diff options
author | David Howells <dhowells@redhat.com> | 2016-09-02 23:39:45 +0200 |
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committer | David Howells <dhowells@redhat.com> | 2016-09-04 22:41:39 +0200 |
commit | 0b58b8a18be4932849ec88a820b08345c6528ea5 (patch) | |
tree | a6de1494771df343ae8696dfb5dbf08485da11a7 /net/rxrpc/sendmsg.c | |
parent | fs/afs/flock: Remove deprecated create_singlethread_workqueue (diff) | |
download | linux-0b58b8a18be4932849ec88a820b08345c6528ea5.tar.xz linux-0b58b8a18be4932849ec88a820b08345c6528ea5.zip |
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: David Howells <dhowells@redhat.com>
Diffstat (limited to '')
-rw-r--r-- | net/rxrpc/sendmsg.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c new file mode 100644 index 000000000000..ff3e28ddc6d8 --- /dev/null +++ b/net/rxrpc/sendmsg.c @@ -0,0 +1,645 @@ +/* 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/circ_buf.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include "ar-internal.h" + +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); + +/* + * 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; +} |