETSIZE, and the test
+     * that is used on UNIX is unnecessary here.
+     */
+    wsa_sock_open++;		/* count this socket as open */
+				/* set socket nonblocking */
+    if (ttmo_open) WSAEventSelect (sock,event = WSACreateEvent (),FD_CONNECT);
+    else event = 0;		/* no event */
+				/* open connection */
+    err = (connect (sock,sadr,len) == SOCKET_ERROR) ? WSAGetLastError () : NIL;
+				/* if timer in effect, wait for event */
+    if (event) while (err == WSAEWOULDBLOCK)
+      switch (eo = WSAWaitForMultipleEvents (1,&event,T,ttmo_open*1000,NIL)) {
+      case WSA_WAIT_EVENT_0:	/* got an event? */
+	err = (WSAEnumNetworkEvents (sock,event,&events) == SOCKET_ERROR) ?
+	  WSAGetLastError () : events.iErrorCode[FD_CONNECT_BIT];
+	break;
+      case WSA_WAIT_IO_COMPLETION:
+	break;			/* fAlertable is NIL so shouldn't happen */
+      default:			/* all other conditions */
+	err = eo;		/* error from WSAWaitForMultipleEvents() */
+	break;
+      }
+
+    switch (err) {		/* analyze result from connect and wait */
+    case 0:			/* got a connection */
+      s = NIL;
+      if (event) {		/* unset blocking mode */
+	WSAEventSelect (sock,event,NIL);
+	if (ioctlsocket (sock,FIONBIO,&cmd) == SOCKET_ERROR)
+	  sprintf (s = errmsg,"Can't set blocking mode (%d)",
+		   WSAGetLastError ());
+      }
+      break;
+    case WSAECONNREFUSED:
+      s = "Refused";
+      break;
+    case WSAENOBUFS:
+      s = "Insufficient system resources";
+      break;
+    case WSA_WAIT_TIMEOUT: case WSAETIMEDOUT:
+      s = "Timed out";
+      break;
+    case WSAEHOSTUNREACH:
+      s = "Host unreachable";
+      break;
+    default:			/* horrible error 69 */
+      sprintf (s = errmsg,"Unknown error (%d)",err);
+      break;
+    }
+				/* flush event */
+    if (event) WSACloseEvent (event);
+    if (s) {			/* got an error? */
+      sprintf (tmp,"Can't connect to %.80s,%ld: %.80s",hst,port,s);
+      tcp_close_socket (&sock);	/* flush socket */
+      sock = INVALID_SOCKET;
+    }
+  }
+  fs_give ((void **) &sadr);	/* and socket address */
+  return sock;			/* return the socket */
+}
+  
+/* TCP/IP authenticated open
+ * Accepts: NETMBX specifier
+ *	    service name
+ *	    returned user name buffer
+ * Returns: TCP/IP stream if success else NIL
+ */
+
+TCPSTREAM *tcp_aopen (NETMBX *mb,char *service,char *usrbuf)
+{
+  return NIL;			/* always NIL on Windows */
+}
+
+/* TCP receive line
+ * Accepts: TCP stream
+ * Returns: text line string or NIL if failure
+ */
+
+char *tcp_getline (TCPSTREAM *stream)
+{
+  unsigned long n,contd;
+  char *ret = tcp_getline_work (stream,&n,&contd);
+  if (ret && contd) {		/* got a line needing continuation? */
+    STRINGLIST *stl = mail_newstringlist ();
+    STRINGLIST *stc = stl;
+    do {			/* collect additional lines */
+      stc->text.data = (unsigned char *) ret;
+      stc->text.size = n;
+      stc = stc->next = mail_newstringlist ();
+      ret = tcp_getline_work (stream,&n,&contd);
+    } while (ret && contd);
+    if (ret) {			/* stash final part of line on list */
+      stc->text.data = (unsigned char *) ret;
+      stc->text.size = n;
+				/* determine how large a buffer we need */
+      for (n = 0, stc = stl; stc; stc = stc->next) n += stc->text.size;
+      ret = fs_get (n + 1);	/* copy parts into buffer */
+      for (n = 0, stc = stl; stc; n += stc->text.size, stc = stc->next)
+	memcpy (ret + n,stc->text.data,stc->text.size);
+      ret[n] = '\0';
+    }
+    mail_free_stringlist (&stl);/* either way, done with list */
+  }
+  return ret;
+}
+
+/* TCP receive line or partial line
+ * Accepts: TCP stream
+ *	    pointer to return size
+ *	    pointer to return continuation flag
+ * Returns: text line string, size and continuation flag, or NIL if failure
+ */
+
+static char *tcp_getline_work (TCPSTREAM *stream,unsigned long *size,
+			       long *contd)
+{
+  unsigned long n;
+  char *s,*ret,c,d;
+  *contd = NIL;			/* assume no continuation */
+				/* make sure have data */
+  if (!tcp_getdata (stream)) return NIL;
+  for (s = stream->iptr, n = 0, c = '\0'; stream->ictr--; n++, c = d) {
+    d = *stream->iptr++;	/* slurp another character */
+    if ((c == '\015') && (d == '\012')) {
+      ret = (char *) fs_get (n--);
+      memcpy (ret,s,*size = n);	/* copy into a free storage string */
+      ret[n] = '\0';		/* tie off string with null */
+      return ret;
+    }
+  }
+				/* copy partial string from buffer */
+  memcpy ((ret = (char *) fs_get (n)),s,*size = n);
+				/* get more data from the net */
+  if (!tcp_getdata (stream)) fs_give ((void **) &ret);
+				/* special case of newline broken by buffer */
+  else if ((c == '\015') && (*stream->iptr == '\012')) {
+    stream->iptr++;		/* eat the line feed */
+    stream->ictr--;
+    ret[*size = --n] = '\0';	/* tie off string with null */
+  }
+  else *contd = LONGT;		/* continuation needed */
+  return ret;
+}
+
+/* TCP/IP receive buffer
+ * Accepts: TCP/IP stream
+ *	    size in bytes
+ *	    buffer to read into
+ * Returns: T if success, NIL otherwise
+ */
+
+long tcp_getbuffer (TCPSTREAM *stream,unsigned long size,char *s)
+{
+  unsigned long n;
+				/* make sure socket still alive */
+  if (stream->tcpsi == INVALID_SOCKET) return NIL;
+				/* can transfer bytes from buffer? */
+  if (n = min (size,stream->ictr)) {
+    memcpy (s,stream->iptr,n);	/* yes, slurp as much as we can from it */
+    s += n;			/* update pointer */
+    stream->iptr +=n;
+    size -= n;			/* update # of bytes to do */
+    stream->ictr -=n;
+  }
+  if (size) {
+    int i;
+    fd_set fds,efds;
+    struct timeval tmo;
+    time_t t = time (0);
+    blocknotify_t bn=(blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+    (*bn) (BLOCK_TCPREAD,NIL);
+    while (size > 0) {		/* until request satisfied */
+      if (tcpdebug) mm_log ("Reading TCP buffer",TCPDEBUG);
+				/* simple case if not a socket */
+      if (stream->tcpsi != stream->tcpso)
+	while (((i = read (stream->tcpsi,s,(int) min (maxposint,size))) < 0) &&
+	       (errno == EINTR));
+      else {			/* socket case */
+	time_t tl = time (0);
+	time_t now = tl;
+	time_t ti = ttmo_read ? now + ttmo_read : 0;
+	tmo.tv_usec = 0;
+	FD_ZERO (&fds);		/* initialize selection vector */
+	FD_ZERO (&efds);	/* handle errors too */
+				/* set bit in selection vectors */
+	FD_SET (stream->tcpsi,&fds);
+	FD_SET (stream->tcpsi,&efds);
+	errno = NIL;		/* initially no error */
+	do {			/* block under timeout */
+	  tmo.tv_sec = (long) (ti ? ti - now : 0);
+	  i = select (stream->tcpsi+1,&fds,NIL,&efds,ti ? &tmo : NIL);
+	  now = time (0);	/* fake timeout if interrupt & time expired */
+	  if ((i < 0) && ((errno = WSAGetLastError ()) == WSAEINTR) && ti &&
+	      (ti <= now)) i = 0;
+	} while ((i < 0) && (errno == WSAEINTR));
+				/* success from select, read what we can */
+	if (i > 0) while (((i = recv (stream->tcpsi,s,
+				      (int) min (maxposint,size),0)) ==
+			   SOCKET_ERROR) &&
+			  ((errno = WSAGetLastError ()) == WSAEINTR));
+	else if (!i) {		/* timeout, ignore if told to resume */
+	  if (tmoh && (*tmoh) ((long) (now - t),(long) (now - tl), 
+								stream->host))
+		continue;
+				/* otherwise punt */
+	  if (tcpdebug) mm_log ("TCP buffer read timeout",TCPDEBUG);
+	  return tcp_abort (stream);
+	}
+      }
+      if (i <= 0) {		/* error seen? */
+	if (tcpdebug) {
+	  char tmp[MAILTMPLEN];
+	  if (i) sprintf (s = tmp,"TCP buffer read I/O error %d",errno);
+	  else s = "TCP buffer read end of file";
+	  mm_log (s,TCPDEBUG);
+	}
+	return tcp_abort (stream);
+      }
+      s += i;			/* point at new place to write */
+      size -= i;		/* reduce byte count */
+      if (tcpdebug) mm_log ("Successfully read TCP buffer",TCPDEBUG);
+    }
+    (*bn) (BLOCK_NONE,NIL);
+  }
+  *s = '\0';			/* tie off string */
+  return LONGT;
+}
+
+/* TCP/IP receive data
+ * Accepts: TCP/IP stream
+ * Returns: T if success, NIL otherwise
+ */
+
+long tcp_getdata (TCPSTREAM *stream)
+{
+  int i;
+  fd_set fds,efds;
+  struct timeval tmo;
+  time_t t = time (0);
+  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+  if (stream->tcpsi == INVALID_SOCKET) return NIL;
+  (*bn) (BLOCK_TCPREAD,NIL);
+  while (stream->ictr < 1) {	/* if nothing in the buffer */
+    if (tcpdebug) mm_log ("Reading TCP data",TCPDEBUG);
+				/* simple case if not a socket */
+    if (stream->tcpsi != stream->tcpso)
+      while (((i = read (stream->tcpsi,stream->ibuf,BUFLEN)) < 0) &&
+	     (errno == EINTR));
+    else {
+      time_t tl = time (0);
+      time_t now = tl;
+      time_t ti = ttmo_read ? now + ttmo_read : 0;
+      tmo.tv_usec = 0;
+      FD_ZERO (&fds);		/* initialize selection vector */
+      FD_ZERO (&efds);		/* handle errors too */
+				/* set bit in selection vectors */
+      FD_SET (stream->tcpsi,&fds);
+      FD_SET (stream->tcpsi,&efds);
+      errno = NIL;		/* initially no error */
+      do {			/* block under timeout */
+	tmo.tv_sec = (long) (ti ? ti - now : 0);
+	i = select (stream->tcpsi+1,&fds,NIL,&efds,ti ? &tmo : NIL);
+	now = time (0);		/* fake timeout if interrupt & time expired */
+	if ((i < 0) && ((errno = WSAGetLastError ()) == WSAEINTR) && ti &&
+	    (ti <= now)) i = 0;
+      } while ((i < 0) && (errno == WSAEINTR));
+				/* success from select, read what we can */
+      if (i > 0) while (((i = recv (stream->tcpsi,stream->ibuf,BUFLEN,0)) ==
+			 SOCKET_ERROR) &&
+			((errno = WSAGetLastError ()) == WSAEINTR));
+      else if (!i) {		/* timeout, ignore if told to resume */
+	if (tmoh && (*tmoh) ((long) (now - t),(long) (now - tl), stream->host))
+		continue;
+				/* otherwise punt */
+	if (tcpdebug) mm_log ("TCP data read timeout",TCPDEBUG);
+	return tcp_abort (stream);
+      }
+    }
+    if (i <= 0) {		/* error seen? */
+      if (tcpdebug) {
+	char *s,tmp[MAILTMPLEN];
+	if (i) sprintf (s = tmp,"TCP data read I/O error %d",errno);
+	else s = "TCP data read end of file";
+	mm_log (tmp,TCPDEBUG);
+      }
+      return tcp_abort (stream);
+    }
+    stream->iptr = stream->ibuf;/* point at TCP buffer */
+    stream->ictr = i;		/* set new byte count */
+    if (tcpdebug) mm_log ("Successfully read TCP data",TCPDEBUG);
+  }
+  (*bn) (BLOCK_NONE,NIL);
+  return T;
+}
+
+/* TCP/IP send string as record
+ * Accepts: TCP/IP stream
+ *	    string pointer
+ * Returns: T if success else NIL
+ */
+
+long tcp_soutr (TCPSTREAM *stream,char *string)
+{
+  return tcp_sout (stream,string,(unsigned long) strlen (string));
+}
+
+
+/* TCP/IP send string
+ * Accepts: TCP/IP stream
+ *	    string pointer
+ *	    byte count
+ * Returns: T if success else NIL
+ */
+
+long tcp_sout (TCPSTREAM *stream,char *string,unsigned long size)
+{
+  int i;
+  struct timeval tmo;
+  fd_set fds,efds;
+  time_t t = time (0);
+  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+  tmo.tv_sec = ttmo_write;
+  tmo.tv_usec = 0;
+  FD_ZERO (&fds);		/* initialize selection vector */
+  if (stream->tcpso == INVALID_SOCKET) return NIL;
+  (*bn) (BLOCK_TCPWRITE,NIL);
+  while (size > 0) {		/* until request satisfied */
+    if (tcpdebug) mm_log ("Writing to TCP",TCPDEBUG);
+				/* simple case if not a socket */
+    if (stream->tcpsi != stream->tcpso)
+      while (((i = write (stream->tcpso,string,min (size,TCPMAXSEND))) < 0) &&
+	     (errno == EINTR));
+    else {
+      time_t tl = time (0);	/* start of request */
+      time_t now = tl;
+      time_t ti = ttmo_write ? now + ttmo_write : 0;
+      tmo.tv_usec = 0;
+      FD_ZERO (&fds);		/* initialize selection vector */
+      FD_ZERO (&efds);		/* handle errors too */
+				/* set bit in selection vectors */
+      FD_SET (stream->tcpso,&fds);
+      FD_SET(stream->tcpso,&efds);
+      errno = NIL;		/* block and write */
+      do {			/* block under timeout */
+	tmo.tv_sec = (long) (ti ? ti - now : 0);
+	i = select (stream->tcpso+1,NIL,&fds,&efds,ti ? &tmo : NIL);
+	now = time (0);		/* fake timeout if interrupt & time expired */
+	if ((i < 0) && ((errno = WSAGetLastError ()) == WSAEINTR) && ti &&
+	    (ti <= now)) i = 0;
+      } while ((i < 0) && (errno == WSAEINTR));
+				/* OK to send data? */
+      if (i > 0) while (((i = send (stream->tcpso,string,
+				    (int) min (size,TCPMAXSEND),0)) ==
+			 SOCKET_ERROR) &&
+			((errno = WSAGetLastError ()) == WSAEINTR));
+      else if (!i) {		/* timeout, ignore if told to resume */
+	if (tmoh && (*tmoh) ((long) (now - t),(long) (now - tl), stream->host))
+		continue;
+				/* otherwise punt */
+	if (tcpdebug) mm_log ("TCP write timeout",TCPDEBUG);
+	return tcp_abort (stream);
+      }
+    }
+    if (i <= 0) {		/* error seen? */
+      if (tcpdebug) {
+	char tmp[MAILTMPLEN];
+	sprintf (tmp,"TCP write I/O error %d",errno);
+	mm_log (tmp,TCPDEBUG);
+      }
+      return tcp_abort (stream);
+    }
+    string += i;		/* how much we sent */
+    size -= i;			/* count this size */
+    if (tcpdebug) mm_log ("successfully wrote to TCP",TCPDEBUG);
+  }
+  (*bn) (BLOCK_NONE,NIL);
+  return T;			/* all done */
+}
+
+/* TCP/IP close
+ * Accepts: TCP/IP stream
+ */
+
+void tcp_close (TCPSTREAM *stream)
+{
+  tcp_abort (stream);		/* nuke the sockets */
+				/* flush host names */
+  if (stream->host) fs_give ((void **) &stream->host);
+  if (stream->remotehost) fs_give ((void **) &stream->remotehost);
+  if (stream->localhost) fs_give ((void **) &stream->localhost);
+  fs_give ((void **) &stream);	/* flush the stream */
+}
+
+
+/* TCP/IP abort sockets
+ * Accepts: TCP/IP stream
+ * Returns: NIL, always
+ */
+
+long tcp_abort (TCPSTREAM *stream)
+{
+  if (stream->tcpsi != stream->tcpso) tcp_close_socket (&stream->tcpso);
+  else stream->tcpso = INVALID_SOCKET;
+  return tcp_close_socket (&stream->tcpsi);
+}
+
+
+/* TCP/IP abort stream
+ * Accepts: WinSock socket
+ * Returns: NIL, always
+ */
+
+long tcp_close_socket (SOCKET *sock)
+{
+  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+				/* something to close? */
+  if (sock && (*sock != INVALID_SOCKET)) {
+    (*bn) (BLOCK_TCPCLOSE,NIL);
+    closesocket (*sock);	/* WinSock socket close */
+    *sock = INVALID_SOCKET;
+    (*bn) (BLOCK_NONE,NIL);
+    wsa_sock_open--;		/* drop this socket */
+  }
+				/* no more open streams? */
+  if (wsa_initted && !wsa_sock_open) {
+    mm_log ("Winsock cleanup",NIL);
+    wsa_initted = 0;		/* no more sockets, so... */
+    WSACleanup ();		/* free up resources until needed */
+  }
+  return NIL;
+}
+
+/* TCP/IP get host name
+ * Accepts: TCP/IP stream
+ * Returns: host name for this stream
+ */
+
+char *tcp_host (TCPSTREAM *stream)
+{
+  return stream->host;		/* use tcp_remotehost() if want guarantees */
+}
+
+
+/* TCP/IP get remote host name
+ * Accepts: TCP/IP stream
+ * Returns: host name for this stream
+ */
+
+char *tcp_remotehost (TCPSTREAM *stream)
+{
+  if (!stream->remotehost) {
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    stream->remotehost =	/* get socket's peer name */
+      ((getpeername (stream->tcpsi,sadr,&sadrlen) == SOCKET_ERROR) ||
+       (sadrlen <= 0)) ? cpystr (stream->host) : tcp_name (sadr,NIL);
+    fs_give ((void **) &sadr);
+  }
+  return stream->remotehost;
+}
+
+
+/* TCP/IP return port for this stream
+ * Accepts: TCP/IP stream
+ * Returns: port number for this stream
+ */
+
+unsigned long tcp_port (TCPSTREAM *stream)
+{
+  return stream->port;		/* return port number */
+}
+
+
+/* TCP/IP get local host name
+ * Accepts: TCP/IP stream
+ * Returns: local host name
+ */
+
+char *tcp_localhost (TCPSTREAM *stream)
+{
+  if (!stream->localhost) {
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    stream->localhost =		/* get socket's name */
+      ((stream->port & 0xffff000) ||
+       ((getsockname (stream->tcpsi,sadr,&sadrlen) == SOCKET_ERROR) ||
+	(sadrlen <= 0))) ? cpystr (mylocalhost ()) : tcp_name (sadr,NIL);
+    fs_give ((void **) &sadr);
+  }
+  return stream->localhost;	/* return local host name */
+}
+
+/* TCP/IP get client host address (server calls only)
+ * Returns: client host address
+ */
+
+char *tcp_clientaddr ()
+{
+  if (!myClientAddr) {
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    if ((getpeername (0,sadr,(void *) &sadrlen) == SOCKET_ERROR) ||
+	(sadrlen <= 0)) myClientAddr = cpystr ("UNKNOWN");
+    else {			/* get stdin's peer name */
+      myClientAddr = cpystr (ip_sockaddrtostring (sadr));
+      if (myClientPort < 0) myClientPort = ip_sockaddrtoport (sadr);
+    }
+    fs_give ((void **) &sadr);
+  }
+  return myClientAddr;
+}
+
+
+/* TCP/IP get client host name (server calls only)
+ * Returns: client host name
+ */
+
+char *tcp_clienthost ()
+{
+  if (!myClientHost) {
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    if ((getpeername (0,sadr,(void *) &sadrlen) == SOCKET_ERROR) ||
+	(sadrlen <= 0)) myClientHost = cpystr ("UNKNOWN");
+    else {			/* get stdin's peer name */
+      myClientHost = tcp_name (sadr,T);
+      if (!myClientAddr) myClientAddr = cpystr (ip_sockaddrtostring (sadr));
+      if (myClientPort < 0) myClientPort = ip_sockaddrtoport (sadr);
+    }
+    fs_give ((void **) &sadr);
+  }
+  return myClientHost;
+}
+
+
+/* TCP/IP get client port number (server calls only)
+ * Returns: client port number
+ */
+
+long tcp_clientport ()
+{
+  if (!myClientHost && !myClientAddr) tcp_clientaddr ();
+  return myClientPort;
+}
+
+/* TCP/IP get server host address (server calls only)
+ * Returns: server host address
+ */
+
+char *tcp_serveraddr ()
+{
+  if (!myServerAddr) {
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    if (!wsa_initted++) {	/* init Windows Sockets */
+      WSADATA wsock;
+      if (WSAStartup (WINSOCK_VERSION,&wsock)) {
+	wsa_initted = 0;
+	return "random-pc";	/* try again later? */
+      }
+    }
+    if ((getsockname (0,sadr,(void *) &sadrlen) == SOCKET_ERROR) ||
+	(sadrlen <= 0)) myServerAddr = cpystr ("UNKNOWN");
+    else {			/* get stdin's name */
+      myServerAddr = cpystr (ip_sockaddrtostring (sadr));
+      if (myServerPort < 0) myServerPort = ip_sockaddrtoport (sadr);
+    }
+    fs_give ((void **) &sadr);
+  }
+  return myServerAddr;
+}
+
+
+/* TCP/IP get server host name (server calls only)
+ * Returns: server host name
+ */
+
+char *tcp_serverhost ()
+{
+  if (!myServerHost) {		/* once-only */
+    size_t sadrlen;
+    struct sockaddr *sadr = ip_newsockaddr (&sadrlen);
+    if (!wsa_initted++) {	/* init Windows Sockets */
+      WSADATA wsock;
+      if (WSAStartup (WINSOCK_VERSION,&wsock)) {
+	wsa_initted = 0;
+	return "random-pc";	/* try again later? */
+      }
+    }
+				/* get stdin's name */
+    if ((getsockname (0,sadr,(void *) &sadrlen) == SOCKET_ERROR) ||
+	(sadrlen <= 0)) myServerHost = cpystr (mylocalhost ());
+    else {			/* get stdin's name */
+      myServerHost = tcp_name (sadr,NIL);
+      if (!myServerAddr) myServerAddr = cpystr (ip_sockaddrtostring (sadr));
+      if (myServerPort < 0) myServerPort = ip_sockaddrtoport (sadr);
+    }
+    fs_give ((void **) &sadr);
+  }
+  return myServerHost;
+}
+
+
+/* TCP/IP get server port number (server calls only)
+ * Returns: server port number
+ */
+
+long tcp_serverport ()
+{
+  if (!myServerHost && !myServerAddr) tcp_serveraddr ();
+  return myServerPort;
+}
+
+/* TCP/IP return canonical form of host name
+ * Accepts: host name
+ * Returns: canonical form of host name
+ */
+
+char *tcp_canonical (char *name)
+{
+  char *ret,host[MAILTMPLEN];
+  blocknotify_t bn = (blocknotify_t) mail_parameters (NIL,GET_BLOCKNOTIFY,NIL);
+				/* look like domain literal? */
+  if (name[0] == '[' && name[strlen (name) - 1] == ']') return name;
+  (*bn) (BLOCK_DNSLOOKUP,NIL);
+  if (tcpdebug) {
+    sprintf (host,"DNS canonicalization %.80s",name);
+    mm_log (host,TCPDEBUG);
+  }
+				/* get canonical name */
+  if (!ip_nametoaddr (name,NIL,NIL,&ret,NIL)) ret = name;
+  (*bn) (BLOCK_NONE,NIL);	/* alarms OK now */
+  if (tcpdebug) mm_log ("DNS canonicalization done",TCPDEBUG);
+  return ret;
+}
+
+
+/* TCP/IP return name from socket
+ * Accepts: socket
+ *	    verbose flag
+ * Returns: cpystr name
+ */
+
+char *tcp_name (struct sockaddr *sadr,long flag)
+{
+  char *ret,*t,adr[MAILTMPLEN],tmp[MAILTMPLEN];
+  sprintf (ret = adr,"[%.80s]",ip_sockaddrtostring (sadr));
+  if (allowreversedns) {
+    blocknotify_t bn = (blocknotify_t)mail_parameters(NIL,GET_BLOCKNOTIFY,NIL);
+    if (tcpdebug) {
+      sprintf (tmp,"Reverse DNS resolution %s",adr);
+      mm_log (tmp,TCPDEBUG);
+    }
+    (*bn) (BLOCK_DNSLOOKUP,NIL);/* quell alarms */
+				/* translate address to name */
+    if (t = tcp_name_valid (ip_sockaddrtoname (sadr))) {
+				/* produce verbose form if needed */
+      if (flag)	sprintf (ret = tmp,"%s %s",t,adr);
+      else ret = t;
+    }
+    (*bn) (BLOCK_NONE,NIL);	/* alarms OK now */
+    if (tcpdebug) mm_log ("Reverse DNS resolution done",TCPDEBUG);
+  }
+  return cpystr (ret);
+}
+
+/* Validate name
+ * Accepts: domain name
+ * Returns: T if valid, NIL otherwise
+ */
+
+char *tcp_name_valid (char *s)
+{
+  int c;
+  char *ret,*tail;
+				/* must be non-empty and not too long */
+  if ((ret = (s && *s) ? s : NIL) && (tail = ret + NETMAXHOST)) {
+				/* must be alnum, dot, or hyphen */
+    while ((c = *s++) && (s <= tail) &&
+	   (((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z')) ||
+	    ((c >= '0') && (c <= '9')) || (c == '-') || (c == '.')));
+    if (c) ret = NIL;
+  }
+  return ret;
+}