From f2bb4bcc041194d655e41a4fb24789f3966755c3 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Sat, 8 Jul 2017 14:32:00 -0700 Subject: CIFS: Reconnect expired SMB sessions commit 511c54a2f69195b28afb9dd119f03787b1625bb4 upstream. According to the MS-SMB2 spec (3.2.5.1.6) once the client receives STATUS_NETWORK_SESSION_EXPIRED error code from a server it should reconnect the current SMB session. Currently the client doesn't do that. This can result in subsequent client requests failing by the server. The patch adds an additional logic to the demultiplex thread to identify expired sessions and reconnect them. Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/cifs/cifsglob.h | 2 ++ fs/cifs/cifssmb.c | 7 +++++++ fs/cifs/connect.c | 7 +++++++ fs/cifs/smb2ops.c | 16 ++++++++++++++++ 4 files changed, 32 insertions(+) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index e2f6a79e9b01..8225de3c9743 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -351,6 +351,8 @@ struct smb_version_operations { unsigned int (*calc_smb_size)(void *); /* check for STATUS_PENDING and process it in a positive case */ bool (*is_status_pending)(char *, struct TCP_Server_Info *, int); + /* check for STATUS_NETWORK_SESSION_EXPIRED */ + bool (*is_session_expired)(char *); /* send oplock break response */ int (*oplock_response)(struct cifs_tcon *, struct cifs_fid *, struct cifsInodeInfo *); diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index b60150e5b5ce..0c92af11f4f4 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1460,6 +1460,13 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid) return length; server->total_read += length; + if (server->ops->is_session_expired && + server->ops->is_session_expired(buf)) { + cifs_reconnect(server); + wake_up(&server->response_q); + return -1; + } + if (server->ops->is_status_pending && server->ops->is_status_pending(buf, server, 0)) { discard_remaining_data(server); diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index b377aa8f266f..0a2bf9462637 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -850,6 +850,13 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid) cifs_dump_mem("Bad SMB: ", buf, min_t(unsigned int, server->total_read, 48)); + if (server->ops->is_session_expired && + server->ops->is_session_expired(buf)) { + cifs_reconnect(server); + wake_up(&server->response_q); + return -1; + } + if (server->ops->is_status_pending && server->ops->is_status_pending(buf, server, length)) return -1; diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 1d125d3d0d89..e6b1795fbf2a 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -963,6 +963,18 @@ smb2_is_status_pending(char *buf, struct TCP_Server_Info *server, int length) return true; } +static bool +smb2_is_session_expired(char *buf) +{ + struct smb2_hdr *hdr = (struct smb2_hdr *)buf; + + if (hdr->Status != STATUS_NETWORK_SESSION_EXPIRED) + return false; + + cifs_dbg(FYI, "Session expired\n"); + return true; +} + static int smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid, struct cifsInodeInfo *cinode) @@ -1552,6 +1564,7 @@ struct smb_version_operations smb20_operations = { .close_dir = smb2_close_dir, .calc_smb_size = smb2_calc_size, .is_status_pending = smb2_is_status_pending, + .is_session_expired = smb2_is_session_expired, .oplock_response = smb2_oplock_response, .queryfs = smb2_queryfs, .mand_lock = smb2_mand_lock, @@ -1633,6 +1646,7 @@ struct smb_version_operations smb21_operations = { .close_dir = smb2_close_dir, .calc_smb_size = smb2_calc_size, .is_status_pending = smb2_is_status_pending, + .is_session_expired = smb2_is_session_expired, .oplock_response = smb2_oplock_response, .queryfs = smb2_queryfs, .mand_lock = smb2_mand_lock, @@ -1715,6 +1729,7 @@ struct smb_version_operations smb30_operations = { .close_dir = smb2_close_dir, .calc_smb_size = smb2_calc_size, .is_status_pending = smb2_is_status_pending, + .is_session_expired = smb2_is_session_expired, .oplock_response = smb2_oplock_response, .queryfs = smb2_queryfs, .mand_lock = smb2_mand_lock, @@ -1803,6 +1818,7 @@ struct smb_version_operations smb311_operations = { .close_dir = smb2_close_dir, .calc_smb_size = smb2_calc_size, .is_status_pending = smb2_is_status_pending, + .is_session_expired = smb2_is_session_expired, .oplock_response = smb2_oplock_response, .queryfs = smb2_queryfs, .mand_lock = smb2_mand_lock, -- cgit v1.2.3