/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "apr_arch_file_io.h" #include "apr_file_io.h" #include "apr_general.h" #include "apr_strings.h" #include "apr_lib.h" #include "apr_errno.h" #include #include "apr_arch_atime.h" #include "apr_arch_misc.h" /* * read_with_timeout() * Uses async i/o to emulate unix non-blocking i/o with timeouts. */ static apr_status_t read_with_timeout(apr_file_t *file, void *buf, apr_size_t len_in, apr_size_t *nbytes) { apr_status_t rv; DWORD len = (DWORD)len_in; DWORD bytesread = 0; /* Handle the zero timeout non-blocking case */ if (file->timeout == 0) { /* Peek at the pipe. If there is no data available, return APR_EAGAIN. * If data is available, go ahead and read it. */ if (file->pipe) { DWORD bytes; if (!PeekNamedPipe(file->filehand, NULL, 0, NULL, &bytes, NULL)) { rv = apr_get_os_error(); if (rv == APR_FROM_OS_ERROR(ERROR_BROKEN_PIPE)) { rv = APR_EOF; } *nbytes = 0; return rv; } else { if (bytes == 0) { *nbytes = 0; return APR_EAGAIN; } if (len > bytes) { len = bytes; } } } else { /* ToDo: Handle zero timeout non-blocking file i/o * This is not needed until an APR application needs to * timeout file i/o (which means setting file i/o non-blocking) */ } } if (file->pOverlapped && !file->pipe) { file->pOverlapped->Offset = (DWORD)file->filePtr; file->pOverlapped->OffsetHigh = (DWORD)(file->filePtr >> 32); } if (ReadFile(file->filehand, buf, len, &bytesread, file->pOverlapped)) { rv = APR_SUCCESS; } else { rv = apr_get_os_error(); if (rv == APR_FROM_OS_ERROR(ERROR_IO_PENDING)) { DWORD res; /* It seems that ReadFile() return ERROR_IO_PENDING even * when I/O operation completed syncronously. * Use fast macro to check that overlapped I/O already * completed to avoid kernel call. */ if (HasOverlappedIoCompleted(file->pOverlapped)) { res = WAIT_OBJECT_0; } else { /* Wait for the pending i/o, timeout converted from us to ms * Note that we loop if someone gives up the event. * * NOTE: We do not handle WAIT_ABANDONED here because they * can be returned only when waiting for mutex. */ res = apr_wait_for_single_object(file->pOverlapped->hEvent, file->timeout); } /* There is one case that represents entirely * successful operations, otherwise we will cancel * the operation in progress. */ if (res != WAIT_OBJECT_0) { CancelIoEx(file->filehand, file->pOverlapped); } /* Ignore any failures above. Attempt to complete * the overlapped operation and use only _its_ result. * For example, CancelIo or WaitForSingleObject can * fail if the handle is closed, yet the read may have * completed before we attempted to CancelIo... */ if (GetOverlappedResult(file->filehand, file->pOverlapped, &bytesread, TRUE)) { rv = APR_SUCCESS; } else { rv = apr_get_os_error(); if (((rv == APR_FROM_OS_ERROR(ERROR_IO_INCOMPLETE)) || (rv == APR_FROM_OS_ERROR(ERROR_OPERATION_ABORTED))) && (res == WAIT_TIMEOUT)) rv = APR_TIMEUP; } } if (rv == APR_FROM_OS_ERROR(ERROR_BROKEN_PIPE)) { /* Assume ERROR_BROKEN_PIPE signals an EOF reading from a pipe */ rv = APR_EOF; } else if (rv == APR_FROM_OS_ERROR(ERROR_HANDLE_EOF)) { /* Did we hit EOF reading from the handle? */ rv = APR_EOF; } } /* OK and 0 bytes read ==> end of file */ if (rv == APR_SUCCESS && bytesread == 0) rv = APR_EOF; if (rv == APR_SUCCESS && file->pOverlapped && !file->pipe) { file->filePtr += bytesread; } *nbytes = bytesread; return rv; } static apr_status_t read_buffered(apr_file_t *thefile, void *buf, apr_size_t *len) { apr_status_t rv; char *pos = (char *)buf; apr_size_t bytes_read; apr_size_t size; apr_size_t remaining = *len; if (thefile->direction == 1) { rv = apr_file_flush(thefile); if (rv != APR_SUCCESS) { return rv; } thefile->bufpos = 0; thefile->direction = 0; thefile->dataRead = 0; } /* Copy the data we have in the buffer. */ size = thefile->dataRead - thefile->bufpos; if (size > remaining) { size = remaining; } memcpy(pos, thefile->buffer + thefile->bufpos, size); pos += size; remaining -= size; thefile->bufpos += size; if (remaining == 0) { /* Nothing to do more, keep *LEN unchanged and return. */ return APR_SUCCESS; } /* The buffer is empty, but the caller wants more. * Decide on the most appropriate way to read from the file: */ if (remaining > thefile->bufsize) { /* If the remaining chunk won't fit into the buffer, read it into * the destination buffer with a single syscall. */ rv = read_with_timeout(thefile, pos, remaining, &bytes_read); thefile->filePtr += bytes_read; pos += bytes_read; /* Also, copy the last BUFSIZE (or less in case of a short read) bytes * from the chunk to our buffer so that seeking backwards and reading * would work from the buffer. */ size = thefile->bufsize; if (size > bytes_read) { size = bytes_read; } memcpy(thefile->buffer, pos - size, size); thefile->bufpos = size; thefile->dataRead = size; } else { /* The remaining chunk fits into the buffer. Read up to BUFSIZE bytes * from the file to our internal buffer. */ rv = read_with_timeout(thefile, thefile->buffer, thefile->bufsize, &bytes_read); thefile->filePtr += bytes_read; thefile->bufpos = 0; thefile->dataRead = bytes_read; /* Copy the required part to the caller. */ size = remaining; if (size > bytes_read) { size = bytes_read; } memcpy(pos, thefile->buffer, size); pos += size; thefile->bufpos += size; } if (bytes_read == 0 && rv == APR_EOF) { thefile->eof_hit = TRUE; } *len = pos - (char *)buf; if (*len) { rv = APR_SUCCESS; } return rv; } APR_DECLARE(apr_status_t) apr_file_read(apr_file_t *thefile, void *buf, apr_size_t *len) { apr_status_t rv; DWORD bytes_read = 0; if (*len <= 0) { *len = 0; return APR_SUCCESS; } /* If the file is open for xthread support, allocate and * initialize the overlapped and io completion event (hEvent). * Threads should NOT share an apr_file_t or its hEvent. */ if ((thefile->flags & APR_FOPEN_XTHREAD) && !thefile->pOverlapped ) { thefile->pOverlapped = (OVERLAPPED*) apr_pcalloc(thefile->pool, sizeof(OVERLAPPED)); thefile->pOverlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (!thefile->pOverlapped->hEvent) { rv = apr_get_os_error(); return rv; } } /* Handle the ungetchar if there is one */ if (thefile->ungetchar != -1) { bytes_read = 1; *(char *)buf = (char)thefile->ungetchar; buf = (char *)buf + 1; (*len)--; thefile->ungetchar = -1; if (*len == 0) { *len = bytes_read; return APR_SUCCESS; } } if (thefile->buffered) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_lock(thefile->mutex); } rv = read_buffered(thefile, buf, len); if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } } else { /* Unbuffered i/o */ apr_size_t nbytes; rv = read_with_timeout(thefile, buf, *len, &nbytes); if (rv == APR_EOF) thefile->eof_hit = TRUE; *len = nbytes; } return rv; } APR_DECLARE(apr_status_t) apr_file_rotating_check(apr_file_t *thefile) { return APR_ENOTIMPL; } APR_DECLARE(apr_status_t) apr_file_rotating_manual_check(apr_file_t *thefile, apr_time_t n) { return APR_ENOTIMPL; } /* Helper function that adapts WriteFile() to apr_size_t instead * of DWORD. */ static apr_status_t write_helper(HANDLE filehand, const char *buf, apr_size_t len, apr_size_t *pwritten) { apr_size_t remaining = len; *pwritten = 0; do { DWORD to_write; DWORD written; if (remaining > APR_DWORD_MAX) { to_write = APR_DWORD_MAX; } else { to_write = (DWORD)remaining; } if (!WriteFile(filehand, buf, to_write, &written, NULL)) { *pwritten += written; return apr_get_os_error(); } *pwritten += written; remaining -= written; buf += written; } while (remaining); return APR_SUCCESS; } static apr_status_t write_buffered(apr_file_t *thefile, const char *buf, apr_size_t len, apr_size_t *pwritten) { apr_status_t rv; if (thefile->direction == 0) { /* Position file pointer for writing at the offset we are logically reading from */ apr_off_t offset = thefile->filePtr - thefile->dataRead + thefile->bufpos; DWORD offlo = (DWORD)offset; LONG offhi = (LONG)(offset >> 32); if (offset != thefile->filePtr) SetFilePointer(thefile->filehand, offlo, &offhi, FILE_BEGIN); thefile->bufpos = thefile->dataRead = 0; thefile->direction = 1; } *pwritten = 0; while (len > 0) { if (thefile->bufpos == thefile->bufsize) { /* write buffer is full */ rv = apr_file_flush(thefile); if (rv) { return rv; } } /* If our buffer is empty, and we cannot fit the remaining chunk * into it, write the chunk with a single syscall and return. */ if (thefile->bufpos == 0 && len > thefile->bufsize) { apr_size_t written; rv = write_helper(thefile->filehand, buf, len, &written); thefile->filePtr += written; *pwritten += written; return rv; } else { apr_size_t blocksize = len; if (blocksize > thefile->bufsize - thefile->bufpos) { blocksize = thefile->bufsize - thefile->bufpos; } memcpy(thefile->buffer + thefile->bufpos, buf, blocksize); thefile->bufpos += blocksize; buf += blocksize; len -= blocksize; *pwritten += blocksize; } } return APR_SUCCESS; } APR_DECLARE(apr_status_t) apr_file_write(apr_file_t *thefile, const void *buf, apr_size_t *nbytes) { apr_status_t rv; DWORD bwrote; /* If the file is open for xthread support, allocate and * initialize the overlapped and io completion event (hEvent). * Threads should NOT share an apr_file_t or its hEvent. */ if ((thefile->flags & APR_FOPEN_XTHREAD) && !thefile->pOverlapped ) { thefile->pOverlapped = (OVERLAPPED*) apr_pcalloc(thefile->pool, sizeof(OVERLAPPED)); thefile->pOverlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (!thefile->pOverlapped->hEvent) { rv = apr_get_os_error(); return rv; } } if (thefile->buffered) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_lock(thefile->mutex); } rv = write_buffered(thefile, buf, *nbytes, nbytes); if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } return rv; } else { if (thefile->pipe) { rv = WriteFile(thefile->filehand, buf, (DWORD)*nbytes, &bwrote, thefile->pOverlapped); } else if (thefile->append && !thefile->pOverlapped) { OVERLAPPED ov = {0}; /* If the file is opened for synchronous I/O, take advantage of the * documented way to atomically append data by calling WriteFile() * with both the OVERLAPPED.Offset and OffsetHigh members set to * 0xFFFFFFFF. This avoids calling LockFile() that is otherwise * required to avoid a race condition between seeking to the end * and writing data. Not locking the file improves robustness of * such appends and avoids a deadlock when appending to an already * locked file, as described in PR50058. * * We use this approach only for files opened for synchronous I/O * because in this case the I/O Manager maintains the current file * position. Otherwise, the file offset returned or changed by * the SetFilePointer() API is not guaranteed to be valid and that * could, for instance, break apr_file_seek() calls after appending * data. Sadly, if a file is opened for asynchronous I/O, this * call doesn't update the OVERLAPPED.Offset member to reflect the * actual offset used when appending the data (which we could then * use to make seeking and other operations involving filePtr work). * Therefore, when appending to files opened for asynchronous I/O, * we still use the LockFile + SetFilePointer + WriteFile approach. * * References: * https://bz.apache.org/bugzilla/show_bug.cgi?id=50058 * https://msdn.microsoft.com/en-us/library/windows/desktop/aa365747 * https://msdn.microsoft.com/en-us/library/windows/hardware/ff567121 */ ov.Offset = MAXDWORD; ov.OffsetHigh = MAXDWORD; rv = WriteFile(thefile->filehand, buf, (DWORD)*nbytes, &bwrote, &ov); } else { apr_off_t offset = 0; apr_status_t rc; if (thefile->append) { if (thefile->flags & APR_FOPEN_XTHREAD) { /* apr_file_lock will mutex the file across processes. * The call to apr_thread_mutex_lock is added to avoid * a race condition between LockFile and WriteFile * that occasionally leads to deadlocked threads. */ apr_thread_mutex_lock(thefile->mutex); } rc = apr_file_lock(thefile, APR_FLOCK_EXCLUSIVE); if (rc != APR_SUCCESS) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } return rc; } rc = apr_file_seek(thefile, APR_END, &offset); if (rc != APR_SUCCESS) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } return rc; } } if (thefile->pOverlapped) { thefile->pOverlapped->Offset = (DWORD)thefile->filePtr; thefile->pOverlapped->OffsetHigh = (DWORD)(thefile->filePtr >> 32); } rv = WriteFile(thefile->filehand, buf, (DWORD)*nbytes, &bwrote, thefile->pOverlapped); if (thefile->append) { apr_file_unlock(thefile); if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } } } if (rv) { *nbytes = bwrote; rv = APR_SUCCESS; } else { (*nbytes) = 0; rv = apr_get_os_error(); if (rv == APR_FROM_OS_ERROR(ERROR_IO_PENDING)) { DWORD res; /* It seems that WriteFile() return ERROR_IO_PENDING even * when I/O operation completed syncronously. * Use fast macro to check that overlapped I/O already * completed to avoid kernel call. */ if (HasOverlappedIoCompleted(thefile->pOverlapped)) { res = WAIT_OBJECT_0; } else { res = apr_wait_for_single_object(thefile->pOverlapped->hEvent, thefile->timeout); } /* There is one case that represents entirely * successful operations, otherwise we will cancel * the operation in progress. */ if (res != WAIT_OBJECT_0) { CancelIoEx(thefile->filehand, thefile->pOverlapped); } /* Ignore any failures above. Attempt to complete * the overlapped operation and use only _its_ result. * For example, CancelIo or WaitForSingleObject can * fail if the handle is closed, yet the read may have * completed before we attempted to CancelIo... */ if (GetOverlappedResult(thefile->filehand, thefile->pOverlapped, &bwrote, TRUE)) { *nbytes = bwrote; rv = APR_SUCCESS; } else { rv = apr_get_os_error(); if (((rv == APR_FROM_OS_ERROR(ERROR_IO_INCOMPLETE)) || (rv == APR_FROM_OS_ERROR(ERROR_OPERATION_ABORTED))) && (res == WAIT_TIMEOUT)) rv = APR_TIMEUP; if (rv == APR_TIMEUP && thefile->timeout == 0) { rv = APR_EAGAIN; } } } } if (rv == APR_SUCCESS && thefile->pOverlapped && !thefile->pipe) { thefile->filePtr += *nbytes; } } return rv; } /* ToDo: Write for it anyway and test the oslevel! * Too bad WriteFileGather() is not supported on 95&98 (or NT prior to SP2) */ APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile, const struct iovec *vec, apr_size_t nvec, apr_size_t *nbytes) { apr_status_t rv = APR_SUCCESS; apr_size_t i; apr_size_t bwrote = 0; char *buf; *nbytes = 0; for (i = 0; i < nvec; i++) { buf = vec[i].iov_base; bwrote = vec[i].iov_len; rv = apr_file_write(thefile, buf, &bwrote); *nbytes += bwrote; if (rv != APR_SUCCESS) { break; } } return rv; } APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile) { apr_size_t len = 1; return apr_file_write(thefile, &ch, &len); } APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile) { thefile->ungetchar = (unsigned char) ch; return APR_SUCCESS; } APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile) { apr_status_t rc; apr_size_t bread; bread = 1; rc = apr_file_read(thefile, ch, &bread); if (rc) { return rc; } if (bread == 0) { thefile->eof_hit = TRUE; return APR_EOF; } return APR_SUCCESS; } APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile) { apr_size_t len = strlen(str); return apr_file_write(thefile, str, &len); } APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, apr_file_t *thefile) { apr_status_t rv = APR_SUCCESS; apr_size_t nbytes; const char *str_start = str; char *final = str + len - 1; /* If the file is open for xthread support, allocate and * initialize the overlapped and io completion event (hEvent). * Threads should NOT share an apr_file_t or its hEvent. */ if ((thefile->flags & APR_FOPEN_XTHREAD) && !thefile->pOverlapped) { thefile->pOverlapped = (OVERLAPPED*) apr_pcalloc(thefile->pool, sizeof(OVERLAPPED)); thefile->pOverlapped->hEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (!thefile->pOverlapped->hEvent) { rv = apr_get_os_error(); return rv; } } /* Handle the ungetchar if there is one. */ if (thefile->ungetchar != -1 && str < final) { *str = thefile->ungetchar; thefile->ungetchar = -1; if (*str == '\n') { *(++str) = '\0'; return APR_SUCCESS; } ++str; } /* If we have an underlying buffer, we can be *much* more efficient * and skip over the read_with_timeout() calls. */ if (thefile->buffered) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_lock(thefile->mutex); } if (thefile->direction == 1) { rv = apr_file_flush(thefile); if (rv) { if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } return rv; } thefile->direction = 0; thefile->bufpos = 0; thefile->dataRead = 0; } while (str < final) { /* leave room for trailing '\0' */ if (thefile->bufpos < thefile->dataRead) { *str = thefile->buffer[thefile->bufpos++]; } else { nbytes = 1; rv = read_buffered(thefile, str, &nbytes); if (rv != APR_SUCCESS) { break; } } if (*str == '\n') { ++str; break; } ++str; } if (thefile->flags & APR_FOPEN_XTHREAD) { apr_thread_mutex_unlock(thefile->mutex); } } else { while (str < final) { /* leave room for trailing '\0' */ nbytes = 1; rv = read_with_timeout(thefile, str, nbytes, &nbytes); if (rv == APR_EOF) thefile->eof_hit = TRUE; if (rv != APR_SUCCESS) { break; } if (*str == '\n') { ++str; break; } ++str; } } /* We must store a terminating '\0' if we've stored any chars. We can * get away with storing it if we hit an error first. */ *str = '\0'; if (str > str_start) { /* We stored chars; don't report EOF or any other errors; * the app will find out about that on the next call. */ return APR_SUCCESS; } return rv; } APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile) { if (thefile->buffered) { apr_status_t rc = 0; if (thefile->direction == 1 && thefile->bufpos) { apr_size_t written; rc = write_helper(thefile->filehand, thefile->buffer, thefile->bufpos, &written); thefile->filePtr += written; if (rc == 0) thefile->bufpos = 0; } return rc; } /* There isn't anything to do if we aren't buffering the output * so just return success. */ return APR_SUCCESS; } APR_DECLARE(apr_status_t) apr_file_sync(apr_file_t *thefile){ apr_status_t rv; rv = apr_file_flush(thefile); if (rv != APR_SUCCESS) { return rv; } if (!FlushFileBuffers(thefile->filehand)) { rv = apr_get_os_error(); } return rv; } APR_DECLARE(apr_status_t) apr_file_datasync(apr_file_t *thefile){ return apr_file_sync(thefile); } struct apr_file_printf_data { apr_vformatter_buff_t vbuff; apr_file_t *fptr; char *buf; }; static int file_printf_flush(apr_vformatter_buff_t *buff) { struct apr_file_printf_data *data = (struct apr_file_printf_data *)buff; if (apr_file_write_full(data->fptr, data->buf, data->vbuff.curpos - data->buf, NULL)) { return -1; } data->vbuff.curpos = data->buf; return 0; } APR_DECLARE_NONSTD(int) apr_file_printf(apr_file_t *fptr, const char *format, ...) { struct apr_file_printf_data data; va_list ap; int count; data.buf = malloc(HUGE_STRING_LEN); if (data.buf == NULL) { return 0; } data.vbuff.curpos = data.buf; data.vbuff.endpos = data.buf + HUGE_STRING_LEN; data.fptr = fptr; va_start(ap, format); count = apr_vformatter(file_printf_flush, (apr_vformatter_buff_t *)&data, format, ap); /* apr_vformatter does not call flush for the last bits */ if (count >= 0) file_printf_flush((apr_vformatter_buff_t *)&data); va_end(ap); free(data.buf); return count; } APR_DECLARE(apr_status_t) apr_file_pipe_wait(apr_file_t *thepipe, apr_wait_type_t direction) { return APR_ENOTIMPL; }