/*----- 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 };
unsigned short minport, maxport;
} aclnode;
+/* Implicit bind records */
+typedef struct impbind {
+ struct impbind *next;
+ int af, how;
+ ipaddr minaddr, maxaddr, bindaddr;
+} impbind;
+enum { EXPLICIT, SAME };
+
/* A type for an address range */
typedef struct addrrange {
int type;
/* Access control lists */
static aclnode *bind_real, **bind_tail = &bind_real;
static aclnode *connect_real, **connect_tail = &connect_real;
+static impbind *impbinds, **impbind_tail = &impbinds;
/*----- Import the real versions of functions -----------------------------*/
}
}
+/* Store the address A in SA. */
+static void ipaddr_to_sockaddr(struct sockaddr *sa, const ipaddr *a)
+{
+ switch (sa->sa_family) {
+ case AF_INET:
+ SIN(sa)->sin_addr = a->v4;
+ break;
+ case AF_INET6:
+ SIN6(sa)->sin6_addr = a->v6;
+ SIN6(sa)->sin6_scope_id = 0;
+ SIN6(sa)->sin6_flowinfo = 0;
+ break;
+ default:
+ abort();
+ }
+}
+
/* Copy a whole socket address about. */
static void copy_sockaddr(struct sockaddr *sa_dst,
const struct sockaddr *sa_src)
present_sockaddr(sa, 0, buf, sizeof(buf))); })
for (; a; a = a->next) {
D( dump_aclnode(a); )
- if (sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) &&
+ if (a->af == sa->sa_family &&
+ sockaddr_in_range_p(sa, &a->minaddr, &a->maxaddr) &&
a->minport <= port && port <= a->maxport) {
D( fprintf(stderr, "noip(%d): aha! %s\n", pid,
a->act ? "ALLOW" : "DENY"); )
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);
}
struct sockaddr_un wsun;
int 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_from_sockaddr(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);
+ /* 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;
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)),
- want == WANT_EXISTING ? "EXISTING" : "FRESH"); )
+ (f&ENCF_FRESH) ? "FRESH" : "EXISTING"); )
+
+ /* Start making the Unix-domain address. */
sun->sun_family = AF_UNIX;
- if (port_from_sockaddr(sa) || 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_from_sockaddr(sa));
- 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);
}
return (0);
}
+/* We found the real address SA, with length LEN; if it's a Unix-domain
+ * address corresponding to a fake socket, convert it to cover up the
+ * deception. Whatever happens, put the result at FAKE and store its length
+ * at FAKELEN.
+ */
+static void return_fake_name(struct sockaddr *sa, socklen_t len,
+ struct sockaddr *fake, socklen_t *fakelen)
+{
+ address addr;
+ socklen_t alen;
+
+ if (sa->sa_family == AF_UNIX &&
+ !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) {
+ sa = &addr.sa;
+ len = family_socklen(addr.sa.sa_family);
+ }
+ alen = len;
+ if (len > *fakelen) len = *fakelen;
+ if (len > 0) memcpy(fake, sa, len);
+ *fakelen = alen;
+}
+
+/*----- Implicit binding --------------------------------------------------*/
+
+#ifdef DEBUG
+
+static void dump_impbind(const impbind *i)
+{
+ char buf[ADDRBUFSZ];
+
+ fprintf(stderr, "noip(%d): ", getpid());
+ dump_addrrange(i->af, &i->minaddr, &i->maxaddr);
+ switch (i->how) {
+ case SAME: fprintf(stderr, " <self>"); break;
+ case EXPLICIT:
+ fprintf(stderr, " %s", inet_ntop(i->af, &i->bindaddr,
+ buf, sizeof(buf)));
+ break;
+ default: abort();
+ }
+ fputc('\n', stderr);
+}
+
+static void dump_impbind_list(void)
+{
+ const impbind *i;
+
+ for (i = impbinds; i; i = i->next) dump_impbind(i);
+}
+
+#endif
+
/* The socket SK is about to be used to communicate with the remote address
* SA. Assign it a local address so that getpeername(2) does something
* useful.
{
address addr;
socklen_t mylen = sizeof(*sun);
+ const impbind *i;
+ Dpid;
if (acl_allows_p(connect_real, *sa)) {
if (fixup_real_ip_socket(sk, (*sa)->sa_family, 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);
- encode_inet_addr(sun, &addr.sa, WANT_FRESH);
+ 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, WANT_EXISTING);
+ encode_inet_addr(sun, *sa, 0);
*sa = SA(sun);
*len = SUN_LEN(sun);
}
return (0);
}
-/* We found the real address SA, with length LEN; if it's a Unix-domain
- * address corresponding to a fake socket, convert it to cover up the
- * deception. Whatever happens, put the result at FAKE and store its length
- * at FAKELEN.
- */
-static void return_fake_name(struct sockaddr *sa, socklen_t len,
- struct sockaddr *fake, socklen_t *fakelen)
-{
- address addr;
- socklen_t alen;
-
- if (sa->sa_family == AF_UNIX &&
- !decode_inet_addr(&addr.sa, 0, SUN(sa), len)) {
- sa = &addr.sa;
- len = family_socklen(addr.sa.sa_family);
- }
- alen = len;
- if (len > *fakelen) len = *fakelen;
- if (len > 0) memcpy(fake, sa, len);
- *fakelen = alen;
-}
-
/*----- Configuration -----------------------------------------------------*/
/* Return the process owner's home directory. */
}
}
+struct add_impbind_ctx {
+ int af, how;
+ ipaddr addr;
+};
+
+static void add_impbind(int af, const ipaddr *min, const ipaddr *max,
+ void *p)
+{
+ struct add_impbind_ctx *ctx = p;
+ impbind *i;
+
+ if (ctx->af && af != ctx->af) return;
+ NEW(i);
+ i->af = af;
+ i->how = ctx->how;
+ i->minaddr = *min; i->maxaddr = *max;
+ switch (ctx->how) {
+ case EXPLICIT: i->bindaddr = ctx->addr;
+ case SAME: break;
+ default: abort();
+ }
+ *impbind_tail = i; impbind_tail = &i->next;
+}
+
+/* Parse an implicit-bind line. An implicit-bind entry has the form
+ * ADDR-RANGE {ADDR | same}
+ */
+static void parse_impbind_line(char **pp)
+{
+ struct add_impbind_ctx ctx;
+ char *p = *pp, *q;
+ addrrange r;
+ int del;
+
+ for (;;) {
+ if (parse_addrrange(&p, &r)) goto bad;
+ SKIPSPC;
+ if (KWMATCHP("same")) {
+ ctx.how = SAME;
+ ctx.af = 0;
+ } else {
+ ctx.how = EXPLICIT;
+ parse_nextaddr(&p, &q, &del);
+ ctx.af = guess_address_family(q);
+ if (inet_pton(ctx.af, q, &ctx.addr) < 0) goto bad;
+ RESCAN(del);
+ }
+ foreach_addrrange(&r, add_impbind, &ctx);
+ SKIPSPC;
+ if (*p != ',') break;
+ if (*p) p++;
+ }
+ if (*p) goto bad;
+ *pp = p;
+ return;
+
+bad:
+ D( fprintf(stderr, "noip(%d): bad implicit-bind spec (ignored)\n",
+ getpid()); )
+ return;
+}
+
+/* Parse implicit-bind instructions from an environment variable VAR,
+ * attaching it to the list.
+ */
+static void parse_impbind_env(const char *var)
+{
+ char *p, *q;
+
+ if ((p = getenv(var)) != 0) {
+ p = q = xstrdup(p);
+ parse_impbind_line(&q);
+ free(p);
+ }
+}
+
/* Parse the autoports configuration directive. Syntax is MIN - MAX. */
static void parse_autoports(char **pp)
{
SKIPSPC;
NEXTNUMBER(q, del); x = strtoul(q, 0, 0); RESCAN(del);
SKIPSPC;
- if (*p != '-') goto bad; p++;
+ if (*p != '-') goto bad;
+ p++;
NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del);
minautoport = x; maxautoport = y;
SKIPSPC; if (*p) goto bad;
parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail);
parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail);
+ parse_impbind_env("NOIP_IMPBIND_BEFORE");
if ((p = getenv("NOIP_AUTOPORTS")) != 0) {
p = q = xstrdup(p);
parse_autoports(&q);
parse_acl_line(&p, &bind_tail);
else if (strcmp(cmd, "realconnect") == 0)
parse_acl_line(&p, &connect_tail);
+ else if (strcmp(cmd, "impbind") == 0)
+ parse_impbind_line(&p);
else if (strcmp(cmd, "autoports") == 0)
parse_autoports(&p);
else if (strcmp(cmd, "debug") == 0)
debug = *p ? atoi(p) : 1;
else
- D( fprintf(stderr, "noip: bad config command %s\n", cmd); )
+ D( fprintf(stderr, "noip(%d): bad config command %s\n", pid, cmd); )
}
fclose(fp);
done:
parse_acl_env("NOIP_REALBIND", &bind_tail);
parse_acl_env("NOIP_REALCONNECT", &connect_tail);
+ parse_impbind_env("NOIP_IMPBIND");
parse_acl_env("NOIP_REALBIND_AFTER", &bind_tail);
parse_acl_env("NOIP_REALCONNECT_AFTER", &connect_tail);
+ parse_impbind_env("NOIP_IMPBIND_AFTER");
*bind_tail = 0;
*connect_tail = 0;
+ *impbind_tail = 0;
if (!sockdir) sockdir = getenv("NOIP_SOCKETDIR");
if (!sockdir) {
snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user());
fprintf(stderr, "noip(%d): realbind acl:\n", pid);
dump_acl(bind_real);
fprintf(stderr, "noip(%d): realconnect acl:\n", pid);
- dump_acl(connect_real); )
+ dump_acl(connect_real);
+ fprintf(stderr, "noip(%d): impbind list:\n", pid);
+ dump_impbind_list(); )
}
/*----- Overridden system calls -------------------------------------------*/
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