[CRIU] [PATCH 06/11] net: save network namespaces for sockets

Andrei Vagin avagin at virtuozzo.com
Wed Feb 8 16:53:25 PST 2017


On Wed, Feb 08, 2017 at 12:48:00PM +0300, Pavel Emelyanov wrote:
> On 02/02/2017 03:04 AM, Andrei Vagin wrote:
> > From: Andrei Vagin <avagin at virtuozzo.com>
> > 
> > Each socket has to be restored in a proper namespaces where
> > it has been created.
> > 
> > Here is an issue about unconnected and unbound sockets,
> > they are not reported via socket-diag and we can't to
> > get their network namespaces.
> > 
> > Signed-off-by: Andrei Vagin <avagin at virtuozzo.com>
> > ---
> >  criu/include/namespaces.h |  2 ++
> >  criu/include/sockets.h    |  3 ++-
> >  criu/net.c                | 25 +++++++++++++++++++++++++
> >  criu/sk-inet.c            | 16 ++++++++++++++--
> >  criu/sk-netlink.c         | 14 +++++++++++++-
> >  criu/sk-packet.c          |  5 ++++-
> >  criu/sk-unix.c            |  4 +++-
> >  criu/sockets.c            |  3 ++-
> >  images/packet-sock.proto  |  1 +
> >  images/sk-inet.proto      |  1 +
> >  images/sk-netlink.proto   |  1 +
> >  images/sk-packet.proto    |  1 +
> >  images/sk-unix.proto      |  2 ++
> >  13 files changed, 71 insertions(+), 7 deletions(-)
> > 
> > diff --git a/criu/include/namespaces.h b/criu/include/namespaces.h
> > index c9f3e8a..18eafb2 100644
> > --- a/criu/include/namespaces.h
> > +++ b/criu/include/namespaces.h
> > @@ -184,4 +184,6 @@ extern int __userns_call(const char *func_name, uns_call_t call, int flags,
> >  
> >  extern int add_ns_shared_cb(int (*actor)(void *data), void *data);
> >  
> > +extern struct ns_id *get_socket_ns(int lfd);
> > +
> >  #endif /* __CR_NS_H__ */
> > diff --git a/criu/include/sockets.h b/criu/include/sockets.h
> > index 18e20d1..7685eeb 100644
> > --- a/criu/include/sockets.h
> > +++ b/criu/include/sockets.h
> > @@ -18,6 +18,7 @@ struct socket_desc {
> >  	unsigned int		family;
> >  	unsigned int		ino;
> >  	struct socket_desc	*next;
> > +	struct ns_id		*sk_ns;
> >  	int			already_dumped;
> >  };
> >  
> > @@ -30,7 +31,7 @@ extern void preload_socket_modules(void);
> >  
> >  extern bool socket_test_collect_bit(unsigned int family, unsigned int proto);
> >  
> > -extern int sk_collect_one(unsigned ino, int family, struct socket_desc *d);
> > +extern int sk_collect_one(unsigned ino, int family, struct socket_desc *d, struct ns_id *ns);
> >  struct ns_id;
> >  extern int collect_sockets(struct ns_id *);
> >  extern int collect_inet_sockets(void);
> > diff --git a/criu/net.c b/criu/net.c
> > index 0666fa9..7dadc8d 100644
> > --- a/criu/net.c
> > +++ b/criu/net.c
> > @@ -1915,6 +1915,7 @@ err_nl:
> >  	goto out;
> >  }
> >  
> > +static int netns_nr;
> >  static int collect_net_ns(struct ns_id *ns, void *oarg)
> >  {
> >  	bool for_dump = (oarg == (void *)1);
> > @@ -1925,6 +1926,8 @@ static int collect_net_ns(struct ns_id *ns, void *oarg)
> >  	if (ret)
> >  		return ret;
> >  
> > +	netns_nr++;
> > +
> >  	if (!for_dump)
> >  		return 0;
> >  
> > @@ -1939,6 +1942,28 @@ int collect_net_namespaces(bool for_dump)
> >  
> >  struct ns_desc net_ns_desc = NS_DESC_ENTRY(CLONE_NEWNET, "net");
> >  
> > +static struct ns_id *get_root_netns()
> > +{
> > +	static struct ns_id *root_netns = NULL;
> > +
> > +	if (root_item->ids == NULL)
> > +		return NULL;
> 
> Shouldn't we check this under if (root_netns == NULL) check?

Yes, we should
> 
> > +
> > +	if (root_netns == NULL)
> > +		root_netns = lookup_ns_by_id(root_item->ids->net_ns_id, &net_ns_desc);
> > +
> > +	return root_netns;
> > +}
> > +
> > +struct ns_id *get_socket_ns(int lfd)
> 
> Please, rename to get_uncollected_socket_ns() and add a comment
> describing what the problem is.

hmmmm, this function works for all sockets. Let's add a comment and save
the function name. If you still think that we have to rename this
function, could you just rename it before appling this patch.
> 
> > +{
> > +	if (netns_nr == 1)
> 
> This is called under root_ns_mask & CLONE_NEWNET, so we want to
> check whether there are NS_OTHER net namespaces or not. Right?

yes, if netns_nr is 1, it means that there is only NS_ROOT.

> 
> > +		return get_root_netns();
> > +
> > +	pr_perror("Unable to get a socket net namespace");
> > +	return NULL;
> > +}
> > +
> >  static int move_to_bridge(struct external *ext, void *arg)
> >  {
> >  	int s = *(int *)arg;
> > diff --git a/criu/sk-inet.c b/criu/sk-inet.c
> > index b8bd9e2..bb898d5 100644
> > --- a/criu/sk-inet.c
> > +++ b/criu/sk-inet.c
> > @@ -25,6 +25,7 @@
> >  #include "sk-inet.h"
> >  #include "protobuf.h"
> >  #include "util.h"
> > +#include "namespaces.h"
> >  
> >  #define PB_ALEN_INET	1
> >  #define PB_ALEN_INET6	4
> > @@ -210,9 +211,16 @@ static struct inet_sk_desc *gen_uncon_sk(int lfd, const struct fd_parms *p, int
> >  {
> >  	struct inet_sk_desc *sk;
> >  	union libsoccr_addr address;
> > +	struct ns_id *ns = NULL;
> >  	socklen_t aux;
> >  	int ret;
> >  
> > +	if (root_ns_mask & CLONE_NEWNET) {
> > +		ns = get_socket_ns(lfd);
> > +		if (ns == NULL)
> > +			return NULL;
> > +	}
> > +
> >  	sk = xzalloc(sizeof(*sk));
> >  	if (!sk)
> >  		goto err;
> > @@ -272,7 +280,7 @@ static struct inet_sk_desc *gen_uncon_sk(int lfd, const struct fd_parms *p, int
> >  
> >  	sk->state = TCP_CLOSE;
> >  
> > -	sk_collect_one(sk->sd.ino, sk->sd.family, &sk->sd);
> > +	sk_collect_one(sk->sd.ino, sk->sd.family, &sk->sd, ns);
> >  
> >  	return sk;
> >  err:
> > @@ -341,6 +349,10 @@ static int do_dump_one_inet_fd(int lfd, u32 id, const struct fd_parms *p, int fa
> >  
> >  	ie.id		= id;
> >  	ie.ino		= sk->sd.ino;
> > +	if (sk->sd.sk_ns) {
> > +		ie.ns_id	= sk->sd.sk_ns->id;
> > +		ie.has_ns_id	= true;
> > +	}
> >  	ie.family	= family;
> >  	ie.proto	= proto;
> >  	ie.type		= sk->type;
> > @@ -477,7 +489,7 @@ int inet_collect_one(struct nlmsghdr *h, int family, int type, struct ns_id *ns)
> >  	else
> >  		pr_err_once("Can't check shutdown state of inet socket\n");
> >  
> > -	ret = sk_collect_one(m->idiag_inode, family, &d->sd);
> > +	ret = sk_collect_one(m->idiag_inode, family, &d->sd, ns);
> >  
> >  	show_one_inet("Collected", d);
> >  
> > diff --git a/criu/sk-netlink.c b/criu/sk-netlink.c
> > index 0fb873c..4ef934a 100644
> > --- a/criu/sk-netlink.c
> > +++ b/criu/sk-netlink.c
> > @@ -12,6 +12,7 @@
> >  #include "images/sk-netlink.pb-c.h"
> >  #include "netlink_diag.h"
> >  #include "libnetlink.h"
> > +#include "namespaces.h"
> >  
> >  struct netlink_sk_desc {
> >  	struct socket_desc	sd;
> > @@ -61,7 +62,7 @@ int netlink_receive_one(struct nlmsghdr *hdr, struct ns_id *ns, void *arg)
> >  		sd->gsize = 0;
> >  	}
> >  
> > -	return sk_collect_one(m->ndiag_ino, PF_NETLINK, &sd->sd);
> > +	return sk_collect_one(m->ndiag_ino, PF_NETLINK, &sd->sd, ns);
> >  }
> >  
> >  static bool can_dump_netlink_sk(int lfd)
> > @@ -94,6 +95,8 @@ static int dump_one_netlink_fd(int lfd, u32 id, const struct fd_parms *p)
> >  	if (sk) {
> >  		BUG_ON(sk->sd.already_dumped);
> >  
> > +		ne.ns_id = sk->sd.sk_ns->id;
> > +		ne.has_ns_id = true;
> >  		ne.protocol = sk->protocol;
> >  		ne.portid = sk->portid;
> >  		ne.groups = sk->groups;
> > @@ -120,9 +123,18 @@ static int dump_one_netlink_fd(int lfd, u32 id, const struct fd_parms *p)
> >  		ne.dst_portid = sk->dst_portid;
> >  		ne.dst_group = sk->dst_group;
> >  	} else { /* unconnected and unbound socket */
> > +		struct ns_id *nsid;
> >  		int val;
> >  		socklen_t aux = sizeof(val);
> >  
> > +		if (root_ns_mask & CLONE_NEWNET) {
> > +			nsid = get_socket_ns(lfd);
> > +			if (nsid == NULL)
> > +				return -1;
> > +			ne.ns_id = nsid->id;
> > +			ne.has_ns_id = true;
> > +		}
> > +
> >  		if (getsockopt(lfd, SOL_SOCKET, SO_PROTOCOL, &val, &aux) < 0) {
> >  			pr_perror("Unable to get protocol for netlink socket");
> >  			goto err;
> > diff --git a/criu/sk-packet.c b/criu/sk-packet.c
> > index cdd0595..f1cf117 100644
> > --- a/criu/sk-packet.c
> > +++ b/criu/sk-packet.c
> > @@ -20,6 +20,7 @@
> >  #include "xmalloc.h"
> >  #include "images/packet-sock.pb-c.h"
> >  #include "images/fdinfo.pb-c.h"
> > +#include "namespaces.h"
> >  
> >  struct packet_sock_info {
> >  	PacketSockEntry *pse;
> > @@ -162,6 +163,8 @@ static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
> >  	sd->sd.already_dumped = 1;
> >  
> >  	psk.id = sd->file_id = id;
> > +	psk.ns_id = sd->sd.sk_ns->id;
> > +	psk.has_ns_id = true;
> >  	psk.type = sd->type;
> >  	psk.flags = p->flags;
> >  	psk.fown = (FownEntry *)&p->fown;
> > @@ -296,7 +299,7 @@ int packet_receive_one(struct nlmsghdr *hdr, struct ns_id *ns, void *arg)
> >  		memcpy(sd->tx, RTA_DATA(tb[PACKET_DIAG_TX_RING]), sizeof(*sd->tx));
> >  	}
> >  
> > -	return sk_collect_one(m->pdiag_ino, PF_PACKET, &sd->sd);
> > +	return sk_collect_one(m->pdiag_ino, PF_PACKET, &sd->sd, ns);
> >  err:
> >  	xfree(sd->tx);
> >  	xfree(sd->rx);
> > diff --git a/criu/sk-unix.c b/criu/sk-unix.c
> > index f0048ea..35c4d32 100644
> > --- a/criu/sk-unix.c
> > +++ b/criu/sk-unix.c
> > @@ -297,6 +297,8 @@ static int dump_one_unix_fd(int lfd, u32 id, const struct fd_parms *p)
> >  
> >  	ue->id		= id;
> >  	ue->ino		= sk->sd.ino;
> > +	ue->ns_id	= sk->sd.sk_ns->id;
> > +	ue->has_ns_id	= true;
> >  	ue->type	= sk->type;
> >  	ue->state	= sk->state;
> >  	ue->flags	= p->flags;
> > @@ -660,7 +662,7 @@ static int unix_collect_one(const struct unix_diag_msg *m,
> >  		d->wqlen = rq->udiag_wqueue;
> >  	}
> >  
> > -	sk_collect_one(m->udiag_ino, AF_UNIX, &d->sd);
> > +	sk_collect_one(m->udiag_ino, AF_UNIX, &d->sd, ns);
> >  	list_add_tail(&d->list, &unix_sockets);
> >  	show_one_unix("Collected", d);
> >  
> > diff --git a/criu/sockets.c b/criu/sockets.c
> > index fa551eb..86a6b21 100644
> > --- a/criu/sockets.c
> > +++ b/criu/sockets.c
> > @@ -353,13 +353,14 @@ struct socket_desc *lookup_socket(unsigned ino, int family, int proto)
> >  	return NULL;
> >  }
> >  
> > -int sk_collect_one(unsigned ino, int family, struct socket_desc *d)
> > +int sk_collect_one(unsigned ino, int family, struct socket_desc *d, struct ns_id *ns)
> >  {
> >  	struct socket_desc **chain;
> >  
> >  	d->ino		= ino;
> >  	d->family	= family;
> >  	d->already_dumped = 0;
> > +	d->sk_ns	= ns;
> >  
> >  	chain = &sockets[ino % SK_HASH_SIZE];
> >  	d->next = *chain;
> > diff --git a/images/packet-sock.proto b/images/packet-sock.proto
> > index f6198c1..25875b4 100644
> > --- a/images/packet-sock.proto
> > +++ b/images/packet-sock.proto
> > @@ -43,4 +43,5 @@ message packet_sock_entry {
> >  	optional uint32		fanout		= 17 [ default = 0xffffffff ];
> >  	optional packet_ring	rx_ring		= 18;
> >  	optional packet_ring	tx_ring		= 19;
> > +	optional uint32		ns_id		= 20;
> >  }
> > diff --git a/images/sk-inet.proto b/images/sk-inet.proto
> > index 01dda87..09c5a47 100644
> > --- a/images/sk-inet.proto
> > +++ b/images/sk-inet.proto
> > @@ -39,4 +39,5 @@ message inet_sk_entry {
> >  	/* for ipv6, we need to send the ifindex to bind(); we keep the ifname
> >  	 * here and convert it on restore */
> >  	optional string			ifname		= 17;
> > +	optional uint32			ns_id		= 18;
> >  }
> > diff --git a/images/sk-netlink.proto b/images/sk-netlink.proto
> > index ed24c50..402281d 100644
> > --- a/images/sk-netlink.proto
> > +++ b/images/sk-netlink.proto
> > @@ -16,4 +16,5 @@ message netlink_sk_entry {
> >  	required uint32			dst_group	=  10;
> >  	required fown_entry		fown		=  11;
> >  	required sk_opts_entry		opts		=  12;
> > +	optional uint32			ns_id		=  13;
> >  }
> > diff --git a/images/sk-packet.proto b/images/sk-packet.proto
> > index 5f61c73..33ace1d 100644
> > --- a/images/sk-packet.proto
> > +++ b/images/sk-packet.proto
> > @@ -3,4 +3,5 @@ syntax = "proto2";
> >  message sk_packet_entry {
> >  	required uint32		id_for		= 1;
> >  	required uint32		length		= 2;
> > +	optional uint32		ns_id		= 4;
> 
> Why is ns_id needed here? The id_for is unique across namespaces, isn't it?

Ooops. It is my fault, it should not be here. Thanks!
I just added ns_id to all [SK_TYPE]_sk_entry and added this ns_id by mistake.

Why do we have two images for packet sockets?

[root at fc24 criu]# ls -l images/*sock*.proto
-rw-r--r-- 1 root root 1171 Feb  9 02:55 images/packet-sock.proto
[root at fc24 criu]# ls -l images/sk-*.proto
-rw-r--r-- 1 root root 1247 Feb  9 02:55 images/sk-inet.proto
-rw-r--r-- 1 root root  537 Feb  9 02:55 images/sk-netlink.proto
-rw-r--r-- 1 root root  678 Nov 22 11:07 images/sk-opts.proto
-rw-r--r-- 1 root root  110 Feb  9 03:02 images/sk-packet.proto
-rw-r--r-- 1 root root 1306 Feb  9 03:04 images/sk-unix.proto

> 
> >  }
> > diff --git a/images/sk-unix.proto b/images/sk-unix.proto
> > index 3026214..d695070 100644
> > --- a/images/sk-unix.proto
> > +++ b/images/sk-unix.proto
> > @@ -48,4 +48,6 @@ message unix_sk_entry {
> >  	 */
> >  	optional string			name_dir	= 14;
> >  	optional bool			deleted		= 15;
> > +
> > +	optional uint32			ns_id		= 16;
> >  }
> > 
> 


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