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NetBSD/usr.bin/at/at.c

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/* $NetBSD: at.c,v 1.18 2000/10/15 14:51:14 kleink Exp $ */
/*
* at.c : Put file into atrun queue
* Copyright (C) 1993, 1994 Thomas Koenig
*
* Atrun & Atq modifications
* Copyright (C) 1993 David Parsons
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. The name of the author(s) may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* System Headers */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>
#include <locale.h>
/* Local headers */
#include "at.h"
#include "panic.h"
#include "parsetime.h"
#include "perm.h"
#include "pathnames.h"
#include "stime.h"
#define MAIN
#include "privs.h"
/* Macros */
#define ALARMC 10 /* Number of seconds to wait for timeout */
#define TIMESIZE 50
enum { ATQ, ATRM, AT, BATCH, CAT }; /* what program we want to run */
/* File scope variables */
#ifndef lint
#if 0
static char rcsid[] = "$OpenBSD: at.c,v 1.15 1998/06/03 16:20:26 deraadt Exp $";
#else
__RCSID("$NetBSD: at.c,v 1.18 2000/10/15 14:51:14 kleink Exp $");
#endif
#endif
char *no_export[] =
{
"TERM", "TERMCAP", "DISPLAY", "_"
};
static int send_mail = 0;
/* External variables */
extern char **environ;
int fcreated;
char *namep;
char atfile[FILENAME_MAX];
char *atinput = (char *)0; /* where to get input from */
char atqueue = 0; /* which queue to examine for jobs (atq) */
char atverify = 0; /* verify time instead of queuing job */
/* Function declarations */
static void sigc (int);
static void alarmc (int);
static char *cwdname (void);
static int nextjob (void);
static void writefile (time_t, char);
static void list_jobs (void);
static void process_jobs (int, char **, int);
/* Signal catching functions */
/*ARGSUSED*/
static void
sigc(int signo)
{
/* If the user presses ^C, remove the spool file and exit. */
if (fcreated) {
PRIV_START
(void)unlink(atfile);
PRIV_END
}
exit(EXIT_FAILURE);
}
/*ARGSUSED*/
static void
alarmc(int signo)
{
/* Time out after some seconds. */
panic("File locking timed out");
}
/* Local functions */
static char *
cwdname(void)
{
/*
* Read in the current directory; the name will be overwritten on
* subsequent calls.
*/
static char path[MAXPATHLEN];
return (getcwd(path, sizeof(path)));
}
static int
nextjob(void)
{
int jobno;
FILE *fid;
if ((fid = fopen(_PATH_SEQFILE, "r+")) != NULL) {
if (fscanf(fid, "%5x", &jobno) == 1) {
(void)rewind(fid);
jobno = (1+jobno) % 0xfffff; /* 2^20 jobs enough? */
(void)fprintf(fid, "%05x\n", jobno);
} else
jobno = EOF;
(void)fclose(fid);
return (jobno);
} else if ((fid = fopen(_PATH_SEQFILE, "w")) != NULL) {
(void)fprintf(fid, "%05x\n", jobno = 1);
(void)fclose(fid);
return (1);
}
return (EOF);
}
static void
writefile(time_t runtimer, char queue)
{
/*
* This does most of the work if at or batch are invoked for
* writing a job.
*/
int jobno;
char *ap, *ppos;
const char *mailname;
struct passwd *pass_entry;
struct stat statbuf;
int fdes, lockdes, fd2;
FILE *fp, *fpin;
struct sigaction act;
char **atenv;
int ch;
mode_t cmask;
struct flock lock;
(void)setlocale(LC_TIME, "");
/*
* Install the signal handler for SIGINT; terminate after removing the
* spool file if necessary
*/
memset(&act, 0, sizeof act);
act.sa_handler = sigc;
sigemptyset(&(act.sa_mask));
act.sa_flags = 0;
sigaction(SIGINT, &act, NULL);
(void)strncpy(atfile, _PATH_ATJOBS, sizeof(atfile) - 1);
ppos = atfile + strlen(atfile);
/*
* Loop over all possible file names for running something at this
* particular time, see if a file is there; the first empty slot at
* any particular time is used. Lock the file _PATH_LOCKFILE first
* to make sure we're alone when doing this.
*/
PRIV_START
if ((lockdes = open(_PATH_LOCKFILE, O_WRONLY | O_CREAT, S_IWUSR | S_IRUSR)) < 0)
perr2("Cannot open lockfile ", _PATH_LOCKFILE);
lock.l_type = F_WRLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 0;
act.sa_handler = alarmc;
sigemptyset(&(act.sa_mask));
act.sa_flags = 0;
/*
* Set an alarm so a timeout occurs after ALARMC seconds, in case
* something is seriously broken.
*/
sigaction(SIGALRM, &act, NULL);
alarm(ALARMC);
fcntl(lockdes, F_SETLKW, &lock);
alarm(0);
if ((jobno = nextjob()) == EOF)
perr("Cannot generate job number");
(void)snprintf(ppos, sizeof(atfile) - (ppos - atfile),
"%c%5x%8lx", queue, jobno, (unsigned long) (runtimer/60));
for (ap = ppos; *ap != '\0'; ap++)
if (*ap == ' ')
*ap = '0';
if (stat(atfile, &statbuf) != 0)
if (errno != ENOENT)
perr2("Cannot access ", _PATH_ATJOBS);
/*
* Create the file. The x bit is only going to be set after it has
* been completely written out, to make sure it is not executed in
* the meantime. To make sure they do not get deleted, turn off
* their r bit. Yes, this is a kluge.
*/
cmask = umask(S_IRUSR | S_IWUSR | S_IXUSR);
if ((fdes = open(atfile, O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR)) == -1)
perr("Cannot create atjob file");
if ((fd2 = dup(fdes)) < 0)
perr("Error in dup() of job file");
if (fchown(fd2, real_uid, real_gid) != 0)
perr("Cannot give away file");
PRIV_END
/*
* We've successfully created the file; let's set the flag so it
* gets removed in case of an interrupt or error.
*/
fcreated = 1;
/* Now we can release the lock, so other people can access it */
lock.l_type = F_UNLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 0;
(void)fcntl(lockdes, F_SETLKW, &lock);
(void)close(lockdes);
if ((fp = fdopen(fdes, "w")) == NULL)
panic("Cannot reopen atjob file");
/*
* Get the userid to mail to, first by trying getlogin(), which reads
* /etc/utmp, then from $LOGNAME or $USER, finally from getpwuid().
*/
mailname = getlogin();
if (mailname == NULL && (mailname = getenv("LOGNAME")) == NULL)
mailname = getenv("USER");
if ((mailname == NULL) || (mailname[0] == '\0') ||
(strlen(mailname) > LOGIN_NAME_MAX) || (getpwnam(mailname) == NULL)) {
pass_entry = getpwuid(real_uid);
if (pass_entry != NULL)
mailname = pass_entry->pw_name;
}
if (atinput != NULL) {
fpin = freopen(atinput, "r", stdin);
if (fpin == NULL)
perr("Cannot open input file");
}
(void)fprintf(fp, "#!/bin/sh\n# atrun uid=%u gid=%u\n# mail %s %d\n",
real_uid, real_gid, mailname, send_mail);
/* Write out the umask at the time of invocation */
(void)fprintf(fp, "umask %o\n", cmask);
/*
* Write out the environment. Anything that may look like a special
* character to the shell is quoted, except for \n, which is done
* with a pair of "'s. Dont't export the no_export list (such as
* TERM or DISPLAY) because we don't want these.
*/
for (atenv = environ; *atenv != NULL; atenv++) {
int export = 1;
char *eqp;
eqp = strchr(*atenv, '=');
if (eqp == NULL)
eqp = *atenv;
else {
int i;
for (i = 0;i < sizeof(no_export) /
sizeof(no_export[0]); i++) {
export = export
&& (strncmp(*atenv, no_export[i],
(size_t) (eqp - *atenv)) != 0);
}
eqp++;
}
if (export) {
(void)fwrite(*atenv, sizeof(char), eqp - *atenv, fp);
for (ap = eqp; *ap != '\0'; ap++) {
if (*ap == '\n')
(void)fprintf(fp, "\"\n\"");
else {
if (!isalnum(*ap)) {
switch (*ap) {
case '%': case '/': case '{':
case '[': case ']': case '=':
case '}': case '@': case '+':
case '#': case ',': case '.':
case ':': case '-': case '_':
break;
default:
(void)fputc('\\', fp);
break;
}
}
(void)fputc(*ap, fp);
}
}
(void)fputs("; export ", fp);
(void)fwrite(*atenv, sizeof(char), eqp - *atenv - 1, fp);
(void)fputc('\n', fp);
}
}
/*
* Cd to the directory at the time and write out all the
* commands the user supplies from stdin.
*/
(void)fputs("cd ", fp);
for (ap = cwdname(); *ap != '\0'; ap++) {
if (*ap == '\n')
(void)fprintf(fp, "\"\n\"");
else {
if (*ap != '/' && !isalnum(*ap))
(void)fputc('\\', fp);
(void)fputc(*ap, fp);
}
}
/*
* Test cd's exit status: die if the original directory has been
* removed, become unreadable or whatever.
*/
(void)fprintf(fp, " || {\n\t echo 'Execution directory inaccessible' >&2\n\t exit 1\n}\n");
if ((ch = getchar()) == EOF)
panic("Input error");
do {
(void)fputc(ch, fp);
} while ((ch = getchar()) != EOF);
(void)fprintf(fp, "\n");
if (ferror(fp))
panic("Output error");
if (ferror(stdin))
panic("Input error");
(void)fclose(fp);
PRIV_START
/*
* Set the x bit so that we're ready to start executing
*/
if (fchmod(fd2, S_IRUSR | S_IWUSR | S_IXUSR) < 0)
perr("Cannot give away file");
PRIV_END
(void)close(fd2);
(void)fprintf(stderr, "Job %d will be executed using /bin/sh\n", jobno);
}
static void
list_jobs(void)
{
/*
* List all a user's jobs in the queue, by looping through
* _PATH_ATJOBS, or everybody's if we are root
*/
struct passwd *pw;
DIR *spool;
struct dirent *dirent;
struct stat buf;
struct tm runtime;
unsigned long ctm;
char queue;
int jobno;
time_t runtimer;
char timestr[TIMESIZE];
int first = 1;
PRIV_START
if (chdir(_PATH_ATJOBS) != 0)
perr2("Cannot change to ", _PATH_ATJOBS);
if ((spool = opendir(".")) == NULL)
perr2("Cannot open ", _PATH_ATJOBS);
/* Loop over every file in the directory */
while ((dirent = readdir(spool)) != NULL) {
if (stat(dirent->d_name, &buf) != 0)
perr2("Cannot stat in ", _PATH_ATJOBS);
/*
* See it's a regular file and has its x bit turned on and
* is the user's
*/
if (!S_ISREG(buf.st_mode)
|| ((buf.st_uid != real_uid) && !(real_uid == 0))
|| !(S_IXUSR & buf.st_mode || atverify))
continue;
if (sscanf(dirent->d_name, "%c%5x%8lx", &queue, &jobno, &ctm) != 3)
continue;
if (atqueue && (queue != atqueue))
continue;
runtimer = 60 * (time_t) ctm;
runtime = *localtime(&runtimer);
strftime(timestr, TIMESIZE, "%X %x", &runtime);
if (first) {
(void)printf("%-*s %-*s %-*s %s\n",
(int)strlen(timestr), "Date",
LOGIN_NAME_MAX, "Owner",
7, "Queue",
"Job");
first = 0;
}
pw = getpwuid(buf.st_uid);
(void)printf("%s %-*s %c%-*s %d\n",
timestr,
LOGIN_NAME_MAX, pw ? pw->pw_name : "???",
queue,
6, (S_IXUSR & buf.st_mode) ? "" : "(done)",
jobno);
}
PRIV_END
}
static void
process_jobs(int argc, char **argv, int what)
{
/* Delete every argument (job - ID) given */
int i;
struct stat buf;
DIR *spool;
struct dirent *dirent;
unsigned long ctm;
char queue;
int jobno;
PRIV_START
if (chdir(_PATH_ATJOBS) != 0)
perr2("Cannot change to ", _PATH_ATJOBS);
if ((spool = opendir(".")) == NULL)
perr2("Cannot open ", _PATH_ATJOBS);
PRIV_END
/* Loop over every file in the directory */
while((dirent = readdir(spool)) != NULL) {
PRIV_START
if (stat(dirent->d_name, &buf) != 0)
perr2("Cannot stat in ", _PATH_ATJOBS);
PRIV_END
if (sscanf(dirent->d_name, "%c%5x%8lx", &queue, &jobno, &ctm) !=3)
continue;
for (i = optind; i < argc; i++) {
if (atoi(argv[i]) == jobno) {
if ((buf.st_uid != real_uid) && !(real_uid == 0)) {
errx(EXIT_FAILURE, "%s: Not owner", argv[i]);
}
switch (what) {
case ATRM:
PRIV_START
if (unlink(dirent->d_name) != 0)
perr(dirent->d_name);
PRIV_END
break;
case CAT:
{
FILE *fp;
int ch;
PRIV_START
fp = fopen(dirent->d_name, "r");
PRIV_END
if (!fp)
perr("Cannot open file");
while((ch = getc(fp)) != EOF)
putchar(ch);
}
break;
default:
errx(EXIT_FAILURE, "Internal error, process_jobs = %d",
what);
break;
}
}
}
}
} /* delete_jobs */
/* Global functions */
int
main(int argc, char **argv)
{
int c;
char queue = DEFAULT_AT_QUEUE;
char queue_set = 0;
char time_set = 0;
char *pgm;
int program = AT; /* our default program */
char *options = "q:f:t:mvldbrVc"; /* default options for at */
int disp_version = 0;
time_t timer;
RELINQUISH_PRIVS
/* Eat any leading paths */
if ((pgm = strrchr(argv[0], '/')) == NULL)
pgm = argv[0];
else
pgm++;
namep = pgm;
/* find out what this program is supposed to do */
if (strcmp(pgm, "atq") == 0) {
program = ATQ;
options = "q:vV";
} else if (strcmp(pgm, "atrm") == 0) {
program = ATRM;
options = "V";
} else if (strcmp(pgm, "batch") == 0) {
program = BATCH;
options = "f:q:t:mvV";
}
/* process whatever options we can process */
opterr = 1;
while ((c = getopt(argc, argv, options)) != -1)
switch (c) {
case 'v': /* verify time settings */
atverify = 1;
break;
case 'm': /* send mail when job is complete */
send_mail = 1;
break;
case 'f':
atinput = optarg;
break;
case 'q': /* specify queue */
if (strlen(optarg) > 1)
usage();
atqueue = queue = *optarg;
if (!(islower(queue) || isupper(queue)))
usage();
queue_set = 1;
break;
case 't': /* touch(1) date format */
timer = stime(optarg);
time_set = 1;
break;
case 'd':
case 'r':
if (program != AT)
usage();
program = ATRM;
options = "V";
break;
case 'l':
if (program != AT)
usage();
program = ATQ;
options = "q:vV";
break;
case 'b':
if (program != AT)
usage();
program = BATCH;
options = "f:q:mvV";
break;
case 'V':
disp_version = 1;
break;
case 'c':
program = CAT;
options = "";
break;
default:
usage();
break;
}
/* end of options eating */
if (disp_version)
(void)fprintf(stderr, "%s version %.1f\n", namep, AT_VERSION);
if (!check_permission()) {
errx(EXIT_FAILURE, "You do not have permission to use %s.", namep);
}
/* select our program */
switch (program) {
case ATQ:
if (optind != argc)
usage();
list_jobs();
break;
case ATRM:
case CAT:
if (optind == argc)
usage();
process_jobs(argc, argv, program);
break;
case AT:
if (argc > optind) {
/* -t and timespec argument are mutually exclusive */
if (time_set) {
usage();
exit(EXIT_FAILURE);
} else {
timer = parsetime(argc, argv);
time_set = 1;
}
}
if (atverify) {
struct tm *tm = localtime(&timer);
(void)fprintf(stderr, "%s\n", asctime(tm));
}
writefile(timer, queue);
break;
case BATCH:
if (queue_set)
queue = toupper(queue);
else
queue = DEFAULT_BATCH_QUEUE;
if (argc > optind) {
/* -t and timespec argument are mutually exclusive */
if (time_set) {
usage();
exit(EXIT_FAILURE);
} else {
timer = parsetime(argc, argv);
time_set = 1;
}
} else if (!time_set) {
timer = time(NULL);
}
if (atverify) {
struct tm *tm = localtime(&timer);
(void)fprintf(stderr, "%s\n", asctime(tm));
}
writefile(timer, queue);
break;
default:
panic("Internal error");
break;
}
exit(EXIT_SUCCESS);
/*NOTREACHED*/
}
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