src/server/tcl_server.c

   1 /***************************************************************************
   2  *   Copyright (C) 2008                                                    *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   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, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  18  ***************************************************************************/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <stdarg.h>
  25 #include "tcl_server.h"
  26
  27 #include "log.h"
  28 #include "command.h"
  29
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <errno.h>
  33 #include <string.h>
  34 #include <ctype.h>
  35
  36 #define TCL_SERVER_VERSION      "TCL Server 0.1"
  37 #define TCL_MAX_LINE            (4096)
  38
  39 typedef struct tcl_connection_s {
  40         int tc_linedrop;
  41         int tc_lineoffset;
  42         char tc_line[TCL_MAX_LINE];
  43         int tc_outerror; /* flag an output error */
  44 } tcl_connection_t;
  45
  46 static unsigned short tcl_port = 0;
  47
  48 /* commands */
  49 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  50
  51 /* handlers */
  52 static int tcl_new_connection(connection_t *connection);
  53 static int tcl_input(connection_t *connection);
  54 static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
  55 static int tcl_closed(connection_t *connection);
  56
  57 /* write data out to a socket.
  58  *
  59  * this is a blocking write, so the return value must equal the length, if
  60  * that is not the case then flag the connection with an output error.
  61  */
  62 int tcl_output(connection_t *connection, const void *data, ssize_t len)
  63 {
  64         ssize_t wlen;
  65         tcl_connection_t *tclc;
  66
  67         tclc = connection->priv;
  68         if (tclc->tc_outerror)
  69                 return ERROR_SERVER_REMOTE_CLOSED;
  70
  71         wlen = write_socket(connection->fd, data, len);
  72         if (wlen == len)
  73                 return ERROR_OK;
  74
  75         LOG_ERROR("error during write: %d != %d", (int)wlen, (int)len);
  76         tclc->tc_outerror = 1;
  77         return ERROR_SERVER_REMOTE_CLOSED;
  78 }
  79
  80 /* connections */
  81 static int tcl_new_connection(connection_t *connection)
  82 {
  83         tcl_connection_t *tclc;
  84
  85         tclc = malloc(sizeof(tcl_connection_t));
  86         if (tclc == NULL)
  87                 return ERROR_CONNECTION_REJECTED;
  88
  89         memset(tclc, 0, sizeof(tcl_connection_t));
  90         connection->priv = tclc;
  91         return ERROR_OK;
  92 }
  93
  94 static int tcl_input(connection_t *connection)
  95 {
  96         int retval;
  97         int i;
  98         ssize_t rlen;
  99         const char *result;
 100         int reslen;
 101         tcl_connection_t *tclc;
 102         char in[256];
 103
 104         rlen = read_socket(connection->fd, &in, sizeof(in));
 105         if (rlen <= 0) {
 106                 if (rlen < 0)
 107                         LOG_ERROR("error during read: %s", strerror(errno));
 108                 return ERROR_SERVER_REMOTE_CLOSED;
 109         }
 110
 111         tclc = connection->priv;
 112         if (tclc == NULL)
 113                 return ERROR_CONNECTION_REJECTED;
 114
 115         /* push as much data into the line as possible */
 116         for (i = 0; i < rlen; i++)
 117         {
 118                 if (!isprint(in[i]) && !isspace(in[i]))
 119                 {
 120                         /* drop this line */
 121                         tclc->tc_linedrop = 1;
 122                         continue;
 123                 }
 124
 125                 /* buffer the data */
 126                 tclc->tc_line[tclc->tc_lineoffset] = in[i];
 127                 if (tclc->tc_lineoffset < TCL_MAX_LINE)
 128                         tclc->tc_lineoffset++;
 129                 else
 130                         tclc->tc_linedrop = 1;
 131
 132                 if (in[i] != '\n')
 133                         continue;
 134
 135                 /* process the line */
 136                 if (tclc->tc_linedrop) {
 137 #define ESTR "line too long\n"
 138                         retval = tcl_output(connection, ESTR, sizeof(ESTR));
 139                         if (retval != ERROR_OK)
 140                                 return retval;
 141 #undef ESTR
 142                 }
 143                 else {
 144                         tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 145                         retval = Jim_Eval_Named(interp, tclc->tc_line, "remote:connection",1);
 146                         result = Jim_GetString(Jim_GetResult(interp), &reslen);
 147                         retval = tcl_output(connection, result, reslen);
 148                         if (retval != ERROR_OK)
 149                                 return retval;
 150                         if (memchr(result, '\n', reslen) == NULL)
 151                                 tcl_output(connection, "\n", 1);
 152                 }
 153
 154                 tclc->tc_lineoffset = 0;
 155                 tclc->tc_linedrop = 0;
 156         }
 157
 158         return ERROR_OK;
 159 }
 160
 161 static int tcl_closed(connection_t *connection)
 162 {
 163         /* cleanup connection context */
 164         if (connection->priv) {
 165                 free(connection->priv);
 166                 connection->priv = NULL;
 167         }
 168         return ERROR_OK;
 169 }
 170
 171 int tcl_init(void)
 172 {
 173         int retval;
 174
 175         if (tcl_port == 0)
 176         {
 177                 LOG_WARNING("no tcl port specified, using default port 6666");
 178                 tcl_port = 6666;
 179         }
 180
 181         retval = add_service("tcl", CONNECTION_TCP, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 182         return retval;
 183 }
 184
 185 int tcl_register_commands(command_context_t *cmd_ctx)
 186 {
 187         register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "port on which to listen for incoming TCL syntax");
 188         return ERROR_OK;
 189 }
 190
 191 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 192 {
 193         if (argc == 1) {
 194                 tcl_port = strtoul(args[0], NULL, 0);
 195         }
 196         return ERROR_OK;
 197 }