X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=daemon.c;h=331ca767049cc7347425d0dad96140ff629da659;hb=589c6288c6e7ece516991d4e9b9be5eb78148416;hp=cfb6e53e4b756ff57049992e2997fe240c9f3716;hpb=db5358a3bc37a9bffb5a4b4b679d206081450754;p=~andy%2Ffetchmail diff --git a/daemon.c b/daemon.c index cfb6e53e..331ca767 100644 --- a/daemon.c +++ b/daemon.c @@ -1,120 +1,164 @@ -/* Copyright 1993-95 by Carl Harris, Jr. Copyright 1996 by Eric S. Raymond - * All rights reserved. +/* + * daemon.c -- turn a process into a daemon under POSIX, SYSV, BSD. + * * For license terms, see the file COPYING in this directory. */ - -/*********************************************************************** - module: daemon - project: popclient - programmer: Carl Harris, ceharris@mal.com - description: This module contains all of the code needed to - turn a process into a daemon for POSIX, SysV, and - BSD systems. - - ***********************************************************************/ - - -#include +#include "config.h" #include -#include -#include +#include #include +#include +#include +#ifdef HAVE_SYS_WAIT_H +#include +#endif +#ifdef HAVE_FCNTL_H #include +#else /* !HAVE_FCNTL_H */ +#ifdef HAVE_SYS_FCNTL_H +#include +#endif /* HAVE_SYS_FCNTL_H */ +#endif /* !HAVE_FCNTL_H */ +#include /* get umask(2) prototyped */ -#if defined(HAVE_SYS_WAIT_H) -# include +#if defined(HAVE_UNISTD_H) +#include #endif -#if defined(HAVE_UNISTD_H) -# include +#if defined(STDC_HEADERS) +#include #endif +#if defined(QNX) +#include +#endif -#include "popclient.h" +#if !defined(HAVE_SETSID) && defined(SIGTSTP) +#if defined(HAVE_TERMIOS_H) +# include /* for TIOCNOTTY under Linux */ +#endif -static void (*my_termhook)(void); +#if !defined(TIOCNOTTY) && defined(HAVE_SGTTY_H) +# include /* for TIOCNOTTY under NEXTSTEP */ +#endif +#endif /* !defined(HAVE_SETSID) && defined(SIGTSTP) */ + +/* BSD portability hack */ +#if !defined(SIGCHLD) && defined(SIGCLD) +#define SIGCHLD SIGCLD +#endif -/****************************************************************** - function: sigchld_handler - description: Process the SIGCHLD (a.k.a SIGCLD) signal by calling - a wait() variant to obtain the exit code of the - terminating process. - arguments: none. - ret. value: none (or undefined if REGSIGTYPE is int). - globals: none. - calls: none. - *****************************************************************/ +#include "fetchmail.h" +#include "tunable.h" RETSIGTYPE -sigchld_handler () +sigchld_handler (int sig) +/* process SIGCHLD to obtain the exit code of the terminating process */ { - pid_t pid; + extern volatile int lastsig; /* last signal received */ + pid_t pid; -#if defined(HAVE_UNION_WAIT) - union wait status; +#if defined(HAVE_WAITPID) /* the POSIX way */ + int status; + + while ((pid = waitpid(-1, &status, WNOHANG)) > 0) + continue; /* swallow 'em up. */ +#elif defined(HAVE_WAIT3) /* the BSD way */ +#if defined(HAVE_UNION_WAIT) && !defined(__FreeBSD__) + union wait status; #else - int status; + int status; #endif - if (my_termhook) - (*my_termhook)(); - -#if defined(HAVE_WAIT3) - while ((pid = wait3(&status, WNOHANG, (struct rusage *) 0)) > 0) - ; /* swallow 'em up. */ -#elif defined(HAVE_WAITPID) - while ((pid = waitpid(-1, &status, WNOHANG)) > 0) - ; /* swallow 'em up. */ + while ((pid = wait3(&status, WNOHANG, 0)) > 0) + continue; /* swallow 'em up. */ #else /* Zooks! Nothing to do but wait(), and hope we don't block... */ - wait(&status); -#endif + int status; + wait(&status); +#endif + lastsig = SIGCHLD; } +/* + * This function is called by other parts of the program to + * setup the sigchld handler after a change to the signal context. + * This is done to improve robustness of the signal handling code. + */ +void deal_with_sigchld(void) +{ + RETSIGTYPE sigchld_handler(int); +#ifdef HAVE_SIGACTION + struct sigaction sa_new; + memset (&sa_new, 0, sizeof sa_new); + sigemptyset (&sa_new.sa_mask); + /* sa_new.sa_handler = SIG_IGN; pointless */ -/****************************************************************** - function: daemonize - description: become a daemon process; i.e. detach from the - control terminal, don't reacquire a control terminal, - become process group leader of our own process group, - and set up to catch child process termination signals. - arguments: - logfile file to direct stdout and stderr to, if non-NULL. - - ret. value: none. - globals: refers to the address of sigchld_handler(). - calls: none. - *****************************************************************/ + /* set up to catch child process termination signals */ + sa_new.sa_handler = sigchld_handler; +#ifdef SA_RESTART /* SunOS 4.1 portability hack */ + sa_new.sa_flags = SA_RESTART | SA_NOCLDSTOP; +#endif + sigaction (SIGCHLD, &sa_new, NULL); +#if defined(SIGPWR) + sigaction (SIGPWR, &sa_new, NULL); +#endif +#else /* HAVE_SIGACTION */ + signal(SIGCHLD, sigchld_handler); +#if defined(SIGPWR) + signal(SIGPWR, sigchld_handler); +#endif +#endif /* HAVE_SIGACTION */ +} int -daemonize (logfile, termhook) -const char *logfile; -void (*termhook)(void); +daemonize (const char *logfile, void (*termhook)(int)) +/* detach from control TTY, become process group leader, catch SIGCHLD */ { int fd; pid_t childpid; - RETSIGTYPE sigchld_handler(); +#ifdef HAVE_SIGACTION + struct sigaction sa_new; +#endif /* HAVE_SIGACTION */ /* if we are started by init (process 1) via /etc/inittab we needn't bother to detach from our process group context */ - my_termhook = termhook; - if (getppid() == 1) goto nottyDetach; /* Ignore BSD terminal stop signals */ +#ifdef HAVE_SIGACTION + memset (&sa_new, 0, sizeof sa_new); + sigemptyset (&sa_new.sa_mask); + sa_new.sa_handler = SIG_IGN; +#ifdef SA_RESTART /* SunOS 4.1 portability hack */ + sa_new.sa_flags = SA_RESTART; +#endif +#endif /* HAVE_SIGACTION */ #ifdef SIGTTOU +#ifndef HAVE_SIGACTION signal(SIGTTOU, SIG_IGN); +#else + sigaction (SIGTTOU, &sa_new, NULL); +#endif /* HAVE_SIGACTION */ #endif #ifdef SIGTTIN +#ifndef HAVE_SIGACTION signal(SIGTTIN, SIG_IGN); +#else + sigaction (SIGTTIN, &sa_new, NULL); +#endif /* HAVE_SIGACTION */ #endif #ifdef SIGTSTP +#ifndef HAVE_SIGACTION signal(SIGTSTP, SIG_IGN); +#else + sigaction (SIGTSTP, &sa_new, NULL); +#endif /* HAVE_SIGACTION */ #endif /* In case we were not started in the background, fork and let @@ -122,7 +166,7 @@ void (*termhook)(void); group leader */ if ((childpid = fork()) < 0) { - perror("fork"); + report(stderr, "fork (%s)\n", strerror(errno)); return(PS_IOERR); } else if (childpid > 0) @@ -135,26 +179,33 @@ void (*termhook)(void); #if defined(HAVE_SETSID) /* POSIX */ /* POSIX makes this soooo easy to do */ if (setsid() < 0) { - perror("setsid"); + report(stderr, "setsid (%s)\n", strerror(errno)); return(PS_IOERR); } #elif defined(SIGTSTP) /* BSD */ /* change process group */ +#ifndef __EMX__ setpgrp(0, getpid()); - +#endif /* lose controlling tty */ if ((fd = open("/dev/tty", O_RDWR)) >= 0) { ioctl(fd, TIOCNOTTY, (char *) 0); - close(fd); + close(fd); /* not checking should be safe, there were no writes */ } #else /* SVR3 and older */ /* change process group */ +#ifndef __EMX__ setpgrp(); +#endif /* lose controlling tty */ +#ifndef HAVE_SIGACTION signal(SIGHUP, SIG_IGN); - if ((childpid = fork) < 0) { - perror("fork"); +#else + sigaction (SIGHUP, &sa_new, NULL); +#endif /* HAVE_SIGACTION */ + if ((childpid = fork()) < 0) { + report(stderr, "fork (%)\n", strerror(errno)); return(PS_IOERR); } else if (childpid > 0) { @@ -173,24 +224,24 @@ nottyDetach: for (fd = 19; fd >= 0; fd--) #endif { - close(fd); + close(fd); /* not checking this should be safe, no writes */ } /* Reopen stdin descriptor on /dev/null */ if ((fd = open("/dev/null", O_RDWR)) < 0) { /* stdin */ - perror("open: /dev/null"); + report(stderr, "open: /dev/null (%s)\n", strerror(errno)); return(PS_IOERR); } if (logfile) - fd = open(logfile, O_CREAT|O_WRONLY, 0777); /* stdout */ + fd = open(logfile, O_CREAT|O_WRONLY|O_APPEND, 0666); /* stdout */ else if (dup(fd) < 0) { /* stdout */ - perror("dup"); + report(stderr, "dup (%s)\n", strerror(errno)); return(PS_IOERR); } if (dup(fd) < 0) { /* stderr */ - perror("dup"); + report(stderr, "dup (%s)\n", strerror(errno)); return(PS_IOERR); } @@ -204,7 +255,26 @@ nottyDetach: umask(022); #endif - /* set up to catch child process termination signals */ - signal(SIGCLD, sigchld_handler); + deal_with_sigchld(); + return(0); } + +flag isafile(int fd) +/* is the given fd attached to a file? (used to control logging) */ +{ + struct stat stbuf; + + /* + * We'd like just to return 1 on (S_IFREG | S_IFBLK), + * but weirdly enough, Linux ptys seem to have S_IFBLK + * so this test would fail when run on an xterm. + */ + if (isatty(fd) || fstat(fd, &stbuf)) + return(0); + else if (stbuf.st_mode & (S_IFREG)) + return(1); + return(0); +} + +/* daemon.c ends here */