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;; -*- mode: common-lisp; package: net.aserve -*-
;;
;; parse.cl
;;
;;
;; copyright (c) 1986-2005 Franz Inc, Berkeley, CA - All rights reserved.
;; copyright (c) 2000-2007 Franz Inc, Oakland, CA - All rights reserved.
;;
;; This code is free software; you can redistribute it and/or
;; modify it under the terms of the version 2.1 of
;; the GNU Lesser General Public License as published by
;; the Free Software Foundation, as clarified by the AllegroServe
;; prequel found in license-allegroserve.txt.
;;
;; This code is distributed in the hope that it will be useful,
;; but without any warranty; without even the implied warranty of
;; merchantability or fitness for a particular purpose. See the GNU
;; Lesser General Public License for more details.
;;
;; Version 2.1 of the GNU Lesser General Public License is in the file
;; license-lgpl.txt that was distributed with this file.
;; If it is not present, you can access it from
;; http://www.gnu.org/copyleft/lesser.txt (until superseded by a newer
;; version) or write to the Free Software Foundation, Inc., 59 Temple Place,
;; Suite 330, Boston, MA 02111-1307 USA
;;

;;
;; $Id: parse.cl,v 1.42 2007/04/17 22:05:04 layer Exp $

;; Description:
;; parsing and encoding code

;;- This code in this file obeys the Lisp Coding Standard found in
;;- http://www.franz.com/~jkf/coding_standards.html
;;-


(in-package :net.aserve)

(check-smp-consistency)

;; parseobj -- used for cons-free parsing of strings
(defconstant parseobj-size 20)

(defstruct parseobj
  (start (make-array parseobj-size)) ; first charpos
  (end (make-array parseobj-size)) ; charpos after last
  (next 0) ; next index to use
  (max parseobj-size)
  )

(defvar-mp *parseobjs* nil) ;; never bound; this is a global variable

(defun allocate-parseobj ()
  (smp-case
   ((t :macros)
    (let ((res (pop-atomic *parseobjs*)))
(if* res
then (setf (parseobj-next res) 0)
res
else (make-parseobj))))
   (nil
    (let (res)
      (mp::without-scheduling ;; in a #-smp form
(if* (setq res (pop *parseobjs*))
then (setf (parseobj-next res) 0)
res
else (make-parseobj)))))))

(defun free-parseobj (po)
  (smp-case
   ((t :macros)
    (push-atomic po (si:global-symbol-value '*parseobjs*)))
   (nil
    (mp::without-scheduling ;; in a #-smp form
      (push po *parseobjs*)))))

(defun add-to-parseobj (po start end)
  ;; add the given start,end pair to the parseobj
  (let ((next (parseobj-next po)))
    (if* (>= next (parseobj-max po))
       then ; must grow it
(let ((ostart (parseobj-start po))
(oend (parseobj-end po)))
(let ((nstart (make-array (+ 10 (length ostart))))
(nend (make-array (+ 10 (length ostart)))))
(dotimes (i (length ostart))
(setf (svref nstart i) (svref ostart i))
(setf (svref nend i) (svref oend i)))
(setf (parseobj-start po) nstart)
(setf (parseobj-end po) nend)
(setf (parseobj-max po) (length nstart))
)))
  
    (setf (svref (parseobj-start po) next) start)
    (setf (svref (parseobj-end po) next) end)
    (setf (parseobj-next po) (1+ next))
    next))

;;;;;;


















(defun parse-http-command (buffer end)
  ;; buffer is a string buffer, with 'end' bytes in it.
  ;; return 3 values
  ;; command (kwd naming it or nil if bogus)
  ;; url uri object
  ;; protocol (kwd naming it or nil if bogus)
  ;;
  (let ((blankpos)
(cmd)
(urlstart))

    ; search for command first
    (dolist (possible *http-command-list*
(return-from parse-http-command nil) ; failure
)
      (let ((str (car possible)))
(if* (buffer-match buffer 0 str)
then ; got it
(setq cmd (cdr possible))
(setq urlstart (length (car possible)))
(return))))
    
    
    (setq blankpos (find-it #\space buffer urlstart end))
    
    (if* (eq blankpos urlstart)
       then ; bogus, no url
(return-from parse-http-command nil))
    
    
    (if* (null blankpos)
       then ; must be http/0.9
(return-from parse-http-command (values cmd
(parse-uri
(buffer-substr buffer
urlstart
end))
:http/0.9)))
    
    (let ((url (buffer-substr buffer urlstart blankpos))
(prot))
      
      ; parse url and if that fails get out right away
      (if* (null (setq url (parse-uri url)))
then (return-from parse-http-command nil))
      
      (if* (buffer-match buffer (1+ blankpos) "HTTP/1.")
then (if* (eq #\0 (schar buffer (+ 8 blankpos)))
then (setq prot :http/1.0)
elseif (eq #\1 (schar buffer (+ 8 blankpos)))
then (setq prot :http/1.1)))
      
      (values cmd url prot))))






(defun new-read-request-headers (req sock)
  ;; use the new strategy to read in the request headers
  ;;
  ;; return nil if we don't get all the way to the crlf crlf
  (let ((buff (get-sresource *header-block-sresource*))
(end))

    (setf (request-header-block req) buff)
    ;; read in all the headers, stop at the last crlf
    (if* (setq end (read-headers-into-buffer sock buff))
       then (let ((otherheaders (parse-header-block buff 0 end)))

(if* otherheaders
then ; non standard headers present...store
; separately
(dolist (otherheader otherheaders)
(setf (car otherheader)
(header-keywordify (car otherheader))))

(setf (request-headers req)
(append (request-headers req) otherheaders))))

t)))

(defvar *headername-to-kwd* nil)

(defun header-keywordify (name)
  ;; convert name to keyword.. check cache first

  ;; mm 2010-12: This code is not SMP-safe but little is lost thereby.
  ;; The way this is coded, some kw conversions might get lost and
  ;; thus need to be repeated, if a push gets overwritten.
  ;; There may be duplicates in the alist if two threads try to add
  ;; the same kw at the same time.
  ;; But adding a lock seems like overkill.
  ;; Even the cache may be of dubious value (intern may be faster than assoc).

  (or (cdr (assoc name *headername-to-kwd* :test #'equal))
      (let ((kwd (intern (if* (eq *current-case-mode* :case-insensitive-upper)
then (string-upcase name)
else name)
(find-package :keyword))))
(push (cons name kwd) *headername-to-kwd*)

kwd)))
 





(defun read-headers-into-buffer (sock buff)
  ;; read the header data into the buffer
  ;; return the index of the character following the last header
  ;; or nil if the whole header wasn't read in
  ;;
  (let ((len (- (length buff) 500)) ; leave space for index at end
(i 0)
(state 2)
(echo (member :xmit *debug-current*)))

    (loop
      (if* (>= i len)
then (return nil)) ; failure
      
      (let ((ch (read-byte sock nil nil)))
(if* (null ch)
then (return nil) ; eof - failure
)

; enable this if things are really messed
; up and you need to see characters as they come in
#+ignore
(if* echo
then (write-char (code-char ch) *debug-stream*)
(force-output *debug-stream*))


(setf (aref buff i) ch)
(incf i)
(case state
(0 ; seen nothing interesting
(if* (eq ch #.(char-code #\linefeed))
then (setq state 2)
elseif (eq ch #.(char-code #\return))
then (setq state 1)))
(1 ; seen cr
(if* (eq ch #.(char-code #\linefeed))
then (setq state 2)
elseif (eq ch #.(char-code #\return))
then nil ; stay in 1
else (setq state 0)))
(2 ; seen [cr] lf
(if* (eq ch #.(char-code #\linefeed))
then (setq state 4)
elseif (eq ch #.(char-code #\return))
then (setq state 3)
else (setq state 0)))
(3 ; seen [cr] lf cr
(if* (eq ch #.(char-code #\linefeed))
then (setq state 4)
elseif (eq ch #.(char-code #\return))
then (setq state 1)
else (setq state 0))))

(if* (eql state 4)
then ; all done
; back up over [cr] lf
(if* (>= i 2)
then (decf i 2) ; i points at cr if there is one
(if* (not (eq (aref buff i) #.(char-code #\return)))
then (incf i)))
; i points to the [cr] lf
(if* echo
then (write-sequence buff *debug-stream*
:start 0
:end i))
(return i))))))



    







   
    
    
;------- header value parsing
;
; most headers value this format
; value
; value1, value2, value3
; value; param=val; param2=val
;
; notes: in the comma separated lists, it's legal to use more than one
; comma between values in which case the intermediate "null" values
; are ignored e.g a,,b is the same as a,b
;
; the semicolon introduces a parameter, it doesn't end a value.
; the semicolon has a higher binding power than the comma,
; so A; b=c; d=e, F
; is two values, A and F, with A having parameters b=c and d=e.
;
; A header value that doesn't follow the above rules in
; the one for set-cookie
; set-cookie: val=yes; expires=Fri, 01-Jan-2010 08:00:00 GMT; path=/
; note how it starts off with param=val, and then the value
; can have commas in it, thus we don't use comm as a separator

(defconstant ch-alpha 0)
(defconstant ch-space 1)
(defconstant ch-sep 2) ; separators

(defvar *syntax-table*
    (let ((arr (make-array 256 :initial-element ch-alpha)))
      
      ; the default so we don't have to set it
      #+ignore (do ((code (char-code #\!) (1+ code)))
((> code #.(char-code #\~)))
(setf (svref arr code) ch-alpha))
      
      (setf (svref arr (char-code #\space)) ch-space)
      (setf (svref arr (char-code #\ff)) ch-space)
      (setf (svref arr (char-code #\tab)) ch-space)
      (setf (svref arr (char-code #\return)) ch-space)
      (setf (svref arr (char-code #\linefeed)) ch-space)
      
      (setf (svref arr (char-code #\,)) ch-sep)
      (setf (svref arr (char-code #\;)) ch-sep)
      (setf (svref arr (char-code #\()) ch-sep)
      
      arr))



(defun header-value-nth (parsed-value n)
  ;; return the nth value in the list of header values
  ;; a value is either a string or a list (:param value params..)
  ;;
  ;; nil is returned if we've asked for a non-existant element
  ;; (nil is never a valid value).
  ;;
  (if* (and parsed-value (not (consp parsed-value)))
     then (error "bad parsed value ~s" parsed-value))
  
  (let ((val (nth n parsed-value)))
    (if* (atom val)
       then val
       else ; (:param value ...)
(cadr val))))
  

(defun header-value-member (val parsed-value)
  ;; test to see if the given value is a member of the list
  ;; of values in the parsed value. parse the value if needed
  (if* parsed-value
     then (setq parsed-value (ensure-value-parsed parsed-value))
(dolist (par parsed-value)
(if* (consp par)
then (setq par (cadr par)))
(if* (equalp val par)
then (return t)))))

(defun ensure-value-parsed (str &optional singlep)
  ;; parse the header value if it hasn't been parsed.
  ;; a parsed value is a cons.. easy to distinguish
  (if* (consp str)
     then str
     else (parse-header-value str singlep)))




(defun parse-header-value (str &optional singlep (start 0) (end (length str)))
  ;; scan the given string and return either a single value
  ;; or a list of values.
  ;; A single value is a string or (:param value paramval ....) for
  ;; values with parameters. A paramval is either a string or
  ;; a cons of two strings (name . value) which are the parameter
  ;; and its value.
  ;;
  ;; if singlep is true then we expect to see a single value which
  ;; main contain commas. This is seen when Netscape sends
  ;; an if-modified-since header and it may in fact be a bug in
  ;; Netscape (since parameters aren't defined for if-modified-since's value)
  ;;

  ;; split by comma first
  (let (po res)
    
    (if* singlep
       then ; don't do the comma split, make everything
; one string
(setq po (allocate-parseobj))
(setf (svref (parseobj-start po) 0) start)
(setf (svref (parseobj-end po) 0) end)
(setf (parseobj-next po) 1)
       else (setq po (split-string str #\, t nil nil start end)))
    

    
    ; now for each split, by semicolon
    
    (dotimes (i (parseobj-next po))
      (let ((stindex (parseobj-next po))
(params)
(thisvalue))
(split-string str #\; t nil po
(svref (parseobj-start po) i)
(svref (parseobj-end po) i))
; the first object we take whole
(setq thisvalue (trimmed-parseobj str po stindex))
(if* (not (equal thisvalue ""))
then ; ok, it's real, look for params
(do ((i (1+ stindex) (1+ i))
(max (parseobj-next po))
(paramkey nil nil)
(paramvalue nil nil))
((>= i max)
(setq params (nreverse params))
)

; split the param by =
(split-string str #\= t 1 po
(svref (parseobj-start po) i)
(svref (parseobj-end po) i))
(setq paramkey (trimmed-parseobj str po max))
(if* (> (parseobj-next po) (1+ max))
then ; must have been an equal
(setq paramvalue (trimmed-parseobj str po
(1+ max))))
(push (if* paramvalue
then (cons paramkey paramvalue)
else paramkey)
params)

(setf (parseobj-next po) max))

(push (if* params
then `(:param ,thisvalue
,@params)
else thisvalue)
res))))
    
    (free-parseobj po)
    
    (nreverse res)))
    



(defun parse-header-line-equals (str &optional (start 0) (end (length str)))
  ;; parse a header line consisting of comma separated values
  ;;
  ;; a=b, c="d asd", e="fff"
  ;;
  ;; return (("a" . "b") ("c" . "d asd") ("e" . "fff"))
  ;;
  (let ((po (allocate-parseobj))
(res))
    
    (unwind-protect
(progn
(split-string str #\, nil nil po start end)

(do ((i 0 (1+ i))
(max (parseobj-next po))
(paramkey nil nil)
(paramvalue nil nil))

((>= i max))

(split-string str #\= nil 1 po
(svref (parseobj-start po) i)
(svref (parseobj-end po) i))

(setq paramkey (trimmed-parseobj str po max))

(if* (> (parseobj-next po) (1+ max))
then ; must have been an equal
(setq paramvalue (trimmed-parseobj str po
(1+ max))))

(push (cons paramkey paramvalue) res)

(setf (parseobj-next po) max)))
      
      (free-parseobj po))
      
    (nreverse res)))

(defun assoc-paramval (key paramvals)
  ;; search the paramvals for the given key.
  ;; this takes into account that paramvals isn't an assoc
  ;; list since the items my be strings or (string . string)
  ;; Also we use equalp as the test
  ;;
  (dolist (val paramvals)
    (if* (stringp val)
       then (if* (equalp key val)
then (return val))
     elseif (equalp (car val) key)
       then (return val))))

  


(defun trimmed-parseobj (str po index)
  ;; return the string pointed to by the given index in
  ;; the parseobj -- trimming blanks around both sides
  ;;
  ;; if surrounded by double quotes, trim them off too
  
  (let ((start (svref (parseobj-start po) index))
(end (svref (parseobj-end po) index)))
    
    ;; trim left
    (loop
      (if* (>= start end)
then (return-from trimmed-parseobj "")
else (let ((ch (schar str start)))
(if* (eq ch-space (svref *syntax-table*
(char-code ch)))
then (incf start)
else (return)))))
    
    ; trim right
    (loop
      (decf end)
      (let ((ch (schar str end)))
(if* (not (eq ch-space (svref *syntax-table* (char-code ch))))
then (incf end)
(return))))
    
    ; trim matching double quotes
    (if* (and (> end (1+ start))
(eq #\" (schar str start))
(eq #\" (schar str (1- end))))
       then (incf start)
(decf end))
    
    ; make string
    (let ((newstr (make-string (- end start))))
      (dotimes (i (- end start))
(setf (schar newstr i)
(schar str (+ start i))))
      
      newstr)))
    
    




    

(defun split-string (str split &optional
magic-parens
count
parseobj
(start 0)
(end (length str)))
  ;; divide the string where the character split occurs
  ;; return the results in parseobj object
  (let ((po (or parseobj (allocate-parseobj)))
(st start)
)
    ; states
    ; 0 initial, scanning for interesting char or end
    (loop
      (if* (>= start end)
then (add-to-parseobj po st start)
(return)
else (let ((ch (schar str start)))

(if* (eq ch split)
then ; end this one
(add-to-parseobj po st start)
(setq st (incf start))
(if* (and count (zerop (decf count)))
then ; get out now
(add-to-parseobj po st end)
(return))
elseif (and magic-parens (eq ch #\())
then ; scan until matching paren
(let ((count 1))
(loop
(incf start)
(if* (>= start end)
then (return)
else (setq ch (schar str start))
(if* (eq ch #\))
then (if* (zerop (decf count))
then (return))
elseif (eq ch #\()
then (incf count)))))

(if* (>= start end)
then (add-to-parseobj po st start)
(return))
elseif (eq ch #\")
then ; double quoted value.. skip over this
(loop
(incf start)
(if* (>= start end)
then (return)
else (setq ch (schar str start))
(if* (eq ch #\")
then (return)
elseif (eq ch #\\)
then ; single char quote
(incf start)
(if* (>= start end)
then (return)))))
(if* (>= start end)
then (add-to-parseobj po st start)
(return)
else (incf start))
else (incf start)))))
    po))


(defun split-on-character (str char &key count)
  ;; given a string return a list of the strings between occurances
  ;; of the given character.
  ;; If the character isn't present then the list will contain just
  ;; the given string.
  (let ((loc (position char str))
(start 0)
(res))
    (if* (null loc)
       then ; doesn't appear anywhere, just the original string
(list str)
       else ; must do some work
(loop
(push (subseq str start loc) res)
(setq start (1+ loc))
(if* count then (decf count))
(setq loc (position char str :start start))
(if* (or (null loc)
(eql 0 count))
then (if* (< start (length str))
then (push (subseq str start) res)
else (push "" res))
(return (nreverse res)))))))

    


(defun split-into-words (str)
  ;; split the given string into words (items separated by white space)
  ;;
  (let ((state 0)
(i 0)
(len (length str))
(start nil)
(res)
(ch)
(spacep))
    (loop
      (if* (>= i len)
then (setq ch #\space)
else (setq ch (char str i)))
      (setq spacep (eq ch-space (svref *syntax-table* (char-code ch))))
      
      (case state
(0 ; looking for non-space
(if* (not spacep)
then (setq start i
state 1)))
(1 ; have left anchor, looking for space
(if* spacep
then (push (subseq str start i) res)
(setq state 0))))
      (if* (>= i len) then (return))
      (incf i))
    (nreverse res)))


(defun parse-range-value (str)
  ;; parse the value passed to a Range header
  ;; return (n . m) n and m integers meaning bytes from n to m inclusive
  ;; (nil . m) meaning the last m bytes
  ;; (n . nil) meaning bytes from n to the end
  ;;
  (let ((top (split-on-character str #\=))
(res))
    (and (equalp (car top) "bytes")
(stringp (cadr top))
(dolist (range (split-on-character (cadr top) #\,))
(let ((startend (split-on-character range #\-))
(first)
(second))
(if* (not (equal "" (car startend)))
then (setq first (string-to-number (car startend))))
(if* (not (equal "" (cadr startend)))
then (setq second (string-to-number (cadr startend))))
(push (cons first second) res))))
    (nreverse res)))




;; this isn't needed while the web server is running, it just
;; needs to be run periodically as new mime types are introduced.
#+ignore-until-mime-table-changed
(defun generate-mime-table (&optional (file "/etc/mime.types"))
  ;; generate a file type to mime type table based on file type
  (let (res)
    (with-open-file (p file :direction :input)
      (loop
(let ((line (read-line p nil nil)))
(if* (null line) then (return))
(if* (and (> (length line) 0)
(eq #\# (schar line 0)))
thenret ; comment
else ; real stuff
(let ((data (split-into-words line)))
(if* data then (push data res)))))))
    (nreverse res)))
  
  
(defun match-head-p (val1 val2)
  ;; return t if val1 is a prefix of val2
  ;; val1 and val2 are simple strings
  (let ((len1 (length val1))
(len2 (length val2)))
    (if* (<= len1 len2)
       then (dotimes (i len1 t)
(if* (not (eq (schar val1 i) (schar val2 i)))
then (return nil))))))

(defun match-tail-p (val1 val2)
  ;; return t if val1 is a suffix of val2
  ;; val1 and val2 are simple strings
  (let ((len1 (length val1))
(len2 (length val2)))
    (if* (<= len1 len2)
       then (let ((diff (- len2 len1)))
(dotimes (i len1 t)
(if* (not (eq (schar val1 i) (schar val2 (+ diff i))))
then (return nil)))))))

  
;----
(defun split-namestring (file)
  ;; split the namestring into root and tail and then the tail
  ;; into name and type
  ;;
  ;; any of the return value can be nil if the corresponding item
  ;; isn't present.
  ;;
  ;; rules for splitting the tail into name and type components:
  ;; if the last period in the tail is at the beginning or end of the
  ;; tail, then the name is exactly the tail and type is nil.
  ;; Thus .foo and bar. are just names, no type
  ;; but .foo.c has a name of ".foo" and a type of "c"
  ;; Thus if there is a non-nil type then it means that
  ;; 1. there will be a non nil name as well
  ;; 2. to reconstruct the filename you need to add a period between
  ;; the name and type.
  ;;
  (let ((pos (min (or (or (position #\/ file :from-end t) most-positive-fixnum)
#+mswindows (position #\\ file :from-end t))))
root
tail)
    
    (if* (equal file "") then (return-from split-namestring nil))
    
    (if* (and pos (< pos most-positive-fixnum))
       then ; we have root and tail
(if* (eql pos (1- (length file)))
then ; just have root
(return-from split-namestring
(values file nil nil nil)))

    
(setq root (subseq file 0 (1+ pos))
tail (subseq file (1+ pos)))
       else (setq tail file))
    
    
    ; split the tail
    (let ((pos (position #\. tail :from-end t)))
      (if* (or (null pos)
(zerop pos)
(equal pos (1- (length tail))))
then ; name begins or ends with . so it's not
; a type separator
(values root tail tail nil)
else ; have all pieces
(values root tail
(subseq tail 0 pos)
(subseq tail (1+ pos)))))))
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