/*
- * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
+ * Copyright (C) 1996-2017 The Squid Software Foundation and contributors
*
* Squid software is distributed under GPLv2+ license and includes
* contributions from numerous individuals and organizations.
#include "profiler/Profiler.h"
#include "SquidConfig.h"
-Http::One::RequestParser::RequestParser() :
+// the right debugs() level for parsing errors
+inline static int
+ErrorLevel() {
+ return Config.onoff.relaxed_header_parser < 0 ? DBG_IMPORTANT : 5;
+}
+
+Http::One::RequestParser::RequestParser(bool preserveParsed) :
Parser(),
- firstLineGarbage_(0)
+ preserveParsed_(preserveParsed)
{}
Http1::Parser::size_type
* Governed by:
* RFC 1945 section 5.1
* RFC 7230 section 2.6, 3.1 and 3.5
- *
- * Parsing state is stored between calls. The current implementation uses
- * checkpoints after each successful request-line field.
- * The return value tells you whether the parsing is completed or not.
- *
- * \retval -1 an error occurred. parseStatusCode indicates HTTP status result.
- * \retval 1 successful parse. method_ is filled and buffer consumed including first delimiter.
- * \retval 0 more data is needed to complete the parse
*/
-int
-Http::One::RequestParser::parseMethodField(Http1::Tokenizer &tok, const CharacterSet &WspDelim)
+bool
+Http::One::RequestParser::parseMethodField(Http1::Tokenizer &tok)
{
- // scan for up to 16 valid method characters.
- static const size_t maxMethodLength = 16; // TODO: make this configurable?
-
// method field is a sequence of TCHAR.
- SBuf methodFound;
- if (tok.prefix(methodFound, CharacterSet::TCHAR, maxMethodLength) && tok.skipOne(WspDelim)) {
-
- method_ = HttpRequestMethod(methodFound);
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
-
- } else if (tok.atEnd()) {
- debugs(74, 5, "Parser needs more data to find method");
- return 0;
-
- } // else error(s)
+ // Limit to 32 characters to prevent overly long sequences of non-HTTP
+ // being sucked in before mismatch is detected. 32 is itself annoyingly
+ // big but there are methods registered by IANA that reach 17 bytes:
+ // http://www.iana.org/assignments/http-methods
+ static const size_t maxMethodLength = 32; // TODO: make this configurable?
- // non-delimiter found after accepted method bytes means ...
- if (methodFound.length() == maxMethodLength) {
- // method longer than acceptible.
- // RFC 7230 section 3.1.1 mandatory (SHOULD) 501 response
- parseStatusCode = Http::scNotImplemented;
- debugs(33, 5, "invalid request-line. method too long");
- } else {
- // invalid character in the URL
- // RFC 7230 section 3.1.1 required (SHOULD) 400 response
+ SBuf methodFound;
+ if (!tok.prefix(methodFound, CharacterSet::TCHAR, maxMethodLength)) {
+ debugs(33, ErrorLevel(), "invalid request-line: missing or malformed method");
parseStatusCode = Http::scBadRequest;
- debugs(33, 5, "invalid request-line. missing method delimiter");
+ return false;
}
- return -1;
+ method_ = HttpRequestMethod(methodFound);
+
+ if (!skipDelimiter(tok.skipAll(DelimiterCharacters()), "after method"))
+ return false;
+
+ return true;
}
-static CharacterSet
-uriValidCharacters()
+/// the characters which truly are valid within URI
+static const CharacterSet &
+UriValidCharacters()
{
- CharacterSet UriChars("URI-Chars","");
-
/* RFC 3986 section 2:
* "
* A URI is composed from a limited set of characters consisting of
* digits, letters, and a few graphic symbols.
* "
*/
- // RFC 3986 section 2.1 - percent encoding "%" HEXDIG
- UriChars.add('%');
- UriChars += CharacterSet::HEXDIG;
- // RFC 3986 section 2.2 - reserved characters
- UriChars += CharacterSet("gen-delims", ":/?#[]@");
- UriChars += CharacterSet("sub-delims", "!$&'()*+,;=");
- // RFC 3986 section 2.3 - unreserved characters
- UriChars += CharacterSet::ALPHA;
- UriChars += CharacterSet::DIGIT;
- UriChars += CharacterSet("unreserved", "-._~");
+ static const CharacterSet UriChars =
+ CharacterSet("URI-Chars","") +
+ // RFC 3986 section 2.2 - reserved characters
+ CharacterSet("gen-delims", ":/?#[]@") +
+ CharacterSet("sub-delims", "!$&'()*+,;=") +
+ // RFC 3986 section 2.3 - unreserved characters
+ CharacterSet::ALPHA +
+ CharacterSet::DIGIT +
+ CharacterSet("unreserved", "-._~") +
+ // RFC 3986 section 2.1 - percent encoding "%" HEXDIG
+ CharacterSet("pct-encoded", "%") +
+ CharacterSet::HEXDIG;
return UriChars;
}
-int
-Http::One::RequestParser::parseUriField(Http1::Tokenizer &tok)
+/// characters which Squid will accept in the HTTP request-target (URI)
+const CharacterSet &
+Http::One::RequestParser::RequestTargetCharacters()
{
- // URI field is a sequence of ... what? segments all have different valid charset
- // go with non-whitespace non-binary characters for now
- static CharacterSet UriChars = uriValidCharacters();
+ if (Config.onoff.relaxed_header_parser) {
+#if USE_HTTP_VIOLATIONS
+ static const CharacterSet RelaxedExtended =
+ UriValidCharacters() +
+ // accept whitespace (extended), it will be dealt with later
+ DelimiterCharacters() +
+ // RFC 2396 unwise character set which must never be transmitted
+ // in un-escaped form. But many web services do anyway.
+ CharacterSet("RFC2396-unwise","\"\\|^<>`{}") +
+ // UTF-8 because we want to be future-proof
+ CharacterSet("UTF-8", 128, 255);
+
+ return RelaxedExtended;
+#else
+ static const CharacterSet RelaxedCompliant =
+ UriValidCharacters() +
+ // accept whitespace (extended), it will be dealt with later.
+ DelimiterCharacters();
+
+ return RelaxedCompliant;
+#endif
+ }
+
+ // strict parse only accepts what the RFC say we can
+ return UriValidCharacters();
+}
+bool
+Http::One::RequestParser::parseUriField(Http1::Tokenizer &tok)
+{
/* Arbitrary 64KB URI upper length limit.
*
* Not quite as arbitrary as it seems though. Old SquidString objects
* Not that it matters but RFC 7230 section 3.1.1 requires (RECOMMENDED)
* at least 8000 octets for the whole line, including method and version.
*/
- const size_t maxUriLength = min(static_cast<size_t>(Config.maxRequestHeaderSize) - firstLineSize(),
- static_cast<size_t>((64*1024)-1));
+ const size_t maxUriLength = static_cast<size_t>((64*1024)-1);
SBuf uriFound;
-
- // RFC 7230 HTTP/1.x URI are followed by at least one whitespace delimiter
- if (tok.prefix(uriFound, UriChars, maxUriLength) && tok.skipOne(CharacterSet::SP)) {
- uri_ = uriFound;
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
-
- // RFC 1945 for GET the line terminator may follow URL instead of a delimiter
- } else if (method_ == Http::METHOD_GET && skipLineTerminator(tok)) {
- debugs(33, 5, "HTTP/0.9 syntax request-line detected");
- msgProtocol_ = Http::ProtocolVersion(0,9);
- uri_ = uriFound; // found by successful prefix() call earlier.
- parseStatusCode = Http::scOkay;
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
-
- } else if (tok.atEnd()) {
- debugs(74, 5, "Parser needs more data to find URI");
- return 0;
+ if (!tok.prefix(uriFound, RequestTargetCharacters())) {
+ parseStatusCode = Http::scBadRequest;
+ debugs(33, ErrorLevel(), "invalid request-line: missing or malformed URI");
+ return false;
}
- // else errors...
-
- if (uriFound.length() == maxUriLength) {
+ if (uriFound.length() > maxUriLength) {
// RFC 7230 section 3.1.1 mandatory (MUST) 414 response
parseStatusCode = Http::scUriTooLong;
- debugs(33, 5, "invalid request-line. URI longer than " << maxUriLength << " bytes");
- } else {
- // RFC 7230 section 3.1.1 required (SHOULD) 400 response
- parseStatusCode = Http::scBadRequest;
- debugs(33, 5, "invalid request-line. missing URI delimiter");
+ debugs(33, ErrorLevel(), "invalid request-line: " << uriFound.length() <<
+ "-byte URI exceeds " << maxUriLength << "-byte limit");
+ return false;
}
- return -1;
+
+ uri_ = uriFound;
+ return true;
}
-int
+bool
Http::One::RequestParser::parseHttpVersionField(Http1::Tokenizer &tok)
{
- // partial match of HTTP/1 magic prefix
- if (tok.remaining().length() < Http1magic.length() && Http1magic.startsWith(tok.remaining())) {
- debugs(74, 5, "Parser needs more data to find version");
- return 0;
- }
-
- if (!tok.skip(Http1magic)) {
- debugs(74, 5, "invalid request-line. not HTTP/1 protocol");
- parseStatusCode = Http::scHttpVersionNotSupported;
- return -1;
+ static const SBuf http1p0("HTTP/1.0");
+ static const SBuf http1p1("HTTP/1.1");
+ const auto savedTok = tok;
+
+ // Optimization: Expect (and quickly parse) HTTP/1.1 or HTTP/1.0 in
+ // the vast majority of cases.
+ if (tok.skipSuffix(http1p1)) {
+ msgProtocol_ = Http::ProtocolVersion(1, 1);
+ return true;
+ } else if (tok.skipSuffix(http1p0)) {
+ msgProtocol_ = Http::ProtocolVersion(1, 0);
+ return true;
+ } else {
+ // RFC 7230 section 2.6:
+ // HTTP-version = HTTP-name "/" DIGIT "." DIGIT
+ static const CharacterSet period("Decimal point", ".");
+ static const SBuf proto("HTTP/");
+ SBuf majorDigit;
+ SBuf minorDigit;
+ if (tok.suffix(minorDigit, CharacterSet::DIGIT) &&
+ tok.skipOneTrailing(period) &&
+ tok.suffix(majorDigit, CharacterSet::DIGIT) &&
+ tok.skipSuffix(proto)) {
+ const bool multiDigits = majorDigit.length() > 1 || minorDigit.length() > 1;
+ // use '0.0' for unsupported multiple digit version numbers
+ const unsigned int major = multiDigits ? 0 : (*majorDigit.rawContent() - '0');
+ const unsigned int minor = multiDigits ? 0 : (*minorDigit.rawContent() - '0');
+ msgProtocol_ = Http::ProtocolVersion(major, minor);
+ return true;
+ }
}
- if (tok.atEnd()) {
- debugs(74, 5, "Parser needs more data to find version");
- return 0;
+ // A GET request might use HTTP/0.9 syntax
+ if (method_ == Http::METHOD_GET) {
+ // RFC 1945 - no HTTP version field at all
+ tok = savedTok; // in case the URI ends with a digit
+ // report this assumption as an error if configured to triage parsing
+ debugs(33, ErrorLevel(), "assuming HTTP/0.9 request-line");
+ msgProtocol_ = Http::ProtocolVersion(0,9);
+ return true;
}
- // get the version minor DIGIT
- SBuf digit;
- if (tok.prefix(digit, CharacterSet::DIGIT, 1) && skipLineTerminator(tok)) {
+ debugs(33, ErrorLevel(), "invalid request-line: not HTTP");
+ parseStatusCode = Http::scBadRequest;
+ return false;
+}
- // found version fully AND terminator
- msgProtocol_ = Http::ProtocolVersion(1, (*digit.rawContent() - '0'));
- parseStatusCode = Http::scOkay;
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
+/**
+ * Skip characters separating request-line fields.
+ * To handle bidirectional parsing, the caller does the actual skipping and
+ * we just check how many character the caller has skipped.
+ */
+bool
+Http::One::RequestParser::skipDelimiter(const size_t count, const char *where)
+{
+ if (count <= 0) {
+ debugs(33, ErrorLevel(), "invalid request-line: missing delimiter " << where);
+ parseStatusCode = Http::scBadRequest;
+ return false;
+ }
- } else if (tok.atEnd() || (tok.skip('\r') && tok.atEnd())) {
- debugs(74, 5, "Parser needs more data to find version");
- return 0;
+ // tolerant parser allows multiple whitespace characters between request-line fields
+ if (count > 1 && !Config.onoff.relaxed_header_parser) {
+ debugs(33, ErrorLevel(), "invalid request-line: too many delimiters " << where);
+ parseStatusCode = Http::scBadRequest;
+ return false;
+ }
- } // else error ...
+ return true;
+}
- // non-DIGIT. invalid version number.
- parseStatusCode = Http::scHttpVersionNotSupported;
- debugs(33, 5, "invalid request-line. garbage before line terminator");
- return -1;
+/// Parse CRs at the end of request-line, just before the terminating LF.
+bool
+Http::One::RequestParser::skipTrailingCrs(Http1::Tokenizer &tok)
+{
+ if (Config.onoff.relaxed_header_parser) {
+ (void)tok.skipAllTrailing(CharacterSet::CR); // optional; multiple OK
+ } else {
+ if (!tok.skipOneTrailing(CharacterSet::CR)) {
+ debugs(33, ErrorLevel(), "invalid request-line: missing CR before LF");
+ parseStatusCode = Http::scBadRequest;
+ return false;
+ }
+ }
+ return true;
}
/**
* RFC 1945 section 5.1
* RFC 7230 section 2.6, 3.1 and 3.5
*
- * Parsing state is stored between calls. The current implementation uses
- * checkpoints after each successful request-line field.
- * The return value tells you whether the parsing is completed or not.
- *
* \retval -1 an error occurred. parseStatusCode indicates HTTP status result.
* \retval 1 successful parse. member fields contain the request-line items
* \retval 0 more data is needed to complete the parse
int
Http::One::RequestParser::parseRequestFirstLine()
{
- Http1::Tokenizer tok(buf_);
-
debugs(74, 5, "parsing possible request: buf.length=" << buf_.length());
debugs(74, DBG_DATA, buf_);
- // NP: would be static, except it need to change with reconfigure
- CharacterSet WspDelim = CharacterSet::SP; // strict parse only accepts SP
+ SBuf line;
- if (Config.onoff.relaxed_header_parser) {
- // RFC 7230 section 3.5
- // tolerant parser MAY accept any of SP, HTAB, VT (%x0B), FF (%x0C), or bare CR
- // as whitespace between request-line fields
- WspDelim += CharacterSet::HTAB
- + CharacterSet("VT,FF","\x0B\x0C")
- + CharacterSet::CR;
- }
+ // Earlier, skipGarbageLines() took care of any leading LFs (if allowed).
+ // Now, the request line has to end at the first LF.
+ static const CharacterSet lineChars = CharacterSet::LF.complement("notLF");
+ ::Parser::Tokenizer lineTok(buf_);
+ if (!lineTok.prefix(line, lineChars) || !lineTok.skip('\n')) {
+ if (buf_.length() >= Config.maxRequestHeaderSize) {
+ /* who should we blame for our failure to parse this line? */
- // only search for method if we have not yet found one
- if (method_ == Http::METHOD_NONE) {
- const int res = parseMethodField(tok, WspDelim);
- if (res < 1)
- return res;
- // else keep going...
- }
+ Http1::Tokenizer methodTok(buf_);
+ if (!parseMethodField(methodTok))
+ return -1; // blame a bad method (or its delimiter)
- // tolerant parser allows multiple whitespace characters between request-line fields
- if (Config.onoff.relaxed_header_parser) {
- const size_t garbage = tok.skipAll(WspDelim);
- if (garbage > 0) {
- firstLineGarbage_ += garbage;
- buf_ = tok.remaining(); // re-checkpoint after garbage
+ // assume it is the URI
+ debugs(74, ErrorLevel(), "invalid request-line: URI exceeds " <<
+ Config.maxRequestHeaderSize << "-byte limit");
+ parseStatusCode = Http::scUriTooLong;
+ return -1;
}
- }
- if (tok.atEnd()) {
debugs(74, 5, "Parser needs more data");
return 0;
}
- // from here on, we have two possible parse paths: whitespace tolerant, and strict
- if (Config.onoff.relaxed_header_parser) {
- // whitespace tolerant
-
- // NOTES:
- // * this would be static, except WspDelim changes with reconfigure
- // * HTTP-version charset is included by uriValidCharacters()
- // * terminal CR is included by WspDelim here in relaxed parsing
- CharacterSet LfDelim = uriValidCharacters() + WspDelim;
-
- // seek the LF character, then tokenize the line in reverse
- SBuf line;
- if (tok.prefix(line, LfDelim) && tok.skip('\n')) {
- Http1::Tokenizer rTok(line);
- SBuf nil;
- (void)rTok.suffix(nil,CharacterSet::CR); // optional CR in terminator
- SBuf digit;
- if (rTok.suffix(digit,CharacterSet::DIGIT) && rTok.skipSuffix(Http1magic) && rTok.suffix(nil,WspDelim)) {
- uri_ = rTok.remaining();
- msgProtocol_ = Http::ProtocolVersion(1, (*digit.rawContent() - '0'));
- if (uri_.isEmpty()) {
- debugs(33, 5, "invalid request-line. missing URL");
- parseStatusCode = Http::scBadRequest;
- return -1;
- }
-
- parseStatusCode = Http::scOkay;
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
-
- } else if (method_ == Http::METHOD_GET) {
- // RFC 1945 - for GET the line terminator may follow URL instead of a delimiter
- debugs(33, 5, "HTTP/0.9 syntax request-line detected");
- msgProtocol_ = Http::ProtocolVersion(0,9);
- static const SBuf cr("\r",1);
- uri_ = line.trim(cr,false,true);
- parseStatusCode = Http::scOkay;
- buf_ = tok.remaining(); // incremental parse checkpoint
- return 1;
- }
-
- debugs(33, 5, "invalid request-line. not HTTP");
- parseStatusCode = Http::scBadRequest;
- return -1;
- }
+ Http1::Tokenizer tok(line);
- debugs(74, 5, "Parser needs more data");
- return 0;
- }
- // else strict non-whitespace tolerant parse
-
- // only search for request-target (URL) if we have not yet found one
- if (uri_.isEmpty()) {
- const int res = parseUriField(tok);
- if (res < 1 || msgProtocol_.protocol == AnyP::PROTO_HTTP)
- return res;
- // else keep going...
- }
+ if (!parseMethodField(tok))
+ return -1;
- if (tok.atEnd()) {
- debugs(74, 5, "Parser needs more data");
- return 0;
- }
+ /* now parse backwards, to leave just the URI */
+ if (!skipTrailingCrs(tok))
+ return -1;
+
+ if (!parseHttpVersionField(tok))
+ return -1;
- // HTTP/1 version suffix (protocol magic) followed by CR*LF
- if (msgProtocol_.protocol == AnyP::PROTO_NONE) {
- return parseHttpVersionField(tok);
+ if (!http0() && !skipDelimiter(tok.skipAllTrailing(DelimiterCharacters()), "before protocol version"))
+ return -1;
+
+ /* parsed everything before and after the URI */
+
+ if (!parseUriField(tok))
+ return -1;
+
+ if (!tok.atEnd()) {
+ debugs(33, ErrorLevel(), "invalid request-line: garbage after URI");
+ parseStatusCode = Http::scBadRequest;
+ return -1;
}
- // If we got here this method has been called too many times
- parseStatusCode = Http::scInternalServerError;
- debugs(33, 5, "ERROR: Parser already processed request-line");
- return -1;
+ parseStatusCode = Http::scOkay;
+ buf_ = lineTok.remaining(); // incremental parse checkpoint
+ return 1;
}
bool
Http::One::RequestParser::parse(const SBuf &aBuf)
+{
+ const bool result = doParse(aBuf);
+ if (preserveParsed_) {
+ assert(aBuf.length() >= remaining().length());
+ parsed_.append(aBuf.substr(0, aBuf.length() - remaining().length())); // newly parsed bytes
+ }
+
+ return result;
+}
+
+// raw is not a reference because a reference might point back to our own buf_ or parsed_
+bool
+Http::One::RequestParser::doParse(const SBuf &aBuf)
{
buf_ = aBuf;
debugs(74, DBG_DATA, "Parse buf={length=" << aBuf.length() << ", data='" << aBuf << "'}");
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