21 Sep
2017
21 Sep
'17
6:17 p.m.
On Thu, Sep 21, 2017 at 09:13:38AM -0700, Jon Steinhart wrote:
Maybe this is naive of me, but I have never liked
parts of the sockets
interface. I understand that at some level it was a political/legal
keeping the networking code independent of the rest of the kernel.
If you look in the lmbench code I sort of had similar thoughts but did
them as functions. I've never been fond of the socket API though I
am sympathetic, it's easy to do the easy parts as /dev/tcp but as I
recall there are all sorts of weird cases that don't fit. I've tried
to come up with a /dev/tcp style that covers all the cases and I failed.
lib_tcp.h
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
int tcp_server(int prog, int rdwr);
int tcp_done(int prog);
int tcp_accept(int sock, int rdwr);
int tcp_connect(char *host, int prog, int rdwr);
void sock_optimize(int sock, int rdwr);
int sockport(int s);
#ifndef NO_PORTMAPPER
u_short pmap_getport(struct sockaddr_in *addr, u_long prognum, u_long versnum,
u_int protocol);
bool_t pmap_set(u_long prognum, u_long versnum, u_long protocol, u_short port);
bool_t pmap_unset(u_long prognum, u_long versnum);
#endif
From a technical and historical standpoint, I view
it as the tip of
the iceberg bloating the number of system calls.
In particular, I have often thought that it would have been a better
and more consistent with the philosophy to have it implemented as
open("/dev/tcp") and so on. Granted that networking added some new
functionality that justified some of the system calls, just not socket().