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Diffstat (limited to 'src/lookups/json.c')
| -rw-r--r-- | src/lookups/json.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/src/lookups/json.c b/src/lookups/json.c new file mode 100644 index 0000000..0aaaba7 --- /dev/null +++ b/src/lookups/json.c @@ -0,0 +1,195 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) Jeremy Harris 2019-2020 */ +/* See the file NOTICE for conditions of use and distribution. */ + +#include "../exim.h" +#include "lf_functions.h" +#include <jansson.h> + + + +/* All use of allocations will be done against the POOL_SEARCH memory, +which is freed once by search_tidyup(). Make the free call a dummy. +This burns some 300kB in handling a 37kB JSON file, for the benefit of +a fast free. The alternative of staying with malloc is nearly as bad, +eyeballing the activity there are 20% the number of free vs. alloc +calls (before the big bunch at the end). + +Assume that the file is trusted, so no tainting */ + +static void * +json_malloc(size_t nbytes) +{ +void * p = store_get((int)nbytes, FALSE); +/* debug_printf("%s %d: %p\n", __FUNCTION__, (int)nbytes, p); */ +return p; +} +static void +json_free(void * p) +{ +/* debug_printf("%s: %p\n", __FUNCTION__, p); */ +} + +/************************************************* +* Open entry point * +*************************************************/ + +/* See local README for interface description */ + +static void * +json_open(const uschar * filename, uschar ** errmsg) +{ +FILE * f; + +json_set_alloc_funcs(json_malloc, json_free); + +if (!(f = Ufopen(filename, "rb"))) + { + int save_errno = errno; + *errmsg = string_open_failed(errno, "%s for json search", filename); + errno = save_errno; + return NULL; + } +return f; +} + + + +/************************************************* +* Check entry point * +*************************************************/ + +static BOOL +json_check(void *handle, const uschar *filename, int modemask, uid_t *owners, + gid_t *owngroups, uschar **errmsg) +{ +return lf_check_file(fileno((FILE *)handle), filename, S_IFREG, modemask, + owners, owngroups, "json", errmsg) == 0; +} + + + +/************************************************* +* Find entry point for lsearch * +*************************************************/ + +/* See local README for interface description */ + +static int +json_find(void * handle, const uschar * filename, const uschar * keystring, + int length, uschar ** result, uschar ** errmsg, uint * do_cache, + const uschar * opts) +{ +FILE * f = handle; +json_t * j, * j0; +json_error_t jerr; +uschar * key; +int sep = 0; + +length = length; /* Keep picky compilers happy */ +do_cache = do_cache; /* Keep picky compilers happy */ + +rewind(f); +if (!(j = json_loadf(f, 0, &jerr))) + { + *errmsg = string_sprintf("json error on open: %.*s\n", + JSON_ERROR_TEXT_LENGTH, jerr.text); + return FAIL; + } +j0 = j; + +for (int k = 1; (key = string_nextinlist(&keystring, &sep, NULL, 0)); k++) + { + BOOL numeric = TRUE; + for (uschar * s = key; *s; s++) if (!isdigit(*s)) { numeric = FALSE; break; } + + if (!(j = numeric + ? json_array_get(j, (size_t) strtoul(CS key, NULL, 10)) + : json_object_get(j, CCS key) + ) ) + { + DEBUG(D_lookup) debug_printf_indent("%s, for key %d: '%s'\n", + numeric + ? US"bad index, or not json array" + : US"no such key, or not json object", + k, key); + json_decref(j0); + return FAIL; + } + } + +switch (json_typeof(j)) + { + case JSON_STRING: + *result = string_copyn(CUS json_string_value(j), json_string_length(j)); + break; + case JSON_INTEGER: + *result = string_sprintf("%" JSON_INTEGER_FORMAT, json_integer_value(j)); + break; + case JSON_REAL: + *result = string_sprintf("%f", json_real_value(j)); + break; + case JSON_TRUE: *result = US"true"; break; + case JSON_FALSE: *result = US"false"; break; + case JSON_NULL: *result = NULL; break; + default: *result = US json_dumps(j, 0); break; + } +json_decref(j0); +return OK; +} + + + +/************************************************* +* Close entry point * +*************************************************/ + +/* See local README for interface description */ + +static void +json_close(void *handle) +{ +(void)fclose((FILE *)handle); +} + + + +/************************************************* +* Version reporting entry point * +*************************************************/ + +/* See local README for interface description. */ + +#include "../version.h" + +void +json_version_report(FILE *f) +{ +fprintf(f, "Library version: json: Jansonn version %s\n", JANSSON_VERSION); +} + + +static lookup_info json_lookup_info = { + .name = US"json", /* lookup name */ + .type = lookup_absfile, /* uses absolute file name */ + .open = json_open, /* open function */ + .check = json_check, /* check function */ + .find = json_find, /* find function */ + .close = json_close, /* close function */ + .tidy = NULL, /* no tidy function */ + .quote = NULL, /* no quoting function */ + .version_report = json_version_report /* version reporting */ +}; + + +#ifdef DYNLOOKUP +#define json_lookup_module_info _lookup_module_info +#endif + +static lookup_info *_lookup_list[] = { &json_lookup_info }; +lookup_module_info json_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 }; + +/* End of lookups/json.c */ |