Hi,
On 14/08/2022 23:53, Lev Stipakov wrote:
From: Lev Stipakov <l...@openvpn.net>
Device interface is a path which is used by userspace
to access device. A driver can create one or more device
interfaces and specify "reference string", so that userspace
could enumerate all device interfaces in the list and pick
the corrct one which ends with reference string.
Before our code had an assumption that either driver
creates only one device interface or the "right" interface
is alwways first in the list. As it turned out, that assumtion
does not always hold, so here we iterate through all device
interfaces in the list.
In follow-up dco-win patch we pick the device interface
from the list which ends with specific reference string.
Signed-off-by: Lev Stipakov <l...@openvpn.net>
[This is actually v3]
The commit message does not say anything using gc_malloc() (although it
is reported below in te version log). Maybe one line could be added on
the fly before commit? :-)
The reason for switching to gc_malloc is that this buffer is actually
used like a string and not like an actual buffer, so it does not make
sense to use the struct buffer at all.
I tested this patch with Lev and it works as expected.
The windows API does not say anything about the empty string at the end
of the list, but having that seems to be the actual behaviour.
Acked-by: Antonio Quartulli <a...@unstable.cc>
---
v3: use gc_malloc() and "char *" instead of buffer and improve commit message
v2: uncrustify
src/openvpn/tun.c | 40 +++++++++++++++++++++++-----------------
src/openvpn/tun.h | 2 +-
2 files changed, 24 insertions(+), 18 deletions(-)
diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 11025267..50193939 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -3722,7 +3722,6 @@ get_device_instance_id_interface(struct gc_arena *gc)
LONG status;
ULONG dev_interface_list_size;
CONFIGRET cr;
- struct buffer dev_interface_list;
ZeroMemory(&device_info_data, sizeof(SP_DEVINFO_DATA));
device_info_data.cbSize = sizeof(SP_DEVINFO_DATA);
@@ -3775,9 +3774,9 @@ get_device_instance_id_interface(struct gc_arena *gc)
goto next;
}
- dev_interface_list = alloc_buf_gc(dev_interface_list_size, gc);
+ char *dev_interface_list = gc_malloc(dev_interface_list_size, false,
gc);
cr = CM_Get_Device_Interface_List((LPGUID)&GUID_DEVINTERFACE_NET,
device_instance_id,
- BSTR(&dev_interface_list),
+ dev_interface_list,
dev_interface_list_size,
CM_GET_DEVICE_INTERFACE_LIST_PRESENT);
if (cr != CR_SUCCESS)
@@ -3785,21 +3784,29 @@ get_device_instance_id_interface(struct gc_arena *gc)
goto next;
}
- struct device_instance_id_interface *dev_if;
- ALLOC_OBJ_CLEAR_GC(dev_if, struct device_instance_id_interface, gc);
- dev_if->net_cfg_instance_id = (unsigned char *)string_alloc((char
*)net_cfg_instance_id, gc);
- dev_if->device_interface_list =
string_alloc(BSTR(&dev_interface_list), gc);
+ char *dev_if = dev_interface_list;
- /* link into return list */
- if (!first)
+ /* device interface list ends with empty string */
+ while (strlen(dev_if) > 0)
{
- first = dev_if;
- }
- if (last)
- {
- last->next = dev_if;
+ struct device_instance_id_interface *dev_iif;
+ ALLOC_OBJ_CLEAR_GC(dev_iif, struct device_instance_id_interface,
gc);
+ dev_iif->net_cfg_instance_id = (unsigned char *)string_alloc((char
*)net_cfg_instance_id, gc);
+ dev_iif->device_interface = string_alloc(dev_if, gc);
+
+ /* link into return list */
+ if (!first)
+ {
+ first = dev_iif;
+ }
+ if (last)
+ {
+ last->next = dev_iif;
+ }
+ last = dev_iif;
+
+ dev_if += strlen(dev_if) + 1;
}
- last = dev_if;
next:
RegCloseKey(dev_key);
@@ -6475,12 +6482,11 @@ tun_try_open_device(struct tuntap *tt, const char
*device_guid, const struct dev
{
const struct device_instance_id_interface *dev_if;
- /* Open Wintun adapter */
for (dev_if = device_instance_id_interface; dev_if != NULL; dev_if =
dev_if->next)
{
if (strcmp((const char *)dev_if->net_cfg_instance_id,
device_guid) == 0)
{
- path = dev_if->device_interface_list;
+ path = dev_if->device_interface;
break;
}
}
diff --git a/src/openvpn/tun.h b/src/openvpn/tun.h
index ea4946e9..661e4d01 100644
--- a/src/openvpn/tun.h
+++ b/src/openvpn/tun.h
@@ -388,7 +388,7 @@ struct panel_reg
struct device_instance_id_interface
{
LPBYTE net_cfg_instance_id;
- const char *device_interface_list;
+ const char *device_interface;
struct device_instance_id_interface *next;
};
--
Antonio Quartulli
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