s3:smbd factor out volume serial number generation

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14765
RN: add new smb.conf parameter "volume serial number" to allow overriding the
generated default value

Signed-off-by: Christian Ambach <ambi@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>

diff --git a/source3/smbd/smb2_trans2.c b/source3/smbd/smb2_trans2.c
index f4cc0b98b9260c0831ecc9b4c06ed68d664f0971..633309f00765b0d77084c1c1fcabe554f33ed51a 100644 (file)
--- a/source3/smbd/smb2_trans2.c
+++ b/source3/smbd/smb2_trans2.c
@@ -59,6 +59,10 @@ static char *store_file_unix_basic_info2(connection_struct *conn,
                                files_struct *fsp,
                                const SMB_STRUCT_STAT *psbuf);
 
+static uint32_t generate_volume_serial_number(
+                               const struct loadparm_substitution *lp_sub,
+                               int snum);
+
 /****************************************************************************
  Check if an open file handle is a symlink.
 ****************************************************************************/
@@ -2121,6 +2125,7 @@ NTSTATUS smbd_do_qfsinfo(struct smbXsrv_connection *xconn,
        SMB_STRUCT_STAT st;
        NTSTATUS status = NT_STATUS_OK;
        uint64_t df_ret;
+       uint32_t serial;
 
        if (fname == NULL || fname->base_name == NULL) {
                filename = ".";
@@ -2219,7 +2224,8 @@ cBytesSector=%u, cUnitTotal=%u, cUnitAvail=%d\n", (unsigned int)st.st_ex_dev, (u
                         * Add volume serial number - hash of a combination of
                         * the called hostname and the service name.
                         */
-                       SIVAL(pdata,0,str_checksum(lp_servicename(talloc_tos(), lp_sub, snum)) ^ (str_checksum(get_local_machine_name())<<16) );
+                       serial = generate_volume_serial_number(lp_sub, snum);
+                       SIVAL(pdata,0,serial);
                        /*
                         * Win2k3 and previous mess this up by sending a name length
                         * one byte short. I believe only older clients (OS/2 Win9x) use
@@ -2236,9 +2242,10 @@ cBytesSector=%u, cUnitTotal=%u, cUnitAvail=%d\n", (unsigned int)st.st_ex_dev, (u
                        }
                        SCVAL(pdata,l2_vol_cch,len);
                        data_len = l2_vol_szVolLabel + len;
-                       DEBUG(5,("smbd_do_qfsinfo : time = %x, namelen = %u, name = %s\n",
+                       DEBUG(5,("smbd_do_qfsinfo : time = %x, namelen = %u, "
+                                "name = %s serial = 0x%04"PRIx32"\n",
                                 (unsigned)convert_timespec_to_time_t(st.st_ex_ctime),
-                                (unsigned)len, vname));
+                                (unsigned)len, vname, serial));
                        break;
 
                case SMB_QUERY_FS_ATTRIBUTE_INFO:
@@ -2302,8 +2309,8 @@ cBytesSector=%u, cUnitTotal=%u, cUnitAvail=%d\n", (unsigned int)st.st_ex_dev, (u
                         * Add volume serial number - hash of a combination of
                         * the called hostname and the service name.
                         */
-                       SIVAL(pdata,8,str_checksum(lp_servicename(talloc_tos(), lp_sub, snum)) ^
-                               (str_checksum(get_local_machine_name())<<16));
+                       serial = generate_volume_serial_number(lp_sub, snum);
+                       SIVAL(pdata,8,serial);
 
                        /* Max label len is 32 characters. */
                        status = srvstr_push(pdata, flags2, pdata+18, vname,
@@ -2315,9 +2322,12 @@ cBytesSector=%u, cUnitTotal=%u, cUnitAvail=%d\n", (unsigned int)st.st_ex_dev, (u
                        SIVAL(pdata,12,len);
                        data_len = 18+len;
 
-                       DEBUG(5,("smbd_do_qfsinfo : SMB_QUERY_FS_VOLUME_INFO namelen = %d, vol=%s serv=%s\n",
-                               (int)strlen(vname),vname,
-                               lp_servicename(talloc_tos(), lp_sub, snum)));
+                       DEBUG(5,("smbd_do_qfsinfo : SMB_QUERY_FS_VOLUME_INFO "
+                                "namelen = %d, vol=%s serv=%s "
+                                "serial=0x%04"PRIx32"\n",
+                                (int)strlen(vname),vname,
+                                lp_servicename(talloc_tos(), lp_sub, snum),
+                                serial));
                        if (max_data_bytes >= 24 && data_len > max_data_bytes) {
                                /* the client only requested a portion of the
                                   volume label */
@@ -6957,3 +6967,11 @@ NTSTATUS smbd_do_setfilepathinfo(connection_struct *conn,
        *ret_data_size = data_return_size;
        return NT_STATUS_OK;
 }
+
+static uint32_t generate_volume_serial_number(
+                       const struct loadparm_substitution *lp_sub,
+                       int snum)
+{
+       return str_checksum(lp_servicename(talloc_tos(), lp_sub, snum)) ^
+               (str_checksum(get_local_machine_name())<<16);
+}