From 31d3ad832948c75139b0e5b653912f7898a1d5d5 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 1 Dec 2017 15:08:59 -0800 Subject: netdevsim: add bpf offload support Add support for loading programs for netdevsim devices and expose the related information via DebugFS. Both offload of XDP and cls_bpf programs is supported. Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Quentin Monnet Signed-off-by: Daniel Borkmann --- drivers/net/netdevsim/Makefile | 1 + drivers/net/netdevsim/bpf.c | 373 ++++++++++++++++++++++++++++++++++++++ drivers/net/netdevsim/netdev.c | 116 +++++++++++- drivers/net/netdevsim/netdevsim.h | 40 ++++ 4 files changed, 529 insertions(+), 1 deletion(-) create mode 100644 drivers/net/netdevsim/bpf.c diff --git a/drivers/net/netdevsim/Makefile b/drivers/net/netdevsim/Makefile index 07867bfe873b..074ddebbc41d 100644 --- a/drivers/net/netdevsim/Makefile +++ b/drivers/net/netdevsim/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_NETDEVSIM) += netdevsim.o netdevsim-objs := \ netdev.o \ + bpf.o \ 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 +#include +#include +#include +#include +#include + +#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); +} diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c index 7599c72c477a..828c1ce49a8b 100644 --- a/drivers/net/netdevsim/netdev.c +++ b/drivers/net/netdevsim/netdev.c @@ -13,16 +13,45 @@ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. */ +#include #include #include #include #include #include #include +#include #include #include "netdevsim.h" +static int nsim_init(struct net_device *dev) +{ + struct netdevsim *ns = netdev_priv(dev); + int err; + + ns->netdev = dev; + ns->ddir = debugfs_create_dir(netdev_name(dev), nsim_ddir); + + err = nsim_bpf_init(ns); + if (err) + goto err_debugfs_destroy; + + return 0; + +err_debugfs_destroy: + debugfs_remove_recursive(ns->ddir); + return err; +} + +static void nsim_uninit(struct net_device *dev) +{ + struct netdevsim *ns = netdev_priv(dev); + + debugfs_remove_recursive(ns->ddir); + nsim_bpf_uninit(ns); +} + static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct netdevsim *ns = netdev_priv(dev); @@ -41,6 +70,19 @@ static void nsim_set_rx_mode(struct net_device *dev) { } +static int nsim_change_mtu(struct net_device *dev, int new_mtu) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (ns->xdp_prog_mode == XDP_ATTACHED_DRV && + new_mtu > NSIM_XDP_MAX_MTU) + return -EBUSY; + + dev->mtu = new_mtu; + + return 0; +} + static void nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) { @@ -54,12 +96,66 @@ nsim_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats) } while (u64_stats_fetch_retry(&ns->syncp, start)); } +static int +nsim_setup_tc_block_cb(enum tc_setup_type type, void *type_data, void *cb_priv) +{ + return nsim_bpf_setup_tc_block_cb(type, type_data, cb_priv); +} + +static int +nsim_setup_tc_block(struct net_device *dev, struct tc_block_offload *f) +{ + struct netdevsim *ns = netdev_priv(dev); + + if (f->binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS) + return -EOPNOTSUPP; + + switch (f->command) { + case TC_BLOCK_BIND: + return tcf_block_cb_register(f->block, nsim_setup_tc_block_cb, + ns, ns); + case TC_BLOCK_UNBIND: + tcf_block_cb_unregister(f->block, nsim_setup_tc_block_cb, ns); + return 0; + default: + return -EOPNOTSUPP; + } +} + +static int +nsim_setup_tc(struct net_device *dev, enum tc_setup_type type, void *type_data) +{ + switch (type) { + case TC_SETUP_BLOCK: + return nsim_setup_tc_block(dev, type_data); + default: + return -EOPNOTSUPP; + } +} + +static int +nsim_set_features(struct net_device *dev, netdev_features_t features) +{ + struct netdevsim *ns = netdev_priv(dev); + + if ((dev->features & NETIF_F_HW_TC) > (features & NETIF_F_HW_TC)) + return nsim_bpf_disable_tc(ns); + + return 0; +} + static const struct net_device_ops nsim_netdev_ops = { + .ndo_init = nsim_init, + .ndo_uninit = nsim_uninit, .ndo_start_xmit = nsim_start_xmit, .ndo_set_rx_mode = nsim_set_rx_mode, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, + .ndo_change_mtu = nsim_change_mtu, .ndo_get_stats64 = nsim_get_stats64, + .ndo_setup_tc = nsim_setup_tc, + .ndo_set_features = nsim_set_features, + .ndo_bpf = nsim_bpf, }; static void nsim_setup(struct net_device *dev) @@ -80,6 +176,7 @@ static void nsim_setup(struct net_device *dev) NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | NETIF_F_TSO; + dev->hw_features |= NETIF_F_HW_TC; dev->max_mtu = ETH_MAX_MTU; } @@ -102,14 +199,31 @@ static struct rtnl_link_ops nsim_link_ops __read_mostly = { .validate = nsim_validate, }; +struct dentry *nsim_ddir; + static int __init nsim_module_init(void) { - return rtnl_link_register(&nsim_link_ops); + int err; + + nsim_ddir = debugfs_create_dir(DRV_NAME, NULL); + if (IS_ERR(nsim_ddir)) + return PTR_ERR(nsim_ddir); + + err = rtnl_link_register(&nsim_link_ops); + if (err) + goto err_debugfs_destroy; + + return 0; + +err_debugfs_destroy: + debugfs_remove_recursive(nsim_ddir); + return err; } static void __exit nsim_module_exit(void) { rtnl_link_unregister(&nsim_link_ops); + debugfs_remove_recursive(nsim_ddir); } module_init(nsim_module_init); diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h index 4558c6f11598..8779e6a8f885 100644 --- a/drivers/net/netdevsim/netdevsim.h +++ b/drivers/net/netdevsim/netdevsim.h @@ -14,13 +14,53 @@ */ #include +#include #include #include #define DRV_NAME "netdevsim" +#define NSIM_XDP_MAX_MTU 4000 + +#define NSIM_EA(extack, msg) NL_SET_ERR_MSG_MOD((extack), msg) + +struct bpf_prog; +struct dentry; + struct netdevsim { + struct net_device *netdev; + u64 tx_packets; u64 tx_bytes; struct u64_stats_sync syncp; + + struct dentry *ddir; + + struct bpf_prog *bpf_offloaded; + u32 bpf_offloaded_id; + + u32 xdp_flags; + int xdp_prog_mode; + struct bpf_prog *xdp_prog; + + u32 prog_id_gen; + + bool bpf_bind_accept; + u32 bpf_bind_verifier_delay; + struct dentry *ddir_bpf_bound_progs; + struct list_head bpf_bound_progs; + + bool bpf_tc_accept; + bool bpf_tc_non_bound_accept; + bool bpf_xdpdrv_accept; + bool bpf_xdpoffload_accept; }; + +extern struct dentry *nsim_ddir; + +int nsim_bpf_init(struct netdevsim *ns); +void nsim_bpf_uninit(struct netdevsim *ns); +int nsim_bpf(struct net_device *dev, struct netdev_bpf *bpf); +int nsim_bpf_disable_tc(struct netdevsim *ns); +int nsim_bpf_setup_tc_block_cb(enum tc_setup_type type, + void *type_data, void *cb_priv); -- cgit v1.2.3-55-g7522