1 /* RxRPC packet transmission
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/net.h>
15 #include <linux/gfp.h>
16 #include <linux/skbuff.h>
17 #include <linux/export.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
22 struct rxrpc_ack_buffer {
23 struct rxrpc_wire_header whdr;
24 struct rxrpc_ackpacket ack;
27 struct rxrpc_ackinfo ackinfo;
30 struct rxrpc_abort_buffer {
31 struct rxrpc_wire_header whdr;
36 * Fill out an ACK packet.
38 static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
39 struct rxrpc_ack_buffer *pkt,
40 rxrpc_seq_t *_hard_ack,
44 rxrpc_serial_t serial;
45 rxrpc_seq_t hard_ack, top, seq;
50 /* Barrier against rxrpc_input_data(). */
51 serial = call->ackr_serial;
52 hard_ack = READ_ONCE(call->rx_hard_ack);
53 top = smp_load_acquire(&call->rx_top);
54 *_hard_ack = hard_ack;
57 pkt->ack.bufferSpace = htons(8);
58 pkt->ack.maxSkew = htons(call->ackr_skew);
59 pkt->ack.firstPacket = htonl(hard_ack + 1);
60 pkt->ack.previousPacket = htonl(call->ackr_prev_seq);
61 pkt->ack.serial = htonl(serial);
62 pkt->ack.reason = reason;
63 pkt->ack.nAcks = top - hard_ack;
65 if (reason == RXRPC_ACK_PING)
66 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
68 if (after(top, hard_ack)) {
71 ix = seq & RXRPC_RXTX_BUFF_MASK;
72 if (call->rxtx_buffer[ix])
73 *ackp++ = RXRPC_ACK_TYPE_ACK;
75 *ackp++ = RXRPC_ACK_TYPE_NACK;
77 } while (before_eq(seq, top));
80 mtu = call->conn->params.peer->if_mtu;
81 mtu -= call->conn->params.peer->hdrsize;
82 jmax = (call->nr_jumbo_bad > 3) ? 1 : rxrpc_rx_jumbo_max;
83 pkt->ackinfo.rxMTU = htonl(rxrpc_rx_mtu);
84 pkt->ackinfo.maxMTU = htonl(mtu);
85 pkt->ackinfo.rwind = htonl(call->rx_winsize);
86 pkt->ackinfo.jumbo_max = htonl(jmax);
91 return top - hard_ack + 3;
95 * Send an ACK call packet.
97 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
99 struct rxrpc_connection *conn;
100 struct rxrpc_ack_buffer *pkt;
103 rxrpc_serial_t serial;
104 rxrpc_seq_t hard_ack, top;
109 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
112 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
118 msg.msg_name = &call->peer->srx.transport;
119 msg.msg_namelen = call->peer->srx.transport_len;
120 msg.msg_control = NULL;
121 msg.msg_controllen = 0;
124 pkt->whdr.epoch = htonl(conn->proto.epoch);
125 pkt->whdr.cid = htonl(call->cid);
126 pkt->whdr.callNumber = htonl(call->call_id);
128 pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
129 pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
130 pkt->whdr.userStatus = 0;
131 pkt->whdr.securityIndex = call->security_ix;
133 pkt->whdr.serviceId = htons(call->service_id);
135 spin_lock_bh(&call->lock);
137 reason = RXRPC_ACK_PING;
139 reason = call->ackr_reason;
140 if (!call->ackr_reason) {
141 spin_unlock_bh(&call->lock);
145 call->ackr_reason = 0;
147 n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
149 spin_unlock_bh(&call->lock);
151 iov[0].iov_base = pkt;
152 iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
153 iov[1].iov_base = &pkt->ackinfo;
154 iov[1].iov_len = sizeof(pkt->ackinfo);
155 len = iov[0].iov_len + iov[1].iov_len;
157 serial = atomic_inc_return(&conn->serial);
158 pkt->whdr.serial = htonl(serial);
159 trace_rxrpc_tx_ack(call, serial,
160 ntohl(pkt->ack.firstPacket),
161 ntohl(pkt->ack.serial),
162 pkt->ack.reason, pkt->ack.nAcks);
165 call->ping_serial = serial;
167 /* We need to stick a time in before we send the packet in case
168 * the reply gets back before kernel_sendmsg() completes - but
169 * asking UDP to send the packet can take a relatively long
170 * time, so we update the time after, on the assumption that
171 * the packet transmission is more likely to happen towards the
172 * end of the kernel_sendmsg() call.
174 call->ping_time = ktime_get_real();
175 set_bit(RXRPC_CALL_PINGING, &call->flags);
176 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
179 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
181 call->ping_time = ktime_get_real();
183 if (call->state < RXRPC_CALL_COMPLETE) {
186 clear_bit(RXRPC_CALL_PINGING, &call->flags);
187 rxrpc_propose_ACK(call, pkt->ack.reason,
188 ntohs(pkt->ack.maxSkew),
189 ntohl(pkt->ack.serial),
191 rxrpc_propose_ack_retry_tx);
193 spin_lock_bh(&call->lock);
194 if (after(hard_ack, call->ackr_consumed))
195 call->ackr_consumed = hard_ack;
196 if (after(top, call->ackr_seen))
197 call->ackr_seen = top;
198 spin_unlock_bh(&call->lock);
208 * Send an ABORT call packet.
210 int rxrpc_send_abort_packet(struct rxrpc_call *call)
212 struct rxrpc_connection *conn;
213 struct rxrpc_abort_buffer pkt;
216 rxrpc_serial_t serial;
219 if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
224 msg.msg_name = &call->peer->srx.transport;
225 msg.msg_namelen = call->peer->srx.transport_len;
226 msg.msg_control = NULL;
227 msg.msg_controllen = 0;
230 pkt.whdr.epoch = htonl(conn->proto.epoch);
231 pkt.whdr.cid = htonl(call->cid);
232 pkt.whdr.callNumber = htonl(call->call_id);
234 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
235 pkt.whdr.flags = conn->out_clientflag;
236 pkt.whdr.userStatus = 0;
237 pkt.whdr.securityIndex = call->security_ix;
239 pkt.whdr.serviceId = htons(call->service_id);
240 pkt.abort_code = htonl(call->abort_code);
242 iov[0].iov_base = &pkt;
243 iov[0].iov_len = sizeof(pkt);
245 serial = atomic_inc_return(&conn->serial);
246 pkt.whdr.serial = htonl(serial);
248 ret = kernel_sendmsg(conn->params.local->socket,
249 &msg, iov, 1, sizeof(pkt));
255 * send a packet through the transport endpoint
257 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
260 struct rxrpc_connection *conn = call->conn;
261 struct rxrpc_wire_header whdr;
262 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
265 rxrpc_serial_t serial;
270 _enter(",{%d}", skb->len);
272 /* Each transmission of a Tx packet needs a new serial number */
273 serial = atomic_inc_return(&conn->serial);
275 whdr.epoch = htonl(conn->proto.epoch);
276 whdr.cid = htonl(call->cid);
277 whdr.callNumber = htonl(call->call_id);
278 whdr.seq = htonl(sp->hdr.seq);
279 whdr.serial = htonl(serial);
280 whdr.type = RXRPC_PACKET_TYPE_DATA;
281 whdr.flags = sp->hdr.flags;
283 whdr.securityIndex = call->security_ix;
284 whdr._rsvd = htons(sp->hdr._rsvd);
285 whdr.serviceId = htons(call->service_id);
287 iov[0].iov_base = &whdr;
288 iov[0].iov_len = sizeof(whdr);
289 iov[1].iov_base = skb->head;
290 iov[1].iov_len = skb->len;
291 len = iov[0].iov_len + iov[1].iov_len;
293 msg.msg_name = &call->peer->srx.transport;
294 msg.msg_namelen = call->peer->srx.transport_len;
295 msg.msg_control = NULL;
296 msg.msg_controllen = 0;
299 /* If our RTT cache needs working on, request an ACK. Also request
300 * ACKs if a DATA packet appears to have been lost.
302 if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
304 call->cong_mode == RXRPC_CALL_SLOW_START ||
305 (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
306 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
308 whdr.flags |= RXRPC_REQUEST_ACK;
310 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
312 if ((lose++ & 7) == 7) {
319 _proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
321 /* send the packet with the don't fragment bit set if we currently
322 * think it's small enough */
323 if (iov[1].iov_len >= call->peer->maxdata)
324 goto send_fragmentable;
326 down_read(&conn->params.local->defrag_sem);
327 /* send the packet by UDP
328 * - returns -EMSGSIZE if UDP would have to fragment the packet
329 * to go out of the interface
330 * - in which case, we'll have processed the ICMP error
331 * message and update the peer record
333 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
335 up_read(&conn->params.local->defrag_sem);
336 if (ret == -EMSGSIZE)
337 goto send_fragmentable;
340 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
343 ktime_t now = ktime_get_real();
346 sp->hdr.serial = serial;
347 if (whdr.flags & RXRPC_REQUEST_ACK) {
348 call->peer->rtt_last_req = now;
349 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
352 _leave(" = %d [%u]", ret, call->peer->maxdata);
356 /* attempt to send this message with fragmentation enabled */
357 _debug("send fragment");
359 down_write(&conn->params.local->defrag_sem);
361 switch (conn->params.local->srx.transport.family) {
363 opt = IP_PMTUDISC_DONT;
364 ret = kernel_setsockopt(conn->params.local->socket,
365 SOL_IP, IP_MTU_DISCOVER,
366 (char *)&opt, sizeof(opt));
368 ret = kernel_sendmsg(conn->params.local->socket, &msg,
371 opt = IP_PMTUDISC_DO;
372 kernel_setsockopt(conn->params.local->socket, SOL_IP,
374 (char *)&opt, sizeof(opt));
378 #ifdef CONFIG_AF_RXRPC_IPV6
380 opt = IPV6_PMTUDISC_DONT;
381 ret = kernel_setsockopt(conn->params.local->socket,
382 SOL_IPV6, IPV6_MTU_DISCOVER,
383 (char *)&opt, sizeof(opt));
385 ret = kernel_sendmsg(conn->params.local->socket, &msg,
388 opt = IPV6_PMTUDISC_DO;
389 kernel_setsockopt(conn->params.local->socket,
390 SOL_IPV6, IPV6_MTU_DISCOVER,
391 (char *)&opt, sizeof(opt));
400 up_write(&conn->params.local->defrag_sem);
405 * reject packets through the local endpoint
407 void rxrpc_reject_packets(struct rxrpc_local *local)
409 struct sockaddr_rxrpc srx;
410 struct rxrpc_skb_priv *sp;
411 struct rxrpc_wire_header whdr;
418 _enter("%d", local->debug_id);
420 iov[0].iov_base = &whdr;
421 iov[0].iov_len = sizeof(whdr);
422 iov[1].iov_base = &code;
423 iov[1].iov_len = sizeof(code);
424 size = sizeof(whdr) + sizeof(code);
426 msg.msg_name = &srx.transport;
427 msg.msg_control = NULL;
428 msg.msg_controllen = 0;
431 memset(&whdr, 0, sizeof(whdr));
432 whdr.type = RXRPC_PACKET_TYPE_ABORT;
434 while ((skb = skb_dequeue(&local->reject_queue))) {
435 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
438 if (rxrpc_extract_addr_from_skb(&srx, skb) == 0) {
439 msg.msg_namelen = srx.transport_len;
441 code = htonl(skb->priority);
443 whdr.epoch = htonl(sp->hdr.epoch);
444 whdr.cid = htonl(sp->hdr.cid);
445 whdr.callNumber = htonl(sp->hdr.callNumber);
446 whdr.serviceId = htons(sp->hdr.serviceId);
447 whdr.flags = sp->hdr.flags;
448 whdr.flags ^= RXRPC_CLIENT_INITIATED;
449 whdr.flags &= RXRPC_CLIENT_INITIATED;
451 kernel_sendmsg(local->socket, &msg, iov, 2, size);
454 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);