X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=networking%2Fdnsd.c;h=fe98400f7d6047fc38c40e02f317afa8e51b4c2d;hb=1f56e51ca1d96b70635eb1b9df1d1ab0edd98a72;hp=e73e244b0767747bd97cde5dda4d03e6ad73397d;hpb=343dfd7abe44a32b329379ec9039f2560543518d;p=oweals%2Fbusybox.git

diff --git a/networking/dnsd.c b/networking/dnsd.c
index e73e244b0..fe98400f7 100644
--- a/networking/dnsd.c
+++ b/networking/dnsd.c
@@ -6,7 +6,7 @@
  * Copyright (C) 2005 Odd Arild Olsen (oao at fibula dot no)
  * Copyright (C) 2003 Paul Sheer
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  *
  * Odd Arild Olsen started out with the sheerdns [1] of Paul Sheer and rewrote
  * it into a shape which I believe is both easier to understand and maintain.
@@ -17,6 +17,21 @@
  * the first porting of oao' scdns to busybox also.
  */
 
+//usage:#define dnsd_trivial_usage
+//usage:       "[-dvs] [-c CONFFILE] [-t TTL_SEC] [-p PORT] [-i ADDR]"
+//usage:#define dnsd_full_usage "\n\n"
+//usage:       "Small static DNS server daemon\n"
+//usage:     "\n	-c FILE	Config file"
+//usage:     "\n	-t SEC	TTL"
+//usage:     "\n	-p PORT	Listen on PORT"
+//usage:     "\n	-i ADDR	Listen on ADDR"
+//usage:     "\n	-d	Daemonize"
+//usage:     "\n	-v	Verbose"
+//usage:     "\n	-s	Send successful replies only. Use this if you want"
+//usage:     "\n		to use /etc/resolv.conf with two nameserver lines:"
+//usage:     "\n			nameserver DNSD_SERVER"
+//usage:     "\n			nameserver NORMAL_DNS_SERVER"
+
 #include "libbb.h"
 #include <syslog.h>
 
@@ -44,10 +59,15 @@ struct dns_head {
 	uint16_t nauth;
 	uint16_t nadd;
 };
+/* Structure used to access type and class fields.
+ * They are totally unaligned, but gcc 4.3.4 thinks that pointer of type uint16_t*
+ * is 16-bit aligned and replaces 16-bit memcpy (in move_from_unaligned16 macro)
+ * with aligned halfword access on arm920t!
+ * Oh well. Slapping PACKED everywhere seems to help: */
 struct type_and_class {
-	uint16_t type;
-	uint16_t class;
-};
+	uint16_t type PACKED;
+	uint16_t class PACKED;
+} PACKED;
 /* element of known name, ip address and reversed ip address */
 struct dns_entry {
 	struct dns_entry *next;
@@ -376,11 +396,6 @@ static int process_packet(struct dns_entry *conf_data,
 	/* QR = 1 "response", RCODE = 4 "Not Implemented" */
 	outr_flags = htons(0x8000 | 4);
 	err_msg = NULL;
-	/* OPCODE != 0 "standard query" ? */
-	if ((head->flags & htons(0x7800)) != 0) {
-		err_msg = "opcode != 0";
-		goto empty_packet;
-	}
 
 	/* start of query string */
 	query_string = (void *)(head + 1);
@@ -388,10 +403,15 @@ static int process_packet(struct dns_entry *conf_data,
 	query_len = strlen(query_string) + 1;
 	/* may be unaligned! */
 	unaligned_type_class = (void *)(query_string + query_len);
-	query_len += sizeof(unaligned_type_class);
+	query_len += sizeof(*unaligned_type_class);
 	/* where to append answer block */
 	answb = (void *)(unaligned_type_class + 1);
 
+	/* OPCODE != 0 "standard query"? */
+	if ((head->flags & htons(0x7800)) != 0) {
+		err_msg = "opcode != 0";
+		goto empty_packet;
+	}
 	move_from_unaligned16(class, &unaligned_type_class->class);
 	if (class != htons(1)) { /* not class INET? */
 		err_msg = "class != 1";
@@ -480,7 +500,8 @@ int dnsd_main(int argc UNUSED_PARAM, char **argv)
 	unsigned lsa_size;
 	int udps, opts;
 	uint16_t port = 53;
-	uint8_t buf[MAX_PACK_LEN + 1];
+	/* Ensure buf is 32bit aligned (we need 16bit, but 32bit can't hurt) */
+	uint8_t buf[MAX_PACK_LEN + 1] ALIGN4;
 
 	opts = getopt32(argv, "vsi:c:t:p:d", &listen_interface, &fileconf, &sttl, &sport);
 	//if (opts & (1 << 0)) // -v