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 << "lyx: Disabling LyX socket." << endl;
  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         }
  85         address_.removeFile();
  86         LYXERR(Debug::LYXSERVER, "lyx: Server socket quitting");
  87 }
  88
  89
  90 string const ServerSocket::address() const
  91 {
  92         return address_.absFilename();
  93 }
  94
  95
  96 // Creates a new LyXDataSocket and checks to see if the connection
  97 // is OK and if the number of clients does not exceed MAX_CLIENTS
  98 void ServerSocket::serverCallback()
  99 {
 100         int const client_fd = socktools::accept(fd_);
 101
 102         if (fd_ == -1) {
 103                 LYXERR(Debug::LYXSERVER, "lyx: Failed to accept new client");
 104                 return;
 105         }
 106
 107         if (clients.size() >= MAX_CLIENTS) {
 108                 writeln("BYE:Too many clients connected");
 109                 return;
 110         }
 111
 112         // Register the new client.
 113         clients[client_fd] =
 114                 shared_ptr<LyXDataSocket>(new LyXDataSocket(client_fd));
 115         theApp()->registerSocketCallback(
 116                 client_fd,
 117                 boost::bind(&ServerSocket::dataCallback,
 118                             this, client_fd)
 119                 );
 120 }
 121
 122
 123 // Reads and processes input from client and check
 124 // if the connection has been closed
 125 void ServerSocket::dataCallback(int fd)
 126 {
 127         shared_ptr<LyXDataSocket> client = clients[fd];
 128
 129         string line;
 130         size_t pos;
 131         bool saidbye = false;
 132         while (!saidbye && client->readln(line)) {
 133                 // The protocol must be programmed here
 134                 // Split the key and the data
 135                 if ((pos = line.find(':')) == string::npos) {
 136                         client->writeln("ERROR:" + line + ":malformed message");
 137                         continue;
 138                 }
 139
 140                 string const key = line.substr(0, pos);
 141                 if (key == "LYXCMD") {
 142                         string const cmd = line.substr(pos + 1);
 143                         func->dispatch(lyxaction.lookupFunc(cmd));
 144                         string const rval = to_utf8(func->getMessage());
 145                         if (func->errorStat()) {
 146                                 client->writeln("ERROR:" + cmd + ':' + rval);
 147                         } else {
 148                                 client->writeln("INFO:" + cmd + ':' + rval);
 149                         }
 150                 } else if (key == "HELLO") {
 151                         // no use for client name!
 152                         client->writeln("HELLO:");
 153                 } else if (key == "BYE") {
 154                         saidbye = true;
 155                 } else {
 156                         client->writeln("ERROR:unknown key " + key);
 157                 }
 158         }
 159
 160         if (saidbye || !client->connected()) {
 161                 clients.erase(fd);
 162         }
 163 }
 164
 165
 166 void ServerSocket::writeln(string const & line)
 167 {
 168         string const linen = line + '\n';
 169         int const size = linen.size();
 170         int const written = ::write(fd_, linen.c_str(), size);
 171         if (written < size) { // Always mean end of connection.
 172                 if (written == -1 && errno == EPIPE) {
 173                         // The program will also receive a SIGPIPE
 174                         // that must be caught
 175                         lyxerr << "lyx: Server socket " << fd_
 176                                << " connection closed while writing." << endl;
 177                 } else {
 178                         // Anything else, including errno == EAGAIN, must be
 179                         // considered IO error. EAGAIN should never happen
 180                         // when line is small
 181                         lyxerr << "lyx: Server socket " << fd_
 182                              << " IO error: " << strerror(errno);
 183                 }
 184         }
 185 }
 186
 187 // Debug
 188 // void ServerSocket::dump() const
 189 // {
 190 //      lyxerr << "ServerSocket debug dump.\n"
 191 //           << "fd = " << fd_ << ", address = " << address_.absFilename() << ".\n"
 192 //           << "Clients: " << clients.size() << ".\n";
 193 //      map<int, shared_ptr<LyXDataSocket> >::const_iterator client = clients.begin();
 194 //      map<int, shared_ptr<LyXDataSocket> >::const_iterator end = clients.end();
 195 //      for (; client != end; ++client)
 196 //              lyxerr << "fd = " << client->first << '\n';
 197 // }
 198
 199
 200 LyXDataSocket::LyXDataSocket(int fd)
 201         : fd_(fd), connected_(true)
 202 {
 203         LYXERR(Debug::LYXSERVER, "lyx: New data socket " << fd_);
 204 }
 205
 206
 207 LyXDataSocket::~LyXDataSocket()
 208 {
 209         if (::close(fd_) != 0)
 210                 lyxerr << "lyx: Data socket " << fd_
 211                        << " IO error on closing: " << strerror(errno);
 212
 213         theApp()->unregisterSocketCallback(fd_);
 214         LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_ << " quitting.");
 215 }
 216
 217
 218 bool LyXDataSocket::connected() const
 219 {
 220         return connected_;
 221 }
 222
 223
 224 // Returns true if there was a complete line to input
 225 bool LyXDataSocket::readln(string & line)
 226 {
 227         int const charbuf_size = 100;
 228         char charbuf[charbuf_size]; // buffer for the ::read() system call
 229         int count;
 230
 231         // read and store characters in buffer
 232         while ((count = ::read(fd_, charbuf, charbuf_size - 1)) > 0) {
 233                 buffer_.append(charbuf, charbuf + count);
 234         }
 235
 236         // Error conditions. The buffer must still be
 237         // processed for lines read
 238         if (count == 0) { // EOF -- connection closed
 239                 LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_
 240                                          << ": connection closed.");
 241                 connected_ = false;
 242         } else if ((count == -1) && (errno != EAGAIN)) { // IO error
 243                 lyxerr << "lyx: Data socket " << fd_
 244                        << ": IO error." << endl;
 245                 connected_ = false;
 246         }
 247
 248         // Cut a line from buffer
 249         size_t pos = buffer_.find('\n');
 250         if (pos == string::npos) {
 251                 LYXERR(Debug::LYXSERVER, "lyx: Data socket " << fd_
 252                                          << ": line not completed.");
 253                 return false; // No complete line stored
 254         }
 255         line = buffer_.substr(0, pos);
 256         buffer_.erase(0, pos + 1);
 257         return true;
 258 }
 259
 260
 261 // Write a line of the form <key>:<value> to the socket
 262 void LyXDataSocket::writeln(string const & line)
 263 {
 264         string const linen = line + '\n';
 265         int const size = linen.size();
 266         int const written = ::write(fd_, linen.c_str(), size);
 267         if (written < size) { // Always mean end of connection.
 268                 if (written == -1 && errno == EPIPE) {
 269                         // The program will also receive a SIGPIPE
 270                         // that must be catched
 271                         lyxerr << "lyx: Data socket " << fd_
 272                                << " connection closed while writing." << endl;
 273                 } else {
 274                         // Anything else, including errno == EAGAIN, must be
 275                         // considered IO error. EAGAIN should never happen
 276                         // when line is small
 277                         lyxerr << "lyx: Data socket " << fd_
 278                              << " IO error: " << strerror(errno);
 279                 }
 280                 connected_ = false;
 281         }
 282 }
 283
 284
 285 } // namespace lyx