#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <arpa/inet.h>

#include <string.h>

#include "sha1.h"

#include "base64.h"

#include "uuid.h"

char *substring(char *string, int position, int length)

{

char *pointer;

int c;

pointer = (char*)malloc(length+1);

if (pointer == NULL)

{

printf("Unable to allocate memory.\n");

exit(1);

}

for (c = 0 ; c < position -1 ; c++)

string++;

for (c = 0 ; c < length ; c++)

{

*(pointer+c) = *string;

string++;

}

*(pointer+c) = '\0';

return pointer;

}

char* extract_substring(char *string, char *pattern_start,char *pattern_end)

{

char* pch;

char* spch;

pch = strstr(string,pattern_start);

if (pch==NULL) return NULL;

spch = strstr(pch,pattern_end);

if (pch==NULL) return NULL;

char* s = substring(pch+strlen(pattern_start), 0, spch - pch - strlen(pattern_start)- 1);

return s;

}

void send_sock_text(int clientSock, char* msg) {

unsigned int len = strlen(msg);

unsigned char buffer[1024];

memset(buffer, 0, sizeof(buffer));

// 0x80 means final fragment and 0x01 means opecode is text frame

buffer[0] = 0x01 | 0x80; // opcode

buffer[1] = len; // payload length

memcpy(buffer + 2, msg, len);

write(clientSock, buffer, strlen(buffer));

}

unsigned char* decoded_message(unsigned char* buffer)

{

if (buffer[0] == 0x81){

//Is text frame and final message

int decode_msg_length = buffer[1] & 0x7F;

//printf("decode_msg_length=%d\n",decode_msg_length);

unsigned char encoded_key[4];

encoded_key[0]=buffer[2];

encoded_key[1]=buffer[3];

encoded_key[2]=buffer[4];

encoded_key[3]=buffer[5];

unsigned char* decoded_msg = (unsigned char*) malloc(decode_msg_length);

int i;

for(i=0;i< decode_msg_length ;i++){

decoded_msg[i] = (buffer[i+6] ^ encoded_key[i % 4]);

//printf("[%c]\n", decoded_msg[i]);

}

/*

if ((decoded_msg[0] == 'a') && (decode_msg_length == 1)){

send_sock_text(clientSock,"get a\r\n");

}

*/

return decoded_msg;

}else {

return NULL;

}

}

void handle_message_loop(int clientSock)

{

unsigned char buffer[1024];

memset(buffer,0,sizeof(buffer));

while(1){

int byteCount = read(clientSock , buffer, sizeof(buffer));

if ( byteCount >= 0 ) {

unsigned char* decoded_msg = decoded_message(buffer);

if (decoded_msg == NULL){

if (buffer[0] == 0x88){

printf("socket suddenly close\n");

break;

}

//----------------------------------------------------

int i;

for(i=0;i<(int)strlen(buffer);i++){

//printf("\ni=%d/%d\n",i,(int) strlen(read_buf));

//printf("[%s]\n", read_buf);

printf("0x%02x ",buffer[i]);

}

printf("\n");

//----------------------------------------------------

}else{

printf("Get message [%s]\n",decoded_msg);

char *get_val;

if ( (get_val = extract_substring(decoded_msg,"connection:", "\n")) != NULL){

printf("get_val=connection:%s\n",get_val);

char*client_msg=(char*)malloc(512);

strcpy(client_msg,"connection:");

strcat(client_msg,get_val);

//strcat(client_msg,"\n");

send_sock_text(clientSock,client_msg);

}else if ( (get_val = extract_substring(decoded_msg,"input:", "\n")) != NULL){

printf("get_val=input:%s\n",get_val);

char*client_msg=(char*)malloc(512);

strcpy(client_msg,"input:");

strcat(client_msg,get_val);

send_sock_text(clientSock,client_msg);

}

}

}

}

}

int handle_header(int clientSock, char* buffer)

{

char *Sec_WebSocket_Key = extract_substring(buffer ,"Sec-WebSocket-Key: ","\n");

//printf("[%s]\n",Sec_WebSocket_Key);

char *magickey = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

char *str = malloc(strlen(Sec_WebSocket_Key)+strlen(magickey));

memset(str,0,strlen(str));

strcpy(str,Sec_WebSocket_Key);

strcat(str,magickey);

unsigned char *sha1_str;

sha1_str = getsha1 (str ,strlen(str));

unsigned char *base64_str;

size_t len;

base64_str = base64_encode(sha1_str, strlen(sha1_str), &len);

//printf("[%s]\n",base64_str);

char buf[512];

sprintf(buf, "HTTP/1.1 101 Switching Protocols\r\nUpgrade: websocket\r\nConnection: Upgrade\r\nSec-WebSocket-Accept: %s\r\nSec-WebSocket-Protocol: chat\r\n\r\n",base64_str);

/*

printf("----sending to client----\n");

printf("%s\n",buf);

printf("-------------------------\n");

*/

int byteCount = write(clientSock, buf, strlen(buf));

if (byteCount > 0)

return 0;

else

return 1;

}

int main( int argc, char const *argv[])

{

int serverSock ;

int val = 1;

struct sockaddr_in serverAddr ;

struct sockaddr_in clientAddr ;

socklen_t clientAddrLen = sizeof (clientAddr);

char buffer [512];

char * uuid = random_uuid();

fprintf(stdout , "%s, %s\n" ,"Start", uuid);

fprintf(stdout , "%s, %s\n" ,"Another", random_uuid());

serverSock = socket(AF_INET, SOCK_STREAM , 0 );

if (serverSock == -1 ) {

fprintf (stderr, "%s\n" ,"open socket fail");

return - 1;

}

// Make sure the port can be immediately re-used

if (setsockopt(serverSock, SOL_SOCKET , SO_REUSEADDR, &val , sizeof(val )) < 0 ) {

fprintf (stderr, "%s\n" ,"can't reuse socket");

close (serverSock);

return - 1;

}

memset(&serverAddr , 0 , sizeof (serverAddr));

serverAddr.sin_family = AF_INET;

serverAddr.sin_addr .s_addr = htonl(INADDR_ANY );

serverAddr.sin_port = htons(12345);

if (bind( serverSock, (struct sockaddr *) & serverAddr, sizeof(serverAddr )) != 0 ) {

fprintf (stderr, "%s\n" ,"can't bind socket");

close (serverSock);

return - 1;

}

// Listen to socket

fprintf(stdout , "%s\n" ,"start listen port 12345");

if (listen( serverSock, 1024) < 0 ) {

return - 1;

}

while(1){

//accept will wait for message coming

fprintf (stdout, "%s\n" ,"wait accept");

int clientSock = accept(serverSock , ( struct sockaddr *) &clientAddr, &clientAddrLen );

int total_byte_cnt = 0;

for (;;) {

int byteCount = read(clientSock , buffer + total_byte_cnt, sizeof(buffer ) - total_byte_cnt - 1);

if ( byteCount >= 0 ) {

total_byte_cnt += byteCount;

buffer [total_byte_cnt] = 0;

/*

fprintf (stdout, "[1] %d bytes read\n" , byteCount);

fprintf (stdout, "%s\n" , "========================" );

fprintf (stdout, "%s\n" , buffer);

fprintf (stdout, "%s\n" , "========================" );

*/

//

char *pch = strstr(buffer,"GET / HTTP/1.1");

char *Upgrade = extract_substring(buffer ,"Upgrade: ","\n");

char *Connection = extract_substring(buffer ,"Connection: ","\n");

//Sec-WebSocket-Protocol should be "chat"

char *Sec_WebSocket_Protocol = extract_substring(buffer ,"Sec-WebSocket-Protocol: ","\n");

if (pch == NULL) printf("pch is null");

//printf("[%s]\n", Upgrade);

//printf("[%s]\n", Connection);

if ((pch == buffer) && ((strcmp(Upgrade,"websocket") == 0) || (strcmp(Upgrade,"Websocket") == 0)) && ((strcmp(Connection,"Upgrade") == 0) || (strcmp(Connection,"keep-alive, Upgrade") == 0)) ){

handle_header(clientSock, buffer);

handle_message_loop(clientSock);

}

//

break;

} else {

//fprintf (stdout, "%s\n" ,"[3] oh no");

break;

}

}

}

fprintf(stdout , "%s\n" ,"Finish");

return 0;

}