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 && __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SECURING) { 232 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST); 233 rxrpc_notify_socket(call); 234 } 235 } 236 237 /* 238 * connection-level Rx packet processor 239 */ 240 static int rxrpc_process_event(struct rxrpc_connection *conn, 241 struct sk_buff *skb) 242 { 243 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 244 int ret; 245 246 if (conn->state == RXRPC_CONN_ABORTED) 247 return -ECONNABORTED; 248 249 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial); 250 251 switch (sp->hdr.type) { 252 case RXRPC_PACKET_TYPE_CHALLENGE: 253 return conn->security->respond_to_challenge(conn, skb); 254 255 case RXRPC_PACKET_TYPE_RESPONSE: 256 ret = conn->security->verify_response(conn, skb); 257 if (ret < 0) 258 return ret; 259 260 ret = conn->security->init_connection_security( 261 conn, conn->key->payload.data[0]); 262 if (ret < 0) 263 return ret; 264 265 spin_lock_irq(&conn->state_lock); 266 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) 267 conn->state = RXRPC_CONN_SERVICE; 268 spin_unlock_irq(&conn->state_lock); 269 270 if (conn->state == RXRPC_CONN_SERVICE) { 271 /* Offload call state flipping to the I/O thread. As 272 * we've already received the packet, put it on the 273 * front of the queue. 274 */ 275 skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED; 276 rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured); 277 skb_queue_head(&conn->local->rx_queue, skb); 278 rxrpc_wake_up_io_thread(conn->local); 279 } 280 return 0; 281 282 default: 283 WARN_ON_ONCE(1); 284 return -EPROTO; 285 } 286 } 287 288 /* 289 * set up security and issue a challenge 290 */ 291 static void rxrpc_secure_connection(struct rxrpc_connection *conn) 292 { 293 if (conn->security->issue_challenge(conn) < 0) 294 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM, 295 rxrpc_abort_nomem); 296 } 297 298 /* 299 * Process delayed final ACKs that we haven't subsumed into a subsequent call. 300 */ 301 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force) 302 { 303 unsigned long j = jiffies, next_j; 304 unsigned int channel; 305 bool set; 306 307 again: 308 next_j = j + LONG_MAX; 309 set = false; 310 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) { 311 struct rxrpc_channel *chan = &conn->channels[channel]; 312 unsigned long ack_at; 313 314 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags)) 315 continue; 316 317 ack_at = chan->final_ack_at; 318 if (time_before(j, ack_at) && !force) { 319 if (time_before(ack_at, next_j)) { 320 next_j = ack_at; 321 set = true; 322 } 323 continue; 324 } 325 326 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, 327 &conn->flags)) 328 rxrpc_conn_retransmit_call(conn, NULL, channel); 329 } 330 331 j = jiffies; 332 if (time_before_eq(next_j, j)) 333 goto again; 334 if (set) 335 rxrpc_reduce_conn_timer(conn, next_j); 336 } 337 338 /* 339 * connection-level event processor 340 */ 341 static void rxrpc_do_process_connection(struct rxrpc_connection *conn) 342 { 343 struct sk_buff *skb; 344 int ret; 345 346 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) 347 rxrpc_secure_connection(conn); 348 349 /* go through the conn-level event packets, releasing the ref on this 350 * connection that each one has when we've finished with it */ 351 while ((skb = skb_dequeue(&conn->rx_queue))) { 352 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work); 353 ret = rxrpc_process_event(conn, skb); 354 switch (ret) { 355 case -ENOMEM: 356 case -EAGAIN: 357 skb_queue_head(&conn->rx_queue, skb); 358 rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work); 359 break; 360 default: 361 rxrpc_free_skb(skb, rxrpc_skb_put_conn_work); 362 break; 363 } 364 } 365 } 366 367 void rxrpc_process_connection(struct work_struct *work) 368 { 369 struct rxrpc_connection *conn = 370 container_of(work, struct rxrpc_connection, processor); 371 372 rxrpc_see_connection(conn, rxrpc_conn_see_work); 373 374 if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) { 375 rxrpc_do_process_connection(conn); 376 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work); 377 } 378 } 379 380 /* 381 * post connection-level events to the connection 382 * - this includes challenges, responses, some aborts and call terminal packet 383 * retransmission. 384 */ 385 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn, 386 struct sk_buff *skb) 387 { 388 _enter("%p,%p", conn, skb); 389 390 rxrpc_get_skb(skb, rxrpc_skb_get_conn_work); 391 skb_queue_tail(&conn->rx_queue, skb); 392 rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work); 393 } 394 395 /* 396 * Input a connection-level packet. 397 */ 398 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb) 399 { 400 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 401 402 switch (sp->hdr.type) { 403 case RXRPC_PACKET_TYPE_BUSY: 404 /* Just ignore BUSY packets for now. */ 405 return true; 406 407 case RXRPC_PACKET_TYPE_ABORT: 408 if (rxrpc_is_conn_aborted(conn)) 409 return true; 410 rxrpc_input_conn_abort(conn, skb); 411 rxrpc_abort_calls(conn); 412 return true; 413 414 case RXRPC_PACKET_TYPE_CHALLENGE: 415 case RXRPC_PACKET_TYPE_RESPONSE: 416 if (rxrpc_is_conn_aborted(conn)) { 417 if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED) 418 rxrpc_send_conn_abort(conn); 419 return true; 420 } 421 rxrpc_post_packet_to_conn(conn, skb); 422 return true; 423 424 default: 425 WARN_ON_ONCE(1); 426 return true; 427 } 428 } 429 430 /* 431 * Input a connection event. 432 */ 433 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb) 434 { 435 unsigned int loop; 436 437 if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events)) 438 rxrpc_abort_calls(conn); 439 440 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 /* Process delayed ACKs whose time has come. */ 451 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 452 rxrpc_process_delayed_final_acks(conn, false); 453 } 454