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crond: implement "SHELL=prog" in crontab. Export LOGNAME as POSIX wants

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function                                             old     new   delta
fork_job                                             343     456    +113
load_crontab                                         688     777     +89
crond_main                                          1456    1434     -22
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(add/remove: 0/0 grow/shrink: 2/1 up/down: 202/-22)           Total: 180 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-04-30 17:38:27 +02:00
parent d5929d602e
commit 43b8a1cc38
1 changed files with 49 additions and 25 deletions
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74
miscutils/crond.c
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@ -104,6 +104,7 @@ typedef struct CronLine {
int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */ int cl_empty_mail_size; /* size of mail header only, 0 if no mailfile */
char *cl_mailto; /* whom to mail results, may be NULL */ char *cl_mailto; /* whom to mail results, may be NULL */
#endif #endif
char *cl_shell;
/* ordered by size, not in natural order. makes code smaller: */ /* ordered by size, not in natural order. makes code smaller: */
char cl_Dow[7]; /* 0-6, beginning sunday */ char cl_Dow[7]; /* 0-6, beginning sunday */
char cl_Mons[12]; /* 0-11 */ char cl_Mons[12]; /* 0-11 */
@ -135,6 +136,8 @@ struct globals {
#if SETENV_LEAKS #if SETENV_LEAKS
char *env_var_user; char *env_var_user;
char *env_var_home; char *env_var_home;
char *env_var_shell;
char *env_var_logname;
#endif #endif
} FIX_ALIASING; } FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1) #define G (*(struct globals*)&bb_common_bufsiz1)
@ -397,6 +400,7 @@ static void load_crontab(const char *fileName)
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
char *mailTo = NULL; char *mailTo = NULL;
#endif #endif
char *shell = NULL;
delete_cronfile(fileName); delete_cronfile(fileName);
@ -441,7 +445,12 @@ static void load_crontab(const char *fileName)
#endif /* otherwise just ignore such lines */ #endif /* otherwise just ignore such lines */
continue; continue;
} }
//TODO: handle SHELL=, HOME= too? "man crontab" says: if (0 == strncmp(tokens[0], "SHELL=", 6)) {
free(shell);
shell = xstrdup(&tokens[0][6]);
continue;
}
//TODO: handle HOME= too? "man crontab" says:
//name = value //name = value
// //
//where the spaces around the equal-sign (=) are optional, and any subsequent //where the spaces around the equal-sign (=) are optional, and any subsequent
@ -453,6 +462,7 @@ static void load_crontab(const char *fileName)
//SHELL is set to /bin/sh, and LOGNAME and HOME are set from the /etc/passwd //SHELL is set to /bin/sh, and LOGNAME and HOME are set from the /etc/passwd
//line of the crontab's owner. HOME and SHELL may be overridden by settings //line of the crontab's owner. HOME and SHELL may be overridden by settings
//in the crontab; LOGNAME may not. //in the crontab; LOGNAME may not.
/* check if a minimum of tokens is specified */ /* check if a minimum of tokens is specified */
if (n < 6) if (n < 6)
continue; continue;
@ -472,9 +482,9 @@ static void load_crontab(const char *fileName)
/* copy mailto (can be NULL) */ /* copy mailto (can be NULL) */
line->cl_mailto = xstrdup(mailTo); line->cl_mailto = xstrdup(mailTo);
#endif #endif
line->cl_shell = xstrdup(shell);
/* copy command */ /* copy command */
line->cl_cmd = xstrdup(tokens[5]); line->cl_cmd = xstrdup(tokens[5]);
log5(" command:%s", tokens[5]);
pline = &line->cl_next; 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]); //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]);
} }
@ -484,6 +494,10 @@ static void load_crontab(const char *fileName)
G.cron_files = file; G.cron_files = file;
} }
config_close(parser); config_close(parser);
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL
free(mailTo);
#endif
free(shell);
} }
static void process_cron_update_file(void) static void process_cron_update_file(void)
@ -555,19 +569,22 @@ static void safe_setenv(char **pvar_val, const char *var, const char *val)
} }
#endif #endif
static void set_env_vars(struct passwd *pas) static void set_env_vars(struct passwd *pas, const char *shell)
{ {
/* POSIX requires crond to set up at least HOME, LOGNAME, PATH, SHELL.
* We assume crond inherited suitable PATH.
*/
#if SETENV_LEAKS #if SETENV_LEAKS
safe_setenv(&G.env_var_logname, "LOGNAME", pas->pw_name);
safe_setenv(&G.env_var_user, "USER", pas->pw_name); safe_setenv(&G.env_var_user, "USER", pas->pw_name);
safe_setenv(&G.env_var_home, "HOME", pas->pw_dir); safe_setenv(&G.env_var_home, "HOME", pas->pw_dir);
/* if we want to set user's shell instead: */ safe_setenv(&G.env_var_shell, "SHELL", shell);
/*safe_setenv(G.env_var_shell, "SHELL", pas->pw_shell);*/
#else #else
xsetenv("LOGNAME", pas->pw_name);
xsetenv("USER", pas->pw_name); xsetenv("USER", pas->pw_name);
xsetenv("HOME", pas->pw_dir); xsetenv("HOME", pas->pw_dir);
xsetenv("SHELL", shell);
#endif #endif
/* currently, we use constant one: */
/*setenv("SHELL", DEFAULT_SHELL, 1); - done earlier */
} }
static void change_user(struct passwd *pas) static void change_user(struct passwd *pas)
@ -584,12 +601,11 @@ static void change_user(struct passwd *pas)
#if ENABLE_FEATURE_CROND_CALL_SENDMAIL #if ENABLE_FEATURE_CROND_CALL_SENDMAIL
static pid_t static pid_t
fork_job(const char *user, int mailFd, fork_job(const char *user, int mailFd, CronLine *line, bool run_sendmail)
const char *prog, {
const char *shell_cmd /* if NULL, we run sendmail */
) {
smallint sv_logmode;
struct passwd *pas; struct passwd *pas;
const char *shell, *prog;
smallint sv_logmode;
pid_t pid; pid_t pid;
/* prepare things before vfork */ /* prepare things before vfork */
@ -598,7 +614,11 @@ fork_job(const char *user, int mailFd,
bb_error_msg("can't get uid for %s", user); bb_error_msg("can't get uid for %s", user);
goto err; goto err;
} }
set_env_vars(pas);
shell = line->cl_shell ? line->cl_shell : DEFAULT_SHELL;
prog = run_sendmail ? SENDMAIL : shell;
set_env_vars(pas, shell);
sv_logmode = logmode; sv_logmode = logmode;
pid = vfork(); pid = vfork();
@ -608,12 +628,15 @@ fork_job(const char *user, int mailFd,
change_user(pas); change_user(pas);
log5("child running %s", prog); log5("child running %s", prog);
if (mailFd >= 0) { if (mailFd >= 0) {
xmove_fd(mailFd, shell_cmd ? 1 : 0); xmove_fd(mailFd, run_sendmail ? 0 : 1);
dup2(1, 2); dup2(1, 2);
} }
/* crond 3.0pl1-100 puts tasks in separate process groups */ /* crond 3.0pl1-100 puts tasks in separate process groups */
bb_setpgrp(); bb_setpgrp();
execlp(prog, prog, (shell_cmd ? "-c" : SENDMAIL_ARGS), shell_cmd, (char *) NULL); if (!run_sendmail)
execlp(prog, prog, "-c", line->cl_cmd, (char *) NULL);
else
execlp(prog, prog, SENDMAIL_ARGS, (char *) NULL);
/* /*
* I want this error message on stderr too, * I want this error message on stderr too,
* even if other messages go only to syslog: * even if other messages go only to syslog:
@ -662,7 +685,7 @@ static void start_one_job(const char *user, CronLine *line)
} }
} }
line->cl_pid = fork_job(user, mailFd, DEFAULT_SHELL, line->cl_cmd); line->cl_pid = fork_job(user, mailFd, line, /*sendmail?*/ 0);
if (mailFd >= 0) { if (mailFd >= 0) {
if (line->cl_pid <= 0) { if (line->cl_pid <= 0) {
unlink(mailFile); unlink(mailFile);
@ -718,13 +741,14 @@ static void process_finished_job(const char *user, CronLine *line)
} }
line->cl_empty_mail_size = 0; line->cl_empty_mail_size = 0;
/* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */ /* if (line->cl_mailto) - always true if cl_empty_mail_size was nonzero */
line->cl_pid = fork_job(user, mailFd, SENDMAIL, NULL); line->cl_pid = fork_job(user, mailFd, line, /*sendmail?*/ 1);
} }
#else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */ #else /* !ENABLE_FEATURE_CROND_CALL_SENDMAIL */
static void start_one_job(const char *user, CronLine *line) static void start_one_job(const char *user, CronLine *line)
{ {
const char *shell;
struct passwd *pas; struct passwd *pas;
pid_t pid; pid_t pid;
@ -735,7 +759,8 @@ static void start_one_job(const char *user, CronLine *line)
} }
/* Prepare things before vfork */ /* Prepare things before vfork */
set_env_vars(pas); shell = line->cl_shell ? line->cl_shell : DEFAULT_SHELL;
set_env_vars(pas, shell);
/* Fork as the user in question and run program */ /* Fork as the user in question and run program */
pid = vfork(); pid = vfork();
@ -743,11 +768,11 @@ static void start_one_job(const char *user, CronLine *line)
/* CHILD */ /* CHILD */
/* initgroups, setgid, setuid, and chdir to home or CRON_DIR */ /* initgroups, setgid, setuid, and chdir to home or CRON_DIR */
change_user(pas); change_user(pas);
log5("child running %s", DEFAULT_SHELL); log5("child running %s", shell);
/* crond 3.0pl1-100 puts tasks in separate process groups */ /* crond 3.0pl1-100 puts tasks in separate process groups */
bb_setpgrp(); bb_setpgrp();
execl(DEFAULT_SHELL, DEFAULT_SHELL, "-c", line->cl_cmd, (char *) NULL); execl(shell, shell, "-c", line->cl_cmd, (char *) NULL);
bb_error_msg_and_die("can't execute '%s' for user %s", DEFAULT_SHELL, user); bb_error_msg_and_die("can't execute '%s' for user %s", shell, user);
} }
if (pid < 0) { if (pid < 0) {
bb_perror_msg("vfork"); bb_perror_msg("vfork");
@ -916,11 +941,10 @@ int crond_main(int argc UNUSED_PARAM, char **argv)
logmode = LOGMODE_SYSLOG; logmode = LOGMODE_SYSLOG;
} }
reopen_logfile_to_stderr();
xchdir(G.crontab_dir_name);
//signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */ //signal(SIGHUP, SIG_IGN); /* ? original crond dies on HUP... */
xsetenv("SHELL", DEFAULT_SHELL); /* once, for all future children */
reopen_logfile_to_stderr();
xchdir(G.crontab_dir_name);
log8("crond (busybox "BB_VER") started, log level %d", G.log_level); log8("crond (busybox "BB_VER") started, log level %d", G.log_level);
rescan_crontab_dir(); rescan_crontab_dir();
write_pidfile(CONFIG_PID_FILE_PATH "/crond.pid"); write_pidfile(CONFIG_PID_FILE_PATH "/crond.pid");