From 7e682f766f289887c5cbf7c0a1e4970103f01ac4 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 31 Aug 2017 21:34:24 -0500 Subject: Fix warning messages when mounting to older servers When mounting to older servers, such as Windows XP (or even Windows 7), the limited error messages that can be passed back to user space can get confusing since the default dialect has changed from SMB1 (CIFS) to more secure SMB3 dialect. Log additional information when the user chooses to use the default dialects and when the server does not support the dialect requested. Signed-off-by: Steve French Reviewed-by: Ronnie Sahlberg Acked-by: Pavel Shilovsky --- fs/cifs/connect.c | 22 +++++++++++++++++++++- fs/cifs/smb2pdu.c | 7 ++++++- 2 files changed, 27 insertions(+), 2 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 59647eb72c5f..83a8f52cd879 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1223,6 +1223,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, char *tmp_end, *value; char delim; bool got_ip = false; + bool got_version = false; unsigned short port = 0; struct sockaddr *dstaddr = (struct sockaddr *)&vol->dstaddr; @@ -1874,24 +1875,35 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, pr_warn("CIFS: server netbiosname longer than 15 truncated.\n"); break; case Opt_ver: + /* version of mount userspace tools, not dialect */ string = match_strdup(args); if (string == NULL) goto out_nomem; + /* If interface changes in mount.cifs bump to new ver */ if (strncasecmp(string, "1", 1) == 0) { + if (strlen(string) > 1) { + pr_warn("Bad mount helper ver=%s. Did " + "you want SMB1 (CIFS) dialect " + "and mean to type vers=1.0 " + "instead?\n", string); + goto cifs_parse_mount_err; + } /* This is the default */ break; } /* For all other value, error */ - pr_warn("CIFS: Invalid version specified\n"); + pr_warn("CIFS: Invalid mount helper version specified\n"); goto cifs_parse_mount_err; case Opt_vers: + /* protocol version (dialect) */ string = match_strdup(args); if (string == NULL) goto out_nomem; if (cifs_parse_smb_version(string, vol) != 0) goto cifs_parse_mount_err; + got_version = true; break; case Opt_sec: string = match_strdup(args); @@ -1973,6 +1985,14 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, else if (override_gid == 1) pr_notice("CIFS: ignoring forcegid mount option specified with no gid= option.\n"); + if (got_version == false) + pr_warn("No dialect specified on mount. Default has changed to " + "a more secure dialect, SMB3 (vers=3.0), from CIFS " + "(SMB1). To use the less secure SMB1 dialect to access " + "old servers which do not support SMB3 specify vers=1.0" + " on mount. For somewhat newer servers such as Windows " + "7 try vers=2.1.\n"); + kfree(mountdata_copy); return 0; diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 97edb4d376cd..7aa67206f6da 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -514,7 +514,12 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) * No tcon so can't do * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]); */ - if (rc != 0) + if (rc == -EOPNOTSUPP) { + cifs_dbg(VFS, "Dialect not supported by server. Consider " + "specifying vers=1.0 or vers=2.1 on mount for accessing" + " older servers\n"); + goto neg_exit; + } else if (rc != 0) goto neg_exit; cifs_dbg(FYI, "mode 0x%x\n", rsp->SecurityMode); -- cgit