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", (int)wlen, (int)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        tcl_connection_t *tclc;
  88
  89        tclc = malloc(sizeof(tcl_connection_t));
  90        if (tclc == NULL)
  91                return ERROR_CONNECTION_REJECTED;
  92
  93        memset(tclc, 0, sizeof(tcl_connection_t));
  94        connection->priv = tclc;
  95        return ERROR_OK;
  96 }
  97
  98 static int tcl_input(connection_t *connection)
  99 {
 100        int retval;
 101        int i;
 102        ssize_t rlen;
 103        const char *result;
 104        int reslen;
 105        tcl_connection_t *tclc;
 106        char in[256];
 107
 108        rlen = read_socket(connection->fd, &in, sizeof(in));
 109        if (rlen <= 0) {
 110                if (rlen < 0)
 111                        LOG_ERROR("error during read: %s", strerror(errno));
 112                return ERROR_SERVER_REMOTE_CLOSED;
 113        }
 114
 115        tclc = connection->priv;
 116        if (tclc == NULL)
 117                return ERROR_CONNECTION_REJECTED;
 118
 119        /* push as much data into the line as possible */
 120        for (i = 0; i < rlen; i++)
 121        {
 122                if (!isprint(in[i]) && !isspace(in[i]))
 123                {
 124                        /* drop this line */
 125                        tclc->tc_linedrop = 1;
 126                        continue;
 127                }
 128
 129                /* buffer the data */
 130                tclc->tc_line[tclc->tc_lineoffset] = in[i];
 131                if (tclc->tc_lineoffset < TCL_MAX_LINE)
 132                        tclc->tc_lineoffset++;
 133                else
 134                        tclc->tc_linedrop = 1;
 135
 136                if (in[i] != '\n')
 137                        continue;
 138
 139                /* process the line */
 140                if (tclc->tc_linedrop) {
 141 #define ESTR "line too long\n"
 142                        retval = tcl_output(connection, ESTR, sizeof(ESTR));
 143                        if (retval != ERROR_OK)
 144                                return retval;
 145 #undef ESTR
 146                } else {
 147                        tclc->tc_line[tclc->tc_lineoffset-1] = '\0';
 148                        retval = Jim_Eval(interp, tclc->tc_line);
 149                        result = Jim_GetString(Jim_GetResult(interp), &reslen);
 150                        retval = tcl_output(connection, result, reslen);
 151                        if (retval != ERROR_OK)
 152                                return retval;
 153                        if (memchr(result, '\n', reslen) == NULL)
 154                                tcl_output(connection, "\n", 1);
 155                }
 156                tclc->tc_lineoffset = 0;
 157                tclc->tc_linedrop = 0;
 158        }
 159
 160        return ERROR_OK;
 161 }
 162
 163 static int tcl_closed(connection_t *connection)
 164 {
 165        /* cleanup connection context */
 166        if (connection->priv) {
 167                free(connection->priv);
 168                connection->priv = NULL;
 169        }
 170        return ERROR_OK;
 171 }
 172
 173 int tcl_init(void)
 174 {
 175        int retval;
 176
 177        if (tcl_port == 0)
 178        {
 179                LOG_WARNING("no tcl port specified, using default port 6666");
 180                tcl_port = 6666;
 181        }
 182
 183        retval = add_service("tcl", CONNECTION_TCL, tcl_port, 1, tcl_new_connection, tcl_input, tcl_closed, NULL);
 184        return retval;
 185 }
 186
 187
 188 int tcl_register_commands(command_context_t *cmd_ctx)
 189 {
 190        register_command(cmd_ctx, NULL, "tcl_port", handle_tcl_port_command, COMMAND_CONFIG, "");
 191        return ERROR_OK;
 192 }
 193
 194 static int handle_tcl_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
 195 {
 196        if (argc == 1) {
 197                tcl_port = strtoul(args[0], NULL, 0);
 198        }
 199        return ERROR_OK;
 200 }