hush/miscutils/crond.c

936 lines
22 KiB
C

/* vi: set sw=4 ts=4: */
/*
* crond -d[#] -c <crondir> -f -b
*
* run as root, but NOT setuid root
*
* Copyright 1994 Matthew Dillon (dillon@apollo.west.oic.com)
* (version 2.3.2)
* Vladimir Oleynik <dzo@simtreas.ru> (C) 2002
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
#include "libbb.h"
#include <syslog.h>
/* glibc frees previous setenv'ed value when we do next setenv()
* of the same variable. uclibc does not do this! */
#if (defined(__GLIBC__) && !defined(__UCLIBC__)) /* || OTHER_SAFE_LIBC... */
#define SETENV_LEAKS 0
#else
#define SETENV_LEAKS 1
#endif
#ifndef CRONTABS
#define CRONTABS "/var/spool/cron/crontabs"
#endif
#ifndef TMPDIR
#define TMPDIR "/var/spool/cron"
#endif
#ifndef SENDMAIL
#define SENDMAIL "sendmail"
#endif
#ifndef SENDMAIL_ARGS
#define SENDMAIL_ARGS "-ti", "oem"
#endif
#ifndef CRONUPDATE
#define CRONUPDATE "cron.update"
#endif
#ifndef MAXLINES
#define MAXLINES 256 /* max lines in non-root crontabs */
#endif
typedef struct CronFile {
struct CronFile *cf_Next;
struct CronLine *cf_LineBase;
char *cf_User; /* username */
smallint cf_Ready; /* bool: one or more jobs ready */
smallint cf_Running; /* bool: one or more jobs running */
smallint cf_Deleted; /* marked for deletion, ignore */
} CronFile;
typedef struct CronLine {
struct CronLine *cl_Next;
char *cl_Shell; /* shell command */
pid_t cl_Pid; /* running pid, 0, or armed (-1) */
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
int cl_MailPos; /* 'empty file' size */
smallint cl_MailFlag; /* running pid is for mail */
char *cl_MailTo; /* whom to mail results */
#endif
/* ordered by size, not in natural order. makes code smaller: */
char cl_Dow[7]; /* 0-6, beginning sunday */
char cl_Mons[12]; /* 0-11 */
char cl_Hrs[24]; /* 0-23 */
char cl_Days[32]; /* 1-31 */
char cl_Mins[60]; /* 0-59 */
} CronLine;
#define DaemonUid 0
enum {
OPT_l = (1 << 0),
OPT_L = (1 << 1),
OPT_f = (1 << 2),
OPT_b = (1 << 3),
OPT_S = (1 << 4),
OPT_c = (1 << 5),
OPT_d = (1 << 6) * ENABLE_FEATURE_CROND_D,
};
#if ENABLE_FEATURE_CROND_D
#define DebugOpt (option_mask32 & OPT_d)
#else
#define DebugOpt 0
#endif
struct globals {
unsigned LogLevel; /* = 8; */
const char *LogFile;
const char *CDir; /* = CRONTABS; */
CronFile *FileBase;
#if SETENV_LEAKS
char *env_var_user;
char *env_var_home;
#endif
};
#define G (*(struct globals*)&bb_common_bufsiz1)
#define LogLevel (G.LogLevel )
#define LogFile (G.LogFile )
#define CDir (G.CDir )
#define FileBase (G.FileBase )
#define env_var_user (G.env_var_user )
#define env_var_home (G.env_var_home )
#define INIT_G() do { \
LogLevel = 8; \
CDir = CRONTABS; \
} while (0)
static void CheckUpdates(void);
static void SynchronizeDir(void);
static int TestJobs(time_t t1, time_t t2);
static void RunJobs(void);
static int CheckJobs(void);
static void RunJob(const char *user, CronLine *line);
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
static void EndJob(const char *user, CronLine *line);
#else
#define EndJob(user, line) ((line)->cl_Pid = 0)
#endif
static void DeleteFile(const char *userName);
#define LVL5 "\x05"
#define LVL7 "\x07"
#define LVL8 "\x08"
#define LVL9 "\x09"
#define WARN9 "\x49"
#define DIE9 "\xc9"
/* level >= 20 is "error" */
#define ERR20 "\x14"
static void crondlog(const char *ctl, ...)
{
va_list va;
int level = (ctl[0] & 0x1f);
va_start(va, ctl);
if (level >= (int)LogLevel) {
/* Debug mode: all to (non-redirected) stderr, */
/* Syslog mode: all to syslog (logmode = LOGMODE_SYSLOG), */
if (!DebugOpt && LogFile) {
/* Otherwise (log to file): we reopen log file at every write: */
int logfd = open3_or_warn(LogFile, O_WRONLY | O_CREAT | O_APPEND, 0600);
if (logfd >= 0)
xmove_fd(logfd, STDERR_FILENO);
}
// TODO: ERR -> error, WARN -> warning, LVL -> info
bb_verror_msg(ctl + 1, va, /* strerr: */ NULL);
}
va_end(va);
if (ctl[0] & 0x80)
exit(20);
}
int crond_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int crond_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
INIT_G();
/* "-b after -f is ignored", and so on for every pair a-b */
opt_complementary = "f-b:b-f:S-L:L-S" USE_FEATURE_CROND_D(":d-l")
":l+:d+"; /* -l and -d have numeric param */
opt = getopt32(argv, "l:L:fbSc:" USE_FEATURE_CROND_D("d:"),
&LogLevel, &LogFile, &CDir
USE_FEATURE_CROND_D(,&LogLevel));
/* both -d N and -l N set the same variable: LogLevel */
if (!(opt & OPT_f)) {
/* close stdin, stdout, stderr.
* close unused descriptors - don't need them. */
bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
}
if (!DebugOpt && LogFile == NULL) {
/* logging to syslog */
openlog(applet_name, LOG_CONS | LOG_PID, LOG_CRON);
logmode = LOGMODE_SYSLOG;
}
xchdir(CDir);
//signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */
crondlog(LVL9 "crond (busybox "BB_VER") started, log level %d", LogLevel);
SynchronizeDir();
/* main loop - synchronize to 1 second after the minute, minimum sleep
* of 1 second. */
{
time_t t1 = time(NULL);
time_t t2;
long dt;
int rescan = 60;
int sleep_time = 60;
write_pidfile("/var/run/crond.pid");
for (;;) {
sleep((sleep_time + 1) - (time(NULL) % sleep_time));
t2 = time(NULL);
dt = (long)t2 - (long)t1;
/*
* The file 'cron.update' is checked to determine new cron
* jobs. The directory is rescanned once an hour to deal
* with any screwups.
*
* check for disparity. Disparities over an hour either way
* result in resynchronization. A reverse-indexed disparity
* less then an hour causes us to effectively sleep until we
* match the original time (i.e. no re-execution of jobs that
* have just been run). A forward-indexed disparity less then
* an hour causes intermediate jobs to be run, but only once
* in the worst case.
*
* when running jobs, the inequality used is greater but not
* equal to t1, and less then or equal to t2.
*/
if (--rescan == 0) {
rescan = 60;
SynchronizeDir();
}
CheckUpdates();
if (DebugOpt)
crondlog(LVL5 "wakeup dt=%ld", dt);
if (dt < -60 * 60 || dt > 60 * 60) {
crondlog(WARN9 "time disparity of %d minutes detected", dt / 60);
} else if (dt > 0) {
TestJobs(t1, t2);
RunJobs();
sleep(5);
if (CheckJobs() > 0) {
sleep_time = 10;
} else {
sleep_time = 60;
}
}
t1 = t2;
}
}
return 0; /* not reached */
}
#if SETENV_LEAKS
/* We set environment *before* vfork (because we want to use vfork),
* so we cannot use setenv() - repeated calls to setenv() may leak memory!
* Using putenv(), and freeing memory after unsetenv() won't leak */
static void safe_setenv4(char **pvar_val, const char *var, const char *val /*, int len*/)
{
const int len = 4; /* both var names are 4 char long */
char *var_val = *pvar_val;
if (var_val) {
var_val[len] = '\0'; /* nuke '=' */
unsetenv(var_val);
free(var_val);
}
*pvar_val = xasprintf("%s=%s", var, val);
putenv(*pvar_val);
}
#endif
static void SetEnv(struct passwd *pas)
{
#if SETENV_LEAKS
safe_setenv4(&env_var_user, "USER", pas->pw_name);
safe_setenv4(&env_var_home, "HOME", pas->pw_dir);
/* if we want to set user's shell instead: */
/*safe_setenv(env_var_user, "SHELL", pas->pw_shell, 5);*/
#else
xsetenv("USER", pas->pw_name);
xsetenv("HOME", pas->pw_dir);
#endif
/* currently, we use constant one: */
/*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */
}
static void ChangeUser(struct passwd *pas)
{
/* careful: we're after vfork! */
change_identity(pas); /* - initgroups, setgid, setuid */
if (chdir(pas->pw_dir) < 0) {
crondlog(LVL9 "can't chdir(%s)", pas->pw_dir);
if (chdir(TMPDIR) < 0) {
crondlog(DIE9 "can't chdir(%s)", TMPDIR); /* exits */
}
}
}
static const char DowAry[] ALIGN1 =
"sun""mon""tue""wed""thu""fri""sat"
/* "Sun""Mon""Tue""Wed""Thu""Fri""Sat" */
;
static const char MonAry[] ALIGN1 =
"jan""feb""mar""apr""may""jun""jul""aug""sep""oct""nov""dec"
/* "Jan""Feb""Mar""Apr""May""Jun""Jul""Aug""Sep""Oct""Nov""Dec" */
;
static void ParseField(char *user, char *ary, int modvalue, int off,
const char *names, char *ptr)
/* 'names' is a pointer to a set of 3-char abbreviations */
{
char *base = ptr;
int n1 = -1;
int n2 = -1;
// this can't happen due to config_read()
/*if (base == NULL)
return;*/
while (1) {
int skip = 0;
/* Handle numeric digit or symbol or '*' */
if (*ptr == '*') {
n1 = 0; /* everything will be filled */
n2 = modvalue - 1;
skip = 1;
++ptr;
} else if (isdigit(*ptr)) {
if (n1 < 0) {
n1 = strtol(ptr, &ptr, 10) + off;
} else {
n2 = strtol(ptr, &ptr, 10) + off;
}
skip = 1;
} else if (names) {
int i;
for (i = 0; names[i]; i += 3) {
/* was using strncmp before... */
if (strncasecmp(ptr, &names[i], 3) == 0) {
ptr += 3;
if (n1 < 0) {
n1 = i / 3;
} else {
n2 = i / 3;
}
skip = 1;
break;
}
}
}
/* handle optional range '-' */
if (skip == 0) {
goto err;
}
if (*ptr == '-' && n2 < 0) {
++ptr;
continue;
}
/*
* collapse single-value ranges, handle skipmark, and fill
* in the character array appropriately.
*/
if (n2 < 0) {
n2 = n1;
}
if (*ptr == '/') {
skip = strtol(ptr + 1, &ptr, 10);
}
/*
* fill array, using a failsafe is the easiest way to prevent
* an endless loop
*/
{
int s0 = 1;
int failsafe = 1024;
--n1;
do {
n1 = (n1 + 1) % modvalue;
if (--s0 == 0) {
ary[n1 % modvalue] = 1;
s0 = skip;
}
if (--failsafe == 0) {
goto err;
}
} while (n1 != n2);
}
if (*ptr != ',') {
break;
}
++ptr;
n1 = -1;
n2 = -1;
}
if (*ptr) {
err:
crondlog(WARN9 "user %s: parse error at %s", user, base);
return;
}
if (DebugOpt && (LogLevel <= 5)) { /* like LVL5 */
/* can't use crondlog, it inserts '\n' */
int i;
for (i = 0; i < modvalue; ++i)
fprintf(stderr, "%d", (unsigned char)ary[i]);
fputc('\n', stderr);
}
}
static void FixDayDow(CronLine *line)
{
unsigned i;
int weekUsed = 0;
int daysUsed = 0;
for (i = 0; i < ARRAY_SIZE(line->cl_Dow); ++i) {
if (line->cl_Dow[i] == 0) {
weekUsed = 1;
break;
}
}
for (i = 0; i < ARRAY_SIZE(line->cl_Days); ++i) {
if (line->cl_Days[i] == 0) {
daysUsed = 1;
break;
}
}
if (weekUsed != daysUsed) {
if (weekUsed)
memset(line->cl_Days, 0, sizeof(line->cl_Days));
else /* daysUsed */
memset(line->cl_Dow, 0, sizeof(line->cl_Dow));
}
}
static void SynchronizeFile(const char *fileName)
{
struct parser_t *parser;
struct stat sbuf;
int maxLines;
char *tokens[6];
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
char *mailTo = NULL;
#endif
if (!fileName)
return;
DeleteFile(fileName);
parser = config_open(fileName);
if (!parser)
return;
maxLines = (strcmp(fileName, "root") == 0) ? 65535 : MAXLINES;
if (fstat(fileno(parser->fp), &sbuf) == 0 && sbuf.st_uid == DaemonUid) {
CronFile *file = xzalloc(sizeof(CronFile));
CronLine **pline;
int n;
file->cf_User = xstrdup(fileName);
pline = &file->cf_LineBase;
while (1) {
CronLine *line;
if (!--maxLines)
break;
n = config_read(parser, tokens, 6, 1, "# \t", PARSE_NORMAL | PARSE_KEEP_COPY);
if (!n)
break;
if (DebugOpt)
crondlog(LVL5 "user:%s entry:%s", fileName, parser->data);
/* check if line is setting MAILTO= */
if (0 == strncmp(tokens[0], "MAILTO=", 7)) {
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
free(mailTo);
mailTo = (tokens[0][7]) ? xstrdup(&tokens[0][7]) : NULL;
#endif /* otherwise just ignore such lines */
continue;
}
/* check if a minimum of tokens is specified */
if (n < 6)
continue;
*pline = line = xzalloc(sizeof(*line));
/* parse date ranges */
ParseField(file->cf_User, line->cl_Mins, 60, 0, NULL, tokens[0]);
ParseField(file->cf_User, line->cl_Hrs, 24, 0, NULL, tokens[1]);
ParseField(file->cf_User, line->cl_Days, 32, 0, NULL, tokens[2]);
ParseField(file->cf_User, line->cl_Mons, 12, -1, MonAry, tokens[3]);
ParseField(file->cf_User, line->cl_Dow, 7, 0, DowAry, tokens[4]);
/*
* fix days and dow - if one is not "*" and the other
* is "*", the other is set to 0, and vise-versa
*/
FixDayDow(line);
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
/* copy mailto (can be NULL) */
line->cl_MailTo = xstrdup(mailTo);
#endif
/* copy command */
line->cl_Shell = xstrdup(tokens[5]);
if (DebugOpt) {
crondlog(LVL5 " command:%s", tokens[5]);
}
pline = &line->cl_Next;
//bb_error_msg("M[%s]F[%s][%s][%s][%s][%s][%s]", mailTo, tokens[0], tokens[1], tokens[2], tokens[3], tokens[4], tokens[5]);
}
*pline = NULL;
file->cf_Next = FileBase;
FileBase = file;
if (maxLines == 0) {
crondlog(WARN9 "user %s: too many lines", fileName);
}
}
config_close(parser);
}
static void CheckUpdates(void)
{
FILE *fi;
char buf[256];
fi = fopen_for_read(CRONUPDATE);
if (fi != NULL) {
unlink(CRONUPDATE);
while (fgets(buf, sizeof(buf), fi) != NULL) {
/* use first word only */
SynchronizeFile(strtok(buf, " \t\r\n"));
}
fclose(fi);
}
}
static void SynchronizeDir(void)
{
CronFile *file;
/* Attempt to delete the database. */
again:
for (file = FileBase; file; file = file->cf_Next) {
if (!file->cf_Deleted) {
DeleteFile(file->cf_User);
goto again;
}
}
/*
* Remove cron update file
*
* Re-chdir, in case directory was renamed & deleted, or otherwise
* screwed up.
*
* scan directory and add associated users
*/
unlink(CRONUPDATE);
if (chdir(CDir) < 0) {
crondlog(DIE9 "can't chdir(%s)", CDir);
}
{
DIR *dir = opendir(".");
struct dirent *den;
if (!dir)
crondlog(DIE9 "can't chdir(%s)", "."); /* exits */
while ((den = readdir(dir)) != NULL) {
if (strchr(den->d_name, '.') != NULL) {
continue;
}
if (getpwnam(den->d_name)) {
SynchronizeFile(den->d_name);
} else {
crondlog(LVL7 "ignoring %s", den->d_name);
}
}
closedir(dir);
}
}
/*
* DeleteFile() - delete user database
*
* Note: multiple entries for same user may exist if we were unable to
* completely delete a database due to running processes.
*/
static void DeleteFile(const char *userName)
{
CronFile **pfile = &FileBase;
CronFile *file;
while ((file = *pfile) != NULL) {
if (strcmp(userName, file->cf_User) == 0) {
CronLine **pline = &file->cf_LineBase;
CronLine *line;
file->cf_Running = 0;
file->cf_Deleted = 1;
while ((line = *pline) != NULL) {
if (line->cl_Pid > 0) {
file->cf_Running = 1;
pline = &line->cl_Next;
} else {
*pline = line->cl_Next;
free(line->cl_Shell);
free(line);
}
}
if (file->cf_Running == 0) {
*pfile = file->cf_Next;
free(file->cf_User);
free(file);
} else {
pfile = &file->cf_Next;
}
} else {
pfile = &file->cf_Next;
}
}
}
/*
* TestJobs()
*
* determine which jobs need to be run. Under normal conditions, the
* period is about a minute (one scan). Worst case it will be one
* hour (60 scans).
*/
static int TestJobs(time_t t1, time_t t2)
{
int nJobs = 0;
time_t t;
/* Find jobs > t1 and <= t2 */
for (t = t1 - t1 % 60; t <= t2; t += 60) {
struct tm *tp;
CronFile *file;
CronLine *line;
if (t <= t1)
continue;
tp = localtime(&t);
for (file = FileBase; file; file = file->cf_Next) {
if (DebugOpt)
crondlog(LVL5 "file %s:", file->cf_User);
if (file->cf_Deleted)
continue;
for (line = file->cf_LineBase; line; line = line->cl_Next) {
if (DebugOpt)
crondlog(LVL5 " line %s", line->cl_Shell);
if (line->cl_Mins[tp->tm_min] && line->cl_Hrs[tp->tm_hour]
&& (line->cl_Days[tp->tm_mday] || line->cl_Dow[tp->tm_wday])
&& line->cl_Mons[tp->tm_mon]
) {
if (DebugOpt) {
crondlog(LVL5 " job: %d %s",
(int)line->cl_Pid, line->cl_Shell);
}
if (line->cl_Pid > 0) {
crondlog(LVL8 "user %s: process already running: %s",
file->cf_User, line->cl_Shell);
} else if (line->cl_Pid == 0) {
line->cl_Pid = -1;
file->cf_Ready = 1;
++nJobs;
}
}
}
}
}
return nJobs;
}
static void RunJobs(void)
{
CronFile *file;
CronLine *line;
for (file = FileBase; file; file = file->cf_Next) {
if (!file->cf_Ready)
continue;
file->cf_Ready = 0;
for (line = file->cf_LineBase; line; line = line->cl_Next) {
if (line->cl_Pid >= 0)
continue;
RunJob(file->cf_User, line);
crondlog(LVL8 "USER %s pid %3d cmd %s",
file->cf_User, (int)line->cl_Pid, line->cl_Shell);
if (line->cl_Pid < 0) {
file->cf_Ready = 1;
} else if (line->cl_Pid > 0) {
file->cf_Running = 1;
}
}
}
}
/*
* CheckJobs() - check for job completion
*
* Check for job completion, return number of jobs still running after
* all done.
*/
static int CheckJobs(void)
{
CronFile *file;
CronLine *line;
int nStillRunning = 0;
for (file = FileBase; file; file = file->cf_Next) {
if (file->cf_Running) {
file->cf_Running = 0;
for (line = file->cf_LineBase; line; line = line->cl_Next) {
int status, r;
if (line->cl_Pid <= 0)
continue;
r = waitpid(line->cl_Pid, &status, WNOHANG);
if (r < 0 || r == line->cl_Pid) {
EndJob(file->cf_User, line);
if (line->cl_Pid) {
file->cf_Running = 1;
}
} else if (r == 0) {
file->cf_Running = 1;
}
}
}
nStillRunning += file->cf_Running;
}
return nStillRunning;
}
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
// TODO: sendmail should be _run-time_ option, not compile-time!
static void
ForkJob(const char *user, CronLine *line, int mailFd,
const char *prog, const char *cmd, const char *arg,
const char *mail_filename)
{
struct passwd *pas;
pid_t pid;
/* prepare things before vfork */
pas = getpwnam(user);
if (!pas) {
crondlog(LVL9 "can't get uid for %s", user);
goto err;
}
SetEnv(pas);
pid = vfork();
if (pid == 0) {
/* CHILD */
/* change running state to the user in question */
ChangeUser(pas);
if (DebugOpt) {
crondlog(LVL5 "child running %s", prog);
}
if (mailFd >= 0) {
xmove_fd(mailFd, mail_filename ? 1 : 0);
dup2(1, 2);
}
/* crond 3.0pl1-100 puts tasks in separate process groups */
bb_setpgrp();
execlp(prog, prog, cmd, arg, NULL);
crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user, prog, cmd, arg);
if (mail_filename) {
fdprintf(1, "Exec failed: %s -c %s\n", prog, arg);
}
_exit(EXIT_SUCCESS);
}
line->cl_Pid = pid;
if (pid < 0) {
/* FORK FAILED */
crondlog(ERR20 "can't vfork");
err:
line->cl_Pid = 0;
if (mail_filename) {
unlink(mail_filename);
}
} else if (mail_filename) {
/* PARENT, FORK SUCCESS
* rename mail-file based on pid of process
*/
char mailFile2[128];
snprintf(mailFile2, sizeof(mailFile2), "%s/cron.%s.%d", TMPDIR, user, pid);
rename(mail_filename, mailFile2); // TODO: xrename?
}
/*
* Close the mail file descriptor.. we can't just leave it open in
* a structure, closing it later, because we might run out of descriptors
*/
if (mailFd >= 0) {
close(mailFd);
}
}
static void RunJob(const char *user, CronLine *line)
{
char mailFile[128];
int mailFd = -1;
line->cl_Pid = 0;
line->cl_MailFlag = 0;
if (line->cl_MailTo) {
/* open mail file - owner root so nobody can screw with it. */
snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, getpid());
mailFd = open(mailFile, O_CREAT | O_TRUNC | O_WRONLY | O_EXCL | O_APPEND, 0600);
if (mailFd >= 0) {
line->cl_MailFlag = 1;
fdprintf(mailFd, "To: %s\nSubject: cron: %s\n\n", line->cl_MailTo,
line->cl_Shell);
line->cl_MailPos = lseek(mailFd, 0, SEEK_CUR);
} else {
crondlog(ERR20 "cannot create mail file %s for user %s, "
"discarding output", mailFile, user);
}
}
ForkJob(user, line, mailFd, DEFAULT_SHELL, "-c", line->cl_Shell, mailFile);
}
/*
* EndJob - called when job terminates and when mail terminates
*/
static void EndJob(const char *user, CronLine *line)
{
int mailFd;
char mailFile[128];
struct stat sbuf;
/* No job */
if (line->cl_Pid <= 0) {
line->cl_Pid = 0;
return;
}
/*
* End of job and no mail file
* End of sendmail job
*/
snprintf(mailFile, sizeof(mailFile), "%s/cron.%s.%d", TMPDIR, user, line->cl_Pid);
line->cl_Pid = 0;
if (line->cl_MailFlag == 0) {
return;
}
line->cl_MailFlag = 0;
/*
* End of primary job - check for mail file. If size has increased and
* the file is still valid, we sendmail it.
*/
mailFd = open(mailFile, O_RDONLY);
unlink(mailFile);
if (mailFd < 0) {
return;
}
if (fstat(mailFd, &sbuf) < 0 || sbuf.st_uid != DaemonUid
|| sbuf.st_nlink != 0 || sbuf.st_size == line->cl_MailPos
|| !S_ISREG(sbuf.st_mode)
) {
close(mailFd);
return;
}
if (line->cl_MailTo)
ForkJob(user, line, mailFd, SENDMAIL, SENDMAIL_ARGS, NULL);
}
#else /* crond without sendmail */
static void RunJob(const char *user, CronLine *line)
{
struct passwd *pas;
pid_t pid;
/* prepare things before vfork */
pas = getpwnam(user);
if (!pas) {
crondlog(LVL9 "can't get uid for %s", user);
goto err;
}
SetEnv(pas);
/* fork as the user in question and run program */
pid = vfork();
if (pid == 0) {
/* CHILD */
/* change running state to the user in question */
ChangeUser(pas);
if (DebugOpt) {
crondlog(LVL5 "child running %s", DEFAULT_SHELL);
}
/* crond 3.0pl1-100 puts tasks in separate process groups */
bb_setpgrp();
execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_Shell, NULL);
crondlog(ERR20 "can't exec, user %s cmd %s %s %s", user,
DEFAULT_SHELL, "-c", line->cl_Shell);
_exit(EXIT_SUCCESS);
}
if (pid < 0) {
/* FORK FAILED */
crondlog(ERR20 "can't vfork");
err:
pid = 0;
}
line->cl_Pid = pid;
}
#endif /* ENABLE_FEATURE_CROND_CALL_SENDMAIL */