Gitiles
Code Review Sign In
gerrit.osmocom.org / osmo-msc / 0ab6babbde30c2f01b071a68542f59d94a604ae0 / . / openbsc / src / nat / bsc_sccp.c
blob: 8c14aa8922ce14a8c541305b77c1ee07cb9c9959 [file] [log] [blame]
Holger Hans Peter Freyther0ab6bab2010-06-15 18:47:49 +0800[diff] [blame^]1/* SCCP patching and handling routines */
2/*
3 * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
4 * (C) 2010 by On-Waves
5 * All Rights Reserved
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 */
22
23#include <openbsc/debug.h>
24#include <openbsc/bsc_nat.h>
25
26#include <osmocore/talloc.h>
27
28#include <string.h>
29
30/*
31 * SCCP patching below
32 */
33
34/* check if we are using this ref for patched already */
35static int sccp_ref_is_free(struct sccp_source_reference *ref, struct bsc_nat *nat)
36{
37 struct sccp_connections *conn;
38
39 llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
40 if (memcmp(ref, &conn->patched_ref, sizeof(*ref)) == 0)
41 return -1;
42 }
43
44 return 0;
45}
46
47/* copied from sccp.c */
48static int assign_src_local_reference(struct sccp_source_reference *ref, struct bsc_nat *nat)
49{
50 static u_int32_t last_ref = 0x50000;
51 int wrapped = 0;
52
53 do {
54 struct sccp_source_reference reference;
55 reference.octet1 = (last_ref >> 0) & 0xff;
56 reference.octet2 = (last_ref >> 8) & 0xff;
57 reference.octet3 = (last_ref >> 16) & 0xff;
58
59 ++last_ref;
60 /* do not use the reversed word and wrap around */
61 if ((last_ref & 0x00FFFFFF) == 0x00FFFFFF) {
62 LOGP(DNAT, LOGL_NOTICE, "Wrapped searching for a free code\n");
63 last_ref = 0;
64 ++wrapped;
65 }
66
67 if (sccp_ref_is_free(&reference, nat) == 0) {
68 *ref = reference;
69 return 0;
70 }
71 } while (wrapped != 2);
72
73 LOGP(DNAT, LOGL_ERROR, "Finding a free reference failed\n");
74 return -1;
75}
76
77int create_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
78{
79 struct sccp_connections *conn;
80
81 conn = talloc_zero(bsc->nat, struct sccp_connections);
82 if (!conn) {
83 LOGP(DNAT, LOGL_ERROR, "Memory allocation failure.\n");
84 return -1;
85 }
86
87 conn->real_ref = *parsed->src_local_ref;
88 if (assign_src_local_reference(&conn->patched_ref, bsc->nat) != 0) {
89 LOGP(DNAT, LOGL_ERROR, "Failed to assign a ref.\n");
90 talloc_free(conn);
91 return -1;
92 }
93
94 return 0;
95}
96
97void remove_sccp_src_ref(struct bsc_connection *bsc, struct msgb *msg, struct bsc_nat_parsed *parsed)
98{
99 struct sccp_connections *conn;
100
101 llist_for_each_entry(conn, &bsc->nat->sccp_connections, list_entry) {
102 if (memcmp(parsed->src_local_ref,
103 &conn->real_ref, sizeof(conn->real_ref)) == 0) {
104 if (bsc != conn->bsc) {
105 LOGP(DNAT, LOGL_ERROR, "Someone else...\n");
106 continue;
107 }
108
109
110 llist_del(&conn->list_entry);
111 talloc_free(conn);
112 return;
113 }
114 }
115
116 LOGP(DNAT, LOGL_ERROR, "Unknown connection.\n");
117}
118
119struct bsc_connection *patch_sccp_src_ref_to_bsc(struct msgb *msg,
120 struct bsc_nat_parsed *parsed,
121 struct bsc_nat *nat)
122{
123 struct sccp_connections *conn;
124 llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
125 if (memcmp(parsed->dest_local_ref,
126 &conn->real_ref, sizeof(*parsed->dest_local_ref)) == 0) {
127 memcpy(parsed->dest_local_ref,
128 &conn->patched_ref, sizeof(*parsed->dest_local_ref));
129 return conn->bsc;
130 }
131 }
132
133 return NULL;
134}
135
136struct bsc_connection *patch_sccp_src_ref_to_msc(struct msgb *msg,
137 struct bsc_nat_parsed *parsed,
138 struct bsc_nat *nat)
139{
140 struct sccp_connections *conn;
141 llist_for_each_entry(conn, &nat->sccp_connections, list_entry) {
142 if (memcmp(parsed->src_local_ref,
143 &conn->real_ref, sizeof(*parsed->src_local_ref)) == 0) {
144 memcpy(parsed->src_local_ref,
145 &conn->patched_ref, sizeof(*parsed->src_local_ref));
146 return conn->bsc;
147 }
148 }
149
150 return NULL;
151}