Путь: Toys/Pending, команды версии: Ver.4 Ver.9 crond Комментарии в файле crond.c :
Исходный текст в файле crond.c #define FOR_crond
#include "toys.h"
GLOBALS(
char *crontabs_dir;
char *logfile;
int loglevel_d;
int loglevel;
time_t crontabs_dir_mtime;
uint8_t flagd;
)
typedef struct _var {
struct _var *next, *prev;
char *name, *val;
} VAR;
typedef struct _job {
struct _job *next, *prev;
char min[60], hour[24], dom[31], mon[12], dow[7], *cmd;
int isrunning, needstart, mailsize;
pid_t pid;
} JOB;
typedef struct _cronfile {
struct _cronfile *next, *prev;
struct double_list *job, *var;
char *username, *mailto;
int invalid;
} CRONFILE;
static char days[]={"sun""mon""tue""wed""thu""fri""sat"};
static char months[]={"jan""feb""mar""apr""may""jun""jul"
"aug""sep""oct""nov""dec"};
CRONFILE *gclist;
#define LOG_EXIT 0
#define LOG_LEVEL5 5
#define LOG_LEVEL7 7
#define LOG_LEVEL8 8
#define LOG_LEVEL9 9 // warning
#define LOG_ERROR 20
static void loginfo(uint8_t loglevel, char *msg, ...)
{
va_list s, d;
va_start(s, msg);
va_copy(d, s);
if (loglevel >= TT.loglevel) {
int used;
char *smsg;
if (!TT.flagd && TT.logfile) {
int fd = open(TT.logfile, O_WRONLY | O_CREAT | O_APPEND, 0666);
if (fd==-1) perror_msg("'%s", TT.logfile);
else {
dup2(fd, 2);
close(fd);
}
}
used = vsnprintf(NULL, 0, msg, d);
smsg = xzalloc(++used);
vsnprintf(smsg, used, msg, s);
if (TT.flagd || TT.logfile) {
fflush(NULL);
smsg[used-1] = '\n';
writeall((loglevel > 8) ? 2 : 1, smsg, used);
} else syslog((loglevel > 8) ? LOG_ERR : LOG_INFO, "%s", smsg);
free(smsg);
}
va_end(d);
va_end(s);
if (!loglevel) exit(20);
}
/*
* Names can also be used for the 'month' and 'day of week' fields
* (First three letters of the particular day or month).
*/
static int getindex(char *src, int size)
{
int i;
char *field = (size == 12) ? months : days;
// strings are not allowed for min, hour and dom fields.
if (!(size == 7 || size == 12)) return -1;
for (i = 0; field[i]; i += 3) {
if (!strncasecmp(src, &field[i], 3))
return (i/3);
}
return -1;
}
// set elements of minute, hour, day of month, month and day of week arrays.
static void fillarray(char *dst, int start, int end, int skip)
{
int sk = 1;
if (end < 0) {
dst[start] = 1;
return;
}
if (!skip) skip = 1;
do {
if (!--sk) {
dst[start] = 1;
sk = skip;
}
} while (start++ != end);
}
static long getval(char *num, long low, long high)
{
long val = strtol(num, &num, 10);
if (*num || (val < low) || (val > high)) return -1;
return val;
}
//static int parse_and_fillarray(char *dst, int size, char *src)
static int parse_and_fillarray(char *dst, int min, int max, char *src)
{
int start, end, skip = 0;
char *ptr = strchr(src, '/');
if (ptr) {
*ptr++ = 0;
if ((skip = getval(ptr, min, (min ? max: max-1))) < 0) goto ERROR;
}
if (*src == '-' || *src == ',') goto ERROR;
if (*src == '*') {
if (*(src+1)) goto ERROR;
fillarray(dst, 0, max-1, skip);
} else {
for (;;) {
char *ctoken = strsep(&src, ","), *dtoken;
if (!ctoken) break;
if (!*ctoken) goto ERROR;
// Get start position.
dtoken = strsep(&ctoken, "-");
if (isdigit(*dtoken)) {
if ((start = getval(dtoken, min, (min ? max : max-1))) < 0) goto ERROR;
start = min ? (start-1) : start;
} else if ((start = getindex(dtoken, max)) < 0) goto ERROR;
// Get end position.
if (!ctoken) end = -1; // e.g. N1,N2,N3
else if (*ctoken) {// e.g. N-M
if (isdigit(*ctoken)) {
if ((end = getval(ctoken, min, (min ? max : max-1))) < 0) goto ERROR;
end = min ? (end-1) : end;
} else if ((end = getindex(ctoken, max)) < 0) goto ERROR;
if (end == start) end = -1;
} else goto ERROR; // error condition 'N-'
fillarray(dst, start, end, skip);
}
}
if (TT.flagd && (TT.loglevel <= 5)) {
for (start = 0; start < max; start++)
fprintf(stderr, "%d", (unsigned char)dst[start]);
fputc('\n', stderr);
}
return 0;
ERROR:
loginfo(LOG_LEVEL9, "parse error at %s", src);
return -1;
}
static char *omitspace(char *line)
{
while (*line == ' ' || *line == '\t') line++;
return line;
}
static void parse_line(char *line, CRONFILE *cfile)
{
int count = 0;
char *name, *val, *tokens[5] = {0,};
VAR *v;
JOB *j;
line = omitspace(line);
if (!*line || *line == '#') return;
/*
* TODO: Enhancement to support 8 special strings
* @reboot -> Run once at startup.
* @yearly -> Run once a year (0 0 1 1 *).
* @annually -> Same as above.
* @monthly -> Run once a month (0 0 1 * *).
* @weekly -> Run once a week (0 0 * * 0).
* @daily -> Run once a day (0 0 * * *).
* @midnight -> same as above.
* @hourly -> Run once an hour (0 * * * *).
*/
if (*line == '@') return;
if (TT.flagd) loginfo(LOG_LEVEL5, "user:%s entry:%s", cfile->username, line);
while (count<5) {
int len = strcspn(line, " \t");
if (line[len]) line[len++] = '\0';
tokens[count++] = line;
line += len;
line = omitspace(line);
if (!*line) break;
}
switch (count) {
case 1: // form SHELL=/bin/sh
name = tokens[0];
if ((val = strchr(name, '='))) *val++ = 0;
if (!val || !*val) return;
break;
case 2: // form SHELL =/bin/sh or SHELL= /bin/sh
name = tokens[0];
if ((val = strchr(name, '='))) {
*val = 0;
val = tokens[1];
} else {
if (*(tokens[1]) != '=') return;
val = tokens[1] + 1;
}
if (!*val) return;
break;
case 3: // NAME = VAL
name = tokens[0];
val = tokens[2];
if (*(tokens[1]) != '=') return;
break;
case 5:
// don't have any cmd to execute.
if (!*line) return;
j = xzalloc(sizeof(JOB));
if (parse_and_fillarray(j->min, 0, sizeof(j->min), tokens[0]))
goto STOP_PARSING;
if (parse_and_fillarray(j->hour, 0, sizeof(j->hour), tokens[1]))
goto STOP_PARSING;
if (parse_and_fillarray(j->dom, 1, sizeof(j->dom), tokens[2]))
goto STOP_PARSING;
if (parse_and_fillarray(j->mon, 1, sizeof(j->mon), tokens[3]))
goto STOP_PARSING;
if (parse_and_fillarray(j->dow, 0, sizeof(j->dow), tokens[4]))
goto STOP_PARSING;
j->cmd = xstrdup(line);
if (TT.flagd) loginfo(LOG_LEVEL5, " command:%s", j->cmd);
dlist_add_nomalloc((struct double_list **)&cfile->job, (struct double_list *)j);
return;
STOP_PARSING:
free(j);
return;
default: return;
}
if (!strcmp(name, "MAILTO")) cfile->mailto = xstrdup(val);
else {
v = xzalloc(sizeof(VAR));
v->name = xstrdup(name);
v->val = xstrdup(val);
dlist_add_nomalloc((struct double_list **)&cfile->var, (struct double_list *)v);
}
}
static void free_jobs(JOB **jlist)
{
JOB *j = dlist_pop(jlist);
free(j->cmd);
free(j);
}
static void free_cronfile(CRONFILE **list)
{
CRONFILE *l = dlist_pop(list);
VAR *v, *vnode = (VAR *)l->var;
if (l->username != l->mailto) free(l->mailto);
free(l->username);
while (vnode && (v = dlist_pop(&vnode))) {
free(v->name);
free(v->val);
free(v);
}
free(l);
}
/*
* Iterate all cronfiles to identify the completed jobs and freed them.
* If all jobs got completed for a cronfile, freed cronfile too.
*/
static void remove_completed_jobs()
{
CRONFILE *lstart, *list = gclist;
lstart = list;
while (list) {
int delete = 1;
JOB *jstart, *jlist = (JOB *)list->job;
list->invalid = 1;
jstart = jlist;
while (jlist) {
jlist->isrunning = 0;
if (jlist->pid > 0) {
jlist->isrunning = 1;
delete = 0;
jlist = jlist->next;
} else {
if (jlist == jstart) { // if 1st node has to delete.
jstart = jstart->next;
free_jobs(&jlist);
continue;
} else free_jobs(&jlist);
}
if (jlist == jstart) break;
}
list->job = (struct double_list *)jlist;
if (delete) {
if (lstart == list) {
lstart = lstart->next;
free_cronfile(&list);
continue;
} else free_cronfile(&list);
}
list = list->next;
if (lstart == list) break;
}
gclist = list;
}
// Scan cronfiles and prepare the list of cronfiles with their jobs.
static void scan_cronfiles()
{
DIR *dp;
struct dirent *entry;
remove_completed_jobs();
if (chdir(TT.crontabs_dir)) loginfo(LOG_EXIT, "chdir(%s)", TT.crontabs_dir);
if (!(dp = opendir("."))) loginfo(LOG_EXIT, "chdir(%s)", ".");
while ((entry = readdir(dp))) {
CRONFILE *cfile;
FILE *fp;
char *line = 0;
size_t allocated_length = 0;
if (isdotdot(entry->d_name)) continue;
if (!getpwnam(entry->d_name)) {
loginfo(LOG_LEVEL7, "ignoring file '%s' (no such user)", entry->d_name);
continue;
}
if (!(fp = fopen(entry->d_name, "r"))) continue;
// one node for each user
cfile = xzalloc(sizeof(CRONFILE));
cfile->username = xstrdup(entry->d_name);
while (getline(&line, &allocated_length, fp) > 0) {
parse_line(line, cfile);
}
free(line);
fclose(fp);
// If there is no job for a cron, remove the VAR list.
if (!cfile->job) {
VAR *v, *vnode = (VAR *)cfile->var;
free(cfile->username);
if (cfile->mailto) free(cfile->mailto);
while (vnode && (v = dlist_pop(&vnode))) {
free(v->name);
free(v->val);
free(v);
}
free(cfile);
} else {
if (!cfile->mailto) cfile->mailto = cfile->username;
dlist_add_nomalloc((struct double_list **)&gclist,
(struct double_list *)cfile);
}
}
closedir(dp);
}
/*
* Set env variables, if any in the cronfile. Execute given job with the given
* SHELL or Default SHELL and send an e-mail with respect to every successfully
* completed job (as per the given param 'prog').
*/
static void do_fork(CRONFILE *cfile, JOB *job, int fd, char *prog)
{
pid_t pid = vfork();
if (pid == 0) {
VAR *v, *vstart = (VAR *)cfile->var;
struct passwd *pwd = getpwnam(cfile->username);
if (!pwd) loginfo(LOG_LEVEL9, "can't get uid for %s", cfile->username);
else {
char *file = "/bin/sh";
if (setenv("USER", pwd->pw_name, 1)) _exit(1);
for (v = vstart; v;) {
if (!strcmp("SHELL", v->name)) file = v->val;
if (setenv(v->name, v->val, 1)) _exit(1);
if ((v=v->next) == vstart) break;
}
if (!getenv("HOME")) {
if (setenv("HOME", pwd->pw_dir, 1))
_exit(1);
}
xsetuser(pwd);
if (chdir(pwd->pw_dir)) loginfo(LOG_LEVEL9, "chdir(%s)", pwd->pw_dir);
if (prog) file = prog;
if (TT.flagd) loginfo(LOG_LEVEL5, "child running %s", file);
if (fd >= 0) {
int newfd = prog ? 0 : 1;
if (fd != newfd) {
dup2(fd, newfd);
close(fd);
}
dup2(1, 2);
}
setpgrp();
execlp(file, file, (prog ? "-ti" : "-c"), (prog ? NULL : job->cmd), (char *) NULL);
loginfo(LOG_ERROR, "can't execute '%s' for user %s", file, cfile->username);
if (!prog) dprintf(1, "Exec failed: %s -c %s\n", file, job->cmd);
_exit(EXIT_SUCCESS);
}
}
if (pid < 0) {
loginfo(LOG_ERROR, "can't vfork");
pid = 0;
}
if (fd >=0) close(fd);
job->pid = pid;
}
// Send an e-mail for each successfully completed jobs.
static void sendmail(CRONFILE *cfile, JOB *job)
{
pid_t pid = job->pid;
int mailfd;
struct stat sb;
job->pid = 0;
if (pid <=0 || job->mailsize <=0) {
job->isrunning = 0;
job->needstart = 1;
return;
}
snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
cfile->username, (int)pid);
mailfd = open(toybuf, O_RDONLY);
unlink(toybuf);
if (mailfd < 0) return;
if (fstat(mailfd, &sb) == -1 || sb.st_uid != 0 || sb.st_nlink != 0
|| sb.st_size == job->mailsize || !S_ISREG(sb.st_mode)) {
xclose(mailfd);
return;
}
job->mailsize = 0;
do_fork(cfile, job, mailfd, "sendmail");
}
// Count the number of jobs, which are not completed.
static int count_running_jobs()
{
CRONFILE *cfile = gclist;
JOB *job, *jstart;
int count = 0;
while (cfile) {
job = jstart = (JOB *)cfile->job;
while (job) {
int ret;
if (!job->isrunning || job->pid<=0) goto NEXT_JOB;
job->isrunning = 0;
ret = waitpid(job->pid, NULL, WNOHANG);
if (ret < 0 || ret == job->pid) {
sendmail(cfile, job);
if (job->pid) count += (job->isrunning=1);
else {
job->isrunning = 0;
job->needstart = 1;
}
}
else count += (job->isrunning=1);
NEXT_JOB:
if ((job = job->next) == jstart) break;
}
if ((cfile = cfile->next) == gclist) break;
}
return count;
}
// Execute jobs one by one and prepare for the e-mail sending.
static void execute_jobs(void)
{
CRONFILE *cfile = gclist;
JOB *job, *jstart;
while (cfile) {
job = jstart = (JOB *)cfile->job;
while (job) {
if (job->needstart) {
job->needstart = 0;
if (job->pid < 0) {
int mailfd = -1;
job->mailsize = job->pid = 0;
snprintf(toybuf, sizeof(toybuf), "/var/spool/cron/cron.%s.%d",
cfile->username, getpid());
if ((mailfd = open(toybuf, O_CREAT|O_TRUNC|O_WRONLY|O_EXCL|O_APPEND,
0600)) < 0) {
loginfo(LOG_ERROR, "can't create mail file %s for user %s, "
"discarding output", toybuf, cfile->username);
} else {
dprintf(mailfd, "To: %s\nSubject: cron: %s\n\n", cfile->mailto, job->cmd);
job->mailsize = lseek(mailfd, 0, SEEK_CUR);
}
do_fork(cfile, job, mailfd, NULL);
if (mailfd >= 0) {
if (job->pid <= 0) unlink(toybuf);
else {
char *mailfile = xmprintf("/var/spool/cron/cron.%s.%d",
cfile->username, (int)job->pid);
rename(toybuf, mailfile);
free(mailfile);
}
}
loginfo(LOG_LEVEL8, "USER %s pid %3d cmd %s",
cfile->username, job->pid, job->cmd);
if (job->pid < 0) job->needstart = 1;
else job->isrunning = 1;
}
}
if ((job = job->next) == jstart) break;
}
if ((cfile = cfile->next) == gclist) break;
}
}
// Identify jobs, which needs to be started at the given time interval.
static void schedule_jobs(time_t ctime, time_t ptime)
{
time_t tm = ptime-ptime%60;
for (; tm <= ctime; tm += 60) {
struct tm *lt;
CRONFILE *cfile = gclist;
JOB *job, *jstart;
if (tm <= ptime) continue;
lt = localtime(&tm);
while (cfile) {
if (TT.flagd) loginfo(LOG_LEVEL5, "file %s:", cfile->username);
if (cfile->invalid) goto NEXT_CRONFILE;
job = jstart = (JOB *)cfile->job;
while (job) {
if (TT.flagd) loginfo(LOG_LEVEL5, " line %s", job->cmd);
if (job->min[lt->tm_min] && job->hour[lt->tm_hour]
&& (job->dom[lt->tm_mday] || job->dow[lt->tm_wday])
&& job->mon[lt->tm_mon-1]) {
if (TT.flagd)
loginfo(LOG_LEVEL5, " job: %d %s\n", (int)job->pid, job->cmd);
if (job->pid > 0) {
loginfo(LOG_LEVEL8, "user %s: process already running: %s",
cfile->username, job->cmd);
} else if (!job->pid) {
job->pid = -1;
job->needstart = 1;
job->isrunning = 0;
}
}
if ((job = job->next) == jstart) break;
}
NEXT_CRONFILE:
if ((cfile = cfile->next) == gclist) break;
}
}
}
void crond_main(void)
{
time_t ctime, ptime;
int sleepfor = 60;
struct stat sb;
TT.flagd = (toys.optflags & FLAG_d);
// Setting default params.
if (TT.flagd) TT.loglevel = TT.loglevel_d;
if (!(toys.optflags & (FLAG_f | FLAG_b))) toys.optflags |= FLAG_b;
if (!(toys.optflags & (FLAG_S | FLAG_L))) toys.optflags |= FLAG_S;
if ((toys.optflags & FLAG_c)
&& (TT.crontabs_dir[strlen(TT.crontabs_dir)-1] != '/'))
TT.crontabs_dir = xmprintf("%s/", TT.crontabs_dir);
if (!TT.crontabs_dir) TT.crontabs_dir = xstrdup("/var/spool/cron/crontabs/");
if (toys.optflags & FLAG_b) daemon(0,0);
if (!TT.flagd && !TT.logfile)
openlog(toys.which->name, LOG_CONS | LOG_PID, LOG_CRON);
// Set default shell once.
if (setenv("SHELL", "/bin/sh", 1)) error_exit("Can't set default shell");
xchdir(TT.crontabs_dir);
loginfo(LOG_LEVEL8, "crond started, log level %d", TT.loglevel);
if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
TT.crontabs_dir_mtime = sb.st_mtime;
scan_cronfiles();
ctime = time(NULL);
while (1) {
long tdiff;
ptime = ctime;
sleep(sleepfor - (ptime%sleepfor) +1);
tdiff =(long) ((ctime = time(NULL)) - ptime);
if (stat(TT.crontabs_dir, &sb)) sb.st_mtime = 0;
if (TT.crontabs_dir_mtime != sb.st_mtime) {
TT.crontabs_dir_mtime = sb.st_mtime;
scan_cronfiles();
}
if (TT.flagd) loginfo(LOG_LEVEL5, "wakeup diff=%ld\n", tdiff);
if (tdiff < -60 * 60 || tdiff > 60 * 60)
loginfo(LOG_LEVEL9, "time disparity of %ld minutes detected", tdiff / 60);
else if (tdiff > 0) {
schedule_jobs(ctime, ptime);
execute_jobs();
if (count_running_jobs()) sleepfor = 10;
else sleepfor = 60;
}
}
} |
 |