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170ab110 JH |
1 | /* |
2 | * (C) Copyright 2012 | |
3 | * Joe Hershberger, National Instruments, joe.hershberger@ni.com | |
4 | * | |
1a459660 | 5 | * SPDX-License-Identifier: GPL-2.0+ |
170ab110 JH |
6 | */ |
7 | ||
30fd4fad JH |
8 | #ifdef USE_HOSTCC /* Eliminate "ANSI does not permit..." warnings */ |
9 | #include <stdint.h> | |
10 | #include <stdio.h> | |
11 | #include <linux/linux_string.h> | |
12 | #else | |
170ab110 | 13 | #include <common.h> |
30fd4fad JH |
14 | #endif |
15 | ||
170ab110 JH |
16 | #include <env_attr.h> |
17 | #include <errno.h> | |
18 | #include <linux/string.h> | |
19 | #include <malloc.h> | |
20 | ||
21 | /* | |
22 | * Iterate through the whole list calling the callback for each found element. | |
23 | * "attr_list" takes the form: | |
24 | * attributes = [^,:\s]* | |
25 | * entry = name[:attributes] | |
26 | * list = entry[,list] | |
27 | */ | |
28 | int env_attr_walk(const char *attr_list, | |
29 | int (*callback)(const char *name, const char *attributes)) | |
30 | { | |
31 | const char *entry, *entry_end; | |
32 | char *name, *attributes; | |
33 | ||
34 | if (!attr_list) | |
35 | /* list not found */ | |
36 | return 1; | |
37 | ||
38 | entry = attr_list; | |
39 | do { | |
40 | char *entry_cpy = NULL; | |
41 | ||
42 | entry_end = strchr(entry, ENV_ATTR_LIST_DELIM); | |
43 | /* check if this is the last entry in the list */ | |
44 | if (entry_end == NULL) { | |
45 | int entry_len = strlen(entry); | |
46 | ||
47 | if (entry_len) { | |
48 | /* | |
49 | * allocate memory to copy the entry into since | |
50 | * we will need to inject '\0' chars and squash | |
51 | * white-space before calling the callback | |
52 | */ | |
53 | entry_cpy = malloc(entry_len + 1); | |
54 | if (entry_cpy) | |
55 | /* copy the rest of the list */ | |
56 | strcpy(entry_cpy, entry); | |
57 | else | |
58 | return -ENOMEM; | |
59 | } | |
60 | } else { | |
61 | int entry_len = entry_end - entry; | |
62 | ||
63 | if (entry_len) { | |
64 | /* | |
65 | * allocate memory to copy the entry into since | |
66 | * we will need to inject '\0' chars and squash | |
67 | * white-space before calling the callback | |
68 | */ | |
69 | entry_cpy = malloc(entry_len + 1); | |
70 | if (entry_cpy) { | |
71 | /* copy just this entry and null term */ | |
72 | strncpy(entry_cpy, entry, entry_len); | |
73 | entry_cpy[entry_len] = '\0'; | |
74 | } else | |
75 | return -ENOMEM; | |
76 | } | |
77 | } | |
78 | ||
79 | /* check if there is anything to process (e.g. not ",,,") */ | |
80 | if (entry_cpy != NULL) { | |
81 | attributes = strchr(entry_cpy, ENV_ATTR_SEP); | |
82 | /* check if there is a ':' */ | |
83 | if (attributes != NULL) { | |
84 | /* replace the ':' with '\0' to term name */ | |
85 | *attributes++ = '\0'; | |
86 | /* remove white-space from attributes */ | |
87 | attributes = strim(attributes); | |
88 | } | |
89 | /* remove white-space from name */ | |
90 | name = strim(entry_cpy); | |
91 | ||
92 | /* only call the callback if there is a name */ | |
93 | if (strlen(name) != 0) { | |
94 | int retval = 0; | |
95 | ||
96 | retval = callback(name, attributes); | |
97 | if (retval) { | |
98 | free(entry_cpy); | |
99 | return retval; | |
100 | } | |
101 | } | |
102 | } | |
103 | ||
104 | free(entry_cpy); | |
105 | entry = entry_end + 1; | |
106 | } while (entry_end != NULL); | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | /* | |
112 | * Search for the last matching string in another string with the option to | |
113 | * start looking at a certain point (i.e. ignore anything beyond that point). | |
114 | */ | |
115 | static char *reverse_strstr(const char *searched, const char *search_for, | |
116 | const char *searched_start) | |
117 | { | |
118 | char *result = NULL; | |
119 | ||
120 | if (*search_for == '\0') | |
121 | return (char *)searched; | |
122 | ||
123 | for (;;) { | |
124 | char *match = strstr(searched, search_for); | |
125 | ||
126 | /* | |
127 | * Stop looking if no new match is found or looking past the | |
128 | * searched_start pointer | |
129 | */ | |
130 | if (match == NULL || (searched_start != NULL && | |
131 | match + strlen(search_for) > searched_start)) | |
132 | break; | |
133 | ||
134 | result = match; | |
135 | searched = match + 1; | |
136 | } | |
137 | ||
138 | return result; | |
139 | } | |
140 | ||
141 | /* | |
142 | * Retrieve the attributes string associated with a single name in the list | |
143 | * There is no protection on attributes being too small for the value | |
144 | */ | |
145 | int env_attr_lookup(const char *attr_list, const char *name, char *attributes) | |
146 | { | |
147 | const char *entry = NULL; | |
148 | ||
149 | if (!attributes) | |
150 | /* bad parameter */ | |
151 | return -1; | |
152 | if (!attr_list) | |
153 | /* list not found */ | |
154 | return 1; | |
155 | ||
156 | entry = reverse_strstr(attr_list, name, NULL); | |
157 | while (entry != NULL) { | |
158 | const char *prevch = entry - 1; | |
159 | const char *nextch = entry + strlen(name); | |
160 | ||
161 | /* Skip spaces */ | |
162 | while (*prevch == ' ') | |
163 | prevch--; | |
164 | while (*nextch == ' ') | |
165 | nextch++; | |
166 | ||
167 | /* check for an exact match */ | |
168 | if ((entry == attr_list || | |
169 | *prevch == ENV_ATTR_LIST_DELIM) && | |
170 | (*nextch == ENV_ATTR_SEP || | |
171 | *nextch == ENV_ATTR_LIST_DELIM || | |
172 | *nextch == '\0')) | |
173 | break; | |
174 | ||
175 | entry = reverse_strstr(attr_list, name, entry); | |
176 | } | |
177 | if (entry != NULL) { | |
178 | int len; | |
179 | ||
180 | /* skip the name */ | |
181 | entry += strlen(name); | |
182 | /* skip spaces */ | |
183 | while (*entry == ' ') | |
184 | entry++; | |
185 | if (*entry != ENV_ATTR_SEP) | |
186 | len = 0; | |
187 | else { | |
188 | const char *delim; | |
189 | static const char delims[] = { | |
190 | ENV_ATTR_LIST_DELIM, ' ', '\0'}; | |
191 | ||
192 | /* skip the attr sep */ | |
193 | entry += 1; | |
194 | /* skip spaces */ | |
195 | while (*entry == ' ') | |
196 | entry++; | |
197 | ||
198 | delim = strpbrk(entry, delims); | |
199 | if (delim == NULL) | |
200 | len = strlen(entry); | |
201 | else | |
202 | len = delim - entry; | |
203 | memcpy(attributes, entry, len); | |
204 | } | |
205 | attributes[len] = '\0'; | |
206 | ||
207 | /* success */ | |
208 | return 0; | |
209 | } | |
210 | ||
211 | /* not found in list */ | |
212 | return 2; | |
213 | } |