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Users who want to share a single public IP address for outgoing connections
between several hosts traditionally reach for SNAT. However, SNAT requires
state keeping on the node(s) performing the NAT.
A stateless alternative exists, where a single IP address used for egress
can be shared between several hosts by partitioning the available ephemeral
port range. In such a setup:
1. Each host gets assigned a disjoint range of ephemeral ports.
2. Applications open connections from the host-assigned port range.
3. Return traffic gets routed to the host based on both, the destination IP
and the destination port.
An application which wants to open an outgoing connection (connect) from a
given port range today can choose between two solutions:
1. Manually pick the source port by bind()'ing to it before connect()'ing
the socket.
This approach has a couple of downsides:
a) Search for a free port has to be implemented in the user-space. If
the chosen 4-tuple happens to be busy, the application needs to retry
from a different local port number.
Detecting if 4-tuple is busy can be either easy (TCP) or hard
(UDP). In TCP case, the application simply has to check if connect()
returned an error (EADDRNOTAVAIL). That is assuming that the local
port sharing was enabled (REUSEADDR) by all the sockets.
# Assume desired local port range is 60_000-60_511
s = socket(AF_INET, SOCK_STREAM)
s.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
s.bind(("192.0.2.1", 60_000))
s.connect(("1.1.1.1", 53))
# Fails only if 192.0.2.1:60000 -> 1.1.1.1:53 is busy
# Application must retry with another local port
In case of UDP, the network stack allows binding more than one socket
to the same 4-tuple, when local port sharing is enabled
(REUSEADDR). Hence detecting the conflict is much harder and involves
querying sock_diag and toggling the REUSEADDR flag [1].
b) For TCP, bind()-ing to a port within the ephemeral port range means
that no connecting sockets, that is those which leave it to the
network stack to find a free local port at connect() time, can use
the this port.
IOW, the bind hash bucket tb->fastreuse will be 0 or 1, and the port
will be skipped during the free port search at connect() time.
2. Isolate the app in a dedicated netns and use the use the per-netns
ip_local_port_range sysctl to adjust the ephemeral port range bounds.
The per-netns setting affects all sockets, so this approach can be used
only if:
- there is just one egress IP address, or
- the desired egress port range is the same for all egress IP addresses
used by the application.
For TCP, this approach avoids the downsides of (1). Free port search and
4-tuple conflict detection is done by the network stack:
system("sysctl -w net.ipv4.ip_local_port_range='60000 60511'")
s = socket(AF_INET, SOCK_STREAM)
s.setsockopt(SOL_IP, IP_BIND_ADDRESS_NO_PORT, 1)
s.bind(("192.0.2.1", 0))
s.connect(("1.1.1.1", 53))
# Fails if all 4-tuples 192.0.2.1:60000-60511 -> 1.1.1.1:53 are busy
For UDP this approach has limited applicability. Setting the
IP_BIND_ADDRESS_NO_PORT socket option does not result in local source
port being shared with other connected UDP sockets.
Hence relying on the network stack to find a free source port, limits the
number of outgoing UDP flows from a single IP address down to the number
of available ephemeral ports.
To put it another way, partitioning the ephemeral port range between hosts
using the existing Linux networking API is cumbersome.
To address this use case, add a new socket option at the SOL_IP level,
named IP_LOCAL_PORT_RANGE. The new option can be used to clamp down the
ephemeral port range for each socket individually.
The option can be used only to narrow down the per-netns local port
range. If the per-socket range lies outside of the per-netns range, the
latter takes precedence.
UAPI-wise, the low and high range bounds are passed to the kernel as a pair
of u16 values in host byte order packed into a u32. This avoids pointer
passing.
PORT_LO = 40_000
PORT_HI = 40_511
s = socket(AF_INET, SOCK_STREAM)
v = struct.pack("I", PORT_HI << 16 | PORT_LO)
s.setsockopt(SOL_IP, IP_LOCAL_PORT_RANGE, v)
s.bind(("127.0.0.1", 0))
s.getsockname()
# Local address between ("127.0.0.1", 40_000) and ("127.0.0.1", 40_511),
# if there is a free port. EADDRINUSE otherwise.
[1] https://github.com/cloudflare/cloudflare-blog/blob/232b432c1d57/2022-02-connectx/connectx.py#L116
Reviewed-by: Marek Majkowski <marek@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix spelling in net/ Kconfig files.
(reported by codespell)
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Cc: Florian Westphal <fw@strlen.de>
Cc: coreteam@netfilter.org
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Link: https://lore.kernel.org/r/20230124181724.18166-1-rdunlap@infradead.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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In the following call path:
ethnl_default_dumpit
-> ethnl_default_dump_one
-> ctx->ops->prepare_data
-> pause_prepare_data
struct genl_info *info will be passed as NULL, and pause_prepare_data()
dereferences it while getting the extended ack pointer.
To avoid that, just set the extack to NULL if "info" is NULL, since the
netlink extack handling messages know how to deal with that.
The pattern "info ? info->extack : NULL" is present in quite a few other
"prepare_data" implementations, so it's clear that it's a more general
problem to be dealt with at a higher level, but the code should have at
least adhered to the current conventions to avoid the NULL dereference.
Fixes: 04692c9020b7 ("net: ethtool: netlink: retrieve stats from multiple sources (eMAC, pMAC)")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reported-by: syzbot+9d44aae2720fc40b8474@syzkaller.appspotmail.com
Signed-off-by: David S. Miller <davem@davemloft.net>
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In the following call path:
ethnl_default_dumpit
-> ethnl_default_dump_one
-> ctx->ops->prepare_data
-> stats_prepare_data
struct genl_info *info will be passed as NULL, and stats_prepare_data()
dereferences it while getting the extended ack pointer.
To avoid that, just set the extack to NULL if "info" is NULL, since the
netlink extack handling messages know how to deal with that.
The pattern "info ? info->extack : NULL" is present in quite a few other
"prepare_data" implementations, so it's clear that it's a more general
problem to be dealt with at a higher level, but the code should have at
least adhered to the current conventions to avoid the NULL dereference.
Fixes: 04692c9020b7 ("net: ethtool: netlink: retrieve stats from multiple sources (eMAC, pMAC)")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The struct device for ISM devices was part of struct smcd_dev. Move to
struct ism_dev, provide a new API call in struct smcd_ops, and convert
existing SMCD code accordingly.
Furthermore, remove struct smcd_dev from struct ism_dev.
This is the final part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The ism module had SMC-D-specific code sprinkled across the entire module.
We are now consolidating the SMC-D-specific parts into the latter parts
of the module, so it becomes more clear what code is intended for use with
ISM, and which parts are glue code for usage in the context of SMC-D.
This is the fourth part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We separate the code implementing the struct smcd_ops API in the ISM
device driver from the functions that may be used by other exploiters of
ISM devices.
Note: We start out small, and don't offer the whole breadth of the ISM
device for public use, as many functions are specific to or likely only
ever used in the context of SMC-D.
This is the third part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Register the smc module with the new ism device driver API.
This is the second part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a new API that allows other drivers to concurrently access ISM devices.
To do so, we introduce a new API that allows other modules to register for
ISM device usage. Furthermore, we move the GID to struct ism, where it
belongs conceptually, and rename and relocate struct smcd_event to struct
ism_event.
This is the first part of a bigger overhaul of the interfaces between SMC
and ISM.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Conceptually, a DMB is a structure that belongs to ISM devices. However,
SMC currently 'owns' this structure. So future exploiters of ISM devices
would be forced to include SMC headers to work - which is just weird.
Therefore, we switch ISM to struct ism_dmb, introduce a new public header
with the definition (will be populated with further API calls later on),
and, add a thin wrapper to please SMC. Since structs smcd_dmb and ism_dmb
are identical, we can simply convert between the two for now.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Removing an ISM device prior to terminating its associated connections
doesn't end well.
Signed-off-by: Stefan Raspl <raspl@linux.ibm.com>
Signed-off-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: Wenjia Zhang <wenjia@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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virtio queue index can be maximum of 65535. 16 bytes are enough to store
the vq name with the existing string prefix.
With this change, send queue struct saves 24 bytes and receive
queue saves whole cache line worth 64 bytes per structure
due to saving in alignment bytes.
Pahole results before:
pahole -s drivers/net/virtio_net.o | \
grep -e "send_queue" -e "receive_queue"
send_queue 1112 0
receive_queue 1280 1
Pahole results after:
pahole -s drivers/net/virtio_net.o | \
grep -e "send_queue" -e "receive_queue"
send_queue 1088 0
receive_queue 1216 1
Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Build bot detects that err may be returned uninitialized in
devlink_fmsg_prepare_skb(). This is not really true because
all fmsgs users should create at least one outer nest, and
therefore fmsg can't be completely empty.
That said the assumption is not trivial to confirm, so let's
follow the bots advice, anyway.
This code does not seem to have changed since its inception in
commit 1db64e8733f6 ("devlink: Add devlink formatted message (fmsg) API")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230124035231.787381-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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We don't read the verify_enabled variable from hardware in the MAC Merge
layer state GET operation, instead we always leave it set to "false".
The user may think something is wrong if they set verify_enabled to
true, then read it back and see it's still false, even though the
configuration took place.
Fixes: 6505b6805655 ("net: mscc: ocelot: add MAC Merge layer support for VSC9959")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20230123184538.3420098-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The changes in this patch are as follows:
- Alter the logic of get/set_eeprom functions to use the helper function
nfp_app_from_netdev() which handles differentiating between an nfp_net
and a nfp_repr. This allows us to get an agnostic backpointer to the
pdev.
- Enable the various eeprom commands by adding the 'get_eeprom_len',
'get_eeprom', 'set_eeprom' callbacks to the nfp_port_ethtool_ops struct.
This allows the eeprom commands to work on representor interfaces,
similar to a previous patch which added it to the vnics.
Currently these are being used to configure persistent MAC addresses for
the physical ports on the nfp.
Signed-off-by: James Hershaw <james.hershaw@corigine.com>
Reviewed-by: Louis Peens <louis.peens@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20230123134135.293278-1-simon.horman@corigine.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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This function is only used in net/ipv6/route.c and has no reason to be
visible outside of it.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/50706db7f675e40b3594d62011d9363dce32b92e.1674495822.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Commit 2c7bc10d0f7b ("netlink: add macro for checking dump ctx size")
misspelled the name of the assert as asset, missing an R.
Reported-by: Ido Schimmel <idosch@idosch.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20230123222224.732338-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Add a CLI sample which can take in arbitrary request
in JSON format, convert it to Netlink and do the inverse
for output.
It's meant as a development tool primarily and perhaps
for selftests which need to tickle netlink in a special way.
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Generate and plug in the spec-based tables.
A little bit of renaming is needed in the FOU code.
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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We'll need to link two objects together to form the fou module.
This means the source can't be called fou, the build system expects
fou.o to be the combined object.
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Regenerate the FOU uAPI header from the YAML spec.
The flags now come before attributes which use them,
and the comments for type disappear (coders should look
at the spec instead).
Acked-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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