mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
bpf, xdp: Extract common XDP program attachment logic
Further refactor XDP attachment code. dev_change_xdp_fd() is split into two parts: getting bpf_progs from FDs and attachment logic, working with bpf_progs. This makes attachment logic a bit more straightforward and prepares code for bpf_xdp_link inclusion, which will share the common logic. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722064603.3350758-4-andriin@fb.com
This commit is contained in:
parent
7f0a838254
commit
d4baa9368a
1 changed files with 97 additions and 80 deletions
173
net/core/dev.c
173
net/core/dev.c
|
@ -8815,6 +8815,82 @@ static void dev_xdp_uninstall(struct net_device *dev)
|
|||
}
|
||||
}
|
||||
|
||||
static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
|
||||
struct bpf_prog *new_prog, struct bpf_prog *old_prog,
|
||||
u32 flags)
|
||||
{
|
||||
struct bpf_prog *cur_prog;
|
||||
enum bpf_xdp_mode mode;
|
||||
bpf_op_t bpf_op;
|
||||
int err;
|
||||
|
||||
ASSERT_RTNL();
|
||||
|
||||
/* just one XDP mode bit should be set, zero defaults to SKB mode */
|
||||
if (hweight32(flags & XDP_FLAGS_MODES) > 1) {
|
||||
NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
|
||||
return -EINVAL;
|
||||
}
|
||||
/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
|
||||
if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
|
||||
NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
mode = dev_xdp_mode(flags);
|
||||
cur_prog = dev_xdp_prog(dev, mode);
|
||||
if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
|
||||
NL_SET_ERR_MSG(extack, "Active program does not match expected");
|
||||
return -EEXIST;
|
||||
}
|
||||
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
|
||||
NL_SET_ERR_MSG(extack, "XDP program already attached");
|
||||
return -EBUSY;
|
||||
}
|
||||
|
||||
if (new_prog) {
|
||||
bool offload = mode == XDP_MODE_HW;
|
||||
enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
|
||||
? XDP_MODE_DRV : XDP_MODE_SKB;
|
||||
|
||||
if (!offload && dev_xdp_prog(dev, other_mode)) {
|
||||
NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
|
||||
return -EEXIST;
|
||||
}
|
||||
if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
|
||||
NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
|
||||
return -EINVAL;
|
||||
}
|
||||
if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
|
||||
NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
|
||||
return -EINVAL;
|
||||
}
|
||||
if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
|
||||
NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
|
||||
return -EINVAL;
|
||||
}
|
||||
}
|
||||
|
||||
/* don't call drivers if the effective program didn't change */
|
||||
if (new_prog != cur_prog) {
|
||||
bpf_op = dev_xdp_bpf_op(dev, mode);
|
||||
if (!bpf_op) {
|
||||
NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
|
||||
dev_xdp_set_prog(dev, mode, new_prog);
|
||||
if (cur_prog)
|
||||
bpf_prog_put(cur_prog);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* dev_change_xdp_fd - set or clear a bpf program for a device rx path
|
||||
* @dev: device
|
||||
|
@ -8828,96 +8904,37 @@ static void dev_xdp_uninstall(struct net_device *dev)
|
|||
int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
|
||||
int fd, int expected_fd, u32 flags)
|
||||
{
|
||||
const struct net_device_ops *ops = dev->netdev_ops;
|
||||
enum bpf_xdp_mode mode = dev_xdp_mode(flags);
|
||||
bool offload = mode == XDP_MODE_HW;
|
||||
u32 prog_id, expected_id = 0;
|
||||
struct bpf_prog *prog;
|
||||
bpf_op_t bpf_op;
|
||||
struct bpf_prog *new_prog = NULL, *old_prog = NULL;
|
||||
int err;
|
||||
|
||||
ASSERT_RTNL();
|
||||
|
||||
bpf_op = dev_xdp_bpf_op(dev, mode);
|
||||
if (!bpf_op) {
|
||||
NL_SET_ERR_MSG(extack, "underlying driver does not support XDP in native mode");
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
prog_id = dev_xdp_prog_id(dev, mode);
|
||||
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) {
|
||||
enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
|
||||
? XDP_MODE_DRV : XDP_MODE_SKB;
|
||||
|
||||
if (!offload && dev_xdp_prog_id(dev, other_mode)) {
|
||||
NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
|
||||
return -EEXIST;
|
||||
new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
|
||||
mode != XDP_MODE_SKB);
|
||||
if (IS_ERR(new_prog))
|
||||
return PTR_ERR(new_prog);
|
||||
}
|
||||
|
||||
if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) {
|
||||
NL_SET_ERR_MSG(extack, "XDP program already attached");
|
||||
return -EBUSY;
|
||||
if (expected_fd >= 0) {
|
||||
old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
|
||||
mode != XDP_MODE_SKB);
|
||||
if (IS_ERR(old_prog)) {
|
||||
err = PTR_ERR(old_prog);
|
||||
old_prog = NULL;
|
||||
goto err_out;
|
||||
}
|
||||
}
|
||||
|
||||
prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
|
||||
bpf_op == ops->ndo_bpf);
|
||||
if (IS_ERR(prog))
|
||||
return PTR_ERR(prog);
|
||||
err = dev_xdp_attach(dev, extack, new_prog, old_prog, flags);
|
||||
|
||||
if (!offload && bpf_prog_is_dev_bound(prog->aux)) {
|
||||
NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
|
||||
bpf_prog_put(prog);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (prog->expected_attach_type == BPF_XDP_DEVMAP) {
|
||||
NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
|
||||
bpf_prog_put(prog);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
if (prog->expected_attach_type == BPF_XDP_CPUMAP) {
|
||||
NL_SET_ERR_MSG(extack,
|
||||
"BPF_XDP_CPUMAP programs can not be attached to a device");
|
||||
bpf_prog_put(prog);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* prog->aux->id may be 0 for orphaned device-bound progs */
|
||||
if (prog->aux->id && prog->aux->id == prog_id) {
|
||||
bpf_prog_put(prog);
|
||||
return 0;
|
||||
}
|
||||
} else {
|
||||
if (!prog_id)
|
||||
return 0;
|
||||
prog = NULL;
|
||||
}
|
||||
|
||||
err = dev_xdp_install(dev, mode, bpf_op, extack, flags, prog);
|
||||
if (err < 0 && prog) {
|
||||
bpf_prog_put(prog);
|
||||
err_out:
|
||||
if (err && new_prog)
|
||||
bpf_prog_put(new_prog);
|
||||
if (old_prog)
|
||||
bpf_prog_put(old_prog);
|
||||
return err;
|
||||
}
|
||||
dev_xdp_set_prog(dev, mode, prog);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
Loading…
Reference in a new issue