From ae6f8dd4d0c87bfb72da9d9b56342adf53e69c31 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Thu, 17 Nov 2016 13:59:23 -0800 Subject: CIFS: Allow to switch on encryption with seal mount option This allows users to inforce encryption for SMB3 shares if a server supports it. Signed-off-by: Pavel Shilovsky --- fs/cifs/connect.c | 41 ++++++++++++++++++++++++++++------------- 1 file changed, 28 insertions(+), 13 deletions(-) (limited to 'fs/cifs/connect.c') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 325e3cb17c4c..777ad9f4fc3c 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2630,12 +2630,18 @@ get_ses_fail: return ERR_PTR(rc); } -static int match_tcon(struct cifs_tcon *tcon, const char *unc) +static int match_tcon(struct cifs_tcon *tcon, struct smb_vol *volume_info) { if (tcon->tidStatus == CifsExiting) return 0; - if (strncmp(tcon->treeName, unc, MAX_TREE_SIZE)) + if (strncmp(tcon->treeName, volume_info->UNC, MAX_TREE_SIZE)) return 0; + if (tcon->seal != volume_info->seal) + return 0; +#ifdef CONFIG_CIFS_SMB2 + if (tcon->snapshot_time != volume_info->snapshot_time) + return 0; +#endif /* CONFIG_CIFS_SMB2 */ return 1; } @@ -2648,14 +2654,8 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb_vol *volume_info) spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &ses->tcon_list) { tcon = list_entry(tmp, struct cifs_tcon, tcon_list); - if (!match_tcon(tcon, volume_info->UNC)) - continue; - -#ifdef CONFIG_CIFS_SMB2 - if (tcon->snapshot_time != volume_info->snapshot_time) + if (!match_tcon(tcon, volume_info)) continue; -#endif /* CONFIG_CIFS_SMB2 */ - ++tcon->tc_count; spin_unlock(&cifs_tcp_ses_lock); return tcon; @@ -2701,8 +2701,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info) cifs_dbg(FYI, "Found match on UNC path\n"); /* existing tcon already has a reference */ cifs_put_smb_ses(ses); - if (tcon->seal != volume_info->seal) - cifs_dbg(VFS, "transport encryption setting conflicts with existing tid\n"); return tcon; } @@ -2758,7 +2756,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info) tcon->Flags &= ~SMB_SHARE_IS_IN_DFS; cifs_dbg(FYI, "DFS disabled (%d)\n", tcon->Flags); } - tcon->seal = volume_info->seal; tcon->use_persistent = false; /* check if SMB2 or later, CIFS does not support persistent handles */ if (volume_info->persistent) { @@ -2795,6 +2792,24 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info) tcon->use_resilient = true; } + if (volume_info->seal) { + if (ses->server->vals->protocol_id == 0) { + cifs_dbg(VFS, + "SMB3 or later required for encryption\n"); + rc = -EOPNOTSUPP; + goto out_fail; +#ifdef CONFIG_CIFS_SMB2 + } else if (tcon->ses->server->capabilities & + SMB2_GLOBAL_CAP_ENCRYPTION) + tcon->seal = true; + else { + cifs_dbg(VFS, "Encryption is not supported on share\n"); + rc = -EOPNOTSUPP; + goto out_fail; +#endif /* CONFIG_CIFS_SMB2 */ + } + } + /* * We can have only one retry value for a connection to a share so for * resources mounted more than once to the same server share the last @@ -2926,7 +2941,7 @@ cifs_match_super(struct super_block *sb, void *data) if (!match_server(tcp_srv, volume_info) || !match_session(ses, volume_info) || - !match_tcon(tcon, volume_info->UNC) || + !match_tcon(tcon, volume_info) || !match_prepath(sb, mnt_data)) { rc = 0; goto out; -- cgit v1.2.3-55-g7522