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From: Petr Oros <poros@redhat.com>
To: Nicolas Dichtel <nicolas.dichtel@6wind.com>, stephen@networkplumber.org
Cc: netdev@vger.kernel.org, dsahern@gmail.com
Subject: Re: [PATCH iproute2] ipnetns: enable to dump nsid conversion table
Date: Mon, 07 Oct 2019 16:32:41 +0200	[thread overview]
Message-ID: <caf06d0ee97fe234daa3a375a1912dc4bf536f58.camel@redhat.com> (raw)
In-Reply-To: <20191007134447.20077-1-nicolas.dichtel@6wind.com>

Nicolas Dichtel píše v Po 07. 10. 2019 v 15:44 +0200:
> This patch enables to dump/get nsid from a netns into another netns.
> 
> Example:
> $ ./test.sh
> + ip netns add foo
> + ip netns add bar
> + touch /var/run/netns/init_net
> + mount --bind /proc/1/ns/net /var/run/netns/init_net
> + ip netns set init_net 11
> + ip netns set foo 12
> + ip netns set bar 13
> + ip netns
> init_net (id: 11)
> bar (id: 13)
> foo (id: 12)
> + ip -n foo netns set init_net 21
> + ip -n foo netns set foo 22
> + ip -n foo netns set bar 23
> + ip -n foo netns
> init_net (id: 21)
> bar (id: 23)
> foo (id: 22)
> + ip -n bar netns set init_net 31
> + ip -n bar netns set foo 32
> + ip -n bar netns set bar 33
> + ip -n bar netns
> init_net (id: 31)
> bar (id: 33)
> foo (id: 32)
> + ip netns list-id target-nsid 12
> nsid 21 current-nsid 11 (iproute2 netns name: init_net)
> nsid 22 current-nsid 12 (iproute2 netns name: foo)
> nsid 23 current-nsid 13 (iproute2 netns name: bar)
> + ip -n foo netns list-id target-nsid 21
> nsid 11 current-nsid 21 (iproute2 netns name: init_net)
> nsid 12 current-nsid 22 (iproute2 netns name: foo)
> nsid 13 current-nsid 23 (iproute2 netns name: bar)
> + ip -n bar netns list-id target-nsid 33 nsid 32
> nsid 32 current-nsid 32 (iproute2 netns name: foo)
> + ip -n bar netns list-id target-nsid 31 nsid 32
> nsid 12 current-nsid 32 (iproute2 netns name: foo)
> + ip netns list-id nsid 13
> nsid 13 (iproute2 netns name: bar)
> 
> CC: Petr Oros <poros@redhat.com>
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
> ---
>  include/libnetlink.h |   5 +-
>  ip/ip_common.h       |   1 +
>  ip/ipnetns.c         | 115 +++++++++++++++++++++++++++++++++++++++++--
>  lib/libnetlink.c     |  15 ++++--
>  4 files changed, 126 insertions(+), 10 deletions(-)
> 
> diff --git a/include/libnetlink.h b/include/libnetlink.h
> index 311cf3fc90f8..8ebdc6d3d03e 100644
> --- a/include/libnetlink.h
> +++ b/include/libnetlink.h
> @@ -71,8 +71,6 @@ int rtnl_mdbdump_req(struct rtnl_handle *rth, int family)
>  	__attribute__((warn_unused_result));
>  int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
>  	__attribute__((warn_unused_result));
> -int rtnl_nsiddump_req(struct rtnl_handle *rth, int family)
> -	__attribute__((warn_unused_result));
>  
>  int rtnl_linkdump_req(struct rtnl_handle *rth, int fam)
>  	__attribute__((warn_unused_result));
> @@ -85,6 +83,9 @@ int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int fam,
>  int rtnl_fdb_linkdump_req_filter_fn(struct rtnl_handle *rth,
>  				    req_filter_fn_t filter_fn)
>  	__attribute__((warn_unused_result));
> +int rtnl_nsiddump_req_filter_fn(struct rtnl_handle *rth, int family,
> +				req_filter_fn_t filter_fn)
> +	__attribute__((warn_unused_result));
>  int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
>  	__attribute__((warn_unused_result));
>  int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,
> diff --git a/ip/ip_common.h b/ip/ip_common.h
> index cd916ec87c26..879287e3e506 100644
> --- a/ip/ip_common.h
> +++ b/ip/ip_common.h
> @@ -24,6 +24,7 @@ struct link_filter {
>  	int master;
>  	char *kind;
>  	char *slave_kind;
> +	int target_nsid;
>  };
>  
>  int get_operstate(const char *name);
> diff --git a/ip/ipnetns.c b/ip/ipnetns.c
> index a883f210d7ba..20110ef0f58e 100644
> --- a/ip/ipnetns.c
> +++ b/ip/ipnetns.c
> @@ -36,7 +36,7 @@ static int usage(void)
>  		"	ip netns pids NAME\n"
>  		"	ip [-all] netns exec [NAME] cmd ...\n"
>  		"	ip netns monitor\n"
> -		"	ip netns list-id\n"
> +		"	ip netns list-id [target-nsid POSITIVE-INT] [nsid POSITIVE-INT]\n"
>  		"NETNSID := auto | POSITIVE-INT\n");
>  	exit(-1);
>  }
> @@ -46,6 +46,7 @@ static struct rtnl_handle rtnsh = { .fd = -1 };
>  
>  static int have_rtnl_getnsid = -1;
>  static int saved_netns = -1;
> +static struct link_filter filter;
>  
>  static int ipnetns_accept_msg(struct rtnl_ctrl_data *ctrl,
>  			      struct nlmsghdr *n, void *arg)
> @@ -294,7 +295,7 @@ int print_nsid(struct nlmsghdr *n, void *arg)
>  	FILE *fp = (FILE *)arg;
>  	struct nsid_cache *c;
>  	char name[NAME_MAX];
> -	int nsid;
> +	int nsid, current;
>  
>  	if (n->nlmsg_type != RTM_NEWNSID && n->nlmsg_type != RTM_DELNSID)
>  		return 0;
> @@ -317,9 +318,22 @@ int print_nsid(struct nlmsghdr *n, void *arg)
>  		print_bool(PRINT_ANY, "deleted", "Deleted ", true);
>  
>  	nsid = rta_getattr_u32(tb[NETNSA_NSID]);
> -	print_uint(PRINT_ANY, "nsid", "nsid %u ", nsid);
> +	if (nsid < 0)
> +		print_string(PRINT_ANY, "nsid", "nsid %s ", "not-assigned");
> +	else
> +		print_uint(PRINT_ANY, "nsid", "nsid %u ", nsid);
> +
> +	if (tb[NETNSA_CURRENT_NSID]) {
> +		current = rta_getattr_u32(tb[NETNSA_CURRENT_NSID]);
> +		if (current < 0)
> +			print_string(PRINT_ANY, "current-nsid",
> +				     "current-nsid %s ", "not-assigned");
> +		else
> +			print_uint(PRINT_ANY, "current-nsid",
> +				   "current-nsid %u ", current);
> +	}
>  
> -	c = netns_map_get_by_nsid(nsid);
> +	c = netns_map_get_by_nsid(tb[NETNSA_CURRENT_NSID] ? current : nsid);
>  	if (c != NULL) {
>  		print_string(PRINT_ANY, "name",
>  			     "(iproute2 netns name: %s)", c->name);
> @@ -340,15 +354,106 @@ int print_nsid(struct nlmsghdr *n, void *arg)
>  	return 0;
>  }
>  
> +static int get_netnsid_from_netnsid(int nsid)
> +{
> +	struct {
> +		struct nlmsghdr n;
> +		struct rtgenmsg g;
> +		char            buf[1024];
> +	} req = {
> +		.n.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct rtgenmsg))),
> +		.n.nlmsg_flags = NLM_F_REQUEST,
> +		.n.nlmsg_type = RTM_GETNSID,
> +		.g.rtgen_family = AF_UNSPEC,
> +	};
> +	struct nlmsghdr *answer;
> +	int err;
> +
> +	netns_nsid_socket_init();
> +
> +	err = addattr32(&req.n, sizeof(req), NETNSA_NSID, nsid);
> +	if (err)
> +		return err;
> +
> +	if (filter.target_nsid >= 0) {
> +		err = addattr32(&req.n, sizeof(req), NETNSA_TARGET_NSID,
> +				filter.target_nsid);
> +		if (err)
> +			return err;
> +	}
> +
> +	if (rtnl_talk(&rtnsh, &req.n, &answer) < 0)
> +		return -2;
> +
> +	/* Validate message and parse attributes */
> +	if (answer->nlmsg_type == NLMSG_ERROR)
> +		goto err_out;
> +
> +	new_json_obj(json);
> +	err = print_nsid(answer, stdout);
> +	delete_json_obj();
> +err_out:
> +	free(answer);
> +	return err;
> +}
> +
> +static int netns_filter_req(struct nlmsghdr *nlh, int reqlen)
> +{
> +	int err;
> +
> +	if (filter.target_nsid >= 0) {
> +		err = addattr32(nlh, reqlen, NETNSA_TARGET_NSID,
> +				filter.target_nsid);
> +		if (err)
> +			return err;
> +	}
> +
> +	return 0;
> +}
> +
>  static int netns_list_id(int argc, char **argv)
>  {
> +	int nsid = -1;
> +
>  	if (!ipnetns_have_nsid()) {
>  		fprintf(stderr,
>  			"RTM_GETNSID is not supported by the kernel.\n");
>  		return -ENOTSUP;
>  	}
>  
> -	if (rtnl_nsiddump_req(&rth, AF_UNSPEC) < 0) {
> +	filter.target_nsid = -1;
> +	while (argc > 0) {
> +		if (strcmp(*argv, "target-nsid") == 0) {
> +			if (filter.target_nsid >= 0)
> +				duparg("target-nsid", *argv);
> +			NEXT_ARG();
> +
> +			if (get_integer(&filter.target_nsid, *argv, 0))
> +				invarg("\"target-nsid\" value is invalid\n",
> +				       *argv);
> +			else if (filter.target_nsid < 0)
> +				invarg("\"target-nsid\" value should be >= 0\n",
> +				       argv[1]);
> +		} else if (strcmp(*argv, "nsid") == 0) {
> +			if (nsid >= 0)
> +				duparg("nsid", *argv);
> +			NEXT_ARG();
> +
> +			if (get_integer(&nsid, *argv, 0))
> +				invarg("\"nsid\" value is invalid\n", *argv);
> +			else if (nsid < 0)
> +				invarg("\"nsid\" value should be >= 0\n",
> +				       argv[1]);
> +		} else
> +			usage();
> +		argc--; argv++;
> +	}
> +
> +	if (nsid >= 0)
> +		return get_netnsid_from_netnsid(nsid);
> +
> +	if (rtnl_nsiddump_req_filter_fn(&rth, AF_UNSPEC,
> +					netns_filter_req) < 0) {
>  		perror("Cannot send dump request");
>  		exit(1);
>  	}
> diff --git a/lib/libnetlink.c b/lib/libnetlink.c
> index 8c490f896326..6ce8b199f441 100644
> --- a/lib/libnetlink.c
> +++ b/lib/libnetlink.c
> @@ -438,12 +438,13 @@ int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
>  	return send(rth->fd, &req, sizeof(req), 0);
>  }
>  
> -int rtnl_nsiddump_req(struct rtnl_handle *rth, int family)
> +int rtnl_nsiddump_req_filter_fn(struct rtnl_handle *rth, int family,
> +				req_filter_fn_t filter_fn)
>  {
>  	struct {
>  		struct nlmsghdr nlh;
>  		struct rtgenmsg rtm;
> -		char buf[0] __aligned(NLMSG_ALIGNTO);
> +		char buf[1024];
>  	} req = {
>  		.nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct rtgenmsg))),
>  		.nlh.nlmsg_type = RTM_GETNSID,
> @@ -451,8 +452,16 @@ int rtnl_nsiddump_req(struct rtnl_handle *rth, int family)
>  		.nlh.nlmsg_seq = rth->dump = ++rth->seq,
>  		.rtm.rtgen_family = family,
>  	};
> +	int err;
>  
> -	return send(rth->fd, &req, sizeof(req), 0);
> +	if (!filter_fn)
> +		return -EINVAL;
> +
> +	err = filter_fn(&req.nlh, sizeof(req));
> +	if (err)
> +		return err;
> +
> +	return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
>  }
>  
>  static int __rtnl_linkdump_req(struct rtnl_handle *rth, int family)

Works great. Thanks, Nicolas.

Tested-by: Petr Oros <poros@redhat.com>



  reply	other threads:[~2019-10-07 14:32 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-07 13:44 [PATCH iproute2] ipnetns: enable to dump nsid conversion table Nicolas Dichtel
2019-10-07 14:32 ` Petr Oros [this message]
2019-10-14 20:15 ` Stephen Hemminger
2019-10-15  7:33   ` Nicolas Dichtel
2019-10-15 16:25     ` Stephen Hemminger

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