Re: [RFC PATCH bpf-next v4 4/7] bpf: add bpf queue and stack maps
On 10/04/2018 10:40 PM, Mauricio Vasquez wrote:
On 10/04/2018 06:57 PM, Alexei Starovoitov wrote:
On Thu, Oct 04, 2018 at 07:12:44PM +0200, Mauricio Vasquez B wrote:
Implement two new kind of maps that support the peek, push and pop
operations.
A use case for this is to keep track of a pool of elements, like
network ports in a SNAT.
Signed-off-by: Mauricio Vasquez B
---
include/linux/bpf.h | 7 +
include/linux/bpf_types.h | 2
include/uapi/linux/bpf.h | 35 -
kernel/bpf/Makefile | 2
kernel/bpf/core.c | 3
kernel/bpf/helpers.c | 43 ++
kernel/bpf/queue_stack_maps.c | 300
+
kernel/bpf/syscall.c | 31 +++-
kernel/bpf/verifier.c | 14 +-
net/core/filter.c | 6 +
10 files changed, 424 insertions(+), 19 deletions(-)
create mode 100644 kernel/bpf/queue_stack_maps.c
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 98c7eeb6d138..cad3bc5cffd1 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -40,6 +40,9 @@ struct bpf_map_ops {
int (*map_update_elem)(struct bpf_map *map, void *key, void
*value, u64 flags);
int (*map_delete_elem)(struct bpf_map *map, void *key);
void *(*map_lookup_and_delete_elem)(struct bpf_map *map, void
*key);
+ int (*map_push_elem)(struct bpf_map *map, void *value, u64 flags);
+ int (*map_pop_elem)(struct bpf_map *map, void *value);
+ int (*map_peek_elem)(struct bpf_map *map, void *value);
/* funcs called by prog_array and perf_event_array map */
void *(*map_fd_get_ptr)(struct bpf_map *map, struct file
*map_file,
@@ -139,6 +142,7 @@ enum bpf_arg_type {
ARG_CONST_MAP_PTR, /* const argument used as pointer to
bpf_map */
ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
+ ARG_PTR_TO_UNINIT_MAP_VALUE, /* pointer to valid memory used
to store a map value */
/* the following constraints used to prototype bpf_memcmp()
and other
* functions that access data on eBPF program stack
@@ -825,6 +829,9 @@ static inline int
bpf_fd_reuseport_array_update_elem(struct bpf_map *map,
extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
extern const struct bpf_func_proto bpf_map_update_elem_proto;
extern const struct bpf_func_proto bpf_map_delete_elem_proto;
+extern const struct bpf_func_proto bpf_map_push_elem_proto;
+extern const struct bpf_func_proto bpf_map_pop_elem_proto;
+extern const struct bpf_func_proto bpf_map_peek_elem_proto;
extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 658509daacd4..a2ec73aa1ec7 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -69,3 +69,5 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops)
#endif
#endif
+BPF_MAP_TYPE(BPF_MAP_TYPE_QUEUE, queue_map_ops)
+BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 3bb94aa2d408..bfa042273fad 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -129,6 +129,8 @@ enum bpf_map_type {
BPF_MAP_TYPE_CGROUP_STORAGE,
BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
+ BPF_MAP_TYPE_QUEUE,
+ BPF_MAP_TYPE_STACK,
};
enum bpf_prog_type {
@@ -463,6 +465,28 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
+ * int bpf_map_push_elem(struct bpf_map *map, const void *value,
u64 flags)
+ * Description
+ * Push an element *value* in *map*. *flags* is one of:
+ *
+ * **BPF_EXIST**
+ * If the queue/stack is full, the oldest element is
removed to
+ * make room for this.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_pop_elem(struct bpf_map *map, void *value)
+ * Description
+ * Pop an element from *map*.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_peek_elem(struct bpf_map *map, void *value)
+ * Description
+ * Get an element from *map* without removing it.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
* int bpf_probe_read(void *dst, u32 size, const void *src)
* Description
* For tracing programs, safely attempt to read *size*
bytes from
@@ -790,14 +814,14 @@ union bpf_attr {
*
* int ret;
* struct bpf_tunnel_key key = {};
- *
+ *
* ret = bpf_skb_get_tunnel_key(skb, ,
sizeof(key), 0);
* if (ret < 0)
* return TC_ACT_SHOT; // drop
Re: [RFC PATCH bpf-next v4 4/7] bpf: add bpf queue and stack maps
On Thu, Oct 04, 2018 at 10:40:55PM -0500, Mauricio Vasquez wrote: > > > > + /* Round up queue size to nearest power of 2 */ > > > + max_entries = index_mask + 1; > > what's the point of roundup ? > > If the size of the buffer is power of two we can wrap the indexes with an > AND operation instead of MOD. > > > The memory waste becomes quite large when max_entries are high. > Yes, you are right, we have the different choices described below. > > > > > If queue/stack is sized to exact max_entries, > > then 'count' can be removed too, right? > > If we don't use 'count' and we want to use the AND operation for wrapping > indexes, the max entries should be 2^ - 1 because a slot is lost to > distinguish between full/empty queue/stack. > > Just to summarize, we have these options: > 1. Allow any size, round up, use the AND operation and 'count' (current). > 2. Allow only power of 2 sizes, use the AND operation and 'count'. > 3. Allow any size, no roundup, use the MOD operation and leaving an empty > slot. > > I prefer 1 or 2, but I don't have a strong opinion, maybe allowing only > power of two max entries could be too limiting. > Another consideration: is this really too bad to waste memory when user > requires a size far away of the next power of 2? I think there is 4th option. Neither AND nor MOD is necessary. Pls take a look at ptr_ring implementation.
Re: [RFC PATCH bpf-next v4 4/7] bpf: add bpf queue and stack maps
On Thu, Oct 04, 2018 at 07:12:44PM +0200, Mauricio Vasquez B wrote:
> Implement two new kind of maps that support the peek, push and pop
> operations.
>
> A use case for this is to keep track of a pool of elements, like
> network ports in a SNAT.
>
> Signed-off-by: Mauricio Vasquez B
> ---
> include/linux/bpf.h |7 +
> include/linux/bpf_types.h |2
> include/uapi/linux/bpf.h | 35 -
> kernel/bpf/Makefile |2
> kernel/bpf/core.c |3
> kernel/bpf/helpers.c | 43 ++
> kernel/bpf/queue_stack_maps.c | 300
> +
> kernel/bpf/syscall.c | 31 +++-
> kernel/bpf/verifier.c | 14 +-
> net/core/filter.c |6 +
> 10 files changed, 424 insertions(+), 19 deletions(-)
> create mode 100644 kernel/bpf/queue_stack_maps.c
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 98c7eeb6d138..cad3bc5cffd1 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -40,6 +40,9 @@ struct bpf_map_ops {
> int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64
> flags);
> int (*map_delete_elem)(struct bpf_map *map, void *key);
> void *(*map_lookup_and_delete_elem)(struct bpf_map *map, void *key);
> + int (*map_push_elem)(struct bpf_map *map, void *value, u64 flags);
> + int (*map_pop_elem)(struct bpf_map *map, void *value);
> + int (*map_peek_elem)(struct bpf_map *map, void *value);
>
> /* funcs called by prog_array and perf_event_array map */
> void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
> @@ -139,6 +142,7 @@ enum bpf_arg_type {
> ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
> ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
> ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
> + ARG_PTR_TO_UNINIT_MAP_VALUE,/* pointer to valid memory used to
> store a map value */
>
> /* the following constraints used to prototype bpf_memcmp() and other
>* functions that access data on eBPF program stack
> @@ -825,6 +829,9 @@ static inline int
> bpf_fd_reuseport_array_update_elem(struct bpf_map *map,
> extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
> extern const struct bpf_func_proto bpf_map_update_elem_proto;
> extern const struct bpf_func_proto bpf_map_delete_elem_proto;
> +extern const struct bpf_func_proto bpf_map_push_elem_proto;
> +extern const struct bpf_func_proto bpf_map_pop_elem_proto;
> +extern const struct bpf_func_proto bpf_map_peek_elem_proto;
>
> extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
> extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
> diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
> index 658509daacd4..a2ec73aa1ec7 100644
> --- a/include/linux/bpf_types.h
> +++ b/include/linux/bpf_types.h
> @@ -69,3 +69,5 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops)
> BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops)
> #endif
> #endif
> +BPF_MAP_TYPE(BPF_MAP_TYPE_QUEUE, queue_map_ops)
> +BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops)
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 3bb94aa2d408..bfa042273fad 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -129,6 +129,8 @@ enum bpf_map_type {
> BPF_MAP_TYPE_CGROUP_STORAGE,
> BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
> BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
> + BPF_MAP_TYPE_QUEUE,
> + BPF_MAP_TYPE_STACK,
> };
>
> enum bpf_prog_type {
> @@ -463,6 +465,28 @@ union bpf_attr {
> * Return
> * 0 on success, or a negative error in case of failure.
> *
> + * int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
> + * Description
> + * Push an element *value* in *map*. *flags* is one of:
> + *
> + * **BPF_EXIST**
> + * If the queue/stack is full, the oldest element is removed to
> + * make room for this.
> + * Return
> + * 0 on success, or a negative error in case of failure.
> + *
> + * int bpf_map_pop_elem(struct bpf_map *map, void *value)
> + * Description
> + * Pop an element from *map*.
> + * Return
> + * 0 on success, or a negative error in case of failure.
> + *
> + * int bpf_map_peek_elem(struct bpf_map *map, void *value)
> + * Description
> + * Get an element from *map* without removing it.
> + * Return
> + * 0 on success, or a negative error in case of failure.
> + *
> * int bpf_probe_read(void *dst, u32 size, const void *src)
> * Description
> * For tracing programs, safely attempt to read *size* bytes from
> @@ -790,14 +814,14 @@ union bpf_attr {
> *
> * int ret;
> * struct bpf_tunnel_key key = {};
> - *
> + *
> * ret =
[RFC PATCH bpf-next v4 4/7] bpf: add bpf queue and stack maps
Implement two new kind of maps that support the peek, push and pop
operations.
A use case for this is to keep track of a pool of elements, like
network ports in a SNAT.
Signed-off-by: Mauricio Vasquez B
---
include/linux/bpf.h |7 +
include/linux/bpf_types.h |2
include/uapi/linux/bpf.h | 35 -
kernel/bpf/Makefile |2
kernel/bpf/core.c |3
kernel/bpf/helpers.c | 43 ++
kernel/bpf/queue_stack_maps.c | 300 +
kernel/bpf/syscall.c | 31 +++-
kernel/bpf/verifier.c | 14 +-
net/core/filter.c |6 +
10 files changed, 424 insertions(+), 19 deletions(-)
create mode 100644 kernel/bpf/queue_stack_maps.c
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 98c7eeb6d138..cad3bc5cffd1 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -40,6 +40,9 @@ struct bpf_map_ops {
int (*map_update_elem)(struct bpf_map *map, void *key, void *value, u64
flags);
int (*map_delete_elem)(struct bpf_map *map, void *key);
void *(*map_lookup_and_delete_elem)(struct bpf_map *map, void *key);
+ int (*map_push_elem)(struct bpf_map *map, void *value, u64 flags);
+ int (*map_pop_elem)(struct bpf_map *map, void *value);
+ int (*map_peek_elem)(struct bpf_map *map, void *value);
/* funcs called by prog_array and perf_event_array map */
void *(*map_fd_get_ptr)(struct bpf_map *map, struct file *map_file,
@@ -139,6 +142,7 @@ enum bpf_arg_type {
ARG_CONST_MAP_PTR, /* const argument used as pointer to bpf_map */
ARG_PTR_TO_MAP_KEY, /* pointer to stack used as map key */
ARG_PTR_TO_MAP_VALUE, /* pointer to stack used as map value */
+ ARG_PTR_TO_UNINIT_MAP_VALUE,/* pointer to valid memory used to
store a map value */
/* the following constraints used to prototype bpf_memcmp() and other
* functions that access data on eBPF program stack
@@ -825,6 +829,9 @@ static inline int bpf_fd_reuseport_array_update_elem(struct
bpf_map *map,
extern const struct bpf_func_proto bpf_map_lookup_elem_proto;
extern const struct bpf_func_proto bpf_map_update_elem_proto;
extern const struct bpf_func_proto bpf_map_delete_elem_proto;
+extern const struct bpf_func_proto bpf_map_push_elem_proto;
+extern const struct bpf_func_proto bpf_map_pop_elem_proto;
+extern const struct bpf_func_proto bpf_map_peek_elem_proto;
extern const struct bpf_func_proto bpf_get_prandom_u32_proto;
extern const struct bpf_func_proto bpf_get_smp_processor_id_proto;
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 658509daacd4..a2ec73aa1ec7 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -69,3 +69,5 @@ BPF_MAP_TYPE(BPF_MAP_TYPE_XSKMAP, xsk_map_ops)
BPF_MAP_TYPE(BPF_MAP_TYPE_REUSEPORT_SOCKARRAY, reuseport_array_ops)
#endif
#endif
+BPF_MAP_TYPE(BPF_MAP_TYPE_QUEUE, queue_map_ops)
+BPF_MAP_TYPE(BPF_MAP_TYPE_STACK, stack_map_ops)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 3bb94aa2d408..bfa042273fad 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -129,6 +129,8 @@ enum bpf_map_type {
BPF_MAP_TYPE_CGROUP_STORAGE,
BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
+ BPF_MAP_TYPE_QUEUE,
+ BPF_MAP_TYPE_STACK,
};
enum bpf_prog_type {
@@ -463,6 +465,28 @@ union bpf_attr {
* Return
* 0 on success, or a negative error in case of failure.
*
+ * int bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
+ * Description
+ * Push an element *value* in *map*. *flags* is one of:
+ *
+ * **BPF_EXIST**
+ * If the queue/stack is full, the oldest element is removed to
+ * make room for this.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_pop_elem(struct bpf_map *map, void *value)
+ * Description
+ * Pop an element from *map*.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
+ * int bpf_map_peek_elem(struct bpf_map *map, void *value)
+ * Description
+ * Get an element from *map* without removing it.
+ * Return
+ * 0 on success, or a negative error in case of failure.
+ *
* int bpf_probe_read(void *dst, u32 size, const void *src)
* Description
* For tracing programs, safely attempt to read *size* bytes from
@@ -790,14 +814,14 @@ union bpf_attr {
*
* int ret;
* struct bpf_tunnel_key key = {};
- *
+ *
* ret = bpf_skb_get_tunnel_key(skb, , sizeof(key), 0);
* if (ret < 0)
* return TC_ACT_SHOT; // drop packet
- *
+ *
* if
