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0b58b8a18b
Split the sendmsg code from the packet transmission code (mostly to be found in output.c). Signed-off-by: David Howells <dhowells@redhat.com>
90 lines
2.5 KiB
C
90 lines
2.5 KiB
C
/* RxRPC packet transmission
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*
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* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/net.h>
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#include <linux/gfp.h>
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#include <linux/skbuff.h>
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#include <linux/export.h>
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#include <net/sock.h>
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#include <net/af_rxrpc.h>
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#include "ar-internal.h"
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/*
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* send a packet through the transport endpoint
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*/
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int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
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{
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struct kvec iov[1];
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struct msghdr msg;
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int ret, opt;
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_enter(",{%d}", skb->len);
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iov[0].iov_base = skb->head;
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iov[0].iov_len = skb->len;
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msg.msg_name = &conn->params.peer->srx.transport;
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msg.msg_namelen = conn->params.peer->srx.transport_len;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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msg.msg_flags = 0;
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/* send the packet with the don't fragment bit set if we currently
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* think it's small enough */
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if (skb->len - sizeof(struct rxrpc_wire_header) < conn->params.peer->maxdata) {
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down_read(&conn->params.local->defrag_sem);
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/* send the packet by UDP
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* - returns -EMSGSIZE if UDP would have to fragment the packet
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* to go out of the interface
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* - in which case, we'll have processed the ICMP error
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* message and update the peer record
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*/
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ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
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iov[0].iov_len);
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up_read(&conn->params.local->defrag_sem);
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if (ret == -EMSGSIZE)
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goto send_fragmentable;
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_leave(" = %d [%u]", ret, conn->params.peer->maxdata);
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return ret;
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}
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send_fragmentable:
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/* attempt to send this message with fragmentation enabled */
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_debug("send fragment");
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down_write(&conn->params.local->defrag_sem);
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switch (conn->params.local->srx.transport.family) {
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case AF_INET:
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opt = IP_PMTUDISC_DONT;
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ret = kernel_setsockopt(conn->params.local->socket,
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SOL_IP, IP_MTU_DISCOVER,
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(char *)&opt, sizeof(opt));
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if (ret == 0) {
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ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
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iov[0].iov_len);
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opt = IP_PMTUDISC_DO;
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kernel_setsockopt(conn->params.local->socket, SOL_IP,
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IP_MTU_DISCOVER,
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(char *)&opt, sizeof(opt));
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}
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break;
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}
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up_write(&conn->params.local->defrag_sem);
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_leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
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return ret;
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}
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