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/* 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.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/net.h>
#include <linux/gfp.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
struct rxrpc_pkt_buffer {
struct rxrpc_wire_header whdr;
union {
struct {
struct rxrpc_ackpacket ack;
u8 acks[255];
u8 pad[3];
};
__be32 abort_code;
};
struct rxrpc_ackinfo ackinfo;
};
/*
* Fill out an ACK packet.
*/
static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
struct rxrpc_pkt_buffer *pkt)
{
u32 mtu, jmax;
u8 *ackp = pkt->acks;
pkt->ack.bufferSpace = htons(8);
pkt->ack.maxSkew = htons(0);
pkt->ack.firstPacket = htonl(call->rx_data_eaten + 1);
pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
pkt->ack.serial = htonl(call->ackr_serial);
pkt->ack.reason = RXRPC_ACK_IDLE;
pkt->ack.nAcks = 0;
mtu = call->peer->if_mtu;
mtu -= call->peer->hdrsize;
jmax = rxrpc_rx_jumbo_max;
pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
pkt->ackinfo.maxMTU = htonl(mtu);
pkt->ackinfo.rwind = htonl(rxrpc_rx_window_size);
pkt->ackinfo.jumbo_max = htonl(jmax);
*ackp++ = 0;
*ackp++ = 0;
*ackp++ = 0;
return 3;
}
/*
* Send a final ACK or ABORT call packet.
*/
int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
{
struct rxrpc_connection *conn = NULL;
struct rxrpc_pkt_buffer *pkt;
struct msghdr msg;
struct kvec iov[2];
rxrpc_serial_t serial;
size_t len, n;
int ioc, ret;
u32 abort_code;
_enter("%u,%s", call->debug_id, rxrpc_pkts[type]);
spin_lock_bh(&call->lock);
if (call->conn)
conn = rxrpc_get_connection_maybe(call->conn);
spin_unlock_bh(&call->lock);
if (!conn)
return -ECONNRESET;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt) {
rxrpc_put_connection(conn);
return -ENOMEM;
}
serial = atomic_inc_return(&conn->serial);
msg.msg_name = &call->peer->srx.transport;
msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
pkt->whdr.epoch = htonl(conn->proto.epoch);
pkt->whdr.cid = htonl(call->cid);
pkt->whdr.callNumber = htonl(call->call_id);
pkt->whdr.seq = 0;
pkt->whdr.serial = htonl(serial);
pkt->whdr.type = type;
pkt->whdr.flags = conn->out_clientflag;
pkt->whdr.userStatus = 0;
pkt->whdr.securityIndex = call->security_ix;
pkt->whdr._rsvd = 0;
pkt->whdr.serviceId = htons(call->service_id);
iov[0].iov_base = pkt;
iov[0].iov_len = sizeof(pkt->whdr);
len = sizeof(pkt->whdr);
switch (type) {
case RXRPC_PACKET_TYPE_ACK:
spin_lock_bh(&call->lock);
n = rxrpc_fill_out_ack(call, pkt);
call->ackr_reason = 0;
spin_unlock_bh(&call->lock);
_proto("Tx ACK %%%u { m=%hu f=#%u p=#%u s=%%%u r=%s n=%u }",
serial,
ntohs(pkt->ack.maxSkew),
ntohl(pkt->ack.firstPacket),
ntohl(pkt->ack.previousPacket),
ntohl(pkt->ack.serial),
rxrpc_acks(pkt->ack.reason),
pkt->ack.nAcks);
iov[0].iov_len += sizeof(pkt->ack) + n;
iov[1].iov_base = &pkt->ackinfo;
iov[1].iov_len = sizeof(pkt->ackinfo);
len += sizeof(pkt->ack) + n + sizeof(pkt->ackinfo);
ioc = 2;
break;
case RXRPC_PACKET_TYPE_ABORT:
abort_code = call->abort_code;
pkt->abort_code = htonl(abort_code);
_proto("Tx ABORT %%%u { %d }", serial, abort_code);
iov[0].iov_len += sizeof(pkt->abort_code);
len += sizeof(pkt->abort_code);
ioc = 1;
break;
default:
BUG();
ret = -ENOANO;
goto out;
}
ret = kernel_sendmsg(conn->params.local->socket,
&msg, iov, ioc, len);
out:
rxrpc_put_connection(conn);
kfree(pkt);
return ret;
}
/*
* send a packet through the transport endpoint
*/
int rxrpc_send_data_packet(struct rxrpc_connection *conn, 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 = &conn->params.peer->srx.transport;
msg.msg_namelen = conn->params.peer->srx.transport_len;
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_wire_header) < conn->params.peer->maxdata) {
down_read(&conn->params.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(conn->params.local->socket, &msg, iov, 1,
iov[0].iov_len);
up_read(&conn->params.local->defrag_sem);
if (ret == -EMSGSIZE)
goto send_fragmentable;
_leave(" = %d [%u]", ret, conn->params.peer->maxdata);
return ret;
}
send_fragmentable:
/* attempt to send this message with fragmentation enabled */
_debug("send fragment");
down_write(&conn->params.local->defrag_sem);
switch (conn->params.local->srx.transport.family) {
case AF_INET:
opt = IP_PMTUDISC_DONT;
ret = kernel_setsockopt(conn->params.local->socket,
SOL_IP, IP_MTU_DISCOVER,
(char *)&opt, sizeof(opt));
if (ret == 0) {
ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
iov[0].iov_len);
opt = IP_PMTUDISC_DO;
kernel_setsockopt(conn->params.local->socket, SOL_IP,
IP_MTU_DISCOVER,
(char *)&opt, sizeof(opt));
}
break;
}
up_write(&conn->params.local->defrag_sem);
_leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
return ret;
}
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