mirror of
https://git.robbyzambito.me/zaprus
synced 2026-02-04 00:14:52 +00:00
Move RawSocket and clean it up
This commit is contained in:
161
src/RawSocket.zig
Normal file
161
src/RawSocket.zig
Normal file
@@ -0,0 +1,161 @@
|
||||
const RawSocket = @This();
|
||||
|
||||
fd: i32,
|
||||
sockaddr_ll: std.posix.sockaddr.ll,
|
||||
mac: [6]u8,
|
||||
|
||||
const Ifconf = extern struct {
|
||||
ifc_len: i32,
|
||||
ifc_ifcu: extern union {
|
||||
ifcu_buf: ?[*]u8,
|
||||
ifcu_req: ?[*]std.os.linux.ifreq,
|
||||
},
|
||||
};
|
||||
|
||||
pub fn init() !RawSocket {
|
||||
const socket: i32 = @intCast(std.os.linux.socket(std.os.linux.AF.PACKET, std.os.linux.SOCK.RAW, 0));
|
||||
if (socket < 0) return error.SocketError;
|
||||
|
||||
var ifreq_storage: [16]std.os.linux.ifreq = undefined;
|
||||
var ifc = Ifconf{
|
||||
.ifc_len = @sizeOf(@TypeOf(ifreq_storage)),
|
||||
.ifc_ifcu = .{ .ifcu_req = &ifreq_storage },
|
||||
};
|
||||
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFCONF, @intFromPtr(&ifc)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
|
||||
const count = @divExact(ifc.ifc_len, @sizeOf(std.os.linux.ifreq));
|
||||
|
||||
// Get the first non loopback interface
|
||||
var ifr = for (ifreq_storage[0..@intCast(count)]) |*ifr| {
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFFLAGS, @intFromPtr(ifr)) == 0) {
|
||||
if (ifr.ifru.flags.LOOPBACK) continue;
|
||||
break ifr;
|
||||
}
|
||||
} else return error.NoInterfaceFound;
|
||||
|
||||
// 2. Get Interface Index
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFINDEX, @intFromPtr(ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
const ifindex: i32 = ifr.ifru.ivalue;
|
||||
|
||||
// 3. Get Real MAC Address
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFHWADDR, @intFromPtr(ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
var mac: [6]u8 = ifr.ifru.hwaddr.data[0..6].*;
|
||||
if (builtin.cpu.arch.endian() == .little) std.mem.reverse(u8, &mac);
|
||||
|
||||
// 4. Set Flags (Promiscuous/Broadcast)
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFFLAGS, @intFromPtr(ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
ifr.ifru.flags.BROADCAST = true;
|
||||
ifr.ifru.flags.PROMISC = true;
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCSIFFLAGS, @intFromPtr(ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
|
||||
const sockaddr_ll = std.mem.zeroInit(std.posix.sockaddr.ll, .{
|
||||
.family = std.posix.AF.PACKET,
|
||||
.ifindex = ifindex,
|
||||
.protocol = std.mem.nativeToBig(u16, @as(u16, std.os.linux.ETH.P.IP)),
|
||||
});
|
||||
|
||||
const bind_ret = std.os.linux.bind(socket, @ptrCast(&sockaddr_ll), @sizeOf(@TypeOf(sockaddr_ll)));
|
||||
if (bind_ret != 0) return error.BindError;
|
||||
|
||||
const timeout: std.os.linux.timeval = .{ .sec = 600, .usec = 0 };
|
||||
const timeout_ret = std.os.linux.setsockopt(socket, std.os.linux.SOL.SOCKET, std.os.linux.SO.RCVTIMEO, @ptrCast(&timeout), @sizeOf(@TypeOf(timeout)));
|
||||
if (timeout_ret != 0) return error.SetTimeoutError;
|
||||
|
||||
return .{
|
||||
.fd = socket,
|
||||
.sockaddr_ll = sockaddr_ll,
|
||||
.mac = mac,
|
||||
};
|
||||
}
|
||||
|
||||
pub fn deinit(self: *RawSocket) void {
|
||||
_ = std.os.linux.close(self.fd);
|
||||
self.* = undefined;
|
||||
}
|
||||
|
||||
pub fn send(self: RawSocket, payload: []const u8) !void {
|
||||
const sent_bytes = std.os.linux.sendto(
|
||||
self.fd,
|
||||
payload.ptr,
|
||||
payload.len,
|
||||
0,
|
||||
@ptrCast(&self.sockaddr_ll),
|
||||
@sizeOf(@TypeOf(self.sockaddr_ll)),
|
||||
);
|
||||
_ = sent_bytes;
|
||||
}
|
||||
|
||||
pub fn receive(self: RawSocket, buf: []u8) ![]u8 {
|
||||
const len = std.os.linux.recvfrom(
|
||||
self.fd,
|
||||
buf.ptr,
|
||||
buf.len,
|
||||
0,
|
||||
null,
|
||||
null,
|
||||
);
|
||||
if (std.os.linux.errno(len) != .SUCCESS) {
|
||||
return error.Timeout; // TODO: get the real error, assume timeout for now.
|
||||
}
|
||||
return buf[0..len];
|
||||
}
|
||||
|
||||
pub fn attachSaprusPortFilter(self: RawSocket, port: u16) !void {
|
||||
const BPF = std.os.linux.BPF;
|
||||
// BPF instruction structure for classic BPF
|
||||
const SockFilter = extern struct {
|
||||
code: u16,
|
||||
jt: u8,
|
||||
jf: u8,
|
||||
k: u32,
|
||||
};
|
||||
|
||||
const SockFprog = extern struct {
|
||||
len: u16,
|
||||
filter: [*]const SockFilter,
|
||||
};
|
||||
|
||||
// Build the filter program
|
||||
const filter = [_]SockFilter{
|
||||
// Load 2 bytes at offset 46 (absolute)
|
||||
.{ .code = BPF.LD | BPF.H | BPF.ABS, .jt = 0, .jf = 0, .k = 46 },
|
||||
// Jump if equal to port (skip 0 if true, skip 1 if false)
|
||||
.{ .code = BPF.JMP | BPF.JEQ | BPF.K, .jt = 0, .jf = 1, .k = @as(u32, port) },
|
||||
// Return 0xffff (pass)
|
||||
.{ .code = BPF.RET | BPF.K, .jt = 0, .jf = 0, .k = 0xffff },
|
||||
// Return 0x0 (fail)
|
||||
.{ .code = BPF.RET | BPF.K, .jt = 0, .jf = 0, .k = 0x0 },
|
||||
};
|
||||
|
||||
const fprog = SockFprog{
|
||||
.len = filter.len,
|
||||
.filter = &filter,
|
||||
};
|
||||
|
||||
// Attach filter to socket using setsockopt
|
||||
const rc = std.os.linux.setsockopt(
|
||||
self.fd,
|
||||
std.os.linux.SOL.SOCKET,
|
||||
std.os.linux.SO.ATTACH_FILTER,
|
||||
@ptrCast(&fprog),
|
||||
@sizeOf(SockFprog),
|
||||
);
|
||||
|
||||
if (rc != 0) {
|
||||
return error.BpfAttachFailed;
|
||||
}
|
||||
}
|
||||
|
||||
const std = @import("std");
|
||||
const builtin = @import("builtin");
|
||||
185
src/main.zig
185
src/main.zig
@@ -229,6 +229,7 @@ pub fn main(init: std.process.Init) !void {
|
||||
var res_buf: [4096]u8 = undefined;
|
||||
|
||||
var res = socket.receive(&res_buf) catch continue;
|
||||
try init.io.sleep(.fromMilliseconds(40), .real);
|
||||
|
||||
headers.udp.dst_port = udp_dest_port;
|
||||
headers.ip.id = rand.int(u16);
|
||||
@@ -244,6 +245,7 @@ pub fn main(init: std.process.Init) !void {
|
||||
|
||||
while (true) {
|
||||
res = socket.receive(&res_buf) catch continue :reconnect;
|
||||
try init.io.sleep(.fromMilliseconds(40), .real);
|
||||
const connection_res = blk: {
|
||||
const msg: SaprusMessage = try .parse(res[42..]);
|
||||
break :blk msg.connection;
|
||||
@@ -320,187 +322,6 @@ const RawSocketWriter = zaprus.RawSocketWriter;
|
||||
const AF = std.os.linux.AF;
|
||||
const SOCK = std.os.linux.SOCK;
|
||||
|
||||
const RawSocket = struct {
|
||||
fd: i32,
|
||||
sockaddr_ll: std.posix.sockaddr.ll,
|
||||
mac: [6]u8,
|
||||
|
||||
const IFF_LOOPBACK = 0x8;
|
||||
|
||||
const ifconf = extern struct {
|
||||
ifc_len: i32,
|
||||
ifc_ifcu: extern union {
|
||||
ifcu_buf: ?[*]u8,
|
||||
ifcu_req: ?[*]std.os.linux.ifreq,
|
||||
},
|
||||
};
|
||||
|
||||
fn init() !RawSocket {
|
||||
const socket: i32 = @intCast(std.os.linux.socket(std.posix.AF.PACKET, std.posix.SOCK.RAW, 0));
|
||||
if (socket < 0) return error.SocketError;
|
||||
|
||||
// 1. Enumerate interfaces
|
||||
var ifreq_storage: [16]std.os.linux.ifreq = undefined;
|
||||
var ifc = ifconf{
|
||||
.ifc_len = @sizeOf(@TypeOf(ifreq_storage)),
|
||||
.ifc_ifcu = .{ .ifcu_req = &ifreq_storage },
|
||||
};
|
||||
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFCONF, @intFromPtr(&ifc)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
|
||||
const count = @divExact(ifc.ifc_len, @sizeOf(std.os.linux.ifreq));
|
||||
var target_ifr: ?std.os.linux.ifreq = null;
|
||||
|
||||
for (ifreq_storage[0..@intCast(count)]) |ifr| {
|
||||
var temp_ifr = ifr;
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFFLAGS, @intFromPtr(&temp_ifr)) == 0) {
|
||||
// Cast the packed flags to u16 to match the kernel's ifr_flags size
|
||||
const flags: u16 = @bitCast(temp_ifr.ifru.flags);
|
||||
if (flags & IFF_LOOPBACK != 0) continue;
|
||||
|
||||
target_ifr = ifr;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
var ifr = target_ifr orelse return error.NoInterfaceFound;
|
||||
|
||||
// 2. Get Interface Index
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFINDEX, @intFromPtr(&ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
const ifindex: i32 = ifr.ifru.ivalue;
|
||||
|
||||
// 3. Get Real MAC Address
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFHWADDR, @intFromPtr(&ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
var mac: [6]u8 = ifr.ifru.hwaddr.data[0..6].*;
|
||||
std.mem.reverse(u8, &mac);
|
||||
|
||||
// 4. Set Flags (Promiscuous/Broadcast)
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCGIFFLAGS, @intFromPtr(&ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
ifr.ifru.flags.BROADCAST = true;
|
||||
ifr.ifru.flags.PROMISC = true;
|
||||
if (std.os.linux.ioctl(socket, std.os.linux.SIOCSIFFLAGS, @intFromPtr(&ifr)) != 0) {
|
||||
return error.NicError;
|
||||
}
|
||||
|
||||
const sockaddr_ll = std.posix.sockaddr.ll{
|
||||
.family = std.posix.AF.PACKET,
|
||||
.ifindex = ifindex,
|
||||
.protocol = std.mem.nativeToBig(u16, @as(u16, std.os.linux.ETH.P.IP)),
|
||||
.halen = 0,
|
||||
.addr = .{ 0, 0, 0, 0, 0, 0, 0, 0 },
|
||||
.pkttype = 0,
|
||||
.hatype = 0,
|
||||
};
|
||||
|
||||
const bind_ret = std.os.linux.bind(socket, @ptrCast(&sockaddr_ll), @sizeOf(@TypeOf(sockaddr_ll)));
|
||||
if (bind_ret != 0) return error.BindError;
|
||||
|
||||
const timeout: std.os.linux.timeval = .{ .sec = 600, .usec = 0 };
|
||||
const timeout_ret = std.os.linux.setsockopt(socket, std.os.linux.SOL.SOCKET, std.os.linux.SO.RCVTIMEO, @ptrCast(&timeout), @sizeOf(@TypeOf(timeout)));
|
||||
if (timeout_ret != 0) return error.SetTimeoutError;
|
||||
|
||||
return .{
|
||||
.fd = socket,
|
||||
.sockaddr_ll = sockaddr_ll,
|
||||
.mac = mac,
|
||||
};
|
||||
}
|
||||
|
||||
fn deinit(self: *RawSocket) void {
|
||||
_ = std.os.linux.close(self.fd);
|
||||
self.* = undefined;
|
||||
}
|
||||
|
||||
fn send(self: RawSocket, payload: []const u8) !void {
|
||||
const sent_bytes = std.os.linux.sendto(
|
||||
self.fd,
|
||||
payload.ptr,
|
||||
payload.len,
|
||||
0,
|
||||
@ptrCast(&self.sockaddr_ll),
|
||||
@sizeOf(@TypeOf(self.sockaddr_ll)),
|
||||
);
|
||||
_ = sent_bytes;
|
||||
}
|
||||
|
||||
fn receive(self: RawSocket, buf: []u8) ![]u8 {
|
||||
const len = std.os.linux.recvfrom(
|
||||
self.fd,
|
||||
buf.ptr,
|
||||
buf.len,
|
||||
0,
|
||||
null,
|
||||
null,
|
||||
);
|
||||
if (std.os.linux.errno(len) != .SUCCESS) {
|
||||
return error.Timeout; // TODO: get the real error, assume timeout for now.
|
||||
}
|
||||
return buf[0..len];
|
||||
}
|
||||
|
||||
fn attachSaprusPortFilter(self: RawSocket, port: u16) !void {
|
||||
const linux = std.os.linux;
|
||||
// BPF instruction structure for classic BPF
|
||||
const sock_filter = extern struct {
|
||||
code: u16,
|
||||
jt: u8,
|
||||
jf: u8,
|
||||
k: u32,
|
||||
};
|
||||
|
||||
const sock_fprog = extern struct {
|
||||
len: u16,
|
||||
filter: [*]const sock_filter,
|
||||
};
|
||||
|
||||
// BPF instruction opcodes
|
||||
const BPF_LD = 0x00;
|
||||
const BPF_H = 0x08; // Half-word (2 bytes)
|
||||
const BPF_ABS = 0x20;
|
||||
const BPF_JMP = 0x05;
|
||||
const BPF_JEQ = 0x10;
|
||||
const BPF_K = 0x00;
|
||||
const BPF_RET = 0x06;
|
||||
|
||||
// Build the filter program
|
||||
const filter = [_]sock_filter{
|
||||
// Load 2 bytes at offset 46 (absolute)
|
||||
.{ .code = BPF_LD | BPF_H | BPF_ABS, .jt = 0, .jf = 0, .k = 46 },
|
||||
// Jump if equal to port (skip 0 if true, skip 1 if false)
|
||||
.{ .code = BPF_JMP | BPF_JEQ | BPF_K, .jt = 0, .jf = 1, .k = @as(u32, port) },
|
||||
// Return 0xffff (pass)
|
||||
.{ .code = BPF_RET | BPF_K, .jt = 0, .jf = 0, .k = 0xffff },
|
||||
// Return 0x0 (fail)
|
||||
.{ .code = BPF_RET | BPF_K, .jt = 0, .jf = 0, .k = 0x0 },
|
||||
};
|
||||
|
||||
const fprog = sock_fprog{
|
||||
.len = filter.len,
|
||||
.filter = &filter,
|
||||
};
|
||||
|
||||
// Attach filter to socket using setsockopt
|
||||
const SO_ATTACH_FILTER = 26;
|
||||
const rc = linux.setsockopt(
|
||||
self.fd,
|
||||
linux.SOL.SOCKET,
|
||||
SO_ATTACH_FILTER,
|
||||
@ptrCast(&fprog),
|
||||
@sizeOf(sock_fprog),
|
||||
);
|
||||
|
||||
if (rc != 0) {
|
||||
return error.BpfAttachFailed;
|
||||
}
|
||||
}
|
||||
};
|
||||
const RawSocket = @import("./RawSocket.zig");
|
||||
|
||||
const Writer = std.Io.Writer;
|
||||
|
||||
Reference in New Issue
Block a user