1 /*
2 * IE/TLV fragmentation/defragmentation support for
3 * Broadcom 802.11bang Networking Device Driver
4 *
5 * Copyright (C) 2020, Broadcom.
6 *
7 * Unless you and Broadcom execute a separate written software license
8 * agreement governing use of this software, this software is licensed to you
9 * under the terms of the GNU General Public License version 2 (the "GPL"),
10 * available at http://www.broadcom.com/licenses/GPLv2.php, with the
11 * following added to such license:
12 *
13 * As a special exception, the copyright holders of this software give you
14 * permission to link this software with independent modules, and to copy and
15 * distribute the resulting executable under terms of your choice, provided that
16 * you also meet, for each linked independent module, the terms and conditions of
17 * the license of that module. An independent module is a module which is not
18 * derived from this software. The special exception does not apply to any
19 * modifications of the software.
20 *
21 *
22 * <<Broadcom-WL-IPTag/Dual:>>
23 */
24
25 #include <bcmutils.h>
26 #include <frag.h>
27 #include <802.11.h>
28
29 /* defrag a fragmented dot11 ie/tlv. if space does not permit, return the needed
30 * ie length to contain all the fragments with status BCME_BUFTOOSHORT.
31 * out_len is in/out parameter, max length on input, used/required length on output
32 */
33 int
bcm_tlv_dot11_defrag(const void * buf,uint buf_len,uint8 id,bool id_ext,uint8 * out,uint * out_len)34 bcm_tlv_dot11_defrag(const void *buf, uint buf_len, uint8 id, bool id_ext,
35 uint8 *out, uint *out_len)
36 {
37 int err = BCME_OK;
38 const bcm_tlv_t *ie;
39 uint tot_len = 0;
40 uint out_left;
41
42 /* find the ie; includes validation */
43 ie = bcm_parse_tlvs_dot11(buf, buf_len, id, id_ext);
44 if (!ie) {
45 err = BCME_IE_NOTFOUND;
46 goto done;
47 }
48
49 out_left = (out && out_len) ? *out_len : 0;
50
51 /* first fragment */
52 tot_len = id_ext ? ie->len - 1 : ie->len;
53
54 /* copy out if output space permits */
55 if (out_left < tot_len) {
56 err = BCME_BUFTOOSHORT;
57 out_left = 0; /* prevent further copy */
58 } else {
59 memcpy(out, &ie->data[id_ext ? 1 : 0], tot_len);
60 out += tot_len;
61 out_left -= tot_len;
62 }
63
64 /* if not fragmened or not fragmentable per 802.11 table 9-77 11md0.1 bail
65 * we can introduce the latter check later
66 */
67 if (ie->len != BCM_TLV_MAX_DATA_SIZE) {
68 goto done;
69 }
70
71 /* adjust buf_len to length after ie including it */
72 buf_len -= (uint)(((const uint8 *)ie - (const uint8 *)buf));
73
74 /* update length from fragments, okay if no next ie */
75 while ((ie = bcm_next_tlv(ie, &buf_len)) &&
76 (ie->id == DOT11_MNG_FRAGMENT_ID)) {
77 /* note: buf_len starts at next ie and last frag may be partial */
78 if (out_left < ie->len) {
79 err = BCME_BUFTOOSHORT;
80 out_left = 0;
81 } else {
82 memcpy(out, &ie->data[0], ie->len);
83 out += ie->len;
84 out_left -= ie->len;
85 }
86
87 tot_len += ie->len + BCM_TLV_HDR_SIZE;
88
89 /* all but last should be of max size */
90 if (ie->len < BCM_TLV_MAX_DATA_SIZE) {
91 break;
92 }
93 }
94
95 done:
96 if (out_len) {
97 *out_len = tot_len;
98 }
99
100 return err;
101 }
102
103 int
bcm_tlv_dot11_frag_tot_len(const void * buf,uint buf_len,uint8 id,bool id_ext,uint * ie_len)104 bcm_tlv_dot11_frag_tot_len(const void *buf, uint buf_len,
105 uint8 id, bool id_ext, uint *ie_len)
106 {
107 return bcm_tlv_dot11_defrag(buf, buf_len, id, id_ext, NULL, ie_len);
108 }
109