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[Lost] [Patch] [RFC] tcpip: DNS
Ist eher noch nicht commitbereit, aber für blöde Kommentare ist es mit
Sicherheit schon geeignet. ;-)
Index: include/dns.h
===================================================================
--- include/dns.h (Revision 0)
+++ include/dns.h (Revision 0)
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2007 The LOST Project. All rights reserved.
+ *
+ * This code is derived from software contributed to the LOST Project
+ * by Kevin Wolf.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the LOST Project
+ * and its contributors.
+ * 4. Neither the name of the LOST Project 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 HOLDERS 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.
+ */
+
+#ifndef _DNS_H_
+#define _DNS_H_
+
+#include <stdint.h>
+
+#define DNS_PORT 53
+
+struct dns_header {
+ uint16_t id;
+ uint16_t flags;
+ uint16_t qd_count;
+ uint16_t an_count;
+ uint16_t ns_count;
+ uint16_t ar_count;
+} __attribute__((packed));
+
+
+// Konstanten für die Header-Flags
+
+/// 0 = Query; 1 = Response
+#define DNS_QR 0x80
+
+/// Authoritative Answer? (Nur in Antwort)
+#define DNS_AA 0x04
+
+/// Truncation - Nachricht ist abgeschnitten
+#define DNS_TC 0x02
+
+/// Recursion Desired
+#define DNS_RD 0x01
+
+/// Recursion Available
+#define DNS_RA 0x8000
+
+/// Opcode aus einem DNS-Header
+#define dns_get_opde(x) (((x) >> 3) & 0x0F)
+
+/// Opcode in einem DNS-Header setzen
+static inline void dns_set_opcode(struct dns_header* header, uint8_t opcode)
+{
+ header->flags &= ~0x78;
+ header->flags |= (opcode << 3);
+}
+
+// Opcodes
+#define DNS_OPCODE_QUERY 0x00
+#define DNS_OPCODE_IQUERY 0x01
+#define DNS_OPCODE_STATUS 0x02
+
+// Response Codes
+#define DNS_RCODE_OK 0x00
+#define DNS_RCODE_EFORMAT 0x01
+#define DNS_RCODE_ESERVER 0x02
+#define DNS_RCODE_ENAME 0x03
+#define DNS_RCODE_EIMPL 0x04
+#define DNS_RCODE_EREFUSED 0x05
+
+/// Reponse Code aus einem DNS-Header
+#define dns_get_rcode(x) (((x) >> 8) & 0x0F)
+
+dword dns_request(char* domain);
+
+#endif
Eigenschaftsänderungen: include/dns.h
___________________________________________________________________
Name: svn:eol-style
+ native
Index: dns.c
===================================================================
--- dns.c (Revision 0)
+++ dns.c (Revision 0)
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 2007 The LOST Project. All rights reserved.
+ *
+ * This code is derived from software contributed to the LOST Project
+ * by Kevin Wolf.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the LOST Project
+ * and its contributors.
+ * 4. Neither the name of the LOST Project 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 HOLDERS 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 <types.h>
+#include <string.h>
+#include <network.h>
+#include <stdio.h>
+
+#include "dns.h"
+#include "tcp.h"
+
+static dword dns_ip =
+// big_endian_dword(0xc0a80103);
+ 0x7cad61c2;
+
+dword dns_request(char* domain)
+{
+ // TODO Caching
+
+ printf("DNS: Oeffne Verbindung\n");
+ struct tcp_connection* conn = tcp_open_connection(dns_ip, DNS_PORT);
+ if (conn == NULL) {
+ printf("DNS: Konnte Verbindung nicht aufbauen.\n");
+ return 0;
+ }
+
+ size_t domain_len = strlen(domain);
+ char data[2 + sizeof(struct dns_header) + domain_len + 6];
+
+ // 2 Bytes Präfix für TCP-Transport
+ *((word*) data) =
+ big_endian_word(sizeof(struct dns_header) + domain_len + 6);
+
+ // DNS-Header
+ struct dns_header* header = (struct dns_header*) &data[2];
+ header->id = 0;
+ header->flags = DNS_RD;
+ header->qd_count = big_endian_word(1);
+ header->an_count = 0;
+ header->ns_count = 0;
+ header->ar_count = 0;
+
+ // Question Section
+ // Die Question Section besteht aus einzelnen Labels, d.h. Bestandteilen
+ // einer Domain (www.xyz.de hat die drei Labels www, xyz und de).
+ // Vor jedem Label gibt ein Byte die Länge dieses Labels an. Daher von
+ // hinten durchgehen und mitzählen und bei jedem Punkt den aktuellen
+ // Zählerstand setzen.
+ char* qname = &data[2 + sizeof(struct dns_header)];
+ size_t label_len = 0;
+ int i;
+
+ for (i = domain_len; i; i--) {
+ if (domain[i - 1] != '.') {
+ qname[i] = domain[i - 1];
+ label_len++;
+ } else {
+ qname[i] = label_len;
+ label_len = 0;
+ }
+ }
+ qname[0] = label_len;
+
+ // Das Ende wird durch ein Label der Laenge 0 markiert
+ qname[domain_len + 1] = '\0';
+
+ // QTYPE = A und QCLASS = IN
+ *((word*) &data[2 + sizeof(struct dns_header) + domain_len + 2]) =
+ big_endian_word(1);
+ *((word*) &data[2 + sizeof(struct dns_header) + domain_len + 4]) =
+ big_endian_word(1);
+
+ // Senden
+ struct tcp_out_buffer out_buffer = {
+ .size = 2 + sizeof(struct dns_header) + domain_len + 6,
+ .data = data
+ };
+ list_insert(conn->out_buffer, list_size(conn->out_buffer), &out_buffer);
+ tcp_send_ack(conn);
+
+ // Auf Antwort warten
+ printf("DNS: Warte auf Antwort\n");
+ struct tcp_in_buffer* in_buffer;
+ while(1) {
+ if ((in_buffer = list_pop(conn->to_lostio))) {
+ void* reply = in_buffer->data;
+/*
+ {
+ int j;
+ for (j = 0; j < in_buffer->size; j++) {
+ printf(" %02hhx", *((byte*) reply + j));
+ }
+ }
+*/
+
+ // 2 Bytes TCP-Präfix
+ reply += 2;
+
+ // Header ignorieren
+ int qd_count =
+ big_endian_word(((struct dns_header*) reply)->qd_count);
+ int an_count =
+ big_endian_word(((struct dns_header*) reply)->an_count);
+ reply += sizeof(struct dns_header);
+
+/*
+ printf("Ignoriere Header. qd = %d, an = %d\n", qd_count, an_count);
+ printf("[a] reply = %08x\n", (dword) reply);
+*/
+
+ // Question Section ignorieren
+ for (i = 0; i < qd_count; i++) {
+ // QNAMEs
+ int label_len;
+ while ((label_len = *((byte*) reply))) {
+ reply += label_len + 1;
+ }
+
+ // Null-Label, QTYPE und QCLASS
+// printf(" *reply = %08x\n", big_endian_dword(*((dword*) reply)));
+ reply += 5;
+// printf("[b] reply = %08x\n", (dword) reply);
+ }
+
+ // Hier kommt die Antwort - alles ignorieren, was den falschen
+ // Typ hat, und beim ersten Treffer die IP zurückgeben.
+ for (i = 0; i < an_count; i++)
+ {
+ // QNAMEs - interessieren nicht
+ int label_len;
+ while ((label_len = *((byte*) reply))) {
+
+ if (label_len & 0xC0) {
+ // Pointer
+ reply += 2;
+// printf("\n[c] reply = %08x\n", (dword) reply);
+ break;
+ } else {
+// printf(" 0x%x Bytes Label:\n", label_len);
+ int j;
+ for (j = 0; j < label_len; j++) {
+ printf(" %02hhx", *((byte*) reply + j));
+ }
+ reply += label_len + 1;
+// printf("\n[c] reply = %08x\n", (dword) reply);
+ }
+ }
+
+ // QTYPE - Hostadressen (A = 0x1 big-endian) interessieren
+ size_t answer_len =
+ 10 + big_endian_word(*((word*) (reply + 8)));
+/* printf("[d] reply = %08x; answer_len = 0x%x\n", (dword) reply,
+ answer_len);*/
+
+ if (*((word*) reply) == 0x100) {
+ return *((dword*) (reply + 10));
+ } else {
+ reply += answer_len;
+ }
+ }
+
+ break;
+ }
+ wait_for_rpc();
+ }
+ printf("DNS: Antwort erhalten\n");
+
+ // TODO Verbindung schliessen
+
+ return 0;
+}
Eigenschaftsänderungen: dns.c
___________________________________________________________________
Name: svn:eol-style
+ native
Index: lostio_if.c
===================================================================
--- lostio_if.c (Revision 636)
+++ lostio_if.c (Arbeitskopie)
@@ -44,6 +44,7 @@
#include "network.h"
#include "ip.h"
#include "tcp.h"
+#include "dns.h"
//Hier koennen die Debug-Nachrichten aktiviert werden
#define DEBUG 0
@@ -129,6 +130,15 @@
*delim = '\0';
dword ip = string_to_ip(*path + 1);
+ if (!ip) {
+ ip = dns_request(*path + 1);
+ }
+
+ if (!ip) {
+ DEBUG_MSG("Konnte Adresse nicht aufloesen");
+ return FALSE;
+ }
+
*delim = ':';
char* port_string = delim + 1;