1 (in-package :sb-bsd-sockets)
2 #|| <a name="name-service"><h2>Name Service</h2></a>
4 <p>Presently name service is implemented by calling whatever
5 gethostbyname(2) uses. This may be any or all of /etc/hosts, NIS, DNS,
6 or something completely different. Typically it's controlled by
9 <p> Direct links to the asynchronous resolver(3) routines would be nice to have
10 eventually, so that we can do DNS lookups in parallel with other things
14 ((name :initarg :name :accessor host-ent-name)
15 (aliases :initarg :aliases :accessor host-ent-aliases)
16 (address-type :initarg :type :accessor host-ent-address-type)
17 ; presently always AF_INET
18 (addresses :initarg :addresses :accessor host-ent-addresses)))
20 (defgeneric host-ent-address (host-ent))
22 (defmethod host-ent-address ((host-ent host-ent))
23 (car (host-ent-addresses host-ent)))
25 ;(define-condition host-not-found-error (socket-error)) ; host unknown
26 ;(define-condition no-address-error (socket-error)) ; valid name but no IP address
27 ;(define-condition no-recovery-error (socket-error)) ; name server error
28 ;(define-condition try-again-error (socket-error)) ; temporary
30 (defun make-host-ent (h)
31 (if (sb-grovel::foreign-nullp h) (name-service-error "gethostbyname"))
32 (let* ((length (sockint::hostent-length h))
33 (aliases (loop for i = 0 then (1+ i)
34 for al = (sb-alien:deref (sockint::hostent-aliases h) i)
38 (loop for i = 0 then (1+ i)
39 for ad = (sb-alien:deref (sockint::hostent-addresses h) i)
40 until (sb-alien:null-alien ad)
41 collect (ecase (sockint::hostent-type h)
44 (let ((addr (make-array 4 :element-type '(unsigned-byte 8))))
45 (loop for i from 0 below length
46 do (setf (elt addr i) (sb-alien:deref ad i)))
49 (sb-alien:cast ad sb-alien:c-string))))))
50 (make-instance 'host-ent
51 :name (sockint::hostent-name h)
52 :type (sockint::hostent-type h)
54 :addresses addresses)))
56 (defun get-host-by-name (host-name)
57 "Returns a HOST-ENT instance for HOST-NAME or throws some kind of condition.
58 HOST-NAME may also be an IP address in dotted quad notation or some other
59 weird stuff - see gethostbyname(3) for grisly details."
60 (make-host-ent (sockint::gethostbyname host-name)))
62 (defun get-host-by-address (address)
63 "Returns a HOST-ENT instance for ADDRESS, which should be a vector of
64 (integer 0 255), or throws some kind of error. See gethostbyaddr(3) for
66 (sockint::with-in-addr packed-addr ()
67 (let ((addr-vector (coerce address 'vector)))
68 (loop for i from 0 below (length addr-vector)
69 do (setf (sb-alien:deref (sockint::in-addr-addr packed-addr) i)
71 (make-host-ent (sockint::gethostbyaddr packed-addr
75 ;;; The remainder is my fault - gw
77 (defvar *name-service-errno* 0
78 "The value of h_errno, after it's been fetched from Unix-land by calling
79 GET-NAME-SERVICE-ERRNO")
81 (defun name-service-error (where)
82 (get-name-service-errno)
83 ;; Comment next to NETDB_INTERNAL in netdb.h says "See errno.".
84 ;; This special case treatment hasn't actually been tested yet.
85 (if (= *name-service-errno* sockint::NETDB-INTERNAL)
88 (condition-for-name-service-errno *name-service-errno*)))
89 (error condition :errno *name-service-errno* :syscall where))))
91 (define-condition name-service-error (condition)
94 :reader name-service-error-errno)
95 (symbol :initform nil :initarg :symbol :reader name-service-error-symbol)
96 (syscall :initform "an unknown location" :initarg :syscall :reader name-service-error-syscall))
97 (:report (lambda (c s)
98 (let ((num (name-service-error-errno c)))
99 (format s "Name service error in \"~A\": ~A (~A)"
100 (name-service-error-syscall c)
101 (or (name-service-error-symbol c)
102 (name-service-error-errno c))
103 (get-name-service-error-message num))))))
105 (defmacro define-name-service-condition (symbol name)
107 (define-condition ,name (name-service-error)
108 ((symbol :reader name-service-error-symbol :initform (quote ,symbol))))
109 (push (cons ,symbol (quote ,name)) *conditions-for-name-service-errno*)))
111 (defparameter *conditions-for-name-service-errno* nil)
113 (define-name-service-condition sockint::NETDB-INTERNAL netdb-internal-error)
114 (define-name-service-condition sockint::NETDB-SUCCESS netdb-success-error)
115 (define-name-service-condition sockint::HOST-NOT-FOUND host-not-found-error)
116 (define-name-service-condition sockint::TRY-AGAIN try-again-error)
117 (define-name-service-condition sockint::NO-RECOVERY no-recovery-error)
118 ;; this is the same as the next one
119 ;;(define-name-service-condition sockint::NO-DATA no-data-error)
120 (define-name-service-condition sockint::NO-ADDRESS no-address-error)
122 (defun condition-for-name-service-errno (err)
123 (or (cdr (assoc err *conditions-for-name-service-errno* :test #'eql))
128 (defun get-name-service-errno ()
129 (setf *name-service-errno*
130 (sb-alien:alien-funcall
131 (sb-alien:extern-alien "get_h_errno" (function integer)))))
136 (sb-alien:define-alien-routine "hstrerror"
140 (alien:def-alien-routine "hstrerror"
143 (defun get-name-service-error-message (num)