xref: /titanic_41/usr/src/lib/gss_mechs/mech_krb5/krb5/os/net_read.c (revision 159d09a20817016f09b3ea28d1bdada4a336bb91)
1 /*
2  * lib/krb5/os/net_read.c
3  *
4  * Copyright 1987, 1988, 1990 by the Massachusetts Institute of Technology.
5  * All Rights Reserved.
6  *
7  * Export of this software from the United States of America may
8  *   require a specific license from the United States Government.
9  *   It is the responsibility of any person or organization contemplating
10  *   export to obtain such a license before exporting.
11  *
12  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13  * distribute this software and its documentation for any purpose and
14  * without fee is hereby granted, provided that the above copyright
15  * notice appear in all copies and that both that copyright notice and
16  * this permission notice appear in supporting documentation, and that
17  * the name of M.I.T. not be used in advertising or publicity pertaining
18  * to distribution of the software without specific, written prior
19  * permission.  Furthermore if you modify this software you must label
20  * your software as modified software and not distribute it in such a
21  * fashion that it might be confused with the original M.I.T. software.
22  * M.I.T. makes no representations about the suitability of
23  * this software for any purpose.  It is provided "as is" without express
24  * or implied warranty.
25  *
26  */
27 
28 #include "k5-int.h"
29 
30 /*
31  * krb5_net_read() reads from the file descriptor "fd" to the buffer
32  * "buf", until either 1) "len" bytes have been read or 2) cannot
33  * read anymore from "fd".  It returns the number of bytes read
34  * or a read() error.  (The calling interface is identical to
35  * read(2).)
36  *
37  * XXX must not use non-blocking I/O
38  */
39 
40 /*ARGSUSED*/
41 int
krb5_net_read(krb5_context context,int fd,register char * buf,register int len)42 krb5_net_read(krb5_context context, int fd, register char *buf, register int len)
43 {
44     int cc, len2 = 0;
45 
46     do {
47 	cc = SOCKET_READ((SOCKET)fd, buf, len);
48 	if (cc < 0) {
49 	    if (SOCKET_ERRNO == SOCKET_EINTR)
50 		continue;
51 
52 		/* XXX this interface sucks! */
53         errno = SOCKET_ERRNO;
54 
55 	    return(cc);		 /* errno is already set */
56 	}
57 	else if (cc == 0) {
58 	    return(len2);
59 	} else {
60 	    buf += cc;
61 	    len2 += cc;
62 	    len -= cc;
63 	}
64     } while (len > 0);
65     return(len2);
66 }
67