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lpd: small shrink

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lpd_main     761     747     -14
This commit is contained in:
Denis Vlasenko
2008-03-25 06:03:19 +00:00
parent f7d5665969
commit 0c3b0d501e
1 changed files with 35 additions and 50 deletions
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85
printutils/lpd.c
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@@ -87,43 +87,6 @@ static char *sane(char *str)
return str;
}
// we can use leaky setenv since we are about to exec or exit
static void exec_helper(char **filenames, char **argv) ATTRIBUTE_NORETURN;
static void exec_helper(char **filenames, char **argv)
{
char *p, *q;
char var[2];
var[1] = '\0';
// read and delete ctrlfile
q = xmalloc_open_read_close(filenames[0], NULL);
unlink(filenames[0]);
// provide datafile name
xsetenv("DATAFILE", filenames[1]);
// parse control file by "\n"
while ((p = strchr(q, '\n')) != NULL
&& isalpha(*q)
) {
*p++ = '\0';
// q is a line of <SYM><VALUE>,
// we are setting environment string <SYM>=<VALUE>.
// Ignoring "l<datafile>", exporting others:
if (*q != 'l') {
var[0] = *q++;
xsetenv(var, q);
}
// next line, plz!
q = p;
}
// we are the helper, we wanna be silent.
// this call reopens stdio fds to "/dev/null"
// (no daemonization is done)
bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO | DAEMON_ONLY_SANITIZE, NULL);
BB_EXECVP(*argv, argv);
exit(127); // it IS error if helper cannot be executed!
}
static char *xmalloc_read_stdin(void)
{
// SECURITY:
@@ -184,12 +147,42 @@ int lpd_main(int argc ATTRIBUTE_UNUSED, char *argv[])
// N.B. we bail out on any error
s = xmalloc_read_stdin();
if (!s) { // (probably) EOF
if (spooling /* && 7 != spooling - always true */) {
// we didn't see both ctrlfile & datafile!
goto err_exit;
char *p, *q, var[2];
// non-spooling mode or no spool helper specified
if (!spooling || !*argv)
return EXIT_SUCCESS; // the only non-error exit
// spooling mode but we didn't see both ctrlfile & datafile
if (spooling != 7)
goto err_exit; // reject job
// spooling mode and spool helper specified -> exec spool helper
// (we exit 127 if helper cannot be executed)
var[1] = '\0';
// read and delete ctrlfile
q = xmalloc_open_read_close(filenames[0], NULL);
unlink(filenames[0]);
// provide datafile name
// we can use leaky setenv since we are about to exec or exit
xsetenv("DATAFILE", filenames[1]);
// parse control file by "\n"
while ((p = strchr(q, '\n')) != NULL && isalpha(*q)) {
*p++ = '\0';
// q is a line of <SYM><VALUE>,
// we are setting environment string <SYM>=<VALUE>.
// Ignoring "l<datafile>", exporting others:
if (*q != 'l') {
var[0] = *q++;
xsetenv(var, q);
}
q = p; // next line
}
// one of only two non-error exits
return EXIT_SUCCESS;
// helper should not talk over network.
// this call reopens stdio fds to "/dev/null"
// (no daemonization is done)
bb_daemonize_or_rexec(DAEMON_DEVNULL_STDIO | DAEMON_ONLY_SANITIZE, NULL);
BB_EXECVP(*argv, argv);
exit(127);
}
// validate input.
@@ -269,14 +262,6 @@ int lpd_main(int argc ATTRIBUTE_UNUSED, char *argv[])
free(s);
close(fd); // NB: can do close(-1). Who cares?
// spawn spool helper and exit if all files are dumped
if (7 == spooling && *argv) {
// signal OK
safe_write(STDOUT_FILENO, "", 1);
// does not return (exits 0)
exec_helper(filenames, argv);
}
} // while (1)
err_exit: