diff options
Diffstat (limited to '')
| -rw-r--r-- | net/rxrpc/sendmsg.c | 882 |
1 files changed, 882 insertions, 0 deletions
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c new file mode 100644 index 000000000..71e40f91d --- /dev/null +++ b/net/rxrpc/sendmsg.c @@ -0,0 +1,882 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* AF_RXRPC sendmsg() implementation. + * + * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#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" + +/* + * Return true if there's sufficient Tx queue space. + */ +static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win) +{ + unsigned int win_size = + min_t(unsigned int, call->tx_winsize, + call->cong_cwnd + call->cong_extra); + rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack); + + if (_tx_win) + *_tx_win = tx_win; + return call->tx_top - tx_win < win_size; +} + +/* + * Wait for space to appear in the Tx queue or a signal to occur. + */ +static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx, + struct rxrpc_call *call, + long *timeo) +{ + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (rxrpc_check_tx_space(call, NULL)) + return 0; + + if (call->state >= RXRPC_CALL_COMPLETE) + return call->error; + + if (signal_pending(current)) + return sock_intr_errno(*timeo); + + trace_rxrpc_transmit(call, rxrpc_transmit_wait); + *timeo = schedule_timeout(*timeo); + } +} + +/* + * Wait for space to appear in the Tx queue uninterruptibly, but with + * a timeout of 2*RTT if no progress was made and a signal occurred. + */ +static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx, + struct rxrpc_call *call) +{ + rxrpc_seq_t tx_start, tx_win; + signed long rtt, timeout; + + rtt = READ_ONCE(call->peer->srtt_us) >> 3; + rtt = usecs_to_jiffies(rtt) * 2; + if (rtt < 2) + rtt = 2; + + timeout = rtt; + tx_start = READ_ONCE(call->tx_hard_ack); + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + + tx_win = READ_ONCE(call->tx_hard_ack); + if (rxrpc_check_tx_space(call, &tx_win)) + return 0; + + if (call->state >= RXRPC_CALL_COMPLETE) + return call->error; + + if (timeout == 0 && + tx_win == tx_start && signal_pending(current)) + return -EINTR; + + if (tx_win != tx_start) { + timeout = rtt; + tx_start = tx_win; + } + + trace_rxrpc_transmit(call, rxrpc_transmit_wait); + timeout = schedule_timeout(timeout); + } +} + +/* + * Wait for space to appear in the Tx queue uninterruptibly. + */ +static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx, + struct rxrpc_call *call, + long *timeo) +{ + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (rxrpc_check_tx_space(call, NULL)) + return 0; + + if (call->state >= RXRPC_CALL_COMPLETE) + return call->error; + + trace_rxrpc_transmit(call, rxrpc_transmit_wait); + *timeo = schedule_timeout(*timeo); + } +} + +/* + * 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, + bool waitall) +{ + 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); + + switch (call->interruptibility) { + case RXRPC_INTERRUPTIBLE: + if (waitall) + ret = rxrpc_wait_for_tx_window_waitall(rx, call); + else + ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo); + break; + case RXRPC_PREINTERRUPTIBLE: + case RXRPC_UNINTERRUPTIBLE: + default: + ret = rxrpc_wait_for_tx_window_nonintr(rx, call, 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] = + (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) | + RXRPC_TX_ANNO_RETRANS; + if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events)) + rxrpc_queue_call(call); + } + + spin_unlock_bh(&call->lock); +} + +/* + * Notify the owner of the call that the transmit phase is ended and the last + * packet has been queued. + */ +static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call, + rxrpc_notify_end_tx_t notify_end_tx) +{ + if (notify_end_tx) + notify_end_tx(&rx->sk, call, call->user_call_ID); +} + +/* + * Queue a DATA packet for transmission, set the resend timeout and send + * the packet immediately. Returns the error from rxrpc_send_data_packet() + * in case the caller wants to do something with it. + */ +static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call, + struct sk_buff *skb, bool last, + rxrpc_notify_end_tx_t notify_end_tx) +{ + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + unsigned long now; + 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_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; + rxrpc_notify_end_tx(rx, call, notify_end_tx); + break; + case RXRPC_CALL_SERVER_ACK_REQUEST: + call->state = RXRPC_CALL_SERVER_SEND_REPLY; + now = jiffies; + WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET); + if (call->ackr_reason == RXRPC_ACK_DELAY) + call->ackr_reason = 0; + trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now); + if (!last) + break; + fallthrough; + case RXRPC_CALL_SERVER_SEND_REPLY: + call->state = RXRPC_CALL_SERVER_AWAIT_ACK; + rxrpc_notify_end_tx(rx, call, notify_end_tx); + 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) { + switch (ret) { + case -ENETUNREACH: + case -EHOSTUNREACH: + case -ECONNREFUSED: + rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, + 0, ret); + goto out; + } + _debug("need instant resend %d", ret); + rxrpc_instant_resend(call, ix); + } else { + unsigned long now = jiffies; + unsigned long resend_at = now + call->peer->rto_j; + + WRITE_ONCE(call->resend_at, resend_at); + rxrpc_reduce_call_timer(call, resend_at, now, + rxrpc_timer_set_for_send); + } + +out: + rxrpc_free_skb(skb, rxrpc_skb_freed); + _leave(" = %d", ret); + return ret; +} + +/* + * 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, + rxrpc_notify_end_tx_t notify_end_tx, + bool *_dropped_lock) +{ + struct rxrpc_skb_priv *sp; + struct sk_buff *skb; + struct sock *sk = &rx->sk; + enum rxrpc_call_state state; + long timeo; + bool more = msg->msg_flags & MSG_MORE; + int ret, copied = 0; + + timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); + + /* this should be in poll */ + sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); + +reload: + ret = -EPIPE; + if (sk->sk_shutdown & SEND_SHUTDOWN) + goto maybe_error; + state = READ_ONCE(call->state); + ret = -ESHUTDOWN; + if (state >= RXRPC_CALL_COMPLETE) + goto maybe_error; + ret = -EPROTO; + if (state != RXRPC_CALL_CLIENT_SEND_REQUEST && + state != RXRPC_CALL_SERVER_ACK_REQUEST && + state != RXRPC_CALL_SERVER_SEND_REPLY) + goto maybe_error; + + ret = -EMSGSIZE; + if (call->tx_total_len != -1) { + if (len - copied > call->tx_total_len) + goto maybe_error; + if (!more && len - copied != call->tx_total_len) + goto maybe_error; + } + + skb = call->tx_pending; + call->tx_pending = NULL; + rxrpc_see_skb(skb, rxrpc_skb_seen); + + 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, NULL); + + if (!skb) { + size_t remain, bufsize, chunk, offset; + + _debug("alloc"); + + if (!rxrpc_check_tx_space(call, NULL)) + goto wait_for_space; + + /* Work out the maximum size of a packet. Assume that + * the security header is going to be in the padded + * region (enc blocksize), but the trailer is not. + */ + remain = more ? INT_MAX : msg_data_left(msg); + ret = call->conn->security->how_much_data(call, remain, + &bufsize, &chunk, &offset); + if (ret < 0) + goto maybe_error; + + _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset); + + /* create a buffer that we can retain until it's ACK'd */ + skb = sock_alloc_send_skb( + sk, bufsize, msg->msg_flags & MSG_DONTWAIT, &ret); + if (!skb) + goto maybe_error; + + sp = rxrpc_skb(skb); + sp->rx_flags |= RXRPC_SKB_TX_BUFFER; + rxrpc_new_skb(skb, rxrpc_skb_new); + + _debug("ALLOC SEND %p", skb); + + ASSERTCMP(skb->mark, ==, 0); + + __skb_put(skb, offset); + + 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; + + 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 = call->security->secure_packet(call, skb, skb->mark); + if (ret < 0) + goto out; + + ret = rxrpc_queue_packet(rx, call, skb, + !msg_data_left(msg) && !more, + notify_end_tx); + /* Should check for failure here */ + skb = NULL; + } + } while (msg_data_left(msg) > 0); + +success: + ret = copied; + if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) { + read_lock_bh(&call->state_lock); + if (call->error < 0) + ret = call->error; + read_unlock_bh(&call->state_lock); + } +out: + call->tx_pending = skb; + _leave(" = %d", ret); + return ret; + +call_terminated: + rxrpc_free_skb(skb, rxrpc_skb_freed); + _leave(" = %d", call->error); + return call->error; + +maybe_error: + if (copied) + goto success; + goto out; + +efault: + ret = -EFAULT; + goto out; + +wait_for_space: + ret = -EAGAIN; + if (msg->msg_flags & MSG_DONTWAIT) + goto maybe_error; + mutex_unlock(&call->user_mutex); + *_dropped_lock = true; + ret = rxrpc_wait_for_tx_window(rx, call, &timeo, + msg->msg_flags & MSG_WAITALL); + if (ret < 0) + goto maybe_error; + if (call->interruptibility == RXRPC_INTERRUPTIBLE) { + if (mutex_lock_interruptible(&call->user_mutex) < 0) { + ret = sock_intr_errno(timeo); + goto maybe_error; + } + } else { + mutex_lock(&call->user_mutex); + } + *_dropped_lock = false; + goto reload; +} + +/* + * 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->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg); + } else { + if (len != sizeof(unsigned long)) + return -EINVAL; + p->call.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_CHARGE_ACCEPT: + if (p->command != RXRPC_CMD_SEND_DATA) + return -EINVAL; + p->command = RXRPC_CMD_CHARGE_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->call.tx_total_len != -1 || len != sizeof(__s64)) + return -EINVAL; + p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg); + if (p->call.tx_total_len < 0) + return -EINVAL; + break; + + case RXRPC_SET_CALL_TIMEOUT: + if (len & 3 || len < 4 || len > 12) + return -EINVAL; + memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len); + p->call.nr_timeouts = len / 4; + if (p->call.timeouts.hard > INT_MAX / HZ) + return -ERANGE; + if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000) + return -ERANGE; + if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000) + return -ERANGE; + break; + + default: + return -EINVAL; + } + } + + if (!got_user_ID) + return -EINVAL; + if (p->call.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) + __acquires(&call->user_mutex) +{ + 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; + cp.exclusive = rx->exclusive | p->exclusive; + cp.upgrade = p->upgrade; + cp.service_id = srx->srx_service; + call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL, + atomic_inc_return(&rxrpc_debug_id)); + /* The socket is now unlocked */ + + rxrpc_put_peer(cp.peer); + _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) + __releases(&rx->sk.sk_lock.slock) + __releases(&call->user_mutex) +{ + enum rxrpc_call_state state; + struct rxrpc_call *call; + unsigned long now, j; + bool dropped_lock = false; + int ret; + + struct rxrpc_send_params p = { + .call.tx_total_len = -1, + .call.user_call_ID = 0, + .call.nr_timeouts = 0, + .call.interruptibility = RXRPC_INTERRUPTIBLE, + .abort_code = 0, + .command = RXRPC_CMD_SEND_DATA, + .exclusive = false, + .upgrade = false, + }; + + _enter(""); + + ret = rxrpc_sendmsg_cmsg(msg, &p); + if (ret < 0) + goto error_release_sock; + + if (p.command == RXRPC_CMD_CHARGE_ACCEPT) { + ret = -EINVAL; + if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) + goto error_release_sock; + ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID); + goto error_release_sock; + } + + call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID); + if (!call) { + ret = -EBADSLT; + if (p.command != RXRPC_CMD_SEND_DATA) + goto error_release_sock; + call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p); + /* The socket is now unlocked... */ + if (IS_ERR(call)) + return PTR_ERR(call); + /* ... and we have the call lock. */ + ret = 0; + if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) + goto out_put_unlock; + } else { + switch (READ_ONCE(call->state)) { + case RXRPC_CALL_UNINITIALISED: + case RXRPC_CALL_CLIENT_AWAIT_CONN: + case RXRPC_CALL_SERVER_PREALLOC: + case RXRPC_CALL_SERVER_SECURING: + rxrpc_put_call(call, rxrpc_call_put); + ret = -EBUSY; + goto error_release_sock; + default: + break; + } + + ret = mutex_lock_interruptible(&call->user_mutex); + release_sock(&rx->sk); + if (ret < 0) { + ret = -ERESTARTSYS; + goto error_put; + } + + if (p.call.tx_total_len != -1) { + ret = -EINVAL; + if (call->tx_total_len != -1 || + call->tx_pending || + call->tx_top != 0) + goto out_put_unlock; + call->tx_total_len = p.call.tx_total_len; + } + } + + switch (p.call.nr_timeouts) { + case 3: + j = msecs_to_jiffies(p.call.timeouts.normal); + if (p.call.timeouts.normal > 0 && j == 0) + j = 1; + WRITE_ONCE(call->next_rx_timo, j); + fallthrough; + case 2: + j = msecs_to_jiffies(p.call.timeouts.idle); + if (p.call.timeouts.idle > 0 && j == 0) + j = 1; + WRITE_ONCE(call->next_req_timo, j); + fallthrough; + case 1: + if (p.call.timeouts.hard > 0) { + j = p.call.timeouts.hard * HZ; + now = jiffies; + j += now; + WRITE_ONCE(call->expect_term_by, j); + rxrpc_reduce_call_timer(call, j, now, + rxrpc_timer_set_for_hard); + } + break; + } + + state = READ_ONCE(call->state); + _debug("CALL %d USR %lx ST %d on CONN %p", + call->debug_id, call->user_call_ID, state, call->conn); + + if (state >= RXRPC_CALL_COMPLETE) { + /* it's too late for this call */ + ret = -ESHUTDOWN; + } else if (p.command == RXRPC_CMD_SEND_ABORT) { + ret = 0; + if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED)) + ret = rxrpc_send_abort_packet(call); + } else if (p.command != RXRPC_CMD_SEND_DATA) { + ret = -EINVAL; + } else { + ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock); + } + +out_put_unlock: + if (!dropped_lock) + mutex_unlock(&call->user_mutex); +error_put: + rxrpc_put_call(call, rxrpc_call_put); + _leave(" = %d", ret); + return ret; + +error_release_sock: + release_sock(&rx->sk); + 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 + * @notify_end_tx: Notification that the last packet is queued. + * + * 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, + rxrpc_notify_end_tx_t notify_end_tx) +{ + bool dropped_lock = false; + int ret; + + _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]); + + ASSERTCMP(msg->msg_name, ==, NULL); + ASSERTCMP(msg->msg_control, ==, NULL); + + mutex_lock(&call->user_mutex); + + _debug("CALL %d USR %lx ST %d on CONN %p", + call->debug_id, call->user_call_ID, call->state, call->conn); + + switch (READ_ONCE(call->state)) { + case RXRPC_CALL_CLIENT_SEND_REQUEST: + case RXRPC_CALL_SERVER_ACK_REQUEST: + case RXRPC_CALL_SERVER_SEND_REPLY: + ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len, + notify_end_tx, &dropped_lock); + break; + case RXRPC_CALL_COMPLETE: + read_lock_bh(&call->state_lock); + ret = call->error; + read_unlock_bh(&call->state_lock); + break; + default: + /* Request phase complete for this client call */ + trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send")); + ret = -EPROTO; + break; + } + + if (!dropped_lock) + mutex_unlock(&call->user_mutex); + _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 + * and return true if the call was aborted, false if it was already complete. + */ +bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call, + u32 abort_code, int error, const char *why) +{ + bool aborted; + + _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why); + + mutex_lock(&call->user_mutex); + + aborted = rxrpc_abort_call(why, call, 0, abort_code, error); + if (aborted) + rxrpc_send_abort_packet(call); + + mutex_unlock(&call->user_mutex); + return aborted; +} +EXPORT_SYMBOL(rxrpc_kernel_abort_call); + +/** + * rxrpc_kernel_set_tx_length - Set the total Tx length on a call + * @sock: The socket the call is on + * @call: The call to be informed + * @tx_total_len: The amount of data to be transmitted for this call + * + * Allow a kernel service to set the total transmit length on a call. This + * allows buffer-to-packet encrypt-and-copy to be performed. + * + * This function is primarily for use for setting the reply length since the + * request length can be set when beginning the call. + */ +void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call, + s64 tx_total_len) +{ + WARN_ON(call->tx_total_len != -1); + call->tx_total_len = tx_total_len; +} +EXPORT_SYMBOL(rxrpc_kernel_set_tx_length); |