/* * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers. * All rights reserved. * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Chris Torek. * * By using this file, you agree to the terms and conditions set * forth in the LICENSE file which can be found at the top level of * the sendmail distribution. */ #include SM_RCSID("@(#)$Id: fpos.c,v 1.1.1.1 2002/02/17 21:56:43 gshapiro Exp $") #include #include #include #include #include #include #include #include #include "local.h" static jmp_buf TellTimeOut; /* ** TELLALRM -- handler when timeout activated for sm_io_tell() ** ** Returns flow of control to where setjmp(TellTimeOut) was set. ** ** Parameters: ** sig -- unused ** ** Returns: ** does not return ** ** Side Effects: ** returns flow of control to setjmp(TellTimeOut). ** ** NOTE: THIS CAN BE CALLED FROM A SIGNAL HANDLER. DO NOT ADD ** ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE ** DOING. */ /* ARGSUSED0 */ static void tellalrm(sig) int sig; { longjmp(TellTimeOut, 1); } /* ** SM_IO_TELL -- position the file pointer ** ** Paramters: ** fp -- the file pointer to get repositioned ** timeout -- time to complete the tell (milliseconds) ** ** Returns: ** Success -- the repositioned location. ** Failure -- -1 (minus 1) and sets errno */ long sm_io_tell(fp, timeout) register SM_FILE_T *fp; int SM_NONVOLATILE timeout; { register off_t pos; SM_EVENT *evt = NULL; SM_REQUIRE_ISA(fp, SmFileMagic); if (fp->f_seek == NULL) { errno = ESPIPE; /* historic practice */ return -1L; } if (timeout == SM_TIME_DEFAULT) timeout = fp->f_timeout; if (timeout == SM_TIME_IMMEDIATE) { /* ** Filling the buffer will take time and we are wanted to ** return immediately. So... */ errno = EAGAIN; return -1L; } /* ** Find offset of underlying I/O object, then adjust byte position ** may adjust seek offset on append stream */ (void) sm_flush(fp, (int *) &timeout); /* This is where we start the timeout */ if (timeout != SM_TIME_FOREVER) { if (setjmp(TellTimeOut) != 0) { errno = EAGAIN; return -1L; } evt = sm_seteventm(timeout, tellalrm, 0); } if (fp->f_flags & SMOFF) pos = fp->f_lseekoff; else { /* XXX only set the timeout here? */ pos = (*fp->f_seek)(fp, (off_t) 0, SM_IO_SEEK_CUR); if (pos == -1L) goto clean; } if (fp->f_flags & SMRD) { /* ** Reading. Any unread characters (including ** those from ungetc) cause the position to be ** smaller than that in the underlying object. */ pos -= fp->f_r; if (HASUB(fp)) pos -= fp->f_ur; } else if (fp->f_flags & SMWR && fp->f_p != NULL) { /* ** Writing. Any buffered characters cause the ** position to be greater than that in the ** underlying object. */ pos += fp->f_p - fp->f_bf.smb_base; } clean: /* We're back. So undo our timeout and handler */ if (evt != NULL) sm_clrevent(evt); return pos; }