From: Edward Cree <ecree@solarflare.com>
Date: Mon, 2 Jul 2018 16:14:12 +0100
Subject: net: ipv4: listified version of ip_rcv
Patch-mainline: v4.19-rc1
Git-commit: 17266ee939849cb095ed7dd9edbec4162172226b
References: bsc#1109837
Also involved adding a way to run a netfilter hook over a list of packets.
Rather than attempting to make netfilter know about lists (which would be
a major project in itself) we just let it call the regular okfn (in this
case ip_rcv_finish()) for any packets it steals, and have it give us back
a list of packets it's synchronously accepted (which normally NF_HOOK
would automatically call okfn() on, but we want to be able to potentially
pass the list to a listified version of okfn().)
The netfilter hooks themselves are indirect calls that still happen per-
packet (see nf_hook_entry_hookfn()), but again, changing that can be left
for future work.
There is potential for out-of-order receives if the netfilter hook ends up
synchronously stealing packets, as they will be processed before any
accepts earlier in the list. However, it was already possible for an
asynchronous accept to cause out-of-order receives, so presumably this is
considered OK.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
include/linux/netdevice.h | 3 ++
include/linux/netfilter.h | 22 ++++++++++++++
include/net/ip.h | 2 +
net/core/dev.c | 8 +++--
net/ipv4/af_inet.c | 1
net/ipv4/ip_input.c | 68 +++++++++++++++++++++++++++++++++++++++++-----
6 files changed, 94 insertions(+), 10 deletions(-)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2266,6 +2266,9 @@ struct packet_type {
struct net_device *,
struct packet_type *,
struct net_device *);
+ void (*list_func) (struct list_head *,
+ struct packet_type *,
+ struct net_device *);
bool (*id_match)(struct packet_type *ptype,
struct sock *sk);
void *af_packet_priv;
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -258,6 +258,20 @@ NF_HOOK(uint8_t pf, unsigned int hook, s
return ret;
}
+static inline void
+NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
+ struct list_head *head, struct net_device *in, struct net_device *out,
+ int (*okfn)(struct net *, struct sock *, struct sk_buff *))
+{
+ struct sk_buff *skb, *next;
+
+ list_for_each_entry_safe(skb, next, head, list) {
+ int ret = nf_hook(pf, hook, net, sk, skb, in, out, okfn);
+ if (ret != 1)
+ list_del(&skb->list);
+ }
+}
+
/* Call setsockopt() */
int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
unsigned int len);
@@ -372,6 +386,14 @@ NF_HOOK(uint8_t pf, unsigned int hook, s
return okfn(net, sk, skb);
}
+static inline void
+NF_HOOK_LIST(uint8_t pf, unsigned int hook, struct net *net, struct sock *sk,
+ struct list_head *head, struct net_device *in, struct net_device *out,
+ int (*okfn)(struct net *, struct sock *, struct sk_buff *))
+{
+ /* nothing to do */
+}
+
static inline int nf_hook(u_int8_t pf, unsigned int hook, struct net *net,
struct sock *sk, struct sk_buff *skb,
struct net_device *indev, struct net_device *outdev,
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -116,6 +116,8 @@ int ip_build_and_send_pkt(struct sk_buff
struct ip_options_rcu *opt);
int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
struct net_device *orig_dev);
+void ip_list_rcv(struct list_head *head, struct packet_type *pt,
+ struct net_device *orig_dev);
int ip_local_deliver(struct sk_buff *skb);
int ip_mr_input(struct sk_buff *skb);
int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4781,9 +4781,11 @@ static inline void __netif_receive_skb_l
return;
if (list_empty(head))
return;
-
- list_for_each_entry_safe(skb, next, head, list)
- pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+ if (pt_prev->list_func != NULL)
+ pt_prev->list_func(head, pt_prev, orig_dev);
+ else
+ list_for_each_entry_safe(skb, next, head, list)
+ pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
}
static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1835,6 +1835,7 @@ fs_initcall(ipv4_offload_init);
static struct packet_type ip_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_IP),
.func = ip_rcv,
+ .list_func = ip_list_rcv,
};
static int __init inet_init(void)
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -409,10 +409,9 @@ drop_error:
/*
* Main IP Receive routine.
*/
-int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
+static struct sk_buff *ip_rcv_core(struct sk_buff *skb, struct net *net)
{
const struct iphdr *iph;
- struct net *net;
u32 len;
/* When the interface is in promisc. mode, drop all the crap
@@ -422,7 +421,6 @@ int ip_rcv(struct sk_buff *skb, struct n
goto drop;
- net = dev_net(dev);
__IP_UPD_PO_STATS(net, IPSTATS_MIB_IN, skb->len);
skb = skb_share_check(skb, GFP_ATOMIC);
@@ -490,9 +488,7 @@ int ip_rcv(struct sk_buff *skb, struct n
/* Must drop socket now because of tproxy. */
skb_orphan(skb);
- return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
- net, NULL, skb, dev, NULL,
- ip_rcv_finish);
+ return skb;
csum_error:
__IP_INC_STATS(net, IPSTATS_MIB_CSUMERRORS);
@@ -501,5 +497,63 @@ inhdr_error:
drop:
kfree_skb(skb);
out:
- return NET_RX_DROP;
+ return NULL;
+}
+
+/*
+ * IP receive entry point
+ */
+int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
+ struct net_device *orig_dev)
+{
+ struct net *net = dev_net(dev);
+
+ skb = ip_rcv_core(skb, net);
+ if (skb == NULL)
+ return NET_RX_DROP;
+ return NF_HOOK(NFPROTO_IPV4, NF_INET_PRE_ROUTING,
+ net, NULL, skb, dev, NULL,
+ ip_rcv_finish);
+}
+
+static void ip_sublist_rcv(struct list_head *head, struct net_device *dev,
+ struct net *net)
+{
+ struct sk_buff *skb, *next;
+
+ NF_HOOK_LIST(NFPROTO_IPV4, NF_INET_PRE_ROUTING, net, NULL,
+ head, dev, NULL, ip_rcv_finish);
+ list_for_each_entry_safe(skb, next, head, list)
+ ip_rcv_finish(net, NULL, skb);
+}
+
+/* Receive a list of IP packets */
+void ip_list_rcv(struct list_head *head, struct packet_type *pt,
+ struct net_device *orig_dev)
+{
+ struct net_device *curr_dev = NULL;
+ struct net *curr_net = NULL;
+ struct sk_buff *skb, *next;
+ struct list_head sublist;
+
+ list_for_each_entry_safe(skb, next, head, list) {
+ struct net_device *dev = skb->dev;
+ struct net *net = dev_net(dev);
+
+ skb = ip_rcv_core(skb, net);
+ if (skb == NULL)
+ continue;
+
+ if (curr_dev != dev || curr_net != net) {
+ /* dispatch old sublist */
+ list_cut_before(&sublist, head, &skb->list);
+ if (!list_empty(&sublist))
+ ip_sublist_rcv(&sublist, dev, net);
+ /* start new sublist */
+ curr_dev = dev;
+ curr_net = net;
+ }
+ }
+ /* dispatch final sublist */
+ ip_sublist_rcv(head, curr_dev, curr_net);
}