socket_unix_listen.c

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/*
 * This file is part of the Fun programming language.
 * https://fun-lang.xyz/
 *
 * Copyright 2025 Johannes Findeisen <you@hanez.org>
 * Licensed under the terms of the Apache-2.0 license.
 * https://opensource.org/license/apache-2-0
 */


case OP_SOCK_UNIX_LISTEN: {
 /* Pops backlog, path; returns listen fd (>0) or 0 */
 Value backlogv = pop_value(vm);
 Value pathv = pop_value(vm);
 int fd = 0;
#ifdef __unix__
 if (pathv.type != VAL_STRING || backlogv.type != VAL_INT) {
 fprintf(stderr, "Runtime type error: unix_listen expects (string path, int backlog)\n");
 free_value(backlogv);
 free_value(pathv);
 push_value(vm, make_int(0));
 break;
 }
 char *path = value_to_string_alloc(&pathv);
 int backlog = (int)backlogv.i;
 if (path) {
 int s = socket(AF_UNIX, SOCK_STREAM, 0);
 if (s >= 0) {
 struct sockaddr_un addr;
 memset(&addr, 0, sizeof(addr));
 addr.sun_family = AF_UNIX;
 size_t maxlen = sizeof(addr.sun_path) - 1;
 strncpy(addr.sun_path, path, maxlen);
 addr.sun_path[maxlen] = '\0';
 unlink(addr.sun_path); /* best effort */
 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == 0) {
 if (listen(s, backlog > 0 ? backlog : 1) == 0) {
 fd = s;
 } else {
 close(s);
 }
 } else {
 close(s);
 }
 }
 free(path);
 }
#endif
 free_value(backlogv);
 free_value(pathv);
 push_value(vm, make_int(fd > 0 ? fd : 0));
 break;
}