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-rw-r--r--net/rxrpc/sendmsg.c606
1 files changed, 606 insertions, 0 deletions
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
new file mode 100644
index 000000000000..3322543d460a
--- /dev/null
+++ b/net/rxrpc/sendmsg.c
@@ -0,0 +1,606 @@
+/* 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 <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 */
+};
+
+/*
+ * 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);
+ 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;
+}
+
+/*
+ * 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;
+ 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
+ * - 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, 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_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+
+ 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;
+ }
+
+ /* 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 = 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,
+ 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;
+}
+
+/*
+ * 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, rxrpc_call_put);
+ 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);
+ }
+
+ _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) {
+ ret = 0;
+ if (rxrpc_abort_call("CMD", call, 0, abort_code, ECONNABORTED))
+ ret = rxrpc_send_call_packet(call,
+ RXRPC_PACKET_TYPE_ABORT);
+ } 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, rxrpc_call_put);
+ _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
+ * @error: Local error value
+ * @why: 3-char string indicating why.
+ *
+ * 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, int error, const char *why)
+{
+ _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
+
+ lock_sock(sock->sk);
+
+ if (rxrpc_abort_call(why, call, 0, abort_code, error))
+ rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+
+ release_sock(sock->sk);
+ _leave("");
+}
+
+EXPORT_SYMBOL(rxrpc_kernel_abort_call);