From: Paul J R <me@pjr.cc>
Date: Thu, 25 Oct 2012 06:14:31 +0000 (+1100)
Subject: handling data from the client properly for gzdecoding and
X-Git-Url: http://git.pjr.cc/?p=gwvp-mini.git;a=commitdiff_plain;h=7c855df8f42cc8508f556068a707c9258cd40e43

handling data from the client properly for gzdecoding and
receiving/sending properly.... painful experience
---

diff --git a/gwvpmini/gwvpmini_gitbackend.php b/gwvpmini/gwvpmini_gitbackend.php
index 27ccee7..424c108 100644
--- a/gwvpmini/gwvpmini_gitbackend.php
+++ b/gwvpmini/gwvpmini_gitbackend.php
@@ -289,14 +289,6 @@ function gwvpmini_callGitBackend($username, $repo)
 		
 		error_log("path trans'd is /$repo_base/$repo.git/$euri from $ruri with ".$_REQUEST["q"]." $strrem pre is ".print_r($_REQUEST,true)." and foff ".print_r($headers, true));
 		
-		if(isset($headers["Content-Encoding"])) {
-			if($headers["Content-Encoding"] == "gzip") {
-				error_log("DAM YOU GIT CLIENT");
-			}
-		}
-		
-		
-
 		$pwd = "/$repo_base/";
 		
 		$proc = proc_open("/usr/lib/git-core/git-http-backend", array(array("pipe","rb"),array("pipe","wb"),array("file","/tmp/err", "a")), $pipes, $pwd, $procenv);
@@ -332,19 +324,29 @@ function gwvpmini_callGitBackend($username, $repo)
 		
 		$stlimit = 0;
 		$fp = fopen("/tmp/gitup.".rand(0,4000000), "w");
+		$from_client_data = "";
 		// i was going to use stream_select, but i feel this works better like this
 		while($continue) {
 			// do client
+			
+			// lets start again....
+				
 			if(!feof($fh)) {
-				$from_client_data = fread($fh,8192);
+				if(isset($headers["Content-Length"])) {
+					$cl = $headers["Content-Length"];
+					while(strlen($from_client_data) < $cl) {
+						error_log("re-read ".strlen($from_client_data));
+						$from_client_data .= fread($fh, $cl);
+					}
+				} else 	$from_client_data = fread($fh,8192);
 				
-				// TODO: BIG TODO: must rewrite this bit. I need to read the entire client bit if its posting in one piece so i can then decode.
-				// if the client sends more then 8192, i could be very well screwed. must handle content-length on read...
+				// TODO: BIG TODO: must rewrite this bit. its ugly as sin, it works, but it probably shouldnt.
 				
 				if(isset($headers["Content-Encoding"])) {
 					if($headers["Content-Encoding"] == "gzip") {
 						//error_log("DAM YOU GIT CLIENT and your retarded gzip encoding");
 						$from_client_data = gzinflate(substr($from_client_data, 10));
+						//$from_client_data = gzdecode($from_client_data);
 					}
 				}
 				if($from_client_data !== false) {
@@ -389,6 +391,7 @@ function gwvpmini_callGitBackend($username, $repo)
 				}
 				
 				if($from_cgi_data !== false) {
+					error_log("send to client");
 					echo $from_cgi_data;
 					flush();
 				}
@@ -398,18 +401,20 @@ function gwvpmini_callGitBackend($username, $repo)
 				$cgi_len = 0;
 			}
 			
+			flush();
+			
 			if(feof($pipes[1])) $continue = false;
 			else {
 				if($client_len == 0 && $cgi_len == 0) {
 					usleep(200000);
 					error_log("sleep tick");
 					$stlimit++;
-					if($stlimit > 50) $continue = false;
+					if($stlimit > 5000) $continue = false;
 				} else {
 					$stlimit = 0;
 					error_log("sizes: $client_len, $cgi_len");
 					if($cgi_len > 0) {
-						error_log("from cgi: \"$from_cgi_data\"");
+						//error_log("from cgi: \"$from_cgi_data\"");
 					}
 				}
 			}
@@ -480,4 +485,115 @@ function gwvpmini_createGitRepo($name, $ownerid, $desc, $defperms, $clonefrom, $
 	return true;
 }
 
+function gzdecode($data,&$filename='',&$error='',$maxlength=null)
+{
+	$len = strlen($data);
+	if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {
+		$error = "Not in GZIP format.";
+		return null;  // Not GZIP format (See RFC 1952)
+	}
+	$method = ord(substr($data,2,1));  // Compression method
+	$flags  = ord(substr($data,3,1));  // Flags
+	if ($flags & 31 != $flags) {
+		$error = "Reserved bits not allowed.";
+		return null;
+	}
+	// NOTE: $mtime may be negative (PHP integer limitations)
+	$mtime = unpack("V", substr($data,4,4));
+	$mtime = $mtime[1];
+	$xfl   = substr($data,8,1);
+	$os    = substr($data,8,1);
+	$headerlen = 10;
+	$extralen  = 0;
+	$extra     = "";
+	if ($flags & 4) {
+		// 2-byte length prefixed EXTRA data in header
+		if ($len - $headerlen - 2 < 8) {
+			return false;  // invalid
+		}
+		$extralen = unpack("v",substr($data,8,2));
+		$extralen = $extralen[1];
+		if ($len - $headerlen - 2 - $extralen < 8) {
+			return false;  // invalid
+		}
+		$extra = substr($data,10,$extralen);
+		$headerlen += 2 + $extralen;
+	}
+	$filenamelen = 0;
+	$filename = "";
+	if ($flags & 8) {
+		// C-style string
+		if ($len - $headerlen - 1 < 8) {
+			return false; // invalid
+		}
+		$filenamelen = strpos(substr($data,$headerlen),chr(0));
+		if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
+			return false; // invalid
+		}
+		$filename = substr($data,$headerlen,$filenamelen);
+		$headerlen += $filenamelen + 1;
+	}
+	$commentlen = 0;
+	$comment = "";
+	if ($flags & 16) {
+		// C-style string COMMENT data in header
+		if ($len - $headerlen - 1 < 8) {
+			return false;    // invalid
+		}
+		$commentlen = strpos(substr($data,$headerlen),chr(0));
+		if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
+			return false;    // Invalid header format
+		}
+		$comment = substr($data,$headerlen,$commentlen);
+		$headerlen += $commentlen + 1;
+	}
+	$headercrc = "";
+	if ($flags & 2) {
+		// 2-bytes (lowest order) of CRC32 on header present
+		if ($len - $headerlen - 2 < 8) {
+			return false;    // invalid
+		}
+		$calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;
+		$headercrc = unpack("v", substr($data,$headerlen,2));
+		$headercrc = $headercrc[1];
+		if ($headercrc != $calccrc) {
+			$error = "Header checksum failed.";
+			return false;    // Bad header CRC
+		}
+		$headerlen += 2;
+	}
+	// GZIP FOOTER
+	$datacrc = unpack("V",substr($data,-8,4));
+	$datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF);
+	$isize = unpack("V",substr($data,-4));
+	$isize = $isize[1];
+	// decompression:
+	$bodylen = $len-$headerlen-8;
+	if ($bodylen < 1) {
+		// IMPLEMENTATION BUG!
+		return null;
+	}
+	$body = substr($data,$headerlen,$bodylen);
+	$data = "";
+	if ($bodylen > 0) {
+		switch ($method) {
+			case 8:
+				// Currently the only supported compression method:
+				$data = gzinflate($body,$maxlength);
+				break;
+			default:
+				$error = "Unknown compression method.";
+				return false;
+		}
+	}  // zero-byte body content is allowed
+	// Verifiy CRC32
+	$crc   = sprintf("%u",crc32($data));
+	$crcOK = $crc == $datacrc;
+	$lenOK = $isize == strlen($data);
+	if (!$lenOK || !$crcOK) {
+		$error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.');
+		return false;
+	}
+	return $data;
+}
 ?>
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