posix: add package

core/sys/posix/arpa_inet.odin

@@ -0,0 +1,58 @@
+package posix
+
+import "core:c"
+
+when ODIN_OS == .Darwin {
+	foreign import lib "system:System.framework"
+} else {
+	foreign import lib "system:c"
+}
+
+// arpa/inet.h - definitions for internet operations
+
+foreign lib {
+	// Use Odin's native big endian types `u32be` and `u16be` instead.
+	// htonl :: proc(c.uint32_t) -> c.uint32_t ---
+	// htons :: proc(c.uint16_t) -> c.uint16_t ---
+	// ntohl :: proc(c.uint32_t) -> c.uint32_t ---
+	// ntohs :: proc(c.uint16_t) -> c.uint16_t ---
+
+	// Use of this function is problematic because -1 is a valid address (255.255.255.255).
+	// Avoid its use in favor of inet_aton(), inet_pton(3), or getaddrinfo(3) which provide a cleaner way to indicate error return.
+	// inet_addr :: proc(cstring) -> in_addr_t ---
+
+	// Convert the Internet host address specified by in to a string in the Internet standard dot notation.
+	//
+	// NOTE: returns a static string overwritten by further calls.
+	//
+	// [[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntoa.html ]]
+	inet_ntoa :: proc(in_addr) -> cstring ---
+
+	// Convert a numeric address into a text string suitable for presentation.
+	//
+	// Returns `nil` and sets `errno` on failure.
+	//
+	// [[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntop.html ]]
+	inet_ntop :: proc(
+		af:   AF,        // INET or INET6
+		src:  rawptr,    // either ^in_addr or ^in_addr6 
+		dst:  [^]byte,   // use `INET_ADDRSTRLEN` or `INET6_ADDRSTRLEN` for minimum lengths
+		size: socklen_t,
+	) -> cstring ---
+
+	// Convert an address in its standard text presentation form into its numeric binary form.
+	//
+	// [[ More; https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntop.html ]]
+	inet_pton :: proc(
+		af:   AF,        // INET or INET6
+		src:  cstring,
+		dst:  rawptr,    // either ^in_addr or ^in_addr6
+		size: socklen_t, // size_of(dst^)
+	) -> pton_result ---
+}
+
+pton_result :: enum c.int {
+	AFNOSUPPORT = -1,
+	INVALID     = 0,
+	SUCCESS     = 1,
+}