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(&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(&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 bool rxrpc_input_conn_abort(struct rxrpc_connection *conn, 67 struct sk_buff *skb) 68 { 69 return rxrpc_set_conn_aborted(conn, skb, skb->priority, -ECONNABORTED, 70 RXRPC_CALL_REMOTELY_ABORTED); 71 } 72 73 /* 74 * Retransmit terminal ACK or ABORT of the previous call. 75 */ 76 void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn, 77 struct sk_buff *skb, 78 unsigned int channel) 79 { 80 struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL; 81 struct rxrpc_channel *chan; 82 struct msghdr msg; 83 struct kvec iov[3]; 84 struct { 85 struct rxrpc_wire_header whdr; 86 union { 87 __be32 abort_code; 88 struct rxrpc_ackpacket ack; 89 }; 90 } __attribute__((packed)) pkt; 91 struct rxrpc_ackinfo ack_info; 92 size_t len; 93 int ret, ioc; 94 u32 serial, mtu, call_id, padding; 95 96 _enter("%d", conn->debug_id); 97 98 chan = &conn->channels[channel]; 99 100 /* If the last call got moved on whilst we were waiting to run, just 101 * ignore this packet. 102 */ 103 call_id = READ_ONCE(chan->last_call); 104 /* Sync with __rxrpc_disconnect_call() */ 105 smp_rmb(); 106 if (skb && call_id != sp->hdr.callNumber) 107 return; 108 109 msg.msg_name = &conn->peer->srx.transport; 110 msg.msg_namelen = conn->peer->srx.transport_len; 111 msg.msg_control = NULL; 112 msg.msg_controllen = 0; 113 msg.msg_flags = 0; 114 115 iov[0].iov_base = &pkt; 116 iov[0].iov_len = sizeof(pkt.whdr); 117 iov[1].iov_base = &padding; 118 iov[1].iov_len = 3; 119 iov[2].iov_base = &ack_info; 120 iov[2].iov_len = sizeof(ack_info); 121 122 pkt.whdr.epoch = htonl(conn->proto.epoch); 123 pkt.whdr.cid = htonl(conn->proto.cid | channel); 124 pkt.whdr.callNumber = htonl(call_id); 125 pkt.whdr.seq = 0; 126 pkt.whdr.type = chan->last_type; 127 pkt.whdr.flags = conn->out_clientflag; 128 pkt.whdr.userStatus = 0; 129 pkt.whdr.securityIndex = conn->security_ix; 130 pkt.whdr._rsvd = 0; 131 pkt.whdr.serviceId = htons(conn->service_id); 132 133 len = sizeof(pkt.whdr); 134 switch (chan->last_type) { 135 case RXRPC_PACKET_TYPE_ABORT: 136 pkt.abort_code = htonl(chan->last_abort); 137 iov[0].iov_len += sizeof(pkt.abort_code); 138 len += sizeof(pkt.abort_code); 139 ioc = 1; 140 break; 141 142 case RXRPC_PACKET_TYPE_ACK: 143 mtu = conn->peer->if_mtu; 144 mtu -= conn->peer->hdrsize; 145 pkt.ack.bufferSpace = 0; 146 pkt.ack.maxSkew = htons(skb ? skb->priority : 0); 147 pkt.ack.firstPacket = htonl(chan->last_seq + 1); 148 pkt.ack.previousPacket = htonl(chan->last_seq); 149 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0); 150 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE; 151 pkt.ack.nAcks = 0; 152 ack_info.rxMTU = htonl(rxrpc_rx_mtu); 153 ack_info.maxMTU = htonl(mtu); 154 ack_info.rwind = htonl(rxrpc_rx_window_size); 155 ack_info.jumbo_max = htonl(rxrpc_rx_jumbo_max); 156 pkt.whdr.flags |= RXRPC_SLOW_START_OK; 157 padding = 0; 158 iov[0].iov_len += sizeof(pkt.ack); 159 len += sizeof(pkt.ack) + 3 + sizeof(ack_info); 160 ioc = 3; 161 break; 162 163 default: 164 return; 165 } 166 167 /* Resync with __rxrpc_disconnect_call() and check that the last call 168 * didn't get advanced whilst we were filling out the packets. 169 */ 170 smp_rmb(); 171 if (READ_ONCE(chan->last_call) != call_id) 172 return; 173 174 serial = atomic_inc_return(&conn->serial); 175 pkt.whdr.serial = htonl(serial); 176 177 switch (chan->last_type) { 178 case RXRPC_PACKET_TYPE_ABORT: 179 break; 180 case RXRPC_PACKET_TYPE_ACK: 181 trace_rxrpc_tx_ack(chan->call_debug_id, serial, 182 ntohl(pkt.ack.firstPacket), 183 ntohl(pkt.ack.serial), 184 pkt.ack.reason, 0); 185 break; 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 spin_lock(&conn->bundle->channel_lock); 211 212 for (i = 0; i < RXRPC_MAXCALLS; i++) { 213 call = rcu_dereference_protected( 214 conn->channels[i].call, 215 lockdep_is_held(&conn->bundle->channel_lock)); 216 if (call) 217 rxrpc_set_call_completion(call, 218 conn->completion, 219 conn->abort_code, 220 conn->error); 221 } 222 223 spin_unlock(&conn->bundle->channel_lock); 224 _leave(""); 225 } 226 227 /* 228 * mark a call as being on a now-secured channel 229 * - must be called with BH's disabled. 230 */ 231 static void rxrpc_call_is_secure(struct rxrpc_call *call) 232 { 233 _enter("%p", call); 234 if (call) { 235 write_lock(&call->state_lock); 236 if (call->state == RXRPC_CALL_SERVER_SECURING) { 237 call->state = RXRPC_CALL_SERVER_RECV_REQUEST; 238 rxrpc_notify_socket(call); 239 } 240 write_unlock(&call->state_lock); 241 } 242 } 243 244 /* 245 * connection-level Rx packet processor 246 */ 247 static int rxrpc_process_event(struct rxrpc_connection *conn, 248 struct sk_buff *skb) 249 { 250 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 251 int loop, ret; 252 253 if (conn->state == RXRPC_CONN_ABORTED) 254 return -ECONNABORTED; 255 256 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 257 258 switch (sp->hdr.type) { 259 case RXRPC_PACKET_TYPE_CHALLENGE: 260 return conn->security->respond_to_challenge(conn, skb); 261 262 case RXRPC_PACKET_TYPE_RESPONSE: 263 ret = conn->security->verify_response(conn, skb); 264 if (ret < 0) 265 return ret; 266 267 ret = conn->security->init_connection_security( 268 conn, conn->key->payload.data[0]); 269 if (ret < 0) 270 return ret; 271 272 spin_lock(&conn->bundle->channel_lock); 273 spin_lock(&conn->state_lock); 274 275 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) { 276 conn->state = RXRPC_CONN_SERVICE; 277 spin_unlock(&conn->state_lock); 278 for (loop = 0; loop < RXRPC_MAXCALLS; loop++) 279 rxrpc_call_is_secure( 280 rcu_dereference_protected( 281 conn->channels[loop].call, 282 lockdep_is_held(&conn->bundle->channel_lock))); 283 } else { 284 spin_unlock(&conn->state_lock); 285 } 286 287 spin_unlock(&conn->bundle->channel_lock); 288 return 0; 289 290 default: 291 WARN_ON_ONCE(1); 292 return -EPROTO; 293 } 294 } 295 296 /* 297 * set up security and issue a challenge 298 */ 299 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 300 { 301 if (conn->security->issue_challenge(conn) < 0) 302 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM, 303 rxrpc_abort_nomem); 304 } 305 306 /* 307 * Process delayed final ACKs that we haven't subsumed into a subsequent call. 308 */ 309 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force) 310 { 311 unsigned long j = jiffies, next_j; 312 unsigned int channel; 313 bool set; 314 315 again: 316 next_j = j + LONG_MAX; 317 set = false; 318 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) { 319 struct rxrpc_channel *chan = &conn->channels[channel]; 320 unsigned long ack_at; 321 322 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags)) 323 continue; 324 325 smp_rmb(); /* vs rxrpc_disconnect_client_call */ 326 ack_at = READ_ONCE(chan->final_ack_at); 327 328 if (time_before(j, ack_at) && !force) { 329 if (time_before(ack_at, next_j)) { 330 next_j = ack_at; 331 set = true; 332 } 333 continue; 334 } 335 336 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, 337 &conn->flags)) 338 rxrpc_conn_retransmit_call(conn, NULL, channel); 339 } 340 341 j = jiffies; 342 if (time_before_eq(next_j, j)) 343 goto again; 344 if (set) 345 rxrpc_reduce_conn_timer(conn, next_j); 346 } 347 348 /* 349 * connection-level event processor 350 */ 351 static void rxrpc_do_process_connection(struct rxrpc_connection *conn) 352 { 353 struct sk_buff *skb; 354 int ret; 355 356 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 357 rxrpc_secure_connection(conn); 358 359 /* go through the conn-level event packets, releasing the ref on this 360 * connection that each one has when we've finished with it */ 361 while ((skb = skb_dequeue(&conn->rx_queue))) { 362 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work); 363 ret = rxrpc_process_event(conn, skb); 364 switch (ret) { 365 case -ENOMEM: 366 case -EAGAIN: 367 skb_queue_head(&conn->rx_queue, skb); 368 rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work); 369 break; 370 default: 371 rxrpc_free_skb(skb, rxrpc_skb_put_conn_work); 372 break; 373 } 374 } 375 } 376 377 void rxrpc_process_connection(struct work_struct *work) 378 { 379 struct rxrpc_connection *conn = 380 container_of(work, struct rxrpc_connection, processor); 381 382 rxrpc_see_connection(conn, rxrpc_conn_see_work); 383 384 if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) { 385 rxrpc_do_process_connection(conn); 386 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work); 387 } 388 } 389 390 /* 391 * post connection-level events to the connection 392 * - this includes challenges, responses, some aborts and call terminal packet 393 * retransmission. 394 */ 395 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 396 struct sk_buff *skb) 397 { 398 _enter("%p,%p", conn, skb); 399 400 rxrpc_get_skb(skb, rxrpc_skb_get_conn_work); 401 skb_queue_tail(&conn->rx_queue, skb); 402 rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work); 403 } 404 405 /* 406 * Input a connection-level packet. 407 */ 408 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb) 409 { 410 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 411 412 switch (sp->hdr.type) { 413 case RXRPC_PACKET_TYPE_BUSY: 414 /* Just ignore BUSY packets for now. */ 415 return true; 416 417 case RXRPC_PACKET_TYPE_ABORT: 418 if (rxrpc_is_conn_aborted(conn)) 419 return true; 420 rxrpc_input_conn_abort(conn, skb); 421 rxrpc_abort_calls(conn); 422 return true; 423 424 case RXRPC_PACKET_TYPE_CHALLENGE: 425 case RXRPC_PACKET_TYPE_RESPONSE: 426 if (rxrpc_is_conn_aborted(conn)) { 427 if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED) 428 rxrpc_send_conn_abort(conn); 429 return true; 430 } 431 rxrpc_post_packet_to_conn(conn, skb); 432 return true; 433 434 default: 435 WARN_ON_ONCE(1); 436 return true; 437 } 438 } 439 440 /* 441 * Input a connection event. 442 */ 443 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb) 444 { 445 if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events)) 446 rxrpc_abort_calls(conn); 447 448 /* Process delayed ACKs whose time has come. */ 449 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 450 rxrpc_process_delayed_final_acks(conn, false); 451 } 452