Use project memory-management for json lookup
[exim.git] / src / src / lookups / json.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) Jeremy Harris 2019 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 #include "../exim.h"
9 #include "lf_functions.h"
10 #include <jansson.h>
11
12
13
14 /* All use of allocations will be done against the POOL_SEARCH memory,
15 which is freed once by search_tidyup(). Make the free call a dummy.
16 This burns some 300kB in handling a 37kB JSON file, for the benefit of
17 a fast free. The alternative of staying with malloc is nearly as bad,
18 eyeballing the activity there are 20% the number of free vs. alloc
19 calls (before the big bunch at the end). */
20
21 static void *
22 json_malloc(size_t nbytes)
23 {
24 void * p = store_get((int)nbytes);
25 /* debug_printf("%s %d: %p\n", __FUNCTION__, (int)nbytes, p); */
26 return p;
27 }
28 static void
29 json_free(void * p)
30 {
31 /* debug_printf("%s: %p\n", __FUNCTION__, p); */
32 }
33
34 /*************************************************
35 * Open entry point *
36 *************************************************/
37
38 /* See local README for interface description */
39
40 static void *
41 json_open(uschar *filename, uschar **errmsg)
42 {
43 FILE * f;
44
45 json_set_alloc_funcs(json_malloc, json_free);
46
47 if (!(f = Ufopen(filename, "rb")))
48 {
49 int save_errno = errno;
50 *errmsg = string_open_failed(errno, "%s for json search", filename);
51 errno = save_errno;
52 return NULL;
53 }
54 return f;
55 }
56
57
58
59 /*************************************************
60 * Check entry point *
61 *************************************************/
62
63 static BOOL
64 json_check(void *handle, uschar *filename, int modemask, uid_t *owners,
65 gid_t *owngroups, uschar **errmsg)
66 {
67 return lf_check_file(fileno((FILE *)handle), filename, S_IFREG, modemask,
68 owners, owngroups, "json", errmsg) == 0;
69 }
70
71
72
73 /*************************************************
74 * Find entry point for lsearch *
75 *************************************************/
76
77 /* See local README for interface description */
78
79 static int
80 json_find(void *handle, uschar *filename, const uschar *keystring, int length,
81 uschar **result, uschar **errmsg, uint *do_cache)
82 {
83 FILE * f = handle;
84 json_t * j, * j0;
85 json_error_t jerr;
86 uschar * key;
87 int sep = 0;
88
89 length = length; /* Keep picky compilers happy */
90 do_cache = do_cache; /* Keep picky compilers happy */
91
92 rewind(f);
93 if (!(j = json_loadf(f, 0, &jerr)))
94 {
95 *errmsg = string_sprintf("json error on open: %.*s\n",
96 JSON_ERROR_TEXT_LENGTH, jerr.text);
97 return FAIL;
98 }
99 j0 = j;
100
101 for (int k = 1; (key = string_nextinlist(&keystring, &sep, NULL, 0)); k++)
102 {
103 BOOL numeric = TRUE;
104 for (uschar * s = key; *s; s++) if (!isdigit(*s)) { numeric = FALSE; break; }
105
106 if (!(j = numeric
107 ? json_array_get(j, (size_t) strtoul(CS key, NULL, 10))
108 : json_object_get(j, CCS key)
109 ) )
110 {
111 DEBUG(D_lookup) debug_printf("%s, for key %d: '%s'\n",
112 numeric
113 ? US"bad index, or not json array"
114 : US"no such key, or not json object",
115 k, key);
116 json_decref(j0);
117 return FAIL;
118 }
119 }
120
121 switch (json_typeof(j))
122 {
123 case JSON_STRING:
124 *result = string_copyn(CUS json_string_value(j), json_string_length(j));
125 break;
126 case JSON_INTEGER:
127 *result = string_sprintf("%" JSON_INTEGER_FORMAT, json_integer_value(j));
128 break;
129 case JSON_REAL:
130 *result = string_sprintf("%f", json_real_value(j));
131 break;
132 case JSON_TRUE: *result = US"true"; break;
133 case JSON_FALSE: *result = US"false"; break;
134 case JSON_NULL: *result = NULL; break;
135 default: *result = US json_dumps(j, 0); break;
136 }
137 json_decref(j0);
138 return OK;
139 }
140
141
142
143 /*************************************************
144 * Close entry point *
145 *************************************************/
146
147 /* See local README for interface description */
148
149 static void
150 json_close(void *handle)
151 {
152 (void)fclose((FILE *)handle);
153 }
154
155
156
157 /*************************************************
158 * Version reporting entry point *
159 *************************************************/
160
161 /* See local README for interface description. */
162
163 #include "../version.h"
164
165 void
166 json_version_report(FILE *f)
167 {
168 fprintf(f, "Library version: json: Jansonn version %s\n", JANSSON_VERSION);
169 }
170
171
172 static lookup_info json_lookup_info = {
173 US"json", /* lookup name */
174 lookup_absfile, /* uses absolute file name */
175 json_open, /* open function */
176 json_check, /* check function */
177 json_find, /* find function */
178 json_close, /* close function */
179 NULL, /* no tidy function */
180 NULL, /* no quoting function */
181 json_version_report /* version reporting */
182 };
183
184
185 #ifdef DYNLOOKUP
186 #define json_lookup_module_info _lookup_module_info
187 #endif
188
189 static lookup_info *_lookup_list[] = { &json_lookup_info };
190 lookup_module_info json_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
191
192 /* End of lookups/json.c */