/*----- Data structures ---------------------------------------------------*/
-enum { UNUSED, STALE, USED }; /* Unix socket status values */
-enum { WANT_FRESH, WANT_EXISTING }; /* Socket address dispositions */
+/* Unix socket status values. */
+#define UNUSED 0u /* No sign of anyone using it */
+#define STALE 1u /* Socket exists, but is abandoned */
+#define USED 16u /* Socket is in active use */
+#define LISTEN 2u /* Socket has an active listener */
+
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;
+ union {
+ struct { int af; ipaddr min, max; } range;
+ } u;
+} addrrange;
+enum { EMPTY, ANY, LOCAL, RANGE };
+
/* Local address records */
typedef struct full_ipaddr {
int af;
/* 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)
{ memcpy(sa_dst, sa_src, family_socklen(sa_src->sa_family)); }
+/* Convert an AF_INET socket address into the equivalent IPv4-mapped AF_INET6
+ * address.
+ */
+static void map_ipv4_sockaddr(struct sockaddr_in6 *a6,
+ const struct sockaddr_in *a4)
+{
+ size_t i;
+ in_addr_t a = ntohl(a4->sin_addr.s_addr);
+
+ a6->sin6_family = AF_INET6;
+ a6->sin6_port = a4->sin_port;
+ a6->sin6_scope_id = 0;
+ a6->sin6_flowinfo = 0;
+ for (i = 0; i < 10; i++) a6->sin6_addr.s6_addr[i] = 0;
+ for (i = 10; i < 12; i++) a6->sin6_addr.s6_addr[i] = 0xff;
+ for (i = 0; i < 4; i++) a6->sin6_addr.s6_addr[15 - i] = (a >> 8*i)&0xff;
+}
+
+/* Convert an AF_INET6 socket address containing an IPv4-mapped IPv6 address
+ * into the equivalent AF_INET4 address. Return zero on success, or -1 if
+ * the address has the wrong form.
+ */
+static int unmap_ipv4_sockaddr(struct sockaddr_in *a4,
+ const struct sockaddr_in6 *a6)
+{
+ size_t i;
+ in_addr_t a;
+
+ for (i = 0; i < 10; i++) if (a6->sin6_addr.s6_addr[i] != 0) return (-1);
+ for (i = 10; i < 12; i++) if (a6->sin6_addr.s6_addr[i] != 0xff) return (-1);
+ for (i = 0, a = 0; i < 4; i++) a |= a6->sin6_addr.s6_addr[15 - i] << 8*i;
+ a4->sin_family = AF_INET;
+ a4->sin_port = a6->sin6_port;
+ a4->sin_addr.s_addr = htonl(a);
+ return (0);
+}
+
/* Answer whether two addresses are equal. */
static int ipaddr_equal_p(int af, const ipaddr *a, const ipaddr *b)
{
#ifdef DEBUG
-/* Write to standard error a description of the ACL node A. */
-static void dump_aclnode(const aclnode *a)
+static void dump_addrrange(int af, const ipaddr *min, const ipaddr *max)
{
char buf[ADDRBUFSZ];
const char *p;
int plen;
- fprintf(stderr, "noip(%d): %c ", getpid(), a->act ? '+' : '-');
- plen = common_prefix_length(a->af, &a->minaddr, &a->maxaddr);
- p = inet_ntop(a->af, &a->minaddr, buf, sizeof(buf));
+ plen = common_prefix_length(af, min, max);
+ p = inet_ntop(af, min, buf, sizeof(buf));
fprintf(stderr, strchr(p, ':') ? "[%s]" : "%s", p);
if (plen < 0) {
- p = inet_ntop(a->af, &a->maxaddr, buf, sizeof(buf));
+ p = inet_ntop(af, &max, buf, sizeof(buf));
fprintf(stderr, strchr(p, ':') ? "-[%s]" : "-%s", p);
- } else if (plen < address_width(a->af))
+ } else if (plen < address_width(af))
fprintf(stderr, "/%d", plen);
+}
+
+/* Write to standard error a description of the ACL node A. */
+static void dump_aclnode(const aclnode *a)
+{
+ fprintf(stderr, "noip(%d): %c ", getpid(), a->act ? '+' : '-');
+ dump_addrrange(a->af, &a->minaddr, &a->maxaddr);
if (a->minport != 0 || a->maxport != 0xffff) {
fprintf(stderr, ":%u", (unsigned)a->minport);
if (a->minport != a->maxport)
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"); )
FILE *fp = 0;
size_t len, n;
int rc;
+ unsigned long f;
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;
if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */
len = strlen(sun->sun_path);
+ rc = 0;
while (fgets(buf, sizeof(buf), fp)) {
n = strlen(buf);
if (n >= len + 2 && buf[n - len - 2] == ' ' && buf[n - 1] == '\n' &&
- memcmp(buf + n - len - 1, sun->sun_path, len) == 0)
- goto done;
+ memcmp(buf + n - len - 1, sun->sun_path, len) == 0) {
+ rc |= USED;
+ if (sscanf(buf, "%*s %*x %*x %lx", &f) < 0 || (f&0x00010000))
+ rc |= LISTEN;
+ }
}
if (ferror(fp))
goto done;
- rc = STALE;
+ if (!rc) 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)));
+ rc = unix_socket_status(sun, quickp);
+ if (rc == STALE) unlink(sun->sun_path);
return (rc);
}
-/* 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.
+/* 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.
*/
+static int encode_unused_inet_addr(struct sockaddr *sa,
+ struct sockaddr_un *sun,
+ int desperatep)
+{
+ address waddr, maddr;
+ struct sockaddr_un wsun;
+ 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.)
+ */
+ 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);
+ if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED)
+ return (-1);
+
+ /* We're not done yet. If this is an IPv4 address, then /also/ check (a)
+ * the v6-mapped version, (b) the v6-mapped v4 wildcard, /and/ (c) the v6
+ * wildcard. Ugh!
+ */
+ if (sa->sa_family == AF_INET) {
+ map_ipv4_sockaddr(&maddr.sin6, SIN(&sa));
+ if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED)
+ return (-1);
+
+ map_ipv4_sockaddr(&maddr.sin6, &waddr.sin);
+ if (encode_single_inet_addr(&maddr.sa, &wsun, !desperatep)&USED)
+ return (-1);
+
+ wildcard_address(AF_INET6, &waddr.sa);
+ port_to_sockaddr(&waddr.sa, port);
+ if (encode_single_inet_addr(&waddr.sa, &wsun, !desperatep)&USED)
+ return (-1);
+ }
+
+ /* All is well. */
+ return (0);
+}
+
+/* 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
+#define ENCF_REUSEADDR 2u
static int encode_inet_addr(struct sockaddr_un *sun,
const struct sockaddr *sa,
- int want)
+ unsigned f)
{
int i;
int desperatep = 0;
address addr;
- char buf[ADDRBUFSZ];
+ struct sockaddr_in6 sin6;
+ int port = port_from_sockaddr(sa);
int rc;
+ char buf[ADDRBUFSZ];
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) {
- 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 (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.
+ */
+ rc = encode_single_inet_addr(sa, sun, 0);
+ if ((f&ENCF_REUSEADDR) && !(rc&LISTEN)) unlink(sun->sun_path);
+ if ((rc&USED) || (f&ENCF_FRESH)) goto found;
+
+ /* We're looking for a socket which already exists. This is
+ * unfortunately difficult, because we must deal both with wildcards and
+ * v6-mapped IPv4 addresses.
+ *
+ * * We've just tried searching for a socket whose name is an exact
+ * match for our remote address. If the remote address is IPv4, then
+ * we should try again with the v6-mapped equivalent.
+ *
+ * * Failing that, we try again with the wildcard address for the
+ * appropriate address family.
+ *
+ * * Failing /that/, if the remote address is IPv4, then we try
+ * /again/, increasingly desperately, first with the v6-mapped IPv4
+ * wildcard address, and then with the IPv6 wildcard address. This
+ * will cause magic v6-mapping to occur when the connection is
+ * accepted, which we hope won't cause too much trouble.
+ */
+
+ if (sa->sa_family == AF_INET) {
+ map_ipv4_sockaddr(&addr.sin6, SIN(sa));
+ if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found;
}
+
+ wildcard_address(sa->sa_family, &addr.sa);
+ port_to_sockaddr(&addr.sa, port);
+ if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found;
+
+ if (sa->sa_family == AF_INET) {
+ map_ipv4_sockaddr(&sin6, &addr.sin);
+ if (encode_single_inet_addr(SA(&sin6), sun, 0)&USED) goto found;
+ wildcard_address(AF_INET6, &addr.sa);
+ port_to_sockaddr(&addr.sa, port);
+ if (encode_single_inet_addr(&addr.sa, sun, 0)&USED) goto found;
+ }
+
+ /* Well, this isn't going to work (unless a miraculous race is lost), but
+ * we might as well try.
+ */
+ encode_single_inet_addr(sa, sun, 1);
+
} 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));
- snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
- present_sockaddr(&addr.sa, 0, buf, sizeof(buf)));
- if (unix_socket_status(sun, 1) == UNUSED) goto found;
+ 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);
- snprintf(sun->sun_path, sizeof(sun->sun_path), "%s/%s", sockdir,
- present_sockaddr(&addr.sa, 0, buf, sizeof(buf)));
- rc = unix_socket_status(sun, !desperatep);
- switch (rc) {
- case STALE: unlink(sun->sun_path);
- case UNUSED: goto found;
- }
+ 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);
}
-/* 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.
- */
-static int do_implicit_bind(int sk, const struct sockaddr **sa,
- socklen_t *len, struct sockaddr_un *sun)
-{
- address addr;
- socklen_t mylen = sizeof(*sun);
-
- 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]) {
- wildcard_address((*sa)->sa_family, &addr.sa);
- encode_inet_addr(sun, &addr.sa, WANT_FRESH);
- if (real_bind(sk, SA(sun), SUN_LEN(sun))) return (-1);
- }
- encode_inet_addr(sun, *sa, WANT_EXISTING);
- *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.
*/
+#define FNF_V6MAPPED 1u
static void return_fake_name(struct sockaddr *sa, socklen_t len,
- struct sockaddr *fake, socklen_t *fakelen)
+ struct sockaddr *fake, socklen_t *fakelen,
+ unsigned f)
{
address addr;
+ struct sockaddr_in6 sin6;
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);
+ if (addr.sa.sa_family != AF_INET || !(f&FNF_V6MAPPED)) {
+ sa = &addr.sa;
+ len = family_socklen(addr.sa.sa_family);
+ } else {
+ map_ipv4_sockaddr(&sin6, &addr.sin);
+ sa = SA(&sin6);
+ len = family_socklen(AF_INET6);
+ }
}
alen = len;
if (len > *fakelen) len = *fakelen;
*fakelen = alen;
}
+/* Variant of `return_fake_name' above, specifically handling the weirdness
+ * of remote v6-mapped IPv4 addresses. If SK's fake local address is IPv6,
+ * and the remote address is IPv4, then return a v6-mapped version of the
+ * remote address.
+ */
+static void return_fake_peer(int sk, struct sockaddr *sa, socklen_t len,
+ struct sockaddr *fake, socklen_t *fakelen)
+{
+ char sabuf[1024];
+ socklen_t mylen = sizeof(sabuf);
+ unsigned fnf = 0;
+ address addr;
+ int rc;
+
+ PRESERVING_ERRNO({
+ rc = real_getsockname(sk, SA(sabuf), &mylen);
+ if (!rc && sa->sa_family == AF_UNIX &&
+ !decode_inet_addr(&addr.sa, 0, SUN(sabuf), mylen) &&
+ addr.sa.sa_family == AF_INET6)
+ fnf |= FNF_V6MAPPED;
+ });
+ return_fake_name(sa, len, fake, fakelen, fnf);
+}
+
+/*----- 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.
+ *
+ * If the flag `IBF_V6MAPPED' is set then, then SA must be an `AF_INET'
+ * address; after deciding on the appropriate local address, convert it to be
+ * an IPv4-mapped IPv6 address before final conversion to a Unix-domain
+ * socket address and actually binding. Note that this could well mean that
+ * the socket ends up bound to the v6-mapped v4 wildcard address
+ * ::ffff:0.0.0.0, which looks very strange but is meaningful.
+ */
+#define IBF_V6MAPPED 1u
+static int do_implicit_bind(int sk, const struct sockaddr *sa, unsigned f)
+{
+ address addr;
+ struct sockaddr_in6 sin6;
+ struct sockaddr_un sun;
+ const impbind *i;
+ Dpid;
+
+ 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:
+ if (addr.sa.sa_family != AF_INET || !(f&IBF_V6MAPPED)) sa = &addr.sa;
+ else { map_ipv4_sockaddr(&sin6, &addr.sin); sa = SA(&sin6); }
+ encode_inet_addr(&sun, sa, ENCF_FRESH);
+ D( fprintf(stderr, "noip(%d): implicitly binding to %s\n",
+ pid, sun.sun_path); )
+ 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)
+{
+ struct sockaddr_in sin;
+ socklen_t mylen = sizeof(*sun);
+ const struct sockaddr *sa = *sa_r;
+ unsigned ibf = 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;
+
+ /* If the remote address is v6-mapped IPv4, then unmap it so as to search
+ * for IPv4 servers. Also remember to v6-map the local address when we
+ * autobind.
+ */
+ if (sa->sa_family == AF_INET6 && !(unmap_ipv4_sockaddr(&sin, SIN6(sa)))) {
+ sa = SA(&sin);
+ ibf |= IBF_V6MAPPED;
+ }
+
+ /* 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);
+ }
+
+ /* 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, ibf)) 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);
+}
+
/*----- Configuration -----------------------------------------------------*/
/* Return the process owner's home directory. */
*pp = p;
}
-/* Make a new ACL node. ACT is the verdict; AF is the address family;
- * MINADDR and MAXADDR are the ranges on IP addresses; MINPORT and MAXPORT
- * are the ranges on port numbers; TAIL is the list tail to attach the new
- * node to.
- */
-#define ACLNODE(tail_, act_, \
- af_, minaddr_, maxaddr_, minport_, maxport_) do { \
- aclnode *a_; \
- NEW(a_); \
- a_->act = (act_); \
- a_->af = (af_); \
- a_->minaddr = (minaddr_); a_->maxaddr = (maxaddr_); \
- a_->minport = (minport_); a_->maxport = (maxport_); \
- *tail_ = a_; tail_ = &a_->next; \
-} while (0)
-
-/* Parse an ACL line. *PP points to the end of the line; *TAIL points to
- * the list tail (i.e., the final link in the list). An ACL entry has the
- * form +|- [any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT] PORTS
- * where PORTS is parsed by parse_ports above; an ACL line consists of a
- * comma-separated sequence of entries..
+/* Parse an address range designator starting at PP and store a
+ * representation of it in R. An address range designator has the form:
+ *
+ * any | local | ADDR | ADDR - ADDR | ADDR/ADDR | ADDR/INT
*/
-static void parse_acl_line(char **pp, aclnode ***tail)
+static int parse_addrrange(char **pp, addrrange *r)
{
- ipaddr minaddr, maxaddr;
- unsigned short minport, maxport;
- int i, af, n;
- int act;
+ char *p = *pp, *q;
+ int n;
int del;
- char *p = *pp;
- char *q;
+ int af;
- for (;;) {
+ SKIPSPC;
+ if (KWMATCHP("any")) r->type = ANY;
+ else if (KWMATCHP("local")) r->type = LOCAL;
+ else {
+ parse_nextaddr(&p, &q, &del);
+ af = guess_address_family(q);
+ if (inet_pton(af, q, &r->u.range.min) <= 0) goto bad;
+ RESCAN(del);
SKIPSPC;
- if (*p == '+') act = ALLOW;
- else if (*p == '-') act = DENY;
- else goto bad;
+ if (*p == '-') {
+ p++;
+ parse_nextaddr(&p, &q, &del);
+ if (inet_pton(af, q, &r->u.range.max) <= 0) goto bad;
+ RESCAN(del);
+ } else if (*p == '/') {
+ p++;
+ NEXTNUMBER(q, del);
+ n = strtoul(q, 0, 0);
+ r->u.range.max = r->u.range.min;
+ mask_address(af, &r->u.range.min, n, 0);
+ mask_address(af, &r->u.range.max, n, 1);
+ RESCAN(del);
+ } else
+ r->u.range.max = r->u.range.min;
+ r->type = RANGE;
+ r->u.range.af = af;
+ }
+ *pp = p;
+ return (0);
- p++;
- SKIPSPC;
- if (KWMATCHP("any")) {
- parse_ports(&p, &minport, &maxport);
+bad:
+ return (-1);
+}
+
+/* Call FUNC on each individual address range in R. */
+static void foreach_addrrange(const addrrange *r,
+ void (*func)(int af,
+ const ipaddr *min,
+ const ipaddr *max,
+ void *p),
+ void *p)
+{
+ ipaddr minaddr, maxaddr;
+ int i, af;
+
+ switch (r->type) {
+ case EMPTY:
+ break;
+ case ANY:
for (i = 0; address_families[i] >= 0; i++) {
af = address_families[i];
memset(&minaddr, 0, sizeof(minaddr));
maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1);
- ACLNODE(*tail, act, af, minaddr, maxaddr, minport, maxport);
+ func(af, &minaddr, &maxaddr, p);
}
- } else if (KWMATCHP("local")) {
- parse_ports(&p, &minport, &maxport);
+ break;
+ case LOCAL:
for (i = 0; address_families[i] >= 0; i++) {
af = address_families[i];
memset(&minaddr, 0, sizeof(minaddr));
maxaddr = minaddr; mask_address(af, &maxaddr, 0, 1);
- ACLNODE(*tail, act, af, minaddr, minaddr, minport, maxport);
- ACLNODE(*tail, act, af, maxaddr, maxaddr, minport, maxport);
+ func(af, &minaddr, &minaddr, p);
+ func(af, &maxaddr, &maxaddr, p);
}
for (i = 0; i < n_local_ipaddrs; i++) {
- ACLNODE(*tail, act, local_ipaddrs[i].af,
- local_ipaddrs[i].addr, local_ipaddrs[i].addr,
- minport, maxport);
+ func(local_ipaddrs[i].af,
+ &local_ipaddrs[i].addr, &local_ipaddrs[i].addr,
+ p);
}
+ break;
+ case RANGE:
+ func(r->u.range.af, &r->u.range.min, &r->u.range.max, p);
+ break;
+ default:
+ abort();
+ }
+}
+
+struct add_aclnode_ctx {
+ int act;
+ unsigned short minport, maxport;
+ aclnode ***tail;
+};
+
+static void add_aclnode(int af, const ipaddr *min, const ipaddr *max,
+ void *p)
+{
+ struct add_aclnode_ctx *ctx = p;
+ aclnode *a;
+
+ NEW(a);
+ a->act = ctx->act;
+ a->af = af;
+ a->minaddr = *min; a->maxaddr = *max;
+ a->minport = ctx->minport; a->maxport = ctx->maxport;
+ **ctx->tail = a; *ctx->tail = &a->next;
+}
+
+/* Parse an ACL line. *PP points to the end of the line; *TAIL points to
+ * the list tail (i.e., the final link in the list). An ACL entry has the
+ * form +|- ADDR-RANGE PORTS
+ * where PORTS is parsed by parse_ports above; an ACL line consists of a
+ * comma-separated sequence of entries..
+ */
+static void parse_acl_line(char **pp, aclnode ***tail)
+{
+ struct add_aclnode_ctx ctx;
+ addrrange r;
+ char *p = *pp;
+
+ ctx.tail = tail;
+ for (;;) {
+ SKIPSPC;
+ if (*p == '+') ctx.act = ALLOW;
+ else if (*p == '-') ctx.act = DENY;
+ else goto bad;
+
+ p++;
+ if (parse_addrrange(&p, &r)) goto bad;
+ parse_ports(&p, &ctx.minport, &ctx.maxport);
+ foreach_addrrange(&r, add_aclnode, &ctx);
+ SKIPSPC;
+ if (*p != ',') break;
+ if (*p) p++;
+ }
+ if (*p) goto bad;
+ *pp = p;
+ return;
+
+bad:
+ D( fprintf(stderr, "noip(%d): bad acl spec (ignored)\n", getpid()); )
+ return;
+}
+
+/* Parse an ACL from an environment variable VAR, attaching it to the list
+ * TAIL.
+ */
+static void parse_acl_env(const char *var, aclnode ***tail)
+{
+ char *p, *q;
+
+ if ((p = getenv(var)) != 0) {
+ p = q = xstrdup(p);
+ parse_acl_line(&q, tail);
+ free(p);
+ }
+}
+
+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);
- af = guess_address_family(q);
- if (inet_pton(af, q, &minaddr) <= 0) goto bad;
+ ctx.af = guess_address_family(q);
+ if (inet_pton(ctx.af, q, &ctx.addr) < 0) goto bad;
RESCAN(del);
- SKIPSPC;
- if (*p == '-') {
- p++;
- parse_nextaddr(&p, &q, &del);
- if (inet_pton(af, q, &maxaddr) <= 0) goto bad;
- RESCAN(del);
- } else if (*p == '/') {
- p++;
- NEXTNUMBER(q, del);
- n = strtoul(q, 0, 0);
- maxaddr = minaddr;
- mask_address(af, &minaddr, n, 0);
- mask_address(af, &maxaddr, n, 1);
- RESCAN(del);
- } else
- maxaddr = minaddr;
- parse_ports(&p, &minport, &maxport);
- ACLNODE(*tail, act, af, minaddr, maxaddr, minport, maxport);
}
+ foreach_addrrange(&r, add_impbind, &ctx);
SKIPSPC;
if (*p != ',') break;
if (*p) p++;
return;
bad:
- D( fprintf(stderr, "noip(%d): bad acl spec (ignored)\n", getpid()); )
+ 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;
return;
}
-/* Parse an ACL from an environment variable VAR, attaching it to the list
- * TAIL. */
-static void parse_acl_env(const char *var, aclnode ***tail)
-{
- char *p, *q;
-
- if ((p = getenv(var)) != 0) {
- p = q = xstrdup(p);
- parse_acl_line(&q, tail);
- free(p);
- }
-}
-
/* Read the configuration from the config file and environment. */
static void readconfig(void)
{
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 -------------------------------------------*/
{
struct sockaddr_un sun;
int rc;
+ unsigned f;
+ int reusep;
+ socklen_t n;
Dpid;
D({ char buf[ADDRBUFSZ];
if (fixup_real_ip_socket(sk, sa->sa_family, 0))
return (-1);
} else {
- encode_inet_addr(&sun, sa, WANT_FRESH);
+ f = ENCF_FRESH;
+ n = sizeof(reusep);
+ if (!getsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &reusep, &n) && reusep)
+ f |= ENCF_REUSEADDR;
+ encode_inet_addr(&sun, sa, f);
sa = SA(&sun);
len = SUN_LEN(&sun);
}
} 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, " -> null addr; pass through"); )
n = real_recvfrom(sk, buf, len, flags, 0, 0);
} else {
- PRESERVING_ERRNO({
- n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen);
- if (n >= 0) {
- D( fprintf(stderr, " -> converting...\n"); )
- return_fake_name(SA(sabuf), mylen, from, fromlen);
- D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); )
- }
- });
+ n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen);
+ if (n >= 0) {
+ D( fprintf(stderr, " -> converting...\n"); )
+ PRESERVING_ERRNO({
+ return_fake_peer(sk, SA(sabuf), mylen, from, fromlen);
+ });
+ D( fprintf(stderr, "noip(%d): ... RECVFROM", pid); )
+ }
}
D( dump_addrresult(n, from, fromlen ? *fromlen : 0); )
return (n);
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;
});
D( fprintf(stderr, " -> null addr; pass through"); )
return (real_recvmsg(sk, msg, flags));
} else {
- PRESERVING_ERRNO({
- msg->msg_name = sabuf;
- msg->msg_namelen = sizeof(sabuf);
- n = real_recvmsg(sk, msg, flags);
- if (n >= 0) {
- D( fprintf(stderr, " -> converting...\n"); )
- return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len);
- D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); )
- }
- msg->msg_name = sa;
- msg->msg_namelen = len;
- });
+ msg->msg_name = sabuf;
+ msg->msg_namelen = sizeof(sabuf);
+ n = real_recvmsg(sk, msg, flags);
+ if (n >= 0) {
+ D( fprintf(stderr, " -> converting...\n"); )
+ PRESERVING_ERRNO({
+ return_fake_peer(sk, SA(sabuf), msg->msg_namelen, sa, &len);
+ });
+ }
+ D( fprintf(stderr, "noip(%d): ... RECVMSG", pid); )
+ msg->msg_name = sa;
+ msg->msg_namelen = len;
}
D( dump_addrresult(n, sa, len); )
return (n);
else if (!sa) D( fprintf(stderr, " -> address not wanted"); )
else {
D( fprintf(stderr, " -> converting...\n"); )
- return_fake_name(SA(sabuf), mylen, sa, len);
+ return_fake_peer(sk, SA(sabuf), mylen, sa, len);
D( fprintf(stderr, "noip(%d): ... ACCEPT", pid); )
}
D( dump_addrresult(nsk, sa, len ? *len : 0); )
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, 0);
+ 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_peer(sk, SA(sabuf), mylen, sa, len);
+ D( fprintf(stderr, "noip(%d): ... GETPEERNAME", pid); )
+ }
D( dump_addrresult(rc, sa, *len); )
- return (0);
+ return (rc);
}
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) {