Merge branch 'smc-fixes-next'

Ursula Braun says:

====================
smc: fixes 2017-12-07

here are some smc-patches. The initial 4 patches are cleanups.
Patch 5 gets rid of ib_post_sends in tasklet context to avoid peer drops due
to out-of-order receivals.
Patch 6 makes sure, the Linux SMC code understands variable sized CLC proposal
messages built according to RFC7609.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 118 insertions, 55 deletions

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 6451c5013e06..daf8075f5a4c 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -520,7 +520,7 @@ decline_rdma:
 	smc->use_fallback = true;
 	if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
 		rc = smc_clc_send_decline(smc, reason_code);
-		if (rc < sizeof(struct smc_clc_msg_decline))
+		if (rc < 0)
 			goto out_err;
 	}
 	goto out_connected;
@@ -751,14 +751,16 @@ static void smc_listen_work(struct work_struct *work)
 {
 	struct smc_sock *new_smc = container_of(work, struct smc_sock,
 						smc_listen_work);
+	struct smc_clc_msg_proposal_prefix *pclc_prfx;
 	struct socket *newclcsock = new_smc->clcsock;
 	struct smc_sock *lsmc = new_smc->listen_smc;
 	struct smc_clc_msg_accept_confirm cclc;
 	int local_contact = SMC_REUSE_CONTACT;
 	struct sock *newsmcsk = &new_smc->sk;
-	struct smc_clc_msg_proposal pclc;
+	struct smc_clc_msg_proposal *pclc;
 	struct smc_ib_device *smcibdev;
 	struct sockaddr_in peeraddr;
+	u8 buf[SMC_CLC_MAX_LEN];
 	struct smc_link *link;
 	int reason_code = 0;
 	int rc = 0, len;
@@ -775,7 +777,7 @@ static void smc_listen_work(struct work_struct *work)
 	/* do inband token exchange -
 	 *wait for and receive SMC Proposal CLC message
 	 */
-	reason_code = smc_clc_wait_msg(new_smc, &pclc, sizeof(pclc),
+	reason_code = smc_clc_wait_msg(new_smc, &buf, sizeof(buf),
 				       SMC_CLC_PROPOSAL);
 	if (reason_code < 0)
 		goto out_err;
@@ -804,8 +806,11 @@ static void smc_listen_work(struct work_struct *work)
 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 		goto decline_rdma;
 	}
-	if ((pclc.outgoing_subnet != subnet) ||
-	    (pclc.prefix_len != prefix_len)) {
+
+	pclc = (struct smc_clc_msg_proposal *)&buf;
+	pclc_prfx = smc_clc_proposal_get_prefix(pclc);
+	if (pclc_prfx->outgoing_subnet != subnet ||
+	    pclc_prfx->prefix_len != prefix_len) {
 		reason_code = SMC_CLC_DECL_CNFERR; /* configuration error */
 		goto decline_rdma;
 	}
@@ -816,7 +821,7 @@ static void smc_listen_work(struct work_struct *work)
 	/* allocate connection / link group */
 	mutex_lock(&smc_create_lgr_pending);
 	local_contact = smc_conn_create(new_smc, peeraddr.sin_addr.s_addr,
-					smcibdev, ibport, &pclc.lcl, 0);
+					smcibdev, ibport, &pclc->lcl, 0);
 	if (local_contact < 0) {
 		rc = local_contact;
 		if (rc == -ENOMEM)
@@ -879,11 +884,9 @@ static void smc_listen_work(struct work_struct *work)
 		}
 		/* QP confirmation over RoCE fabric */
 		reason_code = smc_serv_conf_first_link(new_smc);
-		if (reason_code < 0) {
+		if (reason_code < 0)
 			/* peer is not aware of a problem */
-			rc = reason_code;
 			goto out_err_unlock;
-		}
 		if (reason_code > 0)
 			goto decline_rdma_unlock;
 	}
@@ -916,8 +919,7 @@ decline_rdma:
 	smc_conn_free(&new_smc->conn);
 	new_smc->use_fallback = true;
 	if (reason_code && (reason_code != SMC_CLC_DECL_REPLY)) {
-		rc = smc_clc_send_decline(new_smc, reason_code);
-		if (rc < sizeof(struct smc_clc_msg_decline))
+		if (smc_clc_send_decline(new_smc, reason_code) < 0)
 			goto out_err;
 	}
 	goto out_connected;
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 87f7bede6eab..d4155ff6acde 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -213,6 +213,9 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 		/* guarantee 0 <= bytes_to_rcv <= rmbe_size */
 		smp_mb__after_atomic();
 		smc->sk.sk_data_ready(&smc->sk);
+	} else if ((conn->local_rx_ctrl.prod_flags.write_blocked) ||
+		   (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req)) {
+		smc->sk.sk_data_ready(&smc->sk);
 	}
 
 	if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
@@ -234,15 +237,6 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
 		/* trigger socket release if connection closed */
 		smc_close_wake_tx_prepared(smc);
 	}
-
-	/* socket connected but not accepted */
-	if (!smc->sk.sk_socket)
-		return;
-
-	/* data available */
-	if ((conn->local_rx_ctrl.prod_flags.write_blocked) ||
-	    (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req))
-		smc_tx_consumer_update(conn);
 }
 
 /* called under tasklet context */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 1800e16b2a02..abf7ceb6690b 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -22,6 +22,54 @@
 #include "smc_clc.h"
 #include "smc_ib.h"
 
+/* check if received message has a correct header length and contains valid
+ * heading and trailing eyecatchers
+ */
+static bool smc_clc_msg_hdr_valid(struct smc_clc_msg_hdr *clcm)
+{
+	struct smc_clc_msg_proposal_prefix *pclc_prfx;
+	struct smc_clc_msg_accept_confirm *clc;
+	struct smc_clc_msg_proposal *pclc;
+	struct smc_clc_msg_decline *dclc;
+	struct smc_clc_msg_trail *trl;
+
+	if (memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)))
+		return false;
+	switch (clcm->type) {
+	case SMC_CLC_PROPOSAL:
+		pclc = (struct smc_clc_msg_proposal *)clcm;
+		pclc_prfx = smc_clc_proposal_get_prefix(pclc);
+		if (ntohs(pclc->hdr.length) !=
+			sizeof(*pclc) + ntohs(pclc->iparea_offset) +
+			sizeof(*pclc_prfx) +
+			pclc_prfx->ipv6_prefixes_cnt *
+				sizeof(struct smc_clc_ipv6_prefix) +
+			sizeof(*trl))
+			return false;
+		trl = (struct smc_clc_msg_trail *)
+			((u8 *)pclc + ntohs(pclc->hdr.length) - sizeof(*trl));
+		break;
+	case SMC_CLC_ACCEPT:
+	case SMC_CLC_CONFIRM:
+		clc = (struct smc_clc_msg_accept_confirm *)clcm;
+		if (ntohs(clc->hdr.length) != sizeof(*clc))
+			return false;
+		trl = &clc->trl;
+		break;
+	case SMC_CLC_DECLINE:
+		dclc = (struct smc_clc_msg_decline *)clcm;
+		if (ntohs(dclc->hdr.length) != sizeof(*dclc))
+			return false;
+		trl = &dclc->trl;
+		break;
+	default:
+		return false;
+	}
+	if (memcmp(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)))
+		return false;
+	return true;
+}
+
 /* Wait for data on the tcp-socket, analyze received data
  * Returns:
  * 0 if success and it was not a decline that we received.
@@ -72,9 +120,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	}
 	datlen = ntohs(clcm->length);
 	if ((len < sizeof(struct smc_clc_msg_hdr)) ||
-	    (datlen < sizeof(struct smc_clc_msg_decline)) ||
-	    (datlen > sizeof(struct smc_clc_msg_accept_confirm)) ||
-	    memcmp(clcm->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER)) ||
+	    (datlen > buflen) ||
 	    ((clcm->type != SMC_CLC_DECLINE) &&
 	     (clcm->type != expected_type))) {
 		smc->sk.sk_err = EPROTO;
@@ -89,7 +135,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 	krflags = MSG_WAITALL;
 	smc->clcsock->sk->sk_rcvtimeo = CLC_WAIT_TIME;
 	len = kernel_recvmsg(smc->clcsock, &msg, &vec, 1, datlen, krflags);
-	if (len < datlen) {
+	if (len < datlen || !smc_clc_msg_hdr_valid(clcm)) {
 		smc->sk.sk_err = EPROTO;
 		reason_code = -EPROTO;
 		goto out;
@@ -133,7 +179,7 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 		smc->sk.sk_err = EPROTO;
 	if (len < 0)
 		smc->sk.sk_err = -len;
-	return len;
+	return sock_error(&smc->sk);
 }
 
 /* send CLC PROPOSAL message across internal TCP socket */
@@ -141,33 +187,43 @@ int smc_clc_send_proposal(struct smc_sock *smc,
 			  struct smc_ib_device *smcibdev,
 			  u8 ibport)
 {
+	struct smc_clc_msg_proposal_prefix pclc_prfx;
 	struct smc_clc_msg_proposal pclc;
+	struct smc_clc_msg_trail trl;
 	int reason_code = 0;
+	struct kvec vec[3];
 	struct msghdr msg;
-	struct kvec vec;
-	int len, rc;
+	int len, plen, rc;
 
 	/* send SMC Proposal CLC message */
+	plen = sizeof(pclc) + sizeof(pclc_prfx) + sizeof(trl);
 	memset(&pclc, 0, sizeof(pclc));
 	memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 	pclc.hdr.type = SMC_CLC_PROPOSAL;
-	pclc.hdr.length = htons(sizeof(pclc));
+	pclc.hdr.length = htons(plen);
 	pclc.hdr.version = SMC_CLC_V1;		/* SMC version */
 	memcpy(pclc.lcl.id_for_peer, local_systemid, sizeof(local_systemid));
 	memcpy(&pclc.lcl.gid, &smcibdev->gid[ibport - 1], SMC_GID_SIZE);
 	memcpy(&pclc.lcl.mac, &smcibdev->mac[ibport - 1], ETH_ALEN);
+	pclc.iparea_offset = htons(0);
 
+	memset(&pclc_prfx, 0, sizeof(pclc_prfx));
 	/* determine subnet and mask from internal TCP socket */
-	rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc.outgoing_subnet,
-				  &pclc.prefix_len);
+	rc = smc_netinfo_by_tcpsk(smc->clcsock, &pclc_prfx.outgoing_subnet,
+				  &pclc_prfx.prefix_len);
 	if (rc)
 		return SMC_CLC_DECL_CNFERR; /* configuration error */
-	memcpy(pclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+	pclc_prfx.ipv6_prefixes_cnt = 0;
+	memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
 	memset(&msg, 0, sizeof(msg));
-	vec.iov_base = &pclc;
-	vec.iov_len = sizeof(pclc);
+	vec[0].iov_base = &pclc;
+	vec[0].iov_len = sizeof(pclc);
+	vec[1].iov_base = &pclc_prfx;
+	vec[1].iov_len = sizeof(pclc_prfx);
+	vec[2].iov_base = &trl;
+	vec[2].iov_len = sizeof(trl);
 	/* due to the few bytes needed for clc-handshake this cannot block */
-	len = kernel_sendmsg(smc->clcsock, &msg, &vec, 1, sizeof(pclc));
+	len = kernel_sendmsg(smc->clcsock, &msg, vec, 3, plen);
 	if (len < sizeof(pclc)) {
 		if (len >= 0) {
 			reason_code = -ENETUNREACH;
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 12a9af1539a2..c145a0f36a68 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -44,7 +44,7 @@ struct smc_clc_msg_hdr {	/* header1 of clc messages */
 #if defined(__BIG_ENDIAN_BITFIELD)
 	u8 version : 4,
 	   flag    : 1,
-	   rsvd	   : 3;
+	   rsvd    : 3;
 #elif defined(__LITTLE_ENDIAN_BITFIELD)
 	u8 rsvd    : 3,
 	   flag    : 1,
@@ -62,17 +62,31 @@ struct smc_clc_msg_local {	/* header2 of clc messages */
 	u8 mac[6];		/* mac of ib_device port */
 };
 
-struct smc_clc_msg_proposal {	/* clc proposal message */
-	struct smc_clc_msg_hdr hdr;
-	struct smc_clc_msg_local lcl;
-	__be16 iparea_offset;	/* offset to IP address information area */
+struct smc_clc_ipv6_prefix {
+	u8 prefix[4];
+	u8 prefix_len;
+} __packed;
+
+struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
 	__be32 outgoing_subnet;	/* subnet mask */
 	u8 prefix_len;		/* number of significant bits in mask */
 	u8 reserved[2];
 	u8 ipv6_prefixes_cnt;	/* number of IPv6 prefixes in prefix array */
-	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
 } __aligned(4);
 
+struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
+	struct smc_clc_msg_hdr hdr;
+	struct smc_clc_msg_local lcl;
+	__be16 iparea_offset;	/* offset to IP address information area */
+} __aligned(4);
+
+#define SMC_CLC_PROPOSAL_MAX_OFFSET	0x28
+#define SMC_CLC_PROPOSAL_MAX_PREFIX	(8 * sizeof(struct smc_clc_ipv6_prefix))
+#define SMC_CLC_MAX_LEN		(sizeof(struct smc_clc_msg_proposal) + \
+				 SMC_CLC_PROPOSAL_MAX_OFFSET + \
+				 SMC_CLC_PROPOSAL_MAX_PREFIX + \
+				 sizeof(struct smc_clc_msg_trail))
+
 struct smc_clc_msg_accept_confirm {	/* clc accept / confirm message */
 	struct smc_clc_msg_hdr hdr;
 	struct smc_clc_msg_local lcl;
@@ -102,6 +116,14 @@ struct smc_clc_msg_decline {	/* clc decline message */
 	struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
 } __aligned(4);
 
+/* determine start of the prefix area within the proposal message */
+static inline struct smc_clc_msg_proposal_prefix *
+smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)
+{
+	return (struct smc_clc_msg_proposal_prefix *)
+	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));
+}
+
 struct smc_sock;
 struct smc_ib_device;
 
diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index 48615d2ac4aa..e194c6cc308a 100644
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -113,7 +113,7 @@ static int smc_close_abort(struct smc_connection *conn)
 /* terminate smc socket abnormally - active abort
  * RDMA communication no longer possible
  */
-void smc_close_active_abort(struct smc_sock *smc)
+static void smc_close_active_abort(struct smc_sock *smc)
 {
 	struct smc_cdc_conn_state_flags *txflags =
 		&smc->conn.local_tx_ctrl.conn_state_flags;
diff --git a/net/smc/smc_close.h b/net/smc/smc_close.h
index ed82506b1b0a..8c498885d758 100644
--- a/net/smc/smc_close.h
+++ b/net/smc/smc_close.h
@@ -20,7 +20,6 @@
 #define SMC_CLOSE_SOCK_PUT_DELAY		HZ
 
 void smc_close_wake_tx_prepared(struct smc_sock *smc);
-void smc_close_active_abort(struct smc_sock *smc);
 int smc_close_active(struct smc_sock *smc);
 void smc_close_sock_put_work(struct work_struct *work);
 int smc_close_shutdown_write(struct smc_sock *smc);
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index cbf58637ee14..9dc392ca06bf 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -65,7 +65,6 @@ static int smc_rx_wait_data(struct smc_sock *smc, long *timeo)
 	rc = sk_wait_event(sk, timeo,
 			   sk->sk_err ||
 			   sk->sk_shutdown & RCV_SHUTDOWN ||
-			   sock_flag(sk, SOCK_DONE) ||
 			   atomic_read(&conn->bytes_to_rcv) ||
 			   smc_cdc_rxed_any_close_or_senddone(conn),
 			   &wait);
@@ -116,7 +115,7 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
 		if (read_done) {
 			if (sk->sk_err ||
 			    sk->sk_state == SMC_CLOSED ||
-			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
+			    sk->sk_shutdown & RCV_SHUTDOWN ||
 			    !timeo ||
 			    signal_pending(current) ||
 			    smc_cdc_rxed_any_close_or_senddone(conn) ||
@@ -124,8 +123,6 @@ int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
 			    peer_conn_abort)
 				break;
 		} else {
-			if (sock_flag(sk, SOCK_DONE))
-				break;
 			if (sk->sk_err) {
 				read_done = sock_error(sk);
 				break;
diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c
index c48dc2d5fd3a..2e50fddf8ce9 100644
--- a/net/smc/smc_tx.c
+++ b/net/smc/smc_tx.c
@@ -104,14 +104,12 @@ static int smc_tx_wait_memory(struct smc_sock *smc, int flags)
 		if (atomic_read(&conn->sndbuf_space))
 			break; /* at least 1 byte of free space available */
 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
-		sk->sk_write_pending++;
 		sk_wait_event(sk, &timeo,
 			      sk->sk_err ||
 			      (sk->sk_shutdown & SEND_SHUTDOWN) ||
 			      smc_cdc_rxed_any_close_or_senddone(conn) ||
 			      atomic_read(&conn->sndbuf_space),
 			      &wait);
-		sk->sk_write_pending--;
 	}
 	remove_wait_queue(sk_sleep(sk), &wait);
 	return rc;
@@ -450,9 +448,7 @@ static void smc_tx_work(struct work_struct *work)
 void smc_tx_consumer_update(struct smc_connection *conn)
 {
 	union smc_host_cursor cfed, cons;
-	struct smc_cdc_tx_pend *pend;
-	struct smc_wr_buf *wr_buf;
-	int to_confirm, rc;
+	int to_confirm;
 
 	smc_curs_write(&cons,
 		       smc_curs_read(&conn->local_tx_ctrl.cons, conn),
@@ -466,10 +462,7 @@ void smc_tx_consumer_update(struct smc_connection *conn)
 	    ((to_confirm > conn->rmbe_update_limit) &&
 	     ((to_confirm > (conn->rmbe_size / 2)) ||
 	      conn->local_rx_ctrl.prod_flags.write_blocked))) {
-		rc = smc_cdc_get_free_slot(conn, &wr_buf, &pend);
-		if (!rc)
-			rc = smc_cdc_msg_send(conn, wr_buf, pend);
-		if (rc < 0) {
+		if (smc_cdc_get_slot_and_msg_send(conn) < 0) {
 			schedule_delayed_work(&conn->tx_work,
 					      SMC_TX_WORK_DELAY);
 			return;