169 lines
3.7 KiB
C
169 lines
3.7 KiB
C
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/*
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* This file is part of Jehanne.
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*
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* Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
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*
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* This is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as
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* published by the Free Software Foundation, version 3 of the License.
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*
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* Jehanne is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with Jehanne. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <u.h>
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#include <lib9.h>
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#include <posix.h>
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#include "internal.h"
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#define __POSIX_SIGNAL_PREFIX_LEN (sizeof(__POSIX_SIGNAL_PREFIX)-1)
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static PosixSignalTrampoline __libposix_signal_trampoline;
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static int
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note_all_writable_processes(int *errnop, char *note)
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{
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// TODO: loop over writable note files and post note.
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*errnop = __libposix_get_errno(PosixEPERM);
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return -1;
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}
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int
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POSIX_kill(int *errnop, int pid, int sig)
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{
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char msg[64], file[128];
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int mode;
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int ret;
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snprint(msg, sizeof(msg), __POSIX_SIGNAL_PREFIX "%d", sig);
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switch(pid){
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case 0:
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mode = PNGROUP;
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break;
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case -1:
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return note_all_writable_processes(errnop, msg);
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default:
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if(pid < 0){
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mode = PNGROUP;
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pid = -pid;
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} else {
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mode = PNPROC;
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}
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}
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snprint(file, sizeof(file), "/proc/%d/note", pid);
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if(access(file, AWRITE) != 0){
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if(access(file, AEXIST) == 0)
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*errnop = __libposix_get_errno(PosixEPERM);
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else
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*errnop = __libposix_get_errno(PosixESRCH);
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return -1;
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}
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ret = postnote(mode, pid, msg);
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if(ret != 0){
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*errnop = __libposix_translate_errstr((uintptr_t)POSIX_kill);
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return -1;
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}
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return 0;
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}
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static int
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translate_jehanne_note(char *note)
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{
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// TODO: implement
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return 0;
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}
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static void
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terminated_by_signal(int sig)
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{
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char buf[64];
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__libposix_free_wait_list();
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snprint(buf, sizeof(buf), __POSIX_EXIT_SIGNAL_PREFIX "%d", sig);
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exits(buf);
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}
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static int
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send_control_msg(int pid, char *msg)
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{
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int fd, n;
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char buf[256];
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n = snprint(buf, sizeof(buf), "/proc/%d/ctl", pid);
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if(n < 0)
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goto ErrorBeforeOpen;
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fd = open(buf, OWRITE);
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if(fd < 0)
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goto ErrorBeforeOpen;
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n = snprint(buf, sizeof(buf), "%s", msg);
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if(n < 0)
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goto ErrorAfterOpen;
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if(write(fd, buf, n) < n)
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goto ErrorAfterOpen;
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close(fd);
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return 1;
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ErrorAfterOpen:
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close(fd);
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ErrorBeforeOpen:
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return 0;
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}
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int
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POSIX_signal_execute(int sig, PosixSignalDisposition action, int pid)
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{
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switch(action){
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case SignalHandled:
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return 1;
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case TerminateTheProcess:
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case TerminateTheProcessAndCoreDump:
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terminated_by_signal(sig);
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break;
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case StopTheProcess:
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if(pid < 0)
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sysfatal("libposix: signal %d with stop disposition reached process %d", sig, pid);
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return send_control_msg(pid, "stop");
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case ResumeTheProcess:
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if(pid < 0)
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sysfatal("libposix: signal %d with continue disposition reached process %d", sig, pid);
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return send_control_msg(pid, "start");
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}
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return 0;
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}
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int
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__libposix_note_handler(void *ureg, char *note)
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{
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int sig;
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PosixSignalDisposition action;
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if(strncmp(note, __POSIX_SIGNAL_PREFIX, __POSIX_SIGNAL_PREFIX_LEN) != 0)
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return translate_jehanne_note(note); // TODO: should we translate common notes?
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sig = atoi(note+__POSIX_SIGNAL_PREFIX_LEN);
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action = __libposix_signal_trampoline(sig);
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return POSIX_signal_execute(sig, action, -1);
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}
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int
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libposix_set_signal_trampoline(PosixSignalTrampoline trampoline)
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{
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if(__libposix_initialized())
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return 0;
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if(trampoline == nil)
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return 0;
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__libposix_signal_trampoline = trampoline;
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return 1;
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}
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void
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__libposix_signal_check_conf(void)
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{
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if(__libposix_signal_trampoline == nil)
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sysfatal("libposix: no signal trampoline");
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}
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