/
srv.arc
705 lines (572 loc) · 20.6 KB
/
srv.arc
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; HTTP Server.
; To improve performance with static files, set static-max-age*.
(= arcdir* "arc/" logdir* "arc/logs/" staticdir* "static/")
(= quitsrv* nil breaksrv* nil)
(def serve ((o port 8080))
(wipe quitsrv*)
(ensure-srvdirs)
(map [apply new-bgthread _] pending-bgthreads*)
(w/socket s port
(setuid 2) ; XXX switch from root to pg
(prn "ready to serve port " port)
(flushout)
(= currsock* s)
(until quitsrv*
(handle-request s breaksrv*)))
(prn "quit server"))
(def serve1 ((o port 8080))
(w/socket s port (handle-request s t)))
(def ensure-srvdirs ()
(map ensure-dir (list arcdir* logdir* staticdir*)))
(= srv-noisy* nil)
; http requests currently capped at 2 meg by socket-accept
; should threads process requests one at a time? no, then
; a browser that's slow consuming the data could hang the
; whole server.
; wait for a connection from a browser and start a thread
; to handle it. also arrange to kill that thread if it
; has not completed in threadlife* seconds.
(= threadlife* 30 requests* 0 requests/ip* (table)
throttle-ips* (table) ignore-ips* (table) spurned* (table))
(def handle-request (s breaksrv)
(if breaksrv
(handle-request-1 s)
(errsafe (handle-request-1 s))))
(def handle-request-1 (s)
(with ((in out ip) (socket-accept s)
th1 nil th2 nil)
(++ requests*)
(let ip-wrapper (fn args
(if args
(= ip car.args)
ip))
(= th1 (thread
(after (handle-request-thread in out ip-wrapper)
(close in out)
(kill-thread th2))))
(= th2 (thread
(sleep threadlife*)
(unless (dead th1)
(prn "srv thread took too long for " ip))
(kill-thread th1)
(force-close in out))))))
; Returns true if ip has made req-limit* requests in less than
; req-window* seconds. If an ip is throttled, only 1 request is
; allowed per req-window* seconds. If an ip makes req-limit*
; requests in less than dos-window* seconds, it is a treated as a DoS
; attack and put in ignore-ips* (for this server invocation).
; To adjust this while running, adjust the req-window* time, not
; req-limit*, because algorithm doesn't enforce decreases in the latter.
(= req-times* (table) req-limit* 30 req-window* 10 dos-window* 2)
(wipe show-abuse*)
(def abusive-ip (ip)
(++ (requests/ip* ip 0))
(if show-abuse*
(if (ignore-ips* ip)
(prn ip " ignored")
(prn ip " " (if (abusive-ip-core ip) "" "not ") "abusive (" requests/ip*.ip ")")))
(and (or (ignore-ips* ip) (abusive-ip-core ip))
(++ (spurned* ip 0))))
(def abusive-ip-core (ip)
(and (only.> (requests/ip* ip) 250)
(let now (seconds)
(do1 (if (req-times* ip)
(and (>= (qlen (req-times* ip))
(if (throttle-ips* ip) 1 req-limit*))
(let dt (- now (deq (req-times* ip)))
(if (< dt dos-window*) (set (ignore-ips* ip)))
(< dt req-window*)))
(do (= (req-times* ip) (queue))
nil))
(enq now (req-times* ip))))))
(let proxy-header "X-Forwarded-For: "
(def strip-header(s)
(subst "" proxy-header s))
(def proxy-ip(ip-wrapper lines)
(aif (only.strip-header (car:keep [headmatch proxy-header _] lines))
(ip-wrapper it)
(ip-wrapper))))
(wipe show-requests*)
(def handle-request-thread (in out ip-wrapper)
(with (nls 0 lines nil line nil responded nil t0 (msec))
(after
(whilet c (unless responded (readc in))
(if srv-noisy* (pr c))
(if (is c #\newline)
(if (is (++ nls) 2)
(let (type op args clen cooks ctype) (parseheader (rev lines))
(if show-requests* (prn lines))
(unless (abusive-ip (proxy-ip ip-wrapper lines))
(let t1 (msec)
(case type
get (respond out op args cooks 0 in "" (ip-wrapper))
post (handle-post in out op args clen cooks ctype (ip-wrapper))
(respond-err out "Unknown request: " (car lines)))
(log-request type op args cooks (ip-wrapper) t0 t1)))
(set responded))
(do (push (string (rev line)) lines)
(wipe line)))
(unless (is c #\return)
(push c line)
(= nls 0))))
(close in out)))
(harvest-fnids))
(def log-request (type op args cooks ip t0 t1)
(with (parsetime (- t1 t0) respondtime (- (msec) t1))
(srvlog 'srv ip
parsetime
respondtime
(if (> (+ parsetime respondtime) 1000) "***" "")
type
op
(let arg1 (car args)
(if (caris arg1 "fnid") "" arg1))
cooks)))
(= header* "HTTP/1.1 200 OK\r
Content-Type: text/html; charset=utf-8\r
Connection: close")
(= err-header* "HTTP/1.1 404 Not Found\r
Content-Type: text/html; charset=utf-8\r
Connection: close")
(= type-header* (table))
(def gen-type-header (ctype)
(+ "HTTP/1.0 200 OK\r
Content-Type: "
ctype
"\r
Connection: close"))
(map (fn ((k v)) (= (type-header* k) (gen-type-header v)))
'((gif "image/gif")
(jpg "image/jpeg")
(png "image/png")
(text/html "text/html; charset=utf-8")))
(= rdheader* "HTTP/1.0 302 Moved")
(= srvops* (table) redirector* (table) optimes* (table) opcounts* (table))
(def save-optime (name elapsed)
; this is the place to put a/b testing
; toggle a flag and push elapsed into one of two lists
(++ (opcounts* name 0))
(unless (optimes* name) (= (optimes* name) (queue)))
(enq-limit elapsed (optimes* name) 1000))
; For ops that want to add their own headers. They must thus remember
; to prn a blank line before anything meant to be part of the page.
(mac defop-raw (name parms . body)
(w/uniq t1
`(= (srvops* ',name)
(fn ,parms
(let ,t1 (msec)
(do1 (do ,@body)
(save-optime ',name (- (msec) ,t1))))))))
(mac defopr-raw (name parms . body)
`(= (redirector* ',name) t
(srvops* ',name) (fn ,parms ,@body)))
(mac defop (name parm . body)
(w/uniq gs
`(do (wipe (redirector* ',name))
(defop-raw ,name (,gs ,parm)
(w/stdout ,gs (prn) ,@body)))))
; Defines op as a redirector. Its retval is new location.
(mac defopr (name parm . body)
(w/uniq gs
`(do (set (redirector* ',name))
(defop-raw ,name (,gs ,parm)
,@body))))
;(mac testop (name . args) `((srvops* ',name) ,@args))
(deftem request
args nil
cooks nil
ctype nil
clen 0
in nil
ip nil)
(= unknown-msg* "Unknown." max-age* (table) static-max-age* nil)
(def respond (str op args cooks clen ctype in ip)
(w/stdout str
(iflet f (srvops* op)
(let req (inst 'request 'args args 'cooks cooks 'ctype ctype 'clen clen 'in in 'ip ip)
(if (redirector* op)
(do (prn rdheader*)
(prn "Location: " (f str req))
(prn))
(do (prn header*)
(awhen (max-age* op)
(prn "Cache-Control: max-age=" it))
(f str req))))
(let filetype (static-filetype op)
(aif (and filetype (file-exists (string staticdir* op)))
(do (prn (type-header* filetype))
(awhen static-max-age*
(prn "Cache-Control: max-age=" it))
(prn)
(w/infile i it
(whilet b (readb i)
(writeb b str))))
(respond-err str unknown-msg*))))))
(def handle-post (in out op args clen cooks ctype ip)
(if (no clen)
(respond-err out "Post request without Content-Length.")
(respond out op (+ args
(if (~begins downcase.ctype "multipart/form-data")
(parseargs:string:readchars clen in)
(parse-multipart-args multipart-boundary.ctype in)))
cooks clen ctype in ip)))
(def multipart-boundary(s)
(let delim "boundary="
(+ "--" (cut s (+ (findsubseq delim s)
len.delim)))))
(def parse-multipart-args(boundary in)
(scan-past boundary in) ; skip prelude
(accum yield
(until (multipart-end boundary in)
(withs (headers scan-headers.in
; only place that may contain multi-byte chars
body (scan-body boundary in))
(when headers
(yield:parse-multipart-part headers body))))))
; "The final boundary is followed by two more hyphens to indicate that no
; further parts follow."
; -- http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html
; We've already read the boundary itself.
(def multipart-end(boundary in)
(aif peekc.in
(and (is #\- it) readc.in
(or (is #\- peekc.in)
; "one #\- shalt thou not count,
; excepting that thou then proceed to two"
(ero "malformed multipart input; boundary followed by just one '-'. Is it the final part or isn't it?")))
(ero "malformed multipart input; request didn't have a final boundary")))
(def scan-headers(in)
; "The boundary must be followed immediately either by another CRLF and the
; header fields for the next part, or by two CRLFs, in which case there are no
; header fields for the next part.."
; -- http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html
(parse-mime-header:bytes-string:scan-past "\r\n\r\n" in))
(def scan-body(boundary in)
; "The CRLF preceding the encapsulation line is considered part of the
; boundary.."
; -- http://www.w3.org/Protocols/rfc1341/7_2_Multipart.html
(scan-past (+ "\r\n" boundary) in))
(def parse-multipart-part(headers body)
(awhen (and headers (alref headers "name"))
(list unstring.it
(w/table multipart-arg
(= (multipart-arg "contents") body)
(each (property val) headers
(unless (iso "name" property)
(= multipart-arg.property val)))))))
; parse lines of the form a=b; c=d; e=f; ..
; segments without '=' are passed through as single-elem lists
(def parse-mime-header(line)
(map [tokens _ #\=]
(tokens downcase.line (orf whitec (testify #\;)))))
; return list of bytes until pat is encountered
; pat is read from input but dropped from result
; all chars in pat must be 1-byte
(def scan-past(pat in)
(= pat (map int (rev:coerce pat 'cons)))
(let buffer nil
(until (iso pat (firstn len.pat buffer))
(push readb.in buffer))
(rev:nthcdr len.pat buffer)))
; convert list of bytes to string
(def bytes-string(l)
(coerce (map [coerce _ 'char]
l)
'string))
; "\"abc\"" => "abc"
(def unstring(s)
(if (iso #\" s.0)
(cut s 1 -1)
s))
(def static-filetype (sym)
(let fname (coerce sym 'string)
(and (~findsubseq ".." fname) ; for security
(case (downcase (last (check (tokens fname #\.) ~single)))
"gif" 'gif
"jpg" 'jpg
"jpeg" 'jpg
"png" 'png
"css" 'text/html
"txt" 'text/html
"htm" 'text/html
"html" 'text/html
"arc" 'text/html
))))
(def respond-err (str msg . args)
(w/stdout str
(prn err-header*)
(prn)
(apply pr msg args)))
(def parseheader (lines)
(let (type op args) (parseurl (car lines))
(list type
op
args
(and (is type 'post)
(some (fn (s)
(and (begins downcase.s "content-length:")
(errsafe:coerce (cadr (tokens s)) 'int)))
(cdr lines)))
(some (fn (s)
(and (begins downcase.s "cookie:")
(parsecookies s)))
(cdr lines))
(and (is type 'post)
(some (fn (s)
(and (begins downcase.s "content-type: ")
(cut s (len "content-type: "))))
(cdr lines))))))
; (parseurl "GET /p1?foo=bar&ug etc") -> (get p1 (("foo" "bar") ("ug")))
(def parseurl (s)
(let (type url) (tokens s)
(let (base args) (tokens url #\?)
(list (sym (downcase type))
(sym (cut base 1))
(if args
(parseargs args)
nil)))))
; I don't urldecode field names or anything in cookies; correct?
(def parseargs (s)
(map (fn ((k v)) (list k urldecode.v))
(map [tokens _ #\=] (tokens s #\&))))
(def parsecookies (s)
(map [tokens _ #\=]
(cdr (tokens s [or whitec._ (is _ #\;)]))))
(def arg (req key)
(acheck (alref req!args key) [~isa _ 'table]
; deref multipart params by default
(it "contents")))
(def multipart-metadata(req arg key)
(let val (alref req!args arg)
(if (isa val 'table)
val.key)))
; *** Warning: does not currently urlencode args, so if need to do
; that replace v with (urlencode v).
(def reassemble-args (req)
(aif req!args
(apply string "?" (intersperse '&
(map (fn ((k v))
(string k '= v))
it)))
""))
(= fns* (table) fnids* nil timed-fnids* nil)
; count on huge (expt 64 10) size of fnid space to avoid clashes
(def new-fnid ()
(check (sym (rand-string 10)) ~fns* (new-fnid)))
(def fnid (f)
(atlet key (new-fnid)
(= (fns* key) f)
(push key fnids*)
key))
(def timed-fnid (lasts f)
(atlet key (new-fnid)
(= (fns* key) f)
(push (list key (seconds) lasts) timed-fnids*)
key))
; Within f, it will be bound to the fn's own fnid. Remember that this is
; so low-level that need to generate the newline to separate from the headers
; within the body of f.
(mac afnid (f)
`(atlet it (new-fnid)
(= (fns* it) ,f)
(push it fnids*)
it))
;(defop test-afnid req
; (tag (a href (url-for (afnid (fn (req) (prn) (pr "my fnid is " it)))))
; (pr "click here")))
; To be more sophisticated, instead of killing fnids, could first
; replace them with fns that tell the server it's harvesting too
; aggressively if they start to get called. But the right thing to
; do is estimate what the max no of fnids can be and set the harvest
; limit there-- beyond that the only solution is to buy more memory.
(def harvest-fnids ((o n 50000)) ; was 20000
(when (len> fns* n)
(pull (fn ((id created lasts))
(when (> (since created) lasts)
(wipe (fns* id))
t))
timed-fnids*)
(atlet nharvest (trunc (/ n 10))
(let (kill keep) (split (rev fnids*) nharvest)
(= fnids* (rev keep))
(each id kill
(wipe (fns* id)))))))
(= fnurl* "/x" rfnurl* "/r" rfnurl2* "/y" jfnurl* "/a")
(= dead-msg* "\nUnknown or expired link.")
(defop-raw x (str req)
(w/stdout str
(aif (arg req "fnid")
(aif (fns* sym.it)
(it req)
(pr dead-msg*))
(pr "\nno fnid"))))
(defopr-raw y (str req)
(aif (fns* (sym (arg req "fnid")))
(w/stdout str (it req))
"deadlink"))
; For asynchronous calls; discards the page. Would be better to tell
; the fn not to generate it.
(defop-raw a (str req)
(aif (fns* (sym (arg req "fnid")))
(tostring (it req))))
(defopr r req
(aif (fns* (sym (arg req "fnid")))
(it req)
"deadlink"))
(defop deadlink req
(pr dead-msg*))
(def url-for (fnid)
(string fnurl* "?fnid=" fnid))
(def flink (f)
(string fnurl* "?fnid=" (fnid (fn (req) (prn) (f req)))))
(def rflink (f)
(string rfnurl* "?fnid=" (fnid f)))
; Since it's just an expr, gensym a parm for (ignored) args.
(mac w/link (expr . body)
`(tag (a href (flink (fn (,(uniq)) ,expr)))
,@body))
(mac w/rlink (expr . body)
`(tag (a href (rflink (fn (,(uniq)) ,expr)))
,@body))
(mac onlink (text . body)
`(w/link (do ,@body) (pr ,text)))
(mac onrlink (text . body)
`(w/rlink (do ,@body) (pr ,text)))
; bad to have both flink and linkf; rename flink something like fnid-link
(mac linkf (text parms . body)
`(tag (a href (flink (fn ,parms ,@body))) (pr ,text)))
(mac rlinkf (text parms . body)
`(tag (a href (rflink (fn ,parms ,@body))) (pr ,text)))
;(defop top req (linkf 'whoami? (req) (pr "I am " (get-user req))))
;(defop testf req (w/link (pr "ha ha ha") (pr "laugh")))
(mac w/link-if (test expr . body)
`(tag-if ,test (a href (flink (fn (,(uniq)) ,expr)))
,@body))
(def fnid-field (id)
(gentag input type 'hidden name 'fnid value id))
; f should be a fn of one arg, which will be http request args.
(def fnform (f bodyfn (o redir))
(tag (form method 'post action (if redir rfnurl2* fnurl*))
(fnid-field (fnid f))
(bodyfn)))
; Could also make a version that uses just an expr, and var capture.
; Is there a way to ensure user doesn't use "fnid" as a key?
(mac aform (f . body)
(w/uniq ga
`(tag (form method 'post action fnurl*)
(fnid-field (fnid (fn (,ga)
(prn)
(,f ,ga))))
,@body)))
(mac aform-multi (f . body)
(w/uniq ga
`(tag (form method 'post
enctype "multipart/form-data"
action (string fnurl* "?fnid="
(fnid (fn (,ga)
(prn)
(,f ,ga)))))
,@body)))
(mac form-multi (action . body)
(w/uniq ga
`(tag (form method 'post
enctype "multipart/form-data"
action ,action)
,@body)))
;(defop test1 req
; (fnform (fn (req) (prn) (pr req))
; (fn () (single-input "" 'foo 20 "submit"))))
;(defop test2 req
; (aform (fn (req) (pr req))
; (single-input "" 'foo 20 "submit")))
; Like aform except creates a fnid that will last for lasts seconds
; (unless the server is restarted).
(mac taform (lasts f . body)
(w/uniq (gl gf gi ga)
`(withs (,gl ,lasts
,gf (fn (,ga) (prn) (,f ,ga)))
(tag (form method 'post action fnurl*)
(fnid-field (if ,gl (timed-fnid ,gl ,gf) (fnid ,gf)))
,@body))))
(mac arform (f . body)
`(tag (form method 'post action rfnurl*)
(fnid-field (fnid ,f))
,@body))
; overlong
(mac tarform (lasts f . body)
(w/uniq (gl gf)
`(withs (,gl ,lasts ,gf ,f)
(tag (form method 'post action rfnurl*)
(fnid-field (if ,gl (timed-fnid ,gl ,gf) (fnid ,gf)))
,@body))))
(mac aformh (f . body)
`(tag (form method 'post action fnurl*)
(fnid-field (fnid ,f))
,@body))
(mac arformh (f . body)
`(tag (form method 'post action rfnurl2*)
(fnid-field (fnid ,f))
,@body))
; only unique per server invocation
(= unique-ids* (table))
(def unique-id ((o len 8))
(let id (sym (rand-string (max 5 len)))
(if (unique-ids* id)
(unique-id)
(= (unique-ids* id) id))))
(def srvlog (type . args)
(ontofile (logfile-name type)
(atomic (apply prs (seconds) args) (prn))))
(def logfile-name (type)
(string logdir* type "-" (memodate)))
(with (lastasked nil lastval nil)
(def memodate ()
(let now (seconds)
(if (or (no lastasked) (> (- now lastasked) 60))
(= lastasked now lastval (datestring))
lastval)))
)
(defop || req (pr "It's alive."))
(defop topips req
(when (admin (get-user req))
(whitepage
(sptab
(each ip (let leaders nil
(maptable (fn (ip n)
(when (> n 100)
(insort (compare > requests/ip*)
ip
leaders)))
requests/ip*)
leaders)
(let n (requests/ip* ip)
(row ip n (pr (num (* 100 (/ n requests*)) 1)))))))))
(defop spurned req
(when (admin (get-user req))
(whitepage
(sptab
(map (fn ((ip n)) (row ip n))
(sortable spurned*))))))
; eventually promote to general util
(def sortable (ht (o f >))
(let res nil
(maptable (fn kv
(insort (compare f cadr) kv res))
ht)
res))
; Background Threads
(= bgthreads* (table) pending-bgthreads* nil)
(def new-bgthread (id f sec)
(aif (bgthreads* id) (break-thread it))
(= (bgthreads* id) (new-thread (fn ()
(while t
(sleep sec)
(f))))))
; should be a macro for this?
(mac defbg (id sec . body)
`(do (pull [caris _ ',id] pending-bgthreads*)
(push (list ',id (fn () ,@body) ,sec)
pending-bgthreads*)))
; Idea: make form fields that know their value type because of
; gensymed names, and so the receiving fn gets args that are not
; strings but parsed values.