selftests: xsk: Generate packets from specification

Generate packets from a specification instead of something hard
coded. The idea is that a test generates one or more packet
specifications and provides it/them to both Tx and Rx. The Tx thread
will generate from this specification and Rx will validate that it
receives what is in the specification. The specification can be the
same on both ends, meaning that everything that was sent should be
received, or different which means that Rx will only receive part of
the sent packets.

Currently, the packet specification is the same for both Rx and Tx and
the same for each test. This will change in later work as features
and tests are added.

The data path functions are also renamed to better reflect what
actions they are performing after introducing this feature.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210825093722.10219-15-magnus.karlsson@gmail.com

tools/testing/selftests/bpf/xdpxceiver.h

@@ -40,6 +40,7 @@
 #define POLL_TMOUT 1000
 #define DEFAULT_PKT_CNT (4 * 1024)
 #define RX_FULL_RXQSIZE 32
+#define XSK_UMEM__INVALID_FRAME_SIZE (XSK_UMEM__DEFAULT_FRAME_SIZE + 1)
 
 #define print_verbose(x...) do { if (opt_verbose) ksft_print_msg(x); } while (0)
 
@@ -74,13 +75,10 @@ static u32 num_frames = DEFAULT_PKT_CNT / 4;
 static bool second_step;
 static int test_type;
 
-static u32 opt_pkt_count = DEFAULT_PKT_CNT;
 static u8 opt_verbose;
 
 static u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
 static u32 xdp_bind_flags = XDP_USE_NEED_WAKEUP | XDP_COPY;
-static u32 pkt_counter;
-static int sigvar;
 static int stat_test_type;
 static u32 rxqsize;
 static u32 frame_headroom;
@@ -107,6 +105,17 @@ struct flow_vector {
 	} vector;
 };
 
+struct pkt {
+	u64 addr;
+	u32 len;
+	u32 payload;
+};
+
+struct pkt_stream {
+	u32 nb_pkts;
+	struct pkt *pkts;
+};
+
 struct ifobject {
 	char ifname[MAX_INTERFACE_NAME_CHARS];
 	char nsname[MAX_INTERFACES_NAMESPACE_CHARS];
@@ -116,6 +125,7 @@ struct ifobject {
 	struct xsk_umem_info *umem;
 	void *(*func_ptr)(void *arg);
 	struct flow_vector fv;
+	struct pkt_stream *pkt_stream;
 	int ns_fd;
 	u32 dst_ip;
 	u32 src_ip;