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 typedef struct tcl_connection_s {
  31         int tc_linedrop;
  32         int tc_lineoffset;
  33         char tc_line[TCL_MAX_LINE];
  34         int tc_outerror; /* flag an output error */
  35 } tcl_connection_t;
  36
  37 static unsigned short tcl_port = 6666;
  38
  39 /* handlers */
  40 static int tcl_new_connection(connection_t *connection);
  41 static int tcl_input(connection_t *connection);
  42 static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
  43 static int tcl_closed(connection_t *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(connection_t *connection, const void *data, ssize_t len)
  51 {
  52         ssize_t wlen;
  53         tcl_connection_t *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(connection_t *connection)
  70 {
  71         tcl_connection_t *tclc;
  72
  73         tclc = malloc(sizeof(tcl_connection_t));
  74         if (tclc == NULL)
  75                 return ERROR_CONNECTION_REJECTED;
  76
  77         memset(tclc, 0, sizeof(tcl_connection_t));
  78         connection->priv = tclc;
  79         return ERROR_OK;
  80 }
  81
  82 static int tcl_input(connection_t *connection)
  83 {
  84         int retval;
  85         int i;
  86         ssize_t rlen;
  87         const char *result;
  88         int reslen;
  89         tcl_connection_t *tclc;
  90         char in[256];
  91
  92         rlen = read_socket(connection->fd, &in, sizeof(in));
  93         if (rlen <= 0) {
  94                 if (rlen < 0)
  95                         LOG_ERROR("error during read: %s", strerror(errno));
  96                 return ERROR_SERVER_REMOTE_CLOSED;
  97         }
  98
  99         tclc = connection->priv;
 100         if (tclc == NULL)
 101                 return ERROR_CONNECTION_REJECTED;
 102
 103         /* push as much data into the line as possible */
 104         for (i = 0; i < rlen; i++)
 105         {
 106                 if (!isprint(in[i]) && !isspace(in[i]))
 107                 {
 108                         /* drop this line */
 109                         tclc->tc_linedrop = 1;
 110                         continue;
 111                 }
 112
 113                 /* buffer the data */
 114                 tclc->tc_line[tclc->tc_lineoffset] = in[i];
 115                 if (tclc->tc_lineoffset < TCL_MAX_LINE)
 116                         tclc->tc_lineoffset++;
 117                 else
 118                         tclc->tc_linedrop = 1;
 119
 120                 if (in[i] != '\n')
 121                         continue;
 122
 123                 /* process the line */
 124                 if (tclc->tc_linedrop) {
 125 #define ESTR "line too long\n"
 126                         retval = tcl_output(connection, ESTR, sizeof(ESTR));
 127                         if (retval != ERROR_OK)
 128                                 return retval;
 129 #undef ESTR
 130                 }
 131                 else {
 132                         tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 133                         retval = Jim_Eval_Named(interp, tclc->tc_line, "remote:connection",1);
 134                         result = Jim_GetString(Jim_GetResult(interp), &reslen);
 135                         retval = tcl_output(connection, result, reslen);
 136                         if (retval != ERROR_OK)
 137                                 return retval;
 138                         if (memchr(result, '\n', reslen) == NULL)
 139                                 tcl_output(connection, "\n", 1);
 140                 }
 141
 142                 tclc->tc_lineoffset = 0;
 143                 tclc->tc_linedrop = 0;
 144         }
 145
 146         return ERROR_OK;
 147 }
 148
 149 static int tcl_closed(connection_t *connection)
 150 {
 151         /* cleanup connection context */
 152         if (connection->priv) {
 153                 free(connection->priv);
 154                 connection->priv = NULL;
 155         }
 156         return ERROR_OK;
 157 }
 158
 159 int tcl_init(void)
 160 {
 161         int retval;
 162
 163         if (tcl_port == 0)
 164         {
 165                 LOG_INFO("tcl port disabled");
 166                 return ERROR_OK;
 167         }
 168
 169         retval = add_service("tcl", CONNECTION_TCP, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 170         return retval;
 171 }
 172
 173 static int handle_tcl_port_command(struct command_context_s *cmd_ctx,
 174                 char *cmd, char **args, int argc)
 175 {
 176         return server_port_command(cmd_ctx, cmd, args, argc, &tcl_port);
 177 }
 178
 179 int tcl_register_commands(command_context_t *cmd_ctx)
 180 {
 181         register_command(cmd_ctx, NULL, "tcl_port",
 182                         handle_tcl_port_command, COMMAND_CONFIG,
 183                         "port on which to listen for incoming TCL syntax");
 184         return ERROR_OK;
 185 }