JSON lookup

(cherry picked from commits 854bd65fa7, 11b31159ac, 19cb5e2f14, 9669c6e06f, 6db8b72c86)

9 files changed, 212 insertions, 3 deletions

diff --git a/src/scripts/MakeLinks b/src/scripts/MakeLinks
index f69bde437..b71736797 100755
--- a/src/scripts/MakeLinks
+++ b/src/scripts/MakeLinks
@@ -30,7 +30,7 @@ echo ">>> Creating links to source files..."
 mkdir lookups
 cd lookups
 # Makefile is generated
-for f in README cdb.c dbmdb.c dnsdb.c dsearch.c ibase.c ldap.h ldap.c \
+for f in README cdb.c dbmdb.c dnsdb.c dsearch.c ibase.c json.c ldap.h ldap.c \
   lmdb.c lsearch.c mysql.c redis.c nis.c nisplus.c oracle.c passwd.c \
   pgsql.c spf.c sqlite.c testdb.c whoson.c \
   lf_functions.h lf_check_file.c lf_quote.c lf_sqlperform.c
diff --git a/src/scripts/lookups-Makefile b/src/scripts/lookups-Makefile
index db2d184a7..498184ff6 100755
--- a/src/scripts/lookups-Makefile
+++ b/src/scripts/lookups-Makefile
@@ -160,7 +160,7 @@ exec > "$target"
 sed -n "1,/$tag_marker/p" < "$input"
 
 for name_mod in \
-    CDB DBM:dbmdb DNSDB DSEARCH IBASE LSEARCH MYSQL NIS NISPLUS ORACLE \
+    CDB DBM:dbmdb DNSDB DSEARCH IBASE JSON LSEARCH MYSQL NIS NISPLUS ORACLE \
     PASSWD PGSQL REDIS SQLITE TESTDB WHOSON
 do
   emit_module_rule $name_mod
diff --git a/src/src/EDITME b/src/src/EDITME
index 15360db9a..b2c27dafe 100644
--- a/src/src/EDITME
+++ b/src/src/EDITME
@@ -309,6 +309,7 @@ LOOKUP_DNSDB=yes
 # LOOKUP_CDB=yes
 # LOOKUP_DSEARCH=yes
 # LOOKUP_IBASE=yes
+# LOOKUP_JSON=yes
 # LOOKUP_LDAP=yes
 # LOOKUP_MYSQL=yes
 # LOOKUP_MYSQL_PC=mariadb
@@ -376,7 +377,7 @@ PCRE_CONFIG=yes
 # don't need to set LOOKUP_INCLUDE if the relevant directories are already
 # specified in INCLUDE. The settings below are just examples; -lpq is for
 # PostgreSQL, -lgds is for Interbase, -lsqlite3 is for SQLite, -lhiredis
-# is for Redis.
+# is for Redis, -ljansson for JSON.
 #
 # You do not need to use this for any lookup information added via pkg-config.
 
diff --git a/src/src/config.h.defaults b/src/src/config.h.defaults
index 74ec3f4df..55688295d 100644
--- a/src/src/config.h.defaults
+++ b/src/src/config.h.defaults
@@ -93,6 +93,7 @@ Do not put spaces between # and the 'define'.
 #define LOOKUP_DNSDB
 #define LOOKUP_DSEARCH
 #define LOOKUP_IBASE
+#define LOOKUP_JSON
 #define LOOKUP_LDAP
 #define LOOKUP_LSEARCH
 #define LOOKUP_MYSQL
diff --git a/src/src/drtables.c b/src/src/drtables.c
index 54d03edab..b7024297d 100644
--- a/src/src/drtables.c
+++ b/src/src/drtables.c
@@ -564,6 +564,9 @@ extern lookup_module_info dsearch_lookup_module_info;
 #if defined(LOOKUP_IBASE) && LOOKUP_IBASE!=2
 extern lookup_module_info ibase_lookup_module_info;
 #endif
+#if defined(LOOKUP_JSON)
+extern lookup_module_info json_lookup_module_info;
+#endif
 #if defined(LOOKUP_LDAP)
 extern lookup_module_info ldap_lookup_module_info;
 #endif
@@ -649,6 +652,10 @@ init_lookup_list(void)
   addlookupmodule(NULL, &ldap_lookup_module_info);
 #endif
 
+#ifdef LOOKUP_JSON
+  addlookupmodule(NULL, &json_lookup_module_info);
+#endif
+
 #if defined(LOOKUP_LSEARCH) && LOOKUP_LSEARCH!=2
   addlookupmodule(NULL, &lsearch_lookup_module_info);
 #endif
diff --git a/src/src/exim.c b/src/src/exim.c
index d693c9f98..8e700f711 100644
--- a/src/src/exim.c
+++ b/src/src/exim.c
@@ -930,6 +930,9 @@ fprintf(fp, "Lookups (built-in):");
 #if defined(LOOKUP_IBASE) && LOOKUP_IBASE!=2
   fprintf(fp, " ibase");
 #endif
+#if defined(LOOKUP_JSON) && LOOKUP_JSON!=2
+  fprintf(fp, " json");
+#endif
 #if defined(LOOKUP_LDAP) && LOOKUP_LDAP!=2
   fprintf(fp, " ldap ldapdn ldapm");
 #endif
diff --git a/src/src/lookups/Makefile b/src/src/lookups/Makefile
index 7c9700690..01910d542 100644
--- a/src/src/lookups/Makefile
+++ b/src/src/lookups/Makefile
@@ -35,6 +35,7 @@ dsearch.o:       $(PHDRS) dsearch.c
 ibase.o:         $(PHDRS) ibase.c
 ldap.o:          $(PHDRS) ldap.c
 lmdb.o:          $(PHDRS) lmdb.c
+json.o:          $(PHDRS) json.c
 lsearch.o:       $(PHDRS) lsearch.c
 mysql.o:         $(PHDRS) mysql.c
 nis.o:           $(PHDRS) nis.c
@@ -53,6 +54,7 @@ dbmdb.so:         $(PHDRS) dbmdb.c
 dnsdb.so:         $(PHDRS) dnsdb.c
 dsearch.so:       $(PHDRS) dsearch.c
 ibase.so:         $(PHDRS) ibase.c
+json.so:          $(PHDRS) json.c
 ldap.so:          $(PHDRS) ldap.c
 lmdb.so:          $(PHDRS) lmdb.c
 lsearch.so:       $(PHDRS) lsearch.c
diff --git a/src/src/lookups/json.c b/src/src/lookups/json.c
new file mode 100644
index 000000000..0b28b731e
--- /dev/null
+++ b/src/src/lookups/json.c
@@ -0,0 +1,192 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) Jeremy Harris 2019 */
+/* 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). */
+
+static void *
+json_malloc(size_t nbytes)
+{
+void * p = store_get((int)nbytes);
+/* 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(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, 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, uschar *filename, const uschar *keystring, int length,
+  uschar **result, uschar **errmsg, uint *do_cache)
+{
+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("%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 = {
+  US"json",                      /* lookup name */
+  lookup_absfile,                /* uses absolute file name */
+  json_open,                  /* open function */
+  json_check,                 /* check function */
+  json_find,                  /* find function */
+  json_close,                 /* close function */
+  NULL,                          /* no tidy function */
+  NULL,                          /* no quoting function */
+  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 */
diff --git a/src/src/macro_predef.c b/src/src/macro_predef.c
index 84a33282d..f92671ae2 100644
--- a/src/src/macro_predef.c
+++ b/src/src/macro_predef.c
@@ -223,6 +223,9 @@ due to conflicts with other common macros. */
   builtin_macro_create(US"_HAVE_LOOKUP_IBASE");
 #endif
 #ifdef LOOKUP_LDAP
+  builtin_macro_create(US"_HAVE_LOOKUP_JSON");
+#endif
+#ifdef LOOKUP_LDAP
   builtin_macro_create(US"_HAVE_LOOKUP_LDAP");
 #endif
 #ifdef EXPERIMENTAL_LMDB