1/*-
2 * Copyright (c) 2017 Broadcom. All rights reserved.
3 * The term "Broadcom" refers to Broadcom Limited and/or its subsidiaries.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 *    this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 *    this list of conditions and the following disclaimer in the documentation
13 *    and/or other materials provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
23 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/**
33 * @file
34 * OCS VPD parser
35 */
36
37#if !defined(__OCS_VPD_H__)
38#define __OCS_VPD_H__
39
40/**
41 * @brief VPD buffer structure
42 */
43
44typedef struct {
45	uint8_t *buffer;
46	uint32_t length;
47	uint32_t offset;
48	uint8_t checksum;
49	} vpdbuf_t;
50
51/**
52 * @brief return next VPD byte
53 *
54 * Returns next VPD byte and updates accumulated checksum
55 *
56 * @param vpd pointer to vpd buffer
57 *
58 * @return returns next byte for success, or a negative error code value for failure.
59 *
60 */
61
62static inline int
63vpdnext(vpdbuf_t *vpd)
64{
65	int rc = -1;
66	if (vpd->offset < vpd->length) {
67		rc = vpd->buffer[vpd->offset++];
68		vpd->checksum += rc;
69	}
70	return rc;
71}
72
73/**
74 * @brief return true if no more vpd buffer data
75 *
76 * return true if the vpd buffer data has been completely consumed
77 *
78 * @param vpd pointer to vpd buffer
79 *
80 * @return returns true if no more data
81 *
82 */
83static inline int
84vpddone(vpdbuf_t *vpd)
85{
86	return vpd->offset >= vpd->length;
87}
88/**
89 * @brief return pointer to current VPD data location
90 *
91 * Returns a pointer to the current location in the VPD data
92 *
93 * @param vpd pointer to vpd buffer
94 *
95 * @return pointer to current VPD data location
96 */
97
98static inline uint8_t *
99vpdref(vpdbuf_t *vpd)
100{
101	return &vpd->buffer[vpd->offset];
102}
103
104#define VPD_LARGE_RESOURCE_TYPE_ID_STRING_TAG	0x82
105#define VPD_LARGE_RESOURCE_TYPE_R_TAG		0x90
106#define VPD_LARGE_RESOURCE_TYPE_W_TAG		0x91
107#define VPD_SMALL_RESOURCE_TYPE_END_TAG		0x78
108
109/**
110 * @brief find a VPD entry
111 *
112 * Finds a VPD entry given the two character code
113 *
114 * @param vpddata pointer to raw vpd data buffer
115 * @param vpddata_length length of vpddata buffer in bytes
116 * @param key key to look up
117
118 * @return returns a pointer to the key location or NULL if not found or checksum error
119 */
120
121static inline uint8_t *
122ocs_find_vpd(uint8_t *vpddata, uint32_t vpddata_length, const char *key)
123{
124	vpdbuf_t vpdbuf;
125	uint8_t *pret = NULL;
126	uint8_t c0 = key[0];
127	uint8_t c1 = key[1];
128
129	vpdbuf.buffer = (uint8_t*) vpddata;
130	vpdbuf.length = vpddata_length;
131	vpdbuf.offset = 0;
132	vpdbuf.checksum = 0;
133
134	while (!vpddone(&vpdbuf)) {
135		int type = vpdnext(&vpdbuf);
136		int len_lo;
137		int len_hi;
138		int len;
139		int i;
140
141		if (type == VPD_SMALL_RESOURCE_TYPE_END_TAG) {
142			break;
143		}
144
145		len_lo = vpdnext(&vpdbuf);
146		len_hi = vpdnext(&vpdbuf);
147		len = len_lo + (len_hi << 8);
148
149		if ((type == VPD_LARGE_RESOURCE_TYPE_R_TAG) || (type == VPD_LARGE_RESOURCE_TYPE_W_TAG)) {
150			while (len > 0) {
151				int rc0;
152				int rc1;
153				int sublen;
154				uint8_t *pstart;
155
156				rc0 = vpdnext(&vpdbuf);
157				rc1 = vpdnext(&vpdbuf);
158
159				/* Mark this location */
160				pstart = vpdref(&vpdbuf);
161
162				sublen = vpdnext(&vpdbuf);
163
164				/* Adjust remaining len */
165				len -= (sublen + 3);
166
167				/* check for match with request */
168				if ((c0 == rc0) && (c1 == rc1)) {
169					pret = pstart;
170					for (i = 0; i < sublen; i++) {
171						vpdnext(&vpdbuf);
172					}
173				/* check for "RV" end */
174				} else if ('R' == rc0 && 'V' == rc1) {
175					/* Read the checksum */
176					for (i = 0; i < sublen; i++) {
177						vpdnext(&vpdbuf);
178					}
179
180					/* The accumulated checksum should be zero here */
181					if (vpdbuf.checksum != 0) {
182						ocs_log_test(NULL, "checksum error\n");
183						return NULL;
184					}
185				}
186				else
187					for (i = 0; i < sublen; i++) {
188						vpdnext(&vpdbuf);
189					}
190			}
191		}
192
193		for (i = 0; i < len; i++) {
194			vpdnext(&vpdbuf);
195		}
196	}
197
198	return pret;
199}
200#endif
201