Merge pull request #100 from painless-security/milestone/monitoring

[trust_router.git] / mon / mon_req_decode.c

diff --git a/mon/mon_req_decode.c b/mon/mon_req_decode.c
new file mode 100644 (file)
index 0000000..2d05620
--- /dev/null
+++ b/mon/mon_req_decode.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2018, JANET(UK)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of JANET(UK) nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+
+#include <talloc.h>
+#include <jansson.h>
+
+#include <mon_internal.h>
+
+/* Monitoring request decoders */
+
+/**
+ * Decode a single option
+ *
+ * Format:
+ * { "type": "some_tpye" }
+ *
+ * @param opt_json JSON object reference
+ * @param dest allocated memory for the result
+ * @return MON_SUCCESS on success, error on error
+ */
+static MON_RC mon_decode_one_opt(json_t *opt_json, MON_OPT *dest)
+{
+  json_t *jstr = NULL;
+  MON_OPT_TYPE opt_type = OPT_TYPE_UNKNOWN;
+
+  if ( (opt_json == NULL) || (dest == NULL))
+    return MON_BADARG;
+
+  if (! json_is_object(opt_json))
+    return MON_NOPARSE;
+
+  jstr = json_object_get(opt_json, "type");
+  if ( (jstr == NULL) || (! json_is_string(jstr)) )
+    return MON_NOPARSE;
+
+  opt_type = mon_opt_type_from_string(json_string_value(jstr));
+  if (opt_type == OPT_TYPE_UNKNOWN)
+    return MON_NOPARSE;
+
+  dest->type = opt_type;
+  return MON_SUCCESS;
+}
+
+/**
+ * Decode options array
+ *
+ * Format:
+ * [{option}, {option}, ...]
+ *
+ */
+static MON_RC mon_options_decode(json_t *opts_json, MON_REQ *req)
+{
+  MON_OPT opt; // not a pointer
+  size_t n_opts=0;
+  size_t ii=0;
+
+  if ( (opts_json == NULL) || (req == NULL))
+    return MON_BADARG;
+
+  if (! json_is_array(opts_json))
+    return MON_NOPARSE;
+
+  n_opts = json_array_size(opts_json);
+  for (ii=0; ii < n_opts; ii++) {
+    if (mon_decode_one_opt(json_array_get(opts_json, ii),
+                           &opt) != MON_SUCCESS) {
+      return MON_NOPARSE;
+    }
+    if (MON_SUCCESS != mon_req_add_option(req, opt.type)){
+      return MON_NOPARSE;
+    }
+  }
+  return MON_SUCCESS;
+}
+
+/**
+ * Parse a JSON string into a request
+ */
+MON_REQ *mon_req_parse(TALLOC_CTX *mem_ctx, const char *input)
+{
+  json_t *parsed_json = NULL;
+  json_error_t json_error;
+
+  parsed_json = json_loads(input, JSON_REJECT_DUPLICATES, &json_error);
+  return mon_req_decode(mem_ctx, parsed_json);
+}
+
+/**
+ * Decode a JSON request
+ *
+ * Expected format:
+ * {
+ *   "command": "some_command_name",
+ *   "options": [{option1}, ...]
+ * }
+ *
+ * (options are optional)
+ *
+ * Caller must free the return value with mon_req_free().
+ *
+ * @param mem_ctx talloc context for the returned struct
+ * @param req_json reference to JSON request object
+ * @return decoded request struct or NULL on failure
+ */
+MON_REQ *mon_req_decode(TALLOC_CTX *mem_ctx, json_t *req_json)
+{
+  TALLOC_CTX *tmp_ctx = talloc_new(NULL);
+  MON_REQ *req = NULL;
+  json_t *jval = NULL;
+  json_t *opts_json = NULL;
+  MON_CMD cmd = MON_CMD_UNKNOWN;
+
+  if (! json_is_object(req_json))
+    goto cleanup;
+
+  // Get the command and verify that it is a string value
+  jval = json_object_get(req_json, "command");
+  if (! json_is_string(jval))
+    goto cleanup;
+
+  cmd = mon_cmd_from_string(json_string_value(jval));
+  if (cmd == MON_CMD_UNKNOWN)
+    goto cleanup;
+
+  /* Command is good. Allocate the request in the tmp context */
+  req = mon_req_new(tmp_ctx, cmd);
+  if (req == NULL)
+    goto cleanup;
+
+  /* Parse options if we have any */
+  opts_json = json_object_get(req_json, "options");
+  if (opts_json) {
+    if (mon_options_decode(opts_json, req) != MON_SUCCESS) {
+      req = NULL; // memory still in tmp_ctx, so it will be cleaned up
+      goto cleanup;
+    }
+  }
+
+  /* Success! Put the request in the caller's talloc context */
+  talloc_steal(mem_ctx, req);
+
+cleanup:
+  talloc_free(tmp_ctx);
+
+  return req;
+}