Dear all, since gcc uses -Werror=address-of-packed-member, I get warnings for my variant of packetdrill, which supports SCTP. Here is why: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/sctp.h?h=v5.7 contains: struct sctp_paddrparams { sctp_assoc_t spp_assoc_id; struct sockaddr_storage spp_address; __u32 spp_hbinterval; __u16 spp_pathmaxrxt; __u32 spp_pathmtu; __u32 spp_sackdelay; __u32 spp_flags; __u32 spp_ipv6_flowlabel; __u8 spp_dscp; } __attribute__((packed, aligned(4))); This structure is only used in the IPPROTO_SCTP level socket option SCTP_PEER_ADDR_PARAMS. Why is it packed? Accessing spp_address, spp_pathmtu, spp_sackdelay, spp_flags, and spp_ipv6_flowlabel results in warnings related to -Werror=address-of-packed-member. Am I supposed to access these fields via memcpy only? Please note that a similar problem exists also with other structures in that file, I used struct sctp_paddrparams as an example. Best regards Michael
