lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20180830100116.12016-1-vincent.whitchurch@axis.com> Date: Thu, 30 Aug 2018 12:01:16 +0200 From: Vincent Whitchurch <vincent.whitchurch@...s.com> To: davem@...emloft.net Cc: netdev@...r.kernel.org, willemb@...gle.com, Vincent Whitchurch <rabinv@...s.com> Subject: [PATCH net-next] packet: add sockopt to ignore outgoing packets Currently, the only way to ignore outgoing packets on a packet socket is via the BPF filter. With MSG_ZEROCOPY, packets that are looped into AF_PACKET are copied in dev_queue_xmit_nit(), and this copy happens even if the filter run from packet_rcv() would reject them. So the presence of a packet socket on the interface takes away the benefits of MSG_ZEROCOPY, even if the packet socket is not interested in outgoing packets. (Even when MSG_ZEROCOPY is not used, the skb is unnecessarily cloned, but the cost for that is much lower.) Add a socket option to allow AF_PACKET sockets to ignore outgoing packets to solve this. Note that the *BSDs already have something similar: BIOCSSEESENT/BIOCSDIRECTION and BIOCSDIRFILT. The first intended user is lldpd. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@...s.com> --- include/linux/netdevice.h | 1 + include/uapi/linux/if_packet.h | 1 + net/core/dev.c | 3 +++ net/packet/af_packet.c | 15 +++++++++++++++ 4 files changed, 20 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ca5ab98053c8..8ef14d9edc58 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2317,6 +2317,7 @@ static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb, struct packet_type { __be16 type; /* This is really htons(ether_type). */ + bool ignore_outgoing; struct net_device *dev; /* NULL is wildcarded here */ int (*func) (struct sk_buff *, struct net_device *, diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h index 67b61d91d89b..467b654bd4c7 100644 --- a/include/uapi/linux/if_packet.h +++ b/include/uapi/linux/if_packet.h @@ -57,6 +57,7 @@ struct sockaddr_ll { #define PACKET_QDISC_BYPASS 20 #define PACKET_ROLLOVER_STATS 21 #define PACKET_FANOUT_DATA 22 +#define PACKET_IGNORE_OUTGOING 23 #define PACKET_FANOUT_HASH 0 #define PACKET_FANOUT_LB 1 diff --git a/net/core/dev.c b/net/core/dev.c index 325fc5088370..0addb4f0abfe 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1947,6 +1947,9 @@ static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb) if (!ptype->af_packet_priv || !skb->sk) return false; + if (ptype->ignore_outgoing) + return true; + if (ptype->id_match) return ptype->id_match(ptype, skb->sk); else if ((struct sock *)ptype->af_packet_priv == skb->sk) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 5610061e7f2e..37bbafad724a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3805,6 +3805,18 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv return fanout_set_data(po, optval, optlen); } + case PACKET_IGNORE_OUTGOING: + { + int val; + + if (optlen != sizeof(val)) + return -EINVAL; + if (copy_from_user(&val, optval, sizeof(val))) + return -EFAULT; + + po->prot_hook.ignore_outgoing = !!val; + return 0; + } case PACKET_TX_HAS_OFF: { unsigned int val; @@ -3928,6 +3940,9 @@ static int packet_getsockopt(struct socket *sock, int level, int optname, ((u32)po->fanout->flags << 24)) : 0); break; + case PACKET_IGNORE_OUTGOING: + val = po->prot_hook.ignore_outgoing; + break; case PACKET_ROLLOVER_STATS: if (!po->rollover) return -EINVAL; -- 2.11.0
Powered by blists - more mailing lists