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7877a4a4 DH |
1 | /* Service connection management |
2 | * | |
3 | * Copyright (C) 2016 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 Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/slab.h> | |
13 | #include "ar-internal.h" | |
14 | ||
15 | /* | |
16 | * get a record of an incoming connection | |
17 | */ | |
18 | struct rxrpc_connection *rxrpc_incoming_connection(struct rxrpc_local *local, | |
19 | struct rxrpc_peer *peer, | |
20 | struct sk_buff *skb) | |
21 | { | |
22 | struct rxrpc_connection *conn, *candidate = NULL; | |
23 | struct rxrpc_skb_priv *sp = rxrpc_skb(skb); | |
24 | struct rb_node *p, **pp; | |
25 | const char *new = "old"; | |
26 | u32 epoch, cid; | |
27 | ||
28 | _enter(""); | |
29 | ||
30 | ASSERT(sp->hdr.flags & RXRPC_CLIENT_INITIATED); | |
31 | ||
32 | epoch = sp->hdr.epoch; | |
33 | cid = sp->hdr.cid & RXRPC_CIDMASK; | |
34 | ||
35 | /* search the connection list first */ | |
36 | read_lock_bh(&peer->conn_lock); | |
37 | ||
38 | p = peer->service_conns.rb_node; | |
39 | while (p) { | |
40 | conn = rb_entry(p, struct rxrpc_connection, service_node); | |
41 | ||
42 | _debug("maybe %x", conn->proto.cid); | |
43 | ||
44 | if (epoch < conn->proto.epoch) | |
45 | p = p->rb_left; | |
46 | else if (epoch > conn->proto.epoch) | |
47 | p = p->rb_right; | |
48 | else if (cid < conn->proto.cid) | |
49 | p = p->rb_left; | |
50 | else if (cid > conn->proto.cid) | |
51 | p = p->rb_right; | |
52 | else | |
53 | goto found_extant_connection; | |
54 | } | |
55 | read_unlock_bh(&peer->conn_lock); | |
56 | ||
57 | /* not yet present - create a candidate for a new record and then | |
58 | * redo the search */ | |
59 | candidate = rxrpc_alloc_connection(GFP_NOIO); | |
60 | if (!candidate) { | |
61 | _leave(" = -ENOMEM"); | |
62 | return ERR_PTR(-ENOMEM); | |
63 | } | |
64 | ||
65 | candidate->proto.local = local; | |
66 | candidate->proto.epoch = sp->hdr.epoch; | |
67 | candidate->proto.cid = sp->hdr.cid & RXRPC_CIDMASK; | |
68 | candidate->proto.in_clientflag = RXRPC_CLIENT_INITIATED; | |
69 | candidate->params.local = local; | |
70 | candidate->params.peer = peer; | |
71 | candidate->params.service_id = sp->hdr.serviceId; | |
72 | candidate->security_ix = sp->hdr.securityIndex; | |
73 | candidate->out_clientflag = 0; | |
74 | candidate->state = RXRPC_CONN_SERVICE; | |
75 | if (candidate->params.service_id) | |
76 | candidate->state = RXRPC_CONN_SERVICE_UNSECURED; | |
77 | ||
78 | write_lock_bh(&peer->conn_lock); | |
79 | ||
80 | pp = &peer->service_conns.rb_node; | |
81 | p = NULL; | |
82 | while (*pp) { | |
83 | p = *pp; | |
84 | conn = rb_entry(p, struct rxrpc_connection, service_node); | |
85 | ||
86 | if (epoch < conn->proto.epoch) | |
87 | pp = &(*pp)->rb_left; | |
88 | else if (epoch > conn->proto.epoch) | |
89 | pp = &(*pp)->rb_right; | |
90 | else if (cid < conn->proto.cid) | |
91 | pp = &(*pp)->rb_left; | |
92 | else if (cid > conn->proto.cid) | |
93 | pp = &(*pp)->rb_right; | |
94 | else | |
95 | goto found_extant_second; | |
96 | } | |
97 | ||
98 | /* we can now add the new candidate to the list */ | |
99 | conn = candidate; | |
100 | candidate = NULL; | |
101 | rb_link_node(&conn->service_node, p, pp); | |
102 | rb_insert_color(&conn->service_node, &peer->service_conns); | |
103 | rxrpc_get_peer(peer); | |
104 | rxrpc_get_local(local); | |
105 | ||
106 | write_unlock_bh(&peer->conn_lock); | |
107 | ||
108 | write_lock(&rxrpc_connection_lock); | |
109 | list_add_tail(&conn->link, &rxrpc_connections); | |
110 | write_unlock(&rxrpc_connection_lock); | |
111 | ||
112 | new = "new"; | |
113 | ||
114 | success: | |
115 | _net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->proto.cid); | |
116 | ||
117 | _leave(" = %p {u=%d}", conn, atomic_read(&conn->usage)); | |
118 | return conn; | |
119 | ||
120 | /* we found the connection in the list immediately */ | |
121 | found_extant_connection: | |
122 | if (sp->hdr.securityIndex != conn->security_ix) { | |
123 | read_unlock_bh(&peer->conn_lock); | |
124 | goto security_mismatch; | |
125 | } | |
126 | rxrpc_get_connection(conn); | |
127 | read_unlock_bh(&peer->conn_lock); | |
128 | goto success; | |
129 | ||
130 | /* we found the connection on the second time through the list */ | |
131 | found_extant_second: | |
132 | if (sp->hdr.securityIndex != conn->security_ix) { | |
133 | write_unlock_bh(&peer->conn_lock); | |
134 | goto security_mismatch; | |
135 | } | |
136 | rxrpc_get_connection(conn); | |
137 | write_unlock_bh(&peer->conn_lock); | |
138 | kfree(candidate); | |
139 | goto success; | |
140 | ||
141 | security_mismatch: | |
142 | kfree(candidate); | |
143 | _leave(" = -EKEYREJECTED"); | |
144 | return ERR_PTR(-EKEYREJECTED); | |
145 | } |