kernel/linux.git/net/ipv4/igmp.c, branch v6.19.11

ipv4: igmp: annotate data-races around idev->mr_maxdelay

2026-03-04T12:20:29+00:00

[ Upstream commit e4faaf65a75f650ac4366ddff5dabb826029ca5a ] idev->mr_maxdelay is read and written locklessly, add READ_ONCE()/WRITE_ONCE() annotations. While we are at it, make this field an u32. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20260122172247.2429403-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ipv4: adopt dst_dev, skb_dst_dev and skb_dst_dev_net[_rcu]

2025-07-02T21:32:30+00:00

Use the new helpers as a first step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com Signed-off-by: Jakub Kicinski

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

netlink: support dumping IPv4 multicast addresses

2025-02-11T10:26:53+00:00

Extended RTM_GETMULTICAST to support dumping joined IPv4 multicast addresses, in addition to the existing IPv6 functionality. This allows userspace applications to retrieve both IPv4 and IPv6 multicast addresses through similar netlink command and then monitor future changes by registering to RTNLGRP_IPV4_MCADDR and RTNLGRP_IPV6_MCADDR. Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Reviewed-by: Eric Dumazet Signed-off-by: Yuyang Huang Link: https://patch.msgid.link/20250207110836.2407224-1-yuyanghuang@google.com Signed-off-by: Paolo Abeni

netlink: correct nlmsg size for multicast notifications

2024-12-23T18:26:43+00:00

Corrected the netlink message size calculation for multicast group join/leave notifications. The previous calculation did not account for the inclusion of both IPv4/IPv6 addresses and ifa_cacheinfo in the payload. This fix ensures that the allocated message size is sufficient to hold all necessary information. This patch also includes the following improvements: * Uses GFP_KERNEL instead of GFP_ATOMIC when holding the RTNL mutex. * Uses nla_total_size(sizeof(struct in6_addr)) instead of nla_total_size(16). * Removes unnecessary EXPORT_SYMBOL(). Fixes: 2c2b61d2138f ("netlink: add IGMP/MLD join/leave notifications") Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Signed-off-by: Yuyang Huang Link: https://patch.msgid.link/20241221100007.1910089-1-yuyanghuang@google.com Signed-off-by: Jakub Kicinski

netlink: add IGMP/MLD join/leave notifications

2024-12-15T12:31:35+00:00

This change introduces netlink notifications for multicast address changes. The following features are included: * Addition and deletion of multicast addresses are reported using RTM_NEWMULTICAST and RTM_DELMULTICAST messages with AF_INET and AF_INET6. * Two new notification groups: RTNLGRP_IPV4_MCADDR and RTNLGRP_IPV6_MCADDR are introduced for receiving these events. This change allows user space applications (e.g., ip monitor) to efficiently track multicast group memberships by listening for netlink events. Previously, applications relied on inefficient polling of procfs, introducing delays. With netlink notifications, applications receive realtime updates on multicast group membership changes, enabling more precise metrics collection and system monitoring. This change also unlocks the potential for implementing a wide range of sophisticated multicast related features in user space by allowing applications to combine kernel provided multicast address information with user space data and communicate decisions back to the kernel for more fine grained control. This mechanism can be used for various purposes, including multicast filtering, IGMP/MLD offload, and IGMP/MLD snooping. Cc: Maciej Żenczykowski Cc: Lorenzo Colitti Co-developed-by: Patrick Ruddy Signed-off-by: Patrick Ruddy Link: https://lore.kernel.org/r/20180906091056.21109-1-pruddy@vyatta.att-mail.com Signed-off-by: Yuyang Huang Signed-off-by: David S. Miller

net: ipv4: igmp: optimize ____ip_mc_inc_group() using mc_hash

2024-10-09T11:50:11+00:00

The runtime cost of joining a single multicast group in the current implementation of ____ip_mc_inc_group grows linearly with the number of existing memberships. This is caused by the linear search for an existing group record in the multicast address list. This linear complexity results in quadratic complexity when successively adding memberships, which becomes a performance bottleneck when setting up large numbers of multicast memberships. If available, use the existing multicast hash map mc_hash to quickly search for an existing group membership record. This leads to near-constant complexity on the addition of a new multicast record, significantly improving performance for workloads involving many multicast memberships. On profiling with a loopback device, this patch presented a speedup of around 6 when successively setting up 2000 multicast groups using setsockopt without measurable drawbacks on smaller numbers of multicast groups. Signed-off-by: Jonas Rebmann Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller

ipv4: Set scope explicitly in ip_route_output().

2024-04-08T12:20:51+00:00

Add a "scope" parameter to ip_route_output() so that callers don't have to override the tos parameter with the RTO_ONLINK flag if they want a local scope. This will allow converting flowi4_tos to dscp_t in the future, thus allowing static analysers to flag invalid interactions between "tos" (the DSCP bits) and ECN. Only three users ask for local scope (bonding, arp and atm). The others continue to use RT_SCOPE_UNIVERSE. While there, add a comment to warn users about the limitations of ip_route_output(). Signed-off-by: Guillaume Nault Acked-by: Leon Romanovsky # infiniband Signed-off-by: David S. Miller

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