/* Serial interface for raw TCP connections on Un*x like systems.
- Copyright (C) 1992-2013 Free Software Foundation, Inc.
+ Copyright (C) 1992-2019 Free Software Foundation, Inc.
This file is part of GDB.
#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> /* For FIONBIO. */
#endif
-#include <sys/time.h>
+#include "gdbsupport/gdb_sys_time.h"
#ifdef USE_WIN32API
-#include <winsock2.h>
+#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
#endif
#include <signal.h>
-#include "gdb_string.h"
#include "gdb_select.h"
+#include <algorithm>
#ifndef HAVE_SOCKLEN_T
typedef int socklen_t;
#endif
-void _initialize_ser_tcp (void);
-
/* For "set tcp" and "show tcp". */
static struct cmd_list_element *tcp_set_cmdlist;
/* Whether to auto-retry refused connections. */
-static int tcp_auto_retry = 1;
+static bool tcp_auto_retry = true;
/* Timeout period for connections, in seconds. */
#define POLL_INTERVAL 5
-/* Helper function to wait a while. If SCB is non-null, wait on its
- file descriptor. Otherwise just wait on a timeout, updating *POLLS.
- Returns -1 on timeout or interrupt, otherwise the value of select. */
+/* 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
-wait_for_connect (struct serial *scb, unsigned int *polls)
+wait_for_connect (int sock, unsigned int *polls)
{
struct timeval t;
int n;
t.tv_usec = 0;
}
- if (scb)
+ if (sock >= 0)
{
fd_set rset, wset, eset;
FD_ZERO (&rset);
- FD_SET (scb->fd, &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.
-
+
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 (scb->fd + 1, &rset, &wset, &eset, &t);
+ n = select (sock + 1, &rset, &wset, &eset, &t);
}
else
/* Use gdb_select here, since we have no file descriptors, and on
return n;
}
-/* Open a tcp socket. */
+/* 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. */
-int
-net_open (struct serial *scb, const char *name)
+static int
+try_connect (const struct addrinfo *ainfo, unsigned int *polls)
{
- char *port_str, hostname[100];
- int n, port, tmp;
- int use_udp;
- struct hostent *hostent;
- struct sockaddr_in sockaddr;
+ 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;
+ u_long ioarg = 1;
#else
- int ioarg;
+ int ioarg = 1;
#endif
- unsigned int polls = 0;
-
- use_udp = 0;
- if (strncmp (name, "udp:", 4) == 0)
- {
- use_udp = 1;
- name = name + 4;
- }
- else if (strncmp (name, "tcp:", 4) == 0)
- name = name + 4;
-
- port_str = strchr (name, ':');
-
- if (!port_str)
- error (_("net_open: No colon in host name!")); /* Shouldn't ever
- happen. */
-
- 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);
-
- /* Default hostname is localhost. */
- if (!hostname[0])
- strcpy (hostname, "localhost");
-
- hostent = gethostbyname (hostname);
- if (!hostent)
- {
- fprintf_unfiltered (gdb_stderr, "%s: unknown host\n", hostname);
- errno = ENOENT;
- 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));
-
- retry:
- if (use_udp)
- scb->fd = socket (PF_INET, SOCK_DGRAM, 0);
- else
- scb->fd = socket (PF_INET, SOCK_STREAM, 0);
-
- if (scb->fd == -1)
- return -1;
-
- /* Set socket nonblocking. */
- ioarg = 1;
- ioctl (scb->fd, FIONBIO, &ioarg);
+ ioctl (sock, FIONBIO, &ioarg);
/* Use Non-blocking connect. connect() will return 0 if connected
already. */
- n = connect (scb->fd, (struct sockaddr *) &sockaddr, sizeof (sockaddr));
-
- if (n < 0)
+ if (connect (sock, ainfo->ai_addr, ainfo->ai_addrlen) < 0)
{
#ifdef USE_WIN32API
int err = WSAGetLastError();
int err = errno;
#endif
- /* Maybe we're waiting for the remote target to become ready to
- accept connections. */
- if (tcp_auto_retry
+ /* If we've got a "connection refused" error, just return
+ -1. The caller will know what to do. */
+ if (
#ifdef USE_WIN32API
- && err == WSAECONNREFUSED
+ err == WSAECONNREFUSED
#else
- && err == ECONNREFUSED
+ err == ECONNREFUSED
#endif
- && wait_for_connect (NULL, &polls) >= 0)
+ )
{
- close (scb->fd);
- goto retry;
+ 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. */
#endif
)
{
+ close (sock);
errno = err;
- net_close (scb);
return -1;
}
/* Looks like we need to wait for the connect. */
- do
- {
- n = wait_for_connect (scb, &polls);
- }
+ int n;
+
+ do
+ n = wait_for_connect (sock, polls);
while (n == 0);
+
if (n < 0)
{
- net_close (scb);
+ 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 res, err;
- socklen_t len;
-
- len = sizeof (err);
- /* On Windows, the fourth parameter to getsockopt is a "char *";
- on UNIX systems it is generally "void *". The cast to "void *"
- is OK everywhere, since in C "void *" can be implicitly
- converted to any pointer type. */
- res = getsockopt (scb->fd, SOL_SOCKET, SO_ERROR, (void *) &err, &len);
- if (res < 0 || err)
- {
- /* Maybe the target still isn't ready to accept the connection. */
- if (tcp_auto_retry
+ 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;
+ }
+
+ /* 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;
+
+ parsed_connection_spec parsed = parse_connection_spec (name, &hint);
+
+ if (parsed.port_str.empty ())
+ error (_("Missing port on hostname '%s'"), name);
+
+ int r = getaddrinfo (parsed.host_str.c_str (),
+ parsed.port_str.c_str (),
+ &hint, &ainfo);
+
+ if (r != 0)
+ {
+ fprintf_unfiltered (gdb_stderr, _("%s: cannot resolve name: %s\n"),
+ name, gai_strerror (r));
+ errno = ENOENT;
+ return -1;
+ }
+
+ 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
+ {
+ got_connrefused = false;
+
+ for (addrinfo *iter = ainfo; iter != NULL; iter = iter->ai_next)
+ {
+ /* 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)
+ {
+ /* We've gotten a successful connection. Save its
+ 'struct addrinfo', the socket, and break. */
+ success_ainfo = iter;
+ scb->fd = sock;
+ break;
+ }
+ else if (
#ifdef USE_WIN32API
- && err == WSAECONNREFUSED
+ errno == WSAECONNREFUSED
#else
- && err == ECONNREFUSED
+ errno == ECONNREFUSED
#endif
- && wait_for_connect (NULL, &polls) >= 0)
- {
- close (scb->fd);
- goto retry;
- }
- if (err)
- errno = err;
- net_close (scb);
- return -1;
- }
- }
+ )
+ got_connrefused = true;
+ }
+ }
+ /* Just retry if:
+
+ - 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. */
- ioarg = 0;
+#ifdef USE_WIN32API
+ u_long ioarg = 0;
+#else
+ int ioarg = 0;
+#endif
+
ioctl (scb->fd, FIONBIO, &ioarg);
- if (use_udp == 0)
+ if (success_ainfo->ai_protocol == IPPROTO_TCP)
{
/* Disable Nagle algorithm. Needed in some cases. */
- tmp = 1;
+ int tmp = 1;
+
setsockopt (scb->fd, IPPROTO_TCP, TCP_NODELAY,
- (char *)&tmp, sizeof (tmp));
+ (char *) &tmp, sizeof (tmp));
}
#ifdef SIGPIPE
int
net_read_prim (struct serial *scb, size_t count)
{
- return recv (scb->fd, scb->buf, count, 0);
+ /* 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)
{
- return send (scb->fd, buf, count, 0);
+ /* 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
/* Support for "set tcp" and "show tcp" commands. */
static void
-set_tcp_cmd (char *args, int from_tty)
+set_tcp_cmd (const char *args, int from_tty)
{
- help_list (tcp_set_cmdlist, "set tcp ", -1, gdb_stdout);
+ help_list (tcp_set_cmdlist, "set tcp ", all_commands, gdb_stdout);
}
static void
-show_tcp_cmd (char *args, int from_tty)
+show_tcp_cmd (const char *args, int from_tty)
{
- help_list (tcp_show_cmdlist, "show tcp ", -1, gdb_stdout);
+ help_list (tcp_show_cmdlist, "show tcp ", all_commands, gdb_stdout);
}
+#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)
/* Do nothing; the TCP serial operations will be initialized in
ser-mingw.c. */
#else
- struct serial_ops *ops;
-
- ops = XMALLOC (struct serial_ops);
- memset (ops, 0, sizeof (struct serial_ops));
- ops->name = "tcp";
- ops->next = 0;
- ops->open = net_open;
- ops->close = net_close;
- ops->readchar = ser_base_readchar;
- ops->write = ser_base_write;
- ops->flush_output = ser_base_flush_output;
- ops->flush_input = ser_base_flush_input;
- ops->send_break = ser_tcp_send_break;
- ops->go_raw = ser_base_raw;
- ops->get_tty_state = ser_base_get_tty_state;
- ops->copy_tty_state = ser_base_copy_tty_state;
- ops->set_tty_state = ser_base_set_tty_state;
- ops->print_tty_state = ser_base_print_tty_state;
- ops->noflush_set_tty_state = ser_base_noflush_set_tty_state;
- ops->setbaudrate = ser_base_setbaudrate;
- ops->setstopbits = ser_base_setstopbits;
- ops->drain_output = ser_base_drain_output;
- ops->async = ser_base_async;
- ops->read_prim = net_read_prim;
- ops->write_prim = net_write_prim;
- serial_add_interface (ops);
+ serial_add_interface (&tcp_ops);
#endif /* USE_WIN32API */
add_prefix_cmd ("tcp", class_maintenance, set_tcp_cmd, _("\
-TCP protocol specific variables\n\
-Configure variables specific to remote TCP connections"),
+TCP protocol specific variables.\n\
+Configure variables specific to remote TCP connections."),
&tcp_set_cmdlist, "set tcp ",
0 /* allow-unknown */, &setlist);
add_prefix_cmd ("tcp", class_maintenance, show_tcp_cmd, _("\
-TCP protocol specific variables\n\
-Configure variables specific to remote TCP connections"),
+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"),
+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"), _("\
+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."),