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3 Commits

Author SHA1 Message Date
5ff532ecd9 Started working on 'url_to_path' function 2023-03-09 08:08:38 -06:00
418861d53c Started working on making socket connection 2023-03-09 08:08:09 -06:00
b85d83d0ea Updated easysock files 2023-03-09 08:07:43 -06:00
4 changed files with 118 additions and 5 deletions

View File

@@ -77,13 +77,36 @@ int create_local (int network, char transport, char* address, int port,struct so
int create_remote (int network,char transport,char* address,int port,struct sockaddr* remote_addr_struct) {
struct addrinfo hints; /* Used to tell getaddrinfo what kind of address we want */
struct addrinfo* results; /* Used by getaddrinfo to store the addresses */
if (check_ip_ver(address) < 0) { /* If the address is a domain name */
int err_code;
char* port_str = malloc(10 * sizeof(char));
sprintf(port_str,"%d",port); /* getaddrinfo expects a string for its port */
memset(&hints,'\0',sizeof(hints));
hints.ai_socktype = char_to_socktype(transport);
err_code = getaddrinfo(address,port_str,&hints,&results);
if (err_code != 0) {
exit(err_code);
}
remote_addr_struct = results->ai_addr;
network = inet_to_int(results->ai_family);
} else {
create_addr(network,address,port,remote_addr_struct);
}
int socket = create_socket(network,transport);
if (socket < 0) {
exit(errno);
}
create_addr(network,address,port,remote_addr_struct);
int addrlen;
int addrlen;
if (network == 4) {
addrlen = sizeof(struct sockaddr_in);
} else if (network == 6) {
@@ -102,3 +125,45 @@ int create_remote (int network,char transport,char* address,int port,struct sock
}
return socket;
}
int check_ip_ver(char* address) {
char buffer[16]; /* 16 chars - 128 bits - is enough to hold an ipv6 address */
if (inet_pton(AF_INET,address,buffer) == 1) {
return 4;
} else if (inet_pton(AF_INET6,address,buffer) == 1) {
return 6;
} else {
return -1;
}
}
int int_to_inet(int network) {
if (network == 4) {
return AF_INET;
} else if (network == 6) {
return AF_INET6;
} else {
exit(207);
}
}
int inet_to_int(int af_type) {
if (af_type == AF_INET) {
return 4;
} else if (af_type == AF_INET6) {
return 6;
} else {
exit(207);
}
}
int char_to_socktype(char transport) {
if (transport == 'T') {
return SOCK_STREAM;
} else if (transport == 'U') {
return SOCK_DGRAM;
} else {
exit(250);
}
}

View File

@@ -2,7 +2,9 @@
#define EASYSOCK_H_
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <stdio.h>
@@ -50,5 +52,24 @@ It prints the error returned by 'connect' if something went wrong, and exits wit
int create_remote (int network,char transport,char* address,int port,struct sockaddr* remote_addr_struct);
/* check_ip_ver - This function checks if the given string is an IPv4 address (returns 4),
IPv6 address (returns 6) or neither (returns -1). */
int check_ip_ver(char* address);
/* int_to_inet - Takes an int value (4 for IPv4, 6 for IPv6) and returns AF_INET or
AF_INET6 respectively. */
int int_to_inet(int network);
/* char_to_socktype - Takes a character that represents a transport-layer protocol
(currently only supports 'T' for TCP or 'U' for UDP - exits with error code 250 if
the given characters is neither of these) and return the appropriate SOCKTYPE value. */
int char_to_socktype(char transport);
/* inet_to_int - Takes an int value that corresponds to AF_INET or AF_INET6,
and returns the appropriate int value. */
int inet_to_int(int af_type);
#endif

23
main.c
View File

@@ -6,6 +6,7 @@
#include <Xm/Form.h>
#include <XmHTML/XmHTML.h>
#include "easysock.h"
#include "url_manipulation.h"
void testFunc(Widget,XtPointer,XmPushButtonCallbackStruct *);
@@ -60,7 +61,29 @@ void testFunc(Widget w, XtPointer client_data, XmPushButtonCallbackStruct *callb
Widget* widget_list = (Widget *)client_data;
Widget result_widget = widget_list[1];
Widget text_widget = widget_list[0];
int port;
char* url = XmTextFieldGetString(text_widget);
char* protocol = url_to_proto(url); /* Extract the protocol string from the URL input */
if (strcmp(protocol,"http") == 0) {
port = 80;
} else if (strcmp(protocol,"https") == 0) {
port = 443;
} else {
exit(50); /* I haven't added support for other protocols yet */
}
/* We call the create_remote function to create an address, bind it to a socket,
and make the connection for us. It returns the socket, so that the HTTP request can be made.
First parameter is IP version - set to -1 because we don't know yet if the address is IPv4 or IPv6. */
struct sockaddr* address_struct;
int remote_socket = create_remote(-1,'T',url_to_hostname(url),port,address_struct);
XmHTMLTextSetString(result_widget,"");
// printf("%d\n",val);
// exit(2);

View File

@@ -16,9 +16,8 @@ char* url_to_proto(char* url) {
char* url_to_hostname(char* url) {
/* This function relies on a hack-y assumption: that, given a string
that represents a URL (e.g. https://www.example.com), the host portion
of the address is the length of the address minus (length of protocol + 3 ("://").
In this case that would be 23 - [5 (h,t,t,p,s) + 3 = 8]. */
that represents a URL (e.g. https://www.example.com/index.html), the length of the host portion
of the address is the distance between the second slash (:/'/') and the third ('/'index.html). */
size_t length = strlen(url);
char* protocol = url_to_proto(url);
@@ -35,3 +34,8 @@ char* url_to_hostname(char* url) {
}
char* url_to_path(char* url) {
/* Assumption: The path starts from the third slash to the end of the string. */
}