When sg_filter_run() is invoked it runs the attached eBPF
prog of type BPF_PROG_TYPE_SOCKET_SG_FILTER which deals with
struct scatterlist.
Signed-off-by: Tushar Dave <tushar.n.d...@oracle.com>
Acked-by: Sowmini Varadhan <sowmini.varad...@oracle.com>
---
include/linux/filter.h | 8 ++++++++
include/uapi/linux/bpf.h | 6 ++++++
net/core/filter.c | 35 +++++++++++++++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 6 ++++++
4 files changed, 55 insertions(+)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 6791a0a..ae664a9 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1113,4 +1113,12 @@ struct bpf_sock_ops_kern {
*/
};
+enum __socksg_action {
+ __SOCKSG_PASS = 0,
+ __SOCKSG_DROP,
+ __SOCKSG_REDIRECT,
+};
+
+int sg_filter_run(struct sock *sk, struct scatterlist *sg);
+
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 6ec1e32..1e11789 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2428,6 +2428,12 @@ enum sk_action {
SK_PASS,
};
+enum socksg_action {
+ SOCKSG_PASS = 0,
+ SOCKSG_DROP,
+ SOCKSG_REDIRECT,
+};
+
/* user accessible metadata for SK_MSG packet hook, new fields must
* be added to the end of this structure
*/
diff --git a/net/core/filter.c b/net/core/filter.c
index 469c488..a3afc61 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -121,6 +121,41 @@ int sk_filter_trim_cap(struct sock *sk, struct sk_buff
*skb, unsigned int cap)
}
EXPORT_SYMBOL(sk_filter_trim_cap);
+int sg_filter_run(struct sock *sk, struct scatterlist *sg)
+{
+ struct sk_filter *filter;
+ int result = 0;
+
+ if (!sg)
+ return result;
+
+ rcu_read_lock();
+ filter = rcu_dereference(sk->sk_filter);
+ if (filter) {
+ struct sk_msg_buff mb = {0};
+
+ memcpy(mb.sg_data, sg, sizeof(*sg) * MAX_SKB_FRAGS);
+ mb.sg_start = 0;
+ mb.sg_end = sg_nents(sg);
+ mb.data = sg_virt(sg);
+ mb.data_end = mb.data + sg->length;
+ mb.sg_copy[mb.sg_end - 1] = true;
+
+ result = BPF_PROG_RUN(filter->prog, &mb);
+
+ /* BPF prog may have changed mb.sg_data e.g. may linearize
+ * multiple scatterlist entries into one. Therefore, make sure
+ * to update original sg and mark the sg end.
+ */
+ memcpy(sg, mb.sg_data, sizeof(*sg) * MAX_SKB_FRAGS);
+ sg_mark_end(&sg[mb.sg_end - 1]);
+ }
+ rcu_read_unlock();
+
+ return result;
+}
+EXPORT_SYMBOL(sg_filter_run);
+
BPF_CALL_1(bpf_skb_get_pay_offset, struct sk_buff *, skb)
{
return skb_get_poff(skb);
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 6ec1e32..1e11789 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2428,6 +2428,12 @@ enum sk_action {
SK_PASS,
};
+enum socksg_action {
+ SOCKSG_PASS = 0,
+ SOCKSG_DROP,
+ SOCKSG_REDIRECT,
+};
+
/* user accessible metadata for SK_MSG packet hook, new fields must
* be added to the end of this structure
*/
--
1.8.3.1
