1 files changed, 658 insertions, 0 deletions

diff --git a/net/rxrpc/ar-output.c b/net/rxrpc/ar-output.c
new file mode 100644
index 000000000000..67aa9510f09b
--- /dev/null
+++ b/net/rxrpc/ar-output.c
@@ -0,0 +1,658 @@
+/* RxRPC packet transmission
+ *
+ * Copyright (C) 2007 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 License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/circ_buf.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include "ar-internal.h"
+
+int rxrpc_resend_timeout = 4;
+
+static int rxrpc_send_data(struct kiocb *iocb,
+                           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 rxrpc_sock *rx, struct msghdr *msg,
+                              unsigned long *user_call_ID,
+                              enum rxrpc_command *command,
+                              u32 *abort_code,
+                              bool server)
+{
+        struct cmsghdr *cmsg;
+        int len;
+
+        *command = RXRPC_CMD_SEND_DATA;
+
+        if (msg->msg_controllen == 0)
+                return -EINVAL;
+
+        for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+                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);
+                        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;
+                        if (!server)
+                                return -EISCONN;
+                        break;
+
+                default:
+                        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)
+{
+        write_lock_bh(&call->state_lock);
+
+        if (call->state <= RXRPC_CALL_COMPLETE) {
+                call->state = RXRPC_CALL_LOCALLY_ABORTED;
+                call->abort_code = abort_code;
+                set_bit(RXRPC_CALL_ABORT, &call->events);
+                del_timer_sync(&call->resend_timer);
+                del_timer_sync(&call->ack_timer);
+                clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+                clear_bit(RXRPC_CALL_ACK, &call->events);
+                clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+                schedule_work(&call->processor);
+        }
+
+        write_unlock_bh(&call->state_lock);
+}
+
+/*
+ * 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_client_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
+                         struct rxrpc_transport *trans, struct msghdr *msg,
+                         size_t len)
+{
+        struct rxrpc_conn_bundle *bundle;
+        enum rxrpc_command cmd;
+        struct rxrpc_call *call;
+        unsigned long user_call_ID = 0;
+        struct key *key;
+        __be16 service_id;
+        u32 abort_code = 0;
+        int ret;
+
+        _enter("");
+
+        ASSERT(trans != NULL);
+
+        ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+                                 false);
+        if (ret < 0)
+                return ret;
+
+        bundle = NULL;
+        if (trans) {
+                service_id = rx->service_id;
+                if (msg->msg_name) {
+                        struct sockaddr_rxrpc *srx =
+                                (struct sockaddr_rxrpc *) msg->msg_name;
+                        service_id = htons(srx->srx_service);
+                }
+                key = rx->key;
+                if (key && !rx->key->payload.data)
+                        key = NULL;
+                bundle = rxrpc_get_bundle(rx, trans, key, service_id,
+                                          GFP_KERNEL);
+                if (IS_ERR(bundle))
+                        return PTR_ERR(bundle);
+        }
+
+        call = rxrpc_get_client_call(rx, trans, bundle, user_call_ID,
+                                     abort_code == 0, GFP_KERNEL);
+        if (trans)
+                rxrpc_put_bundle(trans, bundle);
+        if (IS_ERR(call)) {
+                _leave(" = %ld", PTR_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) {
+                rxrpc_send_abort(call, abort_code);
+        } else if (cmd != RXRPC_CMD_SEND_DATA) {
+                ret = -EINVAL;
+        } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
+                /* request phase complete for this client call */
+                ret = -EPROTO;
+        } else {
+                ret = rxrpc_send_data(iocb, rx, call, msg, len);
+        }
+
+        rxrpc_put_call(call);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * send a message through a server socket
+ * - caller holds the socket locked
+ */
+int rxrpc_server_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
+                         struct msghdr *msg, size_t len)
+{
+        enum rxrpc_command cmd;
+        struct rxrpc_call *call;
+        unsigned long user_call_ID = 0;
+        u32 abort_code = 0;
+        int ret;
+
+        _enter("");
+
+        ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
+                                 true);
+        if (ret < 0)
+                return ret;
+
+        if (cmd == RXRPC_CMD_ACCEPT)
+                return rxrpc_accept_call(rx, user_call_ID);
+
+        call = rxrpc_find_server_call(rx, user_call_ID);
+        if (!call)
+                return -EBADSLT;
+        if (call->state >= RXRPC_CALL_COMPLETE) {
+                ret = -ESHUTDOWN;
+                goto out;
+        }
+
+        switch (cmd) {
+        case RXRPC_CMD_SEND_DATA:
+                if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
+                    call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
+                    call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
+                        /* Tx phase not yet begun for this call */
+                        ret = -EPROTO;
+                        break;
+                }
+
+                ret = rxrpc_send_data(iocb, rx, call, msg, len);
+                break;
+
+        case RXRPC_CMD_SEND_ABORT:
+                rxrpc_send_abort(call, abort_code);
+                break;
+        default:
+                BUG();
+        }
+
+        out:
+        rxrpc_put_call(call);
+        _leave(" = %d", ret);
+        return ret;
+}
+
+/*
+ * send a packet through the transport endpoint
+ */
+int rxrpc_send_packet(struct rxrpc_transport *trans, struct sk_buff *skb)
+{
+        struct kvec iov[1];
+        struct msghdr msg;
+        int ret, opt;
+
+        _enter(",{%d}", skb->len);
+
+        iov[0].iov_base = skb->head;
+        iov[0].iov_len = skb->len;
+
+        msg.msg_name = &trans->peer->srx.transport.sin;
+        msg.msg_namelen = sizeof(trans->peer->srx.transport.sin);
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+        msg.msg_flags = 0;
+
+        /* send the packet with the don't fragment bit set if we currently
+         * think it's small enough */
+        if (skb->len - sizeof(struct rxrpc_header) < trans->peer->maxdata) {
+                down_read(&trans->local->defrag_sem);
+                /* send the packet by UDP
+                 * - returns -EMSGSIZE if UDP would have to fragment the packet
+                 *   to go out of the interface
+                 *   - in which case, we'll have processed the ICMP error
+                 *     message and update the peer record
+                 */
+                ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
+                                     iov[0].iov_len);
+
+                up_read(&trans->local->defrag_sem);
+                if (ret == -EMSGSIZE)
+                        goto send_fragmentable;
+
+                _leave(" = %d [%u]", ret, trans->peer->maxdata);
+                return ret;
+        }
+
+send_fragmentable:
+        /* attempt to send this message with fragmentation enabled */
+        _debug("send fragment");
+
+        down_write(&trans->local->defrag_sem);
+        opt = IP_PMTUDISC_DONT;
+        ret = kernel_setsockopt(trans->local->socket, SOL_IP, IP_MTU_DISCOVER,
+                                (char *) &opt, sizeof(opt));
+        if (ret == 0) {
+                ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
+                                     iov[0].iov_len);
+
+                opt = IP_PMTUDISC_DO;
+                kernel_setsockopt(trans->local->socket, SOL_IP,
+                                  IP_MTU_DISCOVER, (char *) &opt, sizeof(opt));
+        }
+
+        up_write(&trans->local->defrag_sem);
+        _leave(" = %d [frag %u]", ret, trans->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, call->acks_tail, call->acks_winsz),
+               *timeo);
+
+        add_wait_queue(&call->tx_waitq, &myself);
+
+        for (;;) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                ret = 0;
+                if (CIRC_SPACE(call->acks_head, 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->tx_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_RESEND_TIMER, &call->events))
+                        schedule_work(&call->processor);
+        }
+        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 }",
+               ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
+
+        sp->need_resend = 0;
+        sp->resend_at = jiffies + rxrpc_resend_timeout * HZ;
+        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 */
+                ret = rxrpc_send_packet(call->conn->trans, 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 = 1;
+                rxrpc_instant_resend(call);
+        }
+
+        _leave("");
+}
+
+/*
+ * send data through a socket
+ * - must be called in process context
+ * - caller holds the socket locked
+ */
+static int rxrpc_send_data(struct kiocb *iocb,
+                           struct rxrpc_sock *rx,
+                           struct rxrpc_call *call,
+                           struct msghdr *msg, size_t len)
+{
+        struct rxrpc_skb_priv *sp;
+        unsigned char __user *from;
+        struct sk_buff *skb;
+        struct iovec *iov;
+        struct sock *sk = &rx->sk;
+        long timeo;
+        bool more;
+        int ret, ioc, segment, copied;
+
+        _enter(",,,{%zu},%zu", msg->msg_iovlen, len);
+
+        timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+        /* this should be in poll */
+        clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+        if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+                return -EPIPE;
+
+        iov = msg->msg_iov;
+        ioc = msg->msg_iovlen - 1;
+        from = iov->iov_base;
+        segment = iov->iov_len;
+        iov++;
+        more = msg->msg_flags & MSG_MORE;
+
+        skb = call->tx_pending;
+        call->tx_pending = NULL;
+
+        copied = 0;
+        do {
+                int copy;
+
+                if (segment > len)
+                        segment = len;
+
+                _debug("SEGMENT %d @%p", segment, from);
+
+                if (!skb) {
+                        size_t size, chunk, max, space;
+
+                        _debug("alloc");
+
+                        if (CIRC_SPACE(call->acks_head, 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->trans->peer->maxdata;
+                        max -= call->conn->security_size;
+                        max &= ~(call->conn->size_align - 1UL);
+
+                        chunk = max;
+                        if (chunk > len)
+                                chunk = len;
+
+                        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 */
+                copy = skb_tailroom(skb);
+                ASSERTCMP(copy, >, 0);
+                if (copy > segment)
+                        copy = segment;
+                if (copy > sp->remain)
+                        copy = sp->remain;
+
+                _debug("add");
+                ret = skb_add_data(skb, from, copy);
+                _debug("added");
+                if (ret < 0)
+                        goto efault;
+                sp->remain -= copy;
+                skb->mark += copy;
+
+                len -= copy;
+                segment -= copy;
+                from += copy;
+                while (segment == 0 && ioc > 0) {
+                        from = iov->iov_base;
+                        segment = iov->iov_len;
+                        iov++;
+                        ioc--;
+                }
+                if (len == 0) {
+                        segment = 0;
+                        ioc = 0;
+                }
+
+                /* check for the far side aborting the call or a network error
+                 * occurring */
+                if (call->state > RXRPC_CALL_COMPLETE)
+                        goto call_aborted;
+
+                /* add the packet to the send queue if it's now full */
+                if (sp->remain <= 0 || (segment == 0 && !more)) {
+                        struct rxrpc_connection *conn = call->conn;
+                        size_t pad;
+
+                        /* pad out if we're using security */
+                        if (conn->security) {
+                                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);
+                        }
+
+                        sp->hdr.epoch = conn->epoch;
+                        sp->hdr.cid = call->cid;
+                        sp->hdr.callNumber = call->call_id;
+                        sp->hdr.seq =
+                                htonl(atomic_inc_return(&call->sequence));
+                        sp->hdr.serial =
+                                htonl(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 = conn->service_id;
+
+                        sp->hdr.flags = conn->out_clientflag;
+                        if (len == 0 && !more)
+                                sp->hdr.flags |= RXRPC_LAST_PACKET;
+                        else if (CIRC_SPACE(call->acks_head, call->acks_tail,
+                                            call->acks_winsz) > 1)
+                                sp->hdr.flags |= RXRPC_MORE_PACKETS;
+
+                        ret = rxrpc_secure_packet(
+                                call, skb, skb->mark,
+                                skb->head + sizeof(struct rxrpc_header));
+                        if (ret < 0)
+                                goto out;
+
+                        memcpy(skb->head, &sp->hdr,
+                               sizeof(struct rxrpc_header));
+                        rxrpc_queue_packet(call, skb, segment == 0 && !more);
+                        skb = NULL;
+                }
+
+        } while (segment > 0);
+
+out:
+        call->tx_pending = skb;
+        _leave(" = %d", ret);
+        return ret;
+
+call_aborted:
+        rxrpc_free_skb(skb);
+        if (call->state == RXRPC_CALL_NETWORK_ERROR)
+                ret = call->conn->trans->peer->net_error;
+        else
+                ret = -ECONNABORTED;
+        _leave(" = %d", ret);
+        return ret;
+
+maybe_error:
+        if (copied)
+                ret = copied;
+        goto out;
+
+efault:
+        ret = -EFAULT;
+        goto out;
+}