root / trunk / code / projects / colonet / ColonetServer / ConnectionPool.cpp @ 453
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1 | 11 | emarinel | /**
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2 | 29 | jknichel | * @file ConnectionPool.cpp
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3 | *
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4 | 11 | emarinel | * @author Jason Knichel
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5 | * @date 7/22/07
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6 | 144 | jknichel | *
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7 | 11 | emarinel | */
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8 | |||
9 | #include <sys/select.h> |
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10 | #include <ctype.h> |
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11 | #include <errno.h> |
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12 | #include <unistd.h> |
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13 | #include <string.h> |
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14 | #include <stdlib.h> |
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15 | #include <stdio.h> |
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16 | |||
17 | 391 | emarinel | #include <ConnectionPool.h> |
18 | #include <Command.h> |
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19 | #include <colonet_defs.h> |
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20 | 161 | emarinel | |
21 | 118 | emarinel | #include <colonet_wireless.h> |
22 | 11 | emarinel | |
23 | 29 | jknichel | /**
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24 | * @brief The default constructor for ConnectionPool
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25 | */
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26 | 453 | emarinel | ConnectionPool::ConnectionPool(ColonetServer* cs) { |
27 | colonet_server = cs; |
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28 | |||
29 | 11 | emarinel | max_file_descriptor = 0;
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30 | next_available_slot = 0;
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31 | number_clients_ready = 0;
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32 | |||
33 | FD_ZERO(&ready_set); |
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34 | FD_ZERO(&read_set); |
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35 | FD_ZERO(&write_set); |
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36 | |||
37 | memset(&client_file_descriptor_array, 0, sizeof(int)*MAX_CONNECTIONS); |
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38 | memset(&read_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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39 | memset(&read_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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40 | memset(&write_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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41 | memset(&write_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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42 | } |
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43 | |||
44 | 29 | jknichel | /**
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45 | * @brief The destructor for ConnectionPool
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46 | */
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47 | 11 | emarinel | ConnectionPool::~ConnectionPool() { |
48 | } |
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49 | |||
50 | 29 | jknichel | /**
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51 | * @brief Adds a client to the connection pool
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52 | *
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53 | * @param client_file_descriptor The file descriptor to add to the connection pool
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54 | *
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55 | * @return 0 on success, negative error code on failure
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56 | */
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57 | 11 | emarinel | int ConnectionPool::add_client(int client_file_descriptor) { |
58 | if (client_file_descriptor < 0) { |
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59 | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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60 | } |
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61 | |||
62 | if (next_available_slot == MAX_CONNECTIONS) {
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63 | return ERROR_TOO_MANY_CLIENTS;
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64 | } |
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65 | |||
66 | if (client_file_descriptor > max_file_descriptor) {
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67 | max_file_descriptor = client_file_descriptor; |
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68 | } |
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69 | |||
70 | FD_SET(client_file_descriptor, &ready_set); |
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71 | |||
72 | int next_slot = next_available_slot;
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73 | |||
74 | client_file_descriptor_array[next_slot] = client_file_descriptor; |
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75 | read_buffer[next_slot] = (char*) malloc(sizeof(char) * READ_BUFFER_SIZE); |
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76 | if (!(read_buffer[next_slot])) {
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77 | return ERROR_ALLOCATING_MEMORY;
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78 | } |
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79 | read_buffer_size[next_slot] = 0;
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80 | write_buffer[next_slot] = (char *)malloc(sizeof(char) * WRITE_BUFFER_SIZE); |
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81 | |||
82 | if (!(write_buffer[next_slot])) {
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83 | free(read_buffer[next_slot]); |
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84 | return ERROR_ALLOCATING_MEMORY;
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85 | } |
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86 | |||
87 | write_buffer_size[next_slot] = 0;
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88 | |||
89 | next_available_slot++; |
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90 | |||
91 | return 0; |
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92 | } |
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93 | |||
94 | 29 | jknichel | /**
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95 | * @brief Removes a client from the connection pool
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96 | *
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97 | * @param The index in the pool of the client to remove
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98 | *
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99 | * @return 0 on success, negative error code on failure
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100 | */
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101 | 27 | jknichel | int ConnectionPool::remove_client(int pool_index) { |
102 | if (pool_index < 0 || pool_index >= next_available_slot) { |
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103 | 11 | emarinel | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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104 | } |
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105 | |||
106 | 27 | jknichel | int client_file_descriptor = client_file_descriptor_array[pool_index];
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107 | 11 | emarinel | |
108 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &ready_set)) {
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109 | FD_CLR(client_file_descriptor, &ready_set); |
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110 | 11 | emarinel | } |
111 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &read_set)) {
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112 | FD_CLR(client_file_descriptor, &read_set); |
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113 | 11 | emarinel | } |
114 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &write_set)) {
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115 | FD_CLR(client_file_descriptor, &write_set); |
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116 | 11 | emarinel | } |
117 | |||
118 | 27 | jknichel | free(read_buffer[pool_index]); |
119 | free(write_buffer[pool_index]); |
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120 | for (int j = pool_index; j < next_available_slot - 1; j++) { |
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121 | client_file_descriptor_array[pool_index] = client_file_descriptor_array[pool_index+1];
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122 | read_buffer[pool_index] = read_buffer[pool_index+1];
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123 | read_buffer_size[pool_index] = read_buffer_size[pool_index+1];
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124 | write_buffer[pool_index] = write_buffer[pool_index+1];
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125 | write_buffer_size[pool_index] = write_buffer_size[pool_index+1];
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126 | 11 | emarinel | } |
127 | next_available_slot--; |
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128 | int temp_max_file_descriptor = 0; |
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129 | |||
130 | for (int j = 0; j < next_available_slot; j++) { |
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131 | if (client_file_descriptor_array[j] > temp_max_file_descriptor)
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132 | temp_max_file_descriptor = client_file_descriptor_array[j]; |
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133 | } |
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134 | max_file_descriptor = temp_max_file_descriptor; |
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135 | |||
136 | printf("Removing client.\n");
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137 | |||
138 | return 0; |
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139 | } |
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140 | |||
141 | 29 | jknichel | /**
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142 | * @brief Checks the status of the clients
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143 | *
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144 | * Sees is any clients are ready to read from their file descriptor or are
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145 | * ready to write to their file descriptor.
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146 | *
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147 | * @return 0 on success, negative error code on error
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148 | */
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149 | 11 | emarinel | //TODO: test that it drops commands properly if it gets sent too much data
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150 | // do we want it to drop the data or drop the connection?
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151 | 118 | emarinel | int ConnectionPool::check_clients() {
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152 | 11 | emarinel | int i;
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153 | |||
154 | for (i = 0; i < next_available_slot; i++) { |
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155 | 145 | jknichel | int client_file_descriptor = client_file_descriptor_array[i];
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156 | 11 | emarinel | |
157 | if (FD_ISSET(client_file_descriptor, &read_set)) {
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158 | 145 | jknichel | if (read_data(i, client_file_descriptor) == DECREMENT_INDEX_COUNTER) {
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159 | i--; |
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160 | continue;
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161 | 11 | emarinel | } |
162 | } |
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163 | |||
164 | if (FD_ISSET(client_file_descriptor, &write_set)) {
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165 | 145 | jknichel | write_data(i, client_file_descriptor); |
166 | 11 | emarinel | } |
167 | } |
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168 | |||
169 | return 0; |
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170 | } |
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171 | |||
172 | 29 | jknichel | /**
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173 | * @brief Puts text into a write buffer that will be written to a client's file
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174 | * descriptor sometime when the client is ready to write.
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175 | *
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176 | * @param pool_index Index in the pool of the client to write to
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177 | * @param message The message to be written
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178 | * @param length The length of the message
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179 | *
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180 | * @return 0 on success, negative error code on failure
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181 | */
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182 | 14 | jknichel | int ConnectionPool::write_to_client(int pool_index, char * message, int length) { |
183 | 22 | jknichel | if (pool_index < 0 || pool_index >= next_available_slot) { |
184 | return ERROR_INVALID_CLIENT_ID;
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185 | } |
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186 | |||
187 | if (!message) {
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188 | return ERROR_INVALID_MESSAGE;
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189 | } |
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190 | |||
191 | if (length < 0) { |
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192 | return ERROR_INVALID_MESSAGE_LENGTH;
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193 | } |
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194 | |||
195 | 34 | emarinel | if (length > (WRITE_BUFFER_SIZE-write_buffer_size[pool_index])) {
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196 | //TODO: make this a logging statement instead of a print statement
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197 | printf("There is not enough room in the write buffer to send the data to the client.\n");
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198 | return ERROR_NOT_ENOUGH_ROOM;
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199 | } |
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200 | 11 | emarinel | |
201 | 334 | gtress | printf("Connection pool: attempting to write [%s], length %i to index %i.\n", message, length, pool_index);
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202 | |||
203 | 14 | jknichel | memcpy(write_buffer[pool_index], message, length); |
204 | write_buffer_size[pool_index] += length; |
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205 | |||
206 | return 0; |
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207 | } |
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208 | |||
209 | 29 | jknichel | /**
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210 | * @brief Sets the socket to listen on
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211 | *
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212 | * @param listen_socket The socket to listen on
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213 | *
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214 | * @return void
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215 | */
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216 | 143 | jknichel | void ConnectionPool::add_new_socket_to_pool(int new_socket) { |
217 | if (new_socket < 0) |
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218 | 58 | jknichel | return;
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219 | |||
220 | 143 | jknichel | FD_SET(new_socket, &ready_set); |
221 | |||
222 | if (new_socket > max_file_descriptor) {
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223 | max_file_descriptor = new_socket; |
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224 | } |
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225 | 11 | emarinel | } |
226 | |||
227 | 29 | jknichel | /**
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228 | * @brief Find out what file descriptors are ready to write to and read from
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229 | *
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230 | * @param listen_socket The socket to listen on
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231 | * @param select_timeout The timeout for the select statement
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232 | *
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233 | * @return 0
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234 | */
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235 | 58 | jknichel | int ConnectionPool::perform_select(int listen_socket) { |
236 | 11 | emarinel | read_set = ready_set; |
237 | write_set = ready_set; |
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238 | |||
239 | 58 | jknichel | struct timeval select_timeout;
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240 | memset(&select_timeout, 0, sizeof(select_timeout)); |
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241 | |||
242 | 11 | emarinel | //TODO(Jason): think about why I put this there
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243 | if (max_file_descriptor < listen_socket)
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244 | max_file_descriptor = listen_socket; |
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245 | |||
246 | 58 | jknichel | number_clients_ready = select(max_file_descriptor+1, &(read_set), &(write_set), NULL, &select_timeout); |
247 | 11 | emarinel | |
248 | 59 | jknichel | if (number_clients_ready < 0) { |
249 | perror(__FUNCTION__); |
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250 | } |
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251 | |||
252 | 11 | emarinel | return 0; |
253 | } |
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254 | |||
255 | int ConnectionPool::is_socket_ready_to_read(int socket) { |
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256 | return FD_ISSET(socket, &read_set);
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257 | } |
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258 | |||
259 | int ConnectionPool::get_number_clients_ready() {
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260 | return number_clients_ready;
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261 | } |
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262 | |||
263 | 424 | emarinel | /**
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264 | */
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265 | 145 | jknichel | int ConnectionPool::read_data(int pool_index, int client_file_descriptor) { |
266 | char temporary_buffer[READ_BUFFER_SIZE];
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267 | char temporary_command_buffer[READ_BUFFER_SIZE+1]; |
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268 | int num_bytes_read;
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269 | int length;
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270 | int command_length;
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271 | |||
272 | num_bytes_read = read(client_file_descriptor, temporary_buffer, READ_BUFFER_SIZE); |
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273 | |||
274 | if (num_bytes_read == 0 || (num_bytes_read == -1 && errno == ECONNRESET)) { |
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275 | remove_client(pool_index); |
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276 | return DECREMENT_INDEX_COUNTER;
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277 | } |
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278 | |||
279 | while (num_bytes_read > 0) { |
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280 | length = num_bytes_read; |
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281 | |||
282 | if (length + read_buffer_size[pool_index] > READ_BUFFER_SIZE) {
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283 | length = READ_BUFFER_SIZE - read_buffer_size[pool_index]; |
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284 | } |
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285 | |||
286 | memcpy(read_buffer[pool_index]+read_buffer_size[pool_index], temporary_buffer, length); |
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287 | read_buffer_size[pool_index] += length; |
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288 | num_bytes_read -= length; |
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289 | |||
290 | if (num_bytes_read > 0) { |
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291 | memmove(temporary_buffer, temporary_buffer+length, READ_BUFFER_SIZE - length); |
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292 | } |
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293 | |||
294 | 424 | emarinel | printf("read_data: Read buffer is %s\n", read_buffer[pool_index]);
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295 | 145 | jknichel | |
296 | char* newline_position;
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297 | |||
298 | while ((newline_position = strstr(read_buffer[pool_index], "\n"))) { |
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299 | |||
300 | 161 | emarinel | //if no newline if found in the entire readbuffer (when its full),
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301 | 145 | jknichel | //toss out the command
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302 | // because either the command being given is too long or someone is trying
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303 | // to do something bad to the server
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304 | //TODO: this is from before all this code was put in the loop. reconsider
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305 | // how to check this error condition and do it elsewhere
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306 | if (!newline_position && (read_buffer_size[pool_index] == READ_BUFFER_SIZE)) {
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307 | 424 | emarinel | read_buffer_size[pool_index] = 0;
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308 | break;
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309 | 145 | jknichel | } |
310 | |||
311 | //if no newline is found then there is not a command in the buffer
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312 | if (!newline_position) {
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313 | 424 | emarinel | break;
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314 | 145 | jknichel | } |
315 | |||
316 | command_length = (newline_position - read_buffer[pool_index])+1;
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317 | |||
318 | //the newline was found in garbage in the currently not used portion
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319 | // of the read buffer
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320 | if (command_length > read_buffer_size[pool_index]) {
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321 | 424 | emarinel | break;
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322 | 145 | jknichel | } |
323 | |||
324 | memcpy(temporary_command_buffer, read_buffer[pool_index], command_length); |
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325 | //do command_length-1 to get rid of the newline terminating the command
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326 | temporary_command_buffer[command_length-1] = '\0'; |
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327 | //did this because telnet was putting a \r\n on the end instead of just \n
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328 | if (isspace(temporary_command_buffer[command_length-2])) { |
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329 | 424 | emarinel | temporary_command_buffer[command_length-2] = '\0'; |
330 | 145 | jknichel | } |
331 | |||
332 | memmove(read_buffer[pool_index], read_buffer[pool_index]+command_length, read_buffer_size[pool_index] - command_length); |
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333 | read_buffer_size[pool_index] -= command_length; |
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334 | |||
335 | if (command_length > MAX_COMMAND_LEN) {
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336 | 424 | emarinel | fprintf(stderr, "Command was too long. Tossing command out.\n");
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337 | break;
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338 | 145 | jknichel | } |
339 | |||
340 | 453 | emarinel | Command command(this, colonet_server);
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341 | 408 | emarinel | if (command.parse_command(temporary_command_buffer, pool_index) != 0) { |
342 | 424 | emarinel | fprintf(stderr, "Error parsing command\n");
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343 | break;
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344 | 145 | jknichel | } |
345 | } |
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346 | } |
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347 | |||
348 | return 0; |
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349 | } |
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350 | |||
351 | int ConnectionPool::write_data(int pool_index, int client_file_descriptor) { |
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352 | if (write_buffer_size[pool_index] == 0) { |
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353 | return 0; |
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354 | } |
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355 | |||
356 | int sent = write(client_file_descriptor, write_buffer[pool_index], write_buffer_size[pool_index]);
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357 | memmove(write_buffer[pool_index], write_buffer[pool_index]+sent, WRITE_BUFFER_SIZE - sent); |
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358 | 161 | emarinel | write_buffer_size[pool_index] -= sent; |
359 | 145 | jknichel | |
360 | return 0; |
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361 | } |