1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
{- Url downloading.
-
- Copyright 2011,2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Utility.Url (
URLString,
UserAgent,
check,
checkBoth,
exists,
download,
downloadQuiet,
parseURIRelaxed
) where
import Common
import Network.URI
import qualified Network.Browser as Browser
import Network.HTTP
import Data.Either
import qualified Build.SysConfig
type URLString = String
type Headers = [String]
type UserAgent = String
{- Checks that an url exists and could be successfully downloaded,
- also checking that its size, if available, matches a specified size. -}
checkBoth :: URLString -> Headers -> Maybe Integer -> Maybe UserAgent -> IO Bool
checkBoth url headers expected_size ua = do
v <- check url headers expected_size ua
return (fst v && snd v)
check :: URLString -> Headers -> Maybe Integer -> Maybe UserAgent -> IO (Bool, Bool)
check url headers expected_size = handle <$$> exists url headers
where
handle (False, _) = (False, False)
handle (True, Nothing) = (True, True)
handle (True, s) = case expected_size of
Just _ -> (True, expected_size == s)
Nothing -> (True, True)
{- Checks that an url exists and could be successfully downloaded,
- also returning its size if available.
-
- For a file: url, check it directly.
-
- Uses curl otherwise, when available, since curl handles https better
- than does Haskell's Network.Browser.
-}
exists :: URLString -> Headers -> Maybe UserAgent -> IO (Bool, Maybe Integer)
exists url headers ua = case parseURIRelaxed url of
Just u
| uriScheme u == "file:" -> do
s <- catchMaybeIO $ getFileStatus (unEscapeString $ uriPath u)
case s of
Just stat -> return (True, Just $ fromIntegral $ fileSize stat)
Nothing -> dne
| otherwise -> if Build.SysConfig.curl
then do
output <- readProcess "curl" $ toCommand curlparams
case lastMaybe (lines output) of
Just ('2':_:_) -> return (True, extractsize output)
_ -> dne
else do
r <- request u headers HEAD ua
case rspCode r of
(2,_,_) -> return (True, size r)
_ -> return (False, Nothing)
Nothing -> dne
where
dne = return (False, Nothing)
curlparams = addUserAgent ua $
[ Param "-s"
, Param "--head"
, Param "-L", Param url
, Param "-w", Param "%{http_code}"
] ++ concatMap (\h -> [Param "-H", Param h]) headers
extractsize s = case lastMaybe $ filter ("Content-Length:" `isPrefixOf`) (lines s) of
Just l -> case lastMaybe $ words l of
Just sz -> readish sz
_ -> Nothing
_ -> Nothing
size = liftM Prelude.read . lookupHeader HdrContentLength . rspHeaders
-- works for both wget and curl commands
addUserAgent :: Maybe UserAgent -> [CommandParam] -> [CommandParam]
addUserAgent Nothing ps = ps
addUserAgent (Just ua) ps = ps ++ [Param "--user-agent", Param ua]
{- Used to download large files, such as the contents of keys.
-
- Uses wget or curl program for its progress bar. (Wget has a better one,
- so is preferred.) Which program to use is determined at run time; it
- would not be appropriate to test at configure time and build support
- for only one in.
-}
download :: URLString -> Headers -> [CommandParam] -> FilePath -> Maybe UserAgent -> IO Bool
download = download' False
{- No output, even on error. -}
downloadQuiet :: URLString -> Headers -> [CommandParam] -> FilePath -> Maybe UserAgent -> IO Bool
downloadQuiet = download' True
download' :: Bool -> URLString -> Headers -> [CommandParam] -> FilePath -> Maybe UserAgent -> IO Bool
download' quiet url headers options file ua =
case parseURIRelaxed url of
Just u
| uriScheme u == "file:" -> do
-- curl does not create destination file
-- for an empty file:// url, so pre-create
writeFile file ""
curl
| otherwise -> ifM (inPath "wget") (wget , curl)
_ -> return False
where
headerparams = map (\h -> Param $ "--header=" ++ h) headers
wget = go "wget" $ headerparams ++ quietopt "-q" ++ wgetparams
{- Regular wget needs --clobber to continue downloading an existing
- file. On Android, busybox wget is used, which does not
- support, or need that option. -}
#ifndef __ANDROID__
wgetparams = [Params "--clobber -c -O"]
#else
wgetparams = [Params "-c -O"]
#endif
{- Uses the -# progress display, because the normal
- one is very confusing when resuming, showing
- the remainder to download as the whole file,
- and not indicating how much percent was
- downloaded before the resume. -}
curl = go "curl" $ headerparams ++ quietopt "-s" ++
[Params "-f -L -C - -# -o"]
go cmd opts = boolSystem cmd $
addUserAgent ua $ options++opts++[File file, File url]
quietopt s
| quiet = [Param s]
| otherwise = []
{- Uses Network.Browser to make a http request of an url.
- For example, HEAD can be used to check if the url exists,
- or GET used to get the url content (best for small urls).
-
- This does its own redirect following because Browser's is buggy for HEAD
- requests.
-
- Unfortunately, does not handle https, so should only be used
- when curl is not available.
-}
request :: URI -> Headers -> RequestMethod -> Maybe UserAgent -> IO (Response String)
request url headers requesttype ua = go 5 url
where
go :: Int -> URI -> IO (Response String)
go 0 _ = error "Too many redirects "
go n u = do
rsp <- Browser.browse $ do
maybe noop Browser.setUserAgent ua
Browser.setErrHandler ignore
Browser.setOutHandler ignore
Browser.setAllowRedirects False
let req = mkRequest requesttype u :: Request_String
snd <$> Browser.request (addheaders req)
case rspCode rsp of
(3,0,x) | x /= 5 -> redir (n - 1) u rsp
_ -> return rsp
addheaders req = setHeaders req (rqHeaders req ++ userheaders)
userheaders = rights $ map parseHeader headers
ignore = const noop
redir n u rsp = case retrieveHeaders HdrLocation rsp of
[] -> return rsp
(Header _ newu:_) ->
case parseURIReference newu of
Nothing -> return rsp
Just newURI -> go n $
#if defined VERSION_network
#if ! MIN_VERSION_network(2,4,0)
#define WITH_OLD_URI
#endif
#endif
#ifdef WITH_OLD_URI
fromMaybe newURI (newURI `relativeTo` u)
#else
newURI `relativeTo` u
#endif
{- Allows for spaces and other stuff in urls, properly escaping them. -}
parseURIRelaxed :: URLString -> Maybe URI
parseURIRelaxed = parseURI . escapeURIString isAllowedInURI
|
