Hi.
I'm looking for some help parsing an HTTP POST request from an EthernetClient.
I have an Ethernet2 shield connected to a Mega2560 and am using the Ethernet2 and TextFinder libraries.
A browser submits an HTML page containing an HTML form to my ethernet shield.
The form contains a single file upload element:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<form action="http://192.168.100.150/" enctype="multipart/form-data" method="post">
<input type="file" name="iniFileName" id="iniFileId">
<input type="submit" value="Submit">
</form>
</body>
</html>
The ethernet shield receives the submitted data and i want to extract just the binary (uploaded file) data.
The HTTP request looks like this:
/ HTTP/1.1
Host: 192.168.100.150
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,/;q=0.8
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
Connection: keep-alive
Content-Type: multipart/form-data; boundary=---------------------------163482754226683
Content-Length: 378-----------------------------163482754226683
Content-Disposition: form-data; name="iniFileName"; filename="network.ini"
Content-Type: application/octet-streammy config file
[network]
dns = 192.168.100.1
gateway = 192.168.100.1
ip = 192.168.100.150
mac = 90-A2-DA-10-71-9F
port = 80
subnet = 255.255.255.0-----------------------------163482754226683--
The uploaded file contents are:
my config file
[network]
dns = 192.168.100.1
gateway = 192.168.100.1
ip = 192.168.100.150
mac = 90-A2-DA-10-71-9F
port = 80
subnet = 255.255.255.0
It's an ini file that starts with a comment and ends with a trailing new line.
I want to extract the binary data which is my uploaded file and save it to an SD card in the ethernet shield.
I have a class which has a method and in this method i'm currently trying this:
boolean StorageManager::writeFile(EthernetClient ethernetClient){
boolean success=false;
TextFinder textFinder(ethernetClient);
// using 96 as max number of chars in the boundary value
char boundaryValue[96];
int charsRead=textFinder.getString("boundary=", "\r\n", boundaryValue, 96);
if(charsRead>0){
boundaryValue[charsRead]='\0';
strcat(boundaryValue, "--");
Serial.print("boundary: ");
Serial.println(boundaryValue);
// max filename length is 8.3 filename + null terminator = 13 chars
char filenameValue[13];
charsRead=textFinder.getString("filename=\"", "\"", filenameValue, 12);
if(charsRead>0){
filenameValue[charsRead]='\0';
Serial.print("filename: ");
Serial.println(filenameValue);
if(textFinder.find("octet-stream\r\n\r\n")){
File file=SD.open(filenameValue, O_WRITE | O_CREAT | O_TRUNC);
if(file){
while(ethernetClient.available()){
file.print((char) ethernetClient.read());
}
file.close();
success=true;
}
}
}
}
return success;
}
The code currently saves this data to my SD card:
lan2fsk config file
[network]
dns = 192.168.100.1
gateway = 192.168.100.1
ip = 192.168.100.150
mac = 90-A2-DA-10-71-9F
port = 80
subnet = 255.255.255.0-----------------------------7280166718996--
My question is how to remove that trailing boundary value "-----------------------------7280166718996--"?
I could modify my while loop:
while(ethernetClient.available()){
char c=(char) ethernetClient.read();
if(some_condition){
// what condition can i test for to see if the final line "-----------------------------7280166718996--" has been reached?
} else {
file.print(c);
}
}
I could create a char array buffer and read each line of binary data into the buffer then compare the buffer to the boundary value - this would tell me whether or not i want to write the buffer to the file.
And this is what i was about to start coding.
BUT...
This method will not only save text based ini files, it will also be used to upload and save binary hex files - i want to be able to upload my compiled sketch (after an update) to the shield and am then hoping to (remotely) flash the updated sketch from the SD card.
My sketch is currently around 30KBs in size when compiled.
Imagine a text file with a single line of 30,000 characters.
I wouldn't be able to read that single line into a buffer and compare it to my boundary value.
So the solution i was about to start coding would work when i upload a simple text ini file.
But it wouldn't be able to handle a large binary file.
Does that all make sense?
How can i get all data in the EthernetClient Stream up to but not including the last line - the line that contains my boundary value?
Thanks a lot for any help.
.