ftp.c

ELinks is an advanced and well-established feature-rich text mode web (HTTP/FTP/..) browser. ELinks

/* ftp.c
 * ftp:// processing
 * (c) 2002 Mikulas Patocka
 * This file is a part of the Links program, released under GPL.
 */

#include "links.h"

#define FTP_BUF	16384

struct ftp_connection_info {
	int pending_commands;
	int opc;
	int pasv;
	int dir;
	int rest_sent;
	int conn_st;
	int d;
	int dpos;
	int buf_pos;
	unsigned char ftp_buffer[FTP_BUF];
	unsigned char cmdbuf[1];
};

void ftp_get_banner(struct connection *);
void ftp_got_banner(struct connection *, struct read_buffer *);
void ftp_login(struct connection *);
void ftp_logged(struct connection *);
void ftp_sent_passwd(struct connection *);
void ftp_got_reply(struct connection *, struct read_buffer *);
void ftp_got_info(struct connection *, struct read_buffer *);
void ftp_got_user_info(struct connection *, struct read_buffer *);
void ftp_dummy_info(struct connection *, struct read_buffer *);
void ftp_pass_info(struct connection *, struct read_buffer *);
void ftp_send_retr_req(struct connection *, int);
struct ftp_connection_info *add_file_cmd_to_str(struct connection *);
void ftp_retr_1(struct connection *);
void ftp_retr_file(struct connection *, struct read_buffer *);
void ftp_got_final_response(struct connection *, struct read_buffer *);
void created_data_connection(struct connection *);
void got_something_from_data_connection(struct connection *);
void ftp_end_request(struct connection *);
int get_ftp_response(struct connection *, struct read_buffer *, int);
int ftp_process_dirlist(struct cache_entry *, off_t *, int *, unsigned char *, int, int, int *);


int get_ftp_response(struct connection *c, struct read_buffer *rb, int part)
{
	int l;
	set_timeout(c);
	again:
	for (l = 0; l < rb->len; l++) if (rb->data[l] == 10) {
		unsigned char *e;
		long k = strtoul(rb->data, (char **)(void *)&e, 10);
		if (e != rb->data + 3 || k < 100 || k >= 1000) return -1;
		if (*e == '-') {
			int i;
			for (i = 0; i < rb->len - 5; i++) {
				if (rb->data[i] == 10 && !memcmp(rb->data+i+1, rb->data, 3) && rb->data[i+4] == ' ') {
					for (i++; i < rb->len; i++) if (rb->data[i] == 10) goto ok;
					return 0;
				}
			}
			return 0;
			ok:
			l = i;
		}
		if (!part && k >= 100 && k < 200) {
			kill_buffer_data(rb, l + 1);
			goto again;
		}
		if (part == 2) return k;
		kill_buffer_data(rb, l + 1);
		return k;
	}
	return 0;
}

void ftp_func(struct connection *c)
{
	/*setcstate(c, S_CONN);*/
	/*set_timeout(c);*/
	if (get_keepalive_socket(c)) {
		int p;
		if ((p = get_port(c->url)) == -1) {
			setcstate(c, S_INTERNAL);
			abort_connection(c);
			return;
		}
		make_connection(c, p, &c->sock1, ftp_options.fast_ftp ? ftp_login : ftp_get_banner);
	} else ftp_send_retr_req(c, S_SENT);
}

void ftp_get_banner(struct connection *c)
{
	struct read_buffer *rb;
	set_timeout(c);
	setcstate(c, S_SENT);
	if (!(rb = alloc_read_buffer(c))) return;
	read_from_socket(c, c->sock1, rb, ftp_got_banner);
}

void ftp_got_banner(struct connection *c, struct read_buffer *rb)
{
	int g = get_ftp_response(c, rb, 0);
	if (g == -1) { setcstate(c, S_FTP_ERROR); abort_connection(c); return; }
	if (!g) { read_from_socket(c, c->sock1, rb, ftp_got_banner); return; }
	if (g >= 400) { setcstate(c, S_FTP_UNAVAIL); retry_connection(c); return; }
	ftp_login(c);
}

void ftp_login(struct connection *c)
{
	unsigned char *login;
	unsigned char *u;
	int logl = 0;
	set_timeout(c);
	login = init_str();
	add_to_str(&login, &logl, "USER ");
	if ((u = get_user_name(c->url)) && *u) add_to_str(&login, &logl, u);
	else add_to_str(&login, &logl, "anonymous");
	if (u) mem_free(u);
	if (ftp_options.fast_ftp) {
		struct ftp_connection_info *fi;
		add_to_str(&login, &logl, "\r\nPASS ");
		if ((u = get_pass(c->url)) && *u) add_to_str(&login, &logl, u);
		else add_to_str(&login, &logl, ftp_options.anon_pass);
		if (u) mem_free(u);
		add_to_str(&login, &logl, "\r\n");
		if (!(fi = add_file_cmd_to_str(c))) {
			mem_free(login);
			return;
		}
		add_to_str(&login, &logl, fi->cmdbuf);
	} else add_to_str(&login, &logl, "\r\n");
	write_to_socket(c, c->sock1, login, strlen(login), ftp_logged);
	mem_free(login);
	setcstate(c, S_SENT);
}

void ftp_logged(struct connection *c)
{
	struct read_buffer *rb;
	if (!(rb = alloc_read_buffer(c))) return;
	if (!ftp_options.fast_ftp) {
		ftp_got_user_info(c, rb);
		return;
	}
	read_from_socket(c, c->sock1, rb, ftp_got_info);
}

void ftp_got_info(struct connection *c, struct read_buffer *rb)
{
	int g = get_ftp_response(c, rb, 0);
	if (g == -1) { setcstate(c, S_FTP_ERROR); abort_connection(c); return; }
	if (!g) { read_from_socket(c, c->sock1, rb, ftp_got_info); return; }
	if (g >= 400) { setcstate(c, S_FTP_UNAVAIL); retry_connection(c); return; }
	ftp_got_user_info(c, rb);
}

void ftp_got_user_info(struct connection *c, struct read_buffer *rb)
{
	int g = get_ftp_response(c, rb, 0);
	if (g == -1) { setcstate(c, S_FTP_ERROR); abort_connection(c); return; }
	if (!g) { read_from_socket(c, c->sock1, rb, ftp_got_user_info); return; }
	if (g >= 530 && g < 540) { setcstate(c, S_FTP_LOGIN); retry_connection(c); return; }
	if (g >= 400) { setcstate(c, S_FTP_UNAVAIL); retry_connection(c); return; }
	if (g >= 200 && g < 300) {
		if (ftp_options.fast_ftp) ftp_dummy_info(c, rb);
		else ftp_send_retr_req(c, S_GETH);
	} else {
		if (ftp_options.fast_ftp) ftp_pass_info(c, rb);
		else {
			unsigned char *login;
			unsigned char *u;
			int logl = 0;
			login = init_str();
			add_to_str(&login, &logl, "PASS ");
			if ((u = get_pass(c->url)) && *u) add_to_str(&login, &logl, u);
			else add_to_str(&login, &logl, ftp_options.anon_pass);
			if (u) mem_free(u);
			add_to_str(&login, &logl, "\r\n");
			write_to_socket(c, c->sock1, login, strlen(login), ftp_sent_passwd);
			mem_free(login);
			setcstate(c, S_LOGIN);
		}
	}
}

void ftp_dummy_info(struct connection *c, struct read_buffer *rb)
{
	int g = get_ftp_response(c, rb, 0);
	if (g == -1) { setcstate(c, S_FTP_ERROR); abort_connection(c); return; }
	if (!g) { read_from_socket(c, c->sock1, rb, ftp_dummy_info); return; }
	ftp_retr_file(c, rb);
}

void ftp_sent_passwd(struct connection *c)
{
	struct read_buffer *rb;
	if (!(rb = alloc_read_buffer(c))) return;
	read_from_socket(c, c->sock1, rb, ftp_pass_info);
}

void ftp_pass_info(struct connection *c, struct read_buffer *rb)
{
	int g = get_ftp_response(c, rb, 0);
	if (g == -1) { setcstate(c, S_FTP_ERROR); abort_connection(c); return; }
	if (!g) { read_from_socket(c, c->sock1, rb, ftp_pass_info); setcstate(c, S_LOGIN); return; }
	if (g >= 530 && g < 540) { setcstate(c, S_FTP_LOGIN); abort_connection(c); return; }
	if (g >= 400) { setcstate(c, S_FTP_UNAVAIL); abort_connection(c); return; }
	if (ftp_options.fast_ftp) ftp_retr_file(c, rb);
	else ftp_send_retr_req(c, S_GETH);
}

struct ftp_connection_info *add_file_cmd_to_str(struct connection *c)
{
	unsigned char *d = get_url_data(c->url);
	unsigned char *de;
	int del;
	unsigned char pc[6];
	int ps;
	struct ftp_connection_info *inf, *inf2;
	unsigned char *s;
	int l;
	if (!d) {
		internal("get_url_data failed");
		setcstate(c, S_INTERNAL);
		abort_connection(c);
		return NULL;
	}
	de = init_str(), del = 0;
	add_conv_str(&de, &del, d, strlen(d), -2);
	d = de;
	inf = mem_alloc(sizeof(struct ftp_connection_info));
	memset(inf, 0, sizeof(struct ftp_connection_info));
	l = 0;
	s = init_str();
	inf->pasv = ftp_options.passive_ftp;
	if (*c->socks_proxy) inf->pasv = 1;
	c->info = inf;
	if (!inf->pasv) if ((ps = get_pasv_socket(c, c->sock1, &c->sock2, pc))) {
		mem_free(d);
		return NULL;
	}
#ifdef HAVE_IPTOS
	if (ftp_options.set_tos) {
		int on = IPTOS_THROUGHPUT;
		setsockopt(c->sock2, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int));
	}
#endif
	if (!(de = strchr(d, POST_CHAR))) de = d + strlen(d);
	if (d == de || de[-1] == '/') {
		inf->dir = 1;
		inf->pending_commands = 4;
		add_to_str(&s, &l, "TYPE A\r\n");
		if (!inf->pasv) {
			add_to_str(&s, &l, "PORT ");
			add_num_to_str(&s, &l, pc[0]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[1]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[2]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[3]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[4]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[5]);
			add_to_str(&s, &l, "\r\n");
		} else {
			add_to_str(&s, &l, "PASV\r\n");
		}
		add_to_str(&s, &l, "CWD /");
		add_bytes_to_str(&s, &l, d, de - d);
		add_to_str(&s, &l, "\r\nLIST\r\n");
		c->from = 0;
	} else {
		inf->dir = 0;
		inf->pending_commands = 3;
		add_to_str(&s, &l, "TYPE I\r\n");
		if (!inf->pasv) {
			add_to_str(&s, &l, "PORT ");
			add_num_to_str(&s, &l, pc[0]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[1]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[2]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[3]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[4]);
			add_chr_to_str(&s, &l, ',');
			add_num_to_str(&s, &l, pc[5]);
			add_to_str(&s, &l, "\r\n");
		} else {
			add_to_str(&s, &l, "PASV\r\n");
		}
		if (c->from && c->no_cache < NC_IF_MOD) {
			add_to_str(&s, &l, "REST ");
			add_num_to_str(&s, &l, c->from);
			add_to_str(&s, &l, "\r\n");
			inf->rest_sent = 1;
			inf->pending_commands++;
		} else c->from = 0;
		add_to_str(&s, &l, "RETR /");
		add_bytes_to_str(&s, &l, d, de - d);
		add_to_str(&s, &l, "\r\n");
	}
	inf->opc = inf->pending_commands;
	if ((unsigned)l > MAXINT - sizeof(struct ftp_connection_info) - 1) overalloc();
	inf2 = mem_realloc(inf, sizeof(struct ftp_connection_info) + l + 1);
	strcpy((inf = inf2)->cmdbuf, s);
	mem_free(s);
	c->info = inf;
	mem_free(d);
	return inf;
}


void ftp_send_retr_req(struct connection *c, int state)
{
	struct ftp_connection_info *fi;
	unsigned char *login;
	int logl = 0;
	set_timeout(c);
	login = init_str();
	if (!c->info && !(fi = add_file_cmd_to_str(c))) {
		mem_free(login);
		return;
	} else fi = c->info;
	if (ftp_options.fast_ftp) a:add_to_str(&login, &logl, fi->cmdbuf);
	else {
		unsigned char *nl = strchr(fi->cmdbuf, '\n');
		if (!nl) goto a;
		nl++;
		add_bytes_to_str(&login, &logl, fi->cmdbuf, nl - fi->cmdbuf);
		memmove(fi->cmdbuf, nl, strlen(nl) + 1);
	}
	write_to_socket(c, c->sock1, login, strlen(login), ftp_retr_1);
	mem_free(login);
	setcstate(c, state);
}

void ftp_retr_1(struct connection *c)
{
	struct read_buffer *rb;
	if (!(rb = alloc_read_buffer(c))) return;
	read_from_socket(c, c->sock1, rb, ftp_retr_file);
}

void ftp_retr_file(struct connection *c, struct read_buffer *rb)
{
	int g;
	struct ftp_connection_info *inf = c->info;
	if (0) {
		rep:
		if (!ftp_options.fast_ftp) {
			ftp_send_retr_req(c, S_GETH);
			return;
		}
	}
	if (inf->pending_commands > 1) {
		unsigned char pc[6];
		if (inf->pasv && inf->opc - (inf->pending_commands - 1) == 2) {
			int i = 3, j;
			while (i < rb->len) {
				if (rb->data[i] >= '0' && rb->data[i] <= '9') {
					for (j = 0; j < 6; j++) {
						int n = 0;
						while (rb->data[i] >= '0' && rb->data[i] <= '9') {
							n = n * 10 + rb->data[i] - '0';
							if (n >= 256) goto no_pasv;
							if (++i >= rb->len) goto no_pasv;
						}
						pc[j] = n;
						if (j != 5) {
							if (rb->data[i] != ',') goto xa;
							if (++i >= rb->len) goto xa;
							if (rb->data[i] < '0' || rb->data[i] > '9') {
								xa:
								if (j != 1) goto no_pasv;
								pc[4] = pc[0];
								pc[5] = pc[1];
								{
									unsigned a;
									struct sockaddr_in sa;
									socklen_t nl = sizeof(sa);
									if (getpeername(c->sock1, (struct sockaddr *)(void *)&sa, &nl)) goto no_pasv;
									if (nl != sizeof(sa)) goto no_pasv;
									a = ntohl(sa.sin_addr.s_addr);
									pc[0] = a >> 24;
									pc[1] = a >> 16;
									pc[2] = a >> 8;