[PATCH kexec-tools 0/2] kexec/ifdown.c: minimise errors printed

[PATCH kexec-tools 0/2] kexec/ifdown.c: minimise errors printed

[Mason Rocha]

On some embedded configurations, kexec generates messages when rebooting
to the new kernel.  This patch line helps eliminate these messages in
the event certain kernel options are set.  I'm not too worried about the
second patch, but it is along the same line as the first patch and I
thought that it should included.  Thanks!

Mason Rocha (2):
  kexec/ifdown.c: Use AF_NETLINK instead of AF_INET
  kexec/ifdown.c: Hide error if sockets are disabled

 kexec/ifdown.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--
2.51.0

[PATCH kexec-tools 1/2] kexec/ifdown.c: Use AF_NETLINK instead of AF_INET

[Mason Rocha]

On embedded systems, there is no guarantee that INET support has been
built in.  However, as long as network support is built into the kernel,
we can use the netlink protocol to create a socket to still then use for
the ioctl calls since they don't require any certain family.  This will
help prevent EAFNOSUPPORT from being returned and printed to the console
on these systems.

Signed-off-by: Mason Rocha <mrocha@turretllc.us>
---
 kexec/ifdown.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kexec/ifdown.c b/kexec/ifdown.c
index 3ac19c1..6a60bcb 100644
--- a/kexec/ifdown.c
+++ b/kexec/ifdown.c
@@ -31,7 +31,7 @@ int ifdown(void)
 	struct ifreq ifr;
 	int fd, shaper;
 
-	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+	if ((fd = socket(AF_NETLINK, SOCK_DGRAM, 0)) < 0) {
 		fprintf(stderr, "ifdown: ");
 		perror("socket");
 		goto error;
-- 
2.51.0

[PATCH kexec-tools 2/2] kexec/ifdown.c: Hide error if sockets are disabled

[Mason Rocha]

Prevents the message "Function not implemented" from being logged when
a system with networking support disabled, as there couldn't possibly be
any interfaces to bring down to the point where we need to make sure the
user knows that the interfaces were not brought down.

Signed-off-by: Mason Rocha <mrocha@turretllc.us>
---
 kexec/ifdown.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/kexec/ifdown.c b/kexec/ifdown.c
index 6a60bcb..e6ea0ae 100644
--- a/kexec/ifdown.c
+++ b/kexec/ifdown.c
@@ -32,8 +32,10 @@ int ifdown(void)
 	int fd, shaper;
 
 	if ((fd = socket(AF_NETLINK, SOCK_DGRAM, 0)) < 0) {
-		fprintf(stderr, "ifdown: ");
-		perror("socket");
+		if(errno != ENOSYS) {
+			fprintf(stderr, "ifdown: ");
+			perror("socket");
+		}
 		goto error;
 	}
 
-- 
2.51.0

Re: [PATCH kexec-tools 2/2] kexec/ifdown.c: Hide error if sockets are disabled

[Simon Horman]

On Tue, Oct 21, 2025 at 09:07:04PM -0500, Mason Rocha wrote:
> Prevents the message "Function not implemented" from being logged when
> a system with networking support disabled, as there couldn't possibly be
> any interfaces to bring down to the point where we need to make sure the
> user knows that the interfaces were not brought down.
> 
> Signed-off-by: Mason Rocha <mrocha@turretllc.us>
> ---
>  kexec/ifdown.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/kexec/ifdown.c b/kexec/ifdown.c
> index 6a60bcb..e6ea0ae 100644
> --- a/kexec/ifdown.c
> +++ b/kexec/ifdown.c
> @@ -32,8 +32,10 @@ int ifdown(void)
>  	int fd, shaper;
>  
>  	if ((fd = socket(AF_NETLINK, SOCK_DGRAM, 0)) < 0) {
> -		fprintf(stderr, "ifdown: ");
> -		perror("socket");
> +		if(errno != ENOSYS) {

nit: I'd prefer a space between 'if' and '('

     I added one when applying this series.

> +			fprintf(stderr, "ifdown: ");
> +			perror("socket");
> +		}
>  		goto error;
>  	}
>  
> -- 
> 2.51.0
> 

Re: [PATCH kexec-tools 0/2] kexec/ifdown.c: minimise errors printed

[Simon Horman]

On Tue, Oct 21, 2025 at 09:07:02PM -0500, Mason Rocha wrote:
> On some embedded configurations, kexec generates messages when rebooting
> to the new kernel.  This patch line helps eliminate these messages in
> the event certain kernel options are set.  I'm not too worried about the
> second patch, but it is along the same line as the first patch and I
> thought that it should included.  Thanks!

Thanks, applied.

- kexec/ifdown.c: Hide error if sockets are disabled
  https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=86c3d1f7b646
- kexec/ifdown.c: Use AF_NETLINK instead of AF_INET
  https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/commit/?id=eb8609a29363