1 // SPDX-License-Identifier: ISC
2 /*
3  * Copyright (c) 2019 Broadcom
4  */
5 
6 #include <asm/unaligned.h>
7 
8 #include <linux/math.h>
9 #include <linux/string.h>
10 #include <linux/bug.h>
11 
12 #include "xtlv.h"
13 
brcmf_xtlv_header_size(u16 opts)14 static int brcmf_xtlv_header_size(u16 opts)
15 {
16 	int len = (int)offsetof(struct brcmf_xtlv, data);
17 
18 	if (opts & BRCMF_XTLV_OPTION_IDU8)
19 		--len;
20 	if (opts & BRCMF_XTLV_OPTION_LENU8)
21 		--len;
22 
23 	return len;
24 }
25 
brcmf_xtlv_data_size(int dlen,u16 opts)26 int brcmf_xtlv_data_size(int dlen, u16 opts)
27 {
28 	int hsz;
29 
30 	hsz = brcmf_xtlv_header_size(opts);
31 	if (opts & BRCMF_XTLV_OPTION_ALIGN32)
32 		return roundup(dlen + hsz, 4);
33 
34 	return dlen + hsz;
35 }
36 
brcmf_xtlv_pack_header(struct brcmf_xtlv * xtlv,u16 id,u16 len,const u8 * data,u16 opts)37 void brcmf_xtlv_pack_header(struct brcmf_xtlv *xtlv, u16 id, u16 len,
38 			    const u8 *data, u16 opts)
39 {
40 	u8 *data_buf;
41 	u16 mask = BRCMF_XTLV_OPTION_IDU8 | BRCMF_XTLV_OPTION_LENU8;
42 
43 	if (!(opts & mask)) {
44 		u8 *idp = (u8 *)xtlv;
45 		u8 *lenp = idp + sizeof(xtlv->id);
46 
47 		put_unaligned_le16(id, idp);
48 		put_unaligned_le16(len, lenp);
49 		data_buf = lenp + sizeof(u16);
50 	} else if ((opts & mask) == mask) { /* u8 id and u8 len */
51 		u8 *idp = (u8 *)xtlv;
52 		u8 *lenp = idp + 1;
53 
54 		*idp = (u8)id;
55 		*lenp = (u8)len;
56 		data_buf = lenp + sizeof(u8);
57 	} else if (opts & BRCMF_XTLV_OPTION_IDU8) { /* u8 id, u16 len */
58 		u8 *idp = (u8 *)xtlv;
59 		u8 *lenp = idp + 1;
60 
61 		*idp = (u8)id;
62 		put_unaligned_le16(len, lenp);
63 		data_buf = lenp + sizeof(u16);
64 	} else if (opts & BRCMF_XTLV_OPTION_LENU8) { /* u16 id, u8 len */
65 		u8 *idp = (u8 *)xtlv;
66 		u8 *lenp = idp + sizeof(u16);
67 
68 		put_unaligned_le16(id, idp);
69 		*lenp = (u8)len;
70 		data_buf = lenp + sizeof(u8);
71 	} else {
72 		WARN(true, "Unexpected xtlv option");
73 		return;
74 	}
75 
76 	if (opts & BRCMF_XTLV_OPTION_LENU8) {
77 		WARN_ON(len > 0x00ff);
78 		len &= 0xff;
79 	}
80 
81 	if (data)
82 		memcpy(data_buf, data, len);
83 }
84 
85