Commit 0b58b8a1 authored by David Howells's avatar David Howells
Browse files

rxrpc: Split sendmsg from packet transmission code 



Split the sendmsg code from the packet transmission code (mostly to be
found in output.c).

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent 434e6120

net/rxrpc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ af-rxrpc-y := \ 
	peer_object.o \

	recvmsg.o \

	security.o \

	sendmsg.o \

	skbuff.o \

	utils.o

net/rxrpc/ar-internal.h

+6 −3
Original line number Diff line number Diff line
@@ -814,6 +814,7 @@ extern unsigned int rxrpc_idle_ack_delay; 
extern unsigned int rxrpc_rx_window_size;

extern unsigned int rxrpc_rx_mtu;

extern unsigned int rxrpc_rx_jumbo_max;

extern unsigned int rxrpc_resend_timeout;



extern const char *const rxrpc_pkts[];

extern const s8 rxrpc_ack_priority[];
@@ -823,10 +824,7 @@ extern const char *rxrpc_acks(u8 reason); 
/*

 * output.c

 */

extern unsigned int rxrpc_resend_timeout;



int rxrpc_send_data_packet(struct rxrpc_connection *, struct sk_buff *);

int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);



/*

 * peer_event.c
@@ -889,6 +887,11 @@ void rxrpc_exit_security(void); 
int rxrpc_init_client_conn_security(struct rxrpc_connection *);

int rxrpc_init_server_conn_security(struct rxrpc_connection *);

 

/*

 * sendmsg.c

 */

int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);



/*

 * skbuff.c

 */

net/rxrpc/misc.c

+5 −0
Original line number Diff line number Diff line
@@ -64,6 +64,11 @@ unsigned int rxrpc_rx_mtu = 5692; 
 */

unsigned int rxrpc_rx_jumbo_max = 4;



/*

 * Time till packet resend (in jiffies).

 */

unsigned int rxrpc_resend_timeout = 4 * HZ;



const char *const rxrpc_pkts[] = {

	"?00",

	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",

net/rxrpc/output.c

+0 −630
Original line number Diff line number Diff line
@@ -14,298 +14,11 @@ 
#include <linux/net.h>

#include <linux/gfp.h>

#include <linux/skbuff.h>

#include <linux/circ_buf.h>

#include <linux/export.h>

#include <net/sock.h>

#include <net/af_rxrpc.h>

#include "ar-internal.h"



/*

 * Time till packet resend (in jiffies).

 */

unsigned int rxrpc_resend_timeout = 4 * HZ;



static int rxrpc_send_data(struct rxrpc_sock *rx,

			   struct rxrpc_call *call,

			   struct msghdr *msg, size_t len);



/*

 * extract control messages from the sendmsg() control buffer

 */

static int rxrpc_sendmsg_cmsg(struct msghdr *msg,

			      unsigned long *user_call_ID,

			      enum rxrpc_command *command,

			      u32 *abort_code,

			      bool *_exclusive)

{

	struct cmsghdr *cmsg;

	bool got_user_ID = false;

	int len;



	*command = RXRPC_CMD_SEND_DATA;



	if (msg->msg_controllen == 0)

		return -EINVAL;



	for_each_cmsghdr(cmsg, msg) {

		if (!CMSG_OK(msg, cmsg))

			return -EINVAL;



		len = cmsg->cmsg_len - CMSG_ALIGN(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;

				*user_call_ID = *(u32 *) CMSG_DATA(cmsg);

			} else {

				if (len != sizeof(unsigned long))

					return -EINVAL;

				*user_call_ID = *(unsigned long *)

					CMSG_DATA(cmsg);

			}

			_debug("User Call ID %lx", *user_call_ID);

			got_user_ID = true;

			break;



		case RXRPC_ABORT:

			if (*command != RXRPC_CMD_SEND_DATA)

				return -EINVAL;

			*command = RXRPC_CMD_SEND_ABORT;

			if (len != sizeof(*abort_code))

				return -EINVAL;

			*abort_code = *(unsigned int *) CMSG_DATA(cmsg);

			_debug("Abort %x", *abort_code);

			if (*abort_code == 0)

				return -EINVAL;

			break;



		case RXRPC_ACCEPT:

			if (*command != RXRPC_CMD_SEND_DATA)

				return -EINVAL;

			*command = RXRPC_CMD_ACCEPT;

			if (len != 0)

				return -EINVAL;

			break;



		case RXRPC_EXCLUSIVE_CALL:

			*_exclusive = true;

			if (len != 0)

				return -EINVAL;

			break;

		default:

			return -EINVAL;

		}

	}



	if (!got_user_ID)

		return -EINVAL;

	_leave(" = 0");

	return 0;

}



/*

 * abort a call, sending an ABORT packet to the peer

 */

static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)

{

	if (call->state >= RXRPC_CALL_COMPLETE)

		return;



	write_lock_bh(&call->state_lock);



	if (__rxrpc_abort_call(call, abort_code, ECONNABORTED)) {

		del_timer_sync(&call->resend_timer);

		del_timer_sync(&call->ack_timer);

		clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);

		clear_bit(RXRPC_CALL_EV_ACK, &call->events);

		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);

		rxrpc_queue_call(call);

	}



	write_unlock_bh(&call->state_lock);

}



/*

 * Create a new client call for sendmsg().

 */

static struct rxrpc_call *

rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,

				  unsigned long user_call_ID, bool exclusive)

{

	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)

		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;

	cp.exclusive		= rx->exclusive | exclusive;

	cp.service_id		= srx->srx_service;

	call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);



	_leave(" = %p\n", call);

	return call;

}



/*

 * send a message forming part of a client call through an RxRPC socket

 * - caller holds the socket locked

 * - the socket may be either a client socket or a server socket

 */

int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)

{

	enum rxrpc_command cmd;

	struct rxrpc_call *call;

	unsigned long user_call_ID = 0;

	bool exclusive = false;

	u32 abort_code = 0;

	int ret;



	_enter("");



	ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,

				 &exclusive);

	if (ret < 0)

		return ret;



	if (cmd == RXRPC_CMD_ACCEPT) {

		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)

			return -EINVAL;

		call = rxrpc_accept_call(rx, user_call_ID, NULL);

		if (IS_ERR(call))

			return PTR_ERR(call);

		rxrpc_put_call(call);

		return 0;

	}



	call = rxrpc_find_call_by_user_ID(rx, user_call_ID);

	if (!call) {

		if (cmd != RXRPC_CMD_SEND_DATA)

			return -EBADSLT;

		call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,

							 exclusive);

		if (IS_ERR(call))

			return PTR_ERR(call);

	}



	rxrpc_see_call(call);

	_debug("CALL %d USR %lx ST %d on CONN %p",

	       call->debug_id, call->user_call_ID, call->state, call->conn);



	if (call->state >= RXRPC_CALL_COMPLETE) {

		/* it's too late for this call */

		ret = -ESHUTDOWN;

	} else if (cmd == RXRPC_CMD_SEND_ABORT) {

		rxrpc_send_abort(call, abort_code);

		ret = 0;

	} else if (cmd != RXRPC_CMD_SEND_DATA) {

		ret = -EINVAL;

	} else if (rxrpc_is_client_call(call) &&

		   call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {

		/* request phase complete for this client call */

		ret = -EPROTO;

	} else if (rxrpc_is_service_call(call) &&

		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&

		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {

		/* Reply phase not begun or not complete for service call. */

		ret = -EPROTO;

	} else {

		ret = rxrpc_send_data(rx, call, msg, len);

	}



	rxrpc_put_call(call);

	_leave(" = %d", ret);

	return ret;

}



/**

 * rxrpc_kernel_send_data - Allow a kernel service to send data on a call

 * @sock: The socket the call is on

 * @call: The call to send data through

 * @msg: The data to send

 * @len: The amount of data to send

 *

 * Allow a kernel service to send data on a call.  The call must be in an state

 * appropriate to sending data.  No control data should be supplied in @msg,

 * nor should an address be supplied.  MSG_MORE should be flagged if there's

 * more data to come, otherwise this data will end the transmission phase.

 */

int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,

			   struct msghdr *msg, size_t len)

{

	int ret;



	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);



	ASSERTCMP(msg->msg_name, ==, NULL);

	ASSERTCMP(msg->msg_control, ==, NULL);



	lock_sock(sock->sk);



	_debug("CALL %d USR %lx ST %d on CONN %p",

	       call->debug_id, call->user_call_ID, call->state, call->conn);



	if (call->state >= RXRPC_CALL_COMPLETE) {

		ret = -ESHUTDOWN; /* it's too late for this call */

	} else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&

		   call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&

		   call->state != RXRPC_CALL_SERVER_SEND_REPLY) {

		ret = -EPROTO; /* request phase complete for this client call */

	} else {

		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);

	}



	release_sock(sock->sk);

	_leave(" = %d", ret);

	return ret;

}

EXPORT_SYMBOL(rxrpc_kernel_send_data);



/**

 * rxrpc_kernel_abort_call - Allow a kernel service to abort a call

 * @sock: The socket the call is on

 * @call: The call to be aborted

 * @abort_code: The abort code to stick into the ABORT packet

 *

 * Allow a kernel service to abort a call, if it's still in an abortable state.

 */

void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,

			     u32 abort_code)

{

	_enter("{%d},%d", call->debug_id, abort_code);



	lock_sock(sock->sk);



	_debug("CALL %d USR %lx ST %d on CONN %p",

	       call->debug_id, call->user_call_ID, call->state, call->conn);



	rxrpc_send_abort(call, abort_code);



	release_sock(sock->sk);

	_leave("");

}



EXPORT_SYMBOL(rxrpc_kernel_abort_call);



/*

 * send a packet through the transport endpoint

 */
@@ -375,346 +88,3 @@ int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb) 
	_leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);

	return ret;

}
 


/*

 * 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(",{%d},%ld",

	       CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),

			  call->acks_winsz),

	       *timeo);



	add_wait_queue(&call->waitq, &myself);



	for (;;) {

		set_current_state(TASK_INTERRUPTIBLE);

		ret = 0;

		if (CIRC_SPACE(call->acks_head, ACCESS_ONCE(call->acks_tail),

			       call->acks_winsz) > 0)

			break;

		if (signal_pending(current)) {

			ret = sock_intr_errno(*timeo);

			break;

		}



		release_sock(&rx->sk);

		*timeo = schedule_timeout(*timeo);

		lock_sock(&rx->sk);

	}



	remove_wait_queue(&call->waitq, &myself);

	set_current_state(TASK_RUNNING);

	_leave(" = %d", ret);

	return ret;

}



/*

 * attempt to schedule an instant Tx resend

 */

static inline void rxrpc_instant_resend(struct rxrpc_call *call)

{

	read_lock_bh(&call->state_lock);

	if (try_to_del_timer_sync(&call->resend_timer) >= 0) {

		clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);

		if (call->state < RXRPC_CALL_COMPLETE &&

		    !test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))

			rxrpc_queue_call(call);

	}

	read_unlock_bh(&call->state_lock);

}



/*

 * queue a packet for transmission, set the resend timer and attempt

 * to 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);

	int ret;



	_net("queue skb %p [%d]", skb, call->acks_head);



	ASSERT(call->acks_window != NULL);

	call->acks_window[call->acks_head] = (unsigned long) skb;

	smp_wmb();

	call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);



	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;

			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);

	}



	_proto("Tx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);



	sp->need_resend = false;

	sp->resend_at = jiffies + rxrpc_resend_timeout;

	if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {

		_debug("run timer");

		call->resend_timer.expires = sp->resend_at;

		add_timer(&call->resend_timer);

	}



	/* attempt to cancel the rx-ACK timer, deferring reply transmission if

	 * we're ACK'ing the request phase of an incoming call */

	ret = -EAGAIN;

	if (try_to_del_timer_sync(&call->ack_timer) >= 0) {

		/* the packet may be freed by rxrpc_process_call() before this

		 * returns */

		if (rxrpc_is_client_call(call))

			rxrpc_expose_client_call(call);

		ret = rxrpc_send_data_packet(call->conn, skb);

		_net("sent skb %p", skb);

	} else {

		_debug("failed to delete ACK timer");

	}



	if (ret < 0) {

		_debug("need instant resend %d", ret);

		sp->need_resend = true;

		rxrpc_instant_resend(call);

	}



	_leave("");

}



/*

 * Convert a host-endian header into a network-endian header.

 */

static void rxrpc_insert_header(struct sk_buff *skb)

{

	struct rxrpc_wire_header whdr;

	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);



	whdr.epoch	= htonl(sp->hdr.epoch);

	whdr.cid	= htonl(sp->hdr.cid);

	whdr.callNumber	= htonl(sp->hdr.callNumber);

	whdr.seq	= htonl(sp->hdr.seq);

	whdr.serial	= htonl(sp->hdr.serial);

	whdr.type	= sp->hdr.type;

	whdr.flags	= sp->hdr.flags;

	whdr.userStatus	= sp->hdr.userStatus;

	whdr.securityIndex = sp->hdr.securityIndex;

	whdr._rsvd	= htons(sp->hdr._rsvd);

	whdr.serviceId	= htons(sp->hdr.serviceId);



	memcpy(skb->head, &whdr, sizeof(whdr));

}



/*

 * send data through a socket

 * - must be called in process context

 * - caller holds the socket locked

 */

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;



	skb = call->tx_pending;

	call->tx_pending = NULL;

	rxrpc_see_skb(skb);



	copied = 0;

	do {

		if (!skb) {

			size_t size, chunk, max, space;



			_debug("alloc");



			if (CIRC_SPACE(call->acks_head,

				       ACCESS_ONCE(call->acks_tail),

				       call->acks_winsz) <= 0) {

				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 = call->conn->params.peer->maxdata;

			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->header_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);



			_debug("ALLOC SEND %p", skb);



			ASSERTCMP(skb->mark, ==, 0);



			_debug("HS: %u", call->conn->header_size);

			skb_reserve(skb, call->conn->header_size);

			skb->len += call->conn->header_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;

		}



		/* 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)

					memset(skb_put(skb, pad), 0, pad);

			}



			seq = atomic_inc_return(&call->sequence);



			sp->hdr.epoch	= conn->proto.epoch;

			sp->hdr.cid	= call->cid;

			sp->hdr.callNumber = call->call_id;

			sp->hdr.seq	= seq;

			sp->hdr.serial	= atomic_inc_return(&conn->serial);

			sp->hdr.type	= RXRPC_PACKET_TYPE_DATA;

			sp->hdr.userStatus = 0;

			sp->hdr.securityIndex = conn->security_ix;

			sp->hdr._rsvd	= 0;

			sp->hdr.serviceId = call->service_id;



			sp->hdr.flags = conn->out_clientflag;

			if (msg_data_left(msg) == 0 && !more)

				sp->hdr.flags |= RXRPC_LAST_PACKET;

			else if (CIRC_SPACE(call->acks_head,

					    ACCESS_ONCE(call->acks_tail),

					    call->acks_winsz) > 1)

				sp->hdr.flags |= RXRPC_MORE_PACKETS;

			if (more && seq & 1)

				sp->hdr.flags |= RXRPC_REQUEST_ACK;



			ret = conn->security->secure_packet(

				call, skb, skb->mark,

				skb->head + sizeof(struct rxrpc_wire_header));

			if (ret < 0)

				goto out;



			rxrpc_insert_header(skb);

			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);

	_leave(" = %d", -call->error);

	return ret;



maybe_error:

	if (copied)

		goto success;

	goto out;



efault:

	ret = -EFAULT;

	goto out;

}

net/rxrpc/sendmsg.c

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