selftests/bpf: Update sockopt_sk test to the use bpf_set_retval

The tests would break without this patch, because at one point it calls
  getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen)
This getsockopt receives the kernel-set -EINVAL. Prior to this patch
series, the eBPF getsockopt hook's -EPERM would override kernel's
-EINVAL, however, after this patch series, return 0's automatic
-EPERM will not; the eBPF prog has to explicitly bpf_set_retval(-EPERM)
if that is wanted.

I also removed the explicit mentions of EPERM in the comments in the
prog.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/4f20b77cb46812dbc2bdcd7e3fa87c7573bde55e.1639619851.git.zhuyifei@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
index 4b937e5dbacae4e882033b4772bfee2852636cfc..30a99d2ed5c62c18e080d0a1f14ae8078020008d 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockopt_sk.c
@@ -173,11 +173,11 @@ static int getsetsockopt(void)
        }
 
        memset(&buf, 0, sizeof(buf));
-       buf.zc.address = 12345; /* rejected by BPF */
+       buf.zc.address = 12345; /* Not page aligned. Rejected by tcp_zerocopy_receive() */
        optlen = sizeof(buf.zc);
        errno = 0;
        err = getsockopt(fd, SOL_TCP, TCP_ZEROCOPY_RECEIVE, &buf, &optlen);
-       if (errno != EPERM) {
+       if (errno != EINVAL) {
                log_err("Unexpected getsockopt(TCP_ZEROCOPY_RECEIVE) err=%d errno=%d",
                        err, errno);
                goto err;

diff --git a/tools/testing/selftests/bpf/progs/sockopt_sk.c b/tools/testing/selftests/bpf/progs/sockopt_sk.c
index 79c8139b63b803c45b72da131546c150ca9c81f1..d0298dccedcd1112671826f0fde74bd53216f776 100644 (file)
--- a/tools/testing/selftests/bpf/progs/sockopt_sk.c
+++ b/tools/testing/selftests/bpf/progs/sockopt_sk.c
@@ -73,17 +73,17 @@ int _getsockopt(struct bpf_sockopt *ctx)
                 */
 
                if (optval + sizeof(struct tcp_zerocopy_receive) > optval_end)
-                       return 0; /* EPERM, bounds check */
+                       return 0; /* bounds check */
 
                if (((struct tcp_zerocopy_receive *)optval)->address != 0)
-                       return 0; /* EPERM, unexpected data */
+                       return 0; /* unexpected data */
 
                return 1;
        }
 
        if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {
                if (optval + 1 > optval_end)
-                       return 0; /* EPERM, bounds check */
+                       return 0; /* bounds check */
 
                ctx->retval = 0; /* Reset system call return value to zero */
 
@@ -96,24 +96,24 @@ int _getsockopt(struct bpf_sockopt *ctx)
                 * bytes of data.
                 */
                if (optval_end - optval != page_size)
-                       return 0; /* EPERM, unexpected data size */
+                       return 0; /* unexpected data size */
 
                return 1;
        }
 
        if (ctx->level != SOL_CUSTOM)
-               return 0; /* EPERM, deny everything except custom level */
+               return 0; /* deny everything except custom level */
 
        if (optval + 1 > optval_end)
-               return 0; /* EPERM, bounds check */
+               return 0; /* bounds check */
 
        storage = bpf_sk_storage_get(&socket_storage_map, ctx->sk, 0,
                                     BPF_SK_STORAGE_GET_F_CREATE);
        if (!storage)
-               return 0; /* EPERM, couldn't get sk storage */
+               return 0; /* couldn't get sk storage */
 
        if (!ctx->retval)
-               return 0; /* EPERM, kernel should not have handled
+               return 0; /* kernel should not have handled
                           * SOL_CUSTOM, something is wrong!
                           */
        ctx->retval = 0; /* Reset system call return value to zero */
@@ -152,7 +152,7 @@ int _setsockopt(struct bpf_sockopt *ctx)
                /* Overwrite SO_SNDBUF value */
 
                if (optval + sizeof(__u32) > optval_end)
-                       return 0; /* EPERM, bounds check */
+                       return 0; /* bounds check */
 
                *(__u32 *)optval = 0x55AA;
                ctx->optlen = 4;
@@ -164,7 +164,7 @@ int _setsockopt(struct bpf_sockopt *ctx)
                /* Always use cubic */
 
                if (optval + 5 > optval_end)
-                       return 0; /* EPERM, bounds check */
+                       return 0; /* bounds check */
 
                memcpy(optval, "cubic", 5);
                ctx->optlen = 5;
@@ -175,10 +175,10 @@ int _setsockopt(struct bpf_sockopt *ctx)
        if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {
                /* Original optlen is larger than PAGE_SIZE. */
                if (ctx->optlen != page_size * 2)
-                       return 0; /* EPERM, unexpected data size */
+                       return 0; /* unexpected data size */
 
                if (optval + 1 > optval_end)
-                       return 0; /* EPERM, bounds check */
+                       return 0; /* bounds check */
 
                /* Make sure we can trim the buffer. */
                optval[0] = 0;
@@ -189,21 +189,21 @@ int _setsockopt(struct bpf_sockopt *ctx)
                 * bytes of data.
                 */
                if (optval_end - optval != page_size)
-                       return 0; /* EPERM, unexpected data size */
+                       return 0; /* unexpected data size */
 
                return 1;
        }
 
        if (ctx->level != SOL_CUSTOM)
-               return 0; /* EPERM, deny everything except custom level */
+               return 0; /* deny everything except custom level */
 
        if (optval + 1 > optval_end)
-               return 0; /* EPERM, bounds check */
+               return 0; /* bounds check */
 
        storage = bpf_sk_storage_get(&socket_storage_map, ctx->sk, 0,
                                     BPF_SK_STORAGE_GET_F_CREATE);
        if (!storage)
-               return 0; /* EPERM, couldn't get sk storage */
+               return 0; /* couldn't get sk storage */
 
        storage->val = optval[0];
        ctx->optlen = -1; /* BPF has consumed this option, don't call kernel