1 /* Serial interface for a pipe to a separate program 2 Copyright (C) 1999, 2000, 2001, 2007, 2008, 2009, 2010 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 35 #include <signal.h> 36 37 static int pipe_open (struct serial *scb, const char *name); 38 static void pipe_close (struct serial *scb); 39 40 extern void _initialize_ser_pipe (void); 41 42 struct pipe_state 43 { 44 int pid; 45 }; 46 47 /* Open up a raw pipe */ 48 49 static int 50 pipe_open (struct serial *scb, const char *name) 51 { 52 #if !HAVE_SOCKETPAIR 53 return -1; 54 #else 55 struct pipe_state *state; 56 /* This chunk: */ 57 /* Copyright (c) 1988, 1993 58 * The Regents of the University of California. All rights reserved. 59 * 60 * This code is derived from software written by Ken Arnold and 61 * published in UNIX Review, Vol. 6, No. 8. 62 */ 63 int pdes[2]; 64 int err_pdes[2]; 65 int pid; 66 67 if (socketpair (AF_UNIX, SOCK_STREAM, 0, pdes) < 0) 68 return -1; 69 if (socketpair (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0) 70 { 71 close (pdes[0]); 72 close (pdes[1]); 73 return -1; 74 } 75 76 /* Create the child process to run the command in. Note that the 77 apparent call to vfork() below *might* actually be a call to 78 fork() due to the fact that autoconf will ``#define vfork fork'' 79 on certain platforms. */ 80 pid = vfork (); 81 82 /* Error. */ 83 if (pid == -1) 84 { 85 close (pdes[0]); 86 close (pdes[1]); 87 close (err_pdes[0]); 88 close (err_pdes[1]); 89 return -1; 90 } 91 92 if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1) 93 { 94 close (err_pdes[0]); 95 close (err_pdes[1]); 96 err_pdes[0] = err_pdes[1] = -1; 97 } 98 99 /* Child. */ 100 if (pid == 0) 101 { 102 /* We don't want ^c to kill the connection. */ 103 #ifdef HAVE_SETSID 104 pid_t sid = setsid (); 105 if (sid == -1) 106 signal (SIGINT, SIG_IGN); 107 #else 108 signal (SIGINT, SIG_IGN); 109 #endif 110 111 /* re-wire pdes[1] to stdin/stdout */ 112 close (pdes[0]); 113 if (pdes[1] != STDOUT_FILENO) 114 { 115 dup2 (pdes[1], STDOUT_FILENO); 116 close (pdes[1]); 117 } 118 dup2 (STDOUT_FILENO, STDIN_FILENO); 119 120 if (err_pdes[0] != -1) 121 { 122 close (err_pdes[0]); 123 dup2 (err_pdes[1], STDERR_FILENO); 124 close (err_pdes[1]); 125 } 126 #if 0 127 /* close any stray FD's - FIXME - how? */ 128 /* POSIX.2 B.3.2.2 "popen() shall ensure that any streams 129 from previous popen() calls that remain open in the 130 parent process are closed in the new child process. */ 131 for (old = pidlist; old; old = old->next) 132 close (fileno (old->fp)); /* don't allow a flush */ 133 #endif 134 execl ("/bin/sh", "sh", "-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 = XMALLOC (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 } 154 155 static void 156 pipe_close (struct serial *scb) 157 { 158 struct pipe_state *state = scb->state; 159 160 if (state != NULL) 161 { 162 int pid = state->pid; 163 close (scb->fd); 164 scb->fd = -1; 165 if (scb->error_fd != -1) 166 close (scb->error_fd); 167 scb->error_fd = -1; 168 xfree (state); 169 scb->state = NULL; 170 kill (pid, SIGTERM); 171 /* Might be useful to check that the child does die, 172 and while we're waiting for it to die print any remaining 173 stderr output. */ 174 } 175 } 176 177 void 178 _initialize_ser_pipe (void) 179 { 180 struct serial_ops *ops = XMALLOC (struct serial_ops); 181 182 memset (ops, 0, sizeof (struct serial_ops)); 183 ops->name = "pipe"; 184 ops->next = 0; 185 ops->open = pipe_open; 186 ops->close = pipe_close; 187 ops->readchar = ser_base_readchar; 188 ops->write = ser_base_write; 189 ops->flush_output = ser_base_flush_output; 190 ops->flush_input = ser_base_flush_input; 191 ops->send_break = ser_base_send_break; 192 ops->go_raw = ser_base_raw; 193 ops->get_tty_state = ser_base_get_tty_state; 194 ops->set_tty_state = ser_base_set_tty_state; 195 ops->print_tty_state = ser_base_print_tty_state; 196 ops->noflush_set_tty_state = ser_base_noflush_set_tty_state; 197 ops->setbaudrate = ser_base_setbaudrate; 198 ops->setstopbits = ser_base_setstopbits; 199 ops->drain_output = ser_base_drain_output; 200 ops->async = ser_base_async; 201 ops->read_prim = ser_unix_read_prim; 202 ops->write_prim = ser_unix_write_prim; 203 serial_add_interface (ops); 204 } 205