src/server/rtt_server.c

   1 /*
   2  * Copyright (C) 2016-2017 by Marc Schink <dev@zapb.de>
   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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21
  22 #include <stdint.h>
  23 #include <rtt/rtt.h>
  24
  25 #include "server.h"
  26 #include "rtt_server.h"
  27
  28 /**
  29  * @file
  30  *
  31  * RTT server.
  32  *
  33  * This server allows access to Real Time Transfer (RTT) channels via TCP
  34  * connections.
  35  */
  36
  37 struct rtt_service {
  38         unsigned int channel;
  39 };
  40
  41 static int read_callback(unsigned int channel, const uint8_t *buffer,
  42                 size_t length, void *user_data)
  43 {
  44         int ret;
  45         struct connection *connection;
  46         size_t offset;
  47
  48         connection = (struct connection *)user_data;
  49         offset = 0;
  50
  51         while (offset < length) {
  52                 ret = connection_write(connection, buffer + offset, length - offset);
  53
  54                 if (ret < 0) {
  55                         LOG_ERROR("Failed to write data to socket.");
  56                         return ERROR_FAIL;
  57                 }
  58
  59                 offset += ret;
  60         }
  61
  62         return ERROR_OK;
  63 }
  64
  65 static int rtt_new_connection(struct connection *connection)
  66 {
  67         int ret;
  68         struct rtt_service *service;
  69
  70         service = connection->service->priv;
  71
  72         LOG_DEBUG("rtt: New connection for channel %u", service->channel);
  73
  74         ret = rtt_register_sink(service->channel, &read_callback, connection);
  75
  76         if (ret != ERROR_OK)
  77                 return ret;
  78
  79         return ERROR_OK;
  80 }
  81
  82 static int rtt_connection_closed(struct connection *connection)
  83 {
  84         struct rtt_service *service;
  85
  86         service = (struct rtt_service *)connection->service->priv;
  87         rtt_unregister_sink(service->channel, &read_callback, connection);
  88
  89         LOG_DEBUG("rtt: Connection for channel %u closed", service->channel);
  90
  91         return ERROR_OK;
  92 }
  93
  94 static int rtt_input(struct connection *connection)
  95 {
  96         int bytes_read;
  97         unsigned char buffer[1024];
  98         struct rtt_service *service;
  99         size_t length;
 100
 101         service = (struct rtt_service *)connection->service->priv;
 102         bytes_read = connection_read(connection, buffer, sizeof(buffer));
 103
 104         if (!bytes_read)
 105                 return ERROR_SERVER_REMOTE_CLOSED;
 106         else if (bytes_read < 0) {
 107                 LOG_ERROR("error during read: %s", strerror(errno));
 108                 return ERROR_SERVER_REMOTE_CLOSED;
 109         }
 110
 111         length = bytes_read;
 112         rtt_write_channel(service->channel, buffer, &length);
 113
 114         return ERROR_OK;
 115 }
 116
 117 static const struct service_driver rtt_service_driver = {
 118         .name = "rtt",
 119         .new_connection_during_keep_alive_handler = NULL,
 120         .new_connection_handler = rtt_new_connection,
 121         .input_handler = rtt_input,
 122         .connection_closed_handler = rtt_connection_closed,
 123         .keep_client_alive_handler = NULL,
 124 };
 125
 126 COMMAND_HANDLER(handle_rtt_start_command)
 127 {
 128         int ret;
 129         struct rtt_service *service;
 130
 131         if (CMD_ARGC != 2)
 132                 return ERROR_COMMAND_SYNTAX_ERROR;
 133
 134         service = malloc(sizeof(struct rtt_service));
 135
 136         if (!service)
 137                 return ERROR_FAIL;
 138
 139         COMMAND_PARSE_NUMBER(uint, CMD_ARGV[1], service->channel);
 140
 141         ret = add_service(&rtt_service_driver, CMD_ARGV[0], CONNECTION_LIMIT_UNLIMITED, service);
 142
 143         if (ret != ERROR_OK) {
 144                 free(service);
 145                 return ERROR_FAIL;
 146         }
 147
 148         return ERROR_OK;
 149 }
 150
 151 COMMAND_HANDLER(handle_rtt_stop_command)
 152 {
 153         if (CMD_ARGC != 1)
 154                 return ERROR_COMMAND_SYNTAX_ERROR;
 155
 156         remove_service("rtt", CMD_ARGV[0]);
 157
 158         return ERROR_OK;
 159 }
 160
 161 static const struct command_registration rtt_server_subcommand_handlers[] = {
 162         {
 163                 .name = "start",
 164                 .handler = handle_rtt_start_command,
 165                 .mode = COMMAND_ANY,
 166                 .help = "Start a RTT server",
 167                 .usage = "<port> <channel>"
 168         },
 169         {
 170                 .name = "stop",
 171                 .handler = handle_rtt_stop_command,
 172                 .mode = COMMAND_ANY,
 173                 .help = "Stop a RTT server",
 174                 .usage = "<port>"
 175         },
 176         COMMAND_REGISTRATION_DONE
 177 };
 178
 179 static const struct command_registration rtt_server_command_handlers[] = {
 180         {
 181                 .name = "server",
 182                 .mode = COMMAND_ANY,
 183                 .help = "RTT server",
 184                 .usage = "",
 185                 .chain = rtt_server_subcommand_handlers
 186         },
 187         COMMAND_REGISTRATION_DONE
 188 };
 189
 190 static const struct command_registration rtt_command_handlers[] = {
 191         {
 192                 .name = "rtt",
 193                 .mode = COMMAND_ANY,
 194                 .help = "RTT",
 195                 .usage = "",
 196                 .chain = rtt_server_command_handlers
 197         },
 198         COMMAND_REGISTRATION_DONE
 199 };
 200
 201 int rtt_server_register_commands(struct command_context *ctx)
 202 {
 203         return register_commands(ctx, NULL, rtt_command_handlers);
 204 }