linux/net/ipv4/ip_input.c, branch v4.1

netfilter: Pass socket pointer down through okfn().

2015-04-07T19:25:55Z

On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller

ipv4: coding style: comparison for inequality with NULL

2015-04-03T16:11:15Z

The ipv4 code uses a mixture of coding styles. In some instances check for non-NULL pointer is done as x != NULL and sometimes as x. x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

ipv4: coding style: comparison for equality with NULL

2015-04-03T16:11:15Z

The ipv4 code uses a mixture of coding styles. In some instances check for NULL pointer is done as x == NULL and sometimes as !x. !x is preferred according to checkpatch and this patch makes the code consistent by adopting the latter form. No changes detected by objdiff. Signed-off-by: Ian Morris Signed-off-by: David S. Miller

net: Fix memory leak if TPROXY used with TCP early demux

2014-01-28T00:22:11Z

I see a memory leak when using a transparent HTTP proxy using TPROXY together with TCP early demux and Kernel v3.8.13.15 (Ubuntu stable): unreferenced object 0xffff88008cba4a40 (size 1696): comm "softirq", pid 0, jiffies 4294944115 (age 8907.520s) hex dump (first 32 bytes): 0a e0 20 6a 40 04 1b 37 92 be 32 e2 e8 b4 00 00 .. j@..7..2..... 02 00 07 01 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] kmem_cache_alloc+0xad/0xb9 [] sk_prot_alloc+0x29/0xc5 [] sk_clone_lock+0x14/0x283 [] inet_csk_clone_lock+0xf/0x7b [] netlink_broadcast+0x14/0x16 [] tcp_create_openreq_child+0x1b/0x4c3 [] tcp_v4_syn_recv_sock+0x38/0x25d [] tcp_check_req+0x25c/0x3d0 [] tcp_v4_do_rcv+0x287/0x40e [] ip_route_input_noref+0x843/0xa55 [] tcp_v4_rcv+0x4c9/0x725 [] ip_local_deliver_finish+0xe9/0x154 [] __netif_receive_skb+0x4b2/0x514 [] process_backlog+0xee/0x1c5 [] net_rx_action+0xa7/0x200 [] add_interrupt_randomness+0x39/0x157 But there are many more, resulting in the machine going OOM after some days. From looking at the TPROXY code, and with help from Florian, I see that the memory leak is introduced in tcp_v4_early_demux(): void tcp_v4_early_demux(struct sk_buff *skb) { /* ... */ iph = ip_hdr(skb); th = tcp_hdr(skb); if (th->doff < sizeof(struct tcphdr) / 4) return; sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, iph->saddr, th->source, iph->daddr, ntohs(th->dest), skb->skb_iif); if (sk) { skb->sk = sk; where the socket is assigned unconditionally to skb->sk, also bumping the refcnt on it. This is problematic, because in our case the skb has already a socket assigned in the TPROXY target. This then results in the leak I see. The very same issue seems to be with IPv6, but haven't tested. Reviewed-by: Florian Westphal Signed-off-by: Holger Eitzenberger Signed-off-by: David S. Miller

net: add SNMP counters tracking incoming ECN bits

2013-08-09T05:24:59Z

With GRO/LRO processing, there is a problem because Ip[6]InReceives SNMP counters do not count the number of frames, but number of aggregated segments. Its probably too late to change this now. This patch adds four new counters, tracking number of frames, regardless of LRO/GRO, and on a per ECN status basis, for IPv4 and IPv6. Ip[6]NoECTPkts : Number of packets received with NOECT Ip[6]ECT1Pkts : Number of packets received with ECT(1) Ip[6]ECT0Pkts : Number of packets received with ECT(0) Ip[6]CEPkts : Number of packets received with Congestion Experienced lph37:~# nstat | egrep "Pkts|InReceive" IpInReceives 1634137 0.0 Ip6InReceives 3714107 0.0 Ip6InNoECTPkts 19205 0.0 Ip6InECT0Pkts 52651828 0.0 IpExtInNoECTPkts 33630 0.0 IpExtInECT0Pkts 15581379 0.0 IpExtInCEPkts 6 0.0 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: set transport header earlier

2013-07-16T19:59:28Z

commit 45f00f99d6e ("ipv4: tcp: clean up tcp_v4_early_demux()") added a performance regression for non GRO traffic, basically disabling IP early demux. IPv6 stack resets transport header in ip6_rcv() before calling IP early demux in ip6_rcv_finish(), while IPv4 does this only in ip_local_deliver_finish(), _after_ IP early demux. GRO traffic happened to enable IP early demux because transport header is also set in inet_gro_receive() Instead of reverting the faulty commit, we can make IPv4/IPv6 behave the same : transport_header should be set in ip_rcv() instead of ip_local_deliver_finish() ip_local_deliver_finish() can also use skb_network_header_len() which is faster than ip_hdrlen() Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Tom Herbert Signed-off-by: David S. Miller

net: Add MIB counters for checksum errors

2013-04-29T19:14:03Z

Add MIB counters for checksum errors in IP layer, and TCP/UDP/ICMP layers, to help diagnose problems. $ nstat -a | grep Csum IcmpInCsumErrors 72 0.0 TcpInCsumErrors 382 0.0 UdpInCsumErrors 463221 0.0 Icmp6InCsumErrors 75 0.0 Udp6InCsumErrors 173442 0.0 IpExtInCsumErrors 10884 0.0 Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv[4|6]: correct dropwatch false positive in local_deliver_finish

2013-03-01T20:56:29Z

I had a report recently of a user trying to use dropwatch to localise some frame loss, and they were getting false positives. Turned out they were using a user space SCTP stack that used raw sockets to grab frames. When we don't have a registered protocol for a given packet, we record it as a drop, even if a raw socket receieves the frame. We should only record the drop in the event a raw socket doesnt exist to receive the frames Tested by the reported successfully Signed-off-by: Neil Horman Reported-by: William Reich Tested-by: William Reich CC: "David S. Miller" CC: William Reich CC: eric.dumazet@gmail.com Acked-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: Disallow non-namespace aware protocols to register.

2013-02-05T19:42:23Z

All in-tree ipv4 protocol implementations are now namespace aware. Therefore all the run-time checks are superfluous. Reject registry of any non-namespace aware ipv4 protocol. Eventually we'll remove prot->netns_ok and this registry time check as well. Signed-off-by: David S. Miller

net: TCP early demux cleanup

2012-07-30T21:53:21Z

early_demux() handlers should be called in RCU context, and as we use skb_dst_set_noref(skb, dst), caller must not exit from RCU context before dst use (skb_dst(skb)) or release (skb_drop(dst)) Therefore, rcu_read_lock()/rcu_read_unlock() pairs around ->early_demux() are confusing and not needed : Protocol handlers are already in an RCU read lock section. (__netif_receive_skb() does the rcu_read_lock() ) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller