svn commit: [26070] trunk/busybox: networking util-linux

vda at busybox.net vda at busybox.net
Sun Apr 12 12:16:21 UTC 2009


Author: vda
Date: 2009-04-12 12:16:21 +0000 (Sun, 12 Apr 2009)
New Revision: 26070

Log:
mount: users report that CIFS support is breaking things,
 mostly remove it.



Modified:
   trunk/busybox/networking/dnsd.c
   trunk/busybox/util-linux/mount.c


Changeset:
Modified: trunk/busybox/networking/dnsd.c
===================================================================
--- trunk/busybox/networking/dnsd.c	2009-04-12 04:20:22 UTC (rev 26069)
+++ trunk/busybox/networking/dnsd.c	2009-04-12 12:16:21 UTC (rev 26070)
@@ -136,17 +136,18 @@
 
 /*
  * Look query up in dns records and return answer if found.
- * qs is the query string.
  */
-static int table_lookup(uint8_t *as, struct dns_entry *d, uint16_t type, uint8_t *qs)
+static char *table_lookup(struct dns_entry *d,
+		uint16_t type,
+		char* query_string)
 {
 	while (d) {
 		unsigned len = d->name[0];
 		/* d->name[len] is the last (non NUL) char */
 #if DEBUG
 		char *p, *q;
-		q = (char *)&(qs[1]);
-		p = &(d->name[1]);
+		q = query_string + 1;
+		p = d->name + 1;
 		fprintf(stderr, "%d/%d p:%s q:%s %d\n",
 			(int)strlen(p), len,
 			p, q, (int)strlen(q)
@@ -155,31 +156,40 @@
 		if (type == htons(REQ_A)) {
 			/* search by host name */
 			if (len != 1 || d->name[1] != '*') {
-				if (strcasecmp(d->name, (char*)qs) != 0)
+/* we are lax, hope no name component is ever >64 so that length
+ * (which will be represented as 'A','B'...) matches a lowercase letter.
+ * Actually, I think false matches are hard to construct.
+ * Example.
+ * [31] len is represented as '1', [65] as 'A', [65+32] as 'a'.
+ * [65]   <65 same chars>[31]<31 same chars>NUL
+ * [65+32]<65 same chars>1   <31 same chars>NUL
+ * This example seems to be the minimal case when false match occurs.
+ */
+				if (strcasecmp(d->name, query_string) != 0)
 					goto next;
 			}
-			move_to_unaligned32((uint32_t *)as, d->ip);
+			return (char *)&d->ip;
 #if DEBUG
-			fprintf(stderr, "OK as:%x\n", (int)d->ip);
+			fprintf(stderr, "Found IP:%x\n", (int)d->ip);
 #endif
 			return 0;
 		}
 		/* search by IP-address */
 		if ((len != 1 || d->name[1] != '*')
-		/* assume (do not check) that qs ends in ".in-addr.arpa" */
-		 && strncmp(d->rip, (char*)qs, strlen(d->rip)) == 0
+		/* we assume (do not check) that query_string
+		 * ends in ".in-addr.arpa" */
+		 && strncmp(d->rip, query_string, strlen(d->rip)) == 0
 		) {
-			strcpy((char *)as, d->name);
 #if DEBUG
-			fprintf(stderr, "OK as:%s\n", as);
+			fprintf(stderr, "Found name:%s\n", d->name);
 #endif
-			return 0;
+			return d->name;
 		}
  next:
 		d = d->next;
 	}
 
-	return -1;
+	return NULL;
 }
 
 /*
@@ -193,12 +203,11 @@
 ...
 
 4.1.1. Header section format
-                                    1  1  1  1  1  1
-      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+      0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
     |                      ID                       |
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-    |QR|   OPCODE  |AA|TC|RD|RA|   Z    |   RCODE   |
+    |QR|   OPCODE  |AA|TC|RD|RA| 0  0  0|   RCODE   |
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
     |                    QDCOUNT                    |
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@@ -208,20 +217,18 @@
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
     |                    ARCOUNT                    |
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
-ID      16 bit random identifier assigned by query.
+ID      16 bit random identifier assigned by querying peer.
         Used to match query/response.
 QR      message is a query (0), or a response (1).
 OPCODE  0   standard query (QUERY)
         1   inverse query (IQUERY)
         2   server status request (STATUS)
-AA      Authoritative Answer - this bit is valid in responses,
-        and specifies that the responding name server is an
-        authority for the domain name in question section.
-        Note that the contents of the answer section may have
-        multiple owner names because of aliases.  The AA bit
-        corresponds to the name which matches the query name, or
-        the first owner name in the answer section.
-TC      TrunCation - specifies that this message was truncated.
+AA      Authoritative Answer - this bit is valid in responses.
+        Responding name server is an authority for the domain name
+	in question section. Answer section may have multiple owner names
+	because of aliases.  The AA bit corresponds to the name which matches
+	the query name, or the first owner name in the answer section.
+TC      TrunCation - this message was truncated.
 RD      Recursion Desired - this bit may be set in a query and
         is copied into the response.  If RD is set, it directs
         the name server to pursue the query recursively.
@@ -229,30 +236,25 @@
 RA      Recursion Available - this be is set or cleared in a
         response, and denotes whether recursive query support is
         available in the name server.
-Z       Reserved for future use.  Must be zero.
 RCODE   Response code.
         0   No error condition
         1   Format error
-        2   Server failure - The name server was
-            unable to process this query due to a
-            problem with the name server.
-        3   Name Error - Meaningful only for
-            responses from an authoritative name
-            server, this code signifies that the
-            domain name referenced in the query does
-            not exist.
+        2   Server failure - server was unable to process the query
+	    due to a problem with the name server.
+        3   Name Error - meaningful only for responses from
+	    an authoritative name server. The referenced domain name
+	    does  not exist.
         4   Not Implemented.
         5   Refused.
 QDCOUNT number of entries in the question section.
-ANCOUNT number of resource records in the answer section.
-NSCOUNT number of name server resource records in the authority records section.
-ARCOUNT number of resource records in the additional records section.
+ANCOUNT number of records in the answer section.
+NSCOUNT number of records in the authority records section.
+ARCOUNT number of records in the additional records section.
 
 4.1.2. Question section format
 
-The section contains QDCOUNT (usually 1) entries, each of the following format:
-                                    1  1  1  1  1  1
-      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+The section contains QDCOUNT (usually 1) entries, each of this format:
+      0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
     /                     QNAME                     /
     /                                               /
@@ -296,12 +298,11 @@
 
 4.1.3. Resource record format
 
-The answer, authority, and additional sections all share the same
-format: a variable number of resource records, where the number of
-records is specified in the corresponding count field in the header.
-Each resource record has the following format:
-                                    1  1  1  1  1  1
-      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+The answer, authority, and additional sections all share the same format:
+a variable number of resource records, where the number of records
+is specified in the corresponding count field in the header.
+Each resource record has this format:
+      0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
     /                                               /
     /                      NAME                     /
@@ -320,30 +321,21 @@
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
 NAME    a domain name to which this resource record pertains.
 TYPE    two octets containing one of the RR type codes.  This
-        field specifies the meaning of the data in the RDATA
-        field.
-CLASS   two octets which specify the class of the data in the
-        RDATA field.
-TTL     a 32 bit unsigned integer that specifies the time
-        interval (in seconds) that the resource record may be
-        cached before it should be discarded.  Zero values are
-        interpreted to mean that the RR can only be used for the
-        transaction in progress, and should not be cached.
-RDLENGTH an unsigned 16 bit integer that specifies the length in
-        octets of the RDATA field.
-RDATA   a variable length string of octets that describes the
-        resource.  The format of this information varies
-        according to the TYPE and CLASS of the resource record.
-        For example, if the TYPE is A and the CLASS is IN,
-        the RDATA field is a 4 octet ARPA Internet address.
+        field specifies the meaning of the data in the RDATA field.
+CLASS   two octets which specify the class of the data in the RDATA field.
+TTL     a 32 bit unsigned integer that specifies the time interval
+        (in seconds) that the record may be cached.
+RDLENGTH a 16 bit integer, length in octets of the RDATA field.
+RDATA   a variable length string of octets that describes the resource.
+        The format of this information varies according to the TYPE
+        and CLASS of the resource record.
+        If the TYPE is A and the CLASS is IN, it's a 4 octet IP address.
 
 4.1.4. Message compression
 
-In order to reduce the size of messages, the domain system utilizes a
-compression scheme which eliminates the repetition of domain names in a
-message.  In this scheme, an entire domain name or a list of labels at
-the end of a domain name is replaced with a pointer to a prior occurance
-of the same name.
+In order to reduce the size of messages, domain names coan be compressed.
+An entire domain name or a list of labels at the end of a domain name
+is replaced with a pointer to a prior occurance of the same name.
 
 The pointer takes the form of a two octet sequence:
     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
@@ -355,27 +347,26 @@
 an offset from the start of the message (i.e., the first octet
 of the ID field in the domain header).
 A zero offset specifies the first byte of the ID field, etc.
-
-The compression scheme allows a domain name in a message to be
-represented as either:
+Domain name in a message can be represented as either:
    - a sequence of labels ending in a zero octet
    - a pointer
    - a sequence of labels ending with a pointer
  */
-static int process_packet(struct dns_entry *conf_data, uint32_t conf_ttl, uint8_t *buf)
+static int process_packet(struct dns_entry *conf_data,
+		uint32_t conf_ttl,
+		uint8_t *buf)
 {
-	uint8_t answstr[MAX_NAME_LEN + 1];
+	char *answstr;
 	struct dns_head *head;
 	struct dns_prop *unaligned_qprop;
-	uint8_t *from, *answb;
+	char *query_string;
+	uint8_t *answb;
 	uint16_t outr_rlen;
 	uint16_t outr_flags;
 	uint16_t type;
 	uint16_t class;
 	int querystr_len;
 
-	answstr[0] = '\0';
-
 	head = (struct dns_head *)buf;
 	if (head->nquer == 0) {
 		bb_error_msg("packet has 0 queries, ignored");
@@ -388,15 +379,15 @@
 	}
 
 	/* start of query string */
-	from = (void *)(head + 1);
+	query_string = (void *)(head + 1);
 	/* caller guarantees strlen is <= MAX_PACK_LEN */
-	querystr_len = strlen((char *)from) + 1;
+	querystr_len = strlen(query_string) + 1;
 	/* may be unaligned! */
-	unaligned_qprop = (void *)(from + querystr_len);
+	unaligned_qprop = (void *)(query_string + querystr_len);
+	querystr_len += sizeof(unaligned_qprop);
 	/* where to append answer block */
 	answb = (void *)(unaligned_qprop + 1);
 
-	outr_rlen = 0;
 	/* QR = 1 "response", RCODE = 4 "Not Implemented" */
 	outr_flags = htons(0x8000 | 4);
 
@@ -414,29 +405,29 @@
 		goto empty_packet;
 	}
 
-	bb_info_msg("%s", (char *)from);
-	if (table_lookup(answstr, conf_data, type, from) != 0) {
+	/* look up the name */
+#if DEBUG
+	/* need to convert lengths to dots before we can use it in non-debug */
+	bb_info_msg("%s", query_string);
+#endif
+	answstr = table_lookup(conf_data, type, query_string);
+	outr_rlen = 4;
+	if (answstr && type == htons(REQ_PTR)) {
+		/* return a host name */
+		outr_rlen = strlen(answstr) + 1;
+	}
+	if (!answstr
+	 || (unsigned)(answb - buf) + querystr_len + 4 + 2 + outr_rlen > MAX_PACK_LEN
+	) {
 		/* QR = 1 "response"
 		 * AA = 1 "Authoritative Answer"
 		 * RCODE = 3 "Name Error" */
 		outr_flags = htons(0x8000 | 0x0400 | 3);
 		goto empty_packet;
 	}
-	/* return an address */
-	outr_rlen = 4;
-	if (type == htons(REQ_PTR)) {
-		/* return a host name */
-		outr_rlen = strlen((char *)answstr) + 1;
-	}
-	/* QR = 1 "response",
-	 * AA = 1 "Authoritative Answer",
-	 * RCODE = 0 "success" */
-	outr_flags = htons(0x8000 | 0x0400 | 0);
-	/* we have one answer */
-	head->nansw = htons(1);
+
 	/* copy query block to answer block */
-	querystr_len += sizeof(unaligned_qprop);
-	memcpy(answb, from, querystr_len);
+	memcpy(answb, query_string, querystr_len);
 	answb += querystr_len;
 	/* append answer Resource Record */
 	move_to_unaligned32((uint32_t *)answb, htonl(conf_ttl));
@@ -446,6 +437,13 @@
 	memcpy(answb, answstr, outr_rlen);
 	answb += outr_rlen;
 
+	/* QR = 1 "response",
+	 * AA = 1 "Authoritative Answer",
+	 * RCODE = 0 "success" */
+	outr_flags = htons(0x8000 | 0x0400 | 0);
+	/* we have one answer */
+	head->nansw = htons(1);
+
  empty_packet:
 	head->flags |= outr_flags;
 	head->nauth = head->nadd = 0;

Modified: trunk/busybox/util-linux/mount.c
===================================================================
--- trunk/busybox/util-linux/mount.c	2009-04-12 04:20:22 UTC (rev 26069)
+++ trunk/busybox/util-linux/mount.c	2009-04-12 12:16:21 UTC (rev 26070)
@@ -419,12 +419,12 @@
 			int errno_save = errno;
 			args[0] = xasprintf("mount.%s", mp->mnt_type);
 			rc = 1;
+			args[rc++] = mp->mnt_fsname;
+			args[rc++] = mp->mnt_dir;
 			if (filteropts) {
 				args[rc++] = (char *)"-o";
 				args[rc++] = filteropts;
 			}
-			args[rc++] = mp->mnt_fsname;
-			args[rc++] = mp->mnt_dir;
 			args[rc] = NULL;
 			rc = wait4pid(spawn(args));
 			free(args[0]);
@@ -1605,22 +1605,24 @@
 	 && (mp->mnt_fsname[0] == '/' || mp->mnt_fsname[0] == '\\')
 	 && mp->mnt_fsname[0] == mp->mnt_fsname[1]
 	) {
+#if 0 /* reported to break things */
 		len_and_sockaddr *lsa;
 		char *ip, *dotted;
 		char *s;
 
-		rc = 1;
 		// Replace '/' with '\' and verify that unc points to "//server/share".
 		for (s = mp->mnt_fsname; *s; ++s)
 			if (*s == '/') *s = '\\';
 
 		// Get server IP
 		s = strrchr(mp->mnt_fsname, '\\');
-		if (s <= mp->mnt_fsname+1) goto report_error;
+		if (s <= mp->mnt_fsname+1)
+			goto report_error;
 		*s = '\0';
 		lsa = host2sockaddr(mp->mnt_fsname+2, 0);
 		*s = '\\';
-		if (!lsa) goto report_error;
+		if (!lsa)
+			goto report_error;
 
 		// Insert ip=... option into string flags.
 		dotted = xmalloc_sockaddr2dotted_noport(&lsa->u.sa);
@@ -1630,18 +1632,19 @@
 		// Compose new unc '\\server-ip\share'
 		// (s => slash after hostname)
 		mp->mnt_fsname = xasprintf("\\\\%s%s", dotted, s);
-
-		// Lock is required
+#endif
+		// Lock is required [why?]
 		vfsflags |= MS_MANDLOCK;
-
 		mp->mnt_type = (char*)"cifs";
 		rc = mount_it_now(mp, vfsflags, filteropts);
+#if 0
 		if (ENABLE_FEATURE_CLEAN_UP) {
 			free(mp->mnt_fsname);
 			free(ip);
 			free(dotted);
 			free(lsa);
 		}
+#endif
 		goto report_error;
 	}
 



More information about the busybox-cvs mailing list