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Set WINS servers via interactice service
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At the moments WINS servers are set either:

 - via DHCP, which works only for tap-windows6 driver
 - via netsh when running without interactice service

This means that in 2.6 default setup (interactive service and dco)
WINS is silently ignored.

Add WINS support for non-DHCP drivers (like dco) by passing
WINS settings to interactive service and set them there with
netsh call, similar approach as we use for setting DNS.

Fixes #373

Change-Id: I47c22dcb728011dcedaae47cd03a57219e9c7607
Signed-off-by: Lev Stipakov <[email protected]>
Acked-by: Frank Lichtenheld <[email protected]>
Message-Id: <[email protected]>
URL: https://www.mail-archive.com/[email protected]/msg26903.html
Signed-off-by: Gert Doering <[email protected]>
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@lstipakov @cron2
lstipakov authored and cron2 committed Aug 11, 2023
1 parent bd95104 commit 18826de
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Showing 3 changed files with 226 additions and 1 deletion.
11 changes: 10 additions & 1 deletion include/openvpn-msg.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,9 @@ typedef enum {
msg_register_dns,
msg_enable_dhcp,
msg_register_ring_buffers,
msg_set_mtu
msg_set_mtu,
msg_add_wins_cfg,
msg_del_wins_cfg
} message_type_t;

typedef struct {
Expand Down Expand Up @@ -86,6 +88,13 @@ typedef struct {
inet_address_t addr[4]; /* support up to 4 dns addresses */
} dns_cfg_message_t;

typedef struct {
message_header_t header;
interface_t iface;
int addr_len;
inet_address_t addr[4]; /* support up to 4 dns addresses */
} wins_cfg_message_t;

typedef struct {
message_header_t header;
interface_t iface;
Expand Down
68 changes: 68 additions & 0 deletions src/openvpn/tun.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -279,6 +279,72 @@ do_dns_service(bool add, const short family, const struct tuntap *tt)
return ret;
}

static bool
do_wins_service(bool add, const struct tuntap *tt)
{
bool ret = false;
ack_message_t ack;
struct gc_arena gc = gc_new();
HANDLE pipe = tt->options.msg_channel;
int len = tt->options.wins_len;
int addr_len = add ? len : 0;

if (addr_len == 0 && add) /* no addresses to add */
{
return true;
}

wins_cfg_message_t wins = {
.header = {
(add ? msg_add_wins_cfg : msg_del_wins_cfg),
sizeof(wins_cfg_message_t),
0
},
.iface = {.index = tt->adapter_index, .name = "" },
.addr_len = addr_len
};

/* interface name is required */
strncpy(wins.iface.name, tt->actual_name, sizeof(wins.iface.name));
wins.iface.name[sizeof(wins.iface.name) - 1] = '\0';

if (addr_len > _countof(wins.addr))
{
addr_len = _countof(wins.addr);
wins.addr_len = addr_len;
msg(M_WARN, "Number of WINS addresses sent to service truncated to %d",
addr_len);
}

for (int i = 0; i < addr_len; ++i)
{
wins.addr[i].ipv4.s_addr = htonl(tt->options.wins[i]);
}

msg(D_LOW, "%s WINS servers on '%s' (if_index = %d) using service",
(add ? "Setting" : "Deleting"), wins.iface.name, wins.iface.index);

if (!send_msg_iservice(pipe, &wins, sizeof(wins), &ack, "TUN"))
{
goto out;
}

if (ack.error_number != NO_ERROR)
{
msg(M_WARN, "TUN: %s WINS failed using service: %s [status=%u if_name=%s]",
(add ? "adding" : "deleting"), strerror_win32(ack.error_number, &gc),
ack.error_number, wins.iface.name);
goto out;
}

msg(M_INFO, "WINS servers %s using service", (add ? "set" : "deleted"));
ret = true;

out:
gc_free(&gc);
return ret;
}

static bool
do_set_mtu_service(const struct tuntap *tt, const short family, const int mtu)
{
Expand Down Expand Up @@ -1555,6 +1621,7 @@ do_ifconfig_ipv4(struct tuntap *tt, const char *ifname, int tun_mtu,
do_address_service(true, AF_INET, tt);
do_dns_service(true, AF_INET, tt);
do_dns_domain_service(true, tt);
do_wins_service(true, tt);
}
else
{
Expand Down Expand Up @@ -6977,6 +7044,7 @@ close_tun(struct tuntap *tt, openvpn_net_ctx_t *ctx)
}
else if (tt->options.msg_channel)
{
do_wins_service(false, tt);
do_dns_domain_service(false, tt);
do_dns_service(false, AF_INET, tt);
do_address_service(false, AF_INET, tt);
Expand Down
148 changes: 148 additions & 0 deletions src/openvpnserv/interactive.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,7 @@ typedef enum {
undo_dns6,
undo_domain,
undo_ring_buffer,
undo_wins,
_undo_type_max
} undo_type_t;
typedef list_item_t *undo_lists_t[_undo_type_max];
Expand Down Expand Up @@ -1083,6 +1084,63 @@ netsh_dns_cmd(const wchar_t *action, const wchar_t *proto, const wchar_t *if_nam
return err;
}

/**
* Run the command: netsh interface ip $action wins $if_name [static] $addr
* @param action "delete", "add" or "set"
* @param if_name "name_of_interface"
* @param addr IPv4 address as a string
*
* If addr is null and action = "delete" all addresses are deleted.
* if action = "set" then "static" is added before $addr
*/
static DWORD
netsh_wins_cmd(const wchar_t *action, const wchar_t *if_name, const wchar_t *addr)
{
DWORD err = 0;
int timeout = 30000; /* in msec */
wchar_t argv0[MAX_PATH];
wchar_t *cmdline = NULL;
const wchar_t *addr_static = (wcscmp(action, L"set") == 0) ? L"static" : L"";

if (!addr)
{
if (wcscmp(action, L"delete") == 0)
{
addr = L"all";
}
else /* nothing to do -- return success*/
{
goto out;
}
}

/* Path of netsh */
openvpn_swprintf(argv0, _countof(argv0), L"%ls\\%ls", get_win_sys_path(), L"netsh.exe");

/* cmd template:
* netsh interface ip $action wins $if_name $static $addr
*/
const wchar_t *fmt = L"netsh interface ip %ls wins \"%ls\" %ls %ls";

/* max cmdline length in wchars -- include room for worst case and some */
size_t ncmdline = wcslen(fmt) + wcslen(if_name) + wcslen(action) + wcslen(addr)
+wcslen(addr_static) + 32 + 1;
cmdline = malloc(ncmdline * sizeof(wchar_t));
if (!cmdline)
{
err = ERROR_OUTOFMEMORY;
goto out;
}

openvpn_swprintf(cmdline, ncmdline, fmt, action, if_name, addr_static, addr);

err = ExecCommand(argv0, cmdline, timeout);

out:
free(cmdline);
return err;
}

/**
* Run command: wmic nicconfig (InterfaceIndex=$if_index) call $action ($data)
* @param if_index "index of interface"
Expand Down Expand Up @@ -1298,6 +1356,86 @@ HandleDNSConfigMessage(const dns_cfg_message_t *msg, undo_lists_t *lists)
return err;
}

static DWORD
HandleWINSConfigMessage(const wins_cfg_message_t *msg, undo_lists_t *lists)
{
DWORD err = 0;
wchar_t addr[16]; /* large enough to hold string representation of an ipv4 */
int addr_len = msg->addr_len;

/* sanity check */
if (addr_len > _countof(msg->addr))
{
addr_len = _countof(msg->addr);
}

if (!msg->iface.name[0]) /* interface name is required */
{
return ERROR_MESSAGE_DATA;
}

/* use a non-const reference with limited scope to enforce null-termination of strings from client */
{
wins_cfg_message_t *msgptr = (wins_cfg_message_t *)msg;
msgptr->iface.name[_countof(msg->iface.name) - 1] = '\0';
}

wchar_t *wide_name = utf8to16(msg->iface.name); /* utf8 to wide-char */
if (!wide_name)
{
return ERROR_OUTOFMEMORY;
}

/* We delete all current addresses before adding any
* OR if the message type is del_wins_cfg
*/
if (addr_len > 0 || msg->header.type == msg_del_wins_cfg)
{
err = netsh_wins_cmd(L"delete", wide_name, NULL);
if (err)
{
goto out;
}
free(RemoveListItem(&(*lists)[undo_wins], CmpWString, wide_name));
}

if (msg->header.type == msg_del_wins_cfg)
{
goto out; /* job done */
}

for (int i = 0; i < addr_len; ++i)
{
RtlIpv4AddressToStringW(&msg->addr[i].ipv4, addr);
err = netsh_wins_cmd(i == 0 ? L"set" : L"add", wide_name, addr);
if (i == 0 && err)
{
goto out;
}
/* We do not check for duplicate addresses, so any error in adding
* additional addresses is ignored.
*/
}

err = 0;

if (addr_len > 0)
{
wchar_t *tmp_name = _wcsdup(wide_name);
if (!tmp_name || AddListItem(&(*lists)[undo_wins], tmp_name))
{
free(tmp_name);
netsh_wins_cmd(L"delete", wide_name, NULL);
err = ERROR_OUTOFMEMORY;
goto out;
}
}

out:
free(wide_name);
return err;
}

static DWORD
HandleEnableDHCPMessage(const enable_dhcp_message_t *dhcp)
{
Expand Down Expand Up @@ -1487,6 +1625,7 @@ HandleMessage(HANDLE pipe, HANDLE ovpn_proc,
enable_dhcp_message_t dhcp;
register_ring_buffers_message_t rrb;
set_mtu_message_t mtu;
wins_cfg_message_t wins;
} msg;
ack_message_t ack = {
.header = {
Expand Down Expand Up @@ -1547,6 +1686,11 @@ HandleMessage(HANDLE pipe, HANDLE ovpn_proc,
ack.error_number = HandleDNSConfigMessage(&msg.dns, lists);
break;

case msg_add_wins_cfg:
case msg_del_wins_cfg:
ack.error_number = HandleWINSConfigMessage(&msg.wins, lists);
break;

case msg_enable_dhcp:
if (msg.header.size == sizeof(msg.dhcp))
{
Expand Down Expand Up @@ -1608,6 +1752,10 @@ Undo(undo_lists_t *lists)
DeleteDNS(AF_INET6, item->data);
break;

case undo_wins:
netsh_wins_cmd(L"delete", item->data, NULL);
break;

case undo_domain:
SetDNSDomain(item->data, "", NULL);
break;
Expand Down

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