Let's say an HTTP POST request is made with this header
Content-Type: multipart/form-data; boundary=...
and then, the body is built accordingly.
If I understand correctly, when the web server transmits the request to a CGI application, it sets some environments variables and the body is sent as stdin. So, the CGI app does not have access to the headers (except through some environment variables).
Then, how can a CGI application decode the body (stdin) if it does not have access to the header (Content-Type)?
There is a CONTENT-TYPE as part of the environment variable that a CGI application has access to. This link explains in details how a CGI application can read a multipart form.
Related
I'm running an LWIP http webserver on an STM32F4 discovery board. It displays a webpage when its IP address is entered on a web broswer. I need to send a string back to the webpage when the LWIP CGI handler is called. The javascript code in the html page is expecting this. how do I do that? The only thing I can send to the web page is a URL to another local html page.
here is the setup:
the project was created using the STM32 cubeIDE. Its using the LWIP stack with FreeRTOS. This web page sends a CGI command to the stm32 board using the http GET method. Then LWIP CGI handler is automatically called and executes. I can retrieve the data sent by the webpage.
This is the what the CGI handler looks like:
const char *my_cgi_handler(int iIndex, int iNumParams, char *pcParam[],
char *pcValue[])
{
//do some stuff with retrieved data
// return a filename
return "/index.html";
}
here is a simple LWIP CGI example code
This handler does not give the socket descriptor so that I can directly send data to the web page. Also The LWIP documentation says I should not write directly to the web page.
The simple CGI support offered here works with GET method requests
only and can handle up to 16 parameters encoded into the URI. The
handler function may not write directly to the HTTP output but must
return a filename that the HTTP server will send to the browser as a
response to the incoming CGI request.
How will I solve this problem without editing the HTML page?
You can use lwIP SSI (Server-Side Includes) for this. See documentation on configuration #define switches. The HTTP server documentation has some information on SSI, and there's also some SSI example code.
Basically,
#define LWIP_HTTPD_SSI in your configuration header
add a file to the lwIP HTTP server which only contains /*#TagName*/
register a callback with http_set_ssi_handler. This callback will be called when a http client requests the new file. The callback will receive information about the tag and you can write an arbitrary answer to a supplied buffer. By default, the response is limited to LWIP_HTTPD_MAX_TAG_INSERT_LEN bytes. If that's not sufficient, you can #define LWIP_HTTPD_SSI_MULTIPART to make longer responses.
I have 10 http requests in http file and want to run them on single click instead of clicking each request and see the output. Subsequent requests use output from previous requests so I want to run them serially in automated way.
At the moment IDEA's text-based HTTP client supports variable substitution and allows to write some simple JavaScript to access response.
All you have to do is create .http file with all your requests defined in a sequence. Then after each request you can add JavaScript block to fill variables that next request(s) require. Example:
### getting json and setting variable retrieved from response body
GET http://httpbin.org/json
> {%
client.global.set("title",response.body["slideshow"]["title"])
%}
### making request using previously set variable as a body
POST http://httpbin.org/anything
Content-Type: text/plain
{{title}}
Next step is running all requests at once like this:
You could use "Run/Debug Configurations", create a few separated files and setup order in window. But you'll get a big task, you cannot wait and setup timeouts for requests.
I guess you should use Jmeter for real work.
You also could try setup simple curl requests in the Linux bases os.
I am trying to create an app with Cordova which receives push notifications from my server. Can anyone tell me that I need a https:// connection for the APNS to work or it should work with http:// as well?
All FCM/GCM endpoints are https, the same endpoints are used whether you are sending to Android, iOS or web so you should always use https when sending messages through FCM/GCM.
Based from this documentation, the sample POST request should be https://gcm-http.googleapis.com/gcm/send.
A message request is made of 2 parts: HTTP header and HTTP body.
The HTTP header must contain the following headers:
Authorization: key=YOUR_API_KEY
Content-Type: application/json for JSON; application/x-www-form-urlencoded;charset=UTF-8 for plain text. If
Content-Type is omitted, the format is assumed to be plain text.
The HTTP body content depends on whether you're using JSON or plain
text.
You can follow this tutorial.
Is there any way to configure Apache to programatically examine a request and cancel the response if the request is invalid. I mean, my intention is to skip responding and just disconnect the client. I'm currently developing a fault-tolerance server fronted by Apache which needs to (stakeholder requirement) ignore answering requests which aren't authorize (I can't even send 401). If I can't use Apache, is there any other way to do it?
Continuation of above comments ...
I dont know how much control you have in JBoss over headers and output sent to the browser, but you can mimic an closed/aborted request like this. From within an application.
Send these Headers, flush and stop all output:
HTTP/1.0 204 No Content
Content-Length: 0
Content-Type: text/html
For example, this is the recommended method the Amazon API suggests as a response to any call that does not want a response.
I'm building a web server as an exercise. When I receive a raw request, it gets parsed into an simple syntax tree, and a response is built by evaluating this tree. My question this: When sending an HTTP Response, does the Content-Type field get set by taking the file extension of the requested resource and looking it up in a dictionary of MIME-types? A good example would be the anatomy of how the response for a favicon.ico is built. Any insight into this would be most helpful. Thanks.
By default, web server looks into file extension and select what kind of Content Type it should interpret the file as. However, server-side scripting can send custom header ( e.g. header() function of PHP ) to override the settings . For example, a JPEG can be interpreted as PNG if you send Content Type as image/png to web server with the following code:
header('Content-Type: image/png');
For non-file requests, the web server looks into custom header directly.
Web server maps extension with MIME type. As you tag apache, Apache uses AddType directive to identify file's MIME type, while IIS and other web servers have similar settings .