10 #include <netinet/in.h>
14 const char * query_str="QUERY_STRING";
15 const char * uri_str="REQUEST_URI";
16 const char * method_str="REQUEST_METHOD";
17 const char * iotcloudroot_str="IOTCLOUD_ROOT";
18 const char * length_str="CONTENT_LENGTH";
20 IoTQuery::IoTQuery(FCGX_Request *request) :
31 requestsequencenumber(0),
32 numqueueentries(DEFAULT_SIZE),
40 IoTQuery::~IoTQuery() {
50 * Returns true if the account directory exists.
53 bool IoTQuery::checkDirectory() {
55 int err=stat(directory, &s);
58 return S_ISDIR(s.st_mode);
62 * Decodes query string from client. Extracts type of request,
63 * sequence number, and whether the request changes the number of
67 void IoTQuery::decodeQuery() {
68 int len=strlen(query);
69 char * str=new char[len+1];
70 memcpy(str, query, len+1);
74 char *command=strsep(&tok_ptr, "&");
75 if (strncmp(command, "req=putslot", 11) == 0)
77 else if (strncmp(command, "req=getslot", 11) == 0)
79 else if (strncmp(command, "req=setsalt", 11) == 0)
81 else if (strncmp(command, "req=getsalt", 11) == 0)
84 /* Load Sequence Number for request */
85 char *sequencenumber_str = strsep(&tok_ptr, "&");
86 if (sequencenumber_str != NULL &&
87 strncmp(sequencenumber_str, "seq=", 4) == 0) {
88 sequencenumber_str = strchr(sequencenumber_str, '=');
89 if (sequencenumber_str != NULL) {
90 requestsequencenumber = strtoll(sequencenumber_str + 1, NULL, 10);
94 /* don't allow a really old sequence number */
95 if (requestsequencenumber < oldestentry)
96 requestsequencenumber = oldestentry;
98 /* Update size if we get request */
99 char * numqueueentries_str = tok_ptr;
100 if (numqueueentries_str != NULL &&
101 strncmp(numqueueentries_str, "max=", 4) == 0) {
102 numqueueentries_str = strchr(numqueueentries_str, '=') + 1;
103 numqueueentries = strtoll(numqueueentries_str, NULL, 10);
110 * Helper function to write data to file.
113 void doWrite(int fd, char *data, long long length) {
116 long long byteswritten=write(fd, &data[offset], length);
117 if (byteswritten > 0) {
118 length -= byteswritten;
119 offset += byteswritten;
121 cerr << "Bytes not written" << endl;
122 if (byteswritten < 0) {
123 cerr << strerror(errno) << " error writing slot file" << endl;
127 } while(length != 0);
130 /** Helper function to read data from file. */
131 bool doRead(int fd, void *buf, int numbytes) {
133 char *ptr=(char *)buf;
135 int bytesread=read(fd, ptr+offset, numbytes);
138 numbytes -= bytesread;
141 } while (numbytes!=0);
146 * Function that handles a getSlot request.
149 void IoTQuery::getSlot() {
150 int numrequeststosend = (int)((newestentry-requestsequencenumber)+1);
151 if (numrequeststosend < 0)
152 numrequeststosend = 0;
153 long long numbytes = 0;
154 int filesizes[numrequeststosend];
155 int fdarray[numrequeststosend];
157 for(long long seqn = requestsequencenumber; seqn <= newestentry; seqn++, index++) {
159 char *filename=getSlotFileName(seqn);
160 if (stat(filename, &st) == 0) {
161 fdarray[index]=open(filename, O_RDONLY);
162 filesizes[index]=st.st_size;
163 numbytes+=filesizes[index];
170 const char header[]="getslot";
172 /* Size is the header + the payload + space for number of requests
173 plus sizes of each slot */
175 long long size=sizeof(header)-1+sizeof(numrequeststosend)+4*numrequeststosend+numbytes;
176 char * response = new char[size];
178 memcpy(response, header, sizeof(header)-1);
179 offset+=sizeof(header)-1;
180 int numreq=htonl(numrequeststosend);
181 memcpy(response + offset, &numreq, sizeof(numreq));
182 offset+=sizeof(numrequeststosend);
183 for(int i=0; i<numrequeststosend; i++) {
184 int filesize=htonl(filesizes[i]);
185 memcpy(response + offset, &filesize, sizeof(filesize));
189 /* Read the file data into the buffer */
190 for(int i=0; i<numrequeststosend; i++) {
192 doRead(fdarray[i], response+offset, filesizes[i]);
193 offset+=filesizes[i];
197 /* Send the response out to the webserver. */
198 sendResponse(response, size);
200 /* Delete the response buffer and close the files. */
202 for(int i=0; i<numrequeststosend; i++) {
209 * The method setSalt handles a setSalt request from the client.
212 void IoTQuery::setSalt() {
213 /* Write the slot data we received to a SLOT file */
214 char *filename = getSaltFileName();
215 int saltfd = open(filename, O_CREAT|O_WRONLY, S_IRUSR| S_IWUSR);
216 doWrite(saltfd, data, length);
218 sendResponse(response, 0);
224 * The method getSalt handles a setSalt request from the client.
227 void IoTQuery::getSalt() {
228 /* Write the slot data we received to a SLOT file */
229 char *filename = getSaltFileName();
232 if (stat(filename, &st) == 0) {
238 int saltfd = open(filename, O_RDONLY);
239 int responsesize = filesize + sizeof(int);
240 char * response = new char[responsesize];
241 doRead(saltfd, response+ sizeof(int), filesize);
242 int n_filesize=htonl(filesize);
243 *((int*) response) = n_filesize;
244 sendResponse(response, responsesize);
251 * The method putSlot handles a putSlot request from the client
254 void IoTQuery::putSlot() {
255 /* Check if the request is stale and send update in that case. This
256 servers as an implicit failure of the request. */
257 if (requestsequencenumber!=(newestentry+1)) {
262 /* See if we have too many slots and if so, delete the old one */
263 int numberofliveslots=(int) ((newestentry-oldestentry)+1);
264 if (numberofliveslots >= numqueueentries) {
268 /* Write the slot data we received to a SLOT file */
269 char *filename = getSlotFileName(requestsequencenumber);
270 int slotfd = open(filename, O_CREAT|O_WRONLY, S_IRUSR| S_IWUSR);
271 doWrite(slotfd, data, length);
274 newestentry = requestsequencenumber;
276 /* Update the seuqence numbers and other status file information. */
279 /* Send response acknowledging success */
280 char command[]="putslot";
281 sendResponse(command, sizeof(command)-1);
285 * Method sends response. It wraps in appropriate headers for web
289 void IoTQuery::sendResponse(char * bytes, int len) {
290 cout << "Accept-Ranges: bytes\r\n"
291 << "Content-Length: " << len << "\r\n"
293 cout.write(bytes, len);
297 * Computes the name for a slot file for the given sequence number.
300 char * IoTQuery::getSlotFileName(long long seqnum) {
301 int directorylen=strlen(directory);
303 /* Size is 19 digits for ASCII representation of a long + 4
304 characters for SLOT string + 1 character for null termination +
307 char * filename=new char[25+directorylen];
308 snprintf(filename, 25+directorylen, "%s/SLOT%lld", directory, seqnum);
313 * Computes the name for a salt file
316 char * IoTQuery::getSaltFileName() {
317 int directorylen=strlen(directory);
319 /* Size is 4 characters for SALT string + 1 character for null
320 termination + directory size*/
322 char * filename=new char[6+directorylen];
323 snprintf(filename, 6+directorylen, "%s/SALT", directory);
328 * Removes the oldest slot file
331 void IoTQuery::removeOldestSlot() {
332 if (oldestentry!=0) {
333 char * filename=getSlotFileName(oldestentry);
341 * Processes the query sent to the fastcgi handler.
344 void IoTQuery::processQuery() {
349 /* Verify that we receive a post request. */
350 if (strncmp(method, "POST", 4) != 0) {
351 cerr << "Not POST Request" << endl;
355 /* Make sure the directory is okay. */
356 if (directory == NULL ||
358 cerr << "Directory " << directory << " does not exist" << endl;
362 /* Get queue state from the status file. If it doesn't exist,
364 if (!openStatusFile()) {
365 cerr << "Failed to open status file" << endl;
369 /* Lock status file to keep other requests out. */
375 /* Handle request. */
385 cerr << "No recognized request" << endl;
391 * Reads in data for request. This is used for the slot to be
395 void IoTQuery::readData() {
397 data = new char[length+1];
398 memset(data, 0, length+1);
399 cin.read(data, length);
404 } while (!cin.eof());
409 * Reads relevant environmental variables to find out the request.
412 void IoTQuery::getQuery() {
413 uri = FCGX_GetParam(uri_str, request->envp);
414 query = FCGX_GetParam(query_str, request->envp);
415 method = FCGX_GetParam(method_str, request->envp);
416 iotcloudroot = FCGX_GetParam(iotcloudroot_str, request->envp);
418 /** We require the content-length header to be sent. */
419 char * reqlength = FCGX_GetParam(length_str, request->envp);
421 length=strtoll(reqlength, NULL, 10);
428 * Initializes directory field from environmental variables.
431 void IoTQuery::getDirectory() {
432 char * split = strchr((char *)uri, '?');
435 int split_len = (int) (split-uri);
436 int rootdir_len = strlen(iotcloudroot);
437 int directory_len = split_len + rootdir_len + 1;
438 directory = new char[directory_len];
439 memcpy(directory, iotcloudroot, rootdir_len);
440 memcpy(directory + rootdir_len, uri, split_len);
441 directory[directory_len-1]=0;
445 * Helper function that is used to read the status file.
448 int doread(int fd, void *ptr, size_t count, off_t offset) {
450 size_t bytesread=pread(fd, ptr, count, offset);
451 if (bytesread==count) {
453 } else if (bytesread==0) {
461 * Writes the current state to the status file.
464 void IoTQuery::updateStatusFile() {
465 pwrite(fd, &numqueueentries, sizeof(numqueueentries), OFFSET_MAX);
466 pwrite(fd, &oldestentry, sizeof(oldestentry), OFFSET_OLD);
467 pwrite(fd, &newestentry, sizeof(newestentry), OFFSET_NEW);
471 * Reads in queue state from the status file. Returns true if
475 bool IoTQuery::openStatusFile() {
476 char statusfile[]="queuestatus";
477 int len=strlen(directory);
479 char * filename=new char[len+sizeof(statusfile)+2];
480 memcpy(filename, directory, len);
482 memcpy(filename+len+1, statusfile, sizeof(statusfile));
483 filename[len+sizeof(statusfile)+1]=0;
484 fd=open(filename, O_CREAT| O_RDWR, S_IRUSR| S_IWUSR);
488 cerr << strerror(errno) << " error opening statusfile" << endl;
492 /* Read in queue size, oldest sequence number, and newest sequence number. */
495 if (doread(fd, &size, sizeof(size), OFFSET_MAX))
496 numqueueentries=size;
501 if (doread(fd, &entry, sizeof(entry), OFFSET_OLD))
506 if (doread(fd, &entry, sizeof(entry), OFFSET_NEW))