/*

* Part of Very Secure FTPd

* Licence: GPL v2

* Author: Chris Evans

* ftpdataio.c

*

* Code to handle FTP data connections. This includes both PORT (server

* connects) and PASV (client connects) modes of data transfer. This

* includes sends and receives, files and directories.

*/

#include "ftpdataio.h"

#include "session.h"

#include "ftpcmdio.h"

#include "ftpcodes.h"

#include "utility.h"

#include "tunables.h"

#include "defs.h"

#include "str.h"

#include "strlist.h"

#include "sysutil.h"

#include "logging.h"

#include "secbuf.h"

#include "sysstr.h"

#include "sysdeputil.h"

#include "ascii.h"

#include "oneprocess.h"

#include "twoprocess.h"

#include "ls.h"

#include "ssl.h"

#include "readwrite.h"

#include "privsock.h"

static void init_data_sock_params(struct vsf_session* p_sess, int sock_fd);

static filesize_t calc_num_send(int file_fd, filesize_t init_offset);

static struct vsf_transfer_ret do_file_send_sendfile(

struct vsf_session* p_sess, int net_fd, int file_fd,

filesize_t curr_file_offset, filesize_t bytes_to_send);

static struct vsf_transfer_ret do_file_send_rwloop(

struct vsf_session* p_sess, int file_fd, int is_ascii);

static struct vsf_transfer_ret do_file_recv(

struct vsf_session* p_sess, int file_fd, int is_ascii);

static void handle_sigalrm(void* p_private);

static void start_data_alarm(struct vsf_session* p_sess);

static void handle_io(int retval, int fd, void* p_private);

static int transfer_dir_internal(

struct vsf_session* p_sess, int is_control, struct vsf_sysutil_dir* p_dir,

const struct mystr* p_base_dir_str, const struct mystr* p_option_str,

const struct mystr* p_filter_str, int is_verbose);

static int write_dir_list(struct vsf_session* p_sess,

struct mystr_list* p_dir_list,

enum EVSFRWTarget target);

static unsigned int get_chunk_size();

int

vsf_ftpdataio_dispose_transfer_fd(struct vsf_session* p_sess)

{

int dispose_ret = 1;

int retval;

if (p_sess->data_fd == -1)

{

bug("no data descriptor in vsf_ftpdataio_dispose_transfer_fd");

}

/* Reset the data connection alarm so it runs anew with the blocking close */

start_data_alarm(p_sess);

vsf_sysutil_uninstall_io_handler();

if (p_sess->data_use_ssl && p_sess->ssl_slave_active)

{

char result;

priv_sock_send_cmd(p_sess->ssl_consumer_fd, PRIV_SOCK_DO_SSL_CLOSE);

result = priv_sock_get_result(p_sess->ssl_consumer_fd);

if (result != PRIV_SOCK_RESULT_OK)

{

dispose_ret = 0;

}

}

else if (p_sess->p_data_ssl)

{

dispose_ret = ssl_data_close(p_sess);

}

/* This close() blocks because we set SO_LINGER */

retval = vsf_sysutil_close_failok(p_sess->data_fd);

if (vsf_sysutil_retval_is_error(retval))

{

/* Do it again without blocking. */

vsf_sysutil_deactivate_linger_failok(p_sess->data_fd);

(void) vsf_sysutil_close_failok(p_sess->data_fd);

}

if (tunable_data_connection_timeout > 0)

{

vsf_sysutil_clear_alarm();

}

p_sess->data_fd = -1;

return dispose_ret;

}

int

vsf_ftpdataio_get_pasv_fd(struct vsf_session* p_sess)

{

int remote_fd;

if (tunable_one_process_model)

{

remote_fd = vsf_one_process_get_pasv_fd(p_sess);

}

else

{

remote_fd = vsf_two_process_get_pasv_fd(p_sess);

}

/* Yes, yes, hardcoded bad I know. */

if (remote_fd == -1)

{

vsf_cmdio_write(p_sess, FTP_BADSENDCONN,

"Failed to establish connection.");

return remote_fd;

}

else if (remote_fd == -2)

{

vsf_cmdio_write(p_sess, FTP_BADSENDCONN, "Security: Bad IP connecting.");

vsf_sysutil_close(remote_fd);

return -1;

}

init_data_sock_params(p_sess, remote_fd);

return remote_fd;

}

int

vsf_ftpdataio_get_port_fd(struct vsf_session* p_sess)

{

int remote_fd;

if (tunable_one_process_model || tunable_port_promiscuous)

{

remote_fd = vsf_one_process_get_priv_data_sock(p_sess);

}

else

{

remote_fd = vsf_two_process_get_priv_data_sock(p_sess);

}

if (vsf_sysutil_retval_is_error(remote_fd))

{

vsf_cmdio_write(p_sess, FTP_BADSENDCONN,

"Failed to establish connection.");

return -1;

}

init_data_sock_params(p_sess, remote_fd);

return remote_fd;

}

int

vsf_ftpdataio_post_mark_connect(struct vsf_session* p_sess)

{

int ret = 0;

if (!p_sess->data_use_ssl)

{

return 1;

}

if (!p_sess->ssl_slave_active)

{

ret = ssl_accept(p_sess, p_sess->data_fd);

}

else

{

int sock_ret;

priv_sock_send_cmd(p_sess->ssl_consumer_fd, PRIV_SOCK_DO_SSL_HANDSHAKE);

priv_sock_send_fd(p_sess->ssl_consumer_fd, p_sess->data_fd);

sock_ret = priv_sock_get_result(p_sess->ssl_consumer_fd);

if (sock_ret == PRIV_SOCK_RESULT_OK)

{

ret = 1;

}

}

if (ret != 1)

{

static struct mystr s_err_msg;

str_alloc_text(&s_err_msg, "SSL connection failed");

if (tunable_require_ssl_reuse)

{

str_append_text(&s_err_msg, "; session reuse required");

str_append_text(

&s_err_msg, ": see require_ssl_reuse option in vsftpd.conf man page");

}

vsf_cmdio_write_str(p_sess, FTP_DATATLSBAD, &s_err_msg);

}

return ret;

}

static void

handle_sigalrm(void* p_private)

{

struct vsf_session* p_sess = (struct vsf_session*) p_private;

if (!p_sess->data_progress)

{

vsf_cmdio_write_exit(p_sess, FTP_DATA_TIMEOUT,

"Data timeout. Reconnect. Sorry.");

}

p_sess->data_progress = 0;

start_data_alarm(p_sess);

}

void

start_data_alarm(struct vsf_session* p_sess)

{

if (tunable_data_connection_timeout > 0)

{

vsf_sysutil_install_sighandler(kVSFSysUtilSigALRM,

handle_sigalrm,

p_sess,

1);

vsf_sysutil_set_alarm(tunable_data_connection_timeout);

}

else if (tunable_idle_session_timeout > 0)

{

vsf_sysutil_clear_alarm();

}

}

static void

init_data_sock_params(struct vsf_session* p_sess, int sock_fd)

{

if (p_sess->data_fd != -1)

{

bug("data descriptor still present in init_data_sock_params");

}

p_sess->data_fd = sock_fd;

p_sess->data_progress = 0;

vsf_sysutil_activate_keepalive(sock_fd);

/* And in the vague hope it might help... */

vsf_sysutil_set_iptos_throughput(sock_fd);

/* Set up lingering, so that we wait for all data to transfer, and report

* more accurate transfer rates.

*/

vsf_sysutil_activate_linger(sock_fd);

/* Start the timeout monitor */

vsf_sysutil_install_io_handler(handle_io, p_sess);

start_data_alarm(p_sess);

}

static void

handle_io(int retval, int fd, void* p_private)

{

long curr_sec;

long curr_usec;

unsigned int bw_rate;

double elapsed;

double pause_time;

double rate_ratio;

struct vsf_session* p_sess = (struct vsf_session*) p_private;

if (p_sess->data_fd != fd || vsf_sysutil_retval_is_error(retval) ||

retval == 0)

{

return;

}

/* Note that the session hasn't stalled, i.e. don't time it out */

p_sess->data_progress = 1;

/* Apply bandwidth quotas via a little pause, if necessary */

if (p_sess->bw_rate_max == 0)

{

return;

}

/* Calculate bandwidth rate */

curr_sec = vsf_sysutil_get_time_sec();

curr_usec = vsf_sysutil_get_time_usec();

elapsed = (double) (curr_sec - p_sess->bw_send_start_sec);

elapsed += (double) (curr_usec - p_sess->bw_send_start_usec) /

(double) 1000000;

if (elapsed <= (double) 0)

{

elapsed = (double) 0.01;

}

bw_rate = (unsigned int) ((double) retval / elapsed);

if (bw_rate <= p_sess->bw_rate_max)

{

p_sess->bw_send_start_sec = curr_sec;

p_sess->bw_send_start_usec = curr_usec;

return;

}

/* Tut! Rate exceeded, calculate a pause to bring things back into line */

rate_ratio = (double) bw_rate / (double) p_sess->bw_rate_max;

pause_time = (rate_ratio - (double) 1) * elapsed;

vsf_sysutil_sleep(pause_time);

p_sess->bw_send_start_sec = vsf_sysutil_get_time_sec();

p_sess->bw_send_start_usec = vsf_sysutil_get_time_usec();

}

int

vsf_ftpdataio_transfer_dir(struct vsf_session* p_sess, int is_control,

int is_verbose)

{

return transfer_dir_internal(p_sess, is_control, p_dir, p_base_dir_str,

p_option_str, p_filter_str, is_verbose);

}

static int

transfer_dir_internal(struct vsf_session* p_sess, int is_control,

int is_verbose)

{

struct mystr_list dir_list = INIT_STRLIST;

struct mystr_list subdir_list = INIT_STRLIST;

struct mystr dir_prefix_str = INIT_MYSTR;

struct mystr_list* p_subdir_list = 0;

struct str_locate_result loc_result = str_locate_char(p_option_str, 'R');

int failed = 0;

enum EVSFRWTarget target = kVSFRWData;

if (is_control)

{

target = kVSFRWControl;

}

if (loc_result.found && tunable_ls_recurse_enable)

{

p_subdir_list = &subdir_list;

}

vsf_ls_populate_dir_list(&dir_list, p_subdir_list, p_dir, p_base_dir_str,

p_option_str, p_filter_str, is_verbose);

if (p_subdir_list)

{

int retval;

str_copy(&dir_prefix_str, p_base_dir_str);

str_append_text(&dir_prefix_str, ":\r\n");

retval = ftp_write_str(p_sess, &dir_prefix_str, target);

if (retval != 0)

{

failed = 1;

}

}

if (!failed)

{

failed = write_dir_list(p_sess, &dir_list, target);

}

/* Recurse into the subdirectories if required... */

if (!failed)

{

struct mystr sub_str = INIT_MYSTR;

unsigned int num_subdirs = str_list_get_length(&subdir_list);

unsigned int subdir_index;

for (subdir_index = 0; subdir_index < num_subdirs; subdir_index++)

{

int retval;

struct vsf_sysutil_dir* p_subdir;

const struct mystr* p_subdir_str =

str_list_get_pstr(&subdir_list, subdir_index);

if (str_equal_text(p_subdir_str, ".") ||

str_equal_text(p_subdir_str, ".."))

{

continue;

}

str_copy(&sub_str, p_base_dir_str);

str_append_char(&sub_str, '/');

str_append_str(&sub_str, p_subdir_str);

p_subdir = str_opendir(&sub_str);

if (p_subdir == 0)

{

/* Unreadable, gone missing, etc. - no matter */

continue;

}

str_alloc_text(&dir_prefix_str, "\r\n");

retval = ftp_write_str(p_sess, &dir_prefix_str, target);

if (retval != 0)

{

failed = 1;

break;

}

retval = transfer_dir_internal(p_sess, is_control, p_subdir, &sub_str,

p_option_str, p_filter_str, is_verbose);

vsf_sysutil_closedir(p_subdir);

if (retval != 0)

{

failed = 1;

break;

}

}

str_free(&sub_str);

}

str_list_free(&dir_list);

str_list_free(&subdir_list);

str_free(&dir_prefix_str);

if (!failed)

{

return 0;

}

else

{

return -1;

}

}

/* XXX - really, this should be refactored into a "buffered writer" object */

static int

write_dir_list(struct vsf_session* p_sess, struct mystr_list* p_dir_list,

enum EVSFRWTarget target)

{

/* This function writes out a list of strings to the client, over the

* data socket. We now coalesce the strings into fewer write() syscalls,

* which saved 33% CPU time writing a large directory.

*/

int retval = 0;

unsigned int dir_index_max = str_list_get_length(p_dir_list);

unsigned int dir_index;

struct mystr buf_str = INIT_MYSTR;

str_reserve(&buf_str, VSFTP_DIR_BUFSIZE);

for (dir_index = 0; dir_index < dir_index_max; dir_index++)

{

str_append_str(&buf_str, str_list_get_pstr(p_dir_list, dir_index));

if (dir_index == dir_index_max - 1 ||

str_getlen(&buf_str) +

str_getlen(str_list_get_pstr(p_dir_list, dir_index + 1)) >

VSFTP_DIR_BUFSIZE)

{

/* Writeout needed - we're either at the end, or we filled the buffer */

int writeret = ftp_write_str(p_sess, &buf_str, target);

if (writeret != 0)

{

retval = 1;

break;

}

str_empty(&buf_str);

}

}

str_free(&buf_str);

return retval;

}

struct vsf_transfer_ret

vsf_ftpdataio_transfer_file(struct vsf_session* p_sess, int remote_fd,

int file_fd, int is_recv, int is_ascii)

{

if (!is_recv)

{

if (is_ascii || p_sess->data_use_ssl)

{

return do_file_send_rwloop(p_sess, file_fd, is_ascii);

}

else

{

filesize_t curr_offset = vsf_sysutil_get_file_offset(file_fd);

filesize_t num_send = calc_num_send(file_fd, curr_offset);

return do_file_send_sendfile(

p_sess, remote_fd, file_fd, curr_offset, num_send);

}

}

else

{

return do_file_recv(p_sess, file_fd, is_ascii);

}

}

static struct vsf_transfer_ret

do_file_send_rwloop(struct vsf_session* p_sess, int file_fd, int is_ascii)

{

static char* p_readbuf;

static char* p_asciibuf;

struct vsf_transfer_ret ret_struct = { 0, 0 };

unsigned int chunk_size = get_chunk_size();

char* p_writefrom_buf;

int prev_cr = 0;

if (p_readbuf == 0)

{

vsf_secbuf_alloc(&p_readbuf, VSFTP_DATA_BUFSIZE);

}

if (is_ascii)

{

if (p_asciibuf == 0)

{

/* NOTE!! * 2 factor because we can double the data by doing our ASCII

* linefeed mangling

*/

vsf_secbuf_alloc(&p_asciibuf, VSFTP_DATA_BUFSIZE * 2);

}

p_writefrom_buf = p_asciibuf;

}

else

{

p_writefrom_buf = p_readbuf;

}

while (1)

{

unsigned int num_to_write;

int retval = vsf_sysutil_read(file_fd, p_readbuf, chunk_size);

if (vsf_sysutil_retval_is_error(retval))

{

ret_struct.retval = -1;

return ret_struct;

}

else if (retval == 0)

{

/* Success - cool */

return ret_struct;

}

if (is_ascii)

{

struct bin_to_ascii_ret ret =

vsf_ascii_bin_to_ascii(p_readbuf,

p_asciibuf,

(unsigned int) retval,

prev_cr);

num_to_write = ret.stored;

prev_cr = ret.last_was_cr;

}

else

{

num_to_write = (unsigned int) retval;

}

retval = ftp_write_data(p_sess, p_writefrom_buf, num_to_write);

if (!vsf_sysutil_retval_is_error(retval))

{

ret_struct.transferred += (unsigned int) retval;

}

if (vsf_sysutil_retval_is_error(retval) ||

(unsigned int) retval != num_to_write)

{

ret_struct.retval = -2;

return ret_struct;

}

}

}

static struct vsf_transfer_ret

do_file_send_sendfile(struct vsf_session* p_sess, int net_fd, int file_fd,

filesize_t curr_file_offset, filesize_t bytes_to_send)

{

int retval;

unsigned int chunk_size = 0;

struct vsf_transfer_ret ret_struct = { 0, 0 };

filesize_t init_file_offset = curr_file_offset;

filesize_t bytes_sent;

if (p_sess->bw_rate_max)

{

chunk_size = get_chunk_size();

}

/* Just because I can ;-) */

retval = vsf_sysutil_sendfile(net_fd, file_fd, &curr_file_offset,

bytes_to_send, chunk_size);

bytes_sent = curr_file_offset - init_file_offset;

ret_struct.transferred = bytes_sent;

if (vsf_sysutil_retval_is_error(retval))

{

ret_struct.retval = -2;

return ret_struct;

}

else if (bytes_sent != bytes_to_send)

{

ret_struct.retval = -2;

return ret_struct;

}

return ret_struct;

}

static filesize_t

calc_num_send(int file_fd, filesize_t init_offset)

{

static struct vsf_sysutil_statbuf* s_p_statbuf;

filesize_t bytes_to_send;

/* Work out how many bytes to send based on file size minus current offset */

vsf_sysutil_fstat(file_fd, &s_p_statbuf);

bytes_to_send = vsf_sysutil_statbuf_get_size(s_p_statbuf);

if (init_offset < 0 || bytes_to_send < 0)

{

die("calc_num_send: negative file offset or send count");

}

/* Don't underflow if some bonehead sets a REST greater than the file size */

if (init_offset > bytes_to_send)

{

bytes_to_send = 0;

}

else

{

bytes_to_send -= init_offset;

}

return bytes_to_send;

}

static struct vsf_transfer_ret

do_file_recv(struct vsf_session* p_sess, int file_fd, int is_ascii)

{

static char* p_recvbuf;

unsigned int num_to_write;

struct vsf_transfer_ret ret_struct = { 0, 0 };

unsigned int chunk_size = get_chunk_size();

int prev_cr = 0;

if (p_recvbuf == 0)

{

/* Now that we do ASCII conversion properly, the plus one is to cater for

* the fact we may need to stick a '\r' at the front of the buffer if the

* last buffer fragment eneded in a '\r' and the current buffer fragment

* does not start with a '\n'.

*/

vsf_secbuf_alloc(&p_recvbuf, VSFTP_DATA_BUFSIZE + 1);

}

while (1)

{

const char* p_writebuf = p_recvbuf + 1;

int retval = ftp_read_data(p_sess, p_recvbuf + 1, chunk_size);

if (vsf_sysutil_retval_is_error(retval))

{

ret_struct.retval = -2;

return ret_struct;

}

else if (retval == 0 && !prev_cr)

{

/* Transfer done, nifty */

return ret_struct;

}

num_to_write = (unsigned int) retval;

ret_struct.transferred += num_to_write;

if (is_ascii)

{

/* Handle ASCII conversion if we have to. Note that using the same

* buffer for source and destination is safe, because the ASCII ->

* binary transform only ever results in a smaller file.

*/

struct ascii_to_bin_ret ret =

vsf_ascii_ascii_to_bin(p_recvbuf, num_to_write, prev_cr);

num_to_write = ret.stored;

prev_cr = ret.last_was_cr;

p_writebuf = ret.p_buf;

}

retval = vsf_sysutil_write_loop(file_fd, p_writebuf, num_to_write);

if (vsf_sysutil_retval_is_error(retval) ||

(unsigned int) retval != num_to_write)

{

ret_struct.retval = -1;

return ret_struct;

}

}

}

static unsigned int

get_chunk_size()

{

unsigned int ret = VSFTP_DATA_BUFSIZE;

if (tunable_trans_chunk_size < VSFTP_DATA_BUFSIZE &&

tunable_trans_chunk_size > 0)

{

ret = tunable_trans_chunk_size;

if (ret < 4096)

{

ret = 4096;

}

}

return ret;

}