linux/include/net/ip.h, branch v6.16

net: use netif_disable_lro in ipv6_add_dev

2025-04-03T22:32:08Z

ipv6_add_dev might call dev_disable_lro which unconditionally grabs instance lock, so it will deadlock during NETDEV_REGISTER. Switch to netif_disable_lro. Make sure all callers hold the instance lock as well. Cc: Cosmin Ratiu Fixes: ad7c7b2172c3 ("net: hold netdev instance lock during sysfs operations") Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250401163452.622454-4-sdf@fomichev.me Signed-off-by: Jakub Kicinski

inet: call inet6_ehashfn() once from inet6_hash_connect()

2025-03-06T23:26:02Z

inet6_ehashfn() being called from __inet6_check_established() has a big impact on performance, as shown in the Tested section. After prior patch, we can compute the hash for port 0 from inet6_hash_connect(), and derive each hash in __inet_hash_connect() from this initial hash: hash(saddr, lport, daddr, dport) == hash(saddr, 0, daddr, dport) + lport Apply the same principle for __inet_check_established(), although inet_ehashfn() has a smaller cost. Tested: Server: ulimit -n 40000; neper/tcp_crr -T 200 -F 30000 -6 --nolog Client: ulimit -n 40000; neper/tcp_crr -T 200 -F 30000 -6 --nolog -c -H server Before this patch: utime_start=0.286131 utime_end=4.378886 stime_start=11.952556 stime_end=1991.655533 num_transactions=1446830 latency_min=0.001061085 latency_max=12.075275028 latency_mean=0.376375302 latency_stddev=1.361969596 num_samples=306383 throughput=151866.56 perf top: 50.01% [kernel] [k] __inet6_check_established 20.65% [kernel] [k] __inet_hash_connect 15.81% [kernel] [k] inet6_ehashfn 2.92% [kernel] [k] rcu_all_qs 2.34% [kernel] [k] __cond_resched 0.50% [kernel] [k] _raw_spin_lock 0.34% [kernel] [k] sched_balance_trigger 0.24% [kernel] [k] queued_spin_lock_slowpath After this patch: utime_start=0.315047 utime_end=9.257617 stime_start=7.041489 stime_end=1923.688387 num_transactions=3057968 latency_min=0.003041375 latency_max=7.056589232 latency_mean=0.141075048 # Better latency metrics latency_stddev=0.526900516 num_samples=312996 throughput=320677.21 # 111 % increase, and 229 % for the series perf top: inet6_ehashfn is no longer seen. 39.67% [kernel] [k] __inet_hash_connect 37.06% [kernel] [k] __inet6_check_established 4.79% [kernel] [k] rcu_all_qs 3.82% [kernel] [k] __cond_resched 1.76% [kernel] [k] sched_balance_domains 0.82% [kernel] [k] _raw_spin_lock 0.81% [kernel] [k] sched_balance_rq 0.81% [kernel] [k] sched_balance_trigger 0.76% [kernel] [k] queued_spin_lock_slowpath Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Tested-by: Jason Xing Reviewed-by: Jason Xing Link: https://patch.msgid.link/20250305034550.879255-3-edumazet@google.com Signed-off-by: Jakub Kicinski

ipv4: remove get_rttos

2025-02-19T02:27:19Z

Initialize the ip cookie tos field when initializing the cookie, in ipcm_init_sk. The existing code inverts the standard pattern for initializing cookie fields. Default is to initialize the field from the sk, then possibly overwrite that when parsing cmsgs (the unlikely case). This field inverts that, setting the field to an illegal value and after cmsg parsing checking whether the value is still illegal and thus should be overridden. Be careful to always apply mask INET_DSCP_MASK, as before. Signed-off-by: Willem de Bruijn Reviewed-by: David Ahern Link: https://patch.msgid.link/20250214222720.3205500-5-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

ipv4: initialize inet socket cookies with sockcm_init

2025-02-19T02:27:19Z

Avoid open coding the same logic. Signed-off-by: Willem de Bruijn Reviewed-by: David Ahern Link: https://patch.msgid.link/20250214222720.3205500-4-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

net: introduce EXPORT_IPV6_MOD() and EXPORT_IPV6_MOD_GPL()

2025-02-14T21:09:38Z

We have many EXPORT_SYMBOL(x) in networking tree because IPv6 can be built as a module. CONFIG_IPV6=y is becoming the norm. Define a EXPORT_IPV6_MOD(x) which only exports x for modular IPv6. Same principle applies to EXPORT_IPV6_MOD_GPL() Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Mateusz Polchlopek Link: https://patch.msgid.link/20250212132418.1524422-2-edumazet@google.com Signed-off-by: Jakub Kicinski

ipv4: use RCU protection in ip_dst_mtu_maybe_forward()

2025-02-07T00:14:14Z

ip_dst_mtu_maybe_forward() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: f87c10a8aa1e8 ("ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against pmtu spoofing") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250205155120.1676781-4-edumazet@google.com Signed-off-by: Jakub Kicinski

sock: support SO_PRIORITY cmsg

2024-12-17T02:13:44Z

The Linux socket API currently allows setting SO_PRIORITY at the socket level, applying a uniform priority to all packets sent through that socket. The exception to this is IP_TOS, when the priority value is calculated during the handling of ancillary data, as implemented in commit f02db315b8d8 ("ipv4: IP_TOS and IP_TTL can be specified as ancillary data"). However, this is a computed value, and there is currently no mechanism to set a custom priority via control messages prior to this patch. According to this patch, if SO_PRIORITY is specified as ancillary data, the packet is sent with the priority value set through sockc->priority, overriding the socket-level values set via the traditional setsockopt() method. This is analogous to the existing support for SO_MARK, as implemented in commit c6af0c227a22 ("ip: support SO_MARK cmsg"). If both cmsg SO_PRIORITY and IP_TOS are passed, then the one that takes precedence is the last one in the cmsg list. This patch has the side effect that raw_send_hdrinc now interprets cmsg IP_TOS. Reviewed-by: Willem de Bruijn Suggested-by: Ferenc Fejes Signed-off-by: Anna Emese Nyiri Link: https://patch.msgid.link/20241213084457.45120-3-annaemesenyiri@gmail.com Signed-off-by: Jakub Kicinski

ipv4: Switch inet_addr_hash() to less predictable hash.

2024-10-23T11:17:35Z

Recently, commit 4a0ec2aa0704 ("ipv6: switch inet6_addr_hash() to less predictable hash") and commit 4daf4dc275f1 ("ipv6: switch inet6_acaddr_hash() to less predictable hash") hardened IPv6 address hash functions. inet_addr_hash() is also highly predictable, and a malicious use could abuse a specific bucket. Let's follow the change on IPv4 by using jhash_1word(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20241018014100.93776-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni

ipv4: tcp: give socket pointer to control skbs

2024-10-15T00:39:37Z

ip_send_unicast_reply() send orphaned 'control packets'. These are RST packets and also ACK packets sent from TIME_WAIT. Some eBPF programs would prefer to have a meaningful skb->sk pointer as much as possible. This means that TCP can now attach TIME_WAIT sockets to outgoing skbs. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Reviewed-by: Brian Vazquez Link: https://patch.msgid.link/20241010174817.1543642-6-edumazet@google.com Signed-off-by: Jakub Kicinski

ipv4: Convert ip_route_input() to dscp_t.

2024-10-03T23:21:21Z

Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input() to consider are: * input_action_end_dx4_finish() and input_action_end_dt4() in net/ipv6/seg6_local.c. These functions set the tos parameter to 0, which is already a valid dscp_t value, so they don't need to be adjusted for the new prototype. * icmp_route_lookup(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(), which get the DSCP directly from IPv4 headers. Define a helper to read the .tos field of struct iphdr as dscp_t, so that these function don't have to do the conversion manually. While there, declare *iph as const in br_nf_pre_routing_finish(), declare its local variables in reverse-christmas-tree order and move the "err = ip_route_input()" assignment out of the conditional to avoid checkpatch warning. Signed-off-by: Guillaume Nault Reviewed-by: David Ahern Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski