Re: [RFC v3 net-next 4/5] rds: invoke socket sg filter attached to rds socket

2018-08-20 Thread Santosh Shilimkar

On 8/17/2018 4:08 PM, Tushar Dave wrote:

RDS module sits on top of TCP (rds_tcp) and IB (rds_rdma), so messages
arrive in form of skb (over TCP) and scatterlist (over IB/RDMA).
However, because socket filter only deal with skb (e.g. struct skb as
bpf context) we can only use socket filter for rds_tcp and not for
rds_rdma.

Considering one filtering solution for RDS, it seems that the common
denominator between sk_buff and scatterlist is scatterlist. Therefore,
this patch converts skb to sgvec and invoke sg_filter_run for
rds_tcp and simply invoke sg_filter_run for IB/rds_rdma.

Signed-off-by: Tushar Dave 
Reviewed-by: Sowmini Varadhan 
---


Looks good Tushar !!

Acked-by: Santosh Shilimkar 


[RFC v3 net-next 4/5] rds: invoke socket sg filter attached to rds socket

2018-08-17 Thread Tushar Dave
RDS module sits on top of TCP (rds_tcp) and IB (rds_rdma), so messages
arrive in form of skb (over TCP) and scatterlist (over IB/RDMA).
However, because socket filter only deal with skb (e.g. struct skb as
bpf context) we can only use socket filter for rds_tcp and not for
rds_rdma.

Considering one filtering solution for RDS, it seems that the common
denominator between sk_buff and scatterlist is scatterlist. Therefore,
this patch converts skb to sgvec and invoke sg_filter_run for
rds_tcp and simply invoke sg_filter_run for IB/rds_rdma.

Signed-off-by: Tushar Dave 
Reviewed-by: Sowmini Varadhan 
---
 net/rds/ib.c   |  1 +
 net/rds/ib.h   |  1 +
 net/rds/ib_recv.c  | 12 
 net/rds/rds.h  |  2 ++
 net/rds/recv.c | 17 +
 net/rds/tcp.c  |  2 ++
 net/rds/tcp.h  |  2 ++
 net/rds/tcp_recv.c | 38 ++
 8 files changed, 75 insertions(+)

diff --git a/net/rds/ib.c b/net/rds/ib.c
index 89c6333..6ba1f75 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -532,6 +532,7 @@ struct rds_transport rds_ib_transport = {
.conn_path_shutdown = rds_ib_conn_path_shutdown,
.inc_copy_to_user   = rds_ib_inc_copy_to_user,
.inc_free   = rds_ib_inc_free,
+   .inc_to_sg_get  = rds_ib_inc_to_sg_get,
.cm_initiate_connect= rds_ib_cm_initiate_connect,
.cm_handle_connect  = rds_ib_cm_handle_connect,
.cm_connect_complete= rds_ib_cm_connect_complete,
diff --git a/net/rds/ib.h b/net/rds/ib.h
index 73427ff..0a12b41 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -404,6 +404,7 @@ int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
 void rds_ib_recv_free_caches(struct rds_ib_connection *ic);
 void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp);
 void rds_ib_inc_free(struct rds_incoming *inc);
+int rds_ib_inc_to_sg_get(struct rds_incoming *inc, struct scatterlist **sg);
 int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to);
 void rds_ib_recv_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc,
 struct rds_ib_ack_state *state);
diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index d300186..2f76a91 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -219,6 +219,18 @@ void rds_ib_inc_free(struct rds_incoming *inc)
rds_ib_recv_cache_put(>ii_cache_entry, >i_cache_incs);
 }
 
+int rds_ib_inc_to_sg_get(struct rds_incoming *inc, struct scatterlist **sg)
+{
+   struct rds_ib_incoming *ibinc;
+   struct rds_page_frag *frag;
+
+   ibinc = container_of(inc, struct rds_ib_incoming, ii_inc);
+   frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
+   *sg =  >f_sg;
+
+   return 0;
+}
+
 static void rds_ib_recv_clear_one(struct rds_ib_connection *ic,
  struct rds_ib_recv_work *recv)
 {
diff --git a/net/rds/rds.h b/net/rds/rds.h
index c4dcf65..abcd5ce 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -542,6 +542,8 @@ struct rds_transport {
int (*recv_path)(struct rds_conn_path *cp);
int (*inc_copy_to_user)(struct rds_incoming *inc, struct iov_iter *to);
void (*inc_free)(struct rds_incoming *inc);
+   int (*inc_to_sg_get)(struct rds_incoming *inc, struct scatterlist **sg);
+   void (*inc_to_sg_put)(struct scatterlist **sg);
 
int (*cm_handle_connect)(struct rdma_cm_id *cm_id,
 struct rdma_cm_event *event, bool isv6);
diff --git a/net/rds/recv.c b/net/rds/recv.c
index 504cd6b..261904c 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -292,6 +292,8 @@ void rds_recv_incoming(struct rds_connection *conn, struct 
in6_addr *saddr,
struct sock *sk;
unsigned long flags;
struct rds_conn_path *cp;
+   struct sk_filter *filter;
+   int result = __SOCKSG_PASS;
 
inc->i_conn = conn;
inc->i_rx_jiffies = jiffies;
@@ -376,6 +378,21 @@ void rds_recv_incoming(struct rds_connection *conn, struct 
in6_addr *saddr,
/* We can be racing with rds_release() which marks the socket dead. */
sk = rds_rs_to_sk(rs);
 
+   rcu_read_lock();
+   filter = rcu_dereference(sk->sk_filter);
+   if (filter) {
+   if (conn->c_trans->inc_to_sg_get) {
+   struct scatterlist *sg;
+
+   if (conn->c_trans->inc_to_sg_get(inc, ) == 0) {
+   result = sg_filter_run(sk, sg);
+   if (conn->c_trans->inc_to_sg_put)
+   conn->c_trans->inc_to_sg_put();
+   }
+   }
+   }
+   rcu_read_unlock();
+
/* serialize with rds_release -> sock_orphan */
write_lock_irqsave(>rs_recv_lock, flags);
if (!sock_flag(sk, SOCK_DEAD)) {
diff --git a/net/rds/tcp.c b/net/rds/tcp.c
index 2c7b7c3..35454c7 100644
--- a/net/rds/tcp.c
+++