| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Stanislav Fomichev | 3411 | 30.36% | 22 | 12.36% |
| Andrey Ignatov | 1766 | 15.72% | 12 | 6.74% |
| Andrii Nakryiko | 1403 | 12.49% | 14 | 7.87% |
| Alexei Starovoitov | 1345 | 11.97% | 19 | 10.67% |
| Roman Gushchin | 833 | 7.41% | 12 | 6.74% |
| Daniel Mack | 397 | 3.53% | 2 | 1.12% |
| YiFei Zhu | 394 | 3.51% | 4 | 2.25% |
| Tadeusz Struk | 217 | 1.93% | 1 | 0.56% |
| Sean Young | 215 | 1.91% | 2 | 1.12% |
| Dave Marchevsky | 214 | 1.90% | 1 | 0.56% |
| Yonghong Song | 122 | 1.09% | 3 | 1.69% |
| Daan De Meyer | 67 | 0.60% | 2 | 1.12% |
| Daniel Borkmann | 55 | 0.49% | 10 | 5.62% |
| Martin KaFai Lau | 51 | 0.45% | 3 | 1.69% |
| Eduard Zingerman | 47 | 0.42% | 1 | 0.56% |
| Paul Menage | 47 | 0.42% | 3 | 1.69% |
| Lawrence Brakmo | 44 | 0.39% | 2 | 1.12% |
| Tejun Heo | 42 | 0.37% | 3 | 1.69% |
| Kamalesh Babulal | 38 | 0.34% | 1 | 0.56% |
| David Ahern | 38 | 0.34% | 2 | 1.12% |
| Ilya Leoshkevich | 35 | 0.31% | 2 | 1.12% |
| Breno Leitão | 32 | 0.28% | 2 | 1.12% |
| Pu Lehui | 31 | 0.28% | 2 | 1.12% |
| Maxim Levitsky | 30 | 0.27% | 1 | 0.56% |
| Prankur gupta | 26 | 0.23% | 1 | 0.56% |
| Arnd Bergmann | 26 | 0.23% | 1 | 0.56% |
| Christoph Hellwig | 25 | 0.22% | 1 | 0.56% |
| Linus Torvalds (pre-git) | 25 | 0.22% | 9 | 5.06% |
| Loris Reiff | 24 | 0.21% | 2 | 1.12% |
| He Fengqing | 24 | 0.21% | 1 | 0.56% |
| Song Liu | 20 | 0.18% | 1 | 0.56% |
| Pavel Emelyanov | 16 | 0.14% | 2 | 1.12% |
| John Fastabend | 16 | 0.14% | 2 | 1.12% |
| Willem de Bruijn | 16 | 0.14% | 1 | 0.56% |
| Glauber de Oliveira Costa | 12 | 0.11% | 1 | 0.56% |
| Yue haibing | 10 | 0.09% | 1 | 0.56% |
| Eric W. Biedermann | 10 | 0.09% | 2 | 1.12% |
| KP Singh | 9 | 0.08% | 1 | 0.56% |
| Ingo Molnar | 8 | 0.07% | 1 | 0.56% |
| John Levon | 8 | 0.07% | 1 | 0.56% |
| Aristeu Sergio Rozanski Filho | 8 | 0.07% | 1 | 0.56% |
| Linus Torvalds | 7 | 0.06% | 1 | 0.56% |
| Jakub Sitnicki | 7 | 0.06% | 2 | 1.12% |
| Mauricio Vásquez | 7 | 0.06% | 1 | 0.56% |
| Yuntao Wang | 7 | 0.06% | 1 | 0.56% |
| Dmitrii Banshchikov | 6 | 0.05% | 1 | 0.56% |
| James Hogan | 6 | 0.05% | 1 | 0.56% |
| Brian Vazquez | 6 | 0.05% | 1 | 0.56% |
| Randy Dunlap | 5 | 0.04% | 1 | 0.56% |
| Shaun Pereira | 4 | 0.04% | 1 | 0.56% |
| Lorenz Bauer | 4 | 0.04% | 1 | 0.56% |
| Paul E. McKenney | 3 | 0.03% | 1 | 0.56% |
| Gustavo A. R. Silva | 2 | 0.02% | 1 | 0.56% |
| Jiri Olsa | 2 | 0.02% | 1 | 0.56% |
| Li Zefan | 2 | 0.02% | 1 | 0.56% |
| Thomas Gleixner | 2 | 0.02% | 1 | 0.56% |
| Hao Luo | 2 | 0.02% | 1 | 0.56% |
| Serge E. Hallyn | 1 | 0.01% | 1 | 0.56% |
| Arun Sharma | 1 | 0.01% | 1 | 0.56% |
| Pankaj Bharadiya | 1 | 0.01% | 1 | 0.56% |
| Eric Dumazet | 1 | 0.01% | 1 | 0.56% |
| Matthew Wilcox | 1 | 0.01% | 1 | 0.56% |
| Mickaël Salaün | 1 | 0.01% | 1 | 0.56% |
| Total | 11235 | 178 |
// SPDX-License-Identifier: GPL-2.0-only /* * Functions to manage eBPF programs attached to cgroups * * Copyright (c) 2016 Daniel Mack */ #include <linux/kernel.h> #include <linux/atomic.h> #include <linux/cgroup.h> #include <linux/filter.h> #include <linux/slab.h> #include <linux/sysctl.h> #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_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; cgroup_lock(); if (--cgroup_lsm_atype[i].refcnt <= 0) cgroup_lsm_atype[i].attach_btf_id = 0; WARN_ON_ONCE(cgroup_lsm_atype[i].refcnt < 0); cgroup_unlock(); } #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 * @work: work structure embedded into the cgroup to modify */ static void cgroup_bpf_release(struct work_struct *work) { struct cgroup *p, *cgrp = container_of(work, struct cgroup, bpf.release_work); struct bpf_prog_array *old_array; struct list_head *storages = &cgrp->bpf.storages; struct bpf_cgroup_storage *storage, *stmp; unsigned int atype; cgroup_lock(); 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[atype]); } old_array = rcu_dereference_protected( 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); } cgroup_unlock(); for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p)) cgroup_bpf_put(p); percpu_ref_exit(&cgrp->bpf.refcnt); cgroup_put(cgrp); } /** * cgroup_bpf_release_fn() - callback used to schedule releasing * of bpf cgroup data * @ref: percpu ref counter structure */ static void cgroup_bpf_release_fn(struct percpu_ref *ref) { struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt); INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release); 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 hlist_head *head) { struct bpf_prog_list *pl; u32 cnt = 0; hlist_for_each_entry(pl, head, node) { if (!prog_list_prog(pl)) continue; cnt++; } return cnt; } /* if parent has non-overridable prog attached, * disallow attaching new programs to the descendent cgroup. * if parent has overridable or multi-prog, allow attaching */ static bool hierarchy_allows_attach(struct cgroup *cgrp, enum cgroup_bpf_attach_type atype) { struct cgroup *p; p = cgroup_parent(cgrp); if (!p) return true; do { u32 flags = p->bpf.flags[atype]; u32 cnt; if (flags & BPF_F_ALLOW_MULTI) return true; cnt = prog_list_length(&p->bpf.progs[atype]); WARN_ON_ONCE(cnt > 1); if (cnt == 1) return !!(flags & BPF_F_ALLOW_OVERRIDE); p = cgroup_parent(p); } while (p); return true; } /* compute a chain of effective programs for a given cgroup: * start from the list of programs in this cgroup and add * all parent programs. * Note that parent's F_ALLOW_OVERRIDE-type program is yielding * to programs in this cgroup */ static int compute_effective_progs(struct cgroup *cgrp, enum cgroup_bpf_attach_type atype, struct bpf_prog_array **array) { struct bpf_prog_array_item *item; struct bpf_prog_array *progs; struct bpf_prog_list *pl; struct cgroup *p = cgrp; int cnt = 0; /* count number of effective programs by walking parents */ do { 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); progs = bpf_prog_array_alloc(cnt, GFP_KERNEL); if (!progs) return -ENOMEM; /* populate the array with effective progs */ cnt = 0; p = cgrp; do { if (cnt > 0 && !(p->bpf.flags[atype] & BPF_F_ALLOW_MULTI)) continue; hlist_for_each_entry(pl, &p->bpf.progs[atype], node) { if (!prog_list_prog(pl)) continue; 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))); *array = progs; return 0; } static void activate_effective_progs(struct cgroup *cgrp, enum cgroup_bpf_attach_type atype, struct bpf_prog_array *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 */ bpf_prog_array_free(old_array); } /** * cgroup_bpf_inherit() - inherit effective programs from parent * @cgrp: the cgroup to modify */ int cgroup_bpf_inherit(struct cgroup *cgrp) { /* 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; cgroup_lock(); ret = __cgroup_bpf_attach(cgrp, prog, replace_prog, link, type, flags); cgroup_unlock(); 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 * @new_prog: &struct bpf_prog for the target BPF program with its refcnt * incremented * * 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); cgroup_lock(); /* 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: cgroup_unlock(); 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; cgroup_lock(); ret = __cgroup_bpf_detach(cgrp, prog, NULL, type); cgroup_unlock(); 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; cgroup_lock(); ret = __cgroup_bpf_query(cgrp, attr, uattr); cgroup_unlock(); 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; cgroup_lock(); /* re-check cgroup under lock again */ if (!cg_link->cgroup) { cgroup_unlock(); 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; cgroup_unlock(); 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; cgroup_lock(); if (cg_link->cgroup) cg_id = cgroup_id(cg_link->cgroup); cgroup_unlock(); 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; cgroup_lock(); if (cg_link->cgroup) cg_id = cgroup_id(cg_link->cgroup); cgroup_unlock(); 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 * @atype: 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_network_offset(skb); struct sock *save_sk; void *saved_data_end; struct cgroup *cgrp; int ret; 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 * @atype: 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 * @uaddrlen: Pointer to the size of the sockaddr struct provided by user. It is * read-only for AF_INET[6] uaddr but can be modified for AF_UNIX * uaddr. * @atype: 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, INET6 or UNIX. * * 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, int *uaddrlen, 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; int ret; /* 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 && sk->sk_family != AF_UNIX) return 0; if (!ctx.uaddr) { memset(&unspec, 0, sizeof(unspec)); ctx.uaddr = (struct sockaddr *)&unspec; ctx.uaddrlen = 0; } else { ctx.uaddrlen = *uaddrlen; } cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); ret = bpf_prog_run_array_cg(&cgrp->bpf, atype, &ctx, bpf_prog_run, 0, flags); if (!ret && uaddr) *uaddrlen = ctx.uaddrlen; return ret; } 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. * @atype: 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, prog); } } 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 * @atype: 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, sockptr_t 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_sockptr(ctx.optval, optval, min(*optlen, max_optlen))) { 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 */ if (*optlen > PAGE_SIZE && ctx.optlen >= 0) { pr_info_once("bpf setsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n", ctx.optlen, max_optlen); ret = 0; goto out; } 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, sockptr_t optval, sockptr_t 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 orig_optlen; int ret; orig_optlen = max_optlen; 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 (copy_from_sockptr(&ctx.optlen, optlen, sizeof(ctx.optlen))) { ret = -EFAULT; goto out; } if (ctx.optlen < 0) { ret = -EFAULT; goto out; } orig_optlen = ctx.optlen; if (copy_from_sockptr(ctx.optval, optval, min(ctx.optlen, max_optlen))) { 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 (!sockptr_is_null(optval) && (ctx.optlen > max_optlen || ctx.optlen < 0)) { if (orig_optlen > PAGE_SIZE && ctx.optlen >= 0) { pr_info_once("bpf getsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n", ctx.optlen, max_optlen); ret = retval; goto out; } ret = -EFAULT; goto out; } if (ctx.optlen != 0) { if (!sockptr_is_null(optval) && copy_to_sockptr(optval, ctx.optval, ctx.optlen)) { ret = -EFAULT; goto out; } if (copy_to_sockptr(optlen, &ctx.optlen, sizeof(ctx.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, prog); } } 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_RAW_INSN( BPF_CLASS(si->code) | BPF_MEM | BPF_SIZEOF(u32), treg, si->src_reg, bpf_ctx_narrow_access_offset( 0, sizeof(u32), sizeof(loff_t)), si->imm); *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, prog); } } 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_READ_FIELD(F) \ BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F), \ si->dst_reg, si->src_reg, \ offsetof(struct bpf_sockopt_kern, F)) #define CG_SOCKOPT_WRITE_FIELD(F) \ BPF_RAW_INSN((BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F) | \ BPF_MEM | BPF_CLASS(si->code)), \ si->dst_reg, si->src_reg, \ offsetof(struct bpf_sockopt_kern, F), \ si->imm) 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_READ_FIELD(sk); break; case offsetof(struct bpf_sockopt, level): if (type == BPF_WRITE) *insn++ = CG_SOCKOPT_WRITE_FIELD(level); else *insn++ = CG_SOCKOPT_READ_FIELD(level); break; case offsetof(struct bpf_sockopt, optname): if (type == BPF_WRITE) *insn++ = CG_SOCKOPT_WRITE_FIELD(optname); else *insn++ = CG_SOCKOPT_READ_FIELD(optname); break; case offsetof(struct bpf_sockopt, optlen): if (type == BPF_WRITE) *insn++ = CG_SOCKOPT_WRITE_FIELD(optlen); else *insn++ = CG_SOCKOPT_READ_FIELD(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_RAW_INSN(BPF_CLASS(si->code) | BPF_MEM | BPF_FIELD_SIZEOF(struct bpf_cg_run_ctx, retval), treg, si->src_reg, offsetof(struct bpf_cg_run_ctx, retval), si->imm); *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_READ_FIELD(optval); break; case offsetof(struct bpf_sockopt, optval_end): *insn++ = CG_SOCKOPT_READ_FIELD(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_UNIX_RECVMSG: case BPF_CGROUP_INET4_GETPEERNAME: case BPF_CGROUP_INET6_GETPEERNAME: case BPF_CGROUP_UNIX_GETPEERNAME: case BPF_CGROUP_INET4_GETSOCKNAME: case BPF_CGROUP_INET6_GETSOCKNAME: case BPF_CGROUP_UNIX_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_UNIX_RECVMSG: case BPF_CGROUP_INET4_GETPEERNAME: case BPF_CGROUP_INET6_GETPEERNAME: case BPF_CGROUP_UNIX_GETPEERNAME: case BPF_CGROUP_INET4_GETSOCKNAME: case BPF_CGROUP_INET6_GETSOCKNAME: case BPF_CGROUP_UNIX_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; #ifdef CONFIG_CGROUP_NET_CLASSID case BPF_FUNC_get_cgroup_classid: return &bpf_get_cgroup_classid_curr_proto; #endif default: return NULL; } }
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