Thu Apr 30 00:48:10 2020 UTC ()
New kernel example module written by Ayushi Sharma
(christos)
diff -r1.10 -r1.11 src/sys/modules/examples/Makefile
diff -r1.14 -r1.15 src/sys/modules/examples/README
diff -r1.3 -r1.4 src/sys/modules/examples/ping/ping.c
diff -r0 -r1.1 src/sys/modules/examples/pollpal/Makefile
diff -r0 -r1.1 src/sys/modules/examples/pollpal/cmd_pollpal.c
diff -r0 -r1.1 src/sys/modules/examples/pollpal/pollpal.c
--- src/sys/modules/examples/Makefile 2020/04/04 21:15:04 1.10
+++ src/sys/modules/examples/Makefile 2020/04/30 00:48:10 1.11
| @@ -1,20 +1,21 @@ | | | @@ -1,20 +1,21 @@ |
1 | # $NetBSD: Makefile,v 1.10 2020/04/04 21:15:04 kamil Exp $ | | 1 | # $NetBSD: Makefile,v 1.11 2020/04/30 00:48:10 christos Exp $ |
2 | | | 2 | |
3 | .include <bsd.own.mk> | | 3 | .include <bsd.own.mk> |
4 | | | 4 | |
5 | SUBDIR+= current_time | | 5 | SUBDIR+= current_time |
6 | SUBDIR+= executor | | 6 | SUBDIR+= executor |
7 | SUBDIR+= fopsmapper # Needs an additional helper program | | 7 | SUBDIR+= fopsmapper # Needs an additional helper program |
8 | SUBDIR+= hello | | 8 | SUBDIR+= hello |
9 | #SUBDIR+= luahello # Nothing to build here, only text files | | 9 | #SUBDIR+= luahello # Nothing to build here, only text files |
10 | SUBDIR+= luareadhappy # Needs an additional Lua script | | 10 | SUBDIR+= luareadhappy # Needs an additional Lua script |
11 | SUBDIR+= mapper # Needs an additional helper program | | 11 | SUBDIR+= mapper # Needs an additional helper program |
12 | SUBDIR+= panic_string # Crashes the system | | 12 | SUBDIR+= panic_string # Crashes the system |
13 | SUBDIR+= ping # Needs an additional helper program | | 13 | SUBDIR+= ping # Needs an additional helper program |
14 | SUBDIR+= ping_block # Needs an additional helper program | | 14 | SUBDIR+= ping_block # Needs an additional helper program |
| | | 15 | SUBDIR+= pollpal # Needs an additional helper program |
15 | SUBDIR+= properties | | 16 | SUBDIR+= properties |
16 | SUBDIR+= readhappy | | 17 | SUBDIR+= readhappy |
17 | SUBDIR+= readhappy_mpsafe # Contains an additional helper program | | 18 | SUBDIR+= readhappy_mpsafe # Contains an additional helper program |
18 | SUBDIR+= sysctl | | 19 | SUBDIR+= sysctl |
19 | | | 20 | |
20 | .include <bsd.subdir.mk> | | 21 | .include <bsd.subdir.mk> |
--- src/sys/modules/examples/README 2020/04/04 21:15:04 1.14
+++ src/sys/modules/examples/README 2020/04/30 00:48:10 1.15
| @@ -1,32 +1,33 @@ | | | @@ -1,32 +1,33 @@ |
1 | $NetBSD: README,v 1.14 2020/04/04 21:15:04 kamil Exp $ | | 1 | $NetBSD: README,v 1.15 2020/04/30 00:48:10 christos Exp $ |
2 | | | 2 | |
3 | Kernel Developer's Manual | | 3 | Kernel Developer's Manual |
4 | | | 4 | |
5 | DESCRIPTION | | 5 | DESCRIPTION |
6 | The kernel example dynamic modules. | | 6 | The kernel example dynamic modules. |
7 | | | 7 | |
8 | This directory contains the following example modules: | | 8 | This directory contains the following example modules: |
9 | * current_time - prints current date and time in GMT/UTC | | 9 | * current_time - prints current date and time in GMT/UTC |
10 | * executor - basic implementation of callout and RUN_ONCE | | 10 | * executor - basic implementation of callout and RUN_ONCE |
11 | * fopsmapper - basic implementation of mmap with fileops fo_mmap | | 11 | * fopsmapper - basic implementation of mmap with fileops fo_mmap |
12 | * hello - the simplest `hello world' module | | 12 | * hello - the simplest `hello world' module |
13 | * luahello - the simplest `hello world' Lua module | | 13 | * luahello - the simplest `hello world' Lua module |
14 | * luareadhappy - demonstrates calling Lua code from C | | 14 | * luareadhappy - demonstrates calling Lua code from C |
15 | * mapper - basic implementation of mmap | | 15 | * mapper - basic implementation of mmap |
16 | * panic_string - shows how panic is being called through a device | | 16 | * panic_string - shows how panic is being called through a device |
17 | * ping - basic ioctl(9) | | 17 | * ping - basic ioctl(9) |
18 | * ping_block - basic ioctl(9) with a block device | | 18 | * ping_block - basic ioctl(9) with a block device |
19 | * properties - handle incoming properties during the module load | | 19 | * properties - handle incoming properties during the module load |
| | | 20 | * pollpal - implementation of basic poll(9) using palindrome |
20 | * readhappy - basic implementation of read(9) with happy numbers | | 21 | * readhappy - basic implementation of read(9) with happy numbers |
21 | * readhappy_mpsafe- demonstrates how to make a module MPSAFE | | 22 | * readhappy_mpsafe- demonstrates how to make a module MPSAFE |
22 | * sysctl - demonstrates adding a sysctl handle dynamically | | 23 | * sysctl - demonstrates adding a sysctl handle dynamically |
23 | | | 24 | |
24 | To build the examples you need a local copy of NetBSD sources. You also | | 25 | To build the examples you need a local copy of NetBSD sources. You also |
25 | need the comp set with toolchain. To build the module just enter a | | 26 | need the comp set with toolchain. To build the module just enter a |
26 | directory with example modules and use make(1): | | 27 | directory with example modules and use make(1): |
27 | | | 28 | |
28 | # make | | 29 | # make |
29 | | | 30 | |
30 | To load, unload, and stat the module use modload(8), modunload(8) and | | 31 | To load, unload, and stat the module use modload(8), modunload(8) and |
31 | modstat(8). | | 32 | modstat(8). |
32 | | | 33 | |
| @@ -72,15 +73,18 @@ HISTORY | | | @@ -72,15 +73,18 @@ HISTORY |
72 | | | 73 | |
73 | The mapper module first appeared in NetBSD 9.0 and was authored by | | 74 | The mapper module first appeared in NetBSD 9.0 and was authored by |
74 | Akul Pillai. | | 75 | Akul Pillai. |
75 | | | 76 | |
76 | The ping_block module first appeared in NetBSD 10.0 and was authored by | | 77 | The ping_block module first appeared in NetBSD 10.0 and was authored by |
77 | Nisarg Joshi. | | 78 | Nisarg Joshi. |
78 | | | 79 | |
79 | The fopsmapper module first appeared in NetBSD 10.0 and was authored by | | 80 | The fopsmapper module first appeared in NetBSD 10.0 and was authored by |
80 | Aditya Vardhan Padala. | | 81 | Aditya Vardhan Padala. |
81 | | | 82 | |
82 | The current_time module first appeared in NetBSD 10.0 and was authored by | | 83 | The current_time module first appeared in NetBSD 10.0 and was authored by |
83 | Apurva Nandan. | | 84 | Apurva Nandan. |
84 | | | 85 | |
| | | 86 | The pollpall module first appeared in NetBSD 10.0 and was authored by |
| | | 87 | Ayushi Sharma. |
| | | 88 | |
85 | AUTHORS | | 89 | AUTHORS |
86 | This document was written by Kamil Rytarowski. | | 90 | This document was written by Kamil Rytarowski. |
--- src/sys/modules/examples/ping/ping.c 2020/02/05 14:10:46 1.3
+++ src/sys/modules/examples/ping/ping.c 2020/04/30 00:48:10 1.4
| @@ -1,14 +1,14 @@ | | | @@ -1,14 +1,14 @@ |
1 | /* $NetBSD: ping.c,v 1.3 2020/02/05 14:10:46 pgoyette Exp $ */ | | 1 | /* $NetBSD: ping.c,v 1.4 2020/04/30 00:48:10 christos Exp $ */ |
2 | | | 2 | |
3 | /*- | | 3 | /*- |
4 | * Copyright (c) 2015 The NetBSD Foundation, Inc. | | 4 | * Copyright (c) 2015 The NetBSD Foundation, Inc. |
5 | * All rights reserved. | | 5 | * All rights reserved. |
6 | * | | 6 | * |
7 | * Redistribution and use in source and binary forms, with or without | | 7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions | | 8 | * modification, are permitted provided that the following conditions |
9 | * are met: | | 9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright | | 10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. | | 11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright | | 12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the | | 13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. | | 14 | * documentation and/or other materials provided with the distribution. |
| @@ -17,33 +17,35 @@ | | | @@ -17,33 +17,35 @@ |
17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | | 17 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | | 18 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS | | 19 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | | 20 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | | 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | | 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | | 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | | 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | | 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
26 | * POSSIBILITY OF SUCH DAMAGE. | | 26 | * POSSIBILITY OF SUCH DAMAGE. |
27 | */ | | 27 | */ |
28 | | | 28 | |
29 | #include <sys/cdefs.h> | | 29 | #include <sys/cdefs.h> |
30 | __KERNEL_RCSID(0, "$NetBSD: ping.c,v 1.3 2020/02/05 14:10:46 pgoyette Exp $"); | | 30 | __KERNEL_RCSID(0, "$NetBSD: ping.c,v 1.4 2020/04/30 00:48:10 christos Exp $"); |
31 | | | 31 | |
| | | 32 | #define DDB |
32 | #include <sys/param.h> | | 33 | #include <sys/param.h> |
33 | #include <sys/conf.h> | | 34 | #include <sys/conf.h> |
34 | #include <sys/device.h> | | 35 | #include <sys/device.h> |
35 | #include <sys/kernel.h> | | 36 | #include <sys/kernel.h> |
36 | #include <sys/module.h> | | 37 | #include <sys/module.h> |
| | | 38 | #include <sys/systm.h> |
37 | | | 39 | |
38 | #include "ping.h" | | 40 | #include "ping.h" |
39 | | | 41 | |
40 | /* | | 42 | /* |
41 | * Create a device /dev/ping in order to test this module. | | 43 | * Create a device /dev/ping in order to test this module. |
42 | * | | 44 | * |
43 | * To use this device you need to do: | | 45 | * To use this device you need to do: |
44 | * mknod /dev/ping c 351 0 | | 46 | * mknod /dev/ping c 351 0 |
45 | * | | 47 | * |
46 | */ | | 48 | */ |
47 | | | 49 | |
48 | dev_type_open(ping_open); | | 50 | dev_type_open(ping_open); |
49 | dev_type_close(ping_close); | | 51 | dev_type_close(ping_close); |
| @@ -89,26 +91,27 @@ ping_close(dev_t self __unused, int flag | | | @@ -89,26 +91,27 @@ ping_close(dev_t self __unused, int flag |
89 | { | | 91 | { |
90 | --sc.refcnt; | | 92 | --sc.refcnt; |
91 | | | 93 | |
92 | return 0; | | 94 | return 0; |
93 | } | | 95 | } |
94 | | | 96 | |
95 | int | | 97 | int |
96 | ping_ioctl(dev_t self __unused, u_long cmd, void *data, int flag, | | 98 | ping_ioctl(dev_t self __unused, u_long cmd, void *data, int flag, |
97 | struct lwp *l __unused) | | 99 | struct lwp *l __unused) |
98 | { | | 100 | { |
99 | switch(cmd) { | | 101 | switch(cmd) { |
100 | case CMD_PING: | | 102 | case CMD_PING: |
101 | printf("ping: pong!\n"); | | 103 | printf("ping: pong!\n"); |
| | | 104 | Debugger(); |
102 | return 0; | | 105 | return 0; |
103 | default: | | 106 | default: |
104 | return ENOTTY; | | 107 | return ENOTTY; |
105 | } | | 108 | } |
106 | } | | 109 | } |
107 | | | 110 | |
108 | MODULE(MODULE_CLASS_MISC, ping, NULL); | | 111 | MODULE(MODULE_CLASS_MISC, ping, NULL); |
109 | | | 112 | |
110 | static int | | 113 | static int |
111 | ping_modcmd(modcmd_t cmd, void *arg __unused) | | 114 | ping_modcmd(modcmd_t cmd, void *arg __unused) |
112 | { | | 115 | { |
113 | /* The major should be verified and changed if needed to avoid | | 116 | /* The major should be verified and changed if needed to avoid |
114 | * conflicts with other devices. */ | | 117 | * conflicts with other devices. */ |
# $NetBSD: Makefile,v 1.1 2020/04/30 00:48:10 christos Exp $
.include "../Makefile.inc"
#S?= /usr/src/sys
KMOD= pollpal
SRCS= pollpal.c
.include <bsd.kmodule.mk>
# To make use of this module, you'll need to separately build the
# cmd_pollpall program, with a Makefile similar to
#
# MKMAN= NO
# PROG= cmd_pollpal
# .include <bsd.prog.mk>
/* $NetBSD: cmd_pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $ */
/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: cmd_pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $");
#include <sys/mman.h>
#include <errno.h>
#include <err.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#define BUFFLEN 100
#define TIMEOUT 10000
static int fd;
static __dead __printflike(2, 3) void
done(int e, const char *msg, ...)
{
if (msg) {
va_list ap;
va_start(ap, msg);
verr(e, msg, ap);
/*NOTREACHED*/
va_end(ap);
}
exit(e);
}
static __dead void
handler(int sig)
{
done(EXIT_SUCCESS, NULL);
}
static const char dev[] = "/dev/pollpal";
static const char wbuf[] = "abcdefghijklmnopqrstuvwxyz";
int
main(int argc, char **argv)
{
struct pollfd fds;
ssize_t ret;
size_t i;
char rbuf[BUFFLEN];
setprogname(argv[0]);
fd = open(dev, O_RDWR, 0);
if (fd == -1)
err(EXIT_FAILURE, "open `%s'", dev);
fds.fd = fd;
fds.events = POLLOUT|POLLIN;
signal(SIGINT, handler);
for (i = 1; i <= 100; i++) {
ret = poll(&fds, 1, TIMEOUT);
if (ret == -1) {
if (errno == EINTR)
continue;
done(EXIT_FAILURE, "poll");
}
printf("Poll_executing %zu times\n", i);
if (ret == 0) {
printf("%d seconds elapsed \n.TIMEOUT.\n",
TIMEOUT / 1000);
done(EXIT_SUCCESS, NULL);
}
if (fds.revents & (POLLERR | POLLHUP | POLLNVAL))
done(EXIT_FAILURE, "ERR|HUP|NVAL");
if (fds.revents & POLLOUT) {
do {
ret = write(fd, wbuf, sizeof(wbuf) - 1);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
done(EXIT_FAILURE, "write");
}
printf("Wrote %zd byte\n", ret);
}
if (fds.revents & POLLIN) {
memset(rbuf, 0, BUFFLEN);
do {
ret = read(fd, rbuf, BUFFLEN);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
done(EXIT_FAILURE, "read");
}
printf("Read %zd bytes\n", ret);
}
}
done(EXIT_SUCCESS, NULL);
}
/* $NetBSD: pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $ */
/*-
* Copyright (c) 2020 The NetBSD Foundation, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: pollpal.c,v 1.1 2020/04/30 00:48:10 christos Exp $");
#include <sys/module.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/condvar.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/mutex.h>
#include <sys/kmem.h>
#include <sys/poll.h>
#include <sys/select.h>
/*
* Create a device /dev/pollpal
*
* To use this device you need to do:
* mknod /dev/pollpal c 351 0
*
*/
dev_type_open(pollpal_open);
static struct cdevsw pollpal_cdevsw = {
.d_open = pollpal_open,
.d_close = noclose,
.d_read = noread,
.d_write = nowrite,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER
};
static int pollpal_nopen = 0;
static int pollpal_close(file_t *);
static int pollpal_write(file_t *, off_t *, struct uio *, kauth_cred_t,
int);
static int pollpal_read(file_t *, off_t *, struct uio *, kauth_cred_t,
int);
static int pollpal_poll(file_t *, int);
const struct fileops pollpal_fileops = {
.fo_read = pollpal_read,
.fo_write = pollpal_write,
.fo_ioctl = fbadop_ioctl,
.fo_fcntl = fnullop_fcntl,
.fo_poll = pollpal_poll,
.fo_stat = fbadop_stat,
.fo_close = pollpal_close,
.fo_kqfilter = fnullop_kqfilter,
.fo_restart = fnullop_restart,
};
typedef struct pollpal_softc {
kmutex_t lock;
kcondvar_t sc_cv;
struct selinfo psel;
char *buf;
size_t buf_len;
/* Device can have two states 1.READ_WAITING, 2.WRITE_WAITING. */
enum states {
READ_WAITING = 0,
WRITE_WAITING = 1
} sc_state;
} pal_t;
static int
check_pal(const char *str, size_t len)
{
size_t n;
n = 0;
while (n <= len / 2) {
if (str[n] != str[len - n - 1])
return 0;
n++;
}
return 1;
}
int
pollpal_open(dev_t dev, int flag, int mode, struct lwp *l __unused)
{
struct file *fp;
int error, fd;
pal_t *pl;
error = fd_allocfile(&fp, &fd);
if (error)
return error;
++pollpal_nopen;
pl = kmem_zalloc(sizeof(*pl), KM_SLEEP);
pl->sc_state = READ_WAITING;
mutex_init(&pl->lock, MUTEX_DEFAULT, IPL_NONE);
cv_init(&pl->sc_cv, "sc_cv");
selinit(&pl->psel);
return fd_clone(fp, fd, flag, &pollpal_fileops, pl);
}
int
pollpal_close(file_t * fp)
{
pal_t * pl = fp->f_data;
KASSERT(pl != NULL);
if (pl->buf != NULL)
kmem_free(pl->buf, pl->buf_len);
seldestroy(&pl->psel);
cv_destroy(&pl->sc_cv);
mutex_destroy(&pl->lock);
kmem_free(pl, sizeof(*pl));
--pollpal_nopen;
return 0;
}
/*
* Device would write only in READ_WAITING state and then update the state to
* WRITE_WAITING.
*/
int
pollpal_write(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
int flag)
{
pal_t *pl = fp->f_data;
int error;
error = 0;
/* To ensure that only single process can write in device at a time. */
mutex_enter(&pl->lock);
cv_broadcast(&pl->sc_cv);
switch (pl->sc_state) {
case READ_WAITING:
pl->sc_state = WRITE_WAITING;
selnotify(&pl->psel, POLLOUT | POLLWRNORM, 0);
while (pl->sc_state == WRITE_WAITING) {
if (pl->buf) {
error = cv_wait_sig(&pl->sc_cv, &pl->lock);
if (error)
goto ret;
}
pl->buf_len = uio->uio_iov->iov_len;
pl->buf = kmem_alloc(pl->buf_len, KM_SLEEP);
uiomove(pl->buf, pl->buf_len, uio);
printf("Use cat to know the result.\n");
break;
}
break;
case WRITE_WAITING:
printf("State: WRITE_WAITING\n");
break;
}
ret:
mutex_exit(&pl->lock);
return error;
}
/*
* Device would read only in WRITE_WAITING state and then update the state to
* READ_WAITING.
*/
int
pollpal_read(file_t *fp, off_t *offset, struct uio *uio, kauth_cred_t cred,
int flags)
{
pal_t *pl = fp->f_data;
int error;
error = 0;
/* To ensure that only single process can read device at a time. */
mutex_enter(&pl->lock);
cv_broadcast(&pl->sc_cv);
switch (pl->sc_state) {
case READ_WAITING:
printf("State: READ_WAITING\n");
printf("You need to write something to the module first!\n");
goto ret;
case WRITE_WAITING:
pl->sc_state = READ_WAITING;
selnotify(&pl->psel, POLLIN | POLLRDNORM, 0);
while (pl->sc_state == READ_WAITING) {
if (!pl->buf) {
error = cv_wait_sig(&pl->sc_cv, &pl->lock);
if (error)
goto ret;
}
printf("The string you entered was: ");
uiomove(pl->buf, pl->buf_len, uio);
printf("\n");
if (check_pal(pl->buf, pl->buf_len))
printf("String '%s' was a palindrome.\n",
pl->buf);
else
printf("String '%s' was not a palindrome.\n",
pl->buf);
break;
}
break;
}
kmem_free(pl->buf, pl->buf_len);
pl->buf = NULL;
ret:
mutex_exit(&pl->lock);
return error;
}
int
pollpal_poll(struct file *fp, int events)
{
pal_t *pl = fp->f_data;
int revents;
revents = 0;
mutex_enter(&pl->lock);
switch (pl->sc_state) {
case READ_WAITING:
if (events & (POLLOUT | POLLWRNORM)) {
/* When device is in READ_WAITING state it can write */
revents |= POLLOUT | POLLWRNORM;
} else {
/* Record the request if it wasn't satisfied. */
selrecord(curlwp, &pl->psel);
}
break;
case WRITE_WAITING:
if (events && (POLLIN | POLLRDNORM)) {
/* When device is in WRITE_WAITING state it can read. */
revents |= POLLIN;
} else {
/* Record the request if it wasn't satisfied. */
selrecord(curlwp, &pl->psel);
}
break;
}
mutex_exit(&pl->lock);
return revents;
}
MODULE(MODULE_CLASS_MISC, pollpal, NULL);
static int
pollpal_modcmd(modcmd_t cmd, void *arg __unused)
{
int cmajor = 351, bmajor = -1;
switch (cmd) {
case MODULE_CMD_INIT:
if (devsw_attach("pollpal", NULL, &bmajor, &pollpal_cdevsw,
&cmajor))
return ENXIO;
return 0;
case MODULE_CMD_FINI:
if (pollpal_nopen != 0)
return EBUSY;
return devsw_detach(NULL, &pollpal_cdevsw);
default:
return ENOTTY;
}
}