1 /* 2 * Copyright (c) 2000-2002 Proofpoint, Inc. and its suppliers. 3 * All rights reserved. 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Chris Torek. 9 * 10 * By using this file, you agree to the terms and conditions set 11 * forth in the LICENSE file which can be found at the top level of 12 * the sendmail distribution. 13 */ 14 15 #include <sm/gen.h> 16 SM_RCSID("@(#)$Id: wsetup.c,v 1.21 2013/11/22 20:51:44 ca Exp $") 17 #include <stdlib.h> 18 #include <errno.h> 19 #include <sm/io.h> 20 #include "local.h" 21 22 /* 23 ** SM_WSETUP -- check writing is safe 24 ** 25 ** Various output routines call wsetup to be sure it is safe to write, 26 ** because either flags does not include SMMWR, or buf is NULL. 27 ** Used in the macro "cantwrite" found in "local.h". 28 ** 29 ** Parameters: 30 ** fp -- the file pointer 31 ** 32 ** Results: 33 ** Failure: SM_IO_EOF and sets errno 34 ** Success: 0 (zero) 35 */ 36 37 int 38 sm_wsetup(fp) 39 register SM_FILE_T *fp; 40 { 41 /* make sure stdio is set up */ 42 if (!Sm_IO_DidInit) 43 sm_init(); 44 45 /* If we are not writing, we had better be reading and writing. */ 46 if ((fp->f_flags & SMWR) == 0) 47 { 48 if ((fp->f_flags & SMRW) == 0) 49 { 50 errno = EBADF; 51 return SM_IO_EOF; 52 } 53 if (fp->f_flags & SMRD) 54 { 55 /* clobber any ungetc data */ 56 if (HASUB(fp)) 57 FREEUB(fp); 58 59 /* discard read buffer */ 60 fp->f_flags &= ~(SMRD|SMFEOF); 61 fp->f_r = 0; 62 fp->f_p = fp->f_bf.smb_base; 63 } 64 fp->f_flags |= SMWR; 65 } 66 67 /* Make a buffer if necessary, then set w. */ 68 if (fp->f_bf.smb_base == NULL) 69 sm_makebuf(fp); 70 if (fp->f_flags & SMLBF) 71 { 72 /* 73 ** It is line buffered, so make lbfsize be -bufsize 74 ** for the sm_putc() macro. We will change lbfsize back 75 ** to 0 whenever we turn off SMWR. 76 */ 77 78 fp->f_w = 0; 79 fp->f_lbfsize = -fp->f_bf.smb_size; 80 } 81 else 82 fp->f_w = fp->f_flags & SMNBF ? 0 : fp->f_bf.smb_size; 83 return 0; 84 } 85