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-rw-r--r--include/linux/bpf-cgroup.h54
-rw-r--r--include/linux/bpf.h35
-rw-r--r--include/linux/filter.h2
-rw-r--r--include/uapi/linux/bpf.h55
-rw-r--r--kernel/bpf/cgroup.c513
-rw-r--r--kernel/bpf/core.c69
-rw-r--r--kernel/bpf/syscall.c71
-rw-r--r--kernel/bpf/verifier.c40
-rw-r--r--kernel/cgroup/cgroup.c38
-rw-r--r--samples/bpf/cgroup_helpers.c4
-rw-r--r--samples/bpf/test_cgrp2_attach2.c224
-rw-r--r--tools/include/uapi/linux/bpf.h55
-rw-r--r--tools/lib/bpf/bpf.c32
-rw-r--r--tools/lib/bpf/bpf.h4
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c72
15 files changed, 1086 insertions, 182 deletions
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index d41d40ac3efd..359b6f5d3d90 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -14,27 +14,46 @@ struct bpf_sock_ops_kern;
extern struct static_key_false cgroup_bpf_enabled_key;
#define cgroup_bpf_enabled static_branch_unlikely(&cgroup_bpf_enabled_key)
+struct bpf_prog_list {
+ struct list_head node;
+ struct bpf_prog *prog;
+};
+
+struct bpf_prog_array;
+
struct cgroup_bpf {
- /*
- * Store two sets of bpf_prog pointers, one for programs that are
- * pinned directly to this cgroup, and one for those that are effective
- * when this cgroup is accessed.
+ /* array of effective progs in this cgroup */
+ struct bpf_prog_array __rcu *effective[MAX_BPF_ATTACH_TYPE];
+
+ /* attached progs to this cgroup and attach flags
+ * when flags == 0 or BPF_F_ALLOW_OVERRIDE the progs list will
+ * have either zero or one element
+ * when BPF_F_ALLOW_MULTI the list can have up to BPF_CGROUP_MAX_PROGS
*/
- struct bpf_prog *prog[MAX_BPF_ATTACH_TYPE];
- struct bpf_prog __rcu *effective[MAX_BPF_ATTACH_TYPE];
- bool disallow_override[MAX_BPF_ATTACH_TYPE];
+ struct list_head progs[MAX_BPF_ATTACH_TYPE];
+ u32 flags[MAX_BPF_ATTACH_TYPE];
+
+ /* temp storage for effective prog array used by prog_attach/detach */
+ struct bpf_prog_array __rcu *inactive;
};
void cgroup_bpf_put(struct cgroup *cgrp);
-void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent);
-
-int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent,
- struct bpf_prog *prog, enum bpf_attach_type type,
- bool overridable);
-
-/* Wrapper for __cgroup_bpf_update() protected by cgroup_mutex */
-int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog,
- enum bpf_attach_type type, bool overridable);
+int cgroup_bpf_inherit(struct cgroup *cgrp);
+
+int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags);
+int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags);
+int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+ union bpf_attr __user *uattr);
+
+/* Wrapper for __cgroup_bpf_*() protected by cgroup_mutex */
+int cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags);
+int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags);
+int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+ union bpf_attr __user *uattr);
int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
@@ -96,8 +115,7 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
struct cgroup_bpf {};
static inline void cgroup_bpf_put(struct cgroup *cgrp) {}
-static inline void cgroup_bpf_inherit(struct cgroup *cgrp,
- struct cgroup *parent) {}
+static inline int cgroup_bpf_inherit(struct cgroup *cgrp) { return 0; }
#define BPF_CGROUP_RUN_PROG_INET_INGRESS(sk,skb) ({ 0; })
#define BPF_CGROUP_RUN_PROG_INET_EGRESS(sk,skb) ({ 0; })
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 252f4bc9eb25..a67daea731ab 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -241,6 +241,41 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
union bpf_attr __user *uattr);
+/* an array of programs to be executed under rcu_lock.
+ *
+ * Typical usage:
+ * ret = BPF_PROG_RUN_ARRAY(&bpf_prog_array, ctx, BPF_PROG_RUN);
+ *
+ * the structure returned by bpf_prog_array_alloc() should be populated
+ * with program pointers and the last pointer must be NULL.
+ * The user has to keep refcnt on the program and make sure the program
+ * is removed from the array before bpf_prog_put().
+ * The 'struct bpf_prog_array *' should only be replaced with xchg()
+ * since other cpus are walking the array of pointers in parallel.
+ */
+struct bpf_prog_array {
+ struct rcu_head rcu;
+ struct bpf_prog *progs[0];
+};
+
+struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags);
+void bpf_prog_array_free(struct bpf_prog_array __rcu *progs);
+int bpf_prog_array_length(struct bpf_prog_array __rcu *progs);
+int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
+ __u32 __user *prog_ids, u32 cnt);
+
+#define BPF_PROG_RUN_ARRAY(array, ctx, func) \
+ ({ \
+ struct bpf_prog **_prog; \
+ u32 _ret = 1; \
+ rcu_read_lock(); \
+ _prog = rcu_dereference(array)->progs; \
+ for (; *_prog; _prog++) \
+ _ret &= func(*_prog, ctx); \
+ rcu_read_unlock(); \
+ _ret; \
+ })
+
#ifdef CONFIG_BPF_SYSCALL
DECLARE_PER_CPU(int, bpf_prog_active);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 911d454af107..2d2db394b0ca 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -481,7 +481,7 @@ struct sk_filter {
struct bpf_prog *prog;
};
-#define BPF_PROG_RUN(filter, ctx) (*filter->bpf_func)(ctx, filter->insnsi)
+#define BPF_PROG_RUN(filter, ctx) (*(filter)->bpf_func)(ctx, (filter)->insnsi)
#define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6d2137b4cf38..cb2b9f95160a 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -92,6 +92,7 @@ enum bpf_cmd {
BPF_PROG_GET_FD_BY_ID,
BPF_MAP_GET_FD_BY_ID,
BPF_OBJ_GET_INFO_BY_FD,
+ BPF_PROG_QUERY,
};
enum bpf_map_type {
@@ -143,11 +144,47 @@ enum bpf_attach_type {
#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
-/* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
- * to the given target_fd cgroup the descendent cgroup will be able to
- * override effective bpf program that was inherited from this cgroup
+/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
+ *
+ * NONE(default): No further bpf programs allowed in the subtree.
+ *
+ * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
+ * the program in this cgroup yields to sub-cgroup program.
+ *
+ * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
+ * that cgroup program gets run in addition to the program in this cgroup.
+ *
+ * Only one program is allowed to be attached to a cgroup with
+ * NONE or BPF_F_ALLOW_OVERRIDE flag.
+ * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
+ * release old program and attach the new one. Attach flags has to match.
+ *
+ * Multiple programs are allowed to be attached to a cgroup with
+ * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
+ * (those that were attached first, run first)
+ * The programs of sub-cgroup are executed first, then programs of
+ * this cgroup and then programs of parent cgroup.
+ * When children program makes decision (like picking TCP CA or sock bind)
+ * parent program has a chance to override it.
+ *
+ * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
+ * A cgroup with NONE doesn't allow any programs in sub-cgroups.
+ * Ex1:
+ * cgrp1 (MULTI progs A, B) ->
+ * cgrp2 (OVERRIDE prog C) ->
+ * cgrp3 (MULTI prog D) ->
+ * cgrp4 (OVERRIDE prog E) ->
+ * cgrp5 (NONE prog F)
+ * the event in cgrp5 triggers execution of F,D,A,B in that order.
+ * if prog F is detached, the execution is E,D,A,B
+ * if prog F and D are detached, the execution is E,A,B
+ * if prog F, E and D are detached, the execution is C,A,B
+ *
+ * All eligible programs are executed regardless of return code from
+ * earlier programs.
*/
#define BPF_F_ALLOW_OVERRIDE (1U << 0)
+#define BPF_F_ALLOW_MULTI (1U << 1)
/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
* verifier will perform strict alignment checking as if the kernel
@@ -175,6 +212,9 @@ enum bpf_attach_type {
/* Specify numa node during map creation */
#define BPF_F_NUMA_NODE (1U << 2)
+/* flags for BPF_PROG_QUERY */
+#define BPF_F_QUERY_EFFECTIVE (1U << 0)
+
#define BPF_OBJ_NAME_LEN 16U
union bpf_attr {
@@ -253,6 +293,15 @@ union bpf_attr {
__u32 info_len;
__aligned_u64 info;
} info;
+
+ struct { /* anonymous struct used by BPF_PROG_QUERY command */
+ __u32 target_fd; /* container object to query */
+ __u32 attach_type;
+ __u32 query_flags;
+ __u32 attach_flags;
+ __aligned_u64 prog_ids;
+ __u32 prog_cnt;
+ } query;
} __attribute__((aligned(8)));
/* BPF helper function descriptions:
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 546113430049..e88abc0865d5 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -27,129 +27,407 @@ void cgroup_bpf_put(struct cgroup *cgrp)
{
unsigned int type;
- for (type = 0; type < ARRAY_SIZE(cgrp->bpf.prog); type++) {
- struct bpf_prog *prog = cgrp->bpf.prog[type];
-
- if (prog) {
- bpf_prog_put(prog);
+ for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) {
+ struct list_head *progs = &cgrp->bpf.progs[type];
+ struct bpf_prog_list *pl, *tmp;
+
+ list_for_each_entry_safe(pl, tmp, progs, node) {
+ list_del(&pl->node);
+ bpf_prog_put(pl->prog);
+ kfree(pl);
static_branch_dec(&cgroup_bpf_enabled_key);
}
+ bpf_prog_array_free(cgrp->bpf.effective[type]);
+ }
+}
+
+/* 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)
+{
+ struct bpf_prog_list *pl;
+ u32 cnt = 0;
+
+ list_for_each_entry(pl, head, node) {
+ if (!pl->prog)
+ 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 bpf_attach_type type,
+ u32 new_flags)
+{
+ struct cgroup *p;
+
+ p = cgroup_parent(cgrp);
+ if (!p)
+ return true;
+ do {
+ u32 flags = p->bpf.flags[type];
+ u32 cnt;
+
+ if (flags & BPF_F_ALLOW_MULTI)
+ return true;
+ cnt = prog_list_length(&p->bpf.progs[type]);
+ 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 bpf_attach_type type,
+ struct bpf_prog_array __rcu **array)
+{
+ struct bpf_prog_array __rcu *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[type] & BPF_F_ALLOW_MULTI))
+ cnt += prog_list_length(&p->bpf.progs[type]);
+ 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[type] & BPF_F_ALLOW_MULTI))
+ list_for_each_entry(pl,
+ &p->bpf.progs[type], node) {
+ if (!pl->prog)
+ continue;
+ rcu_dereference_protected(progs, 1)->
+ progs[cnt++] = pl->prog;
+ }
+ p = cgroup_parent(p);
+ } while (p);
+
+ *array = progs;
+ return 0;
+}
+
+static void activate_effective_progs(struct cgroup *cgrp,
+ enum bpf_attach_type type,
+ struct bpf_prog_array __rcu *array)
+{
+ struct bpf_prog_array __rcu *old_array;
+
+ old_array = xchg(&cgrp->bpf.effective[type], array);
+ /* 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
- * @parent: the parent to inherit from
*/
-void cgroup_bpf_inherit(struct cgroup *cgrp, struct cgroup *parent)
+int cgroup_bpf_inherit(struct cgroup *cgrp)
{
- unsigned int type;
+/* 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 __rcu *arrays[NR] = {};
+ int i;
- for (type = 0; type < ARRAY_SIZE(cgrp->bpf.effective); type++) {
- struct bpf_prog *e;
+ for (i = 0; i < NR; i++)
+ INIT_LIST_HEAD(&cgrp->bpf.progs[i]);
- e = rcu_dereference_protected(parent->bpf.effective[type],
- lockdep_is_held(&cgroup_mutex));
- rcu_assign_pointer(cgrp->bpf.effective[type], e);
- cgrp->bpf.disallow_override[type] = parent->bpf.disallow_override[type];
- }
+ 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]);
+ return -ENOMEM;
}
+#define BPF_CGROUP_MAX_PROGS 64
+
/**
- * __cgroup_bpf_update() - Update the pinned program of a cgroup, and
+ * __cgroup_bpf_attach() - Attach the program to a cgroup, and
* propagate the change to descendants
* @cgrp: The cgroup which descendants to traverse
- * @parent: The parent of @cgrp, or %NULL if @cgrp is the root
- * @prog: A new program to pin
- * @type: Type of pinning operation (ingress/egress)
- *
- * Each cgroup has a set of two pointers for bpf programs; one for eBPF
- * programs it owns, and which is effective for execution.
- *
- * If @prog is not %NULL, this function attaches a new program to the cgroup
- * and releases the one that is currently attached, if any. @prog is then made
- * the effective program of type @type in that cgroup.
- *
- * If @prog is %NULL, the currently attached program of type @type is released,
- * and the effective program of the parent cgroup (if any) is inherited to
- * @cgrp.
- *
- * Then, the descendants of @cgrp are walked and the effective program for
- * each of them is set to the effective program of @cgrp unless the
- * descendant has its own program attached, in which case the subbranch is
- * skipped. This ensures that delegated subcgroups with own programs are left
- * untouched.
+ * @prog: A program to attach
+ * @type: Type of attach operation
*
* Must be called with cgroup_mutex held.
*/
-int __cgroup_bpf_update(struct cgroup *cgrp, struct cgroup *parent,
- struct bpf_prog *prog, enum bpf_attach_type type,
- bool new_overridable)
+int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags)
{
- struct bpf_prog *old_prog, *effective = NULL;
- struct cgroup_subsys_state *pos;
- bool overridable = true;
-
- if (parent) {
- overridable = !parent->bpf.disallow_override[type];
- effective = rcu_dereference_protected(parent->bpf.effective[type],
- lockdep_is_held(&cgroup_mutex));
- }
-
- if (prog && effective && !overridable)
- /* if parent has non-overridable prog attached, disallow
- * attaching new programs to descendent cgroup
- */
+ struct list_head *progs = &cgrp->bpf.progs[type];
+ struct bpf_prog *old_prog = NULL;
+ struct cgroup_subsys_state *css;
+ struct bpf_prog_list *pl;
+ bool pl_was_allocated;
+ u32 old_flags;
+ int err;
+
+ if ((flags & BPF_F_ALLOW_OVERRIDE) && (flags & BPF_F_ALLOW_MULTI))
+ /* invalid combination */
+ return -EINVAL;
+
+ if (!hierarchy_allows_attach(cgrp, type, flags))
return -EPERM;
- if (prog && effective && overridable != new_overridable)
- /* if parent has overridable prog attached, only
- * allow overridable programs in descendent cgroup
+ if (!list_empty(progs) && cgrp->bpf.flags[type] != flags)
+ /* Disallow attaching non-overridable on top
+ * of existing overridable in this cgroup.
+ * Disallow attaching multi-prog if overridable or none
*/
return -EPERM;
- old_prog = cgrp->bpf.prog[type];
-
- if (prog) {
- overridable = new_overridable;
- effective = prog;
- if (old_prog &&
- cgrp->bpf.disallow_override[type] == new_overridable)
- /* disallow attaching non-overridable on top
- * of existing overridable in this cgroup
- * and vice versa
- */
- return -EPERM;
+ 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;
+
+ pl = kmalloc(sizeof(*pl), GFP_KERNEL);
+ if (!pl)
+ return -ENOMEM;
+ pl_was_allocated = true;
+ pl->prog = prog;
+ list_add_tail(&pl->node, progs);
+ } else {
+ if (list_empty(progs)) {
+ pl = kmalloc(sizeof(*pl), GFP_KERNEL);
+ if (!pl)
+ return -ENOMEM;
+ pl_was_allocated = true;
+ list_add_tail(&pl->node, progs);
+ } else {
+ pl = list_first_entry(progs, typeof(*pl), node);
+ old_prog = pl->prog;
+ pl_was_allocated = false;
+ }
+ pl->prog = prog;
}
- if (!prog && !old_prog)
- /* report error when trying to detach and nothing is attached */
- return -ENOENT;
-
- cgrp->bpf.prog[type] = prog;
+ old_flags = cgrp->bpf.flags[type];
+ cgrp->bpf.flags[type] = flags;
- css_for_each_descendant_pre(pos, &cgrp->self) {
- struct cgroup *desc = container_of(pos, struct cgroup, self);
+ /* allocate and recompute effective prog arrays */
+ css_for_each_descendant_pre(css, &cgrp->self) {
+ struct cgroup *desc = container_of(css, struct cgroup, self);
- /* skip the subtree if the descendant has its own program */
- if (desc->bpf.prog[type] && desc != cgrp) {
- pos = css_rightmost_descendant(pos);
- } else {
- rcu_assign_pointer(desc->bpf.effective[type],
- effective);
- desc->bpf.disallow_override[type] = !overridable;
- }
+ err = compute_effective_progs(desc, type, &desc->bpf.inactive);
+ if (err)
+ goto cleanup;
}
- if (prog)
- static_branch_inc(&cgroup_bpf_enabled_key);
+ /* 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);
+
+ activate_effective_progs(desc, type, desc->bpf.inactive);
+ desc->bpf.inactive = NULL;
+ }
+ static_branch_inc(&cgroup_bpf_enabled_key);
if (old_prog) {
bpf_prog_put(old_prog);
static_branch_dec(&cgroup_bpf_enabled_key);
}
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;
+ }
+
+ /* and cleanup the prog list */
+ pl->prog = old_prog;
+ if (pl_was_allocated) {
+ list_del(&pl->node);
+ kfree(pl);
+ }
+ return err;
+}
+
+/**
+ * __cgroup_bpf_detach() - Detach the program from a cgroup, 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
+ *
+ * Must be called with cgroup_mutex held.
+ */
+int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 unused_flags)
+{
+ struct list_head *progs = &cgrp->bpf.progs[type];
+ u32 flags = cgrp->bpf.flags[type];
+ struct bpf_prog *old_prog = NULL;
+ struct cgroup_subsys_state *css;
+ struct bpf_prog_list *pl;
+ int err;
+
+ 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;
+ }
+
+ 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;
+ break;
+ }
+ if (!old_prog)
+ return -ENOENT;
+ } else {
+ /* to maintain backward compatibility NONE and OVERRIDE cgroups
+ * allow detaching with invalid FD (prog==NULL)
+ */
+ pl = list_first_entry(progs, typeof(*pl), node);
+ old_prog = pl->prog;
+ pl->prog = NULL;
+ }
+
+ /* allocate and recompute effective prog arrays */
+ css_for_each_descendant_pre(css, &cgrp->self) {
+ struct cgroup *desc = container_of(css, struct cgroup, self);
+
+ err = compute_effective_progs(desc, type, &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);
+
+ activate_effective_progs(desc, type, desc->bpf.inactive);
+ desc->bpf.inactive = NULL;
+ }
+
+ /* now can actually delete it from this cgroup list */
+ list_del(&pl->node);
+ kfree(pl);
+ if (list_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);
+ 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;
+ }
+
+ /* and restore back old_prog */
+ pl->prog = old_prog;
+ return err;
+}
+
+/* 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)
+{
+ __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];
+ int cnt, ret = 0, i;
+
+ if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE)
+ cnt = bpf_prog_array_length(cgrp->bpf.effective[type]);
+ else
+ cnt = prog_list_length(progs);
+
+ if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
+ return -EFAULT;
+ if (copy_to_user(&uattr->query.prog_cnt, &cnt, sizeof(cnt)))
+ return -EFAULT;
+ if (attr->query.prog_cnt == 0 || !prog_ids || !cnt)
+ /* return early if user requested only program count + flags */
+ return 0;
+ if (attr->query.prog_cnt < cnt) {
+ cnt = attr->query.prog_cnt;
+ ret = -ENOSPC;
+ }
+
+ if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) {
+ return bpf_prog_array_copy_to_user(cgrp->bpf.effective[type],
+ 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;
+ }
+ }
+ return ret;
}
/**
@@ -171,36 +449,26 @@ int __cgroup_bpf_run_filter_skb(struct sock *sk,
struct sk_buff *skb,
enum bpf_attach_type type)
{
- struct bpf_prog *prog;
+ unsigned int offset = skb->data - skb_network_header(skb);
+ struct sock *save_sk;
struct cgroup *cgrp;
- int ret = 0;
+ int ret;
if (!sk || !sk_fullsock(sk))
return 0;
- if (sk->sk_family != AF_INET &&
- sk->sk_family != AF_INET6)
+ if (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)
return 0;
cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
-
- rcu_read_lock();
-
- prog = rcu_dereference(cgrp->bpf.effective[type]);
- if (prog) {
- unsigned int offset = skb->data - skb_network_header(skb);
- struct sock *save_sk = skb->sk;
-
- skb->sk = sk;
- __skb_push(skb, offset);
- ret = bpf_prog_run_save_cb(prog, skb) == 1 ? 0 : -EPERM;
- __skb_pull(skb, offset);
- skb->sk = save_sk;
- }
-
- rcu_read_unlock();
-
- return ret;
+ save_sk = skb->sk;
+ skb->sk = sk;
+ __skb_push(skb, offset);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], skb,
+ bpf_prog_run_save_cb);
+ __skb_pull(skb, offset);
+ skb->sk = save_sk;
+ return ret == 1 ? 0 : -EPERM;
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_skb);
@@ -221,19 +489,10 @@ int __cgroup_bpf_run_filter_sk(struct sock *sk,
enum bpf_attach_type type)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- struct bpf_prog *prog;
- int ret = 0;
-
-
- rcu_read_lock();
-
- prog = rcu_dereference(cgrp->bpf.effective[type]);
- if (prog)
- ret = BPF_PROG_RUN(prog, sk) == 1 ? 0 : -EPERM;
-
- rcu_read_unlock();
+ int ret;
- return ret;
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sk, BPF_PROG_RUN);
+ return ret == 1 ? 0 : -EPERM;
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sk);
@@ -258,18 +517,10 @@ int __cgroup_bpf_run_filter_sock_ops(struct sock *sk,
enum bpf_attach_type type)
{
struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
- struct bpf_prog *prog;
- int ret = 0;
-
-
- rcu_read_lock();
+ int ret;
- prog = rcu_dereference(cgrp->bpf.effective[type]);
- if (prog)
- ret = BPF_PROG_RUN(prog, sock_ops) == 1 ? 0 : -EPERM;
-
- rcu_read_unlock();
-
- return ret;
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[type], sock_ops,
+ BPF_PROG_RUN);
+ return ret == 1 ? 0 : -EPERM;
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sock_ops);
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 917cc04a0a94..eba966c09053 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1381,6 +1381,75 @@ struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
}
EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
+/* to avoid allocating empty bpf_prog_array for cgroups that
+ * don't have bpf program attached use one global 'empty_prog_array'
+ * It will not be modified the caller of bpf_prog_array_alloc()
+ * (since caller requested prog_cnt == 0)
+ * that pointer should be 'freed' by bpf_prog_array_free()
+ */
+static struct {
+ struct bpf_prog_array hdr;
+ struct bpf_prog *null_prog;
+} empty_prog_array = {
+ .null_prog = NULL,
+};
+
+struct bpf_prog_array __rcu *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
+{
+ if (prog_cnt)
+ return kzalloc(sizeof(struct bpf_prog_array) +
+ sizeof(struct bpf_prog *) * (prog_cnt + 1),
+ flags);
+
+ return &empty_prog_array.hdr;
+}
+
+void bpf_prog_array_free(struct bpf_prog_array __rcu *progs)
+{
+ if (!progs ||
+ progs == (struct bpf_prog_array __rcu *)&empty_prog_array.hdr)
+ return;
+ kfree_rcu(progs, rcu);
+}
+
+int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
+{
+ struct bpf_prog **prog;
+ u32 cnt = 0;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++)
+ cnt++;
+ rcu_read_unlock();
+ return cnt;
+}
+
+int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
+ __u32 __user *prog_ids, u32 cnt)
+{
+ struct bpf_prog **prog;
+ u32 i = 0, id;
+
+ rcu_read_lock();
+ prog = rcu_dereference(progs)->progs;
+ for (; *prog; prog++) {
+ id = (*prog)->aux->id;
+ if (copy_to_user(prog_ids + i, &id, sizeof(id))) {
+ rcu_read_unlock();
+ return -EFAULT;
+ }
+ if (++i == cnt) {
+ prog++;
+ break;
+ }
+ }
+ rcu_read_unlock();
+ if (*prog)
+ return -ENOSPC;
+ return 0;
+}
+
static void bpf_prog_free_deferred(struct work_struct *work)
{
struct bpf_prog_aux *aux;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index b927da66f653..0048cb24ba7b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1168,6 +1168,9 @@ static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)
return 0;
}
+#define BPF_F_ATTACH_MASK \
+ (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
+
static int bpf_prog_attach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
@@ -1181,7 +1184,7 @@ static int bpf_prog_attach(const union bpf_attr *attr)
if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;
- if (attr->attach_flags & ~BPF_F_ALLOW_OVERRIDE)
+ if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
return -EINVAL;
switch (attr->attach_type) {
@@ -1212,8 +1215,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
return PTR_ERR(cgrp);
}
- ret = cgroup_bpf_update(cgrp, prog, attr->attach_type,
- attr->attach_flags & BPF_F_ALLOW_OVERRIDE);
+ ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
+ attr->attach_flags);
if (ret)
bpf_prog_put(prog);
cgroup_put(cgrp);
@@ -1225,6 +1228,8 @@ static int bpf_prog_attach(const union bpf_attr *attr)
static int bpf_prog_detach(const union bpf_attr *attr)
{
+ enum bpf_prog_type ptype;
+ struct bpf_prog *prog;
struct cgroup *cgrp;
int ret;
@@ -1237,26 +1242,67 @@ static int bpf_prog_detach(const union bpf_attr *attr)
switch (attr->attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
+ ptype = BPF_PROG_TYPE_CGROUP_SKB;
+ break;
case BPF_CGROUP_INET_SOCK_CREATE:
+ ptype = BPF_PROG_TYPE_CGROUP_SOCK;
+ break;
case BPF_CGROUP_SOCK_OPS:
- cgrp = cgroup_get_from_fd(attr->target_fd);
- if (IS_ERR(cgrp))
- return PTR_ERR(cgrp);
-
- ret = cgroup_bpf_update(cgrp, NULL, attr->attach_type, false);
- cgroup_put(cgrp);
+ ptype = BPF_PROG_TYPE_SOCK_OPS;
break;
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
- ret = sockmap_get_from_fd(attr, false);
- break;
+ return sockmap_get_from_fd(attr, false);
default:
return -EINVAL;
}
+ 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, 0);
+ if (prog)
+ bpf_prog_put(prog);
+ cgroup_put(cgrp);
return ret;
}
+#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
+
+static int bpf_prog_query(const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ struct cgroup *cgrp;
+ int ret;
+
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+ if (CHECK_ATTR(BPF_PROG_QUERY))
+ return -EINVAL;
+ if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
+ return -EINVAL;
+
+ switch (attr->query.attach_type) {
+ case BPF_CGROUP_INET_INGRESS:
+ case BPF_CGROUP_INET_EGRESS:
+ case BPF_CGROUP_INET_SOCK_CREATE:
+ case BPF_CGROUP_SOCK_OPS:
+ break;
+ default:
+ return -EINVAL;
+ }
+ 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;
+}
#endif /* CONFIG_CGROUP_BPF */
#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
@@ -1553,6 +1599,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
case BPF_PROG_DETACH:
err = bpf_prog_detach(&attr);
break;
+ case BPF_PROG_QUERY:
+ err = bpf_prog_query(&attr, uattr);
+ break;
#endif
case BPF_PROG_TEST_RUN:
err = bpf_prog_test_run(&attr, uattr);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 4cf9b72c59a0..52b022310f6a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3073,6 +3073,43 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn)
return 0;
}
+static int check_return_code(struct bpf_verifier_env *env)
+{
+ struct bpf_reg_state *reg;
+ struct tnum range = tnum_range(0, 1);
+
+ switch (env->prog->type) {
+ case BPF_PROG_TYPE_CGROUP_SKB:
+ case BPF_PROG_TYPE_CGROUP_SOCK:
+ case BPF_PROG_TYPE_SOCK_OPS:
+ break;
+ default:
+ return 0;
+ }
+
+ reg = &env->cur_state.regs[BPF_REG_0];
+ if (reg->type != SCALAR_VALUE) {
+ verbose("At program exit the register R0 is not a known value (%s)\n",
+ reg_type_str[reg->type]);
+ return -EINVAL;
+ }
+
+ if (!tnum_in(range, reg->var_off)) {
+ verbose("At program exit the register R0 ");
+ if (!tnum_is_unknown(reg->var_off)) {
+ char tn_buf[48];
+
+ tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off);
+ verbose("has value %s", tn_buf);
+ } else {
+ verbose("has unknown scalar value");
+ }
+ verbose(" should have been 0 or 1\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
/* non-recursive DFS pseudo code
* 1 procedure DFS-iterative(G,v):
* 2 label v as discovered
@@ -3863,6 +3900,9 @@ static int do_check(struct bpf_verifier_env *env)
return -EACCES;
}
+ err = check_return_code(env);
+ if (err)
+ return err;
process_bpf_exit:
insn_idx = pop_stack(env, &prev_insn_idx);
if (insn_idx < 0) {
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index d6551cd45238..269512b94a94 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1896,6 +1896,9 @@ int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask, int ref_flags)
if (ret)
goto destroy_root;
+ ret = cgroup_bpf_inherit(root_cgrp);
+ WARN_ON_ONCE(ret);
+
trace_cgroup_setup_root(root);
/*
@@ -4713,6 +4716,9 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
cgrp->self.parent = &parent->self;
cgrp->root = root;
cgrp->level = level;
+ ret = cgroup_bpf_inherit(cgrp);
+ if (ret)
+ goto out_idr_free;
for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) {
cgrp->ancestor_ids[tcgrp->level] = tcgrp->id;
@@ -4747,13 +4753,12 @@ static struct cgroup *cgroup_create(struct cgroup *parent)
if (!cgroup_on_dfl(cgrp))
cgrp->subtree_control = cgroup_control(cgrp);
- if (parent)
- cgroup_bpf_inherit(cgrp, parent);
-
cgroup_propagate_control(cgrp);
return cgrp;
+out_idr_free:
+ cgroup_idr_remove(&root->cgroup_idr, cgrp->id);
out_cancel_ref:
percpu_ref_exit(&cgrp->self.refcnt);
out_free_cgrp:
@@ -5736,14 +5741,33 @@ void cgroup_sk_free(struct sock_cgroup_data *skcd)
#endif /* CONFIG_SOCK_CGROUP_DATA */
#ifdef CONFIG_CGROUP_BPF
-int cgroup_bpf_update(struct cgroup *cgrp, struct bpf_prog *prog,
- enum bpf_attach_type type, bool overridable)
+int cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags)
+{
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+ ret = __cgroup_bpf_attach(cgrp, prog, type, flags);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+int cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog,
+ enum bpf_attach_type type, u32 flags)
+{
+ int ret;
+
+ mutex_lock(&cgroup_mutex);
+ ret = __cgroup_bpf_detach(cgrp, prog, type, flags);
+ mutex_unlock(&cgroup_mutex);
+ return ret;
+}
+int cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
{
- struct cgroup *parent = cgroup_parent(cgrp);
int ret;
mutex_lock(&cgroup_mutex);
- ret = __cgroup_bpf_update(cgrp, parent, prog, type, overridable);
+ ret = __cgroup_bpf_query(cgrp, attr, uattr);
mutex_unlock(&cgroup_mutex);
return ret;
}
diff --git a/samples/bpf/cgroup_helpers.c b/samples/bpf/cgroup_helpers.c
index 9d1be9426401..88bdcf4b1670 100644
--- a/samples/bpf/cgroup_helpers.c
+++ b/samples/bpf/cgroup_helpers.c
@@ -56,7 +56,7 @@ int setup_cgroup_environment(void)
return 1;
}
- if (mount("none", CGROUP_MOUNT_PATH, "cgroup2", 0, NULL)) {
+ if (mount("none", CGROUP_MOUNT_PATH, "cgroup2", 0, NULL) && errno != EBUSY) {
log_err("mount cgroup2");
return 1;
}
@@ -163,7 +163,7 @@ int create_and_get_cgroup(char *path)
format_cgroup_path(cgroup_path, path);
if (mkdir(cgroup_path, 0777) && errno != EEXIST) {
- log_err("mkdiring cgroup");
+ log_err("mkdiring cgroup %s .. %s", path, cgroup_path);
return 0;
}
diff --git a/samples/bpf/test_cgrp2_attach2.c b/samples/bpf/test_cgrp2_attach2.c
index 3049b1f26267..3e8232cc04a8 100644
--- a/samples/bpf/test_cgrp2_attach2.c
+++ b/samples/bpf/test_cgrp2_attach2.c
@@ -30,7 +30,7 @@
#define FOO "/foo"
#define BAR "/foo/bar/"
-#define PING_CMD "ping -c1 -w1 127.0.0.1"
+#define PING_CMD "ping -c1 -w1 127.0.0.1 > /dev/null"
char bpf_log_buf[BPF_LOG_BUF_SIZE];
@@ -55,8 +55,7 @@ static int prog_load(int verdict)
return ret;
}
-
-int main(int argc, char **argv)
+static int test_foo_bar(void)
{
int drop_prog, allow_prog, foo = 0, bar = 0, rc = 0;
@@ -189,8 +188,223 @@ out:
close(bar);
cleanup_cgroup_environment();
if (!rc)
- printf("PASS\n");
+ printf("### override:PASS\n");
else
- printf("FAIL\n");
+ printf("### override:FAIL\n");
return rc;
}
+
+static int map_fd = -1;
+
+static int prog_load_cnt(int verdict, int val)
+{
+ if (map_fd < 0)
+ map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
+ if (map_fd < 0) {
+ printf("failed to create map '%s'\n", strerror(errno));
+ return -1;
+ }
+
+ struct bpf_insn prog[] = {
+ BPF_MOV32_IMM(BPF_REG_0, 0),
+ BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
+ BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+ BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+ BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+ BPF_MOV64_IMM(BPF_REG_1, val), /* r1 = 1 */
+ BPF_RAW_INSN(BPF_STX | BPF_XADD | BPF_DW, BPF_REG_0, BPF_REG_1, 0, 0), /* xadd r0 += r1 */
+ BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */
+ BPF_EXIT_INSN(),
+ };
+ size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
+ int ret;
+
+ ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
+ prog, insns_cnt, "GPL", 0,
+ bpf_log_buf, BPF_LOG_BUF_SIZE);
+
+ if (ret < 0) {
+ log_err("Loading program");
+ printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);
+ return 0;
+ }
+ return ret;
+}
+
+
+static int test_multiprog(void)
+{
+ __u32 prog_ids[4], prog_cnt = 0, attach_flags, saved_prog_id;
+ int cg1 = 0, cg2 = 0, cg3 = 0, cg4 = 0, cg5 = 0, key = 0;
+ int drop_prog, allow_prog[6] = {}, rc = 0;
+ unsigned long long value;
+ int i = 0;
+
+ for (i = 0; i < 6; i++) {
+ allow_prog[i] = prog_load_cnt(1, 1 << i);
+ if (!allow_prog[i])
+ goto err;
+ }
+ drop_prog = prog_load_cnt(0, 1);
+ if (!drop_prog)
+ goto err;
+
+ if (setup_cgroup_environment())
+ goto err;
+
+ cg1 = create_and_get_cgroup("/cg1");
+ if (!cg1)
+ goto err;
+ cg2 = create_and_get_cgroup("/cg1/cg2");
+ if (!cg2)
+ goto err;
+ cg3 = create_and_get_cgroup("/cg1/cg2/cg3");
+ if (!cg3)
+ goto err;
+ cg4 = create_and_get_cgroup("/cg1/cg2/cg3/cg4");
+ if (!cg4)
+ goto err;
+ cg5 = create_and_get_cgroup("/cg1/cg2/cg3/cg4/cg5");
+ if (!cg5)
+ goto err;
+
+ if (join_cgroup("/cg1/cg2/cg3/cg4/cg5"))
+ goto err;
+
+ if (bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
+ log_err("Attaching prog to cg1");
+ goto err;
+ }
+ if (!bpf_prog_attach(allow_prog[0], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
+ log_err("Unexpected success attaching the same prog to cg1");
+ goto err;
+ }
+ if (bpf_prog_attach(allow_prog[1], cg1, BPF_CGROUP_INET_EGRESS, 2)) {
+ log_err("Attaching prog2 to cg1");
+ goto err;
+ }
+ if (bpf_prog_attach(allow_prog[2], cg2, BPF_CGROUP_INET_EGRESS, 1)) {
+ log_err("Attaching prog to cg2");
+ goto err;
+ }
+ if (bpf_prog_attach(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS, 2)) {
+ log_err("Attaching prog to cg3");
+ goto err;
+ }
+ if (bpf_prog_attach(allow_prog[4], cg4, BPF_CGROUP_INET_EGRESS, 1)) {
+ log_err("Attaching prog to cg4");
+ goto err;
+ }
+ if (bpf_prog_attach(allow_prog[5], cg5, BPF_CGROUP_INET_EGRESS, 0)) {
+ log_err("Attaching prog to cg5");
+ goto err;
+ }
+ assert(system(PING_CMD) == 0);
+ assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+ assert(value == 1 + 2 + 8 + 32);
+
+ /* query the number of effective progs in cg5 */
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
+ NULL, NULL, &prog_cnt) == 0);
+ assert(prog_cnt == 4);
+ /* retrieve prog_ids of effective progs in cg5 */
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
+ &attach_flags, prog_ids, &prog_cnt) == 0);
+ assert(prog_cnt == 4);
+ assert(attach_flags == 0);
+ saved_prog_id = prog_ids[0];
+ /* check enospc handling */
+ prog_ids[0] = 0;
+ prog_cnt = 2;
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
+ &attach_flags, prog_ids, &prog_cnt) == -1 &&
+ errno == ENOSPC);
+ assert(prog_cnt == 4);
+ /* check that prog_ids are returned even when buffer is too small */
+ assert(prog_ids[0] == saved_prog_id);
+ /* retrieve prog_id of single attached prog in cg5 */
+ prog_ids[0] = 0;
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
+ NULL, prog_ids, &prog_cnt) == 0);
+ assert(prog_cnt == 1);
+ assert(prog_ids[0] == saved_prog_id);
+
+ /* detach bottom program and ping again */
+ if (bpf_prog_detach2(-1, cg5, BPF_CGROUP_INET_EGRESS)) {
+ log_err("Detaching prog from cg5");
+ goto err;
+ }
+ value = 0;
+ assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
+ assert(system(PING_CMD) == 0);
+ assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+ assert(value == 1 + 2 + 8 + 16);
+
+ /* detach 3rd from bottom program and ping again */
+ errno = 0;
+ if (!bpf_prog_detach2(0, cg3, BPF_CGROUP_INET_EGRESS)) {
+ log_err("Unexpected success on detach from cg3");
+ goto err;
+ }
+ if (bpf_prog_detach2(allow_prog[3], cg3, BPF_CGROUP_INET_EGRESS)) {
+ log_err("Detaching from cg3");
+ goto err;
+ }
+ value = 0;
+ assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
+ assert(system(PING_CMD) == 0);
+ assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+ assert(value == 1 + 2 + 16);
+
+ /* detach 2nd from bottom program and ping again */
+ if (bpf_prog_detach2(-1, cg4, BPF_CGROUP_INET_EGRESS)) {
+ log_err("Detaching prog from cg4");
+ goto err;
+ }
+ value = 0;
+ assert(bpf_map_update_elem(map_fd, &key, &value, 0) == 0);
+ assert(system(PING_CMD) == 0);
+ assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+ assert(value == 1 + 2 + 4);
+
+ prog_cnt = 4;
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, BPF_F_QUERY_EFFECTIVE,
+ &attach_flags, prog_ids, &prog_cnt) == 0);
+ assert(prog_cnt == 3);
+ assert(attach_flags == 0);
+ assert(bpf_prog_query(cg5, BPF_CGROUP_INET_EGRESS, 0,
+ NULL, prog_ids, &prog_cnt) == 0);
+ assert(prog_cnt == 0);
+ goto out;
+err:
+ rc = 1;
+
+out:
+ for (i = 0; i < 6; i++)
+ if (allow_prog[i] > 0)
+ close(allow_prog[i]);
+ close(cg1);
+ close(cg2);
+ close(cg3);
+ close(cg4);
+ close(cg5);
+ cleanup_cgroup_environment();
+ if (!rc)
+ printf("### multi:PASS\n");
+ else
+ printf("### multi:FAIL\n");
+ return rc;
+}
+
+int main(int argc, char **argv)
+{
+ int rc = 0;
+
+ rc = test_foo_bar();
+ if (rc)
+ return rc;
+
+ return test_multiprog();
+}
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 6d2137b4cf38..cb2b9f95160a 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -92,6 +92,7 @@ enum bpf_cmd {
BPF_PROG_GET_FD_BY_ID,
BPF_MAP_GET_FD_BY_ID,
BPF_OBJ_GET_INFO_BY_FD,
+ BPF_PROG_QUERY,
};
enum bpf_map_type {
@@ -143,11 +144,47 @@ enum bpf_attach_type {
#define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
-/* If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
- * to the given target_fd cgroup the descendent cgroup will be able to
- * override effective bpf program that was inherited from this cgroup
+/* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
+ *
+ * NONE(default): No further bpf programs allowed in the subtree.
+ *
+ * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
+ * the program in this cgroup yields to sub-cgroup program.
+ *
+ * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
+ * that cgroup program gets run in addition to the program in this cgroup.
+ *
+ * Only one program is allowed to be attached to a cgroup with
+ * NONE or BPF_F_ALLOW_OVERRIDE flag.
+ * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
+ * release old program and attach the new one. Attach flags has to match.
+ *
+ * Multiple programs are allowed to be attached to a cgroup with
+ * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
+ * (those that were attached first, run first)
+ * The programs of sub-cgroup are executed first, then programs of
+ * this cgroup and then programs of parent cgroup.
+ * When children program makes decision (like picking TCP CA or sock bind)
+ * parent program has a chance to override it.
+ *
+ * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
+ * A cgroup with NONE doesn't allow any programs in sub-cgroups.
+ * Ex1:
+ * cgrp1 (MULTI progs A, B) ->
+ * cgrp2 (OVERRIDE prog C) ->
+ * cgrp3 (MULTI prog D) ->
+ * cgrp4 (OVERRIDE prog E) ->
+ * cgrp5 (NONE prog F)
+ * the event in cgrp5 triggers execution of F,D,A,B in that order.
+ * if prog F is detached, the execution is E,D,A,B
+ * if prog F and D are detached, the execution is E,A,B
+ * if prog F, E and D are detached, the execution is C,A,B
+ *
+ * All eligible programs are executed regardless of return code from
+ * earlier programs.
*/
#define BPF_F_ALLOW_OVERRIDE (1U << 0)
+#define BPF_F_ALLOW_MULTI (1U << 1)
/* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
* verifier will perform strict alignment checking as if the kernel
@@ -175,6 +212,9 @@ enum bpf_attach_type {
/* Specify numa node during map creation */
#define BPF_F_NUMA_NODE (1U << 2)
+/* flags for BPF_PROG_QUERY */
+#define BPF_F_QUERY_EFFECTIVE (1U << 0)
+
#define BPF_OBJ_NAME_LEN 16U
union bpf_attr {
@@ -253,6 +293,15 @@ union bpf_attr {
__u32 info_len;
__aligned_u64 info;
} info;
+
+ struct { /* anonymous struct used by BPF_PROG_QUERY command */
+ __u32 target_fd; /* container object to query */
+ __u32 attach_type;
+ __u32 query_flags;
+ __u32 attach_flags;
+ __aligned_u64 prog_ids;
+ __u32 prog_cnt;
+ } query;
} __attribute__((aligned(8)));
/* BPF helper function descriptions:
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index daf624e4c720..5128677e4117 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -291,6 +291,38 @@ int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
}
+int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
+{
+ union bpf_attr attr;
+
+ bzero(&attr, sizeof(attr));
+ attr.target_fd = target_fd;
+ attr.attach_bpf_fd = prog_fd;
+ attr.attach_type = type;
+
+ return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
+}
+
+int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
+ __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt)
+{
+ union bpf_attr attr;
+ int ret;
+
+ bzero(&attr, sizeof(attr));
+ attr.query.target_fd = target_fd;
+ attr.query.attach_type = type;
+ attr.query.query_flags = query_flags;
+ attr.query.prog_cnt = *prog_cnt;
+ attr.query.prog_ids = ptr_to_u64(prog_ids);
+
+ ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
+ if (attach_flags)
+ *attach_flags = attr.query.attach_flags;
+ *prog_cnt = attr.query.prog_cnt;
+ return ret;
+}
+
int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
void *data_out, __u32 *size_out, __u32 *retval,
__u32 *duration)
diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 118d00535a0d..6534889e2b2f 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -66,6 +66,7 @@ int bpf_obj_get(const char *pathname);
int bpf_prog_attach(int prog_fd, int attachable_fd, enum bpf_attach_type type,
unsigned int flags);
int bpf_prog_detach(int attachable_fd, enum bpf_attach_type type);
+int bpf_prog_detach2(int prog_fd, int attachable_fd, enum bpf_attach_type type);
int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
void *data_out, __u32 *size_out, __u32 *retval,
__u32 *duration);
@@ -74,5 +75,6 @@ int bpf_map_get_next_id(__u32 start_id, __u32 *next_id);
int bpf_prog_get_fd_by_id(__u32 id);
int bpf_map_get_fd_by_id(__u32 id);
int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len);
-
+int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
+ __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt);
#endif
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 290d5056c165..cc91d0159f43 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -6892,6 +6892,78 @@ static struct bpf_test tests[] = {
.result = ACCEPT,
.prog_type = BPF_PROG_TYPE_XDP,
},
+ {
+ "bpf_exit with invalid return code. test1",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "R0 has value (0x0; 0xffffffff)",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test2",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test3",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
+ BPF_ALU64_IMM(BPF_AND, BPF_REG_0, 3),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "R0 has value (0x0; 0x3)",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test4",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .result = ACCEPT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test5",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "R0 has value (0x2; 0x0)",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test6",
+ .insns = {
+ BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "R0 is not a known value (ctx)",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
+ {
+ "bpf_exit with invalid return code. test7",
+ .insns = {
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_1, 0),
+ BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 4),
+ BPF_ALU64_REG(BPF_MUL, BPF_REG_0, BPF_REG_2),
+ BPF_EXIT_INSN(),
+ },
+ .errstr = "R0 has unknown scalar value",
+ .result = REJECT,
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCK,
+ },
};
static int probe_filter_length(const struct bpf_insn *fp)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-28 08:15:35 +0000