printutils/lpr.c - busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * bare bones version of lpr & lpq: BSD printing utilities
  *
  * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
  *
  * Original idea and code:
  *      Walter Harms <WHarms@bfs.de>
  *
  * Licensed under GPLv2, see file LICENSE in this source tree.
  *
  * See RFC 1179 for protocol description.
  */
 //config:config LPR
 //config:	bool "lpr (9.9 kb)"
 //config:	default y
 //config:	help
 //config:	lpr sends files (or standard input) to a print spooling daemon.
 //config:
 //config:config LPQ
 //config:	bool "lpq (9.9 kb)"
 //config:	default y
 //config:	help
 //config:	lpq is a print spool queue examination and manipulation program.

 //              APPLET_ODDNAME:name main  location        suid_type     help
 //applet:IF_LPQ(APPLET_ODDNAME(lpq, lpqr, BB_DIR_USR_BIN, BB_SUID_DROP, lpq))
 //applet:IF_LPR(APPLET_ODDNAME(lpr, lpqr, BB_DIR_USR_BIN, BB_SUID_DROP, lpr))

 //kbuild:lib-$(CONFIG_LPR) += lpr.o
 //kbuild:lib-$(CONFIG_LPQ) += lpr.o

 //usage:#define lpr_trivial_usage
 //usage:       "-P queue[@host[:port]] -U USERNAME -J TITLE -Vmh [FILE]..."
 /* -C CLASS exists too, not shown.
  * CLASS is supposed to be printed on banner page, if one is requested */
 //usage:#define lpr_full_usage "\n\n"
 //usage:       "	-P	lp service to connect to (else uses $PRINTER)"
 //usage:     "\n	-m	Send mail on completion"
 //usage:     "\n	-h	Print banner page too"
 //usage:     "\n	-V	Verbose"
 //usage:
 //usage:#define lpq_trivial_usage
 //usage:       "[-P queue[@host[:port]]] [-U USERNAME] [-d JOBID]... [-fs]"
 //usage:#define lpq_full_usage "\n\n"
 //usage:       "	-P	lp service to connect to (else uses $PRINTER)"
 //usage:     "\n	-d	Delete jobs"
 //usage:     "\n	-f	Force any waiting job to be printed"
 //usage:     "\n	-s	Short display"

 #include "libbb.h"

 /*
  * LPD returns binary 0 on success.
  * Otherwise it returns error message.
  */
 static void get_response_or_say_and_die(int fd, const char *errmsg)
 {
 	ssize_t sz;
 	char buf[128];

 	buf[0] = ' ';
 	sz = safe_read(fd, buf, 1);
 	if ('\0' != buf[0]) {
 		// request has failed
 		// try to make sure last char is '\n', but do not add
 		// superfluous one
 		sz = full_read(fd, buf + 1, 126);
 		bb_error_msg("error while %s%s", errmsg,
 				(sz > 0 ? ". Server said:" : ""));
 		if (sz > 0) {
 			// sz = (bytes in buf) - 1
 			if (buf[sz] != '\n')
 				buf[++sz] = '\n';
 			safe_write(STDERR_FILENO, buf, sz + 1);
 		}
 		xfunc_die();
 	}
 }

 int lpqr_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
 int lpqr_main(int argc UNUSED_PARAM, char *argv[])
 {
 	enum {
 		OPT_P           = 1 << 0, // -P queue[@host[:port]]. If no -P is given use $PRINTER, then "lp@localhost:515"
 		OPT_U           = 1 << 1, // -U username

 		LPR_V           = 1 << 2, // -V: be verbose
 		LPR_h           = 1 << 3, // -h: want banner printed
 		LPR_C           = 1 << 4, // -C class: job "class" (? supposedly printed on banner)
 		LPR_J           = 1 << 5, // -J title: the job title for the banner page
 		LPR_m           = 1 << 6, // -m: send mail back to user

 		LPQ_SHORT_FMT   = 1 << 2, // -s: short listing format
 		LPQ_DELETE      = 1 << 3, // -d: delete job(s)
 		LPQ_FORCE       = 1 << 4, // -f: force waiting job(s) to be printed
 	};
 	char tempfile[sizeof("/tmp/lprXXXXXX")];
 	const char *job_title;
 	const char *printer_class = "";   // printer class, max 32 char
 	const char *queue;                // name of printer queue
 	const char *server = "localhost"; // server[:port] of printer queue
 	char *hostname;
 	// N.B. IMHO getenv("USER") can be way easily spoofed!
 	const char *user = xuid2uname(getuid());
 	unsigned job;
 	unsigned opts;
 	int fd;

 	queue = getenv("PRINTER");
 	if (!queue)
 		queue = "lp";

 	// parse options
 	// TODO: set opt_complementary: s,d,f are mutually exclusive
 	opts = getopt32(argv,
 		(/*lp*/'r' == applet_name[2]) ? "P:U:VhC:J:m" : "P:U:sdf"
 		, &queue, &user
 		, &printer_class, &job_title
 	);
 	argv += optind;

 	{
 		// queue name is to the left of '@'
 		char *s = strchr(queue, '@');
 		if (s) {
 			// server name is to the right of '@'
 			*s = '\0';
 			server = s + 1;
 		}
 	}

 	// do connect
 	fd = create_and_connect_stream_or_die(server, 515);

 	//
 	// LPQ ------------------------
 	//
 	if (/*lp*/'q' == applet_name[2]) {
 		char cmd;
 		// force printing of every job still in queue
 		if (opts & LPQ_FORCE) {
 			cmd = 1;
 			goto command;
 		// delete job(s)
 		} else if (opts & LPQ_DELETE) {
 			fdprintf(fd, "\x5" "%s %s", queue, user);
 			while (*argv) {
 				fdprintf(fd, " %s", *argv++);
 			}
 			bb_putchar('\n');
 		// dump current jobs status
 		// N.B. periodical polling should be achieved
 		// via "watch -n delay lpq"
 		// They say it's the UNIX-way :)
 		} else {
 			cmd = (opts & LPQ_SHORT_FMT) ? 3 : 4;
  command:
 			fdprintf(fd, "%c" "%s\n", cmd, queue);
 			bb_copyfd_eof(fd, STDOUT_FILENO);
 		}

 		return EXIT_SUCCESS;
 	}

 	//
 	// LPR ------------------------
 	//
 	if (opts & LPR_V)
 		bb_simple_error_msg("connected to server");

 	job = getpid() % 1000;
 	hostname = safe_gethostname();

 	// no files given on command line? -> use stdin
 	if (!*argv)
 		*--argv = (char *)"-";

 	fdprintf(fd, "\x2" "%s\n", queue);
 	get_response_or_say_and_die(fd, "setting queue");

 	// process files
 	do {
 		unsigned cflen;
 		int dfd;
 		struct stat st;
 		char *c;
 		char *remote_filename;
 		char *controlfile;

 		// if data file is stdin, we need to dump it first
 		if (LONE_DASH(*argv)) {
 			strcpy(tempfile, "/tmp/lprXXXXXX");
 			dfd = xmkstemp(tempfile);
 			bb_copyfd_eof(STDIN_FILENO, dfd);
 			xlseek(dfd, 0, SEEK_SET);
 			*argv = (char*)bb_msg_standard_input;
 		} else {
 			dfd = xopen(*argv, O_RDONLY);
 		}

 		st.st_size = 0; /* paranoia: fstat may theoretically fail */
 		fstat(dfd, &st);

 		/* Apparently, some servers are buggy and won't accept 0-sized jobs.
 		 * Standard lpr works around it by refusing to send such jobs:
 		 */
 		if (st.st_size == 0) {
 			bb_simple_error_msg("nothing to print");
 			continue;
 		}

 		/* "The name ... should start with ASCII "cfA",
 		 * followed by a three digit job number, followed
 		 * by the host name which has constructed the file."
 		 * We supply 'c' or 'd' as needed for control/data file. */
 		remote_filename = xasprintf("fA%03u%s", job, hostname);

 		// create control file
 		// TODO: all lines but 2 last are constants! How we can use this fact?
 		controlfile = xasprintf(
 			"H" "%.32s\n" "P" "%.32s\n" /* H HOST, P USER */
 			"C" "%.32s\n" /* C CLASS - printed on banner page (if L cmd is also given) */
 			"J" "%.99s\n" /* J JOBNAME */
 			/* "class name for banner page and job name
 			 * for banner page commands must precede L command" */
 			"L" "%.32s\n" /* L USER - print banner page, with given user's name */
 			"M" "%.32s\n" /* M WHOM_TO_MAIL */
 			"l" "d%.31s\n" /* l DATA_FILE_NAME ("dfAxxx") */
 			, hostname, user
 			, printer_class /* can be "" */
 			, ((opts & LPR_J) ? job_title : *argv)
 			, (opts & LPR_h) ? user : ""
 			, (opts & LPR_m) ? user : ""
 			, remote_filename
 		);
 		// delete possible "\nX\n" (that is, one-char) patterns
 		c = controlfile;
 		while ((c = strchr(c, '\n')) != NULL) {
 			if (c[1] && c[2] == '\n') {
 				overlapping_strcpy(c, c+2);
 			} else {
 				c++;
 			}
 		}

 		// send control file
 		if (opts & LPR_V)
 			bb_simple_error_msg("sending control file");
 		/* "Acknowledgement processing must occur as usual
 		 * after the command is sent." */
 		cflen = (unsigned)strlen(controlfile);
 		fdprintf(fd, "\x2" "%u c%s\n", cflen, remote_filename);
 		get_response_or_say_and_die(fd, "sending control file");
 		/* "Once all of the contents have
 		 * been delivered, an octet of zero bits is sent as
 		 * an indication that the file being sent is complete.
 		 * A second level of acknowledgement processing
 		 * must occur at this point." */
 		full_write(fd, controlfile, cflen + 1); /* writes NUL byte too */
 		get_response_or_say_and_die(fd, "sending control file");

 		// send data file, with name "dfaXXX"
 		if (opts & LPR_V)
 			bb_simple_error_msg("sending data file");
 		fdprintf(fd, "\x3" "%"OFF_FMT"u d%s\n", st.st_size, remote_filename);
 		get_response_or_say_and_die(fd, "sending data file");
 		if (bb_copyfd_size(dfd, fd, st.st_size) != st.st_size) {
 			// We're screwed. We sent less bytes than we advertised.
 			bb_simple_error_msg_and_die("local file changed size?!");
 		}
 		write(fd, "", 1); // send ACK
 		get_response_or_say_and_die(fd, "sending data file");

 		// delete temporary file if we dumped stdin
 		if (*argv == (char*)bb_msg_standard_input)
 			unlink(tempfile);

 		// cleanup
 		close(fd);
 		free(remote_filename);
 		free(controlfile);

 		// say job accepted
 		if (opts & LPR_V)
 			bb_simple_error_msg("job accepted");

 		// next, please!
 		job = (job + 1) % 1000;
 	} while (*++argv);

 	return EXIT_SUCCESS;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* bare bones version of lpr & lpq: BSD printing utilities
	*
	* Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
	*
	* Original idea and code:
	* Walter Harms <WHarms@bfs.de>
	*
	* Licensed under GPLv2, see file LICENSE in this source tree.
	*
	* See RFC 1179 for protocol description.
	*/
	//config:config LPR
	//config: bool "lpr (9.9 kb)"
	//config: default y
	//config: help
	//config: lpr sends files (or standard input) to a print spooling daemon.
	//config:
	//config:config LPQ
	//config: bool "lpq (9.9 kb)"
	//config: default y
	//config: help
	//config: lpq is a print spool queue examination and manipulation program.

	// APPLET_ODDNAME:name main location suid_type help
	//applet:IF_LPQ(APPLET_ODDNAME(lpq, lpqr, BB_DIR_USR_BIN, BB_SUID_DROP, lpq))
	//applet:IF_LPR(APPLET_ODDNAME(lpr, lpqr, BB_DIR_USR_BIN, BB_SUID_DROP, lpr))

	//kbuild:lib-$(CONFIG_LPR) += lpr.o
	//kbuild:lib-$(CONFIG_LPQ) += lpr.o

	//usage:#define lpr_trivial_usage
	//usage: "-P queue[@host[:port]] -U USERNAME -J TITLE -Vmh [FILE]..."
	/* -C CLASS exists too, not shown.
	* CLASS is supposed to be printed on banner page, if one is requested */
	//usage:#define lpr_full_usage "\n\n"
	//usage: " -P lp service to connect to (else uses $PRINTER)"
	//usage: "\n -m Send mail on completion"
	//usage: "\n -h Print banner page too"
	//usage: "\n -V Verbose"
	//usage:
	//usage:#define lpq_trivial_usage
	//usage: "[-P queue[@host[:port]]] [-U USERNAME] [-d JOBID]... [-fs]"
	//usage:#define lpq_full_usage "\n\n"
	//usage: " -P lp service to connect to (else uses $PRINTER)"
	//usage: "\n -d Delete jobs"
	//usage: "\n -f Force any waiting job to be printed"
	//usage: "\n -s Short display"

	#include "libbb.h"

	/*
	* LPD returns binary 0 on success.
	* Otherwise it returns error message.
	*/
	static void get_response_or_say_and_die(int fd, const char *errmsg)
	{
	ssize_t sz;
	char buf[128];

	buf[0] = ' ';
	sz = safe_read(fd, buf, 1);
	if ('\0' != buf[0]) {
	// request has failed
	// try to make sure last char is '\n', but do not add
	// superfluous one
	sz = full_read(fd, buf + 1, 126);
	bb_error_msg("error while %s%s", errmsg,
	(sz > 0 ? ". Server said:" : ""));
	if (sz > 0) {
	// sz = (bytes in buf) - 1
	if (buf[sz] != '\n')
	buf[++sz] = '\n';
	safe_write(STDERR_FILENO, buf, sz + 1);
	}
	xfunc_die();
	}
	}

	int lpqr_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
	int lpqr_main(int argc UNUSED_PARAM, char *argv[])
	{
	enum {
	OPT_P = 1 << 0, // -P queue[@host[:port]]. If no -P is given use $PRINTER, then "lp@localhost:515"
	OPT_U = 1 << 1, // -U username

	LPR_V = 1 << 2, // -V: be verbose
	LPR_h = 1 << 3, // -h: want banner printed
	LPR_C = 1 << 4, // -C class: job "class" (? supposedly printed on banner)
	LPR_J = 1 << 5, // -J title: the job title for the banner page
	LPR_m = 1 << 6, // -m: send mail back to user

	LPQ_SHORT_FMT = 1 << 2, // -s: short listing format
	LPQ_DELETE = 1 << 3, // -d: delete job(s)
	LPQ_FORCE = 1 << 4, // -f: force waiting job(s) to be printed
	};
	char tempfile[sizeof("/tmp/lprXXXXXX")];
	const char *job_title;
	const char *printer_class = ""; // printer class, max 32 char
	const char *queue; // name of printer queue
	const char *server = "localhost"; // server[:port] of printer queue
	char *hostname;
	// N.B. IMHO getenv("USER") can be way easily spoofed!
	const char *user = xuid2uname(getuid());
	unsigned job;
	unsigned opts;
	int fd;

	queue = getenv("PRINTER");
	if (!queue)
	queue = "lp";

	// parse options
	// TODO: set opt_complementary: s,d,f are mutually exclusive
	opts = getopt32(argv,
	(/lp/'r' == applet_name[2]) ? "P:U:VhC:J:m" : "P:U:sdf"
	, &queue, &user
	, &printer_class, &job_title
	);
	argv += optind;

	{
	// queue name is to the left of '@'
	char *s = strchr(queue, '@');
	if (s) {
	// server name is to the right of '@'
	*s = '\0';
	server = s + 1;
	}
	}

	// do connect
	fd = create_and_connect_stream_or_die(server, 515);

	//
	// LPQ ------------------------
	//
	if (/lp/'q' == applet_name[2]) {
	char cmd;
	// force printing of every job still in queue
	if (opts & LPQ_FORCE) {
	cmd = 1;
	goto command;
	// delete job(s)
	} else if (opts & LPQ_DELETE) {
	fdprintf(fd, "\x5" "%s %s", queue, user);
	while (*argv) {
	fdprintf(fd, " %s", *argv++);
	}
	bb_putchar('\n');
	// dump current jobs status
	// N.B. periodical polling should be achieved
	// via "watch -n delay lpq"
	// They say it's the UNIX-way :)
	} else {
	cmd = (opts & LPQ_SHORT_FMT) ? 3 : 4;
	command:
	fdprintf(fd, "%c" "%s\n", cmd, queue);
	bb_copyfd_eof(fd, STDOUT_FILENO);
	}

	return EXIT_SUCCESS;
	}

	//
	// LPR ------------------------
	//
	if (opts & LPR_V)
	bb_simple_error_msg("connected to server");

	job = getpid() % 1000;
	hostname = safe_gethostname();

	// no files given on command line? -> use stdin
	if (!*argv)
	--argv = (char )"-";

	fdprintf(fd, "\x2" "%s\n", queue);
	get_response_or_say_and_die(fd, "setting queue");

	// process files
	do {
	unsigned cflen;
	int dfd;
	struct stat st;
	char *c;
	char *remote_filename;
	char *controlfile;

	// if data file is stdin, we need to dump it first
	if (LONE_DASH(*argv)) {
	strcpy(tempfile, "/tmp/lprXXXXXX");
	dfd = xmkstemp(tempfile);
	bb_copyfd_eof(STDIN_FILENO, dfd);
	xlseek(dfd, 0, SEEK_SET);
	argv = (char)bb_msg_standard_input;
	} else {
	dfd = xopen(*argv, O_RDONLY);
	}

	st.st_size = 0; /* paranoia: fstat may theoretically fail */
	fstat(dfd, &st);

	/* Apparently, some servers are buggy and won't accept 0-sized jobs.
	* Standard lpr works around it by refusing to send such jobs:
	*/
	if (st.st_size == 0) {
	bb_simple_error_msg("nothing to print");
	continue;
	}

	/* "The name ... should start with ASCII "cfA",
	* followed by a three digit job number, followed
	* by the host name which has constructed the file."
	* We supply 'c' or 'd' as needed for control/data file. */
	remote_filename = xasprintf("fA%03u%s", job, hostname);

	// create control file
	// TODO: all lines but 2 last are constants! How we can use this fact?
	controlfile = xasprintf(
	"H" "%.32s\n" "P" "%.32s\n" /* H HOST, P USER */
	"C" "%.32s\n" /* C CLASS - printed on banner page (if L cmd is also given) */
	"J" "%.99s\n" /* J JOBNAME */
	/* "class name for banner page and job name
	* for banner page commands must precede L command" */
	"L" "%.32s\n" /* L USER - print banner page, with given user's name */
	"M" "%.32s\n" /* M WHOM_TO_MAIL */
	"l" "d%.31s\n" /* l DATA_FILE_NAME ("dfAxxx") */
	, hostname, user
	, printer_class /* can be "" */
	, ((opts & LPR_J) ? job_title : *argv)
	, (opts & LPR_h) ? user : ""
	, (opts & LPR_m) ? user : ""
	, remote_filename
	);
	// delete possible "\nX\n" (that is, one-char) patterns
	c = controlfile;
	while ((c = strchr(c, '\n')) != NULL) {
	if (c[1] && c[2] == '\n') {
	overlapping_strcpy(c, c+2);
	} else {
	c++;
	}
	}

	// send control file
	if (opts & LPR_V)
	bb_simple_error_msg("sending control file");
	/* "Acknowledgement processing must occur as usual
	* after the command is sent." */
	cflen = (unsigned)strlen(controlfile);
	fdprintf(fd, "\x2" "%u c%s\n", cflen, remote_filename);
	get_response_or_say_and_die(fd, "sending control file");
	/* "Once all of the contents have
	* been delivered, an octet of zero bits is sent as
	* an indication that the file being sent is complete.
	* A second level of acknowledgement processing
	* must occur at this point." */
	full_write(fd, controlfile, cflen + 1); /* writes NUL byte too */
	get_response_or_say_and_die(fd, "sending control file");

	// send data file, with name "dfaXXX"
	if (opts & LPR_V)
	bb_simple_error_msg("sending data file");
	fdprintf(fd, "\x3" "%"OFF_FMT"u d%s\n", st.st_size, remote_filename);
	get_response_or_say_and_die(fd, "sending data file");
	if (bb_copyfd_size(dfd, fd, st.st_size) != st.st_size) {
	// We're screwed. We sent less bytes than we advertised.
	bb_simple_error_msg_and_die("local file changed size?!");
	}
	write(fd, "", 1); // send ACK
	get_response_or_say_and_die(fd, "sending data file");

	// delete temporary file if we dumped stdin
	if (argv == (char)bb_msg_standard_input)
	unlink(tempfile);

	// cleanup
	close(fd);
	free(remote_filename);
	free(controlfile);

	// say job accepted
	if (opts & LPR_V)
	bb_simple_error_msg("job accepted");

	// next, please!
	job = (job + 1) % 1000;
	} while (*++argv);

	return EXIT_SUCCESS;
	}