[C] problema invio HTTP Request google maps api

[marilynm69]

Ciao a tutti, ho un problema con un programma, il cui scopo principale è spedire richieste GET a maps.googleapis.com e ricevere il file JSON da analizzare in seguito.
Sto scrivendo su linux,questo è il mio codice, file main e di seguito l'header

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mysocketfn.h"

#define HOST "maps.googleapis.com"
#define PORT 443

int main()
{
char request[]=
"GET https://"
HOST
"/maps/api/distancematrix/json?origins=roma&destinations=milano&mode=driving&language=it-IT\r\n"
"Host: maps.googleapis.com\r\n"
"\r\n";

send_message(HOST,PORT,request);

return 0;
}



/* mysocketfn.h */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>

#define BUF_MAX 1000

void send_message(char*addressname, int port, char*message_to_send)
{
struct hostent *hs;
struct sockaddr_in serveraddr;

fprintf(stdout,"Retrieving information about %s\n",addressname);
//resolve hostname
hs = gethostbyname(addressname);
if (hs == NULL) // do some error checking
{
fprintf(stdout,"Errore gethostbyname(%s)",addressname);
herror("gethostbyname");
exit(1);
}

// print information about this host:
fprintf(stdout,"Official name is: %s\n", hs->h_name);
fprintf(stdout,"IP address: %s\n", inet_ntoa(*(struct in_addr*)hs->h_addr));

unsigned long ula = *((unsigned long *)hs->h_addr_list[0]);

fprintf(stdout, "gethostbyname(%s) result: %lu\n",addressname, ula);

// Configure settings of the server address struct
// Set IP address
serveraddr.sin_addr.s_addr=ula;
// Address family = Internet
serveraddr.sin_family = AF_INET;
// Set port number, using htons function to use proper byte order
serveraddr.sin_port = htons(port);

memset(&serveraddr.sin_zero, 0, sizeof(serveraddr.sin_zero));

fprintf(stdout,"*Address in the correct form: %s\n",inet_ntoa(serveraddr.sin_addr));

//***********************************************************************************
//* CREATE SOCKET, CONNECT, SEND MESSAGE, RECEIVE RESPONSE, CLOSE SOCKET CONNECTION *
int sock; // socket descriptor
int chkerr;
char buff[BUF_MAX];

fprintf(stdout,"Creating socket...\n");

//Create socket descriptor
sock=socket(AF_INET,SOCK_STREAM,0);
if (sock < 0)
fprintf(stdout,"Error creating socket.\n");
else fprintf(stdout,"Socket created\n");

fprintf(stdout,"Connecting to %s on port %d...\n",inet_ntoa(serveraddr.sin_addr),port);

//Connect to server
chkerr=connect(sock,(struct sockaddr *)&serveraddr, sizeof(serveraddr));
if (chkerr<0)
fprintf(stdout,"Error connecting to the server\n");
else fprintf(stdout,"Connected to server\n");

fprintf(stdout,"Sending data...\n");

//Send data
fprintf(stdout,"Data:\n%s\n",message_to_send);
chkerr=send(sock,message_to_send,sizeof(message_to_send),0);
if (chkerr<0)
fprintf(stdout,"Data sending error\n");
else fprintf(stdout,"Data send\n");

fprintf(stdout,"Server response:\n\n");

//Receive response
memset(buff,0,sizeof(buff));
while((chkerr=recv(sock,buff,sizeof(buff),0)) != 0)
{
if (chkerr<0)
fprintf(stdout,"Data reception error\n");
else if (chkerr==0) fprintf(stdout,"End of data reception");
else fprintf(stdout,"%s",buff);
}

//CLOSE socket descriptor
close(sock);
fprintf(stdout,"Connection closed\n");

}


questo è ciò che ottengo:
...
Connecting to 216.58.205.138 on port 443...
Connected to server
Sending data...
Data:
GET https://maps.googleapis.com/maps/api/distancematrix/json?origins=roma&destinations=milano&mode=driving&language=it-IT
Host: maps.googleapis.com


Data send
Server response:

Connection closed


se come prova faccio:
int main()
{
send_message("google.com",80,"GET /\r\n\r\n");

return 0;
}

il risultato ...
...
Connecting to 216.58.205.174 on port 80...
Connected to server
Sending data...
Data:
GET /


Data send
Server response:

HTTP/1.0 302 Found
Cache-Control: private
Content-Type: text/html; charset=UTF-8
Referrer-Policy: no-referrer
Location: http://www.google.it/?gfe_rd=cr&dcr=0&ei=-MBYWp-MNrPCXqTXseAM
Content-Length: 266
Date: Fri, 12 Jan 2018 14:06:48 GMT

<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="http://www.google.it/?gfe_rd=cr&amp;dcr=0&amp;ei=-MBYWp-MNrPCXqTXseAM">here</A>.
</BODY></HTML>
Connection closed


dunque il messaggio viene inviato senza problemi...
quindi mi chiedo...perchè non ricevo niente inviando a googleapis? sto sbagliando a livello di c o la richiesta http?

Scusate se non mi sono spiegato bene e grazie mille in anticipo

[Pbdz]

il problema potrebbe risiedere nell'header della richiesta http.

Prova a modificare la variabile request[] così:

char request[]=
"GET /maps/api/distancematrix/json?origins=roma&destinations=milano&mode=driving&language=it-IT HTTP/1.1\r\n"
"Host: maps.googleapis.com\r\n"
"\r\n";

[marilynm69]

provato lo stesso, mi da:
Data send
Server response:

Connection closed