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Message-Id: <20190619165957.235580-2-sdf@google.com>
Date: Wed, 19 Jun 2019 09:59:49 -0700
From: Stanislav Fomichev <sdf@...gle.com>
To: netdev@...r.kernel.org, bpf@...r.kernel.org
Cc: davem@...emloft.net, ast@...nel.org, daniel@...earbox.net,
Stanislav Fomichev <sdf@...gle.com>, Martin Lau <kafai@...com>
Subject: [PATCH bpf-next v7 1/9] bpf: implement getsockopt and setsockopt hooks
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, continue with next BPF program in the cgroup chain
v7:
* return only 0 or 1 (Alexei Starovoitov)
* always run all progs (Alexei Starovoitov)
* use optval=0 as kernel bypass in setsockopt (Alexei Starovoitov)
(decided to use optval=-1 instead, optval=0 might be a valid input)
* call getsockopt hook after kernel handlers (Alexei Starovoitov)
v6:
* rework cgroup chaining; stop as soon as bpf program returns
0 or 2; see patch with the documentation for the details
* drop Andrii's and Martin's Acked-by (not sure they are comfortable
with the new state of things)
v5:
* skip copy_to_user() and put_user() when ret == 0 (Martin Lau)
v4:
* don't export bpf_sk_fullsock helper (Martin Lau)
* size != sizeof(__u64) for uapi pointers (Martin Lau)
* offsetof instead of bpf_ctx_range when checking ctx access (Martin Lau)
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)
Cc: Martin Lau <kafai@...com>
Signed-off-by: Stanislav Fomichev <sdf@...gle.com>
---
include/linux/bpf-cgroup.h | 43 +++++
include/linux/bpf.h | 2 +
include/linux/bpf_types.h | 1 +
include/linux/filter.h | 14 ++
include/uapi/linux/bpf.h | 14 ++
kernel/bpf/cgroup.c | 317 +++++++++++++++++++++++++++++++++++++
kernel/bpf/core.c | 9 ++
kernel/bpf/syscall.c | 19 +++
kernel/bpf/verifier.c | 13 ++
net/core/filter.c | 2 +-
net/socket.c | 16 ++
11 files changed, 449 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index b631ee75762d..84bc98ecaa59 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -124,6 +124,14 @@ 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 *sk, int level,
+ int optname, char __user *optval,
+ int __user *optlen, int max_optlen,
+ int retval);
+
static inline enum bpf_cgroup_storage_type cgroup_storage_type(
struct bpf_map *map)
{
@@ -280,6 +288,36 @@ 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_GETSOCKOPT_MAX_OPTLEN(optlen) \
+({ \
+ int __ret = 0; \
+ if (cgroup_bpf_enabled) \
+ get_user(__ret, optlen); \
+ __ret; \
+})
+
+#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, optlen, \
+ max_optlen, retval) \
+({ \
+ int __ret = retval; \
+ if (cgroup_bpf_enabled) \
+ __ret = __cgroup_bpf_run_filter_getsockopt(sock, level, \
+ optname, optval, \
+ optlen, max_optlen, \
+ retval); \
+ __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 +387,11 @@ 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_GETSOCKOPT_MAX_OPTLEN(optlen) ({ 0; })
+#define BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock, level, optname, optval, \
+ optlen, max_optlen, retval) (retval)
+#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 b15fb5fcb741..c9d4625831f2 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -521,6 +521,7 @@ 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);
@@ -1055,6 +1056,7 @@ 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_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..f4274f6337f0 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1199,4 +1199,18 @@ 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;
+ s32 retval;
+
+ /* 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 d0a23476f887..67059b4c663f 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
};
@@ -3539,4 +3542,15 @@ 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;
+ __s32 retval;
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 1b65ab0df457..24e36e66689e 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 +925,185 @@ 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_enabled ||
+ __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) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ lock_sock(sk);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_SETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ if (!ret) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ if (ctx.optlen == -1)
+ /* optlen set to -1, bypass kernel */
+ ret = 1;
+ else if (ctx.optlen == optlen)
+ /* optlen not changed, run kernel handler */
+ ret = 0;
+ else
+ /* any other value is rejected */
+ ret = -EFAULT;
+
+out:
+ 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, int max_optlen,
+ int retval)
+{
+ struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
+ struct bpf_sockopt_kern ctx = {
+ .sk = sk,
+ .level = level,
+ .optname = optname,
+ .retval = retval,
+ };
+ 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_enabled ||
+ __cgroup_bpf_prog_array_is_empty(cgrp, BPF_CGROUP_GETSOCKOPT))
+ return retval;
+
+ ret = sockopt_alloc_buf(&ctx, max_optlen);
+ if (ret)
+ return ret;
+
+ if (!retval) {
+ /* If kernel getsockopt finished successfully,
+ * copy whatever was returned to the user back
+ * into our temporary buffer. Set optlen to the
+ * one that kernel returned as well to let
+ * BPF programs inspect the value.
+ */
+
+ if (get_user(ctx.optlen, optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (ctx.optlen > max_optlen)
+ ctx.optlen = max_optlen;
+
+ if (copy_from_user(ctx.optval, optval, ctx.optlen) != 0) {
+ ret = -EFAULT;
+ goto out;
+ }
+ }
+
+ lock_sock(sk);
+ ret = BPF_PROG_RUN_ARRAY(cgrp->bpf.effective[BPF_CGROUP_GETSOCKOPT],
+ &ctx, BPF_PROG_RUN);
+ release_sock(sk);
+
+ if (!ret) {
+ ret = -EPERM;
+ goto out;
+ }
+
+ if (ctx.optlen > max_optlen) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ /* BPF programs only allowed to set retval to 0, not some
+ * arbitrary value.
+ */
+ if (ctx.retval != 0 && ctx.retval != retval) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (copy_to_user(optval, ctx.optval, ctx.optlen) ||
+ put_user(ctx.optlen, optlen)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = ctx.retval;
+
+out:
+ sockopt_free_buf(&ctx);
+ 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 +1364,140 @@ 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_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, retval):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type ==
+ BPF_CGROUP_GETSOCKOPT;
+ case offsetof(struct bpf_sockopt, optlen):
+ return size == size_default;
+ default:
+ return false;
+ }
+ }
+
+ switch (off) {
+ case offsetof(struct bpf_sockopt, sk):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_SOCKET;
+ break;
+ case offsetof(struct bpf_sockopt, optval):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_PACKET;
+ break;
+ case offsetof(struct bpf_sockopt, optval_end):
+ if (size != sizeof(__u64))
+ return false;
+ info->reg_type = PTR_TO_PACKET_END;
+ break;
+ case offsetof(struct bpf_sockopt, retval):
+ if (size != size_default)
+ return false;
+ return prog->expected_attach_type == BPF_CGROUP_GETSOCKOPT;
+ 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, retval):
+ if (type == BPF_WRITE)
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_STX_MEM, retval);
+ else
+ *insn++ = CG_SOCKOPT_ACCESS_FIELD(BPF_LDX_MEM, retval);
+ 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 8d1786357a09..95ce6cea2e23 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1720,6 +1720,18 @@ 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;
}
@@ -5540,6 +5552,7 @@ static int check_return_code(struct bpf_verifier_env *env)
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
break;
default:
return 0;
diff --git a/net/core/filter.c b/net/core/filter.c
index 8c18f2781afa..e2ad8144cf6e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -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..79eb12016685 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,
@@ -2099,6 +2108,7 @@ static int __sys_getsockopt(int fd, int level, int optname,
{
int err, fput_needed;
struct socket *sock;
+ int max_optlen;
sock = sockfd_lookup_light(fd, &err, &fput_needed);
if (sock != NULL) {
@@ -2106,6 +2116,8 @@ static int __sys_getsockopt(int fd, int level, int optname,
if (err)
goto out_put;
+ max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);
+
if (level == SOL_SOCKET)
err =
sock_getsockopt(sock, level, optname, optval,
@@ -2114,6 +2126,10 @@ static int __sys_getsockopt(int fd, int level, int optname,
err =
sock->ops->getsockopt(sock, level, optname, optval,
optlen);
+
+ err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
+ optval, optlen,
+ max_optlen, err);
out_put:
fput_light(sock->file, fput_needed);
}
--
2.22.0.410.gd8fdbe21b5-goog
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