mirror of https://github.com/mirror/busybox.git
80 lines
2.0 KiB
C
80 lines
2.0 KiB
C
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/* vi: set sw=4 ts=4: */
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/*
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* micro lpd - a small non-queueing lpd
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*
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* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
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*
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* Licensed under GPLv2, see file LICENSE in this tarball for details.
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*/
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#include "libbb.h"
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int lpd_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
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int lpd_main(int argc, char *argv[])
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{
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char *s;
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// goto spool directory
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// spool directory contains either links to real printer devices or just simple files
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// these links or files are called "queues"
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if (!argv[1])
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bb_show_usage();
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xchdir(argv[1]);
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xdup2(1, 2);
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// read command
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s = xmalloc_reads(STDIN_FILENO, NULL);
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// N.B. we keep things simple
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// only "receive job" command is meaningful here...
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if (2 == *s) {
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char *queue;
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// parse command: "\x2QUEUE_NAME\n"
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queue = s + 1;
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*strchrnul(s, '\n') = '\0';
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while (1) {
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// signal OK
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write(STDOUT_FILENO, "", 1);
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// get subcommand
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s = xmalloc_reads(STDIN_FILENO, NULL);
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if (!s)
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return EXIT_SUCCESS; // EOF (probably)
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// valid s must be of form: SUBCMD | LEN | SP | FNAME
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// N.B. we bail out on any error
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// control or data file follows
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if (2 == s[0] || 3 == s[0]) {
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int fd;
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size_t len;
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// 2: control file (ignoring), 3: data file
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fd = -1;
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if (3 == s[0])
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fd = xopen(queue, O_RDWR | O_APPEND);
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// get data length
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*strchrnul(s, ' ') = '\0';
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len = xatou(s + 1);
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// dump exactly len bytes to file, or die
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bb_copyfd_exact_size(STDIN_FILENO, fd, len);
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close(fd); // NB: can do close(-1). Who cares?
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free(s);
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// got no ACK? -> bail out
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if (safe_read(STDIN_FILENO, s, 1) <= 0 || s[0]) {
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// don't talk to peer - it obviously
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// don't follow the protocol
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return EXIT_FAILURE;
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}
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} else {
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// any other subcommand aborts receiving job
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// N.B. abort subcommand itself doesn't contain
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// fname so it failed earlier...
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break;
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}
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}
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}
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printf("Command %02x not supported\n", (unsigned char)*s);
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return EXIT_FAILURE;
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}
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