#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include "ourhdr.h"
#include <errno.h> /* for definition of errno */
#include <stdarg.h> /* ANSI C header file */
#include "ourhdr.h"
#include <signal.h>
#include <sys/types.h> /* required for some of our prototypes */
#include <stdio.h> /* for convenience */
#include <stdlib.h> /* for convenience */
#include <string.h> /* for convenience */
#include <unistd.h> /* for convenience */
static void err_doit(int, const char *, va_list);
#define MAXLINE 4096 /* max line length */
#define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
/* default file access permissions for new files */
#define DIR_MODE (FILE_MODE | S_IXUSR | S_IXGRP | S_IXOTH)
/* default permissions for new directories */
//typedef void Sigfunc(int); /* for signal handlers */
/* 4.3BSD Reno doesn't define SIG_ERR */
#if defined(SIG_IGN) && !defined(SIG_ERR)
#define SIG_ERR ((Sigfunc *)-1)
#endif
#define min(a,b) ((a) < (b) ? (a) : (b))
#define max(a,b) ((a) > (b) ? (a) : (b))
/* prototypes for our own functions */
char *path_alloc(int *); /* {Prog pathalloc} */
int open_max(void); /* {Prog openmax} */
void clr_fl(int, int); /* {Prog setfl} */
void set_fl(int, int); /* {Prog setfl} */
void pr_exit(int); /* {Prog prexit} */
void pr_mask(const char *); /* {Prog prmask} */
Sigfunc *signal_intr(int, Sigfunc *);/* {Prog signal_intr_function} */
int tty_cbreak(int); /* {Prog raw} */
int tty_raw(int); /* {Prog raw} */
int tty_reset(int); /* {Prog raw} */
void tty_atexit(void); /* {Prog raw} */
#ifdef ECHO /* only if has been included */
struct termios *tty_termios(void); /* {Prog raw} */
#endif
void sleep_us(unsigned int); /* {Ex sleepus} */
ssize_t readn(int, void *, size_t);/* {Prog readn} */
ssize_t writen(int, const void *, size_t);/* {Prog writen} */
int daemon_init(void); /* {Prog daemoninit} */
int s_pipe(int *); /* {Progs svr4_spipe bsd_spipe} */
int recv_fd(int, ssize_t (*func)(int, const void *, size_t));
/* {Progs recvfd_svr4 recvfd_43bsd} */
int send_fd(int, int); /* {Progs sendfd_svr4 sendfd_43bsd} */
int send_err(int, int, const char *);/* {Prog senderr} */
int serv_listen(const char *); /* {Progs servlisten_svr4 servlisten_44bsd} */
int serv_accept(int, uid_t *); /* {Progs servaccept_svr4 servaccept_44bsd} */
int cli_conn(const char *); /* {Progs cliconn_svr4 cliconn_44bsd} */
int buf_args(char *, int (*func)(int, char **));
/* {Prog bufargs} */
int ptym_open(char *); /* {Progs ptyopen_svr4 ptyopen_44bsd} */
int ptys_open(int, char *); /* {Progs ptyopen_svr4 ptyopen_44bsd} */
#ifdef TIOCGWINSZ
pid_t pty_fork(int *, char *, const struct termios *,
const struct winsize *); /* {Prog ptyfork} */
#endif
int
lock_reg(int fd, int cmd, int type, off_t offset, int whence, off_t len)
{
struct flock lock;
lock.l_type = type; /* F_RDLCK, F_WRLCK, F_UNLCK */
lock.l_start = offset; /* byte offset, relative to l_whence */
lock.l_whence = whence; /* SEEK_SET, SEEK_CUR, SEEK_END */
lock.l_len = len; /* #bytes (0 means to EOF) */
return( fcntl(fd, cmd, &lock) );
}
int lock_reg(int, int, int, off_t, int, off_t);
/* {Prog lockreg} */
#define read_lock(fd, offset, whence, len) \
lock_reg(fd, F_SETLK, F_RDLCK, offset, whence, len)
#define readw_lock(fd, offset, whence, len) \
lock_reg(fd, F_SETLKW, F_RDLCK, offset, whence, len)
#define write_lock(fd, offset, whence, len) \
lock_reg(fd, F_SETLK, F_WRLCK, offset, whence, len)
#define writew_lock(fd, offset, whence, len) \
lock_reg(fd, F_SETLKW, F_WRLCK, offset, whence, len)
#define un_lock(fd, offset, whence, len) \
lock_reg(fd, F_SETLK, F_UNLCK, offset, whence, len)
pid_t lock_test(int, int, off_t, int, off_t);
/* {Prog locktest} */
#define is_readlock(fd, offset, whence, len) \
lock_test(fd, F_RDLCK, offset, whence, len)
#define is_writelock(fd, offset, whence, len) \
lock_test(fd, F_WRLCK, offset, whence, len)
void err_dump(const char *, ...); /* {App misc_source} */
void err_msg(const char *, ...);
void err_quit(const char *, ...);
void err_ret(const char *, ...);
void err_sys(const char *, ...);
void log_msg(const char *, ...); /* {App misc_source} */
void log_open(const char *, int, int);
void log_quit(const char *, ...);
void log_ret(const char *, ...);
void log_sys(const char *, ...);
void TELL_WAIT(void); /* parent/child from {Sec race_conditions} */
void TELL_PARENT(pid_t);
void TELL_CHILD(pid_t);
void WAIT_PARENT(void);
void WAIT_CHILD(void);
char *pname = NULL; /* caller can set this from argv[0] */
/* Nonfatal error related to a system call.
* Print a message and return. */
void
err_ret(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(1, fmt, ap);
va_end(ap);
return;
}
/* Fatal error related to a system call.
* Print a message and terminate. */
void
err_sys(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(1, fmt, ap);
va_end(ap);
exit(1);
}
/* Fatal error related to a system call.
* Print a message, dump core, and terminate. */
void
err_dump(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(1, fmt, ap);
va_end(ap);
abort(); /* dump core and terminate */
exit(1); /* shouldn't get here */
}
/* Nonfatal error unrelated to a system call.
* Print a message and return. */
void
err_msg(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(0, fmt, ap);
va_end(ap);
return;
}
/* Fatal error unrelated to a system call.
* Print a message and terminate. */
void
err_quit(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
err_doit(0, fmt, ap);
va_end(ap);
exit(1);
}
/* Print a message and return to caller.
* Caller specifies "errnoflag". */
static void
err_doit(int errnoflag, const char *fmt, va_list ap)
{
int errno_save;
char buf[MAXLINE];
errno_save = errno; /* value caller might want printed */
vsprintf(buf, fmt, ap);
if (errnoflag)
sprintf(buf+strlen(buf), ": %s", strerror(errno_save));
strcat(buf, "\n");
fflush(stdout); /* in case stdout and stderr are the same */
fputs(buf, stderr);
fflush(NULL); /* flushes all stdio output streams */
return;
}
#define PIDFILE "daemon.pid"
int
main(void)
{
int fd, val;
char buf[10];
if ( (fd = open(PIDFILE, O_WRONLY | O_CREAT, FILE_MODE)) < 0)
err_sys("open error");
/* try and set a write lock on the entire file */
if (write_lock(fd, 0, SEEK_SET, 0) < 0) {
if (errno == EACCES || errno == EAGAIN)
{printf("the process is running");exit(0);} /* gracefully exit, daemon is already running */
else
err_sys("write_lock error");
}
/* truncate to zero length, now that we have the lock */
if (ftruncate(fd, 0) < 0)
err_sys("ftruncate error");
/* and write our process ID */
sprintf(buf, "%d\n", getpid());
if (write(fd, buf, strlen(buf)) != strlen(buf))
err_sys("write error");
/* set close-on-exec flag for descriptor */
if ( (val = fcntl(fd, F_GETFD, 0)) < 0)
err_sys("fcntl F_GETFD error");
val |= FD_CLOEXEC;
if (fcntl(fd, F_SETFD, val) < 0)
err_sys("fcntl F_SETFD error");
/* leave file open until we terminate: lock will be held */
/* do whatever ... */
while(1)
pause();
exit(0);
}
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