source: MondoRescue/branches/3.0/mindi-busybox/printutils/lpr.c@ 2899

/* 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.
 */
#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;

    // 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;

    // if queue is not specified -> use $PRINTER
    if (!(opts & OPT_P))
        queue = getenv("PRINTER");
    // if queue is still not specified ->
    if (!queue) {
        // ... queue defaults to "lp"
        // server defaults to "localhost"
        queue = "lp";
    // if queue is specified ->
    } else {
        // 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_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);
        }

        /* "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" patterns
        c = controlfile;
        cflen = (unsigned)strlen(controlfile);
        while ((c = strchr(c, '\n')) != NULL) {
            if (c[1] && c[2] == '\n') {
                /* can't use strcpy, results are undefined */
                memmove(c, c+2, cflen - (c-controlfile) - 1);
                cflen -= 2;
            } else {
                c++;
            }
        }

        // send control file
        if (opts & LPR_V)
            bb_error_msg("sending control file");
        /* "Acknowledgement processing must occur as usual
         * after the command is sent." */
        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_error_msg("sending data file");
        st.st_size = 0; /* paranoia: fstat may theoretically fail */
        fstat(dfd, &st);
        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_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_error_msg("job accepted");

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

    return EXIT_SUCCESS;
}