HTTP protocol.. RFC study notes

Alright, I sholud have done this atleast 2 years ago and was too much of an idiot to not do this, better late than never.

Study Notes — http protocol (RFC 7230 – 7235)*

RFC 7230 — Message syntax and Routing

Key parties:
1. HTTP Server: the sytem that responds to http requets with http responses
2. User Agent/http client: the system that sends the http requests

Intermediaries:
There are some intermediate parties in the communication between 1 and 2. (Because of how tcp/ip works).
Note: these are relevant because, some of the keywords are related to these. (aka, this is where the http vs tcp/ip abstraction leaks)
1. proxy:
message-forwarding agent selected by client(via configurable rules),
commonly used to group an organizations’ requests
2. gateway:
an intermediary that acts as origin(http) server for a outbound connection but translates the requests and forwards them inbound to other servers.
3. tunnel:
Tunnel is a blind relay between 2 connections, that passes on messages. it differs from gateway, but not translating the requests, but blindly passing them on. Generally used in situations like TLS + https secure communication via a firewall proxy

Caches:
Details in RFC 7234.
1. Local store of previous response messages
2. A response may or may not be cached based on :
a, cacheable flag is set.
b, A set of constraints defined in rfc7234

Versioning:
A Message has atleast these fields:
Version is .

HTTP-version = HTTP-name “/” DIGIT “.” DIGIT
HTTP-name = %x48.54.54.50 ; “HTTP”, case-sensitive

Major version denotes http messaging syntax, while minor version is the client’s communication capabilities.
Hmm.. these two don’t seem well-defined so far in the rfc.
My guess is the major version corresponds to tell the server which protocol-specific syntax, (ie: http/https/ftp/etc.) to connect with the server is used for the request.
While minor version is which version client understands, so the response can be formatted in a compatible manner.
My guess about major num is wrong.

The intention of HTTP’s versioning design is that the major number
will only be incremented if an incompatible message syntax is
introduced, and that the minor number will only be incremented when
changes made to the protocol have the effect of adding to the message
semantics or implying additional capabilities of the sender.
However, the minor version was not incremented for the changes
introduced between [RFC2068] and [RFC2616], and this revision has
specifically avoided any such changes to the protocol.

Uniform Resource Identifiers:
1. identifies resources
For the URI syntax, I’ll just quote from the links on the rfc.

URI-reference =
absolute-URI =
relative-part =
scheme =
authority =
uri-host =
port =
path-abempty =
segment =
query =
fragment =

absolute-path = 1*( “/” segment )
partial-URI = relative-part [ “?” query ]

http URI Scheme:

* — Original RFC was 2616 http://ift.tt/1qWngNQ, but it was superseded by these.

from HTTP protocol.. RFC study notes

from Tumblr http://ift.tt/1TJ1z20

via IFTTT

from HTTP protocol.. RFC study notes

from Tumblr http://ift.tt/1YUABVk

via IFTTT

from HTTP protocol.. RFC study notes
from Tumblr http://ift.tt/1RmDqIV
via IFTTT

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s