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ser-pipe.c
Go to the documentation of this file.
1/* Serial interface for a pipe to a separate program
2 Copyright (C) 1999-2023 Free Software Foundation, Inc.
3
4 Contributed by Cygnus Solutions.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20
21#include "defs.h"
22#include "serial.h"
23#include "ser-base.h"
24#include "ser-unix.h"
25
26#include "gdb_vfork.h"
27
28#include <sys/types.h>
29#include <sys/socket.h>
30#include "gdbsupport/gdb_sys_time.h"
31#include <fcntl.h>
32#include "gdbsupport/filestuff.h"
33#include "gdbsupport/pathstuff.h"
34
35#include <signal.h>
36
37static int pipe_open (struct serial *scb, const char *name);
38static void pipe_close (struct serial *scb);
39
40struct pipe_state
41 {
42 int pid;
43 };
44
45/* Open up a raw pipe. */
46
47static int
48pipe_open (struct serial *scb, const char *name)
49{
50#if !HAVE_SOCKETPAIR
51 return -1;
52#else
53 struct pipe_state *state;
54 /* This chunk: */
55 /* Copyright (c) 1988, 1993
56 * The Regents of the University of California. All rights reserved.
57 *
58 * This code is derived from software written by Ken Arnold and
59 * published in UNIX Review, Vol. 6, No. 8.
60 */
61 int pdes[2];
62 int err_pdes[2];
63 int pid;
64
65 if (*name == '|')
66 {
67 name++;
68 name = skip_spaces (name);
69 }
70
71 if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
72 return -1;
73 if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0)
74 {
75 close (pdes[0]);
76 close (pdes[1]);
77 return -1;
78 }
79
80 /* Create the child process to run the command in. Note that the
81 apparent call to vfork() below *might* actually be a call to
82 fork() due to the fact that autoconf will ``#define vfork fork''
83 on certain platforms. */
84 pid = vfork ();
85
86 /* Error. */
87 if (pid == -1)
88 {
89 close (pdes[0]);
90 close (pdes[1]);
91 close (err_pdes[0]);
92 close (err_pdes[1]);
93 return -1;
94 }
95
96 if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1)
97 {
98 close (err_pdes[0]);
99 close (err_pdes[1]);
100 err_pdes[0] = err_pdes[1] = -1;
101 }
102
103 /* Child. */
104 if (pid == 0)
105 {
106 /* We don't want ^c to kill the connection. */
107#ifdef HAVE_SETSID
108 pid_t sid = setsid ();
109 if (sid == -1)
110 signal (SIGINT, SIG_IGN);
111#else
112 signal (SIGINT, SIG_IGN);
113#endif
114
115 /* Re-wire pdes[1] to stdin/stdout. */
116 close (pdes[0]);
117 if (pdes[1] != STDOUT_FILENO)
118 {
119 dup2 (pdes[1], STDOUT_FILENO);
120 close (pdes[1]);
121 }
122 dup2 (STDOUT_FILENO, STDIN_FILENO);
123
124 if (err_pdes[0] != -1)
125 {
126 close (err_pdes[0]);
127 dup2 (err_pdes[1], STDERR_FILENO);
128 close (err_pdes[1]);
129 }
130
131 close_most_fds ();
132
133 const char *shellfile = get_shell ();
134 execl (shellfile, shellfile, "-c", name, (char *) 0);
135 _exit (127);
136 }
137
138 /* Parent. */
139 close (pdes[1]);
140 if (err_pdes[1] != -1)
141 close (err_pdes[1]);
142 /* :end chunk */
143 state = XNEW (struct pipe_state);
144 state->pid = pid;
145 scb->fd = pdes[0];
146 scb->error_fd = err_pdes[0];
147 scb->state = state;
148
149 /* If we don't do this, GDB simply exits when the remote side dies. */
150 signal (SIGPIPE, SIG_IGN);
151 return 0;
152#endif
153}
154
155static void
156pipe_close (struct serial *scb)
157{
158 struct pipe_state *state = (struct pipe_state *) scb->state;
159
160 close (scb->fd);
161 scb->fd = -1;
162
163 if (state != NULL)
164 {
165 int wait_result, status;
166
167 /* Don't kill the task right away, give it a chance to shut down cleanly.
168 But don't wait forever though. */
169#define PIPE_CLOSE_TIMEOUT 5
170
171 /* Assume the program will exit after SIGTERM. Might be
172 useful to print any remaining stderr output from
173 scb->error_fd while waiting. */
174#define SIGTERM_TIMEOUT INT_MAX
175
176 wait_result = -1;
177#ifdef HAVE_WAITPID
178 wait_result = wait_to_die_with_timeout (state->pid, &status,
180#endif
181 if (wait_result == -1)
182 {
183 kill (state->pid, SIGTERM);
184#ifdef HAVE_WAITPID
185 wait_to_die_with_timeout (state->pid, &status, SIGTERM_TIMEOUT);
186#endif
187 }
188
189 if (scb->error_fd != -1)
190 close (scb->error_fd);
191 scb->error_fd = -1;
192 xfree (state);
193 scb->state = NULL;
194 }
195}
196
197int
198gdb_pipe (int pdes[2])
199{
200#if !HAVE_SOCKETPAIR
201 errno = ENOSYS;
202 return -1;
203#else
204
205 if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
206 return -1;
207
208 /* If we don't do this, GDB simply exits when the remote side
209 dies. */
210 signal (SIGPIPE, SIG_IGN);
211 return 0;
212#endif
213}
214
239
241void
const char *const name
void xfree(void *)
mach_port_t mach_port_t name mach_port_t mach_port_t name kern_return_t int int rusage_t pid_t pid
Definition gnu-nat.c:1791
mach_port_t mach_port_t name mach_port_t mach_port_t name kern_return_t int status
Definition gnu-nat.c:1790
void ser_base_async(struct serial *scb, int async_p)
Definition ser-base.c:587
void ser_base_print_tty_state(struct serial *scb, serial_ttystate ttystate, struct ui_file *stream)
Definition ser-base.c:556
void ser_base_raw(struct serial *scb)
Definition ser-base.c:530
int ser_base_set_tty_state(struct serial *scb, serial_ttystate ttystate)
Definition ser-base.c:550
serial_ttystate ser_base_get_tty_state(struct serial *scb)
Definition ser-base.c:536
int ser_base_drain_output(struct serial *scb)
Definition ser-base.c:524
int ser_base_send_break(struct serial *scb)
Definition ser-base.c:518
int ser_base_setbaudrate(struct serial *scb, int rate)
Definition ser-base.c:565
serial_ttystate ser_base_copy_tty_state(struct serial *scb, serial_ttystate ttystate)
Definition ser-base.c:543
int ser_base_write(struct serial *scb, const void *buf, size_t count)
Definition ser-base.c:475
int ser_base_setstopbits(struct serial *scb, int num)
Definition ser-base.c:571
int ser_base_flush_output(struct serial *scb)
Definition ser-base.c:499
int ser_base_flush_input(struct serial *scb)
Definition ser-base.c:505
int ser_base_readchar(struct serial *scb, int timeout)
Definition ser-base.c:469
int ser_base_setparity(struct serial *scb, int parity)
Definition ser-base.c:579
void _initialize_ser_pipe()
Definition ser-pipe.c:242
int gdb_pipe(int pdes[2])
Definition ser-pipe.c:198
#define SIGTERM_TIMEOUT
#define PIPE_CLOSE_TIMEOUT
static void pipe_close(struct serial *scb)
Definition ser-pipe.c:156
static const struct serial_ops pipe_ops
Definition ser-pipe.c:215
static int pipe_open(struct serial *scb, const char *name)
Definition ser-pipe.c:48
int ser_unix_write_prim(struct serial *scb, const void *buf, size_t len)
Definition ser-unix.c:592
int ser_unix_read_prim(struct serial *scb, size_t count)
Definition ser-unix.c:586
void serial_add_interface(const struct serial_ops *optable)
Definition serial.c:154
int fd
Definition serial.h:238
void * state
Definition serial.h:245
int error_fd
Definition serial.h:243