1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
/*
* (C) Copyright 2012
* Joe Hershberger, National Instruments, joe.hershberger@ni.com
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */
#include <stdint.h>
#include <stdio.h>
#include <linux/linux_string.h>
#else
#include <common.h>
#endif
#include <env_attr.h>
#include <errno.h>
#include <linux/string.h>
#include <malloc.h>
/*
* Iterate through the whole list calling the callback for each found element.
* "attr_list" takes the form:
* attributes = [^,:\s]*
* entry = name[:attributes]
* list = entry[,list]
*/
int env_attr_walk(const char *attr_list,
int (*callback)(const char *name, const char *attributes, void *priv),
void *priv)
{
const char *entry, *entry_end;
char *name, *attributes;
if (!attr_list)
/* list not found */
return 1;
entry = attr_list;
do {
char *entry_cpy = NULL;
entry_end = strchr(entry, ENV_ATTR_LIST_DELIM);
/* check if this is the last entry in the list */
if (entry_end == NULL) {
int entry_len = strlen(entry);
if (entry_len) {
/*
* allocate memory to copy the entry into since
* we will need to inject '\0' chars and squash
* white-space before calling the callback
*/
entry_cpy = malloc(entry_len + 1);
if (entry_cpy)
/* copy the rest of the list */
strcpy(entry_cpy, entry);
else
return -ENOMEM;
}
} else {
int entry_len = entry_end - entry;
if (entry_len) {
/*
* allocate memory to copy the entry into since
* we will need to inject '\0' chars and squash
* white-space before calling the callback
*/
entry_cpy = malloc(entry_len + 1);
if (entry_cpy) {
/* copy just this entry and null term */
strncpy(entry_cpy, entry, entry_len);
entry_cpy[entry_len] = '\0';
} else
return -ENOMEM;
}
}
/* check if there is anything to process (e.g. not ",,,") */
if (entry_cpy != NULL) {
attributes = strchr(entry_cpy, ENV_ATTR_SEP);
/* check if there is a ':' */
if (attributes != NULL) {
/* replace the ':' with '\0' to term name */
*attributes++ = '\0';
/* remove white-space from attributes */
attributes = strim(attributes);
}
/* remove white-space from name */
name = strim(entry_cpy);
/* only call the callback if there is a name */
if (strlen(name) != 0) {
int retval = 0;
retval = callback(name, attributes, priv);
if (retval) {
free(entry_cpy);
return retval;
}
}
}
free(entry_cpy);
entry = entry_end + 1;
} while (entry_end != NULL);
return 0;
}
/*
* Search for the last exactly matching name in an attribute list
*/
static int reverse_name_search(const char *searched, const char *search_for,
const char **result)
{
int result_size = 0;
const char *cur_searched = searched;
if (result)
*result = NULL;
if (*search_for == '\0') {
if (result)
*result = searched;
return strlen(searched);
}
for (;;) {
const char *match = strstr(cur_searched, search_for);
const char *prevch;
const char *nextch;
/* Stop looking if no new match is found */
if (match == NULL)
break;
prevch = match - 1;
nextch = match + strlen(search_for);
/* Skip spaces */
while (*prevch == ' ' && prevch >= searched)
prevch--;
while (*nextch == ' ')
nextch++;
/* Start looking past the current match so last is found */
cur_searched = match + 1;
/* Check for an exact match */
if (match != searched &&
*prevch != ENV_ATTR_LIST_DELIM &&
prevch != searched - 1)
continue;
if (*nextch != ENV_ATTR_SEP &&
*nextch != ENV_ATTR_LIST_DELIM &&
*nextch != '\0')
continue;
if (result)
*result = match;
result_size = strlen(search_for);
}
return result_size;
}
/*
* Retrieve the attributes string associated with a single name in the list
* There is no protection on attributes being too small for the value
*/
int env_attr_lookup(const char *attr_list, const char *name, char *attributes)
{
const char *entry = NULL;
int entry_len;
if (!attributes)
/* bad parameter */
return -EINVAL;
if (!attr_list)
/* list not found */
return -EINVAL;
entry_len = reverse_name_search(attr_list, name, &entry);
if (entry != NULL) {
int len;
/* skip the name */
entry += entry_len;
/* skip spaces */
while (*entry == ' ')
entry++;
if (*entry != ENV_ATTR_SEP)
len = 0;
else {
const char *delim;
static const char delims[] = {
ENV_ATTR_LIST_DELIM, ' ', '\0'};
/* skip the attr sep */
entry += 1;
/* skip spaces */
while (*entry == ' ')
entry++;
delim = strpbrk(entry, delims);
if (delim == NULL)
len = strlen(entry);
else
len = delim - entry;
memcpy(attributes, entry, len);
}
attributes[len] = '\0';
/* success */
return 0;
}
/* not found in list */
return -ENOENT;
}
|
