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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Jakub Kicinski](/assets/img/avatar_default.png)
Merge in the left-over fixes before the net-next pull-request. Conflicts: drivers/net/ethernet/mediatek/mtk_ppe.cae3ed15da5
("net: ethernet: mtk_eth_soc: fix state in __mtk_foe_entry_clear")9d8cb4c096
("net: ethernet: mtk_eth_soc: add foe_entry_size to mtk_eth_soc") https://lore.kernel.org/all/6cb6893b-4921-a068-4c30-1109795110bb@tessares.net/ kernel/bpf/helpers.c8addbfc7b3
("bpf: Gate dynptr API behind CAP_BPF")5679ff2f13
("bpf: Move bpf_loop and bpf_for_each_map_elem under CAP_BPF")8a67f2de9b
("bpf: expose bpf_strtol and bpf_strtoul to all program types") https://lore.kernel.org/all/20221003201957.13149-1-daniel@iogearbox.net/ Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2543 lines
66 KiB
C
2543 lines
66 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Functions to manage eBPF programs attached to cgroups
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*
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* Copyright (c) 2016 Daniel Mack
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*/
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#include <linux/kernel.h>
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#include <linux/atomic.h>
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#include <linux/cgroup.h>
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#include <linux/filter.h>
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#include <linux/slab.h>
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#include <linux/sysctl.h>
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#include <linux/string.h>
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#include <linux/bpf.h>
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#include <linux/bpf-cgroup.h>
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#include <linux/bpf_lsm.h>
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#include <linux/bpf_verifier.h>
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#include <net/sock.h>
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#include <net/bpf_sk_storage.h>
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#include "../cgroup/cgroup-internal.h"
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DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE);
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EXPORT_SYMBOL(cgroup_bpf_enabled_key);
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/* __always_inline is necessary to prevent indirect call through run_prog
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* function pointer.
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*/
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static __always_inline int
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bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
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enum cgroup_bpf_attach_type atype,
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const void *ctx, bpf_prog_run_fn run_prog,
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int retval, u32 *ret_flags)
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{
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const struct bpf_prog_array_item *item;
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const struct bpf_prog *prog;
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const struct bpf_prog_array *array;
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struct bpf_run_ctx *old_run_ctx;
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struct bpf_cg_run_ctx run_ctx;
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u32 func_ret;
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run_ctx.retval = retval;
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migrate_disable();
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rcu_read_lock();
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array = rcu_dereference(cgrp->effective[atype]);
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item = &array->items[0];
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old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
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while ((prog = READ_ONCE(item->prog))) {
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run_ctx.prog_item = item;
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func_ret = run_prog(prog, ctx);
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if (ret_flags) {
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*(ret_flags) |= (func_ret >> 1);
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func_ret &= 1;
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}
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if (!func_ret && !IS_ERR_VALUE((long)run_ctx.retval))
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run_ctx.retval = -EPERM;
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item++;
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}
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bpf_reset_run_ctx(old_run_ctx);
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rcu_read_unlock();
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migrate_enable();
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return run_ctx.retval;
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}
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unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx,
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const struct bpf_insn *insn)
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{
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const struct bpf_prog *shim_prog;
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struct sock *sk;
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struct cgroup *cgrp;
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int ret = 0;
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u64 *args;
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args = (u64 *)ctx;
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sk = (void *)(unsigned long)args[0];
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/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
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shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
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cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
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if (likely(cgrp))
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ret = bpf_prog_run_array_cg(&cgrp->bpf,
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shim_prog->aux->cgroup_atype,
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ctx, bpf_prog_run, 0, NULL);
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return ret;
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}
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unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx,
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const struct bpf_insn *insn)
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{
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const struct bpf_prog *shim_prog;
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struct socket *sock;
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struct cgroup *cgrp;
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int ret = 0;
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u64 *args;
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args = (u64 *)ctx;
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sock = (void *)(unsigned long)args[0];
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/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
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shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
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cgrp = sock_cgroup_ptr(&sock->sk->sk_cgrp_data);
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if (likely(cgrp))
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ret = bpf_prog_run_array_cg(&cgrp->bpf,
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shim_prog->aux->cgroup_atype,
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ctx, bpf_prog_run, 0, NULL);
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return ret;
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}
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unsigned int __cgroup_bpf_run_lsm_current(const void *ctx,
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const struct bpf_insn *insn)
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{
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const struct bpf_prog *shim_prog;
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struct cgroup *cgrp;
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int ret = 0;
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/*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/
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shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi));
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/* We rely on trampoline's __bpf_prog_enter_lsm_cgroup to grab RCU read lock. */
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cgrp = task_dfl_cgroup(current);
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if (likely(cgrp))
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ret = bpf_prog_run_array_cg(&cgrp->bpf,
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shim_prog->aux->cgroup_atype,
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ctx, bpf_prog_run, 0, NULL);
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return ret;
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}
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#ifdef CONFIG_BPF_LSM
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struct cgroup_lsm_atype {
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u32 attach_btf_id;
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int refcnt;
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};
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static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM];
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static enum cgroup_bpf_attach_type
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bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
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{
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int i;
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lockdep_assert_held(&cgroup_mutex);
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if (attach_type != BPF_LSM_CGROUP)
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return to_cgroup_bpf_attach_type(attach_type);
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for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
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if (cgroup_lsm_atype[i].attach_btf_id == attach_btf_id)
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return CGROUP_LSM_START + i;
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for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++)
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if (cgroup_lsm_atype[i].attach_btf_id == 0)
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return CGROUP_LSM_START + i;
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return -E2BIG;
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}
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void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype)
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{
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int i = cgroup_atype - CGROUP_LSM_START;
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lockdep_assert_held(&cgroup_mutex);
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WARN_ON_ONCE(cgroup_lsm_atype[i].attach_btf_id &&
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cgroup_lsm_atype[i].attach_btf_id != attach_btf_id);
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cgroup_lsm_atype[i].attach_btf_id = attach_btf_id;
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cgroup_lsm_atype[i].refcnt++;
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}
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void bpf_cgroup_atype_put(int cgroup_atype)
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{
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int i = cgroup_atype - CGROUP_LSM_START;
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mutex_lock(&cgroup_mutex);
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if (--cgroup_lsm_atype[i].refcnt <= 0)
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cgroup_lsm_atype[i].attach_btf_id = 0;
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WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0);
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mutex_unlock(&cgroup_mutex);
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}
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#else
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static enum cgroup_bpf_attach_type
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bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id)
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{
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if (attach_type != BPF_LSM_CGROUP)
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return to_cgroup_bpf_attach_type(attach_type);
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return -EOPNOTSUPP;
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}
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#endif /* CONFIG_BPF_LSM */
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void cgroup_bpf_offline(struct cgroup *cgrp)
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{
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cgroup_get(cgrp);
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percpu_ref_kill(&cgrp->bpf.refcnt);
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}
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static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[])
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{
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enum bpf_cgroup_storage_type stype;
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for_each_cgroup_storage_type(stype)
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bpf_cgroup_storage_free(storages[stype]);
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}
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static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[],
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struct bpf_cgroup_storage *new_storages[],
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enum bpf_attach_type type,
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struct bpf_prog *prog,
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struct cgroup *cgrp)
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{
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enum bpf_cgroup_storage_type stype;
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struct bpf_cgroup_storage_key key;
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struct bpf_map *map;
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key.cgroup_inode_id = cgroup_id(cgrp);
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key.attach_type = type;
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for_each_cgroup_storage_type(stype) {
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map = prog->aux->cgroup_storage[stype];
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if (!map)
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continue;
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storages[stype] = cgroup_storage_lookup((void *)map, &key, false);
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if (storages[stype])
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continue;
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storages[stype] = bpf_cgroup_storage_alloc(prog, stype);
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if (IS_ERR(storages[stype])) {
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bpf_cgroup_storages_free(new_storages);
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return -ENOMEM;
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}
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new_storages[stype] = storages[stype];
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}
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return 0;
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}
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static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[],
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struct bpf_cgroup_storage *src[])
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{
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enum bpf_cgroup_storage_type stype;
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for_each_cgroup_storage_type(stype)
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dst[stype] = src[stype];
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}
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static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[],
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struct cgroup *cgrp,
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enum bpf_attach_type attach_type)
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{
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enum bpf_cgroup_storage_type stype;
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for_each_cgroup_storage_type(stype)
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bpf_cgroup_storage_link(storages[stype], cgrp, attach_type);
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}
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/* Called when bpf_cgroup_link is auto-detached from dying cgroup.
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* It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It
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* doesn't free link memory, which will eventually be done by bpf_link's
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* release() callback, when its last FD is closed.
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*/
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static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link)
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{
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cgroup_put(link->cgroup);
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link->cgroup = NULL;
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}
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/**
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* cgroup_bpf_release() - put references of all bpf programs and
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* release all cgroup bpf data
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* @work: work structure embedded into the cgroup to modify
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*/
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static void cgroup_bpf_release(struct work_struct *work)
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{
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struct cgroup *p, *cgrp = container_of(work, struct cgroup,
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bpf.release_work);
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struct bpf_prog_array *old_array;
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struct list_head *storages = &cgrp->bpf.storages;
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struct bpf_cgroup_storage *storage, *stmp;
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unsigned int atype;
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mutex_lock(&cgroup_mutex);
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for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) {
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struct hlist_head *progs = &cgrp->bpf.progs[atype];
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struct bpf_prog_list *pl;
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struct hlist_node *pltmp;
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hlist_for_each_entry_safe(pl, pltmp, progs, node) {
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hlist_del(&pl->node);
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if (pl->prog) {
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if (pl->prog->expected_attach_type == BPF_LSM_CGROUP)
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bpf_trampoline_unlink_cgroup_shim(pl->prog);
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bpf_prog_put(pl->prog);
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}
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if (pl->link) {
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if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP)
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bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog);
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bpf_cgroup_link_auto_detach(pl->link);
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}
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kfree(pl);
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static_branch_dec(&cgroup_bpf_enabled_key[atype]);
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}
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old_array = rcu_dereference_protected(
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cgrp->bpf.effective[atype],
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lockdep_is_held(&cgroup_mutex));
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bpf_prog_array_free(old_array);
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}
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list_for_each_entry_safe(storage, stmp, storages, list_cg) {
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bpf_cgroup_storage_unlink(storage);
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bpf_cgroup_storage_free(storage);
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}
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mutex_unlock(&cgroup_mutex);
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for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
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cgroup_bpf_put(p);
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percpu_ref_exit(&cgrp->bpf.refcnt);
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cgroup_put(cgrp);
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}
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/**
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* cgroup_bpf_release_fn() - callback used to schedule releasing
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* of bpf cgroup data
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* @ref: percpu ref counter structure
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*/
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static void cgroup_bpf_release_fn(struct percpu_ref *ref)
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{
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struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt);
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INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release);
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queue_work(system_wq, &cgrp->bpf.release_work);
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}
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/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through
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* link or direct prog.
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*/
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static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl)
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{
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if (pl->prog)
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return pl->prog;
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if (pl->link)
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return pl->link->link.prog;
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return NULL;
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}
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/* count number of elements in the list.
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* it's slow but the list cannot be long
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*/
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static u32 prog_list_length(struct hlist_head *head)
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{
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struct bpf_prog_list *pl;
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u32 cnt = 0;
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hlist_for_each_entry(pl, head, node) {
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if (!prog_list_prog(pl))
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continue;
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cnt++;
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}
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return cnt;
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}
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/* if parent has non-overridable prog attached,
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* disallow attaching new programs to the descendent cgroup.
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* if parent has overridable or multi-prog, allow attaching
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*/
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static bool hierarchy_allows_attach(struct cgroup *cgrp,
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enum cgroup_bpf_attach_type atype)
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{
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struct cgroup *p;
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p = cgroup_parent(cgrp);
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if (!p)
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return true;
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do {
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u32 flags = p->bpf.flags[atype];
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u32 cnt;
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if (flags & BPF_F_ALLOW_MULTI)
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return true;
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cnt = prog_list_length(&p->bpf.progs[atype]);
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WARN_ON_ONCE(cnt > 1);
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if (cnt == 1)
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return !!(flags & BPF_F_ALLOW_OVERRIDE);
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p = cgroup_parent(p);
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} while (p);
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return true;
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}
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/* compute a chain of effective programs for a given cgroup:
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* start from the list of programs in this cgroup and add
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* all parent programs.
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* Note that parent's F_ALLOW_OVERRIDE-type program is yielding
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* to programs in this cgroup
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*/
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static int compute_effective_progs(struct cgroup *cgrp,
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enum cgroup_bpf_attach_type atype,
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struct bpf_prog_array **array)
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{
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struct bpf_prog_array_item *item;
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struct bpf_prog_array *progs;
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struct bpf_prog_list *pl;
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struct cgroup *p = cgrp;
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int cnt = 0;
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/* count number of effective programs by walking parents */
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do {
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if (cnt == 0 || (p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
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cnt += prog_list_length(&p->bpf.progs[atype]);
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p = cgroup_parent(p);
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} while (p);
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progs = bpf_prog_array_alloc(cnt, GFP_KERNEL);
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if (!progs)
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return -ENOMEM;
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/* populate the array with effective progs */
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cnt = 0;
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p = cgrp;
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do {
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if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
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continue;
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hlist_for_each_entry(pl, &p->bpf.progs[atype], node) {
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if (!prog_list_prog(pl))
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continue;
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item = &progs->items[cnt];
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item->prog = prog_list_prog(pl);
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bpf_cgroup_storages_assign(item->cgroup_storage,
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pl->storage);
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cnt++;
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}
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} while ((p = cgroup_parent(p)));
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*array = progs;
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return 0;
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}
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static void activate_effective_progs(struct cgroup *cgrp,
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enum cgroup_bpf_attach_type atype,
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struct bpf_prog_array *old_array)
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{
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old_array = rcu_replace_pointer(cgrp->bpf.effective[atype], old_array,
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lockdep_is_held(&cgroup_mutex));
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/* free prog array after grace period, since __cgroup_bpf_run_*()
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* might be still walking the array
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*/
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bpf_prog_array_free(old_array);
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}
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/**
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* cgroup_bpf_inherit() - inherit effective programs from parent
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* @cgrp: the cgroup to modify
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*/
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int cgroup_bpf_inherit(struct cgroup *cgrp)
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{
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|
/* has to use marco instead of const int, since compiler thinks
|
|
* that array below is variable length
|
|
*/
|
|
#define NR ARRAY_SIZE(cgrp->bpf.effective)
|
|
struct bpf_prog_array *arrays[NR] = {};
|
|
struct cgroup *p;
|
|
int ret, i;
|
|
|
|
ret = percpu_ref_init(&cgrp->bpf.refcnt, cgroup_bpf_release_fn, 0,
|
|
GFP_KERNEL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
|
|
cgroup_bpf_get(p);
|
|
|
|
for (i = 0; i < NR; i++)
|
|
INIT_HLIST_HEAD(&cgrp->bpf.progs[i]);
|
|
|
|
INIT_LIST_HEAD(&cgrp->bpf.storages);
|
|
|
|
for (i = 0; i < NR; i++)
|
|
if (compute_effective_progs(cgrp, i, &arrays[i]))
|
|
goto cleanup;
|
|
|
|
for (i = 0; i < NR; i++)
|
|
activate_effective_progs(cgrp, i, arrays[i]);
|
|
|
|
return 0;
|
|
cleanup:
|
|
for (i = 0; i < NR; i++)
|
|
bpf_prog_array_free(arrays[i]);
|
|
|
|
for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p))
|
|
cgroup_bpf_put(p);
|
|
|
|
percpu_ref_exit(&cgrp->bpf.refcnt);
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int update_effective_progs(struct cgroup *cgrp,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
int err;
|
|
|
|
/* allocate and recompute effective prog arrays */
|
|
css_for_each_descendant_pre(css, &cgrp->self) {
|
|
struct cgroup *desc = container_of(css, struct cgroup, self);
|
|
|
|
if (percpu_ref_is_zero(&desc->bpf.refcnt))
|
|
continue;
|
|
|
|
err = compute_effective_progs(desc, atype, &desc->bpf.inactive);
|
|
if (err)
|
|
goto cleanup;
|
|
}
|
|
|
|
/* all allocations were successful. Activate all prog arrays */
|
|
css_for_each_descendant_pre(css, &cgrp->self) {
|
|
struct cgroup *desc = container_of(css, struct cgroup, self);
|
|
|
|
if (percpu_ref_is_zero(&desc->bpf.refcnt)) {
|
|
if (unlikely(desc->bpf.inactive)) {
|
|
bpf_prog_array_free(desc->bpf.inactive);
|
|
desc->bpf.inactive = NULL;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
activate_effective_progs(desc, atype, desc->bpf.inactive);
|
|
desc->bpf.inactive = NULL;
|
|
}
|
|
|
|
return 0;
|
|
|
|
cleanup:
|
|
/* oom while computing effective. Free all computed effective arrays
|
|
* since they were not activated
|
|
*/
|
|
css_for_each_descendant_pre(css, &cgrp->self) {
|
|
struct cgroup *desc = container_of(css, struct cgroup, self);
|
|
|
|
bpf_prog_array_free(desc->bpf.inactive);
|
|
desc->bpf.inactive = NULL;
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
#define BPF_CGROUP_MAX_PROGS 64
|
|
|
|
static struct bpf_prog_list *find_attach_entry(struct hlist_head *progs,
|
|
struct bpf_prog *prog,
|
|
struct bpf_cgroup_link *link,
|
|
struct bpf_prog *replace_prog,
|
|
bool allow_multi)
|
|
{
|
|
struct bpf_prog_list *pl;
|
|
|
|
/* single-attach case */
|
|
if (!allow_multi) {
|
|
if (hlist_empty(progs))
|
|
return NULL;
|
|
return hlist_entry(progs->first, typeof(*pl), node);
|
|
}
|
|
|
|
hlist_for_each_entry(pl, progs, node) {
|
|
if (prog && pl->prog == prog && prog != replace_prog)
|
|
/* disallow attaching the same prog twice */
|
|
return ERR_PTR(-EINVAL);
|
|
if (link && pl->link == link)
|
|
/* disallow attaching the same link twice */
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
/* direct prog multi-attach w/ replacement case */
|
|
if (replace_prog) {
|
|
hlist_for_each_entry(pl, progs, node) {
|
|
if (pl->prog == replace_prog)
|
|
/* a match found */
|
|
return pl;
|
|
}
|
|
/* prog to replace not found for cgroup */
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* __cgroup_bpf_attach() - Attach the program or the link to a cgroup, and
|
|
* propagate the change to descendants
|
|
* @cgrp: The cgroup which descendants to traverse
|
|
* @prog: A program to attach
|
|
* @link: A link to attach
|
|
* @replace_prog: Previously attached program to replace if BPF_F_REPLACE is set
|
|
* @type: Type of attach operation
|
|
* @flags: Option flags
|
|
*
|
|
* Exactly one of @prog or @link can be non-null.
|
|
* Must be called with cgroup_mutex held.
|
|
*/
|
|
static int __cgroup_bpf_attach(struct cgroup *cgrp,
|
|
struct bpf_prog *prog, struct bpf_prog *replace_prog,
|
|
struct bpf_cgroup_link *link,
|
|
enum bpf_attach_type type, u32 flags)
|
|
{
|
|
u32 saved_flags = (flags & (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI));
|
|
struct bpf_prog *old_prog = NULL;
|
|
struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
|
|
struct bpf_cgroup_storage *new_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {};
|
|
struct bpf_prog *new_prog = prog ? : link->link.prog;
|
|
enum cgroup_bpf_attach_type atype;
|
|
struct bpf_prog_list *pl;
|
|
struct hlist_head *progs;
|
|
int err;
|
|
|
|
if (((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI)) ||
|
|
((flags & BPF_F_REPLACE) && !(flags & BPF_F_ALLOW_MULTI)))
|
|
/* invalid combination */
|
|
return -EINVAL;
|
|
if (link && (prog || replace_prog))
|
|
/* only either link or prog/replace_prog can be specified */
|
|
return -EINVAL;
|
|
if (!!replace_prog != !!(flags & BPF_F_REPLACE))
|
|
/* replace_prog implies BPF_F_REPLACE, and vice versa */
|
|
return -EINVAL;
|
|
|
|
atype = bpf_cgroup_atype_find(type, new_prog->aux->attach_btf_id);
|
|
if (atype < 0)
|
|
return -EINVAL;
|
|
|
|
progs = &cgrp->bpf.progs[atype];
|
|
|
|
if (!hierarchy_allows_attach(cgrp, atype))
|
|
return -EPERM;
|
|
|
|
if (!hlist_empty(progs) && cgrp->bpf.flags[atype] != saved_flags)
|
|
/* Disallow attaching non-overridable on top
|
|
* of existing overridable in this cgroup.
|
|
* Disallow attaching multi-prog if overridable or none
|
|
*/
|
|
return -EPERM;
|
|
|
|
if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS)
|
|
return -E2BIG;
|
|
|
|
pl = find_attach_entry(progs, prog, link, replace_prog,
|
|
flags & BPF_F_ALLOW_MULTI);
|
|
if (IS_ERR(pl))
|
|
return PTR_ERR(pl);
|
|
|
|
if (bpf_cgroup_storages_alloc(storage, new_storage, type,
|
|
prog ? : link->link.prog, cgrp))
|
|
return -ENOMEM;
|
|
|
|
if (pl) {
|
|
old_prog = pl->prog;
|
|
} else {
|
|
struct hlist_node *last = NULL;
|
|
|
|
pl = kmalloc(sizeof(*pl), GFP_KERNEL);
|
|
if (!pl) {
|
|
bpf_cgroup_storages_free(new_storage);
|
|
return -ENOMEM;
|
|
}
|
|
if (hlist_empty(progs))
|
|
hlist_add_head(&pl->node, progs);
|
|
else
|
|
hlist_for_each(last, progs) {
|
|
if (last->next)
|
|
continue;
|
|
hlist_add_behind(&pl->node, last);
|
|
break;
|
|
}
|
|
}
|
|
|
|
pl->prog = prog;
|
|
pl->link = link;
|
|
bpf_cgroup_storages_assign(pl->storage, storage);
|
|
cgrp->bpf.flags[atype] = saved_flags;
|
|
|
|
if (type == BPF_LSM_CGROUP) {
|
|
err = bpf_trampoline_link_cgroup_shim(new_prog, atype);
|
|
if (err)
|
|
goto cleanup;
|
|
}
|
|
|
|
err = update_effective_progs(cgrp, atype);
|
|
if (err)
|
|
goto cleanup_trampoline;
|
|
|
|
if (old_prog) {
|
|
if (type == BPF_LSM_CGROUP)
|
|
bpf_trampoline_unlink_cgroup_shim(old_prog);
|
|
bpf_prog_put(old_prog);
|
|
} else {
|
|
static_branch_inc(&cgroup_bpf_enabled_key[atype]);
|
|
}
|
|
bpf_cgroup_storages_link(new_storage, cgrp, type);
|
|
return 0;
|
|
|
|
cleanup_trampoline:
|
|
if (type == BPF_LSM_CGROUP)
|
|
bpf_trampoline_unlink_cgroup_shim(new_prog);
|
|
|
|
cleanup:
|
|
if (old_prog) {
|
|
pl->prog = old_prog;
|
|
pl->link = NULL;
|
|
}
|
|
bpf_cgroup_storages_free(new_storage);
|
|
if (!old_prog) {
|
|
hlist_del(&pl->node);
|
|
kfree(pl);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int cgroup_bpf_attach(struct cgroup *cgrp,
|
|
struct bpf_prog *prog, struct bpf_prog *replace_prog,
|
|
struct bpf_cgroup_link *link,
|
|
enum bpf_attach_type type,
|
|
u32 flags)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags);
|
|
mutex_unlock(&cgroup_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/* Swap updated BPF program for given link in effective program arrays across
|
|
* all descendant cgroups. This function is guaranteed to succeed.
|
|
*/
|
|
static void replace_effective_prog(struct cgroup *cgrp,
|
|
enum cgroup_bpf_attach_type atype,
|
|
struct bpf_cgroup_link *link)
|
|
{
|
|
struct bpf_prog_array_item *item;
|
|
struct cgroup_subsys_state *css;
|
|
struct bpf_prog_array *progs;
|
|
struct bpf_prog_list *pl;
|
|
struct hlist_head *head;
|
|
struct cgroup *cg;
|
|
int pos;
|
|
|
|
css_for_each_descendant_pre(css, &cgrp->self) {
|
|
struct cgroup *desc = container_of(css, struct cgroup, self);
|
|
|
|
if (percpu_ref_is_zero(&desc->bpf.refcnt))
|
|
continue;
|
|
|
|
/* find position of link in effective progs array */
|
|
for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
|
|
if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
|
|
continue;
|
|
|
|
head = &cg->bpf.progs[atype];
|
|
hlist_for_each_entry(pl, head, node) {
|
|
if (!prog_list_prog(pl))
|
|
continue;
|
|
if (pl->link == link)
|
|
goto found;
|
|
pos++;
|
|
}
|
|
}
|
|
found:
|
|
BUG_ON(!cg);
|
|
progs = rcu_dereference_protected(
|
|
desc->bpf.effective[atype],
|
|
lockdep_is_held(&cgroup_mutex));
|
|
item = &progs->items[pos];
|
|
WRITE_ONCE(item->prog, link->link.prog);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* __cgroup_bpf_replace() - Replace link's program and propagate the change
|
|
* to descendants
|
|
* @cgrp: The cgroup which descendants to traverse
|
|
* @link: A link for which to replace BPF program
|
|
* @type: Type of attach operation
|
|
*
|
|
* Must be called with cgroup_mutex held.
|
|
*/
|
|
static int __cgroup_bpf_replace(struct cgroup *cgrp,
|
|
struct bpf_cgroup_link *link,
|
|
struct bpf_prog *new_prog)
|
|
{
|
|
enum cgroup_bpf_attach_type atype;
|
|
struct bpf_prog *old_prog;
|
|
struct bpf_prog_list *pl;
|
|
struct hlist_head *progs;
|
|
bool found = false;
|
|
|
|
atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id);
|
|
if (atype < 0)
|
|
return -EINVAL;
|
|
|
|
progs = &cgrp->bpf.progs[atype];
|
|
|
|
if (link->link.prog->type != new_prog->type)
|
|
return -EINVAL;
|
|
|
|
hlist_for_each_entry(pl, progs, node) {
|
|
if (pl->link == link) {
|
|
found = true;
|
|
break;
|
|
}
|
|
}
|
|
if (!found)
|
|
return -ENOENT;
|
|
|
|
old_prog = xchg(&link->link.prog, new_prog);
|
|
replace_effective_prog(cgrp, atype, link);
|
|
bpf_prog_put(old_prog);
|
|
return 0;
|
|
}
|
|
|
|
static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
|
|
struct bpf_prog *old_prog)
|
|
{
|
|
struct bpf_cgroup_link *cg_link;
|
|
int ret;
|
|
|
|
cg_link = container_of(link, struct bpf_cgroup_link, link);
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
/* link might have been auto-released by dying cgroup, so fail */
|
|
if (!cg_link->cgroup) {
|
|
ret = -ENOLINK;
|
|
goto out_unlock;
|
|
}
|
|
if (old_prog && link->prog != old_prog) {
|
|
ret = -EPERM;
|
|
goto out_unlock;
|
|
}
|
|
ret = __cgroup_bpf_replace(cg_link->cgroup, cg_link, new_prog);
|
|
out_unlock:
|
|
mutex_unlock(&cgroup_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static struct bpf_prog_list *find_detach_entry(struct hlist_head *progs,
|
|
struct bpf_prog *prog,
|
|
struct bpf_cgroup_link *link,
|
|
bool allow_multi)
|
|
{
|
|
struct bpf_prog_list *pl;
|
|
|
|
if (!allow_multi) {
|
|
if (hlist_empty(progs))
|
|
/* report error when trying to detach and nothing is attached */
|
|
return ERR_PTR(-ENOENT);
|
|
|
|
/* to maintain backward compatibility NONE and OVERRIDE cgroups
|
|
* allow detaching with invalid FD (prog==NULL) in legacy mode
|
|
*/
|
|
return hlist_entry(progs->first, typeof(*pl), node);
|
|
}
|
|
|
|
if (!prog && !link)
|
|
/* to detach MULTI prog the user has to specify valid FD
|
|
* of the program or link to be detached
|
|
*/
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
/* find the prog or link and detach it */
|
|
hlist_for_each_entry(pl, progs, node) {
|
|
if (pl->prog == prog && pl->link == link)
|
|
return pl;
|
|
}
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
|
|
/**
|
|
* purge_effective_progs() - After compute_effective_progs fails to alloc new
|
|
* cgrp->bpf.inactive table we can recover by
|
|
* recomputing the array in place.
|
|
*
|
|
* @cgrp: The cgroup which descendants to travers
|
|
* @prog: A program to detach or NULL
|
|
* @link: A link to detach or NULL
|
|
* @atype: Type of detach operation
|
|
*/
|
|
static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
|
|
struct bpf_cgroup_link *link,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct cgroup_subsys_state *css;
|
|
struct bpf_prog_array *progs;
|
|
struct bpf_prog_list *pl;
|
|
struct hlist_head *head;
|
|
struct cgroup *cg;
|
|
int pos;
|
|
|
|
/* recompute effective prog array in place */
|
|
css_for_each_descendant_pre(css, &cgrp->self) {
|
|
struct cgroup *desc = container_of(css, struct cgroup, self);
|
|
|
|
if (percpu_ref_is_zero(&desc->bpf.refcnt))
|
|
continue;
|
|
|
|
/* find position of link or prog in effective progs array */
|
|
for (pos = 0, cg = desc; cg; cg = cgroup_parent(cg)) {
|
|
if (pos && !(cg->bpf.flags[atype] & BPF_F_ALLOW_MULTI))
|
|
continue;
|
|
|
|
head = &cg->bpf.progs[atype];
|
|
hlist_for_each_entry(pl, head, node) {
|
|
if (!prog_list_prog(pl))
|
|
continue;
|
|
if (pl->prog == prog && pl->link == link)
|
|
goto found;
|
|
pos++;
|
|
}
|
|
}
|
|
|
|
/* no link or prog match, skip the cgroup of this layer */
|
|
continue;
|
|
found:
|
|
progs = rcu_dereference_protected(
|
|
desc->bpf.effective[atype],
|
|
lockdep_is_held(&cgroup_mutex));
|
|
|
|
/* Remove the program from the array */
|
|
WARN_ONCE(bpf_prog_array_delete_safe_at(progs, pos),
|
|
"Failed to purge a prog from array at index %d", pos);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* __cgroup_bpf_detach() - Detach the program or link from a cgroup, and
|
|
* propagate the change to descendants
|
|
* @cgrp: The cgroup which descendants to traverse
|
|
* @prog: A program to detach or NULL
|
|
* @link: A link to detach or NULL
|
|
* @type: Type of detach operation
|
|
*
|
|
* At most one of @prog or @link can be non-NULL.
|
|
* Must be called with cgroup_mutex held.
|
|
*/
|
|
static int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
|
|
struct bpf_cgroup_link *link, enum bpf_attach_type type)
|
|
{
|
|
enum cgroup_bpf_attach_type atype;
|
|
struct bpf_prog *old_prog;
|
|
struct bpf_prog_list *pl;
|
|
struct hlist_head *progs;
|
|
u32 attach_btf_id = 0;
|
|
u32 flags;
|
|
|
|
if (prog)
|
|
attach_btf_id = prog->aux->attach_btf_id;
|
|
if (link)
|
|
attach_btf_id = link->link.prog->aux->attach_btf_id;
|
|
|
|
atype = bpf_cgroup_atype_find(type, attach_btf_id);
|
|
if (atype < 0)
|
|
return -EINVAL;
|
|
|
|
progs = &cgrp->bpf.progs[atype];
|
|
flags = cgrp->bpf.flags[atype];
|
|
|
|
if (prog && link)
|
|
/* only one of prog or link can be specified */
|
|
return -EINVAL;
|
|
|
|
pl = find_detach_entry(progs, prog, link, flags & BPF_F_ALLOW_MULTI);
|
|
if (IS_ERR(pl))
|
|
return PTR_ERR(pl);
|
|
|
|
/* mark it deleted, so it's ignored while recomputing effective */
|
|
old_prog = pl->prog;
|
|
pl->prog = NULL;
|
|
pl->link = NULL;
|
|
|
|
if (update_effective_progs(cgrp, atype)) {
|
|
/* if update effective array failed replace the prog with a dummy prog*/
|
|
pl->prog = old_prog;
|
|
pl->link = link;
|
|
purge_effective_progs(cgrp, old_prog, link, atype);
|
|
}
|
|
|
|
/* now can actually delete it from this cgroup list */
|
|
hlist_del(&pl->node);
|
|
|
|
kfree(pl);
|
|
if (hlist_empty(progs))
|
|
/* last program was detached, reset flags to zero */
|
|
cgrp->bpf.flags[atype] = 0;
|
|
if (old_prog) {
|
|
if (type == BPF_LSM_CGROUP)
|
|
bpf_trampoline_unlink_cgroup_shim(old_prog);
|
|
bpf_prog_put(old_prog);
|
|
}
|
|
static_branch_dec(&cgroup_bpf_enabled_key[atype]);
|
|
return 0;
|
|
}
|
|
|
|
static int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
|
|
enum bpf_attach_type type)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
ret = __cgroup_bpf_detach(cgrp, prog, NULL, type);
|
|
mutex_unlock(&cgroup_mutex);
|
|
return ret;
|
|
}
|
|
|
|
/* Must be called with cgroup_mutex held to avoid races. */
|
|
static int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
__u32 __user *prog_attach_flags = u64_to_user_ptr(attr->query.prog_attach_flags);
|
|
bool effective_query = attr->query.query_flags & BPF_F_QUERY_EFFECTIVE;
|
|
__u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
|
|
enum bpf_attach_type type = attr->query.attach_type;
|
|
enum cgroup_bpf_attach_type from_atype, to_atype;
|
|
enum cgroup_bpf_attach_type atype;
|
|
struct bpf_prog_array *effective;
|
|
int cnt, ret = 0, i;
|
|
int total_cnt = 0;
|
|
u32 flags;
|
|
|
|
if (effective_query && prog_attach_flags)
|
|
return -EINVAL;
|
|
|
|
if (type == BPF_LSM_CGROUP) {
|
|
if (!effective_query && attr->query.prog_cnt &&
|
|
prog_ids && !prog_attach_flags)
|
|
return -EINVAL;
|
|
|
|
from_atype = CGROUP_LSM_START;
|
|
to_atype = CGROUP_LSM_END;
|
|
flags = 0;
|
|
} else {
|
|
from_atype = to_cgroup_bpf_attach_type(type);
|
|
if (from_atype < 0)
|
|
return -EINVAL;
|
|
to_atype = from_atype;
|
|
flags = cgrp->bpf.flags[from_atype];
|
|
}
|
|
|
|
for (atype = from_atype; atype <= to_atype; atype++) {
|
|
if (effective_query) {
|
|
effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
|
|
lockdep_is_held(&cgroup_mutex));
|
|
total_cnt += bpf_prog_array_length(effective);
|
|
} else {
|
|
total_cnt += prog_list_length(&cgrp->bpf.progs[atype]);
|
|
}
|
|
}
|
|
|
|
/* always output uattr->query.attach_flags as 0 during effective query */
|
|
flags = effective_query ? 0 : flags;
|
|
if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
|
|
return -EFAULT;
|
|
if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt)))
|
|
return -EFAULT;
|
|
if (attr->query.prog_cnt == 0 || !prog_ids || !total_cnt)
|
|
/* return early if user requested only program count + flags */
|
|
return 0;
|
|
|
|
if (attr->query.prog_cnt < total_cnt) {
|
|
total_cnt = attr->query.prog_cnt;
|
|
ret = -ENOSPC;
|
|
}
|
|
|
|
for (atype = from_atype; atype <= to_atype && total_cnt; atype++) {
|
|
if (effective_query) {
|
|
effective = rcu_dereference_protected(cgrp->bpf.effective[atype],
|
|
lockdep_is_held(&cgroup_mutex));
|
|
cnt = min_t(int, bpf_prog_array_length(effective), total_cnt);
|
|
ret = bpf_prog_array_copy_to_user(effective, prog_ids, cnt);
|
|
} else {
|
|
struct hlist_head *progs;
|
|
struct bpf_prog_list *pl;
|
|
struct bpf_prog *prog;
|
|
u32 id;
|
|
|
|
progs = &cgrp->bpf.progs[atype];
|
|
cnt = min_t(int, prog_list_length(progs), total_cnt);
|
|
i = 0;
|
|
hlist_for_each_entry(pl, progs, node) {
|
|
prog = prog_list_prog(pl);
|
|
id = prog->aux->id;
|
|
if (copy_to_user(prog_ids + i, &id, sizeof(id)))
|
|
return -EFAULT;
|
|
if (++i == cnt)
|
|
break;
|
|
}
|
|
|
|
if (prog_attach_flags) {
|
|
flags = cgrp->bpf.flags[atype];
|
|
|
|
for (i = 0; i < cnt; i++)
|
|
if (copy_to_user(prog_attach_flags + i,
|
|
&flags, sizeof(flags)))
|
|
return -EFAULT;
|
|
prog_attach_flags += cnt;
|
|
}
|
|
}
|
|
|
|
prog_ids += cnt;
|
|
total_cnt -= cnt;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
ret = __cgroup_bpf_query(cgrp, attr, uattr);
|
|
mutex_unlock(&cgroup_mutex);
|
|
return ret;
|
|
}
|
|
|
|
int cgroup_bpf_prog_attach(const union bpf_attr *attr,
|
|
enum bpf_prog_type ptype, struct bpf_prog *prog)
|
|
{
|
|
struct bpf_prog *replace_prog = NULL;
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
cgrp = cgroup_get_from_fd(attr->target_fd);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
|
|
if ((attr->attach_flags & BPF_F_ALLOW_MULTI) &&
|
|
(attr->attach_flags & BPF_F_REPLACE)) {
|
|
replace_prog = bpf_prog_get_type(attr->replace_bpf_fd, ptype);
|
|
if (IS_ERR(replace_prog)) {
|
|
cgroup_put(cgrp);
|
|
return PTR_ERR(replace_prog);
|
|
}
|
|
}
|
|
|
|
ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL,
|
|
attr->attach_type, attr->attach_flags);
|
|
|
|
if (replace_prog)
|
|
bpf_prog_put(replace_prog);
|
|
cgroup_put(cgrp);
|
|
return ret;
|
|
}
|
|
|
|
int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype)
|
|
{
|
|
struct bpf_prog *prog;
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
cgrp = cgroup_get_from_fd(attr->target_fd);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
|
|
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
|
|
if (IS_ERR(prog))
|
|
prog = NULL;
|
|
|
|
ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type);
|
|
if (prog)
|
|
bpf_prog_put(prog);
|
|
|
|
cgroup_put(cgrp);
|
|
return ret;
|
|
}
|
|
|
|
static void bpf_cgroup_link_release(struct bpf_link *link)
|
|
{
|
|
struct bpf_cgroup_link *cg_link =
|
|
container_of(link, struct bpf_cgroup_link, link);
|
|
struct cgroup *cg;
|
|
|
|
/* link might have been auto-detached by dying cgroup already,
|
|
* in that case our work is done here
|
|
*/
|
|
if (!cg_link->cgroup)
|
|
return;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
|
|
/* re-check cgroup under lock again */
|
|
if (!cg_link->cgroup) {
|
|
mutex_unlock(&cgroup_mutex);
|
|
return;
|
|
}
|
|
|
|
WARN_ON(__cgroup_bpf_detach(cg_link->cgroup, NULL, cg_link,
|
|
cg_link->type));
|
|
if (cg_link->type == BPF_LSM_CGROUP)
|
|
bpf_trampoline_unlink_cgroup_shim(cg_link->link.prog);
|
|
|
|
cg = cg_link->cgroup;
|
|
cg_link->cgroup = NULL;
|
|
|
|
mutex_unlock(&cgroup_mutex);
|
|
|
|
cgroup_put(cg);
|
|
}
|
|
|
|
static void bpf_cgroup_link_dealloc(struct bpf_link *link)
|
|
{
|
|
struct bpf_cgroup_link *cg_link =
|
|
container_of(link, struct bpf_cgroup_link, link);
|
|
|
|
kfree(cg_link);
|
|
}
|
|
|
|
static int bpf_cgroup_link_detach(struct bpf_link *link)
|
|
{
|
|
bpf_cgroup_link_release(link);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void bpf_cgroup_link_show_fdinfo(const struct bpf_link *link,
|
|
struct seq_file *seq)
|
|
{
|
|
struct bpf_cgroup_link *cg_link =
|
|
container_of(link, struct bpf_cgroup_link, link);
|
|
u64 cg_id = 0;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
if (cg_link->cgroup)
|
|
cg_id = cgroup_id(cg_link->cgroup);
|
|
mutex_unlock(&cgroup_mutex);
|
|
|
|
seq_printf(seq,
|
|
"cgroup_id:\t%llu\n"
|
|
"attach_type:\t%d\n",
|
|
cg_id,
|
|
cg_link->type);
|
|
}
|
|
|
|
static int bpf_cgroup_link_fill_link_info(const struct bpf_link *link,
|
|
struct bpf_link_info *info)
|
|
{
|
|
struct bpf_cgroup_link *cg_link =
|
|
container_of(link, struct bpf_cgroup_link, link);
|
|
u64 cg_id = 0;
|
|
|
|
mutex_lock(&cgroup_mutex);
|
|
if (cg_link->cgroup)
|
|
cg_id = cgroup_id(cg_link->cgroup);
|
|
mutex_unlock(&cgroup_mutex);
|
|
|
|
info->cgroup.cgroup_id = cg_id;
|
|
info->cgroup.attach_type = cg_link->type;
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_link_ops bpf_cgroup_link_lops = {
|
|
.release = bpf_cgroup_link_release,
|
|
.dealloc = bpf_cgroup_link_dealloc,
|
|
.detach = bpf_cgroup_link_detach,
|
|
.update_prog = cgroup_bpf_replace,
|
|
.show_fdinfo = bpf_cgroup_link_show_fdinfo,
|
|
.fill_link_info = bpf_cgroup_link_fill_link_info,
|
|
};
|
|
|
|
int cgroup_bpf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
|
|
{
|
|
struct bpf_link_primer link_primer;
|
|
struct bpf_cgroup_link *link;
|
|
struct cgroup *cgrp;
|
|
int err;
|
|
|
|
if (attr->link_create.flags)
|
|
return -EINVAL;
|
|
|
|
cgrp = cgroup_get_from_fd(attr->link_create.target_fd);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
|
|
link = kzalloc(sizeof(*link), GFP_USER);
|
|
if (!link) {
|
|
err = -ENOMEM;
|
|
goto out_put_cgroup;
|
|
}
|
|
bpf_link_init(&link->link, BPF_LINK_TYPE_CGROUP, &bpf_cgroup_link_lops,
|
|
prog);
|
|
link->cgroup = cgrp;
|
|
link->type = attr->link_create.attach_type;
|
|
|
|
err = bpf_link_prime(&link->link, &link_primer);
|
|
if (err) {
|
|
kfree(link);
|
|
goto out_put_cgroup;
|
|
}
|
|
|
|
err = cgroup_bpf_attach(cgrp, NULL, NULL, link,
|
|
link->type, BPF_F_ALLOW_MULTI);
|
|
if (err) {
|
|
bpf_link_cleanup(&link_primer);
|
|
goto out_put_cgroup;
|
|
}
|
|
|
|
return bpf_link_settle(&link_primer);
|
|
|
|
out_put_cgroup:
|
|
cgroup_put(cgrp);
|
|
return err;
|
|
}
|
|
|
|
int cgroup_bpf_prog_query(const union bpf_attr *attr,
|
|
union bpf_attr __user *uattr)
|
|
{
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
cgrp = cgroup_get_from_fd(attr->query.target_fd);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
|
|
ret = cgroup_bpf_query(cgrp, attr, uattr);
|
|
|
|
cgroup_put(cgrp);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* __cgroup_bpf_run_filter_skb() - Run a program for packet filtering
|
|
* @sk: The socket sending or receiving traffic
|
|
* @skb: The skb that is being sent or received
|
|
* @type: The type of program to be executed
|
|
*
|
|
* If no socket is passed, or the socket is not of type INET or INET6,
|
|
* this function does nothing and returns 0.
|
|
*
|
|
* The program type passed in via @type must be suitable for network
|
|
* filtering. No further check is performed to assert that.
|
|
*
|
|
* For egress packets, this function can return:
|
|
* NET_XMIT_SUCCESS (0) - continue with packet output
|
|
* NET_XMIT_DROP (1) - drop packet and notify TCP to call cwr
|
|
* NET_XMIT_CN (2) - continue with packet output and notify TCP
|
|
* to call cwr
|
|
* -err - drop packet
|
|
*
|
|
* For ingress packets, this function will return -EPERM if any
|
|
* attached program was found and if it returned != 1 during execution.
|
|
* Otherwise 0 is returned.
|
|
*/
|
|
int __cgroup_bpf_run_filter_skb(struct sock *sk,
|
|
struct sk_buff *skb,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
unsigned int offset = skb->data - skb_network_header(skb);
|
|
struct sock *save_sk;
|
|
void *saved_data_end;
|
|
struct cgroup *cgrp;
|
|
int ret;
|
|
|
|
if (!sk || !sk_fullsock(sk))
|
|
return 0;
|
|
|
|
if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
|
|
return 0;
|
|
|
|
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
save_sk = skb->sk;
|
|
skb->sk = sk;
|
|
__skb_push(skb, offset);
|
|
|
|
/* compute pointers for the bpf prog */
|
|
bpf_compute_and_save_data_end(skb, &saved_data_end);
|
|
|
|
if (atype == CGROUP_INET_EGRESS) {
|
|
u32 flags = 0;
|
|
bool cn;
|
|
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, skb,
|
|
__bpf_prog_run_save_cb, 0, &flags);
|
|
|
|
/* Return values of CGROUP EGRESS BPF programs are:
|
|
* 0: drop packet
|
|
* 1: keep packet
|
|
* 2: drop packet and cn
|
|
* 3: keep packet and cn
|
|
*
|
|
* The returned value is then converted to one of the NET_XMIT
|
|
* or an error code that is then interpreted as drop packet
|
|
* (and no cn):
|
|
* 0: NET_XMIT_SUCCESS skb should be transmitted
|
|
* 1: NET_XMIT_DROP skb should be dropped and cn
|
|
* 2: NET_XMIT_CN skb should be transmitted and cn
|
|
* 3: -err skb should be dropped
|
|
*/
|
|
|
|
cn = flags & BPF_RET_SET_CN;
|
|
if (ret && !IS_ERR_VALUE((long)ret))
|
|
ret = -EFAULT;
|
|
if (!ret)
|
|
ret = (cn ? NET_XMIT_CN : NET_XMIT_SUCCESS);
|
|
else
|
|
ret = (cn ? NET_XMIT_DROP : ret);
|
|
} else {
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, atype,
|
|
skb, __bpf_prog_run_save_cb, 0,
|
|
NULL);
|
|
if (ret && !IS_ERR_VALUE((long)ret))
|
|
ret = -EFAULT;
|
|
}
|
|
bpf_restore_data_end(skb, saved_data_end);
|
|
__skb_pull(skb, offset);
|
|
skb->sk = save_sk;
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
|
|
|
|
/**
|
|
* __cgroup_bpf_run_filter_sk() - Run a program on a sock
|
|
* @sk: sock structure to manipulate
|
|
* @type: The type of program to be executed
|
|
*
|
|
* socket is passed is expected to be of type INET or INET6.
|
|
*
|
|
* The program type passed in via @type must be suitable for sock
|
|
* filtering. No further check is performed to assert that.
|
|
*
|
|
* This function will return %-EPERM if any if an attached program was found
|
|
* and if it returned != 1 during execution. In all other cases, 0 is returned.
|
|
*/
|
|
int __cgroup_bpf_run_filter_sk(struct sock *sk,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
|
|
return bpf_prog_run_array_cg(&cgrp->bpf, atype, sk, bpf_prog_run, 0,
|
|
NULL);
|
|
}
|
|
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
|
|
|
|
/**
|
|
* __cgroup_bpf_run_filter_sock_addr() - Run a program on a sock and
|
|
* provided by user sockaddr
|
|
* @sk: sock struct that will use sockaddr
|
|
* @uaddr: sockaddr struct provided by user
|
|
* @type: The type of program to be executed
|
|
* @t_ctx: Pointer to attach type specific context
|
|
* @flags: Pointer to u32 which contains higher bits of BPF program
|
|
* return value (OR'ed together).
|
|
*
|
|
* socket is expected to be of type INET or INET6.
|
|
*
|
|
* This function will return %-EPERM if an attached program is found and
|
|
* returned value != 1 during execution. In all other cases, 0 is returned.
|
|
*/
|
|
int __cgroup_bpf_run_filter_sock_addr(struct sock *sk,
|
|
struct sockaddr *uaddr,
|
|
enum cgroup_bpf_attach_type atype,
|
|
void *t_ctx,
|
|
u32 *flags)
|
|
{
|
|
struct bpf_sock_addr_kern ctx = {
|
|
.sk = sk,
|
|
.uaddr = uaddr,
|
|
.t_ctx = t_ctx,
|
|
};
|
|
struct sockaddr_storage unspec;
|
|
struct cgroup *cgrp;
|
|
|
|
/* Check socket family since not all sockets represent network
|
|
* endpoint (e.g. AF_UNIX).
|
|
*/
|
|
if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
|
|
return 0;
|
|
|
|
if (!ctx.uaddr) {
|
|
memset(&unspec, 0, sizeof(unspec));
|
|
ctx.uaddr = (struct sockaddr *)&unspec;
|
|
}
|
|
|
|
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
return bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run,
|
|
0, flags);
|
|
}
|
|
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr);
|
|
|
|
/**
|
|
* __cgroup_bpf_run_filter_sock_ops() - Run a program on a sock
|
|
* @sk: socket to get cgroup from
|
|
* @sock_ops: bpf_sock_ops_kern struct to pass to program. Contains
|
|
* sk with connection information (IP addresses, etc.) May not contain
|
|
* cgroup info if it is a req sock.
|
|
* @type: The type of program to be executed
|
|
*
|
|
* socket passed is expected to be of type INET or INET6.
|
|
*
|
|
* The program type passed in via @type must be suitable for sock_ops
|
|
* filtering. No further check is performed to assert that.
|
|
*
|
|
* This function will return %-EPERM if any if an attached program was found
|
|
* and if it returned != 1 during execution. In all other cases, 0 is returned.
|
|
*/
|
|
int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
|
|
struct bpf_sock_ops_kern *sock_ops,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
|
|
return bpf_prog_run_array_cg(&cgrp->bpf, atype, sock_ops, bpf_prog_run,
|
|
0, NULL);
|
|
}
|
|
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
|
|
|
|
int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
|
|
short access, enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct cgroup *cgrp;
|
|
struct bpf_cgroup_dev_ctx ctx = {
|
|
.access_type = (access << 16) | dev_type,
|
|
.major = major,
|
|
.minor = minor,
|
|
};
|
|
int ret;
|
|
|
|
rcu_read_lock();
|
|
cgrp = task_dfl_cgroup(current);
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
|
|
NULL);
|
|
rcu_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
|
|
{
|
|
/* flags argument is not used now,
|
|
* but provides an ability to extend the API.
|
|
* verifier checks that its value is correct.
|
|
*/
|
|
enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
|
|
struct bpf_cgroup_storage *storage;
|
|
struct bpf_cg_run_ctx *ctx;
|
|
void *ptr;
|
|
|
|
/* get current cgroup storage from BPF run context */
|
|
ctx = container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
|
|
storage = ctx->prog_item->cgroup_storage[stype];
|
|
|
|
if (stype == BPF_CGROUP_STORAGE_SHARED)
|
|
ptr = &READ_ONCE(storage->buf)->data[0];
|
|
else
|
|
ptr = this_cpu_ptr(storage->percpu_buf);
|
|
|
|
return (unsigned long)ptr;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_local_storage_proto = {
|
|
.func = bpf_get_local_storage,
|
|
.gpl_only = false,
|
|
.ret_type = RET_PTR_TO_MAP_VALUE,
|
|
.arg1_type = ARG_CONST_MAP_PTR,
|
|
.arg2_type = ARG_ANYTHING,
|
|
};
|
|
|
|
BPF_CALL_0(bpf_get_retval)
|
|
{
|
|
struct bpf_cg_run_ctx *ctx =
|
|
container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
|
|
|
|
return ctx->retval;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_retval_proto = {
|
|
.func = bpf_get_retval,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
BPF_CALL_1(bpf_set_retval, int, retval)
|
|
{
|
|
struct bpf_cg_run_ctx *ctx =
|
|
container_of(current->bpf_ctx, struct bpf_cg_run_ctx, run_ctx);
|
|
|
|
ctx->retval = retval;
|
|
return 0;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_set_retval_proto = {
|
|
.func = bpf_set_retval,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *func_proto;
|
|
|
|
func_proto = cgroup_common_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
func_proto = cgroup_current_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
switch (func_id) {
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_event_output_data_proto;
|
|
default:
|
|
return bpf_base_func_proto(func_id);
|
|
}
|
|
}
|
|
|
|
static bool cgroup_dev_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
const int size_default = sizeof(__u32);
|
|
|
|
if (type == BPF_WRITE)
|
|
return false;
|
|
|
|
if (off < 0 || off + size > sizeof(struct bpf_cgroup_dev_ctx))
|
|
return false;
|
|
/* The verifier guarantees that size > 0. */
|
|
if (off % size != 0)
|
|
return false;
|
|
|
|
switch (off) {
|
|
case bpf_ctx_range(struct bpf_cgroup_dev_ctx, access_type):
|
|
bpf_ctx_record_field_size(info, size_default);
|
|
if (!bpf_ctx_narrow_access_ok(off, size, size_default))
|
|
return false;
|
|
break;
|
|
default:
|
|
if (size != size_default)
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
const struct bpf_prog_ops cg_dev_prog_ops = {
|
|
};
|
|
|
|
const struct bpf_verifier_ops cg_dev_verifier_ops = {
|
|
.get_func_proto = cgroup_dev_func_proto,
|
|
.is_valid_access = cgroup_dev_is_valid_access,
|
|
};
|
|
|
|
/**
|
|
* __cgroup_bpf_run_filter_sysctl - Run a program on sysctl
|
|
*
|
|
* @head: sysctl table header
|
|
* @table: sysctl table
|
|
* @write: sysctl is being read (= 0) or written (= 1)
|
|
* @buf: pointer to buffer (in and out)
|
|
* @pcount: value-result argument: value is size of buffer pointed to by @buf,
|
|
* result is size of @new_buf if program set new value, initial value
|
|
* otherwise
|
|
* @ppos: value-result argument: value is position at which read from or write
|
|
* to sysctl is happening, result is new position if program overrode it,
|
|
* initial value otherwise
|
|
* @type: type of program to be executed
|
|
*
|
|
* Program is run when sysctl is being accessed, either read or written, and
|
|
* can allow or deny such access.
|
|
*
|
|
* This function will return %-EPERM if an attached program is found and
|
|
* returned value != 1 during execution. In all other cases 0 is returned.
|
|
*/
|
|
int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
|
|
struct ctl_table *table, int write,
|
|
char **buf, size_t *pcount, loff_t *ppos,
|
|
enum cgroup_bpf_attach_type atype)
|
|
{
|
|
struct bpf_sysctl_kern ctx = {
|
|
.head = head,
|
|
.table = table,
|
|
.write = write,
|
|
.ppos = ppos,
|
|
.cur_val = NULL,
|
|
.cur_len = PAGE_SIZE,
|
|
.new_val = NULL,
|
|
.new_len = 0,
|
|
.new_updated = 0,
|
|
};
|
|
struct cgroup *cgrp;
|
|
loff_t pos = 0;
|
|
int ret;
|
|
|
|
ctx.cur_val = kmalloc_track_caller(ctx.cur_len, GFP_KERNEL);
|
|
if (!ctx.cur_val ||
|
|
table->proc_handler(table, 0, ctx.cur_val, &ctx.cur_len, &pos)) {
|
|
/* Let BPF program decide how to proceed. */
|
|
ctx.cur_len = 0;
|
|
}
|
|
|
|
if (write && *buf && *pcount) {
|
|
/* BPF program should be able to override new value with a
|
|
* buffer bigger than provided by user.
|
|
*/
|
|
ctx.new_val = kmalloc_track_caller(PAGE_SIZE, GFP_KERNEL);
|
|
ctx.new_len = min_t(size_t, PAGE_SIZE, *pcount);
|
|
if (ctx.new_val) {
|
|
memcpy(ctx.new_val, *buf, ctx.new_len);
|
|
} else {
|
|
/* Let BPF program decide how to proceed. */
|
|
ctx.new_len = 0;
|
|
}
|
|
}
|
|
|
|
rcu_read_lock();
|
|
cgrp = task_dfl_cgroup(current);
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0,
|
|
NULL);
|
|
rcu_read_unlock();
|
|
|
|
kfree(ctx.cur_val);
|
|
|
|
if (ret == 1 && ctx.new_updated) {
|
|
kfree(*buf);
|
|
*buf = ctx.new_val;
|
|
*pcount = ctx.new_len;
|
|
} else {
|
|
kfree(ctx.new_val);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_NET
|
|
static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen,
|
|
struct bpf_sockopt_buf *buf)
|
|
{
|
|
if (unlikely(max_optlen < 0))
|
|
return -EINVAL;
|
|
|
|
if (unlikely(max_optlen > PAGE_SIZE)) {
|
|
/* We don't expose optvals that are greater than PAGE_SIZE
|
|
* to the BPF program.
|
|
*/
|
|
max_optlen = PAGE_SIZE;
|
|
}
|
|
|
|
if (max_optlen <= sizeof(buf->data)) {
|
|
/* When the optval fits into BPF_SOCKOPT_KERN_BUF_SIZE
|
|
* bytes avoid the cost of kzalloc.
|
|
*/
|
|
ctx->optval = buf->data;
|
|
ctx->optval_end = ctx->optval + max_optlen;
|
|
return max_optlen;
|
|
}
|
|
|
|
ctx->optval = kzalloc(max_optlen, GFP_USER);
|
|
if (!ctx->optval)
|
|
return -ENOMEM;
|
|
|
|
ctx->optval_end = ctx->optval + max_optlen;
|
|
|
|
return max_optlen;
|
|
}
|
|
|
|
static void sockopt_free_buf(struct bpf_sockopt_kern *ctx,
|
|
struct bpf_sockopt_buf *buf)
|
|
{
|
|
if (ctx->optval == buf->data)
|
|
return;
|
|
kfree(ctx->optval);
|
|
}
|
|
|
|
static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
|
|
struct bpf_sockopt_buf *buf)
|
|
{
|
|
return ctx->optval != buf->data;
|
|
}
|
|
|
|
int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
|
|
int *optname, char __user *optval,
|
|
int *optlen, char **kernel_optval)
|
|
{
|
|
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
struct bpf_sockopt_buf buf = {};
|
|
struct bpf_sockopt_kern ctx = {
|
|
.sk = sk,
|
|
.level = *level,
|
|
.optname = *optname,
|
|
};
|
|
int ret, max_optlen;
|
|
|
|
/* Allocate a bit more than the initial user buffer for
|
|
* BPF program. The canonical use case is overriding
|
|
* TCP_CONGESTION(nv) to TCP_CONGESTION(cubic).
|
|
*/
|
|
max_optlen = max_t(int, 16, *optlen);
|
|
max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
|
|
if (max_optlen < 0)
|
|
return max_optlen;
|
|
|
|
ctx.optlen = *optlen;
|
|
|
|
if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
lock_sock(sk);
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_SETSOCKOPT,
|
|
&ctx, bpf_prog_run, 0, NULL);
|
|
release_sock(sk);
|
|
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (ctx.optlen == -1) {
|
|
/* optlen set to -1, bypass kernel */
|
|
ret = 1;
|
|
} else if (ctx.optlen > max_optlen || ctx.optlen < -1) {
|
|
/* optlen is out of bounds */
|
|
ret = -EFAULT;
|
|
} else {
|
|
/* optlen within bounds, run kernel handler */
|
|
ret = 0;
|
|
|
|
/* export any potential modifications */
|
|
*level = ctx.level;
|
|
*optname = ctx.optname;
|
|
|
|
/* optlen == 0 from BPF indicates that we should
|
|
* use original userspace data.
|
|
*/
|
|
if (ctx.optlen != 0) {
|
|
*optlen = ctx.optlen;
|
|
/* We've used bpf_sockopt_kern->buf as an intermediary
|
|
* storage, but the BPF program indicates that we need
|
|
* to pass this data to the kernel setsockopt handler.
|
|
* No way to export on-stack buf, have to allocate a
|
|
* new buffer.
|
|
*/
|
|
if (!sockopt_buf_allocated(&ctx, &buf)) {
|
|
void *p = kmalloc(ctx.optlen, GFP_USER);
|
|
|
|
if (!p) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
memcpy(p, ctx.optval, ctx.optlen);
|
|
*kernel_optval = p;
|
|
} else {
|
|
*kernel_optval = ctx.optval;
|
|
}
|
|
/* export and don't free sockopt buf */
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
out:
|
|
sockopt_free_buf(&ctx, &buf);
|
|
return ret;
|
|
}
|
|
|
|
int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
|
|
int optname, char __user *optval,
|
|
int __user *optlen, int max_optlen,
|
|
int retval)
|
|
{
|
|
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
struct bpf_sockopt_buf buf = {};
|
|
struct bpf_sockopt_kern ctx = {
|
|
.sk = sk,
|
|
.level = level,
|
|
.optname = optname,
|
|
.current_task = current,
|
|
};
|
|
int ret;
|
|
|
|
ctx.optlen = max_optlen;
|
|
max_optlen = sockopt_alloc_buf(&ctx, max_optlen, &buf);
|
|
if (max_optlen < 0)
|
|
return max_optlen;
|
|
|
|
if (!retval) {
|
|
/* If kernel getsockopt finished successfully,
|
|
* copy whatever was returned to the user back
|
|
* into our temporary buffer. Set optlen to the
|
|
* one that kernel returned as well to let
|
|
* BPF programs inspect the value.
|
|
*/
|
|
|
|
if (get_user(ctx.optlen, optlen)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
if (ctx.optlen < 0) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
if (copy_from_user(ctx.optval, optval,
|
|
min(ctx.optlen, max_optlen)) != 0) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
lock_sock(sk);
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
|
|
&ctx, bpf_prog_run, retval, NULL);
|
|
release_sock(sk);
|
|
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
if (ctx.optlen > max_optlen || ctx.optlen < 0) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
|
|
if (ctx.optlen != 0) {
|
|
if (copy_to_user(optval, ctx.optval, ctx.optlen) ||
|
|
put_user(ctx.optlen, optlen)) {
|
|
ret = -EFAULT;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
out:
|
|
sockopt_free_buf(&ctx, &buf);
|
|
return ret;
|
|
}
|
|
|
|
int __cgroup_bpf_run_filter_getsockopt_kern(struct sock *sk, int level,
|
|
int optname, void *optval,
|
|
int *optlen, int retval)
|
|
{
|
|
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
|
|
struct bpf_sockopt_kern ctx = {
|
|
.sk = sk,
|
|
.level = level,
|
|
.optname = optname,
|
|
.optlen = *optlen,
|
|
.optval = optval,
|
|
.optval_end = optval + *optlen,
|
|
.current_task = current,
|
|
};
|
|
int ret;
|
|
|
|
/* Note that __cgroup_bpf_run_filter_getsockopt doesn't copy
|
|
* user data back into BPF buffer when reval != 0. This is
|
|
* done as an optimization to avoid extra copy, assuming
|
|
* kernel won't populate the data in case of an error.
|
|
* Here we always pass the data and memset() should
|
|
* be called if that data shouldn't be "exported".
|
|
*/
|
|
|
|
ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT,
|
|
&ctx, bpf_prog_run, retval, NULL);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (ctx.optlen > *optlen)
|
|
return -EFAULT;
|
|
|
|
/* BPF programs can shrink the buffer, export the modifications.
|
|
*/
|
|
if (ctx.optlen != 0)
|
|
*optlen = ctx.optlen;
|
|
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
|
|
size_t *lenp)
|
|
{
|
|
ssize_t tmp_ret = 0, ret;
|
|
|
|
if (dir->header.parent) {
|
|
tmp_ret = sysctl_cpy_dir(dir->header.parent, bufp, lenp);
|
|
if (tmp_ret < 0)
|
|
return tmp_ret;
|
|
}
|
|
|
|
ret = strscpy(*bufp, dir->header.ctl_table[0].procname, *lenp);
|
|
if (ret < 0)
|
|
return ret;
|
|
*bufp += ret;
|
|
*lenp -= ret;
|
|
ret += tmp_ret;
|
|
|
|
/* Avoid leading slash. */
|
|
if (!ret)
|
|
return ret;
|
|
|
|
tmp_ret = strscpy(*bufp, "/", *lenp);
|
|
if (tmp_ret < 0)
|
|
return tmp_ret;
|
|
*bufp += tmp_ret;
|
|
*lenp -= tmp_ret;
|
|
|
|
return ret + tmp_ret;
|
|
}
|
|
|
|
BPF_CALL_4(bpf_sysctl_get_name, struct bpf_sysctl_kern *, ctx, char *, buf,
|
|
size_t, buf_len, u64, flags)
|
|
{
|
|
ssize_t tmp_ret = 0, ret;
|
|
|
|
if (!buf)
|
|
return -EINVAL;
|
|
|
|
if (!(flags & BPF_F_SYSCTL_BASE_NAME)) {
|
|
if (!ctx->head)
|
|
return -EINVAL;
|
|
tmp_ret = sysctl_cpy_dir(ctx->head->parent, &buf, &buf_len);
|
|
if (tmp_ret < 0)
|
|
return tmp_ret;
|
|
}
|
|
|
|
ret = strscpy(buf, ctx->table->procname, buf_len);
|
|
|
|
return ret < 0 ? ret : tmp_ret + ret;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_sysctl_get_name_proto = {
|
|
.func = bpf_sysctl_get_name,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_MEM,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
.arg4_type = ARG_ANYTHING,
|
|
};
|
|
|
|
static int copy_sysctl_value(char *dst, size_t dst_len, char *src,
|
|
size_t src_len)
|
|
{
|
|
if (!dst)
|
|
return -EINVAL;
|
|
|
|
if (!dst_len)
|
|
return -E2BIG;
|
|
|
|
if (!src || !src_len) {
|
|
memset(dst, 0, dst_len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcpy(dst, src, min(dst_len, src_len));
|
|
|
|
if (dst_len > src_len) {
|
|
memset(dst + src_len, '\0', dst_len - src_len);
|
|
return src_len;
|
|
}
|
|
|
|
dst[dst_len - 1] = '\0';
|
|
|
|
return -E2BIG;
|
|
}
|
|
|
|
BPF_CALL_3(bpf_sysctl_get_current_value, struct bpf_sysctl_kern *, ctx,
|
|
char *, buf, size_t, buf_len)
|
|
{
|
|
return copy_sysctl_value(buf, buf_len, ctx->cur_val, ctx->cur_len);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_sysctl_get_current_value_proto = {
|
|
.func = bpf_sysctl_get_current_value,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_sysctl_get_new_value, struct bpf_sysctl_kern *, ctx, char *, buf,
|
|
size_t, buf_len)
|
|
{
|
|
if (!ctx->write) {
|
|
if (buf && buf_len)
|
|
memset(buf, '\0', buf_len);
|
|
return -EINVAL;
|
|
}
|
|
return copy_sysctl_value(buf, buf_len, ctx->new_val, ctx->new_len);
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_sysctl_get_new_value_proto = {
|
|
.func = bpf_sysctl_get_new_value,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
BPF_CALL_3(bpf_sysctl_set_new_value, struct bpf_sysctl_kern *, ctx,
|
|
const char *, buf, size_t, buf_len)
|
|
{
|
|
if (!ctx->write || !ctx->new_val || !ctx->new_len || !buf || !buf_len)
|
|
return -EINVAL;
|
|
|
|
if (buf_len > PAGE_SIZE - 1)
|
|
return -E2BIG;
|
|
|
|
memcpy(ctx->new_val, buf, buf_len);
|
|
ctx->new_len = buf_len;
|
|
ctx->new_updated = 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = {
|
|
.func = bpf_sysctl_set_new_value,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX,
|
|
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
|
|
.arg3_type = ARG_CONST_SIZE,
|
|
};
|
|
|
|
static const struct bpf_func_proto *
|
|
sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *func_proto;
|
|
|
|
func_proto = cgroup_common_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
func_proto = cgroup_current_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
switch (func_id) {
|
|
case BPF_FUNC_sysctl_get_name:
|
|
return &bpf_sysctl_get_name_proto;
|
|
case BPF_FUNC_sysctl_get_current_value:
|
|
return &bpf_sysctl_get_current_value_proto;
|
|
case BPF_FUNC_sysctl_get_new_value:
|
|
return &bpf_sysctl_get_new_value_proto;
|
|
case BPF_FUNC_sysctl_set_new_value:
|
|
return &bpf_sysctl_set_new_value_proto;
|
|
case BPF_FUNC_ktime_get_coarse_ns:
|
|
return &bpf_ktime_get_coarse_ns_proto;
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_event_output_data_proto;
|
|
default:
|
|
return bpf_base_func_proto(func_id);
|
|
}
|
|
}
|
|
|
|
static bool sysctl_is_valid_access(int off, int size, enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
const int size_default = sizeof(__u32);
|
|
|
|
if (off < 0 || off + size > sizeof(struct bpf_sysctl) || off % size)
|
|
return false;
|
|
|
|
switch (off) {
|
|
case bpf_ctx_range(struct bpf_sysctl, write):
|
|
if (type != BPF_READ)
|
|
return false;
|
|
bpf_ctx_record_field_size(info, size_default);
|
|
return bpf_ctx_narrow_access_ok(off, size, size_default);
|
|
case bpf_ctx_range(struct bpf_sysctl, file_pos):
|
|
if (type == BPF_READ) {
|
|
bpf_ctx_record_field_size(info, size_default);
|
|
return bpf_ctx_narrow_access_ok(off, size, size_default);
|
|
} else {
|
|
return size == size_default;
|
|
}
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
static u32 sysctl_convert_ctx_access(enum bpf_access_type type,
|
|
const struct bpf_insn *si,
|
|
struct bpf_insn *insn_buf,
|
|
struct bpf_prog *prog, u32 *target_size)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
u32 read_size;
|
|
|
|
switch (si->off) {
|
|
case offsetof(struct bpf_sysctl, write):
|
|
*insn++ = BPF_LDX_MEM(
|
|
BPF_SIZE(si->code), si->dst_reg, si->src_reg,
|
|
bpf_target_off(struct bpf_sysctl_kern, write,
|
|
sizeof_field(struct bpf_sysctl_kern,
|
|
write),
|
|
target_size));
|
|
break;
|
|
case offsetof(struct bpf_sysctl, file_pos):
|
|
/* ppos is a pointer so it should be accessed via indirect
|
|
* loads and stores. Also for stores additional temporary
|
|
* register is used since neither src_reg nor dst_reg can be
|
|
* overridden.
|
|
*/
|
|
if (type == BPF_WRITE) {
|
|
int treg = BPF_REG_9;
|
|
|
|
if (si->src_reg == treg || si->dst_reg == treg)
|
|
--treg;
|
|
if (si->src_reg == treg || si->dst_reg == treg)
|
|
--treg;
|
|
*insn++ = BPF_STX_MEM(
|
|
BPF_DW, si->dst_reg, treg,
|
|
offsetof(struct bpf_sysctl_kern, tmp_reg));
|
|
*insn++ = BPF_LDX_MEM(
|
|
BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
|
|
treg, si->dst_reg,
|
|
offsetof(struct bpf_sysctl_kern, ppos));
|
|
*insn++ = BPF_STX_MEM(
|
|
BPF_SIZEOF(u32), treg, si->src_reg,
|
|
bpf_ctx_narrow_access_offset(
|
|
0, sizeof(u32), sizeof(loff_t)));
|
|
*insn++ = BPF_LDX_MEM(
|
|
BPF_DW, treg, si->dst_reg,
|
|
offsetof(struct bpf_sysctl_kern, tmp_reg));
|
|
} else {
|
|
*insn++ = BPF_LDX_MEM(
|
|
BPF_FIELD_SIZEOF(struct bpf_sysctl_kern, ppos),
|
|
si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_sysctl_kern, ppos));
|
|
read_size = bpf_size_to_bytes(BPF_SIZE(si->code));
|
|
*insn++ = BPF_LDX_MEM(
|
|
BPF_SIZE(si->code), si->dst_reg, si->dst_reg,
|
|
bpf_ctx_narrow_access_offset(
|
|
0, read_size, sizeof(loff_t)));
|
|
}
|
|
*target_size = sizeof(u32);
|
|
break;
|
|
}
|
|
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
|
|
.get_func_proto = sysctl_func_proto,
|
|
.is_valid_access = sysctl_is_valid_access,
|
|
.convert_ctx_access = sysctl_convert_ctx_access,
|
|
};
|
|
|
|
const struct bpf_prog_ops cg_sysctl_prog_ops = {
|
|
};
|
|
|
|
#ifdef CONFIG_NET
|
|
BPF_CALL_1(bpf_get_netns_cookie_sockopt, struct bpf_sockopt_kern *, ctx)
|
|
{
|
|
const struct net *net = ctx ? sock_net(ctx->sk) : &init_net;
|
|
|
|
return net->net_cookie;
|
|
}
|
|
|
|
static const struct bpf_func_proto bpf_get_netns_cookie_sockopt_proto = {
|
|
.func = bpf_get_netns_cookie_sockopt,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_PTR_TO_CTX_OR_NULL,
|
|
};
|
|
#endif
|
|
|
|
static const struct bpf_func_proto *
|
|
cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
const struct bpf_func_proto *func_proto;
|
|
|
|
func_proto = cgroup_common_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
func_proto = cgroup_current_func_proto(func_id, prog);
|
|
if (func_proto)
|
|
return func_proto;
|
|
|
|
switch (func_id) {
|
|
#ifdef CONFIG_NET
|
|
case BPF_FUNC_get_netns_cookie:
|
|
return &bpf_get_netns_cookie_sockopt_proto;
|
|
case BPF_FUNC_sk_storage_get:
|
|
return &bpf_sk_storage_get_proto;
|
|
case BPF_FUNC_sk_storage_delete:
|
|
return &bpf_sk_storage_delete_proto;
|
|
case BPF_FUNC_setsockopt:
|
|
if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
|
|
return &bpf_sk_setsockopt_proto;
|
|
return NULL;
|
|
case BPF_FUNC_getsockopt:
|
|
if (prog->expected_attach_type == BPF_CGROUP_SETSOCKOPT)
|
|
return &bpf_sk_getsockopt_proto;
|
|
return NULL;
|
|
#endif
|
|
#ifdef CONFIG_INET
|
|
case BPF_FUNC_tcp_sock:
|
|
return &bpf_tcp_sock_proto;
|
|
#endif
|
|
case BPF_FUNC_perf_event_output:
|
|
return &bpf_event_output_data_proto;
|
|
default:
|
|
return bpf_base_func_proto(func_id);
|
|
}
|
|
}
|
|
|
|
static bool cg_sockopt_is_valid_access(int off, int size,
|
|
enum bpf_access_type type,
|
|
const struct bpf_prog *prog,
|
|
struct bpf_insn_access_aux *info)
|
|
{
|
|
const int size_default = sizeof(__u32);
|
|
|
|
if (off < 0 || off >= sizeof(struct bpf_sockopt))
|
|
return false;
|
|
|
|
if (off % size != 0)
|
|
return false;
|
|
|
|
if (type == BPF_WRITE) {
|
|
switch (off) {
|
|
case offsetof(struct bpf_sockopt, retval):
|
|
if (size != size_default)
|
|
return false;
|
|
return prog->expected_attach_type ==
|
|
BPF_CGROUP_GETSOCKOPT;
|
|
case offsetof(struct bpf_sockopt, optname):
|
|
fallthrough;
|
|
case offsetof(struct bpf_sockopt, level):
|
|
if (size != size_default)
|
|
return false;
|
|
return prog->expected_attach_type ==
|
|
BPF_CGROUP_SETSOCKOPT;
|
|
case offsetof(struct bpf_sockopt, optlen):
|
|
return size == size_default;
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
switch (off) {
|
|
case offsetof(struct bpf_sockopt, sk):
|
|
if (size != sizeof(__u64))
|
|
return false;
|
|
info->reg_type = PTR_TO_SOCKET;
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optval):
|
|
if (size != sizeof(__u64))
|
|
return false;
|
|
info->reg_type = PTR_TO_PACKET;
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optval_end):
|
|
if (size != sizeof(__u64))
|
|
return false;
|
|
info->reg_type = PTR_TO_PACKET_END;
|
|
break;
|
|
case offsetof(struct bpf_sockopt, retval):
|
|
if (size != size_default)
|
|
return false;
|
|
return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
|
|
default:
|
|
if (size != size_default)
|
|
return false;
|
|
break;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
#define CG_SOCKOPT_ACCESS_FIELD(T, F) \
|
|
T(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F), \
|
|
si->dst_reg, si->src_reg, \
|
|
offsetof(struct bpf_sockopt_kern, F))
|
|
|
|
static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
|
|
const struct bpf_insn *si,
|
|
struct bpf_insn *insn_buf,
|
|
struct bpf_prog *prog,
|
|
u32 *target_size)
|
|
{
|
|
struct bpf_insn *insn = insn_buf;
|
|
|
|
switch (si->off) {
|
|
case offsetof(struct bpf_sockopt, sk):
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, sk);
|
|
break;
|
|
case offsetof(struct bpf_sockopt, level):
|
|
if (type == BPF_WRITE)
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, level);
|
|
else
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, level);
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optname):
|
|
if (type == BPF_WRITE)
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optname);
|
|
else
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optname);
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optlen):
|
|
if (type == BPF_WRITE)
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optlen);
|
|
else
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optlen);
|
|
break;
|
|
case offsetof(struct bpf_sockopt, retval):
|
|
BUILD_BUG_ON(offsetof(struct bpf_cg_run_ctx, run_ctx) != 0);
|
|
|
|
if (type == BPF_WRITE) {
|
|
int treg = BPF_REG_9;
|
|
|
|
if (si->src_reg == treg || si->dst_reg == treg)
|
|
--treg;
|
|
if (si->src_reg == treg || si->dst_reg == treg)
|
|
--treg;
|
|
*insn++ = BPF_STX_MEM(BPF_DW, si->dst_reg, treg,
|
|
offsetof(struct bpf_sockopt_kern, tmp_reg));
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
|
|
treg, si->dst_reg,
|
|
offsetof(struct bpf_sockopt_kern, current_task));
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
|
|
treg, treg,
|
|
offsetof(struct task_struct, bpf_ctx));
|
|
*insn++ = BPF_STX_MEM(BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
|
|
treg, si->src_reg,
|
|
offsetof(struct bpf_cg_run_ctx, retval));
|
|
*insn++ = BPF_LDX_MEM(BPF_DW, treg, si->dst_reg,
|
|
offsetof(struct bpf_sockopt_kern, tmp_reg));
|
|
} else {
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, current_task),
|
|
si->dst_reg, si->src_reg,
|
|
offsetof(struct bpf_sockopt_kern, current_task));
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct task_struct, bpf_ctx),
|
|
si->dst_reg, si->dst_reg,
|
|
offsetof(struct task_struct, bpf_ctx));
|
|
*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval),
|
|
si->dst_reg, si->dst_reg,
|
|
offsetof(struct bpf_cg_run_ctx, retval));
|
|
}
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optval):
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval);
|
|
break;
|
|
case offsetof(struct bpf_sockopt, optval_end):
|
|
*insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval_end);
|
|
break;
|
|
}
|
|
|
|
return insn - insn_buf;
|
|
}
|
|
|
|
static int cg_sockopt_get_prologue(struct bpf_insn *insn_buf,
|
|
bool direct_write,
|
|
const struct bpf_prog *prog)
|
|
{
|
|
/* Nothing to do for sockopt argument. The data is kzalloc'ated.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
|
|
.get_func_proto = cg_sockopt_func_proto,
|
|
.is_valid_access = cg_sockopt_is_valid_access,
|
|
.convert_ctx_access = cg_sockopt_convert_ctx_access,
|
|
.gen_prologue = cg_sockopt_get_prologue,
|
|
};
|
|
|
|
const struct bpf_prog_ops cg_sockopt_prog_ops = {
|
|
};
|
|
|
|
/* Common helpers for cgroup hooks. */
|
|
const struct bpf_func_proto *
|
|
cgroup_common_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_get_local_storage:
|
|
return &bpf_get_local_storage_proto;
|
|
case BPF_FUNC_get_retval:
|
|
switch (prog->expected_attach_type) {
|
|
case BPF_CGROUP_INET_INGRESS:
|
|
case BPF_CGROUP_INET_EGRESS:
|
|
case BPF_CGROUP_SOCK_OPS:
|
|
case BPF_CGROUP_UDP4_RECVMSG:
|
|
case BPF_CGROUP_UDP6_RECVMSG:
|
|
case BPF_CGROUP_INET4_GETPEERNAME:
|
|
case BPF_CGROUP_INET6_GETPEERNAME:
|
|
case BPF_CGROUP_INET4_GETSOCKNAME:
|
|
case BPF_CGROUP_INET6_GETSOCKNAME:
|
|
return NULL;
|
|
default:
|
|
return &bpf_get_retval_proto;
|
|
}
|
|
case BPF_FUNC_set_retval:
|
|
switch (prog->expected_attach_type) {
|
|
case BPF_CGROUP_INET_INGRESS:
|
|
case BPF_CGROUP_INET_EGRESS:
|
|
case BPF_CGROUP_SOCK_OPS:
|
|
case BPF_CGROUP_UDP4_RECVMSG:
|
|
case BPF_CGROUP_UDP6_RECVMSG:
|
|
case BPF_CGROUP_INET4_GETPEERNAME:
|
|
case BPF_CGROUP_INET6_GETPEERNAME:
|
|
case BPF_CGROUP_INET4_GETSOCKNAME:
|
|
case BPF_CGROUP_INET6_GETSOCKNAME:
|
|
return NULL;
|
|
default:
|
|
return &bpf_set_retval_proto;
|
|
}
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
/* Common helpers for cgroup hooks with valid process context. */
|
|
const struct bpf_func_proto *
|
|
cgroup_current_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
|
|
{
|
|
switch (func_id) {
|
|
case BPF_FUNC_get_current_uid_gid:
|
|
return &bpf_get_current_uid_gid_proto;
|
|
case BPF_FUNC_get_current_pid_tgid:
|
|
return &bpf_get_current_pid_tgid_proto;
|
|
case BPF_FUNC_get_current_comm:
|
|
return &bpf_get_current_comm_proto;
|
|
case BPF_FUNC_get_current_cgroup_id:
|
|
return &bpf_get_current_cgroup_id_proto;
|
|
case BPF_FUNC_get_current_ancestor_cgroup_id:
|
|
return &bpf_get_current_ancestor_cgroup_id_proto;
|
|
#ifdef CONFIG_CGROUP_NET_CLASSID
|
|
case BPF_FUNC_get_cgroup_classid:
|
|
return &bpf_get_cgroup_classid_curr_proto;
|
|
#endif
|
|
default:
|
|
return NULL;
|
|
}
|
|
}
|