diff options
Diffstat (limited to 'drivers/net/netdevsim/bpf.c')
| -rw-r--r-- | drivers/net/netdevsim/bpf.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c new file mode 100644 index 000000000000..8e4398a50903 --- /dev/null +++ b/drivers/net/netdevsim/bpf.c @@ -0,0 +1,373 @@ +/* + * Copyright (C) 2017 Netronome Systems, Inc. + * + * This software is licensed under the GNU General License Version 2, + * June 1991 as shown in the file COPYING in the top-level directory of this + * source tree. + * + * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" + * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE + * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME + * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + */ + +#include <linux/bpf.h> +#include <linux/bpf_verifier.h> +#include <linux/debugfs.h> +#include <linux/kernel.h> +#include <linux/rtnetlink.h> +#include <net/pkt_cls.h> + +#include "netdevsim.h" + +struct nsim_bpf_bound_prog { + struct netdevsim *ns; + struct bpf_prog *prog; + struct dentry *ddir; + const char *state; + bool is_loaded; + struct list_head l; +}; + +static int nsim_debugfs_bpf_string_read(struct seq_file *file, void *data) +{ + const char **str = file->private; + + if (*str) + seq_printf(file, "%s\n", *str); + + return 0; +} + +static int nsim_debugfs_bpf_string_open(struct inode *inode, struct file *f) +{ + return single_open(f, nsim_debugfs_bpf_string_read, inode->i_private); +} + +static const struct file_operations nsim_bpf_string_fops = { + .owner = THIS_MODULE, + .open = nsim_debugfs_bpf_string_open, + .release = single_release, + .read = seq_read, + .llseek = seq_lseek +}; + +static int +nsim_bpf_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn) +{ + struct nsim_bpf_bound_prog *state; + + state = env->prog->aux->offload->dev_priv; + if (state->ns->bpf_bind_verifier_delay && !insn_idx) + msleep(state->ns->bpf_bind_verifier_delay); + + return 0; +} + +static const struct bpf_ext_analyzer_ops nsim_bpf_analyzer_ops = { + .insn_hook = nsim_bpf_verify_insn, +}; + +static bool nsim_xdp_offload_active(struct netdevsim *ns) +{ + return ns->xdp_prog_mode == XDP_ATTACHED_HW; +} + +static void nsim_prog_set_loaded(struct bpf_prog *prog, bool loaded) +{ + struct nsim_bpf_bound_prog *state; + + if (!prog || !prog->aux->offload) + return; + + state = prog->aux->offload->dev_priv; + state->is_loaded = loaded; +} + +static int +nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog *prog, bool oldprog) +{ + nsim_prog_set_loaded(ns->bpf_offloaded, false); + + WARN(!!ns->bpf_offloaded != oldprog, + "bad offload state, expected offload %sto be active", + oldprog ? "" : "not "); + ns->bpf_offloaded = prog; + ns->bpf_offloaded_id = prog ? prog->aux->id : 0; + nsim_prog_set_loaded(prog, true); + + return 0; +} + +int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type, + void *type_data, void *cb_priv) +{ + struct tc_cls_bpf_offload *cls_bpf = type_data; + struct bpf_prog *prog = cls_bpf->prog; + struct netdevsim *ns = cb_priv; + bool skip_sw; + + if (type != TC_SETUP_CLSBPF || + !tc_can_offload(ns->netdev) || + cls_bpf->common.protocol != htons(ETH_P_ALL) || + cls_bpf->common.chain_index) + return -EOPNOTSUPP; + + skip_sw = cls_bpf->gen_flags & TCA_CLS_FLAGS_SKIP_SW; + + if (nsim_xdp_offload_active(ns)) + return -EBUSY; + + if (!ns->bpf_tc_accept) + return -EOPNOTSUPP; + /* Note: progs without skip_sw will probably not be dev bound */ + if (prog && !prog->aux->offload && !ns->bpf_tc_non_bound_accept) + return -EOPNOTSUPP; + + switch (cls_bpf->command) { + case TC_CLSBPF_REPLACE: + return nsim_bpf_offload(ns, prog, true); + case TC_CLSBPF_ADD: + return nsim_bpf_offload(ns, prog, false); + case TC_CLSBPF_DESTROY: + return nsim_bpf_offload(ns, NULL, true); + default: + return -EOPNOTSUPP; + } +} + +int nsim_bpf_disable_tc(struct netdevsim *ns) +{ + if (ns->bpf_offloaded && !nsim_xdp_offload_active(ns)) + return -EBUSY; + return 0; +} + +static int nsim_xdp_offload_prog(struct netdevsim *ns, struct netdev_bpf *bpf) +{ + if (!nsim_xdp_offload_active(ns) && !bpf->prog) + return 0; + if (!nsim_xdp_offload_active(ns) && bpf->prog && ns->bpf_offloaded) { + NSIM_EA(bpf->extack, "TC program is already loaded"); + return -EBUSY; + } + + return nsim_bpf_offload(ns, bpf->prog, nsim_xdp_offload_active(ns)); +} + +static int nsim_xdp_set_prog(struct netdevsim *ns, struct netdev_bpf *bpf) +{ + int err; + + if (ns->xdp_prog && (bpf->flags ^ ns->xdp_flags) & XDP_FLAGS_MODES) { + NSIM_EA(bpf->extack, "program loaded with different flags"); + return -EBUSY; + } + + if (bpf->command == XDP_SETUP_PROG && !ns->bpf_xdpdrv_accept) { + NSIM_EA(bpf->extack, "driver XDP disabled in DebugFS"); + return -EOPNOTSUPP; + } + if (bpf->command == XDP_SETUP_PROG_HW && !ns->bpf_xdpoffload_accept) { + NSIM_EA(bpf->extack, "XDP offload disabled in DebugFS"); + return -EOPNOTSUPP; + } + + if (bpf->command == XDP_SETUP_PROG_HW) { + err = nsim_xdp_offload_prog(ns, bpf); + if (err) + return err; + } + + if (ns->xdp_prog) + bpf_prog_put(ns->xdp_prog); + + ns->xdp_prog = bpf->prog; + ns->xdp_flags = bpf->flags; + + if (!bpf->prog) + ns->xdp_prog_mode = XDP_ATTACHED_NONE; + else if (bpf->command == XDP_SETUP_PROG) + ns->xdp_prog_mode = XDP_ATTACHED_DRV; + else + ns->xdp_prog_mode = XDP_ATTACHED_HW; + + return 0; +} + +int nsim_bpf_create_prog(struct netdevsim *ns, struct bpf_prog *prog) +{ + struct nsim_bpf_bound_prog *state; + char name[16]; + int err; + + state = kzalloc(sizeof(*state), GFP_KERNEL); + if (!state) + return -ENOMEM; + + state->ns = ns; + state->prog = prog; + state->state = "verify"; + + /* Program id is not populated yet when we create the state. */ + sprintf(name, "%u", ns->prog_id_gen++); + state->ddir = debugfs_create_dir(name, ns->ddir_bpf_bound_progs); + if (IS_ERR(state->ddir)) { + err = PTR_ERR(state->ddir); + kfree(state); + return err; + } + + debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id); + debugfs_create_file("state", 0400, state->ddir, + &state->state, &nsim_bpf_string_fops); + debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded); + + list_add_tail(&state->l, &ns->bpf_bound_progs); + + prog->aux->offload->dev_priv = state; + + return 0; +} + +void nsim_bpf_destroy_prog(struct bpf_prog *prog) +{ + struct nsim_bpf_bound_prog *state; + + state = prog->aux->offload->dev_priv; + WARN(state->is_loaded, + "offload state destroyed while program still bound"); + debugfs_remove_recursive(state->ddir); + list_del(&state->l); + kfree(state); +} + +static int nsim_setup_prog_checks(struct netdevsim *ns, struct netdev_bpf *bpf) +{ + if (bpf->prog && bpf->prog->aux->offload) { + NSIM_EA(bpf->extack, "attempt to load offloaded prog to drv"); + return -EINVAL; + } + if (ns->netdev->mtu > NSIM_XDP_MAX_MTU) { + NSIM_EA(bpf->extack, "MTU too large w/ XDP enabled"); + return -EINVAL; + } + if (nsim_xdp_offload_active(ns)) { + NSIM_EA(bpf->extack, "xdp offload active, can't load drv prog"); + return -EBUSY; + } + return 0; +} + +static int +nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf) +{ + struct nsim_bpf_bound_prog *state; + + if (!bpf->prog) + return 0; + + if (!bpf->prog->aux->offload) { + NSIM_EA(bpf->extack, "xdpoffload of non-bound program"); + return -EINVAL; + } + if (bpf->prog->aux->offload->netdev != ns->netdev) { + NSIM_EA(bpf->extack, "program bound to different dev"); + return -EINVAL; + } + + state = bpf->prog->aux->offload->dev_priv; + if (WARN_ON(strcmp(state->state, "xlated"))) { + NSIM_EA(bpf->extack, "offloading program in bad state"); + return -EINVAL; + } + return 0; +} + +int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf) +{ + struct netdevsim *ns = netdev_priv(dev); + struct nsim_bpf_bound_prog *state; + int err; + + ASSERT_RTNL(); + + switch (bpf->command) { + case BPF_OFFLOAD_VERIFIER_PREP: + if (!ns->bpf_bind_accept) + return -EOPNOTSUPP; + + err = nsim_bpf_create_prog(ns, bpf->verifier.prog); + if (err) + return err; + + bpf->verifier.ops = &nsim_bpf_analyzer_ops; + return 0; + case BPF_OFFLOAD_TRANSLATE: + state = bpf->offload.prog->aux->offload->dev_priv; + + state->state = "xlated"; + return 0; + case BPF_OFFLOAD_DESTROY: + nsim_bpf_destroy_prog(bpf->offload.prog); + return 0; + case XDP_QUERY_PROG: + bpf->prog_attached = ns->xdp_prog_mode; + bpf->prog_id = ns->xdp_prog ? ns->xdp_prog->aux->id : 0; + bpf->prog_flags = ns->xdp_prog ? ns->xdp_flags : 0; + return 0; + case XDP_SETUP_PROG: + err = nsim_setup_prog_checks(ns, bpf); + if (err) + return err; + + return nsim_xdp_set_prog(ns, bpf); + case XDP_SETUP_PROG_HW: + err = nsim_setup_prog_hw_checks(ns, bpf); + if (err) + return err; + + return nsim_xdp_set_prog(ns, bpf); + default: + return -EINVAL; + } +} + +int nsim_bpf_init(struct netdevsim *ns) +{ + INIT_LIST_HEAD(&ns->bpf_bound_progs); + + debugfs_create_u32("bpf_offloaded_id", 0400, ns->ddir, + &ns->bpf_offloaded_id); + + ns->bpf_bind_accept = true; + debugfs_create_bool("bpf_bind_accept", 0600, ns->ddir, + &ns->bpf_bind_accept); + debugfs_create_u32("bpf_bind_verifier_delay", 0600, ns->ddir, + &ns->bpf_bind_verifier_delay); + ns->ddir_bpf_bound_progs = + debugfs_create_dir("bpf_bound_progs", ns->ddir); + + ns->bpf_tc_accept = true; + debugfs_create_bool("bpf_tc_accept", 0600, ns->ddir, + &ns->bpf_tc_accept); + debugfs_create_bool("bpf_tc_non_bound_accept", 0600, ns->ddir, + &ns->bpf_tc_non_bound_accept); + ns->bpf_xdpdrv_accept = true; + debugfs_create_bool("bpf_xdpdrv_accept", 0600, ns->ddir, + &ns->bpf_xdpdrv_accept); + ns->bpf_xdpoffload_accept = true; + debugfs_create_bool("bpf_xdpoffload_accept", 0600, ns->ddir, + &ns->bpf_xdpoffload_accept); + + return 0; +} + +void nsim_bpf_uninit(struct netdevsim *ns) +{ + WARN_ON(!list_empty(&ns->bpf_bound_progs)); + WARN_ON(ns->xdp_prog); + WARN_ON(ns->bpf_offloaded); +} |