crazywisdom / nftp-codec

A efficient parser for nftp (customized ftp)

nftp-codec

It's a lightweight ftp parser, and provide a convenient maker & handler mechanism to make or handle the package comply to nftp.

Features

• Support P to P / N to 1 / 1 to N

• Lightweight and no runtime

• Embeddable

• Support asynchronous send / recv

• NFTP Version 1.1 standard docs are Here

Quick start

Sender

#include "nftp.h"

int sender() {
	int rv;
	char * fname = "demo.txt";
	uint8_t * s; // something to send
	uint8_t * r; // something to recv
	size_t slen; // length of s
	size_t rlen; // length of r

	nftp_proto_init();
	nftp_proto_send_start(fname);
	nftp_proto_maker(fname, NFTP_TYPE_HELLO, 0, 0, &s, &slen);
	test_send(s, slen); // your send function. for example tcp_send()
	free(s);

	// waiting for ack
	test_recv(&r, &rlen); // your recv function. for example tcp_recv();
	// handle ack
	rv = nftp_proto_handler(r, rlen, &s, &slen);
	free(r);
	if (rv != 0) {
		goto done; // The ack is invalid or other errors happened
	}

	nftp_file_blocks(fname, &blocks);

	// Note. index start from 0, and end with blocks-1
	for (int i=0; i<blocks; ++i) {
		nftp_proto_maker(fname, NFTP_TYPE_FILE, 0, i, &s, &slen);
		test_send(s, slen);
		free(s);
	}

done:
	nftp_proto_fini();
}

Recver

#include "nftp.h"

int recver() {
	int rv, blocks;
	char * fname = "demo.txt";
	uint8_t * s; // something to send
	uint8_t * r; // something to recv
	size_t slen; // length of s
	size_t rlen; // length of r

	nftp_proto_init();

	while (1) {
		test_recv(&r, &rlen); // your recv function. for example tcp_recv();

		rv = nftp_proto_handler(r, rlen, &s, &slen);
		free(r);
		if (rv != 0) {
			goto done; // Errors happened when recving
		}

		if (s) {
			// recved an hello and send an ack as response(if u want)
			test_send(s, slen);
			free(s);
		} else {
			printf("File transferring...\n");
		}
	}

done:
	nftp_proto_fini();
}

How it works

Process

(sync)
sender  --HELLO-->  recver
sender  <---ACK---  recver

(async allowed)
sender  ---FILE-->  recver
sender  ---FILE-->  recver
sender  ---FILE-->  recver
sender  ---END--->  recver

How do discontinued transmission

A good question! TODO :)

Something u should know

Property	iter	vector	iovs	codec	file	hash	proto
Thread-safe	X	O	O	O	X	O	X

TODO List

• More easy to use
• Support discontinued transmission
• And so on...