1 #pragma ident	"%Z%%M%	%I%	%E% SMI"
2 /*
3  * lib/krb5/os/net_read.c
4  *
5  * Copyright 1987, 1988, 1990 by the Massachusetts Institute of Technology.
6  * All Rights Reserved.
7  *
8  * Export of this software from the United States of America may
9  *   require a specific license from the United States Government.
10  *   It is the responsibility of any person or organization contemplating
11  *   export to obtain such a license before exporting.
12  *
13  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
14  * distribute this software and its documentation for any purpose and
15  * without fee is hereby granted, provided that the above copyright
16  * notice appear in all copies and that both that copyright notice and
17  * this permission notice appear in supporting documentation, and that
18  * the name of M.I.T. not be used in advertising or publicity pertaining
19  * to distribution of the software without specific, written prior
20  * permission.  Furthermore if you modify this software you must label
21  * your software as modified software and not distribute it in such a
22  * fashion that it might be confused with the original M.I.T. software.
23  * M.I.T. makes no representations about the suitability of
24  * this software for any purpose.  It is provided "as is" without express
25  * or implied warranty.
26  *
27  */
28 
29 #define NEED_LOWLEVEL_IO
30 #define NEED_SOCKETS
31 #include <k5-int.h>
32 
33 /*
34  * krb5_net_read() reads from the file descriptor "fd" to the buffer
35  * "buf", until either 1) "len" bytes have been read or 2) cannot
36  * read anymore from "fd".  It returns the number of bytes read
37  * or a read() error.  (The calling interface is identical to
38  * read(2).)
39  *
40  * XXX must not use non-blocking I/O
41  */
42 
43 /*ARGSUSED*/
44 int
45 krb5_net_read(context, fd, buf, len)
46     krb5_context context;
47     int fd;
48     register char *buf;
49     register int len;
50 {
51     int cc, len2 = 0;
52 
53     do {
54 	cc = SOCKET_READ((SOCKET)fd, buf, len);
55 	if (cc < 0) {
56 	    if (SOCKET_ERRNO == SOCKET_EINTR)
57 		continue;
58 
59 		/* XXX this interface sucks! */
60         errno = SOCKET_ERRNO;
61 
62 	    return(cc);		 /* errno is already set */
63 	}
64 	else if (cc == 0) {
65 	    return(len2);
66 	} else {
67 	    buf += cc;
68 	    len2 += cc;
69 	    len -= cc;
70 	}
71     } while (len > 0);
72     return(len2);
73 }
74