static void
handle_eprt(struct vsf_session* p_sess)
{
static struct mystr s_part1_str;
static struct mystr s_part2_str;
int proto;
int port;
const unsigned char* p_raw_addr;
int is_ipv6 = vsf_sysutil_sockaddr_is_ipv6(p_sess->p_local_addr);
port_cleanup(p_sess);
pasv_cleanup(p_sess);
str_copy(&s_part1_str, &p_sess->ftp_arg_str);
str_split_char(&s_part1_str, &s_part2_str, '|');
if (!str_isempty(&s_part1_str))
{
goto bad_eprt;
}
/* Split out the protocol and check it */
str_split_char(&s_part2_str, &s_part1_str, '|');
proto = str_atoi(&s_part2_str);
if (!is_ipv6 || proto != 2)
{
vsf_cmdio_write(p_sess, FTP_BADCMD, "Bad EPRT protocol.");
return;
}
/* Split out address and parse it */
str_split_char(&s_part1_str, &s_part2_str, '|');
p_raw_addr = vsf_sysutil_parse_ipv6(&s_part1_str);
if (!p_raw_addr)
{
goto bad_eprt;
}
/* Split out port and parse it */
str_split_char(&s_part2_str, &s_part1_str, '|');
if (!str_isempty(&s_part1_str) || str_isempty(&s_part2_str))
{
goto bad_eprt;
}
port = str_atoi(&s_part2_str);
if (port < 0 || port > 65535)
{
goto bad_eprt;
}
vsf_sysutil_sockaddr_alloc_ipv6(&p_sess->p_port_sockaddr);
vsf_sysutil_sockaddr_set_ipv6addr(p_sess->p_port_sockaddr, p_raw_addr);
vsf_sysutil_sockaddr_set_port(p_sess->p_port_sockaddr, (unsigned short)port);
/* SECURITY:
* 1) Reject requests not connecting to the control socket IP
* 2) Reject connects to privileged ports
*/
if (!tunable_port_promiscuous)
{
if (!vsf_sysutil_sockaddr_addr_equal(p_sess->p_remote_addr,
p_sess->p_port_sockaddr) ||
vsf_sysutil_is_port_reserved(port))
{
vsf_cmdio_write(p_sess, FTP_BADCMD, "Illegal EPRT command.");
port_cleanup(p_sess);
return;
}
}
vsf_cmdio_write(p_sess, FTP_EPRTOK,
"EPRT command successful. Consider using EPSV.");
return;
bad_eprt:
vsf_cmdio_write(p_sess, FTP_BADCMD, "Bad EPRT command.");
}
static void
handle_pasv(struct vsf_session* p_sess, int is_epsv)
{
static struct mystr s_pasv_res_str;
static struct vsf_sysutil_sockaddr* s_p_sockaddr;
int bind_retries = 10;
unsigned short the_port = 0;
int is_ipv6 = vsf_sysutil_sockaddr_is_ipv6(p_sess->p_local_addr);
if (is_epsv && !str_isempty(&p_sess->ftp_arg_str))
{
int argval;
str_upper(&p_sess->ftp_arg_str);
if (str_equal_text(&p_sess->ftp_arg_str, "ALL"))
{
p_sess->epsv_all = 1;
vsf_cmdio_write(p_sess, FTP_EPSVALLOK, "EPSV ALL ok.");
return;
}
argval = vsf_sysutil_atoi(str_getbuf(&p_sess->ftp_arg_str));
if (!is_ipv6 || argval != 2)
{
vsf_cmdio_write(p_sess, FTP_EPSVBAD, "Bad network protocol.");
return;
}
}
pasv_cleanup(p_sess);
port_cleanup(p_sess);
if (is_epsv && is_ipv6)
{
p_sess->pasv_listen_fd = vsf_sysutil_get_ipv6_sock();
}
else
{
p_sess->pasv_listen_fd = vsf_sysutil_get_ipv4_sock();
}
vsf_sysutil_activate_reuseaddr(p_sess->pasv_listen_fd);
while (--bind_retries)
{
int retval;
double scaled_port;
/* IPPORT_RESERVED */
unsigned short min_port = 1024;
unsigned short max_port = 65535;
if (tunable_pasv_min_port > min_port && tunable_pasv_min_port <= max_port)
{
min_port = tunable_pasv_min_port;
}
if (tunable_pasv_max_port >= min_port && tunable_pasv_max_port < max_port)
{
max_port = tunable_pasv_max_port;
}
the_port = vsf_sysutil_get_random_byte();
the_port <<= 8;
the_port |= vsf_sysutil_get_random_byte();
scaled_port = (double) min_port;
scaled_port += ((double) the_port / (double) 65536) *
((double) max_port - min_port + 1);
the_port = (unsigned short) scaled_port;
vsf_sysutil_sockaddr_clone(&s_p_sockaddr, p_sess->p_local_addr);
vsf_sysutil_sockaddr_set_port(s_p_sockaddr, the_port);
retval = vsf_sysutil_bind(p_sess->pasv_listen_fd, s_p_sockaddr);
if (!vsf_sysutil_retval_is_error(retval))
{
break;
}
if (vsf_sysutil_get_error() == kVSFSysUtilErrADDRINUSE)
{
continue;
}
die("vsf_sysutil_bind");
}
if (!bind_retries)
{
die("vsf_sysutil_bind");
}
vsf_sysutil_listen(p_sess->pasv_listen_fd, 1);
if (is_epsv)
{
str_alloc_text(&s_pasv_res_str, "Entering Extended Passive Mode (|||");
str_append_ulong(&s_pasv_res_str, (unsigned long) the_port);
str_append_text(&s_pasv_res_str, "|)");
vsf_cmdio_write_str(p_sess, FTP_EPSVOK, &s_pasv_res_str);
return;
}
if (tunable_pasv_address != 0)
{
/* Report passive address as specified in configuration */
if (vsf_sysutil_inet_aton(tunable_pasv_address, s_p_sockaddr) == 0)
{
die("invalid pasv_address");
}
}
str_alloc_text(&s_pasv_res_str, "Entering Passive Mode (");
if (!is_ipv6)
{
str_append_text(&s_pasv_res_str, vsf_sysutil_inet_ntop(s_p_sockaddr));
}
else
{
const void* p_v4addr = vsf_sysutil_sockaddr_ipv6_v4(s_p_sockaddr);
if (p_v4addr)
{
str_append_text(&s_pasv_res_str, vsf_sysutil_inet_ntoa(p_v4addr));
}
}
str_replace_char(&s_pasv_res_str, '.', ',');
str_append_text(&s_pasv_res_str, ",");
str_append_ulong(&s_pasv_res_str, the_port >> 8);
str_append_text(&s_pasv_res_str, ",");
str_append_ulong(&s_pasv_res_str, the_port & 255);
str_append_text(&s_pasv_res_str, ")");
vsf_cmdio_write_str(p_sess, FTP_PASVOK, &s_pasv_res_str);
}
unsigned short
vsf_privop_pasv_listen(struct vsf_session* p_sess)
{
static struct vsf_sysutil_sockaddr* s_p_sockaddr;
int bind_retries = 10;
unsigned short the_port = 0;
/* IPPORT_RESERVED */
unsigned short min_port = 1024;
unsigned short max_port = 65535;
int is_ipv6 = vsf_sysutil_sockaddr_is_ipv6(p_sess->p_local_addr);
if (is_ipv6)
{
p_sess->pasv_listen_fd = vsf_sysutil_get_ipv6_sock();
}
else
{
p_sess->pasv_listen_fd = vsf_sysutil_get_ipv4_sock();
}
vsf_sysutil_activate_reuseaddr(p_sess->pasv_listen_fd);
if (tunable_pasv_min_port > min_port && tunable_pasv_min_port <= max_port)
{
min_port = tunable_pasv_min_port;
}
if (tunable_pasv_max_port >= min_port && tunable_pasv_max_port < max_port)
{
max_port = tunable_pasv_max_port;
}
while (--bind_retries)
{
int retval;
double scaled_port;
the_port = vsf_sysutil_get_random_byte();
the_port <<= 8;
the_port |= vsf_sysutil_get_random_byte();
scaled_port = (double) min_port;
scaled_port += ((double) the_port / (double) 65536) *
((double) max_port - min_port + 1);
the_port = (unsigned short) scaled_port;
vsf_sysutil_sockaddr_clone(&s_p_sockaddr, p_sess->p_local_addr);
vsf_sysutil_sockaddr_set_port(s_p_sockaddr, the_port);
retval = vsf_sysutil_bind(p_sess->pasv_listen_fd, s_p_sockaddr);
if (!vsf_sysutil_retval_is_error(retval))
{
retval = vsf_sysutil_listen(p_sess->pasv_listen_fd, 1);
if (!vsf_sysutil_retval_is_error(retval))
{
break;
}
}
/* SELinux systems can give you an inopportune EACCES, it seems. */
if (vsf_sysutil_get_error() == kVSFSysUtilErrADDRINUSE ||
vsf_sysutil_get_error() == kVSFSysUtilErrACCES)
{
continue;
}
die("vsf_sysutil_bind / listen");
}
if (!bind_retries)
{
die("vsf_sysutil_bind");
}
return the_port;
}
