cifs: Split lanman auth from CIFS_SessSetup()
In preparation for splitting CIFS_SessSetup() into smaller more
manageable chunks, we first add helper functions.
We then proceed to split out lanman auth out of CIFS_SessSetup()
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index e87387d..36d0b90 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -520,6 +520,240 @@
}
}
+struct sess_data {
+ unsigned int xid;
+ struct cifs_ses *ses;
+ struct nls_table *nls_cp;
+ void (*func)(struct sess_data *);
+ int result;
+
+ /* we will send the SMB in three pieces:
+ * a fixed length beginning part, an optional
+ * SPNEGO blob (which can be zero length), and a
+ * last part which will include the strings
+ * and rest of bcc area. This allows us to avoid
+ * a large buffer 17K allocation
+ */
+ int buf0_type;
+ struct kvec iov[3];
+};
+
+static int
+sess_alloc_buffer(struct sess_data *sess_data, int wct)
+{
+ int rc;
+ struct cifs_ses *ses = sess_data->ses;
+ struct smb_hdr *smb_buf;
+
+ rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
+ (void **)&smb_buf);
+
+ if (rc)
+ return rc;
+
+ sess_data->iov[0].iov_base = (char *)smb_buf;
+ sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
+ /*
+ * This variable will be used to clear the buffer
+ * allocated above in case of any error in the calling function.
+ */
+ sess_data->buf0_type = CIFS_SMALL_BUFFER;
+
+ /* 2000 big enough to fit max user, domain, NOS name etc. */
+ sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
+ if (!sess_data->iov[2].iov_base) {
+ rc = -ENOMEM;
+ goto out_free_smb_buf;
+ }
+
+ return 0;
+
+out_free_smb_buf:
+ kfree(smb_buf);
+ sess_data->iov[0].iov_base = NULL;
+ sess_data->iov[0].iov_len = 0;
+ sess_data->buf0_type = CIFS_NO_BUFFER;
+ return rc;
+}
+
+static void
+sess_free_buffer(struct sess_data *sess_data)
+{
+
+ free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base);
+ sess_data->buf0_type = CIFS_NO_BUFFER;
+ kfree(sess_data->iov[2].iov_base);
+}
+
+static int
+sess_establish_session(struct sess_data *sess_data)
+{
+ struct cifs_ses *ses = sess_data->ses;
+
+ mutex_lock(&ses->server->srv_mutex);
+ if (!ses->server->session_estab) {
+ if (ses->server->sign) {
+ ses->server->session_key.response =
+ kmemdup(ses->auth_key.response,
+ ses->auth_key.len, GFP_KERNEL);
+ if (!ses->server->session_key.response) {
+ mutex_unlock(&ses->server->srv_mutex);
+ return -ENOMEM;
+ }
+ ses->server->session_key.len =
+ ses->auth_key.len;
+ }
+ ses->server->sequence_number = 0x2;
+ ses->server->session_estab = true;
+ }
+ mutex_unlock(&ses->server->srv_mutex);
+
+ cifs_dbg(FYI, "CIFS session established successfully\n");
+ spin_lock(&GlobalMid_Lock);
+ ses->status = CifsGood;
+ ses->need_reconnect = false;
+ spin_unlock(&GlobalMid_Lock);
+
+ return 0;
+}
+
+static int
+sess_sendreceive(struct sess_data *sess_data)
+{
+ int rc;
+ struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
+ __u16 count;
+
+ count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
+ smb_buf->smb_buf_length =
+ cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);
+ put_bcc(count, smb_buf);
+
+ rc = SendReceive2(sess_data->xid, sess_data->ses,
+ sess_data->iov, 3 /* num_iovecs */,
+ &sess_data->buf0_type,
+ CIFS_LOG_ERROR);
+
+ return rc;
+}
+
+/*
+ * LANMAN and plaintext are less secure and off by default.
+ * So we make this explicitly be turned on in kconfig (in the
+ * build) and turned on at runtime (changed from the default)
+ * in proc/fs/cifs or via mount parm. Unfortunately this is
+ * needed for old Win (e.g. Win95), some obscure NAS and OS/2
+ */
+#ifdef CONFIG_CIFS_WEAK_PW_HASH
+static void
+sess_auth_lanman(struct sess_data *sess_data)
+{
+ int rc = 0;
+ struct smb_hdr *smb_buf;
+ SESSION_SETUP_ANDX *pSMB;
+ char *bcc_ptr;
+ struct cifs_ses *ses = sess_data->ses;
+ char lnm_session_key[CIFS_AUTH_RESP_SIZE];
+ __u32 capabilities;
+ __u16 bytes_remaining;
+
+ /* lanman 2 style sessionsetup */
+ /* wct = 10 */
+ rc = sess_alloc_buffer(sess_data, 10);
+ if (rc)
+ goto out;
+
+ pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
+ bcc_ptr = sess_data->iov[2].iov_base;
+ capabilities = cifs_ssetup_hdr(ses, pSMB);
+
+ pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;
+
+ /* no capabilities flags in old lanman negotiation */
+ pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
+
+ /* Calculate hash with password and copy into bcc_ptr.
+ * Encryption Key (stored as in cryptkey) gets used if the
+ * security mode bit in Negottiate Protocol response states
+ * to use challenge/response method (i.e. Password bit is 1).
+ */
+ rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
+ ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
+ true : false, lnm_session_key);
+
+ memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
+ bcc_ptr += CIFS_AUTH_RESP_SIZE;
+
+ /*
+ * can not sign if LANMAN negotiated so no need
+ * to calculate signing key? but what if server
+ * changed to do higher than lanman dialect and
+ * we reconnected would we ever calc signing_key?
+ */
+
+ cifs_dbg(FYI, "Negotiating LANMAN setting up strings\n");
+ /* Unicode not allowed for LANMAN dialects */
+ ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
+
+ sess_data->iov[2].iov_len = (long) bcc_ptr -
+ (long) sess_data->iov[2].iov_base;
+
+ rc = sess_sendreceive(sess_data);
+ if (rc)
+ goto out;
+
+ pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
+ smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
+
+ /* lanman response has a word count of 3 */
+ if (smb_buf->WordCount != 3) {
+ rc = -EIO;
+ cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
+ goto out;
+ }
+
+ if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
+ cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
+
+ ses->Suid = smb_buf->Uid; /* UID left in wire format (le) */
+ cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
+
+ bytes_remaining = get_bcc(smb_buf);
+ bcc_ptr = pByteArea(smb_buf);
+
+ /* BB check if Unicode and decode strings */
+ if (bytes_remaining == 0) {
+ /* no string area to decode, do nothing */
+ } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
+ /* unicode string area must be word-aligned */
+ if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+ ++bcc_ptr;
+ --bytes_remaining;
+ }
+ decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
+ sess_data->nls_cp);
+ } else {
+ decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
+ sess_data->nls_cp);
+ }
+
+ rc = sess_establish_session(sess_data);
+out:
+ sess_data->result = rc;
+ sess_data->func = NULL;
+ sess_free_buffer(sess_data);
+}
+
+#else
+
+static void
+sess_auth_lanman(struct sess_data *sess_data)
+{
+ sess_data->result = -EOPNOTSUPP;
+ sess_data->func = NULL;
+}
+#endif
+
int
CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
const struct nls_table *nls_cp)
@@ -540,12 +774,21 @@
__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
u16 blob_len;
char *ntlmsspblob = NULL;
+ struct sess_data *sess_data;
if (ses == NULL) {
WARN(1, "%s: ses == NULL!", __func__);
return -EINVAL;
}
+ sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
+ if (!sess_data)
+ return -ENOMEM;
+ sess_data->xid = xid;
+ sess_data->ses = ses;
+ sess_data->buf0_type = CIFS_NO_BUFFER;
+ sess_data->nls_cp = (struct nls_table *) nls_cp;
+
type = select_sectype(ses->server, ses->sectype);
cifs_dbg(FYI, "sess setup type %d\n", type);
if (type == Unspecified) {
@@ -554,6 +797,14 @@
return -EINVAL;
}
+ switch (type) {
+ case LANMAN:
+ sess_auth_lanman(sess_data);
+ goto out;
+ default:
+ cifs_dbg(FYI, "Continuing with CIFS_SessSetup\n");
+ }
+
if (type == RawNTLMSSP) {
/* if memory allocation is successful, caller of this function
* frees it.
@@ -569,17 +820,7 @@
if (phase == NtLmChallenge)
phase = NtLmAuthenticate; /* if ntlmssp, now final phase */
- if (type == LANMAN) {
-#ifndef CONFIG_CIFS_WEAK_PW_HASH
- /* LANMAN and plaintext are less secure and off by default.
- So we make this explicitly be turned on in kconfig (in the
- build) and turned on at runtime (changed from the default)
- in proc/fs/cifs or via mount parm. Unfortunately this is
- needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
- return -EOPNOTSUPP;
-#endif
- wct = 10; /* lanman 2 style sessionsetup */
- } else if ((type == NTLM) || (type == NTLMv2)) {
+ if ((type == NTLM) || (type == NTLMv2)) {
/* For NTLMv2 failures eventually may need to retry NTLM */
wct = 13; /* old style NTLM sessionsetup */
} else /* same size: negotiate or auth, NTLMSSP or extended security */
@@ -618,39 +859,7 @@
iov[1].iov_base = NULL;
iov[1].iov_len = 0;
- if (type == LANMAN) {
-#ifdef CONFIG_CIFS_WEAK_PW_HASH
- char lnm_session_key[CIFS_AUTH_RESP_SIZE];
-
- pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;
-
- /* no capabilities flags in old lanman negotiation */
-
- pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
-
- /* Calculate hash with password and copy into bcc_ptr.
- * Encryption Key (stored as in cryptkey) gets used if the
- * security mode bit in Negottiate Protocol response states
- * to use challenge/response method (i.e. Password bit is 1).
- */
-
- rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
- ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
- true : false, lnm_session_key);
-
- memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
- bcc_ptr += CIFS_AUTH_RESP_SIZE;
-
- /* can not sign if LANMAN negotiated so no need
- to calculate signing key? but what if server
- changed to do higher than lanman dialect and
- we reconnected would we ever calc signing_key? */
-
- cifs_dbg(FYI, "Negotiating LANMAN setting up strings\n");
- /* Unicode not allowed for LANMAN dialects */
- ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
-#endif
- } else if (type == NTLM) {
+ if (type == NTLM) {
pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
pSMB->req_no_secext.CaseInsensitivePasswordLength =
cpu_to_le16(CIFS_AUTH_RESP_SIZE);
@@ -889,7 +1098,6 @@
}
if (phase == NtLmChallenge) {
rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
- /* now goto beginning for ntlmssp authenticate phase */
if (rc)
goto ssetup_exit;
}
@@ -962,4 +1170,9 @@
kfree(ses->ntlmssp);
return rc;
+
+out:
+ rc = sess_data->result;
+ kfree(sess_data);
+ return rc;
}