diff options
Diffstat (limited to 'kernel/bpf/cgroup.c')
-rw-r--r-- | kernel/bpf/cgroup.c | 1713 |
1 files changed, 1346 insertions, 367 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 9a500fadbef5..bf2fdb33fb31 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -14,20 +14,259 @@ #include <linux/string.h> #include <linux/bpf.h> #include <linux/bpf-cgroup.h> +#include <linux/bpf_lsm.h> +#include <linux/bpf_verifier.h> #include <net/sock.h> #include <net/bpf_sk_storage.h> #include "../cgroup/cgroup-internal.h" -DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key); +DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE); EXPORT_SYMBOL(cgroup_bpf_enabled_key); +/* __always_inline is necessary to prevent indirect call through run_prog + * function pointer. + */ +static __always_inline int +bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp, + enum cgroup_bpf_attach_type atype, + const void *ctx, bpf_prog_run_fn run_prog, + int retval, u32 *ret_flags) +{ + const struct bpf_prog_array_item *item; + const struct bpf_prog *prog; + const struct bpf_prog_array *array; + struct bpf_run_ctx *old_run_ctx; + struct bpf_cg_run_ctx run_ctx; + u32 func_ret; + + run_ctx.retval = retval; + migrate_disable(); + rcu_read_lock(); + array = rcu_dereference(cgrp->effective[atype]); + item = &array->items[0]; + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + while ((prog = READ_ONCE(item->prog))) { + run_ctx.prog_item = item; + func_ret = run_prog(prog, ctx); + if (ret_flags) { + *(ret_flags) |= (func_ret >> 1); + func_ret &= 1; + } + if (!func_ret && !IS_ERR_VALUE((long)run_ctx.retval)) + run_ctx.retval = -EPERM; + item++; + } + bpf_reset_run_ctx(old_run_ctx); + rcu_read_unlock(); + migrate_enable(); + return run_ctx.retval; +} + +unsigned int __cgroup_bpf_run_lsm_sock(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct sock *sk; + struct cgroup *cgrp; + int ret = 0; + u64 *args; + + args = (u64 *)ctx; + sk = (void *)(unsigned long)args[0]; + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +unsigned int __cgroup_bpf_run_lsm_socket(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct socket *sock; + struct cgroup *cgrp; + int ret = 0; + u64 *args; + + args = (u64 *)ctx; + sock = (void *)(unsigned long)args[0]; + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + cgrp = sock_cgroup_ptr(&sock->sk->sk_cgrp_data); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +unsigned int __cgroup_bpf_run_lsm_current(const void *ctx, + const struct bpf_insn *insn) +{ + const struct bpf_prog *shim_prog; + struct cgroup *cgrp; + int ret = 0; + + /*shim_prog = container_of(insn, struct bpf_prog, insnsi);*/ + shim_prog = (const struct bpf_prog *)((void *)insn - offsetof(struct bpf_prog, insnsi)); + + /* We rely on trampoline's __bpf_prog_enter_lsm_cgroup to grab RCU read lock. */ + cgrp = task_dfl_cgroup(current); + if (likely(cgrp)) + ret = bpf_prog_run_array_cg(&cgrp->bpf, + shim_prog->aux->cgroup_atype, + ctx, bpf_prog_run, 0, NULL); + return ret; +} + +#ifdef CONFIG_BPF_LSM +struct cgroup_lsm_atype { + u32 attach_btf_id; + int refcnt; +}; + +static struct cgroup_lsm_atype cgroup_lsm_atype[CGROUP_LSM_NUM]; + +static enum cgroup_bpf_attach_type +bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id) +{ + int i; + + lockdep_assert_held(&cgroup_mutex); + + if (attach_type != BPF_LSM_CGROUP) + return to_cgroup_bpf_attach_type(attach_type); + + for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++) + if (cgroup_lsm_atype[i].attach_btf_id == attach_btf_id) + return CGROUP_LSM_START + i; + + for (i = 0; i < ARRAY_SIZE(cgroup_lsm_atype); i++) + if (cgroup_lsm_atype[i].attach_btf_id == 0) + return CGROUP_LSM_START + i; + + return -E2BIG; + +} + +void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype) +{ + int i = cgroup_atype - CGROUP_LSM_START; + + lockdep_assert_held(&cgroup_mutex); + + WARN_ON_ONCE(cgroup_lsm_atype[i].attach_btf_id && + cgroup_lsm_atype[i].attach_btf_id != attach_btf_id); + + cgroup_lsm_atype[i].attach_btf_id = attach_btf_id; + cgroup_lsm_atype[i].refcnt++; +} + +void bpf_cgroup_atype_put(int cgroup_atype) +{ + int i = cgroup_atype - CGROUP_LSM_START; + + mutex_lock(&cgroup_mutex); + if (--cgroup_lsm_atype[i].refcnt <= 0) + cgroup_lsm_atype[i].attach_btf_id = 0; + WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0); + mutex_unlock(&cgroup_mutex); +} +#else +static enum cgroup_bpf_attach_type +bpf_cgroup_atype_find(enum bpf_attach_type attach_type, u32 attach_btf_id) +{ + if (attach_type != BPF_LSM_CGROUP) + return to_cgroup_bpf_attach_type(attach_type); + return -EOPNOTSUPP; +} +#endif /* CONFIG_BPF_LSM */ + void cgroup_bpf_offline(struct cgroup *cgrp) { cgroup_get(cgrp); percpu_ref_kill(&cgrp->bpf.refcnt); } +static void bpf_cgroup_storages_free(struct bpf_cgroup_storage *storages[]) +{ + enum bpf_cgroup_storage_type stype; + + for_each_cgroup_storage_type(stype) + bpf_cgroup_storage_free(storages[stype]); +} + +static int bpf_cgroup_storages_alloc(struct bpf_cgroup_storage *storages[], + struct bpf_cgroup_storage *new_storages[], + enum bpf_attach_type type, + struct bpf_prog *prog, + struct cgroup *cgrp) +{ + enum bpf_cgroup_storage_type stype; + struct bpf_cgroup_storage_key key; + struct bpf_map *map; + + key.cgroup_inode_id = cgroup_id(cgrp); + key.attach_type = type; + + for_each_cgroup_storage_type(stype) { + map = prog->aux->cgroup_storage[stype]; + if (!map) + continue; + + storages[stype] = cgroup_storage_lookup((void *)map, &key, false); + if (storages[stype]) + continue; + + storages[stype] = bpf_cgroup_storage_alloc(prog, stype); + if (IS_ERR(storages[stype])) { + bpf_cgroup_storages_free(new_storages); + return -ENOMEM; + } + + new_storages[stype] = storages[stype]; + } + + return 0; +} + +static void bpf_cgroup_storages_assign(struct bpf_cgroup_storage *dst[], + struct bpf_cgroup_storage *src[]) +{ + enum bpf_cgroup_storage_type stype; + + for_each_cgroup_storage_type(stype) + dst[stype] = src[stype]; +} + +static void bpf_cgroup_storages_link(struct bpf_cgroup_storage *storages[], + struct cgroup *cgrp, + enum bpf_attach_type attach_type) +{ + enum bpf_cgroup_storage_type stype; + + for_each_cgroup_storage_type(stype) + bpf_cgroup_storage_link(storages[stype], cgrp, attach_type); +} + +/* Called when bpf_cgroup_link is auto-detached from dying cgroup. + * It drops cgroup and bpf_prog refcounts, and marks bpf_link as defunct. It + * doesn't free link memory, which will eventually be done by bpf_link's + * release() callback, when its last FD is closed. + */ +static void bpf_cgroup_link_auto_detach(struct bpf_cgroup_link *link) +{ + cgroup_put(link->cgroup); + link->cgroup = NULL; +} + /** * cgroup_bpf_release() - put references of all bpf programs and * release all cgroup bpf data @@ -37,32 +276,45 @@ static void cgroup_bpf_release(struct work_struct *work) { struct cgroup *p, *cgrp = container_of(work, struct cgroup, bpf.release_work); - enum bpf_cgroup_storage_type stype; struct bpf_prog_array *old_array; - unsigned int type; + struct list_head *storages = &cgrp->bpf.storages; + struct bpf_cgroup_storage *storage, *stmp; - mutex_lock(&cgroup_mutex); + unsigned int atype; - for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) { - struct list_head *progs = &cgrp->bpf.progs[type]; - struct bpf_prog_list *pl, *tmp; + mutex_lock(&cgroup_mutex); - list_for_each_entry_safe(pl, tmp, progs, node) { - list_del(&pl->node); - bpf_prog_put(pl->prog); - for_each_cgroup_storage_type(stype) { - bpf_cgroup_storage_unlink(pl->storage[stype]); - bpf_cgroup_storage_free(pl->storage[stype]); + for (atype = 0; atype < ARRAY_SIZE(cgrp->bpf.progs); atype++) { + struct hlist_head *progs = &cgrp->bpf.progs[atype]; + struct bpf_prog_list *pl; + struct hlist_node *pltmp; + + hlist_for_each_entry_safe(pl, pltmp, progs, node) { + hlist_del(&pl->node); + if (pl->prog) { + if (pl->prog->expected_attach_type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(pl->prog); + bpf_prog_put(pl->prog); + } + if (pl->link) { + if (pl->link->link.prog->expected_attach_type == BPF_LSM_CGROUP) + bpf_trampoline_unlink_cgroup_shim(pl->link->link.prog); + bpf_cgroup_link_auto_detach(pl->link); } kfree(pl); - static_branch_dec(&cgroup_bpf_enabled_key); + static_branch_dec(&cgroup_bpf_enabled_key[atype]); } old_array = rcu_dereference_protected( - cgrp->bpf.effective[type], + cgrp->bpf.effective[atype], lockdep_is_held(&cgroup_mutex)); bpf_prog_array_free(old_array); } + list_for_each_entry_safe(storage, stmp, storages, list_cg) { + bpf_cgroup_storage_unlink(storage); + bpf_cgroup_storage_free(storage); + } + mutex_unlock(&cgroup_mutex); for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p)) @@ -85,16 +337,28 @@ static void cgroup_bpf_release_fn(struct percpu_ref *ref) queue_work(system_wq, &cgrp->bpf.release_work); } +/* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through + * link or direct prog. + */ +static struct bpf_prog *prog_list_prog(struct bpf_prog_list *pl) +{ + if (pl->prog) + return pl->prog; + if (pl->link) + return pl->link->link.prog; + return NULL; +} + /* count number of elements in the list. * it's slow but the list cannot be long */ -static u32 prog_list_length(struct list_head *head) +static u32 prog_list_length(struct hlist_head *head) { struct bpf_prog_list *pl; u32 cnt = 0; - list_for_each_entry(pl, head, node) { - if (!pl->prog) + hlist_for_each_entry(pl, head, node) { + if (!prog_list_prog(pl)) continue; cnt++; } @@ -106,7 +370,7 @@ static u32 prog_list_length(struct list_head *head) * if parent has overridable or multi-prog, allow attaching */ static bool hierarchy_allows_attach(struct cgroup *cgrp, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *p; @@ -114,12 +378,12 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp, if (!p) return true; do { - u32 flags = p->bpf.flags[type]; + u32 flags = p->bpf.flags[atype]; u32 cnt; if (flags & BPF_F_ALLOW_MULTI) return true; - cnt = prog_list_length(&p->bpf.progs[type]); + cnt = prog_list_length(&p->bpf.progs[atype]); WARN_ON_ONCE(cnt > 1); if (cnt == 1) return !!(flags & BPF_F_ALLOW_OVERRIDE); @@ -135,10 +399,10 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp, * to programs in this cgroup */ static int compute_effective_progs(struct cgroup *cgrp, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, struct bpf_prog_array **array) { - enum bpf_cgroup_storage_type stype; + struct bpf_prog_array_item *item; struct bpf_prog_array *progs; struct bpf_prog_list *pl; struct cgroup *p = cgrp; @@ -146,8 +410,8 @@ static int compute_effective_progs(struct cgroup *cgrp, /* count number of effective programs by walking parents */ do { - if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) - cnt += prog_list_length(&p->bpf.progs[type]); + if (cnt == 0 || (p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) + cnt += prog_list_length(&p->bpf.progs[atype]); p = cgroup_parent(p); } while (p); @@ -159,17 +423,17 @@ static int compute_effective_progs(struct cgroup *cgrp, cnt = 0; p = cgrp; do { - if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) continue; - list_for_each_entry(pl, &p->bpf.progs[type], node) { - if (!pl->prog) + hlist_for_each_entry(pl, &p->bpf.progs[atype], node) { + if (!prog_list_prog(pl)) continue; - progs->items[cnt].prog = pl->prog; - for_each_cgroup_storage_type(stype) - progs->items[cnt].cgroup_storage[stype] = - pl->storage[stype]; + item = &progs->items[cnt]; + item->prog = prog_list_prog(pl); + bpf_cgroup_storages_assign(item->cgroup_storage, + pl->storage); cnt++; } } while ((p = cgroup_parent(p))); @@ -179,10 +443,10 @@ static int compute_effective_progs(struct cgroup *cgrp, } static void activate_effective_progs(struct cgroup *cgrp, - enum bpf_attach_type type, + enum cgroup_bpf_attach_type atype, struct bpf_prog_array *old_array) { - old_array = rcu_replace_pointer(cgrp->bpf.effective[type], old_array, + old_array = rcu_replace_pointer(cgrp->bpf.effective[atype], old_array, lockdep_is_held(&cgroup_mutex)); /* free prog array after grace period, since __cgroup_bpf_run_*() * might be still walking the array @@ -213,7 +477,9 @@ int cgroup_bpf_inherit(struct cgroup *cgrp) cgroup_bpf_get(p); for (i = 0; i < NR; i++) - INIT_LIST_HEAD(&cgrp->bpf.progs[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])) @@ -227,13 +493,16 @@ 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 bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup_subsys_state *css; int err; @@ -245,7 +514,7 @@ static int update_effective_progs(struct cgroup *cgrp, if (percpu_ref_is_zero(&desc->bpf.refcnt)) continue; - err = compute_effective_progs(desc, type, &desc->bpf.inactive); + err = compute_effective_progs(desc, atype, &desc->bpf.inactive); if (err) goto cleanup; } @@ -262,7 +531,7 @@ static int update_effective_progs(struct cgroup *cgrp, continue; } - activate_effective_progs(desc, type, desc->bpf.inactive); + activate_effective_progs(desc, atype, desc->bpf.inactive); desc->bpf.inactive = NULL; } @@ -284,39 +553,93 @@ cleanup: #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 to a cgroup, and + * __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. */ -int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, - struct bpf_prog *replace_prog, - enum bpf_attach_type type, u32 flags) +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 list_head *progs = &cgrp->bpf.progs[type]; struct bpf_prog *old_prog = NULL; - struct bpf_cgroup_storage *storage[MAX_BPF_CGROUP_STORAGE_TYPE], - *old_storage[MAX_BPF_CGROUP_STORAGE_TYPE] = {NULL}; - struct bpf_prog_list *pl, *replace_pl = NULL; - enum bpf_cgroup_storage_type stype; + 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; - if (!hierarchy_allows_attach(cgrp, type)) + 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 (!list_empty(progs) && cgrp->bpf.flags[type] != saved_flags) + 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 @@ -326,215 +649,483 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS) return -E2BIG; - if (flags & BPF_F_ALLOW_MULTI) { - list_for_each_entry(pl, progs, node) { - if (pl->prog == prog) - /* disallow attaching the same prog twice */ - return -EINVAL; - if (pl->prog == replace_prog) - replace_pl = pl; - } - if ((flags & BPF_F_REPLACE) && !replace_pl) - /* prog to replace not found for cgroup */ - return -ENOENT; - } else if (!list_empty(progs)) { - replace_pl = list_first_entry(progs, typeof(*pl), node); - } + pl = find_attach_entry(progs, prog, link, replace_prog, + flags & BPF_F_ALLOW_MULTI); + if (IS_ERR(pl)) + return PTR_ERR(pl); - for_each_cgroup_storage_type(stype) { - storage[stype] = bpf_cgroup_storage_alloc(prog, stype); - if (IS_ERR(storage[stype])) { - storage[stype] = NULL; - for_each_cgroup_storage_type(stype) - bpf_cgroup_storage_free(storage[stype]); - return -ENOMEM; - } - } + if (bpf_cgroup_storages_alloc(storage, new_storage, type, + prog ? : link->link.prog, cgrp)) + return -ENOMEM; - if (replace_pl) { - pl = replace_pl; + if (pl) { old_prog = pl->prog; - for_each_cgroup_storage_type(stype) { - old_storage[stype] = pl->storage[stype]; - bpf_cgroup_storage_unlink(old_storage[stype]); - } } else { + struct hlist_node *last = NULL; + pl = kmalloc(sizeof(*pl), GFP_KERNEL); if (!pl) { - for_each_cgroup_storage_type(stype) - bpf_cgroup_storage_free(storage[stype]); + bpf_cgroup_storages_free(new_storage); return -ENOMEM; } - list_add_tail(&pl->node, progs); + 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; - for_each_cgroup_storage_type(stype) - pl->storage[stype] = storage[stype]; + pl->link = link; + bpf_cgroup_storages_assign(pl->storage, storage); + cgrp->bpf.flags[atype] = saved_flags; - cgrp->bpf.flags[type] = 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, type); + err = update_effective_progs(cgrp, atype); if (err) - goto cleanup; + goto cleanup_trampoline; - static_branch_inc(&cgroup_bpf_enabled_key); - for_each_cgroup_storage_type(stype) { - if (!old_storage[stype]) - continue; - bpf_cgroup_storage_free(old_storage[stype]); - } 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); + } else { + static_branch_inc(&cgroup_bpf_enabled_key[atype]); } - for_each_cgroup_storage_type(stype) - bpf_cgroup_storage_link(storage[stype], cgrp, type); + 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: - /* and cleanup the prog list */ - pl->prog = old_prog; - for_each_cgroup_storage_type(stype) { - bpf_cgroup_storage_free(pl->storage[stype]); - pl->storage[stype] = old_storage[stype]; - bpf_cgroup_storage_link(old_storage[stype], cgrp, type); + if (old_prog) { + pl->prog = old_prog; + pl->link = NULL; } - if (!replace_pl) { - list_del(&pl->node); + 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_detach() - Detach the program from a cgroup, and - * propagate the change to descendants + * __cgroup_bpf_replace() - Replace link's program and propagate the change + * to descendants * @cgrp: The cgroup which descendants to traverse - * @prog: A program to detach or NULL - * @type: Type of detach operation + * @link: A link for which to replace BPF program + * @type: Type of attach operation * * Must be called with cgroup_mutex held. */ -int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, - enum bpf_attach_type type) +static int __cgroup_bpf_replace(struct cgroup *cgrp, + struct bpf_cgroup_link *link, + struct bpf_prog *new_prog) { - struct list_head *progs = &cgrp->bpf.progs[type]; - enum bpf_cgroup_storage_type stype; - u32 flags = cgrp->bpf.flags[type]; - struct bpf_prog *old_prog = NULL; + enum cgroup_bpf_attach_type atype; + struct bpf_prog *old_prog; struct bpf_prog_list *pl; - int err; + struct hlist_head *progs; + bool found = false; - if (flags & BPF_F_ALLOW_MULTI) { - if (!prog) - /* to detach MULTI prog the user has to specify valid FD - * of the program to be detached - */ - return -EINVAL; - } else { - if (list_empty(progs)) - /* report error when trying to detach and nothing is attached */ - return -ENOENT; - } + atype = bpf_cgroup_atype_find(link->type, new_prog->aux->attach_btf_id); + if (atype < 0) + return -EINVAL; - if (flags & BPF_F_ALLOW_MULTI) { - /* find the prog and detach it */ - list_for_each_entry(pl, progs, node) { - if (pl->prog != prog) - continue; - old_prog = prog; - /* mark it deleted, so it's ignored while - * recomputing effective - */ - pl->prog = NULL; + 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 (!old_prog) - return -ENOENT; - } else { + } + 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) + * allow detaching with invalid FD (prog==NULL) in legacy mode */ - pl = list_first_entry(progs, typeof(*pl), node); - old_prog = pl->prog; - pl->prog = NULL; + return hlist_entry(progs->first, typeof(*pl), node); } - err = update_effective_progs(cgrp, type); - if (err) - goto cleanup; + 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); - /* now can actually delete it from this cgroup list */ - list_del(&pl->node); - for_each_cgroup_storage_type(stype) { - bpf_cgroup_storage_unlink(pl->storage[stype]); - bpf_cgroup_storage_free(pl->storage[stype]); + /* 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 (list_empty(progs)) + if (hlist_empty(progs)) /* last program was detached, reset flags to zero */ - cgrp->bpf.flags[type] = 0; - - bpf_prog_put(old_prog); - static_branch_dec(&cgroup_bpf_enabled_key); + 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; +} -cleanup: - /* and restore back old_prog */ - pl->prog = old_prog; - return err; +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. */ -int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, - union bpf_attr __user *uattr) +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; - struct list_head *progs = &cgrp->bpf.progs[type]; - u32 flags = cgrp->bpf.flags[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; - effective = rcu_dereference_protected(cgrp->bpf.effective[type], - lockdep_is_held(&cgroup_mutex)); + if (effective_query && prog_attach_flags) + return -EINVAL; - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) - cnt = bpf_prog_array_length(effective); - else - cnt = prog_list_length(progs); + 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, &cnt, sizeof(cnt))) + if (copy_to_user(&uattr->query.prog_cnt, &total_cnt, sizeof(total_cnt))) return -EFAULT; - if (attr->query.prog_cnt == 0 || !prog_ids || !cnt) + 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 < cnt) { - cnt = attr->query.prog_cnt; + + if (attr->query.prog_cnt < total_cnt) { + total_cnt = attr->query.prog_cnt; ret = -ENOSPC; } - if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { - return bpf_prog_array_copy_to_user(effective, prog_ids, cnt); - } else { - struct bpf_prog_list *pl; - u32 id; - - i = 0; - list_for_each_entry(pl, progs, node) { - id = pl->prog->aux->id; - if (copy_to_user(prog_ids + i, &id, sizeof(id))) - return -EFAULT; - if (++i == cnt) - break; + 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) { @@ -555,8 +1146,8 @@ int cgroup_bpf_prog_attach(const union bpf_attr *attr, } } - ret = cgroup_bpf_attach(cgrp, prog, replace_prog, attr->attach_type, - attr->attach_flags); + ret = cgroup_bpf_attach(cgrp, prog, replace_prog, NULL, + attr->attach_type, attr->attach_flags); if (replace_prog) bpf_prog_put(replace_prog); @@ -578,7 +1169,7 @@ int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) if (IS_ERR(prog)) prog = NULL; - ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0); + ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type); if (prog) bpf_prog_put(prog); @@ -586,6 +1177,143 @@ int cgroup_bpf_prog_detach(const union bpf_attr *attr, enum bpf_prog_type ptype) 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) { @@ -606,7 +1334,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, * __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 exectuted + * @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. @@ -619,7 +1347,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, * 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 - * -EPERM - drop packet + * -err - drop packet * * For ingress packets, this function will return -EPERM if any * attached program was found and if it returned != 1 during execution. @@ -627,7 +1355,7 @@ int cgroup_bpf_prog_query(const union bpf_attr *attr, */ int __cgroup_bpf_run_filter_skb(struct sock *sk, struct sk_buff *skb, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { unsigned int offset = skb->data - skb_network_header(skb); struct sock *save_sk; @@ -649,13 +1377,41 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk, /* compute pointers for the bpf prog */ bpf_compute_and_save_data_end(skb, &saved_data_end); - if (type == BPF_CGROUP_INET_EGRESS) { - ret = BPF_PROG_CGROUP_INET_EGRESS_RUN_ARRAY( - cgrp->bpf.effective[type], skb, __bpf_prog_run_save_cb); + 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(cgrp->bpf.effective[type], skb, - __bpf_prog_run_save_cb); - ret = (ret == 1 ? 0 : -EPERM); + 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); @@ -668,7 +1424,7 @@ 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 exectuted + * @type: The type of program to be executed * * socket is passed is expected to be of type INET or INET6. * @@ -679,13 +1435,12 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb); * and if it returned != 1 during execution. In all other cases, 0 is returned. */ int __cgroup_bpf_run_filter_sk(struct sock *sk, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN); - return ret == 1 ? 0 : -EPERM; + return bpf_prog_run_array_cg(&cgrp->bpf, atype, sk, bpf_prog_run, 0, + NULL); } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); @@ -694,8 +1449,10 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); * provided by user sockaddr * @sk: sock struct that will use sockaddr * @uaddr: sockaddr struct provided by user - * @type: The type of program to be exectuted + * @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. * @@ -704,8 +1461,9 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk); */ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, struct sockaddr *uaddr, - enum bpf_attach_type type, - void *t_ctx) + enum cgroup_bpf_attach_type atype, + void *t_ctx, + u32 *flags) { struct bpf_sock_addr_kern ctx = { .sk = sk, @@ -714,7 +1472,6 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, }; struct sockaddr_storage unspec; struct cgroup *cgrp; - int ret; /* Check socket family since not all sockets represent network * endpoint (e.g. AF_UNIX). @@ -728,9 +1485,8 @@ int __cgroup_bpf_run_filter_sock_addr(struct sock *sk, } cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN); - - return ret == 1 ? 0 : -EPERM; + return bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, + 0, flags); } EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr); @@ -740,7 +1496,7 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr); * @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 exectuted + * @type: The type of program to be executed * * socket passed is expected to be of type INET or INET6. * @@ -752,19 +1508,17 @@ EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_addr); */ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk, struct bpf_sock_ops_kern *sock_ops, - enum bpf_attach_type type) + enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); - int ret; - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops, - BPF_PROG_RUN); - return ret == 1 ? 0 : -EPERM; + 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 bpf_attach_type type) + short access, enum cgroup_bpf_attach_type atype) { struct cgroup *cgrp; struct bpf_cgroup_dev_ctx ctx = { @@ -772,53 +1526,97 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor, .major = major, .minor = minor, }; - int allow = 1; + int ret; rcu_read_lock(); cgrp = task_dfl_cgroup(current); - allow = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], &ctx, - BPF_PROG_RUN); + ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0, + NULL); rcu_read_unlock(); - return !allow; + return ret; } -EXPORT_SYMBOL(__cgroup_bpf_check_dev_permission); -static const struct bpf_func_proto * -cgroup_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) +BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags) { - switch (func_id) { - case BPF_FUNC_map_lookup_elem: - return &bpf_map_lookup_elem_proto; - case BPF_FUNC_map_update_elem: - return &bpf_map_update_elem_proto; - case BPF_FUNC_map_delete_elem: - return &bpf_map_delete_elem_proto; - case BPF_FUNC_map_push_elem: - return &bpf_map_push_elem_proto; - case BPF_FUNC_map_pop_elem: - return &bpf_map_pop_elem_proto; - case BPF_FUNC_map_peek_elem: - return &bpf_map_peek_elem_proto; - case BPF_FUNC_get_current_uid_gid: - return &bpf_get_current_uid_gid_proto; - case BPF_FUNC_get_local_storage: - return &bpf_get_local_storage_proto; - case BPF_FUNC_get_current_cgroup_id: - return &bpf_get_current_cgroup_id_proto; - case BPF_FUNC_trace_printk: - if (capable(CAP_SYS_ADMIN)) - return bpf_get_trace_printk_proto(); - /* fall through */ - default: - return NULL; - } + /* 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) { - return cgroup_base_func_proto(func_id, 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, @@ -865,16 +1663,13 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = { * @head: sysctl table header * @table: sysctl table * @write: sysctl is being read (= 0) or written (= 1) - * @buf: pointer to buffer passed by user space + * @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 - * @new_buf: pointer to pointer to new buffer that will be allocated if program - * overrides new value provided by user space on sysctl write - * NOTE: it's caller responsibility to free *new_buf if it was set * @type: type of program to be executed * * Program is run when sysctl is being accessed, either read or written, and @@ -885,9 +1680,8 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = { */ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, struct ctl_table *table, int write, - void __user *buf, size_t *pcount, - loff_t *ppos, void **new_buf, - enum bpf_attach_type type) + char **buf, size_t *pcount, loff_t *ppos, + enum cgroup_bpf_attach_type atype) { struct bpf_sysctl_kern ctx = { .head = head, @@ -901,75 +1695,71 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head, .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) { - mm_segment_t old_fs; - loff_t pos = 0; - - old_fs = get_fs(); - set_fs(KERNEL_DS); - if (table->proc_handler(table, 0, (void __user *)ctx.cur_val, - &ctx.cur_len, &pos)) { - /* Let BPF program decide how to proceed. */ - ctx.cur_len = 0; - } - set_fs(old_fs); - } else { + 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) { + 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 || - copy_from_user(ctx.new_val, buf, ctx.new_len)) + 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(cgrp->bpf.effective[type], &ctx, BPF_PROG_RUN); + 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) { - *new_buf = ctx.new_val; + kfree(*buf); + *buf = ctx.new_val; *pcount = ctx.new_len; } else { kfree(ctx.new_val); } - return ret == 1 ? 0 : -EPERM; + return ret; } -EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl); #ifdef CONFIG_NET -static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp, - enum bpf_attach_type attach_type) +static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen, + struct bpf_sockopt_buf *buf) { - struct bpf_prog_array *prog_array; - bool empty; - - rcu_read_lock(); - prog_array = rcu_dereference(cgrp->bpf.effective[attach_type]); - empty = bpf_prog_array_is_empty(prog_array); - rcu_read_unlock(); + if (unlikely(max_optlen < 0)) + return -EINVAL; - return empty; -} + 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; + } -static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen) -{ - if (unlikely(max_optlen > PAGE_SIZE) || max_optlen < 0) - return -EINVAL; + 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) @@ -977,19 +1767,29 @@ static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen) ctx->optval_end = ctx->optval + max_optlen; - return 0; + return max_optlen; } -static void sockopt_free_buf(struct bpf_sockopt_kern *ctx) +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, @@ -997,40 +1797,29 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, }; int ret, max_optlen; - /* Opportunistic check to see whether we have any BPF program - * attached to the hook so we don't waste time allocating - * memory and locking the socket. - */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT)) - return 0; - /* 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); - - ret = sockopt_alloc_buf(&ctx, max_optlen); - if (ret) - return ret; + 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, *optlen) != 0) { + if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) { ret = -EFAULT; goto out; } lock_sock(sk); - ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_SETSOCKOPT, + &ctx, bpf_prog_run, 0, NULL); release_sock(sk); - if (!ret) { - ret = -EPERM; + if (ret) goto out; - } if (ctx.optlen == -1) { /* optlen set to -1, bypass kernel */ @@ -1045,16 +1834,39 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level, /* export any potential modifications */ *level = ctx.level; *optname = ctx.optname; - *optlen = ctx.optlen; - *kernel_optval = ctx.optval; + + /* 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: - if (ret) - sockopt_free_buf(&ctx); + sockopt_free_buf(&ctx, &buf); return ret; } -EXPORT_SYMBOL(__cgroup_bpf_run_filter_setsockopt); int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, int optname, char __user *optval, @@ -1062,27 +1874,19 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, 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, - .retval = retval, + .current_task = current, }; int ret; - /* Opportunistic check to see whether we have any BPF program - * attached to the hook so we don't waste time allocating - * memory and locking the socket. - */ - if (!cgroup_bpf_enabled || - __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT)) - return retval; - - ret = sockopt_alloc_buf(&ctx, max_optlen); - if (ret) - return 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, @@ -1097,51 +1901,83 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, goto out; } - if (ctx.optlen > max_optlen) - ctx.optlen = max_optlen; + if (ctx.optlen < 0) { + ret = -EFAULT; + goto out; + } - if (copy_from_user(ctx.optval, optval, ctx.optlen) != 0) { + 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(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT], - &ctx, BPF_PROG_RUN); + ret = bpf_prog_run_array_cg(&cgrp->bpf, CGROUP_GETSOCKOPT, + &ctx, bpf_prog_run, retval, NULL); release_sock(sk); - if (!ret) { - ret = -EPERM; + if (ret < 0) goto out; - } - if (ctx.optlen > max_optlen) { + if (ctx.optlen > max_optlen || ctx.optlen < 0) { ret = -EFAULT; goto out; } - /* BPF programs only allowed to set retval to 0, not some - * arbitrary value. - */ - if (ctx.retval != 0 && ctx.retval != retval) { - 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; + } } - 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; +} - ret = ctx.retval; +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; -out: - sockopt_free_buf(&ctx); return ret; } -EXPORT_SYMBOL(__cgroup_bpf_run_filter_getsockopt); #endif static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp, @@ -1288,18 +2124,24 @@ static const struct bpf_func_proto bpf_sysctl_set_new_value_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, - .arg2_type = ARG_PTR_TO_MEM, + .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_strtol: - return &bpf_strtol_proto; - case BPF_FUNC_strtoul: - return &bpf_strtoul_proto; case BPF_FUNC_sysctl_get_name: return &bpf_sysctl_get_name_proto; case BPF_FUNC_sysctl_get_current_value: @@ -1308,8 +2150,12 @@ sysctl_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) 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 cgroup_base_func_proto(func_id, prog); + return bpf_base_func_proto(func_id); } } @@ -1411,22 +2257,60 @@ const struct bpf_verifier_ops cg_sysctl_verifier_ops = { 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 cgroup_base_func_proto(func_id, prog); + return bpf_base_func_proto(func_id); } } @@ -1451,7 +2335,7 @@ static bool cg_sockopt_is_valid_access(int off, int size, return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT; case offsetof(struct bpf_sockopt, optname): - /* fallthrough */ + fallthrough; case offsetof(struct bpf_sockopt, level): if (size != size_default) return false; @@ -1528,10 +2412,39 @@ static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type, *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optlen); break; case offsetof(struct bpf_sockopt, retval): - if (type == BPF_WRITE) - *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, retval); - else - *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, 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); @@ -1562,3 +2475,69 @@ const struct bpf_verifier_ops cg_sockopt_verifier_ops = { 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; + } +} |