release/src/router/busybox/printutils/lpr.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * bare bones version of lpr & lpq: BSD printing utilities
   4  *
   5  * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
   6  *
   7  * Original idea and code:
   8  *      Walter Harms <WHarms@bfs.de>
   9  *
  10  * Licensed under GPLv2, see file LICENSE in this source tree.
  11  *
  12  * See RFC 1179 for protocol description.
  13  */
  14
  15 //usage:#define lpr_trivial_usage
  16 //usage:       "-P queue[@host[:port]] -U USERNAME -J TITLE -Vmh [FILE]..."
  17 /* -C CLASS exists too, not shown.
  18  * CLASS is supposed to be printed on banner page, if one is requested */
  19 //usage:#define lpr_full_usage "\n\n"
  20 //usage:       "        -P      lp service to connect to (else uses $PRINTER)"
  21 //usage:     "\n        -m      Send mail on completion"
  22 //usage:     "\n        -h      Print banner page too"
  23 //usage:     "\n        -V      Verbose"
  24 //usage:
  25 //usage:#define lpq_trivial_usage
  26 //usage:       "[-P queue[@host[:port]]] [-U USERNAME] [-d JOBID]... [-fs]"
  27 //usage:#define lpq_full_usage "\n\n"
  28 //usage:       "        -P      lp service to connect to (else uses $PRINTER)"
  29 //usage:     "\n        -d      Delete jobs"
  30 //usage:     "\n        -f      Force any waiting job to be printed"
  31 //usage:     "\n        -s      Short display"
  32
  33 #include "libbb.h"
  34
  35 /*
  36  * LPD returns binary 0 on success.
  37  * Otherwise it returns error message.
  38  */
  39 static void get_response_or_say_and_die(int fd, const char *errmsg)
  40 {
  41         ssize_t sz;
  42         char buf[128];
  43
  44         buf[0] = ' ';
  45         sz = safe_read(fd, buf, 1);
  46         if ('\0' != buf[0]) {
  47                 // request has failed
  48                 // try to make sure last char is '\n', but do not add
  49                 // superfluous one
  50                 sz = full_read(fd, buf + 1, 126);
  51                 bb_error_msg("error while %s%s", errmsg,
  52                                 (sz > 0 ? ". Server said:" : ""));
  53                 if (sz > 0) {
  54                         // sz = (bytes in buf) - 1
  55                         if (buf[sz] != '\n')
  56                                 buf[++sz] = '\n';
  57                         safe_write(STDERR_FILENO, buf, sz + 1);
  58                 }
  59                 xfunc_die();
  60         }
  61 }
  62
  63 int lpqr_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
  64 int lpqr_main(int argc UNUSED_PARAM, char *argv[])
  65 {
  66         enum {
  67                 OPT_P           = 1 << 0, // -P queue[@host[:port]]. If no -P is given use $PRINTER, then "lp@localhost:515"
  68                 OPT_U           = 1 << 1, // -U username
  69
  70                 LPR_V           = 1 << 2, // -V: be verbose
  71                 LPR_h           = 1 << 3, // -h: want banner printed
  72                 LPR_C           = 1 << 4, // -C class: job "class" (? supposedly printed on banner)
  73                 LPR_J           = 1 << 5, // -J title: the job title for the banner page
  74                 LPR_m           = 1 << 6, // -m: send mail back to user
  75
  76                 LPQ_SHORT_FMT   = 1 << 2, // -s: short listing format
  77                 LPQ_DELETE      = 1 << 3, // -d: delete job(s)
  78                 LPQ_FORCE       = 1 << 4, // -f: force waiting job(s) to be printed
  79         };
  80         char tempfile[sizeof("/tmp/lprXXXXXX")];
  81         const char *job_title;
  82         const char *printer_class = "";   // printer class, max 32 char
  83         const char *queue;                // name of printer queue
  84         const char *server = "localhost"; // server[:port] of printer queue
  85         char *hostname;
  86         // N.B. IMHO getenv("USER") can be way easily spoofed!
  87         const char *user = xuid2uname(getuid());
  88         unsigned job;
  89         unsigned opts;
  90         int fd;
  91
  92         // parse options
  93         // TODO: set opt_complementary: s,d,f are mutually exclusive
  94         opts = getopt32(argv,
  95                 (/*lp*/'r' == applet_name[2]) ? "P:U:VhC:J:m" : "P:U:sdf"
  96                 , &queue, &user
  97                 , &printer_class, &job_title
  98         );
  99         argv += optind;
 100
 101         // if queue is not specified -> use $PRINTER
 102         if (!(opts & OPT_P))
 103                 queue = getenv("PRINTER");
 104         // if queue is still not specified ->
 105         if (!queue) {
 106                 // ... queue defaults to "lp"
 107                 // server defaults to "localhost"
 108                 queue = "lp";
 109         // if queue is specified ->
 110         } else {
 111                 // queue name is to the left of '@'
 112                 char *s = strchr(queue, '@');
 113                 if (s) {
 114                         // server name is to the right of '@'
 115                         *s = '\0';
 116                         server = s + 1;
 117                 }
 118         }
 119
 120         // do connect
 121         fd = create_and_connect_stream_or_die(server, 515);
 122
 123         //
 124         // LPQ ------------------------
 125         //
 126         if (/*lp*/'q' == applet_name[2]) {
 127                 char cmd;
 128                 // force printing of every job still in queue
 129                 if (opts & LPQ_FORCE) {
 130                         cmd = 1;
 131                         goto command;
 132                 // delete job(s)
 133                 } else if (opts & LPQ_DELETE) {
 134                         fdprintf(fd, "\x5" "%s %s", queue, user);
 135                         while (*argv) {
 136                                 fdprintf(fd, " %s", *argv++);
 137                         }
 138                         bb_putchar('\n');
 139                 // dump current jobs status
 140                 // N.B. periodical polling should be achieved
 141                 // via "watch -n delay lpq"
 142                 // They say it's the UNIX-way :)
 143                 } else {
 144                         cmd = (opts & LPQ_SHORT_FMT) ? 3 : 4;
 145  command:
 146                         fdprintf(fd, "%c" "%s\n", cmd, queue);
 147                         bb_copyfd_eof(fd, STDOUT_FILENO);
 148                 }
 149
 150                 return EXIT_SUCCESS;
 151         }
 152
 153         //
 154         // LPR ------------------------
 155         //
 156         if (opts & LPR_V)
 157                 bb_error_msg("connected to server");
 158
 159         job = getpid() % 1000;
 160         hostname = safe_gethostname();
 161
 162         // no files given on command line? -> use stdin
 163         if (!*argv)
 164                 *--argv = (char *)"-";
 165
 166         fdprintf(fd, "\x2" "%s\n", queue);
 167         get_response_or_say_and_die(fd, "setting queue");
 168
 169         // process files
 170         do {
 171                 unsigned cflen;
 172                 int dfd;
 173                 struct stat st;
 174                 char *c;
 175                 char *remote_filename;
 176                 char *controlfile;
 177
 178                 // if data file is stdin, we need to dump it first
 179                 if (LONE_DASH(*argv)) {
 180                         strcpy(tempfile, "/tmp/lprXXXXXX");
 181                         dfd = xmkstemp(tempfile);
 182                         bb_copyfd_eof(STDIN_FILENO, dfd);
 183                         xlseek(dfd, 0, SEEK_SET);
 184                         *argv = (char*)bb_msg_standard_input;
 185                 } else {
 186                         dfd = xopen(*argv, O_RDONLY);
 187                 }
 188
 189                 /* "The name ... should start with ASCII "cfA",
 190                  * followed by a three digit job number, followed
 191                  * by the host name which has constructed the file."
 192                  * We supply 'c' or 'd' as needed for control/data file. */
 193                 remote_filename = xasprintf("fA%03u%s", job, hostname);
 194
 195                 // create control file
 196                 // TODO: all lines but 2 last are constants! How we can use this fact?
 197                 controlfile = xasprintf(
 198                         "H" "%.32s\n" "P" "%.32s\n" /* H HOST, P USER */
 199                         "C" "%.32s\n" /* C CLASS - printed on banner page (if L cmd is also given) */
 200                         "J" "%.99s\n" /* J JOBNAME */
 201                         /* "class name for banner page and job name
 202                          * for banner page commands must precede L command" */
 203                         "L" "%.32s\n" /* L USER - print banner page, with given user's name */
 204                         "M" "%.32s\n" /* M WHOM_TO_MAIL */
 205                         "l" "d%.31s\n" /* l DATA_FILE_NAME ("dfAxxx") */
 206                         , hostname, user
 207                         , printer_class /* can be "" */
 208                         , ((opts & LPR_J) ? job_title : *argv)
 209                         , (opts & LPR_h) ? user : ""
 210                         , (opts & LPR_m) ? user : ""
 211                         , remote_filename
 212                 );
 213                 // delete possible "\nX\n" patterns
 214                 c = controlfile;
 215                 cflen = (unsigned)strlen(controlfile);
 216                 while ((c = strchr(c, '\n')) != NULL) {
 217                         if (c[1] && c[2] == '\n') {
 218                                 /* can't use strcpy, results are undefined */
 219                                 memmove(c, c+2, cflen - (c-controlfile) - 1);
 220                                 cflen -= 2;
 221                         } else {
 222                                 c++;
 223                         }
 224                 }
 225
 226                 // send control file
 227                 if (opts & LPR_V)
 228                         bb_error_msg("sending control file");
 229                 /* "Acknowledgement processing must occur as usual
 230                  * after the command is sent." */
 231                 fdprintf(fd, "\x2" "%u c%s\n", cflen, remote_filename);
 232                 get_response_or_say_and_die(fd, "sending control file");
 233                 /* "Once all of the contents have
 234                  * been delivered, an octet of zero bits is sent as
 235                  * an indication that the file being sent is complete.
 236                  * A second level of acknowledgement processing
 237                  * must occur at this point." */
 238                 full_write(fd, controlfile, cflen + 1); /* writes NUL byte too */
 239                 get_response_or_say_and_die(fd, "sending control file");
 240
 241                 // send data file, with name "dfaXXX"
 242                 if (opts & LPR_V)
 243                         bb_error_msg("sending data file");
 244                 st.st_size = 0; /* paranoia: fstat may theoretically fail */
 245                 fstat(dfd, &st);
 246                 fdprintf(fd, "\x3" "%"OFF_FMT"u d%s\n", st.st_size, remote_filename);
 247                 get_response_or_say_and_die(fd, "sending data file");
 248                 if (bb_copyfd_size(dfd, fd, st.st_size) != st.st_size) {
 249                         // We're screwed. We sent less bytes than we advertised.
 250                         bb_error_msg_and_die("local file changed size?!");
 251                 }
 252                 write(fd, "", 1); // send ACK
 253                 get_response_or_say_and_die(fd, "sending data file");
 254
 255                 // delete temporary file if we dumped stdin
 256                 if (*argv == (char*)bb_msg_standard_input)
 257                         unlink(tempfile);
 258
 259                 // cleanup
 260                 close(fd);
 261                 free(remote_filename);
 262                 free(controlfile);
 263
 264                 // say job accepted
 265                 if (opts & LPR_V)
 266                         bb_error_msg("job accepted");
 267
 268                 // next, please!
 269                 job = (job + 1) % 1000;
 270         } while (*++argv);
 271
 272         return EXIT_SUCCESS;
 273 }