Add tojson xlat for escaping json strings

FreeRADIUS · Jan 16, 2015 · 7611ede · 7611ede
1 parent e90c8cf
commit 7611ede
Showing 1 changed file with 70 additions and 0 deletions.
diff --git a/src/modules/rlm_rest/rlm_rest.c b/src/modules/rlm_rest/rlm_rest.c
@@ -129,6 +129,75 @@ static void rlm_rest_cleanup(rlm_rest_t *instance, rlm_rest_section_t *section,
 	rest_request_cleanup(instance, section, handle);
 }
 
+static ssize_t json_escape_xlat(UNUSED void *instance, UNUSED REQUEST *request,
+			 	char const *fmt, char *out, size_t outlen)
+{
+	char const *p;
+	size_t freespace = outlen;
+	size_t len;
+
+	for (p = fmt; *p != '\0'; p++) {
+		/* Indicate truncation */
+		if (freespace < 3) return outlen + 1;
+
+		if (*p == '"') {
+			*out++ = '\\';
+			*out++ = '"';
+			freespace -= 2;
+		} else if (*p == '\\') {
+			*out++ = '\\';
+			*out++ = '\\';
+			freespace -= 2;
+		} else if (*p == '/') {
+			*out++ = '\\';
+			*out++ = '/';
+			freespace -= 2;
+		} else if (*p >= ' ') {
+			*out++ = *p;
+			freespace--;
+		/*
+		 *	Unprintable chars
+		 */
+		} else {
+			*out++ = '\\';
+			freespace--;
+
+			switch (*p) {
+			case '\b':
+				*out++ = 'b';
+				freespace--;
+				break;
+
+			case '\f':
+				*out++ = 'f';
+				freespace--;
+				break;
+
+			case '\n':
+				*out++ = 'b';
+				freespace--;
+				break;
+
+			case '\r':
+				*out++ = 'r';
+				freespace--;
+				break;
+
+			case '\t':
+				*out++ = 't';
+				freespace--;
+				break;
+			default:
+				len = snprintf(out, freespace, "u%04X", *p);
+				if (is_truncated(len, freespace)) return (outlen - freespace) + len;
+				out += len;
+				freespace -= len;
+			}
+		}
+	}
+
+	return outlen - freespace;
+}
 /*
  *	Simple xlat to read text data from a URL
  */
@@ -732,6 +801,7 @@ static int mod_instantiate(CONF_SECTION *conf, void *instance)
 	 *	Register the rest xlat function
 	 */
 	xlat_register(inst->xlat_name, rest_xlat, rest_uri_escape, inst);
+	xlat_register("tojson", json_escape_xlat, NULL, inst);
 
 	/*
 	 *	Parse sub-section configs.