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

net: ipconfig: Replace strncpy with strscpy in ic_proto_name

2025-11-29T04:19:16+00:00

strncpy() is deprecated [1] for NUL-terminated destination buffers because it does not guarantee NUL termination. Replace it with strscpy() to ensure the destination buffer is always NUL-terminated and to avoid any additional NUL padding. Although the identifier buffer has 252 usable bytes, strncpy() copied only up to 251 bytes to the zero-initialized buffer, relying on the last byte to act as an implicit NUL terminator. Switching to strscpy() avoids this implicit behavior and does not use magic numbers. The source string is also NUL-terminated and satisfies the __must_be_cstr() requirement of strscpy(). Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Signed-off-by: Thorsten Blum Link: https://patch.msgid.link/20251126220804.102160-2-thorsten.blum@linux.dev Signed-off-by: Jakub Kicinski

net: ipconfig: convert timeouts to secs_to_jiffies()

2025-07-10T02:25:01+00:00

Commit b35108a51cf7 ("jiffies: Define secs_to_jiffies()") introduced secs_to_jiffies(). As the value here is a multiple of 1000, use secs_to_jiffies() instead of msecs_to_jiffies to avoid the multiplication. This is converted using scripts/coccinelle/misc/secs_to_jiffies.cocci with the following Coccinelle rules: @depends on patch@ expression E; @@ -msecs_to_jiffies(E * 1000) +secs_to_jiffies(E) -msecs_to_jiffies(E * MSEC_PER_SEC) +secs_to_jiffies(E) While here, manually convert a couple timeouts denominated in seconds Signed-off-by: Easwar Hariharan Link: https://patch.msgid.link/20250707-netdev-secs-to-jiffies-part-2-v2-2-b7817036342f@linux.microsoft.com Signed-off-by: Jakub Kicinski

net: ipconfig: move ic_nameservers_fallback into #ifdef block

2023-05-22T10:17:55+00:00

The new variable is only used when IPCONFIG_BOOTP is defined and otherwise causes a warning: net/ipv4/ipconfig.c:177:12: error: 'ic_nameservers_fallback' defined but not used [-Werror=unused-variable] Move it next to the user. Fixes: 81ac2722fa19 ("net: ipconfig: Allow DNS to be overwritten by DHCPACK") Signed-off-by: Arnd Bergmann Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: ipconfig: Allow DNS to be overwritten by DHCPACK

2023-05-10T08:20:47+00:00

Some DHCP server implementations only send the important requested DHCP options in the final BOOTP reply (DHCPACK). One example is systemd-networkd. However, RFC2131, in section 4.3.1 states: > The server MUST return to the client: > [...] > o Parameters requested by the client, according to the following > rules: > > -- IF the server has been explicitly configured with a default > value for the parameter, the server MUST include that value > in an appropriate option in the 'option' field, ELSE I've reported the issue here: https://github.com/systemd/systemd/issues/27471 Linux PNP DHCP client implementation only takes into account the DNS servers received in the first BOOTP reply (DHCPOFFER). This usually isn't an issue as servers are required to put the same values in the DHCPOFFER and DHCPACK. However, RFC2131, in section 4.3.2 states: > Any configuration parameters in the DHCPACK message SHOULD NOT > conflict with those in the earlier DHCPOFFER message to which the > client is responding. The client SHOULD use the parameters in the > DHCPACK message for configuration. When making Linux PNP DHCP client (cmdline ip=dhcp) interact with systemd-networkd DHCP server, an interesting "protocol misunderstanding" happens: Because DNS servers were only specified in the DHCPACK and not in the DHCPOFFER, Linux will not catch the correct DNS servers: in the first BOOTP reply (DHCPOFFER), it sees that there is no DNS, and sets as fallback the IP of the DHCP server itself. When the second BOOTP reply comes (DHCPACK), it's already too late: the kernel will not overwrite the fallback setting it has set previously. This patch makes the kernel overwrite its DNS fallback by DNS servers specified in the DHCPACK if any. Signed-off-by: Martin Wetterwald Signed-off-by: David S. Miller

Merge tag 'driver-core-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2022-08-04T18:31:20+00:00

Pull driver core / kernfs updates from Greg KH: "Here is the set of driver core and kernfs changes for 6.0-rc1. The "biggest" thing in here is some scalability improvements for kernfs for large systems. Other than that, included in here are: - arch topology and cache info changes that have been reviewed and discussed a lot. - potential error path cleanup fixes - deferred driver probe cleanups - firmware loader cleanups and tweaks - documentation updates - other small things All of these have been in the linux-next tree for a while with no reported problems" * tag 'driver-core-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (63 commits) docs: embargoed-hardware-issues: fix invalid AMD contact email firmware_loader: Replace kmap() with kmap_local_page() sysfs docs: ABI: Fix typo in comment kobject: fix Kconfig.debug "its" grammar kernfs: Fix typo 'the the' in comment docs: driver-api: firmware: add driver firmware guidelines. (v3) arch_topology: Fix cache attributes detection in the CPU hotplug path ACPI: PPTT: Leave the table mapped for the runtime usage cacheinfo: Use atomic allocation for percpu cache attributes drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist MAINTAINERS: Change mentions of mpm to olivia docs: ABI: sysfs-devices-soc: Update Lee Jones' email address docs: ABI: sysfs-class-pwm: Update Lee Jones' email address Documentation/process: Add embargoed HW contact for LLVM Revert "kernfs: Change kernfs_notify_list to llist." ACPI: Remove the unused find_acpi_cpu_cache_topology() arch_topology: Warn that topology for nested clusters is not supported arch_topology: Add support for parsing sockets in /cpu-map arch_topology: Set cluster identifier in each core/thread from /cpu-map arch_topology: Limit span of cpu_clustergroup_mask() ...

net: ipconfig: use strscpy to replace strlcpy

2022-07-04T09:28:00+00:00

The strlcpy should not be used because it doesn't limit the source length. Preferred is strscpy. Signed-off-by: XueBing Chen Signed-off-by: David S. Miller

net: ipconfig: Relax fw_devlink if we need to mount a network rootfs

2022-06-10T13:57:54+00:00

If there are network devices that could probe without some of their suppliers probing and those network devices are needed to mount a network rootfs, then fw_devlink=on might break that usecase by blocking the network devices from probing by the time IP auto config starts. So, if no network devices are available when IP auto config is enabled and we have a network rootfs, make sure fw_devlink doesn't block the probing of any device that has a driver and then retry finding a network device. Tested-by: Geert Uytterhoeven Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20220601070707.3946847-6-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

net: ipconfig: Release the rtnl_lock while waiting for carrier

2021-10-28T13:36:41+00:00

While waiting for a carrier to come on one of the netdevices, some devices will require to take the rtnl lock at some point to fully initialize all parts of the link. That's the case for SFP, where the rtnl is taken when a module gets detected. This prevents mounting an NFS rootfs over an SFP link. This means that while ipconfig waits for carriers to be detected, no SFP modules can be detected in the meantime, it's only detected after ipconfig times out. This commit releases the rtnl_lock while waiting for the carrier to come up, and re-takes it to check the for the init device and carrier status. Signed-off-by: Maxime Chevallier Signed-off-by: David S. Miller

net: ipconfig: Don't override command-line hostnames or domains

2021-06-02T20:27:03+00:00

If the user specifies a hostname or domain name as part of the ip= command-line option, preserve it and don't overwrite it with one supplied by DHCP/BOOTP. For instance, ip=::::myhostname::dhcp will use "myhostname" rather than ignoring and overwriting it. Fix the comment on ic_bootp_string that suggests it only copies a string "if not already set"; it doesn't have any such logic. Signed-off-by: Josh Triplett Signed-off-by: David S. Miller

net: ipconfig: ic_dev can be NULL in ic_close_devs

2021-03-22T19:57:51+00:00

ic_close_dev contains a generalization of the logic to not close a network interface if it's the host port for a DSA switch. This logic is disguised behind an iteration through the lowers of ic_dev in ic_close_dev. When no interface for ipconfig can be found, ic_dev is NULL, and ic_close_dev: - dereferences a NULL pointer when assigning selected_dev - would attempt to search through the lower interfaces of a NULL net_device pointer So we should protect against that case. The "lower_dev" iterator variable was shortened to "lower" in order to keep the 80 character limit. Fixes: f68cbaed67cb ("net: ipconfig: avoid use-after-free in ic_close_devs") Fixes: 46acf7bdbc72 ("Revert "net: ipv4: handle DSA enabled master network devices"") Signed-off-by: Vladimir Oltean Tested-by: Heiko Thiery Signed-off-by: David S. Miller