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95063bde15
NuttX has no real session/process-group abstraction, so the TTY layer collapses the foreground process group onto the single dev->pid field (pgrp == pid, one member per group). Extend the controlling-terminal support so portable software (e.g. dropbear, socat) that relies on job-control primitives works without losing the existing NuttX-specific behaviour. Driver (serial.c, pty.c): - TIOCSCTTY now accepts a flag: arg > 0 keeps the historical "target PID in arg" semantics (NSH registers the foreground command it just spawned), while arg == 0 selects the calling task via nxsched_getpid(), matching the POSIX flag convention used by dropbear/socat/apue. This preserves all existing callers and makes the previously-dead arg==0 path deliver SIGINT correctly. - Add TIOCGPGRP/TIOCGSID (return dev->pid) and TIOCSPGRP (set it). - pty.c gains the same handlers against pd_pid and includes nuttx/sched.h for nxsched_getpid(). ioctl numbers (tioctl.h): TIOCGPGRP/TIOCSPGRP/TIOCGSID at 0x37-0x39. libc wrappers: - termios: tcgetpgrp(), tcsetpgrp(), tcgetsid() over the new ioctls. - unistd: setsid()/getsid()/setpgid() stubs consistent with the existing getpgrp()/getpgid() single-session model (sid == pgid == pid; setpgid only succeeds for pgid == pid). Declare the new prototypes in unistd.h (tcgetsid was already in termios.h) and register all sources in the Make.defs/CMakeLists. Group-broadcast signalling (kill(-pgrp)) remains unsupported, so tty signals still target the single dev->pid; a real session/process group model is left as a follow-up. Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
87 lines
2.9 KiB
C
87 lines
2.9 KiB
C
/****************************************************************************
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* libs/libc/unistd/lib_setpgid.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <unistd.h>
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#include <errno.h>
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#include <nuttx/sched.h>
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#include <nuttx/signal.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: setpgid
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*
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* Description:
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* Set the process group ID of the process whose process ID is pid to
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* pgid. NuttX does not implement process groups, so a process group
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* always contains a single member and its ID equals the process ID.
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* Consequently this stub only succeeds when the requested pgid matches
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* the target pid (or is zero, which selects the target pid itself).
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*
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* Input Parameters:
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* pid - The process whose process group ID is to be changed. A value of
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* zero refers to the calling process.
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* pgid - The new process group ID. A value of zero uses the target pid.
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*
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* Returned Value:
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* Zero is returned on success. Otherwise, -1 is returned and errno is
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* set: EINVAL if pgid is negative, ESRCH if pid does not exist, EPERM if
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* the requested pgid cannot be honored by this single-member-group model.
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*
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****************************************************************************/
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int setpgid(pid_t pid, pid_t pgid)
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{
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if (pgid < 0)
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{
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set_errno(EINVAL);
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return -1;
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}
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if (pid == 0)
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{
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pid = _SCHED_GETPID();
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}
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else if (_SIG_KILL(pid, 0) < 0)
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{
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return -1;
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}
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/* A process group can only contain the single member 'pid', so the only
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* legal group ID is 'pid' itself (a zero pgid selects it implicitly).
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*/
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if (pgid != 0 && pgid != pid)
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{
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set_errno(EPERM);
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return -1;
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}
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return 0;
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}
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