Add mg_ prefix to mongoose sources

CL: none

PUBLISHED_FROM=d6ebe5fa88c61ae3b8569897d9b09d54610bec73

src/mg_dns_server.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2014 Cesanta Software Limited
+ * All rights reserved
+ */
+
+/*
+ * === DNS server API reference
+ *
+ * Disabled by default; enable with `-DMG_ENABLE_DNS_SERVER`.
+ */
+
+#ifndef CS_MONGOOSE_SRC_DNS_SERVER_H_
+#define CS_MONGOOSE_SRC_DNS_SERVER_H_
+
+#if MG_ENABLE_DNS_SERVER
+
+#include "mongoose/src/mg_dns.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#define MG_DNS_SERVER_DEFAULT_TTL 3600
+
+struct mg_dns_reply {
+  struct mg_dns_message *msg;
+  struct mbuf *io;
+  size_t start;
+};
+
+/*
+ * Creates a DNS reply.
+ *
+ * The reply will be based on an existing query message `msg`.
+ * The query body will be appended to the output buffer.
+ * "reply + recursion allowed" will be added to the message flags and the
+ * message's num_answers will be set to 0.
+ *
+ * Answer records can be appended with `mg_dns_send_reply` or by lower
+ * level function defined in the DNS API.
+ *
+ * In order to send a reply use `mg_dns_send_reply`.
+ * It's possible to use a connection's send buffer as reply buffer,
+ * and it will work for both UDP and TCP connections.
+ *
+ * Example:
+ *
+ * ```c
+ * reply = mg_dns_create_reply(&nc->send_mbuf, msg);
+ * for (i = 0; i < msg->num_questions; i++) {
+ *   rr = &msg->questions[i];
+ *   if (rr->rtype == MG_DNS_A_RECORD) {
+ *     mg_dns_reply_record(&reply, rr, 3600, &dummy_ip_addr, 4);
+ *   }
+ * }
+ * mg_dns_send_reply(nc, &reply);
+ * ```
+ */
+struct mg_dns_reply mg_dns_create_reply(struct mbuf *io,
+                                        struct mg_dns_message *msg);
+
+/*
+ * Appends a DNS reply record to the IO buffer and to the DNS message.
+ *
+ * The message's num_answers field will be incremented. It's the caller's duty
+ * to ensure num_answers is properly initialised.
+ *
+ * Returns -1 on error.
+ */
+int mg_dns_reply_record(struct mg_dns_reply *reply,
+                        struct mg_dns_resource_record *question,
+                        const char *name, int rtype, int ttl, const void *rdata,
+                        size_t rdata_len);
+
+/*
+ * Sends a DNS reply through a connection.
+ *
+ * The DNS data is stored in an IO buffer pointed by reply structure in `r`.
+ * This function mutates the content of that buffer in order to ensure that
+ * the DNS header reflects the size and flags of the message, that might have
+ * been updated either with `mg_dns_reply_record` or by direct manipulation of
+ * `r->message`.
+ *
+ * Once sent, the IO buffer will be trimmed unless the reply IO buffer
+ * is the connection's send buffer and the connection is not in UDP mode.
+ */
+void mg_dns_send_reply(struct mg_connection *nc, struct mg_dns_reply *r);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* MG_ENABLE_DNS_SERVER */
+#endif /* CS_MONGOOSE_SRC_DNS_SERVER_H_ */