in SMB2+ the get_dfs_refer operation uses a FSCTL. The request can be made on any Tree Connection according to the specs. Since Samba only accepted it on an IPC connection until recently, try that first. https://lists.samba.org/archive/samba-technical/2017-February/118859.html 3.2.4.20.3 Application Requests DFS Referral Information: > The client MUST search for an existing Session and TreeConnect to any > share on the server identified by ServerName for the user identified by > UserCredentials. If no Session and TreeConnect are found, the client > MUST establish a new Session and TreeConnect to IPC$ on the target > server as described in section 3.2.4.2 using the supplied ServerName and > UserCredentials. Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx> --- fs/cifs/smb2ops.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/cifs/smb2pdu.h | 8 +++++ 2 files changed, 108 insertions(+) diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 02937cc..fcd524d 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -1104,6 +1104,102 @@ 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; + __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. + */ + spin_lock(&cifs_tcp_ses_lock); + tcon = list_first_entry_or_null(&ses->tcon_list, struct cifs_tcon, tcon_list); + if (tcon) + tcon->tc_count++; + spin_unlock(&cifs_tcp_ses_lock); + + if (!tcon) { + cifs_dbg(VFS, "session %p has no tcon available for a dfs referral request\n", + ses); + rc = -ENOTCONN; + goto out; + } + + 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 { + /* try first with IPC */ + rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, + FSCTL_DFS_GET_REFERRALS, + true /* is_fsctl */, true /* use_ipc */, + (char *)dfs_req, dfs_req_size, + (char **)&dfs_rsp, &dfs_rsp_size); + if (rc == -ENOTCONN) { + /* try with normal tcon */ + rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID, + FSCTL_DFS_GET_REFERRALS, + true /* is_fsctl */, false /*use_ipc*/, + (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: + if (tcon) { + spin_lock(&cifs_tcp_ses_lock); + tcon->tc_count--; + spin_unlock(&cifs_tcp_ses_lock); + } + 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)) @@ -2263,6 +2359,7 @@ struct smb_version_operations smb20_operations = { .clone_range = smb2_clone_range, .wp_retry_size = smb2_wp_retry_size, .dir_needs_close = smb2_dir_needs_close, + .get_dfs_refer = smb2_get_dfs_refer, }; struct smb_version_operations smb21_operations = { @@ -2344,6 +2441,7 @@ struct smb_version_operations smb21_operations = { .wp_retry_size = smb2_wp_retry_size, .dir_needs_close = smb2_dir_needs_close, .enum_snapshots = smb3_enum_snapshots, + .get_dfs_refer = smb2_get_dfs_refer, }; struct smb_version_operations smb30_operations = { @@ -2435,6 +2533,7 @@ struct smb_version_operations smb30_operations = { .free_transform_rq = smb3_free_transform_rq, .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, + .get_dfs_refer = smb2_get_dfs_refer, }; #ifdef CONFIG_CIFS_SMB311 @@ -2527,6 +2626,7 @@ struct smb_version_operations smb311_operations = { .free_transform_rq = smb3_free_transform_rq, .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, + .get_dfs_refer = smb2_get_dfs_refer, }; #endif /* CIFS_SMB311 */ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
