#include<stdio.h>

#include<string.h>

#include<stdlib.h>

#include<unistd.h>

#include<sys/types.h>

#include<sys/stat.h>

#include<sys/socket.h>

#include<arpa/inet.h>

#include<netdb.h>

#include<signal.h>

#include<fcntl.h>

#define CONNMAX 1

#define BYTES 1024

char *ROOT;

char *PORT;

int listenfd, clients[CONNMAX];

void error(char *);

void startServer(char *);

void respond(int);

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

{

struct sockaddr_in clientaddr;

socklen_t addrlen;

char c;

//Default Values PATH = ~/ and PORT=10000

int slot=0;

//Parsing the command line arguments

while ((c = getopt (argc, argv, "p:r:")) != -1)

switch (c)

{

case 'r':

ROOT = malloc(strlen(optarg));

strcpy(ROOT,optarg);

break;

case 'p':

PORT = malloc(strlen(optarg));

strcpy(PORT,optarg);

break;

case '?':

fprintf(stderr,"Wrong arguments given!!!\n");

exit(1);

default:

exit(1);

}

printf("Server started at port no. %s%s%s with root directory as %s%s%s\n","\033[92m",PORT,"\033[0m","\033[92m",ROOT,"\033[0m");

// Setting all elements to -1: signifies there is no client connected

int i;

for (i=0; i<CONNMAX; i++)

clients[i]=-1;

startServer(PORT);

// ACCEPT connections

addrlen = sizeof(clientaddr);

clients[slot] = accept (listenfd, (struct sockaddr *) &clientaddr, &addrlen);

if (clients[slot]<0)

error ("accept() error");

else

{

// add if pid == 0 then do, else don't do (do only if it is a child process!

respond(slot);//1 request but many responds of the same socket

}

return 0;

}

//start server

void startServer(char *port)

{

struct addrinfo hints, *res, *p;

// getaddrinfo for host

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

hints.ai_family = AF_INET;

hints.ai_socktype = SOCK_STREAM;

hints.ai_flags = AI_PASSIVE;

if (getaddrinfo( NULL, port, &hints, &res) != 0)

{

perror ("getaddrinfo() error");

exit(1);

}

// socket and bind

for (p = res; p!=NULL; p=p->ai_next)

{

listenfd = socket (p->ai_family, p->ai_socktype, 0);

if (listenfd == -1) continue;

if (bind(listenfd, p->ai_addr, p->ai_addrlen) == 0) break;

}

if (p==NULL)

{

perror ("socket() or bind()");

exit(1);

}

freeaddrinfo(res);

// listen for incoming connections

if ( listen (listenfd, 1000000) != 0 )

{

perror("listen() error");

exit(1);

}

}

//client connection

void respond(int n)

{

char *result = (char *) malloc(sizeof(char) * 10000);// result return to client

char *pure_path = (char *) malloc(sizeof(char) * 10000);// get path

char *buf = (char *) malloc(sizeof(char) * 10000);

char *cmd1 = (char *) malloc(sizeof(char) * 1000);// command for 'ls -l'

char *cmd2 = (char *) malloc(sizeof(char) * 1000);// command for 'cat '

char *param = "/?param=";

char *pos;

char c;

int index;

FILE *file;// use pipeline

struct stat s;// use to know if the path is a file or a directory

char mesg[99999], *reqline[3], data_to_send[BYTES], path[99999], html[999];

int rcvd, fd, bytes_read;

memset( (void*)mesg, (int)'\0', 99999 );

//rcvd=recv(clients[n], mesg, 99999, 0);

rcvd=read(clients[n], mesg, 99999);

if (rcvd<0) // receive error

fprintf(stderr,("recv() error\n"));

else if (rcvd==0) // receive socket closed

fprintf(stderr,"Client disconnected upexpectedly.\n");

else // message received

{

printf("%s", mesg);

reqline[0] = strtok (mesg, " \t\n");

if ( strncmp(reqline[0], "GET\0", 4)==0 )

{

reqline[1] = strtok (NULL, " \t");

reqline[2] = strtok (NULL, " \t\n");

if ( strncmp( reqline[2], "HTTP/1.0", 8)!=0 && strncmp( reqline[2], "HTTP/1.1", 8)!=0 )

{

write(clients[n], "HTTP/1.0 400 Bad Request\n", 25);

}

else

{

pos = strstr(reqline[1], param) + 8; //get 1st position when meet '/?param=', +8 means pass through until the real path. Ex: /home/ubuntu/syspro

index = 0;

// get path(not include '/?param='), terminate when meet ' '

while ((c = *pos) != NULL) {

pure_path[index++] = c;

pos++;

}

pure_path[index] = '\n';

if (stat(pure_path, &s) == 0) {

if (s.st_mode & S_IFDIR) {

printf("path is a directory\n");

strcat(cmd1, "ls -l ");//initialize comd1 as 'ls -l'

strcat(cmd1, pure_path);//now, it becomes, for example, "ls -l /home/ubuntu/"

file = popen(cmd1, "r");//execute command and open a pipeline

while (fgets(buf, 10000, file))

strcat(result, buf);//read and add content of the pipeline into result

pclose(file);

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

} else if (s.st_mode & S_IFREG) {

printf("path is a file\n");

strcat(cmd2, "cat ");//initialize comd2 as 'cat '

strcat(cmd2, pure_path);//now, it becomes, for example, "cat /home/ubuntu/syspro/f13.c"

file = popen(cmd2, "r");//excute command and open a pipeline

while (fgets(buf, 10000, file))

strcat(result, buf);//read and add content of the pipeline into result

pclose(file);

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

} else {

printf("something else!\n");

}

} else {

strcat(result, "Error!\n");

printf("wtf! Error!!\n");

}

write(clients[n], result,strlen(result));

}

}

}

//Closing SOCKET

shutdown (clients[n], SHUT_RDWR); //All further send and recieve operations are DISABLED...

close(clients[n]);

clients[n]=-1;

exit(0);

}