-/* Serial interface for raw TCP connections on Un*x like systems
- Copyright 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2001
- Free Software Foundation, Inc.
+/* Serial interface for raw TCP connections on Un*x like systems.
+
+ Copyright (C) 1992-2020 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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "serial.h"
-#include "ser-unix.h"
+#include "ser-base.h"
+#include "ser-tcp.h"
+#include "gdbcmd.h"
+#include "cli/cli-decode.h"
+#include "cli/cli-setshow.h"
+#include "gdbsupport/filestuff.h"
+#include "gdbsupport/netstuff.h"
#include <sys/types.h>
-#include <sys/ioctl.h>
-#include <sys/time.h>
+
+#ifdef HAVE_SYS_FILIO_H
+#include <sys/filio.h> /* For FIONBIO. */
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h> /* For FIONBIO. */
+#endif
+
+#include "gdbsupport/gdb_sys_time.h"
+
+#ifdef USE_WIN32API
+#include <ws2tcpip.h>
+#ifndef ETIMEDOUT
+#define ETIMEDOUT WSAETIMEDOUT
+#endif
+/* Gnulib defines close too, but gnulib's replacement
+ doesn't call closesocket unless we import the
+ socketlib module. */
+#undef close
+#define close(fd) closesocket (fd)
+#define ioctl ioctlsocket
+#else
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
+#endif
#include <signal.h>
-#include "gdb_string.h"
+#include "gdbsupport/gdb_select.h"
+#include <algorithm>
+
+#ifndef HAVE_SOCKLEN_T
+typedef int socklen_t;
+#endif
+
+/* For "set tcp" and "show tcp". */
+
+static struct cmd_list_element *tcp_set_cmdlist;
+static struct cmd_list_element *tcp_show_cmdlist;
-static int tcp_open (struct serial *scb, const char *name);
-static void tcp_close (struct serial *scb);
-extern int (*ui_loop_hook) (int);
-void _initialize_ser_tcp (void);
+/* Whether to auto-retry refused connections. */
-/* seconds to wait for connect */
-#define TIMEOUT 15
-/* how many times per second to poll ui_loop_hook */
-#define POLL_INTERVAL 2
+static bool tcp_auto_retry = true;
-/* Open a tcp socket */
+/* Timeout period for connections, in seconds. */
+
+static unsigned int tcp_retry_limit = 15;
+
+/* How many times per second to poll deprecated_ui_loop_hook. */
+
+#define POLL_INTERVAL 5
+
+/* Helper function to wait a while. If SOCK is not -1, wait on its
+ file descriptor. Otherwise just wait on a timeout, updating
+ *POLLS. Returns -1 on timeout or interrupt, otherwise the value of
+ select. */
static int
-tcp_open (struct serial *scb, const char *name)
+wait_for_connect (int sock, unsigned int *polls)
{
- char *port_str, hostname[100];
- int n, port, tmp;
- struct hostent *hostent;
- struct sockaddr_in sockaddr;
+ struct timeval t;
+ int n;
+
+ /* While we wait for the connect to complete,
+ poll the UI so it can update or the user can
+ interrupt. */
+ if (deprecated_ui_loop_hook && deprecated_ui_loop_hook (0))
+ {
+ errno = EINTR;
+ return -1;
+ }
+
+ /* Check for timeout. */
+ if (*polls > tcp_retry_limit * POLL_INTERVAL)
+ {
+ errno = ETIMEDOUT;
+ return -1;
+ }
+
+ /* Back off to polling once per second after the first POLL_INTERVAL
+ polls. */
+ if (*polls < POLL_INTERVAL)
+ {
+ t.tv_sec = 0;
+ t.tv_usec = 1000000 / POLL_INTERVAL;
+ }
+ else
+ {
+ t.tv_sec = 1;
+ t.tv_usec = 0;
+ }
- port_str = strchr (name, ':');
+ if (sock >= 0)
+ {
+ fd_set rset, wset, eset;
- if (!port_str)
- error ("tcp_open: No colon in host name!"); /* Shouldn't ever happen */
+ FD_ZERO (&rset);
+ FD_SET (sock, &rset);
+ wset = rset;
+ eset = rset;
+
+ /* POSIX systems return connection success or failure by signalling
+ wset. Windows systems return success in wset and failure in
+ eset.
- tmp = min (port_str - name, (int) sizeof hostname - 1);
- strncpy (hostname, name, tmp); /* Don't want colon */
- hostname[tmp] = '\000'; /* Tie off host name */
- port = atoi (port_str + 1);
+ We must call select here, rather than gdb_select, because
+ the serial structure has not yet been initialized - the
+ MinGW select wrapper will not know that this FD refers
+ to a socket. */
+ n = select (sock + 1, &rset, &wset, &eset, &t);
+ }
+ else
+ /* Use gdb_select here, since we have no file descriptors, and on
+ Windows, plain select doesn't work in that case. */
+ n = gdb_select (0, NULL, NULL, NULL, &t);
- /* default hostname is localhost */
- if (!hostname[0])
- strcpy (hostname, "localhost");
+ /* If we didn't time out, only count it as one poll. */
+ if (n > 0 || *polls < POLL_INTERVAL)
+ (*polls)++;
+ else
+ (*polls) += POLL_INTERVAL;
- hostent = gethostbyname (hostname);
- if (!hostent)
+ return n;
+}
+
+/* Try to connect to the host represented by AINFO. If the connection
+ succeeds, return its socket. Otherwise, return -1 and set ERRNO
+ accordingly. POLLS is used when 'connect' returns EINPROGRESS, and
+ we need to invoke 'wait_for_connect' to obtain the status. */
+
+static int
+try_connect (const struct addrinfo *ainfo, unsigned int *polls)
+{
+ int sock = gdb_socket_cloexec (ainfo->ai_family, ainfo->ai_socktype,
+ ainfo->ai_protocol);
+
+ if (sock < 0)
+ return -1;
+
+ /* Set socket nonblocking. */
+#ifdef USE_WIN32API
+ u_long ioarg = 1;
+#else
+ int ioarg = 1;
+#endif
+
+ ioctl (sock, FIONBIO, &ioarg);
+
+ /* Use Non-blocking connect. connect() will return 0 if connected
+ already. */
+ if (connect (sock, ainfo->ai_addr, ainfo->ai_addrlen) < 0)
{
- fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
- errno = ENOENT;
+#ifdef USE_WIN32API
+ int err = WSAGetLastError();
+#else
+ int err = errno;
+#endif
+
+ /* If we've got a "connection refused" error, just return
+ -1. The caller will know what to do. */
+ if (
+#ifdef USE_WIN32API
+ err == WSAECONNREFUSED
+#else
+ err == ECONNREFUSED
+#endif
+ )
+ {
+ close (sock);
+ errno = err;
+ return -1;
+ }
+
+ if (
+ /* Any other error (except EINPROGRESS) will be "swallowed"
+ here. We return without specifying a return value, and
+ set errno if the caller wants to inspect what
+ happened. */
+#ifdef USE_WIN32API
+ /* Under Windows, calling "connect" with a non-blocking socket
+ results in WSAEWOULDBLOCK, not WSAEINPROGRESS. */
+ err != WSAEWOULDBLOCK
+#else
+ err != EINPROGRESS
+#endif
+ )
+ {
+ close (sock);
+ errno = err;
+ return -1;
+ }
+
+ /* Looks like we need to wait for the connect. */
+ int n;
+
+ do
+ n = wait_for_connect (sock, polls);
+ while (n == 0);
+
+ if (n < 0)
+ {
+ int saved_errno = errno;
+
+ /* A negative value here means that we either timed out or
+ got interrupted by the user. Just return. */
+ close (sock);
+ errno = saved_errno;
+ return -1;
+ }
+ }
+
+ /* Got something. Is it an error? */
+ int err;
+ socklen_t len = sizeof (err);
+
+ /* On Windows, the fourth parameter to getsockopt is a "char *";
+ on UNIX systems it is generally "void *". The cast to "char *"
+ is OK everywhere, since in C++ any data pointer type can be
+ implicitly converted to "void *". */
+ int ret = getsockopt (sock, SOL_SOCKET, SO_ERROR, (char *) &err, &len);
+
+ if (ret < 0)
+ {
+ int saved_errno = errno;
+
+ close (sock);
+ errno = saved_errno;
+ return -1;
+ }
+ else if (ret == 0 && err != 0)
+ {
+ close (sock);
+ errno = err;
return -1;
}
- scb->fd = socket (PF_INET, SOCK_STREAM, 0);
- if (scb->fd < 0)
- return -1;
-
- sockaddr.sin_family = PF_INET;
- sockaddr.sin_port = htons (port);
- memcpy (&sockaddr.sin_addr.s_addr, hostent->h_addr,
- sizeof (struct in_addr));
+ /* The connection succeeded. Return the socket. */
+ return sock;
+}
+
+/* Open a tcp socket. */
+
+int
+net_open (struct serial *scb, const char *name)
+{
+ struct addrinfo hint;
+ struct addrinfo *ainfo;
+
+ memset (&hint, 0, sizeof (hint));
+ /* Assume no prefix will be passed, therefore we should use
+ AF_UNSPEC. */
+ hint.ai_family = AF_UNSPEC;
+ hint.ai_socktype = SOCK_STREAM;
+ hint.ai_protocol = IPPROTO_TCP;
- /* set socket nonblocking */
- tmp = 1;
- ioctl (scb->fd, FIONBIO, &tmp);
+ parsed_connection_spec parsed = parse_connection_spec (name, &hint);
- /* Use Non-blocking connect. connect() will return 0 if connected already. */
- n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr));
+ if (parsed.port_str.empty ())
+ error (_("Missing port on hostname '%s'"), name);
- if (n < 0 && errno != EINPROGRESS)
+ int r = getaddrinfo (parsed.host_str.c_str (),
+ parsed.port_str.c_str (),
+ &hint, &ainfo);
+
+ if (r != 0)
{
- tcp_close (scb);
+ fprintf_unfiltered (gdb_stderr, _("%s: cannot resolve name: %s\n"),
+ name, gai_strerror (r));
+ errno = ENOENT;
return -1;
}
- if (n)
+ scoped_free_addrinfo free_ainfo (ainfo);
+
+ /* Flag to indicate whether we've got a connection refused. It will
+ be true if any of the connections tried was refused. */
+ bool got_connrefused;
+ /* If a connection succeeds, SUCCESS_AINFO will point to the
+ 'struct addrinfo' that succeed. */
+ struct addrinfo *success_ainfo = NULL;
+ unsigned int polls = 0;
+
+ /* Assume the worst. */
+ scb->fd = -1;
+
+ do
{
- /* looks like we need to wait for the connect */
- struct timeval t;
- fd_set rset, wset;
- int polls = 0;
- FD_ZERO (&rset);
+ got_connrefused = false;
- do
+ for (addrinfo *iter = ainfo; iter != NULL; iter = iter->ai_next)
{
- /* While we wait for the connect to complete
- poll the UI so it can update or the user can
- interrupt. */
- if (ui_loop_hook)
+ /* Iterate over the list of possible addresses to connect
+ to. For each, we'll try to connect and see if it
+ succeeds. */
+ int sock = try_connect (iter, &polls);
+
+ if (sock >= 0)
{
- if (ui_loop_hook (0))
- {
- errno = EINTR;
- tcp_close (scb);
- return -1;
- }
+ /* We've gotten a successful connection. Save its
+ 'struct addrinfo', the socket, and break. */
+ success_ainfo = iter;
+ scb->fd = sock;
+ break;
}
-
- FD_SET (scb->fd, &rset);
- wset = rset;
- t.tv_sec = 0;
- t.tv_usec = 1000000 / POLL_INTERVAL;
-
- n = select (scb->fd + 1, &rset, &wset, NULL, &t);
- polls++;
- }
- while (n == 0 && polls <= TIMEOUT * POLL_INTERVAL);
- if (n < 0 || polls > TIMEOUT * POLL_INTERVAL)
- {
- if (polls > TIMEOUT * POLL_INTERVAL)
- errno = ETIMEDOUT;
- tcp_close (scb);
- return -1;
+ else if (
+#ifdef USE_WIN32API
+ errno == WSAECONNREFUSED
+#else
+ errno == ECONNREFUSED
+#endif
+ )
+ got_connrefused = true;
}
}
+ /* Just retry if:
- /* Got something. Is it an error? */
- {
- int res, err, len;
- len = sizeof(err);
- res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, &err, &len);
- if (res < 0 || err)
- {
- if (err)
- errno = err;
- tcp_close (scb);
- return -1;
- }
- }
-
- /* turn off nonblocking */
- tmp = 0;
- ioctl (scb->fd, FIONBIO, &tmp);
+ - tcp_auto_retry is true, and
+ - We haven't gotten a connection yet, and
+ - Any of our connection attempts returned with ECONNREFUSED, and
+ - wait_for_connect signals that we can keep going. */
+ while (tcp_auto_retry
+ && success_ainfo == NULL
+ && got_connrefused
+ && wait_for_connect (-1, &polls) >= 0);
+ if (success_ainfo == NULL)
+ {
+ net_close (scb);
+ return -1;
+ }
+
+ /* Turn off nonblocking. */
+#ifdef USE_WIN32API
+ u_long ioarg = 0;
+#else
+ int ioarg = 0;
+#endif
+
+ ioctl (scb->fd, FIONBIO, &ioarg);
+
+ if (success_ainfo->ai_protocol == IPPROTO_TCP)
+ {
+ /* Disable Nagle algorithm. Needed in some cases. */
+ int tmp = 1;
+
+ setsockopt (scb->fd, IPPROTO_TCP, TCP_NODELAY,
+ (char *) &tmp, sizeof (tmp));
+ }
+
+#ifdef SIGPIPE
/* If we don't do this, then GDB simply exits
when the remote side dies. */
signal (SIGPIPE, SIG_IGN);
+#endif
return 0;
}
-static void
-tcp_close (struct serial *scb)
+void
+net_close (struct serial *scb)
{
- if (scb->fd < 0)
+ if (scb->fd == -1)
return;
close (scb->fd);
scb->fd = -1;
}
+int
+net_read_prim (struct serial *scb, size_t count)
+{
+ /* Need to cast to silence -Wpointer-sign on MinGW, as Winsock's
+ 'recv' takes 'char *' as second argument, while 'scb->buf' is
+ 'unsigned char *'. */
+ return recv (scb->fd, (char *) scb->buf, count, 0);
+}
+
+int
+net_write_prim (struct serial *scb, const void *buf, size_t count)
+{
+ /* On Windows, the second parameter to send is a "const char *"; on
+ UNIX systems it is generally "const void *". The cast to "const
+ char *" is OK everywhere, since in C++ any data pointer type can
+ be implicitly converted to "const void *". */
+ return send (scb->fd, (const char *) buf, count, 0);
+}
+
+int
+ser_tcp_send_break (struct serial *scb)
+{
+ /* Send telnet IAC and BREAK characters. */
+ return (serial_write (scb, "\377\363", 2));
+}
+
+#ifndef USE_WIN32API
+
+/* The TCP ops. */
+
+static const struct serial_ops tcp_ops =
+{
+ "tcp",
+ net_open,
+ net_close,
+ NULL,
+ ser_base_readchar,
+ ser_base_write,
+ ser_base_flush_output,
+ ser_base_flush_input,
+ ser_tcp_send_break,
+ ser_base_raw,
+ ser_base_get_tty_state,
+ ser_base_copy_tty_state,
+ ser_base_set_tty_state,
+ ser_base_print_tty_state,
+ ser_base_setbaudrate,
+ ser_base_setstopbits,
+ ser_base_setparity,
+ ser_base_drain_output,
+ ser_base_async,
+ net_read_prim,
+ net_write_prim
+};
+
+#endif /* USE_WIN32API */
+
+void _initialize_ser_tcp ();
void
-_initialize_ser_tcp (void)
+_initialize_ser_tcp ()
{
- struct serial_ops *ops = XMALLOC (struct serial_ops);
- memset (ops, sizeof (struct serial_ops), 0);
- ops->name = "tcp";
- ops->next = 0;
- ops->open = tcp_open;
- ops->close = tcp_close;
- ops->readchar = ser_unix_readchar;
- ops->write = ser_unix_write;
- ops->flush_output = ser_unix_nop_flush_output;
- ops->flush_input = ser_unix_flush_input;
- ops->send_break = ser_unix_nop_send_break;
- ops->go_raw = ser_unix_nop_raw;
- ops->get_tty_state = ser_unix_nop_get_tty_state;
- ops->set_tty_state = ser_unix_nop_set_tty_state;
- ops->print_tty_state = ser_unix_nop_print_tty_state;
- ops->noflush_set_tty_state = ser_unix_nop_noflush_set_tty_state;
- ops->setbaudrate = ser_unix_nop_setbaudrate;
- ops->setstopbits = ser_unix_nop_setstopbits;
- ops->drain_output = ser_unix_nop_drain_output;
- ops->async = ser_unix_async;
- serial_add_interface (ops);
+#ifdef USE_WIN32API
+ /* Do nothing; the TCP serial operations will be initialized in
+ ser-mingw.c. */
+#else
+ serial_add_interface (&tcp_ops);
+#endif /* USE_WIN32API */
+
+ add_basic_prefix_cmd ("tcp", class_maintenance, _("\
+TCP protocol specific variables.\n\
+Configure variables specific to remote TCP connections."),
+ &tcp_set_cmdlist, "set tcp ",
+ 0 /* allow-unknown */, &setlist);
+ add_show_prefix_cmd ("tcp", class_maintenance, _("\
+TCP protocol specific variables.\n\
+Configure variables specific to remote TCP connections."),
+ &tcp_show_cmdlist, "show tcp ",
+ 0 /* allow-unknown */, &showlist);
+
+ add_setshow_boolean_cmd ("auto-retry", class_obscure,
+ &tcp_auto_retry, _("\
+Set auto-retry on socket connect."), _("\
+Show auto-retry on socket connect."),
+ NULL, NULL, NULL,
+ &tcp_set_cmdlist, &tcp_show_cmdlist);
+
+ add_setshow_uinteger_cmd ("connect-timeout", class_obscure,
+ &tcp_retry_limit, _("\
+Set timeout limit in seconds for socket connection."), _("\
+Show timeout limit in seconds for socket connection."), _("\
+If set to \"unlimited\", GDB will keep attempting to establish a\n\
+connection forever, unless interrupted with Ctrl-c.\n\
+The default is 15 seconds."),
+ NULL, NULL,
+ &tcp_set_cmdlist, &tcp_show_cmdlist);
}
projects / deliverable / binutils-gdb.git / blobdiff