5 * (c) 1999 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of the `fwd' port forwarder.
12 * `fwd' is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * `fwd' is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with `fwd'; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
35 /*----- Main code ---------------------------------------------------------*/
37 /* --- @writechan@ --- *
39 * Arguments: @int fd@ = file descriptor to write to
40 * @unsigned mode@ = what the descriptor is ready for
41 * @void *vp@ = pointer to channel block
45 * Use: Writes to a channel.
48 static void writechan(int fd
, unsigned mode
, void *vp
)
52 unsigned base
= c
->base
;
53 unsigned len
= c
->len
;
55 /* --- Write data from my buffer --- */
59 /* --- Do the write --- */
61 D( printf("writechan %d: base = %u, len = %u; ", fd
, base
, len
); )
62 if (base
+ len
<= CHAN_BUFSZ
) {
63 D( printf("%u:%u", base
, len
); )
64 w
= write(fd
, c
->buf
+ base
, len
);
67 iov
[0].iov_base
= c
->buf
+ base
;
68 iov
[0].iov_len
= CHAN_BUFSZ
- base
;
69 iov
[1].iov_base
= c
->buf
;
70 iov
[1].iov_len
= len
- iov
[0].iov_len
;
71 D( printf("%u:%u, %u:%u",
72 base
, CHAN_BUFSZ
- base
,
73 0, len
+ base
- CHAN_BUFSZ
); )
74 w
= writev(fd
, iov
, 2);
76 D( printf("; returned %d\n", w
); )
78 /* --- Sift through the results --- */
81 if (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
)
87 else if (c
->len
== CHAN_BUFSZ
&& !(c
->f
& CHANF_CLOSE
))
95 /* --- Close the output end if necessary --- */
99 if (c
->f
& CHANF_CLOSE
)
104 /* --- Force a close if an error occurred --- */
111 /* --- @readchan@ --- *
113 * Arguments: @int fd@ = file descriptor to read from
114 * @unsigned mode@ = what the descriptor is ready for
115 * @void *vp@ = pointer to channel block
119 * Use: Reads from a channel.
122 static void readchan(int fd
, unsigned mode
, void *vp
)
126 unsigned base
= c
->base
;
127 unsigned len
= c
->len
;
129 /* --- Do the read --- */
131 D( printf("readchan %d: base = %u, len = %u; ", fd
, base
, len
); )
133 D( printf("%u:%u", len
, CHAN_BUFSZ
- len
); )
134 r
= read(fd
, c
->buf
+ len
, CHAN_BUFSZ
- len
);
135 } else if (base
+ len
>= CHAN_BUFSZ
) {
136 D( printf("%u:%u", base
+ len
- CHAN_BUFSZ
, CHAN_BUFSZ
- len
); )
137 r
= read(fd
, c
->buf
+ base
+ len
- CHAN_BUFSZ
, CHAN_BUFSZ
- len
);
140 iov
[0].iov_base
= c
->buf
+ base
+ len
;
141 iov
[0].iov_len
= CHAN_BUFSZ
- base
- len
;
142 iov
[1].iov_base
= c
->buf
;
143 iov
[1].iov_len
= base
;
144 D( printf("%u:%u, %u:%u",
145 base
+ len
, CHAN_BUFSZ
- base
- len
,
147 r
= readv(fd
, iov
, 2);
149 D( printf("; returned %d\n", r
); )
151 /* --- Sift through the results --- */
154 if (errno
== EINTR
|| errno
== EAGAIN
|| errno
== EWOULDBLOCK
)
160 else if (c
->len
== 0 && (c
->f
& CHANF_READY
)) {
165 if (c
->len
== CHAN_BUFSZ
)
169 /* --- Close the read end of the channel --- */
173 if (!c
->len
&& (c
->f
& CHANF_READY
)) {
180 /* --- @chan_close@ --- *
182 * Arguments: @chan *c@ = pointer to channel
186 * Use: Closes down a channel prematurely.
189 void chan_close(chan
*c
)
191 if (!(c
->f
& CHANF_CLOSE
) && c
->len
!= CHAN_BUFSZ
)
193 if ((c
->f
& CHANF_READY
) && c
->len
!= 0)
197 /* --- @chan_dest@ --- *
199 * Arguments: @chan *c@ = pointer to channel
200 * @int fd@ = destination file descriptor for channel
204 * Use: Sets the channel's destination so it knows where to put
208 void chan_dest(chan
*c
, int fd
)
210 if (c
->f
& CHANF_READY
)
212 sel_initfile(sel
, &c
->w
, fd
, SEL_WRITE
, writechan
, c
);
213 if (c
->len
|| (c
->f
& CHANF_CLOSE
)) {
220 /* --- @chan_open@ --- *
222 * Arguments: @chan *c@ = pointer to channel to open
223 * @int from, to@ = source and destination file descriptors
224 * @void (*func)(void *p)@ = function to call on closure
225 * @void *p@ = argument to pass to function
229 * Use: Opens a channel. Data is copied from the source to the
230 * destination. The @to@ argument may be @-1@ if the file
231 * descriptor isn't known yet.
234 void chan_open(chan
*c
, int from
, int to
,
235 void (*func
)(void */
*p*/
), void *p
)
244 sel_initfile(sel
, &c
->r
, from
, SEL_READ
, readchan
, c
);
251 /*----- That's all, folks -------------------------------------------------*/