dataServer.c

/*
** server.c -- a stream socket server demo
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <signal.h>
#include <stdbool.h>
#include <sys/sendfile.h>
#include <sys/stat.h>

#include "dataServer.h"
#include "dir.h"


#define BACKLOG 1	 // how many pending connections queue will hold

char buf[512];

int sockfd;

char* port_num;

bool listfile = 1;

char* filename;

int filesize;

void sigchld_handler_data(int s)
{
	// waitpid() might overwrite errno, so we save and restore it:
	int saved_errno = errno;

	while(waitpid(-1, NULL, WNOHANG) > 0);

	errno = saved_errno;
}


// get sockaddr, IPv4 or IPv6:
void *get_in_addr_data(struct sockaddr *sa)
{
	if (sa->sa_family == AF_INET) {
		return &(((struct sockaddr_in*)sa)->sin_addr);
	}

	return &(((struct sockaddr_in6*)sa)->sin6_addr);
}


int listenOnDataConnect(char* port){
	struct addrinfo hints, *servinfo, *p;
	
	struct sigaction sa;
	int yes=1;
	int rv;

	port_num = port;

	memset(&hints, 0, sizeof hints);
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE; // use my IP

	if ((rv = getaddrinfo(NULL, port, &hints, &servinfo)) != 0) {
		fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
		return 1;
	}

	// loop through all the results and bind to the first we can
	for(p = servinfo; p != NULL; p = p->ai_next) {
		if ((sockfd = socket(p->ai_family, p->ai_socktype,
				p->ai_protocol)) == -1) {
			perror("server: socket");
			continue;
		}

		if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes,
				sizeof(int)) == -1) {
			perror("setsockopt");
			exit(1);
		}

		if (bind(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
			close(sockfd);
			perror("server: bind");
			continue;
		}

		break;
	}

	freeaddrinfo(servinfo); // all done with this structure

	if (p == NULL)  {
		fprintf(stderr, "server: failed to bind\n");
		exit(1);
	}

	if (listen(sockfd, BACKLOG) == -1) {
		perror("listen");
		exit(1);
	}

	sa.sa_handler = sigchld_handler_data; // reap all dead processes
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_RESTART;
	if (sigaction(SIGCHLD, &sa, NULL) == -1) {
		perror("sigaction");
		exit(1);
	}

	printf("server: waiting for connections...\n");

	return sockfd;
}

int acceptDataConnect(){
	socklen_t sin_size;
	struct sockaddr_storage their_addr; // connector's address information
	char s[INET6_ADDRSTRLEN];

	int new_fd;  // listen on sock_fd, new connection on new_fd

	sin_size = sizeof their_addr;
	new_fd = accept(sockfd, (struct sockaddr *)&their_addr, &sin_size);        // argv: original file descripter, pointer to the address of the client, size of the struct
	if (new_fd == -1) {
		perror("accept");  // should be 'not accept'?
		//continue;     // back to the beginning of outer while, waiting for connection
	}

	inet_ntop(their_addr.ss_family,
		get_in_addr_data((struct sockaddr *)&their_addr),
		s, sizeof s);
	printf("server: got connection from %s %s\r\n", s, port_num);
	
	if(listfile){
		listFiles(new_fd, "./");
	}
	else{
		FILE *file = fopen(filename, "r");
		sendfile(new_fd, fileno(file), NULL, filesize);
	}

	return new_fd;
}

int getDataSocket(){
    return sockfd;
}

void setListfile(){
	listfile = 0;
}

off_t fsize(const char *filename) {
    struct stat st; 

    if (stat(filename, &st) == 0)
        return st.st_size;

    return -1; 
}

void setFilename(char* name){
	filename = name;
	filesize = fsize(name);
	printf("file size is %d\n", filesize);
}