/* Description * Allocates an object of the type represented by 'local_type_id' in * program BTF. User may use the bpf_core_type_id_local macro to pass the * type ID of a struct in program BTF. * * The 'local_type_id' parameter must be a known constant. * The 'meta' parameter is rewritten by the verifier, no need for BPF * program to set it. * Returns * A pointer to an object of the type corresponding to the passed in * 'local_type_id', or NULL on failure.
*/ externvoid *bpf_obj_new_impl(__u64 local_type_id, void *meta) __ksym;
/* Convenience macro to wrap over bpf_obj_new_impl */ #define bpf_obj_new(type) ((type *)bpf_obj_new_impl(bpf_core_type_id_local(type), NULL))
/* Description * Free an allocated object. All fields of the object that require * destruction will be destructed before the storage is freed. * * The 'meta' parameter is rewritten by the verifier, no need for BPF * program to set it. * Returns * Void.
*/ externvoid bpf_obj_drop_impl(void *kptr, void *meta) __ksym;
/* Convenience macro to wrap over bpf_obj_drop_impl */ #define bpf_obj_drop(kptr) bpf_obj_drop_impl(kptr, NULL)
/* Description * Increment the refcount on a refcounted local kptr, turning the * non-owning reference input into an owning reference in the process. * * The 'meta' parameter is rewritten by the verifier, no need for BPF * program to set it. * Returns * An owning reference to the object pointed to by 'kptr'
*/ externvoid *bpf_refcount_acquire_impl(void *kptr, void *meta) __ksym;
/* Convenience macro to wrap over bpf_refcount_acquire_impl */ #define bpf_refcount_acquire(kptr) bpf_refcount_acquire_impl(kptr, NULL)
/* Description * Add a new entry to the beginning of the BPF linked list. * * The 'meta' and 'off' parameters are rewritten by the verifier, no need * for BPF programs to set them * Returns * 0 if the node was successfully added * -EINVAL if the node wasn't added because it's already in a list
*/ externint bpf_list_push_front_impl(struct bpf_list_head *head, struct bpf_list_node *node, void *meta, __u64 off) __ksym;
/* Convenience macro to wrap over bpf_list_push_front_impl */ #define bpf_list_push_front(head, node) bpf_list_push_front_impl(head, node, NULL, 0)
/* Description * Add a new entry to the end of the BPF linked list. * * The 'meta' and 'off' parameters are rewritten by the verifier, no need * for BPF programs to set them * Returns * 0 if the node was successfully added * -EINVAL if the node wasn't added because it's already in a list
*/ externint bpf_list_push_back_impl(struct bpf_list_head *head, struct bpf_list_node *node, void *meta, __u64 off) __ksym;
/* Convenience macro to wrap over bpf_list_push_back_impl */ #define bpf_list_push_back(head, node) bpf_list_push_back_impl(head, node, NULL, 0)
/* Description * Remove the entry at the beginning of the BPF linked list. * Returns * Pointer to bpf_list_node of deleted entry, or NULL if list is empty.
*/ externstruct bpf_list_node *bpf_list_pop_front(struct bpf_list_head *head) __ksym;
/* Description * Remove the entry at the end of the BPF linked list. * Returns * Pointer to bpf_list_node of deleted entry, or NULL if list is empty.
*/ externstruct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) __ksym;
/* Description * Remove 'node' from rbtree with root 'root' * Returns * Pointer to the removed node, or NULL if 'root' didn't contain 'node'
*/ externstruct bpf_rb_node *bpf_rbtree_remove(struct bpf_rb_root *root, struct bpf_rb_node *node) __ksym;
/* Description * Add 'node' to rbtree with root 'root' using comparator 'less' * * The 'meta' and 'off' parameters are rewritten by the verifier, no need * for BPF programs to set them * Returns * 0 if the node was successfully added * -EINVAL if the node wasn't added because it's already in a tree
*/ externint bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *node, bool (less)(struct bpf_rb_node *a, conststruct bpf_rb_node *b), void *meta, __u64 off) __ksym;
/* Convenience macro to wrap over bpf_rbtree_add_impl */ #define bpf_rbtree_add(head, node, less) bpf_rbtree_add_impl(head, node, less, NULL, 0)
/* Description * Return the first (leftmost) node in input tree * Returns * Pointer to the node, which is _not_ removed from the tree. If the tree * contains no nodes, returns NULL.
*/ externstruct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root) __ksym;
/* Description * Allocates a percpu object of the type represented by 'local_type_id' in * program BTF. User may use the bpf_core_type_id_local macro to pass the * type ID of a struct in program BTF. * * The 'local_type_id' parameter must be a known constant. * The 'meta' parameter is rewritten by the verifier, no need for BPF * program to set it. * Returns * A pointer to a percpu object of the type corresponding to the passed in * 'local_type_id', or NULL on failure.
*/ externvoid *bpf_percpu_obj_new_impl(__u64 local_type_id, void *meta) __ksym;
/* Convenience macro to wrap over bpf_percpu_obj_new_impl */ #define bpf_percpu_obj_new(type) ((type __percpu_kptr *)bpf_percpu_obj_new_impl(bpf_core_type_id_local(type), NULL))
/* Description * Free an allocated percpu object. All fields of the object that require * destruction will be destructed before the storage is freed. * * The 'meta' parameter is rewritten by the verifier, no need for BPF * program to set it. * Returns * Void.
*/ externvoid bpf_percpu_obj_drop_impl(void *kptr, void *meta) __ksym;
/* Convenience macro to wrap over bpf_obj_drop_impl */ #define bpf_percpu_obj_drop(kptr) bpf_percpu_obj_drop_impl(kptr, NULL)
/* Description * Throw a BPF exception from the program, immediately terminating its * execution and unwinding the stack. The supplied 'cookie' parameter * will be the return value of the program when an exception is thrown, * and the default exception callback is used. Otherwise, if an exception * callback is set using the '__exception_cb(callback)' declaration tag * on the main program, the 'cookie' parameter will be the callback's only * input argument. * * Thus, in case of default exception callback, 'cookie' is subjected to * constraints on the program's return value (as with R0 on exit). * Otherwise, the return value of the marked exception callback will be * subjected to the same checks. * * Note that throwing an exception with lingering resources (locks, * references, etc.) will lead to a verification error. * * Note that callbacks *cannot* call this helper. * Returns * Never. * Throws * An exception with the specified 'cookie' value.
*/ externvoid bpf_throw(u64 cookie) __ksym;
/* Description * Acquire a reference on the exe_file member field belonging to the * mm_struct that is nested within the supplied task_struct. The supplied * task_struct must be trusted/referenced. * Returns * A referenced file pointer pointing to the exe_file member field of the * mm_struct nested in the supplied task_struct, or NULL.
*/ externstruct file *bpf_get_task_exe_file(struct task_struct *task) __ksym;
/* Description * Release a reference on the supplied file. The supplied file must be * acquired.
*/ externvoid bpf_put_file(struct file *file) __ksym;
/* Description * Resolve a pathname for the supplied path and store it in the supplied * buffer. The supplied path must be trusted/referenced. * Returns * A positive integer corresponding to the length of the resolved pathname, * including the NULL termination character, stored in the supplied * buffer. On error, a negative integer is returned.
*/ externint bpf_path_d_path(struct path *path, char *buf, size_t buf__sz) __ksym;
/* This macro must be used to mark the exception callback corresponding to the * main program. For example: * * int exception_cb(u64 cookie) { * return cookie; * } * * SEC("tc") * __exception_cb(exception_cb) * int main_prog(struct __sk_buff *ctx) { * ... * return TC_ACT_OK; * } * * Here, exception callback for the main program will be 'exception_cb'. Note * that this attribute can only be used once, and multiple exception callbacks * specified for the main program will lead to verification error.
*/ #define __exception_cb(name) __attribute__((btf_decl_tag("exception_callback:"#name)))
/* C type conversions coupled with comparison operator are tricky. * Make sure BPF program is compiled with -Wsign-compare then * __lhs OP __rhs below will catch the mistake. * Be aware that we check only __lhs to figure out the sign of compare.
*/ #define _bpf_cmp(LHS, OP, RHS, UNLIKELY) \
({ \
typeof(LHS) __lhs = (LHS); \
typeof(RHS) __rhs = (RHS); \ bool ret; \
_Static_assert(sizeof(&(LHS)), "1st argument must be an lvalue expression"); \
(void)(__lhs OP __rhs); \ if (__cmp_cannot_be_signed(OP) || !__is_signed_type(typeof(__lhs))) { \ if (sizeof(__rhs) == 8) \ /* "i" will truncate 64-bit constant into s32, \ * so we have to use extra register via "r". \
*/
ret = __bpf_cmp(__lhs, #OP, "r", __rhs, UNLIKELY); \ else \
ret = __bpf_cmp(__lhs, #OP, "ri", __rhs, UNLIKELY); \
} else { \ if (sizeof(__rhs) == 8) \
ret = __bpf_cmp(__lhs, "s"#OP, "r", __rhs, UNLIKELY); \ else \
ret = __bpf_cmp(__lhs, "s"#OP, "ri", __rhs, UNLIKELY); \
} \
ret; \
})
/* * Note that cond_break can only be portably used in the body of a breakable * construct, whereas can_loop can be used anywhere.
*/ #ifdef __BPF_FEATURE_MAY_GOTO #define can_loop \
({ __label__ l_break, l_continue; \ bool ret = true; \ asmvolatilegoto("may_goto %l[l_break]" \
:::: l_break); \ goto l_continue; \
l_break: ret = false; \
l_continue:; \
ret; \
})
/* Description * Assert that a conditional expression is true. * Returns * Void. * Throws * An exception with the value zero when the assertion fails.
*/ #define bpf_assert(cond) if (!(cond)) bpf_throw(0);
/* Description * Assert that a conditional expression is true. * Returns * Void. * Throws * An exception with the specified value when the assertion fails.
*/ #define bpf_assert_with(cond, value) if (!(cond)) bpf_throw(value);
/* Description * Assert that LHS is in the range [BEG, END] (inclusive of both). This * statement updates the known bounds of LHS during verification. Note * that both BEG and END must be constant values, and must fit within the * data type of LHS. * Returns * Void. * Throws * An exception with the value zero when the assertion fails.
*/ #define bpf_assert_range(LHS, BEG, END) \
({ \
_Static_assert(BEG <= END, "BEG must be <= END"); \
barrier_var(LHS); \
__bpf_assert_op(LHS, >=, BEG, 0, false); \
__bpf_assert_op(LHS, <=, END, 0, false); \
})
/* Description * Assert that LHS is in the range [BEG, END] (inclusive of both). This * statement updates the known bounds of LHS during verification. Note * that both BEG and END must be constant values, and must fit within the * data type of LHS. * Returns * Void. * Throws * An exception with the specified value when the assertion fails.
*/ #define bpf_assert_range_with(LHS, BEG, END, value) \
({ \
_Static_assert(BEG <= END, "BEG must be <= END"); \
barrier_var(LHS); \
__bpf_assert_op(LHS, >=, BEG, value, false); \
__bpf_assert_op(LHS, <=, END, value, false); \
})
