CIFSGetDFSRefer cleanup + dfs_referral_level_3 fixed to conform REFERRAL_V3 the MS-DFSC spec.
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index fc29738..6f8ed93 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -81,6 +81,39 @@
#endif /* CONFIG_CIFS_WEAK_PW_HASH */
#endif /* CIFS_POSIX */
+/* Allocates buffer into dst and copies smb string from src to it.
+ * caller is responsible for freeing dst if function returned 0.
+ * returns:
+ * on success - 0
+ * on failure - errno
+ */
+static int
+cifs_strncpy_to_host(char **dst, const char *src, const int maxlen,
+ const bool is_unicode, const struct nls_table *nls_codepage)
+{
+ int plen;
+
+ if (is_unicode) {
+ plen = UniStrnlen((wchar_t *)src, maxlen);
+ *dst = kmalloc(plen + 2, GFP_KERNEL);
+ if (!*dst)
+ goto cifs_strncpy_to_host_ErrExit;
+ cifs_strfromUCS_le(*dst, (__le16 *)src, plen, nls_codepage);
+ } else {
+ plen = strnlen(src, maxlen);
+ *dst = kmalloc(plen + 2, GFP_KERNEL);
+ if (!*dst)
+ goto cifs_strncpy_to_host_ErrExit;
+ strncpy(*dst, src, plen);
+ }
+ (*dst)[plen] = 0;
+ return 0;
+
+cifs_strncpy_to_host_ErrExit:
+ cERROR(1, ("Failed to allocate buffer for string\n"));
+ return -ENOMEM;
+}
+
/* Mark as invalid, all open files on tree connections since they
were closed when session to server was lost */
@@ -3867,6 +3900,96 @@
return rc;
}
+/* parses DFS refferal V3 structure
+ * caller is responsible for freeing target_nodes
+ * returns:
+ * on success - 0
+ * on failure - errno
+ */
+static int
+parse_DFS_REFERRALS(TRANSACTION2_GET_DFS_REFER_RSP *pSMBr,
+ unsigned int *num_of_nodes,
+ struct dfs_info3_param **target_nodes,
+ const struct nls_table *nls_codepage)
+{
+ int i, rc = 0;
+ char *data_end;
+ bool is_unicode;
+ struct dfs_referral_level_3 *ref;
+
+ is_unicode = pSMBr->hdr.Flags2 & SMBFLG2_UNICODE;
+ *num_of_nodes = le16_to_cpu(pSMBr->NumberOfReferrals);
+
+ if (*num_of_nodes < 1) {
+ cERROR(1, ("num_referrals: must be at least > 0,"
+ "but we get num_referrals = %d\n", *num_of_nodes));
+ rc = -EINVAL;
+ goto parse_DFS_REFERRALS_exit;
+ }
+
+ ref = (struct dfs_referral_level_3 *) &(pSMBr->referrals);
+ if (ref->VersionNumber != 3) {
+ cERROR(1, ("Referrals of V%d version are not supported,"
+ "should be V3", ref->VersionNumber));
+ rc = -EINVAL;
+ goto parse_DFS_REFERRALS_exit;
+ }
+
+ /* get the upper boundary of the resp buffer */
+ data_end = (char *)(&(pSMBr->PathConsumed)) +
+ le16_to_cpu(pSMBr->t2.DataCount);
+
+ cFYI(1, ("num_referrals: %d dfs flags: 0x%x ... \n",
+ *num_of_nodes,
+ le16_to_cpu(pSMBr->DFSFlags)));
+
+ *target_nodes = kzalloc(sizeof(struct dfs_info3_param) *
+ *num_of_nodes, GFP_KERNEL);
+ if (*target_nodes == NULL) {
+ cERROR(1, ("Failed to allocate buffer for target_nodes\n"));
+ rc = -ENOMEM;
+ goto parse_DFS_REFERRALS_exit;
+ }
+
+ /* collect neccessary data from referrals */
+ for (i = 0; i < *num_of_nodes; i++) {
+ char *temp;
+ int max_len;
+ struct dfs_info3_param *node = (*target_nodes)+i;
+
+ node->flags = le16_to_cpu(pSMBr->DFSFlags);
+ node->path_consumed = le16_to_cpu(pSMBr->PathConsumed);
+ node->server_type = le16_to_cpu(ref->ServerType);
+ node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
+
+ /* copy DfsPath */
+ temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
+ max_len = data_end - temp;
+ rc = cifs_strncpy_to_host(&(node->path_name), temp,
+ max_len, is_unicode, nls_codepage);
+ if (rc)
+ goto parse_DFS_REFERRALS_exit;
+
+ /* copy link target UNC */
+ temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
+ max_len = data_end - temp;
+ rc = cifs_strncpy_to_host(&(node->node_name), temp,
+ max_len, is_unicode, nls_codepage);
+ if (rc)
+ goto parse_DFS_REFERRALS_exit;
+
+ ref += ref->Size;
+ }
+
+parse_DFS_REFERRALS_exit:
+ if (rc) {
+ free_dfs_info_array(*target_nodes, *num_of_nodes);
+ *target_nodes = NULL;
+ *num_of_nodes = 0;
+ }
+ return rc;
+}
+
int
CIFSGetDFSRefer(const int xid, struct cifsSesInfo *ses,
const unsigned char *searchName,
@@ -3877,12 +4000,9 @@
/* TRANS2_GET_DFS_REFERRAL */
TRANSACTION2_GET_DFS_REFER_REQ *pSMB = NULL;
TRANSACTION2_GET_DFS_REFER_RSP *pSMBr = NULL;
- struct dfs_referral_level_3 *referrals = NULL;
int rc = 0;
int bytes_returned;
int name_len;
- unsigned int i;
- char *temp;
__u16 params, byte_count;
*num_of_nodes = 0;
*target_nodes = NULL;
@@ -3960,80 +4080,19 @@
rc = validate_t2((struct smb_t2_rsp *)pSMBr);
/* BB Also check if enough total bytes returned? */
- if (rc || (pSMBr->ByteCount < 17))
+ if (rc || (pSMBr->ByteCount < 17)) {
rc = -EIO; /* bad smb */
- else {
- __u16 data_offset = le16_to_cpu(pSMBr->t2.DataOffset);
- __u16 data_count = le16_to_cpu(pSMBr->t2.DataCount);
-
- cFYI(1, ("Decoding GetDFSRefer response BCC: %d Offset %d",
- pSMBr->ByteCount, data_offset));
- referrals =
- (struct dfs_referral_level_3 *)
- (8 /* sizeof start of data block */ +
- data_offset +
- (char *) &pSMBr->hdr.Protocol);
- cFYI(1, ("num_referrals: %d dfs flags: 0x%x ... \n"
- "for referral one refer size: 0x%x srv "
- "type: 0x%x refer flags: 0x%x ttl: 0x%x",
- le16_to_cpu(pSMBr->NumberOfReferrals),
- le16_to_cpu(pSMBr->DFSFlags),
- le16_to_cpu(referrals->ReferralSize),
- le16_to_cpu(referrals->ServerType),
- le16_to_cpu(referrals->ReferralFlags),
- le16_to_cpu(referrals->TimeToLive)));
- /* BB This field is actually two bytes in from start of
- data block so we could do safety check that DataBlock
- begins at address of pSMBr->NumberOfReferrals */
- *num_of_nodes = le16_to_cpu(pSMBr->NumberOfReferrals);
-
- /* BB Fix below so can return more than one referral */
- if (*num_of_nodes > 1)
- *num_of_nodes = 1;
-
- /* get the length of the strings describing refs */
- name_len = 0;
- for (i = 0; i < *num_of_nodes; i++) {
- /* make sure that DfsPathOffset not past end */
- __u16 offset = le16_to_cpu(referrals->DfsPathOffset);
- if (offset > data_count) {
- /* if invalid referral, stop here and do
- not try to copy any more */
- *num_of_nodes = i;
- break;
- }
- temp = ((char *)referrals) + offset;
-
- if (pSMBr->hdr.Flags2 & SMBFLG2_UNICODE) {
- name_len += UniStrnlen((wchar_t *)temp,
- data_count);
- } else {
- name_len += strnlen(temp, data_count);
- }
- referrals++;
- /* BB add check that referral pointer does
- not fall off end PDU */
- }
- /* BB add check for name_len bigger than bcc */
- *target_nodes =
- kmalloc(name_len+1+(*num_of_nodes),
- GFP_KERNEL);
- if (*target_nodes == NULL) {
- rc = -ENOMEM;
- goto GetDFSRefExit;
- }
-
- referrals = (struct dfs_referral_level_3 *)
- (8 /* sizeof data hdr */ + data_offset +
- (char *) &pSMBr->hdr.Protocol);
-
- for (i = 0; i < *num_of_nodes; i++) {
- temp = ((char *)referrals) +
- le16_to_cpu(referrals->DfsPathOffset);
- /* BB update target_uncs pointers */
- referrals++;
- }
+ goto GetDFSRefExit;
}
+
+ cFYI(1, ("Decoding GetDFSRefer response BCC: %d Offset %d",
+ pSMBr->ByteCount,
+ le16_to_cpu(pSMBr->t2.DataOffset)));
+
+ /* parse returned result into more usable form */
+ rc = parse_DFS_REFERRALS(pSMBr, num_of_nodes,
+ target_nodes, nls_codepage);
+
GetDFSRefExit:
if (pSMB)
cifs_buf_release(pSMB);