/* ar-skbuff.c: socket buffer destruction handling * * 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/module.h> #include <linux/net.h> #include <linux/skbuff.h> #include <net/sock.h> #include <net/af_rxrpc.h> #include "ar-internal.h" /* * set up for the ACK at the end of the receive phase when we discard the final * receive phase data packet * - called with softirqs disabled */ static void rxrpc_request_final_ACK(struct rxrpc_call *call) { /* the call may be aborted before we have a chance to ACK it */ write_lock(&call->state_lock); switch (call->state) { case RXRPC_CALL_CLIENT_RECV_REPLY: call->state = RXRPC_CALL_CLIENT_FINAL_ACK; _debug("request final ACK"); /* get an extra ref on the call for the final-ACK generator to * release */ rxrpc_get_call(call); set_bit(RXRPC_CALL_ACK_FINAL, &call->events); if (try_to_del_timer_sync(&call->ack_timer) >= 0) rxrpc_queue_call(call); break; case RXRPC_CALL_SERVER_RECV_REQUEST: call->state = RXRPC_CALL_SERVER_ACK_REQUEST; default: break; } write_unlock(&call->state_lock); } /* * drop the bottom ACK off of the call ACK window and advance the window */ static void rxrpc_hard_ACK_data(struct rxrpc_call *call, struct rxrpc_skb_priv *sp) { int loop; u32 seq; spin_lock_bh(&call->lock); _debug("hard ACK #%u", ntohl(sp->hdr.seq)); for (loop = 0; loop < RXRPC_ACKR_WINDOW_ASZ; loop++) { call->ackr_window[loop] >>= 1; call->ackr_window[loop] |= call->ackr_window[loop + 1] << (BITS_PER_LONG - 1); } seq = ntohl(sp->hdr.seq); ASSERTCMP(seq, ==, call->rx_data_eaten + 1); call->rx_data_eaten = seq; if (call->ackr_win_top < UINT_MAX) call->ackr_win_top++; ASSERTIFCMP(call->state <= RXRPC_CALL_COMPLETE, call->rx_data_post, >=, call->rx_data_recv); ASSERTIFCMP(call->state <= RXRPC_CALL_COMPLETE, call->rx_data_recv, >=, call->rx_data_eaten); if (sp->hdr.flags & RXRPC_LAST_PACKET) { rxrpc_request_final_ACK(call); } else if (atomic_dec_and_test(&call->ackr_not_idle) && test_and_clear_bit(RXRPC_CALL_TX_SOFT_ACK, &call->flags)) { _debug("send Rx idle ACK"); __rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, sp->hdr.serial, true); } spin_unlock_bh(&call->lock); } /* * destroy a packet that has an RxRPC control buffer * - advance the hard-ACK state of the parent call (done here in case something * in the kernel bypasses recvmsg() and steals the packet directly off of the * socket receive queue) */ void rxrpc_packet_destructor(struct sk_buff *skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); struct rxrpc_call *call = sp->call; _enter("%p{%p}", skb, call); if (call) { /* send the final ACK on a client call */ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) rxrpc_hard_ACK_data(call, sp); rxrpc_put_call(call); sp->call = NULL; } if (skb->sk) sock_rfree(skb); _leave(""); } /** * rxrpc_kernel_free_skb - Free an RxRPC socket buffer * @skb: The socket buffer to be freed * * Let RxRPC free its own socket buffer, permitting it to maintain debug * accounting. */ void rxrpc_kernel_free_skb(struct sk_buff *skb) { rxrpc_free_skb(skb); } EXPORT_SYMBOL(rxrpc_kernel_free_skb);