kcm: Remove TCP specific references from kcm and strparser

kcm and strparser need to work with any type of stream socket not just
TCP. Eliminate references to TCP and call generic proto_ops functions of
read_sock and peek_len. Also in strp_init check if the socket support
the proto_ops read_sock and peek_len.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/strparser.h

@@ -137,6 +137,6 @@ void strp_stop(struct strparser *strp);
 void strp_check_rcv(struct strparser *strp);
 int strp_init(struct strparser *strp, struct sock *csk,
 	      struct strp_callbacks *cb);
-void strp_tcp_data_ready(struct strparser *strp);
+void strp_data_ready(struct strparser *strp);
 
 #endif /* __NET_STRPARSER_H_ */

net/kcm/kcmsock.c

@@ -26,7 +26,6 @@
 #include <net/kcm.h>
 #include <net/netns/generic.h>
 #include <net/sock.h>
-#include <net/tcp.h>
 #include <uapi/linux/kcm.h>
 
 unsigned int kcm_net_id;
@@ -340,15 +339,15 @@ static void unreserve_rx_kcm(struct kcm_psock *psock,
 }
 
 /* Lower sock lock held */
-static void psock_tcp_data_ready(struct sock *sk)
+static void psock_data_ready(struct sock *sk)
 {
 	struct kcm_psock *psock;
 
 	read_lock_bh(&sk->sk_callback_lock);
 
 	psock = (struct kcm_psock *)sk->sk_user_data;
 	if (likely(psock))
-		strp_tcp_data_ready(&psock->strp);
+		strp_data_ready(&psock->strp);
 
 	read_unlock_bh(&sk->sk_callback_lock);
 }
@@ -392,7 +391,7 @@ static int kcm_read_sock_done(struct strparser *strp, int err)
 	return err;
 }
 
-static void psock_tcp_state_change(struct sock *sk)
+static void psock_state_change(struct sock *sk)
 {
 	/* TCP only does a POLLIN for a half close. Do a POLLHUP here
 	 * since application will normally not poll with POLLIN
@@ -402,7 +401,7 @@ static void psock_tcp_state_change(struct sock *sk)
 	report_csk_error(sk, EPIPE);
 }
 
-static void psock_tcp_write_space(struct sock *sk)
+static void psock_write_space(struct sock *sk)
 {
 	struct kcm_psock *psock;
 	struct kcm_mux *mux;
@@ -1383,19 +1382,12 @@ static int kcm_attach(struct socket *sock, struct socket *csock,
 	struct list_head *head;
 	int index = 0;
 	struct strp_callbacks cb;
-
-	if (csock->ops->family != PF_INET &&
-	    csock->ops->family != PF_INET6)
-		return -EINVAL;
+	int err;
 
 	csk = csock->sk;
 	if (!csk)
 		return -EINVAL;
 
-	/* Only support TCP for now */
-	if (csk->sk_protocol != IPPROTO_TCP)
-		return -EINVAL;
-
 	psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
 	if (!psock)
 		return -ENOMEM;
@@ -1409,7 +1401,11 @@ static int kcm_attach(struct socket *sock, struct socket *csock,
 	cb.parse_msg = kcm_parse_func_strparser;
 	cb.read_sock_done = kcm_read_sock_done;
 
-	strp_init(&psock->strp, csk, &cb);
+	err = strp_init(&psock->strp, csk, &cb);
+	if (err) {
+		kmem_cache_free(kcm_psockp, psock);
+		return err;
+	}
 
 	sock_hold(csk);
 
@@ -1418,9 +1414,9 @@ static int kcm_attach(struct socket *sock, struct socket *csock,
 	psock->save_write_space = csk->sk_write_space;
 	psock->save_state_change = csk->sk_state_change;
 	csk->sk_user_data = psock;
-	csk->sk_data_ready = psock_tcp_data_ready;
-	csk->sk_write_space = psock_tcp_write_space;
-	csk->sk_state_change = psock_tcp_state_change;
+	csk->sk_data_ready = psock_data_ready;
+	csk->sk_write_space = psock_write_space;
+	csk->sk_state_change = psock_state_change;
 	write_unlock_bh(&csk->sk_callback_lock);
 
 	/* Finished initialization, now add the psock to the MUX. */

net/strparser/strparser.c

@@ -26,7 +26,6 @@
 #include <net/strparser.h>
 #include <net/netns/generic.h>
 #include <net/sock.h>
-#include <net/tcp.h>
 
 static struct workqueue_struct *strp_wq;
 
@@ -80,9 +79,16 @@ static void strp_parser_err(struct strparser *strp, int err,
 	strp->cb.abort_parser(strp, err);
 }
 
+static inline int strp_peek_len(struct strparser *strp)
+{
+	struct socket *sock = strp->sk->sk_socket;
+
+	return sock->ops->peek_len(sock);
+}
+
 /* Lower socket lock held */
-static int strp_tcp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
-			 unsigned int orig_offset, size_t orig_len)
+static int strp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
+		     unsigned int orig_offset, size_t orig_len)
 {
 	struct strparser *strp = (struct strparser *)desc->arg.data;
 	struct _strp_rx_msg *rxm;
@@ -266,12 +272,12 @@ static int strp_tcp_recv(read_descriptor_t *desc, struct sk_buff *orig_skb,
 		if (extra < 0) {
 			/* Message not complete yet. */
 			if (rxm->strp.full_len - rxm->accum_len >
-			    tcp_inq(strp->sk)) {
+			    strp_peek_len(strp)) {
 				/* Don't have the whole messages in the socket
 				 * buffer. Set strp->rx_need_bytes to wait for
 				 * the rest of the message. Also, set "early
 				 * eaten" since we've already buffered the skb
-				 * but don't consume yet per tcp_read_sock.
+				 * but don't consume yet per strp_read_sock.
 				 */
 
 				if (!rxm->accum_len) {
@@ -329,27 +335,26 @@ static int default_read_sock_done(struct strparser *strp, int err)
 }
 
 /* Called with lock held on lower socket */
-static int strp_tcp_read_sock(struct strparser *strp)
+static int strp_read_sock(struct strparser *strp)
 {
+	struct socket *sock = strp->sk->sk_socket;
 	read_descriptor_t desc;
 
 	desc.arg.data = strp;
 	desc.error = 0;
 	desc.count = 1; /* give more than one skb per call */
 
-	/* sk should be locked here, so okay to do tcp_read_sock */
-	tcp_read_sock(strp->sk, &desc, strp_tcp_recv);
+	/* sk should be locked here, so okay to do read_sock */
+	sock->ops->read_sock(strp->sk, &desc, strp_recv);
 
 	desc.error = strp->cb.read_sock_done(strp, desc.error);
 
 	return desc.error;
 }
 
 /* Lower sock lock held */
-void strp_tcp_data_ready(struct strparser *strp)
+void strp_data_ready(struct strparser *strp)
 {
-	struct sock *csk = strp->sk;
-
 	if (unlikely(strp->rx_stopped))
 		return;
 
@@ -360,7 +365,7 @@ void strp_tcp_data_ready(struct strparser *strp)
 	 * allows a thread in BH context to safely check if the process
 	 * lock is held. In this case, if the lock is held, queue work.
 	 */
-	if (sock_owned_by_user(csk)) {
+	if (sock_owned_by_user(strp->sk)) {
 		queue_work(strp_wq, &strp->rx_work);
 		return;
 	}
@@ -369,24 +374,24 @@ void strp_tcp_data_ready(struct strparser *strp)
 		return;
 
 	if (strp->rx_need_bytes) {
-		if (tcp_inq(csk) >= strp->rx_need_bytes)
+		if (strp_peek_len(strp) >= strp->rx_need_bytes)
 			strp->rx_need_bytes = 0;
 		else
 			return;
 	}
 
-	if (strp_tcp_read_sock(strp) == -ENOMEM)
+	if (strp_read_sock(strp) == -ENOMEM)
 		queue_work(strp_wq, &strp->rx_work);
 }
-EXPORT_SYMBOL_GPL(strp_tcp_data_ready);
+EXPORT_SYMBOL_GPL(strp_data_ready);
 
 static void do_strp_rx_work(struct strparser *strp)
 {
 	read_descriptor_t rd_desc;
 	struct sock *csk = strp->sk;
 
-	/* We need the read lock to synchronize with strp_tcp_data_ready. We
-	 * need the socket lock for calling tcp_read_sock.
+	/* We need the read lock to synchronize with strp_data_ready. We
+	 * need the socket lock for calling strp_read_sock.
 	 */
 	lock_sock(csk);
 
@@ -398,7 +403,7 @@ static void do_strp_rx_work(struct strparser *strp)
 
 	rd_desc.arg.data = strp;
 
-	if (strp_tcp_read_sock(strp) == -ENOMEM)
+	if (strp_read_sock(strp) == -ENOMEM)
 		queue_work(strp_wq, &strp->rx_work);
 
 out:
@@ -424,9 +429,14 @@ static void strp_rx_msg_timeout(unsigned long arg)
 int strp_init(struct strparser *strp, struct sock *csk,
 	      struct strp_callbacks *cb)
 {
+	struct socket *sock = csk->sk_socket;
+
 	if (!cb || !cb->rcv_msg || !cb->parse_msg)
 		return -EINVAL;
 
+	if (!sock->ops->read_sock || !sock->ops->peek_len)
+		return -EAFNOSUPPORT;
+
 	memset(strp, 0, sizeof(*strp));
 
 	strp->sk = csk;
@@ -456,7 +466,7 @@ void strp_unpause(struct strparser *strp)
 }
 EXPORT_SYMBOL_GPL(strp_unpause);
 
-/* strp must already be stopped so that strp_tcp_recv will no longer be called.
+/* strp must already be stopped so that strp_recv will no longer be called.
  * Note that strp_done is not called with the lower socket held.
  */
 void strp_done(struct strparser *strp)