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-rw-r--r--src/mm-netlink.c220
1 files changed, 198 insertions, 22 deletions
diff --git a/src/mm-netlink.c b/src/mm-netlink.c
index c54942be..a71b699f 100644
--- a/src/mm-netlink.c
+++ b/src/mm-netlink.c
@@ -15,8 +15,10 @@
* Copyright (C) 2020 Andrew Lassalle <andrewlassalle@chromium.org>
*
* Copyright (C) 2021 Aleksander Morgado <aleksander@aleksander.es>
+ * Copyright (C) 2024 JUCR GmbH
*/
+#include <errno.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <net/if.h>
@@ -160,6 +162,12 @@ netlink_message_new_setlink (guint ifindex,
return msg;
}
+static NetlinkMessage *
+netlink_message_new_getlink (guint ifindex)
+{
+ return netlink_message_new (ifindex, RTM_GETLINK);
+}
+
static void
netlink_message_free (NetlinkMessage *msg)
{
@@ -169,11 +177,14 @@ netlink_message_free (NetlinkMessage *msg)
/*****************************************************************************/
/* Netlink transactions */
+typedef gboolean (*MsgFunc) (GTask *, struct nlmsghdr *, GError **);
+
typedef struct {
MMNetlink *self;
guint32 sequence_id;
GSource *timeout_source;
GTask *completion_task;
+ MsgFunc completion_fn;
} Transaction;
static gboolean
@@ -212,8 +223,9 @@ transaction_complete_with_error (Transaction *tr,
}
static void
-transaction_complete (Transaction *tr,
- gint saved_errno)
+transaction_complete (Transaction *tr,
+ struct nlmsghdr *hdr,
+ gint saved_errno)
{
GTask *task;
guint32 sequence_id;
@@ -225,7 +237,10 @@ transaction_complete (Transaction *tr,
GUINT_TO_POINTER (tr->sequence_id));
if (!saved_errno) {
- g_task_return_boolean (task, TRUE);
+ GError *error = NULL;
+
+ if (!tr->completion_fn (task, hdr, &error))
+ g_task_return_error (task, error);
} else {
g_task_return_new_error (task, G_IO_ERROR, g_io_error_from_errno (saved_errno),
"Netlink message with transaction %u failed",
@@ -248,7 +263,8 @@ static Transaction *
transaction_new (MMNetlink *self,
NetlinkMessage *msg,
guint timeout,
- GTask *task)
+ GTask *task,
+ MsgFunc completion_fn)
{
Transaction *tr;
@@ -266,6 +282,7 @@ transaction_new (MMNetlink *self,
g_main_context_get_thread_default ());
}
tr->completion_task = g_object_ref (task);
+ tr->completion_fn = completion_fn;
g_hash_table_insert (self->transactions,
GUINT_TO_POINTER (tr->sequence_id),
@@ -283,6 +300,14 @@ mm_netlink_setlink_finish (MMNetlink *self,
return g_task_propagate_boolean (G_TASK (res), error);
}
+static gboolean
+setlink_complete (GTask *task, struct nlmsghdr *hdr, GError **error)
+{
+ /* Nothing to do here; errors are handled by transaction_complete() */
+ g_task_return_boolean (task, TRUE);
+ return TRUE;
+}
+
void
mm_netlink_setlink (MMNetlink *self,
guint ifindex,
@@ -310,7 +335,7 @@ mm_netlink_setlink (MMNetlink *self,
msg = netlink_message_new_setlink (ifindex, up, mtu);
/* The task ownership is transferred to the transaction. */
- tr = transaction_new (self, msg, 5, task);
+ tr = transaction_new (self, msg, 5, task, setlink_complete);
bytes_sent = g_socket_send (self->socket,
(const gchar *) msg->data,
@@ -327,44 +352,187 @@ mm_netlink_setlink (MMNetlink *self,
/*****************************************************************************/
+GByteArray *
+mm_netlink_get_hwaddr_finish (MMNetlink *self,
+ GAsyncResult *res,
+ GError **error)
+{
+ return g_task_propagate_pointer (G_TASK (res), error);
+}
+
static gboolean
-netlink_message_cb (GSocket *socket,
- GIOCondition condition,
- MMNetlink *self)
+get_hwaddr_complete (GTask *task, struct nlmsghdr *hdr, GError **error)
{
- g_autoptr(GError) error = NULL;
- gchar buf[512];
- gssize bytes_received;
- guint buffer_len;
- struct nlmsghdr *hdr;
+ const struct ifinfomsg *ifi;
+ GByteArray *hwaddr = NULL;
+ struct rtattr *rta;
+ int attr_len;
+
+ if (hdr->nlmsg_type != RTM_NEWLINK) {
+ g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+ "unexpected GETLINK reply message type %d",
+ hdr->nlmsg_type);
+ return FALSE;
+ }
+
+ ifi = NLMSG_DATA (hdr);
+ if (ifi->ifi_index <= 0) {
+ g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+ "unexpected link index %d",
+ ifi->ifi_index);
+ return FALSE;
+ }
+
+ attr_len = IFLA_PAYLOAD (hdr);
+ rta = IFLA_RTA (ifi);
+ for (; RTA_OK (rta, attr_len); rta = RTA_NEXT (rta, attr_len)) {
+ switch (rta->rta_type) {
+ case IFLA_ADDRESS:
+#define ETH_ADDR_LEN 6
+ if (rta->rta_len < ETH_ADDR_LEN) {
+ g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+ "invalid hardware address length %d",
+ rta->rta_len);
+ return FALSE;
+ }
+ hwaddr = g_byte_array_sized_new (ETH_ADDR_LEN);
+ g_byte_array_append (hwaddr, RTA_DATA (rta), ETH_ADDR_LEN);
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (!hwaddr) {
+ g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+ "no hardware address found");
+ return FALSE;
+ }
+
+ g_task_return_pointer (task, hwaddr, (GDestroyNotify) g_byte_array_unref);
+ return TRUE;
+}
+
+void
+mm_netlink_get_hwaddr (MMNetlink *self,
+ guint ifindex,
+ GCancellable *cancellable,
+ GAsyncReadyCallback callback,
+ gpointer user_data)
+{
+ GTask *task;
+ NetlinkMessage *msg;
+ Transaction *tr;
+ gssize bytes_sent;
+ GError *error = NULL;
+
+ task = g_task_new (self, cancellable, callback, user_data);
+
+ if (!self->socket) {
+ g_task_return_new_error (task, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
+ "netlink support not available");
+ g_object_unref (task);
+ return;
+ }
+
+ msg = netlink_message_new_getlink (ifindex);
+
+ /* The task ownership is transferred to the transaction. */
+ tr = transaction_new (self, msg, 5, task, get_hwaddr_complete);
+
+ bytes_sent = g_socket_send (self->socket,
+ (const gchar *) msg->data,
+ msg->len,
+ cancellable,
+ &error);
+ netlink_message_free (msg);
+
+ if (bytes_sent < 0)
+ transaction_complete_with_error (tr, error);
+
+ g_object_unref (task);
+}
+
+/*****************************************************************************/
+
+static gboolean
+netlink_messages_cb (GSocket *socket,
+ GIOCondition condition,
+ MMNetlink *self)
+{
+ g_autoptr(GError) error = NULL;
+ GInputVector iv;
+ GSocketAddress *addr = NULL;
+ struct sockaddr_nl source_sockaddr;
+ gchar buf[2048];
+ gssize bytes_received;
+ guint buffer_len;
+ struct nlmsghdr *hdr;
if (condition & G_IO_HUP || condition & G_IO_ERR) {
mm_obj_warn (self, "socket connection closed");
return G_SOURCE_REMOVE;
}
- bytes_received = g_socket_receive (socket, buf, sizeof (buf), NULL, &error);
+ iv.buffer = &buf;
+ iv.size = sizeof (buf);
+ bytes_received = g_socket_receive_message (self->socket,
+ &addr,
+ &iv,
+ 1,
+ NULL,
+ NULL,
+ NULL,
+ NULL,
+ &error);
if (bytes_received < 0) {
- mm_obj_warn (self, "socket i/o failure: %s", error->message);
+ mm_obj_warn (self, "failed to read netlink message: %s", error->message);
+ return G_SOURCE_REMOVE;
+ }
+
+ if (!g_socket_address_to_native (addr,
+ &source_sockaddr,
+ sizeof (source_sockaddr),
+ &error)) {
+ mm_obj_warn (self,
+ "failed to read netlink message source address: %s",
+ error->message);
return G_SOURCE_REMOVE;
}
+ /* Ensure the message is from the kernel */
+ if (source_sockaddr.nl_pid != 0) {
+ mm_obj_warn (self,
+ "ignoring non-kernel netlink message from pid %d",
+ source_sockaddr.nl_pid);
+ return G_SOURCE_CONTINUE;
+ }
+
buffer_len = (guint) bytes_received;
for (hdr = (struct nlmsghdr *) buf; NLMSG_OK (hdr, buffer_len);
NLMSG_NEXT (hdr, buffer_len)) {
Transaction *tr;
struct nlmsgerr *err;
-
- if (hdr->nlmsg_type != NLMSG_ERROR)
- continue;
+ gint nlerr = 0;
tr = g_hash_table_lookup (self->transactions,
GUINT_TO_POINTER (hdr->nlmsg_seq));
if (!tr)
continue;
- err = NLMSG_DATA (buf);
- transaction_complete (tr, err->error);
+ switch (hdr->nlmsg_type) {
+ case NLMSG_ERROR:
+ err = NLMSG_DATA (buf);
+ nlerr = err->error;
+ break;
+ case RTM_NEWLINK:
+ case NLMSG_DONE:
+ break;
+ default:
+ continue;
+ }
+
+ transaction_complete (tr, hdr, nlerr);
}
return G_SOURCE_CONTINUE;
}
@@ -375,7 +543,7 @@ setup_netlink_socket (MMNetlink *self,
{
gint socket_fd;
- socket_fd = socket (AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+ socket_fd = socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
if (socket_fd < 0) {
g_set_error (error, MM_CORE_ERROR, MM_CORE_ERROR_FAILED,
"Failed to create netlink socket");
@@ -388,11 +556,19 @@ setup_netlink_socket (MMNetlink *self,
return FALSE;
}
+ if (!g_socket_set_option (self->socket, SOL_SOCKET, SO_PASSCRED, TRUE, NULL)) {
+ int errsv = errno;
+ g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errsv),
+ "Could not set netlink socket options: %s",
+ g_strerror (errsv));
+ return FALSE;
+ }
+
self->source = g_socket_create_source (self->socket,
G_IO_IN | G_IO_ERR | G_IO_HUP,
NULL);
g_source_set_callback (self->source,
- (GSourceFunc) netlink_message_cb,
+ (GSourceFunc) netlink_messages_cb,
self,
NULL);
g_source_attach (self->source, NULL);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-06-08 21:28:06 +0000