1 /* SCTP kernel implementation
2 * Copyright (c) 2003 International Business Machines, Corp.
3 *
4 * This file is part of the SCTP kernel implementation
5 *
6 * These functions manipulate sctp SSN tracker.
7 *
8 * This SCTP 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 * This SCTP 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, see
22 * <http://www.gnu.org/licenses/>.
23 *
24 * Please send any bug reports or fixes you make to the
25 * email address(es):
26 * lksctp developers <linux-sctp@vger.kernel.org>
27 *
28 * Written or modified by:
29 * Jon Grimm <jgrimm@us.ibm.com>
30 */
31
32 #include <linux/types.h>
33 #include <linux/slab.h>
34 #include <net/sctp/sctp.h>
35 #include <net/sctp/sm.h>
36
37 static struct sctp_ssnmap *sctp_ssnmap_init(struct sctp_ssnmap *map, __u16 in,
38 __u16 out);
39
40 /* Storage size needed for map includes 2 headers and then the
41 * specific needs of in or out streams.
42 */
sctp_ssnmap_size(__u16 in,__u16 out)43 static inline size_t sctp_ssnmap_size(__u16 in, __u16 out)
44 {
45 return sizeof(struct sctp_ssnmap) + (in + out) * sizeof(__u16);
46 }
47
48
49 /* Create a new sctp_ssnmap.
50 * Allocate room to store at least 'len' contiguous TSNs.
51 */
sctp_ssnmap_new(__u16 in,__u16 out,gfp_t gfp)52 struct sctp_ssnmap *sctp_ssnmap_new(__u16 in, __u16 out,
53 gfp_t gfp)
54 {
55 struct sctp_ssnmap *retval;
56 int size;
57
58 size = sctp_ssnmap_size(in, out);
59 if (size <= KMALLOC_MAX_SIZE)
60 retval = kmalloc(size, gfp);
61 else
62 retval = (struct sctp_ssnmap *)
63 __get_free_pages(gfp, get_order(size));
64 if (!retval)
65 goto fail;
66
67 if (!sctp_ssnmap_init(retval, in, out))
68 goto fail_map;
69
70 SCTP_DBG_OBJCNT_INC(ssnmap);
71
72 return retval;
73
74 fail_map:
75 if (size <= KMALLOC_MAX_SIZE)
76 kfree(retval);
77 else
78 free_pages((unsigned long)retval, get_order(size));
79 fail:
80 return NULL;
81 }
82
83
84 /* Initialize a block of memory as a ssnmap. */
sctp_ssnmap_init(struct sctp_ssnmap * map,__u16 in,__u16 out)85 static struct sctp_ssnmap *sctp_ssnmap_init(struct sctp_ssnmap *map, __u16 in,
86 __u16 out)
87 {
88 memset(map, 0x00, sctp_ssnmap_size(in, out));
89
90 /* Start 'in' stream just after the map header. */
91 map->in.ssn = (__u16 *)&map[1];
92 map->in.len = in;
93
94 /* Start 'out' stream just after 'in'. */
95 map->out.ssn = &map->in.ssn[in];
96 map->out.len = out;
97
98 return map;
99 }
100
101 /* Clear out the ssnmap streams. */
sctp_ssnmap_clear(struct sctp_ssnmap * map)102 void sctp_ssnmap_clear(struct sctp_ssnmap *map)
103 {
104 size_t size;
105
106 size = (map->in.len + map->out.len) * sizeof(__u16);
107 memset(map->in.ssn, 0x00, size);
108 }
109
110 /* Dispose of a ssnmap. */
sctp_ssnmap_free(struct sctp_ssnmap * map)111 void sctp_ssnmap_free(struct sctp_ssnmap *map)
112 {
113 int size;
114
115 if (unlikely(!map))
116 return;
117
118 size = sctp_ssnmap_size(map->in.len, map->out.len);
119 if (size <= KMALLOC_MAX_SIZE)
120 kfree(map);
121 else
122 free_pages((unsigned long)map, get_order(size));
123
124 SCTP_DBG_OBJCNT_DEC(ssnmap);
125 }
126