brwsh/get.c

#define _POSIX_C_SOURCE 200809l
#define _XOPEN_SOURCE 500

#include <sys/socket.h>
#include <sys/select.h>

#include <arpa/inet.h>

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include <netdb.h>
#include <errno.h>

#include <fcntl.h>
#include <sys/time.h>

#include "xalloc.h"
#include "url.h"

#define CHUNK_SIZE 1024

int send_chunk(int, char *, size_t);
int recv_chunk(int, char **, size_t *);

ssize_t recv_timeout(int, char **, struct timeval *);

int main(int argc, char **argv)
{
	if (argc < 2)
		err(EXIT_FAILURE, "needs a url as argument");
		
	url_t *url = url_parse(argv[1]);
	if (!url)
		err(EXIT_FAILURE, "error parsing url");

	printf("scheme: %s\n"
	       "net_path: %s\n"
	       "abs_path: %s\n"
	       "net_node: %s\n"
	       "net_service: %s\n\n",
	       url->scheme, url->net_path, url->abs_path, url->net_node, url->net_service);

	// got the url parsed, now try to connect
	if (strcmp(url->scheme, "http")) {
		url_free(url);
		free(url);
		err(EXIT_FAILURE, "only supports http");
	}

	// get address information, this gives us a list of addinfos where
	// we can connect to
	struct addrinfo hints = {0};
	struct addrinfo *servinfo = {0};
	int status;

	hints.ai_family = AF_UNSPEC;
	// TODO: adjust hints based on cache and url info (TCP or UDP)
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE;

	status = getaddrinfo(url->net_node, url->net_service, &hints, &servinfo);
	if (status)
		err(status, "getaddrinfo: %s", gai_strerror(status));


	// This will print all available addresses for the given url
	printf("IP addresses for %s:\n", argv[1]);
	char ipstr[INET6_ADDRSTRLEN];
	struct addrinfo *p;
	for(p = servinfo;p != NULL; p = p->ai_next) {
		void *addr;
		char *ipver;
		// get the pointer to the address itself,
		// different fields in IPv4 and IPv6:
		if (p->ai_family == AF_INET) { // IPv4
			struct sockaddr_in *ipv4 = (struct sockaddr_in *)p->ai_addr;
			addr = &(ipv4->sin_addr);
			ipver = "IPv4";
		} else { // IPv6
			struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)p->ai_addr;
			addr = &(ipv6->sin6_addr);
			ipver = "IPv6";
		}
		inet_ntop(p->ai_family, addr, ipstr, sizeof ipstr);
		printf("\t%s: %s\n", ipver, ipstr);
	}
	puts("\n");

	// Connect to the server
	int servsocket;
	struct addrinfo *sai;
	for (sai = servinfo; sai; sai = sai->ai_next) {
		servsocket = socket(sai->ai_family, sai->ai_socktype, sai->ai_protocol);
		if (servsocket != -1)
			break;
	}
	if (servsocket == -1 || !sai)
		err(errno, NULL);


	char port[32];
	void *addr;
	long portn;
	if (sai->ai_family == AF_INET) { // IPv4
		struct sockaddr_in *ipv4 = (struct sockaddr_in *)sai->ai_addr;
		addr = &(ipv4->sin_addr);
		portn = ntohs(ipv4->sin_port);
	} else { // IPv6
		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)sai->ai_addr;
		addr = &(ipv6->sin6_addr);
		portn = ntohl(ipv6->sin6_port);
	}
	snprintf(port, 31, "%ld", portn);
	inet_ntop(sai->ai_family, addr, ipstr, sizeof ipstr);
	printf("Connected to %s:%s\n", ipstr, port);
     

	connect(servsocket, sai->ai_addr, sai->ai_addrlen);

	//make socket non blocking
 	//fcntl(servsocket, F_SETFL, O_NONBLOCK);
	
	char *header;
	xasprintf(&header, "GET /%s HTTP/1.0\r\n"
	                   "Host: %s\r\n"
	                   "\r\n",
	                   url->abs_path, url->net_node);

	printf("HTTP request header:\n");
	printf("%s\n", header);

	if (send_chunk(servsocket, header, strlen(header)) == -1)
		err(errno, NULL);


	char *buf;
	ssize_t bufsize;
	struct timeval timeout = {10, 0};
	if ((bufsize = recv_timeout(servsocket, &buf, &timeout)) < 0)
		err(errno, NULL);

	printf("GOT RESPONSE OF SIZE %ld\n\n", bufsize);
	puts(buf ? buf : "NOTHING RECIVED");

	free(buf);

	free(header);

	close(servsocket);
	freeaddrinfo(servinfo);
	url_free(url);
	free(url);
	return 0;
}

// TODO: also use select here
int send_chunk(int s, char *msg, size_t len)
{
	// send a whole chunk of data
	size_t sent = 0;
	ssize_t st;
	while (sent < len) {
		st = send(s, msg+sent, len-sent, 0);
		if (st == -1)
			return -1;
		sent += st;
	}
	return 0;
}

ssize_t recv_timeout(int s, char **buf, struct timeval *t)
{
	if (!t || !buf) {
		errno = EINVAL;
		return -1;
	}

	fd_set fds;
	int n;
	ssize_t size = 0, sr;
	char chunk[CHUNK_SIZE];

	FD_ZERO(&fds);
	FD_SET(s, &fds);
	*buf = NULL;

	for (;;) {
		n = select(s+1, &fds, NULL, NULL, t);
		if (n == -1)
			goto err;
		if (n == 0)
			break;
		sr = recv(s, chunk, CHUNK_SIZE, 0);
		if (sr == -1)
			goto err;
		if (sr == 0)
			break;
		*buf = xrealloc(*buf, size+sr+1);
		memcpy(&((*buf)[size]), chunk, sr);
		size += sr;
		(*buf)[size] = '\0';
	}

	return size;
	err:
	if (*buf)
		free(*buf);
	return -1;
}