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x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / net / rxrpc / output.c
blob5b67cb5d47f0e7579dcb032dc3c68809e23de477
1 /* RxRPC packet transmission
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
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.
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/net.h>
15 #include <linux/gfp.h>
16 #include <linux/skbuff.h>
17 #include <linux/export.h>
18 #include <net/sock.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
21
22 struct rxrpc_ack_buffer {
23 struct rxrpc_wire_header whdr;
24 struct rxrpc_ackpacket ack;
25 u8 acks[255];
26 u8 pad[3];
27 struct rxrpc_ackinfo ackinfo;
28 };
29
30 struct rxrpc_abort_buffer {
31 struct rxrpc_wire_header whdr;
32 __be32 abort_code;
33 };
34
35 /*
36 * Fill out an ACK packet.
37 */
38 static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
39 struct rxrpc_ack_buffer *pkt,
40 rxrpc_seq_t *_hard_ack,
41 rxrpc_seq_t *_top,
42 u8 reason)
43 {
44 rxrpc_serial_t serial;
45 rxrpc_seq_t hard_ack, top, seq;
46 int ix;
47 u32 mtu, jmax;
48 u8 *ackp = pkt->acks;
49
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;
55 *_top = top;
56
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;
64
65 if (reason == RXRPC_ACK_PING)
66 pkt->whdr.flags |= RXRPC_REQUEST_ACK;
67
68 if (after(top, hard_ack)) {
69 seq = hard_ack + 1;
70 do {
71 ix = seq & RXRPC_RXTX_BUFF_MASK;
72 if (call->rxtx_buffer[ix])
73 *ackp++ = RXRPC_ACK_TYPE_ACK;
74 else
75 *ackp++ = RXRPC_ACK_TYPE_NACK;
76 seq++;
77 } while (before_eq(seq, top));
78 }
79
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);
87
88 *ackp++ = 0;
89 *ackp++ = 0;
90 *ackp++ = 0;
91 return top - hard_ack + 3;
92 }
93
94 /*
95 * Send an ACK call packet.
96 */
97 int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
98 {
99 struct rxrpc_connection *conn = NULL;
100 struct rxrpc_ack_buffer *pkt;
101 struct msghdr msg;
102 struct kvec iov[2];
103 rxrpc_serial_t serial;
104 rxrpc_seq_t hard_ack, top;
105 size_t len, n;
106 int ret;
107 u8 reason;
108
109 spin_lock_bh(&call->lock);
110 if (call->conn)
111 conn = rxrpc_get_connection_maybe(call->conn);
112 spin_unlock_bh(&call->lock);
113 if (!conn)
114 return -ECONNRESET;
115
116 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
117 if (!pkt) {
118 rxrpc_put_connection(conn);
119 return -ENOMEM;
120 }
121
122 msg.msg_name = &call->peer->srx.transport;
123 msg.msg_namelen = call->peer->srx.transport_len;
124 msg.msg_control = NULL;
125 msg.msg_controllen = 0;
126 msg.msg_flags = 0;
127
128 pkt->whdr.epoch = htonl(conn->proto.epoch);
129 pkt->whdr.cid = htonl(call->cid);
130 pkt->whdr.callNumber = htonl(call->call_id);
131 pkt->whdr.seq = 0;
132 pkt->whdr.type = RXRPC_PACKET_TYPE_ACK;
133 pkt->whdr.flags = RXRPC_SLOW_START_OK | conn->out_clientflag;
134 pkt->whdr.userStatus = 0;
135 pkt->whdr.securityIndex = call->security_ix;
136 pkt->whdr._rsvd = 0;
137 pkt->whdr.serviceId = htons(call->service_id);
138
139 spin_lock_bh(&call->lock);
140 if (ping) {
141 reason = RXRPC_ACK_PING;
142 } else {
143 reason = call->ackr_reason;
144 if (!call->ackr_reason) {
145 spin_unlock_bh(&call->lock);
146 ret = 0;
147 goto out;
148 }
149 call->ackr_reason = 0;
150 }
151 n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top, reason);
152
153 spin_unlock_bh(&call->lock);
154
155 iov[0].iov_base = pkt;
156 iov[0].iov_len = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
157 iov[1].iov_base = &pkt->ackinfo;
158 iov[1].iov_len = sizeof(pkt->ackinfo);
159 len = iov[0].iov_len + iov[1].iov_len;
160
161 serial = atomic_inc_return(&conn->serial);
162 pkt->whdr.serial = htonl(serial);
163 trace_rxrpc_tx_ack(call, serial,
164 ntohl(pkt->ack.firstPacket),
165 ntohl(pkt->ack.serial),
166 pkt->ack.reason, pkt->ack.nAcks);
167
168 if (ping) {
169 call->ping_serial = serial;
170 smp_wmb();
171 /* We need to stick a time in before we send the packet in case
172 * the reply gets back before kernel_sendmsg() completes - but
173 * asking UDP to send the packet can take a relatively long
174 * time, so we update the time after, on the assumption that
175 * the packet transmission is more likely to happen towards the
176 * end of the kernel_sendmsg() call.
177 */
178 call->ping_time = ktime_get_real();
179 set_bit(RXRPC_CALL_PINGING, &call->flags);
180 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
181 }
182
183 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
184 if (ping)
185 call->ping_time = ktime_get_real();
186
187 if (call->state < RXRPC_CALL_COMPLETE) {
188 if (ret < 0) {
189 if (ping)
190 clear_bit(RXRPC_CALL_PINGING, &call->flags);
191 rxrpc_propose_ACK(call, pkt->ack.reason,
192 ntohs(pkt->ack.maxSkew),
193 ntohl(pkt->ack.serial),
194 true, true,
195 rxrpc_propose_ack_retry_tx);
196 } else {
197 spin_lock_bh(&call->lock);
198 if (after(hard_ack, call->ackr_consumed))
199 call->ackr_consumed = hard_ack;
200 if (after(top, call->ackr_seen))
201 call->ackr_seen = top;
202 spin_unlock_bh(&call->lock);
203 }
204 }
205
206 out:
207 rxrpc_put_connection(conn);
208 kfree(pkt);
209 return ret;
210 }
211
212 /*
213 * Send an ABORT call packet.
214 */
215 int rxrpc_send_abort_packet(struct rxrpc_call *call)
216 {
217 struct rxrpc_connection *conn = NULL;
218 struct rxrpc_abort_buffer pkt;
219 struct msghdr msg;
220 struct kvec iov[1];
221 rxrpc_serial_t serial;
222 int ret;
223
224 spin_lock_bh(&call->lock);
225 if (call->conn)
226 conn = rxrpc_get_connection_maybe(call->conn);
227 spin_unlock_bh(&call->lock);
228 if (!conn)
229 return -ECONNRESET;
230
231 msg.msg_name = &call->peer->srx.transport;
232 msg.msg_namelen = call->peer->srx.transport_len;
233 msg.msg_control = NULL;
234 msg.msg_controllen = 0;
235 msg.msg_flags = 0;
236
237 pkt.whdr.epoch = htonl(conn->proto.epoch);
238 pkt.whdr.cid = htonl(call->cid);
239 pkt.whdr.callNumber = htonl(call->call_id);
240 pkt.whdr.seq = 0;
241 pkt.whdr.type = RXRPC_PACKET_TYPE_ABORT;
242 pkt.whdr.flags = conn->out_clientflag;
243 pkt.whdr.userStatus = 0;
244 pkt.whdr.securityIndex = call->security_ix;
245 pkt.whdr._rsvd = 0;
246 pkt.whdr.serviceId = htons(call->service_id);
247 pkt.abort_code = htonl(call->abort_code);
248
249 iov[0].iov_base = &pkt;
250 iov[0].iov_len = sizeof(pkt);
251
252 serial = atomic_inc_return(&conn->serial);
253 pkt.whdr.serial = htonl(serial);
254
255 ret = kernel_sendmsg(conn->params.local->socket,
256 &msg, iov, 1, sizeof(pkt));
257
258 rxrpc_put_connection(conn);
259 return ret;
260 }
261
262 /*
263 * send a packet through the transport endpoint
264 */
265 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
266 bool retrans)
267 {
268 struct rxrpc_connection *conn = call->conn;
269 struct rxrpc_wire_header whdr;
270 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
271 struct msghdr msg;
272 struct kvec iov[2];
273 rxrpc_serial_t serial;
274 size_t len;
275 bool lost = false;
276 int ret, opt;
277
278 _enter(",{%d}", skb->len);
279
280 /* Each transmission of a Tx packet needs a new serial number */
281 serial = atomic_inc_return(&conn->serial);
282
283 whdr.epoch = htonl(conn->proto.epoch);
284 whdr.cid = htonl(call->cid);
285 whdr.callNumber = htonl(call->call_id);
286 whdr.seq = htonl(sp->hdr.seq);
287 whdr.serial = htonl(serial);
288 whdr.type = RXRPC_PACKET_TYPE_DATA;
289 whdr.flags = sp->hdr.flags;
290 whdr.userStatus = 0;
291 whdr.securityIndex = call->security_ix;
292 whdr._rsvd = htons(sp->hdr._rsvd);
293 whdr.serviceId = htons(call->service_id);
294
295 if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) &&
296 sp->hdr.seq == 1)
297 whdr.userStatus = RXRPC_USERSTATUS_SERVICE_UPGRADE;
298
299 iov[0].iov_base = &whdr;
300 iov[0].iov_len = sizeof(whdr);
301 iov[1].iov_base = skb->head;
302 iov[1].iov_len = skb->len;
303 len = iov[0].iov_len + iov[1].iov_len;
304
305 msg.msg_name = &call->peer->srx.transport;
306 msg.msg_namelen = call->peer->srx.transport_len;
307 msg.msg_control = NULL;
308 msg.msg_controllen = 0;
309 msg.msg_flags = 0;
310
311 /* If our RTT cache needs working on, request an ACK. Also request
312 * ACKs if a DATA packet appears to have been lost.
313 */
314 if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
315 (retrans ||
316 call->cong_mode == RXRPC_CALL_SLOW_START ||
317 (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
318 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
319 ktime_get_real())))
320 whdr.flags |= RXRPC_REQUEST_ACK;
321
322 if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
323 static int lose;
324 if ((lose++ & 7) == 7) {
325 ret = 0;
326 lost = true;
327 goto done;
328 }
329 }
330
331 _proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
332
333 /* send the packet with the don't fragment bit set if we currently
334 * think it's small enough */
335 if (iov[1].iov_len >= call->peer->maxdata)
336 goto send_fragmentable;
337
338 down_read(&conn->params.local->defrag_sem);
339 /* send the packet by UDP
340 * - returns -EMSGSIZE if UDP would have to fragment the packet
341 * to go out of the interface
342 * - in which case, we'll have processed the ICMP error
343 * message and update the peer record
344 */
345 ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
346
347 up_read(&conn->params.local->defrag_sem);
348 if (ret == -EMSGSIZE)
349 goto send_fragmentable;
350
351 done:
352 trace_rxrpc_tx_data(call, sp->hdr.seq, serial, whdr.flags,
353 retrans, lost);
354 if (ret >= 0) {
355 ktime_t now = ktime_get_real();
356 skb->tstamp = now;
357 smp_wmb();
358 sp->hdr.serial = serial;
359 if (whdr.flags & RXRPC_REQUEST_ACK) {
360 call->peer->rtt_last_req = now;
361 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
362 }
363 }
364 _leave(" = %d [%u]", ret, call->peer->maxdata);
365 return ret;
366
367 send_fragmentable:
368 /* attempt to send this message with fragmentation enabled */
369 _debug("send fragment");
370
371 down_write(&conn->params.local->defrag_sem);
372
373 switch (conn->params.local->srx.transport.family) {
374 case AF_INET:
375 opt = IP_PMTUDISC_DONT;
376 ret = kernel_setsockopt(conn->params.local->socket,
377 SOL_IP, IP_MTU_DISCOVER,
378 (char *)&opt, sizeof(opt));
379 if (ret == 0) {
380 ret = kernel_sendmsg(conn->params.local->socket, &msg,
381 iov, 2, len);
382
383 opt = IP_PMTUDISC_DO;
384 kernel_setsockopt(conn->params.local->socket, SOL_IP,
385 IP_MTU_DISCOVER,
386 (char *)&opt, sizeof(opt));
387 }
388 break;
389
390 #ifdef CONFIG_AF_RXRPC_IPV6
391 case AF_INET6:
392 opt = IPV6_PMTUDISC_DONT;
393 ret = kernel_setsockopt(conn->params.local->socket,
394 SOL_IPV6, IPV6_MTU_DISCOVER,
395 (char *)&opt, sizeof(opt));
396 if (ret == 0) {
397 ret = kernel_sendmsg(conn->params.local->socket, &msg,
398 iov, 2, len);
399
400 opt = IPV6_PMTUDISC_DO;
401 kernel_setsockopt(conn->params.local->socket,
402 SOL_IPV6, IPV6_MTU_DISCOVER,
403 (char *)&opt, sizeof(opt));
404 }
405 break;
406 #endif
407 }
408
409 up_write(&conn->params.local->defrag_sem);
410 goto done;
411 }
412
413 /*
414 * reject packets through the local endpoint
415 */
416 void rxrpc_reject_packets(struct rxrpc_local *local)
417 {
418 struct sockaddr_rxrpc srx;
419 struct rxrpc_skb_priv *sp;
420 struct rxrpc_wire_header whdr;
421 struct sk_buff *skb;
422 struct msghdr msg;
423 struct kvec iov[2];
424 size_t size;
425 __be32 code;
426
427 _enter("%d", local->debug_id);
428
429 iov[0].iov_base = &whdr;
430 iov[0].iov_len = sizeof(whdr);
431 iov[1].iov_base = &code;
432 iov[1].iov_len = sizeof(code);
433 size = sizeof(whdr) + sizeof(code);
434
435 msg.msg_name = &srx.transport;
436 msg.msg_control = NULL;
437 msg.msg_controllen = 0;
438 msg.msg_flags = 0;
439
440 memset(&whdr, 0, sizeof(whdr));
441 whdr.type = RXRPC_PACKET_TYPE_ABORT;
442
443 while ((skb = skb_dequeue(&local->reject_queue))) {
444 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
445 sp = rxrpc_skb(skb);
446
447 if (rxrpc_extract_addr_from_skb(local, &srx, skb) == 0) {
448 msg.msg_namelen = srx.transport_len;
449
450 code = htonl(skb->priority);
451
452 whdr.epoch = htonl(sp->hdr.epoch);
453 whdr.cid = htonl(sp->hdr.cid);
454 whdr.callNumber = htonl(sp->hdr.callNumber);
455 whdr.serviceId = htons(sp->hdr.serviceId);
456 whdr.flags = sp->hdr.flags;
457 whdr.flags ^= RXRPC_CLIENT_INITIATED;
458 whdr.flags &= RXRPC_CLIENT_INITIATED;
459
460 kernel_sendmsg(local->socket, &msg, iov, 2, size);
461 }
462
463 rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
464 }
465
466 _leave("");
467 }
Linux with added FPC-III support