aboutsummaryrefslogtreecommitdiffstats
path: root/net/rxrpc/ar-input.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/rxrpc/ar-input.c')
-rw-r--r--net/rxrpc/ar-input.c791
1 files changed, 791 insertions, 0 deletions
diff --git a/net/rxrpc/ar-input.c b/net/rxrpc/ar-input.c
new file mode 100644
index 000000000000..323c3454561c
--- /dev/null
+++ b/net/rxrpc/ar-input.c
@@ -0,0 +1,791 @@
+/* RxRPC packet reception
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/errqueue.h>
+#include <linux/udp.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/icmp.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <net/ip.h>
+#include "ar-internal.h"
+
+unsigned long rxrpc_ack_timeout = 1;
+
+const char *rxrpc_pkts[] = {
+ "?00",
+ "DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
+ "?09", "?10", "?11", "?12", "?13", "?14", "?15"
+};
+
+/*
+ * queue a packet for recvmsg to pass to userspace
+ * - the caller must hold a lock on call->lock
+ * - must not be called with interrupts disabled (sk_filter() disables BH's)
+ * - eats the packet whether successful or not
+ * - there must be just one reference to the packet, which the caller passes to
+ * this function
+ */
+int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
+ bool force, bool terminal)
+{
+ struct rxrpc_skb_priv *sp;
+ struct sock *sk;
+ int skb_len, ret;
+
+ _enter(",,%d,%d", force, terminal);
+
+ ASSERT(!irqs_disabled());
+
+ sp = rxrpc_skb(skb);
+ ASSERTCMP(sp->call, ==, call);
+
+ /* if we've already posted the terminal message for a call, then we
+ * don't post any more */
+ if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
+ _debug("already terminated");
+ ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
+ skb->destructor = NULL;
+ sp->call = NULL;
+ rxrpc_put_call(call);
+ rxrpc_free_skb(skb);
+ return 0;
+ }
+
+ sk = &call->socket->sk;
+
+ if (!force) {
+ /* cast skb->rcvbuf to unsigned... It's pointless, but
+ * reduces number of warnings when compiling with -W
+ * --ANK */
+// ret = -ENOBUFS;
+// if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
+// (unsigned) sk->sk_rcvbuf)
+// goto out;
+
+ ret = sk_filter(sk, skb);
+ if (ret < 0)
+ goto out;
+ }
+
+ spin_lock_bh(&sk->sk_receive_queue.lock);
+ if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
+ !test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
+ call->socket->sk.sk_state != RXRPC_CLOSE) {
+ skb->destructor = rxrpc_packet_destructor;
+ skb->dev = NULL;
+ skb->sk = sk;
+ atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+
+ /* Cache the SKB length before we tack it onto the receive
+ * queue. Once it is added it no longer belongs to us and
+ * may be freed by other threads of control pulling packets
+ * from the queue.
+ */
+ skb_len = skb->len;
+
+ _net("post skb %p", skb);
+ __skb_queue_tail(&sk->sk_receive_queue, skb);
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_data_ready(sk, skb_len);
+
+ if (terminal) {
+ _debug("<<<< TERMINAL MESSAGE >>>>");
+ set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
+ }
+
+ skb = NULL;
+ } else {
+ spin_unlock_bh(&sk->sk_receive_queue.lock);
+ }
+ ret = 0;
+
+out:
+ /* release the socket buffer */
+ if (skb) {
+ skb->destructor = NULL;
+ sp->call = NULL;
+ rxrpc_put_call(call);
+ rxrpc_free_skb(skb);
+ }
+
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * process a DATA packet, posting the packet to the appropriate queue
+ * - eats the packet if successful
+ */
+static int rxrpc_fast_process_data(struct rxrpc_call *call,
+ struct sk_buff *skb, u32 seq)
+{
+ struct rxrpc_skb_priv *sp;
+ bool terminal;
+ int ret, ackbit, ack;
+
+ _enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
+
+ sp = rxrpc_skb(skb);
+ ASSERTCMP(sp->call, ==, NULL);
+
+ spin_lock(&call->lock);
+
+ if (call->state > RXRPC_CALL_COMPLETE)
+ goto discard;
+
+ ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
+ ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
+ ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
+
+ if (seq < call->rx_data_post) {
+ _debug("dup #%u [-%u]", seq, call->rx_data_post);
+ ack = RXRPC_ACK_DUPLICATE;
+ ret = -ENOBUFS;
+ goto discard_and_ack;
+ }
+
+ /* we may already have the packet in the out of sequence queue */
+ ackbit = seq - (call->rx_data_eaten + 1);
+ ASSERTCMP(ackbit, >=, 0);
+ if (__test_and_set_bit(ackbit, &call->ackr_window)) {
+ _debug("dup oos #%u [%u,%u]",
+ seq, call->rx_data_eaten, call->rx_data_post);
+ ack = RXRPC_ACK_DUPLICATE;
+ goto discard_and_ack;
+ }
+
+ if (seq >= call->ackr_win_top) {
+ _debug("exceed #%u [%u]", seq, call->ackr_win_top);
+ __clear_bit(ackbit, &call->ackr_window);
+ ack = RXRPC_ACK_EXCEEDS_WINDOW;
+ goto discard_and_ack;
+ }
+
+ if (seq == call->rx_data_expect) {
+ clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
+ call->rx_data_expect++;
+ } else if (seq > call->rx_data_expect) {
+ _debug("oos #%u [%u]", seq, call->rx_data_expect);
+ call->rx_data_expect = seq + 1;
+ if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
+ ack = RXRPC_ACK_OUT_OF_SEQUENCE;
+ goto enqueue_and_ack;
+ }
+ goto enqueue_packet;
+ }
+
+ if (seq != call->rx_data_post) {
+ _debug("ahead #%u [%u]", seq, call->rx_data_post);
+ goto enqueue_packet;
+ }
+
+ if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
+ goto protocol_error;
+
+ /* if the packet need security things doing to it, then it goes down
+ * the slow path */
+ if (call->conn->security)
+ goto enqueue_packet;
+
+ sp->call = call;
+ rxrpc_get_call(call);
+ terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
+ !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
+ ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
+ if (ret < 0) {
+ if (ret == -ENOMEM || ret == -ENOBUFS) {
+ __clear_bit(ackbit, &call->ackr_window);
+ ack = RXRPC_ACK_NOSPACE;
+ goto discard_and_ack;
+ }
+ goto out;
+ }
+
+ skb = NULL;
+
+ _debug("post #%u", seq);
+ ASSERTCMP(call->rx_data_post, ==, seq);
+ call->rx_data_post++;
+
+ if (sp->hdr.flags & RXRPC_LAST_PACKET)
+ set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
+
+ /* if we've reached an out of sequence packet then we need to drain
+ * that queue into the socket Rx queue now */
+ if (call->rx_data_post == call->rx_first_oos) {
+ _debug("drain rx oos now");
+ read_lock(&call->state_lock);
+ if (call->state < RXRPC_CALL_COMPLETE &&
+ !test_and_set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events))
+ schedule_work(&call->processor);
+ read_unlock(&call->state_lock);
+ }
+
+ spin_unlock(&call->lock);
+ atomic_inc(&call->ackr_not_idle);
+ rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
+ _leave(" = 0 [posted]");
+ return 0;
+
+protocol_error:
+ ret = -EBADMSG;
+out:
+ spin_unlock(&call->lock);
+ _leave(" = %d", ret);
+ return ret;
+
+discard_and_ack:
+ _debug("discard and ACK packet %p", skb);
+ __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
+discard:
+ spin_unlock(&call->lock);
+ rxrpc_free_skb(skb);
+ _leave(" = 0 [discarded]");
+ return 0;
+
+enqueue_and_ack:
+ __rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
+enqueue_packet:
+ _net("defer skb %p", skb);
+ spin_unlock(&call->lock);
+ skb_queue_tail(&call->rx_queue, skb);
+ atomic_inc(&call->ackr_not_idle);
+ read_lock(&call->state_lock);
+ if (call->state < RXRPC_CALL_DEAD)
+ schedule_work(&call->processor);
+ read_unlock(&call->state_lock);
+ _leave(" = 0 [queued]");
+ return 0;
+}
+
+/*
+ * assume an implicit ACKALL of the transmission phase of a client socket upon
+ * reception of the first reply packet
+ */
+static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
+{
+ write_lock_bh(&call->state_lock);
+
+ switch (call->state) {
+ case RXRPC_CALL_CLIENT_AWAIT_REPLY:
+ call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
+ call->acks_latest = serial;
+
+ _debug("implicit ACKALL %%%u", call->acks_latest);
+ set_bit(RXRPC_CALL_RCVD_ACKALL, &call->events);
+ write_unlock_bh(&call->state_lock);
+
+ if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
+ clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
+ clear_bit(RXRPC_CALL_RESEND, &call->events);
+ clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
+ }
+ break;
+
+ default:
+ write_unlock_bh(&call->state_lock);
+ break;
+ }
+}
+
+/*
+ * post an incoming packet to the nominated call to deal with
+ * - must get rid of the sk_buff, either by freeing it or by queuing it
+ */
+void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ __be32 _abort_code;
+ u32 serial, hi_serial, seq, abort_code;
+
+ _enter("%p,%p", call, skb);
+
+ ASSERT(!irqs_disabled());
+
+#if 0 // INJECT RX ERROR
+ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
+ static int skip = 0;
+ if (++skip == 3) {
+ printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
+ skip = 0;
+ goto free_packet;
+ }
+ }
+#endif
+
+ /* track the latest serial number on this connection for ACK packet
+ * information */
+ serial = ntohl(sp->hdr.serial);
+ hi_serial = atomic_read(&call->conn->hi_serial);
+ while (serial > hi_serial)
+ hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
+ serial);
+
+ /* request ACK generation for any ACK or DATA packet that requests
+ * it */
+ if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
+ _proto("ACK Requested on %%%u", serial);
+ rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial,
+ !(sp->hdr.flags & RXRPC_MORE_PACKETS));
+ }
+
+ switch (sp->hdr.type) {
+ case RXRPC_PACKET_TYPE_ABORT:
+ _debug("abort");
+
+ if (skb_copy_bits(skb, 0, &_abort_code,
+ sizeof(_abort_code)) < 0)
+ goto protocol_error;
+
+ abort_code = ntohl(_abort_code);
+ _proto("Rx ABORT %%%u { %x }", serial, abort_code);
+
+ write_lock_bh(&call->state_lock);
+ if (call->state < RXRPC_CALL_COMPLETE) {
+ call->state = RXRPC_CALL_REMOTELY_ABORTED;
+ call->abort_code = abort_code;
+ set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
+ schedule_work(&call->processor);
+ }
+ goto free_packet_unlock;
+
+ case RXRPC_PACKET_TYPE_BUSY:
+ _proto("Rx BUSY %%%u", serial);
+
+ if (call->conn->out_clientflag)
+ goto protocol_error;
+
+ write_lock_bh(&call->state_lock);
+ switch (call->state) {
+ case RXRPC_CALL_CLIENT_SEND_REQUEST:
+ call->state = RXRPC_CALL_SERVER_BUSY;
+ set_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
+ schedule_work(&call->processor);
+ case RXRPC_CALL_SERVER_BUSY:
+ goto free_packet_unlock;
+ default:
+ goto protocol_error_locked;
+ }
+
+ default:
+ _proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], serial);
+ goto protocol_error;
+
+ case RXRPC_PACKET_TYPE_DATA:
+ seq = ntohl(sp->hdr.seq);
+
+ _proto("Rx DATA %%%u { #%u }", serial, seq);
+
+ if (seq == 0)
+ goto protocol_error;
+
+ call->ackr_prev_seq = sp->hdr.seq;
+
+ /* received data implicitly ACKs all of the request packets we
+ * sent when we're acting as a client */
+ if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
+ rxrpc_assume_implicit_ackall(call, serial);
+
+ switch (rxrpc_fast_process_data(call, skb, seq)) {
+ case 0:
+ skb = NULL;
+ goto done;
+
+ default:
+ BUG();
+
+ /* data packet received beyond the last packet */
+ case -EBADMSG:
+ goto protocol_error;
+ }
+
+ case RXRPC_PACKET_TYPE_ACK:
+ /* ACK processing is done in process context */
+ read_lock_bh(&call->state_lock);
+ if (call->state < RXRPC_CALL_DEAD) {
+ skb_queue_tail(&call->rx_queue, skb);
+ schedule_work(&call->processor);
+ skb = NULL;
+ }
+ read_unlock_bh(&call->state_lock);
+ goto free_packet;
+ }
+
+protocol_error:
+ _debug("protocol error");
+ write_lock_bh(&call->state_lock);
+protocol_error_locked:
+ if (call->state <= RXRPC_CALL_COMPLETE) {
+ call->state = RXRPC_CALL_LOCALLY_ABORTED;
+ call->abort_code = RX_PROTOCOL_ERROR;
+ set_bit(RXRPC_CALL_ABORT, &call->events);
+ schedule_work(&call->processor);
+ }
+free_packet_unlock:
+ write_unlock_bh(&call->state_lock);
+free_packet:
+ rxrpc_free_skb(skb);
+done:
+ _leave("");
+}
+
+/*
+ * split up a jumbo data packet
+ */
+static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
+ struct sk_buff *jumbo)
+{
+ struct rxrpc_jumbo_header jhdr;
+ struct rxrpc_skb_priv *sp;
+ struct sk_buff *part;
+
+ _enter(",{%u,%u}", jumbo->data_len, jumbo->len);
+
+ sp = rxrpc_skb(jumbo);
+
+ do {
+ sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
+
+ /* make a clone to represent the first subpacket in what's left
+ * of the jumbo packet */
+ part = skb_clone(jumbo, GFP_ATOMIC);
+ if (!part) {
+ /* simply ditch the tail in the event of ENOMEM */
+ pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
+ break;
+ }
+ rxrpc_new_skb(part);
+
+ pskb_trim(part, RXRPC_JUMBO_DATALEN);
+
+ if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
+ goto protocol_error;
+
+ if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
+ goto protocol_error;
+ if (!pskb_pull(jumbo, sizeof(jhdr)))
+ BUG();
+
+ sp->hdr.seq = htonl(ntohl(sp->hdr.seq) + 1);
+ sp->hdr.serial = htonl(ntohl(sp->hdr.serial) + 1);
+ sp->hdr.flags = jhdr.flags;
+ sp->hdr._rsvd = jhdr._rsvd;
+
+ _proto("Rx DATA Jumbo %%%u", ntohl(sp->hdr.serial) - 1);
+
+ rxrpc_fast_process_packet(call, part);
+ part = NULL;
+
+ } while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
+
+ rxrpc_fast_process_packet(call, jumbo);
+ _leave("");
+ return;
+
+protocol_error:
+ _debug("protocol error");
+ rxrpc_free_skb(part);
+ rxrpc_free_skb(jumbo);
+ write_lock_bh(&call->state_lock);
+ if (call->state <= RXRPC_CALL_COMPLETE) {
+ call->state = RXRPC_CALL_LOCALLY_ABORTED;
+ call->abort_code = RX_PROTOCOL_ERROR;
+ set_bit(RXRPC_CALL_ABORT, &call->events);
+ schedule_work(&call->processor);
+ }
+ write_unlock_bh(&call->state_lock);
+ _leave("");
+}
+
+/*
+ * post an incoming packet to the appropriate call/socket to deal with
+ * - must get rid of the sk_buff, either by freeing it or by queuing it
+ */
+static void rxrpc_post_packet_to_call(struct rxrpc_connection *conn,
+ struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp;
+ struct rxrpc_call *call;
+ struct rb_node *p;
+ __be32 call_id;
+
+ _enter("%p,%p", conn, skb);
+
+ read_lock_bh(&conn->lock);
+
+ sp = rxrpc_skb(skb);
+
+ /* look at extant calls by channel number first */
+ call = conn->channels[ntohl(sp->hdr.cid) & RXRPC_CHANNELMASK];
+ if (!call || call->call_id != sp->hdr.callNumber)
+ goto call_not_extant;
+
+ _debug("extant call [%d]", call->state);
+ ASSERTCMP(call->conn, ==, conn);
+
+ read_lock(&call->state_lock);
+ switch (call->state) {
+ case RXRPC_CALL_LOCALLY_ABORTED:
+ if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events))
+ schedule_work(&call->processor);
+ case RXRPC_CALL_REMOTELY_ABORTED:
+ case RXRPC_CALL_NETWORK_ERROR:
+ case RXRPC_CALL_DEAD:
+ goto free_unlock;
+ default:
+ break;
+ }
+
+ read_unlock(&call->state_lock);
+ rxrpc_get_call(call);
+ read_unlock_bh(&conn->lock);
+
+ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+ sp->hdr.flags & RXRPC_JUMBO_PACKET)
+ rxrpc_process_jumbo_packet(call, skb);
+ else
+ rxrpc_fast_process_packet(call, skb);
+
+ rxrpc_put_call(call);
+ goto done;
+
+call_not_extant:
+ /* search the completed calls in case what we're dealing with is
+ * there */
+ _debug("call not extant");
+
+ call_id = sp->hdr.callNumber;
+ p = conn->calls.rb_node;
+ while (p) {
+ call = rb_entry(p, struct rxrpc_call, conn_node);
+
+ if (call_id < call->call_id)
+ p = p->rb_left;
+ else if (call_id > call->call_id)
+ p = p->rb_right;
+ else
+ goto found_completed_call;
+ }
+
+dead_call:
+ /* it's a either a really old call that we no longer remember or its a
+ * new incoming call */
+ read_unlock_bh(&conn->lock);
+
+ if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
+ sp->hdr.seq == __constant_cpu_to_be32(1)) {
+ _debug("incoming call");
+ skb_queue_tail(&conn->trans->local->accept_queue, skb);
+ schedule_work(&conn->trans->local->acceptor);
+ goto done;
+ }
+
+ _debug("dead call");
+ skb->priority = RX_CALL_DEAD;
+ rxrpc_reject_packet(conn->trans->local, skb);
+ goto done;
+
+ /* resend last packet of a completed call
+ * - client calls may have been aborted or ACK'd
+ * - server calls may have been aborted
+ */
+found_completed_call:
+ _debug("completed call");
+
+ if (atomic_read(&call->usage) == 0)
+ goto dead_call;
+
+ /* synchronise any state changes */
+ read_lock(&call->state_lock);
+ ASSERTIFCMP(call->state != RXRPC_CALL_CLIENT_FINAL_ACK,
+ call->state, >=, RXRPC_CALL_COMPLETE);
+
+ if (call->state == RXRPC_CALL_LOCALLY_ABORTED ||
+ call->state == RXRPC_CALL_REMOTELY_ABORTED ||
+ call->state == RXRPC_CALL_DEAD) {
+ read_unlock(&call->state_lock);
+ goto dead_call;
+ }
+
+ if (call->conn->in_clientflag) {
+ read_unlock(&call->state_lock);
+ goto dead_call; /* complete server call */
+ }
+
+ _debug("final ack again");
+ rxrpc_get_call(call);
+ set_bit(RXRPC_CALL_ACK_FINAL, &call->events);
+ schedule_work(&call->processor);
+
+free_unlock:
+ read_unlock(&call->state_lock);
+ read_unlock_bh(&conn->lock);
+ rxrpc_free_skb(skb);
+done:
+ _leave("");
+}
+
+/*
+ * post connection-level events to the connection
+ * - this includes challenges, responses and some aborts
+ */
+static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
+ struct sk_buff *skb)
+{
+ _enter("%p,%p", conn, skb);
+
+ atomic_inc(&conn->usage);
+ skb_queue_tail(&conn->rx_queue, skb);
+ schedule_work(&conn->processor);
+}
+
+/*
+ * handle data received on the local endpoint
+ * - may be called in interrupt context
+ */
+void rxrpc_data_ready(struct sock *sk, int count)
+{
+ struct rxrpc_connection *conn;
+ struct rxrpc_transport *trans;
+ struct rxrpc_skb_priv *sp;
+ struct rxrpc_local *local;
+ struct rxrpc_peer *peer;
+ struct sk_buff *skb;
+ int ret;
+
+ _enter("%p, %d", sk, count);
+
+ ASSERT(!irqs_disabled());
+
+ read_lock_bh(&rxrpc_local_lock);
+ local = sk->sk_user_data;
+ if (local && atomic_read(&local->usage) > 0)
+ rxrpc_get_local(local);
+ else
+ local = NULL;
+ read_unlock_bh(&rxrpc_local_lock);
+ if (!local) {
+ _leave(" [local dead]");
+ return;
+ }
+
+ skb = skb_recv_datagram(sk, 0, 1, &ret);
+ if (!skb) {
+ rxrpc_put_local(local);
+ if (ret == -EAGAIN)
+ return;
+ _debug("UDP socket error %d", ret);
+ return;
+ }
+
+ rxrpc_new_skb(skb);
+
+ _net("recv skb %p", skb);
+
+ /* we'll probably need to checksum it (didn't call sock_recvmsg) */
+ if (skb_checksum_complete(skb)) {
+ rxrpc_free_skb(skb);
+ rxrpc_put_local(local);
+ _leave(" [CSUM failed]");
+ return;
+ }
+
+ /* the socket buffer we have is owned by UDP, with UDP's data all over
+ * it, but we really want our own */
+ skb_orphan(skb);
+ sp = rxrpc_skb(skb);
+ memset(sp, 0, sizeof(*sp));
+
+ _net("Rx UDP packet from %08x:%04hu",
+ ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
+
+ /* dig out the RxRPC connection details */
+ if (skb_copy_bits(skb, sizeof(struct udphdr), &sp->hdr,
+ sizeof(sp->hdr)) < 0)
+ goto bad_message;
+ if (!pskb_pull(skb, sizeof(struct udphdr) + sizeof(sp->hdr)))
+ BUG();
+
+ _net("Rx RxRPC %s ep=%x call=%x:%x",
+ sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
+ ntohl(sp->hdr.epoch),
+ ntohl(sp->hdr.cid),
+ ntohl(sp->hdr.callNumber));
+
+ if (sp->hdr.type == 0 || sp->hdr.type >= RXRPC_N_PACKET_TYPES) {
+ _proto("Rx Bad Packet Type %u", sp->hdr.type);
+ goto bad_message;
+ }
+
+ if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
+ (sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
+ goto bad_message;
+
+ peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr, udp_hdr(skb)->source);
+ if (IS_ERR(peer))
+ goto cant_route_call;
+
+ trans = rxrpc_find_transport(local, peer);
+ rxrpc_put_peer(peer);
+ if (!trans)
+ goto cant_route_call;
+
+ conn = rxrpc_find_connection(trans, &sp->hdr);
+ rxrpc_put_transport(trans);
+ if (!conn)
+ goto cant_route_call;
+
+ _debug("CONN %p {%d}", conn, conn->debug_id);
+
+ if (sp->hdr.callNumber == 0)
+ rxrpc_post_packet_to_conn(conn, skb);
+ else
+ rxrpc_post_packet_to_call(conn, skb);
+ rxrpc_put_connection(conn);
+ rxrpc_put_local(local);
+ return;
+
+cant_route_call:
+ _debug("can't route call");
+ if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
+ sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
+ if (sp->hdr.seq == __constant_cpu_to_be32(1)) {
+ _debug("first packet");
+ skb_queue_tail(&local->accept_queue, skb);
+ schedule_work(&local->acceptor);
+ rxrpc_put_local(local);
+ _leave(" [incoming]");
+ return;
+ }
+ skb->priority = RX_INVALID_OPERATION;
+ } else {
+ skb->priority = RX_CALL_DEAD;
+ }
+
+ _debug("reject");
+ rxrpc_reject_packet(local, skb);
+ rxrpc_put_local(local);
+ _leave(" [no call]");
+ return;
+
+bad_message:
+ skb->priority = RX_PROTOCOL_ERROR;
+ rxrpc_reject_packet(local, skb);
+ rxrpc_put_local(local);
+ _leave(" [badmsg]");
+}

Privacy Policy