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 extern Jim_Interp *interp;
  47 static unsigned short tcl_port = 0;
  48
  49 /* commands */
  50 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  51
  52 /* handlers */
  53 static int tcl_new_connection(connection_t *connection);
  54 static int tcl_input(connection_t *connection);
  55 static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
  56 static int tcl_closed(connection_t *connection);
  57
  58 /* write data out to a socket.
  59  *
  60  * this is a blocking write, so the return value must equal the length, if
  61  * that is not the case then flag the connection with an output error.
  62  */
  63 int tcl_output(connection_t *connection, const void *data, ssize_t len)
  64 {
  65         ssize_t wlen;
  66         tcl_connection_t *tclc;
  67
  68         tclc = connection->priv;
  69         if (tclc->tc_outerror)
  70                 return ERROR_SERVER_REMOTE_CLOSED;
  71
  72         wlen = write_socket(connection->fd, data, len);
  73         if (wlen == len)
  74                 return ERROR_OK;
  75
  76         LOG_ERROR("error during write: %d != %d", (int)wlen, (int)len);
  77         tclc->tc_outerror = 1;
  78         return ERROR_SERVER_REMOTE_CLOSED;
  79 }
  80
  81 /* connections */
  82 static int tcl_new_connection(connection_t *connection)
  83 {
  84         tcl_connection_t *tclc;
  85
  86         tclc = malloc(sizeof(tcl_connection_t));
  87         if (tclc == NULL)
  88                 return ERROR_CONNECTION_REJECTED;
  89
  90         memset(tclc, 0, sizeof(tcl_connection_t));
  91         connection->priv = tclc;
  92         return ERROR_OK;
  93 }
  94
  95 static int tcl_input(connection_t *connection)
  96 {
  97         int retval;
  98         int i;
  99         ssize_t rlen;
 100         const char *result;
 101         int reslen;
 102         tcl_connection_t *tclc;
 103         char in[256];
 104
 105         rlen = read_socket(connection->fd, &in, sizeof(in));
 106         if (rlen <= 0) {
 107                 if (rlen < 0)
 108                         LOG_ERROR("error during read: %s", strerror(errno));
 109                 return ERROR_SERVER_REMOTE_CLOSED;
 110         }
 111
 112         tclc = connection->priv;
 113         if (tclc == NULL)
 114                 return ERROR_CONNECTION_REJECTED;
 115
 116         /* push as much data into the line as possible */
 117         for (i = 0; i < rlen; i++)
 118         {
 119                 if (!isprint(in[i]) && !isspace(in[i]))
 120                 {
 121                         /* drop this line */
 122                         tclc->tc_linedrop = 1;
 123                         continue;
 124                 }
 125
 126                 /* buffer the data */
 127                 tclc->tc_line[tclc->tc_lineoffset] = in[i];
 128                 if (tclc->tc_lineoffset < TCL_MAX_LINE)
 129                         tclc->tc_lineoffset++;
 130                 else
 131                         tclc->tc_linedrop = 1;
 132
 133                 if (in[i] != '\n')
 134                         continue;
 135
 136                 /* process the line */
 137                 if (tclc->tc_linedrop) {
 138 #define ESTR "line too long\n"
 139                         retval = tcl_output(connection, ESTR, sizeof(ESTR));
 140                         if (retval != ERROR_OK)
 141                                 return retval;
 142 #undef ESTR
 143                 }
 144                 else {
 145                         tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 146                         retval = Jim_Eval(interp, tclc->tc_line);
 147                         result = Jim_GetString(Jim_GetResult(interp), &reslen);
 148                         retval = tcl_output(connection, result, reslen);
 149                         if (retval != ERROR_OK)
 150                                 return retval;
 151                         if (memchr(result, '\n', reslen) == NULL)
 152                                 tcl_output(connection, "\n", 1);
 153                 }
 154
 155                 tclc->tc_lineoffset = 0;
 156                 tclc->tc_linedrop = 0;
 157         }
 158
 159         return ERROR_OK;
 160 }
 161
 162 static int tcl_closed(connection_t *connection)
 163 {
 164         /* cleanup connection context */
 165         if (connection->priv) {
 166                 free(connection->priv);
 167                 connection->priv = NULL;
 168         }
 169         return ERROR_OK;
 170 }
 171
 172 int tcl_init(void)
 173 {
 174         int retval;
 175
 176         if (tcl_port == 0)
 177         {
 178                 LOG_WARNING("no tcl port specified, using default port 6666");
 179                 tcl_port = 6666;
 180         }
 181
 182         retval = add_service("tcl", CONNECTION_TCL, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 183         return retval;
 184 }
 185
 186 int tcl_register_commands(command_context_t *cmd_ctx)
 187 {
 188         register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "");
 189         return ERROR_OK;
 190 }
 191
 192 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 193 {
 194         if (argc == 1) {
 195                 tcl_port = strtoul(args[0], NULL, 0);
 196         }
 197         return ERROR_OK;
 198 }