1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* connection-level event handling 3 * 4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/module.h> 11 #include <linux/net.h> 12 #include <linux/skbuff.h> 13 #include <linux/errqueue.h> 14 #include <net/sock.h> 15 #include <net/af_rxrpc.h> 16 #include <net/ip.h> 17 #include "ar-internal.h" 18 19 /* 20 * Set the completion state on an aborted connection. 21 */ 22 static bool rxrpc_set_conn_aborted(struct rxrpc_connection *conn, struct sk_buff *skb, 23 s32 abort_code, int err, 24 enum rxrpc_call_completion compl) 25 { 26 bool aborted = false; 27 28 if (conn->state != RXRPC_CONN_ABORTED) { 29 spin_lock_irq(&conn->state_lock); 30 if (conn->state != RXRPC_CONN_ABORTED) { 31 conn->abort_code = abort_code; 32 conn->error = err; 33 conn->completion = compl; 34 /* Order the abort info before the state change. */ 35 smp_store_release(&conn->state, RXRPC_CONN_ABORTED); 36 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); 37 set_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events); 38 aborted = true; 39 } 40 spin_unlock_irq(&conn->state_lock); 41 } 42 43 return aborted; 44 } 45 46 /* 47 * Mark a socket buffer to indicate that the connection it's on should be aborted. 48 */ 49 int rxrpc_abort_conn(struct rxrpc_connection *conn, struct sk_buff *skb, 50 s32 abort_code, int err, enum rxrpc_abort_reason why) 51 { 52 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 53 54 if (rxrpc_set_conn_aborted(conn, skb, abort_code, err, 55 RXRPC_CALL_LOCALLY_ABORTED)) { 56 trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, 57 sp->hdr.seq, abort_code, err); 58 rxrpc_poke_conn(conn, rxrpc_conn_get_poke_abort); 59 } 60 return -EPROTO; 61 } 62 63 /* 64 * Mark a connection as being remotely aborted. 65 */ 66 static void rxrpc_input_conn_abort(struct rxrpc_connection *conn, 67 struct sk_buff *skb) 68 { 69 trace_rxrpc_rx_conn_abort(conn, skb); 70 rxrpc_set_conn_aborted(conn, skb, skb->priority, -ECONNABORTED, 71 RXRPC_CALL_REMOTELY_ABORTED); 72 } 73 74 /* 75 * Retransmit terminal ACK or ABORT of the previous call. 76 */ 77 void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn, 78 struct sk_buff *skb, 79 unsigned int channel) 80 { 81 struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL; 82 struct rxrpc_channel *chan; 83 struct msghdr msg; 84 struct kvec iov[3]; 85 struct { 86 struct rxrpc_wire_header whdr; 87 union { 88 __be32 abort_code; 89 struct rxrpc_ackpacket ack; 90 }; 91 } __attribute__((packed)) pkt; 92 struct rxrpc_acktrailer trailer; 93 size_t len; 94 int ret, ioc; 95 u32 serial, max_mtu, if_mtu, call_id, padding; 96 97 _enter("%d", conn->debug_id); 98 99 if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) { 100 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), 101 &pkt.ack, sizeof(pkt.ack)) < 0) 102 return; 103 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE) 104 return; 105 } 106 107 chan = &conn->channels[channel]; 108 109 /* If the last call got moved on whilst we were waiting to run, just 110 * ignore this packet. 111 */ 112 call_id = chan->last_call; 113 if (skb && call_id != sp->hdr.callNumber) 114 return; 115 116 msg.msg_name = &conn->peer->srx.transport; 117 msg.msg_namelen = conn->peer->srx.transport_len; 118 msg.msg_control = NULL; 119 msg.msg_controllen = 0; 120 msg.msg_flags = 0; 121 122 iov[0].iov_base = &pkt; 123 iov[0].iov_len = sizeof(pkt.whdr); 124 iov[1].iov_base = &padding; 125 iov[1].iov_len = 3; 126 iov[2].iov_base = &trailer; 127 iov[2].iov_len = sizeof(trailer); 128 129 serial = rxrpc_get_next_serial(conn); 130 131 pkt.whdr.epoch = htonl(conn->proto.epoch); 132 pkt.whdr.cid = htonl(conn->proto.cid | channel); 133 pkt.whdr.callNumber = htonl(call_id); 134 pkt.whdr.serial = htonl(serial); 135 pkt.whdr.seq = 0; 136 pkt.whdr.type = chan->last_type; 137 pkt.whdr.flags = conn->out_clientflag; 138 pkt.whdr.userStatus = 0; 139 pkt.whdr.securityIndex = conn->security_ix; 140 pkt.whdr._rsvd = 0; 141 pkt.whdr.serviceId = htons(conn->service_id); 142 143 len = sizeof(pkt.whdr); 144 switch (chan->last_type) { 145 case RXRPC_PACKET_TYPE_ABORT: 146 pkt.abort_code = htonl(chan->last_abort); 147 iov[0].iov_len += sizeof(pkt.abort_code); 148 len += sizeof(pkt.abort_code); 149 ioc = 1; 150 break; 151 152 case RXRPC_PACKET_TYPE_ACK: 153 if_mtu = conn->peer->if_mtu - conn->peer->hdrsize; 154 if (conn->peer->ackr_adv_pmtud) { 155 max_mtu = umax(conn->peer->max_data, rxrpc_rx_mtu); 156 } else { 157 if_mtu = umin(1444, if_mtu); 158 max_mtu = if_mtu; 159 } 160 pkt.ack.bufferSpace = 0; 161 pkt.ack.maxSkew = htons(skb ? skb->priority : 0); 162 pkt.ack.firstPacket = htonl(chan->last_seq + 1); 163 pkt.ack.previousPacket = htonl(chan->last_seq); 164 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0); 165 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE; 166 pkt.ack.nAcks = 0; 167 trailer.maxMTU = htonl(max_mtu); 168 trailer.ifMTU = htonl(if_mtu); 169 trailer.rwind = htonl(rxrpc_rx_window_size); 170 trailer.jumbo_max = 0; 171 pkt.whdr.flags |= RXRPC_SLOW_START_OK; 172 padding = 0; 173 iov[0].iov_len += sizeof(pkt.ack); 174 len += sizeof(pkt.ack) + 3 + sizeof(trailer); 175 ioc = 3; 176 177 trace_rxrpc_tx_ack(chan->call_debug_id, serial, 178 ntohl(pkt.ack.firstPacket), 179 ntohl(pkt.ack.serial), 180 pkt.ack.reason, 0, rxrpc_rx_window_size, 181 rxrpc_propose_ack_retransmit); 182 break; 183 184 default: 185 return; 186 } 187 188 ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len); 189 conn->peer->last_tx_at = ktime_get_seconds(); 190 if (ret < 0) 191 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret, 192 rxrpc_tx_point_call_final_resend); 193 else 194 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr, 195 rxrpc_tx_point_call_final_resend); 196 197 _leave(""); 198 } 199 200 /* 201 * pass a connection-level abort onto all calls on that connection 202 */ 203 static void rxrpc_abort_calls(struct rxrpc_connection *conn) 204 { 205 struct rxrpc_call *call; 206 int i; 207 208 _enter("{%d},%x", conn->debug_id, conn->abort_code); 209 210 for (i = 0; i < RXRPC_MAXCALLS; i++) { 211 call = conn->channels[i].call; 212 if (call) { 213 rxrpc_see_call(call, rxrpc_call_see_conn_abort); 214 rxrpc_set_call_completion(call, 215 conn->completion, 216 conn->abort_code, 217 conn->error); 218 rxrpc_poke_call(call, rxrpc_call_poke_conn_abort); 219 } 220 } 221 222 _leave(""); 223 } 224 225 /* 226 * mark a call as being on a now-secured channel 227 * - must be called with BH's disabled. 228 */ 229 static void rxrpc_call_is_secure(struct rxrpc_call *call) 230 { 231 if (call && __test_and_clear_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags)) 232 rxrpc_notify_socket(call); 233 } 234 235 /* 236 * connection-level Rx packet processor 237 */ 238 static int rxrpc_process_event(struct rxrpc_connection *conn, 239 struct sk_buff *skb) 240 { 241 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 242 int ret; 243 244 if (conn->state == RXRPC_CONN_ABORTED) 245 return -ECONNABORTED; 246 247 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 248 249 switch (sp->hdr.type) { 250 case RXRPC_PACKET_TYPE_CHALLENGE: 251 return conn->security->respond_to_challenge(conn, skb); 252 253 case RXRPC_PACKET_TYPE_RESPONSE: 254 ret = conn->security->verify_response(conn, skb); 255 if (ret < 0) 256 return ret; 257 258 ret = conn->security->init_connection_security( 259 conn, conn->key->payload.data[0]); 260 if (ret < 0) 261 return ret; 262 263 spin_lock_irq(&conn->state_lock); 264 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) 265 conn->state = RXRPC_CONN_SERVICE; 266 spin_unlock_irq(&conn->state_lock); 267 268 if (conn->state == RXRPC_CONN_SERVICE) { 269 /* Offload call state flipping to the I/O thread. As 270 * we've already received the packet, put it on the 271 * front of the queue. 272 */ 273 sp->conn = rxrpc_get_connection(conn, rxrpc_conn_get_poke_secured); 274 skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED; 275 rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured); 276 skb_queue_head(&conn->local->rx_queue, skb); 277 rxrpc_wake_up_io_thread(conn->local); 278 } 279 return 0; 280 281 default: 282 WARN_ON_ONCE(1); 283 return -EPROTO; 284 } 285 } 286 287 /* 288 * set up security and issue a challenge 289 */ 290 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 291 { 292 if (conn->security->issue_challenge(conn) < 0) 293 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM, 294 rxrpc_abort_nomem); 295 } 296 297 /* 298 * Process delayed final ACKs that we haven't subsumed into a subsequent call. 299 */ 300 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force) 301 { 302 unsigned long j = jiffies, next_j; 303 unsigned int channel; 304 bool set; 305 306 again: 307 next_j = j + LONG_MAX; 308 set = false; 309 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) { 310 struct rxrpc_channel *chan = &conn->channels[channel]; 311 unsigned long ack_at; 312 313 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags)) 314 continue; 315 316 ack_at = chan->final_ack_at; 317 if (time_before(j, ack_at) && !force) { 318 if (time_before(ack_at, next_j)) { 319 next_j = ack_at; 320 set = true; 321 } 322 continue; 323 } 324 325 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, 326 &conn->flags)) 327 rxrpc_conn_retransmit_call(conn, NULL, channel); 328 } 329 330 j = jiffies; 331 if (time_before_eq(next_j, j)) 332 goto again; 333 if (set) 334 rxrpc_reduce_conn_timer(conn, next_j); 335 } 336 337 /* 338 * connection-level event processor 339 */ 340 static void rxrpc_do_process_connection(struct rxrpc_connection *conn) 341 { 342 struct sk_buff *skb; 343 int ret; 344 345 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 346 rxrpc_secure_connection(conn); 347 348 /* go through the conn-level event packets, releasing the ref on this 349 * connection that each one has when we've finished with it */ 350 while ((skb = skb_dequeue(&conn->rx_queue))) { 351 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work); 352 ret = rxrpc_process_event(conn, skb); 353 switch (ret) { 354 case -ENOMEM: 355 case -EAGAIN: 356 skb_queue_head(&conn->rx_queue, skb); 357 rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work); 358 break; 359 default: 360 rxrpc_free_skb(skb, rxrpc_skb_put_conn_work); 361 break; 362 } 363 } 364 } 365 366 void rxrpc_process_connection(struct work_struct *work) 367 { 368 struct rxrpc_connection *conn = 369 container_of(work, struct rxrpc_connection, processor); 370 371 rxrpc_see_connection(conn, rxrpc_conn_see_work); 372 373 if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) { 374 rxrpc_do_process_connection(conn); 375 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work); 376 } 377 } 378 379 /* 380 * post connection-level events to the connection 381 * - this includes challenges, responses, some aborts and call terminal packet 382 * retransmission. 383 */ 384 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 385 struct sk_buff *skb) 386 { 387 _enter("%p,%p", conn, skb); 388 389 rxrpc_get_skb(skb, rxrpc_skb_get_conn_work); 390 skb_queue_tail(&conn->rx_queue, skb); 391 rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work); 392 } 393 394 /* 395 * Input a connection-level packet. 396 */ 397 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb) 398 { 399 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 400 401 switch (sp->hdr.type) { 402 case RXRPC_PACKET_TYPE_BUSY: 403 /* Just ignore BUSY packets for now. */ 404 return true; 405 406 case RXRPC_PACKET_TYPE_ABORT: 407 if (rxrpc_is_conn_aborted(conn)) 408 return true; 409 rxrpc_input_conn_abort(conn, skb); 410 rxrpc_abort_calls(conn); 411 return true; 412 413 case RXRPC_PACKET_TYPE_CHALLENGE: 414 case RXRPC_PACKET_TYPE_RESPONSE: 415 if (rxrpc_is_conn_aborted(conn)) { 416 if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED) 417 rxrpc_send_conn_abort(conn); 418 return true; 419 } 420 rxrpc_post_packet_to_conn(conn, skb); 421 return true; 422 423 default: 424 WARN_ON_ONCE(1); 425 return true; 426 } 427 } 428 429 /* 430 * Input a connection event. 431 */ 432 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb) 433 { 434 unsigned int loop; 435 436 if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events)) 437 rxrpc_abort_calls(conn); 438 439 if (skb) { 440 switch (skb->mark) { 441 case RXRPC_SKB_MARK_SERVICE_CONN_SECURED: 442 if (conn->state != RXRPC_CONN_SERVICE) 443 break; 444 445 for (loop = 0; loop < RXRPC_MAXCALLS; loop++) 446 rxrpc_call_is_secure(conn->channels[loop].call); 447 break; 448 } 449 } 450 451 /* Process delayed ACKs whose time has come. */ 452 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 453 rxrpc_process_delayed_final_acks(conn, false); 454 } 455