* Makefile.in: Add new file ser-tcp.c.

* defs.h (memcmp):  Add decl for memcmp to #ifndef MEM_FNS_DECLARED.
	* findvar.c (write_register):  See if we are writing back the same
	value that's already in the register.  If so, don't bother.
	* remote.c (putpkt, getpkt):  Improve handling of communication
	problems.
	* ser-go32.c:  Prototype it to death.  Update serial_ops and add
	dummy routines where appropriate.
	* ser-tcp.c:  New module to implement serial I/O via TCP
	connections.
	* ser-unix.c:  Clean up getting/setting of tty state.  Get rid of
	SERIAL_RESTORE, add SERIAL_{GET|SET}_TTY_STATE interfaces.
	* serial.c:  Add start of support for connect command.
	(serial_open):  Distinguish between tcp and local devices.
	* serial.h (struct serial_ops):  Get rid of restore, add
	get_tty_state and set_tty_state.  Define protoypes and macros for
	this mess.
	* gdbserver/remote-utils.c:  Add tcp support.  (readchar):  Do
	some real buffering.  Handle error conditions gracefully.
	* gdbserver/remote-inflow-sparc.c:  Update to remote-inflow.c
	(Lynx), remove lots of cruft.

gdb/ser-tcp.c

@@ -0,0 +1,270 @@
+/* Serial interface for raw TCP connections on Un*x like systems
+   Copyright 1992, 1993 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "defs.h"
+#include "serial.h"
+#include <sys/types.h>
+#include <sys/time.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <netinet/tcp.h>
+#include "signals.h"
+
+struct tcp_ttystate
+{
+  int bogus;
+};
+
+static int tcp_open PARAMS ((serial_t scb, const char *name));
+static void tcp_raw PARAMS ((serial_t scb));
+static int wait_for PARAMS ((serial_t scb, int timeout));
+static int tcp_readchar PARAMS ((serial_t scb, int timeout));
+static int tcp_setbaudrate PARAMS ((serial_t scb, int rate));
+static int tcp_write PARAMS ((serial_t scb, const char *str, int len));
+static void tcp_restore PARAMS ((serial_t scb));
+static void tcp_close PARAMS ((serial_t scb));
+static serial_ttystate tcp_get_tty_state PARAMS ((serial_t scb));
+static int tcp_set_tty_state PARAMS ((serial_t scb, serial_ttystate state));
+
+/* Open up a raw tcp socket */
+
+static int
+tcp_open(scb, name)
+     serial_t scb;
+     const char *name;
+{
+  char *port_str;
+  int port;
+  struct hostent *hostent;
+  struct sockaddr_in sockaddr;
+  int tmp;
+  char hostname[100];
+
+  port_str = strchr (name, ':');
+
+  if (!port_str)
+    error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
+
+  tmp = min(port_str - name + 1, sizeof hostname);
+  strncpy (hostname, name, tmp - 1); /* Don't want colon */
+  port = atoi (port_str + 1);
+
+  hostent = gethostbyname (hostname);
+
+  if (!hostent)
+    {
+      errno = ENOENT;
+      return -1;
+    }
+
+  scb->fd = socket (PF_INET, SOCK_STREAM, 0);
+  if (scb->fd < 0)
+    return -1;
+
+  /* Allow rapid reuse of this port. */
+  tmp = 1;
+  setsockopt (scb->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&tmp, sizeof(tmp));
+
+  /* Enable TCP keep alive process. */
+  tmp = 1;
+  setsockopt (scb->fd, SOL_SOCKET, SO_KEEPALIVE, (char *)&tmp, sizeof(tmp));
+
+  sockaddr.sin_family = PF_INET;
+  sockaddr.sin_port = htons(port);
+  memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
+	  sizeof (struct in_addr));
+
+  if (connect(scb->fd, &sockaddr, sizeof(sockaddr)))
+    {
+      close(scb->fd);
+      return -1;
+    }
+
+  tmp = 1;
+  if (setsockopt (scb->fd, 6, TCP_NODELAY, (char *)&tmp, sizeof(tmp)))
+    return -1;
+
+  signal(SIGPIPE, SIG_IGN);	/* If we don't do this, then GDB simply exits
+				   when the remote side dies.  */
+
+  return 0;
+}
+
+static serial_ttystate
+tcp_get_tty_state(scb)
+     serial_t scb;
+{
+  struct tcp_ttystate *state;
+
+  state = (struct tcp_ttystate *)xmalloc(sizeof *state);
+
+  return (serial_ttystate)state;
+}
+
+static int
+tcp_set_tty_state(scb, ttystate)
+     serial_t scb;
+     serial_ttystate ttystate;
+{
+  struct tcp_ttystate *state;
+
+  state = (struct tcp_ttystate *)ttystate;
+
+  return 0;
+}
+
+static void
+tcp_raw(scb)
+     serial_t scb;
+{
+  return;			/* Always in raw mode */
+}
+
+/* Wait for input on scb, with timeout seconds.  Returns 0 on success,
+   otherwise SERIAL_TIMEOUT or SERIAL_ERROR.
+
+   For termio{s}, we actually just setup VTIME if necessary, and let the
+   timeout occur in the read() in tcp_read().
+ */
+
+static int
+wait_for(scb, timeout)
+     serial_t scb;
+     int timeout;
+{
+  int numfds;
+  struct timeval tv;
+  fd_set readfds;
+
+  FD_ZERO (&readfds);
+
+  tv.tv_sec = timeout;
+  tv.tv_usec = 0;
+
+  FD_SET(scb->fd, &readfds);
+
+  if (timeout >= 0)
+    numfds = select(scb->fd+1, &readfds, 0, 0, &tv);
+  else
+    numfds = select(scb->fd+1, &readfds, 0, 0, 0);
+
+  if (numfds <= 0)
+    if (numfds == 0)
+      return SERIAL_TIMEOUT;
+    else
+      return SERIAL_ERROR;	/* Got an error from select or poll */
+
+  return 0;
+}
+
+/* Read a character with user-specified timeout.  TIMEOUT is number of seconds
+   to wait, or -1 to wait forever.  Use timeout of 0 to effect a poll.  Returns
+   char if successful.  Returns -2 if timeout expired, EOF if line dropped
+   dead, or -3 for any other error (see errno in that case). */
+
+static int
+tcp_readchar(scb, timeout)
+     serial_t scb;
+     int timeout;
+{
+  int status;
+
+  if (scb->bufcnt-- > 0)
+    return *scb->bufp++;
+
+  status = wait_for(scb, timeout);
+
+  if (status < 0)
+    return status;
+
+  scb->bufcnt = read(scb->fd, scb->buf, BUFSIZ);
+
+  if (scb->bufcnt <= 0)
+    if (scb->bufcnt == 0)
+      return SERIAL_TIMEOUT;	/* 0 chars means timeout [may need to
+				   distinguish between EOF & timeouts
+				   someday] */
+    else
+      return SERIAL_ERROR;	/* Got an error from read */
+
+  scb->bufcnt--;
+  scb->bufp = scb->buf;
+  return *scb->bufp++;
+}
+
+static int
+tcp_setbaudrate(scb, rate)
+     serial_t scb;
+     int rate;
+{
+  return 0;			/* Never fails! */
+}
+
+static int
+tcp_write(scb, str, len)
+     serial_t scb;
+     const char *str;
+     int len;
+{
+  int cc;
+
+  while (len > 0)
+    {
+      cc = write(scb->fd, str, len);
+
+      if (cc < 0)
+	return 1;
+      len -= cc;
+      str += cc;
+    }
+  return 0;
+}
+
+static void
+tcp_close(scb)
+     serial_t scb;
+{
+  if (scb->fd < 0)
+    return;
+
+  close(scb->fd);
+  scb->fd = -1;
+}
+
+static struct serial_ops tcp_ops =
+{
+  "tcp",
+  0,
+  tcp_open,
+  tcp_close,
+  tcp_readchar,
+  tcp_write,
+  tcp_raw,
+  tcp_get_tty_state,
+  tcp_set_tty_state,
+  tcp_setbaudrate,
+};
+
+void
+_initialize_ser_tcp ()
+{
+  serial_add_interface (&tcp_ops);
+}