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6e409ce1 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2011 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
7 | under the terms of the GNU Lesser General Public License as published by |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
6e409ce1 LP |
9 | (at your option) any later version. |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 14 | Lesser General Public License for more details. |
6e409ce1 | 15 | |
5430f7f2 | 16 | You should have received a copy of the GNU Lesser General Public License |
6e409ce1 LP |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
18 | ***/ | |
19 | ||
6e409ce1 | 20 | #include <errno.h> |
07630cea | 21 | #include <string.h> |
6e409ce1 | 22 | |
b5efdb8a | 23 | #include "alloc-util.h" |
6e409ce1 | 24 | #include "hashmap.h" |
cf0fbc49 | 25 | #include "journald-rate-limit.h" |
07630cea | 26 | #include "list.h" |
3df3e884 | 27 | #include "random-util.h" |
07630cea LP |
28 | #include "string-util.h" |
29 | #include "util.h" | |
6e409ce1 LP |
30 | |
31 | #define POOLS_MAX 5 | |
32 | #define BUCKETS_MAX 127 | |
33 | #define GROUPS_MAX 2047 | |
34 | ||
35 | static const int priority_map[] = { | |
36 | [LOG_EMERG] = 0, | |
37 | [LOG_ALERT] = 0, | |
38 | [LOG_CRIT] = 0, | |
39 | [LOG_ERR] = 1, | |
40 | [LOG_WARNING] = 2, | |
41 | [LOG_NOTICE] = 3, | |
42 | [LOG_INFO] = 3, | |
43 | [LOG_DEBUG] = 4 | |
44 | }; | |
45 | ||
46 | typedef struct JournalRateLimitPool JournalRateLimitPool; | |
47 | typedef struct JournalRateLimitGroup JournalRateLimitGroup; | |
48 | ||
49 | struct JournalRateLimitPool { | |
50 | usec_t begin; | |
51 | unsigned num; | |
52 | unsigned suppressed; | |
53 | }; | |
54 | ||
55 | struct JournalRateLimitGroup { | |
56 | JournalRateLimit *parent; | |
57 | ||
58 | char *id; | |
59 | JournalRateLimitPool pools[POOLS_MAX]; | |
0cb3c286 | 60 | uint64_t hash; |
6e409ce1 LP |
61 | |
62 | LIST_FIELDS(JournalRateLimitGroup, bucket); | |
63 | LIST_FIELDS(JournalRateLimitGroup, lru); | |
64 | }; | |
65 | ||
66 | struct JournalRateLimit { | |
67 | usec_t interval; | |
68 | unsigned burst; | |
69 | ||
70 | JournalRateLimitGroup* buckets[BUCKETS_MAX]; | |
71 | JournalRateLimitGroup *lru, *lru_tail; | |
72 | ||
73 | unsigned n_groups; | |
9bf3b535 LP |
74 | |
75 | uint8_t hash_key[16]; | |
6e409ce1 LP |
76 | }; |
77 | ||
78 | JournalRateLimit *journal_rate_limit_new(usec_t interval, unsigned burst) { | |
79 | JournalRateLimit *r; | |
80 | ||
81 | assert(interval > 0 || burst == 0); | |
82 | ||
83 | r = new0(JournalRateLimit, 1); | |
84 | if (!r) | |
85 | return NULL; | |
86 | ||
87 | r->interval = interval; | |
88 | r->burst = burst; | |
89 | ||
9bf3b535 LP |
90 | random_bytes(r->hash_key, sizeof(r->hash_key)); |
91 | ||
6e409ce1 LP |
92 | return r; |
93 | } | |
94 | ||
95 | static void journal_rate_limit_group_free(JournalRateLimitGroup *g) { | |
96 | assert(g); | |
97 | ||
98 | if (g->parent) { | |
99 | assert(g->parent->n_groups > 0); | |
100 | ||
101 | if (g->parent->lru_tail == g) | |
102 | g->parent->lru_tail = g->lru_prev; | |
103 | ||
71fda00f LP |
104 | LIST_REMOVE(lru, g->parent->lru, g); |
105 | LIST_REMOVE(bucket, g->parent->buckets[g->hash % BUCKETS_MAX], g); | |
6e409ce1 | 106 | |
313cefa1 | 107 | g->parent->n_groups--; |
6e409ce1 LP |
108 | } |
109 | ||
110 | free(g->id); | |
111 | free(g); | |
112 | } | |
113 | ||
114 | void journal_rate_limit_free(JournalRateLimit *r) { | |
115 | assert(r); | |
116 | ||
117 | while (r->lru) | |
118 | journal_rate_limit_group_free(r->lru); | |
783d2675 LP |
119 | |
120 | free(r); | |
6e409ce1 LP |
121 | } |
122 | ||
44a6b1b6 | 123 | _pure_ static bool journal_rate_limit_group_expired(JournalRateLimitGroup *g, usec_t ts) { |
6e409ce1 LP |
124 | unsigned i; |
125 | ||
126 | assert(g); | |
127 | ||
128 | for (i = 0; i < POOLS_MAX; i++) | |
129 | if (g->pools[i].begin + g->parent->interval >= ts) | |
130 | return false; | |
131 | ||
132 | return true; | |
133 | } | |
134 | ||
135 | static void journal_rate_limit_vacuum(JournalRateLimit *r, usec_t ts) { | |
136 | assert(r); | |
137 | ||
138 | /* Makes room for at least one new item, but drop all | |
139 | * expored items too. */ | |
140 | ||
141 | while (r->n_groups >= GROUPS_MAX || | |
142 | (r->lru_tail && journal_rate_limit_group_expired(r->lru_tail, ts))) | |
143 | journal_rate_limit_group_free(r->lru_tail); | |
144 | } | |
145 | ||
146 | static JournalRateLimitGroup* journal_rate_limit_group_new(JournalRateLimit *r, const char *id, usec_t ts) { | |
147 | JournalRateLimitGroup *g; | |
b826ab58 | 148 | struct siphash state; |
6e409ce1 LP |
149 | |
150 | assert(r); | |
151 | assert(id); | |
152 | ||
153 | g = new0(JournalRateLimitGroup, 1); | |
154 | if (!g) | |
155 | return NULL; | |
156 | ||
157 | g->id = strdup(id); | |
158 | if (!g->id) | |
159 | goto fail; | |
160 | ||
0cb3c286 | 161 | siphash24_init(&state, r->hash_key); |
b826ab58 | 162 | string_hash_func(g->id, &state); |
933f9cae | 163 | g->hash = siphash24_finalize(&state); |
6e409ce1 LP |
164 | |
165 | journal_rate_limit_vacuum(r, ts); | |
166 | ||
71fda00f LP |
167 | LIST_PREPEND(bucket, r->buckets[g->hash % BUCKETS_MAX], g); |
168 | LIST_PREPEND(lru, r->lru, g); | |
6e409ce1 LP |
169 | if (!g->lru_next) |
170 | r->lru_tail = g; | |
313cefa1 | 171 | r->n_groups++; |
6e409ce1 LP |
172 | |
173 | g->parent = r; | |
174 | return g; | |
175 | ||
176 | fail: | |
177 | journal_rate_limit_group_free(g); | |
178 | return NULL; | |
179 | } | |
180 | ||
6e409ce1 LP |
181 | static unsigned burst_modulate(unsigned burst, uint64_t available) { |
182 | unsigned k; | |
183 | ||
184 | /* Modulates the burst rate a bit with the amount of available | |
185 | * disk space */ | |
186 | ||
187 | k = u64log2(available); | |
188 | ||
189 | /* 1MB */ | |
190 | if (k <= 20) | |
191 | return burst; | |
192 | ||
eeb08480 | 193 | burst = (burst * (k-16)) / 4; |
6e409ce1 LP |
194 | |
195 | /* | |
196 | * Example: | |
197 | * | |
198 | * <= 1MB = rate * 1 | |
199 | * 16MB = rate * 2 | |
200 | * 256MB = rate * 3 | |
201 | * 4GB = rate * 4 | |
202 | * 64GB = rate * 5 | |
203 | * 1TB = rate * 6 | |
204 | */ | |
205 | ||
206 | return burst; | |
207 | } | |
208 | ||
209 | int journal_rate_limit_test(JournalRateLimit *r, const char *id, int priority, uint64_t available) { | |
0cb3c286 | 210 | uint64_t h; |
6e409ce1 LP |
211 | JournalRateLimitGroup *g; |
212 | JournalRateLimitPool *p; | |
b826ab58 | 213 | struct siphash state; |
6e409ce1 LP |
214 | unsigned burst; |
215 | usec_t ts; | |
216 | ||
217 | assert(id); | |
218 | ||
219 | if (!r) | |
220 | return 1; | |
221 | ||
222 | if (r->interval == 0 || r->burst == 0) | |
223 | return 1; | |
224 | ||
225 | burst = burst_modulate(r->burst, available); | |
226 | ||
227 | ts = now(CLOCK_MONOTONIC); | |
228 | ||
0cb3c286 | 229 | siphash24_init(&state, r->hash_key); |
b826ab58 | 230 | string_hash_func(id, &state); |
933f9cae | 231 | h = siphash24_finalize(&state); |
6e409ce1 LP |
232 | g = r->buckets[h % BUCKETS_MAX]; |
233 | ||
234 | LIST_FOREACH(bucket, g, g) | |
235 | if (streq(g->id, id)) | |
236 | break; | |
237 | ||
238 | if (!g) { | |
239 | g = journal_rate_limit_group_new(r, id, ts); | |
240 | if (!g) | |
241 | return -ENOMEM; | |
242 | } | |
243 | ||
244 | p = &g->pools[priority_map[priority]]; | |
245 | ||
246 | if (p->begin <= 0) { | |
247 | p->suppressed = 0; | |
248 | p->num = 1; | |
249 | p->begin = ts; | |
250 | return 1; | |
251 | } | |
252 | ||
253 | if (p->begin + r->interval < ts) { | |
254 | unsigned s; | |
255 | ||
256 | s = p->suppressed; | |
257 | p->suppressed = 0; | |
258 | p->num = 1; | |
259 | p->begin = ts; | |
260 | ||
261 | return 1 + s; | |
262 | } | |
263 | ||
d2665e08 | 264 | if (p->num < burst) { |
6e409ce1 LP |
265 | p->num++; |
266 | return 1; | |
267 | } | |
268 | ||
269 | p->suppressed++; | |
270 | return 0; | |
271 | } |