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[PATCH] Allow remote debugging over a Unix local domain socket.
- From: John Darrington <john at darrington dot wattle dot id dot au>
- To: gdb-patches at sourceware dot org
- Cc: John Darrington <john at darrington dot wattle dot id dot au>
- Date: Mon, 3 Sep 2018 14:17:36 +0200
- Subject: [PATCH] Allow remote debugging over a Unix local domain socket.
- References: <20180903121736.5246-1-john@darrington.wattle.id.au>
Extend the "target remote" and "target extended-remote" commands
such that if the filename provided is a Unix local domain (AF_UNIX)
socket, then it'll be treated as such, instead of trying to open
it as if it were a character device.
gdb/ChangeLog:
* NEWS: Mention changed commands.
* configure.ac (SER_HARDWIRE): Add ser-socket.o.
* ser-socket.c: New file.
* Makefile.in: Add new file.
* serial.c (serial_open): Check if filename is a socket
and lookup the appropriate interface accordingly.
gdb/doc/ChangeLog:
* gdb.texinfo (Remote Connection Commands): Describe
the changes to target remote and target extended-remote
relating to Unix domain sockets.
---
gdb/Makefile.in | 1 +
gdb/NEWS | 5 +++
gdb/configure | 1 +
gdb/configure.ac | 1 +
gdb/doc/gdb.texinfo | 22 +++++++++-
gdb/ser-socket.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/serial.c | 12 +++++-
7 files changed, 155 insertions(+), 2 deletions(-)
create mode 100644 gdb/ser-socket.c
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 118c3c8062..4646ade6c1 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -2323,6 +2323,7 @@ ALLDEPFILES = \
ser-go32.c \
ser-mingw.c \
ser-pipe.c \
+ ser-socket.c \
ser-tcp.c \
sh-nbsd-nat.c \
sh-nbsd-tdep.c \
diff --git a/gdb/NEWS b/gdb/NEWS
index a7a3674375..e5926897a0 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -36,6 +36,11 @@ maint show dwarf unwinders
* Changed commands
+target remote FILENAME
+target extended-remote FILENAME
+ If FILENAME is a Unix domain socket, GDB will attempt to connect
+ to this socket instead of opening FILENAME as a character device.
+
thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
The 'thread apply' command accepts new FLAG arguments.
FLAG arguments allow to control what output to produce and how to handle
diff --git a/gdb/configure b/gdb/configure
index 9cd0036848..21c4f8b6af 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -15586,6 +15586,7 @@ case ${host} in
*go32* ) SER_HARDWIRE=ser-go32.o ;;
*djgpp* ) SER_HARDWIRE=ser-go32.o ;;
*mingw32*) SER_HARDWIRE="ser-base.o ser-tcp.o ser-mingw.o" ;;
+ *) SER_HARDWIRE="$SER_HARDWIRE ser-socket.o" ;;
esac
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 13bc5f9a8f..07c874df96 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1875,6 +1875,7 @@ case ${host} in
*go32* ) SER_HARDWIRE=ser-go32.o ;;
*djgpp* ) SER_HARDWIRE=ser-go32.o ;;
*mingw32*) SER_HARDWIRE="ser-base.o ser-tcp.o ser-mingw.o" ;;
+ *) SER_HARDWIRE="$SER_HARDWIRE ser-socket.o" ;;
esac
AC_SUBST(SER_HARDWIRE)
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 5068c0ac81..dae62c1787 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -20703,7 +20703,8 @@ programs.
@subsection Remote Connection Commands
@cindex remote connection commands
-@value{GDBN} can communicate with the target over a serial line, or
+@value{GDBN} can communicate with the target over a serial line, a
+local Unix domain socket, or
over an @acronym{IP} network using @acronym{TCP} or @acronym{UDP}. In
each case, @value{GDBN} uses the same protocol for debugging your
program; only the medium carrying the debugging packets varies. The
@@ -20728,6 +20729,25 @@ If you're using a serial line, you may want to give @value{GDBN} the
(@pxref{Remote Configuration, set serial baud}) before the
@code{target} command.
+
+@item target remote @var{local-socket}
+@itemx target extended-remote @var{local-socket}
+@cindex local socket, @code{target remote}
+@cindex Unix domain socket
+Use @var{local-socket} to communicate with the target. For example,
+to use a local Unix domain socket bound to the file system entry @file{/tmp/gdb-socket0}:
+
+@smallexample
+target remote /tmp/gdb-socket0
+@end smallexample
+
+Note that this command has the same form as the command to connect
+to a serial line. @value{GDBN} will automatically determine which
+kind of file you have specified and will make the appropriate kind
+of connection.
+This feature is not available if the host system does not support
+Unix domain sockets.
+
@item target remote @code{@var{host}:@var{port}}
@itemx target remote @code{@var{[host]}:@var{port}}
@itemx target remote @code{tcp:@var{host}:@var{port}}
diff --git a/gdb/ser-socket.c b/gdb/ser-socket.c
new file mode 100644
index 0000000000..6275447e2b
--- /dev/null
+++ b/gdb/ser-socket.c
@@ -0,0 +1,115 @@
+/* Serial interface for local domain connections on Un*x like systems.
+
+ Copyright (C) 1992-2018 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 3 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, see <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include "serial.h"
+#include "ser-base.h"
+
+#include <sys/socket.h>
+#include <sys/un.h>
+
+/* Open a AF_UNIX socket. */
+int
+socket_open (struct serial *scb, const char *name)
+{
+ struct sockaddr_un addr;
+
+ memset (&addr, 0, sizeof addr);
+ addr.sun_family = AF_UNIX;
+#ifndef UNIX_MAX_PATH
+# define UNIX_MAX_PATH 108
+#endif
+ strncpy (addr.sun_path, name, UNIX_MAX_PATH - 1);
+
+ int sock = socket (AF_UNIX, SOCK_STREAM, 0);
+
+ if (connect (sock, (struct sockaddr *) &addr,
+ sizeof (struct sockaddr_un)) < 0)
+ {
+ close (sock);
+ scb->fd = -1;
+ return -1;
+ }
+
+ scb->fd = sock;
+
+ return 0;
+}
+
+void
+socket_close (struct serial *scb)
+{
+ if (scb->fd == -1)
+ return;
+
+ close (scb->fd);
+ scb->fd = -1;
+}
+
+static int
+socket_read_prim (struct serial *scb, size_t count)
+{
+ return recv (scb->fd, scb->buf, count, 0);
+}
+
+static int
+socket_write_prim (struct serial *scb, const void *buf, size_t count)
+{
+ return send (scb->fd, buf, count, 0);
+}
+
+static int
+ser_socket_send_break (struct serial *scb)
+{
+ /* Send telnet IAC and BREAK characters. */
+ return (serial_write (scb, "\377\363", 2));
+}
+
+/* The SOCKET ops. */
+
+static const struct serial_ops socket_ops =
+{
+ "socket",
+ socket_open,
+ socket_close,
+ NULL,
+ ser_base_readchar,
+ ser_base_write,
+ ser_base_flush_output,
+ ser_base_flush_input,
+ ser_socket_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,
+ socket_read_prim,
+ socket_write_prim
+};
+
+void
+_initialize_ser_socket (void)
+{
+ serial_add_interface (&socket_ops);
+}
diff --git a/gdb/serial.c b/gdb/serial.c
index fb2b212918..f1fcd95e3c 100644
--- a/gdb/serial.c
+++ b/gdb/serial.c
@@ -213,7 +213,17 @@ serial_open (const char *name)
else if (strchr (name, ':'))
ops = serial_interface_lookup ("tcp");
else
- ops = serial_interface_lookup ("hardwire");
+ {
+#ifndef USE_WIN32API
+ /* Check to see if name is a socket. If it is, then treat it
+ as such. Otherwise assume that it's a character device. */
+ struct stat sb;
+ if (0 == stat (name, &sb) && ((sb.st_mode & S_IFMT) == S_IFSOCK))
+ ops = serial_interface_lookup ("socket");
+ else
+#endif
+ ops = serial_interface_lookup ("hardwire");
+ }
if (!ops)
return NULL;
--
2.11.0