1 /* SCTP kernel reference Implementation
2 * Copyright (c) 2003 International Business Machines, Corp.
3 *
4 * This file is part of the SCTP kernel reference Implementation
5 *
6 * These functions manipulate sctp SSN tracker.
7 *
8 * The SCTP reference implementation is free software;
9 * you can redistribute it and/or modify it under the terms of
10 * the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
12 * any later version.
13 *
14 * The SCTP reference implementation is distributed in the hope that it
15 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
16 * ************************
17 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
18 * See the GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with GNU CC; see the file COPYING. If not, write to
22 * the Free Software Foundation, 59 Temple Place - Suite 330,
23 * Boston, MA 02111-1307, USA.
24 *
25 * Please send any bug reports or fixes you make to the
26 * email address(es):
27 * lksctp developers <lksctp-developers@lists.sourceforge.net>
28 *
29 * Or submit a bug report through the following website:
30 * http://www.sf.net/projects/lksctp
31 *
32 * Written or modified by:
33 * Jon Grimm <jgrimm@us.ibm.com>
34 *
35 * Any bugs reported given to us we will try to fix... any fixes shared will
36 * be incorporated into the next SCTP release.
37 */
38
39 #include <linux/types.h>
40 #include <net/sctp/sctp.h>
41 #include <net/sctp/sm.h>
42
43 #define MAX_KMALLOC_SIZE 131072
44
45 static struct sctp_ssnmap *sctp_ssnmap_init(struct sctp_ssnmap *map, __u16 in,
46 __u16 out);
47
48 /* Storage size needed for map includes 2 headers and then the
49 * specific needs of in or out streams.
50 */
sctp_ssnmap_size(__u16 in,__u16 out)51 static inline size_t sctp_ssnmap_size(__u16 in, __u16 out)
52 {
53 return sizeof(struct sctp_ssnmap) + (in + out) * sizeof(__u16);
54 }
55
56
57 /* Create a new sctp_ssnmap.
58 * Allocate room to store at least 'len' contiguous TSNs.
59 */
sctp_ssnmap_new(__u16 in,__u16 out,int gfp)60 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out, int gfp)
61 {
62 struct sctp_ssnmap *retval;
63 int size;
64
65 size = sctp_ssnmap_size(in, out);
66 if (size <= MAX_KMALLOC_SIZE)
67 retval = kmalloc(size, gfp);
68 else
69 retval = (struct sctp_ssnmap *)
70 __get_free_pages(gfp, get_order(size));
71 if (!retval)
72 goto fail;
73
74 if (!sctp_ssnmap_init(retval, in, out))
75 goto fail_map;
76
77 retval->malloced = 1;
78 SCTP_DBG_OBJCNT_INC(ssnmap);
79
80 return retval;
81
82 fail_map:
83 if (size <= MAX_KMALLOC_SIZE)
84 kfree(retval);
85 else
86 free_pages((unsigned long)retval, get_order(size));
87 fail:
88 return NULL;
89 }
90
91
92 /* Initialize a block of memory as a ssnmap. */
sctp_ssnmap_init(struct sctp_ssnmap * map,__u16 in,__u16 out)93 static struct sctp_ssnmap *sctp_ssnmap_init(struct sctp_ssnmap *map, __u16 in,
94 __u16 out)
95 {
96 memset(map, 0x00, sctp_ssnmap_size(in, out));
97
98 /* Start 'in' stream just after the map header. */
99 map->in.ssn = (__u16 *)&map[1];
100 map->in.len = in;
101
102 /* Start 'out' stream just after 'in'. */
103 map->out.ssn = &map->in.ssn[in];
104 map->out.len = out;
105
106 return map;
107 }
108
109 /* Clear out the ssnmap streams. */
sctp_ssnmap_clear(struct sctp_ssnmap * map)110 void sctp_ssnmap_clear(struct sctp_ssnmap *map)
111 {
112 size_t size;
113
114 size = (map->in.len + map->out.len) * sizeof(__u16);
115 memset(map->in.ssn, 0x00, size);
116 }
117
118 /* Dispose of a ssnmap. */
sctp_ssnmap_free(struct sctp_ssnmap * map)119 void sctp_ssnmap_free(struct sctp_ssnmap *map)
120 {
121 if (map && map->malloced) {
122 int size;
123
124 size = sctp_ssnmap_size(map->in.len, map->out.len);
125 if (size <= MAX_KMALLOC_SIZE)
126 kfree(map);
127 else
128 free_pages((unsigned long)map, get_order(size));
129 SCTP_DBG_OBJCNT_DEC(ssnmap);
130 }
131 }
132