Coverage for libs/sm/core/libiscsi.py: 0%

1# Compatibility layer providing sm-core-libs methods in terms of sm-libs 

2# as much as possible 

3import re 

4 

5from sm.core import iscsi 

6from sm.core import util 

7from sm.core import f_exceptions 

8 

9# Import specific functions to satisfy callers using this name 

10from sm.core.iscsi import parse_IP_port, discovery, get_iscsi_interfaces 

11 

12# COMPATIBILITY FUNCTIONS BELOW 

13# ============================= 

14# Instead of importing these functions, provide methods which match the 

15# sm-core-libs interface (which is different, but with the same function names) 

16 

17def login(portal, target, username, password, uuid, rescan=False): 

18 """This is a slightly revised version of iscsi.login 

19 

20 We are trying to stick as close as possible to the original one but fixing 

21 or improving whatever can be improved, in order to later fix it to the 

22 original one and start using that one both for the transport code and 

23 the old SM code. 

24 

25 For example, 'uuid' is a new addition in order to be able to automatically 

26 refcount in here, instead of relying on the caller to do that. 

27 """ 

28 

29 if username != "" and password != "": 

30 iscsi.set_chap_settings(portal, target, username, password, "", "") 

31 

32 

33 refcount = 0 

34 legacy_refcount = 0 

35 

36 portal_target_ref = iscsi.get_portal_target_ref(portal, target) 

37 

38 # Increment portal/target ref count 

39 refcount = util._incr_iscsiSR_refcount(portal_target_ref, uuid) 

40 

41 if refcount == 1: 

42 cmd = ["iscsiadm", "-m", "node", "-p", portal, "-T", target, "-l"] 

43 try: 

44 failuremessage = "Failed to login to target." 

45 (stdout, stderr) = iscsi.exn_on_failure(cmd, failuremessage) 

46 # Increment legacy refcounter 

47 if uuid: 

48 legacy_refcount = util._incr_iscsiSR_refcount(target, uuid) 

49 except Exception as exc: 

50 util.SMlog("Failed: {}".format(" ".join(cmd)), 

51 ident="Transport") 

52 # Rollback refcount if needed 

53 if uuid: 

54 # This should be in its own try/block and be chained 

55 # with main exception below 

56 util._decr_iscsiSR_refcount(portal_target_ref, uuid) 

57 raise f_exceptions.XenError('ISCSILogin', reason=str(exc)) 

58 

59 # Rescan if requested and more than one refcount of either form 

60 if rescan and (refcount > 1 or legacy_refcount > 1): 

61 util.SMlog("Session already logged in for {}, rescan requested". 

62 format(target)) 

63 iscsi.rescan_target(portal, target) 

64 

65def logout(portal, target, uuid): 

66 """Modified version of iscsi.py:logout to handle refcounting 

67 

68 Given the nature of this refcounting, it is not possible to specifically 

69 logout from one ip/iqn pair without breaking the refcounting. 

70 For this reason, this version does not accept a specific ip and the 

71 parameter 'all'. 

72 """ 

73 util.SMlog("decrease logout refcount of {} ({})". 

74 format(target, uuid), 

75 ident="Transport") 

76 

77 portal_target_ref = iscsi.get_portal_target_ref(portal, target) 

78 

79 if util._decr_iscsiSR_refcount(portal_target_ref, uuid): 

80 # still logged in 

81 return 

82 

83 # Decrement the legacy refcount 

84 if not util._decr_iscsiSR_refcount(target, uuid): 

85 try: 

86 cmd = ["iscsiadm", "-m", "node", "-T", target, "-u"] 

87 failuremessage = "Failed to log out of target" 

88 util.SMlog("logging out {} for {}". 

89 format(target, uuid), 

90 ident="Transport") 

91 (_, _) = iscsi.exn_on_failure(cmd, failuremessage) 

92 except Exception as exc: 

93 raise f_exceptions.XenError('ISCSILogout', reason=str(exc))