This patch allows bpf tcp iter with netadmin cap to call bpf_setsockopt.
To allow a specific bpf iter (tcp here) to call a set of helpers,
get_func_proto function pointer is added to bpf_iter_reg.
Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
---
include/linux/bpf.h | 7 +++++++
kernel/bpf/bpf_iter.c | 22 ++++++++++++++++++++++
kernel/trace/bpf_trace.c | 7 ++++++-
net/core/filter.c | 17 +++++++++++++++++
net/ipv4/tcp_ipv4.c | 15 +++++++++++++++
5 files changed, 67 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f309fc1509f2..31f51a601925 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1397,6 +1397,9 @@ typedef void (*bpf_iter_show_fdinfo_t) (const struct bpf_iter_aux_info *aux,
struct seq_file *seq);
typedef int (*bpf_iter_fill_link_info_t)(const struct bpf_iter_aux_info *aux,
struct bpf_link_info *info);
+typedef const struct bpf_func_proto *
+(*bpf_iter_get_func_proto_t)(enum bpf_func_id func_id,
+ const struct bpf_prog *prog);
enum bpf_iter_feature {
BPF_ITER_RESCHED = BIT(0),
@@ -1409,6 +1412,7 @@ struct bpf_iter_reg {
bpf_iter_detach_target_t detach_target;
bpf_iter_show_fdinfo_t show_fdinfo;
bpf_iter_fill_link_info_t fill_link_info;
+ bpf_iter_get_func_proto_t get_func_proto;
u32 ctx_arg_info_size;
u32 feature;
struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX];
@@ -1431,6 +1435,8 @@ struct bpf_iter__bpf_map_elem {
int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info);
void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info);
bool bpf_iter_prog_supported(struct bpf_prog *prog);
+const struct bpf_func_proto *
+bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog);
int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_prog *prog);
int bpf_iter_new_fd(struct bpf_link *link);
bool bpf_link_is_iter(struct bpf_link *link);
@@ -1997,6 +2003,7 @@ extern const struct bpf_func_proto bpf_task_storage_get_proto;
extern const struct bpf_func_proto bpf_task_storage_delete_proto;
extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
+extern const struct bpf_func_proto bpf_sk_setsockopt_proto;
const struct bpf_func_proto *bpf_tracing_func_proto(
enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 2d4fbdbb194e..2e9d47bb40ff 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -360,6 +360,28 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog)
return supported;
}
+const struct bpf_func_proto *
+bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+ const struct bpf_iter_target_info *tinfo;
+ const struct bpf_func_proto *fn = NULL;
+
+ mutex_lock(&targets_mutex);
+ list_for_each_entry(tinfo, &targets, list) {
+ if (tinfo->btf_id == prog->aux->attach_btf_id) {
+ const struct bpf_iter_reg *reg_info;
+
+ reg_info = tinfo->reg_info;
+ if (reg_info->get_func_proto)
+ fn = reg_info->get_func_proto(func_id, prog);
+ break;
+ }
+ }
+ mutex_unlock(&targets_mutex);
+
+ return fn;
+}
+
static void bpf_iter_link_release(struct bpf_link *link)
{
struct bpf_iter_link *iter_link =
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 7a52bc172841..11e69734d67b 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1428,6 +1428,8 @@ raw_tp_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
const struct bpf_func_proto *
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
+ const struct bpf_func_proto *fn;
+
switch (func_id) {
#ifdef CONFIG_NET
case BPF_FUNC_skb_output:
@@ -1468,7 +1470,10 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_d_path:
return &bpf_d_path_proto;
default:
- return raw_tp_prog_func_proto(func_id, prog);
+ fn = raw_tp_prog_func_proto(func_id, prog);
+ if (!fn && prog->expected_attach_type == BPF_TRACE_ITER)
+ fn = bpf_iter_get_func_proto(func_id, prog);
+ return fn;
}
}
diff --git a/net/core/filter.c b/net/core/filter.c
index d22895caa164..ab4d60c043d4 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5063,6 +5063,23 @@ static const struct bpf_func_proto bpf_sock_ops_setsockopt_proto = {
.arg5_type = ARG_CONST_SIZE,
};
+BPF_CALL_5(bpf_sk_setsockopt, struct sock *, sk, int, level,
+ int, optname, char *, optval, int, optlen)
+{
+ return _bpf_setsockopt(sk, level, optname, optval, optlen);
+}
+
+const struct bpf_func_proto bpf_sk_setsockopt_proto = {
+ .func = bpf_sk_setsockopt,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_MEM,
+ .arg5_type = ARG_CONST_SIZE,
+};
+
static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock,
int optname, const u8 **start)
{
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 856144d33f52..5bfa6233fff1 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -3258,6 +3258,20 @@ static const struct bpf_iter_seq_info tcp_seq_info = {
.seq_priv_size = sizeof(struct bpf_tcp_iter_state),
};
+static const struct bpf_func_proto *
+bpf_iter_tcp_get_func_proto(enum bpf_func_id func_id,
+ const struct bpf_prog *prog)
+{
+ switch (func_id) {
+ case BPF_FUNC_setsockopt:
+ if (capable(CAP_NET_ADMIN))
+ return &bpf_sk_setsockopt_proto;
+ fallthrough;
+ default:
+ return NULL;
+ }
+}
+
static struct bpf_iter_reg tcp_reg_info = {
.target = "tcp",
.ctx_arg_info_size = 1,
@@ -3265,6 +3279,7 @@ static struct bpf_iter_reg tcp_reg_info = {
{ offsetof(struct bpf_iter__tcp, sk_common),
PTR_TO_BTF_ID_OR_NULL },
},
+ .get_func_proto = bpf_iter_tcp_get_func_proto,
.seq_info = &tcp_seq_info,
};
--
2.30.2
