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