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-rw-r--r--net/core/dev.c26
-rw-r--r--net/core/rtnetlink.c14
2 files changed, 35 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index d84541c24446..651a3c28d33a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8655,15 +8655,17 @@ static void dev_xdp_uninstall(struct net_device *dev)
* @dev: device
* @extack: netlink extended ack
* @fd: new program fd or negative value to clear
+ * @expected_fd: old program fd that userspace expects to replace or clear
* @flags: xdp-related flags
*
* Set or clear a bpf program for a device
*/
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
- int fd, u32 flags)
+ int fd, int expected_fd, u32 flags)
{
const struct net_device_ops *ops = dev->netdev_ops;
enum bpf_netdev_command query;
+ u32 prog_id, expected_id = 0;
struct bpf_prog *prog = NULL;
bpf_op_t bpf_op, bpf_chk;
bool offload;
@@ -8684,15 +8686,29 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
if (bpf_op == bpf_chk)
bpf_chk = generic_xdp_install;
- if (fd >= 0) {
- u32 prog_id;
+ prog_id = __dev_xdp_query(dev, bpf_op, query);
+ if (flags & XDP_FLAGS_REPLACE) {
+ if (expected_fd >= 0) {
+ prog = bpf_prog_get_type_dev(expected_fd,
+ BPF_PROG_TYPE_XDP,
+ bpf_op == ops->ndo_bpf);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+ expected_id = prog->aux->id;
+ bpf_prog_put(prog);
+ }
+ if (prog_id != expected_id) {
+ NL_SET_ERR_MSG(extack, "Active program does not match expected");
+ return -EEXIST;
+ }
+ }
+ if (fd >= 0) {
if (!offload && __dev_xdp_query(dev, bpf_chk, XDP_QUERY_PROG)) {
NL_SET_ERR_MSG(extack, "native and generic XDP can't be active at the same time");
return -EEXIST;
}
- prog_id = __dev_xdp_query(dev, bpf_op, query);
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) {
NL_SET_ERR_MSG(extack, "XDP program already attached");
return -EBUSY;
@@ -8715,7 +8731,7 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
return 0;
}
} else {
- if (!__dev_xdp_query(dev, bpf_op, query))
+ if (!prog_id)
return 0;
}
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 14e6ea21c378..709ebbf8ab5b 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1872,7 +1872,9 @@ static const struct nla_policy ifla_port_policy[IFLA_PORT_MAX+1] = {
};
static const struct nla_policy ifla_xdp_policy[IFLA_XDP_MAX + 1] = {
+ [IFLA_XDP_UNSPEC] = { .strict_start_type = IFLA_XDP_EXPECTED_FD },
[IFLA_XDP_FD] = { .type = NLA_S32 },
+ [IFLA_XDP_EXPECTED_FD] = { .type = NLA_S32 },
[IFLA_XDP_ATTACHED] = { .type = NLA_U8 },
[IFLA_XDP_FLAGS] = { .type = NLA_U32 },
[IFLA_XDP_PROG_ID] = { .type = NLA_U32 },
@@ -2799,8 +2801,20 @@ static int do_setlink(const struct sk_buff *skb,
}
if (xdp[IFLA_XDP_FD]) {
+ int expected_fd = -1;
+
+ if (xdp_flags & XDP_FLAGS_REPLACE) {
+ if (!xdp[IFLA_XDP_EXPECTED_FD]) {
+ err = -EINVAL;
+ goto errout;
+ }
+ expected_fd =
+ nla_get_s32(xdp[IFLA_XDP_EXPECTED_FD]);
+ }
+
err = dev_change_xdp_fd(dev, extack,
nla_get_s32(xdp[IFLA_XDP_FD]),
+ expected_fd,
xdp_flags);
if (err)
goto errout;