[1/1] connector: add userspace example code into Documentation/connector/

[1/1] connector: add userspace example code into Documentation/connector/

[Evgeniy Polyakov]

Hello.

I was asked several times to include userspace example code into
Documentation, so if there is no policy against it, consider attached patch 
for 2.6.18. This program works with included Documentation/connector/cn_test.c 
connector module.
Thank you.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

--- /dev/null	2006-08-23 17:09:03.438578500 +0400
+++ ./Documentation/connector/ucon.c	2006-08-25 11:06:57.000000000 +0400
@@ -0,0 +1,205 @@
+/*
+ * 	ucon.c
+ *
+ * Copyright (c) 2004+ Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ * 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/types.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/poll.h>
+
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <arpa/inet.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+
+#include <linux/connector.h>
+
+#define DEBUG
+#define NETLINK_CONNECTOR 	11
+
+#ifdef DEBUG
+#define ulog(f, a...) fprintf(stdout, f, ##a)
+#else
+#define ulog(f, a...) do {} while (0)
+#endif
+
+static int need_exit;
+static __u32 seq;
+
+static int netlink_send(int s, struct cn_msg *msg)
+{
+	struct nlmsghdr *nlh;
+	unsigned int size;
+	int err;
+	char buf[128];
+	struct cn_msg *m;
+	
+	size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
+
+	nlh = (struct nlmsghdr *)buf;
+	nlh->nlmsg_seq = seq++;
+	nlh->nlmsg_pid = getpid();
+	nlh->nlmsg_type = NLMSG_DONE;
+	nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
+	nlh->nlmsg_flags = 0;
+
+	m = NLMSG_DATA(nlh);
+#if 0
+	ulog("%s: [%08x.%08x] len=%u, seq=%u, ack=%u.\n",
+	       __func__, msg->id.idx, msg->id.val, msg->len, msg->seq, msg->ack);
+#endif
+	memcpy(m, msg, sizeof(*m) + msg->len);
+
+	err = send(s, nlh, size, 0);
+	if (err == -1)
+		ulog("Failed to send: %s [%d].\n",
+			strerror(errno), errno);
+
+	return err;
+}
+
+int main(int argc, char *argv[])
+{
+	int s;
+	char buf[1024];
+	int len;
+	struct nlmsghdr *reply;
+	struct sockaddr_nl l_local;
+	struct cn_msg *data;
+	FILE *out;
+	time_t tm;
+	struct pollfd pfd;
+
+	if (argc < 2)
+		out = stdout;
+	else {
+		out = fopen(argv[1], "a+");
+		if (!out) {
+			ulog("Unable to open %s for writing: %s\n",
+				argv[1], strerror(errno));
+			out = stdout;
+		}
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
+	if (s == -1) {
+		perror("socket");
+		return -1;
+	}
+
+	l_local.nl_family = AF_NETLINK;
+	l_local.nl_groups = 0x123;
+	l_local.nl_pid = 0;
+
+	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
+		perror("bind");
+		close(s);
+		return -1;
+	}
+
+	{
+		int on = l_local.nl_groups;
+		setsockopt(s, 270, 1, &on, sizeof(on));
+	}
+	
+	if (0) {
+		int i, j;
+	
+		memset(buf, 0, sizeof(buf));
+		
+		data = (struct cn_msg *)buf;
+
+		data->id.idx = 0x123;
+		data->id.val = 0x456;
+		data->seq = seq++;
+		data->ack = 0;
+		data->len = 0;
+
+		for (j=0; j<10; ++j) {
+			for (i=0; i<1000; ++i) {
+				len = netlink_send(s, data);
+			}
+
+			ulog("%d messages have been sent to %08x.%08x.\n", i, data->id.idx, data->id.val);
+		}
+
+		return 0;
+	}
+		
+
+	pfd.fd = s;
+
+	while (!need_exit) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+		switch (poll(&pfd, 1, -1)) {
+			case 0:
+				need_exit = 1;
+				break;
+			case -1:
+				if (errno != EINTR) {
+					need_exit = 1;
+					break;
+				}
+				continue;
+		} 
+		if (need_exit)
+			break;
+
+		memset(buf, 0, sizeof(buf));
+		len = recv(s, buf, sizeof(buf), 0);
+		if (len == -1) {
+			perror("recv buf");
+			close(s);
+			return -1;
+		}
+		reply = (struct nlmsghdr *)buf;
+
+		switch (reply->nlmsg_type) {
+		case NLMSG_ERROR:
+			fprintf(out, "Error message received.\n");
+			fflush(out);
+			break;
+		case NLMSG_DONE:
+			data = (struct cn_msg *)NLMSG_DATA(reply);
+
+			time(&tm);
+			fprintf(out, "%.24s : [%x.%x] [%08u.%08u].\n",
+				ctime(&tm), data->id.idx, data->id.val, data->seq, data->ack);
+			fflush(out);
+			break;
+		default:
+			break;
+		}
+	}
+
+	close(s);
+	return 0;
+}

-- 
	Evgeniy Polyakov

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Patrick McHardy]

Evgeniy Polyakov wrote:
> Hello.
> 
> I was asked several times to include userspace example code into
> Documentation, so if there is no policy against it, consider attached patch 
> for 2.6.18. This program works with included Documentation/connector/cn_test.c 
> connector module.

> +	l_local.nl_family = AF_NETLINK;
> +	l_local.nl_groups = 0x123;
> +	l_local.nl_pid = 0;
> +
> +	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
> +		perror("bind");
> +		close(s);
> +		return -1;
> +	}
> +
> +	{
> +		int on = l_local.nl_groups;
> +		setsockopt(s, 270, 1, &on, sizeof(on));
> +	}

Example code shouldn't use magic numbers, please use the proper defines.
And the code is wrong, using the same group number for bind (which takes
a bitmask) and setsockopt (which takes a group number) doesn't work.
Its not necessary to use setsockopt if you already used bind anyway.

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Evgeniy Polyakov]

On Fri, Aug 25, 2006 at 08:57:23AM +0200, Patrick McHardy (kaber@trash.net) wrote:
> Evgeniy Polyakov wrote:
> > Hello.
> > 
> > I was asked several times to include userspace example code into
> > Documentation, so if there is no policy against it, consider attached patch 
> > for 2.6.18. This program works with included Documentation/connector/cn_test.c 
> > connector module.
> 
> > +	l_local.nl_family = AF_NETLINK;
> > +	l_local.nl_groups = 0x123;
> > +	l_local.nl_pid = 0;
> > +
> > +	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
> > +		perror("bind");
> > +		close(s);
> > +		return -1;
> > +	}
> > +
> > +	{
> > +		int on = l_local.nl_groups;
> > +		setsockopt(s, 270, 1, &on, sizeof(on));
> > +	}
> 
> Example code shouldn't use magic numbers, please use the proper defines.
> And the code is wrong, using the same group number for bind (which takes
> a bitmask) and setsockopt (which takes a group number) doesn't work.
> Its not necessary to use setsockopt if you already used bind anyway.

I put there explicit socket option to show how it works in case there
will be several group requests, which will not be placed into initial
bind call.
But you are right, that magic numbers are not that good.
I will update program with appropriate changes.
Thank you.

-- 
	Evgeniy Polyakov

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Evgeniy Polyakov]

Hello.

I was asked several times to include userspace example code into
Documentation, so if there is no policy against it, consider attached patch 
for 2.6.18. This program works with included Documentation/connector/cn_test.c 
connector module.
Thank you.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

--- /dev/null	2006-08-23 17:09:03.438578500 +0400
+++ ./Documentation/connector/ucon.c	2006-08-25 11:31:48.000000000 +0400
@@ -0,0 +1,206 @@
+/*
+ * 	ucon.c
+ *
+ * Copyright (c) 2004+ Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ * 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <asm/types.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/poll.h>
+
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <arpa/inet.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+
+#include <linux/connector.h>
+
+#define DEBUG
+#define NETLINK_CONNECTOR 	11
+
+#ifdef DEBUG
+#define ulog(f, a...) fprintf(stdout, f, ##a)
+#else
+#define ulog(f, a...) do {} while (0)
+#endif
+
+static int need_exit;
+static __u32 seq;
+
+static int netlink_send(int s, struct cn_msg *msg)
+{
+	struct nlmsghdr *nlh;
+	unsigned int size;
+	int err;
+	char buf[128];
+	struct cn_msg *m;
+	
+	size = NLMSG_SPACE(sizeof(struct cn_msg) + msg->len);
+
+	nlh = (struct nlmsghdr *)buf;
+	nlh->nlmsg_seq = seq++;
+	nlh->nlmsg_pid = getpid();
+	nlh->nlmsg_type = NLMSG_DONE;
+	nlh->nlmsg_len = NLMSG_LENGTH(size - sizeof(*nlh));
+	nlh->nlmsg_flags = 0;
+
+	m = NLMSG_DATA(nlh);
+#if 0
+	ulog("%s: [%08x.%08x] len=%u, seq=%u, ack=%u.\n",
+	       __func__, msg->id.idx, msg->id.val, msg->len, msg->seq, msg->ack);
+#endif
+	memcpy(m, msg, sizeof(*m) + msg->len);
+
+	err = send(s, nlh, size, 0);
+	if (err == -1)
+		ulog("Failed to send: %s [%d].\n",
+			strerror(errno), errno);
+
+	return err;
+}
+
+int main(int argc, char *argv[])
+{
+	int s;
+	char buf[1024];
+	int len;
+	struct nlmsghdr *reply;
+	struct sockaddr_nl l_local;
+	struct cn_msg *data;
+	FILE *out;
+	time_t tm;
+	struct pollfd pfd;
+
+	if (argc < 2)
+		out = stdout;
+	else {
+		out = fopen(argv[1], "a+");
+		if (!out) {
+			ulog("Unable to open %s for writing: %s\n",
+				argv[1], strerror(errno));
+			out = stdout;
+		}
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
+	if (s == -1) {
+		perror("socket");
+		return -1;
+	}
+
+	l_local.nl_family = AF_NETLINK;
+	l_local.nl_groups = 0x123; /* bitmask of requested groups */
+	l_local.nl_pid = 0;
+
+	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
+		perror("bind");
+		close(s);
+		return -1;
+	}
+
+#if 0
+	{
+		int on = 0x57; /* Additional group number */
+		setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
+	}
+#endif	
+	if (0) {
+		int i, j;
+	
+		memset(buf, 0, sizeof(buf));
+		
+		data = (struct cn_msg *)buf;
+
+		data->id.idx = 0x123;
+		data->id.val = 0x456;
+		data->seq = seq++;
+		data->ack = 0;
+		data->len = 0;
+
+		for (j=0; j<10; ++j) {
+			for (i=0; i<1000; ++i) {
+				len = netlink_send(s, data);
+			}
+
+			ulog("%d messages have been sent to %08x.%08x.\n", i, data->id.idx, data->id.val);
+		}
+
+		return 0;
+	}
+		
+
+	pfd.fd = s;
+
+	while (!need_exit) {
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+		switch (poll(&pfd, 1, -1)) {
+			case 0:
+				need_exit = 1;
+				break;
+			case -1:
+				if (errno != EINTR) {
+					need_exit = 1;
+					break;
+				}
+				continue;
+		} 
+		if (need_exit)
+			break;
+
+		memset(buf, 0, sizeof(buf));
+		len = recv(s, buf, sizeof(buf), 0);
+		if (len == -1) {
+			perror("recv buf");
+			close(s);
+			return -1;
+		}
+		reply = (struct nlmsghdr *)buf;
+
+		switch (reply->nlmsg_type) {
+		case NLMSG_ERROR:
+			fprintf(out, "Error message received.\n");
+			fflush(out);
+			break;
+		case NLMSG_DONE:
+			data = (struct cn_msg *)NLMSG_DATA(reply);
+
+			time(&tm);
+			fprintf(out, "%.24s : [%x.%x] [%08u.%08u].\n",
+				ctime(&tm), data->id.idx, data->id.val, data->seq, data->ack);
+			fflush(out);
+			break;
+		default:
+			break;
+		}
+	}
+
+	close(s);
+	return 0;
+}

-- 
	Evgeniy Polyakov

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Patrick McHardy]

Evgeniy Polyakov wrote:
> +	l_local.nl_family = AF_NETLINK;
> +	l_local.nl_groups = 0x123; /* bitmask of requested groups */
> +	l_local.nl_pid = 0;
> +
> +	if (bind(s, (struct sockaddr *)&l_local, sizeof(struct sockaddr_nl)) == -1) {
> +		perror("bind");
> +		close(s);
> +		return -1;
> +	}
> +
> +#if 0
> +	{
> +		int on = 0x57; /* Additional group number */
> +		setsockopt(s, SOL_NETLINK, NETLINK_ADD_MEMBERSHIP, &on, sizeof(on));
> +	}
> +#endif	
> 

That looks better, thanks.

Re: [1/1] connector: add userspace example code into Documentation/connector/

[David Miller]

From: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Date: Fri, 25 Aug 2006 11:11:02 +0400

> Hello.
> 
> I was asked several times to include userspace example code into
> Documentation, so if there is no policy against it, consider attached patch 
> for 2.6.18. This program works with included Documentation/connector/cn_test.c 
> connector module.
> Thank you.
> 
> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>

Fair enough, applied (after killing all of the trailing whitespace).

Thanks.

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Evgeniy Polyakov]

On Fri, Aug 25, 2006 at 12:52:33AM -0700, David Miller (davem@davemloft.net) wrote:
> From: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
> Date: Fri, 25 Aug 2006 11:11:02 +0400
> 
> > Hello.
> > 
> > I was asked several times to include userspace example code into
> > Documentation, so if there is no policy against it, consider attached patch 
> > for 2.6.18. This program works with included Documentation/connector/cn_test.c 
> > connector module.
> > Thank you.
> > 
> > Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
> 
> Fair enough, applied (after killing all of the trailing whitespace).

I mailed it myself and applied to 2.6.18 git tree - "patch -p1" did not
complain for sure :)

Thank you.

-- 
	Evgeniy Polyakov

Re: [1/1] connector: add userspace example code into Documentation/connector/

[David Miller]

From: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Date: Fri, 25 Aug 2006 12:15:03 +0400

> I mailed it myself and applied to 2.6.18 git tree - "patch -p1" did
> not complain for sure :)

GIT always complains very loudly about any trailing whitespace on any
lines, patch is too dumb to do that.

You do not need to use GIT trees to check this, just run:

git apply --check --whitespace=error-all $PATCH

and it will let you know.

Re: [1/1] connector: add userspace example code into Documentation/connector/

[Evgeniy Polyakov]

On Fri, Aug 25, 2006 at 01:17:27AM -0700, David Miller (davem@davemloft.net) wrote:
> > I mailed it myself and applied to 2.6.18 git tree - "patch -p1" did
> > not complain for sure :)
> 
> GIT always complains very loudly about any trailing whitespace on any
> lines, patch is too dumb to do that.
> 
> You do not need to use GIT trees to check this, just run:
> 
> git apply --check --whitespace=error-all $PATCH
> 
> and it will let you know.

Hmm, how many interesting things git contain...
I will definitely use this feature, thanks David.

-- 
	Evgeniy Polyakov