| 1 | /* Serial interface for a pipe to a separate program |
| 2 | Copyright (C) 1999, 2000, 2001, 2007, 2008, 2009, 2010, 2011 |
| 3 | Free Software Foundation, Inc. |
| 4 | |
| 5 | Contributed by Cygnus Solutions. |
| 6 | |
| 7 | This file is part of GDB. |
| 8 | |
| 9 | This program is free software; you can redistribute it and/or modify |
| 10 | it under the terms of the GNU General Public License as published by |
| 11 | the Free Software Foundation; either version 3 of the License, or |
| 12 | (at your option) any later version. |
| 13 | |
| 14 | This program is distributed in the hope that it will be useful, |
| 15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | GNU General Public License for more details. |
| 18 | |
| 19 | You should have received a copy of the GNU General Public License |
| 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 21 | |
| 22 | #include "defs.h" |
| 23 | #include "serial.h" |
| 24 | #include "ser-base.h" |
| 25 | #include "ser-unix.h" |
| 26 | |
| 27 | #include "gdb_vfork.h" |
| 28 | |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/socket.h> |
| 31 | #include <sys/time.h> |
| 32 | #include <fcntl.h> |
| 33 | #include "gdb_string.h" |
| 34 | #include "gdb_wait.h" |
| 35 | |
| 36 | #include <signal.h> |
| 37 | |
| 38 | static int pipe_open (struct serial *scb, const char *name); |
| 39 | static void pipe_close (struct serial *scb); |
| 40 | |
| 41 | extern void _initialize_ser_pipe (void); |
| 42 | |
| 43 | struct pipe_state |
| 44 | { |
| 45 | int pid; |
| 46 | }; |
| 47 | |
| 48 | /* Open up a raw pipe. */ |
| 49 | |
| 50 | static int |
| 51 | pipe_open (struct serial *scb, const char *name) |
| 52 | { |
| 53 | #if !HAVE_SOCKETPAIR |
| 54 | return -1; |
| 55 | #else |
| 56 | struct pipe_state *state; |
| 57 | /* This chunk: */ |
| 58 | /* Copyright (c) 1988, 1993 |
| 59 | * The Regents of the University of California. All rights reserved. |
| 60 | * |
| 61 | * This code is derived from software written by Ken Arnold and |
| 62 | * published in UNIX Review, Vol. 6, No. 8. |
| 63 | */ |
| 64 | int pdes[2]; |
| 65 | int err_pdes[2]; |
| 66 | int pid; |
| 67 | |
| 68 | if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0) |
| 69 | return -1; |
| 70 | if (socketpair (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0) |
| 71 | { |
| 72 | close (pdes[0]); |
| 73 | close (pdes[1]); |
| 74 | return -1; |
| 75 | } |
| 76 | |
| 77 | /* Create the child process to run the command in. Note that the |
| 78 | apparent call to vfork() below *might* actually be a call to |
| 79 | fork() due to the fact that autoconf will ``#define vfork fork'' |
| 80 | on certain platforms. */ |
| 81 | pid = vfork (); |
| 82 | |
| 83 | /* Error. */ |
| 84 | if (pid == -1) |
| 85 | { |
| 86 | close (pdes[0]); |
| 87 | close (pdes[1]); |
| 88 | close (err_pdes[0]); |
| 89 | close (err_pdes[1]); |
| 90 | return -1; |
| 91 | } |
| 92 | |
| 93 | if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1) |
| 94 | { |
| 95 | close (err_pdes[0]); |
| 96 | close (err_pdes[1]); |
| 97 | err_pdes[0] = err_pdes[1] = -1; |
| 98 | } |
| 99 | |
| 100 | /* Child. */ |
| 101 | if (pid == 0) |
| 102 | { |
| 103 | /* We don't want ^c to kill the connection. */ |
| 104 | #ifdef HAVE_SETSID |
| 105 | pid_t sid = setsid (); |
| 106 | if (sid == -1) |
| 107 | signal (SIGINT, SIG_IGN); |
| 108 | #else |
| 109 | signal (SIGINT, SIG_IGN); |
| 110 | #endif |
| 111 | |
| 112 | /* Re-wire pdes[1] to stdin/stdout. */ |
| 113 | close (pdes[0]); |
| 114 | if (pdes[1] != STDOUT_FILENO) |
| 115 | { |
| 116 | dup2 (pdes[1], STDOUT_FILENO); |
| 117 | close (pdes[1]); |
| 118 | } |
| 119 | dup2 (STDOUT_FILENO, STDIN_FILENO); |
| 120 | |
| 121 | if (err_pdes[0] != -1) |
| 122 | { |
| 123 | close (err_pdes[0]); |
| 124 | dup2 (err_pdes[1], STDERR_FILENO); |
| 125 | close (err_pdes[1]); |
| 126 | } |
| 127 | #if 0 |
| 128 | /* close any stray FD's - FIXME - how? */ |
| 129 | /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams |
| 130 | from previous popen() calls that remain open in the |
| 131 | parent process are closed in the new child process. */ |
| 132 | for (old = pidlist; old; old = old->next) |
| 133 | close (fileno (old->fp)); /* Don't allow a flush. */ |
| 134 | #endif |
| 135 | execl ("/bin/sh", "sh", "-c", name, (char *) 0); |
| 136 | _exit (127); |
| 137 | } |
| 138 | |
| 139 | /* Parent. */ |
| 140 | close (pdes[1]); |
| 141 | if (err_pdes[1] != -1) |
| 142 | close (err_pdes[1]); |
| 143 | /* :end chunk */ |
| 144 | state = XMALLOC (struct pipe_state); |
| 145 | state->pid = pid; |
| 146 | scb->fd = pdes[0]; |
| 147 | scb->error_fd = err_pdes[0]; |
| 148 | scb->state = state; |
| 149 | |
| 150 | /* If we don't do this, GDB simply exits when the remote side dies. */ |
| 151 | signal (SIGPIPE, SIG_IGN); |
| 152 | return 0; |
| 153 | #endif |
| 154 | } |
| 155 | |
| 156 | static void |
| 157 | pipe_close (struct serial *scb) |
| 158 | { |
| 159 | struct pipe_state *state = scb->state; |
| 160 | |
| 161 | close (scb->fd); |
| 162 | scb->fd = -1; |
| 163 | |
| 164 | if (state != NULL) |
| 165 | { |
| 166 | int status; |
| 167 | kill (state->pid, SIGTERM); |
| 168 | #ifdef HAVE_WAITPID |
| 169 | /* Assume the program will exit after SIGTERM. Might be |
| 170 | useful to print any remaining stderr output from |
| 171 | scb->error_fd while waiting. */ |
| 172 | waitpid (state->pid, &status, 0); |
| 173 | #endif |
| 174 | if (scb->error_fd != -1) |
| 175 | close (scb->error_fd); |
| 176 | scb->error_fd = -1; |
| 177 | xfree (state); |
| 178 | scb->state = NULL; |
| 179 | } |
| 180 | } |
| 181 | |
| 182 | int |
| 183 | gdb_pipe (int pdes[2]) |
| 184 | { |
| 185 | #if !HAVE_SOCKETPAIR |
| 186 | errno = ENOSYS; |
| 187 | return -1; |
| 188 | #else |
| 189 | |
| 190 | if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0) |
| 191 | return -1; |
| 192 | |
| 193 | /* If we don't do this, GDB simply exits when the remote side |
| 194 | dies. */ |
| 195 | signal (SIGPIPE, SIG_IGN); |
| 196 | return 0; |
| 197 | #endif |
| 198 | } |
| 199 | |
| 200 | void |
| 201 | _initialize_ser_pipe (void) |
| 202 | { |
| 203 | struct serial_ops *ops = XMALLOC (struct serial_ops); |
| 204 | |
| 205 | memset (ops, 0, sizeof (struct serial_ops)); |
| 206 | ops->name = "pipe"; |
| 207 | ops->next = 0; |
| 208 | ops->open = pipe_open; |
| 209 | ops->close = pipe_close; |
| 210 | ops->readchar = ser_base_readchar; |
| 211 | ops->write = ser_base_write; |
| 212 | ops->flush_output = ser_base_flush_output; |
| 213 | ops->flush_input = ser_base_flush_input; |
| 214 | ops->send_break = ser_base_send_break; |
| 215 | ops->go_raw = ser_base_raw; |
| 216 | ops->get_tty_state = ser_base_get_tty_state; |
| 217 | ops->copy_tty_state = ser_base_copy_tty_state; |
| 218 | ops->set_tty_state = ser_base_set_tty_state; |
| 219 | ops->print_tty_state = ser_base_print_tty_state; |
| 220 | ops->noflush_set_tty_state = ser_base_noflush_set_tty_state; |
| 221 | ops->setbaudrate = ser_base_setbaudrate; |
| 222 | ops->setstopbits = ser_base_setstopbits; |
| 223 | ops->drain_output = ser_base_drain_output; |
| 224 | ops->async = ser_base_async; |
| 225 | ops->read_prim = ser_unix_read_prim; |
| 226 | ops->write_prim = ser_unix_write_prim; |
| 227 | serial_add_interface (ops); |
| 228 | } |