3 * $Id: chan.c,v 1.7 2004/04/08 01:36:25 mdw Exp $
7 * (c) 1999 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of the `fw' port forwarder.
14 * `fw' is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * `fw' is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with `fw'; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
38 #include <sys/types.h>
43 #include <mLib/alloc.h>
44 #include <mLib/conn.h>
56 /*----- Main code ---------------------------------------------------------*/
58 /* --- @writechan@ --- *
60 * Arguments: @int fd@ = file descriptor to write to
61 * @unsigned mode@ = what the descriptor is ready for
62 * @void *vp@ = pointer to channel block
66 * Use: Writes to a channel.
69 static void writechan(int fd
, unsigned mode
, void *vp
)
73 unsigned base
= c
->base
;
74 unsigned len
= c
->len
;
76 /* --- Write data from my buffer --- */
80 /* --- Do the write --- */
82 D( printf("writechan %d: base = %u, len = %u; ", fd
, base
, len
); )
83 if (base
+ len
<= CHAN_BUFSZ
) {
84 D( printf("%u:%u", base
, len
); )
85 w
= write(fd
, c
->buf
+ base
, len
);
88 iov
[0].iov_base
= c
->buf
+ base
;
89 iov
[0].iov_len
= CHAN_BUFSZ
- base
;
90 iov
[1].iov_base
= c
->buf
;
91 iov
[1].iov_len
= len
- iov
[0].iov_len
;
92 D( printf("%u:%u, %u:%u",
93 base
, CHAN_BUFSZ
- base
,
94 0, len
+ base
- CHAN_BUFSZ
); )
95 w
= writev(fd
, iov
, 2);
97 D( printf("; returned %d\n", w
); )
99 /* --- Sift through the results --- */
102 if (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
)
108 else if (c
->len
== CHAN_BUFSZ
&& !(c
->f
& CHANF_CLOSE
))
116 /* --- Close the output end if necessary --- */
120 if (c
->f
& CHANF_CLOSE
)
125 /* --- Force a close if an error occurred --- */
132 /* --- @readchan@ --- *
134 * Arguments: @int fd@ = file descriptor to read from
135 * @unsigned mode@ = what the descriptor is ready for
136 * @void *vp@ = pointer to channel block
140 * Use: Reads from a channel.
143 static void readchan(int fd
, unsigned mode
, void *vp
)
147 unsigned base
= c
->base
;
148 unsigned len
= c
->len
;
150 /* --- Do the read --- */
152 D( printf("readchan %d: base = %u, len = %u; ", fd
, base
, len
); )
154 D( printf("%u:%u", len
, CHAN_BUFSZ
- len
); )
155 r
= read(fd
, c
->buf
+ len
, CHAN_BUFSZ
- len
);
156 } else if (base
+ len
>= CHAN_BUFSZ
) {
157 D( printf("%u:%u", base
+ len
- CHAN_BUFSZ
, CHAN_BUFSZ
- len
); )
158 r
= read(fd
, c
->buf
+ base
+ len
- CHAN_BUFSZ
, CHAN_BUFSZ
- len
);
161 iov
[0].iov_base
= c
->buf
+ base
+ len
;
162 iov
[0].iov_len
= CHAN_BUFSZ
- base
- len
;
163 iov
[1].iov_base
= c
->buf
;
164 iov
[1].iov_len
= base
;
165 D( printf("%u:%u, %u:%u",
166 base
+ len
, CHAN_BUFSZ
- base
- len
,
168 r
= readv(fd
, iov
, 2);
170 D( printf("; returned %d\n", r
); )
172 /* --- Sift through the results --- */
175 if (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
)
181 else if (c
->len
== 0 && (c
->f
& CHANF_READY
)) {
186 if (c
->len
== CHAN_BUFSZ
)
190 /* --- Close the read end of the channel --- */
194 if (!c
->len
&& (c
->f
& CHANF_READY
)) {
201 /* --- @chan_close@ --- *
203 * Arguments: @chan *c@ = pointer to channel
207 * Use: Closes down a channel prematurely.
210 void chan_close(chan
*c
)
212 if (!(c
->f
& CHANF_CLOSE
) && c
->len
!= CHAN_BUFSZ
)
214 if ((c
->f
& CHANF_READY
) && c
->len
!= 0)
218 /* --- @chan_dest@ --- *
220 * Arguments: @chan *c@ = pointer to channel
221 * @int fd@ = destination file descriptor for channel
225 * Use: Sets the channel's destination so it knows where to put
229 void chan_dest(chan
*c
, int fd
)
231 if (c
->f
& CHANF_READY
)
233 sel_initfile(sel
, &c
->w
, fd
, SEL_WRITE
, writechan
, c
);
234 if (c
->len
|| (c
->f
& CHANF_CLOSE
)) {
241 /* --- @chan_open@ --- *
243 * Arguments: @chan *c@ = pointer to channel to open
244 * @int from, to@ = source and destination file descriptors
245 * @void (*func)(void *p)@ = function to call on closure
246 * @void *p@ = argument to pass to function
250 * Use: Opens a channel. Data is copied from the source to the
251 * destination. The @to@ argument may be @-1@ if the file
252 * descriptor isn't known yet.
255 void chan_open(chan
*c
, int from
, int to
,
256 void (*func
)(void */
*p*/
), void *p
)
265 sel_initfile(sel
, &c
->r
, from
, SEL_READ
, readchan
, c
);
272 /*----- That's all, folks -------------------------------------------------*/