kernel/linux.git/net/ipv4/proc.c, branch v6.18.21

ipv4: snmp: do not use SNMP_MIB_SENTINEL anymore

2025-09-09T01:06:20+00:00

Use ARRAY_SIZE(), so that we know the limit at compile time. Signed-off-by: Eric Dumazet Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250905165813.1470708-5-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: add LINUX_MIB_BEYOND_WINDOW

2025-07-15T01:41:42+00:00

Add a new SNMP MIB : LINUX_MIB_BEYOND_WINDOW Incremented when an incoming packet is received beyond the receiver window. nstat -az | grep TcpExtBeyondWindow Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250711114006.480026-3-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: add LINUX_MIB_PAWS_TW_REJECTED counter

2025-04-11T01:29:26+00:00

When TCP is in TIME_WAIT state, PAWS verification uses LINUX_PAWSESTABREJECTED, which is ambiguous and cannot be distinguished from other PAWS verification processes. We added a new counter, like the existing PAWS_OLD_ACK one. Also we update the doc with previously missing PAWS_OLD_ACK. usage: ''' nstat -az | grep PAWSTimewait TcpExtPAWSTimewait 1 0.0 ''' Suggested-by: Eric Dumazet Signed-off-by: Jiayuan Chen Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250409112614.16153-3-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski

tcp: be less liberal in TSEcr received while in SYN_RECV state

2025-02-27T02:11:17+00:00

Yong-Hao Zou mentioned that linux was not strict as other OS in 3WHS, for flows using TCP TS option (RFC 7323) As hinted by an old comment in tcp_check_req(), we can check the TSEcr value in the incoming packet corresponds to one of the SYNACK TSval values we have sent. In this patch, I record the oldest and most recent values that SYNACK packets have used. Send a challenge ACK if we receive a TSEcr outside of this range, and increase a new SNMP counter. nstat -az | grep TSEcrRejected TcpExtTSEcrRejected 0 0.0 Due to TCP fastopen implementation, do not apply yet these checks for fastopen flows. v2: No longer use req->num_timeout, but treq->snt_tsval_first to detect when first SYNACK is prepared. This means we make sure to not send an initial zero TSval. Make sure MPTCP and TCP selftests are passing. Change MIB name to TcpExtTSEcrRejected v1: https://lore.kernel.org/netdev/CADVnQykD8i4ArpSZaPKaoNxLJ2if2ts9m4As+=Jvdkrgx1qMHw@mail.gmail.com/T/ Reported-by: Yong-Hao Zou Signed-off-by: Eric Dumazet Reviewed-by: Matthieu Baerts (NGI0) Reviewed-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250225171048.3105061-1-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: add LINUX_MIB_PAWS_OLD_ACK SNMP counter

2025-01-14T21:28:13+00:00

Prior patch in the series added TCP_RFC7323_PAWS_ACK drop reason. This patch adds the corresponding SNMP counter, for folks using nstat instead of tracing for TCP diagnostics. nstat -az | grep PAWSOldAck Suggested-by: Neal Cardwell Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Reviewed-by: Jason Xing Tested-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250113135558.3180360-4-edumazet@google.com Signed-off-by: Jakub Kicinski

minmax: add a few more MIN_T/MAX_T users

2024-07-28T20:41:14+00:00

Commit 3a7e02c040b1 ("minmax: avoid overly complicated constant expressions in VM code") added the simpler MIN_T/MAX_T macros in order to avoid some excessive expansion from the rather complicated regular min/max macros. The complexity of those macros stems from two issues: (a) trying to use them in situations that require a C constant expression (in static initializers and for array sizes) (b) the type sanity checking and MIN_T/MAX_T avoids both of these issues. Now, in the whole (long) discussion about all this, it was pointed out that the whole type sanity checking is entirely unnecessary for min_t/max_t which get a fixed type that the comparison is done in. But that still leaves min_t/max_t unnecessarily complicated due to worries about the C constant expression case. However, it turns out that there really aren't very many cases that use min_t/max_t for this, and we can just force-convert those. This does exactly that. Which in turn will then allow for much simpler implementations of min_t()/max_t(). All the usual "macros in all upper case will evaluate the arguments multiple times" rules apply. We should do all the same things for the regular min/max() vs MIN/MAX() cases, but that has the added complexity of various drivers defining their own local versions of MIN/MAX, so that needs another level of fixes first. Link: https://lore.kernel.org/all/b47fad1d0cf8449886ad148f8c013dae@AcuMS.aculab.com/ Cc: David Laight Cc: Lorenzo Stoakes Signed-off-by: Linus Torvalds

net: add

2024-05-01T01:46:52+00:00

Move some proto memory definitions out of Very few files need them, and following patch will include from Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240429134025.1233626-5-edumazet@google.com Signed-off-by: Jakub Kicinski

inet: annotate devconf data-races

2024-02-29T03:36:39+00:00

Add READ_ONCE() in ipv4_devconf_get() and corresponding WRITE_ONCE() in ipv4_devconf_set() Add IPV4_DEVCONF_RO() and IPV4_DEVCONF_ALL_RO() macros, and use them when reading devconf fields. Signed-off-by: Eric Dumazet Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20240227092411.2315725-2-edumazet@google.com Signed-off-by: Jakub Kicinski

net/tcp: Ignore specific ICMPs for TCP-AO connections

2023-10-27T09:35:45+00:00

Similarly to IPsec, RFC5925 prescribes: ">> A TCP-AO implementation MUST default to ignore incoming ICMPv4 messages of Type 3 (destination unreachable), Codes 2-4 (protocol unreachable, port unreachable, and fragmentation needed -- ’hard errors’), and ICMPv6 Type 1 (destination unreachable), Code 1 (administratively prohibited) and Code 4 (port unreachable) intended for connections in synchronized states (ESTABLISHED, FIN-WAIT-1, FIN- WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT) that match MKTs." A selftest (later in patch series) verifies that this attack is not possible in this TCP-AO implementation. Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern Signed-off-by: David S. Miller

net/tcp: Add TCP-AO segments counters

2023-10-27T09:35:45+00:00

Introduce segment counters that are useful for troubleshooting/debugging as well as for writing tests. Now there are global snmp counters as well as per-socket and per-key. Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern Signed-off-by: David S. Miller