Re: [B.A.T.M.A.N.] [PATCH v4] batman-adv: Snoop DHCPACKs for DAT

On Dienstag, 15. Mai 2018 17:59:08 CEST Linus Lüssing wrote:

•   magic = skb_header_pointer(skb, offset, sizeof(_magic), &_magic);
  

•   if (!magic || *magic != htonl(BATADV_DHCP_MAGIC))
  

•           return -EINVAL;
  

I just hear a neoraider cry [1] in the background because you've added a new potentially unaligned 4 byte access in the network packet parsing code.

[...]

+static __be32 *batadv_dat_dhcp_get_yiaddr(struct sk_buff *skb, __be32 *buffer) +{

•   unsigned int offset = skb_transport_offset(skb) + sizeof(struct udphdr);
  

•   unsigned int len = sizeof(((struct batadv_dhcp_packet *)0)->yiaddr);
  

•   offset += offsetof(struct batadv_dhcp_packet, yiaddr);
  

•   return skb_header_pointer(skb, offset, len, buffer);
  

+}

Same here

Kind regards, Sven

[1] https://patchwork.open-mesh.org/patch/17253/