selftests/net: test classic bpf fanout mode

Test PACKET_FANOUT_CBPF by inserting a cBPF program that selects a
socket by payload. Requires modifying the test program to send
packets with multiple payloads.

Also fix a bug in testing the return value of mmap()

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 33 insertions, 12 deletions

diff --git a/tools/testing/selftests/net/psock_fanout.c b/tools/testing/selftests/net/psock_fanout.c
index 08c2a36ef7a9..baf46a20e1b3 100644
--- a/tools/testing/selftests/net/psock_fanout.c
+++ b/tools/testing/selftests/net/psock_fanout.c
@@ -19,6 +19,7 @@
  *   - PACKET_FANOUT_LB
  *   - PACKET_FANOUT_CPU
  *   - PACKET_FANOUT_ROLLOVER
+ *   - PACKET_FANOUT_CBPF
  *
  * Todo:
  * - functionality: PACKET_FANOUT_FLAG_DEFRAG
@@ -115,8 +116,8 @@ static char *sock_fanout_open_ring(int fd)
 
         ring = mmap(0, req.tp_block_size * req.tp_block_nr,
                     PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
-        if (!ring) {
-                fprintf(stderr, "packetsock ring mmap\n");
+        if (ring == MAP_FAILED) {
+                perror("packetsock ring mmap");
                 exit(1);
         }
 
@@ -209,6 +210,7 @@ static int test_datapath(uint16_t typeflags, int port_off,
 {
         const int expect0[] = { 0, 0 };
         char *rings[2];
+        uint8_t type = typeflags & 0xFF;
         int fds[2], fds_udp[2][2], ret;
 
         fprintf(stderr, "test: datapath 0x%hx\n", typeflags);
@@ -219,6 +221,9 @@ static int test_datapath(uint16_t typeflags, int port_off,
                 fprintf(stderr, "ERROR: failed open\n");
                 exit(1);
         }
+        if (type == PACKET_FANOUT_CBPF)
+                sock_setfilter(fds[0], SOL_PACKET, PACKET_FANOUT_DATA);
+
         rings[0] = sock_fanout_open_ring(fds[0]);
         rings[1] = sock_fanout_open_ring(fds[1]);
         pair_udp_open(fds_udp[0], PORT_BASE);
@@ -227,11 +232,11 @@ static int test_datapath(uint16_t typeflags, int port_off,
 
         /* Send data, but not enough to overflow a queue */
         pair_udp_send(fds_udp[0], 15);
-        pair_udp_send(fds_udp[1], 5);
+        pair_udp_send_char(fds_udp[1], 5, DATA_CHAR_1);
         ret = sock_fanout_read(fds, rings, expect1);
 
         /* Send more data, overflow the queue */
-        pair_udp_send(fds_udp[0], 15);
+        pair_udp_send_char(fds_udp[0], 15, DATA_CHAR_1);
         /* TODO: ensure consistent order between expect1 and expect2 */
         ret |= sock_fanout_read(fds, rings, expect2);
 
@@ -275,6 +280,7 @@ int main(int argc, char **argv)
         const int expect_rb[2][2]       = { { 15, 5 },  { 20, 15 } };
         const int expect_cpu0[2][2]     = { { 20, 0 },  { 20, 0 } };
         const int expect_cpu1[2][2]     = { { 0, 20 },  { 0, 20 } };
+        const int expect_bpf[2][2]      = { { 15, 5 },  { 15, 20 } };
         int port_off = 2, tries = 5, ret;
 
         test_control_single();
@@ -295,6 +301,8 @@ int main(int argc, char **argv)
                              port_off, expect_lb[0], expect_lb[1]);
         ret |= test_datapath(PACKET_FANOUT_ROLLOVER,
                              port_off, expect_rb[0], expect_rb[1]);
+        ret |= test_datapath(PACKET_FANOUT_CBPF,
+                             port_off, expect_bpf[0], expect_bpf[1]);
 
         set_cpuaffinity(0);
         ret |= test_datapath(PACKET_FANOUT_CPU, port_off,
diff --git a/tools/testing/selftests/net/psock_lib.h b/tools/testing/selftests/net/psock_lib.h
index 37da54ac85a9..24bc7ec1be7d 100644
--- a/tools/testing/selftests/net/psock_lib.h
+++ b/tools/testing/selftests/net/psock_lib.h
@@ -30,6 +30,7 @@
 
 #define DATA_LEN                        100
 #define DATA_CHAR                       'a'
+#define DATA_CHAR_1                     'b'
 
 #define PORT_BASE                       8000
 
@@ -37,29 +38,36 @@
 # define __maybe_unused         __attribute__ ((__unused__))
 #endif
 
-static __maybe_unused void pair_udp_setfilter(int fd)
+static __maybe_unused void sock_setfilter(int fd, int lvl, int optnum)
 {
         struct sock_filter bpf_filter[] = {
                 { 0x80, 0, 0, 0x00000000 },  /* LD  pktlen                    */
-                { 0x35, 0, 5, DATA_LEN   },  /* JGE DATA_LEN  [f goto nomatch]*/
+                { 0x35, 0, 4, DATA_LEN   },  /* JGE DATA_LEN  [f goto nomatch]*/
                 { 0x30, 0, 0, 0x00000050 },  /* LD  ip[80]                    */
-                { 0x15, 0, 3, DATA_CHAR  },  /* JEQ DATA_CHAR [f goto nomatch]*/
-                { 0x30, 0, 0, 0x00000051 },  /* LD  ip[81]                    */
-                { 0x15, 0, 1, DATA_CHAR  },  /* JEQ DATA_CHAR [f goto nomatch]*/
+                { 0x15, 1, 0, DATA_CHAR  },  /* JEQ DATA_CHAR   [t goto match]*/
+                { 0x15, 0, 1, DATA_CHAR_1},  /* JEQ DATA_CHAR_1 [t goto match]*/
                 { 0x06, 0, 0, 0x00000060 },  /* RET match                     */
                 { 0x06, 0, 0, 0x00000000 },  /* RET no match                  */
         };
         struct sock_fprog bpf_prog;
 
+        if (lvl == SOL_PACKET && optnum == PACKET_FANOUT_DATA)
+                bpf_filter[5].code = 0x16;   /* RET A                         */
+
         bpf_prog.filter = bpf_filter;
         bpf_prog.len = sizeof(bpf_filter) / sizeof(struct sock_filter);
-        if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf_prog,
+        if (setsockopt(fd, lvl, optnum, &bpf_prog,
                        sizeof(bpf_prog))) {
                 perror("setsockopt SO_ATTACH_FILTER");
                 exit(1);
         }
 }
 
+static __maybe_unused void pair_udp_setfilter(int fd)
+{
+        sock_setfilter(fd, SOL_SOCKET, SO_ATTACH_FILTER);
+}
+
 static __maybe_unused void pair_udp_open(int fds[], uint16_t port)
 {
         struct sockaddr_in saddr, daddr;
@@ -96,11 +104,11 @@ static __maybe_unused void pair_udp_open(int fds[], uint16_t port)
         }
 }
 
-static __maybe_unused void pair_udp_send(int fds[], int num)
+static __maybe_unused void pair_udp_send_char(int fds[], int num, char payload)
 {
         char buf[DATA_LEN], rbuf[DATA_LEN];
 
-        memset(buf, DATA_CHAR, sizeof(buf));
+        memset(buf, payload, sizeof(buf));
         while (num--) {
                 /* Should really handle EINTR and EAGAIN */
                 if (write(fds[0], buf, sizeof(buf)) != sizeof(buf)) {
@@ -118,6 +126,11 @@ static __maybe_unused void pair_udp_send(int fds[], int num)
         }
 }
 
+static __maybe_unused void pair_udp_send(int fds[], int num)
+{
+        return pair_udp_send_char(fds, num, DATA_CHAR);
+}
+
 static __maybe_unused void pair_udp_close(int fds[])
 {
         close(fds[0]);