@@ -131,4 +131,26 @@ extern int bpf_rbtree_add_impl(struct bpf_rb_root *root, struct bpf_rb_node *nod
*/
extern struct bpf_rb_node *bpf_rbtree_first(struct bpf_rb_root *root) __ksym;
+/* Description
+ * Release the buffer allocated by bpf_dynptr_from_sockopt.
+ * Returns
+ * 0 on success
+ * -EINVAL if the buffer was not allocated by bpf_dynptr_from_sockopt
+ */
+extern int bpf_sockopt_dynptr_release(struct bpf_sockopt *sopt,
+ struct bpf_dynptr *ptr) __ksym;
+
+/* Description
+ * Initialize a dynptr to access the content of optval passing
+ * to {get,set}sockopt()s.
+ * Returns
+ * > 0 on success, the size of the allocated buffer
+ * -ENOMEM or -EINVAL on failure
+ */
+extern int bpf_dynptr_from_sockopt(struct bpf_sockopt *sopt,
+ struct bpf_dynptr *ptr__uninit) __ksym;
+
+extern int bpf_sockopt_grow_to(struct bpf_sockopt *sopt,
+ __u32 newsize) __ksym;
+
#endif
@@ -41,4 +41,26 @@ extern bool bpf_dynptr_is_rdonly(const struct bpf_dynptr *ptr) __ksym;
extern __u32 bpf_dynptr_size(const struct bpf_dynptr *ptr) __ksym;
extern int bpf_dynptr_clone(const struct bpf_dynptr *ptr, struct bpf_dynptr *clone__init) __ksym;
+/* Description
+ * Release the buffer allocated by bpf_dynptr_from_sockopt.
+ * Returns
+ * 0 on success
+ * -EINVAL if the buffer was not allocated by bpf_dynptr_from_sockopt
+ */
+extern int bpf_sockopt_dynptr_release(struct bpf_sockopt *sopt,
+ struct bpf_dynptr *ptr) __ksym;
+
+/* Description
+ * Initialize a dynptr to access the content of optval passing
+ * to {get,set}sockopt()s.
+ * Returns
+ * > 0 on success, the size of the allocated buffer
+ * -ENOMEM or -EINVAL on failure
+ */
+extern int bpf_dynptr_from_sockopt(struct bpf_sockopt *sopt,
+ struct bpf_dynptr *ptr__uninit) __ksym;
+
+extern int bpf_sockopt_grow_to(struct bpf_sockopt *sopt,
+ __u32 newsize) __ksym;
+
#endif
@@ -92,6 +92,7 @@ static int getsetsockopt(void)
}
if (buf.u8[0] != 0x01) {
log_err("Unexpected buf[0] 0x%02x != 0x01", buf.u8[0]);
+ log_err("optlen %d", optlen);
goto err;
}
@@ -220,7 +221,7 @@ static int getsetsockopt(void)
return -1;
}
-static void run_test(int cgroup_fd)
+static void run_test_nonsleepable(int cgroup_fd)
{
struct sockopt_sk *skel;
@@ -246,6 +247,106 @@ static void run_test(int cgroup_fd)
sockopt_sk__destroy(skel);
}
+static void run_test_nonsleepable_mixed(int cgroup_fd)
+{
+ struct sockopt_sk *skel;
+
+ skel = sockopt_sk__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_load"))
+ goto cleanup;
+
+ skel->bss->page_size = getpagesize();
+ skel->bss->skip_sleepable = 1;
+
+ skel->links._setsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._setsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._setsockopt_s, "setsockopt_link (sleepable)"))
+ goto cleanup;
+
+ skel->links._getsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._getsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._getsockopt_s, "getsockopt_link (sleepable)"))
+ goto cleanup;
+
+ skel->links._setsockopt =
+ bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._setsockopt, "setsockopt_link"))
+ goto cleanup;
+
+ skel->links._getsockopt =
+ bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link"))
+ goto cleanup;
+
+ ASSERT_OK(getsetsockopt(), "getsetsockopt");
+
+cleanup:
+ sockopt_sk__destroy(skel);
+}
+
+static void run_test_sleepable(int cgroup_fd)
+{
+ struct sockopt_sk *skel;
+
+ skel = sockopt_sk__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_load"))
+ goto cleanup;
+
+ skel->bss->page_size = getpagesize();
+
+ skel->links._setsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._setsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._setsockopt_s, "setsockopt_link"))
+ goto cleanup;
+
+ skel->links._getsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._getsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._getsockopt_s, "getsockopt_link"))
+ goto cleanup;
+
+ ASSERT_OK(getsetsockopt(), "getsetsockopt");
+
+cleanup:
+ sockopt_sk__destroy(skel);
+}
+
+static void run_test_sleepable_mixed(int cgroup_fd)
+{
+ struct sockopt_sk *skel;
+
+ skel = sockopt_sk__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "skel_load"))
+ goto cleanup;
+
+ skel->bss->page_size = getpagesize();
+ skel->bss->skip_nonsleepable = 1;
+
+ skel->links._setsockopt =
+ bpf_program__attach_cgroup(skel->progs._setsockopt, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._setsockopt, "setsockopt_link (nonsleepable)"))
+ goto cleanup;
+
+ skel->links._getsockopt =
+ bpf_program__attach_cgroup(skel->progs._getsockopt, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._getsockopt, "getsockopt_link (nonsleepable)"))
+ goto cleanup;
+
+ skel->links._setsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._setsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._setsockopt_s, "setsockopt_link"))
+ goto cleanup;
+
+ skel->links._getsockopt_s =
+ bpf_program__attach_cgroup(skel->progs._getsockopt_s, cgroup_fd);
+ if (!ASSERT_OK_PTR(skel->links._getsockopt_s, "getsockopt_link"))
+ goto cleanup;
+
+ ASSERT_OK(getsetsockopt(), "getsetsockopt");
+
+cleanup:
+ sockopt_sk__destroy(skel);
+}
+
void test_sockopt_sk(void)
{
int cgroup_fd;
@@ -254,6 +355,13 @@ void test_sockopt_sk(void)
if (!ASSERT_GE(cgroup_fd, 0, "join_cgroup /sockopt_sk"))
return;
- run_test(cgroup_fd);
+ if (test__start_subtest("nonsleepable"))
+ run_test_nonsleepable(cgroup_fd);
+ if (test__start_subtest("sleepable"))
+ run_test_sleepable(cgroup_fd);
+ if (test__start_subtest("nonsleepable_mixed"))
+ run_test_nonsleepable_mixed(cgroup_fd);
+ if (test__start_subtest("sleepable_mixed"))
+ run_test_sleepable_mixed(cgroup_fd);
close(cgroup_fd);
}
@@ -5,10 +5,16 @@
#include <netinet/in.h>
#include <bpf/bpf_helpers.h>
+typedef int bool;
+#include "bpf_kfuncs.h"
+
char _license[] SEC("license") = "GPL";
int page_size = 0; /* userspace should set it */
+int skip_sleepable = 0;
+int skip_nonsleepable = 0;
+
#ifndef SOL_TCP
#define SOL_TCP IPPROTO_TCP
#endif
@@ -34,6 +40,9 @@ int _getsockopt(struct bpf_sockopt *ctx)
struct sockopt_sk *storage;
struct bpf_sock *sk;
+ if (skip_nonsleepable)
+ return 1;
+
/* Bypass AF_NETLINK. */
sk = ctx->sk;
if (sk && sk->family == AF_NETLINK)
@@ -136,6 +145,133 @@ int _getsockopt(struct bpf_sockopt *ctx)
return 1;
}
+SEC("cgroup/getsockopt.s")
+int _getsockopt_s(struct bpf_sockopt *ctx)
+{
+ struct tcp_zerocopy_receive zcvr;
+ struct bpf_dynptr optval_dynptr;
+ struct sockopt_sk *storage;
+ __u8 *optval, *optval_end;
+ struct bpf_sock *sk;
+ char buf[1];
+ __u64 addr;
+ int ret;
+
+ if (skip_sleepable)
+ return 1;
+
+ /* Bypass AF_NETLINK. */
+ sk = ctx->sk;
+ if (sk && sk->family == AF_NETLINK)
+ return 1;
+
+ optval = ctx->optval;
+ optval_end = ctx->optval_end;
+
+ /* Make sure bpf_get_netns_cookie is callable.
+ */
+ if (bpf_get_netns_cookie(NULL) == 0)
+ return 0;
+
+ if (bpf_get_netns_cookie(ctx) == 0)
+ return 0;
+
+ if (ctx->level == SOL_IP && ctx->optname == IP_TOS) {
+ /* Not interested in SOL_IP:IP_TOS;
+ * let next BPF program in the cgroup chain or kernel
+ * handle it.
+ */
+ return 1;
+ }
+
+ if (ctx->level == SOL_SOCKET && ctx->optname == SO_SNDBUF) {
+ /* Not interested in SOL_SOCKET:SO_SNDBUF;
+ * let next BPF program in the cgroup chain or kernel
+ * handle it.
+ */
+ return 1;
+ }
+
+ if (ctx->level == SOL_TCP && ctx->optname == TCP_CONGESTION) {
+ /* Not interested in SOL_TCP:TCP_CONGESTION;
+ * let next BPF program in the cgroup chain or kernel
+ * handle it.
+ */
+ return 1;
+ }
+
+ if (ctx->level == SOL_TCP && ctx->optname == TCP_ZEROCOPY_RECEIVE) {
+ /* Verify that TCP_ZEROCOPY_RECEIVE triggers.
+ * It has a custom implementation for performance
+ * reasons.
+ */
+
+ bpf_dynptr_from_sockopt(ctx, &optval_dynptr);
+ ret = bpf_dynptr_read(&zcvr, sizeof(zcvr),
+ &optval_dynptr, 0, 0);
+ addr = ret >= 0 ? zcvr.address : 0;
+ bpf_sockopt_dynptr_release(ctx, &optval_dynptr);
+
+ return addr != 0 ? 0 : 1;
+ }
+
+ if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {
+ if (optval + 1 > optval_end)
+ return 0; /* bounds check */
+
+ ctx->retval = 0; /* Reset system call return value to zero */
+
+ /* Always export 0x55 */
+ buf[0] = 0x55;
+ ret = bpf_dynptr_from_sockopt(ctx, &optval_dynptr);
+ if (ret >= 0) {
+ bpf_dynptr_write(&optval_dynptr, 0, buf, 1, 0);
+ }
+ bpf_sockopt_dynptr_release(ctx, &optval_dynptr);
+ if (ret < 0)
+ return 0;
+ ctx->optlen = 1;
+
+ /* Userspace buffer is PAGE_SIZE * 2, but BPF
+ * program can only see the first PAGE_SIZE
+ * bytes of data.
+ */
+ if (optval_end - optval != page_size && 0)
+ return 0; /* unexpected data size */
+
+ return 1;
+ }
+
+ if (ctx->level != SOL_CUSTOM)
+ return 0; /* deny everything except custom level */
+
+ if (optval + 1 > optval_end)
+ 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; /* couldn't get sk storage */
+
+ if (!ctx->retval)
+ return 0; /* kernel should not have handled
+ * SOL_CUSTOM, something is wrong!
+ */
+ ctx->retval = 0; /* Reset system call return value to zero */
+
+ buf[0] = storage->val;
+ ret = bpf_dynptr_from_sockopt(ctx, &optval_dynptr);
+ if (ret >= 0) {
+ bpf_dynptr_write(&optval_dynptr, 0, buf, 1, 0);
+ }
+ bpf_sockopt_dynptr_release(ctx, &optval_dynptr);
+ if (ret < 0)
+ return 0;
+ ctx->optlen = 1;
+
+ return 1;
+}
+
SEC("cgroup/setsockopt")
int _setsockopt(struct bpf_sockopt *ctx)
{
@@ -144,6 +280,9 @@ int _setsockopt(struct bpf_sockopt *ctx)
struct sockopt_sk *storage;
struct bpf_sock *sk;
+ if (skip_nonsleepable)
+ return 1;
+
/* Bypass AF_NETLINK. */
sk = ctx->sk;
if (sk && sk->family == AF_NETLINK)
@@ -236,3 +375,118 @@ int _setsockopt(struct bpf_sockopt *ctx)
ctx->optlen = 0;
return 1;
}
+
+SEC("cgroup/setsockopt.s")
+int _setsockopt_s(struct bpf_sockopt *ctx)
+{
+ struct bpf_dynptr optval_buf;
+ struct sockopt_sk *storage;
+ __u8 *optval, *optval_end;
+ struct bpf_sock *sk;
+ __u8 tmp_u8;
+ __u32 tmp;
+ int ret;
+
+ if (skip_sleepable)
+ return 1;
+
+ optval = ctx->optval;
+ optval_end = ctx->optval_end;
+
+ /* Bypass AF_NETLINK. */
+ sk = ctx->sk;
+ if (sk && sk->family == AF_NETLINK)
+ return -1;
+
+ /* Make sure bpf_get_netns_cookie is callable.
+ */
+ if (bpf_get_netns_cookie(NULL) == 0)
+ return 0;
+
+ if (bpf_get_netns_cookie(ctx) == 0)
+ return 0;
+
+ if (ctx->level == SOL_IP && ctx->optname == IP_TOS) {
+ /* Not interested in SOL_IP:IP_TOS;
+ * let next BPF program in the cgroup chain or kernel
+ * handle it.
+ */
+ ctx->optlen = 0; /* bypass optval>PAGE_SIZE */
+ return 1;
+ }
+
+ if (ctx->level == SOL_SOCKET && ctx->optname == SO_SNDBUF) {
+ /* Overwrite SO_SNDBUF value */
+
+ ret = bpf_dynptr_from_sockopt(ctx, &optval_buf);
+ if (ret >= 0) {
+ tmp = 0x55AA;
+ bpf_dynptr_write(&optval_buf, 0, &tmp, sizeof(tmp), 0);
+ }
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+
+ return ret >= 0 ? 1 : 0;
+ }
+
+ if (ctx->level == SOL_TCP && ctx->optname == TCP_CONGESTION) {
+ /* Always use cubic */
+
+ if (optval + 5 > optval_end)
+ bpf_sockopt_grow_to(ctx, 5);
+ ret = bpf_dynptr_from_sockopt(ctx, &optval_buf);
+ if (ret < 0) {
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+ return 0;
+ }
+ bpf_dynptr_write(&optval_buf, 0, "cubic", 5, 0);
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+ if (ret < 0)
+ return 0;
+ ctx->optlen = 5;
+
+ return 1;
+ }
+
+ if (ctx->level == SOL_IP && ctx->optname == IP_FREEBIND) {
+ /* Original optlen is larger than PAGE_SIZE. */
+ if (ctx->optlen != page_size * 2)
+ return 0; /* unexpected data size */
+
+ ret = bpf_dynptr_from_sockopt(ctx, &optval_buf);
+ if (ret < 0) {
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+ return 0;
+ }
+ tmp_u8 = 0;
+ bpf_dynptr_write(&optval_buf, 0, &tmp_u8, 1, 0);
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+ if (ret < 0)
+ return 0;
+ ctx->optlen = 1;
+
+ return 1;
+ }
+
+ if (ctx->level != SOL_CUSTOM)
+ return 0; /* deny everything except custom level */
+
+ if (optval + 1 > optval_end)
+ 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; /* couldn't get sk storage */
+
+ bpf_dynptr_from_sockopt(ctx, &optval_buf);
+ ret = bpf_dynptr_read(&storage->val, sizeof(__u8), &optval_buf, 0, 0);
+ if (ret >= 0) {
+ ctx->optlen = -1; /* BPF has consumed this option, don't call
+ * kernel setsockopt handler.
+ */
+ }
+ bpf_sockopt_dynptr_release(ctx, &optval_buf);
+
+ return optval ? 1 : 0;
+}
+
@@ -85,7 +85,7 @@
.expected_attach_type = BPF_TRACE_RAW_TP,
.kfunc = "sched_switch",
.result = REJECT,
- .errstr = "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable",
+ .errstr = "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, cgroup, and struct_ops programs can be sleepable",
.flags = BPF_F_SLEEPABLE,
.runs = -1,
},