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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
8530dc44 | 2 | /*** |
8530dc44 | 3 | Copyright 2014 Lennart Poettering |
8530dc44 LP |
4 | ***/ |
5 | ||
a8fbdf54 TA |
6 | #include <errno.h> |
7 | #include <stdlib.h> | |
8 | #include <string.h> | |
9 | ||
62d74c78 | 10 | #include "alloc-util.h" |
a8fbdf54 | 11 | #include "macro.h" |
8530dc44 | 12 | #include "uid-range.h" |
b1d4f8e1 | 13 | #include "user-util.h" |
8530dc44 LP |
14 | |
15 | static bool uid_range_intersect(UidRange *range, uid_t start, uid_t nr) { | |
16 | assert(range); | |
17 | ||
18 | return range->start <= start + nr && | |
19 | range->start + range->nr >= start; | |
20 | } | |
21 | ||
22 | static void uid_range_coalesce(UidRange **p, unsigned *n) { | |
23 | unsigned i, j; | |
24 | ||
25 | assert(p); | |
26 | assert(n); | |
27 | ||
28 | for (i = 0; i < *n; i++) { | |
29 | for (j = i + 1; j < *n; j++) { | |
30 | UidRange *x = (*p)+i, *y = (*p)+j; | |
31 | ||
32 | if (uid_range_intersect(x, y->start, y->nr)) { | |
33 | uid_t begin, end; | |
34 | ||
35 | begin = MIN(x->start, y->start); | |
36 | end = MAX(x->start + x->nr, y->start + y->nr); | |
37 | ||
38 | x->start = begin; | |
39 | x->nr = end - begin; | |
40 | ||
41 | if (*n > j+1) | |
42 | memmove(y, y+1, sizeof(UidRange) * (*n - j -1)); | |
43 | ||
313cefa1 | 44 | (*n)--; |
8530dc44 LP |
45 | j--; |
46 | } | |
47 | } | |
48 | } | |
8530dc44 LP |
49 | } |
50 | ||
51 | static int uid_range_compare(const void *a, const void *b) { | |
52 | const UidRange *x = a, *y = b; | |
53 | ||
54 | if (x->start < y->start) | |
55 | return -1; | |
56 | if (x->start > y->start) | |
57 | return 1; | |
58 | ||
59 | if (x->nr < y->nr) | |
60 | return -1; | |
61 | if (x->nr > y->nr) | |
62 | return 1; | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | int uid_range_add(UidRange **p, unsigned *n, uid_t start, uid_t nr) { | |
68 | bool found = false; | |
69 | UidRange *x; | |
70 | unsigned i; | |
71 | ||
72 | assert(p); | |
73 | assert(n); | |
74 | ||
75 | if (nr <= 0) | |
76 | return 0; | |
77 | ||
78 | for (i = 0; i < *n; i++) { | |
79 | x = (*p) + i; | |
80 | if (uid_range_intersect(x, start, nr)) { | |
81 | found = true; | |
82 | break; | |
83 | } | |
84 | } | |
85 | ||
86 | if (found) { | |
87 | uid_t begin, end; | |
88 | ||
89 | begin = MIN(x->start, start); | |
90 | end = MAX(x->start + x->nr, start + nr); | |
91 | ||
92 | x->start = begin; | |
93 | x->nr = end - begin; | |
94 | } else { | |
95 | UidRange *t; | |
96 | ||
62d74c78 | 97 | t = reallocarray(*p, *n + 1, sizeof(UidRange)); |
8530dc44 LP |
98 | if (!t) |
99 | return -ENOMEM; | |
100 | ||
101 | *p = t; | |
102 | x = t + ((*n) ++); | |
103 | ||
104 | x->start = start; | |
105 | x->nr = nr; | |
106 | } | |
107 | ||
108 | qsort(*p, *n, sizeof(UidRange), uid_range_compare); | |
109 | uid_range_coalesce(p, n); | |
110 | ||
111 | return *n; | |
112 | } | |
113 | ||
114 | int uid_range_add_str(UidRange **p, unsigned *n, const char *s) { | |
115 | uid_t start, nr; | |
116 | const char *t; | |
117 | int r; | |
118 | ||
119 | assert(p); | |
120 | assert(n); | |
121 | assert(s); | |
122 | ||
123 | t = strchr(s, '-'); | |
124 | if (t) { | |
125 | char *b; | |
126 | uid_t end; | |
127 | ||
128 | b = strndupa(s, t - s); | |
129 | r = parse_uid(b, &start); | |
130 | if (r < 0) | |
131 | return r; | |
132 | ||
133 | r = parse_uid(t+1, &end); | |
134 | if (r < 0) | |
135 | return r; | |
136 | ||
137 | if (end < start) | |
138 | return -EINVAL; | |
139 | ||
140 | nr = end - start + 1; | |
141 | } else { | |
142 | r = parse_uid(s, &start); | |
143 | if (r < 0) | |
144 | return r; | |
145 | ||
146 | nr = 1; | |
147 | } | |
148 | ||
149 | return uid_range_add(p, n, start, nr); | |
150 | } | |
151 | ||
152 | int uid_range_next_lower(const UidRange *p, unsigned n, uid_t *uid) { | |
fed1e721 | 153 | uid_t closest = UID_INVALID, candidate; |
8530dc44 LP |
154 | unsigned i; |
155 | ||
156 | assert(p); | |
157 | assert(uid); | |
158 | ||
159 | candidate = *uid - 1; | |
160 | ||
161 | for (i = 0; i < n; i++) { | |
162 | uid_t begin, end; | |
163 | ||
164 | begin = p[i].start; | |
165 | end = p[i].start + p[i].nr - 1; | |
166 | ||
167 | if (candidate >= begin && candidate <= end) { | |
168 | *uid = candidate; | |
169 | return 1; | |
170 | } | |
171 | ||
172 | if (end < candidate) | |
173 | closest = end; | |
174 | } | |
175 | ||
fed1e721 | 176 | if (closest == UID_INVALID) |
8530dc44 LP |
177 | return -EBUSY; |
178 | ||
179 | *uid = closest; | |
180 | return 1; | |
181 | } | |
182 | ||
183 | bool uid_range_contains(const UidRange *p, unsigned n, uid_t uid) { | |
184 | unsigned i; | |
185 | ||
186 | assert(p); | |
187 | assert(uid); | |
188 | ||
189 | for (i = 0; i < n; i++) | |
190 | if (uid >= p[i].start && uid < p[i].start + p[i].nr) | |
191 | return true; | |
192 | ||
193 | return false; | |
194 | } |