Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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 | */ |
| 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 | */ |
| 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. */ |
| 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. */ |
| 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. */ |
| 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 | } |