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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
6e409ce1 LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2011 Lennart Poettering | |
6 | ||
7 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
8 | under the terms of the GNU Lesser General Public License as published by |
9 | the Free Software Foundation; either version 2.1 of the License, or | |
6e409ce1 LP |
10 | (at your option) any later version. |
11 | ||
12 | systemd is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 15 | Lesser General Public License for more details. |
6e409ce1 | 16 | |
5430f7f2 | 17 | You should have received a copy of the GNU Lesser General Public License |
6e409ce1 LP |
18 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
19 | ***/ | |
20 | ||
6e409ce1 | 21 | #include <errno.h> |
07630cea | 22 | #include <string.h> |
6e409ce1 | 23 | |
b5efdb8a | 24 | #include "alloc-util.h" |
6e409ce1 | 25 | #include "hashmap.h" |
cf0fbc49 | 26 | #include "journald-rate-limit.h" |
07630cea | 27 | #include "list.h" |
3df3e884 | 28 | #include "random-util.h" |
07630cea LP |
29 | #include "string-util.h" |
30 | #include "util.h" | |
6e409ce1 LP |
31 | |
32 | #define POOLS_MAX 5 | |
33 | #define BUCKETS_MAX 127 | |
34 | #define GROUPS_MAX 2047 | |
35 | ||
36 | static const int priority_map[] = { | |
37 | [LOG_EMERG] = 0, | |
38 | [LOG_ALERT] = 0, | |
39 | [LOG_CRIT] = 0, | |
40 | [LOG_ERR] = 1, | |
41 | [LOG_WARNING] = 2, | |
42 | [LOG_NOTICE] = 3, | |
43 | [LOG_INFO] = 3, | |
44 | [LOG_DEBUG] = 4 | |
45 | }; | |
46 | ||
47 | typedef struct JournalRateLimitPool JournalRateLimitPool; | |
48 | typedef struct JournalRateLimitGroup JournalRateLimitGroup; | |
49 | ||
50 | struct JournalRateLimitPool { | |
51 | usec_t begin; | |
52 | unsigned num; | |
53 | unsigned suppressed; | |
54 | }; | |
55 | ||
56 | struct JournalRateLimitGroup { | |
57 | JournalRateLimit *parent; | |
58 | ||
59 | char *id; | |
60 | JournalRateLimitPool pools[POOLS_MAX]; | |
0cb3c286 | 61 | uint64_t hash; |
6e409ce1 LP |
62 | |
63 | LIST_FIELDS(JournalRateLimitGroup, bucket); | |
64 | LIST_FIELDS(JournalRateLimitGroup, lru); | |
65 | }; | |
66 | ||
67 | struct JournalRateLimit { | |
68 | usec_t interval; | |
69 | unsigned burst; | |
70 | ||
71 | JournalRateLimitGroup* buckets[BUCKETS_MAX]; | |
72 | JournalRateLimitGroup *lru, *lru_tail; | |
73 | ||
74 | unsigned n_groups; | |
9bf3b535 LP |
75 | |
76 | uint8_t hash_key[16]; | |
6e409ce1 LP |
77 | }; |
78 | ||
79 | JournalRateLimit *journal_rate_limit_new(usec_t interval, unsigned burst) { | |
80 | JournalRateLimit *r; | |
81 | ||
82 | assert(interval > 0 || burst == 0); | |
83 | ||
84 | r = new0(JournalRateLimit, 1); | |
85 | if (!r) | |
86 | return NULL; | |
87 | ||
88 | r->interval = interval; | |
89 | r->burst = burst; | |
90 | ||
9bf3b535 LP |
91 | random_bytes(r->hash_key, sizeof(r->hash_key)); |
92 | ||
6e409ce1 LP |
93 | return r; |
94 | } | |
95 | ||
96 | static void journal_rate_limit_group_free(JournalRateLimitGroup *g) { | |
97 | assert(g); | |
98 | ||
99 | if (g->parent) { | |
100 | assert(g->parent->n_groups > 0); | |
101 | ||
102 | if (g->parent->lru_tail == g) | |
103 | g->parent->lru_tail = g->lru_prev; | |
104 | ||
71fda00f LP |
105 | LIST_REMOVE(lru, g->parent->lru, g); |
106 | LIST_REMOVE(bucket, g->parent->buckets[g->hash % BUCKETS_MAX], g); | |
6e409ce1 | 107 | |
313cefa1 | 108 | g->parent->n_groups--; |
6e409ce1 LP |
109 | } |
110 | ||
111 | free(g->id); | |
112 | free(g); | |
113 | } | |
114 | ||
115 | void journal_rate_limit_free(JournalRateLimit *r) { | |
116 | assert(r); | |
117 | ||
118 | while (r->lru) | |
119 | journal_rate_limit_group_free(r->lru); | |
783d2675 LP |
120 | |
121 | free(r); | |
6e409ce1 LP |
122 | } |
123 | ||
44a6b1b6 | 124 | _pure_ static bool journal_rate_limit_group_expired(JournalRateLimitGroup *g, usec_t ts) { |
6e409ce1 LP |
125 | unsigned i; |
126 | ||
127 | assert(g); | |
128 | ||
129 | for (i = 0; i < POOLS_MAX; i++) | |
130 | if (g->pools[i].begin + g->parent->interval >= ts) | |
131 | return false; | |
132 | ||
133 | return true; | |
134 | } | |
135 | ||
136 | static void journal_rate_limit_vacuum(JournalRateLimit *r, usec_t ts) { | |
137 | assert(r); | |
138 | ||
139 | /* Makes room for at least one new item, but drop all | |
140 | * expored items too. */ | |
141 | ||
142 | while (r->n_groups >= GROUPS_MAX || | |
143 | (r->lru_tail && journal_rate_limit_group_expired(r->lru_tail, ts))) | |
144 | journal_rate_limit_group_free(r->lru_tail); | |
145 | } | |
146 | ||
147 | static JournalRateLimitGroup* journal_rate_limit_group_new(JournalRateLimit *r, const char *id, usec_t ts) { | |
148 | JournalRateLimitGroup *g; | |
b826ab58 | 149 | struct siphash state; |
6e409ce1 LP |
150 | |
151 | assert(r); | |
152 | assert(id); | |
153 | ||
154 | g = new0(JournalRateLimitGroup, 1); | |
155 | if (!g) | |
156 | return NULL; | |
157 | ||
158 | g->id = strdup(id); | |
159 | if (!g->id) | |
160 | goto fail; | |
161 | ||
0cb3c286 | 162 | siphash24_init(&state, r->hash_key); |
b826ab58 | 163 | string_hash_func(g->id, &state); |
933f9cae | 164 | g->hash = siphash24_finalize(&state); |
6e409ce1 LP |
165 | |
166 | journal_rate_limit_vacuum(r, ts); | |
167 | ||
71fda00f LP |
168 | LIST_PREPEND(bucket, r->buckets[g->hash % BUCKETS_MAX], g); |
169 | LIST_PREPEND(lru, r->lru, g); | |
6e409ce1 LP |
170 | if (!g->lru_next) |
171 | r->lru_tail = g; | |
313cefa1 | 172 | r->n_groups++; |
6e409ce1 LP |
173 | |
174 | g->parent = r; | |
175 | return g; | |
176 | ||
177 | fail: | |
178 | journal_rate_limit_group_free(g); | |
179 | return NULL; | |
180 | } | |
181 | ||
6e409ce1 LP |
182 | static unsigned burst_modulate(unsigned burst, uint64_t available) { |
183 | unsigned k; | |
184 | ||
185 | /* Modulates the burst rate a bit with the amount of available | |
186 | * disk space */ | |
187 | ||
188 | k = u64log2(available); | |
189 | ||
190 | /* 1MB */ | |
191 | if (k <= 20) | |
192 | return burst; | |
193 | ||
eeb08480 | 194 | burst = (burst * (k-16)) / 4; |
6e409ce1 LP |
195 | |
196 | /* | |
197 | * Example: | |
198 | * | |
199 | * <= 1MB = rate * 1 | |
200 | * 16MB = rate * 2 | |
201 | * 256MB = rate * 3 | |
202 | * 4GB = rate * 4 | |
203 | * 64GB = rate * 5 | |
204 | * 1TB = rate * 6 | |
205 | */ | |
206 | ||
207 | return burst; | |
208 | } | |
209 | ||
210 | int journal_rate_limit_test(JournalRateLimit *r, const char *id, int priority, uint64_t available) { | |
0cb3c286 | 211 | uint64_t h; |
6e409ce1 LP |
212 | JournalRateLimitGroup *g; |
213 | JournalRateLimitPool *p; | |
b826ab58 | 214 | struct siphash state; |
6e409ce1 LP |
215 | unsigned burst; |
216 | usec_t ts; | |
217 | ||
218 | assert(id); | |
219 | ||
ec6fe7c8 LP |
220 | /* Returns: |
221 | * | |
222 | * 0 → the log message shall be suppressed, | |
223 | * 1 + n → the log message shall be permitted, and n messages were dropped from the peer before | |
224 | * < 0 → error | |
225 | */ | |
226 | ||
6e409ce1 LP |
227 | if (!r) |
228 | return 1; | |
229 | ||
230 | if (r->interval == 0 || r->burst == 0) | |
231 | return 1; | |
232 | ||
233 | burst = burst_modulate(r->burst, available); | |
234 | ||
235 | ts = now(CLOCK_MONOTONIC); | |
236 | ||
0cb3c286 | 237 | siphash24_init(&state, r->hash_key); |
b826ab58 | 238 | string_hash_func(id, &state); |
933f9cae | 239 | h = siphash24_finalize(&state); |
6e409ce1 LP |
240 | g = r->buckets[h % BUCKETS_MAX]; |
241 | ||
242 | LIST_FOREACH(bucket, g, g) | |
243 | if (streq(g->id, id)) | |
244 | break; | |
245 | ||
246 | if (!g) { | |
247 | g = journal_rate_limit_group_new(r, id, ts); | |
248 | if (!g) | |
249 | return -ENOMEM; | |
250 | } | |
251 | ||
252 | p = &g->pools[priority_map[priority]]; | |
253 | ||
254 | if (p->begin <= 0) { | |
255 | p->suppressed = 0; | |
256 | p->num = 1; | |
257 | p->begin = ts; | |
258 | return 1; | |
259 | } | |
260 | ||
261 | if (p->begin + r->interval < ts) { | |
262 | unsigned s; | |
263 | ||
264 | s = p->suppressed; | |
265 | p->suppressed = 0; | |
266 | p->num = 1; | |
267 | p->begin = ts; | |
268 | ||
269 | return 1 + s; | |
270 | } | |
271 | ||
d2665e08 | 272 | if (p->num < burst) { |
6e409ce1 LP |
273 | p->num++; |
274 | return 1; | |
275 | } | |
276 | ||
277 | p->suppressed++; | |
278 | return 0; | |
279 | } |