From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 17 Dec 2020 19:53:52 +0000 (-0800)
Subject: Merge tag 'ceph-for-5.11-rc1' of git://github.com/ceph/ceph-client
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=be695ee29e8fc0af266d9f1882868c47da01a790;p=linux.git

Merge tag 'ceph-for-5.11-rc1' of git://github.com/ceph/ceph-client

Pull ceph updates from Ilya Dryomov:
 "The big ticket item here is support for msgr2 on-wire protocol, which
  adds the option of full in-transit encryption using AES-GCM algorithm
  (myself).

  On top of that we have a series to avoid intermittent errors during
  recovery with recover_session=clean and some MDS request encoding work
  from Jeff, a cap handling fix and assorted observability improvements
  from Luis and Xiubo and a good number of cleanups.

  Luis also ran into a corner case with quotas which sadly means that we
  are back to denying cross-quota-realm renames"

* tag 'ceph-for-5.11-rc1' of git://github.com/ceph/ceph-client: (59 commits)
  libceph: drop ceph_auth_{create,update}_authorizer()
  libceph, ceph: make use of __ceph_auth_get_authorizer() in msgr1
  libceph, ceph: implement msgr2.1 protocol (crc and secure modes)
  libceph: introduce connection modes and ms_mode option
  libceph, rbd: ignore addr->type while comparing in some cases
  libceph, ceph: get and handle cluster maps with addrvecs
  libceph: factor out finish_auth()
  libceph: drop ac->ops->name field
  libceph: amend cephx init_protocol() and build_request()
  libceph, ceph: incorporate nautilus cephx changes
  libceph: safer en/decoding of cephx requests and replies
  libceph: more insight into ticket expiry and invalidation
  libceph: move msgr1 protocol specific fields to its own struct
  libceph: move msgr1 protocol implementation to its own file
  libceph: separate msgr1 protocol implementation
  libceph: export remaining protocol independent infrastructure
  libceph: export zero_page
  libceph: rename and export con->flags bits
  libceph: rename and export con->state states
  libceph: make con->state an int
  ...
---

be695ee29e8fc0af266d9f1882868c47da01a790
diff --cc net/ceph/messenger_v2.c
index 000000000000,5e38c847317b..c1ebb2aa08b5
mode 000000,100644..100644
--- a/net/ceph/messenger_v2.c
+++ b/net/ceph/messenger_v2.c
@@@ -1,0 -1,3443 +1,3443 @@@
+ // SPDX-License-Identifier: GPL-2.0
+ /*
+  * Ceph msgr2 protocol implementation
+  *
+  * Copyright (C) 2020 Ilya Dryomov <idryomov@gmail.com>
+  */
+ 
+ #include <linux/ceph/ceph_debug.h>
+ 
+ #include <crypto/aead.h>
+ #include <crypto/algapi.h>  /* for crypto_memneq() */
+ #include <crypto/hash.h>
 -#include <crypto/sha.h>
++#include <crypto/sha2.h>
+ #include <linux/bvec.h>
+ #include <linux/crc32c.h>
+ #include <linux/net.h>
+ #include <linux/scatterlist.h>
+ #include <linux/socket.h>
+ #include <linux/sched/mm.h>
+ #include <net/sock.h>
+ #include <net/tcp.h>
+ 
+ #include <linux/ceph/ceph_features.h>
+ #include <linux/ceph/decode.h>
+ #include <linux/ceph/libceph.h>
+ #include <linux/ceph/messenger.h>
+ 
+ #include "crypto.h"  /* for CEPH_KEY_LEN and CEPH_MAX_CON_SECRET_LEN */
+ 
+ #define FRAME_TAG_HELLO			1
+ #define FRAME_TAG_AUTH_REQUEST		2
+ #define FRAME_TAG_AUTH_BAD_METHOD	3
+ #define FRAME_TAG_AUTH_REPLY_MORE	4
+ #define FRAME_TAG_AUTH_REQUEST_MORE	5
+ #define FRAME_TAG_AUTH_DONE		6
+ #define FRAME_TAG_AUTH_SIGNATURE	7
+ #define FRAME_TAG_CLIENT_IDENT		8
+ #define FRAME_TAG_SERVER_IDENT		9
+ #define FRAME_TAG_IDENT_MISSING_FEATURES 10
+ #define FRAME_TAG_SESSION_RECONNECT	11
+ #define FRAME_TAG_SESSION_RESET		12
+ #define FRAME_TAG_SESSION_RETRY		13
+ #define FRAME_TAG_SESSION_RETRY_GLOBAL	14
+ #define FRAME_TAG_SESSION_RECONNECT_OK	15
+ #define FRAME_TAG_WAIT			16
+ #define FRAME_TAG_MESSAGE		17
+ #define FRAME_TAG_KEEPALIVE2		18
+ #define FRAME_TAG_KEEPALIVE2_ACK	19
+ #define FRAME_TAG_ACK			20
+ 
+ #define FRAME_LATE_STATUS_ABORTED	0x1
+ #define FRAME_LATE_STATUS_COMPLETE	0xe
+ #define FRAME_LATE_STATUS_ABORTED_MASK	0xf
+ 
+ #define IN_S_HANDLE_PREAMBLE		1
+ #define IN_S_HANDLE_CONTROL		2
+ #define IN_S_HANDLE_CONTROL_REMAINDER	3
+ #define IN_S_PREPARE_READ_DATA		4
+ #define IN_S_PREPARE_READ_DATA_CONT	5
+ #define IN_S_HANDLE_EPILOGUE		6
+ #define IN_S_FINISH_SKIP		7
+ 
+ #define OUT_S_QUEUE_DATA		1
+ #define OUT_S_QUEUE_DATA_CONT		2
+ #define OUT_S_QUEUE_ENC_PAGE		3
+ #define OUT_S_QUEUE_ZEROS		4
+ #define OUT_S_FINISH_MESSAGE		5
+ #define OUT_S_GET_NEXT			6
+ 
+ #define CTRL_BODY(p)	((void *)(p) + CEPH_PREAMBLE_LEN)
+ #define FRONT_PAD(p)	((void *)(p) + CEPH_EPILOGUE_SECURE_LEN)
+ #define MIDDLE_PAD(p)	(FRONT_PAD(p) + CEPH_GCM_BLOCK_LEN)
+ #define DATA_PAD(p)	(MIDDLE_PAD(p) + CEPH_GCM_BLOCK_LEN)
+ 
+ #define CEPH_MSG_FLAGS (MSG_DONTWAIT | MSG_NOSIGNAL)
+ 
+ static int do_recvmsg(struct socket *sock, struct iov_iter *it)
+ {
+ 	struct msghdr msg = { .msg_flags = CEPH_MSG_FLAGS };
+ 	int ret;
+ 
+ 	msg.msg_iter = *it;
+ 	while (iov_iter_count(it)) {
+ 		ret = sock_recvmsg(sock, &msg, msg.msg_flags);
+ 		if (ret <= 0) {
+ 			if (ret == -EAGAIN)
+ 				ret = 0;
+ 			return ret;
+ 		}
+ 
+ 		iov_iter_advance(it, ret);
+ 	}
+ 
+ 	WARN_ON(msg_data_left(&msg));
+ 	return 1;
+ }
+ 
+ /*
+  * Read as much as possible.
+  *
+  * Return:
+  *   1 - done, nothing (else) to read
+  *   0 - socket is empty, need to wait
+  *  <0 - error
+  */
+ static int ceph_tcp_recv(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p %s %zu\n", __func__, con,
+ 	     iov_iter_is_discard(&con->v2.in_iter) ? "discard" : "need",
+ 	     iov_iter_count(&con->v2.in_iter));
+ 	ret = do_recvmsg(con->sock, &con->v2.in_iter);
+ 	dout("%s con %p ret %d left %zu\n", __func__, con, ret,
+ 	     iov_iter_count(&con->v2.in_iter));
+ 	return ret;
+ }
+ 
+ static int do_sendmsg(struct socket *sock, struct iov_iter *it)
+ {
+ 	struct msghdr msg = { .msg_flags = CEPH_MSG_FLAGS };
+ 	int ret;
+ 
+ 	msg.msg_iter = *it;
+ 	while (iov_iter_count(it)) {
+ 		ret = sock_sendmsg(sock, &msg);
+ 		if (ret <= 0) {
+ 			if (ret == -EAGAIN)
+ 				ret = 0;
+ 			return ret;
+ 		}
+ 
+ 		iov_iter_advance(it, ret);
+ 	}
+ 
+ 	WARN_ON(msg_data_left(&msg));
+ 	return 1;
+ }
+ 
+ static int do_try_sendpage(struct socket *sock, struct iov_iter *it)
+ {
+ 	struct msghdr msg = { .msg_flags = CEPH_MSG_FLAGS };
+ 	struct bio_vec bv;
+ 	int ret;
+ 
+ 	if (WARN_ON(!iov_iter_is_bvec(it)))
+ 		return -EINVAL;
+ 
+ 	while (iov_iter_count(it)) {
+ 		/* iov_iter_iovec() for ITER_BVEC */
+ 		bv.bv_page = it->bvec->bv_page;
+ 		bv.bv_offset = it->bvec->bv_offset + it->iov_offset;
+ 		bv.bv_len = min(iov_iter_count(it),
+ 				it->bvec->bv_len - it->iov_offset);
+ 
+ 		/*
+ 		 * sendpage cannot properly handle pages with
+ 		 * page_count == 0, we need to fall back to sendmsg if
+ 		 * that's the case.
+ 		 *
+ 		 * Same goes for slab pages: skb_can_coalesce() allows
+ 		 * coalescing neighboring slab objects into a single frag
+ 		 * which triggers one of hardened usercopy checks.
+ 		 */
+ 		if (sendpage_ok(bv.bv_page)) {
+ 			ret = sock->ops->sendpage(sock, bv.bv_page,
+ 						  bv.bv_offset, bv.bv_len,
+ 						  CEPH_MSG_FLAGS);
+ 		} else {
+ 			iov_iter_bvec(&msg.msg_iter, WRITE, &bv, 1, bv.bv_len);
+ 			ret = sock_sendmsg(sock, &msg);
+ 		}
+ 		if (ret <= 0) {
+ 			if (ret == -EAGAIN)
+ 				ret = 0;
+ 			return ret;
+ 		}
+ 
+ 		iov_iter_advance(it, ret);
+ 	}
+ 
+ 	return 1;
+ }
+ 
+ /*
+  * Write as much as possible.  The socket is expected to be corked,
+  * so we don't bother with MSG_MORE/MSG_SENDPAGE_NOTLAST here.
+  *
+  * Return:
+  *   1 - done, nothing (else) to write
+  *   0 - socket is full, need to wait
+  *  <0 - error
+  */
+ static int ceph_tcp_send(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p have %zu try_sendpage %d\n", __func__, con,
+ 	     iov_iter_count(&con->v2.out_iter), con->v2.out_iter_sendpage);
+ 	if (con->v2.out_iter_sendpage)
+ 		ret = do_try_sendpage(con->sock, &con->v2.out_iter);
+ 	else
+ 		ret = do_sendmsg(con->sock, &con->v2.out_iter);
+ 	dout("%s con %p ret %d left %zu\n", __func__, con, ret,
+ 	     iov_iter_count(&con->v2.out_iter));
+ 	return ret;
+ }
+ 
+ static void add_in_kvec(struct ceph_connection *con, void *buf, int len)
+ {
+ 	BUG_ON(con->v2.in_kvec_cnt >= ARRAY_SIZE(con->v2.in_kvecs));
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.in_iter));
+ 
+ 	con->v2.in_kvecs[con->v2.in_kvec_cnt].iov_base = buf;
+ 	con->v2.in_kvecs[con->v2.in_kvec_cnt].iov_len = len;
+ 	con->v2.in_kvec_cnt++;
+ 
+ 	con->v2.in_iter.nr_segs++;
+ 	con->v2.in_iter.count += len;
+ }
+ 
+ static void reset_in_kvecs(struct ceph_connection *con)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.in_iter));
+ 
+ 	con->v2.in_kvec_cnt = 0;
+ 	iov_iter_kvec(&con->v2.in_iter, READ, con->v2.in_kvecs, 0, 0);
+ }
+ 
+ static void set_in_bvec(struct ceph_connection *con, const struct bio_vec *bv)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.in_iter));
+ 
+ 	con->v2.in_bvec = *bv;
+ 	iov_iter_bvec(&con->v2.in_iter, READ, &con->v2.in_bvec, 1, bv->bv_len);
+ }
+ 
+ static void set_in_skip(struct ceph_connection *con, int len)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.in_iter));
+ 
+ 	dout("%s con %p len %d\n", __func__, con, len);
+ 	iov_iter_discard(&con->v2.in_iter, READ, len);
+ }
+ 
+ static void add_out_kvec(struct ceph_connection *con, void *buf, int len)
+ {
+ 	BUG_ON(con->v2.out_kvec_cnt >= ARRAY_SIZE(con->v2.out_kvecs));
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.out_iter));
+ 	WARN_ON(con->v2.out_zero);
+ 
+ 	con->v2.out_kvecs[con->v2.out_kvec_cnt].iov_base = buf;
+ 	con->v2.out_kvecs[con->v2.out_kvec_cnt].iov_len = len;
+ 	con->v2.out_kvec_cnt++;
+ 
+ 	con->v2.out_iter.nr_segs++;
+ 	con->v2.out_iter.count += len;
+ }
+ 
+ static void reset_out_kvecs(struct ceph_connection *con)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.out_iter));
+ 	WARN_ON(con->v2.out_zero);
+ 
+ 	con->v2.out_kvec_cnt = 0;
+ 
+ 	iov_iter_kvec(&con->v2.out_iter, WRITE, con->v2.out_kvecs, 0, 0);
+ 	con->v2.out_iter_sendpage = false;
+ }
+ 
+ static void set_out_bvec(struct ceph_connection *con, const struct bio_vec *bv,
+ 			 bool zerocopy)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.out_iter));
+ 	WARN_ON(con->v2.out_zero);
+ 
+ 	con->v2.out_bvec = *bv;
+ 	con->v2.out_iter_sendpage = zerocopy;
+ 	iov_iter_bvec(&con->v2.out_iter, WRITE, &con->v2.out_bvec, 1,
+ 		      con->v2.out_bvec.bv_len);
+ }
+ 
+ static void set_out_bvec_zero(struct ceph_connection *con)
+ {
+ 	WARN_ON(iov_iter_count(&con->v2.out_iter));
+ 	WARN_ON(!con->v2.out_zero);
+ 
+ 	con->v2.out_bvec.bv_page = ceph_zero_page;
+ 	con->v2.out_bvec.bv_offset = 0;
+ 	con->v2.out_bvec.bv_len = min(con->v2.out_zero, (int)PAGE_SIZE);
+ 	con->v2.out_iter_sendpage = true;
+ 	iov_iter_bvec(&con->v2.out_iter, WRITE, &con->v2.out_bvec, 1,
+ 		      con->v2.out_bvec.bv_len);
+ }
+ 
+ static void out_zero_add(struct ceph_connection *con, int len)
+ {
+ 	dout("%s con %p len %d\n", __func__, con, len);
+ 	con->v2.out_zero += len;
+ }
+ 
+ static void *alloc_conn_buf(struct ceph_connection *con, int len)
+ {
+ 	void *buf;
+ 
+ 	dout("%s con %p len %d\n", __func__, con, len);
+ 
+ 	if (WARN_ON(con->v2.conn_buf_cnt >= ARRAY_SIZE(con->v2.conn_bufs)))
+ 		return NULL;
+ 
+ 	buf = ceph_kvmalloc(len, GFP_NOIO);
+ 	if (!buf)
+ 		return NULL;
+ 
+ 	con->v2.conn_bufs[con->v2.conn_buf_cnt++] = buf;
+ 	return buf;
+ }
+ 
+ static void free_conn_bufs(struct ceph_connection *con)
+ {
+ 	while (con->v2.conn_buf_cnt)
+ 		kvfree(con->v2.conn_bufs[--con->v2.conn_buf_cnt]);
+ }
+ 
+ static void add_in_sign_kvec(struct ceph_connection *con, void *buf, int len)
+ {
+ 	BUG_ON(con->v2.in_sign_kvec_cnt >= ARRAY_SIZE(con->v2.in_sign_kvecs));
+ 
+ 	con->v2.in_sign_kvecs[con->v2.in_sign_kvec_cnt].iov_base = buf;
+ 	con->v2.in_sign_kvecs[con->v2.in_sign_kvec_cnt].iov_len = len;
+ 	con->v2.in_sign_kvec_cnt++;
+ }
+ 
+ static void clear_in_sign_kvecs(struct ceph_connection *con)
+ {
+ 	con->v2.in_sign_kvec_cnt = 0;
+ }
+ 
+ static void add_out_sign_kvec(struct ceph_connection *con, void *buf, int len)
+ {
+ 	BUG_ON(con->v2.out_sign_kvec_cnt >= ARRAY_SIZE(con->v2.out_sign_kvecs));
+ 
+ 	con->v2.out_sign_kvecs[con->v2.out_sign_kvec_cnt].iov_base = buf;
+ 	con->v2.out_sign_kvecs[con->v2.out_sign_kvec_cnt].iov_len = len;
+ 	con->v2.out_sign_kvec_cnt++;
+ }
+ 
+ static void clear_out_sign_kvecs(struct ceph_connection *con)
+ {
+ 	con->v2.out_sign_kvec_cnt = 0;
+ }
+ 
+ static bool con_secure(struct ceph_connection *con)
+ {
+ 	return con->v2.con_mode == CEPH_CON_MODE_SECURE;
+ }
+ 
+ static int front_len(const struct ceph_msg *msg)
+ {
+ 	return le32_to_cpu(msg->hdr.front_len);
+ }
+ 
+ static int middle_len(const struct ceph_msg *msg)
+ {
+ 	return le32_to_cpu(msg->hdr.middle_len);
+ }
+ 
+ static int data_len(const struct ceph_msg *msg)
+ {
+ 	return le32_to_cpu(msg->hdr.data_len);
+ }
+ 
+ static bool need_padding(int len)
+ {
+ 	return !IS_ALIGNED(len, CEPH_GCM_BLOCK_LEN);
+ }
+ 
+ static int padded_len(int len)
+ {
+ 	return ALIGN(len, CEPH_GCM_BLOCK_LEN);
+ }
+ 
+ static int padding_len(int len)
+ {
+ 	return padded_len(len) - len;
+ }
+ 
+ /* preamble + control segment */
+ static int head_onwire_len(int ctrl_len, bool secure)
+ {
+ 	int head_len;
+ 	int rem_len;
+ 
+ 	if (secure) {
+ 		head_len = CEPH_PREAMBLE_SECURE_LEN;
+ 		if (ctrl_len > CEPH_PREAMBLE_INLINE_LEN) {
+ 			rem_len = ctrl_len - CEPH_PREAMBLE_INLINE_LEN;
+ 			head_len += padded_len(rem_len) + CEPH_GCM_TAG_LEN;
+ 		}
+ 	} else {
+ 		head_len = CEPH_PREAMBLE_PLAIN_LEN;
+ 		if (ctrl_len)
+ 			head_len += ctrl_len + CEPH_CRC_LEN;
+ 	}
+ 	return head_len;
+ }
+ 
+ /* front, middle and data segments + epilogue */
+ static int __tail_onwire_len(int front_len, int middle_len, int data_len,
+ 			     bool secure)
+ {
+ 	if (!front_len && !middle_len && !data_len)
+ 		return 0;
+ 
+ 	if (!secure)
+ 		return front_len + middle_len + data_len +
+ 		       CEPH_EPILOGUE_PLAIN_LEN;
+ 
+ 	return padded_len(front_len) + padded_len(middle_len) +
+ 	       padded_len(data_len) + CEPH_EPILOGUE_SECURE_LEN;
+ }
+ 
+ static int tail_onwire_len(const struct ceph_msg *msg, bool secure)
+ {
+ 	return __tail_onwire_len(front_len(msg), middle_len(msg),
+ 				 data_len(msg), secure);
+ }
+ 
+ /* head_onwire_len(sizeof(struct ceph_msg_header2), false) */
+ #define MESSAGE_HEAD_PLAIN_LEN	(CEPH_PREAMBLE_PLAIN_LEN +		\
+ 				 sizeof(struct ceph_msg_header2) +	\
+ 				 CEPH_CRC_LEN)
+ 
+ static const int frame_aligns[] = {
+ 	sizeof(void *),
+ 	sizeof(void *),
+ 	sizeof(void *),
+ 	PAGE_SIZE
+ };
+ 
+ /*
+  * Discards trailing empty segments, unless there is just one segment.
+  * A frame always has at least one (possibly empty) segment.
+  */
+ static int calc_segment_count(const int *lens, int len_cnt)
+ {
+ 	int i;
+ 
+ 	for (i = len_cnt - 1; i >= 0; i--) {
+ 		if (lens[i])
+ 			return i + 1;
+ 	}
+ 
+ 	return 1;
+ }
+ 
+ static void init_frame_desc(struct ceph_frame_desc *desc, int tag,
+ 			    const int *lens, int len_cnt)
+ {
+ 	int i;
+ 
+ 	memset(desc, 0, sizeof(*desc));
+ 
+ 	desc->fd_tag = tag;
+ 	desc->fd_seg_cnt = calc_segment_count(lens, len_cnt);
+ 	BUG_ON(desc->fd_seg_cnt > CEPH_FRAME_MAX_SEGMENT_COUNT);
+ 	for (i = 0; i < desc->fd_seg_cnt; i++) {
+ 		desc->fd_lens[i] = lens[i];
+ 		desc->fd_aligns[i] = frame_aligns[i];
+ 	}
+ }
+ 
+ /*
+  * Preamble crc covers everything up to itself (28 bytes) and
+  * is calculated and verified irrespective of the connection mode
+  * (i.e. even if the frame is encrypted).
+  */
+ static void encode_preamble(const struct ceph_frame_desc *desc, void *p)
+ {
+ 	void *crcp = p + CEPH_PREAMBLE_LEN - CEPH_CRC_LEN;
+ 	void *start = p;
+ 	int i;
+ 
+ 	memset(p, 0, CEPH_PREAMBLE_LEN);
+ 
+ 	ceph_encode_8(&p, desc->fd_tag);
+ 	ceph_encode_8(&p, desc->fd_seg_cnt);
+ 	for (i = 0; i < desc->fd_seg_cnt; i++) {
+ 		ceph_encode_32(&p, desc->fd_lens[i]);
+ 		ceph_encode_16(&p, desc->fd_aligns[i]);
+ 	}
+ 
+ 	put_unaligned_le32(crc32c(0, start, crcp - start), crcp);
+ }
+ 
+ static int decode_preamble(void *p, struct ceph_frame_desc *desc)
+ {
+ 	void *crcp = p + CEPH_PREAMBLE_LEN - CEPH_CRC_LEN;
+ 	u32 crc, expected_crc;
+ 	int i;
+ 
+ 	crc = crc32c(0, p, crcp - p);
+ 	expected_crc = get_unaligned_le32(crcp);
+ 	if (crc != expected_crc) {
+ 		pr_err("bad preamble crc, calculated %u, expected %u\n",
+ 		       crc, expected_crc);
+ 		return -EBADMSG;
+ 	}
+ 
+ 	memset(desc, 0, sizeof(*desc));
+ 
+ 	desc->fd_tag = ceph_decode_8(&p);
+ 	desc->fd_seg_cnt = ceph_decode_8(&p);
+ 	if (desc->fd_seg_cnt < 1 ||
+ 	    desc->fd_seg_cnt > CEPH_FRAME_MAX_SEGMENT_COUNT) {
+ 		pr_err("bad segment count %d\n", desc->fd_seg_cnt);
+ 		return -EINVAL;
+ 	}
+ 	for (i = 0; i < desc->fd_seg_cnt; i++) {
+ 		desc->fd_lens[i] = ceph_decode_32(&p);
+ 		desc->fd_aligns[i] = ceph_decode_16(&p);
+ 	}
+ 
+ 	/*
+ 	 * This would fire for FRAME_TAG_WAIT (it has one empty
+ 	 * segment), but we should never get it as client.
+ 	 */
+ 	if (!desc->fd_lens[desc->fd_seg_cnt - 1]) {
+ 		pr_err("last segment empty\n");
+ 		return -EINVAL;
+ 	}
+ 
+ 	if (desc->fd_lens[0] > CEPH_MSG_MAX_CONTROL_LEN) {
+ 		pr_err("control segment too big %d\n", desc->fd_lens[0]);
+ 		return -EINVAL;
+ 	}
+ 	if (desc->fd_lens[1] > CEPH_MSG_MAX_FRONT_LEN) {
+ 		pr_err("front segment too big %d\n", desc->fd_lens[1]);
+ 		return -EINVAL;
+ 	}
+ 	if (desc->fd_lens[2] > CEPH_MSG_MAX_MIDDLE_LEN) {
+ 		pr_err("middle segment too big %d\n", desc->fd_lens[2]);
+ 		return -EINVAL;
+ 	}
+ 	if (desc->fd_lens[3] > CEPH_MSG_MAX_DATA_LEN) {
+ 		pr_err("data segment too big %d\n", desc->fd_lens[3]);
+ 		return -EINVAL;
+ 	}
+ 
+ 	return 0;
+ }
+ 
+ static void encode_epilogue_plain(struct ceph_connection *con, bool aborted)
+ {
+ 	con->v2.out_epil.late_status = aborted ? FRAME_LATE_STATUS_ABORTED :
+ 						 FRAME_LATE_STATUS_COMPLETE;
+ 	cpu_to_le32s(&con->v2.out_epil.front_crc);
+ 	cpu_to_le32s(&con->v2.out_epil.middle_crc);
+ 	cpu_to_le32s(&con->v2.out_epil.data_crc);
+ }
+ 
+ static void encode_epilogue_secure(struct ceph_connection *con, bool aborted)
+ {
+ 	memset(&con->v2.out_epil, 0, sizeof(con->v2.out_epil));
+ 	con->v2.out_epil.late_status = aborted ? FRAME_LATE_STATUS_ABORTED :
+ 						 FRAME_LATE_STATUS_COMPLETE;
+ }
+ 
+ static int decode_epilogue(void *p, u32 *front_crc, u32 *middle_crc,
+ 			   u32 *data_crc)
+ {
+ 	u8 late_status;
+ 
+ 	late_status = ceph_decode_8(&p);
+ 	if ((late_status & FRAME_LATE_STATUS_ABORTED_MASK) !=
+ 			FRAME_LATE_STATUS_COMPLETE) {
+ 		/* we should never get an aborted message as client */
+ 		pr_err("bad late_status 0x%x\n", late_status);
+ 		return -EINVAL;
+ 	}
+ 
+ 	if (front_crc && middle_crc && data_crc) {
+ 		*front_crc = ceph_decode_32(&p);
+ 		*middle_crc = ceph_decode_32(&p);
+ 		*data_crc = ceph_decode_32(&p);
+ 	}
+ 
+ 	return 0;
+ }
+ 
+ static void fill_header(struct ceph_msg_header *hdr,
+ 			const struct ceph_msg_header2 *hdr2,
+ 			int front_len, int middle_len, int data_len,
+ 			const struct ceph_entity_name *peer_name)
+ {
+ 	hdr->seq = hdr2->seq;
+ 	hdr->tid = hdr2->tid;
+ 	hdr->type = hdr2->type;
+ 	hdr->priority = hdr2->priority;
+ 	hdr->version = hdr2->version;
+ 	hdr->front_len = cpu_to_le32(front_len);
+ 	hdr->middle_len = cpu_to_le32(middle_len);
+ 	hdr->data_len = cpu_to_le32(data_len);
+ 	hdr->data_off = hdr2->data_off;
+ 	hdr->src = *peer_name;
+ 	hdr->compat_version = hdr2->compat_version;
+ 	hdr->reserved = 0;
+ 	hdr->crc = 0;
+ }
+ 
+ static void fill_header2(struct ceph_msg_header2 *hdr2,
+ 			 const struct ceph_msg_header *hdr, u64 ack_seq)
+ {
+ 	hdr2->seq = hdr->seq;
+ 	hdr2->tid = hdr->tid;
+ 	hdr2->type = hdr->type;
+ 	hdr2->priority = hdr->priority;
+ 	hdr2->version = hdr->version;
+ 	hdr2->data_pre_padding_len = 0;
+ 	hdr2->data_off = hdr->data_off;
+ 	hdr2->ack_seq = cpu_to_le64(ack_seq);
+ 	hdr2->flags = 0;
+ 	hdr2->compat_version = hdr->compat_version;
+ 	hdr2->reserved = 0;
+ }
+ 
+ static int verify_control_crc(struct ceph_connection *con)
+ {
+ 	int ctrl_len = con->v2.in_desc.fd_lens[0];
+ 	u32 crc, expected_crc;
+ 
+ 	WARN_ON(con->v2.in_kvecs[0].iov_len != ctrl_len);
+ 	WARN_ON(con->v2.in_kvecs[1].iov_len != CEPH_CRC_LEN);
+ 
+ 	crc = crc32c(-1, con->v2.in_kvecs[0].iov_base, ctrl_len);
+ 	expected_crc = get_unaligned_le32(con->v2.in_kvecs[1].iov_base);
+ 	if (crc != expected_crc) {
+ 		pr_err("bad control crc, calculated %u, expected %u\n",
+ 		       crc, expected_crc);
+ 		return -EBADMSG;
+ 	}
+ 
+ 	return 0;
+ }
+ 
+ static int verify_epilogue_crcs(struct ceph_connection *con, u32 front_crc,
+ 				u32 middle_crc, u32 data_crc)
+ {
+ 	if (front_len(con->in_msg)) {
+ 		con->in_front_crc = crc32c(-1, con->in_msg->front.iov_base,
+ 					   front_len(con->in_msg));
+ 	} else {
+ 		WARN_ON(!middle_len(con->in_msg) && !data_len(con->in_msg));
+ 		con->in_front_crc = -1;
+ 	}
+ 
+ 	if (middle_len(con->in_msg))
+ 		con->in_middle_crc = crc32c(-1,
+ 					    con->in_msg->middle->vec.iov_base,
+ 					    middle_len(con->in_msg));
+ 	else if (data_len(con->in_msg))
+ 		con->in_middle_crc = -1;
+ 	else
+ 		con->in_middle_crc = 0;
+ 
+ 	if (!data_len(con->in_msg))
+ 		con->in_data_crc = 0;
+ 
+ 	dout("%s con %p msg %p crcs %u %u %u\n", __func__, con, con->in_msg,
+ 	     con->in_front_crc, con->in_middle_crc, con->in_data_crc);
+ 
+ 	if (con->in_front_crc != front_crc) {
+ 		pr_err("bad front crc, calculated %u, expected %u\n",
+ 		       con->in_front_crc, front_crc);
+ 		return -EBADMSG;
+ 	}
+ 	if (con->in_middle_crc != middle_crc) {
+ 		pr_err("bad middle crc, calculated %u, expected %u\n",
+ 		       con->in_middle_crc, middle_crc);
+ 		return -EBADMSG;
+ 	}
+ 	if (con->in_data_crc != data_crc) {
+ 		pr_err("bad data crc, calculated %u, expected %u\n",
+ 		       con->in_data_crc, data_crc);
+ 		return -EBADMSG;
+ 	}
+ 
+ 	return 0;
+ }
+ 
+ static int setup_crypto(struct ceph_connection *con,
+ 			u8 *session_key, int session_key_len,
+ 			u8 *con_secret, int con_secret_len)
+ {
+ 	unsigned int noio_flag;
+ 	void *p;
+ 	int ret;
+ 
+ 	dout("%s con %p con_mode %d session_key_len %d con_secret_len %d\n",
+ 	     __func__, con, con->v2.con_mode, session_key_len, con_secret_len);
+ 	WARN_ON(con->v2.hmac_tfm || con->v2.gcm_tfm || con->v2.gcm_req);
+ 
+ 	if (con->v2.con_mode != CEPH_CON_MODE_CRC &&
+ 	    con->v2.con_mode != CEPH_CON_MODE_SECURE) {
+ 		pr_err("bad con_mode %d\n", con->v2.con_mode);
+ 		return -EINVAL;
+ 	}
+ 
+ 	if (!session_key_len) {
+ 		WARN_ON(con->v2.con_mode != CEPH_CON_MODE_CRC);
+ 		WARN_ON(con_secret_len);
+ 		return 0;  /* auth_none */
+ 	}
+ 
+ 	noio_flag = memalloc_noio_save();
+ 	con->v2.hmac_tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
+ 	memalloc_noio_restore(noio_flag);
+ 	if (IS_ERR(con->v2.hmac_tfm)) {
+ 		ret = PTR_ERR(con->v2.hmac_tfm);
+ 		con->v2.hmac_tfm = NULL;
+ 		pr_err("failed to allocate hmac tfm context: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	WARN_ON((unsigned long)session_key &
+ 		crypto_shash_alignmask(con->v2.hmac_tfm));
+ 	ret = crypto_shash_setkey(con->v2.hmac_tfm, session_key,
+ 				  session_key_len);
+ 	if (ret) {
+ 		pr_err("failed to set hmac key: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	if (con->v2.con_mode == CEPH_CON_MODE_CRC) {
+ 		WARN_ON(con_secret_len);
+ 		return 0;  /* auth_x, plain mode */
+ 	}
+ 
+ 	if (con_secret_len < CEPH_GCM_KEY_LEN + 2 * CEPH_GCM_IV_LEN) {
+ 		pr_err("con_secret too small %d\n", con_secret_len);
+ 		return -EINVAL;
+ 	}
+ 
+ 	noio_flag = memalloc_noio_save();
+ 	con->v2.gcm_tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
+ 	memalloc_noio_restore(noio_flag);
+ 	if (IS_ERR(con->v2.gcm_tfm)) {
+ 		ret = PTR_ERR(con->v2.gcm_tfm);
+ 		con->v2.gcm_tfm = NULL;
+ 		pr_err("failed to allocate gcm tfm context: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	p = con_secret;
+ 	WARN_ON((unsigned long)p & crypto_aead_alignmask(con->v2.gcm_tfm));
+ 	ret = crypto_aead_setkey(con->v2.gcm_tfm, p, CEPH_GCM_KEY_LEN);
+ 	if (ret) {
+ 		pr_err("failed to set gcm key: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	p += CEPH_GCM_KEY_LEN;
+ 	WARN_ON(crypto_aead_ivsize(con->v2.gcm_tfm) != CEPH_GCM_IV_LEN);
+ 	ret = crypto_aead_setauthsize(con->v2.gcm_tfm, CEPH_GCM_TAG_LEN);
+ 	if (ret) {
+ 		pr_err("failed to set gcm tag size: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	con->v2.gcm_req = aead_request_alloc(con->v2.gcm_tfm, GFP_NOIO);
+ 	if (!con->v2.gcm_req) {
+ 		pr_err("failed to allocate gcm request\n");
+ 		return -ENOMEM;
+ 	}
+ 
+ 	crypto_init_wait(&con->v2.gcm_wait);
+ 	aead_request_set_callback(con->v2.gcm_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ 				  crypto_req_done, &con->v2.gcm_wait);
+ 
+ 	memcpy(&con->v2.in_gcm_nonce, p, CEPH_GCM_IV_LEN);
+ 	memcpy(&con->v2.out_gcm_nonce, p + CEPH_GCM_IV_LEN, CEPH_GCM_IV_LEN);
+ 	return 0;  /* auth_x, secure mode */
+ }
+ 
+ static int hmac_sha256(struct ceph_connection *con, const struct kvec *kvecs,
+ 		       int kvec_cnt, u8 *hmac)
+ {
+ 	SHASH_DESC_ON_STACK(desc, con->v2.hmac_tfm);  /* tfm arg is ignored */
+ 	int ret;
+ 	int i;
+ 
+ 	dout("%s con %p hmac_tfm %p kvec_cnt %d\n", __func__, con,
+ 	     con->v2.hmac_tfm, kvec_cnt);
+ 
+ 	if (!con->v2.hmac_tfm) {
+ 		memset(hmac, 0, SHA256_DIGEST_SIZE);
+ 		return 0;  /* auth_none */
+ 	}
+ 
+ 	desc->tfm = con->v2.hmac_tfm;
+ 	ret = crypto_shash_init(desc);
+ 	if (ret)
+ 		return ret;
+ 
+ 	for (i = 0; i < kvec_cnt; i++) {
+ 		WARN_ON((unsigned long)kvecs[i].iov_base &
+ 			crypto_shash_alignmask(con->v2.hmac_tfm));
+ 		ret = crypto_shash_update(desc, kvecs[i].iov_base,
+ 					  kvecs[i].iov_len);
+ 		if (ret)
+ 			return ret;
+ 	}
+ 
+ 	ret = crypto_shash_final(desc, hmac);
+ 	if (ret)
+ 		return ret;
+ 
+ 	shash_desc_zero(desc);
+ 	return 0;  /* auth_x, both plain and secure modes */
+ }
+ 
+ static void gcm_inc_nonce(struct ceph_gcm_nonce *nonce)
+ {
+ 	u64 counter;
+ 
+ 	counter = le64_to_cpu(nonce->counter);
+ 	nonce->counter = cpu_to_le64(counter + 1);
+ }
+ 
+ static int gcm_crypt(struct ceph_connection *con, bool encrypt,
+ 		     struct scatterlist *src, struct scatterlist *dst,
+ 		     int src_len)
+ {
+ 	struct ceph_gcm_nonce *nonce;
+ 	int ret;
+ 
+ 	nonce = encrypt ? &con->v2.out_gcm_nonce : &con->v2.in_gcm_nonce;
+ 
+ 	aead_request_set_ad(con->v2.gcm_req, 0);  /* no AAD */
+ 	aead_request_set_crypt(con->v2.gcm_req, src, dst, src_len, (u8 *)nonce);
+ 	ret = crypto_wait_req(encrypt ? crypto_aead_encrypt(con->v2.gcm_req) :
+ 					crypto_aead_decrypt(con->v2.gcm_req),
+ 			      &con->v2.gcm_wait);
+ 	if (ret)
+ 		return ret;
+ 
+ 	gcm_inc_nonce(nonce);
+ 	return 0;
+ }
+ 
+ static void get_bvec_at(struct ceph_msg_data_cursor *cursor,
+ 			struct bio_vec *bv)
+ {
+ 	struct page *page;
+ 	size_t off, len;
+ 
+ 	WARN_ON(!cursor->total_resid);
+ 
+ 	/* skip zero-length data items */
+ 	while (!cursor->resid)
+ 		ceph_msg_data_advance(cursor, 0);
+ 
+ 	/* get a piece of data, cursor isn't advanced */
+ 	page = ceph_msg_data_next(cursor, &off, &len, NULL);
+ 
+ 	bv->bv_page = page;
+ 	bv->bv_offset = off;
+ 	bv->bv_len = len;
+ }
+ 
+ static int calc_sg_cnt(void *buf, int buf_len)
+ {
+ 	int sg_cnt;
+ 
+ 	if (!buf_len)
+ 		return 0;
+ 
+ 	sg_cnt = need_padding(buf_len) ? 1 : 0;
+ 	if (is_vmalloc_addr(buf)) {
+ 		WARN_ON(offset_in_page(buf));
+ 		sg_cnt += PAGE_ALIGN(buf_len) >> PAGE_SHIFT;
+ 	} else {
+ 		sg_cnt++;
+ 	}
+ 
+ 	return sg_cnt;
+ }
+ 
+ static int calc_sg_cnt_cursor(struct ceph_msg_data_cursor *cursor)
+ {
+ 	int data_len = cursor->total_resid;
+ 	struct bio_vec bv;
+ 	int sg_cnt;
+ 
+ 	if (!data_len)
+ 		return 0;
+ 
+ 	sg_cnt = need_padding(data_len) ? 1 : 0;
+ 	do {
+ 		get_bvec_at(cursor, &bv);
+ 		sg_cnt++;
+ 
+ 		ceph_msg_data_advance(cursor, bv.bv_len);
+ 	} while (cursor->total_resid);
+ 
+ 	return sg_cnt;
+ }
+ 
+ static void init_sgs(struct scatterlist **sg, void *buf, int buf_len, u8 *pad)
+ {
+ 	void *end = buf + buf_len;
+ 	struct page *page;
+ 	int len;
+ 	void *p;
+ 
+ 	if (!buf_len)
+ 		return;
+ 
+ 	if (is_vmalloc_addr(buf)) {
+ 		p = buf;
+ 		do {
+ 			page = vmalloc_to_page(p);
+ 			len = min_t(int, end - p, PAGE_SIZE);
+ 			WARN_ON(!page || !len || offset_in_page(p));
+ 			sg_set_page(*sg, page, len, 0);
+ 			*sg = sg_next(*sg);
+ 			p += len;
+ 		} while (p != end);
+ 	} else {
+ 		sg_set_buf(*sg, buf, buf_len);
+ 		*sg = sg_next(*sg);
+ 	}
+ 
+ 	if (need_padding(buf_len)) {
+ 		sg_set_buf(*sg, pad, padding_len(buf_len));
+ 		*sg = sg_next(*sg);
+ 	}
+ }
+ 
+ static void init_sgs_cursor(struct scatterlist **sg,
+ 			    struct ceph_msg_data_cursor *cursor, u8 *pad)
+ {
+ 	int data_len = cursor->total_resid;
+ 	struct bio_vec bv;
+ 
+ 	if (!data_len)
+ 		return;
+ 
+ 	do {
+ 		get_bvec_at(cursor, &bv);
+ 		sg_set_page(*sg, bv.bv_page, bv.bv_len, bv.bv_offset);
+ 		*sg = sg_next(*sg);
+ 
+ 		ceph_msg_data_advance(cursor, bv.bv_len);
+ 	} while (cursor->total_resid);
+ 
+ 	if (need_padding(data_len)) {
+ 		sg_set_buf(*sg, pad, padding_len(data_len));
+ 		*sg = sg_next(*sg);
+ 	}
+ }
+ 
+ static int setup_message_sgs(struct sg_table *sgt, struct ceph_msg *msg,
+ 			     u8 *front_pad, u8 *middle_pad, u8 *data_pad,
+ 			     void *epilogue, bool add_tag)
+ {
+ 	struct ceph_msg_data_cursor cursor;
+ 	struct scatterlist *cur_sg;
+ 	int sg_cnt;
+ 	int ret;
+ 
+ 	if (!front_len(msg) && !middle_len(msg) && !data_len(msg))
+ 		return 0;
+ 
+ 	sg_cnt = 1;  /* epilogue + [auth tag] */
+ 	if (front_len(msg))
+ 		sg_cnt += calc_sg_cnt(msg->front.iov_base,
+ 				      front_len(msg));
+ 	if (middle_len(msg))
+ 		sg_cnt += calc_sg_cnt(msg->middle->vec.iov_base,
+ 				      middle_len(msg));
+ 	if (data_len(msg)) {
+ 		ceph_msg_data_cursor_init(&cursor, msg, data_len(msg));
+ 		sg_cnt += calc_sg_cnt_cursor(&cursor);
+ 	}
+ 
+ 	ret = sg_alloc_table(sgt, sg_cnt, GFP_NOIO);
+ 	if (ret)
+ 		return ret;
+ 
+ 	cur_sg = sgt->sgl;
+ 	if (front_len(msg))
+ 		init_sgs(&cur_sg, msg->front.iov_base, front_len(msg),
+ 			 front_pad);
+ 	if (middle_len(msg))
+ 		init_sgs(&cur_sg, msg->middle->vec.iov_base, middle_len(msg),
+ 			 middle_pad);
+ 	if (data_len(msg)) {
+ 		ceph_msg_data_cursor_init(&cursor, msg, data_len(msg));
+ 		init_sgs_cursor(&cur_sg, &cursor, data_pad);
+ 	}
+ 
+ 	WARN_ON(!sg_is_last(cur_sg));
+ 	sg_set_buf(cur_sg, epilogue,
+ 		   CEPH_GCM_BLOCK_LEN + (add_tag ? CEPH_GCM_TAG_LEN : 0));
+ 	return 0;
+ }
+ 
+ static int decrypt_preamble(struct ceph_connection *con)
+ {
+ 	struct scatterlist sg;
+ 
+ 	sg_init_one(&sg, con->v2.in_buf, CEPH_PREAMBLE_SECURE_LEN);
+ 	return gcm_crypt(con, false, &sg, &sg, CEPH_PREAMBLE_SECURE_LEN);
+ }
+ 
+ static int decrypt_control_remainder(struct ceph_connection *con)
+ {
+ 	int ctrl_len = con->v2.in_desc.fd_lens[0];
+ 	int rem_len = ctrl_len - CEPH_PREAMBLE_INLINE_LEN;
+ 	int pt_len = padding_len(rem_len) + CEPH_GCM_TAG_LEN;
+ 	struct scatterlist sgs[2];
+ 
+ 	WARN_ON(con->v2.in_kvecs[0].iov_len != rem_len);
+ 	WARN_ON(con->v2.in_kvecs[1].iov_len != pt_len);
+ 
+ 	sg_init_table(sgs, 2);
+ 	sg_set_buf(&sgs[0], con->v2.in_kvecs[0].iov_base, rem_len);
+ 	sg_set_buf(&sgs[1], con->v2.in_buf, pt_len);
+ 
+ 	return gcm_crypt(con, false, sgs, sgs,
+ 			 padded_len(rem_len) + CEPH_GCM_TAG_LEN);
+ }
+ 
+ static int decrypt_message(struct ceph_connection *con)
+ {
+ 	struct sg_table sgt = {};
+ 	int ret;
+ 
+ 	ret = setup_message_sgs(&sgt, con->in_msg, FRONT_PAD(con->v2.in_buf),
+ 			MIDDLE_PAD(con->v2.in_buf), DATA_PAD(con->v2.in_buf),
+ 			con->v2.in_buf, true);
+ 	if (ret)
+ 		goto out;
+ 
+ 	ret = gcm_crypt(con, false, sgt.sgl, sgt.sgl,
+ 			tail_onwire_len(con->in_msg, true));
+ 
+ out:
+ 	sg_free_table(&sgt);
+ 	return ret;
+ }
+ 
+ static int prepare_banner(struct ceph_connection *con)
+ {
+ 	int buf_len = CEPH_BANNER_V2_LEN + 2 + 8 + 8;
+ 	void *buf, *p;
+ 
+ 	buf = alloc_conn_buf(con, buf_len);
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	p = buf;
+ 	ceph_encode_copy(&p, CEPH_BANNER_V2, CEPH_BANNER_V2_LEN);
+ 	ceph_encode_16(&p, sizeof(u64) + sizeof(u64));
+ 	ceph_encode_64(&p, CEPH_MSGR2_SUPPORTED_FEATURES);
+ 	ceph_encode_64(&p, CEPH_MSGR2_REQUIRED_FEATURES);
+ 	WARN_ON(p != buf + buf_len);
+ 
+ 	add_out_kvec(con, buf, buf_len);
+ 	add_out_sign_kvec(con, buf, buf_len);
+ 	ceph_con_flag_set(con, CEPH_CON_F_WRITE_PENDING);
+ 	return 0;
+ }
+ 
+ /*
+  * base:
+  *   preamble
+  *   control body (ctrl_len bytes)
+  *   space for control crc
+  *
+  * extdata (optional):
+  *   control body (extdata_len bytes)
+  *
+  * Compute control crc and gather base and extdata into:
+  *
+  *   preamble
+  *   control body (ctrl_len + extdata_len bytes)
+  *   control crc
+  *
+  * Preamble should already be encoded at the start of base.
+  */
+ static void prepare_head_plain(struct ceph_connection *con, void *base,
+ 			       int ctrl_len, void *extdata, int extdata_len,
+ 			       bool to_be_signed)
+ {
+ 	int base_len = CEPH_PREAMBLE_LEN + ctrl_len + CEPH_CRC_LEN;
+ 	void *crcp = base + base_len - CEPH_CRC_LEN;
+ 	u32 crc;
+ 
+ 	crc = crc32c(-1, CTRL_BODY(base), ctrl_len);
+ 	if (extdata_len)
+ 		crc = crc32c(crc, extdata, extdata_len);
+ 	put_unaligned_le32(crc, crcp);
+ 
+ 	if (!extdata_len) {
+ 		add_out_kvec(con, base, base_len);
+ 		if (to_be_signed)
+ 			add_out_sign_kvec(con, base, base_len);
+ 		return;
+ 	}
+ 
+ 	add_out_kvec(con, base, crcp - base);
+ 	add_out_kvec(con, extdata, extdata_len);
+ 	add_out_kvec(con, crcp, CEPH_CRC_LEN);
+ 	if (to_be_signed) {
+ 		add_out_sign_kvec(con, base, crcp - base);
+ 		add_out_sign_kvec(con, extdata, extdata_len);
+ 		add_out_sign_kvec(con, crcp, CEPH_CRC_LEN);
+ 	}
+ }
+ 
+ static int prepare_head_secure_small(struct ceph_connection *con,
+ 				     void *base, int ctrl_len)
+ {
+ 	struct scatterlist sg;
+ 	int ret;
+ 
+ 	/* inline buffer padding? */
+ 	if (ctrl_len < CEPH_PREAMBLE_INLINE_LEN)
+ 		memset(CTRL_BODY(base) + ctrl_len, 0,
+ 		       CEPH_PREAMBLE_INLINE_LEN - ctrl_len);
+ 
+ 	sg_init_one(&sg, base, CEPH_PREAMBLE_SECURE_LEN);
+ 	ret = gcm_crypt(con, true, &sg, &sg,
+ 			CEPH_PREAMBLE_SECURE_LEN - CEPH_GCM_TAG_LEN);
+ 	if (ret)
+ 		return ret;
+ 
+ 	add_out_kvec(con, base, CEPH_PREAMBLE_SECURE_LEN);
+ 	return 0;
+ }
+ 
+ /*
+  * base:
+  *   preamble
+  *   control body (ctrl_len bytes)
+  *   space for padding, if needed
+  *   space for control remainder auth tag
+  *   space for preamble auth tag
+  *
+  * Encrypt preamble and the inline portion, then encrypt the remainder
+  * and gather into:
+  *
+  *   preamble
+  *   control body (48 bytes)
+  *   preamble auth tag
+  *   control body (ctrl_len - 48 bytes)
+  *   zero padding, if needed
+  *   control remainder auth tag
+  *
+  * Preamble should already be encoded at the start of base.
+  */
+ static int prepare_head_secure_big(struct ceph_connection *con,
+ 				   void *base, int ctrl_len)
+ {
+ 	int rem_len = ctrl_len - CEPH_PREAMBLE_INLINE_LEN;
+ 	void *rem = CTRL_BODY(base) + CEPH_PREAMBLE_INLINE_LEN;
+ 	void *rem_tag = rem + padded_len(rem_len);
+ 	void *pmbl_tag = rem_tag + CEPH_GCM_TAG_LEN;
+ 	struct scatterlist sgs[2];
+ 	int ret;
+ 
+ 	sg_init_table(sgs, 2);
+ 	sg_set_buf(&sgs[0], base, rem - base);
+ 	sg_set_buf(&sgs[1], pmbl_tag, CEPH_GCM_TAG_LEN);
+ 	ret = gcm_crypt(con, true, sgs, sgs, rem - base);
+ 	if (ret)
+ 		return ret;
+ 
+ 	/* control remainder padding? */
+ 	if (need_padding(rem_len))
+ 		memset(rem + rem_len, 0, padding_len(rem_len));
+ 
+ 	sg_init_one(&sgs[0], rem, pmbl_tag - rem);
+ 	ret = gcm_crypt(con, true, sgs, sgs, rem_tag - rem);
+ 	if (ret)
+ 		return ret;
+ 
+ 	add_out_kvec(con, base, rem - base);
+ 	add_out_kvec(con, pmbl_tag, CEPH_GCM_TAG_LEN);
+ 	add_out_kvec(con, rem, pmbl_tag - rem);
+ 	return 0;
+ }
+ 
+ static int __prepare_control(struct ceph_connection *con, int tag,
+ 			     void *base, int ctrl_len, void *extdata,
+ 			     int extdata_len, bool to_be_signed)
+ {
+ 	int total_len = ctrl_len + extdata_len;
+ 	struct ceph_frame_desc desc;
+ 	int ret;
+ 
+ 	dout("%s con %p tag %d len %d (%d+%d)\n", __func__, con, tag,
+ 	     total_len, ctrl_len, extdata_len);
+ 
+ 	/* extdata may be vmalloc'ed but not base */
+ 	if (WARN_ON(is_vmalloc_addr(base) || !ctrl_len))
+ 		return -EINVAL;
+ 
+ 	init_frame_desc(&desc, tag, &total_len, 1);
+ 	encode_preamble(&desc, base);
+ 
+ 	if (con_secure(con)) {
+ 		if (WARN_ON(extdata_len || to_be_signed))
+ 			return -EINVAL;
+ 
+ 		if (ctrl_len <= CEPH_PREAMBLE_INLINE_LEN)
+ 			/* fully inlined, inline buffer may need padding */
+ 			ret = prepare_head_secure_small(con, base, ctrl_len);
+ 		else
+ 			/* partially inlined, inline buffer is full */
+ 			ret = prepare_head_secure_big(con, base, ctrl_len);
+ 		if (ret)
+ 			return ret;
+ 	} else {
+ 		prepare_head_plain(con, base, ctrl_len, extdata, extdata_len,
+ 				   to_be_signed);
+ 	}
+ 
+ 	ceph_con_flag_set(con, CEPH_CON_F_WRITE_PENDING);
+ 	return 0;
+ }
+ 
+ static int prepare_control(struct ceph_connection *con, int tag,
+ 			   void *base, int ctrl_len)
+ {
+ 	return __prepare_control(con, tag, base, ctrl_len, NULL, 0, false);
+ }
+ 
+ static int prepare_hello(struct ceph_connection *con)
+ {
+ 	void *buf, *p;
+ 	int ctrl_len;
+ 
+ 	ctrl_len = 1 + ceph_entity_addr_encoding_len(&con->peer_addr);
+ 	buf = alloc_conn_buf(con, head_onwire_len(ctrl_len, false));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	p = CTRL_BODY(buf);
+ 	ceph_encode_8(&p, CEPH_ENTITY_TYPE_CLIENT);
+ 	ceph_encode_entity_addr(&p, &con->peer_addr);
+ 	WARN_ON(p != CTRL_BODY(buf) + ctrl_len);
+ 
+ 	return __prepare_control(con, FRAME_TAG_HELLO, buf, ctrl_len,
+ 				 NULL, 0, true);
+ }
+ 
+ /* so that head_onwire_len(AUTH_BUF_LEN, false) is 512 */
+ #define AUTH_BUF_LEN	(512 - CEPH_CRC_LEN - CEPH_PREAMBLE_PLAIN_LEN)
+ 
+ static int prepare_auth_request(struct ceph_connection *con)
+ {
+ 	void *authorizer, *authorizer_copy;
+ 	int ctrl_len, authorizer_len;
+ 	void *buf;
+ 	int ret;
+ 
+ 	ctrl_len = AUTH_BUF_LEN;
+ 	buf = alloc_conn_buf(con, head_onwire_len(ctrl_len, false));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	mutex_unlock(&con->mutex);
+ 	ret = con->ops->get_auth_request(con, CTRL_BODY(buf), &ctrl_len,
+ 					 &authorizer, &authorizer_len);
+ 	mutex_lock(&con->mutex);
+ 	if (con->state != CEPH_CON_S_V2_HELLO) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	dout("%s con %p get_auth_request ret %d\n", __func__, con, ret);
+ 	if (ret)
+ 		return ret;
+ 
+ 	authorizer_copy = alloc_conn_buf(con, authorizer_len);
+ 	if (!authorizer_copy)
+ 		return -ENOMEM;
+ 
+ 	memcpy(authorizer_copy, authorizer, authorizer_len);
+ 
+ 	return __prepare_control(con, FRAME_TAG_AUTH_REQUEST, buf, ctrl_len,
+ 				 authorizer_copy, authorizer_len, true);
+ }
+ 
+ static int prepare_auth_request_more(struct ceph_connection *con,
+ 				     void *reply, int reply_len)
+ {
+ 	int ctrl_len, authorizer_len;
+ 	void *authorizer;
+ 	void *buf;
+ 	int ret;
+ 
+ 	ctrl_len = AUTH_BUF_LEN;
+ 	buf = alloc_conn_buf(con, head_onwire_len(ctrl_len, false));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	mutex_unlock(&con->mutex);
+ 	ret = con->ops->handle_auth_reply_more(con, reply, reply_len,
+ 					       CTRL_BODY(buf), &ctrl_len,
+ 					       &authorizer, &authorizer_len);
+ 	mutex_lock(&con->mutex);
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	dout("%s con %p handle_auth_reply_more ret %d\n", __func__, con, ret);
+ 	if (ret)
+ 		return ret;
+ 
+ 	return __prepare_control(con, FRAME_TAG_AUTH_REQUEST_MORE, buf,
+ 				 ctrl_len, authorizer, authorizer_len, true);
+ }
+ 
+ static int prepare_auth_signature(struct ceph_connection *con)
+ {
+ 	void *buf;
+ 	int ret;
+ 
+ 	buf = alloc_conn_buf(con, head_onwire_len(SHA256_DIGEST_SIZE, false));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	ret = hmac_sha256(con, con->v2.in_sign_kvecs, con->v2.in_sign_kvec_cnt,
+ 			  CTRL_BODY(buf));
+ 	if (ret)
+ 		return ret;
+ 
+ 	return prepare_control(con, FRAME_TAG_AUTH_SIGNATURE, buf,
+ 			       SHA256_DIGEST_SIZE);
+ }
+ 
+ static int prepare_client_ident(struct ceph_connection *con)
+ {
+ 	struct ceph_entity_addr *my_addr = &con->msgr->inst.addr;
+ 	struct ceph_client *client = from_msgr(con->msgr);
+ 	u64 global_id = ceph_client_gid(client);
+ 	void *buf, *p;
+ 	int ctrl_len;
+ 
+ 	WARN_ON(con->v2.server_cookie);
+ 	WARN_ON(con->v2.connect_seq);
+ 	WARN_ON(con->v2.peer_global_seq);
+ 
+ 	if (!con->v2.client_cookie) {
+ 		do {
+ 			get_random_bytes(&con->v2.client_cookie,
+ 					 sizeof(con->v2.client_cookie));
+ 		} while (!con->v2.client_cookie);
+ 		dout("%s con %p generated cookie 0x%llx\n", __func__, con,
+ 		     con->v2.client_cookie);
+ 	} else {
+ 		dout("%s con %p cookie already set 0x%llx\n", __func__, con,
+ 		     con->v2.client_cookie);
+ 	}
+ 
+ 	dout("%s con %p my_addr %s/%u peer_addr %s/%u global_id %llu global_seq %llu features 0x%llx required_features 0x%llx cookie 0x%llx\n",
+ 	     __func__, con, ceph_pr_addr(my_addr), le32_to_cpu(my_addr->nonce),
+ 	     ceph_pr_addr(&con->peer_addr), le32_to_cpu(con->peer_addr.nonce),
+ 	     global_id, con->v2.global_seq, client->supported_features,
+ 	     client->required_features, con->v2.client_cookie);
+ 
+ 	ctrl_len = 1 + 4 + ceph_entity_addr_encoding_len(my_addr) +
+ 		   ceph_entity_addr_encoding_len(&con->peer_addr) + 6 * 8;
+ 	buf = alloc_conn_buf(con, head_onwire_len(ctrl_len, con_secure(con)));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	p = CTRL_BODY(buf);
+ 	ceph_encode_8(&p, 2);  /* addrvec marker */
+ 	ceph_encode_32(&p, 1);  /* addr_cnt */
+ 	ceph_encode_entity_addr(&p, my_addr);
+ 	ceph_encode_entity_addr(&p, &con->peer_addr);
+ 	ceph_encode_64(&p, global_id);
+ 	ceph_encode_64(&p, con->v2.global_seq);
+ 	ceph_encode_64(&p, client->supported_features);
+ 	ceph_encode_64(&p, client->required_features);
+ 	ceph_encode_64(&p, 0);  /* flags */
+ 	ceph_encode_64(&p, con->v2.client_cookie);
+ 	WARN_ON(p != CTRL_BODY(buf) + ctrl_len);
+ 
+ 	return prepare_control(con, FRAME_TAG_CLIENT_IDENT, buf, ctrl_len);
+ }
+ 
+ static int prepare_session_reconnect(struct ceph_connection *con)
+ {
+ 	struct ceph_entity_addr *my_addr = &con->msgr->inst.addr;
+ 	void *buf, *p;
+ 	int ctrl_len;
+ 
+ 	WARN_ON(!con->v2.client_cookie);
+ 	WARN_ON(!con->v2.server_cookie);
+ 	WARN_ON(!con->v2.connect_seq);
+ 	WARN_ON(!con->v2.peer_global_seq);
+ 
+ 	dout("%s con %p my_addr %s/%u client_cookie 0x%llx server_cookie 0x%llx global_seq %llu connect_seq %llu in_seq %llu\n",
+ 	     __func__, con, ceph_pr_addr(my_addr), le32_to_cpu(my_addr->nonce),
+ 	     con->v2.client_cookie, con->v2.server_cookie, con->v2.global_seq,
+ 	     con->v2.connect_seq, con->in_seq);
+ 
+ 	ctrl_len = 1 + 4 + ceph_entity_addr_encoding_len(my_addr) + 5 * 8;
+ 	buf = alloc_conn_buf(con, head_onwire_len(ctrl_len, con_secure(con)));
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	p = CTRL_BODY(buf);
+ 	ceph_encode_8(&p, 2);  /* entity_addrvec_t marker */
+ 	ceph_encode_32(&p, 1);  /* my_addrs len */
+ 	ceph_encode_entity_addr(&p, my_addr);
+ 	ceph_encode_64(&p, con->v2.client_cookie);
+ 	ceph_encode_64(&p, con->v2.server_cookie);
+ 	ceph_encode_64(&p, con->v2.global_seq);
+ 	ceph_encode_64(&p, con->v2.connect_seq);
+ 	ceph_encode_64(&p, con->in_seq);
+ 	WARN_ON(p != CTRL_BODY(buf) + ctrl_len);
+ 
+ 	return prepare_control(con, FRAME_TAG_SESSION_RECONNECT, buf, ctrl_len);
+ }
+ 
+ static int prepare_keepalive2(struct ceph_connection *con)
+ {
+ 	struct ceph_timespec *ts = CTRL_BODY(con->v2.out_buf);
+ 	struct timespec64 now;
+ 
+ 	ktime_get_real_ts64(&now);
+ 	dout("%s con %p timestamp %lld.%09ld\n", __func__, con, now.tv_sec,
+ 	     now.tv_nsec);
+ 
+ 	ceph_encode_timespec64(ts, &now);
+ 
+ 	reset_out_kvecs(con);
+ 	return prepare_control(con, FRAME_TAG_KEEPALIVE2, con->v2.out_buf,
+ 			       sizeof(struct ceph_timespec));
+ }
+ 
+ static int prepare_ack(struct ceph_connection *con)
+ {
+ 	void *p;
+ 
+ 	dout("%s con %p in_seq_acked %llu -> %llu\n", __func__, con,
+ 	     con->in_seq_acked, con->in_seq);
+ 	con->in_seq_acked = con->in_seq;
+ 
+ 	p = CTRL_BODY(con->v2.out_buf);
+ 	ceph_encode_64(&p, con->in_seq_acked);
+ 
+ 	reset_out_kvecs(con);
+ 	return prepare_control(con, FRAME_TAG_ACK, con->v2.out_buf, 8);
+ }
+ 
+ static void prepare_epilogue_plain(struct ceph_connection *con, bool aborted)
+ {
+ 	dout("%s con %p msg %p aborted %d crcs %u %u %u\n", __func__, con,
+ 	     con->out_msg, aborted, con->v2.out_epil.front_crc,
+ 	     con->v2.out_epil.middle_crc, con->v2.out_epil.data_crc);
+ 
+ 	encode_epilogue_plain(con, aborted);
+ 	add_out_kvec(con, &con->v2.out_epil, CEPH_EPILOGUE_PLAIN_LEN);
+ }
+ 
+ /*
+  * For "used" empty segments, crc is -1.  For unused (trailing)
+  * segments, crc is 0.
+  */
+ static void prepare_message_plain(struct ceph_connection *con)
+ {
+ 	struct ceph_msg *msg = con->out_msg;
+ 
+ 	prepare_head_plain(con, con->v2.out_buf,
+ 			   sizeof(struct ceph_msg_header2), NULL, 0, false);
+ 
+ 	if (!front_len(msg) && !middle_len(msg)) {
+ 		if (!data_len(msg)) {
+ 			/*
+ 			 * Empty message: once the head is written,
+ 			 * we are done -- there is no epilogue.
+ 			 */
+ 			con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ 			return;
+ 		}
+ 
+ 		con->v2.out_epil.front_crc = -1;
+ 		con->v2.out_epil.middle_crc = -1;
+ 		con->v2.out_state = OUT_S_QUEUE_DATA;
+ 		return;
+ 	}
+ 
+ 	if (front_len(msg)) {
+ 		con->v2.out_epil.front_crc = crc32c(-1, msg->front.iov_base,
+ 						    front_len(msg));
+ 		add_out_kvec(con, msg->front.iov_base, front_len(msg));
+ 	} else {
+ 		/* middle (at least) is there, checked above */
+ 		con->v2.out_epil.front_crc = -1;
+ 	}
+ 
+ 	if (middle_len(msg)) {
+ 		con->v2.out_epil.middle_crc =
+ 			crc32c(-1, msg->middle->vec.iov_base, middle_len(msg));
+ 		add_out_kvec(con, msg->middle->vec.iov_base, middle_len(msg));
+ 	} else {
+ 		con->v2.out_epil.middle_crc = data_len(msg) ? -1 : 0;
+ 	}
+ 
+ 	if (data_len(msg)) {
+ 		con->v2.out_state = OUT_S_QUEUE_DATA;
+ 	} else {
+ 		con->v2.out_epil.data_crc = 0;
+ 		prepare_epilogue_plain(con, false);
+ 		con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ 	}
+ }
+ 
+ /*
+  * Unfortunately the kernel crypto API doesn't support streaming
+  * (piecewise) operation for AEAD algorithms, so we can't get away
+  * with a fixed size buffer and a couple sgs.  Instead, we have to
+  * allocate pages for the entire tail of the message (currently up
+  * to ~32M) and two sgs arrays (up to ~256K each)...
+  */
+ static int prepare_message_secure(struct ceph_connection *con)
+ {
+ 	void *zerop = page_address(ceph_zero_page);
+ 	struct sg_table enc_sgt = {};
+ 	struct sg_table sgt = {};
+ 	struct page **enc_pages;
+ 	int enc_page_cnt;
+ 	int tail_len;
+ 	int ret;
+ 
+ 	ret = prepare_head_secure_small(con, con->v2.out_buf,
+ 					sizeof(struct ceph_msg_header2));
+ 	if (ret)
+ 		return ret;
+ 
+ 	tail_len = tail_onwire_len(con->out_msg, true);
+ 	if (!tail_len) {
+ 		/*
+ 		 * Empty message: once the head is written,
+ 		 * we are done -- there is no epilogue.
+ 		 */
+ 		con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ 		return 0;
+ 	}
+ 
+ 	encode_epilogue_secure(con, false);
+ 	ret = setup_message_sgs(&sgt, con->out_msg, zerop, zerop, zerop,
+ 				&con->v2.out_epil, false);
+ 	if (ret)
+ 		goto out;
+ 
+ 	enc_page_cnt = calc_pages_for(0, tail_len);
+ 	enc_pages = ceph_alloc_page_vector(enc_page_cnt, GFP_NOIO);
+ 	if (IS_ERR(enc_pages)) {
+ 		ret = PTR_ERR(enc_pages);
+ 		goto out;
+ 	}
+ 
+ 	WARN_ON(con->v2.out_enc_pages || con->v2.out_enc_page_cnt);
+ 	con->v2.out_enc_pages = enc_pages;
+ 	con->v2.out_enc_page_cnt = enc_page_cnt;
+ 	con->v2.out_enc_resid = tail_len;
+ 	con->v2.out_enc_i = 0;
+ 
+ 	ret = sg_alloc_table_from_pages(&enc_sgt, enc_pages, enc_page_cnt,
+ 					0, tail_len, GFP_NOIO);
+ 	if (ret)
+ 		goto out;
+ 
+ 	ret = gcm_crypt(con, true, sgt.sgl, enc_sgt.sgl,
+ 			tail_len - CEPH_GCM_TAG_LEN);
+ 	if (ret)
+ 		goto out;
+ 
+ 	dout("%s con %p msg %p sg_cnt %d enc_page_cnt %d\n", __func__, con,
+ 	     con->out_msg, sgt.orig_nents, enc_page_cnt);
+ 	con->v2.out_state = OUT_S_QUEUE_ENC_PAGE;
+ 
+ out:
+ 	sg_free_table(&sgt);
+ 	sg_free_table(&enc_sgt);
+ 	return ret;
+ }
+ 
+ static int prepare_message(struct ceph_connection *con)
+ {
+ 	int lens[] = {
+ 		sizeof(struct ceph_msg_header2),
+ 		front_len(con->out_msg),
+ 		middle_len(con->out_msg),
+ 		data_len(con->out_msg)
+ 	};
+ 	struct ceph_frame_desc desc;
+ 	int ret;
+ 
+ 	dout("%s con %p msg %p logical %d+%d+%d+%d\n", __func__, con,
+ 	     con->out_msg, lens[0], lens[1], lens[2], lens[3]);
+ 
+ 	if (con->in_seq > con->in_seq_acked) {
+ 		dout("%s con %p in_seq_acked %llu -> %llu\n", __func__, con,
+ 		     con->in_seq_acked, con->in_seq);
+ 		con->in_seq_acked = con->in_seq;
+ 	}
+ 
+ 	reset_out_kvecs(con);
+ 	init_frame_desc(&desc, FRAME_TAG_MESSAGE, lens, 4);
+ 	encode_preamble(&desc, con->v2.out_buf);
+ 	fill_header2(CTRL_BODY(con->v2.out_buf), &con->out_msg->hdr,
+ 		     con->in_seq_acked);
+ 
+ 	if (con_secure(con)) {
+ 		ret = prepare_message_secure(con);
+ 		if (ret)
+ 			return ret;
+ 	} else {
+ 		prepare_message_plain(con);
+ 	}
+ 
+ 	ceph_con_flag_set(con, CEPH_CON_F_WRITE_PENDING);
+ 	return 0;
+ }
+ 
+ static int prepare_read_banner_prefix(struct ceph_connection *con)
+ {
+ 	void *buf;
+ 
+ 	buf = alloc_conn_buf(con, CEPH_BANNER_V2_PREFIX_LEN);
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	reset_in_kvecs(con);
+ 	add_in_kvec(con, buf, CEPH_BANNER_V2_PREFIX_LEN);
+ 	add_in_sign_kvec(con, buf, CEPH_BANNER_V2_PREFIX_LEN);
+ 	con->state = CEPH_CON_S_V2_BANNER_PREFIX;
+ 	return 0;
+ }
+ 
+ static int prepare_read_banner_payload(struct ceph_connection *con,
+ 				       int payload_len)
+ {
+ 	void *buf;
+ 
+ 	buf = alloc_conn_buf(con, payload_len);
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	reset_in_kvecs(con);
+ 	add_in_kvec(con, buf, payload_len);
+ 	add_in_sign_kvec(con, buf, payload_len);
+ 	con->state = CEPH_CON_S_V2_BANNER_PAYLOAD;
+ 	return 0;
+ }
+ 
+ static void prepare_read_preamble(struct ceph_connection *con)
+ {
+ 	reset_in_kvecs(con);
+ 	add_in_kvec(con, con->v2.in_buf,
+ 		    con_secure(con) ? CEPH_PREAMBLE_SECURE_LEN :
+ 				      CEPH_PREAMBLE_PLAIN_LEN);
+ 	con->v2.in_state = IN_S_HANDLE_PREAMBLE;
+ }
+ 
+ static int prepare_read_control(struct ceph_connection *con)
+ {
+ 	int ctrl_len = con->v2.in_desc.fd_lens[0];
+ 	int head_len;
+ 	void *buf;
+ 
+ 	reset_in_kvecs(con);
+ 	if (con->state == CEPH_CON_S_V2_HELLO ||
+ 	    con->state == CEPH_CON_S_V2_AUTH) {
+ 		head_len = head_onwire_len(ctrl_len, false);
+ 		buf = alloc_conn_buf(con, head_len);
+ 		if (!buf)
+ 			return -ENOMEM;
+ 
+ 		/* preserve preamble */
+ 		memcpy(buf, con->v2.in_buf, CEPH_PREAMBLE_LEN);
+ 
+ 		add_in_kvec(con, CTRL_BODY(buf), ctrl_len);
+ 		add_in_kvec(con, CTRL_BODY(buf) + ctrl_len, CEPH_CRC_LEN);
+ 		add_in_sign_kvec(con, buf, head_len);
+ 	} else {
+ 		if (ctrl_len > CEPH_PREAMBLE_INLINE_LEN) {
+ 			buf = alloc_conn_buf(con, ctrl_len);
+ 			if (!buf)
+ 				return -ENOMEM;
+ 
+ 			add_in_kvec(con, buf, ctrl_len);
+ 		} else {
+ 			add_in_kvec(con, CTRL_BODY(con->v2.in_buf), ctrl_len);
+ 		}
+ 		add_in_kvec(con, con->v2.in_buf, CEPH_CRC_LEN);
+ 	}
+ 	con->v2.in_state = IN_S_HANDLE_CONTROL;
+ 	return 0;
+ }
+ 
+ static int prepare_read_control_remainder(struct ceph_connection *con)
+ {
+ 	int ctrl_len = con->v2.in_desc.fd_lens[0];
+ 	int rem_len = ctrl_len - CEPH_PREAMBLE_INLINE_LEN;
+ 	void *buf;
+ 
+ 	buf = alloc_conn_buf(con, ctrl_len);
+ 	if (!buf)
+ 		return -ENOMEM;
+ 
+ 	memcpy(buf, CTRL_BODY(con->v2.in_buf), CEPH_PREAMBLE_INLINE_LEN);
+ 
+ 	reset_in_kvecs(con);
+ 	add_in_kvec(con, buf + CEPH_PREAMBLE_INLINE_LEN, rem_len);
+ 	add_in_kvec(con, con->v2.in_buf,
+ 		    padding_len(rem_len) + CEPH_GCM_TAG_LEN);
+ 	con->v2.in_state = IN_S_HANDLE_CONTROL_REMAINDER;
+ 	return 0;
+ }
+ 
+ static void prepare_read_data(struct ceph_connection *con)
+ {
+ 	struct bio_vec bv;
+ 
+ 	if (!con_secure(con))
+ 		con->in_data_crc = -1;
+ 	ceph_msg_data_cursor_init(&con->v2.in_cursor, con->in_msg,
+ 				  data_len(con->in_msg));
+ 
+ 	get_bvec_at(&con->v2.in_cursor, &bv);
+ 	set_in_bvec(con, &bv);
+ 	con->v2.in_state = IN_S_PREPARE_READ_DATA_CONT;
+ }
+ 
+ static void prepare_read_data_cont(struct ceph_connection *con)
+ {
+ 	struct bio_vec bv;
+ 
+ 	if (!con_secure(con))
+ 		con->in_data_crc = ceph_crc32c_page(con->in_data_crc,
+ 						    con->v2.in_bvec.bv_page,
+ 						    con->v2.in_bvec.bv_offset,
+ 						    con->v2.in_bvec.bv_len);
+ 
+ 	ceph_msg_data_advance(&con->v2.in_cursor, con->v2.in_bvec.bv_len);
+ 	if (con->v2.in_cursor.total_resid) {
+ 		get_bvec_at(&con->v2.in_cursor, &bv);
+ 		set_in_bvec(con, &bv);
+ 		WARN_ON(con->v2.in_state != IN_S_PREPARE_READ_DATA_CONT);
+ 		return;
+ 	}
+ 
+ 	/*
+ 	 * We've read all data.  Prepare to read data padding (if any)
+ 	 * and epilogue.
+ 	 */
+ 	reset_in_kvecs(con);
+ 	if (con_secure(con)) {
+ 		if (need_padding(data_len(con->in_msg)))
+ 			add_in_kvec(con, DATA_PAD(con->v2.in_buf),
+ 				    padding_len(data_len(con->in_msg)));
+ 		add_in_kvec(con, con->v2.in_buf, CEPH_EPILOGUE_SECURE_LEN);
+ 	} else {
+ 		add_in_kvec(con, con->v2.in_buf, CEPH_EPILOGUE_PLAIN_LEN);
+ 	}
+ 	con->v2.in_state = IN_S_HANDLE_EPILOGUE;
+ }
+ 
+ static void __finish_skip(struct ceph_connection *con)
+ {
+ 	con->in_seq++;
+ 	prepare_read_preamble(con);
+ }
+ 
+ static void prepare_skip_message(struct ceph_connection *con)
+ {
+ 	struct ceph_frame_desc *desc = &con->v2.in_desc;
+ 	int tail_len;
+ 
+ 	dout("%s con %p %d+%d+%d\n", __func__, con, desc->fd_lens[1],
+ 	     desc->fd_lens[2], desc->fd_lens[3]);
+ 
+ 	tail_len = __tail_onwire_len(desc->fd_lens[1], desc->fd_lens[2],
+ 				     desc->fd_lens[3], con_secure(con));
+ 	if (!tail_len) {
+ 		__finish_skip(con);
+ 	} else {
+ 		set_in_skip(con, tail_len);
+ 		con->v2.in_state = IN_S_FINISH_SKIP;
+ 	}
+ }
+ 
+ static int process_banner_prefix(struct ceph_connection *con)
+ {
+ 	int payload_len;
+ 	void *p;
+ 
+ 	WARN_ON(con->v2.in_kvecs[0].iov_len != CEPH_BANNER_V2_PREFIX_LEN);
+ 
+ 	p = con->v2.in_kvecs[0].iov_base;
+ 	if (memcmp(p, CEPH_BANNER_V2, CEPH_BANNER_V2_LEN)) {
+ 		if (!memcmp(p, CEPH_BANNER, CEPH_BANNER_LEN))
+ 			con->error_msg = "server is speaking msgr1 protocol";
+ 		else
+ 			con->error_msg = "protocol error, bad banner";
+ 		return -EINVAL;
+ 	}
+ 
+ 	p += CEPH_BANNER_V2_LEN;
+ 	payload_len = ceph_decode_16(&p);
+ 	dout("%s con %p payload_len %d\n", __func__, con, payload_len);
+ 
+ 	return prepare_read_banner_payload(con, payload_len);
+ }
+ 
+ static int process_banner_payload(struct ceph_connection *con)
+ {
+ 	void *end = con->v2.in_kvecs[0].iov_base + con->v2.in_kvecs[0].iov_len;
+ 	u64 feat = CEPH_MSGR2_SUPPORTED_FEATURES;
+ 	u64 req_feat = CEPH_MSGR2_REQUIRED_FEATURES;
+ 	u64 server_feat, server_req_feat;
+ 	void *p;
+ 	int ret;
+ 
+ 	p = con->v2.in_kvecs[0].iov_base;
+ 	ceph_decode_64_safe(&p, end, server_feat, bad);
+ 	ceph_decode_64_safe(&p, end, server_req_feat, bad);
+ 
+ 	dout("%s con %p server_feat 0x%llx server_req_feat 0x%llx\n",
+ 	     __func__, con, server_feat, server_req_feat);
+ 
+ 	if (req_feat & ~server_feat) {
+ 		pr_err("msgr2 feature set mismatch: my required > server's supported 0x%llx, need 0x%llx\n",
+ 		       server_feat, req_feat & ~server_feat);
+ 		con->error_msg = "missing required protocol features";
+ 		return -EINVAL;
+ 	}
+ 	if (server_req_feat & ~feat) {
+ 		pr_err("msgr2 feature set mismatch: server's required > my supported 0x%llx, missing 0x%llx\n",
+ 		       feat, server_req_feat & ~feat);
+ 		con->error_msg = "missing required protocol features";
+ 		return -EINVAL;
+ 	}
+ 
+ 	/* no reset_out_kvecs() as our banner may still be pending */
+ 	ret = prepare_hello(con);
+ 	if (ret) {
+ 		pr_err("prepare_hello failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	con->state = CEPH_CON_S_V2_HELLO;
+ 	prepare_read_preamble(con);
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode banner payload\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_hello(struct ceph_connection *con, void *p, void *end)
+ {
+ 	struct ceph_entity_addr *my_addr = &con->msgr->inst.addr;
+ 	struct ceph_entity_addr addr_for_me;
+ 	u8 entity_type;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_HELLO) {
+ 		con->error_msg = "protocol error, unexpected hello";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_8_safe(&p, end, entity_type, bad);
+ 	ret = ceph_decode_entity_addr(&p, end, &addr_for_me);
+ 	if (ret) {
+ 		pr_err("failed to decode addr_for_me: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	dout("%s con %p entity_type %d addr_for_me %s\n", __func__, con,
+ 	     entity_type, ceph_pr_addr(&addr_for_me));
+ 
+ 	if (entity_type != con->peer_name.type) {
+ 		pr_err("bad peer type, want %d, got %d\n",
+ 		       con->peer_name.type, entity_type);
+ 		con->error_msg = "wrong peer at address";
+ 		return -EINVAL;
+ 	}
+ 
+ 	/*
+ 	 * Set our address to the address our first peer (i.e. monitor)
+ 	 * sees that we are connecting from.  If we are behind some sort
+ 	 * of NAT and want to be identified by some private (not NATed)
+ 	 * address, ip option should be used.
+ 	 */
+ 	if (ceph_addr_is_blank(my_addr)) {
+ 		memcpy(&my_addr->in_addr, &addr_for_me.in_addr,
+ 		       sizeof(my_addr->in_addr));
+ 		ceph_addr_set_port(my_addr, 0);
+ 		dout("%s con %p set my addr %s, as seen by peer %s\n",
+ 		     __func__, con, ceph_pr_addr(my_addr),
+ 		     ceph_pr_addr(&con->peer_addr));
+ 	} else {
+ 		dout("%s con %p my addr already set %s\n",
+ 		     __func__, con, ceph_pr_addr(my_addr));
+ 	}
+ 
+ 	WARN_ON(ceph_addr_is_blank(my_addr) || ceph_addr_port(my_addr));
+ 	WARN_ON(my_addr->type != CEPH_ENTITY_ADDR_TYPE_ANY);
+ 	WARN_ON(!my_addr->nonce);
+ 
+ 	/* no reset_out_kvecs() as our hello may still be pending */
+ 	ret = prepare_auth_request(con);
+ 	if (ret) {
+ 		if (ret != -EAGAIN)
+ 			pr_err("prepare_auth_request failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	con->state = CEPH_CON_S_V2_AUTH;
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode hello\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_auth_bad_method(struct ceph_connection *con,
+ 				   void *p, void *end)
+ {
+ 	int allowed_protos[8], allowed_modes[8];
+ 	int allowed_proto_cnt, allowed_mode_cnt;
+ 	int used_proto, result;
+ 	int ret;
+ 	int i;
+ 
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		con->error_msg = "protocol error, unexpected auth_bad_method";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_32_safe(&p, end, used_proto, bad);
+ 	ceph_decode_32_safe(&p, end, result, bad);
+ 	dout("%s con %p used_proto %d result %d\n", __func__, con, used_proto,
+ 	     result);
+ 
+ 	ceph_decode_32_safe(&p, end, allowed_proto_cnt, bad);
+ 	if (allowed_proto_cnt > ARRAY_SIZE(allowed_protos)) {
+ 		pr_err("allowed_protos too big %d\n", allowed_proto_cnt);
+ 		return -EINVAL;
+ 	}
+ 	for (i = 0; i < allowed_proto_cnt; i++) {
+ 		ceph_decode_32_safe(&p, end, allowed_protos[i], bad);
+ 		dout("%s con %p allowed_protos[%d] %d\n", __func__, con,
+ 		     i, allowed_protos[i]);
+ 	}
+ 
+ 	ceph_decode_32_safe(&p, end, allowed_mode_cnt, bad);
+ 	if (allowed_mode_cnt > ARRAY_SIZE(allowed_modes)) {
+ 		pr_err("allowed_modes too big %d\n", allowed_mode_cnt);
+ 		return -EINVAL;
+ 	}
+ 	for (i = 0; i < allowed_mode_cnt; i++) {
+ 		ceph_decode_32_safe(&p, end, allowed_modes[i], bad);
+ 		dout("%s con %p allowed_modes[%d] %d\n", __func__, con,
+ 		     i, allowed_modes[i]);
+ 	}
+ 
+ 	mutex_unlock(&con->mutex);
+ 	ret = con->ops->handle_auth_bad_method(con, used_proto, result,
+ 					       allowed_protos,
+ 					       allowed_proto_cnt,
+ 					       allowed_modes,
+ 					       allowed_mode_cnt);
+ 	mutex_lock(&con->mutex);
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	dout("%s con %p handle_auth_bad_method ret %d\n", __func__, con, ret);
+ 	return ret;
+ 
+ bad:
+ 	pr_err("failed to decode auth_bad_method\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_auth_reply_more(struct ceph_connection *con,
+ 				   void *p, void *end)
+ {
+ 	int payload_len;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		con->error_msg = "protocol error, unexpected auth_reply_more";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_32_safe(&p, end, payload_len, bad);
+ 	ceph_decode_need(&p, end, payload_len, bad);
+ 
+ 	dout("%s con %p payload_len %d\n", __func__, con, payload_len);
+ 
+ 	reset_out_kvecs(con);
+ 	ret = prepare_auth_request_more(con, p, payload_len);
+ 	if (ret) {
+ 		if (ret != -EAGAIN)
+ 			pr_err("prepare_auth_request_more failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode auth_reply_more\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_auth_done(struct ceph_connection *con, void *p, void *end)
+ {
+ 	u8 session_key[CEPH_KEY_LEN];
+ 	u8 con_secret[CEPH_MAX_CON_SECRET_LEN];
+ 	int session_key_len, con_secret_len;
+ 	int payload_len;
+ 	u64 global_id;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		con->error_msg = "protocol error, unexpected auth_done";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, global_id, bad);
+ 	ceph_decode_32_safe(&p, end, con->v2.con_mode, bad);
+ 	ceph_decode_32_safe(&p, end, payload_len, bad);
+ 
+ 	dout("%s con %p global_id %llu con_mode %d payload_len %d\n",
+ 	     __func__, con, global_id, con->v2.con_mode, payload_len);
+ 
+ 	mutex_unlock(&con->mutex);
+ 	session_key_len = 0;
+ 	con_secret_len = 0;
+ 	ret = con->ops->handle_auth_done(con, global_id, p, payload_len,
+ 					 session_key, &session_key_len,
+ 					 con_secret, &con_secret_len);
+ 	mutex_lock(&con->mutex);
+ 	if (con->state != CEPH_CON_S_V2_AUTH) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	dout("%s con %p handle_auth_done ret %d\n", __func__, con, ret);
+ 	if (ret)
+ 		return ret;
+ 
+ 	ret = setup_crypto(con, session_key, session_key_len, con_secret,
+ 			   con_secret_len);
+ 	if (ret)
+ 		return ret;
+ 
+ 	reset_out_kvecs(con);
+ 	ret = prepare_auth_signature(con);
+ 	if (ret) {
+ 		pr_err("prepare_auth_signature failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	con->state = CEPH_CON_S_V2_AUTH_SIGNATURE;
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode auth_done\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_auth_signature(struct ceph_connection *con,
+ 				  void *p, void *end)
+ {
+ 	u8 hmac[SHA256_DIGEST_SIZE];
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_AUTH_SIGNATURE) {
+ 		con->error_msg = "protocol error, unexpected auth_signature";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ret = hmac_sha256(con, con->v2.out_sign_kvecs,
+ 			  con->v2.out_sign_kvec_cnt, hmac);
+ 	if (ret)
+ 		return ret;
+ 
+ 	ceph_decode_need(&p, end, SHA256_DIGEST_SIZE, bad);
+ 	if (crypto_memneq(p, hmac, SHA256_DIGEST_SIZE)) {
+ 		con->error_msg = "integrity error, bad auth signature";
+ 		return -EBADMSG;
+ 	}
+ 
+ 	dout("%s con %p auth signature ok\n", __func__, con);
+ 
+ 	/* no reset_out_kvecs() as our auth_signature may still be pending */
+ 	if (!con->v2.server_cookie) {
+ 		ret = prepare_client_ident(con);
+ 		if (ret) {
+ 			pr_err("prepare_client_ident failed: %d\n", ret);
+ 			return ret;
+ 		}
+ 
+ 		con->state = CEPH_CON_S_V2_SESSION_CONNECT;
+ 	} else {
+ 		ret = prepare_session_reconnect(con);
+ 		if (ret) {
+ 			pr_err("prepare_session_reconnect failed: %d\n", ret);
+ 			return ret;
+ 		}
+ 
+ 		con->state = CEPH_CON_S_V2_SESSION_RECONNECT;
+ 	}
+ 
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode auth_signature\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_server_ident(struct ceph_connection *con,
+ 				void *p, void *end)
+ {
+ 	struct ceph_client *client = from_msgr(con->msgr);
+ 	u64 features, required_features;
+ 	struct ceph_entity_addr addr;
+ 	u64 global_seq;
+ 	u64 global_id;
+ 	u64 cookie;
+ 	u64 flags;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_CONNECT) {
+ 		con->error_msg = "protocol error, unexpected server_ident";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ret = ceph_decode_entity_addrvec(&p, end, true, &addr);
+ 	if (ret) {
+ 		pr_err("failed to decode server addrs: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, global_id, bad);
+ 	ceph_decode_64_safe(&p, end, global_seq, bad);
+ 	ceph_decode_64_safe(&p, end, features, bad);
+ 	ceph_decode_64_safe(&p, end, required_features, bad);
+ 	ceph_decode_64_safe(&p, end, flags, bad);
+ 	ceph_decode_64_safe(&p, end, cookie, bad);
+ 
+ 	dout("%s con %p addr %s/%u global_id %llu global_seq %llu features 0x%llx required_features 0x%llx flags 0x%llx cookie 0x%llx\n",
+ 	     __func__, con, ceph_pr_addr(&addr), le32_to_cpu(addr.nonce),
+ 	     global_id, global_seq, features, required_features, flags, cookie);
+ 
+ 	/* is this who we intended to talk to? */
+ 	if (memcmp(&addr, &con->peer_addr, sizeof(con->peer_addr))) {
+ 		pr_err("bad peer addr/nonce, want %s/%u, got %s/%u\n",
+ 		       ceph_pr_addr(&con->peer_addr),
+ 		       le32_to_cpu(con->peer_addr.nonce),
+ 		       ceph_pr_addr(&addr), le32_to_cpu(addr.nonce));
+ 		con->error_msg = "wrong peer at address";
+ 		return -EINVAL;
+ 	}
+ 
+ 	if (client->required_features & ~features) {
+ 		pr_err("RADOS feature set mismatch: my required > server's supported 0x%llx, need 0x%llx\n",
+ 		       features, client->required_features & ~features);
+ 		con->error_msg = "missing required protocol features";
+ 		return -EINVAL;
+ 	}
+ 
+ 	/*
+ 	 * Both name->type and name->num are set in ceph_con_open() but
+ 	 * name->num may be bogus in the initial monmap.  name->type is
+ 	 * verified in handle_hello().
+ 	 */
+ 	WARN_ON(!con->peer_name.type);
+ 	con->peer_name.num = cpu_to_le64(global_id);
+ 	con->v2.peer_global_seq = global_seq;
+ 	con->peer_features = features;
+ 	WARN_ON(required_features & ~client->supported_features);
+ 	con->v2.server_cookie = cookie;
+ 
+ 	if (flags & CEPH_MSG_CONNECT_LOSSY) {
+ 		ceph_con_flag_set(con, CEPH_CON_F_LOSSYTX);
+ 		WARN_ON(con->v2.server_cookie);
+ 	} else {
+ 		WARN_ON(!con->v2.server_cookie);
+ 	}
+ 
+ 	clear_in_sign_kvecs(con);
+ 	clear_out_sign_kvecs(con);
+ 	free_conn_bufs(con);
+ 	con->delay = 0;  /* reset backoff memory */
+ 
+ 	con->state = CEPH_CON_S_OPEN;
+ 	con->v2.out_state = OUT_S_GET_NEXT;
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode server_ident\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_ident_missing_features(struct ceph_connection *con,
+ 					  void *p, void *end)
+ {
+ 	struct ceph_client *client = from_msgr(con->msgr);
+ 	u64 missing_features;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_CONNECT) {
+ 		con->error_msg = "protocol error, unexpected ident_missing_features";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, missing_features, bad);
+ 	pr_err("RADOS feature set mismatch: server's required > my supported 0x%llx, missing 0x%llx\n",
+ 	       client->supported_features, missing_features);
+ 	con->error_msg = "missing required protocol features";
+ 	return -EINVAL;
+ 
+ bad:
+ 	pr_err("failed to decode ident_missing_features\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_session_reconnect_ok(struct ceph_connection *con,
+ 					void *p, void *end)
+ {
+ 	u64 seq;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_RECONNECT) {
+ 		con->error_msg = "protocol error, unexpected session_reconnect_ok";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, seq, bad);
+ 
+ 	dout("%s con %p seq %llu\n", __func__, con, seq);
+ 	ceph_con_discard_requeued(con, seq);
+ 
+ 	clear_in_sign_kvecs(con);
+ 	clear_out_sign_kvecs(con);
+ 	free_conn_bufs(con);
+ 	con->delay = 0;  /* reset backoff memory */
+ 
+ 	con->state = CEPH_CON_S_OPEN;
+ 	con->v2.out_state = OUT_S_GET_NEXT;
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode session_reconnect_ok\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_session_retry(struct ceph_connection *con,
+ 				 void *p, void *end)
+ {
+ 	u64 connect_seq;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_RECONNECT) {
+ 		con->error_msg = "protocol error, unexpected session_retry";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, connect_seq, bad);
+ 
+ 	dout("%s con %p connect_seq %llu\n", __func__, con, connect_seq);
+ 	WARN_ON(connect_seq <= con->v2.connect_seq);
+ 	con->v2.connect_seq = connect_seq + 1;
+ 
+ 	free_conn_bufs(con);
+ 
+ 	reset_out_kvecs(con);
+ 	ret = prepare_session_reconnect(con);
+ 	if (ret) {
+ 		pr_err("prepare_session_reconnect (cseq) failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode session_retry\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_session_retry_global(struct ceph_connection *con,
+ 					void *p, void *end)
+ {
+ 	u64 global_seq;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_RECONNECT) {
+ 		con->error_msg = "protocol error, unexpected session_retry_global";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, global_seq, bad);
+ 
+ 	dout("%s con %p global_seq %llu\n", __func__, con, global_seq);
+ 	WARN_ON(global_seq <= con->v2.global_seq);
+ 	con->v2.global_seq = ceph_get_global_seq(con->msgr, global_seq);
+ 
+ 	free_conn_bufs(con);
+ 
+ 	reset_out_kvecs(con);
+ 	ret = prepare_session_reconnect(con);
+ 	if (ret) {
+ 		pr_err("prepare_session_reconnect (gseq) failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode session_retry_global\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_session_reset(struct ceph_connection *con,
+ 				 void *p, void *end)
+ {
+ 	bool full;
+ 	int ret;
+ 
+ 	if (con->state != CEPH_CON_S_V2_SESSION_RECONNECT) {
+ 		con->error_msg = "protocol error, unexpected session_reset";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_8_safe(&p, end, full, bad);
+ 	if (!full) {
+ 		con->error_msg = "protocol error, bad session_reset";
+ 		return -EINVAL;
+ 	}
+ 
+ 	pr_info("%s%lld %s session reset\n", ENTITY_NAME(con->peer_name),
+ 		ceph_pr_addr(&con->peer_addr));
+ 	ceph_con_reset_session(con);
+ 
+ 	mutex_unlock(&con->mutex);
+ 	if (con->ops->peer_reset)
+ 		con->ops->peer_reset(con);
+ 	mutex_lock(&con->mutex);
+ 	if (con->state != CEPH_CON_S_V2_SESSION_RECONNECT) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	free_conn_bufs(con);
+ 
+ 	reset_out_kvecs(con);
+ 	ret = prepare_client_ident(con);
+ 	if (ret) {
+ 		pr_err("prepare_client_ident (rst) failed: %d\n", ret);
+ 		return ret;
+ 	}
+ 
+ 	con->state = CEPH_CON_S_V2_SESSION_CONNECT;
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode session_reset\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_keepalive2_ack(struct ceph_connection *con,
+ 				  void *p, void *end)
+ {
+ 	if (con->state != CEPH_CON_S_OPEN) {
+ 		con->error_msg = "protocol error, unexpected keepalive2_ack";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_need(&p, end, sizeof(struct ceph_timespec), bad);
+ 	ceph_decode_timespec64(&con->last_keepalive_ack, p);
+ 
+ 	dout("%s con %p timestamp %lld.%09ld\n", __func__, con,
+ 	     con->last_keepalive_ack.tv_sec, con->last_keepalive_ack.tv_nsec);
+ 
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode keepalive2_ack\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_ack(struct ceph_connection *con, void *p, void *end)
+ {
+ 	u64 seq;
+ 
+ 	if (con->state != CEPH_CON_S_OPEN) {
+ 		con->error_msg = "protocol error, unexpected ack";
+ 		return -EINVAL;
+ 	}
+ 
+ 	ceph_decode_64_safe(&p, end, seq, bad);
+ 
+ 	dout("%s con %p seq %llu\n", __func__, con, seq);
+ 	ceph_con_discard_sent(con, seq);
+ 	return 0;
+ 
+ bad:
+ 	pr_err("failed to decode ack\n");
+ 	return -EINVAL;
+ }
+ 
+ static int process_control(struct ceph_connection *con, void *p, void *end)
+ {
+ 	int tag = con->v2.in_desc.fd_tag;
+ 	int ret;
+ 
+ 	dout("%s con %p tag %d len %d\n", __func__, con, tag, (int)(end - p));
+ 
+ 	switch (tag) {
+ 	case FRAME_TAG_HELLO:
+ 		ret = process_hello(con, p, end);
+ 		break;
+ 	case FRAME_TAG_AUTH_BAD_METHOD:
+ 		ret = process_auth_bad_method(con, p, end);
+ 		break;
+ 	case FRAME_TAG_AUTH_REPLY_MORE:
+ 		ret = process_auth_reply_more(con, p, end);
+ 		break;
+ 	case FRAME_TAG_AUTH_DONE:
+ 		ret = process_auth_done(con, p, end);
+ 		break;
+ 	case FRAME_TAG_AUTH_SIGNATURE:
+ 		ret = process_auth_signature(con, p, end);
+ 		break;
+ 	case FRAME_TAG_SERVER_IDENT:
+ 		ret = process_server_ident(con, p, end);
+ 		break;
+ 	case FRAME_TAG_IDENT_MISSING_FEATURES:
+ 		ret = process_ident_missing_features(con, p, end);
+ 		break;
+ 	case FRAME_TAG_SESSION_RECONNECT_OK:
+ 		ret = process_session_reconnect_ok(con, p, end);
+ 		break;
+ 	case FRAME_TAG_SESSION_RETRY:
+ 		ret = process_session_retry(con, p, end);
+ 		break;
+ 	case FRAME_TAG_SESSION_RETRY_GLOBAL:
+ 		ret = process_session_retry_global(con, p, end);
+ 		break;
+ 	case FRAME_TAG_SESSION_RESET:
+ 		ret = process_session_reset(con, p, end);
+ 		break;
+ 	case FRAME_TAG_KEEPALIVE2_ACK:
+ 		ret = process_keepalive2_ack(con, p, end);
+ 		break;
+ 	case FRAME_TAG_ACK:
+ 		ret = process_ack(con, p, end);
+ 		break;
+ 	default:
+ 		pr_err("bad tag %d\n", tag);
+ 		con->error_msg = "protocol error, bad tag";
+ 		return -EINVAL;
+ 	}
+ 	if (ret) {
+ 		dout("%s con %p error %d\n", __func__, con, ret);
+ 		return ret;
+ 	}
+ 
+ 	prepare_read_preamble(con);
+ 	return 0;
+ }
+ 
+ /*
+  * Return:
+  *   1 - con->in_msg set, read message
+  *   0 - skip message
+  *  <0 - error
+  */
+ static int process_message_header(struct ceph_connection *con,
+ 				  void *p, void *end)
+ {
+ 	struct ceph_frame_desc *desc = &con->v2.in_desc;
+ 	struct ceph_msg_header2 *hdr2 = p;
+ 	struct ceph_msg_header hdr;
+ 	int skip;
+ 	int ret;
+ 	u64 seq;
+ 
+ 	/* verify seq# */
+ 	seq = le64_to_cpu(hdr2->seq);
+ 	if ((s64)seq - (s64)con->in_seq < 1) {
+ 		pr_info("%s%lld %s skipping old message: seq %llu, expected %llu\n",
+ 			ENTITY_NAME(con->peer_name),
+ 			ceph_pr_addr(&con->peer_addr),
+ 			seq, con->in_seq + 1);
+ 		return 0;
+ 	}
+ 	if ((s64)seq - (s64)con->in_seq > 1) {
+ 		pr_err("bad seq %llu, expected %llu\n", seq, con->in_seq + 1);
+ 		con->error_msg = "bad message sequence # for incoming message";
+ 		return -EBADE;
+ 	}
+ 
+ 	ceph_con_discard_sent(con, le64_to_cpu(hdr2->ack_seq));
+ 
+ 	fill_header(&hdr, hdr2, desc->fd_lens[1], desc->fd_lens[2],
+ 		    desc->fd_lens[3], &con->peer_name);
+ 	ret = ceph_con_in_msg_alloc(con, &hdr, &skip);
+ 	if (ret)
+ 		return ret;
+ 
+ 	WARN_ON(!con->in_msg ^ skip);
+ 	if (skip)
+ 		return 0;
+ 
+ 	WARN_ON(!con->in_msg);
+ 	WARN_ON(con->in_msg->con != con);
+ 	return 1;
+ }
+ 
+ static int process_message(struct ceph_connection *con)
+ {
+ 	ceph_con_process_message(con);
+ 
+ 	/*
+ 	 * We could have been closed by ceph_con_close() because
+ 	 * ceph_con_process_message() temporarily drops con->mutex.
+ 	 */
+ 	if (con->state != CEPH_CON_S_OPEN) {
+ 		dout("%s con %p state changed to %d\n", __func__, con,
+ 		     con->state);
+ 		return -EAGAIN;
+ 	}
+ 
+ 	prepare_read_preamble(con);
+ 	return 0;
+ }
+ 
+ static int __handle_control(struct ceph_connection *con, void *p)
+ {
+ 	void *end = p + con->v2.in_desc.fd_lens[0];
+ 	struct ceph_msg *msg;
+ 	int ret;
+ 
+ 	if (con->v2.in_desc.fd_tag != FRAME_TAG_MESSAGE)
+ 		return process_control(con, p, end);
+ 
+ 	ret = process_message_header(con, p, end);
+ 	if (ret < 0)
+ 		return ret;
+ 	if (ret == 0) {
+ 		prepare_skip_message(con);
+ 		return 0;
+ 	}
+ 
+ 	msg = con->in_msg;  /* set in process_message_header() */
+ 	if (!front_len(msg) && !middle_len(msg)) {
+ 		if (!data_len(msg))
+ 			return process_message(con);
+ 
+ 		prepare_read_data(con);
+ 		return 0;
+ 	}
+ 
+ 	reset_in_kvecs(con);
+ 	if (front_len(msg)) {
+ 		WARN_ON(front_len(msg) > msg->front_alloc_len);
+ 		add_in_kvec(con, msg->front.iov_base, front_len(msg));
+ 		msg->front.iov_len = front_len(msg);
+ 
+ 		if (con_secure(con) && need_padding(front_len(msg)))
+ 			add_in_kvec(con, FRONT_PAD(con->v2.in_buf),
+ 				    padding_len(front_len(msg)));
+ 	} else {
+ 		msg->front.iov_len = 0;
+ 	}
+ 	if (middle_len(msg)) {
+ 		WARN_ON(middle_len(msg) > msg->middle->alloc_len);
+ 		add_in_kvec(con, msg->middle->vec.iov_base, middle_len(msg));
+ 		msg->middle->vec.iov_len = middle_len(msg);
+ 
+ 		if (con_secure(con) && need_padding(middle_len(msg)))
+ 			add_in_kvec(con, MIDDLE_PAD(con->v2.in_buf),
+ 				    padding_len(middle_len(msg)));
+ 	} else if (msg->middle) {
+ 		msg->middle->vec.iov_len = 0;
+ 	}
+ 
+ 	if (data_len(msg)) {
+ 		con->v2.in_state = IN_S_PREPARE_READ_DATA;
+ 	} else {
+ 		add_in_kvec(con, con->v2.in_buf,
+ 			    con_secure(con) ? CEPH_EPILOGUE_SECURE_LEN :
+ 					      CEPH_EPILOGUE_PLAIN_LEN);
+ 		con->v2.in_state = IN_S_HANDLE_EPILOGUE;
+ 	}
+ 	return 0;
+ }
+ 
+ static int handle_preamble(struct ceph_connection *con)
+ {
+ 	struct ceph_frame_desc *desc = &con->v2.in_desc;
+ 	int ret;
+ 
+ 	if (con_secure(con)) {
+ 		ret = decrypt_preamble(con);
+ 		if (ret) {
+ 			if (ret == -EBADMSG)
+ 				con->error_msg = "integrity error, bad preamble auth tag";
+ 			return ret;
+ 		}
+ 	}
+ 
+ 	ret = decode_preamble(con->v2.in_buf, desc);
+ 	if (ret) {
+ 		if (ret == -EBADMSG)
+ 			con->error_msg = "integrity error, bad crc";
+ 		else
+ 			con->error_msg = "protocol error, bad preamble";
+ 		return ret;
+ 	}
+ 
+ 	dout("%s con %p tag %d seg_cnt %d %d+%d+%d+%d\n", __func__,
+ 	     con, desc->fd_tag, desc->fd_seg_cnt, desc->fd_lens[0],
+ 	     desc->fd_lens[1], desc->fd_lens[2], desc->fd_lens[3]);
+ 
+ 	if (!con_secure(con))
+ 		return prepare_read_control(con);
+ 
+ 	if (desc->fd_lens[0] > CEPH_PREAMBLE_INLINE_LEN)
+ 		return prepare_read_control_remainder(con);
+ 
+ 	return __handle_control(con, CTRL_BODY(con->v2.in_buf));
+ }
+ 
+ static int handle_control(struct ceph_connection *con)
+ {
+ 	int ctrl_len = con->v2.in_desc.fd_lens[0];
+ 	void *buf;
+ 	int ret;
+ 
+ 	WARN_ON(con_secure(con));
+ 
+ 	ret = verify_control_crc(con);
+ 	if (ret) {
+ 		con->error_msg = "integrity error, bad crc";
+ 		return ret;
+ 	}
+ 
+ 	if (con->state == CEPH_CON_S_V2_AUTH) {
+ 		buf = alloc_conn_buf(con, ctrl_len);
+ 		if (!buf)
+ 			return -ENOMEM;
+ 
+ 		memcpy(buf, con->v2.in_kvecs[0].iov_base, ctrl_len);
+ 		return __handle_control(con, buf);
+ 	}
+ 
+ 	return __handle_control(con, con->v2.in_kvecs[0].iov_base);
+ }
+ 
+ static int handle_control_remainder(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	WARN_ON(!con_secure(con));
+ 
+ 	ret = decrypt_control_remainder(con);
+ 	if (ret) {
+ 		if (ret == -EBADMSG)
+ 			con->error_msg = "integrity error, bad control remainder auth tag";
+ 		return ret;
+ 	}
+ 
+ 	return __handle_control(con, con->v2.in_kvecs[0].iov_base -
+ 				     CEPH_PREAMBLE_INLINE_LEN);
+ }
+ 
+ static int handle_epilogue(struct ceph_connection *con)
+ {
+ 	u32 front_crc, middle_crc, data_crc;
+ 	int ret;
+ 
+ 	if (con_secure(con)) {
+ 		ret = decrypt_message(con);
+ 		if (ret) {
+ 			if (ret == -EBADMSG)
+ 				con->error_msg = "integrity error, bad epilogue auth tag";
+ 			return ret;
+ 		}
+ 
+ 		/* just late_status */
+ 		ret = decode_epilogue(con->v2.in_buf, NULL, NULL, NULL);
+ 		if (ret) {
+ 			con->error_msg = "protocol error, bad epilogue";
+ 			return ret;
+ 		}
+ 	} else {
+ 		ret = decode_epilogue(con->v2.in_buf, &front_crc,
+ 				      &middle_crc, &data_crc);
+ 		if (ret) {
+ 			con->error_msg = "protocol error, bad epilogue";
+ 			return ret;
+ 		}
+ 
+ 		ret = verify_epilogue_crcs(con, front_crc, middle_crc,
+ 					   data_crc);
+ 		if (ret) {
+ 			con->error_msg = "integrity error, bad crc";
+ 			return ret;
+ 		}
+ 	}
+ 
+ 	return process_message(con);
+ }
+ 
+ static void finish_skip(struct ceph_connection *con)
+ {
+ 	dout("%s con %p\n", __func__, con);
+ 
+ 	if (con_secure(con))
+ 		gcm_inc_nonce(&con->v2.in_gcm_nonce);
+ 
+ 	__finish_skip(con);
+ }
+ 
+ static int populate_in_iter(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p state %d in_state %d\n", __func__, con, con->state,
+ 	     con->v2.in_state);
+ 	WARN_ON(iov_iter_count(&con->v2.in_iter));
+ 
+ 	if (con->state == CEPH_CON_S_V2_BANNER_PREFIX) {
+ 		ret = process_banner_prefix(con);
+ 	} else if (con->state == CEPH_CON_S_V2_BANNER_PAYLOAD) {
+ 		ret = process_banner_payload(con);
+ 	} else if ((con->state >= CEPH_CON_S_V2_HELLO &&
+ 		    con->state <= CEPH_CON_S_V2_SESSION_RECONNECT) ||
+ 		   con->state == CEPH_CON_S_OPEN) {
+ 		switch (con->v2.in_state) {
+ 		case IN_S_HANDLE_PREAMBLE:
+ 			ret = handle_preamble(con);
+ 			break;
+ 		case IN_S_HANDLE_CONTROL:
+ 			ret = handle_control(con);
+ 			break;
+ 		case IN_S_HANDLE_CONTROL_REMAINDER:
+ 			ret = handle_control_remainder(con);
+ 			break;
+ 		case IN_S_PREPARE_READ_DATA:
+ 			prepare_read_data(con);
+ 			ret = 0;
+ 			break;
+ 		case IN_S_PREPARE_READ_DATA_CONT:
+ 			prepare_read_data_cont(con);
+ 			ret = 0;
+ 			break;
+ 		case IN_S_HANDLE_EPILOGUE:
+ 			ret = handle_epilogue(con);
+ 			break;
+ 		case IN_S_FINISH_SKIP:
+ 			finish_skip(con);
+ 			ret = 0;
+ 			break;
+ 		default:
+ 			WARN(1, "bad in_state %d", con->v2.in_state);
+ 			return -EINVAL;
+ 		}
+ 	} else {
+ 		WARN(1, "bad state %d", con->state);
+ 		return -EINVAL;
+ 	}
+ 	if (ret) {
+ 		dout("%s con %p error %d\n", __func__, con, ret);
+ 		return ret;
+ 	}
+ 
+ 	if (WARN_ON(!iov_iter_count(&con->v2.in_iter)))
+ 		return -ENODATA;
+ 	dout("%s con %p populated %zu\n", __func__, con,
+ 	     iov_iter_count(&con->v2.in_iter));
+ 	return 1;
+ }
+ 
+ int ceph_con_v2_try_read(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p state %d need %zu\n", __func__, con, con->state,
+ 	     iov_iter_count(&con->v2.in_iter));
+ 
+ 	if (con->state == CEPH_CON_S_PREOPEN)
+ 		return 0;
+ 
+ 	/*
+ 	 * We should always have something pending here.  If not,
+ 	 * avoid calling populate_in_iter() as if we read something
+ 	 * (ceph_tcp_recv() would immediately return 1).
+ 	 */
+ 	if (WARN_ON(!iov_iter_count(&con->v2.in_iter)))
+ 		return -ENODATA;
+ 
+ 	for (;;) {
+ 		ret = ceph_tcp_recv(con);
+ 		if (ret <= 0)
+ 			return ret;
+ 
+ 		ret = populate_in_iter(con);
+ 		if (ret <= 0) {
+ 			if (ret && ret != -EAGAIN && !con->error_msg)
+ 				con->error_msg = "read processing error";
+ 			return ret;
+ 		}
+ 	}
+ }
+ 
+ static void queue_data(struct ceph_connection *con)
+ {
+ 	struct bio_vec bv;
+ 
+ 	con->v2.out_epil.data_crc = -1;
+ 	ceph_msg_data_cursor_init(&con->v2.out_cursor, con->out_msg,
+ 				  data_len(con->out_msg));
+ 
+ 	get_bvec_at(&con->v2.out_cursor, &bv);
+ 	set_out_bvec(con, &bv, true);
+ 	con->v2.out_state = OUT_S_QUEUE_DATA_CONT;
+ }
+ 
+ static void queue_data_cont(struct ceph_connection *con)
+ {
+ 	struct bio_vec bv;
+ 
+ 	con->v2.out_epil.data_crc = ceph_crc32c_page(
+ 		con->v2.out_epil.data_crc, con->v2.out_bvec.bv_page,
+ 		con->v2.out_bvec.bv_offset, con->v2.out_bvec.bv_len);
+ 
+ 	ceph_msg_data_advance(&con->v2.out_cursor, con->v2.out_bvec.bv_len);
+ 	if (con->v2.out_cursor.total_resid) {
+ 		get_bvec_at(&con->v2.out_cursor, &bv);
+ 		set_out_bvec(con, &bv, true);
+ 		WARN_ON(con->v2.out_state != OUT_S_QUEUE_DATA_CONT);
+ 		return;
+ 	}
+ 
+ 	/*
+ 	 * We've written all data.  Queue epilogue.  Once it's written,
+ 	 * we are done.
+ 	 */
+ 	reset_out_kvecs(con);
+ 	prepare_epilogue_plain(con, false);
+ 	con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ }
+ 
+ static void queue_enc_page(struct ceph_connection *con)
+ {
+ 	struct bio_vec bv;
+ 
+ 	dout("%s con %p i %d resid %d\n", __func__, con, con->v2.out_enc_i,
+ 	     con->v2.out_enc_resid);
+ 	WARN_ON(!con->v2.out_enc_resid);
+ 
+ 	bv.bv_page = con->v2.out_enc_pages[con->v2.out_enc_i];
+ 	bv.bv_offset = 0;
+ 	bv.bv_len = min(con->v2.out_enc_resid, (int)PAGE_SIZE);
+ 
+ 	set_out_bvec(con, &bv, false);
+ 	con->v2.out_enc_i++;
+ 	con->v2.out_enc_resid -= bv.bv_len;
+ 
+ 	if (con->v2.out_enc_resid) {
+ 		WARN_ON(con->v2.out_state != OUT_S_QUEUE_ENC_PAGE);
+ 		return;
+ 	}
+ 
+ 	/*
+ 	 * We've queued the last piece of ciphertext (ending with
+ 	 * epilogue) + auth tag.  Once it's written, we are done.
+ 	 */
+ 	WARN_ON(con->v2.out_enc_i != con->v2.out_enc_page_cnt);
+ 	con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ }
+ 
+ static void queue_zeros(struct ceph_connection *con)
+ {
+ 	dout("%s con %p out_zero %d\n", __func__, con, con->v2.out_zero);
+ 
+ 	if (con->v2.out_zero) {
+ 		set_out_bvec_zero(con);
+ 		con->v2.out_zero -= con->v2.out_bvec.bv_len;
+ 		con->v2.out_state = OUT_S_QUEUE_ZEROS;
+ 		return;
+ 	}
+ 
+ 	/*
+ 	 * We've zero-filled everything up to epilogue.  Queue epilogue
+ 	 * with late_status set to ABORTED and crcs adjusted for zeros.
+ 	 * Once it's written, we are done patching up for the revoke.
+ 	 */
+ 	reset_out_kvecs(con);
+ 	prepare_epilogue_plain(con, true);
+ 	con->v2.out_state = OUT_S_FINISH_MESSAGE;
+ }
+ 
+ static void finish_message(struct ceph_connection *con)
+ {
+ 	dout("%s con %p msg %p\n", __func__, con, con->out_msg);
+ 
+ 	/* we end up here both plain and secure modes */
+ 	if (con->v2.out_enc_pages) {
+ 		WARN_ON(!con->v2.out_enc_page_cnt);
+ 		ceph_release_page_vector(con->v2.out_enc_pages,
+ 					 con->v2.out_enc_page_cnt);
+ 		con->v2.out_enc_pages = NULL;
+ 		con->v2.out_enc_page_cnt = 0;
+ 	}
+ 	/* message may have been revoked */
+ 	if (con->out_msg) {
+ 		ceph_msg_put(con->out_msg);
+ 		con->out_msg = NULL;
+ 	}
+ 
+ 	con->v2.out_state = OUT_S_GET_NEXT;
+ }
+ 
+ static int populate_out_iter(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p state %d out_state %d\n", __func__, con, con->state,
+ 	     con->v2.out_state);
+ 	WARN_ON(iov_iter_count(&con->v2.out_iter));
+ 
+ 	if (con->state != CEPH_CON_S_OPEN) {
+ 		WARN_ON(con->state < CEPH_CON_S_V2_BANNER_PREFIX ||
+ 			con->state > CEPH_CON_S_V2_SESSION_RECONNECT);
+ 		goto nothing_pending;
+ 	}
+ 
+ 	switch (con->v2.out_state) {
+ 	case OUT_S_QUEUE_DATA:
+ 		WARN_ON(!con->out_msg);
+ 		queue_data(con);
+ 		goto populated;
+ 	case OUT_S_QUEUE_DATA_CONT:
+ 		WARN_ON(!con->out_msg);
+ 		queue_data_cont(con);
+ 		goto populated;
+ 	case OUT_S_QUEUE_ENC_PAGE:
+ 		queue_enc_page(con);
+ 		goto populated;
+ 	case OUT_S_QUEUE_ZEROS:
+ 		WARN_ON(con->out_msg);  /* revoked */
+ 		queue_zeros(con);
+ 		goto populated;
+ 	case OUT_S_FINISH_MESSAGE:
+ 		finish_message(con);
+ 		break;
+ 	case OUT_S_GET_NEXT:
+ 		break;
+ 	default:
+ 		WARN(1, "bad out_state %d", con->v2.out_state);
+ 		return -EINVAL;
+ 	}
+ 
+ 	WARN_ON(con->v2.out_state != OUT_S_GET_NEXT);
+ 	if (ceph_con_flag_test_and_clear(con, CEPH_CON_F_KEEPALIVE_PENDING)) {
+ 		ret = prepare_keepalive2(con);
+ 		if (ret) {
+ 			pr_err("prepare_keepalive2 failed: %d\n", ret);
+ 			return ret;
+ 		}
+ 	} else if (!list_empty(&con->out_queue)) {
+ 		ceph_con_get_out_msg(con);
+ 		ret = prepare_message(con);
+ 		if (ret) {
+ 			pr_err("prepare_message failed: %d\n", ret);
+ 			return ret;
+ 		}
+ 	} else if (con->in_seq > con->in_seq_acked) {
+ 		ret = prepare_ack(con);
+ 		if (ret) {
+ 			pr_err("prepare_ack failed: %d\n", ret);
+ 			return ret;
+ 		}
+ 	} else {
+ 		goto nothing_pending;
+ 	}
+ 
+ populated:
+ 	if (WARN_ON(!iov_iter_count(&con->v2.out_iter)))
+ 		return -ENODATA;
+ 	dout("%s con %p populated %zu\n", __func__, con,
+ 	     iov_iter_count(&con->v2.out_iter));
+ 	return 1;
+ 
+ nothing_pending:
+ 	WARN_ON(iov_iter_count(&con->v2.out_iter));
+ 	dout("%s con %p nothing pending\n", __func__, con);
+ 	ceph_con_flag_clear(con, CEPH_CON_F_WRITE_PENDING);
+ 	return 0;
+ }
+ 
+ int ceph_con_v2_try_write(struct ceph_connection *con)
+ {
+ 	int ret;
+ 
+ 	dout("%s con %p state %d have %zu\n", __func__, con, con->state,
+ 	     iov_iter_count(&con->v2.out_iter));
+ 
+ 	/* open the socket first? */
+ 	if (con->state == CEPH_CON_S_PREOPEN) {
+ 		WARN_ON(con->peer_addr.type != CEPH_ENTITY_ADDR_TYPE_MSGR2);
+ 
+ 		/*
+ 		 * Always bump global_seq.  Bump connect_seq only if
+ 		 * there is a session (i.e. we are reconnecting and will
+ 		 * send session_reconnect instead of client_ident).
+ 		 */
+ 		con->v2.global_seq = ceph_get_global_seq(con->msgr, 0);
+ 		if (con->v2.server_cookie)
+ 			con->v2.connect_seq++;
+ 
+ 		ret = prepare_read_banner_prefix(con);
+ 		if (ret) {
+ 			pr_err("prepare_read_banner_prefix failed: %d\n", ret);
+ 			con->error_msg = "connect error";
+ 			return ret;
+ 		}
+ 
+ 		reset_out_kvecs(con);
+ 		ret = prepare_banner(con);
+ 		if (ret) {
+ 			pr_err("prepare_banner failed: %d\n", ret);
+ 			con->error_msg = "connect error";
+ 			return ret;
+ 		}
+ 
+ 		ret = ceph_tcp_connect(con);
+ 		if (ret) {
+ 			pr_err("ceph_tcp_connect failed: %d\n", ret);
+ 			con->error_msg = "connect error";
+ 			return ret;
+ 		}
+ 	}
+ 
+ 	if (!iov_iter_count(&con->v2.out_iter)) {
+ 		ret = populate_out_iter(con);
+ 		if (ret <= 0) {
+ 			if (ret && ret != -EAGAIN && !con->error_msg)
+ 				con->error_msg = "write processing error";
+ 			return ret;
+ 		}
+ 	}
+ 
+ 	tcp_sock_set_cork(con->sock->sk, true);
+ 	for (;;) {
+ 		ret = ceph_tcp_send(con);
+ 		if (ret <= 0)
+ 			break;
+ 
+ 		ret = populate_out_iter(con);
+ 		if (ret <= 0) {
+ 			if (ret && ret != -EAGAIN && !con->error_msg)
+ 				con->error_msg = "write processing error";
+ 			break;
+ 		}
+ 	}
+ 
+ 	tcp_sock_set_cork(con->sock->sk, false);
+ 	return ret;
+ }
+ 
+ static u32 crc32c_zeros(u32 crc, int zero_len)
+ {
+ 	int len;
+ 
+ 	while (zero_len) {
+ 		len = min(zero_len, (int)PAGE_SIZE);
+ 		crc = crc32c(crc, page_address(ceph_zero_page), len);
+ 		zero_len -= len;
+ 	}
+ 
+ 	return crc;
+ }
+ 
+ static void prepare_zero_front(struct ceph_connection *con, int resid)
+ {
+ 	int sent;
+ 
+ 	WARN_ON(!resid || resid > front_len(con->out_msg));
+ 	sent = front_len(con->out_msg) - resid;
+ 	dout("%s con %p sent %d resid %d\n", __func__, con, sent, resid);
+ 
+ 	if (sent) {
+ 		con->v2.out_epil.front_crc =
+ 			crc32c(-1, con->out_msg->front.iov_base, sent);
+ 		con->v2.out_epil.front_crc =
+ 			crc32c_zeros(con->v2.out_epil.front_crc, resid);
+ 	} else {
+ 		con->v2.out_epil.front_crc = crc32c_zeros(-1, resid);
+ 	}
+ 
+ 	con->v2.out_iter.count -= resid;
+ 	out_zero_add(con, resid);
+ }
+ 
+ static void prepare_zero_middle(struct ceph_connection *con, int resid)
+ {
+ 	int sent;
+ 
+ 	WARN_ON(!resid || resid > middle_len(con->out_msg));
+ 	sent = middle_len(con->out_msg) - resid;
+ 	dout("%s con %p sent %d resid %d\n", __func__, con, sent, resid);
+ 
+ 	if (sent) {
+ 		con->v2.out_epil.middle_crc =
+ 			crc32c(-1, con->out_msg->middle->vec.iov_base, sent);
+ 		con->v2.out_epil.middle_crc =
+ 			crc32c_zeros(con->v2.out_epil.middle_crc, resid);
+ 	} else {
+ 		con->v2.out_epil.middle_crc = crc32c_zeros(-1, resid);
+ 	}
+ 
+ 	con->v2.out_iter.count -= resid;
+ 	out_zero_add(con, resid);
+ }
+ 
+ static void prepare_zero_data(struct ceph_connection *con)
+ {
+ 	dout("%s con %p\n", __func__, con);
+ 	con->v2.out_epil.data_crc = crc32c_zeros(-1, data_len(con->out_msg));
+ 	out_zero_add(con, data_len(con->out_msg));
+ }
+ 
+ static void revoke_at_queue_data(struct ceph_connection *con)
+ {
+ 	int boundary;
+ 	int resid;
+ 
+ 	WARN_ON(!data_len(con->out_msg));
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.out_iter));
+ 	resid = iov_iter_count(&con->v2.out_iter);
+ 
+ 	boundary = front_len(con->out_msg) + middle_len(con->out_msg);
+ 	if (resid > boundary) {
+ 		resid -= boundary;
+ 		WARN_ON(resid > MESSAGE_HEAD_PLAIN_LEN);
+ 		dout("%s con %p was sending head\n", __func__, con);
+ 		if (front_len(con->out_msg))
+ 			prepare_zero_front(con, front_len(con->out_msg));
+ 		if (middle_len(con->out_msg))
+ 			prepare_zero_middle(con, middle_len(con->out_msg));
+ 		prepare_zero_data(con);
+ 		WARN_ON(iov_iter_count(&con->v2.out_iter) != resid);
+ 		con->v2.out_state = OUT_S_QUEUE_ZEROS;
+ 		return;
+ 	}
+ 
+ 	boundary = middle_len(con->out_msg);
+ 	if (resid > boundary) {
+ 		resid -= boundary;
+ 		dout("%s con %p was sending front\n", __func__, con);
+ 		prepare_zero_front(con, resid);
+ 		if (middle_len(con->out_msg))
+ 			prepare_zero_middle(con, middle_len(con->out_msg));
+ 		prepare_zero_data(con);
+ 		queue_zeros(con);
+ 		return;
+ 	}
+ 
+ 	WARN_ON(!resid);
+ 	dout("%s con %p was sending middle\n", __func__, con);
+ 	prepare_zero_middle(con, resid);
+ 	prepare_zero_data(con);
+ 	queue_zeros(con);
+ }
+ 
+ static void revoke_at_queue_data_cont(struct ceph_connection *con)
+ {
+ 	int sent, resid;  /* current piece of data */
+ 
+ 	WARN_ON(!data_len(con->out_msg));
+ 	WARN_ON(!iov_iter_is_bvec(&con->v2.out_iter));
+ 	resid = iov_iter_count(&con->v2.out_iter);
+ 	WARN_ON(!resid || resid > con->v2.out_bvec.bv_len);
+ 	sent = con->v2.out_bvec.bv_len - resid;
+ 	dout("%s con %p sent %d resid %d\n", __func__, con, sent, resid);
+ 
+ 	if (sent) {
+ 		con->v2.out_epil.data_crc = ceph_crc32c_page(
+ 			con->v2.out_epil.data_crc, con->v2.out_bvec.bv_page,
+ 			con->v2.out_bvec.bv_offset, sent);
+ 		ceph_msg_data_advance(&con->v2.out_cursor, sent);
+ 	}
+ 	WARN_ON(resid > con->v2.out_cursor.total_resid);
+ 	con->v2.out_epil.data_crc = crc32c_zeros(con->v2.out_epil.data_crc,
+ 						con->v2.out_cursor.total_resid);
+ 
+ 	con->v2.out_iter.count -= resid;
+ 	out_zero_add(con, con->v2.out_cursor.total_resid);
+ 	queue_zeros(con);
+ }
+ 
+ static void revoke_at_finish_message(struct ceph_connection *con)
+ {
+ 	int boundary;
+ 	int resid;
+ 
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.out_iter));
+ 	resid = iov_iter_count(&con->v2.out_iter);
+ 
+ 	if (!front_len(con->out_msg) && !middle_len(con->out_msg) &&
+ 	    !data_len(con->out_msg)) {
+ 		WARN_ON(!resid || resid > MESSAGE_HEAD_PLAIN_LEN);
+ 		dout("%s con %p was sending head (empty message) - noop\n",
+ 		     __func__, con);
+ 		return;
+ 	}
+ 
+ 	boundary = front_len(con->out_msg) + middle_len(con->out_msg) +
+ 		   CEPH_EPILOGUE_PLAIN_LEN;
+ 	if (resid > boundary) {
+ 		resid -= boundary;
+ 		WARN_ON(resid > MESSAGE_HEAD_PLAIN_LEN);
+ 		dout("%s con %p was sending head\n", __func__, con);
+ 		if (front_len(con->out_msg))
+ 			prepare_zero_front(con, front_len(con->out_msg));
+ 		if (middle_len(con->out_msg))
+ 			prepare_zero_middle(con, middle_len(con->out_msg));
+ 		con->v2.out_iter.count -= CEPH_EPILOGUE_PLAIN_LEN;
+ 		WARN_ON(iov_iter_count(&con->v2.out_iter) != resid);
+ 		con->v2.out_state = OUT_S_QUEUE_ZEROS;
+ 		return;
+ 	}
+ 
+ 	boundary = middle_len(con->out_msg) + CEPH_EPILOGUE_PLAIN_LEN;
+ 	if (resid > boundary) {
+ 		resid -= boundary;
+ 		dout("%s con %p was sending front\n", __func__, con);
+ 		prepare_zero_front(con, resid);
+ 		if (middle_len(con->out_msg))
+ 			prepare_zero_middle(con, middle_len(con->out_msg));
+ 		con->v2.out_iter.count -= CEPH_EPILOGUE_PLAIN_LEN;
+ 		queue_zeros(con);
+ 		return;
+ 	}
+ 
+ 	boundary = CEPH_EPILOGUE_PLAIN_LEN;
+ 	if (resid > boundary) {
+ 		resid -= boundary;
+ 		dout("%s con %p was sending middle\n", __func__, con);
+ 		prepare_zero_middle(con, resid);
+ 		con->v2.out_iter.count -= CEPH_EPILOGUE_PLAIN_LEN;
+ 		queue_zeros(con);
+ 		return;
+ 	}
+ 
+ 	WARN_ON(!resid);
+ 	dout("%s con %p was sending epilogue - noop\n", __func__, con);
+ }
+ 
+ void ceph_con_v2_revoke(struct ceph_connection *con)
+ {
+ 	WARN_ON(con->v2.out_zero);
+ 
+ 	if (con_secure(con)) {
+ 		WARN_ON(con->v2.out_state != OUT_S_QUEUE_ENC_PAGE &&
+ 			con->v2.out_state != OUT_S_FINISH_MESSAGE);
+ 		dout("%s con %p secure - noop\n", __func__, con);
+ 		return;
+ 	}
+ 
+ 	switch (con->v2.out_state) {
+ 	case OUT_S_QUEUE_DATA:
+ 		revoke_at_queue_data(con);
+ 		break;
+ 	case OUT_S_QUEUE_DATA_CONT:
+ 		revoke_at_queue_data_cont(con);
+ 		break;
+ 	case OUT_S_FINISH_MESSAGE:
+ 		revoke_at_finish_message(con);
+ 		break;
+ 	default:
+ 		WARN(1, "bad out_state %d", con->v2.out_state);
+ 		break;
+ 	}
+ }
+ 
+ static void revoke_at_prepare_read_data(struct ceph_connection *con)
+ {
+ 	int remaining;  /* data + [data padding] + epilogue */
+ 	int resid;
+ 
+ 	WARN_ON(!data_len(con->in_msg));
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.in_iter));
+ 	resid = iov_iter_count(&con->v2.in_iter);
+ 	WARN_ON(!resid);
+ 
+ 	if (con_secure(con))
+ 		remaining = padded_len(data_len(con->in_msg)) +
+ 			    CEPH_EPILOGUE_SECURE_LEN;
+ 	else
+ 		remaining = data_len(con->in_msg) + CEPH_EPILOGUE_PLAIN_LEN;
+ 
+ 	dout("%s con %p resid %d remaining %d\n", __func__, con, resid,
+ 	     remaining);
+ 	con->v2.in_iter.count -= resid;
+ 	set_in_skip(con, resid + remaining);
+ 	con->v2.in_state = IN_S_FINISH_SKIP;
+ }
+ 
+ static void revoke_at_prepare_read_data_cont(struct ceph_connection *con)
+ {
+ 	int recved, resid;  /* current piece of data */
+ 	int remaining;  /* [data padding] + epilogue */
+ 
+ 	WARN_ON(!data_len(con->in_msg));
+ 	WARN_ON(!iov_iter_is_bvec(&con->v2.in_iter));
+ 	resid = iov_iter_count(&con->v2.in_iter);
+ 	WARN_ON(!resid || resid > con->v2.in_bvec.bv_len);
+ 	recved = con->v2.in_bvec.bv_len - resid;
+ 	dout("%s con %p recved %d resid %d\n", __func__, con, recved, resid);
+ 
+ 	if (recved)
+ 		ceph_msg_data_advance(&con->v2.in_cursor, recved);
+ 	WARN_ON(resid > con->v2.in_cursor.total_resid);
+ 
+ 	if (con_secure(con))
+ 		remaining = padding_len(data_len(con->in_msg)) +
+ 			    CEPH_EPILOGUE_SECURE_LEN;
+ 	else
+ 		remaining = CEPH_EPILOGUE_PLAIN_LEN;
+ 
+ 	dout("%s con %p total_resid %zu remaining %d\n", __func__, con,
+ 	     con->v2.in_cursor.total_resid, remaining);
+ 	con->v2.in_iter.count -= resid;
+ 	set_in_skip(con, con->v2.in_cursor.total_resid + remaining);
+ 	con->v2.in_state = IN_S_FINISH_SKIP;
+ }
+ 
+ static void revoke_at_handle_epilogue(struct ceph_connection *con)
+ {
+ 	int resid;
+ 
+ 	WARN_ON(!iov_iter_is_kvec(&con->v2.in_iter));
+ 	resid = iov_iter_count(&con->v2.in_iter);
+ 	WARN_ON(!resid);
+ 
+ 	dout("%s con %p resid %d\n", __func__, con, resid);
+ 	con->v2.in_iter.count -= resid;
+ 	set_in_skip(con, resid);
+ 	con->v2.in_state = IN_S_FINISH_SKIP;
+ }
+ 
+ void ceph_con_v2_revoke_incoming(struct ceph_connection *con)
+ {
+ 	switch (con->v2.in_state) {
+ 	case IN_S_PREPARE_READ_DATA:
+ 		revoke_at_prepare_read_data(con);
+ 		break;
+ 	case IN_S_PREPARE_READ_DATA_CONT:
+ 		revoke_at_prepare_read_data_cont(con);
+ 		break;
+ 	case IN_S_HANDLE_EPILOGUE:
+ 		revoke_at_handle_epilogue(con);
+ 		break;
+ 	default:
+ 		WARN(1, "bad in_state %d", con->v2.in_state);
+ 		break;
+ 	}
+ }
+ 
+ bool ceph_con_v2_opened(struct ceph_connection *con)
+ {
+ 	return con->v2.peer_global_seq;
+ }
+ 
+ void ceph_con_v2_reset_session(struct ceph_connection *con)
+ {
+ 	con->v2.client_cookie = 0;
+ 	con->v2.server_cookie = 0;
+ 	con->v2.global_seq = 0;
+ 	con->v2.connect_seq = 0;
+ 	con->v2.peer_global_seq = 0;
+ }
+ 
+ void ceph_con_v2_reset_protocol(struct ceph_connection *con)
+ {
+ 	iov_iter_truncate(&con->v2.in_iter, 0);
+ 	iov_iter_truncate(&con->v2.out_iter, 0);
+ 	con->v2.out_zero = 0;
+ 
+ 	clear_in_sign_kvecs(con);
+ 	clear_out_sign_kvecs(con);
+ 	free_conn_bufs(con);
+ 
+ 	if (con->v2.out_enc_pages) {
+ 		WARN_ON(!con->v2.out_enc_page_cnt);
+ 		ceph_release_page_vector(con->v2.out_enc_pages,
+ 					 con->v2.out_enc_page_cnt);
+ 		con->v2.out_enc_pages = NULL;
+ 		con->v2.out_enc_page_cnt = 0;
+ 	}
+ 
+ 	con->v2.con_mode = CEPH_CON_MODE_UNKNOWN;
+ 
+ 	if (con->v2.hmac_tfm) {
+ 		crypto_free_shash(con->v2.hmac_tfm);
+ 		con->v2.hmac_tfm = NULL;
+ 	}
+ 	if (con->v2.gcm_req) {
+ 		aead_request_free(con->v2.gcm_req);
+ 		con->v2.gcm_req = NULL;
+ 	}
+ 	if (con->v2.gcm_tfm) {
+ 		crypto_free_aead(con->v2.gcm_tfm);
+ 		con->v2.gcm_tfm = NULL;
+ 	}
+ }