Re: [PATCH 2/3] tools/hotplug: Fix dhcpd symlink removal in vif-nat

[Wei Liu <wl@xxxxxxx>]

On Thu, Aug 20, 2020 at 12:00:23PM +0100, Diego Sueiro wrote:
> Copy temp files used to add/remove dhcpd configurations to avoid
> replacing potential symlinks.
> 

Can you clarify the issue you saw a bit?

Which one of the parameter is a symlink (I assume the latter) and what
problem you see with replacing the symlinks?

> Signed-off-by: Diego Sueiro <diego.sueiro@xxxxxxx>
> ---
>  tools/hotplug/Linux/vif-nat | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/hotplug/Linux/vif-nat b/tools/hotplug/Linux/vif-nat
> index 2614435..1ab80ed 100644
> --- a/tools/hotplug/Linux/vif-nat
> +++ b/tools/hotplug/Linux/vif-nat
> @@ -99,7 +99,8 @@ dhcparg_remove_entry()
>    then
>      rm "$tmpfile"
>    else
> -    mv "$tmpfile" "$dhcpd_arg_file"
> +    cp "$tmpfile" "$dhcpd_arg_file"
> +    rm "$tmpfile"
>    fi

You could've simplified the code a bit here and below now that both
branches issue the same rm command.

But don't resend just yet. Please help me understand your issue first.

Wei.

>  }
>  
> @@ -109,11 +110,11 @@ dhcparg_add_entry()
>    local tmpfile=$(mktemp)
>    # handle Red Hat, SUSE, and Debian styles, with or without quotes
>    sed -e 's/^DHCPDARGS="*\([^"]*\)"*/DHCPDARGS="\1'"${dev} "'"/' \
> -     "$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
> +     "$dhcpd_arg_file" >"$tmpfile" && cp "$tmpfile" "$dhcpd_arg_file"
>    sed -e 's/^DHCPD_INTERFACE="*\([^"]*\)"*/DHCPD_INTERFACE="\1'"${dev} "'"/' 
> \
> -     "$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
> +     "$dhcpd_arg_file" >"$tmpfile" && cp "$tmpfile" "$dhcpd_arg_file"
>    sed -e 's/^INTERFACES="*\([^"]*\)"*/INTERFACES="\1'"${dev} "'"/' \
> -     "$dhcpd_arg_file" >"$tmpfile" && mv "$tmpfile" "$dhcpd_arg_file"
> +     "$dhcpd_arg_file" >"$tmpfile" && cp "$tmpfile" "$dhcpd_arg_file"
>    rm -f "$tmpfile"
>  }
>  
> @@ -125,7 +126,8 @@ dhcp_remove_entry()
>    then
>      rm "$tmpfile"
>    else
> -    mv "$tmpfile" "$dhcpd_conf_file"
> +    cp "$tmpfile" "$dhcpd_conf_file"
> +    rm "$tmpfile"
>    fi
>    dhcparg_remove_entry
>  }
> -- 
> 2.7.4
>