2017-02-23 6:43 GMT-08:00 Aurelien Aptel <aaptel@xxxxxxxx>:
> Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx>
> ---
> fs/cifs/smb2ops.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/cifs/smb2pdu.h | 8 +++++++
> 2 files changed, 80 insertions(+)
>
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index a44b4db..2563fe8 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -1097,6 +1097,78 @@ smb2_new_lease_key(struct cifs_fid *fid)
> generate_random_uuid(fid->lease_key);
> }
>
> +static int
> +smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
> + const char *search_name,
> + struct dfs_info3_param **target_nodes,
> + unsigned int *num_of_nodes,
> + const struct nls_table *nls_codepage, int remap)
> +{
> + int rc = -EINVAL;
> + __le16 *utf16_path = NULL;
> + int utf16_path_len = 0;
> + struct cifs_tcon *tcon;
> + struct fsctl_get_dfs_referral_req *dfs_req = NULL;
> + struct get_dfs_referral_rsp *dfs_rsp = NULL;
> + u32 dfs_req_size = 0, dfs_rsp_size = 0;
> +
> + cifs_dbg(FYI, "smb2_get_dfs_refer path <%s>\n", search_name);
> +
> + /*
> + * Use any tcon from the current session. Here, the first one.
> + */
> + tcon = list_first_entry(&ses->tcon_list, struct cifs_tcon, tcon_list);
> + if (!tcon)
> + goto out;
Accessing the tcon_list should be protected by spin_locks and also a
reference to the tcon should be acquired before using it safely.
Also you can extend SMB2_ioctl argument list to allow passing ipc_tid.
In this case SMB2_ioctl() can choose what to use - ipc_tid or tcon; if
tcon is passed -use it, otherwise - use ipc_tid.
In this case you can fallback to ipc_tid if no tcon is found in the list.
> +
> + utf16_path = cifs_strndup_to_utf16(search_name, PATH_MAX,
> + &utf16_path_len,
> + nls_codepage, remap);
> + if (!utf16_path) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + dfs_req_size = sizeof(*dfs_req) + utf16_path_len;
> + dfs_req = kzalloc(dfs_req_size, GFP_KERNEL);
> + if (!dfs_req) {
> + rc = -ENOMEM;
> + goto out;
> + }
> +
> + /* Highest DFS referral version understood */
> + dfs_req->MaxReferralLevel = cpu_to_le16(DFS_VERSION);
> +
> + /* Path to resolve in an UTF-16 null-terminated string */
> + memcpy(dfs_req->RequestFileName, utf16_path, utf16_path_len);
> +
> + do {
> + rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
> + FSCTL_DFS_GET_REFERRALS, true /* is_fsctl */,
> + (char *)dfs_req, dfs_req_size,
> + (char **)&dfs_rsp, &dfs_rsp_size);
> + } while (rc == -EAGAIN);
> +
> + if (rc) {
> + cifs_dbg(VFS, "ioctl error in smb2_get_dfs_refer rc=%d\n", rc);
> + goto out;
> + }
> +
> + rc = parse_dfs_referrals(dfs_rsp, dfs_rsp_size,
> + num_of_nodes, target_nodes,
> + nls_codepage, remap, search_name,
> + true /* is_unicode */);
> + if (rc) {
> + cifs_dbg(VFS, "parse error in smb2_get_dfs_refer rc=%d\n", rc);
> + goto out;
> + }
> +
> + out:
> + kfree(utf16_path);
> + kfree(dfs_req);
> + kfree(dfs_rsp);
> + return rc;
> +}
> #define SMB2_SYMLINK_STRUCT_SIZE \
> (sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp))
>
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index c03b252..18700fd 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -695,6 +695,14 @@ struct fsctl_get_integrity_information_rsp {
> /* Integrity flags for above */
> #define FSCTL_INTEGRITY_FLAG_CHECKSUM_ENFORCEMENT_OFF 0x00000001
>
> +/* See MS-DFSC 2.2.2 */
> +struct fsctl_get_dfs_referral_req {
> + __le16 MaxReferralLevel;
> + __u8 RequestFileName[];
> +} __packed;
> +
> +/* DFS response is struct get_dfs_refer_rsp */
> +
> /* See MS-SMB2 2.2.31.3 */
> struct network_resiliency_req {
> __le32 Timeout;
> --
> 2.10.2
>
> --
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--
Best regards,
Pavel Shilovsky
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