net: Packet sockets basic support

Support only basic packet socket functionality -- create and bind.
This should be enough to start testing dhclient inside container.
Other stuff (filter, mmaps, fanouts, etc.) will come later.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makefile

@@ -44,6 +44,7 @@ OBJS		+= sockets.o
 OBJS		+= sk-inet.o
 OBJS		+= sk-tcp.o
 OBJS		+= sk-unix.o
+OBJS		+= sk-packet.o
 OBJS		+= sk-queue.o
 OBJS		+= files.o
 OBJS		+= files-reg.o

cr-restore.c

@@ -32,6 +32,7 @@
 #include "syscall.h"
 #include "restorer.h"
 #include "sockets.h"
+#include "sk-packet.h"
 #include "lock.h"
 #include "files.h"
 #include "files-reg.h"
@@ -102,6 +103,9 @@ static int prepare_shared(void)
 	if (collect_unix_sockets())
 		return -1;
 
+	if (collect_packet_sockets())
+		return -1;
+
 	if (collect_eventfd())
 		return -1;
 

image.c

@@ -9,6 +9,7 @@
 #include "uts_ns.h"
 #include "ipc_ns.h"
 #include "sk-inet.h"
+#include "sk-packet.h"
 #include "mount.h"
 #include "net.h"
 #include "protobuf.h"
@@ -107,6 +108,7 @@ struct cr_fd_desc_tmpl fdset_template[CR_FD_MAX] = {
 	FD_ENTRY(SIGACT,	"sigacts-%d",	 show_sigacts),
 	FD_ENTRY(UNIXSK,	"unixsk",	 show_unixsk),
 	FD_ENTRY(INETSK,	"inetsk",	 show_inetsk),
+	FD_ENTRY(PACKETSK,	"packetsk",	 show_packetsk),
 	FD_ENTRY(SK_QUEUES,	"sk-queues",	 show_sk_queues),
 	FD_ENTRY(ITIMERS,	"itimers-%d",	 show_itimers),
 	FD_ENTRY(CREDS,		"creds-%d",	 show_creds),

include/crtools.h

@@ -61,6 +61,7 @@ enum {
 	CR_FD_REG_FILES,
 	CR_FD_INETSK,
 	CR_FD_UNIXSK,
+	CR_FD_PACKETSK,
 	CR_FD_PIPES,
 	CR_FD_PIPES_DATA,
 	CR_FD_FIFO,

include/image.h

@@ -36,6 +36,7 @@
 #define SIGACT_MAGIC		0x55344201 /* Murom */
 #define UNIXSK_MAGIC		0x54373943 /* Ryazan */
 #define INETSK_MAGIC		0x56443851 /* Pereslavl */
+#define PACKETSK_MAGIC		0x60454618 /* Veliky Ustyug */
 #define ITIMERS_MAGIC		0x57464056 /* Kostroma */
 #define SK_QUEUES_MAGIC		0x56264026 /* Suzdal */
 #define UTSNS_MAGIC		0x54473203 /* Smolensk */

include/protobuf.h

@@ -30,6 +30,7 @@ enum {
 	PB_REG_FILES,
 	PB_INETSK,
 	PB_UNIXSK,
+	PB_PACKETSK,
 	PB_PIPES,
 	PB_FIFO,
 	PB_PIPES_DATA,

include/sk-packet.h

+#ifndef __CR_SK_PACKET_H__
+#define __CR_SK_PACKET_H__
+struct cr_fdset;
+struct fd_parms;
+struct cr_options;
+
+int dump_one_packet_sk(struct fd_parms *p, int lfd, const struct cr_fdset *fds);
+int collect_packet_sockets(void);
+void show_packetsk(int fd, struct cr_options *);
+#endif

include/sockets.h

@@ -56,5 +56,6 @@ extern int inet_collect_one(struct nlmsghdr *h, int family, int type, int proto)
 extern int unix_receive_one(struct nlmsghdr *h, void *);
 
 extern int do_dump_opt(int sk, int name, void *val, int len);
+#define dump_opt(s, n, f)	do_dump_opt(s, n, f, sizeof(*f))
 
 #endif /* CR_SOCKETS_H__ */

protobuf.c

@@ -29,6 +29,7 @@
 #include "protobuf/sa.pb-c.h"
 #include "protobuf/sk-unix.pb-c.h"
 #include "protobuf/sk-inet.pb-c.h"
+#include "protobuf/packet-sock.pb-c.h"
 #include "protobuf/sk-packet.pb-c.h"
 #include "protobuf/creds.pb-c.h"
 #include "protobuf/itimer.pb-c.h"
@@ -116,6 +117,7 @@ void cr_pb_init(void)
 	CR_PB_DESC(TCP_STREAM,		TcpStream,	tcp_stream);
 	CR_PB_DESC(MOUNTPOINTS,		Mnt,		mnt);
 	CR_PB_DESC(NETDEV,		NetDevice,	net_device);
+	CR_PB_DESC(PACKETSK,		PacketSock,	packet_sock);
 }
 
 /*

protobuf/Makefile

@@ -44,6 +44,7 @@ PROTO_FILES	+= mm.proto
 PROTO_FILES	+= sk-opts.proto
 PROTO_FILES	+= sk-unix.proto
 PROTO_FILES	+= sk-inet.proto
+PROTO_FILES	+= packet-sock.proto
 PROTO_FILES	+= ipc-var.proto
 PROTO_FILES	+= ipc-desc.proto
 PROTO_FILES	+= ipc-shm.proto

protobuf/fdinfo.proto

@@ -9,6 +9,7 @@ enum fd_types {
 	EVENTPOLL	= 7;
 	INOTIFY		= 8;
 	SIGNALFD	= 9;
+	PACKETSK	= 10;
 }
 
 message fdinfo_entry {

protobuf/packet-sock.proto

+import "fown.proto";
+import "sk-opts.proto";
+
+message packet_sock_entry {
+	required uint32			id		= 1;
+	required uint32			type		= 2;
+	required uint32			protocol	= 3;
+	required uint32			flags		= 4;
+	required uint32			ifindex		= 5;
+
+	required fown_entry		fown		= 6;
+	required sk_opts_entry		opts		= 7;
+}

sk-packet.c

+#include <sys/socket.h>
+#include <netpacket/packet.h>
+#include <unistd.h>
+#include <string.h>
+#include "crtools.h"
+#include "types.h"
+#include "files.h"
+#include "sockets.h"
+#include "sk-packet.h"
+
+#include "protobuf.h"
+#include "protobuf/packet-sock.pb-c.h"
+#include "protobuf/fdinfo.pb-c.h"
+
+struct packet_sock_info {
+	PacketSockEntry *pse;
+	struct file_desc d;
+};
+
+void show_packetsk(int fd, struct cr_options *o)
+{
+	pb_show_plain(fd, PB_PACKETSK);
+}
+
+static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
+{
+	int type;
+	PacketSockEntry psk = PACKET_SOCK_ENTRY__INIT;
+	SkOptsEntry skopts = SK_OPTS_ENTRY__INIT;
+	struct sockaddr_ll addr;
+	socklen_t alen;
+
+	pr_info("Dumping packet socket fd %d id %#x\n", lfd, id);
+
+	if (dump_opt(lfd, SO_TYPE, &type))
+		return -1;
+
+	psk.id = id;
+	psk.type = type;
+	psk.flags = p->flags;
+	psk.fown = (FownEntry *)&p->fown;
+	psk.opts = &skopts;
+
+	if (dump_socket_opts(lfd, &skopts))
+		return -1;
+
+	alen = sizeof(addr);
+	if (getsockname(lfd, (struct sockaddr *)&addr, &alen) < 0) {
+		pr_perror("Can't get packet sock name");
+		return -1;
+	}
+
+	psk.protocol = addr.sll_protocol;
+	psk.ifindex = addr.sll_ifindex;
+
+	return pb_write_one(fdset_fd(glob_fdset, CR_FD_PACKETSK), &psk, PB_PACKETSK);
+}
+
+static const struct fdtype_ops packet_dump_ops = {
+	.type		= FD_TYPES__PACKETSK,
+	.make_gen_id	= make_gen_id,
+	.dump		= dump_one_packet_fd,
+};
+
+int dump_one_packet_sk(struct fd_parms *p, int lfd, const struct cr_fdset *fds)
+{
+	return do_dump_gen_file(p, lfd, &packet_dump_ops, fds);
+}
+
+static int open_packet_sk(struct file_desc *d)
+{
+	struct packet_sock_info *psi;
+	PacketSockEntry *pse;
+	struct sockaddr_ll addr;
+	int sk;
+
+	psi = container_of(d, struct packet_sock_info, d);
+	pse = psi->pse;
+
+	pr_info("Opening packet socket id %#x\n", pse->id);
+
+	sk = socket(PF_PACKET, pse->type, pse->protocol);
+	if (sk < 0) {
+		pr_perror("Can't create packet sock");
+		goto err;
+	}
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sll_family = AF_PACKET;
+	addr.sll_ifindex = pse->ifindex;
+
+	if (bind(sk, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+		pr_perror("Can't bind packet socket");
+		goto err_cl;
+	}
+
+	if (rst_file_params(sk, pse->fown, pse->flags))
+		goto err_cl;
+
+	if (restore_socket_opts(sk, pse->opts))
+		goto err_cl;
+
+	return sk;
+
+err_cl:
+	close(sk);
+err:
+	return -1;
+}
+
+static struct file_desc_ops packet_sock_desc_ops = {
+	.type = FD_TYPES__PACKETSK,
+	.open = open_packet_sk,
+};
+
+static int collect_one_packet_sk(void *o, ProtobufCMessage *base)
+{
+	struct packet_sock_info *si = o;
+
+	si->pse = pb_msg(base, PacketSockEntry);
+	file_desc_add(&si->d, si->pse->id, &packet_sock_desc_ops);
+
+	return 0;
+}
+
+int collect_packet_sockets(void)
+{
+	return collect_image(CR_FD_PACKETSK, PB_PACKETSK,
+			sizeof(struct packet_sock_info), collect_one_packet_sk);
+}

sockets.c

@@ -9,6 +9,7 @@
 #include "inet_diag.h"
 #include "files.h"
 #include "util-net.h"
+#include "sk-packet.h"
 
 #ifndef NETLINK_SOCK_DIAG
 #define NETLINK_SOCK_DIAG NETLINK_INET_DIAG
@@ -99,8 +100,6 @@ int do_dump_opt(int sk, int name, void *val, int len)
 	return 0;
 }
 
-#define dump_opt(s, n, f)	do_dump_opt(s, n, f, sizeof(*f))
-
 int dump_socket_opts(int sk, SkOptsEntry *soe)
 {
 	int ret = 0;
@@ -133,6 +132,8 @@ int dump_socket(struct fd_parms *p, int lfd, const struct cr_fdset *cr_fdset)
 	case AF_INET:
 	case AF_INET6:
 		return dump_one_inet(p, lfd, cr_fdset);
+	case AF_PACKET:
+		return dump_one_packet_sk(p, lfd, cr_fdset);
 	default:
 		pr_err("BUG! Unknown socket collected\n");
 		break;