json.c (5251B)
1/* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 20#include "config.h" 21 22#include "common/json.h" 23 24#include <assert.h> 25#include <stdlib.h> 26#include <string.h> 27 28#include <guacamole/protocol.h> 29#include <guacamole/socket.h> 30#include <guacamole/stream.h> 31#include <guacamole/user.h> 32 33void guac_common_json_flush(guac_user* user, guac_stream* stream, 34 guac_common_json_state* json_state) { 35 36 /* If JSON buffer is non-empty, write contents to blob and reset */ 37 if (json_state->size > 0) { 38 guac_protocol_send_blob(user->socket, stream, 39 json_state->buffer, json_state->size); 40 41 /* Reset JSON buffer size */ 42 json_state->size = 0; 43 44 } 45 46} 47 48int guac_common_json_write(guac_user* user, guac_stream* stream, 49 guac_common_json_state* json_state, const char* buffer, int length) { 50 51 int blob_written = 0; 52 53 /* 54 * Append to and flush the JSON buffer as necessary to write the given 55 * data 56 */ 57 while (length > 0) { 58 59 /* Ensure provided data does not exceed size of buffer */ 60 int blob_length = length; 61 if (blob_length > sizeof(json_state->buffer)) 62 blob_length = sizeof(json_state->buffer); 63 64 /* Flush if more room is needed */ 65 if (json_state->size + blob_length > sizeof(json_state->buffer)) { 66 guac_common_json_flush(user, stream, json_state); 67 blob_written = 1; 68 } 69 70 /* Append data to JSON buffer */ 71 memcpy(json_state->buffer + json_state->size, 72 buffer, blob_length); 73 74 json_state->size += blob_length; 75 76 /* Advance to next blob of data */ 77 buffer += blob_length; 78 length -= blob_length; 79 80 } 81 82 return blob_written; 83 84} 85 86int guac_common_json_write_string(guac_user* user, 87 guac_stream* stream, guac_common_json_state* json_state, 88 const char* str) { 89 90 int blob_written = 0; 91 92 /* Write starting quote */ 93 blob_written |= guac_common_json_write(user, stream, 94 json_state, "\"", 1); 95 96 /* Write given string, escaping as necessary */ 97 const char* current = str; 98 for (; *current != '\0'; current++) { 99 100 /* Escape all quotes and back-slashes */ 101 if (*current == '"' || *current == '\\') { 102 103 /* Write any string content up to current character */ 104 if (current != str) 105 blob_written |= guac_common_json_write(user, stream, 106 json_state, str, current - str); 107 108 /* Escape the character that was just read */ 109 blob_written |= guac_common_json_write(user, stream, 110 json_state, "\\", 1); 111 112 /* Reset string */ 113 str = current; 114 115 } 116 117 } 118 119 /* Write any remaining string content */ 120 if (current != str) 121 blob_written |= guac_common_json_write(user, stream, 122 json_state, str, current - str); 123 124 /* Write ending quote */ 125 blob_written |= guac_common_json_write(user, stream, 126 json_state, "\"", 1); 127 128 return blob_written; 129 130} 131 132int guac_common_json_write_property(guac_user* user, guac_stream* stream, 133 guac_common_json_state* json_state, const char* name, 134 const char* value) { 135 136 int blob_written = 0; 137 138 /* Write leading comma if not first property */ 139 if (json_state->properties_written != 0) 140 blob_written |= guac_common_json_write(user, stream, 141 json_state, ",", 1); 142 143 /* Write property name */ 144 blob_written |= guac_common_json_write_string(user, stream, 145 json_state, name); 146 147 /* Separate name from value with colon */ 148 blob_written |= guac_common_json_write(user, stream, 149 json_state, ":", 1); 150 151 /* Write property value */ 152 blob_written |= guac_common_json_write_string(user, stream, 153 json_state, value); 154 155 json_state->properties_written++; 156 157 return blob_written; 158 159} 160 161void guac_common_json_begin_object(guac_user* user, guac_stream* stream, 162 guac_common_json_state* json_state) { 163 164 /* Init JSON state */ 165 json_state->size = 0; 166 json_state->properties_written = 0; 167 168 /* Write leading brace - no blob can possibly be written by this */ 169 assert(!guac_common_json_write(user, stream, json_state, "{", 1)); 170 171} 172 173int guac_common_json_end_object(guac_user* user, guac_stream* stream, 174 guac_common_json_state* json_state) { 175 176 /* Write final brace of JSON object */ 177 return guac_common_json_write(user, stream, json_state, "}", 1); 178 179} 180