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 "tcl_server.h"
  25
  26
  27 #define TCL_SERVER_VERSION      "TCL Server 0.1"
  28 #define TCL_MAX_LINE            (4096)
  29
  30 struct tcl_connection {
  31         int tc_linedrop;
  32         int tc_lineoffset;
  33         char tc_line[TCL_MAX_LINE];
  34         int tc_outerror; /* flag an output error */
  35 };
  36
  37 static unsigned short tcl_port = 6666;
  38
  39 /* handlers */
  40 static int tcl_new_connection(struct connection *connection);
  41 static int tcl_input(struct connection *connection);
  42 static int tcl_output(struct connection *connection, const void *buf, ssize_t len);
  43 static int tcl_closed(struct connection *connection);
  44
  45 /* write data out to a socket.
  46  *
  47  * this is a blocking write, so the return value must equal the length, if
  48  * that is not the case then flag the connection with an output error.
  49  */
  50 int tcl_output(struct connection *connection, const void *data, ssize_t len)
  51 {
  52         ssize_t wlen;
  53         struct tcl_connection *tclc;
  54
  55         tclc = connection->priv;
  56         if (tclc->tc_outerror)
  57                 return ERROR_SERVER_REMOTE_CLOSED;
  58
  59         wlen = write_socket(connection->fd, data, len);
  60         if (wlen == len)
  61                 return ERROR_OK;
  62
  63         LOG_ERROR("error during write: %d != %d", (int)wlen, (int)len);
  64         tclc->tc_outerror = 1;
  65         return ERROR_SERVER_REMOTE_CLOSED;
  66 }
  67
  68 /* connections */
  69 static int tcl_new_connection(struct connection *connection)
  70 {
  71         struct tcl_connection *tclc;
  72
  73         tclc = malloc(sizeof(struct tcl_connection));
  74         if (tclc == NULL)
  75                 return ERROR_CONNECTION_REJECTED;
  76
  77         memset(tclc, 0, sizeof(struct tcl_connection));
  78         connection->priv = tclc;
  79         return ERROR_OK;
  80 }
  81
  82 static int tcl_input(struct connection *connection)
  83 {
  84         Jim_Interp *interp = (Jim_Interp *)connection->cmd_ctx->interp;
  85         int retval;
  86         int i;
  87         ssize_t rlen;
  88         const char *result;
  89         int reslen;
  90         struct tcl_connection *tclc;
  91         unsigned char in[256];
  92
  93         rlen = read_socket(connection->fd, &in, sizeof(in));
  94         if (rlen <= 0) {
  95                 if (rlen < 0)
  96                         LOG_ERROR("error during read: %s", strerror(errno));
  97                 return ERROR_SERVER_REMOTE_CLOSED;
  98         }
  99
 100         tclc = connection->priv;
 101         if (tclc == NULL)
 102                 return ERROR_CONNECTION_REJECTED;
 103
 104         /* push as much data into the line as possible */
 105         for (i = 0; i < rlen; i++)
 106         {
 107                 if (!isprint(in[i]) && !isspace(in[i]))
 108                 {
 109                         /* drop this line */
 110                         tclc->tc_linedrop = 1;
 111                         continue;
 112                 }
 113
 114                 /* buffer the data */
 115                 tclc->tc_line[tclc->tc_lineoffset] = in[i];
 116                 if (tclc->tc_lineoffset < TCL_MAX_LINE)
 117                         tclc->tc_lineoffset++;
 118                 else
 119                         tclc->tc_linedrop = 1;
 120
 121                 if (in[i] != '\n')
 122                         continue;
 123
 124                 /* process the line */
 125                 if (tclc->tc_linedrop) {
 126 #define ESTR "line too long\n"
 127                         retval = tcl_output(connection, ESTR, sizeof(ESTR));
 128                         if (retval != ERROR_OK)
 129                                 return retval;
 130 #undef ESTR
 131                 }
 132                 else {
 133                         tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 134                         retval = Jim_Eval_Named(interp, tclc->tc_line, "remote:connection",1);
 135                         result = Jim_GetString(Jim_GetResult(interp), &reslen);
 136                         retval = tcl_output(connection, result, reslen);
 137                         if (retval != ERROR_OK)
 138                                 return retval;
 139                         if (memchr(result, '\n', reslen) == NULL)
 140                                 tcl_output(connection, "\n", 1);
 141                 }
 142
 143                 tclc->tc_lineoffset = 0;
 144                 tclc->tc_linedrop = 0;
 145         }
 146
 147         return ERROR_OK;
 148 }
 149
 150 static int tcl_closed(struct connection *connection)
 151 {
 152         /* cleanup connection context */
 153         if (connection->priv) {
 154                 free(connection->priv);
 155                 connection->priv = NULL;
 156         }
 157         return ERROR_OK;
 158 }
 159
 160 int tcl_init(void)
 161 {
 162         int retval;
 163
 164         if (tcl_port == 0)
 165         {
 166                 LOG_INFO("tcl port disabled");
 167                 return ERROR_OK;
 168         }
 169
 170         retval = add_service("tcl", CONNECTION_TCP, tcl_port, 1,
 171                         &tcl_new_connection, &tcl_input,
 172                         &tcl_closed, NULL);
 173         return retval;
 174 }
 175
 176 COMMAND_HANDLER(handle_tcl_port_command)
 177 {
 178         return CALL_COMMAND_HANDLER(server_port_command, &tcl_port);
 179 }
 180
 181 static const struct command_registration tcl_command_handlers[] = {
 182         {
 183                 .name = "tcl_port",
 184                 .handler = handle_tcl_port_command,
 185                 .mode = COMMAND_CONFIG,
 186                 .help = "Specify port on which to listen "
 187                         "for incoming Tcl syntax.  "
 188                         "No arguments reports Tcl port; zero disables.",
 189                 .usage = "[port_num]",
 190         },
 191         COMMAND_REGISTRATION_DONE
 192 };
 193
 194 int tcl_register_commands(struct command_context *cmd_ctx)
 195 {
 196         return register_commands(cmd_ctx, NULL, tcl_command_handlers);
 197 }