src/ServerSocket.cpp

   1 /**
   2  * \file ServerSocket.cpp
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Lars Gullik Bjønnes
   7  * \author Jean-Marc Lasgouttes
   8  * \author Angus Leeming
   9  * \author John Levon
  10  * \author João Luis M. Assirati
  11  *
  12  * Full author contact details are available in file CREDITS.
  13  */
  14
  15 #include <config.h>
  16
  17 #include "ServerSocket.h"
  18
  19 #include "FuncRequest.h"
  20 #include "LyXAction.h"
  21 #include "LyXFunc.h"
  22
  23 #include "frontends/Application.h"
  24
  25 #include "support/debug.h"
  26 #include "support/environment.h"
  27 #include "support/FileName.h"
  28 #include "support/socktools.h"
  29
  30 #include <boost/bind.hpp>
  31
  32 #include <cerrno>
  33 #include <ostream>
  34
  35 #if defined (_WIN32)
  36 # include <io.h>
  37 #endif
  38
  39 using namespace std;
  40 using namespace lyx::support;
  41
  42 using boost::shared_ptr;
  43
  44 namespace lyx {
  45
  46 // Address is the unix address for the socket.
  47 // MAX_CLIENTS is the maximum number of clients
  48 // that can connect at the same time.
  49 ServerSocket::ServerSocket(LyXFunc * f, FileName const & addr)
  50         : func(f),
  51           fd_(socktools::listen(addr, 3)),
  52           address_(addr)
  53 {
  54         if (fd_ == -1) {
  55                 LYXERR(Debug::LYXSERVER, "lyx: Disabling LyX socket.");
  56                 return;
  57         }
  58
  59         // These env vars are used by DVI inverse search
  60         // Needed by xdvi
  61         setEnv("XEDITOR", "lyxclient -g %f %l");
  62         // Needed by lyxclient
  63         setEnv("LYXSOCKET", address_.absFilename());
  64
  65         theApp()->registerSocketCallback(
  66                 fd_,
  67                 boost::bind(&ServerSocket::serverCallback, this)
  68                 );
  69
  70         LYXERR(Debug::LYXSERVER, "lyx: New server socket "
  71                                  << fd_ << ' ' << address_.absFilename());
  72 }
  73
  74
  75 // Close the socket and remove the address of the filesystem.
  76 ServerSocket::~ServerSocket()
  77 {
  78         if (fd_ != -1) {
  79                 BOOST_ASSERT (theApp());
  80                 theApp()->unregisterSocketCallback(fd_);
  81                 if (::close(fd_) != 0)
  82                         lyxerr << "lyx: Server socket " << fd_
  83                                << " IO error on closing: " << strerror(errno)
  84                                << endl;
  85         }
  86         address_.removeFile();
  87         LYXERR(Debug::LYXSERVER, "lyx: Server socket quitting");
  88 }
  89
  90
  91 string const ServerSocket::address() const
  92 {
  93         return address_.absFilename();
  94 }
  95
  96
  97 // Creates a new LyXDataSocket and checks to see if the connection
  98 // is OK and if the number of clients does not exceed MAX_CLIENTS
  99 void ServerSocket::serverCallback()
 100 {
 101         int const client_fd = socktools::accept(fd_);
 102
 103         if (fd_ == -1) {
 104                 LYXERR(Debug::LYXSERVER, "lyx: Failed to accept new client");
 105                 return;
 106         }
 107
 108         if (clients.size() >= MAX_CLIENTS) {
 109                 writeln("BYE:Too many clients connected");
 110                 return;
 111         }
 112
 113         // Register the new client.
 114         clients[client_fd] =
 115                 shared_ptr<LyXDataSocket>(new LyXDataSocket(client_fd));
 116         theApp()->registerSocketCallback(
 117                 client_fd,
 118                 boost::bind(&ServerSocket::dataCallback,
 119                             this, client_fd)
 120                 );
 121 }
 122
 123
 124 // Reads and processes input from client and check
 125 // if the connection has been closed
 126 void ServerSocket::dataCallback(int fd)
 127 {
 128         shared_ptr<LyXDataSocket> client = clients[fd];
 129
 130         string line;
 131         size_t pos;
 132         bool saidbye = false;
 133         while (!saidbye && client->readln(line)) {
 134                 // The protocol must be programmed here
 135                 // Split the key and the data
 136                 if ((pos = line.find(':')) == string::npos) {
 137                         client->writeln("ERROR:" + line + ":malformed message");
 138                         continue;
 139                 }
 140
 141                 string const key = line.substr(0, pos);
 142                 if (key == "LYXCMD") {
 143                         string const cmd = line.substr(pos + 1);
 144                         func->dispatch(lyxaction.lookupFunc(cmd));
 145                         string const rval = to_utf8(func->getMessage());
 146                         if (func->errorStat()) {
 147                                 client->writeln("ERROR:" + cmd + ':' + rval);
 148                         } else {
 149                                 client->writeln("INFO:" + cmd + ':' + rval);
 150                         }
 151                 } else if (key == "HELLO") {
 152                         // no use for client name!
 153                         client->writeln("HELLO:");
 154                 } else if (key == "BYE") {
 155                         saidbye = true;
 156                 } else {
 157                         client->writeln("ERROR:unknown key " + key);
 158                 }
 159         }
 160
 161         if (saidbye || !client->connected()) {
 162                 clients.erase(fd);
 163         }
 164 }
 165
 166
 167 void ServerSocket::writeln(string const & line)
 168 {
 169         string const linen = line + '\n';
 170         int const size = linen.size();
 171         int const written = ::write(fd_, linen.c_str(), size);
 172         if (written < size) { // Always mean end of connection.
 173                 if (written == -1 && errno == EPIPE) {
 174                         // The program will also receive a SIGPIPE
 175                         // that must be caught
 176                         lyxerr << "lyx: Server socket " << fd_
 177                                << " connection closed while writing." << endl;
 178                 } else {
 179                         // Anything else, including errno == EAGAIN, must be
 180                         // considered IO error. EAGAIN should never happen
 181                         // when line is small
 182                         lyxerr << "lyx: Server socket " << fd_
 183                              << " IO error: " << strerror(errno);
 184                 }
 185         }
 186 }
 187
 188 // Debug
 189 // void ServerSocket::dump() const
 190 // {
 191 //      lyxerr << "ServerSocket debug dump.\n"
 192 //           << "fd = " << fd_ << ", address = " << address_.absFilename() << ".\n"
 193 //           << "Clients: " << clients.size() << ".\n";
 194 //      map<int, shared_ptr<LyXDataSocket> >::const_iterator client = clients.begin();
 195 //      map<int, shared_ptr<LyXDataSocket> >::const_iterator end = clients.end();
 196 //      for (; client != end; ++client)
 197 //              lyxerr << "fd = " << client->first << '\n';
 198 // }
 199
 200
 201 LyXDataSocket::LyXDataSocket(int fd)
 202         : fd_(fd), connected_(true)
 203 {
 204         LYXERR(Debug::LYXSERVER, "lyx: New data socket " << fd_);
 205 }
 206
 207
 208 LyXDataSocket::~LyXDataSocket()
 209 {
 210         if (::close(fd_) != 0)
 211                 lyxerr << "lyx: Data socket " << fd_
 212                        << " IO error on closing: " << strerror(errno);
 213
 214         theApp()->unregisterSocketCallback(fd_);
 215         LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_ << " quitting.");
 216 }
 217
 218
 219 bool LyXDataSocket::connected() const
 220 {
 221         return connected_;
 222 }
 223
 224
 225 // Returns true if there was a complete line to input
 226 bool LyXDataSocket::readln(string & line)
 227 {
 228         int const charbuf_size = 100;
 229         char charbuf[charbuf_size]; // buffer for the ::read() system call
 230         int count;
 231
 232         // read and store characters in buffer
 233         while ((count = ::read(fd_, charbuf, charbuf_size - 1)) > 0) {
 234                 buffer_.append(charbuf, charbuf + count);
 235         }
 236
 237         // Error conditions. The buffer must still be
 238         // processed for lines read
 239         if (count == 0) { // EOF -- connection closed
 240                 LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_
 241                                          << ": connection closed.");
 242                 connected_ = false;
 243         } else if ((count == -1) && (errno != EAGAIN)) { // IO error
 244                 lyxerr << "lyx: Data socket " << fd_
 245                        << ": IO error." << endl;
 246                 connected_ = false;
 247         }
 248
 249         // Cut a line from buffer
 250         size_t pos = buffer_.find('\n');
 251         if (pos == string::npos) {
 252                 LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_
 253                                          << ": line not completed.");
 254                 return false; // No complete line stored
 255         }
 256         line = buffer_.substr(0, pos);
 257         buffer_.erase(0, pos + 1);
 258         return true;
 259 }
 260
 261
 262 // Write a line of the form <key>:<value> to the socket
 263 void LyXDataSocket::writeln(string const & line)
 264 {
 265         string const linen = line + '\n';
 266         int const size = linen.size();
 267         int const written = ::write(fd_, linen.c_str(), size);
 268         if (written < size) { // Always mean end of connection.
 269                 if (written == -1 && errno == EPIPE) {
 270                         // The program will also receive a SIGPIPE
 271                         // that must be catched
 272                         lyxerr << "lyx: Data socket " << fd_
 273                                << " connection closed while writing." << endl;
 274                 } else {
 275                         // Anything else, including errno == EAGAIN, must be
 276                         // considered IO error. EAGAIN should never happen
 277                         // when line is small
 278                         lyxerr << "lyx: Data socket " << fd_
 279                              << " IO error: " << strerror(errno);
 280                 }
 281                 connected_ = false;
 282         }
 283 }
 284
 285
 286 } // namespace lyx