/*----- Data structures ---------------------------------------------------*/
enum { UNUSED, STALE, USED }; /* Unix socket status values */
-enum { WANT_FRESH, WANT_EXISTING }; /* Socket address dispositions */
enum { DENY, ALLOW }; /* ACL verdicts */
static int address_families[] = { AF_INET, AF_INET6, -1 };
int rc;
char buf[256];
+ /* If we can't find the socket node, then it's definitely not in use. If
+ * we get some other error, then this socket is weird.
+ */
if (stat(sun->sun_path, &st))
return (errno == ENOENT ? UNUSED : USED);
+
+ /* If it's not a socket, then something weird is going on. If we're just
+ * probing quickly to find a spare port, then existence is sufficient to
+ * discourage us now.
+ */
if (!S_ISSOCK(st.st_mode) || quickp)
return (USED);
+
+ /* The socket's definitely there, but is anyone actually still holding it
+ * open? The only way I know to discover this is to trundle through
+ * `/proc/net/unix'. If there's no entry, then the socket must be stale.
+ */
rc = USED;
if ((fp = fopen("/proc/net/unix", "r")) == 0)
goto done;
rc = STALE;
done:
if (fp) fclose(fp);
+
+ /* All done. */
return (rc);
}
char buf[ADDRBUFSZ];
int port = port_from_sockaddr(sa);
+ /* First, look for an exact match. Only look quickly unless we're
+ * desperate. If the socket is in use, we fail here. (This could get
+ * racy. Let's not worry about that for now.)
+ */
snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
present_sockaddr(sa, 0, buf, sizeof(buf)));
if ((rc = unix_socket_status(sun, !desperatep)) == USED) return (-1);
else if (rc == STALE) unlink(sun->sun_path);
+ /* Next, check the corresponding wildcard address, so as to avoid
+ * inadvertant collisions with listeners. Do this in the same way.
+ */
wildcard_address(sa->sa_family, &waddr.sa);
port_to_sockaddr(&waddr.sa, port);
snprintf(wsun.sun_path, sizeof(wsun.sun_path), "%s/%s", sockdir,
if ((rc = unix_socket_status(&wsun, !desperatep)) == USED) return (-1);
else if (rc == STALE) unlink(wsun.sun_path);
+ /* All is well. */
return (0);
}
-/* Encode the Internet address SA as a Unix-domain address SUN. If WANT is
- * WANT_FRESH, and SA's port number is zero, then we pick an arbitrary local
- * port. Otherwise we pick the port given. There's an unpleasant hack to
- * find servers bound to local wildcard addresses. Returns zero on success;
- * -1 on failure.
+/* Encode the Internet address SA as a Unix-domain address SUN. If the flag
+ * `ENCF_FRESH' is set, and SA's port number is zero, then we pick an
+ * arbitrary local port. Otherwise we pick the port given. There's an
+ * unpleasant hack to find servers bound to local wildcard addresses.
+ * Returns zero on success; -1 on failure.
*/
+#define ENCF_FRESH 1u
static int encode_inet_addr(struct sockaddr_un *sun,
const struct sockaddr *sa,
- int want)
+ unsigned f)
{
int i;
int desperatep = 0;
D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(),
present_sockaddr(sa, 0, buf, sizeof(buf)),
- want == WANT_EXISTING ? "EXISTING" : "FRESH"); )
+ (f&ENCF_FRESH) ? "FRESH" : "EXISTING"); )
+
+ /* Start making the Unix-domain address. */
sun->sun_family = AF_UNIX;
- if (port || want == WANT_EXISTING) {
+
+ if (port || !(f&ENCF_FRESH)) {
+
+ /* Try the address as given. If it's in use, or we don't necessarily
+ * want an existing socket, then we're done.
+ */
snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
present_sockaddr(sa, 0, buf, sizeof(buf)));
rc = unix_socket_status(sun, 0);
if (rc == STALE) unlink(sun->sun_path);
- if (rc != USED && want == WANT_EXISTING) {
- wildcard_address(sa->sa_family, &addr.sa);
- port_to_sockaddr(&addr.sa, port);
- snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
- present_sockaddr(&addr.sa, 0, buf, sizeof(buf)));
- if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path);
- }
+ if (rc == USED || (f&ENCF_FRESH)) goto found;
+
+ /* We're looking for a socket which already exists. Try the
+ * corresponding wildcard address.
+ */
+ wildcard_address(sa->sa_family, &addr.sa);
+ port_to_sockaddr(&addr.sa, port);
+ snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
+ present_sockaddr(&addr.sa, 0, buf, sizeof(buf)));
+ if (unix_socket_status(sun, 0) == STALE) unlink(sun->sun_path);
+
} else {
+ /* We want a fresh new socket. */
+
+ /* Make a copy of the given address, because we're going to mangle it. */
copy_sockaddr(&addr.sa, sa);
+
+ /* Try a few random-ish port numbers to see if any of them is spare. */
for (i = 0; i < 10; i++) {
port_to_sockaddr(&addr.sa, randrange(minautoport, maxautoport));
if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found;
}
+
+ /* Things must be getting tight. Work through all of the autoport range
+ * to see if we can find a spare one. The first time, just do it the
+ * quick way; if that doesn't work, then check harder for stale sockets.
+ */
for (desperatep = 0; desperatep < 2; desperatep++) {
for (i = minautoport; i <= maxautoport; i++) {
port_to_sockaddr(&addr.sa, i);
if (!encode_unused_inet_addr(&addr.sa, sun, 0)) goto found;
}
}
+
+ /* We failed to find any free ports. */
errno = EADDRINUSE;
D( fprintf(stderr, " -- can't resolve\n"); )
return (-1);
- found:;
}
+
+ /* Success. */
+found:
D( fprintf(stderr, " -> `%s'\n", sun->sun_path); )
return (0);
}
D( fprintf(stderr, "noip(%d): no match; using wildcard\n", pid); )
wildcard_address((*sa)->sa_family, &addr.sa);
found:
- encode_inet_addr(sun, &addr.sa, WANT_FRESH);
+ encode_inet_addr(sun, &addr.sa, ENCF_FRESH);
if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1);
}
- encode_inet_addr(sun, *sa, WANT_EXISTING);
+ encode_inet_addr(sun, *sa, 0);
*sa = SA(sun);
*len = SUN_LEN(sun);
}
if (fixup_real_ip_socket(sk, sa->sa_family, 0))
return (-1);
} else {
- encode_inet_addr(&sun, sa, WANT_FRESH);
+ encode_inet_addr(&sun, sa, ENCF_FRESH);
sa = SA(&sun);
len = SUN_LEN(&sun);
}
int getsockname(int sk, struct sockaddr *sa, socklen_t *len)
{
+ char sabuf[1024];
+ socklen_t mylen = sizeof(sabuf);
int rc;
Dpid;
D( fprintf(stderr, "noip(%d): GETSOCKNAME sk=%d", pid, sk); )
- PRESERVING_ERRNO({
- char sabuf[1024];
- socklen_t mylen = sizeof(sabuf);
- rc = real_getsockname(sk, SA(sabuf), &mylen);
- if (rc >= 0) {
- D( fprintf(stderr, " -> converting...\n"); )
- return_fake_name(SA(sabuf), mylen, sa, len);
- D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); )
- }
- });
+ rc = real_getsockname(sk, SA(sabuf), &mylen);
+ if (rc >= 0) {
+ D( fprintf(stderr, " -> converting...\n"); )
+ return_fake_name(SA(sabuf), mylen, sa, len);
+ D( fprintf(stderr, "noip(%d): ... GETSOCKNAME", pid); )
+ }
D( dump_addrresult(rc, sa, *len); )
return (rc);
}
int getpeername(int sk, struct sockaddr *sa, socklen_t *len)
{
+ char sabuf[1024];
+ socklen_t mylen = sizeof(sabuf);
int rc;
Dpid;
D( fprintf(stderr, "noip(%d): GETPEERNAME sk=%d", pid, sk); )
- PRESERVING_ERRNO({
- char sabuf[1024];
- socklen_t mylen = sizeof(sabuf);
- rc = real_getpeername(sk, SA(sabuf), &mylen);
- if (rc >= 0) {
- D( fprintf(stderr, " -> converting...\n"); )
- return_fake_name(SA(sabuf), mylen, sa, len);
- D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); )
- }
- });
+ rc = real_getpeername(sk, SA(sabuf), &mylen);
+ if (rc >= 0) {
+ D( fprintf(stderr, " -> converting...\n"); )
+ return_fake_name(SA(sabuf), mylen, sa, len);
+ D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); )
+ }
D( dump_addrresult(rc, sa, *len); )
return (0);
}
int getsockopt(int sk, int lev, int opt, void *p, socklen_t *len)
{
switch (lev) {
- case SOL_IP:
- case SOL_TCP:
- case SOL_UDP:
+ case IPPROTO_IP:
+ case IPPROTO_IPV6:
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
if (*len > 0)
memset(p, 0, *len);
return (0);
int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len)
{
switch (lev) {
- case SOL_IP:
- case SOL_TCP:
- case SOL_UDP:
+ case IPPROTO_IP:
+ case IPPROTO_IPV6:
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
return (0);
}
switch (opt) {
~mdw / preload-hacks / blobdiff