Port `core:net` to FreeBSD

1 files changed, 158 insertions, 0 deletions

diff --git a/core/net/interface_freebsd.odin b/core/net/interface_freebsd.odin
new file mode 100644
index 000000000..f3c455b21
--- /dev/null
+++ b/core/net/interface_freebsd.odin
@@ -0,0 +1,158 @@
+//+build freebsd
+package net
+
+import "core:c"
+import "core:strings"
+import "core:sys/freebsd"
+
+@(private)
+_enumerate_interfaces :: proc(allocator := context.allocator) -> (interfaces: []Network_Interface, err: Network_Error) {
+	// This is a simplified implementation of `getifaddrs` from the FreeBSD
+	// libc using only Odin and syscalls.
+	context.allocator = allocator
+
+	mib := [6]freebsd.MIB_Identifier {
+		.CTL_NET,
+		cast(freebsd.MIB_Identifier)freebsd.Protocol_Family.ROUTE,
+		freebsd.MIB_Identifier(0),
+		freebsd.MIB_Identifier(0),
+		.NET_RT_IFLISTL,
+		freebsd.MIB_Identifier(0),
+	}
+
+	// Figure out how much space we need.
+	needed: c.size_t = ---
+
+	errno := freebsd.sysctl(mib[:], nil, &needed, nil, 0)
+	if errno != nil {
+		return nil, .Unable_To_Enumerate_Network_Interfaces
+	}
+
+	// Allocate and get the entries.
+	buf, alloc_err := make([]byte, needed)
+	if alloc_err != nil {
+		return nil, .Unable_To_Enumerate_Network_Interfaces
+	}
+	defer delete(buf)
+
+	errno = freebsd.sysctl(mib[:], &buf[0], &needed, nil, 0)
+	if errno != nil {
+		return nil, .Unable_To_Enumerate_Network_Interfaces
+	}
+
+	// Build the interfaces with each message.
+	if_builder: [dynamic]Network_Interface
+	for message_pointer: uintptr = 0; message_pointer < cast(uintptr)needed; /**/ {
+		rtm := cast(^freebsd.Route_Message_Header)&buf[message_pointer]
+		if rtm.version != freebsd.RTM_VERSION {
+			continue
+		}
+
+		#partial switch rtm.type {
+		case .IFINFO:
+			ifm := cast(^freebsd.Interface_Message_Header_Len)&buf[message_pointer]
+			if .IFP not_in ifm.addrs {
+				// No name available.
+				break
+			}
+
+			dl := cast(^freebsd.Socket_Address_Data_Link)&buf[message_pointer + cast(uintptr)ifm.len]
+
+			if_data := cast(^freebsd.Interface_Data)&buf[message_pointer + cast(uintptr)ifm.data_off]
+
+			// This is done this way so the different message types can
+			// dynamically build a `Network_Interface`.
+			resize(&if_builder, max(len(if_builder), 1 + cast(int)ifm.index))
+			interface := if_builder[ifm.index]
+
+			interface.adapter_name = strings.clone_from_bytes(dl.data[0:dl.nlen])
+			interface.mtu = if_data.mtu
+
+			switch if_data.link_state {
+			case .UNKNOWN: /* Do nothing; the default value is valid. */
+			case .UP:   interface.link.state |= { .Up   }
+			case .DOWN: interface.link.state |= { .Down }
+			}
+
+			// TODO: Uncertain if these are equivalent:
+			// interface.link.transmit_speed = if_data.baudrate
+			// interface.link.receive_speed = if_data.baudrate
+
+			if dl.type == .LOOP {
+				interface.link.state |= { .Loopback }
+			} else {
+				interface.physical_address = physical_address_to_string(dl.data[dl.nlen:][:6])
+			}
+
+			if_builder[ifm.index] = interface
+
+		case .NEWADDR:
+			RTA_MASKS :: freebsd.Route_Address_Flags { .IFA, .NETMASK }
+			ifam := cast(^freebsd.Interface_Address_Message_Header_Len)&buf[message_pointer]
+			if ifam.addrs & RTA_MASKS == {} {
+				break
+			}
+
+			resize(&if_builder, max(len(if_builder), 1 + cast(int)ifam.index))
+			interface := if_builder[ifam.index]
+
+			address_pointer := message_pointer + cast(uintptr)ifam.len
+
+			lease: Lease
+			address_set: bool
+			for address_type in ifam.addrs {
+				ptr := cast(^freebsd.Socket_Address_Basic)&buf[address_pointer]
+
+				#partial switch address_type {
+				case .IFA:
+					#partial switch ptr.family {
+					case .INET:
+						real := cast(^freebsd.Socket_Address_Internet)ptr
+						lease.address = cast(IP4_Address)real.addr.addr8
+						address_set = true
+					case .INET6:
+						real := cast(^freebsd.Socket_Address_Internet6)ptr
+						lease.address = cast(IP6_Address)real.addr.addr16
+						address_set = true
+					}
+				case .NETMASK:
+					#partial switch ptr.family {
+					case .INET:
+						real := cast(^freebsd.Socket_Address_Internet)ptr
+						lease.netmask = cast(Netmask)cast(IP4_Address)real.addr.addr8
+					case .INET6:
+						real := cast(^freebsd.Socket_Address_Internet6)ptr
+						lease.netmask = cast(Netmask)cast(IP6_Address)real.addr.addr16
+					}
+				}
+
+				SALIGN : u8 : size_of(c.long) - 1
+				address_advance: uintptr = ---
+				if ptr.len > 0 {
+					address_advance = cast(uintptr)((ptr.len + SALIGN) & ~SALIGN)
+				} else {
+					address_advance = cast(uintptr)(SALIGN + 1)
+				}
+
+				address_pointer += address_advance
+			}
+
+			if address_set {
+				append(&interface.unicast, lease)
+			}
+
+			if_builder[ifam.index] = interface
+		}
+
+		message_pointer += cast(uintptr)rtm.msglen
+	}
+
+	// Remove any interfaces that were allocated but had no name.
+	#no_bounds_check for i := len(if_builder) - 1; i >= 0; i -= 1 {
+		if len(if_builder[i].adapter_name) == 0 {
+			ordered_remove(&if_builder, i)
+		}
+	}
+
+	return if_builder[:], nil
+}