---

yaml
---
r: 368318
b: refs/heads/master
c: 77f65eb
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b0aa73bf081da6810dacd750b9f8186640e172db
+refs/heads/master: 77f65ebdca506870d99bfabe52bde222511022ec

trunk/include/uapi/linux/if_packet.h

@@ -55,6 +55,8 @@ struct sockaddr_ll {
 #define PACKET_FANOUT_HASH		0
 #define PACKET_FANOUT_LB		1
 #define PACKET_FANOUT_CPU		2
+#define PACKET_FANOUT_ROLLOVER		3
+#define PACKET_FANOUT_FLAG_ROLLOVER	0x1000
 #define PACKET_FANOUT_FLAG_DEFRAG	0x8000
 
 struct tpacket_stats {

trunk/net/packet/af_packet.c

@@ -181,6 +181,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 
 struct packet_sock;
 static int tpacket_snd(struct packet_sock *po, struct msghdr *msg);
+static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
+		       struct packet_type *pt, struct net_device *orig_dev);
 
 static void *packet_previous_frame(struct packet_sock *po,
 		struct packet_ring_buffer *rb,
@@ -973,11 +975,11 @@ static void *packet_current_rx_frame(struct packet_sock *po,
 
 static void *prb_lookup_block(struct packet_sock *po,
 				     struct packet_ring_buffer *rb,
-				     unsigned int previous,
+				     unsigned int idx,
 				     int status)
 {
 	struct tpacket_kbdq_core *pkc  = GET_PBDQC_FROM_RB(rb);
-	struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, previous);
+	struct tpacket_block_desc *pbd = GET_PBLOCK_DESC(pkc, idx);
 
 	if (status != BLOCK_STATUS(pbd))
 		return NULL;
@@ -1041,6 +1043,29 @@ static void packet_increment_head(struct packet_ring_buffer *buff)
 	buff->head = buff->head != buff->frame_max ? buff->head+1 : 0;
 }
 
+static bool packet_rcv_has_room(struct packet_sock *po, struct sk_buff *skb)
+{
+	struct sock *sk = &po->sk;
+	bool has_room;
+
+	if (po->prot_hook.func != tpacket_rcv)
+		return (atomic_read(&sk->sk_rmem_alloc) + skb->truesize)
+			<= sk->sk_rcvbuf;
+
+	spin_lock(&sk->sk_receive_queue.lock);
+	if (po->tp_version == TPACKET_V3)
+		has_room = prb_lookup_block(po, &po->rx_ring,
+					    po->rx_ring.prb_bdqc.kactive_blk_num,
+					    TP_STATUS_KERNEL);
+	else
+		has_room = packet_lookup_frame(po, &po->rx_ring,
+					       po->rx_ring.head,
+					       TP_STATUS_KERNEL);
+	spin_unlock(&sk->sk_receive_queue.lock);
+
+	return has_room;
+}
+
 static void packet_sock_destruct(struct sock *sk)
 {
 	skb_queue_purge(&sk->sk_error_queue);
@@ -1066,31 +1091,57 @@ static int fanout_rr_next(struct packet_fanout *f, unsigned int num)
 	return x;
 }
 
-static struct sock *fanout_demux_hash(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
+static unsigned int fanout_demux_hash(struct packet_fanout *f,
+				      struct sk_buff *skb,
+				      unsigned int num)
 {
-	u32 idx, hash = skb->rxhash;
-
-	idx = ((u64)hash * num) >> 32;
-
-	return f->arr[idx];
+	return (((u64)skb->rxhash) * num) >> 32;
 }
 
-static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
+static unsigned int fanout_demux_lb(struct packet_fanout *f,
+				    struct sk_buff *skb,
+				    unsigned int num)
 {
 	int cur, old;
 
 	cur = atomic_read(&f->rr_cur);
 	while ((old = atomic_cmpxchg(&f->rr_cur, cur,
 				     fanout_rr_next(f, num))) != cur)
 		cur = old;
-	return f->arr[cur];
+	return cur;
+}
+
+static unsigned int fanout_demux_cpu(struct packet_fanout *f,
+				     struct sk_buff *skb,
+				     unsigned int num)
+{
+	return smp_processor_id() % num;
 }
 
-static struct sock *fanout_demux_cpu(struct packet_fanout *f, struct sk_buff *skb, unsigned int num)
+static unsigned int fanout_demux_rollover(struct packet_fanout *f,
+					  struct sk_buff *skb,
+					  unsigned int idx, unsigned int skip,
+					  unsigned int num)
 {
-	unsigned int cpu = smp_processor_id();
+	unsigned int i, j;
 
-	return f->arr[cpu % num];
+	i = j = min_t(int, f->next[idx], num - 1);
+	do {
+		if (i != skip && packet_rcv_has_room(pkt_sk(f->arr[i]), skb)) {
+			if (i != j)
+				f->next[idx] = i;
+			return i;
+		}
+		if (++i == num)
+			i = 0;
+	} while (i != j);
+
+	return idx;
+}
+
+static bool fanout_has_flag(struct packet_fanout *f, u16 flag)
+{
+	return f->flags & (flag >> 8);
 }
 
 static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
@@ -1099,7 +1150,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
 	struct packet_fanout *f = pt->af_packet_priv;
 	unsigned int num = f->num_members;
 	struct packet_sock *po;
-	struct sock *sk;
+	unsigned int idx;
 
 	if (!net_eq(dev_net(dev), read_pnet(&f->net)) ||
 	    !num) {
@@ -1110,23 +1161,31 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
 	switch (f->type) {
 	case PACKET_FANOUT_HASH:
 	default:
-		if (f->defrag) {
+		if (fanout_has_flag(f, PACKET_FANOUT_FLAG_DEFRAG)) {
 			skb = ip_check_defrag(skb, IP_DEFRAG_AF_PACKET);
 			if (!skb)
 				return 0;
 		}
 		skb_get_rxhash(skb);
-		sk = fanout_demux_hash(f, skb, num);
+		idx = fanout_demux_hash(f, skb, num);
 		break;
 	case PACKET_FANOUT_LB:
-		sk = fanout_demux_lb(f, skb, num);
+		idx = fanout_demux_lb(f, skb, num);
 		break;
 	case PACKET_FANOUT_CPU:
-		sk = fanout_demux_cpu(f, skb, num);
+		idx = fanout_demux_cpu(f, skb, num);
+		break;
+	case PACKET_FANOUT_ROLLOVER:
+		idx = fanout_demux_rollover(f, skb, 0, (unsigned int) -1, num);
 		break;
 	}
 
-	po = pkt_sk(sk);
+	po = pkt_sk(f->arr[idx]);
+	if (fanout_has_flag(f, PACKET_FANOUT_FLAG_ROLLOVER) &&
+	    unlikely(!packet_rcv_has_room(po, skb))) {
+		idx = fanout_demux_rollover(f, skb, idx, idx, num);
+		po = pkt_sk(f->arr[idx]);
+	}
 
 	return po->prot_hook.func(skb, dev, &po->prot_hook, orig_dev);
 }
@@ -1175,10 +1234,13 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 	struct packet_sock *po = pkt_sk(sk);
 	struct packet_fanout *f, *match;
 	u8 type = type_flags & 0xff;
-	u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
+	u8 flags = type_flags >> 8;
 	int err;
 
 	switch (type) {
+	case PACKET_FANOUT_ROLLOVER:
+		if (type_flags & PACKET_FANOUT_FLAG_ROLLOVER)
+			return -EINVAL;
 	case PACKET_FANOUT_HASH:
 	case PACKET_FANOUT_LB:
 	case PACKET_FANOUT_CPU:
@@ -1203,7 +1265,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 		}
 	}
 	err = -EINVAL;
-	if (match && match->defrag != defrag)
+	if (match && match->flags != flags)
 		goto out;
 	if (!match) {
 		err = -ENOMEM;
@@ -1213,7 +1275,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
 		write_pnet(&match->net, sock_net(sk));
 		match->id = id;
 		match->type = type;
-		match->defrag = defrag;
+		match->flags = flags;
 		atomic_set(&match->rr_cur, 0);
 		INIT_LIST_HEAD(&match->list);
 		spin_lock_init(&match->lock);
@@ -3240,7 +3302,8 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
 	case PACKET_FANOUT:
 		val = (po->fanout ?
 		       ((u32)po->fanout->id |
-			((u32)po->fanout->type << 16)) :
+			((u32)po->fanout->type << 16) |
+			((u32)po->fanout->flags << 24)) :
 		       0);
 		break;
 	case PACKET_TX_HAS_OFF:

trunk/net/packet/internal.h

@@ -77,10 +77,11 @@ struct packet_fanout {
 	unsigned int		num_members;
 	u16			id;
 	u8			type;
-	u8			defrag;
+	u8			flags;
 	atomic_t		rr_cur;
 	struct list_head	list;
 	struct sock		*arr[PACKET_FANOUT_MAX];
+	int			next[PACKET_FANOUT_MAX];
 	spinlock_t		lock;
 	atomic_t		sk_ref;
 	struct packet_type	prot_hook ____cacheline_aligned_in_smp;

trunk/tools/testing/selftests/Makefile

@@ -6,6 +6,7 @@ TARGETS += cpu-hotplug
 TARGETS += memory-hotplug
 TARGETS += efivarfs
 TARGETS += net-socket
+TARGETS += net-afpacket
 
 all:
 	for TARGET in $(TARGETS); do \

trunk/tools/testing/selftests/net-afpacket/Makefile

@@ -0,0 +1,18 @@
+# Makefile for net-socket selftests
+
+CC = $(CROSS_COMPILE)gcc
+CFLAGS = -Wall
+
+CFLAGS += -I../../../../usr/include/
+
+AF_PACKET_PROGS = psock_fanout
+
+all: $(AF_PACKET_PROGS)
+%: %.c
+	$(CC) $(CFLAGS) -o $@ $^
+
+run_tests: all
+	@/bin/sh ./run_afpackettests || echo "afpackettests: [FAIL]"
+
+clean:
+	$(RM) $(AF_PACKET_PROGS)