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 "../jim.h"
  28 #include "log.h"
  29 #include "command.h"
  30
  31 #include <stdlib.h>
  32 #include <unistd.h>
  33 #include <errno.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36
  37 #define TCL_SERVER_VERSION     "TCL Server 0.1"
  38 #define TCL_MAX_LINE           (4096)
  39
  40 typedef struct tcl_connection_s {
  41        int tc_linedrop;
  42        int tc_lineoffset;
  43        char tc_line[TCL_MAX_LINE];
  44
  45        int tc_outerror; /* flag an output error */
  46 } tcl_connection_t;
  47
  48 extern Jim_Interp *interp;
  49 static unsigned short tcl_port = 0;
  50
  51 /* commands */
  52 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
  53
  54 /* handlers */
  55 static int tcl_new_connection(connection_t *connection);
  56 static int tcl_input(connection_t *connection);
  57 static int tcl_output(connection_t *connection, const void *buf, ssize_t len);
  58 static int tcl_closed(connection_t *connection);
  59
  60 /* write data out to a socket.
  61  *
  62  * this is a blocking write, so the return value must equal the length, if
  63  * that is not the case then flag the connection with an output error.
  64  */
  65 int tcl_output(connection_t *connection, const void *data, ssize_t len)
  66 {
  67        ssize_t wlen;
  68        tcl_connection_t *tclc;
  69
  70        tclc = connection->priv;
  71        if (tclc->tc_outerror)
  72                return ERROR_SERVER_REMOTE_CLOSED;
  73
  74        wlen = write_socket(connection->fd, data, len);
  75        if (wlen == len)
  76                return ERROR_OK;
  77
  78        LOG_ERROR("error during write: %d != %d", wlen, len);
  79        tclc->tc_outerror = 1;
  80        return ERROR_SERVER_REMOTE_CLOSED;
  81 }
  82
  83
  84 /* connections */
  85 static int tcl_new_connection(connection_t *connection)
  86 {
  87        int i;
  88        tcl_connection_t *tclc;
  89
  90        tclc = malloc(sizeof(tcl_connection_t));
  91        if (tclc == NULL)
  92                return ERROR_CONNECTION_REJECTED;
  93
  94        memset(tclc, 0, sizeof(tcl_connection_t));
  95        connection->priv = tclc;
  96        return ERROR_OK;
  97 }
  98
  99 static int tcl_input(connection_t *connection)
 100 {
 101        int retval;
 102        int i;
 103        ssize_t rlen;
 104        const char *result;
 105        int reslen;
 106        tcl_connection_t *tclc;
 107        char in[256];
 108
 109        rlen = read_socket(connection->fd, &in, sizeof(in));
 110        if (rlen <= 0) {
 111                if (rlen < 0)
 112                        LOG_ERROR("error during read: %s", strerror(errno));
 113                return ERROR_SERVER_REMOTE_CLOSED;
 114        }
 115
 116        tclc = connection->priv;
 117        if (tclc == NULL)
 118                return ERROR_CONNECTION_REJECTED;
 119
 120        /* push as much data into the line as possible */
 121        for (i = 0; i < rlen; i++)
 122        {
 123                if (!isprint(in[i]) && !isspace(in[i]))
 124                {
 125                        /* drop this line */
 126                        tclc->tc_linedrop = 1;
 127                        continue;
 128                }
 129
 130                /* buffer the data */
 131                tclc->tc_line[tclc->tc_lineoffset] = in[i];
 132                if (tclc->tc_lineoffset < TCL_MAX_LINE)
 133                        tclc->tc_lineoffset++;
 134                else
 135                        tclc->tc_linedrop = 1;
 136
 137                if (in[i] != '\n')
 138                        continue;
 139
 140                /* process the line */
 141                if (tclc->tc_linedrop) {
 142 #define ESTR "line too long\n"
 143                        retval = tcl_output(connection, ESTR, sizeof(ESTR));
 144                        if (retval != ERROR_OK)
 145                                return retval;
 146 #undef ESTR
 147                } else {
 148                        tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 149                        retval = Jim_Eval(interp, tclc->tc_line);
 150                        result = Jim_GetString(Jim_GetResult(interp), &reslen);
 151                        retval = tcl_output(connection, result, reslen);
 152                        if (retval != ERROR_OK)
 153                                return retval;
 154                        if (memchr(result, '\n', reslen) == NULL)
 155                                tcl_output(connection, "\n", 1);
 156                }
 157                tclc->tc_lineoffset = 0;
 158                tclc->tc_linedrop = 0;
 159        }
 160
 161        return ERROR_OK;
 162 }
 163
 164 static int tcl_closed(connection_t *connection)
 165 {
 166        /* cleanup connection context */
 167        if (connection->priv) {
 168                free(connection->priv);
 169                connection->priv = NULL;
 170        }
 171        return ERROR_OK;
 172 }
 173
 174 int tcl_init(void)
 175 {
 176        int retval;
 177
 178        if (tcl_port == 0)
 179        {
 180                LOG_WARNING("no tcl port specified, using default port 5555");
 181                tcl_port = 5555;
 182        }
 183
 184        retval = add_service("tcl", CONNECTION_TCL, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 185        return retval;
 186 }
 187
 188
 189 int tcl_register_commands(command_context_t *cmd_ctx)
 190 {
 191        register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "");
 192        return ERROR_OK;
 193 }
 194
 195 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 196 {
 197        if (argc == 1) {
 198                tcl_port = strtoul(args[0], NULL, 0);
 199        }
 200        return ERROR_OK;
 201 }