OpenSolaris_b135/common/smbsrv/smb_netbios_util.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifdef _KERNEL
#include <sys/types.h>
#include <sys/sunddi.h>
#else
#include <string.h>
#endif
#include <smbsrv/string.h>
#include <smbsrv/netbios.h>
static int domainname_is_valid(char *domain_name);
/*
* Routines than support name compression.
*
* The NetBIOS name representation in all NetBIOS packets (for NAME,
* SESSION, and DATAGRAM services) is defined in the Domain Name
* Service RFC 883[3] as "compressed" name messages. This format is
* called "second-level encoding" in the section entitled
* "Representation of NetBIOS Names" in the Concepts and Methods
* document.
*
* For ease of description, the first two paragraphs from page 31,
* the section titled "Domain name representation and compression",
* of RFC 883 are replicated here:
*
* Domain names messages are expressed in terms of a sequence
* of labels. Each label is represented as a one octet length
* field followed by that number of octets. Since every domain
* name ends with the null label of the root, a compressed
* domain name is terminated by a length byte of zero. The
* high order two bits of the length field must be zero, and
* the remaining six bits of the length field limit the label
* to 63 octets or less.
*
* To simplify implementations, the total length of label
* octets and label length octets that make up a domain name is
* restricted to 255 octets or less.
*
* The following is the uncompressed representation of the NetBIOS name
* "FRED ", which is the 4 ASCII characters, F, R, E, D, followed by 12
* space characters (0x20). This name has the SCOPE_ID: "NETBIOS.COM"
*
* EGFCEFEECACACACACACACACACACACACA.NETBIOS.COM
*
* This uncompressed representation of names is called "first-level
* encoding" in the section entitled "Representation of NetBIOS Names"
* in the Concepts and Methods document.
*
* The following is a pictographic representation of the compressed
* representation of the previous uncompressed Domain Name
* representation.
*
* 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | 0x20 | E (0x45) | G (0x47) | F (0x46) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | C (0x43) | E (0x45) | F (0x46) | E (0x45) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | E (0x45) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0x41) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0x41) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0x41) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0x41) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0x41) | C (0x43) | A (0x41) | C (0x43) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | A (0X41) | 0x07 | N (0x4E) | E (0x45) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | T (0x54) | B (0x42) | I (0x49) | O (0x4F) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | S (0x53) | 0x03 | C (0x43) | O (0x4F) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | M (0x4D) | 0x00 |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Each section of a domain name is called a label [7 (page 31)]. A
* label can be a maximum of 63 bytes. The first byte of a label in
* compressed representation is the number of bytes in the label. For
* the above example, the first 0x20 is the number of bytes in the
* left-most label, EGFCEFEECACACACACACACACACACACACA, of the domain
* name. The bytes following the label length count are the characters
* of the label. The following labels are in sequence after the first
* label, which is the encoded NetBIOS name, until a zero (0x00) length
* count. The zero length count represents the root label, which is
* always null.
*
* A label length count is actually a 6-bit field in the label length
* field. The most significant 2 bits of the field, bits 7 and 6, are
* flags allowing an escape from the above compressed representation.
* If bits 7 and 6 are both set (11), the following 14 bits are an
* offset pointer into the full message to the actual label string from
* another domain name that belongs in this name. This label pointer
* allows for a further compression of a domain name in a packet.
*
* NetBIOS implementations can only use label string pointers in Name
* Service packets. They cannot be used in Session or Datagram Service
* packets.
*
* The other two possible values for bits 7 and 6 (01 and 10) of a label
* length field are reserved for future use by RFC 883[2 (page 32)].
*
* Note that the first octet of a compressed name must contain one of
* the following bit patterns. (An "x" indicates a bit whose value may
* be either 0 or 1.):
*
* 00100000 - Netbios name, length must be 32 (decimal)
* 11xxxxxx - Label string pointer
* 10xxxxxx - Reserved
* 01xxxxxx - Reserved
*/
/*
* netbios_first_level_name_encode
*
* Put test description here.
*
* Inputs:
* char * in -> Name to encode
* char * out -> Buffer to encode into.
* int length -> # of bytes to encode.
*
* Returns:
* Nothing
*/
int
netbios_first_level_name_encode(unsigned char *name, unsigned char *scope,
unsigned char *out, int max_out)
{
unsigned char ch, len;
unsigned char *in;
unsigned char *lp;
unsigned char *op = out;
if (max_out < 0x21)
return (-1);
in = name;
*op++ = 0x20;
for (len = 0; len < NETBIOS_NAME_SZ; len++) {
ch = *in++;
*op++ = 'A' + ((ch >> 4) & 0xF);
*op++ = 'A' + ((ch) & 0xF);
}
max_out -= 0x21;
in = scope;
len = 0;
lp = op++;
while (((ch = *in++) != 0) && (max_out-- > 1)) {
if (ch == 0) {
if ((*lp = len) != 0)
*op++ = 0;
break;
}
if (ch == '.') {
*lp = len;
lp = op++;
len = 0;
} else {
*op++ = ch;
len++;
}
}
*lp = len;
if (len != 0)
*op = 0;
/*LINTED E_PTRDIFF_OVERFLOW*/
return (op - out);
}
/*
* smb_first_level_name_decode
*
* The null terminated string "in" is the name to decode. The output
* is placed in the name_entry structure "name".
*
* The scope field is a series of length designated labels as described
* in the "Domain name representation and compression" section of RFC883.
* The two high order two bits of the length field must be zero, the
* remaining six bits contain the field length. The total length of the
* domain name is restricted to 255 octets but note that the trailing
* root label and its dot are not printed. When converting the labels,
* the length fields are replaced by dots.
*
* Returns the number of bytes scanned or -1 to indicate an error.
*/
int
netbios_first_level_name_decode(char *in, char *name, char *scope)
{
unsigned int length, bytes;
char c1, c2;
char *cp;
char *out;
cp = in;
if ((length = *cp++) != 0x20) {
return (-1);
}
out = name;
while (length > 0) {
c1 = *cp++;
c2 = *cp++;
if ('A' <= c1 && c1 <= 'P' && 'A' <= c2 && c2 <= 'P') {
c1 -= 'A';
c2 -= 'A';
*out++ = (c1 << 4) | (c2);
} else {
return (-1); /* conversion error */
}
length -= 2;
}
out = scope;
bytes = 0;
for (length = *cp++; length != 0; length = *cp++) {
if ((length & 0xc0) != 0x00) {
/*
* This is a pointer or a reserved field. If it's
* a pointer (16-bits) we have to skip the next byte.
*/
if ((length & 0xc0) == 0xc0) {
cp++;
continue;
}
}
/*
* Replace the length with a '.', except for the first one.
*/
if (out != scope) {
*out++ = '.';
bytes++;
}
while (length-- > 0) {
if (bytes++ >= (NETBIOS_DOMAIN_NAME_MAX - 1)) {
return (-1);
}
*out++ = *cp++;
}
}
*out = 0;
/*
* We are supposed to preserve all 8-bits of the domain name
* but due to the single byte representation in the name cache
* and UTF-8 encoding everywhere else, we restrict domain names
* to Appendix 1 - Domain Name Syntax Specification in RFC883.
*/
if (domainname_is_valid(scope)) {
(void) smb_strupr(scope);
/*LINTED E_PTRDIFF_OVERFLOW*/
return (cp - in);
}
scope[0] = '\0';
return (-1);
}
/*
* smb_netbios_name_isvalid
*
* This function is provided to be used by session service
* which runs in kernel in order to hide name_entry definition.
*
* It returns the decoded name in the provided buffer as 'out'
* if it's not null.
*
* Returns 0 if decode fails, 1 if it succeeds.
*/
int
netbios_name_isvalid(char *in, char *out)
{
char name[NETBIOS_NAME_SZ];
char scope[NETBIOS_DOMAIN_NAME_MAX];
if (netbios_first_level_name_decode(in, name, scope) < 0)
return (0);
if (out)
(void) strlcpy(out, name, NETBIOS_NAME_SZ);
return (1);
}
/*
* Characters that we allow in DNS domain names, in addition to
* alphanumeric characters. This is not quite consistent with
* RFC883. This is global so that it can be patched if there is
* a need to change the valid characters in the field.
*/
unsigned char *dns_allowed = (unsigned char *)"-_";
/*
* dns_is_allowed
*
* Check the dns_allowed characters and return true (1) if the character
* is in the table. Otherwise return false (0).
*/
static int
dns_is_allowed(unsigned char c)
{
unsigned char *p = dns_allowed;
while (*p) {
if (c == *p++)
return (1);
}
return (0);
}
/*
* domainname_is_valid
*
* Check the specified domain name for mostly compliance with RFC883
* Appendix 1. Names may contain alphanumeric characters, hyphens,
* underscores and dots. The first character after a dot must be an
* alphabetic character. RFC883 doesn't mention underscores but we
* allow it due to common use, and we don't check that labels end
* with an alphanumeric character.
*
* Returns true (1) if the name is valid. Otherwise returns false (0).
*/
static int
domainname_is_valid(char *domain_name)
{
char *name;
int first_char = 1;
if (domain_name == 0)
return (0);
for (name = domain_name; *name != 0; ++name) {
if (*name == '.') {
first_char = 1;
continue;
}
if (first_char) {
if (smb_isalpha_ascii(*name) == 0)
return (0);
first_char = 0;
continue;
}
if (smb_isalnum_ascii(*name) || dns_is_allowed(*name))
continue;
return (0);
}
return (1);
}