cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts
Fix up multiuser mounts to set the secType and set the username and
password from the key payload in the vol info for non-krb5 auth types.
Look for a key of type "secret" with a description of
"cifs:a:<server address>" or "cifs:d:<domainname>". If that's found,
then scrape the username and password out of the key payload and use
that to create a new user session.
Finally, don't have the code enforce krb5 auth on multiuser mounts,
but do require a kernel with keys support.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index b952a21..28f23c0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -38,6 +38,7 @@
#include <asm/processor.h>
#include <linux/inet.h>
#include <linux/module.h>
+#include <keys/user-type.h>
#include <net/ipv6.h>
#include "cifspdu.h"
#include "cifsglob.h"
@@ -1594,11 +1595,14 @@
}
}
- if (vol->multiuser && !(vol->secFlg & CIFSSEC_MAY_KRB5)) {
- cERROR(1, "Multiuser mounts currently require krb5 "
- "authentication!");
+#ifndef CONFIG_KEYS
+ /* Muliuser mounts require CONFIG_KEYS support */
+ if (vol->multiuser) {
+ cERROR(1, "Multiuser mounts require kernels with "
+ "CONFIG_KEYS enabled.");
goto cifs_parse_mount_err;
}
+#endif
if (vol->UNCip == NULL)
vol->UNCip = &vol->UNC[2];
@@ -2061,6 +2065,132 @@
cifs_put_tcp_session(server);
}
+#ifdef CONFIG_KEYS
+
+/* strlen("cifs:a:") + INET6_ADDRSTRLEN + 1 */
+#define CIFSCREDS_DESC_SIZE (7 + INET6_ADDRSTRLEN + 1)
+
+/* Populate username and pw fields from keyring if possible */
+static int
+cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses)
+{
+ int rc = 0;
+ char *desc, *delim, *payload;
+ ssize_t len;
+ struct key *key;
+ struct TCP_Server_Info *server = ses->server;
+ struct sockaddr_in *sa;
+ struct sockaddr_in6 *sa6;
+ struct user_key_payload *upayload;
+
+ desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
+ if (!desc)
+ return -ENOMEM;
+
+ /* try to find an address key first */
+ switch (server->dstaddr.ss_family) {
+ case AF_INET:
+ sa = (struct sockaddr_in *)&server->dstaddr;
+ sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
+ break;
+ case AF_INET6:
+ sa6 = (struct sockaddr_in6 *)&server->dstaddr;
+ sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
+ break;
+ default:
+ cFYI(1, "Bad ss_family (%hu)", server->dstaddr.ss_family);
+ rc = -EINVAL;
+ goto out_err;
+ }
+
+ cFYI(1, "%s: desc=%s", __func__, desc);
+ key = request_key(&key_type_logon, desc, "");
+ if (IS_ERR(key)) {
+ if (!ses->domainName) {
+ cFYI(1, "domainName is NULL");
+ rc = PTR_ERR(key);
+ goto out_err;
+ }
+
+ /* didn't work, try to find a domain key */
+ sprintf(desc, "cifs:d:%s", ses->domainName);
+ cFYI(1, "%s: desc=%s", __func__, desc);
+ key = request_key(&key_type_logon, desc, "");
+ if (IS_ERR(key)) {
+ rc = PTR_ERR(key);
+ goto out_err;
+ }
+ }
+
+ down_read(&key->sem);
+ upayload = key->payload.data;
+ if (IS_ERR_OR_NULL(upayload)) {
+ rc = PTR_ERR(key);
+ goto out_key_put;
+ }
+
+ /* find first : in payload */
+ payload = (char *)upayload->data;
+ delim = strnchr(payload, upayload->datalen, ':');
+ cFYI(1, "payload=%s", payload);
+ if (!delim) {
+ cFYI(1, "Unable to find ':' in payload (datalen=%d)",
+ upayload->datalen);
+ rc = -EINVAL;
+ goto out_key_put;
+ }
+
+ len = delim - payload;
+ if (len > MAX_USERNAME_SIZE || len <= 0) {
+ cFYI(1, "Bad value from username search (len=%ld)", len);
+ rc = -EINVAL;
+ goto out_key_put;
+ }
+
+ vol->username = kstrndup(payload, len, GFP_KERNEL);
+ if (!vol->username) {
+ cFYI(1, "Unable to allocate %ld bytes for username", len);
+ rc = -ENOMEM;
+ goto out_key_put;
+ }
+ cFYI(1, "%s: username=%s", __func__, vol->username);
+
+ len = key->datalen - (len + 1);
+ if (len > MAX_PASSWORD_SIZE || len <= 0) {
+ cFYI(1, "Bad len for password search (len=%ld)", len);
+ rc = -EINVAL;
+ kfree(vol->username);
+ vol->username = NULL;
+ goto out_key_put;
+ }
+
+ ++delim;
+ vol->password = kstrndup(delim, len, GFP_KERNEL);
+ if (!vol->password) {
+ cFYI(1, "Unable to allocate %ld bytes for password", len);
+ rc = -ENOMEM;
+ kfree(vol->username);
+ vol->username = NULL;
+ goto out_key_put;
+ }
+
+out_key_put:
+ up_read(&key->sem);
+ key_put(key);
+out_err:
+ kfree(desc);
+ cFYI(1, "%s: returning %d", __func__, rc);
+ return rc;
+}
+#else /* ! CONFIG_KEYS */
+static inline int
+cifs_set_cifscreds(struct smb_vol *vol __attribute__((unused)),
+ struct cifs_ses *ses __attribute__((unused)))
+{
+ return -ENOSYS;
+}
+#endif /* CONFIG_KEYS */
+
static bool warned_on_ntlm; /* globals init to false automatically */
static struct cifs_ses *
@@ -3693,16 +3823,38 @@
return rc;
}
+static int
+cifs_set_vol_auth(struct smb_vol *vol, struct cifs_ses *ses)
+{
+ switch (ses->server->secType) {
+ case Kerberos:
+ vol->secFlg = CIFSSEC_MUST_KRB5;
+ return 0;
+ case NTLMv2:
+ vol->secFlg = CIFSSEC_MUST_NTLMV2;
+ break;
+ case NTLM:
+ vol->secFlg = CIFSSEC_MUST_NTLM;
+ break;
+ case RawNTLMSSP:
+ vol->secFlg = CIFSSEC_MUST_NTLMSSP;
+ break;
+ case LANMAN:
+ vol->secFlg = CIFSSEC_MUST_LANMAN;
+ break;
+ }
+
+ return cifs_set_cifscreds(vol, ses);
+}
+
static struct cifs_tcon *
cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid)
{
+ int rc;
struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
struct cifs_ses *ses;
struct cifs_tcon *tcon = NULL;
struct smb_vol *vol_info;
- char username[28]; /* big enough for "krb50x" + hex of ULONG_MAX 6+16 */
- /* We used to have this as MAX_USERNAME which is */
- /* way too big now (256 instead of 32) */
vol_info = kzalloc(sizeof(*vol_info), GFP_KERNEL);
if (vol_info == NULL) {
@@ -3710,8 +3862,6 @@
goto out;
}
- snprintf(username, sizeof(username), "krb50x%x", fsuid);
- vol_info->username = username;
vol_info->local_nls = cifs_sb->local_nls;
vol_info->linux_uid = fsuid;
vol_info->cred_uid = fsuid;
@@ -3721,8 +3871,11 @@
vol_info->local_lease = master_tcon->local_lease;
vol_info->no_linux_ext = !master_tcon->unix_ext;
- /* FIXME: allow for other secFlg settings */
- vol_info->secFlg = CIFSSEC_MUST_KRB5;
+ rc = cifs_set_vol_auth(vol_info, master_tcon->ses);
+ if (rc) {
+ tcon = ERR_PTR(rc);
+ goto out;
+ }
/* get a reference for the same TCP session */
spin_lock(&cifs_tcp_ses_lock);
@@ -3745,6 +3898,8 @@
if (ses->capabilities & CAP_UNIX)
reset_cifs_unix_caps(0, tcon, NULL, vol_info);
out:
+ kfree(vol_info->username);
+ kfree(vol_info->password);
kfree(vol_info);
return tcon;