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