173 lines
3.5 KiB
C
173 lines
3.5 KiB
C
/*
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* ngIRCd -- The Next Generation IRC Daemon
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* Copyright (c)2001-2011 Alexander Barton (alex@barton.de) and Contributors.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* Please read the file COPYING, README and AUTHORS for more information.
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*/
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#include "portab.h"
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/**
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* @file
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* Process management
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*/
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#include <assert.h>
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#include <errno.h>
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#include <signal.h>
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#include <string.h>
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#include <stdlib.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <time.h>
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#include "log.h"
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#include "io.h"
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#include "sighandlers.h"
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#include "proc.h"
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/**
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* Initialize process structure.
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*/
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GLOBAL void
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Proc_InitStruct (PROC_STAT *proc)
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{
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assert(proc != NULL);
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proc->pid = 0;
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proc->pipe_fd = -1;
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}
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/**
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* Fork a child process.
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*/
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GLOBAL pid_t
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Proc_Fork(PROC_STAT *proc, int *pipefds, void (*cbfunc)(int, short), int timeout)
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{
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pid_t pid;
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#ifndef HAVE_ARC4RANDOM
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unsigned int seed;
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#endif
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assert(proc != NULL);
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assert(pipefds != NULL);
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assert(cbfunc != NULL);
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if (pipe(pipefds) != 0) {
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Log(LOG_ALERT, "Can't create output pipe for child process: %s!",
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strerror(errno));
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return -1;
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}
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#ifndef HAVE_ARC4RANDOM
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seed = (unsigned int)rand();
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#endif
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pid = fork();
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switch (pid) {
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case -1:
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/* Error on fork: */
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Log(LOG_CRIT, "Can't fork child process: %s!", strerror(errno));
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close(pipefds[0]);
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close(pipefds[1]);
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return -1;
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case 0:
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/* New child process: */
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#ifdef HAVE_ARC4RANDOM_STIR
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arc4random_stir();
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#endif
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#ifndef HAVE_ARC4RANDOM
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srand(seed ^ (unsigned int)time(NULL) ^ getpid());
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#endif
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Signals_Exit();
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signal(SIGTERM, Proc_GenericSignalHandler);
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signal(SIGALRM, Proc_GenericSignalHandler);
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close(pipefds[0]);
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alarm(timeout);
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return 0;
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}
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/* Old parent process: */
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close(pipefds[1]);
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if (!io_setnonblock(pipefds[0])
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|| !io_event_create(pipefds[0], IO_WANTREAD, cbfunc)) {
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Log(LOG_CRIT, "Can't register callback for child process: %s!",
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strerror(errno));
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close(pipefds[0]);
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return -1;
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}
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proc->pid = pid;
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proc->pipe_fd = pipefds[0];
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return pid;
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}
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/**
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* Generic signal handler for forked child processes.
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*/
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GLOBAL void
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Proc_GenericSignalHandler(int Signal)
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{
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switch(Signal) {
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case SIGTERM:
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#ifdef DEBUG
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Log_Subprocess(LOG_DEBUG, "Child got TERM signal, exiting.");
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#endif
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exit(1);
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case SIGALRM:
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#ifdef DEBUG
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Log_Subprocess(LOG_DEBUG, "Child got ALARM signal, exiting.");
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#endif
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exit(1);
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}
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}
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/**
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* Read bytes from a pipe of a forked child process.
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* In addition, this function makes sure that the child process is ignored
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* after all data has been read or a fatal error occurred.
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*/
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GLOBAL size_t
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Proc_Read(PROC_STAT *proc, void *buffer, size_t buflen)
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{
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ssize_t bytes_read = 0;
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assert(buffer != NULL);
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assert(buflen > 0);
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bytes_read = read(proc->pipe_fd, buffer, buflen);
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if (bytes_read < 0) {
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if (errno == EAGAIN)
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return 0;
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Log(LOG_CRIT, "Can't read from child process %ld: %s",
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proc->pid, strerror(errno));
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Proc_Close(proc);
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bytes_read = 0;
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} else if (bytes_read == 0) {
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/* EOF: clean up */
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LogDebug("Child process %ld: EOF reached, closing pipe.",
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proc->pid);
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Proc_Close(proc);
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}
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return (size_t)bytes_read;
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}
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/**
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* Close pipe to a forked child process.
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*/
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GLOBAL void
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Proc_Close(PROC_STAT *proc)
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{
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/* Close socket, if it exists */
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if (proc->pipe_fd >= 0)
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io_close(proc->pipe_fd);
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Proc_InitStruct(proc);
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}
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/* -eof- */
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