[PATCH V2 net-next 2/6] test_bpf: allow tests to specify an skb fragment.

Nicolas Schichan
2015-08-04T13:23:09Z

This introduce a new test->aux flag (FLAG_SKB_FRAG) to tell the
populate_skb() function to add a fragment to the test skb containing
the data specified in test->frag_data).

Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

---
lib/test_bpf.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 6843d0b..e261751 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -23,6 +23,7 @@
#include <linux/netdevice.h>
#include <linux/if_vlan.h>
#include <linux/random.h>
+#include <linux/highmem.h>

/* General test specific settings */
#define MAX_SUBTESTS 3
@@ -56,6 +57,7 @@
/* Flags that can be passed to test cases */
#define FLAG_NO_DATA BIT(0)
#define FLAG_EXPECTED_FAIL BIT(1)
+#define FLAG_SKB_FRAG BIT(2)

enum {
CLASSIC = BIT(6), /* Old BPF instructions only. */
@@ -81,6 +83,7 @@ struct bpf_test {
__u32 result;
} test[MAX_SUBTESTS];
int (*fill_helper)(struct bpf_test *self);
+ __u8 frag_data[MAX_DATA];
};

/* Large test cases need separate allocation and fill handler. */
@@ -4525,6 +4528,9 @@ static struct sk_buff *populate_skb(char *buf, int size)

static void *generate_test_data(struct bpf_test *test, int sub)
{
+ struct sk_buff *skb;
+ struct page *page;
+
if (test->aux & FLAG_NO_DATA)
return NULL;

@@ -4532,7 +4538,38 @@ static void *generate_test_data(struct bpf_test *test, int sub)
* subtests generate skbs of different sizes based on
* the same data.
*/
- return populate_skb(test->data, test->test[sub].data_size);
+ skb = populate_skb(test->data, test->test[sub].data_size);
+ if (!skb)
+ return NULL;
+
+ if (test->aux & FLAG_SKB_FRAG) {
+ /*
+ * when the test requires a fragmented skb, add a
+ * single fragment to the skb, filled with
+ * test->frag_data.
+ */
+ void *ptr;
+
+ page = alloc_page(GFP_KERNEL);
+
+ if (!page)
+ goto err_kfree_skb;
+
+ ptr = kmap(page);
+ if (!ptr)
+ goto err_free_page;
+ memcpy(ptr, test->frag_data, MAX_DATA);
+ kunmap(page);
+ skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA);
+ }
+
+ return skb;
+
+err_free_page:
+ __free_page(page);
+err_kfree_skb:
+ kfree_skb(skb);
+ return NULL;
}

static void release_test_data(const struct bpf_test *test, void *data)
--
1.9.1