1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
// SPDX-License-Identifier: GPL-3.0-or-later
#include "cached-gid-groupname.h"
// --------------------------------------------------------------------------------------------------------------------
// hashtable for caching gid to groupname mappings
// key is the gid, value is groupname (STRING)
#define SIMPLE_HASHTABLE_KEY_TYPE gid_t
#define SIMPLE_HASHTABLE_VALUE_TYPE CACHED_GROUPNAME
#define SIMPLE_HASHTABLE_VALUE2KEY_FUNCTION cached_groupname_to_gid_ptr
#define SIMPLE_HASHTABLE_COMPARE_KEYS_FUNCTION compar_gid_ptr
#define SIMPLE_HASHTABLE_NAME _GROUPNAMES_CACHE
#include "libnetdata/simple_hashtable/simple_hashtable.h"
static struct {
bool initialized;
SPINLOCK spinlock;
SIMPLE_HASHTABLE_GROUPNAMES_CACHE ht;
} group_cache = {
.initialized = false,
.spinlock = NETDATA_SPINLOCK_INITIALIZER,
.ht = { 0 },
};
static gid_t *cached_groupname_to_gid_ptr(CACHED_GROUPNAME *cu) {
return &cu->gid;
}
static bool compar_gid_ptr(gid_t *a, gid_t *b) {
return *a == *b;
}
void cached_groupname_populate_by_gid(gid_t gid, const char *groupname, uint32_t version) {
internal_fatal(!group_cache.initialized, "system-users cache needs to be initialized");
if(!groupname || !*groupname) return;
spinlock_lock(&group_cache.spinlock);
XXH64_hash_t hash = XXH3_64bits(&gid, sizeof(gid));
SIMPLE_HASHTABLE_SLOT_GROUPNAMES_CACHE *sl = simple_hashtable_get_slot_GROUPNAMES_CACHE(&group_cache.ht, hash, &gid, true);
CACHED_GROUPNAME *cg = SIMPLE_HASHTABLE_SLOT_DATA(sl);
if(!cg || (cg->version && version > cg->version)) {
internal_fatal(cg && cg->gid != gid, "invalid gid matched from cache");
if(cg)
string_freez(cg->groupname);
else
cg = callocz(1, sizeof(*cg));
cg->version = version;
cg->gid = gid;
cg->groupname = string_strdupz(groupname);
simple_hashtable_set_slot_GROUPNAMES_CACHE(&group_cache.ht, sl, hash, cg);
}
spinlock_unlock(&group_cache.spinlock);
}
CACHED_GROUPNAME cached_groupname_get_by_gid(gid_t gid) {
internal_fatal(!group_cache.initialized, "system-users cache needs to be initialized");
spinlock_lock(&group_cache.spinlock);
XXH64_hash_t hash = XXH3_64bits(&gid, sizeof(gid));
SIMPLE_HASHTABLE_SLOT_GROUPNAMES_CACHE *sl = simple_hashtable_get_slot_GROUPNAMES_CACHE(&group_cache.ht, hash, &gid, true);
CACHED_GROUPNAME *cg = SIMPLE_HASHTABLE_SLOT_DATA(sl);
if(!cg) {
cg = callocz(1, sizeof(*cg));
static char tmp[1024]; // we are inside a global spinlock - it is ok to be static
struct group gr, *result = NULL;
if (getgrgid_r(gid, &gr, tmp, sizeof(tmp), &result) != 0 || !result || !gr.gr_name || !(*gr.gr_name)) {
char name[UINT64_MAX_LENGTH];
print_uint64(name, gid);
cg->groupname = string_strdupz(name);
}
else
cg->groupname = string_strdupz(gr.gr_name);
cg->gid = gid;
simple_hashtable_set_slot_GROUPNAMES_CACHE(&group_cache.ht, sl, hash, cg);
}
internal_fatal(cg->gid != gid, "invalid gid matched from cache");
CACHED_GROUPNAME rc = {
.version = cg->version,
.gid = cg->gid,
.groupname = string_dup(cg->groupname),
};
spinlock_unlock(&group_cache.spinlock);
return rc;
}
void cached_groupname_release(CACHED_GROUPNAME cg) {
string_freez(cg.groupname);
}
void cached_groupnames_init(void) {
if(group_cache.initialized) return;
group_cache.initialized = true;
spinlock_init(&group_cache.spinlock);
simple_hashtable_init_GROUPNAMES_CACHE(&group_cache.ht, 100);
}
void cached_groupnames_destroy(void) {
if(!group_cache.initialized) return;
spinlock_lock(&group_cache.spinlock);
for(SIMPLE_HASHTABLE_SLOT_GROUPNAMES_CACHE *sl = simple_hashtable_first_read_only_GROUPNAMES_CACHE(&group_cache.ht);
sl;
sl = simple_hashtable_next_read_only_GROUPNAMES_CACHE(&group_cache.ht, sl)) {
CACHED_GROUPNAME *u = SIMPLE_HASHTABLE_SLOT_DATA(sl);
if(u) {
string_freez(u->groupname);
freez(u);
// simple_hashtable_del_slot_GROUPNAMES_CACHE(&uc.ht, sl);
}
}
simple_hashtable_destroy_GROUPNAMES_CACHE(&group_cache.ht);
group_cache.initialized = false;
spinlock_unlock(&group_cache.spinlock);
}
void cached_groupnames_delete_old_versions(uint32_t version) {
if(!group_cache.initialized) return;
spinlock_lock(&group_cache.spinlock);
for(SIMPLE_HASHTABLE_SLOT_GROUPNAMES_CACHE *sl = simple_hashtable_first_read_only_GROUPNAMES_CACHE(&group_cache.ht);
sl;
sl = simple_hashtable_next_read_only_GROUPNAMES_CACHE(&group_cache.ht, sl)) {
CACHED_GROUPNAME *cg = SIMPLE_HASHTABLE_SLOT_DATA(sl);
if(cg && cg->version && cg->version < version) {
string_freez(cg->groupname);
freez(cg);
simple_hashtable_del_slot_GROUPNAMES_CACHE(&group_cache.ht, sl);
}
}
spinlock_unlock(&group_cache.spinlock);
}
|
