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1 /* Copyright (C) 2010 - 2015 UNISYS CORPORATION
2  * All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11  * NON INFRINGEMENT.  See the GNU General Public License for more
12  * details.
13  */
14 
15 #ifndef __VBUSDEVICEINFO_H__
16 #define __VBUSDEVICEINFO_H__
17 
18 #include <linux/types.h>
19 
20 #pragma pack(push, 1)		/* both GCC and VC now allow this pragma */
21 
22 /* An array of this struct is present in the channel area for each vbus.
23  * (See vbuschannel.h.)
24  * It is filled in by the client side to provide info about the device
25  * and driver from the client's perspective.
26  */
27 struct ultra_vbus_deviceinfo {
28 	u8 devtype[16];		/* short string identifying the device type */
29 	u8 drvname[16];		/* driver .sys file name */
30 	u8 infostrs[96];	/* sequence of tab-delimited id strings: */
31 	/* <DRIVER_REV> <DRIVER_VERTAG> <DRIVER_COMPILETIME> */
32 	u8 reserved[128];	/* pad size to 256 bytes */
33 };
34 
35 #pragma pack(pop)
36 
37 /* Reads chars from the buffer at <src> for <srcmax> bytes, and writes to
38  * the buffer at <p>, which is <remain> bytes long, ensuring never to
39  * overflow the buffer at <p>, using the following rules:
40  * - printable characters are simply copied from the buffer at <src> to the
41  *   buffer at <p>
42  * - intervening streaks of non-printable characters in the buffer at <src>
43  *   are replaced with a single space in the buffer at <p>
44  * Note that we pay no attention to '\0'-termination.
45  * Returns the number of bytes written to <p>.
46  *
47  * Pass <p> == NULL and <remain> == 0 for this special behavior.  In this
48  * case, we simply return the number of bytes that WOULD HAVE been written
49  * to a buffer at <p>, had it been infinitely big.
50  */
51 static inline int
vbuschannel_sanitize_buffer(char * p,int remain,char * src,int srcmax)52 vbuschannel_sanitize_buffer(char *p, int remain, char *src, int srcmax)
53 {
54 	int chars = 0;
55 	int nonprintable_streak = 0;
56 
57 	while (srcmax > 0) {
58 		if ((*src >= ' ') && (*src < 0x7f)) {
59 			if (nonprintable_streak) {
60 				if (remain > 0) {
61 					*p = ' ';
62 					p++;
63 					remain--;
64 					chars++;
65 				} else if (p == NULL) {
66 					chars++;
67 				}
68 				nonprintable_streak = 0;
69 			}
70 			if (remain > 0) {
71 				*p = *src;
72 				p++;
73 				remain--;
74 				chars++;
75 			} else if (p == NULL) {
76 				chars++;
77 			}
78 		} else {
79 			nonprintable_streak = 1;
80 		}
81 		src++;
82 		srcmax--;
83 	}
84 	return chars;
85 }
86 
87 #define VBUSCHANNEL_ADDACHAR(ch, p, remain, chars) \
88 	do {					   \
89 		if (remain <= 0)		   \
90 			break;			   \
91 		*p = ch;			   \
92 		p++;  chars++;  remain--;	   \
93 	} while (0)
94 
95 /* Converts the non-negative value at <num> to an ascii decimal string
96  * at <p>, writing at most <remain> bytes.  Note there is NO '\0' termination
97  * written to <p>.
98  *
99  * Returns the number of bytes written to <p>.
100  *
101  * Note that we create this function because we need to do this operation in
102  * an environment-independent way (since we are in a common header file).
103  */
104 static inline int
vbuschannel_itoa(char * p,int remain,int num)105 vbuschannel_itoa(char *p, int remain, int num)
106 {
107 	int digits = 0;
108 	char s[32];
109 	int i;
110 
111 	if (num == 0) {
112 		/* '0' is a special case */
113 		if (remain <= 0)
114 			return 0;
115 		*p = '0';
116 		return 1;
117 	}
118 	/* form a backwards decimal ascii string in <s> */
119 	while (num > 0) {
120 		if (digits >= (int)sizeof(s))
121 			return 0;
122 		s[digits++] = (num % 10) + '0';
123 		num = num / 10;
124 	}
125 	if (remain < digits) {
126 		/* not enough room left at <p> to hold number, so fill with
127 		 * '?' */
128 		for (i = 0; i < remain; i++, p++)
129 			*p = '?';
130 		return remain;
131 	}
132 	/* plug in the decimal ascii string representing the number, by */
133 	/* reversing the string we just built in <s> */
134 	i = digits;
135 	while (i > 0) {
136 		i--;
137 		*p = s[i];
138 		p++;
139 	}
140 	return digits;
141 }
142 
143 /* Reads <devInfo>, and converts its contents to a printable string at <p>,
144  * writing at most <remain> bytes.  Note there is NO '\0' termination
145  * written to <p>.
146  *
147  * Pass <devix> >= 0 if you want a device index presented.
148  *
149  * Returns the number of bytes written to <p>.
150  */
151 static inline int
vbuschannel_devinfo_to_string(struct ultra_vbus_deviceinfo * devinfo,char * p,int remain,int devix)152 vbuschannel_devinfo_to_string(struct ultra_vbus_deviceinfo *devinfo,
153 			      char *p, int remain, int devix)
154 {
155 	char *psrc;
156 	int nsrc, x, i, pad;
157 	int chars = 0;
158 
159 	psrc = &devinfo->devtype[0];
160 	nsrc = sizeof(devinfo->devtype);
161 	if (vbuschannel_sanitize_buffer(NULL, 0, psrc, nsrc) <= 0)
162 		return 0;
163 
164 	/* emit device index */
165 	if (devix >= 0) {
166 		VBUSCHANNEL_ADDACHAR('[', p, remain, chars);
167 		x = vbuschannel_itoa(p, remain, devix);
168 		p += x;
169 		remain -= x;
170 		chars += x;
171 		VBUSCHANNEL_ADDACHAR(']', p, remain, chars);
172 	} else {
173 		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
174 		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
175 		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
176 	}
177 
178 	/* emit device type */
179 	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
180 	p += x;
181 	remain -= x;
182 	chars += x;
183 	pad = 15 - x;		/* pad device type to be exactly 15 chars */
184 	for (i = 0; i < pad; i++)
185 		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
186 	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
187 
188 	/* emit driver name */
189 	psrc = &devinfo->drvname[0];
190 	nsrc = sizeof(devinfo->drvname);
191 	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
192 	p += x;
193 	remain -= x;
194 	chars += x;
195 	pad = 15 - x;		/* pad driver name to be exactly 15 chars */
196 	for (i = 0; i < pad; i++)
197 		VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
198 	VBUSCHANNEL_ADDACHAR(' ', p, remain, chars);
199 
200 	/* emit strings */
201 	psrc = &devinfo->infostrs[0];
202 	nsrc = sizeof(devinfo->infostrs);
203 	x = vbuschannel_sanitize_buffer(p, remain, psrc, nsrc);
204 	p += x;
205 	remain -= x;
206 	chars += x;
207 	VBUSCHANNEL_ADDACHAR('\n', p, remain, chars);
208 
209 	return chars;
210 }
211 
212 #endif
213