/downloadFTP/main.c

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



struct {
	char* ip;
	char* username;
	char* password;
	int porta;		//porta default 21
	int lport;		//porta para fazer listen
	char* path;		//path para o ficheiro


}Con;


int new_con(char* host, int port);
char* getIP(char* host);
int getArgs(char* arg);
int getLPort(char* buff);



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

	int sock,lsock, bytes=-1, bytesTotal = 0, size,i, tamanhoFicheiro,j;
	char buff[256], temp[256];
	char *data, *dataBuff, **tosend;

	if( argc >= 2){
		if(getArgs(argv[1])<0){
			printf("usage: %s ftp://[<user>:<password>@]<host>/<url-path>\n", argv[0]);
			return 0;
		}
	}
	else {
		printf("usage: %s ftp://[<user>:<password>@]<host>/<url-path>\n", argv[0]);
		return 0;

	}

	tosend = (char**)calloc(100, sizeof(char*));

	//init default Con vars
	Con.porta = 21;
	Con.lport = 0;
	printf("struct {\n");
	printf("	char* ip=%s\n",Con.ip);
	printf("	char* username=%s\n",Con.username);
	printf("	char* password=%s\n",Con.password);
	printf("	int porta=%d\n",Con.porta);
	printf("	int lport=%d\n",Con.lport);
	printf("	char* path=%s\n",Con.path);
	printf(")}Con;\n");

	sock = new_con(Con.ip,21);
	bytes = -1;
	while(bytes == -1)
		bytes = recv(sock,buff,255,0);
	buff[bytes] = '\0';
	printf("A receber -> %s\n", buff);
	//<-- 220 FTP for Alf/Tom/Crazy/Pinguim
	if(strncmp("220",buff,3)!=0){
		printf("ERRO: expected:%s got: %s\n","220",buff);
		return -1;
	}

	tosend[0] = calloc(256, sizeof(char));
	tosend[1] = calloc(256, sizeof(char));
	if(Con.username != NULL){
		strcpy(tosend[0], "user ");
		strcat(tosend[0], Con.username);
		strcat(tosend[0], "\n");
		printf("A enviar -> %s\n", tosend[0]);

		send(sock, tosend[0], strlen(tosend[0]),0);
		bytes = -1;
		while(bytes == -1){printf("bytes = %d\n",bytes);
			bytes = recv(sock,buff,255,0);
			}
		buff[bytes] = '\0';
		printf("A receber -> %s\n", buff);
		//← 331  Please specify the password.
		if(strncmp("331",buff,3)!=0){
			printf("ERRO: expected:%s got: %s\n","331",buff);
			return -1;
		}

		strcpy(tosend[1], "pass ");
		strcat(tosend[1], Con.password);
		strcat(tosend[1], "\n");

		printf("A enviar -> %s\nCon.password = %s\n", tosend[1],Con.password);

		send(sock, tosend[1], strlen(tosend[1]), 0);
		bytes = -1;
		while(bytes == -1)
			bytes = recv(sock,buff,255,0);
		buff[bytes] = '\0';
		printf("A receber -> %s\n", buff);
		//<-- 230 Login successfull.
		if(strncmp("230",buff,3)!=0){
			printf("ERRO: expected:%s got: %s\n","230",buff);
			return -1;
		}

	}

	//TAMANHO DO FICHEIRO
	tosend[3] = calloc(256, sizeof(char));
	strcpy(tosend[3], "size ");
	strcat(tosend[3], Con.path);
	strcat(tosend[3], "\n");

	printf("A enviar -> %s\n", tosend[3]);

	send(sock, tosend[3], strlen(tosend[3]), 0);
	bytes = -1;
	while(bytes == -1)
		bytes = recv(sock,buff,255,0);
	buff[bytes] = '\0';
	printf("A receber -> %s\n", buff);

	//<-- 213 successfull.
	if(strncmp("213",buff,3)!=0){
		printf("ERRO: expected:%s got: %s\n","213",buff);
		return -1;
	}
	i=4;
	strcpy(temp, buff + i++);
	tamanhoFicheiro = atoi(temp);
	printf("TAMANHO (SIZE): %d\n", tamanhoFicheiro);


	//PASV
	printf("A enviar -> %s\n", "pasv");

	send(sock, "pasv\n",5, 0);
	bytes = -1;

	while(bytes == -1)
		bytes = recv(sock,buff,255,0);
	buff[bytes] = '\0';
	printf("A receber -> %s\n", buff);
	//<-- 227 Entering Passive Mode (192,168,50,138,179,4).
	if(strncmp("227",buff,3)!=0){
		printf("ERRO: expected:%s got: %s\n","227",buff);
		return -1;
	}
	printf("entrou\n");
	Con.lport = getLPort(buff);
	printf("PORT: %d\n", Con.lport);

	lsock = new_con(Con.ip,Con.lport);


	tosend[2] = calloc(256, sizeof(char));
	strcpy(tosend[2], "retr ");
	strcat(tosend[2], Con.path);
	strcat(tosend[2], "\n");
	send(sock, tosend[2], strlen(tosend[2]),0);
	bytes = -1;
	while(bytes == -1){printf("bytes = %d\n",bytes);
		bytes = recv(sock,buff,255,0);
		}
	buff[bytes] = '\0';
	printf("A receber -> %s\n", buff);
	//	//← 150 Opening BINARY mode data connection for PATH (XXXX bytes).
	if(strncmp("150",buff,3)!=0){
		printf("ERRO: expected:%s got: %s\n","150",buff);
		return -1;
	}



	i = strlen(Con.path);
	while(i--)
		if(Con.path[i] == '/')
			Con.path += i+1;


	FILE *file = fopen(Con.path, "w");






	//buffer com tamanho do ficheiro
	dataBuff = calloc(tamanhoFicheiro, sizeof(char));
	if(data == 0)
		return -1;
	i=0;
   
	do{
	    j = 0;
		bytes = -1;
		while(bytes == -1){
			bytes = recv(lsock, dataBuff, tamanhoFicheiro, 0);
			size = bytes;
			printf("Bytes: %d\n", bytes);
			if(bytes != -1){
				bytesTotal += bytes;
				while(j<bytes)	
				    fprintf(file,"%c", dataBuff[j++]);
			}
			i++;
		}
	}while(bytesTotal != tamanhoFicheiro);

	i=0;



	send(sock, "quit\n",5, 0);

	close(sock);
	close(lsock);

	//Con.path

	fclose(file);

	return 0;

}





int new_con(char* host_ip, int port){
	int	sockfd;
	struct	sockaddr_in server_addr;

	/*server address handling*/
	bzero((char*)&server_addr,sizeof(server_addr));
	server_addr.sin_family = AF_INET;
	server_addr.sin_addr.s_addr = inet_addr(host_ip);	/*32 bit Internet address network byte ordered*/
	server_addr.sin_port = htons(port);		/*server TCP port must be network byte ordered */

	/*open an TCP socket*/
	if ((sockfd = socket(AF_INET,SOCK_STREAM,0)) < 0) {
		perror("socket()");
		return -1;
	}
	/*connect to the server*/
	if(connect(sockfd,(struct sockaddr *)&server_addr, sizeof(server_addr)) < 0){
		perror("connect()");
		return -1;
	}
	/*send a string to the server*/


	return sockfd;
}
char* getIP(char* host){

	struct hostent *h;


	/*
struct hostent {
	char    *h_name;		Official name of the host.
	char    **h_aliases;	A NULL-terminated array of alternate names for the host.
	int     h_addrtype;		The type of address being returned; usually AF_INET.
	int     h_length;		The length of the address in bytes.
	char    **h_addr_list;	A zero-terminated array of network addresses for the host.
							Host addresses are in Network Byte Order.
};

#define h_addr h_addr_list[0]	The first address in h_addr_list.
	 */
	if ((h=gethostbyname(host)) == NULL) {
		herror("gethostbyname");
		return NULL;
	}

	return inet_ntoa(*((struct in_addr *)h->h_addr));

}

int getArgs(char* arg){
	//arg = ftp://[<user>:<password>@]<host>/<url-path>

	//0 - regex para fazer match a ftp://
	//1 - regex para fazer match a /username:
	//2 - regex para fazer match a :username@
	//3 - regex para fazer match a host_name/
	//4 - regex para fazer match an ip
	//5 - regex para fazer match a path

	char **regex;
	char **match;
	char *temp=0;
	int i = 6;
	int offset;
	regex_t re;
	char buf[256];
	regmatch_t pmatch[100];
	int status;
	char *ps;
	int eflag;


	regex = (char**)calloc(6, sizeof(char*));
	regex[0] = (char*)calloc(8, sizeof(char));
	regex[1] = (char*)calloc(20, sizeof(char));
	regex[2] = (char*)calloc(20, sizeof(char));
	regex[3] = (char*)calloc(95, sizeof(char));
	regex[4] = (char*)calloc(104, sizeof(char));
	regex[5] = (char*)calloc(34, sizeof(char));

	strcpy(regex[0],"^ftp://");
	strcpy(regex[1],"/[a-zA-Z0-9]{1,12}:");
	strcpy(regex[2],":[a-zA-Z0-9]{1,12}@");
	strcpy(regex[3],"(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\\-]*[a-zA-Z0-9])\\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\\-]*[A-Za-z0-9])/");
	strcpy(regex[4],"(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])");
	strcpy(regex[5],"(/[a-zA-Z0-9_\\-]+)+\\.[a-zA-Z0-9]+$");

	match = (char**)calloc(6,sizeof(char*));
	//	printf("\nmatch = %d\n",match);


	//	printf("\n\n\n");
	while(i--){
		if((status = regcomp( &re, regex[5-i], REG_EXTENDED))!= 0){
			regerror(status, &re, buf, 120);
			return -1;
		}
		ps = arg;
		eflag = 0;

		if( status = regexec( &re, ps, 1, pmatch, eflag)== 0){
			offset = pmatch[0].rm_eo-pmatch[0].rm_so;

			match[5-i] = (char*)calloc(offset,sizeof(char));
			strncpy(match[5-i],ps+pmatch[0].rm_so,offset);

		}

		regfree( &re);

	}

	if(match[0] != 0) //começa com ftp://?
		if(match[5]!=0){ //tem path?
			Con.path = (char*)calloc( strlen(match[5])-1, sizeof(char));
			strncpy(Con.path, match[5]+1, strlen(match[5])-1);
		} else return -1; //não tem! logo não se pode fazer download
	else return -1; //o arg não está na forma necessaria

	if((match[1]!=0) && (match[2]!=0)){ //tem username e password?
		Con.username = (char*)calloc( strlen(match[1])-2, sizeof(char));
		Con.password = (char*)calloc( strlen(match[2])-1, sizeof(char));
		strncpy(Con.username, match[1]+1, strlen(match[1])-2);
		strncpy(Con.password, match[2]+1, strlen(match[2])-2);
	} else {
		Con.username = 0;
		Con.password = 0;
	}

	if((match[3]!=0) && (match[4]==0)){//tem hostname mas ip não?
		Con.ip = (char*)calloc(4*3+3, sizeof(char));
		temp = (char*)calloc( strlen(match[3]), sizeof(char));
		strncpy( temp, match[3], strlen(match[3])-1 );
		//match[4]-> null => uso-o como uma var temp para obter o ip do hostname
		match[4] = getIP(temp);
		strncpy(Con.ip, match[4], strlen(match[4]));
		match[4] = 0;
	} else{
		Con.ip = (char*)calloc(4*3+3, sizeof(char));
		strncpy(Con.ip, match[4], strlen(match[4]));
	}


	i=6;
	//limpar apontadores
	while(--i){
		free(regex[i]);
		if(match[i]!=0)
			free(match[i]);
	}

	free(regex);
	free(match);
	if(temp!=0)
		free(temp);

	return 1; //é correcto
}

int getLPort(char* buff){
	char regex[] = "([0-9]{1,3})";
	char** res;
	int status,i=0, port, offset;
	char* ps;
	regex_t re;
	char buf[256];
	regmatch_t pmatch[100];

	if((status = regcomp( &re, regex, REG_EXTENDED))!= 0){
		regerror(status, &re, buf, 120);
		return -1;
	}
	ps = buff;
	res = (char**) calloc(9,sizeof(char*));

	status=1;
	printf("ps : %s", ps);
	while(status!=0){
		if( status = regexec( &re, ps, 1, pmatch, 0) == 0){
			//pmatch[0].rm_eo indice de start
			//pmatch[0].rm_eo indice de end
			offset = pmatch[0].rm_eo - pmatch[0].rm_so;
			res[i] = (char*) calloc(offset,sizeof(char));
			strncpy(res[i], ps+pmatch[0].rm_so, offset);

			ps += pmatch[0].rm_eo;

			i++;

		}
	}


	port = atoi(res[i-2])*256 + atoi(res[i-1]);

	return port;
}