gecko-dev/netwerk/streamconv/converters/nsDirIndexParser.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/* This parsing code originally lived in xpfe/components/directory/ - bbaetz */

#include "nsDirIndexParser.h"

#include "mozilla/ArrayUtils.h"
#include "mozilla/dom/FallbackEncoding.h"
#include "mozilla/Encoding.h"
#include "prprf.h"
#include "nsCRT.h"
#include "nsDirIndex.h"
#include "nsEscape.h"
#include "nsIDirIndex.h"
#include "nsIInputStream.h"
#include "nsITextToSubURI.h"
#include "nsServiceManagerUtils.h"

using namespace mozilla;

NS_IMPL_ISUPPORTS(nsDirIndexParser, nsIRequestObserver, nsIStreamListener,
                  nsIDirIndexParser)

nsDirIndexParser::nsDirIndexParser() : mLineStart(0), mHasDescription(false) {}

nsresult nsDirIndexParser::Init() {
  mLineStart = 0;
  mHasDescription = false;
  mFormat[0] = -1;
  auto encoding = mozilla::dom::FallbackEncoding::FromLocale();
  encoding->Name(mEncoding);

  nsresult rv;
  // XXX not threadsafe
  if (gRefCntParser++ == 0)
    rv = CallGetService(NS_ITEXTTOSUBURI_CONTRACTID, &gTextToSubURI);
  else
    rv = NS_OK;

  return rv;
}

nsDirIndexParser::~nsDirIndexParser() {
  // XXX not threadsafe
  if (--gRefCntParser == 0) {
    NS_IF_RELEASE(gTextToSubURI);
  }
}

NS_IMETHODIMP
nsDirIndexParser::SetListener(nsIDirIndexListener* aListener) {
  mListener = aListener;
  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::GetListener(nsIDirIndexListener** aListener) {
  NS_IF_ADDREF(*aListener = mListener.get());
  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::GetComment(char** aComment) {
  *aComment = ToNewCString(mComment);

  if (!*aComment) return NS_ERROR_OUT_OF_MEMORY;

  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::SetEncoding(const char* aEncoding) {
  mEncoding.Assign(aEncoding);
  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::GetEncoding(char** aEncoding) {
  *aEncoding = ToNewCString(mEncoding);

  if (!*aEncoding) return NS_ERROR_OUT_OF_MEMORY;

  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::OnStartRequest(nsIRequest* aRequest) { return NS_OK; }

NS_IMETHODIMP
nsDirIndexParser::OnStopRequest(nsIRequest* aRequest, nsresult aStatusCode) {
  // Finish up
  if (mBuf.Length() > (uint32_t)mLineStart) {
    ProcessData(aRequest, nullptr);
  }

  return NS_OK;
}

nsDirIndexParser::Field nsDirIndexParser::gFieldTable[] = {
    {"Filename", FIELD_FILENAME},
    {"Description", FIELD_DESCRIPTION},
    {"Content-Length", FIELD_CONTENTLENGTH},
    {"Last-Modified", FIELD_LASTMODIFIED},
    {"Content-Type", FIELD_CONTENTTYPE},
    {"File-Type", FIELD_FILETYPE},
    {nullptr, FIELD_UNKNOWN}};

nsrefcnt nsDirIndexParser::gRefCntParser = 0;
nsITextToSubURI* nsDirIndexParser::gTextToSubURI;

nsresult nsDirIndexParser::ParseFormat(const char* aFormatStr) {
  // Parse a "200" format line, and remember the fields and their
  // ordering in mFormat. Multiple 200 lines stomp on each other.
  unsigned int formatNum = 0;
  mFormat[0] = -1;

  do {
    while (*aFormatStr && nsCRT::IsAsciiSpace(char16_t(*aFormatStr)))
      ++aFormatStr;

    if (!*aFormatStr) break;

    nsAutoCString name;
    int32_t len = 0;
    while (aFormatStr[len] && !nsCRT::IsAsciiSpace(char16_t(aFormatStr[len])))
      ++len;
    name.Append(aFormatStr, len);
    aFormatStr += len;

    // Okay, we're gonna monkey with the nsStr. Bold!
    name.SetLength(nsUnescapeCount(name.BeginWriting()));

    // All tokens are case-insensitive -
    // http://www.mozilla.org/projects/netlib/dirindexformat.html
    if (name.LowerCaseEqualsLiteral("description")) mHasDescription = true;

    for (Field* i = gFieldTable; i->mName; ++i) {
      if (name.EqualsIgnoreCase(i->mName)) {
        mFormat[formatNum] = i->mType;
        mFormat[++formatNum] = -1;
        break;
      }
    }

  } while (*aFormatStr && (formatNum < (ArrayLength(mFormat) - 1)));

  return NS_OK;
}

nsresult nsDirIndexParser::ParseData(nsIDirIndex* aIdx, char* aDataStr,
                                     int32_t aLineLen) {
  // Parse a "201" data line, using the field ordering specified in
  // mFormat.

  if (mFormat[0] == -1) {
    // Ignore if we haven't seen a format yet.
    return NS_OK;
  }

  nsresult rv = NS_OK;
  nsAutoCString filename;
  int32_t lineLen = aLineLen;

  for (int32_t i = 0; mFormat[i] != -1; ++i) {
    // If we've exhausted the data before we run out of fields, just bail.
    if (!*aDataStr || (lineLen < 1)) {
      return NS_OK;
    }

    while ((lineLen > 0) && nsCRT::IsAsciiSpace(*aDataStr)) {
      ++aDataStr;
      --lineLen;
    }

    if (lineLen < 1) {
      // invalid format, bail
      return NS_OK;
    }

    char* value = aDataStr;
    if (*aDataStr == '"' || *aDataStr == '\'') {
      // it's a quoted string. snarf everything up to the next quote character
      const char quotechar = *(aDataStr++);
      lineLen--;
      ++value;
      while ((lineLen > 0) && *aDataStr != quotechar) {
        ++aDataStr;
        --lineLen;
      }
      if (lineLen > 0) {
        *aDataStr++ = '\0';
        --lineLen;
      }

      if (!lineLen) {
        // invalid format, bail
        return NS_OK;
      }
    } else {
      // it's unquoted. snarf until we see whitespace.
      value = aDataStr;
      while ((lineLen > 0) && (!nsCRT::IsAsciiSpace(*aDataStr))) {
        ++aDataStr;
        --lineLen;
      }
      if (lineLen > 0) {
        *aDataStr++ = '\0';
        --lineLen;
      }
      // even if we ran out of line length here, there's still a trailing zero
      // byte afterwards
    }

    fieldType t = fieldType(mFormat[i]);
    switch (t) {
      case FIELD_FILENAME: {
        // don't unescape at this point, so that UnEscapeAndConvert() can
        filename = value;

        bool success = false;

        nsAutoString entryuri;

        if (gTextToSubURI) {
          nsAutoString result;
          if (NS_SUCCEEDED(rv = gTextToSubURI->UnEscapeAndConvert(
                               mEncoding, filename, result))) {
            if (!result.IsEmpty()) {
              aIdx->SetLocation(filename);
              if (!mHasDescription) aIdx->SetDescription(result);
              success = true;
            }
          } else {
            NS_WARNING("UnEscapeAndConvert error");
          }
        }

        if (!success) {
          // if unsuccessfully at charset conversion, then
          // just fallback to unescape'ing in-place
          // XXX - this shouldn't be using UTF8, should it?
          // when can we fail to get the service, anyway? - bbaetz
          aIdx->SetLocation(filename);
          if (!mHasDescription) {
            aIdx->SetDescription(NS_ConvertUTF8toUTF16(value));
          }
        }
      } break;
      case FIELD_DESCRIPTION:
        nsUnescape(value);
        aIdx->SetDescription(NS_ConvertUTF8toUTF16(value));
        break;
      case FIELD_CONTENTLENGTH: {
        int64_t len;
        int32_t status = PR_sscanf(value, "%lld", &len);
        if (status == 1)
          aIdx->SetSize(len);
        else
          aIdx->SetSize(UINT64_MAX);  // UINT64_MAX means unknown
      } break;
      case FIELD_LASTMODIFIED: {
        PRTime tm;
        nsUnescape(value);
        if (PR_ParseTimeString(value, false, &tm) == PR_SUCCESS) {
          aIdx->SetLastModified(tm);
        }
      } break;
      case FIELD_CONTENTTYPE:
        aIdx->SetContentType(nsDependentCString(value));
        break;
      case FIELD_FILETYPE:
        // unescape in-place
        nsUnescape(value);
        if (!nsCRT::strcasecmp(value, "directory")) {
          aIdx->SetType(nsIDirIndex::TYPE_DIRECTORY);
        } else if (!nsCRT::strcasecmp(value, "file")) {
          aIdx->SetType(nsIDirIndex::TYPE_FILE);
        } else if (!nsCRT::strcasecmp(value, "symbolic-link")) {
          aIdx->SetType(nsIDirIndex::TYPE_SYMLINK);
        } else {
          aIdx->SetType(nsIDirIndex::TYPE_UNKNOWN);
        }
        break;
      case FIELD_UNKNOWN:
        // ignore
        break;
    }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsDirIndexParser::OnDataAvailable(nsIRequest* aRequest, nsIInputStream* aStream,
                                  uint64_t aSourceOffset, uint32_t aCount) {
  if (aCount < 1) return NS_OK;

  int32_t len = mBuf.Length();

  // Ensure that our mBuf has capacity to hold the data we're about to
  // read.
  if (!mBuf.SetLength(len + aCount, fallible)) return NS_ERROR_OUT_OF_MEMORY;

  // Now read the data into our buffer.
  nsresult rv;
  uint32_t count;
  rv = aStream->Read(mBuf.BeginWriting() + len, aCount, &count);
  if (NS_FAILED(rv)) return rv;

  // Set the string's length according to the amount of data we've read.
  // Note: we know this to work on nsCString. This isn't guaranteed to
  //       work on other strings.
  mBuf.SetLength(len + count);

  return ProcessData(aRequest, nullptr);
}

nsresult nsDirIndexParser::ProcessData(nsIRequest* aRequest,
                                       nsISupports* aCtxt) {
  if (!mListener) return NS_ERROR_FAILURE;

  int32_t numItems = 0;

  while (true) {
    ++numItems;

    int32_t eol = mBuf.FindCharInSet("\n\r", mLineStart);
    if (eol < 0) break;
    mBuf.SetCharAt(char16_t('\0'), eol);

    const char* line = mBuf.get() + mLineStart;

    int32_t lineLen = eol - mLineStart;
    mLineStart = eol + 1;

    if (lineLen >= 4) {
      nsresult rv;
      const char* buf = line;

      if (buf[0] == '1') {
        if (buf[1] == '0') {
          if (buf[2] == '0' && buf[3] == ':') {
            // 100. Human-readable comment line. Ignore
          } else if (buf[2] == '1' && buf[3] == ':') {
            // 101. Human-readable information line.
            mComment.Append(buf + 4);

            char* value = ((char*)buf) + 4;
            nsUnescape(value);
            mListener->OnInformationAvailable(aRequest, aCtxt,
                                              NS_ConvertUTF8toUTF16(value));

          } else if (buf[2] == '2' && buf[3] == ':') {
            // 102. Human-readable information line, HTML.
            mComment.Append(buf + 4);
          }
        }
      } else if (buf[0] == '2') {
        if (buf[1] == '0') {
          if (buf[2] == '0' && buf[3] == ':') {
            // 200. Define field names
            rv = ParseFormat(buf + 4);
            if (NS_FAILED(rv)) {
              return rv;
            }
          } else if (buf[2] == '1' && buf[3] == ':') {
            // 201. Field data
            nsCOMPtr<nsIDirIndex> idx = new nsDirIndex();

            rv = ParseData(idx, ((char*)buf) + 4, lineLen - 4);
            if (NS_FAILED(rv)) {
              return rv;
            }

            mListener->OnIndexAvailable(aRequest, aCtxt, idx);
          }
        }
      } else if (buf[0] == '3') {
        if (buf[1] == '0') {
          if (buf[2] == '0' && buf[3] == ':') {
            // 300. Self-referring URL
          } else if (buf[2] == '1' && buf[3] == ':') {
            // 301. OUR EXTENSION - encoding
            int i = 4;
            while (buf[i] && nsCRT::IsAsciiSpace(buf[i])) ++i;

            if (buf[i]) SetEncoding(buf + i);
          }
        }
      }
    }
  }

  return NS_OK;
}