Passive Mode about lwip-ftpd

[toelke]

It seems you are correct; one would have to close the listening socket in addition to the accepted one. I would think about doing that in the dataaccept-call as there should always be only one connection to a PASV-port, if I remember correctly.

[mwalters1024]

Thanks for confirming.

I have made the following modifications, and found the problem is resolved:

struct ftpd_msgstate {
	enum ftpd_state_e state;
	sfifo_t fifo;
	vfs_t *vfs;
	struct ip4_addr dataip;
	u16_t dataport;
	struct tcp_pcb *datalistenpcb;			// added by Mark Walters to fix a memory leak in passive FTP sessions
	struct tcp_pcb *datapcb;
	struct ftpd_datastate *datafs;
	int passive;
	char *renamefrom;
};


static void ftpd_dataclose(struct tcp_pcb *pcb, struct ftpd_datastate *fsd)
{
	tcp_arg(pcb, NULL);
	tcp_sent(pcb, NULL);
	tcp_recv(pcb, NULL);

  // Added by Mark Walters to a fix memory leak in passive FTP sessions
  if (fsd->msgfs->datalistenpcb) {
    tcp_arg(fsd->msgfs->datalistenpcb, NULL);
    tcp_accept(fsd->msgfs->datalistenpcb, NULL);
    tcp_close(fsd->msgfs->datalistenpcb);
    fsd->msgfs->datalistenpcb = NULL;
  }

  fsd->msgfs->datafs = NULL;
	sfifo_close(&fsd->fifo);
	free(fsd);
	tcp_arg(pcb, NULL);
	tcp_close(pcb);
}

// Amended by Mark Walters to a fix memory leak in passive FTP sessions
static void cmd_pasv(const char *arg, struct tcp_pcb *pcb, struct ftpd_msgstate *fsm)
{
	static u16_t port = 4096;
	static u16_t start_port = 4096;
	struct tcp_pcb *temppcb;

	/* Allocate memory for the structure that holds the state of the connection. */
	fsm->datafs = malloc(sizeof(struct ftpd_datastate));

	if (fsm->datafs == NULL) {
		send_msg(pcb, fsm, msg451);
		return;
	}
	memset(fsm->datafs, 0, sizeof(struct ftpd_datastate));

	if (sfifo_init(&fsm->datafs->fifo, 2000) != 0) {
		free(fsm->datafs);
		send_msg(pcb, fsm, msg451);
		return;
	}

	fsm->datalistenpcb = tcp_new();

	if (fsm->datalistenpcb == NULL) {
		free(fsm->datafs);
		sfifo_close(&fsm->datafs->fifo);
		send_msg(pcb, fsm, msg451);
		return;
	}

	start_port = port;

	while (1) {
		err_t err;

		if(++port > 0x7fff)
			port = 4096;

		fsm->dataport = port;
		err = tcp_bind(fsm->datalistenpcb, (ip_addr_t*)&pcb->local_ip, fsm->dataport);
		if (err == ERR_OK)
			break;
		if (start_port == port)
			err = ERR_CLSD;
		if (err == ERR_USE) {
			continue;
		} else {
			ftpd_dataclose(fsm->datalistenpcb, fsm->datafs);
			fsm->datalistenpcb = NULL;
			fsm->datafs = NULL;
			return;
		}
	}

	temppcb = tcp_listen(fsm->datalistenpcb);
	if (!temppcb) {
		ftpd_dataclose(fsm->datalistenpcb, fsm->datafs);
		fsm->datalistenpcb = NULL;
		fsm->datafs = NULL;
		return;
	}
	fsm->datalistenpcb = temppcb;

	fsm->passive = 1;
	fsm->datafs->connected = 0;
	fsm->datafs->msgfs = fsm;
	fsm->datafs->msgpcb = pcb;

	/* Tell TCP that this is the structure we wish to be passed for our callbacks. */
	tcp_arg(fsm->datalistenpcb, fsm->datafs);
	tcp_accept(fsm->datalistenpcb, ftpd_dataaccept);
	send_msg(pcb, fsm, msg227, ip4_addr1(ip_2_ip4(&pcb->local_ip)), ip4_addr2(ip_2_ip4(&pcb->local_ip)), ip4_addr3(ip_2_ip4(&pcb->local_ip)), ip4_addr4(ip_2_ip4(&pcb->local_ip)), (fsm->dataport >> 8) & 0xff, (fsm->dataport) & 0xff);
}

[toelke]

That is great. Could you please submit a pull request?

[mwalters1024]

I have submitted a pull request for your review. Regards Mark Walters Tel: [phone] Email: [email protected]

…

On 21 June 2017 at 14:43, Philipp Tölke ***@***.***> wrote: That is great. Could you please submit a pull request? — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#20 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AcG9Q0nwGLKlwIKVIsN596G59v54lsBvks5sGJ9mgaJpZM4N9oSj> .