/* AF_RXRPC sendmsg() implementation. * * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/net.h>#include <linux/gfp.h>#include <linux/skbuff.h>#include <linux/export.h>#include <linux/sched/signal.h> #include <net/sock.h>#include <net/af_rxrpc.h>#include "ar-internal.h" enum rxrpc_command {	RXRPC_CMD_SEND_DATA,		/* send data message */	RXRPC_CMD_SEND_ABORT,		/* request abort generation */	RXRPC_CMD_ACCEPT,		/* [server] accept incoming call */	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */}; struct rxrpc_send_params {	s64			tx_total_len;	/* Total Tx data length (if send data) */	unsigned long		user_call_ID;	/* User's call ID */	u32			abort_code;	/* Abort code to Tx (if abort) */	enum rxrpc_command	command : 8;	/* The command to implement */	bool			exclusive;	/* Shared or exclusive call */	bool			upgrade;	/* If the connection is upgradeable */}; /* * wait for space to appear in the transmit/ACK window * - caller holds the socket locked */static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,				    struct rxrpc_call *call,				    long *timeo){	DECLARE_WAITQUEUE(myself, current);	int ret; 	_enter(",{%u,%u,%u}",	       call->tx_hard_ack, call->tx_top, call->tx_winsize); 	add_wait_queue(&call->waitq, &myself); 	for (;;) {		set_current_state(TASK_INTERRUPTIBLE);		ret = 0;		if (call->tx_top - call->tx_hard_ack <		    min_t(unsigned int, call->tx_winsize,			  call->cong_cwnd + call->cong_extra))			break;		if (call->state >= RXRPC_CALL_COMPLETE) {			ret = -call->error;			break;		}		if (signal_pending(current)) {			ret = sock_intr_errno(*timeo);			break;		} 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);		mutex_unlock(&call->user_mutex);		*timeo = schedule_timeout(*timeo);		if (mutex_lock_interruptible(&call->user_mutex) < 0) {			ret = sock_intr_errno(*timeo);			break;		}	} 	remove_wait_queue(&call->waitq, &myself);	set_current_state(TASK_RUNNING);	_leave(" = %d", ret);	return ret;} /* * Schedule an instant Tx resend. */static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix){	spin_lock_bh(&call->lock); 	if (call->state < RXRPC_CALL_COMPLETE) {		call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))			rxrpc_queue_call(call);	} 	spin_unlock_bh(&call->lock);} /* * Queue a DATA packet for transmission, set the resend timeout and send the * packet immediately */static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,			       bool last){	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);	rxrpc_seq_t seq = sp->hdr.seq;	int ret, ix;	u8 annotation = RXRPC_TX_ANNO_UNACK; 	_net("queue skb %p [%d]", skb, seq); 	ASSERTCMP(seq, ==, call->tx_top + 1); 	if (last)		annotation |= RXRPC_TX_ANNO_LAST; 	/* We have to set the timestamp before queueing as the retransmit	 * algorithm can see the packet as soon as we queue it.	 */	skb->tstamp = ktime_get_real(); 	ix = seq & RXRPC_RXTX_BUFF_MASK;	rxrpc_get_skb(skb, rxrpc_skb_tx_got);	call->rxtx_annotations[ix] = annotation;	smp_wmb();	call->rxtx_buffer[ix] = skb;	call->tx_top = seq;	if (last)		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);	else		trace_rxrpc_transmit(call, rxrpc_transmit_queue); 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {		_debug("________awaiting reply/ACK__________");		write_lock_bh(&call->state_lock);		switch (call->state) {		case RXRPC_CALL_CLIENT_SEND_REQUEST:			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;			break;		case RXRPC_CALL_SERVER_ACK_REQUEST:			call->state = RXRPC_CALL_SERVER_SEND_REPLY;			call->ack_at = call->expire_at;			if (call->ackr_reason == RXRPC_ACK_DELAY)				call->ackr_reason = 0;			__rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,					  ktime_get_real());			if (!last)				break;		case RXRPC_CALL_SERVER_SEND_REPLY:			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;			break;		default:			break;		}		write_unlock_bh(&call->state_lock);	} 	if (seq == 1 && rxrpc_is_client_call(call))		rxrpc_expose_client_call(call); 	ret = rxrpc_send_data_packet(call, skb, false);	if (ret < 0) {		_debug("need instant resend %d", ret);		rxrpc_instant_resend(call, ix);	} else {		ktime_t now = ktime_get_real(), resend_at; 		resend_at = ktime_add_ms(now, rxrpc_resend_timeout); 		if (ktime_before(resend_at, call->resend_at)) {			call->resend_at = resend_at;			rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);		}	} 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);	_leave("");} /* * send data through a socket * - must be called in process context * - The caller holds the call user access mutex, but not the socket lock. */static int rxrpc_send_data(struct rxrpc_sock *rx,			   struct rxrpc_call *call,			   struct msghdr *msg, size_t len){	struct rxrpc_skb_priv *sp;	struct sk_buff *skb;	struct sock *sk = &rx->sk;	long timeo;	bool more;	int ret, copied; 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 	/* this should be in poll */	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))		return -EPIPE; 	more = msg->msg_flags & MSG_MORE; 	if (call->tx_total_len != -1) {		if (len > call->tx_total_len)			return -EMSGSIZE;		if (!more && len != call->tx_total_len)			return -EMSGSIZE;	} 	skb = call->tx_pending;	call->tx_pending = NULL;	rxrpc_see_skb(skb, rxrpc_skb_tx_seen); 	copied = 0;	do {		/* Check to see if there's a ping ACK to reply to. */		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)			rxrpc_send_ack_packet(call, false); 		if (!skb) {			size_t size, chunk, max, space; 			_debug("alloc"); 			if (call->tx_top - call->tx_hard_ack >=			    min_t(unsigned int, call->tx_winsize,				  call->cong_cwnd + call->cong_extra)) {				ret = -EAGAIN;				if (msg->msg_flags & MSG_DONTWAIT)					goto maybe_error;				ret = rxrpc_wait_for_tx_window(rx, call,							       &timeo);				if (ret < 0)					goto maybe_error;			} 			max = RXRPC_JUMBO_DATALEN;			max -= call->conn->security_size;			max &= ~(call->conn->size_align - 1UL); 			chunk = max;			if (chunk > msg_data_left(msg) && !more)				chunk = msg_data_left(msg); 			space = chunk + call->conn->size_align;			space &= ~(call->conn->size_align - 1UL); 			size = space + call->conn->security_size; 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size); 			/* create a buffer that we can retain until it's ACK'd */			skb = sock_alloc_send_skb(				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);			if (!skb)				goto maybe_error; 			rxrpc_new_skb(skb, rxrpc_skb_tx_new); 			_debug("ALLOC SEND %p", skb); 			ASSERTCMP(skb->mark, ==, 0); 			_debug("HS: %u", call->conn->security_size);			skb_reserve(skb, call->conn->security_size);			skb->len += call->conn->security_size; 			sp = rxrpc_skb(skb);			sp->remain = chunk;			if (sp->remain > skb_tailroom(skb))				sp->remain = skb_tailroom(skb); 			_net("skb: hr %d, tr %d, hl %d, rm %d",			       skb_headroom(skb),			       skb_tailroom(skb),			       skb_headlen(skb),			       sp->remain); 			skb->ip_summed = CHECKSUM_UNNECESSARY;		} 		_debug("append");		sp = rxrpc_skb(skb); 		/* append next segment of data to the current buffer */		if (msg_data_left(msg) > 0) {			int copy = skb_tailroom(skb);			ASSERTCMP(copy, >, 0);			if (copy > msg_data_left(msg))				copy = msg_data_left(msg);			if (copy > sp->remain)				copy = sp->remain; 			_debug("add");			ret = skb_add_data(skb, &msg->msg_iter, copy);			_debug("added");			if (ret < 0)				goto efault;			sp->remain -= copy;			skb->mark += copy;			copied += copy;			if (call->tx_total_len != -1)				call->tx_total_len -= copy;		} 		/* check for the far side aborting the call or a network error		 * occurring */		if (call->state == RXRPC_CALL_COMPLETE)			goto call_terminated; 		/* add the packet to the send queue if it's now full */		if (sp->remain <= 0 ||		    (msg_data_left(msg) == 0 && !more)) {			struct rxrpc_connection *conn = call->conn;			uint32_t seq;			size_t pad; 			/* pad out if we're using security */			if (conn->security_ix) {				pad = conn->security_size + skb->mark;				pad = conn->size_align - pad;				pad &= conn->size_align - 1;				_debug("pad %zu", pad);				if (pad)					skb_put_zero(skb, pad);			} 			seq = call->tx_top + 1; 			sp->hdr.seq	= seq;			sp->hdr._rsvd	= 0;			sp->hdr.flags	= conn->out_clientflag; 			if (msg_data_left(msg) == 0 && !more)				sp->hdr.flags |= RXRPC_LAST_PACKET;			else if (call->tx_top - call->tx_hard_ack <				 call->tx_winsize)				sp->hdr.flags |= RXRPC_MORE_PACKETS; 			ret = conn->security->secure_packet(				call, skb, skb->mark, skb->head);			if (ret < 0)				goto out; 			rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);			skb = NULL;		}	} while (msg_data_left(msg) > 0); success:	ret = copied;out:	call->tx_pending = skb;	_leave(" = %d", ret);	return ret; call_terminated:	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);	_leave(" = %d", -call->error);	return -call->error; maybe_error:	if (copied)		goto success;	goto out; efault:	ret = -EFAULT;	goto out;} /* * extract control messages from the sendmsg() control buffer */static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p){	struct cmsghdr *cmsg;	bool got_user_ID = false;	int len; 	if (msg->msg_controllen == 0)		return -EINVAL; 	for_each_cmsghdr(cmsg, msg) {		if (!CMSG_OK(msg, cmsg))			return -EINVAL; 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);		_debug("CMSG %d, %d, %d",		       cmsg->cmsg_level, cmsg->cmsg_type, len); 		if (cmsg->cmsg_level != SOL_RXRPC)			continue; 		switch (cmsg->cmsg_type) {		case RXRPC_USER_CALL_ID:			if (msg->msg_flags & MSG_CMSG_COMPAT) {				if (len != sizeof(u32))					return -EINVAL;				p->user_call_ID = *(u32 *)CMSG_DATA(cmsg);			} else {				if (len != sizeof(unsigned long))					return -EINVAL;				p->user_call_ID = *(unsigned long *)					CMSG_DATA(cmsg);			}			got_user_ID = true;			break; 		case RXRPC_ABORT:			if (p->command != RXRPC_CMD_SEND_DATA)				return -EINVAL;			p->command = RXRPC_CMD_SEND_ABORT;			if (len != sizeof(p->abort_code))				return -EINVAL;			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);			if (p->abort_code == 0)				return -EINVAL;			break; 		case RXRPC_ACCEPT:			if (p->command != RXRPC_CMD_SEND_DATA)				return -EINVAL;			p->command = RXRPC_CMD_ACCEPT;			if (len != 0)				return -EINVAL;			break; 		case RXRPC_EXCLUSIVE_CALL:			p->exclusive = true;			if (len != 0)				return -EINVAL;			break; 		case RXRPC_UPGRADE_SERVICE:			p->upgrade = true;			if (len != 0)				return -EINVAL;			break; 		case RXRPC_TX_LENGTH:			if (p->tx_total_len != -1 || len != sizeof(__s64))				return -EINVAL;			p->tx_total_len = *(__s64 *)CMSG_DATA(cmsg);			if (p->tx_total_len < 0)				return -EINVAL;			break; 		default:			return -EINVAL;		}	} 	if (!got_user_ID)		return -EINVAL;	if (p->tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)		return -EINVAL;	_leave(" = 0");	return 0;} /* * Create a new client call for sendmsg(). * - Called with the socket lock held, which it must release. * - If it returns a call, the call's lock will need releasing by the caller. */static struct rxrpc_call *rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,				  struct rxrpc_send_params *p)	__releases(&rx->sk.sk_lock.slock){	struct rxrpc_conn_parameters cp;	struct rxrpc_call *call;	struct key *key; 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name); 	_enter(""); 	if (!msg->msg_name) {		release_sock(&rx->sk);		return ERR_PTR(-EDESTADDRREQ);	} 	key = rx->key;	if (key && !rx->key->payload.data[0])		key = NULL; 	memset(&cp, 0, sizeof(cp));	cp.local		= rx->local;	cp.key			= rx->key;	cp.security_level	= rx->min_sec_level;

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