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 /* commands */
  40 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  41
  42 /* handlers */
  43 static int tcl_new_connection(connection_t *connection);
  44 static int tcl_input(connection_t *connection);
  45 static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
  46 static int tcl_closed(connection_t *connection);
  47
  48 /* write data out to a socket.
  49  *
  50  * this is a blocking write, so the return value must equal the length, if
  51  * that is not the case then flag the connection with an output error.
  52  */
  53 int tcl_output(connection_t *connection, const void *data, ssize_t len)
  54 {
  55         ssize_t wlen;
  56         tcl_connection_t *tclc;
  57
  58         tclc = connection->priv;
  59         if (tclc->tc_outerror)
  60                 return ERROR_SERVER_REMOTE_CLOSED;
  61
  62         wlen = write_socket(connection->fd, data, len);
  63         if (wlen == len)
  64                 return ERROR_OK;
  65
  66         LOG_ERROR("error during write: %d != %d", (int)wlen, (int)len);
  67         tclc->tc_outerror = 1;
  68         return ERROR_SERVER_REMOTE_CLOSED;
  69 }
  70
  71 /* connections */
  72 static int tcl_new_connection(connection_t *connection)
  73 {
  74         tcl_connection_t *tclc;
  75
  76         tclc = malloc(sizeof(tcl_connection_t));
  77         if (tclc == NULL)
  78                 return ERROR_CONNECTION_REJECTED;
  79
  80         memset(tclc, 0, sizeof(tcl_connection_t));
  81         connection->priv = tclc;
  82         return ERROR_OK;
  83 }
  84
  85 static int tcl_input(connection_t *connection)
  86 {
  87         int retval;
  88         int i;
  89         ssize_t rlen;
  90         const char *result;
  91         int reslen;
  92         tcl_connection_t *tclc;
  93         char in[256];
  94
  95         rlen = read_socket(connection->fd, &in, sizeof(in));
  96         if (rlen <= 0) {
  97                 if (rlen < 0)
  98                         LOG_ERROR("error during read: %s", strerror(errno));
  99                 return ERROR_SERVER_REMOTE_CLOSED;
 100         }
 101
 102         tclc = connection->priv;
 103         if (tclc == NULL)
 104                 return ERROR_CONNECTION_REJECTED;
 105
 106         /* push as much data into the line as possible */
 107         for (i = 0; i < rlen; i++)
 108         {
 109                 if (!isprint(in[i]) && !isspace(in[i]))
 110                 {
 111                         /* drop this line */
 112                         tclc->tc_linedrop = 1;
 113                         continue;
 114                 }
 115
 116                 /* buffer the data */
 117                 tclc->tc_line[tclc->tc_lineoffset] = in[i];
 118                 if (tclc->tc_lineoffset < TCL_MAX_LINE)
 119                         tclc->tc_lineoffset++;
 120                 else
 121                         tclc->tc_linedrop = 1;
 122
 123                 if (in[i] != '\n')
 124                         continue;
 125
 126                 /* process the line */
 127                 if (tclc->tc_linedrop) {
 128 #define ESTR "line too long\n"
 129                         retval = tcl_output(connection, ESTR, sizeof(ESTR));
 130                         if (retval != ERROR_OK)
 131                                 return retval;
 132 #undef ESTR
 133                 }
 134                 else {
 135                         tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 136                         retval = Jim_Eval_Named(interp, tclc->tc_line, "remote:connection",1);
 137                         result = Jim_GetString(Jim_GetResult(interp), &reslen);
 138                         retval = tcl_output(connection, result, reslen);
 139                         if (retval != ERROR_OK)
 140                                 return retval;
 141                         if (memchr(result, '\n', reslen) == NULL)
 142                                 tcl_output(connection, "\n", 1);
 143                 }
 144
 145                 tclc->tc_lineoffset = 0;
 146                 tclc->tc_linedrop = 0;
 147         }
 148
 149         return ERROR_OK;
 150 }
 151
 152 static int tcl_closed(connection_t *connection)
 153 {
 154         /* cleanup connection context */
 155         if (connection->priv) {
 156                 free(connection->priv);
 157                 connection->priv = NULL;
 158         }
 159         return ERROR_OK;
 160 }
 161
 162 int tcl_init(void)
 163 {
 164         int retval;
 165
 166         if (tcl_port == 0)
 167         {
 168                 LOG_INFO("tcl port disabled");
 169                 return ERROR_OK;
 170         }
 171
 172         retval = add_service("tcl", CONNECTION_TCP, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 173         return retval;
 174 }
 175
 176 int tcl_register_commands(command_context_t *cmd_ctx)
 177 {
 178         register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "port on which to listen for incoming TCL syntax");
 179         return ERROR_OK;
 180 }
 181
 182 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 183 {
 184         if (argc == 1) {
 185                 tcl_port = strtoul(args[0], NULL, 0);
 186         }
 187         return ERROR_OK;
 188 }