NetworkManager/src
Wen Liang a8a2e6d727 ip-config: Support configuring per-device IPv4 sysctl forwarding option
Add support for configuring per-interface IPv4 sysctl forwarding setting
in NetworkManager. The feature allows users to configure the
net.ipv4.conf.<interface>.forward setting directly through
NetworkManager, enabling targeted forwarding configurations for
interfaces. This is particularly useful for cases such as enabling
forwarding for MetalLB load balancing without requiring a global
ip_forward=1 setting.

While forwarding setting can be managed via /etc/sysctl.conf,
configuring sysctl options for dynamically created or
software-configured interfaces (e.g., bridges) poses challenges. With
this feature, NetworkManager can configure these settings when
interfaces are created or updated, users no longer need to rely on
nm-dispatcher scripts for per-interface sysctl configuration, which can
be error-prone and complex. This feature ensures a more seamless and
integrated way to manage per-interface forwarding configurations,
reducing user overhead and improving usability in complex network
setups.

We do not support configuring per-device IPv6 sysctl forwarding because
in order to make per-device IPv6 sysctl forwarding work, we also need to
enable the IPv6 global sysctl forwarding setting, but this has potential
security concerns because it changes the behavior of the system to
function as a router, which expose the system to new risks and
unintended traffic flows, especially when enabling forwarding on the
interface the user previously explicitly disabled. Also enabling
per-device IPv6 sysctl setting will change the behavior of router
advertisement (accept_ra), which is not expected. Therefore, we
only support configuring per-device IPv4 sysctl forwarding option in
NetworkManager.

Resolves: https://issues.redhat.com/browse/RHEL-60237
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/2071
https://gitlab.freedesktop.org/NetworkManager/NetworkManager-ci/-/merge_requests/1833
2025-04-01 09:32:46 -04:00
..
c-list c-list: re-import git-subtree for 'src/c-list' 2022-07-19 09:02:36 +02:00
c-rbtree c-rbtree: re-import git-subtree for 'src/c-rbtree' 2022-11-23 18:00:31 +01:00
c-siphash c-siphash: re-import git-subtree for 'src/c-siphash' 2022-11-23 18:00:33 +01:00
c-stdaux c-stdaux: re-import git-subtree for 'src/c-stdaux' 2023-03-03 13:40:38 +01:00
contrib Rephrase certain expressions to avoid the usage of the term "allows to" 2025-03-27 09:44:07 +01:00
core ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
libnm-base dns: Add resolve-mode and certification-authority keys to global-dns 2025-01-29 14:41:47 +01:00
libnm-client-aux-extern libnmc: fix bug checking VersionInfo's capabilities 2024-12-11 15:52:09 +00:00
libnm-client-impl ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
libnm-client-public libnm: fix GObject introspection annotations for NMSecretAgentOld 2025-03-25 14:31:26 +01:00
libnm-client-test typo fix: allows to -> allows one to 2025-03-26 19:22:01 +01:00
libnm-core-aux-extern dispatcher: support device-handler actions 2024-02-21 11:16:04 +01:00
libnm-core-aux-intern libnm-core: remove old DNS parsing functions 2025-01-07 15:41:45 +01:00
libnm-core-impl ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
libnm-core-intern libnm-glib-aux: move nm_keyfile_add_group() 2025-02-04 10:44:48 +01:00
libnm-core-public ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
libnm-crypto Updated code format 2024-04-08 06:35:20 +00:00
libnm-glib-aux typo fix: allow to -> allow one to 2025-03-26 19:22:56 +01:00
libnm-lldp format: run nm-code-format 2024-10-04 11:07:35 +02:00
libnm-log-core core/logging: remove unused nm_logging_init_pre() function 2024-06-19 10:59:56 +00:00
libnm-log-null all: add some README.md files describing the purpose of our sources 2021-08-19 17:51:11 +02:00
libnm-platform libnm-platform: fix not set MACVTAP when cache ops added or updated 2025-03-31 14:58:45 +02:00
libnm-std-aux typo fix: allow to -> allow one to 2025-03-26 19:22:56 +01:00
libnm-systemd-core merge: branch 'systemd' into main 2025-02-04 15:28:11 +01:00
libnm-systemd-shared systemd: accept encoded domain names without terminating zero label 2025-02-04 15:31:45 +01:00
libnm-udev-aux format: reformat source tree with clang-format 13.0 2021-11-29 09:31:09 +00:00
libnmc-base libnmc/client-utils: typo fix, add closing parenthesis 2024-10-30 11:05:50 +01:00
libnmc-setting ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
libnmt-newt nmtui: handle write() errors correctly in nmt_newt_edit_string 2024-06-28 10:58:11 +00:00
linux-headers platform: remove CSME related code 2023-09-25 11:46:24 +00:00
n-acd n-acd: use separate seed state for each probe of the same acd 2023-10-05 09:02:57 +02:00
n-dhcp4 n-dhcp4: send request directly to avoid unnecessary retransmission timeout 2025-01-14 10:58:36 -05:00
nm-cloud-setup Reapply "cloud-setup: create VLANs for multiple VNICs on OCI" 2025-02-26 11:05:19 +01:00
nm-compat-headers all: add src/nm-compat-headers for patching included system headers 2022-09-23 11:43:33 +02:00
nm-daemon-helper nm-daemon-helper: add "service" argument 2024-07-04 15:39:03 +02:00
nm-dispatcher dispatcher: fix serialization of DNS servers 2025-01-07 15:41:45 +01:00
nm-initrd-generator initrd-generator: support rd.net.dns-backend and rd.net.dns-resolve-mode 2025-02-04 10:44:48 +01:00
nm-online all: use NM_MAX() instead of MAX() 2023-11-15 09:32:21 +01:00
nm-priv-helper format: run nm-code-format 2024-10-04 11:07:35 +02:00
nmcli ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
nmtui nmtui/ipv6: add "shared" method to ipv6 options 2025-02-18 12:09:03 +01:00
tests ip-config: Support configuring per-device IPv4 sysctl forwarding option 2025-04-01 09:32:46 -04:00
meson.build ip: configurable address pool and lease time of DHCP server in shared mode 2024-12-11 09:20:15 +01:00
README.md nm-sudo: rename to nm-priv-helper 2022-01-11 21:46:55 +01:00

src/

Most of the subdirectories are static helper libraries, which get linked into one of the final build artifacts (like libnm, nmcli or NetworkManager). Static libraries are internal API.

The only public API is libnm, which is a shared library provided client implementations.

Our own clients (like nmcli and nmtui) also use libnm, the shared library. But they also use additional static helper libraries.

The daemon statically links against a part of libnm, the part that provides connection profiles. That is libnm-core. libnm-core is thus statically linked with libnm and the daemon. It does not get linked by clients that already link with libnm (like nmtui).

Read the individual README.md files in the subdirectories for details:

Directory Description
core/ the NetworkManager daemon
nmcli/ nmcli application, a command line client for NetworkManager
nmtui/ nmtui application, a text UI client for NetworkManager
nm-cloud-setup/ service to automatically configure NetworkManager in cloud environment
nm-initrd-generator/ generates NetworkManager configuration by parsing kernel command line options for dracut/initrd
nm-dispatcher/ NetworkManager-dispatcher service to run user scripts
nm-online/ application which checks whether NetworkManager is done, for implementing NetworkManager-wait-online.service
nm-priv-helper/ internal service for privileged operations
nm-daemon-helper/ internal helper binary spawned by NetworkManager
libnm-std-aux/ internal helper library for standard C
libnm-glib-aux/ internal helper library for glib
libnm-log-null/ internal helper library with dummy (null) logging backend
libnm-log-core/ internal helper library with logging backend (syslog) used by daemon
libnm-base/ internal helper library with base definitions
libnm-platform/ internal helper library for netlink and other platform/kernel API
libnm-udev-aux/ internal helper library for libudev
libnm-core-public/ public API of libnm (libnm-core part)
libnm-core-intern/ internal API of libnm-core, used by libnm and daemon
libnm-core-impl/ implementation of libnm-core
libnm-core-aux-intern/ internal helper library on top of libnm-core (used by libnm-core itself)
libnm-core-aux-extern/ internal helper library on top of libnm-core (not used by libnm-core)
libnm-client-public/ public API of libnm (NMClient part)
libnm-client-impl/ implementation of libnm (NMClient)
libnm-client-aux-extern/ internal helper library on top of libnm (not used by libnm itself)
libnmc-base/ internal helper library for libnm clients
libnmc-setting/ internal helper library for setting connection profiles (used by nmcli)
libnmt-newt/ internal helper library for libnewt for nmtui
linux-headers/ extra Linux kernel UAPI headers
contrib/ sources that are not used by NetworkManager itself
tests/ unit tests that are not specific to one of the other directories
libnm-client-test/ internal helper library with test utils for libnm
c-list/ fork of c-util helper library for intrusive, doubly linked list
c-rbtree/ fork of c-util helper library for intrusive Red-Black Tree
c-siphash/ fork of c-util helper library for SIPHash24
c-stdaux/ fork of c-util general purpose helpers for standard C
n-acd/ fork of nettools IPv4 ACD library
n-dhcp4/ fork of nettools DHCPv4 library
libnm-systemd-core/ fork of systemd code as network library
libnm-systemd-shared/ fork of systemd code as general purpose library