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