linux/include/net/udp.h, branch v4.9

udp: must lock the socket in udp_disconnect()

2016-10-20T18:45:52Z

Baozeng Ding reported KASAN traces showing uses after free in udp_lib_get_port() and other related UDP functions. A CONFIG_DEBUG_PAGEALLOC=y kernel would eventually crash. I could write a reproducer with two threads doing : static int sock_fd; static void *thr1(void *arg) { for (;;) { connect(sock_fd, (const struct sockaddr *)arg, sizeof(struct sockaddr_in)); } } static void *thr2(void *arg) { struct sockaddr_in unspec; for (;;) { memset(&unspec, 0, sizeof(unspec)); connect(sock_fd, (const struct sockaddr *)&unspec, sizeof(unspec)); } } Problem is that udp_disconnect() could run without holding socket lock, and this was causing list corruptions. Signed-off-by: Eric Dumazet Reported-by: Baozeng Ding Signed-off-by: David S. Miller

net: diag: support SOCK_DESTROY for UDP sockets

2016-08-24T06:12:27Z

This implements SOCK_DESTROY for UDP sockets similar to what was done for TCP with commit c1e64e298b8ca ("net: diag: Support destroying TCP sockets.") A process with a UDP socket targeted for destroy is awakened and recvmsg fails with ECONNABORTED. Signed-off-by: David Ahern Signed-off-by: David S. Miller

udp: avoid csum_partial() for validated skb

2016-06-02T00:41:36Z

In commit e6afc8ace6dd5 ("udp: remove headers from UDP packets before queueing"), udp_csum_pull_header() helper was added but missed fact that CHECKSUM_UNNECESSARY packets were now converted to CHECKSUM_NONE and skb->csum_valid was set to 1 for them. Since csum_partial() is quite expensive, even for 8-byte area, it is worth adding a test. We also can use skb->data instead of udp_hdr() as we are pulling UDP headers, as it is sightly faster. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: snmp: kill STATS_BH macros

2016-04-28T02:48:25Z

There is nothing related to BH in SNMP counters anymore, since linux-3.0. Rename helpers to use __ prefix instead of _BH prefix, for contexts where preemption is disabled. This more closely matches convention used to update percpu variables. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: udp: rename UDP_INC_STATS_BH()

2016-04-28T02:48:23Z

Rename UDP_INC_STATS_BH() to __UDP_INC_STATS(), and UDP6_INC_STATS_BH() to __UDP6_INC_STATS() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: snmp: kill various STATS_USER() helpers

2016-04-28T02:48:22Z

In the old days (before linux-3.0), SNMP counters were duplicated, one for user context, and one for BH context. After commit 8f0ea0fe3a03 ("snmp: reduce percpu needs by 50%") we have a single copy, and what really matters is preemption being enabled or disabled, since we use this_cpu_inc() or __this_cpu_inc() respectively. We therefore kill SNMP_INC_STATS_USER(), SNMP_ADD_STATS_USER(), NET_INC_STATS_USER(), NET_ADD_STATS_USER(), SCTP_INC_STATS_USER(), SNMP_INC_STATS64_USER(), SNMP_ADD_STATS64_USER(), TCP_ADD_STATS_USER(), UDP_INC_STATS_USER(), UDP6_INC_STATS_USER(), and XFRM_INC_STATS_USER() Following patches will rename __BH helpers to make clear their usage is not tied to BH being disabled. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

udp: Add GRO functions to UDP socket

2016-04-07T20:53:29Z

This patch adds GRO functions (gro_receive and gro_complete) to UDP sockets. udp_gro_receive is changed to perform socket lookup on a packet. If a socket is found the related GRO functions are called. This features obsoletes using UDP offload infrastructure for GRO (udp_offload). This has the advantage of not being limited to provide offload on a per port basis, GRO is now applied to whatever individual UDP sockets are bound to. This also allows the possbility of "application defined GRO"-- that is we can attach something like a BPF program to a UDP socket to perfrom GRO on an application layer protocol. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

udp: Add udp6_lib_lookup_skb and udp4_lib_lookup_skb

2016-04-07T20:53:14Z

Add externally visible functions to lookup a UDP socket by skb. This will be used for GRO in UDP sockets. These functions also check if skb->dst is set, and if it is not skb->dev is used to get dev_net. This allows calling lookup functions before dst has been set on the skbuff. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

udp: remove headers from UDP packets before queueing

2016-04-05T20:29:37Z

Remove UDP transport headers before queueing packets for reception. This change simplifies a follow-up patch to add MSG_PEEK support. Signed-off-by: Sam Kumar Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

udp: no longer use SLAB_DESTROY_BY_RCU

2016-04-05T02:11:19Z

Tom Herbert would like not touching UDP socket refcnt for encapsulated traffic. For this to happen, we need to use normal RCU rules, with a grace period before freeing a socket. UDP sockets are not short lived in the high usage case, so the added cost of call_rcu() should not be a concern. This actually removes a lot of complexity in UDP stack. Multicast receives no longer need to hold a bucket spinlock. Note that ip early demux still needs to take a reference on the socket. Same remark for functions used by xt_socket and xt_PROXY netfilter modules, but this might be changed later. Performance for a single UDP socket receiving flood traffic from many RX queues/cpus. Simple udp_rx using simple recvfrom() loop : 438 kpps instead of 374 kpps : 17 % increase of the peak rate. v2: Addressed Willem de Bruijn feedback in multicast handling - keep early demux break in __udp4_lib_demux_lookup() Signed-off-by: Eric Dumazet Cc: Tom Herbert Cc: Willem de Bruijn Tested-by: Tom Herbert Signed-off-by: David S. Miller