root / trunk / code / projects / colonet / ColonetServer / ConnectionPool.cpp @ 29
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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 | */
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7 | |||
8 | #include <sys/select.h> |
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9 | #include <ctype.h> |
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10 | #include <errno.h> |
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11 | #include <unistd.h> |
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12 | #include <string.h> |
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13 | #include <stdlib.h> |
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14 | #include <stdio.h> |
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15 | |||
16 | #include "includes/ConnectionPool.h" |
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17 | #include "includes/client.h" |
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18 | #include "../lib/colonet_defs.h" |
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19 | |||
20 | 29 | jknichel | /**
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21 | * @brief The default constructor for ConnectionPool
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22 | */
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23 | 11 | emarinel | ConnectionPool::ConnectionPool() { |
24 | max_file_descriptor = 0;
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25 | next_available_slot = 0;
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26 | number_clients_ready = 0;
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27 | |||
28 | FD_ZERO(&ready_set); |
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29 | FD_ZERO(&read_set); |
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30 | FD_ZERO(&write_set); |
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31 | |||
32 | memset(&client_file_descriptor_array, 0, sizeof(int)*MAX_CONNECTIONS); |
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33 | memset(&read_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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34 | memset(&read_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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35 | memset(&write_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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36 | memset(&write_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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37 | } |
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38 | |||
39 | 29 | jknichel | /**
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40 | * @brief The destructor for ConnectionPool
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41 | */
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42 | 11 | emarinel | ConnectionPool::~ConnectionPool() { |
43 | } |
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44 | |||
45 | 29 | jknichel | /**
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46 | * @brief Adds a client to the connection pool
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47 | *
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48 | * @param client_file_descriptor The file descriptor to add to the connection pool
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49 | *
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50 | * @return 0 on success, negative error code on failure
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51 | */
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52 | 11 | emarinel | int ConnectionPool::add_client(int client_file_descriptor) { |
53 | if (client_file_descriptor < 0) { |
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54 | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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55 | } |
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56 | |||
57 | if (next_available_slot == MAX_CONNECTIONS) {
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58 | return ERROR_TOO_MANY_CLIENTS;
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59 | } |
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60 | |||
61 | if (client_file_descriptor > max_file_descriptor) {
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62 | max_file_descriptor = client_file_descriptor; |
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63 | } |
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64 | |||
65 | FD_SET(client_file_descriptor, &ready_set); |
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66 | |||
67 | int next_slot = next_available_slot;
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68 | |||
69 | client_file_descriptor_array[next_slot] = client_file_descriptor; |
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70 | read_buffer[next_slot] = (char*) malloc(sizeof(char) * READ_BUFFER_SIZE); |
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71 | if (!(read_buffer[next_slot])) {
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72 | return ERROR_ALLOCATING_MEMORY;
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73 | } |
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74 | read_buffer_size[next_slot] = 0;
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75 | write_buffer[next_slot] = (char *)malloc(sizeof(char) * WRITE_BUFFER_SIZE); |
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76 | |||
77 | if (!(write_buffer[next_slot])) {
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78 | free(read_buffer[next_slot]); |
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79 | return ERROR_ALLOCATING_MEMORY;
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80 | } |
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81 | |||
82 | write_buffer_size[next_slot] = 0;
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83 | |||
84 | next_available_slot++; |
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85 | |||
86 | return 0; |
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87 | } |
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88 | |||
89 | 29 | jknichel | /**
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90 | * @brief Removes a client from the connection pool
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91 | *
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92 | * @param The index in the pool of the client to remove
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93 | *
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94 | * @return 0 on success, negative error code on failure
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95 | */
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96 | 27 | jknichel | int ConnectionPool::remove_client(int pool_index) { |
97 | if (pool_index < 0 || pool_index >= next_available_slot) { |
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98 | 11 | emarinel | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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99 | } |
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100 | |||
101 | 27 | jknichel | int client_file_descriptor = client_file_descriptor_array[pool_index];
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102 | 11 | emarinel | |
103 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &ready_set)) {
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104 | FD_CLR(client_file_descriptor, &ready_set); |
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105 | 11 | emarinel | } |
106 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &read_set)) {
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107 | FD_CLR(client_file_descriptor, &read_set); |
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108 | 11 | emarinel | } |
109 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &write_set)) {
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110 | FD_CLR(client_file_descriptor, &write_set); |
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111 | 11 | emarinel | } |
112 | |||
113 | 27 | jknichel | free(read_buffer[pool_index]); |
114 | free(write_buffer[pool_index]); |
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115 | for (int j = pool_index; j < next_available_slot - 1; j++) { |
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116 | client_file_descriptor_array[pool_index] = client_file_descriptor_array[pool_index+1];
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117 | read_buffer[pool_index] = read_buffer[pool_index+1];
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118 | read_buffer_size[pool_index] = read_buffer_size[pool_index+1];
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119 | write_buffer[pool_index] = write_buffer[pool_index+1];
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120 | write_buffer_size[pool_index] = write_buffer_size[pool_index+1];
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121 | 11 | emarinel | } |
122 | next_available_slot--; |
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123 | int temp_max_file_descriptor = 0; |
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124 | |||
125 | for (int j = 0; j < next_available_slot; j++) { |
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126 | if (client_file_descriptor_array[j] > temp_max_file_descriptor)
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127 | temp_max_file_descriptor = client_file_descriptor_array[j]; |
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128 | } |
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129 | max_file_descriptor = temp_max_file_descriptor; |
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130 | |||
131 | printf("Removing client.\n");
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132 | |||
133 | return 0; |
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134 | } |
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135 | |||
136 | 29 | jknichel | /**
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137 | * @brief Checks the status of the clients
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138 | *
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139 | * Sees is any clients are ready to read from their file descriptor or are
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140 | * ready to write to their file descriptor.
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141 | *
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142 | * @param wireless A pointer to the wireless object
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143 | *
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144 | * @return 0 on success, negative error code on error
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145 | */
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146 | 11 | emarinel | //TODO: test that it drops commands properly if it gets sent too much data
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147 | // do we want it to drop the data or drop the connection?
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148 | 22 | jknichel | int ConnectionPool::check_clients(ColonetWireless * wireless) {
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149 | 27 | jknichel | char temporary_buffer[READ_BUFFER_SIZE];
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150 | char temporary_command_buffer[READ_BUFFER_SIZE+1]; |
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151 | 11 | emarinel | int i;
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152 | int client_file_descriptor;
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153 | 27 | jknichel | int num_bytes_read;
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154 | int length;
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155 | 11 | emarinel | int sent;
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156 | 27 | jknichel | int command_length;
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157 | 11 | emarinel | |
158 | for (i = 0; i < next_available_slot; i++) { |
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159 | client_file_descriptor = client_file_descriptor_array[i]; |
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160 | |||
161 | if (FD_ISSET(client_file_descriptor, &read_set)) {
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162 | 27 | jknichel | num_bytes_read = read(client_file_descriptor, temporary_buffer, READ_BUFFER_SIZE); |
163 | 11 | emarinel | |
164 | 27 | jknichel | if (num_bytes_read == 0 || (num_bytes_read == -1 && errno == ECONNRESET)) { |
165 | 11 | emarinel | remove_client(i); |
166 | i--; |
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167 | continue;
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168 | } |
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169 | |||
170 | 27 | jknichel | while (num_bytes_read > 0) { |
171 | length = num_bytes_read; |
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172 | 11 | emarinel | |
173 | 27 | jknichel | if (length + read_buffer_size[i] > READ_BUFFER_SIZE) {
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174 | length = READ_BUFFER_SIZE - read_buffer_size[i]; |
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175 | 11 | emarinel | } |
176 | |||
177 | 27 | jknichel | memcpy(read_buffer[i]+read_buffer_size[i], temporary_buffer, length); |
178 | read_buffer_size[i] += length; |
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179 | num_bytes_read -= length; |
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180 | 11 | emarinel | |
181 | 27 | jknichel | if (num_bytes_read > 0) { |
182 | memmove(temporary_buffer, temporary_buffer+length, READ_BUFFER_SIZE - length); |
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183 | 11 | emarinel | } |
184 | |||
185 | printf("Read buffer is %s\n", read_buffer[i]);
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186 | |||
187 | 27 | jknichel | char* newline_position;
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188 | 11 | emarinel | |
189 | 27 | jknichel | while ((newline_position = strstr(read_buffer[i], "\n"))) { |
190 | 11 | emarinel | |
191 | //if no newline if found in the entire readbuffer (when its full),
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192 | //toss out the command
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193 | // because either the command being given is too long or someone is trying
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194 | // to do something bad to the server
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195 | //TODO: this is from before all this code was put in the loop. reconsider
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196 | // how to check this error condition and do it elsewhere
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197 | 27 | jknichel | if (!newline_position && (read_buffer_size[i] == READ_BUFFER_SIZE)) {
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198 | 11 | emarinel | read_buffer_size[i] = 0;
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199 | break;
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200 | } |
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201 | |||
202 | //if no newline is found then there is not a command in the buffer
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203 | 27 | jknichel | if (!newline_position) {
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204 | 11 | emarinel | break;
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205 | } |
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206 | |||
207 | 27 | jknichel | command_length = (newline_position - read_buffer[i])+1;
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208 | 11 | emarinel | |
209 | //the newline was found in garbage in the currently not used portion
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210 | // of the read buffer
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211 | 27 | jknichel | if (command_length > read_buffer_size[i]) {
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212 | 11 | emarinel | break;
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213 | } |
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214 | |||
215 | 27 | jknichel | memcpy(temporary_command_buffer, read_buffer[i], command_length); |
216 | //do command_length-1 to get rid of the newline terminating the command
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217 | temporary_command_buffer[command_length-1] = '\0'; |
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218 | 11 | emarinel | //did this because telnet was putting a \r\n on the end instead of just \n
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219 | 27 | jknichel | if (isspace(temporary_command_buffer[command_length-2])) { |
220 | temporary_command_buffer[command_length-2] = '\0'; |
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221 | 11 | emarinel | } |
222 | |||
223 | 27 | jknichel | memmove(read_buffer[i], read_buffer[i]+command_length, read_buffer_size[i] - command_length); |
224 | read_buffer_size[i] -= command_length; |
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225 | 11 | emarinel | |
226 | 27 | jknichel | if (command_length > MAX_COMMAND_LEN) {
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227 | 11 | emarinel | printf("The command was too long. Tossing command out.\n");
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228 | break;
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229 | } |
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230 | |||
231 | 27 | jknichel | if (parse_command(temporary_command_buffer, i, wireless) < 0) { |
232 | 11 | emarinel | printf("There was an error parsing command\n");
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233 | break;
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234 | } |
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235 | } |
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236 | } |
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237 | } |
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238 | |||
239 | if (FD_ISSET(client_file_descriptor, &write_set)) {
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240 | if (write_buffer_size[i] == 0) { |
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241 | continue;
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242 | } |
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243 | |||
244 | sent = write(client_file_descriptor, write_buffer[i], write_buffer_size[i]); |
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245 | memmove(write_buffer[i], write_buffer[i]+sent, WRITE_BUFFER_SIZE - sent); |
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246 | write_buffer_size[i] -= sent; |
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247 | } |
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248 | } |
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249 | |||
250 | return 0; |
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251 | } |
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252 | |||
253 | 29 | jknichel | /**
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254 | * @brief Puts text into a write buffer that will be written to a client's file
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255 | * descriptor sometime when the client is ready to write.
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256 | *
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257 | * @param pool_index Index in the pool of the client to write to
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258 | * @param message The message to be written
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259 | * @param length The length of the message
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260 | *
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261 | * @return 0 on success, negative error code on failure
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262 | */
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263 | 14 | jknichel | int ConnectionPool::write_to_client(int pool_index, char * message, int length) { |
264 | 22 | jknichel | if (pool_index < 0 || pool_index >= next_available_slot) { |
265 | return ERROR_INVALID_CLIENT_ID;
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266 | } |
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267 | |||
268 | if (!message) {
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269 | return ERROR_INVALID_MESSAGE;
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270 | } |
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271 | |||
272 | if (length < 0) { |
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273 | return ERROR_INVALID_MESSAGE_LENGTH;
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274 | } |
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275 | |||
276 | 14 | jknichel | if (length > (WRITE_BUFFER_SIZE-write_buffer_size[pool_index]))
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277 | { |
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278 | //TODO: make this a logging statement instead of a print statement
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279 | printf("There is not enough room in the write buffer to send the data to the client.\n");
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280 | 22 | jknichel | return ERROR_NOT_ENOUGH_ROOM;
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281 | 14 | jknichel | } |
282 | 11 | emarinel | |
283 | 14 | jknichel | memcpy(write_buffer[pool_index], message, length); |
284 | write_buffer_size[pool_index] += length; |
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285 | |||
286 | return 0; |
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287 | } |
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288 | |||
289 | 29 | jknichel | /**
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290 | * @brief Sets the socket to listen on
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291 | *
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292 | * @param listen_socket The socket to listen on
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293 | *
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294 | * @return void
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295 | */
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296 | 11 | emarinel | //TODO: put error checking on listen_socket to make sure its a valid socket
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297 | void ConnectionPool::set_listen_socket_in_ready_set(int listen_socket) { |
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298 | FD_SET(listen_socket, &ready_set); |
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299 | } |
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300 | |||
301 | 29 | jknichel | /**
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302 | * @todo Since the listen socket is now a member of the class, the first parameter can be removed
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303 | * @todo Does the select timeout need to be passed in? or can it be specified in the method?
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304 | *
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305 | * @brief Find out what file descriptors are ready to write to and read from
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306 | *
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307 | * @param listen_socket The socket to listen on
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308 | * @param select_timeout The timeout for the select statement
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309 | *
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310 | * @return 0
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311 | */
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312 | 11 | emarinel | int ConnectionPool::perform_select(int listen_socket, struct timeval * select_timeout) { |
313 | read_set = ready_set; |
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314 | write_set = ready_set; |
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315 | |||
316 | //TODO(Jason): think about why I put this there
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317 | if (max_file_descriptor < listen_socket)
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318 | max_file_descriptor = listen_socket; |
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319 | |||
320 | number_clients_ready = select(max_file_descriptor+1, &(read_set), &(write_set), NULL, select_timeout); |
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321 | |||
322 | return 0; |
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323 | } |
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324 | |||
325 | int ConnectionPool::is_socket_ready_to_read(int socket) { |
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326 | return FD_ISSET(socket, &read_set);
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327 | } |
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328 | |||
329 | int ConnectionPool::is_socket_ready_to_write(int socket) { |
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330 | return FD_ISSET(socket, &write_set);
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331 | } |
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332 | |||
333 | int ConnectionPool::get_max_file_descriptor() {
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334 | return max_file_descriptor;
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335 | } |
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336 | |||
337 | void ConnectionPool::set_max_file_descriptor(int new_max_file_descriptor) { |
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338 | max_file_descriptor = new_max_file_descriptor; |
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339 | } |
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340 | |||
341 | int ConnectionPool::get_next_available_slot() {
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342 | return next_available_slot;
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343 | } |
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344 | |||
345 | int ConnectionPool::get_number_clients_ready() {
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346 | return number_clients_ready;
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347 | } |
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348 | |||
349 | void ConnectionPool::set_number_clients_ready(int new_number_clients_ready) { |
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350 | number_clients_ready = new_number_clients_ready; |
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351 | } |
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352 | |||
353 | fd_set ConnectionPool::get_ready_set() { |
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354 | return ready_set;
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355 | } |
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356 | |||
357 | fd_set ConnectionPool::get_read_set() { |
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358 | return read_set;
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359 | } |
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360 | |||
361 | void ConnectionPool::set_read_set(fd_set new_set) {
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362 | read_set = new_set; |
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363 | } |
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364 | |||
365 | fd_set ConnectionPool::get_write_set() { |
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366 | return write_set;
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367 | } |
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368 | |||
369 | void ConnectionPool::set_write_set(fd_set new_set) {
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370 | write_set = new_set; |
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371 | } |
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372 | |||
373 | //TODO: write a function to write data into the write buffers
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374 | //TODO: fix names of variables to obey new style
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375 | 22 | jknichel | int ConnectionPool::parse_command(char* command, int pool_index, ColonetWireless * wireless) { |
376 | 11 | emarinel | char tokens[MAX_TOKENS][MAX_TOKEN_SIZE];
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377 | 29 | jknichel | unsigned cnhar int_tokens[MAX_TOKENS];
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378 | 11 | emarinel | int numTokens = 0; |
379 | char* endptr = NULL; |
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380 | int commandID;
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381 | int i;
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382 | unsigned char args[PACKET_DATA_LEN]; |
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383 | |||
384 | memset(args, 1, PACKET_DATA_LEN);
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385 | |||
386 | if (!command) {
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387 | return -1; |
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388 | } |
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389 | |||
390 | if (pool_index < 0) { |
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391 | return -1; |
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392 | } |
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393 | |||
394 | if (pool_index >= next_available_slot) {
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395 | return -1; |
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396 | } |
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397 | |||
398 | if ((numTokens = tokenize_command(command, tokens)) < 0) { |
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399 | return -1; |
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400 | } |
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401 | |||
402 | //the 10 in the function call indicates number is base 10
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403 | commandID = strtol(tokens[0], &endptr, 10); |
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404 | |||
405 | if (!endptr || *endptr != '\0') { |
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406 | printf("There was an error converting first token into a number.\n");
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407 | return -1; |
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408 | } |
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409 | |||
410 | if (commandID == SEND_TO_ROBOT || REQUEST_FROM_ROBOT) {
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411 | int numIntTokens = numTokens;
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412 | |||
413 | /* Convert tokens to ints */
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414 | for (i = ROBOT_COMMAND_OFFSET; i < numIntTokens; i++) {
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415 | int_tokens[i-ROBOT_COMMAND_OFFSET] = atoi(tokens[i]); |
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416 | } |
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417 | if (commandID == REQUEST_FROM_ROBOT) {
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418 | if (i < MAX_TOKENS) {
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419 | for (;i >= 4; i--) { |
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420 | int_tokens[i] = int_tokens[i-1];
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421 | } |
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422 | int_tokens[3] = pool_index;
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423 | numIntTokens++; |
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424 | } else {
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425 | //TODO: send an error back to client here also
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426 | fprintf(stderr, "Client attempted to request data from the robot but there was not enough room to put in the client's id.\n");
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427 | return -1; |
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428 | } |
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429 | } |
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430 | |||
431 | /* Fill args buffer with args */
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432 | for (i = ROBOT_COMMAND_LEN; i < numIntTokens-ROBOT_COMMAND_OFFSET; i++) {
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433 | args[i-ROBOT_COMMAND_LEN] = int_tokens[i]; |
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434 | } |
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435 | |||
436 | /* Check the tokens */
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437 | if (check_tokens(int_tokens, numIntTokens) < 0) { |
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438 | fprintf(stderr, "%s: Error - Invalid command/request.\n", __FUNCTION__);
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439 | return 0; |
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440 | } |
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441 | |||
442 | /* Send packet to robot */
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443 | fprintf(stderr, "Calling wireless->send(%d, %d, %d, args)\n",
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444 | int_tokens[0], int_tokens[1], int_tokens[2]); |
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445 | 22 | jknichel | wireless->send(int_tokens[0], int_tokens[1], int_tokens[2], args); |
446 | 11 | emarinel | } |
447 | |||
448 | return 0; |
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449 | } |
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450 | |||
451 | int ConnectionPool::tokenize_command(char* command, char tokens[MAX_TOKENS][MAX_TOKEN_SIZE]) { |
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452 | char* nextToken = command;
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453 | char* endToken = NULL; |
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454 | int numTokens = 0; |
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455 | |||
456 | if (!command) {
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457 | return -1; |
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458 | } |
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459 | |||
460 | while ((endToken = strstr(nextToken, " "))) { |
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461 | *endToken = '\0';
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462 | |||
463 | if (strlen(nextToken) > MAX_TOKEN_SIZE-1) { |
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464 | return -1; |
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465 | } |
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466 | |||
467 | strcpy(tokens[numTokens], nextToken); |
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468 | |||
469 | numTokens++; |
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470 | nextToken = endToken + 1;
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471 | |||
472 | while (isspace(*nextToken) && *nextToken != '\0') { |
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473 | nextToken++; |
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474 | } |
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475 | } |
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476 | |||
477 | if (endToken == NULL && *nextToken != '\0') { |
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478 | if (strlen(nextToken) > MAX_TOKEN_SIZE-1) { |
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479 | return -1; |
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480 | } |
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481 | |||
482 | strcpy(tokens[numTokens], nextToken); |
||
483 | |||
484 | numTokens++; |
||
485 | } |
||
486 | |||
487 | return numTokens;
|
||
488 | } |
||
489 | |||
490 | /** @brief checks a list of tokens to see if it's valid
|
||
491 | *
|
||
492 | * @return 0 if tokens is valid
|
||
493 | */
|
||
494 | int ConnectionPool::check_tokens(unsigned char* tokens, int numTokens) { |
||
495 | if (numTokens > 3 + PACKET_DATA_LEN) { |
||
496 | /* Too many tokens */
|
||
497 | return -1; |
||
498 | } |
||
499 | |||
500 | if (numTokens < 3) { |
||
501 | /* Not enough tokens */
|
||
502 | return -1; |
||
503 | } |
||
504 | |||
505 | if (tokens[1] != COLONET_REQUEST && tokens[1] != COLONET_COMMAND) { |
||
506 | /* Invalid message type */
|
||
507 | return -1; |
||
508 | } |
||
509 | |||
510 | return 0; |
||
511 | } |