1 /* Serial interface for a pipe to a separate program 2 Copyright (C) 1999-2013 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 <sys/time.h> 31 #include <fcntl.h> 32 #include "gdb_string.h" 33 34 #include <signal.h> 35 36 static int pipe_open (struct serial *scb, const char *name); 37 static void pipe_close (struct serial *scb); 38 39 extern void _initialize_ser_pipe (void); 40 41 struct pipe_state 42 { 43 int pid; 44 }; 45 46 /* Open up a raw pipe. */ 47 48 static int 49 pipe_open (struct serial *scb, const char *name) 50 { 51 #if !HAVE_SOCKETPAIR 52 return -1; 53 #else 54 struct pipe_state *state; 55 /* This chunk: */ 56 /* Copyright (c) 1988, 1993 57 * The Regents of the University of California. All rights reserved. 58 * 59 * This code is derived from software written by Ken Arnold and 60 * published in UNIX Review, Vol. 6, No. 8. 61 */ 62 int pdes[2]; 63 int err_pdes[2]; 64 int pid; 65 66 if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0) 67 return -1; 68 if (socketpair (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0) 69 { 70 close (pdes[0]); 71 close (pdes[1]); 72 return -1; 73 } 74 75 /* Create the child process to run the command in. Note that the 76 apparent call to vfork() below *might* actually be a call to 77 fork() due to the fact that autoconf will ``#define vfork fork'' 78 on certain platforms. */ 79 pid = vfork (); 80 81 /* Error. */ 82 if (pid == -1) 83 { 84 close (pdes[0]); 85 close (pdes[1]); 86 close (err_pdes[0]); 87 close (err_pdes[1]); 88 return -1; 89 } 90 91 if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1) 92 { 93 close (err_pdes[0]); 94 close (err_pdes[1]); 95 err_pdes[0] = err_pdes[1] = -1; 96 } 97 98 /* Child. */ 99 if (pid == 0) 100 { 101 /* We don't want ^c to kill the connection. */ 102 #ifdef HAVE_SETSID 103 pid_t sid = setsid (); 104 if (sid == -1) 105 signal (SIGINT, SIG_IGN); 106 #else 107 signal (SIGINT, SIG_IGN); 108 #endif 109 110 /* Re-wire pdes[1] to stdin/stdout. */ 111 close (pdes[0]); 112 if (pdes[1] != STDOUT_FILENO) 113 { 114 dup2 (pdes[1], STDOUT_FILENO); 115 close (pdes[1]); 116 } 117 dup2 (STDOUT_FILENO, STDIN_FILENO); 118 119 if (err_pdes[0] != -1) 120 { 121 close (err_pdes[0]); 122 dup2 (err_pdes[1], STDERR_FILENO); 123 close (err_pdes[1]); 124 } 125 #if 0 126 /* close any stray FD's - FIXME - how? */ 127 /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams 128 from previous popen() calls that remain open in the 129 parent process are closed in the new child process. */ 130 for (old = pidlist; old; old = old->next) 131 close (fileno (old->fp)); /* Don't allow a flush. */ 132 #endif 133 execl ("/bin/sh", "sh", "-c", name, (char *) 0); 134 _exit (127); 135 } 136 137 /* Parent. */ 138 close (pdes[1]); 139 if (err_pdes[1] != -1) 140 close (err_pdes[1]); 141 /* :end chunk */ 142 state = XMALLOC (struct pipe_state); 143 state->pid = pid; 144 scb->fd = pdes[0]; 145 scb->error_fd = err_pdes[0]; 146 scb->state = state; 147 148 /* If we don't do this, GDB simply exits when the remote side dies. */ 149 signal (SIGPIPE, SIG_IGN); 150 return 0; 151 #endif 152 } 153 154 static void 155 pipe_close (struct serial *scb) 156 { 157 struct pipe_state *state = scb->state; 158 159 close (scb->fd); 160 scb->fd = -1; 161 162 if (state != NULL) 163 { 164 int wait_result, status; 165 166 /* Don't kill the task right away, give it a chance to shut down cleanly. 167 But don't wait forever though. */ 168 #define PIPE_CLOSE_TIMEOUT 5 169 170 /* Assume the program will exit after SIGTERM. Might be 171 useful to print any remaining stderr output from 172 scb->error_fd while waiting. */ 173 #define SIGTERM_TIMEOUT INT_MAX 174 175 wait_result = -1; 176 #ifdef HAVE_WAITPID 177 wait_result = wait_to_die_with_timeout (state->pid, &status, 178 PIPE_CLOSE_TIMEOUT); 179 #endif 180 if (wait_result == -1) 181 { 182 kill (state->pid, SIGTERM); 183 #ifdef HAVE_WAITPID 184 wait_to_die_with_timeout (state->pid, &status, SIGTERM_TIMEOUT); 185 #endif 186 } 187 188 if (scb->error_fd != -1) 189 close (scb->error_fd); 190 scb->error_fd = -1; 191 xfree (state); 192 scb->state = NULL; 193 } 194 } 195 196 int 197 gdb_pipe (int pdes[2]) 198 { 199 #if !HAVE_SOCKETPAIR 200 errno = ENOSYS; 201 return -1; 202 #else 203 204 if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0) 205 return -1; 206 207 /* If we don't do this, GDB simply exits when the remote side 208 dies. */ 209 signal (SIGPIPE, SIG_IGN); 210 return 0; 211 #endif 212 } 213 214 void 215 _initialize_ser_pipe (void) 216 { 217 struct serial_ops *ops = XMALLOC (struct serial_ops); 218 219 memset (ops, 0, sizeof (struct serial_ops)); 220 ops->name = "pipe"; 221 ops->next = 0; 222 ops->open = pipe_open; 223 ops->close = pipe_close; 224 ops->readchar = ser_base_readchar; 225 ops->write = ser_base_write; 226 ops->flush_output = ser_base_flush_output; 227 ops->flush_input = ser_base_flush_input; 228 ops->send_break = ser_base_send_break; 229 ops->go_raw = ser_base_raw; 230 ops->get_tty_state = ser_base_get_tty_state; 231 ops->copy_tty_state = ser_base_copy_tty_state; 232 ops->set_tty_state = ser_base_set_tty_state; 233 ops->print_tty_state = ser_base_print_tty_state; 234 ops->noflush_set_tty_state = ser_base_noflush_set_tty_state; 235 ops->setbaudrate = ser_base_setbaudrate; 236 ops->setstopbits = ser_base_setstopbits; 237 ops->drain_output = ser_base_drain_output; 238 ops->async = ser_base_async; 239 ops->read_prim = ser_unix_read_prim; 240 ops->write_prim = ser_unix_write_prim; 241 serial_add_interface (ops); 242 } 243