strparser: Generalize strparser

Generalize strparser from more than just being used in conjunction
with read_sock. strparser will also be used in the send path with
zero proxy. The primary change is to create strp_process function
that performs the critical processing on skbs. The documentation
is also updated to reflect the new uses.
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/strparser.h

@@ -18,26 +18,26 @@
 #define STRP_STATS_INCR(stat) ((stat)++)
 
 struct strp_stats {
-	unsigned long long rx_msgs;
-	unsigned long long rx_bytes;
-	unsigned int rx_mem_fail;
-	unsigned int rx_need_more_hdr;
-	unsigned int rx_msg_too_big;
-	unsigned int rx_msg_timeouts;
-	unsigned int rx_bad_hdr_len;
+	unsigned long long msgs;
+	unsigned long long bytes;
+	unsigned int mem_fail;
+	unsigned int need_more_hdr;
+	unsigned int msg_too_big;
+	unsigned int msg_timeouts;
+	unsigned int bad_hdr_len;
 };
 
 struct strp_aggr_stats {
-	unsigned long long rx_msgs;
-	unsigned long long rx_bytes;
-	unsigned int rx_mem_fail;
-	unsigned int rx_need_more_hdr;
-	unsigned int rx_msg_too_big;
-	unsigned int rx_msg_timeouts;
-	unsigned int rx_bad_hdr_len;
-	unsigned int rx_aborts;
-	unsigned int rx_interrupted;
-	unsigned int rx_unrecov_intr;
+	unsigned long long msgs;
+	unsigned long long bytes;
+	unsigned int mem_fail;
+	unsigned int need_more_hdr;
+	unsigned int msg_too_big;
+	unsigned int msg_timeouts;
+	unsigned int bad_hdr_len;
+	unsigned int aborts;
+	unsigned int interrupted;
+	unsigned int unrecov_intr;
 };
 
 struct strparser;
@@ -48,16 +48,18 @@ struct strp_callbacks {
 	void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb);
 	int (*read_sock_done)(struct strparser *strp, int err);
 	void (*abort_parser)(struct strparser *strp, int err);
+	void (*lock)(struct strparser *strp);
+	void (*unlock)(struct strparser *strp);
 };
 
-struct strp_rx_msg {
+struct strp_msg {
 	int full_len;
 	int offset;
 };
 
-static inline struct strp_rx_msg *strp_rx_msg(struct sk_buff *skb)
+static inline struct strp_msg *strp_msg(struct sk_buff *skb)
 {
-	return (struct strp_rx_msg *)((void *)skb->cb +
+	return (struct strp_msg *)((void *)skb->cb +
 		offsetof(struct qdisc_skb_cb, data));
 }
 
@@ -65,18 +67,18 @@ static inline struct strp_rx_msg *strp_rx_msg(struct sk_buff *skb)
 struct strparser {
 	struct sock *sk;
 
-	u32 rx_stopped : 1;
-	u32 rx_paused : 1;
-	u32 rx_aborted : 1;
-	u32 rx_interrupted : 1;
-	u32 rx_unrecov_intr : 1;
-
-	struct sk_buff **rx_skb_nextp;
-	struct timer_list rx_msg_timer;
-	struct sk_buff *rx_skb_head;
-	unsigned int rx_need_bytes;
-	struct delayed_work rx_delayed_work;
-	struct work_struct rx_work;
+	u32 stopped : 1;
+	u32 paused : 1;
+	u32 aborted : 1;
+	u32 interrupted : 1;
+	u32 unrecov_intr : 1;
+
+	struct sk_buff **skb_nextp;
+	struct timer_list msg_timer;
+	struct sk_buff *skb_head;
+	unsigned int need_bytes;
+	struct delayed_work delayed_work;
+	struct work_struct work;
 	struct strp_stats stats;
 	struct strp_callbacks cb;
 };
@@ -84,7 +86,7 @@ struct strparser {
 /* Must be called with lock held for attached socket */
 static inline void strp_pause(struct strparser *strp)
 {
-	strp->rx_paused = 1;
+	strp->paused = 1;
 }
 
 /* May be called without holding lock for attached socket */
@@ -97,37 +99,37 @@ static inline void save_strp_stats(struct strparser *strp,
 
 #define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat +=		\
 				 strp->stats._stat)
-	SAVE_PSOCK_STATS(rx_msgs);
-	SAVE_PSOCK_STATS(rx_bytes);
-	SAVE_PSOCK_STATS(rx_mem_fail);
-	SAVE_PSOCK_STATS(rx_need_more_hdr);
-	SAVE_PSOCK_STATS(rx_msg_too_big);
-	SAVE_PSOCK_STATS(rx_msg_timeouts);
-	SAVE_PSOCK_STATS(rx_bad_hdr_len);
+	SAVE_PSOCK_STATS(msgs);
+	SAVE_PSOCK_STATS(bytes);
+	SAVE_PSOCK_STATS(mem_fail);
+	SAVE_PSOCK_STATS(need_more_hdr);
+	SAVE_PSOCK_STATS(msg_too_big);
+	SAVE_PSOCK_STATS(msg_timeouts);
+	SAVE_PSOCK_STATS(bad_hdr_len);
 #undef SAVE_PSOCK_STATS
 
-	if (strp->rx_aborted)
-		agg_stats->rx_aborts++;
-	if (strp->rx_interrupted)
-		agg_stats->rx_interrupted++;
-	if (strp->rx_unrecov_intr)
-		agg_stats->rx_unrecov_intr++;
+	if (strp->aborted)
+		agg_stats->aborts++;
+	if (strp->interrupted)
+		agg_stats->interrupted++;
+	if (strp->unrecov_intr)
+		agg_stats->unrecov_intr++;
 }
 
 static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
 					struct strp_aggr_stats *agg_stats)
 {
 #define SAVE_PSOCK_STATS(_stat) (agg_stats->_stat += stats->_stat)
-	SAVE_PSOCK_STATS(rx_msgs);
-	SAVE_PSOCK_STATS(rx_bytes);
-	SAVE_PSOCK_STATS(rx_mem_fail);
-	SAVE_PSOCK_STATS(rx_need_more_hdr);
-	SAVE_PSOCK_STATS(rx_msg_too_big);
-	SAVE_PSOCK_STATS(rx_msg_timeouts);
-	SAVE_PSOCK_STATS(rx_bad_hdr_len);
-	SAVE_PSOCK_STATS(rx_aborts);
-	SAVE_PSOCK_STATS(rx_interrupted);
-	SAVE_PSOCK_STATS(rx_unrecov_intr);
+	SAVE_PSOCK_STATS(msgs);
+	SAVE_PSOCK_STATS(bytes);
+	SAVE_PSOCK_STATS(mem_fail);
+	SAVE_PSOCK_STATS(need_more_hdr);
+	SAVE_PSOCK_STATS(msg_too_big);
+	SAVE_PSOCK_STATS(msg_timeouts);
+	SAVE_PSOCK_STATS(bad_hdr_len);
+	SAVE_PSOCK_STATS(aborts);
+	SAVE_PSOCK_STATS(interrupted);
+	SAVE_PSOCK_STATS(unrecov_intr);
 #undef SAVE_PSOCK_STATS
 
 }
@@ -135,8 +137,11 @@ static inline void aggregate_strp_stats(struct strp_aggr_stats *stats,
 void strp_done(struct strparser *strp);
 void strp_stop(struct strparser *strp);
 void strp_check_rcv(struct strparser *strp);
-int strp_init(struct strparser *strp, struct sock *csk,
+int strp_init(struct strparser *strp, struct sock *sk,
 	      struct strp_callbacks *cb);
 void strp_data_ready(struct strparser *strp);
+int strp_process(struct strparser *strp, struct sk_buff *orig_skb,
+		 unsigned int orig_offset, size_t orig_len,
+		 size_t max_msg_size, long timeo);
 
 #endif /* __NET_STRPARSER_H_ */

net/kcm/kcmproc.c

@@ -155,8 +155,8 @@ static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
 	seq_printf(seq,
 		   "   psock-%-5u %-10llu %-16llu %-10llu %-16llu %-8d %-8d %-8d %-8d ",
 		   psock->index,
-		   psock->strp.stats.rx_msgs,
-		   psock->strp.stats.rx_bytes,
+		   psock->strp.stats.msgs,
+		   psock->strp.stats.bytes,
 		   psock->stats.tx_msgs,
 		   psock->stats.tx_bytes,
 		   psock->sk->sk_receive_queue.qlen,
@@ -170,22 +170,22 @@ static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
 	if (psock->tx_stopped)
 		seq_puts(seq, "TxStop ");
 
-	if (psock->strp.rx_stopped)
+	if (psock->strp.stopped)
 		seq_puts(seq, "RxStop ");
 
 	if (psock->tx_kcm)
 		seq_printf(seq, "Rsvd-%d ", psock->tx_kcm->index);
 
-	if (!psock->strp.rx_paused && !psock->ready_rx_msg) {
+	if (!psock->strp.paused && !psock->ready_rx_msg) {
 		if (psock->sk->sk_receive_queue.qlen) {
-			if (psock->strp.rx_need_bytes)
+			if (psock->strp.need_bytes)
 				seq_printf(seq, "RxWait=%u ",
-					   psock->strp.rx_need_bytes);
+					   psock->strp.need_bytes);
 			else
 				seq_printf(seq, "RxWait ");
 		}
 	} else  {
-		if (psock->strp.rx_paused)
+		if (psock->strp.paused)
 			seq_puts(seq, "RxPause ");
 
 		if (psock->ready_rx_msg)
@@ -371,20 +371,20 @@ static int kcm_stats_seq_show(struct seq_file *seq, void *v)
 	seq_printf(seq,
 		   "%-8s %-10llu %-16llu %-10llu %-16llu %-10llu %-10llu %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u %-10u\n",
 		   "",
-		   strp_stats.rx_msgs,
-		   strp_stats.rx_bytes,
+		   strp_stats.msgs,
+		   strp_stats.bytes,
 		   psock_stats.tx_msgs,
 		   psock_stats.tx_bytes,
 		   psock_stats.reserved,
 		   psock_stats.unreserved,
-		   strp_stats.rx_aborts,
-		   strp_stats.rx_interrupted,
-		   strp_stats.rx_unrecov_intr,
-		   strp_stats.rx_mem_fail,
-		   strp_stats.rx_need_more_hdr,
-		   strp_stats.rx_bad_hdr_len,
-		   strp_stats.rx_msg_too_big,
-		   strp_stats.rx_msg_timeouts,
+		   strp_stats.aborts,
+		   strp_stats.interrupted,
+		   strp_stats.unrecov_intr,
+		   strp_stats.mem_fail,
+		   strp_stats.need_more_hdr,
+		   strp_stats.bad_hdr_len,
+		   strp_stats.msg_too_big,
+		   strp_stats.msg_timeouts,
 		   psock_stats.tx_aborts);
 
 	return 0;

net/kcm/kcmsock.c

@@ -96,12 +96,12 @@ static void kcm_update_rx_mux_stats(struct kcm_mux *mux,
 				    struct kcm_psock *psock)
 {
 	STRP_STATS_ADD(mux->stats.rx_bytes,
-		       psock->strp.stats.rx_bytes -
+		       psock->strp.stats.bytes -
 		       psock->saved_rx_bytes);
 	mux->stats.rx_msgs +=
-		psock->strp.stats.rx_msgs - psock->saved_rx_msgs;
-	psock->saved_rx_msgs = psock->strp.stats.rx_msgs;
-	psock->saved_rx_bytes = psock->strp.stats.rx_bytes;
+		psock->strp.stats.msgs - psock->saved_rx_msgs;
+	psock->saved_rx_msgs = psock->strp.stats.msgs;
+	psock->saved_rx_bytes = psock->strp.stats.bytes;
 }
 
 static void kcm_update_tx_mux_stats(struct kcm_mux *mux,
@@ -1118,7 +1118,7 @@ static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
 	struct kcm_sock *kcm = kcm_sk(sk);
 	int err = 0;
 	long timeo;
-	struct strp_rx_msg *rxm;
+	struct strp_msg *stm;
 	int copied = 0;
 	struct sk_buff *skb;
 
@@ -1132,26 +1132,26 @@ static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
 
 	/* Okay, have a message on the receive queue */
 
-	rxm = strp_rx_msg(skb);
+	stm = strp_msg(skb);
 
-	if (len > rxm->full_len)
-		len = rxm->full_len;
+	if (len > stm->full_len)
+		len = stm->full_len;
 
-	err = skb_copy_datagram_msg(skb, rxm->offset, msg, len);
+	err = skb_copy_datagram_msg(skb, stm->offset, msg, len);
 	if (err < 0)
 		goto out;
 
 	copied = len;
 	if (likely(!(flags & MSG_PEEK))) {
 		KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
-		if (copied < rxm->full_len) {
+		if (copied < stm->full_len) {
 			if (sock->type == SOCK_DGRAM) {
 				/* Truncated message */
 				msg->msg_flags |= MSG_TRUNC;
 				goto msg_finished;
 			}
-			rxm->offset += copied;
-			rxm->full_len -= copied;
+			stm->offset += copied;
+			stm->full_len -= copied;
 		} else {
 msg_finished:
 			/* Finished with message */
@@ -1175,7 +1175,7 @@ static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
 	struct sock *sk = sock->sk;
 	struct kcm_sock *kcm = kcm_sk(sk);
 	long timeo;
-	struct strp_rx_msg *rxm;
+	struct strp_msg *stm;
 	int err = 0;
 	ssize_t copied;
 	struct sk_buff *skb;
@@ -1192,12 +1192,12 @@ static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
 
 	/* Okay, have a message on the receive queue */
 
-	rxm = strp_rx_msg(skb);
+	stm = strp_msg(skb);
 
-	if (len > rxm->full_len)
-		len = rxm->full_len;
+	if (len > stm->full_len)
+		len = stm->full_len;
 
-	copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags);
+	copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags);
 	if (copied < 0) {
 		err = copied;
 		goto err_out;
@@ -1205,8 +1205,8 @@ static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
 
 	KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
 
-	rxm->offset += copied;
-	rxm->full_len -= copied;
+	stm->offset += copied;
+	stm->full_len -= copied;
 
 	/* We have no way to return MSG_EOR. If all the bytes have been
 	 * read we still leave the message in the receive socket buffer.