I’m getting a WouldBlock error on my socket read even though my socket should be a blocking socket?
(sorry this socket code is so ugly!)
const socket: std.posix.socket_t = try std.posix.socket(
std.posix.AF.PACKET,
std.posix.SOCK.RAW,
std.mem.nativeToBig(u32, ETH_P_ETHERCAT),
);
var timeout_rcv = std.posix.timeval{
.tv_sec = 0,
.tv_usec = 1,
};
try std.posix.setsockopt(
socket,
std.posix.SOL.SOCKET,
std.posix.SO.RCVTIMEO,
std.mem.asBytes(&timeout_rcv),
);
var timeout_snd = std.posix.timeval{
.tv_sec = 0,
.tv_usec = 1,
};
try std.posix.setsockopt(
socket,
std.posix.SOL.SOCKET,
std.posix.SO.SNDTIMEO,
std.mem.asBytes(&timeout_snd),
);
const dontroute_enable: c_int = 1;
try std.posix.setsockopt(
socket,
std.posix.SOL.SOCKET,
std.posix.SO.DONTROUTE,
std.mem.asBytes(&dontroute_enable),
);
var ifr: std.posix.ifreq = std.mem.zeroInit(std.posix.ifreq, .{});
@memcpy(ifr.ifrn.name[0..ifname.len], ifname);
ifr.ifrn.name[ifname.len] = 0;
try std.posix.ioctl_SIOCGIFINDEX(socket, &ifr);
const ifindex: i32 = ifr.ifru.ivalue;
const IFF_PROMISC = 256;
const IFF_BROADCAST = 2;
const SIOCGIFFLAGS = 0x8913;
const SIOCSIFFLAGS = 0x8914;
var rval = std.posix.errno(std.os.linux.ioctl(socket, SIOCGIFFLAGS, @intFromPtr(&ifr)));
switch (rval) {
.SUCCESS => {},
else => {
return error.nicError;
},
}
ifr.ifru.flags = ifr.ifru.flags | IFF_BROADCAST | IFF_PROMISC;
rval = std.posix.errno(std.os.linux.ioctl(socket, SIOCSIFFLAGS, @intFromPtr(&ifr)));
switch (rval) {
.SUCCESS => {},
else => {
return error.nicError;
},
}
const sockaddr_ll = std.posix.sockaddr.ll{
.family = std.posix.AF.PACKET,
.ifindex = ifindex,
.protocol = std.mem.nativeToBig(u16, @as(u16, ETH_P_ETHERCAT)),
.halen = 0, //not used
.addr = .{ 0, 0, 0, 0, 0, 0, 0, 0 }, //not used
.pkttype = 0, //not used
.hatype = 0, //not used
};
try std.posix.bind(socket, @ptrCast(&sockaddr_ll), @sizeOf(@TypeOf(sockaddr_ll)));