[PATCH net-next 2/8] ipv4: icmp: Pass IPv4 control block structure as an argument to __icmp_send()

[David Ahern]

On 9/1/25 2:30 AM, Ido Schimmel wrote:
> __icmp_send() is used to generate ICMP error messages in response to
> various situations such as MTU errors (i.e., "Fragmentation Required")
> and too many hops (i.e., "Time Exceeded").
> 
> The skb that generated the error does not necessarily come from the IPv4
> layer and does not always have a valid IPv4 control block in skb->cb.
> 
> Therefore, commit 9ef6b42ad6fd ("net: Add __icmp_send helper.") changed
> the function to take the IP options structure as argument instead of
> deriving it from the skb's control block. Some callers of this function
> such as icmp_send() pass the IP options structure from the skb's control
> block as in these call paths the control block is known to be valid, but
> other callers simply pass a zeroed structure.
> 
> A subsequent patch will need __icmp_send() to access more information
> from the IPv4 control block (specifically, the ifindex of the input
> interface). As a preparation for this change, change the function to
> take the IPv4 control block structure as an argument instead of the IP
> options structure. This makes the function similar to its IPv6
> counterpart that already takes the IPv6 control block structure as an
> argument.
> 
> No functional changes intended.
> 
> Reviewed-by: Petr Machata <petrm at nvidia.com>
> Signed-off-by: Ido Schimmel <idosch at nvidia.com>
> ---
>  include/net/icmp.h    | 10 ++++++----
>  net/ipv4/cipso_ipv4.c | 12 ++++++------
>  net/ipv4/icmp.c       | 12 +++++++-----
>  net/ipv4/route.c      | 10 +++++-----
>  4 files changed, 24 insertions(+), 20 deletions(-)
> 

Reviewed-by: David Ahern <dsahern at kernel.org>