* [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks
@ 2019-06-07 16:29 Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 1/8] bpf: implement " Stanislav Fomichev
` (7 more replies)
0 siblings, 8 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
This series implements two new per-cgroup hooks: getsockopt and
setsockopt along with a new sockopt program type. The idea is pretty
similar to recently introduced cgroup sysctl hooks, but
implementation is simpler (no need to convert to/from strings).
What this can be applied to:
* move business logic of what tos/priority/etc can be set by
containers (either pass or reject)
* handle existing options (or introduce new ones) differently by
propagating some information in cgroup/socket local storage
Compared to a simple syscall/{g,s}etsockopt tracepoint, those
hooks are context aware. Meaning, they can access underlying socket
and use cgroup and socket local storage.
Stanislav Fomichev (8):
bpf: implement getsockopt and setsockopt hooks
bpf: sync bpf.h to tools/
libbpf: support sockopt hooks
selftests/bpf: test sockopt section name
selftests/bpf: add sockopt test
selftests/bpf: add sockopt test that exercises sk helpers
bpf: add sockopt documentation
bpftool: support cgroup sockopt
Documentation/bpf/index.rst | 1 +
Documentation/bpf/prog_cgroup_sockopt.rst | 39 +
include/linux/bpf-cgroup.h | 29 +
include/linux/bpf.h | 46 ++
include/linux/bpf_types.h | 1 +
include/linux/filter.h | 13 +
include/uapi/linux/bpf.h | 13 +
kernel/bpf/cgroup.c | 264 ++++++
kernel/bpf/core.c | 9 +
kernel/bpf/syscall.c | 19 +
kernel/bpf/verifier.c | 15 +
net/core/filter.c | 4 +-
net/socket.c | 18 +
.../bpftool/Documentation/bpftool-cgroup.rst | 7 +-
.../bpftool/Documentation/bpftool-prog.rst | 2 +-
tools/bpf/bpftool/bash-completion/bpftool | 8 +-
tools/bpf/bpftool/cgroup.c | 5 +-
tools/bpf/bpftool/main.h | 1 +
tools/bpf/bpftool/prog.c | 3 +-
tools/include/uapi/linux/bpf.h | 14 +
tools/lib/bpf/libbpf.c | 5 +
tools/lib/bpf/libbpf_probes.c | 1 +
tools/testing/selftests/bpf/.gitignore | 2 +
tools/testing/selftests/bpf/Makefile | 4 +-
.../testing/selftests/bpf/progs/sockopt_sk.c | 77 ++
.../selftests/bpf/test_section_names.c | 10 +
tools/testing/selftests/bpf/test_sockopt.c | 773 ++++++++++++++++++
tools/testing/selftests/bpf/test_sockopt_sk.c | 156 ++++
28 files changed, 1528 insertions(+), 11 deletions(-)
create mode 100644 Documentation/bpf/prog_cgroup_sockopt.rst
create mode 100644 tools/testing/selftests/bpf/progs/sockopt_sk.c
create mode 100644 tools/testing/selftests/bpf/test_sockopt.c
create mode 100644 tools/testing/selftests/bpf/test_sockopt_sk.c
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 1/8] bpf: implement getsockopt and setsockopt hooks
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-08 7:08 ` Martin Lau
2019-06-07 16:29 ` [PATCH bpf-next v3 2/8] bpf: sync bpf.h to tools/ Stanislav Fomichev
` (6 subsequent siblings)
7 siblings, 1 reply; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev, Andrii Nakryiko
Implement new BPF_PROG_TYPE_CGROUP_SOCKOPT program type and
BPF_CGROUP_{G,S}ETSOCKOPT cgroup hooks.
BPF_CGROUP_SETSOCKOPT get a read-only view of the setsockopt arguments.
BPF_CGROUP_GETSOCKOPT can modify the supplied buffer.
Both of them reuse existing PTR_TO_PACKET{,_END} infrastructure.
The buffer memory is pre-allocated (because I don't think there is
a precedent for working with __user memory from bpf). This might be
slow to do for each {s,g}etsockopt call, that's why I've added
__cgroup_bpf_prog_array_is_empty that exits early if there is nothing
attached to a cgroup. Note, however, that there is a race between
__cgroup_bpf_prog_array_is_empty and BPF_PROG_RUN_ARRAY where cgroup
program layout might have changed; this should not be a problem
because in general there is a race between multiple calls to
{s,g}etsocktop and user adding/removing bpf progs from a cgroup.
The return code of the BPF program is handled as follows:
* 0: EPERM
* 1: success, execute kernel {s,g}etsockopt path after BPF prog exits
* 2: success, do _not_ execute kernel {s,g}etsockopt path after BPF
prog exits
v3:
* typos in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY comments (Andrii Nakryiko)
* reverse christmas tree in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY (Andrii
Nakryiko)
* use __bpf_md_ptr instead of __u32 for optval{,_end} (Martin Lau)
* use BPF_FIELD_SIZEOF() for consistency (Martin Lau)
* new CG_SOCKOPT_ACCESS macro to wrap repeated parts
v2:
* moved bpf_sockopt_kern fields around to remove a hole (Martin Lau)
* aligned bpf_sockopt_kern->buf to 8 bytes (Martin Lau)
* bpf_prog_array_is_empty instead of bpf_prog_array_length (Martin Lau)
* added [0,2] return code check to verifier (Martin Lau)
* dropped unused buf[64] from the stack (Martin Lau)
* use PTR_TO_SOCKET for bpf_sockopt->sk (Martin Lau)
* dropped bpf_target_off from ctx rewrites (Martin Lau)
* use return code for kernel bypass (Martin Lau & Andrii Nakryiko)
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
include/linux/bpf-cgroup.h | 29 ++++
include/linux/bpf.h | 46 +++++++
include/linux/bpf_types.h | 1 +
include/linux/filter.h | 13 ++
include/uapi/linux/bpf.h | 13 ++
kernel/bpf/cgroup.c | 264 +++++++++++++++++++++++++++++++++++++
kernel/bpf/core.c | 9 ++
kernel/bpf/syscall.c | 19 +++
kernel/bpf/verifier.c | 15 +++
net/core/filter.c | 4 +-
net/socket.c | 18 +++
11 files changed, 429 insertions(+), 2 deletions(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index b631ee75762d..406f1ba82531 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -124,6 +124,13 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
loff_t *ppos, void **new_buf,
enum bpf_attach_type type);
+int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int level,
+ int optname, char __user *optval,
+ unsigned int optlen);
+int __cgroup_bpf_run_filter_getsockopt(struct sock *sock, int level,
+ int optname, char __user *optval,
+ int __user *optlen);
+
static inline enum bpf_cgroup_storage_type cgroup_storage_type(
struct bpf_map *map)
{
@@ -280,6 +287,26 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key,
__ret; \
})
+#define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen) \
+({ \
+ int __ret = 0; \
+ if (cgroup_bpf_enabled) \
+ __ret = __cgroup_bpf_run_filter_setsockopt(sock, level, \
+ optname, optval, \
+ optlen); \
+ __ret; \
+})
+
+#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, optlen) \
+({ \
+ int __ret = 0; \
+ if (cgroup_bpf_enabled) \
+ __ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \
+ optname, optval, \
+ optlen); \
+ __ret; \
+})
+
int cgroup_bpf_prog_attach(const union bpf_attr *attr,
enum bpf_prog_type ptype, struct bpf_prog *prog);
int cgroup_bpf_prog_detach(const union bpf_attr *attr,
@@ -349,6 +376,8 @@ static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map,
#define BPF_CGROUP_RUN_PROG_SOCK_OPS(sock_ops) ({ 0; })
#define BPF_CGROUP_RUN_PROG_DEVICE_CGROUP(type,major,minor,access) ({ 0; })
#define BPF_CGROUP_RUN_PROG_SYSCTL(head,table,write,buf,count,pos,nbuf) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, optlen) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock, level, optname, optval, optlen) ({ 0; })
#define for_each_cgroup_storage_type(stype) for (; false; )
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index e5a309e6a400..13c1ff440b59 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -520,6 +520,7 @@ struct bpf_prog_array {
struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags);
void bpf_prog_array_free(struct bpf_prog_array *progs);
int bpf_prog_array_length(struct bpf_prog_array *progs);
+bool bpf_prog_array_is_empty(struct bpf_prog_array *array);
int bpf_prog_array_copy_to_user(struct bpf_prog_array *progs,
__u32 __user *prog_ids, u32 cnt);
@@ -606,6 +607,49 @@ _out: \
_ret; \
})
+/* To be used by BPF_PROG_TYPE_CGROUP_SOCKOPT program type.
+ *
+ * Expected BPF program return values are:
+ * 0: return -EPERM to the userspace
+ * 1: sockopt was not handled by BPF, kernel should do it
+ * 2: sockopt was handled by BPF, kernel should _not_ do it and return
+ * to the userspace instead
+ *
+ * Note, that return '0' takes precedence over everything else. In other
+ * words, if any single program in the prog array has returned 0,
+ * the userspace will get -EPERM (regardless of what other programs
+ * return).
+ *
+ * The macro itself returns:
+ * 0: sockopt was not handled by BPF, kernel should do it
+ * 1: sockopt was handled by BPF, kernel should _not_ do it
+ * -EPERM: return error back to userspace
+ */
+#define BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY(array, ctx, func) \
+ ({ \
+ struct bpf_prog_array_item *_item; \
+ struct bpf_prog_array *_array; \
+ struct bpf_prog *_prog; \
+ u32 _success = 1; \
+ u32 _bypass = 0; \
+ u32 ret; \
+ preempt_disable(); \
+ rcu_read_lock(); \
+ _array = rcu_dereference(array); \
+ _item = &_array->items[0]; \
+ while ((_prog = READ_ONCE(_item->prog))) { \
+ bpf_cgroup_storage_set(_item->cgroup_storage); \
+ ret = func(_prog, ctx); \
+ _success &= (ret > 0); \
+ _bypass |= (ret == 2); \
+ _item++; \
+ } \
+ rcu_read_unlock(); \
+ preempt_enable(); \
+ ret = _success ? _bypass : -EPERM; \
+ ret; \
+ })
+
#define BPF_PROG_RUN_ARRAY(array, ctx, func) \
__BPF_PROG_RUN_ARRAY(array, ctx, func, false)
@@ -1054,6 +1098,8 @@ extern const struct bpf_func_proto bpf_spin_unlock_proto;
extern const struct bpf_func_proto bpf_get_local_storage_proto;
extern const struct bpf_func_proto bpf_strtol_proto;
extern const struct bpf_func_proto bpf_strtoul_proto;
+extern const struct bpf_func_proto bpf_sk_fullsock_proto;
+extern const struct bpf_func_proto bpf_tcp_sock_proto;
/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);
diff --git a/include/linux/bpf_types.h b/include/linux/bpf_types.h
index 5a9975678d6f..eec5aeeeaf92 100644
--- a/include/linux/bpf_types.h
+++ b/include/linux/bpf_types.h
@@ -30,6 +30,7 @@ BPF_PROG_TYPE(BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE, raw_tracepoint_writable)
#ifdef CONFIG_CGROUP_BPF
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_DEVICE, cg_dev)
BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SYSCTL, cg_sysctl)
+BPF_PROG_TYPE(BPF_PROG_TYPE_CGROUP_SOCKOPT, cg_sockopt)
#endif
#ifdef CONFIG_BPF_LIRC_MODE2
BPF_PROG_TYPE(BPF_PROG_TYPE_LIRC_MODE2, lirc_mode2)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 43b45d6db36d..6e64d01e4e36 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1199,4 +1199,17 @@ struct bpf_sysctl_kern {
u64 tmp_reg;
};
+struct bpf_sockopt_kern {
+ struct sock *sk;
+ u8 *optval;
+ u8 *optval_end;
+ s32 level;
+ s32 optname;
+ u32 optlen;
+
+ /* Small on-stack optval buffer to avoid small allocations.
+ */
+ u8 buf[64] __aligned(8);
+};
+
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 7c6aef253173..afaa7e28d1e4 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -170,6 +170,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_FLOW_DISSECTOR,
BPF_PROG_TYPE_CGROUP_SYSCTL,
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
+ BPF_PROG_TYPE_CGROUP_SOCKOPT,
};
enum bpf_attach_type {
@@ -192,6 +193,8 @@ enum bpf_attach_type {
BPF_LIRC_MODE2,
BPF_FLOW_DISSECTOR,
BPF_CGROUP_SYSCTL,
+ BPF_CGROUP_GETSOCKOPT,
+ BPF_CGROUP_SETSOCKOPT,
__MAX_BPF_ATTACH_TYPE
};
@@ -3533,4 +3536,14 @@ struct bpf_sysctl {
*/
};
+struct bpf_sockopt {
+ __bpf_md_ptr(struct bpf_sock *, sk);
+ __bpf_md_ptr(void *, optval);
+ __bpf_md_ptr(void *, optval_end);
+
+ __s32 level;
+ __s32 optname;
+ __u32 optlen;
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 1b65ab0df457..4fc8429af6fc 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -18,6 +18,7 @@
#include <linux/bpf.h>
#include <linux/bpf-cgroup.h>
#include <net/sock.h>
+#include <net/bpf_sk_storage.h>
DEFINE_STATIC_KEY_FALSE(cgroup_bpf_enabled_key);
EXPORT_SYMBOL(cgroup_bpf_enabled_key);
@@ -924,6 +925,142 @@ int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
}
EXPORT_SYMBOL(__cgroup_bpf_run_filter_sysctl);
+static bool __cgroup_bpf_prog_array_is_empty(struct cgroup *cgrp,
+ enum bpf_attach_type attach_type)
+{
+ struct bpf_prog_array *prog_array;
+ bool empty;
+
+ rcu_read_lock();
+ prog_array = rcu_dereference(cgrp->bpf.effective[attach_type]);
+ empty = bpf_prog_array_is_empty(prog_array);
+ rcu_read_unlock();
+
+ return empty;
+}
+
+static int sockopt_alloc_buf(struct bpf_sockopt_kern *ctx, int max_optlen)
+{
+ if (unlikely(max_optlen > PAGE_SIZE))
+ return -EINVAL;
+
+ if (likely(max_optlen <= sizeof(ctx->buf))) {
+ ctx->optval = ctx->buf;
+ } else {
+ ctx->optval = kzalloc(max_optlen, GFP_USER);
+ if (!ctx->optval)
+ return -ENOMEM;
+ }
+
+ ctx->optval_end = ctx->optval + max_optlen;
+ ctx->optlen = max_optlen;
+
+ return 0;
+}
+
+static void sockopt_free_buf(struct bpf_sockopt_kern *ctx)
+{
+ if (unlikely(ctx->optval != ctx->buf))
+ kfree(ctx->optval);
+}
+
+int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int level,
+ int optname, char __user *optval,
+ unsigned int optlen)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = level,
+ .optname = optname,
+ };
+ int ret;
+
+ /* Opportunistic check to see whether we have any BPF program
+ * attached to the hook so we don't waste time allocating
+ * memory and locking the socket.
+ */
+ if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_SETSOCKOPT))
+ return 0;
+
+ ret = sockopt_alloc_buf(&ctx, optlen);
+ if (ret)
+ return ret;
+
+ if (copy_from_user(ctx.optval, optval, optlen) != 0) {
+ sockopt_free_buf(&ctx);
+ return -EFAULT;
+ }
+
+ lock_sock(sk);
+ ret = BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY(
+ cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ sockopt_free_buf(&ctx);
+
+ return ret;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_setsockopt);
+
+int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
+ int optname, char __user *optval,
+ int __user *optlen)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = level,
+ .optname = optname,
+ };
+ int max_optlen;
+ int ret;
+
+ /* Opportunistic check to see whether we have any BPF program
+ * attached to the hook so we don't waste time allocating
+ * memory and locking the socket.
+ */
+ if (__cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT))
+ return 0;
+
+ if (get_user(max_optlen, optlen))
+ return -EFAULT;
+
+ ret = sockopt_alloc_buf(&ctx, max_optlen);
+ if (ret)
+ return ret;
+
+ lock_sock(sk);
+ ret = BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY(
+ cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ if (ret < 0) {
+ sockopt_free_buf(&ctx);
+ return ret;
+ }
+
+ if (ctx.optlen > max_optlen) {
+ sockopt_free_buf(&ctx);
+ return -EFAULT;
+ }
+
+ if (copy_to_user(optval, ctx.optval, ctx.optlen) != 0) {
+ sockopt_free_buf(&ctx);
+ return -EFAULT;
+ }
+
+ sockopt_free_buf(&ctx);
+
+ if (put_user(ctx.optlen, optlen))
+ return -EFAULT;
+
+ return ret;
+}
+EXPORT_SYMBOL(__cgroup_bpf_run_filter_getsockopt);
+
static ssize_t sysctl_cpy_dir(const struct ctl_dir *dir, char **bufp,
size_t *lenp)
{
@@ -1184,3 +1321,130 @@ const struct bpf_verifier_ops cg_sysctl_verifier_ops = {
const struct bpf_prog_ops cg_sysctl_prog_ops = {
};
+
+static const struct bpf_func_proto *
+cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_sk_fullsock:
+ return &bpf_sk_fullsock_proto;
+ case BPF_FUNC_sk_storage_get:
+ return &bpf_sk_storage_get_proto;
+ case BPF_FUNC_sk_storage_delete:
+ return &bpf_sk_storage_delete_proto;
+#ifdef CONFIG_INET
+ case BPF_FUNC_tcp_sock:
+ return &bpf_tcp_sock_proto;
+#endif
+ default:
+ return cgroup_base_func_proto(func_id, prog);
+ }
+}
+
+static bool cg_sockopt_is_valid_access(int off, int size,
+ enum bpf_access_type type,
+ const struct bpf_prog *prog,
+ struct bpf_insn_access_aux *info)
+{
+ const int size_default = sizeof(__u32);
+
+ if (off < 0 || off >= sizeof(struct bpf_sockopt))
+ return false;
+
+ if (off % size != 0)
+ return false;
+
+ if (type == BPF_WRITE) {
+ switch (off) {
+ case offsetof(struct bpf_sockopt, optlen):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type ==
+ BPF_CGROUP_GETSOCKOPT;
+ default:
+ return false;
+ }
+ }
+
+ switch (off) {
+ case offsetof(struct bpf_sockopt, sk):
+ if (size != sizeof(struct bpf_sock *))
+ return false;
+ info->reg_type = PTR_TO_SOCKET;
+ break;
+ case bpf_ctx_range(struct bpf_sockopt, optval):
+ if (size != sizeof(void *))
+ return false;
+ info->reg_type = PTR_TO_PACKET;
+ break;
+ case bpf_ctx_range(struct bpf_sockopt, optval_end):
+ if (size != sizeof(void *))
+ return false;
+ info->reg_type = PTR_TO_PACKET_END;
+ break;
+ default:
+ if (size != size_default)
+ return false;
+ break;
+ }
+ return true;
+}
+
+#define CG_SOCKOPT_ACCESS_FIELD(T, F) \
+ T(BPF_FIELD_SIZEOF(struct bpf_sockopt_kern, F), \
+ si->dst_reg, si->src_reg, \
+ offsetof(struct bpf_sockopt_kern, F))
+
+static u32 cg_sockopt_convert_ctx_access(enum bpf_access_type type,
+ const struct bpf_insn *si,
+ struct bpf_insn *insn_buf,
+ struct bpf_prog *prog,
+ u32 *target_size)
+{
+ struct bpf_insn *insn = insn_buf;
+
+ switch (si->off) {
+ case offsetof(struct bpf_sockopt, sk):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, sk);
+ break;
+ case offsetof(struct bpf_sockopt, level):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, level);
+ break;
+ case offsetof(struct bpf_sockopt, optname):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optname);
+ break;
+ case offsetof(struct bpf_sockopt, optlen):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, optlen);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optlen);
+ break;
+ case offsetof(struct bpf_sockopt, optval):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval);
+ break;
+ case offsetof(struct bpf_sockopt, optval_end):
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, optval_end);
+ break;
+ }
+
+ return insn - insn_buf;
+}
+
+static int cg_sockopt_get_prologue(struct bpf_insn *insn_buf,
+ bool direct_write,
+ const struct bpf_prog *prog)
+{
+ /* Nothing to do for sockopt argument. The data is kzalloc'ated.
+ */
+ return 0;
+}
+
+const struct bpf_verifier_ops cg_sockopt_verifier_ops = {
+ .get_func_proto = cg_sockopt_func_proto,
+ .is_valid_access = cg_sockopt_is_valid_access,
+ .convert_ctx_access = cg_sockopt_convert_ctx_access,
+ .gen_prologue = cg_sockopt_get_prologue,
+};
+
+const struct bpf_prog_ops cg_sockopt_prog_ops = {
+};
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 33fb292f2e30..e9152ebd66bc 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1813,6 +1813,15 @@ int bpf_prog_array_length(struct bpf_prog_array *array)
return cnt;
}
+bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
+{
+ struct bpf_prog_array_item *item;
+
+ for (item = array->items; item->prog; item++)
+ if (item->prog != &dummy_bpf_prog.prog)
+ return false;
+ return true;
+}
static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
u32 *prog_ids,
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4c53cbd3329d..4ad2b5f1905f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1596,6 +1596,14 @@ bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
default:
return -EINVAL;
}
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+ switch (expected_attach_type) {
+ case BPF_CGROUP_SETSOCKOPT:
+ case BPF_CGROUP_GETSOCKOPT:
+ return 0;
+ default:
+ return -EINVAL;
+ }
default:
return 0;
}
@@ -1846,6 +1854,7 @@ static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
switch (prog->type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
case BPF_PROG_TYPE_CGROUP_SKB:
return prog->enforce_expected_attach_type &&
@@ -1916,6 +1925,10 @@ static int bpf_prog_attach(const union bpf_attr *attr)
case BPF_CGROUP_SYSCTL:
ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
break;
+ case BPF_CGROUP_GETSOCKOPT:
+ case BPF_CGROUP_SETSOCKOPT:
+ ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
+ break;
default:
return -EINVAL;
}
@@ -1997,6 +2010,10 @@ static int bpf_prog_detach(const union bpf_attr *attr)
case BPF_CGROUP_SYSCTL:
ptype = BPF_PROG_TYPE_CGROUP_SYSCTL;
break;
+ case BPF_CGROUP_GETSOCKOPT:
+ case BPF_CGROUP_SETSOCKOPT:
+ ptype = BPF_PROG_TYPE_CGROUP_SOCKOPT;
+ break;
default:
return -EINVAL;
}
@@ -2031,6 +2048,8 @@ static int bpf_prog_query(const union bpf_attr *attr,
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
case BPF_CGROUP_SYSCTL:
+ case BPF_CGROUP_GETSOCKOPT:
+ case BPF_CGROUP_SETSOCKOPT:
break;
case BPF_LIRC_MODE2:
return lirc_prog_query(attr, uattr);
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 5c2cb5bd84ce..fffc668ef536 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1717,6 +1717,18 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
env->seen_direct_write = true;
return true;
+
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+ if (t == BPF_WRITE) {
+ if (env->prog->expected_attach_type ==
+ BPF_CGROUP_GETSOCKOPT) {
+ env->seen_direct_write = true;
+ return true;
+ }
+ return false;
+ }
+ return true;
+
default:
return false;
}
@@ -5524,6 +5536,9 @@ static int check_return_code(struct bpf_verifier_env *env)
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
break;
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
+ range = tnum_range(0, 2);
+ break;
default:
return 0;
}
diff --git a/net/core/filter.c b/net/core/filter.c
index 55bfc941d17a..4652c0a005ca 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1835,7 +1835,7 @@ BPF_CALL_1(bpf_sk_fullsock, struct sock *, sk)
return sk_fullsock(sk) ? (unsigned long)sk : (unsigned long)NULL;
}
-static const struct bpf_func_proto bpf_sk_fullsock_proto = {
+const struct bpf_func_proto bpf_sk_fullsock_proto = {
.func = bpf_sk_fullsock,
.gpl_only = false,
.ret_type = RET_PTR_TO_SOCKET_OR_NULL,
@@ -5636,7 +5636,7 @@ BPF_CALL_1(bpf_tcp_sock, struct sock *, sk)
return (unsigned long)NULL;
}
-static const struct bpf_func_proto bpf_tcp_sock_proto = {
+const struct bpf_func_proto bpf_tcp_sock_proto = {
.func = bpf_tcp_sock,
.gpl_only = false,
.ret_type = RET_PTR_TO_TCP_SOCK_OR_NULL,
diff --git a/net/socket.c b/net/socket.c
index 72372dc5dd70..e8654f1f70e6 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2069,6 +2069,15 @@ static int __sys_setsockopt(int fd, int level, int optname,
if (err)
goto out_put;
+ err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, level, optname,
+ optval, optlen);
+ if (err < 0) {
+ goto out_put;
+ } else if (err > 0) {
+ err = 0;
+ goto out_put;
+ }
+
if (level == SOL_SOCKET)
err =
sock_setsockopt(sock, level, optname, optval,
@@ -2106,6 +2115,15 @@ static int __sys_getsockopt(int fd, int level, int optname,
if (err)
goto out_put;
+ err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
+ optval, optlen);
+ if (err < 0) {
+ goto out_put;
+ } else if (err > 0) {
+ err = 0;
+ goto out_put;
+ }
+
if (level == SOL_SOCKET)
err =
sock_getsockopt(sock, level, optname, optval,
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 2/8] bpf: sync bpf.h to tools/
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 1/8] bpf: implement " Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 3/8] libbpf: support sockopt hooks Stanislav Fomichev
` (5 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Export new prog type and hook points to the libbpf.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/include/uapi/linux/bpf.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 7c6aef253173..174136aa6906 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -170,6 +170,7 @@ enum bpf_prog_type {
BPF_PROG_TYPE_FLOW_DISSECTOR,
BPF_PROG_TYPE_CGROUP_SYSCTL,
BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
+ BPF_PROG_TYPE_CGROUP_SOCKOPT,
};
enum bpf_attach_type {
@@ -192,6 +193,8 @@ enum bpf_attach_type {
BPF_LIRC_MODE2,
BPF_FLOW_DISSECTOR,
BPF_CGROUP_SYSCTL,
+ BPF_CGROUP_GETSOCKOPT,
+ BPF_CGROUP_SETSOCKOPT,
__MAX_BPF_ATTACH_TYPE
};
@@ -3533,4 +3536,15 @@ struct bpf_sysctl {
*/
};
+struct bpf_sockopt {
+ __bpf_md_ptr(struct bpf_sock *, sk);
+ __bpf_md_ptr(void *, optval);
+ __bpf_md_ptr(void *, optval_end);
+
+ __s32 level;
+ __s32 optname;
+
+ __u32 optlen;
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 3/8] libbpf: support sockopt hooks
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 1/8] bpf: implement " Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 2/8] bpf: sync bpf.h to tools/ Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 4/8] selftests/bpf: test sockopt section name Stanislav Fomichev
` (4 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Make libbpf aware of new sockopt hooks so it can derive prog type
and hook point from the section names.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/lib/bpf/libbpf.c | 5 +++++
tools/lib/bpf/libbpf_probes.c | 1 +
2 files changed, 6 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ba89d9727137..cd3c692a8b5d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2243,6 +2243,7 @@ static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
return false;
case BPF_PROG_TYPE_KPROBE:
default:
@@ -3196,6 +3197,10 @@ static const struct {
BPF_CGROUP_UDP6_SENDMSG),
BPF_EAPROG_SEC("cgroup/sysctl", BPF_PROG_TYPE_CGROUP_SYSCTL,
BPF_CGROUP_SYSCTL),
+ BPF_EAPROG_SEC("cgroup/getsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ BPF_CGROUP_GETSOCKOPT),
+ BPF_EAPROG_SEC("cgroup/setsockopt", BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ BPF_CGROUP_SETSOCKOPT),
};
#undef BPF_PROG_SEC_IMPL
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index 5e2aa83f637a..7e21db11dde8 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -101,6 +101,7 @@ probe_load(enum bpf_prog_type prog_type, const struct bpf_insn *insns,
case BPF_PROG_TYPE_SK_REUSEPORT:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
default:
break;
}
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 4/8] selftests/bpf: test sockopt section name
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
` (2 preceding siblings ...)
2019-06-07 16:29 ` [PATCH bpf-next v3 3/8] libbpf: support sockopt hooks Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 5/8] selftests/bpf: add sockopt test Stanislav Fomichev
` (3 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Add tests that make sure libbpf section detection works.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/testing/selftests/bpf/test_section_names.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_section_names.c b/tools/testing/selftests/bpf/test_section_names.c
index bebd4fbca1f4..5f84b3b8c90b 100644
--- a/tools/testing/selftests/bpf/test_section_names.c
+++ b/tools/testing/selftests/bpf/test_section_names.c
@@ -124,6 +124,16 @@ static struct sec_name_test tests[] = {
{0, BPF_PROG_TYPE_CGROUP_SYSCTL, BPF_CGROUP_SYSCTL},
{0, BPF_CGROUP_SYSCTL},
},
+ {
+ "cgroup/getsockopt",
+ {0, BPF_PROG_TYPE_CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT},
+ {0, BPF_CGROUP_GETSOCKOPT},
+ },
+ {
+ "cgroup/setsockopt",
+ {0, BPF_PROG_TYPE_CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT},
+ {0, BPF_CGROUP_SETSOCKOPT},
+ },
};
static int test_prog_type_by_name(const struct sec_name_test *test)
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 5/8] selftests/bpf: add sockopt test
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
` (3 preceding siblings ...)
2019-06-07 16:29 ` [PATCH bpf-next v3 4/8] selftests/bpf: test sockopt section name Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 6/8] selftests/bpf: add sockopt test that exercises sk helpers Stanislav Fomichev
` (2 subsequent siblings)
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Add sockopt selftests:
* require proper expected_attach_type
* enforce context field read/write access
* test bpf_sockopt_handled handler
* test EPERM
* test limiting optlen from getsockopt
* test out-of-bounds access
v3:
* use DW for optval{,_end} loads
v2:
* use return code 2 for kernel bypass
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 3 +-
tools/testing/selftests/bpf/test_sockopt.c | 773 +++++++++++++++++++++
3 files changed, 776 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/test_sockopt.c
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 7470327edcfe..3fe92601223d 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -39,3 +39,4 @@ libbpf.so.*
test_hashmap
test_btf_dump
xdping
+test_sockopt
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2b426ae1cdc9..b982393b9181 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -26,7 +26,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \
test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \
test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \
- test_btf_dump test_cgroup_attach xdping
+ test_btf_dump test_cgroup_attach xdping test_sockopt
BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
TEST_GEN_FILES = $(BPF_OBJ_FILES)
@@ -101,6 +101,7 @@ $(OUTPUT)/test_netcnt: cgroup_helpers.c
$(OUTPUT)/test_sock_fields: cgroup_helpers.c
$(OUTPUT)/test_sysctl: cgroup_helpers.c
$(OUTPUT)/test_cgroup_attach: cgroup_helpers.c
+$(OUTPUT)/test_sockopt: cgroup_helpers.c
.PHONY: force
diff --git a/tools/testing/selftests/bpf/test_sockopt.c b/tools/testing/selftests/bpf/test_sockopt.c
new file mode 100644
index 000000000000..c007ad4d2c85
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_sockopt.c
@@ -0,0 +1,773 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <linux/filter.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_rlimit.h"
+#include "bpf_util.h"
+#include "cgroup_helpers.h"
+
+#define CG_PATH "/sockopt"
+
+static char bpf_log_buf[4096];
+static bool verbose;
+
+enum sockopt_test_error {
+ OK = 0,
+ DENY_LOAD,
+ DENY_ATTACH,
+ EPERM_GETSOCKOPT,
+ EFAULT_GETSOCKOPT,
+ EPERM_SETSOCKOPT,
+};
+
+static struct sockopt_test {
+ const char *descr;
+ const struct bpf_insn insns[64];
+ enum bpf_attach_type attach_type;
+ enum bpf_attach_type expected_attach_type;
+
+ int level;
+ int optname;
+
+ const char set_optval[64];
+ socklen_t set_optlen;
+
+ const char get_optval[64];
+ socklen_t get_optlen;
+ socklen_t get_optlen_ret;
+
+ enum sockopt_test_error error;
+} tests[] = {
+
+ /* ==================== getsockopt ==================== */
+
+ {
+ .descr = "getsockopt: no expected_attach_type",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = 0,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: wrong expected_attach_type",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+ .error = DENY_ATTACH,
+ },
+ {
+ .descr = "getsockopt: bypass bpf hook",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: return EPERM from bpf hook",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .get_optlen = 1,
+ .error = EPERM_GETSOCKOPT,
+ },
+ {
+ .descr = "getsockopt: no optval bounds check, deny loading",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+
+ /* ctx->optval[0] = 0x80 */
+ BPF_MOV64_IMM(BPF_REG_0, 0x80),
+ BPF_STX_MEM(BPF_W, BPF_REG_6, BPF_REG_0, 0),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->level",
+ .insns = {
+ /* r6 = ctx->level */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, level)),
+
+ /* if (ctx->level == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .level = 123,
+
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->level",
+ .insns = {
+ /* ctx->level = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, level)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->optname",
+ .insns = {
+ /* r6 = ctx->optname */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optname)),
+
+ /* if (ctx->optname == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .optname = 123,
+
+ .get_optlen = 1,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optname",
+ .insns = {
+ /* ctx->optname = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optname)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: read ctx->optlen",
+ .insns = {
+ /* r6 = ctx->optlen */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* if (ctx->optlen == 64) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+ },
+ {
+ .descr = "getsockopt: deny bigger ctx->optlen",
+ .insns = {
+ /* ctx->optlen = 65 */
+ BPF_MOV64_IMM(BPF_REG_0, 65),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+
+ .error = EFAULT_GETSOCKOPT,
+ },
+ {
+ .descr = "getsockopt: support smaller ctx->optlen",
+ .insns = {
+ /* ctx->optlen = 32 */
+ BPF_MOV64_IMM(BPF_REG_0, 32),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .get_optlen = 64,
+ .get_optlen_ret = 32,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optval",
+ .insns = {
+ /* ctx->optval = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "getsockopt: deny writing to ctx->optval_end",
+ .insns = {
+ /* ctx->optval_end = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval_end)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+
+ {
+ .descr = "getsockopt: rewrite value",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r2 = ctx->optval */
+ BPF_MOV64_REG(BPF_REG_2, BPF_REG_6),
+ /* r6 = ctx->optval + 1 */
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, 1),
+
+ /* r7 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_6, BPF_REG_7, 1),
+ /* ctx->optval[0] = 0xF0 */
+ BPF_ST_MEM(BPF_B, BPF_REG_2, 0, 0xF0),
+ /* } */
+
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_GETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .get_optval = { 0xF0 },
+ .get_optlen = 1,
+ },
+
+ /* ==================== setsockopt ==================== */
+
+ {
+ .descr = "setsockopt: no expected_attach_type",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = 0,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: wrong expected_attach_type",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_GETSOCKOPT,
+ .error = DENY_ATTACH,
+ },
+ {
+ .descr = "setsockopt: bypass bpf hook",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .set_optval = { 1 << 3 },
+ .set_optlen = 1,
+
+ .get_optval = { 1 << 3 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: return EPERM from bpf hook",
+ .insns = {
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .set_optlen = 1,
+ .error = EPERM_SETSOCKOPT,
+ },
+ {
+ .descr = "setsockopt: no optval bounds check, deny loading",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+
+ /* r0 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6, 0),
+
+ /* return 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: read ctx->level",
+ .insns = {
+ /* r6 = ctx->level */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, level)),
+
+ /* if (ctx->level == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .level = 123,
+
+ .set_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->level",
+ .insns = {
+ /* ctx->level = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, level)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: read ctx->optname",
+ .insns = {
+ /* r6 = ctx->optname */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optname)),
+
+ /* if (ctx->optname == 123) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 123, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .optname = 123,
+
+ .set_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optname",
+ .insns = {
+ /* ctx->optname = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optname)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: read ctx->optlen",
+ .insns = {
+ /* r6 = ctx->optlen */
+ BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optlen)),
+
+ /* if (ctx->optlen == 64) { */
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 64, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_JMP_A(1),
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 64,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optlen",
+ .insns = {
+ /* ctx->optlen = 32 */
+ BPF_MOV64_IMM(BPF_REG_0, 32),
+ BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optlen)),
+ BPF_MOV64_IMM(BPF_REG_0, 2),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .set_optlen = 64,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optval",
+ .insns = {
+ /* ctx->optval = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: deny writing to ctx->optval_end",
+ .insns = {
+ /* ctx->optval_end = 1 */
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0,
+ offsetof(struct bpf_sockopt, optval_end)),
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .error = DENY_LOAD,
+ },
+ {
+ .descr = "setsockopt: allow IP_TOS <= 128",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r7 = ctx->optval + 1 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
+
+ /* r8 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
+
+ /* r9 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
+
+ /* if (ctx->optval[0] < 128) */
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } */
+
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .set_optval = { 0x80 },
+ .set_optlen = 1,
+ .get_optval = { 0x80 },
+ .get_optlen = 1,
+ },
+ {
+ .descr = "setsockopt: deny IP_TOS > 128",
+ .insns = {
+ /* r6 = ctx->optval */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval)),
+ /* r7 = ctx->optval + 1 */
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_6),
+ BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1),
+
+ /* r8 = ctx->optval_end */
+ BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_1,
+ offsetof(struct bpf_sockopt, optval_end)),
+
+ /* if (ctx->optval + 1 <= ctx->optval_end) { */
+ BPF_JMP_REG(BPF_JGT, BPF_REG_7, BPF_REG_8, 4),
+
+ /* r9 = ctx->optval[0] */
+ BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_6, 0),
+
+ /* if (ctx->optval[0] < 128) */
+ BPF_JMP_IMM(BPF_JGT, BPF_REG_9, 128, 2),
+ BPF_MOV64_IMM(BPF_REG_0, 1),
+ BPF_JMP_A(1),
+ /* } */
+
+ /* } else { */
+ BPF_MOV64_IMM(BPF_REG_0, 0),
+ /* } */
+
+ BPF_EXIT_INSN(),
+ },
+ .attach_type = BPF_CGROUP_SETSOCKOPT,
+ .expected_attach_type = BPF_CGROUP_SETSOCKOPT,
+
+ .level = SOL_IP,
+ .optname = IP_TOS,
+
+ .set_optval = { 0x81 },
+ .set_optlen = 1,
+ .get_optval = { 0x00 },
+ .get_optlen = 1,
+
+ .error = EPERM_SETSOCKOPT,
+ },
+};
+
+static int load_prog(const struct bpf_insn *insns,
+ enum bpf_attach_type expected_attach_type)
+{
+ struct bpf_load_program_attr attr = {
+ .prog_type = BPF_PROG_TYPE_CGROUP_SOCKOPT,
+ .expected_attach_type = expected_attach_type,
+ .insns = insns,
+ .license = "GPL",
+ .log_level = 2,
+ };
+ int fd;
+
+ for (;
+ insns[attr.insns_cnt].code != (BPF_JMP | BPF_EXIT);
+ attr.insns_cnt++) {
+ }
+ attr.insns_cnt++;
+
+ fd = bpf_load_program_xattr(&attr, bpf_log_buf, sizeof(bpf_log_buf));
+ if (verbose && fd < 0)
+ fprintf(stderr, "%s\n", bpf_log_buf);
+
+ return fd;
+}
+
+static int run_test(int cgroup_fd, struct sockopt_test *test)
+{
+ int sock_fd, err, prog_fd;
+ void *optval = NULL;
+ int ret = 0;
+
+ prog_fd = load_prog(test->insns, test->expected_attach_type);
+ if (prog_fd < 0) {
+ if (test->error == DENY_LOAD)
+ return 0;
+
+ perror("bpf_program__load");
+ return -1;
+ }
+
+ err = bpf_prog_attach(prog_fd, cgroup_fd, test->attach_type, 0);
+ if (err < 0) {
+ if (test->error == DENY_ATTACH)
+ goto close_prog_fd;
+
+ perror("bpf_prog_attach");
+ ret = -1;
+ goto close_prog_fd;
+ }
+
+ sock_fd = socket(AF_INET, SOCK_STREAM, 0);
+ if (sock_fd < 0) {
+ perror("socket");
+ ret = -1;
+ goto detach_prog;
+ }
+
+ if (test->set_optlen) {
+ err = setsockopt(sock_fd, test->level, test->optname,
+ test->set_optval, test->set_optlen);
+ if (err) {
+ if (errno == EPERM && test->error == EPERM_SETSOCKOPT)
+ goto close_sock_fd;
+
+ perror("setsockopt");
+ ret = -1;
+ goto close_sock_fd;
+ }
+ }
+
+ if (test->get_optlen) {
+ optval = malloc(test->get_optlen);
+ socklen_t optlen = test->get_optlen;
+ socklen_t expected_get_optlen = test->get_optlen_ret ?:
+ test->get_optlen;
+
+ err = getsockopt(sock_fd, test->level, test->optname,
+ optval, &optlen);
+ if (err) {
+ if (errno == EPERM && test->error == EPERM_GETSOCKOPT)
+ goto free_optval;
+ if (errno == EFAULT && test->error == EFAULT_GETSOCKOPT)
+ goto free_optval;
+
+ perror("getsockopt");
+ ret = -1;
+ goto free_optval;
+ }
+
+ if (optlen != expected_get_optlen) {
+ perror("getsockopt optlen");
+ ret = -1;
+ goto free_optval;
+ }
+
+ if (memcmp(optval, test->get_optval, optlen) != 0) {
+ perror("getsockopt optval");
+ ret = -1;
+ goto free_optval;
+ }
+ }
+
+ ret = test->error != OK;
+
+free_optval:
+ free(optval);
+close_sock_fd:
+ close(sock_fd);
+detach_prog:
+ bpf_prog_detach2(prog_fd, cgroup_fd, test->attach_type);
+close_prog_fd:
+ close(prog_fd);
+ return ret;
+}
+
+int main(int args, char **argv)
+{
+ int err = EXIT_FAILURE, error_cnt = 0;
+ int cgroup_fd, i;
+
+ if (setup_cgroup_environment())
+ goto cleanup_obj;
+
+ cgroup_fd = create_and_get_cgroup(CG_PATH);
+ if (cgroup_fd < 0)
+ goto cleanup_cgroup_env;
+
+ if (join_cgroup(CG_PATH))
+ goto cleanup_cgroup;
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ int err = run_test(cgroup_fd, &tests[i]);
+
+ if (err)
+ error_cnt++;
+
+ printf("#%d %s: %s\n", i, err ? "FAIL" : "PASS",
+ tests[i].descr);
+ }
+
+ printf("Summary: %ld PASSED, %d FAILED\n",
+ ARRAY_SIZE(tests) - error_cnt, error_cnt);
+ err = error_cnt ? EXIT_FAILURE : EXIT_SUCCESS;
+
+cleanup_cgroup:
+ close(cgroup_fd);
+cleanup_cgroup_env:
+ cleanup_cgroup_environment();
+cleanup_obj:
+ return err;
+}
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 6/8] selftests/bpf: add sockopt test that exercises sk helpers
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
` (4 preceding siblings ...)
2019-06-07 16:29 ` [PATCH bpf-next v3 5/8] selftests/bpf: add sockopt test Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 7/8] bpf: add sockopt documentation Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 8/8] bpftool: support cgroup sockopt Stanislav Fomichev
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
socktop test that introduces new SOL_CUSTOM sockopt level and
stores whatever users sets in sk storage. Whenever getsockopt
is called, the original value is retrieved.
v3:
* drop (__u8 *)(long) casts for optval{,_end}
v2:
* new test
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/testing/selftests/bpf/.gitignore | 1 +
tools/testing/selftests/bpf/Makefile | 3 +-
.../testing/selftests/bpf/progs/sockopt_sk.c | 77 +++++++++
tools/testing/selftests/bpf/test_sockopt_sk.c | 156 ++++++++++++++++++
4 files changed, 236 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/progs/sockopt_sk.c
create mode 100644 tools/testing/selftests/bpf/test_sockopt_sk.c
diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 3fe92601223d..8ac076c311d4 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -40,3 +40,4 @@ test_hashmap
test_btf_dump
xdping
test_sockopt
+test_sockopt_sk
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index b982393b9181..9c167bd5ac18 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -26,7 +26,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \
test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \
test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \
- test_btf_dump test_cgroup_attach xdping test_sockopt
+ test_btf_dump test_cgroup_attach xdping test_sockopt test_sockopt_sk
BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
TEST_GEN_FILES = $(BPF_OBJ_FILES)
@@ -102,6 +102,7 @@ $(OUTPUT)/test_sock_fields: cgroup_helpers.c
$(OUTPUT)/test_sysctl: cgroup_helpers.c
$(OUTPUT)/test_cgroup_attach: cgroup_helpers.c
$(OUTPUT)/test_sockopt: cgroup_helpers.c
+$(OUTPUT)/test_sockopt_sk: cgroup_helpers.c
.PHONY: force
diff --git a/tools/testing/selftests/bpf/progs/sockopt_sk.c b/tools/testing/selftests/bpf/progs/sockopt_sk.c
new file mode 100644
index 000000000000..17b3d6d894e2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/sockopt_sk.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1;
+
+#define SOL_CUSTOM 0xdeadbeef
+
+struct socket_storage {
+ __u8 val;
+};
+
+struct bpf_map_def SEC("maps") socket_storage_map = {
+ .type = BPF_MAP_TYPE_SK_STORAGE,
+ .key_size = sizeof(int),
+ .value_size = sizeof(struct socket_storage),
+ .map_flags = BPF_F_NO_PREALLOC,
+};
+BPF_ANNOTATE_KV_PAIR(socket_storage_map, int, struct socket_storage);
+
+SEC("cgroup/getsockopt")
+int _getsockopt(struct bpf_sockopt *ctx)
+{
+ __u8 *optval_end = ctx->optval_end;
+ __u8 *optval = ctx->optval;
+ struct socket_storage *storage;
+ struct bpf_sock *sk;
+
+ sk = bpf_sk_fullsock(ctx->sk);
+ if (!sk)
+ return 0; /* EPERM, deny for non-full sockets */
+
+ if (ctx->level != SOL_CUSTOM)
+ return 0; /* EPERM, deny everything except custom level */
+
+ if (optval + 1 > optval_end)
+ return 0; /* EPERM, bounds check */
+
+ storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!storage)
+ return 0; /* EPERM, couldn't get sk storage */
+
+ optval[0] = storage->val;
+ ctx->optlen = 1;
+
+ return 2; /* bypass kernel */
+}
+
+SEC("cgroup/setsockopt")
+int _setsockopt(struct bpf_sockopt *ctx)
+{
+ __u8 *optval_end = ctx->optval_end;
+ __u8 *optval = ctx->optval;
+ struct socket_storage *storage;
+ struct bpf_sock *sk;
+
+ sk = bpf_sk_fullsock(ctx->sk);
+ if (!sk)
+ return 0; /* EPERM, deny for non-full sockets */
+
+ if (ctx->level != SOL_CUSTOM)
+ return 0; /* EPERM, deny everything except custom level */
+
+ if (optval + 1 > optval_end)
+ return 0; /* EPERM, bounds check */
+
+ storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
+ BPF_SK_STORAGE_GET_F_CREATE);
+ if (!storage)
+ return 0; /* EPERM, couldn't get sk storage */
+
+ storage->val = optval[0];
+
+ return 2; /* bypass kernel */
+}
diff --git a/tools/testing/selftests/bpf/test_sockopt_sk.c b/tools/testing/selftests/bpf/test_sockopt_sk.c
new file mode 100644
index 000000000000..1acc055f94ac
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_sockopt_sk.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <linux/filter.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_rlimit.h"
+#include "bpf_util.h"
+#include "cgroup_helpers.h"
+
+#define CG_PATH "/sockopt"
+
+#define SOL_CUSTOM 0xdeadbeef
+
+static int getsetsockopt(void)
+{
+ int fd, err;
+ char buf[4] = { 0x01, 0x00, 0x00, 0x00 };
+ socklen_t optlen;
+
+ fd = socket(AF_INET, SOCK_STREAM, 0);
+ if (fd < 0) {
+ log_err("Failed to create socket");
+ return -1;
+ }
+
+ err = setsockopt(fd, SOL_IP, IP_TOS, buf, 1);
+ if (!err || errno != EPERM) {
+ log_err("Unexpected success from setsockopt");
+ goto err;
+ }
+
+ err = setsockopt(fd, SOL_CUSTOM, 0, buf, 1);
+ if (err) {
+ log_err("Failed to call setsockopt");
+ goto err;
+ }
+
+ buf[0] = 0;
+ optlen = 4;
+ err = getsockopt(fd, SOL_CUSTOM, 0, buf, &optlen);
+ if (err) {
+ log_err("Failed to call getsockopt");
+ goto err;
+ }
+
+ if (optlen != 1) {
+ log_err("Unexpected optlen %d != 1", optlen);
+ goto err;
+ }
+ if (buf[0] != 0x01) {
+ log_err("Unexpected buf[0] 0x%02x != 0x01", buf[0]);
+ goto err;
+ }
+
+ close(fd);
+ return 0;
+err:
+ close(fd);
+ return -1;
+}
+
+static int prog_attach(struct bpf_object *obj, int cgroup_fd, const char *title)
+{
+ enum bpf_attach_type attach_type;
+ enum bpf_prog_type prog_type;
+ struct bpf_program *prog;
+ int err;
+
+ err = libbpf_prog_type_by_name(title, &prog_type, &attach_type);
+ if (err) {
+ log_err("Failed to deduct types for %s BPF program", title);
+ return -1;
+ }
+
+ prog = bpf_object__find_program_by_title(obj, title);
+ if (!prog) {
+ log_err("Failed to find %s BPF program", title);
+ return -1;
+ }
+
+ err = bpf_prog_attach(bpf_program__fd(prog), cgroup_fd,
+ attach_type, 0);
+ if (err) {
+ log_err("Failed to attach %s BPF program", title);
+ return -1;
+ }
+
+ return 0;
+}
+
+static int run_test(int cgroup_fd)
+{
+ struct bpf_prog_load_attr attr = {
+ .file = "./sockopt_sk.o",
+ };
+ struct bpf_object *obj;
+ int ignored;
+ int err;
+
+ err = bpf_prog_load_xattr(&attr, &obj, &ignored);
+ if (err) {
+ log_err("Failed to load BPF object");
+ return -1;
+ }
+
+ err = prog_attach(obj, cgroup_fd, "cgroup/getsockopt");
+ if (err)
+ goto close_bpf_object;
+
+ err = prog_attach(obj, cgroup_fd, "cgroup/setsockopt");
+ if (err)
+ goto close_bpf_object;
+
+ err = getsetsockopt();
+
+close_bpf_object:
+ bpf_object__close(obj);
+ return err;
+}
+
+int main(int args, char **argv)
+{
+ int cgroup_fd;
+ int err = EXIT_SUCCESS;
+
+ if (setup_cgroup_environment())
+ goto cleanup_obj;
+
+ cgroup_fd = create_and_get_cgroup(CG_PATH);
+ if (cgroup_fd < 0)
+ goto cleanup_cgroup_env;
+
+ if (join_cgroup(CG_PATH))
+ goto cleanup_cgroup;
+
+ if (run_test(cgroup_fd))
+ err = EXIT_FAILURE;
+
+ printf("test_sockopt_sk: %s\n",
+ err == EXIT_SUCCESS ? "PASSED" : "FAILED");
+
+cleanup_cgroup:
+ close(cgroup_fd);
+cleanup_cgroup_env:
+ cleanup_cgroup_environment();
+cleanup_obj:
+ return err;
+}
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 7/8] bpf: add sockopt documentation
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
` (5 preceding siblings ...)
2019-06-07 16:29 ` [PATCH bpf-next v3 6/8] selftests/bpf: add sockopt test that exercises sk helpers Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 8/8] bpftool: support cgroup sockopt Stanislav Fomichev
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev
Provide user documentation about sockopt prog type and cgroup hooks.
v2:
* use return code 2 for kernel bypass
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
Documentation/bpf/index.rst | 1 +
Documentation/bpf/prog_cgroup_sockopt.rst | 39 +++++++++++++++++++++++
2 files changed, 40 insertions(+)
create mode 100644 Documentation/bpf/prog_cgroup_sockopt.rst
diff --git a/Documentation/bpf/index.rst b/Documentation/bpf/index.rst
index d3fe4cac0c90..801a6ed3f2e5 100644
--- a/Documentation/bpf/index.rst
+++ b/Documentation/bpf/index.rst
@@ -42,6 +42,7 @@ Program types
.. toctree::
:maxdepth: 1
+ prog_cgroup_sockopt
prog_cgroup_sysctl
prog_flow_dissector
diff --git a/Documentation/bpf/prog_cgroup_sockopt.rst b/Documentation/bpf/prog_cgroup_sockopt.rst
new file mode 100644
index 000000000000..b117451ab571
--- /dev/null
+++ b/Documentation/bpf/prog_cgroup_sockopt.rst
@@ -0,0 +1,39 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+BPF_PROG_TYPE_SOCKOPT
+=====================
+
+``BPF_PROG_TYPE_SOCKOPT`` program type can be attached to two cgroup hooks:
+
+* ``BPF_CGROUP_GETSOCKOPT`` - called every time process executes ``getsockopt``
+ system call.
+* ``BPF_CGROUP_SETSOCKOPT`` - called every time process executes ``setsockopt``
+ system call.
+
+The context (``struct bpf_sockopt``) has associated socket (``sk``) and
+all input arguments: ``level``, ``optname``, ``optval`` and ``optlen``.
+
+BPF_CGROUP_SETSOCKOPT
+=====================
+
+``BPF_CGROUP_SETSOCKOPT`` has a read-only context and this hook has
+access to cgroup and socket local storage.
+
+BPF_CGROUP_GETSOCKOPT
+=====================
+
+``BPF_CGROUP_GETSOCKOPT`` has to fill in ``optval`` and adjust
+``optlen`` accordingly. Input ``optlen`` contains the maximum length
+of data that can be returned to the userspace. In other words, BPF
+program can't increase ``optlen``, it can only decrease it.
+
+Return Type
+===========
+
+* ``0`` - reject the syscall, ``EPERM`` will be returned to the userspace.
+* ``1`` - success: after returning from the BPF hook, kernel will also
+ handle this socket option.
+* ``2`` - success: after returning from the BPF hook, kernel will _not_
+ handle this socket option; control will be returned to the userspace
+ instead.
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH bpf-next v3 8/8] bpftool: support cgroup sockopt
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
` (6 preceding siblings ...)
2019-06-07 16:29 ` [PATCH bpf-next v3 7/8] bpf: add sockopt documentation Stanislav Fomichev
@ 2019-06-07 16:29 ` Stanislav Fomichev
7 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-07 16:29 UTC (permalink / raw)
To: netdev, bpf; +Cc: davem, ast, daniel, Stanislav Fomichev, Jakub Kicinski
Support sockopt prog type and cgroup hooks in the bpftool.
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
---
tools/bpf/bpftool/Documentation/bpftool-cgroup.rst | 7 +++++--
tools/bpf/bpftool/Documentation/bpftool-prog.rst | 2 +-
tools/bpf/bpftool/bash-completion/bpftool | 8 +++++---
tools/bpf/bpftool/cgroup.c | 5 ++++-
tools/bpf/bpftool/main.h | 1 +
tools/bpf/bpftool/prog.c | 3 ++-
6 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
index 36807735e2a5..cac088a320a6 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-cgroup.rst
@@ -29,7 +29,8 @@ CGROUP COMMANDS
| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
| *ATTACH_TYPE* := { **ingress** | **egress** | **sock_create** | **sock_ops** | **device** |
| **bind4** | **bind6** | **post_bind4** | **post_bind6** | **connect4** | **connect6** |
-| **sendmsg4** | **sendmsg6** | **sysctl** }
+| **sendmsg4** | **sendmsg6** | **sysctl** | **getsockopt** |
+| **setsockopt** }
| *ATTACH_FLAGS* := { **multi** | **override** }
DESCRIPTION
@@ -86,7 +87,9 @@ DESCRIPTION
unconnected udp4 socket (since 4.18);
**sendmsg6** call to sendto(2), sendmsg(2), sendmmsg(2) for an
unconnected udp6 socket (since 4.18);
- **sysctl** sysctl access (since 5.2).
+ **sysctl** sysctl access (since 5.2);
+ **getsockopt** call to getsockopt (since 5.3);
+ **setsockopt** call to setsockopt (since 5.3).
**bpftool cgroup detach** *CGROUP* *ATTACH_TYPE* *PROG*
Detach *PROG* from the cgroup *CGROUP* and attach type
diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
index 228a5c863cc7..c6bade35032c 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
@@ -40,7 +40,7 @@ PROG COMMANDS
| **lwt_seg6local** | **sockops** | **sk_skb** | **sk_msg** | **lirc_mode2** |
| **cgroup/bind4** | **cgroup/bind6** | **cgroup/post_bind4** | **cgroup/post_bind6** |
| **cgroup/connect4** | **cgroup/connect6** | **cgroup/sendmsg4** | **cgroup/sendmsg6** |
-| **cgroup/sysctl**
+| **cgroup/sysctl** | **cgroup/getsockopt** | **cgroup/setsockopt**
| }
| *ATTACH_TYPE* := {
| **msg_verdict** | **stream_verdict** | **stream_parser** | **flow_dissector**
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 2725e27dfa42..7afb8b6fbaaa 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -378,7 +378,8 @@ _bpftool()
cgroup/connect4 cgroup/connect6 \
cgroup/sendmsg4 cgroup/sendmsg6 \
cgroup/post_bind4 cgroup/post_bind6 \
- cgroup/sysctl" -- \
+ cgroup/sysctl cgroup/getsockopt \
+ cgroup/setsockopt" -- \
"$cur" ) )
return 0
;;
@@ -688,7 +689,8 @@ _bpftool()
attach|detach)
local ATTACH_TYPES='ingress egress sock_create sock_ops \
device bind4 bind6 post_bind4 post_bind6 connect4 \
- connect6 sendmsg4 sendmsg6 sysctl'
+ connect6 sendmsg4 sendmsg6 sysctl getsockopt \
+ setsockopt'
local ATTACH_FLAGS='multi override'
local PROG_TYPE='id pinned tag'
case $prev in
@@ -698,7 +700,7 @@ _bpftool()
;;
ingress|egress|sock_create|sock_ops|device|bind4|bind6|\
post_bind4|post_bind6|connect4|connect6|sendmsg4|\
- sendmsg6|sysctl)
+ sendmsg6|sysctl|getsockopt|setsockopt)
COMPREPLY=( $( compgen -W "$PROG_TYPE" -- \
"$cur" ) )
return 0
diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c
index 7e22f115c8c1..3083f2e4886e 100644
--- a/tools/bpf/bpftool/cgroup.c
+++ b/tools/bpf/bpftool/cgroup.c
@@ -25,7 +25,8 @@
" ATTACH_TYPE := { ingress | egress | sock_create |\n" \
" sock_ops | device | bind4 | bind6 |\n" \
" post_bind4 | post_bind6 | connect4 |\n" \
- " connect6 | sendmsg4 | sendmsg6 | sysctl }"
+ " connect6 | sendmsg4 | sendmsg6 | sysctl |\n" \
+ " getsockopt | setsockopt }"
static const char * const attach_type_strings[] = {
[BPF_CGROUP_INET_INGRESS] = "ingress",
@@ -42,6 +43,8 @@ static const char * const attach_type_strings[] = {
[BPF_CGROUP_UDP4_SENDMSG] = "sendmsg4",
[BPF_CGROUP_UDP6_SENDMSG] = "sendmsg6",
[BPF_CGROUP_SYSCTL] = "sysctl",
+ [BPF_CGROUP_GETSOCKOPT] = "getsockopt",
+ [BPF_CGROUP_SETSOCKOPT] = "setsockopt",
[__MAX_BPF_ATTACH_TYPE] = NULL,
};
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index 28a2a5857e14..9c5d9c80f71e 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -74,6 +74,7 @@ static const char * const prog_type_name[] = {
[BPF_PROG_TYPE_SK_REUSEPORT] = "sk_reuseport",
[BPF_PROG_TYPE_FLOW_DISSECTOR] = "flow_dissector",
[BPF_PROG_TYPE_CGROUP_SYSCTL] = "cgroup_sysctl",
+ [BPF_PROG_TYPE_CGROUP_SOCKOPT] = "cgroup_sockopt",
};
extern const char * const map_type_name[];
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 1f209c80d906..a201e1c83346 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1070,7 +1070,8 @@ static int do_help(int argc, char **argv)
" sk_reuseport | flow_dissector | cgroup/sysctl |\n"
" cgroup/bind4 | cgroup/bind6 | cgroup/post_bind4 |\n"
" cgroup/post_bind6 | cgroup/connect4 | cgroup/connect6 |\n"
- " cgroup/sendmsg4 | cgroup/sendmsg6 }\n"
+ " cgroup/sendmsg4 | cgroup/sendmsg6 | cgroup/getsockopt |\n"
+ " cgroup/setsockopt }\n"
" ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n"
" flow_dissector }\n"
" " HELP_SPEC_OPTIONS "\n"
--
2.22.0.rc1.311.g5d7573a151-goog
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH bpf-next v3 1/8] bpf: implement getsockopt and setsockopt hooks
2019-06-07 16:29 ` [PATCH bpf-next v3 1/8] bpf: implement " Stanislav Fomichev
@ 2019-06-08 7:08 ` Martin Lau
2019-06-10 16:10 ` Stanislav Fomichev
0 siblings, 1 reply; 11+ messages in thread
From: Martin Lau @ 2019-06-08 7:08 UTC (permalink / raw)
To: Stanislav Fomichev; +Cc: netdev, bpf, davem, ast, daniel, Andrii Nakryiko
On Fri, Jun 07, 2019 at 09:29:13AM -0700, Stanislav Fomichev wrote:
> Implement new BPF_PROG_TYPE_CGROUP_SOCKOPT program type and
> BPF_CGROUP_{G,S}ETSOCKOPT cgroup hooks.
>
> BPF_CGROUP_SETSOCKOPT get a read-only view of the setsockopt arguments.
> BPF_CGROUP_GETSOCKOPT can modify the supplied buffer.
> Both of them reuse existing PTR_TO_PACKET{,_END} infrastructure.
>
> The buffer memory is pre-allocated (because I don't think there is
> a precedent for working with __user memory from bpf). This might be
> slow to do for each {s,g}etsockopt call, that's why I've added
> __cgroup_bpf_prog_array_is_empty that exits early if there is nothing
> attached to a cgroup. Note, however, that there is a race between
> __cgroup_bpf_prog_array_is_empty and BPF_PROG_RUN_ARRAY where cgroup
> program layout might have changed; this should not be a problem
> because in general there is a race between multiple calls to
> {s,g}etsocktop and user adding/removing bpf progs from a cgroup.
>
> The return code of the BPF program is handled as follows:
> * 0: EPERM
> * 1: success, execute kernel {s,g}etsockopt path after BPF prog exits
> * 2: success, do _not_ execute kernel {s,g}etsockopt path after BPF
> prog exits
>
> v3:
> * typos in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY comments (Andrii Nakryiko)
> * reverse christmas tree in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY (Andrii
> Nakryiko)
> * use __bpf_md_ptr instead of __u32 for optval{,_end} (Martin Lau)
> * use BPF_FIELD_SIZEOF() for consistency (Martin Lau)
> * new CG_SOCKOPT_ACCESS macro to wrap repeated parts
>
> v2:
> * moved bpf_sockopt_kern fields around to remove a hole (Martin Lau)
> * aligned bpf_sockopt_kern->buf to 8 bytes (Martin Lau)
> * bpf_prog_array_is_empty instead of bpf_prog_array_length (Martin Lau)
> * added [0,2] return code check to verifier (Martin Lau)
> * dropped unused buf[64] from the stack (Martin Lau)
> * use PTR_TO_SOCKET for bpf_sockopt->sk (Martin Lau)
> * dropped bpf_target_off from ctx rewrites (Martin Lau)
> * use return code for kernel bypass (Martin Lau & Andrii Nakryiko)
>
> diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
> index 1b65ab0df457..4fc8429af6fc 100644
> --- a/kernel/bpf/cgroup.c
> +++ b/kernel/bpf/cgroup.c
[ ... ]
> +static const struct bpf_func_proto *
> +cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> +{
> + switch (func_id) {
> + case BPF_FUNC_sk_fullsock:
> + return &bpf_sk_fullsock_proto;
May be my v2 comment has been missed.
sk here (i.e. PTR_TO_SOCKET) must be a fullsock.
bpf_sk_fullsock() will be a no-op. Hence, there is
no need to expose bpf_sk_fullsock_proto.
> + case BPF_FUNC_sk_storage_get:
> + return &bpf_sk_storage_get_proto;
> + case BPF_FUNC_sk_storage_delete:
> + return &bpf_sk_storage_delete_proto;
> +#ifdef CONFIG_INET
> + case BPF_FUNC_tcp_sock:
> + return &bpf_tcp_sock_proto;
> +#endif
> + default:
> + return cgroup_base_func_proto(func_id, prog);
> + }
> +}
> +
> +static bool cg_sockopt_is_valid_access(int off, int size,
> + enum bpf_access_type type,
> + const struct bpf_prog *prog,
> + struct bpf_insn_access_aux *info)
> +{
> + const int size_default = sizeof(__u32);
> +
> + if (off < 0 || off >= sizeof(struct bpf_sockopt))
> + return false;
> +
> + if (off % size != 0)
> + return false;
> +
> + if (type == BPF_WRITE) {
> + switch (off) {
> + case offsetof(struct bpf_sockopt, optlen):
> + if (size != size_default)
> + return false;
> + return prog->expected_attach_type ==
> + BPF_CGROUP_GETSOCKOPT;
> + default:
> + return false;
> + }
> + }
> +
> + switch (off) {
> + case offsetof(struct bpf_sockopt, sk):
> + if (size != sizeof(struct bpf_sock *))
Based on my understanding in commit b7df9ada9a77 ("bpf: fix pointer offsets in context for 32 bit"),
I think it should be 'size != sizeof(__u64)'
Same for the optval and optval_end below.
> + return false;
> + info->reg_type = PTR_TO_SOCKET;
> + break;
> + case bpf_ctx_range(struct bpf_sockopt, optval):
offsetof(struct bpf_sockopt, optval)
> + if (size != sizeof(void *))
> + return false;
> + info->reg_type = PTR_TO_PACKET;
> + break;
> + case bpf_ctx_range(struct bpf_sockopt, optval_end):
offsetof(struct bpf_sockopt, optval_end)
> + if (size != sizeof(void *))
> + return false;
> + info->reg_type = PTR_TO_PACKET_END;
> + break;
> + default:
> + if (size != size_default)
> + return false;
> + break;
> + }
> + return true;
> +}
> +
[ ... ]
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 55bfc941d17a..4652c0a005ca 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -1835,7 +1835,7 @@ BPF_CALL_1(bpf_sk_fullsock, struct sock *, sk)
> return sk_fullsock(sk) ? (unsigned long)sk : (unsigned long)NULL;
> }
>
> -static const struct bpf_func_proto bpf_sk_fullsock_proto = {
> +const struct bpf_func_proto bpf_sk_fullsock_proto = {
As mentioned above, this change is also not needed.
Others LGTM.
> .func = bpf_sk_fullsock,
> .gpl_only = false,
> .ret_type = RET_PTR_TO_SOCKET_OR_NULL,
> @@ -5636,7 +5636,7 @@ BPF_CALL_1(bpf_tcp_sock, struct sock *, sk)
> return (unsigned long)NULL;
> }
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH bpf-next v3 1/8] bpf: implement getsockopt and setsockopt hooks
2019-06-08 7:08 ` Martin Lau
@ 2019-06-10 16:10 ` Stanislav Fomichev
0 siblings, 0 replies; 11+ messages in thread
From: Stanislav Fomichev @ 2019-06-10 16:10 UTC (permalink / raw)
To: Martin Lau
Cc: Stanislav Fomichev, netdev, bpf, davem, ast, daniel, Andrii Nakryiko
On 06/08, Martin Lau wrote:
> On Fri, Jun 07, 2019 at 09:29:13AM -0700, Stanislav Fomichev wrote:
> > Implement new BPF_PROG_TYPE_CGROUP_SOCKOPT program type and
> > BPF_CGROUP_{G,S}ETSOCKOPT cgroup hooks.
> >
> > BPF_CGROUP_SETSOCKOPT get a read-only view of the setsockopt arguments.
> > BPF_CGROUP_GETSOCKOPT can modify the supplied buffer.
> > Both of them reuse existing PTR_TO_PACKET{,_END} infrastructure.
> >
> > The buffer memory is pre-allocated (because I don't think there is
> > a precedent for working with __user memory from bpf). This might be
> > slow to do for each {s,g}etsockopt call, that's why I've added
> > __cgroup_bpf_prog_array_is_empty that exits early if there is nothing
> > attached to a cgroup. Note, however, that there is a race between
> > __cgroup_bpf_prog_array_is_empty and BPF_PROG_RUN_ARRAY where cgroup
> > program layout might have changed; this should not be a problem
> > because in general there is a race between multiple calls to
> > {s,g}etsocktop and user adding/removing bpf progs from a cgroup.
> >
> > The return code of the BPF program is handled as follows:
> > * 0: EPERM
> > * 1: success, execute kernel {s,g}etsockopt path after BPF prog exits
> > * 2: success, do _not_ execute kernel {s,g}etsockopt path after BPF
> > prog exits
> >
> > v3:
> > * typos in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY comments (Andrii Nakryiko)
> > * reverse christmas tree in BPF_PROG_CGROUP_SOCKOPT_RUN_ARRAY (Andrii
> > Nakryiko)
> > * use __bpf_md_ptr instead of __u32 for optval{,_end} (Martin Lau)
> > * use BPF_FIELD_SIZEOF() for consistency (Martin Lau)
> > * new CG_SOCKOPT_ACCESS macro to wrap repeated parts
> >
> > v2:
> > * moved bpf_sockopt_kern fields around to remove a hole (Martin Lau)
> > * aligned bpf_sockopt_kern->buf to 8 bytes (Martin Lau)
> > * bpf_prog_array_is_empty instead of bpf_prog_array_length (Martin Lau)
> > * added [0,2] return code check to verifier (Martin Lau)
> > * dropped unused buf[64] from the stack (Martin Lau)
> > * use PTR_TO_SOCKET for bpf_sockopt->sk (Martin Lau)
> > * dropped bpf_target_off from ctx rewrites (Martin Lau)
> > * use return code for kernel bypass (Martin Lau & Andrii Nakryiko)
> >
>
> > diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
> > index 1b65ab0df457..4fc8429af6fc 100644
> > --- a/kernel/bpf/cgroup.c
> > +++ b/kernel/bpf/cgroup.c
>
> [ ... ]
>
> > +static const struct bpf_func_proto *
> > +cg_sockopt_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> > +{
> > + switch (func_id) {
> > + case BPF_FUNC_sk_fullsock:
> > + return &bpf_sk_fullsock_proto;
> May be my v2 comment has been missed.
>
> sk here (i.e. PTR_TO_SOCKET) must be a fullsock.
> bpf_sk_fullsock() will be a no-op. Hence, there is
> no need to expose bpf_sk_fullsock_proto.
I think I missed that fact that PTR_TO_SOCKET implies fullsock.
Will remove, thanks!
> > + case BPF_FUNC_sk_storage_get:
> > + return &bpf_sk_storage_get_proto;
> > + case BPF_FUNC_sk_storage_delete:
> > + return &bpf_sk_storage_delete_proto;
> > +#ifdef CONFIG_INET
> > + case BPF_FUNC_tcp_sock:
> > + return &bpf_tcp_sock_proto;
> > +#endif
> > + default:
> > + return cgroup_base_func_proto(func_id, prog);
> > + }
> > +}
> > +
> > +static bool cg_sockopt_is_valid_access(int off, int size,
> > + enum bpf_access_type type,
> > + const struct bpf_prog *prog,
> > + struct bpf_insn_access_aux *info)
> > +{
> > + const int size_default = sizeof(__u32);
> > +
> > + if (off < 0 || off >= sizeof(struct bpf_sockopt))
> > + return false;
> > +
> > + if (off % size != 0)
> > + return false;
> > +
> > + if (type == BPF_WRITE) {
> > + switch (off) {
> > + case offsetof(struct bpf_sockopt, optlen):
> > + if (size != size_default)
> > + return false;
> > + return prog->expected_attach_type ==
> > + BPF_CGROUP_GETSOCKOPT;
> > + default:
> > + return false;
> > + }
> > + }
> > +
> > + switch (off) {
> > + case offsetof(struct bpf_sockopt, sk):
> > + if (size != sizeof(struct bpf_sock *))
> Based on my understanding in commit b7df9ada9a77 ("bpf: fix pointer offsets in context for 32 bit"),
> I think it should be 'size != sizeof(__u64)'
>
> Same for the optval and optval_end below.
Good point. I was actually wondering when converting BPF_W to BPF_DW in
the tests whether that would work correctly on 32 bits. Thanks for
commit pointer, that should, indeed, always be all sizeof(__u64).
> > + return false;
> > + info->reg_type = PTR_TO_SOCKET;
> > + break;
> > + case bpf_ctx_range(struct bpf_sockopt, optval):
> offsetof(struct bpf_sockopt, optval)
Ack. No narrow loads for the pointers.
> > + if (size != sizeof(void *))
> > + return false;
> > + info->reg_type = PTR_TO_PACKET;
> > + break;
> > + case bpf_ctx_range(struct bpf_sockopt, optval_end):
> offsetof(struct bpf_sockopt, optval_end)
>
> > + if (size != sizeof(void *))
> > + return false;
> > + info->reg_type = PTR_TO_PACKET_END;
> > + break;
> > + default:
> > + if (size != size_default)
> > + return false;
> > + break;
> > + }
> > + return true;
> > +}
> > +
>
> [ ... ]
>
> > diff --git a/net/core/filter.c b/net/core/filter.c
> > index 55bfc941d17a..4652c0a005ca 100644
> > --- a/net/core/filter.c
> > +++ b/net/core/filter.c
> > @@ -1835,7 +1835,7 @@ BPF_CALL_1(bpf_sk_fullsock, struct sock *, sk)
> > return sk_fullsock(sk) ? (unsigned long)sk : (unsigned long)NULL;
> > }
> >
> > -static const struct bpf_func_proto bpf_sk_fullsock_proto = {
> > +const struct bpf_func_proto bpf_sk_fullsock_proto = {
> As mentioned above, this change is also not needed.
>
> Others LGTM.
Agreed, will not export.
> > .func = bpf_sk_fullsock,
> > .gpl_only = false,
> > .ret_type = RET_PTR_TO_SOCKET_OR_NULL,
> > @@ -5636,7 +5636,7 @@ BPF_CALL_1(bpf_tcp_sock, struct sock *, sk)
> > return (unsigned long)NULL;
> > }
> >
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2019-06-10 16:10 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-07 16:29 [PATCH bpf-next v3 0/8] bpf: getsockopt and setsockopt hooks Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 1/8] bpf: implement " Stanislav Fomichev
2019-06-08 7:08 ` Martin Lau
2019-06-10 16:10 ` Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 2/8] bpf: sync bpf.h to tools/ Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 3/8] libbpf: support sockopt hooks Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 4/8] selftests/bpf: test sockopt section name Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 5/8] selftests/bpf: add sockopt test Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 6/8] selftests/bpf: add sockopt test that exercises sk helpers Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 7/8] bpf: add sockopt documentation Stanislav Fomichev
2019-06-07 16:29 ` [PATCH bpf-next v3 8/8] bpftool: support cgroup sockopt Stanislav Fomichev
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