Le 27/12/2024 à 21:54, deller@kernel.org a écrit :
> From: Helge Deller <deller@gmx.de>
>
> Share code with IP_ADD_MEMBERSHIP/IP_DROP_MEMBERSHIP.
>
> Signed-off-by: Helge Deller <deller@gmx.de>
> ---
> linux-user/syscall.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index bbe2560927..4360543e20 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -2130,16 +2130,23 @@ static abi_long do_setsockopt(int sockfd, int level, int optname,
> }
> ret = get_errno(setsockopt(sockfd, level, optname, &val, sizeof(val)));
> break;
> + case IP_MULTICAST_IF:
> case IP_ADD_MEMBERSHIP:
> case IP_DROP_MEMBERSHIP:
Could you put in the commit message the information from ip(7):
IP_MULTICAST_IF (since Linux 1.2)
Set the local device for a multicast socket. The argument
for setsockopt(2) is an ip_mreqn or (since Linux 3.5)
ip_mreq structure similar to IP_ADD_MEMBERSHIP, or an
in_addr structure. (The kernel determines which structure
is being passed based on the size passed in optlen.) For
getsockopt(2), the argument is an in_addr structure.
It would help to understand why we merge IP_MULTICAST_IF and IP_ADD_MEMBERSHIP code.
> {
> struct ip_mreqn ip_mreq;
> struct target_ip_mreqn *target_smreqn;
> + int min_size;
>
> QEMU_BUILD_BUG_ON(sizeof(struct ip_mreq) !=
> sizeof(struct target_ip_mreq));
>
> - if (optlen < sizeof (struct target_ip_mreq) ||
> + if (optname == IP_MULTICAST_IF) {
> + min_size = sizeof(struct in_addr);
> + } else {
> + min_size = sizeof(struct target_ip_mreq);
> + }
> + if (optlen < min_size ||
> optlen > sizeof (struct target_ip_mreqn)) {
> return -TARGET_EINVAL;
> }
> @@ -2149,7 +2156,9 @@ static abi_long do_setsockopt(int sockfd, int level, int optname,
> return -TARGET_EFAULT;
> }
> ip_mreq.imr_multiaddr.s_addr = target_smreqn->imr_multiaddr.s_addr;
> - ip_mreq.imr_address.s_addr = target_smreqn->imr_address.s_addr;
> + if (optlen >= sizeof(struct target_ip_mreq)) {
> + ip_mreq.imr_address.s_addr = target_smreqn->imr_address.s_addr;
> + }
I think you should have 3 parts here (like in the kernel):
if (optlen >= sizeof(struct target_ip_mreqn)) {
...
} else {
if (optlen >= sizeof(struct target_ip_mreq)) {
...
} else if (optlen >= sizeof(struct in_addr)) {
...
}
}
> if (optlen == sizeof(struct target_ip_mreqn)) {
> ip_mreq.imr_ifindex = tswapal(target_smreqn->imr_ifindex);
> optlen = sizeof(struct ip_mreqn);
Thanks.