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);
}
+/* Encode SA as a Unix-domain address SUN, and return whether it's currently
+ * in use.
+ */
+static int encode_single_inet_addr(const struct sockaddr *sa,
+ struct sockaddr_un *sun,
+ int quickp)
+{
+ char buf[ADDRBUFSZ];
+ int rc;
+
+ snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
+ present_sockaddr(sa, 0, buf, sizeof(buf)));
+ if ((rc = unix_socket_status(sun, quickp)) == USED) return (USED);
+ else if (rc == STALE) unlink(sun->sun_path);
+ return (UNUSED);
+}
+
/* Convert the IP address SA to a Unix-domain address SUN. Fail if the
* address seems already taken. If DESPARATEP then try cleaning up stale old
* sockets.
{
address waddr;
struct sockaddr_un wsun;
- int rc;
- char buf[ADDRBUFSZ];
int port = port_from_sockaddr(sa);
- 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);
+ /* 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.)
+ */
+ if (encode_single_inet_addr(sa, sun, !desperatep) == USED)
+ return (-1);
+ /* 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,
- present_sockaddr(&waddr.sa, 0, buf, sizeof(buf)));
- if ((rc = unix_socket_status(&wsun, !desperatep)) == USED) return (-1);
- else if (rc == STALE) unlink(wsun.sun_path);
+ if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep) == USED)
+ return (-1);
+ /* All is well. */
return (0);
}
address addr;
int port = port_from_sockaddr(sa);
char buf[ADDRBUFSZ];
- int rc;
D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(),
present_sockaddr(sa, 0, buf, sizeof(buf)),
(f&ENCF_FRESH) ? "FRESH" : "EXISTING"); )
+
+ /* Start making the Unix-domain address. */
sun->sun_family = AF_UNIX;
+
if (port || !(f&ENCF_FRESH)) {
- 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 && !(f&ENCF_FRESH)) {
- 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);
- }
+
+ /* Try the address as given. If it's in use, or we don't necessarily
+ * want an existing socket, then we're done.
+ */
+ if (encode_single_inet_addr(sa, sun, 0) == 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);
+ encode_single_inet_addr(&addr.sa, sun, 0);
+
} 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);
}
* SA. Assign it a local address so that getpeername(2) does something
* useful.
*/
-static int do_implicit_bind(int sk, const struct sockaddr **sa,
- socklen_t *len, struct sockaddr_un *sun)
+static int do_implicit_bind(int sk, const struct sockaddr *sa)
{
address addr;
- socklen_t mylen = sizeof(*sun);
+ struct sockaddr_un sun;
const impbind *i;
Dpid;
- if (acl_allows_p(connect_real, *sa)) {
- if (fixup_real_ip_socket(sk, (*sa)->sa_family, 0)) return (-1);
- } else {
- if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1);
- if (sun->sun_family == AF_UNIX) {
- if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0;
- if (!sun->sun_path[0]) {
- D( fprintf(stderr, "noip(%d): checking impbind list...\n", pid); )
- for (i = impbinds; i; i = i->next) {
- D( dump_impbind(i); )
- if ((*sa)->sa_family == i->af &&
- sockaddr_in_range_p(*sa, &i->minaddr, &i->maxaddr)) {
- D( fprintf(stderr, "noip(%d): match!\n", pid); )
- addr.sa.sa_family = (*sa)->sa_family;
- ipaddr_to_sockaddr(&addr.sa, &i->bindaddr);
- goto found;
- }
- }
- 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, ENCF_FRESH);
- if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1);
- }
- encode_inet_addr(sun, *sa, 0);
- *sa = SA(sun);
- *len = SUN_LEN(sun);
+ D( fprintf(stderr, "noip(%d): checking impbind list...\n", pid); )
+ for (i = impbinds; i; i = i->next) {
+ D( dump_impbind(i); )
+ if (sa->sa_family == i->af &&
+ sockaddr_in_range_p(sa, &i->minaddr, &i->maxaddr)) {
+ D( fprintf(stderr, "noip(%d): match!\n", pid); )
+ addr.sa.sa_family = sa->sa_family;
+ ipaddr_to_sockaddr(&addr.sa, &i->bindaddr);
+ goto found;
}
}
+ 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, ENCF_FRESH);
+ if (real_bind(sk, SA(&sun), SUN_LEN(&sun))) return (-1);
+ return (0);
+}
+
+/* The socket SK is about to communicate with the remote address *SA. Ensure
+ * that the socket has a local address, and adjust *SA to refer to the real
+ * remote endpoint.
+ *
+ * If we need to translate the remote address, then the Unix-domain endpoint
+ * address will end in *SUN, and *SA will be adjusted to point to it.
+ */
+static int fixup_client_socket(int sk, const struct sockaddr **sa_r,
+ socklen_t *len_r, struct sockaddr_un *sun)
+{
+ socklen_t mylen = sizeof(*sun);
+ const struct sockaddr *sa = *sa_r;
+
+ /* If we're allowed to talk to a real remote endpoint, then fix things up
+ * as necessary and proceed.
+ */
+ if (acl_allows_p(connect_real, sa)) {
+ if (fixup_real_ip_socket(sk, (*sa_r)->sa_family, 0)) return (-1);
+ return (0);
+ }
+
+ /* If this isn't a Unix-domain socket then there's nothing to do. */
+ if (real_getsockname(sk, SA(sun), &mylen) < 0) return (-1);
+ if (sun->sun_family != AF_UNIX) return (0);
+ if (mylen < sizeof(*sun)) ((char *)sun)[mylen] = 0;
+
+ /* Speaking of which, if we don't have a local address, then we should
+ * arrange one now.
+ */
+ if (!sun->sun_path[0] && do_implicit_bind(sk, sa)) return (-1);
+
+ /* And then come up with a remote address. */
+ encode_inet_addr(sun, sa, 0);
+ *sa_r = SA(sun);
+ *len_r = SUN_LEN(sun);
return (0);
}
} else {
D( fprintf(stderr, " -> checking...\n"); )
PRESERVING_ERRNO({
- do_implicit_bind(sk, &sa, &len, &sun);
+ fixup_client_socket(sk, &sa, &len, &sun);
});
D( fprintf(stderr, "noip(%d): CONNECT ...", pid); )
rc = real_connect(sk, sa, len);
else {
D( fprintf(stderr, " -> checking...\n"); )
PRESERVING_ERRNO({
- do_implicit_bind(sk, &to, &tolen, &sun);
+ fixup_client_socket(sk, &to, &tolen, &sun);
});
D( fprintf(stderr, "noip(%d): SENDTO ...", pid); )
}
D( fprintf(stderr, " -> checking...\n"); )
PRESERVING_ERRNO({
mymsg = *msg;
- do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun);
+ fixup_client_socket(sk, &sa, &mymsg.msg_namelen, &sun);
mymsg.msg_name = SA(sa);
msg = &mymsg;
});
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);
}
{
switch (lev) {
case IPPROTO_IP:
+ case IPPROTO_IPV6:
case IPPROTO_TCP:
case IPPROTO_UDP:
if (*len > 0)
{
switch (lev) {
case IPPROTO_IP:
+ case IPPROTO_IPV6:
case IPPROTO_TCP:
case IPPROTO_UDP:
return (0);
~mdw / preload-hacks / blobdiff