packet: Rings support

There's no way (currently) to check that the ring got restored.
Will do it once we implement mapping of a packet socket and
tcpdump app test.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/sk-packet.h

@@ -21,5 +21,16 @@ extern int packet_receive_one(struct nlmsghdr *h, void *arg);
 
 #ifndef PACKET_FANOUT
 #define PACKET_FANOUT	18
+
+struct tpacket_req3 {
+	unsigned int tp_block_size;
+	unsigned int tp_block_nr;
+	unsigned int tp_frame_size;
+	unsigned int tp_frame_nr;
+	unsigned int tp_retire_blk_tov;
+	unsigned int tp_sizeof_priv;
+	unsigned int tp_feature_req_word;
+};
 #endif
+
 #endif

protobuf/packet-sock.proto

@@ -7,6 +7,17 @@ message packet_mclist {
 	required bytes	addr	= 3;
 }
 
+message packet_ring {
+	required uint32	block_size	= 1;
+	required uint32	block_nr	= 2;
+	required uint32	frame_size	= 3;
+	required uint32	frame_nr	= 4;
+
+	required uint32	retire_tmo	= 5;
+	required uint32	sizeof_priv	= 6;
+	required uint32	features	= 7;
+}
+
 message packet_sock_entry {
 	required uint32			id		= 1;
 	required uint32			type		= 2;
@@ -27,4 +38,6 @@ message packet_sock_entry {
 	required uint32		copy_thresh	= 15;
 	repeated packet_mclist	mclist		= 16;
 	optional uint32		fanout		= 17 [ default = 0xffffffff ];
+	optional packet_ring	rx_ring		= 18;
+	optional packet_ring	tx_ring		= 19;
 }

sk-packet.c

@@ -36,6 +36,7 @@ struct packet_sock_desc {
 	int mreq_n;
 	struct packet_diag_mclist *mreqs;
 	unsigned int fanout;
+	struct packet_diag_ring *rx, *tx;
 };
 
 #define NO_FANOUT	((unsigned int)-1)
@@ -104,6 +105,44 @@ err:
 	return -1;
 }
 
+static PacketRing *dump_ring(struct packet_diag_ring *dr)
+{
+	PacketRing *ring;
+
+	ring = xmalloc(sizeof(*ring));
+	if (!ring)
+		return NULL;
+
+	packet_ring__init(ring);
+
+	ring->block_size = dr->pdr_block_size;
+	ring->block_nr = dr->pdr_block_nr;
+	ring->frame_size = dr->pdr_frame_size;
+	ring->frame_nr = dr->pdr_frame_nr;
+	ring->retire_tmo = dr->pdr_retire_tmo;
+	ring->sizeof_priv = dr->pdr_sizeof_priv;
+	ring->features = dr->pdr_features;
+
+	return ring;
+}
+
+static int dump_rings(PacketSockEntry *psk, struct packet_sock_desc *sd)
+{
+	if (sd->rx) {
+		psk->rx_ring = dump_ring(sd->rx);
+		if (!psk->rx_ring)
+			return -1;
+	}
+
+	if (sd->tx) {
+		psk->tx_ring = dump_ring(sd->tx);
+		if (!psk->tx_ring)
+			return -1;
+	}
+
+	return 0;
+}
+
 static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
 {
 	PacketSockEntry psk = PACKET_SOCK_ENTRY__INIT;
@@ -148,8 +187,14 @@ static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
 		psk.fanout = sd->fanout;
 	}
 
+	ret = dump_rings(&psk, sd);
+	if (ret)
+		goto out;
+
 	ret = pb_write_one(fdset_fd(glob_fdset, CR_FD_PACKETSK), &psk, PB_PACKETSK);
 out:
+	xfree(psk.rx_ring);
+	xfree(psk.tx_ring);
 	for (i = 0; i < psk.n_mclist; i++)
 		xfree(psk.mclist[i]->addr.data);
 	xfree(psk.mclist);
@@ -215,6 +260,18 @@ int packet_receive_one(struct nlmsghdr *hdr, void *arg)
 	else
 		sd->fanout = NO_FANOUT;
 
+	if (tb[PACKET_DIAG_RX_RING]) {
+		sd->rx = xmalloc(sizeof(*sd->rx));
+		memcpy(sd->rx, RTA_DATA(tb[PACKET_DIAG_RX_RING]), sizeof(*sd->rx));
+	} else
+		sd->rx = NULL;
+
+	if (tb[PACKET_DIAG_TX_RING]) {
+		sd->tx = xmalloc(sizeof(*sd->tx));
+		memcpy(sd->tx, RTA_DATA(tb[PACKET_DIAG_TX_RING]), sizeof(*sd->tx));
+	} else
+		sd->tx = NULL;
+
 	return sk_collect_one(m->pdiag_ino, PF_PACKET, &sd->sd);
 }
 
@@ -246,6 +303,37 @@ static int restore_mreqs(int sk, PacketSockEntry *pse)
 	return 0;
 }
 
+static int restore_ring(int sk, int type, PacketRing *ring)
+{
+	struct tpacket_req3 req;
+
+	if (!ring)
+		return 0;
+
+	pr_debug("\tRestoring %d ring\n", type);
+
+	req.tp_block_size = ring->block_size;
+	req.tp_block_nr = ring->block_nr;
+	req.tp_frame_size = ring->frame_size;
+	req.tp_frame_nr = ring->frame_nr;
+	req.tp_retire_blk_tov = ring->retire_tmo;
+	req.tp_sizeof_priv = ring->sizeof_priv;
+	req.tp_feature_req_word = ring->features;
+
+	return restore_opt(sk, SOL_PACKET, type, &req);
+}
+
+static int restore_rings(int sk, PacketSockEntry *psk)
+{
+	if (restore_ring(sk, PACKET_RX_RING, psk->rx_ring))
+		return -1;
+
+	if (restore_ring(sk, PACKET_TX_RING, psk->tx_ring))
+		return -1;
+
+	return 0;
+}
+
 static int open_packet_sk(struct file_desc *d)
 {
 	struct packet_sock_info *psi;
@@ -312,6 +400,9 @@ static int open_packet_sk(struct file_desc *d)
 	if (restore_mreqs(sk, pse))
 		goto err_cl;
 
+	if (restore_rings(sk, pse))
+		goto err_cl;
+
 	if (pse->has_fanout) {
 		pr_info("Restoring fanout %x\n", pse->fanout);
 		if (restore_opt(sk, SOL_PACKET, PACKET_FANOUT, &pse->fanout))

sockets.c

@@ -274,7 +274,7 @@ int collect_sockets(int pid)
 	req.r.p.sdiag_family	= AF_PACKET;
 	req.r.p.sdiag_protocol	= 0;
 	req.r.p.pdiag_show	= PACKET_SHOW_INFO | PACKET_SHOW_MCLIST |
-					PACKET_SHOW_FANOUT;
+					PACKET_SHOW_FANOUT | PACKET_SHOW_RING_CFG;
 	tmp = do_rtnl_req(nl, &req, sizeof(req), packet_receive_one, NULL);
 	if (tmp)
 		err = tmp;