chibackend/net/nntp.d

   1 /* DigitalMars NNTP reader
   2  * coded by Ketmar // Invisible Vector <ketmar@ketmar.no-ip.org>
   3  * Understanding is not required. Only obedience.
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3 of the License ONLY.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 module chibackend.net.nntp /*is aliced*/;
  18
  19 import std.socket;
  20
  21 import iv.alice;
  22 import iv.cmdcon;
  23
  24 import chibackend : DynStr;
  25 import chibackend.net.linesocket;
  26
  27
  28 /*
  29 usage:
  30
  31 receiving
  32 =========
  33
  34   auto nsk = new SocketNNTP(server);
  35   scope(exit) nsk.close();
  36
  37   nsk.selectGroup(group);
  38   if (nsk.emptyGroup) {
  39     conwriteln("[", name, ":", group, "]: no new articles");
  40     return;
  41   }
  42
  43   uint stnum = inbox.maxNntpIndex+1;
  44   if (stnum == 0) stnum = (nsk.hiwater > 1023 ? nsk.hiwater-1023 : 0);
  45   if (stnum > nsk.hiwater) {
  46     conwriteln("[", name, ":", group, "]: no new articles");
  47     return;
  48   }
  49
  50   conwriteln("[", name, ":", group, "]: ", nsk.hiwater+1-stnum, " (possible) new articles");
  51
  52   // download new articles
  53   foreach (immutable uint anum; stnum..nsk.hiwater+1) {
  54     auto msg = nsk.getArticle(anum);
  55   }
  56
  57 sending
  58 ========
  59   SocketNNTP nsk;
  60   try {
  61     nsk = new SocketNNTP(server);
  62   } catch (Exception e) {
  63     conwriteln("[", name, ":", group, "]: connection error: ", e.msg);
  64     return false;
  65   }
  66   scope(exit) nsk.close();
  67
  68   try {
  69     nsk.selectGroup(group);
  70     nsk.doSend("POST");
  71     nsk.doSendRaw(art.getTextToSend);
  72     auto ln = nsk.readLine;
  73     conwriteln(ln); // 340 Ok, recommended message-ID <o7dq4o$mpm$1@digitalmars.com>
  74     if (ln.length == 0 || ln[0] != '3') throw new Exception(ln.idup);
  75   } catch (Exception e) {
  76     conwriteln("[", name, ":", group, "]: sending error: ", e.msg);
  77     return false;
  78   }
  79 */
  80
  81
  82 // ////////////////////////////////////////////////////////////////////////// //
  83 public final class SocketNNTP : SocketLine {
  84 private:
  85   bool canPost;
  86
  87 public: //WARNING! DO NOT CHANGE!
  88   dynstring group;
  89   uint lowater, hiwater;
  90   bool emptyGroup = true;
  91
  92 public:
  93   this (string server, bool debugdump=false) {
  94     super(server, plainport:119, tlsport:563, debugdump:debugdump);
  95     scope(failure) abort(doshutdown:false);
  96     auto hello = readLine();
  97     if (hello.length < 4 && hello[0] != '2' || hello[1] != '0' || hello[3] != ' ') throw new Exception("invalid hello");
  98          if (hello[2] == '0') canPost = true;
  99     else if (hello[2] == '1') canPost = false;
 100     else throw new Exception("invalid hello");
 101   }
 102
 103   @property bool postingAllowed () const nothrow @safe @nogc { return canPost; }
 104
 105   override void quit () {
 106     if (!active) return;
 107     doSend("QUIT");
 108     auto ln = readLine();
 109   }
 110
 111   void selectGroup (const(char)[] name) {
 112     doSendCmdArg("GROUP", name);
 113     const(char)[] ln;
 114     try {
 115       ln = readLine();
 116     } catch (Throwable e) {
 117       abort(doshutdown:false);
 118       throw e;
 119     }
 120     scope(failure) { group.clear(); lowater = hiwater = 0; emptyGroup = true; }
 121     auto origln = ln;
 122     if (getStrToken(ln) != "211") {
 123       conwriteln("*ERROR: NNTP server GROUP reply: ", origln);
 124       throw new Exception("invalid GROUP reply");
 125     }
 126     auto cnt = getToken!uint(ln);
 127     lowater = getToken!uint(ln);
 128     hiwater = getToken!uint(ln);
 129     if (cnt == 0 || lowater > hiwater || (lowater == 0 && hiwater == 0)) {
 130       lowater = hiwater = 0;
 131       emptyGroup = true;
 132     } else {
 133       emptyGroup = false;
 134     }
 135     group = name;
 136   }
 137
 138   // if `exact` is true, returns line with exact terminators
 139   // returns empty string if there's no such article (this is not a error!)
 140   // can return truncated message if it is too big
 141   DynStr getArticle(bool exact=false) (uint num) {
 142     DynStr res;
 143     doSendCmdArg("ARTICLE", num);
 144     auto ln = readLine();
 145     //conwriteln("|", ln, "|");
 146     auto rescode = getToken!uint(ln);
 147     if (rescode != 220) {
 148       if (rescode == 420 || rescode == 423) {
 149         //throw new Exception("no such article");
 150         return res;
 151       }
 152       close();
 153       throw new Exception("ARTICLE failed");
 154     }
 155     if (getToken!uint(ln) != num) { close(); throw new Exception("invalid replied article number"); }
 156     uint number = num;
 157     //string msgid = getToken(ln).idup;
 158     // add index header
 159     static if (exact) bool needAddEOL = false;
 160     if (number) {
 161       res ~= "NNTP-Index: ";
 162       res.appendNum(number);
 163       static if (exact) needAddEOL = true; else res.append('\n');
 164       if (mDebugDump) conwriteln("+", number);
 165     }
 166     // read text
 167     bool toobig = false;
 168     for (;;) {
 169       ln = readLine!exact;
 170       static if (exact) {
 171         if (needAddEOL && ln.length) {
 172           if (ln.length >= 2 && ln[$-2..$] == "\r\n") res.append("\r\n"); else res.append("\n");
 173           needAddEOL = false;
 174         }
 175       }
 176       if (!toobig) {
 177         res ~= ln;
 178         static if (!exact) res ~= '\n';
 179       }
 180       if (ln.length == 0 || ln[0] != '.') continue;
 181       if (ln.length == 1) break;
 182       static if (exact) {
 183         if (ln.length == 3 && ln == ".\r\n") break;
 184         if (ln.length == 2 && ln == ".\n") break;
 185       }
 186       if (!toobig && res.length > 1024*1024*128) {
 187         conwriteln("WARNING: mail message too big!");
 188         toobig = true;
 189       }
 190     }
 191     static if (exact) {
 192       if (needAddEOL) res.append('\n');
 193     }
 194     return res;
 195   }
 196 }