X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/preload-hacks/blobdiff_plain/8ce11853751d12c81fdd71a67af21e7c176c15e0..72d85cdbe2c457efb39bfe1a9c73ce2f75d7f36f:/noip.c

diff --git a/noip.c b/noip.c
index 173d43f..bcba77f 100644
--- a/noip.c
+++ b/noip.c
@@ -98,7 +98,7 @@ static aclnode *connect_real,  **connect_tail = &connect_real;
   _(sendto, ssize_t, (int, const void *buf, size_t, int,		\
 		      const struct sockaddr *to, socklen_t tolen))	\
   _(recvfrom, ssize_t, (int, void *buf, size_t, int,			\
-		        struct sockaddr *from, socklen_t *fromlen))	\
+			struct sockaddr *from, socklen_t *fromlen))	\
   _(sendmsg, ssize_t, (int, const struct msghdr *, int))		\
   _(recvmsg, ssize_t, (int, struct msghdr *, int))			\
   _(close, int, (int))
@@ -266,7 +266,7 @@ static int unix_socket_status(struct sockaddr_un *sun, int quickp)
   rc = USED;
   if ((fp = fopen("/proc/net/unix", "r")) == 0)
     goto done;
-  fgets(buf, sizeof(buf), fp); /* skip header */
+  if (!fgets(buf, sizeof(buf), fp)) goto done; /* skip header */
   len = strlen(sun->sun_path);
   while (fgets(buf, sizeof(buf), fp)) {
     n = strlen(buf);
@@ -340,11 +340,15 @@ static int encode_inet_addr(struct sockaddr_un *sun,
   return (0);
 }
 
-/* Decode the Unix address SUN to an Internet address SIN.  Returns zero on
- * success; -1 on failure (e.g., it wasn't one of our addresses). */
+/* Decode the Unix address SUN to an Internet address SIN.  If
+ * DECODE_UNBOUND_P is nonzero, an empty address (indicative of an unbound
+ * Unix-domain socket) is translated to a wildcard Internet address.  Returns
+ * zero on success; -1 on failure (e.g., it wasn't one of our addresses).
+ */
 static int decode_inet_addr(struct sockaddr_in *sin,
 			    const struct sockaddr_un *sun,
-			    socklen_t len)
+			    socklen_t len,
+			    int decode_unbound_p)
 {
   char buf[INET_ADDRSTRLEN + 16];
   char *p;
@@ -359,7 +363,7 @@ static int decode_inet_addr(struct sockaddr_in *sin,
   if (len < sizeof(sun)) ((char *)sun)[len] = 0;
   D( fprintf(stderr, "noip: decode (%d) `%s'",
 	     *sun->sun_path, sun->sun_path); )
-  if (!sun->sun_path[0]) {
+  if (decode_unbound_p && !sun->sun_path[0]) {
     sin->sin_family = AF_INET;
     sin->sin_addr.s_addr = INADDR_ANY;
     sin->sin_port = 0;
@@ -425,7 +429,7 @@ static int fixup_real_ip_socket(int sk)
   len = sizeof(sun);
   if (real_getsockname(sk, SA(&sun), &len))
     return (-1);
-  if (decode_inet_addr(&sin, &sun, len))
+  if (decode_inet_addr(&sin, &sun, len, 1))
     return (0); /* Not one of ours */
   len = sizeof(type);
   if (real_getsockopt(sk, SOL_SOCKET, SO_TYPE, &type, &len) < 0 ||
@@ -502,7 +506,8 @@ static void return_fake_name(struct sockaddr *sa, socklen_t len,
   struct sockaddr_in sin;
   socklen_t alen;
 
-  if (sa->sa_family == AF_UNIX && !decode_inet_addr(&sin, SUN(sa), len)) {
+  if (sa->sa_family == AF_UNIX &&
+      !decode_inet_addr(&sin, SUN(sa), len, 0)) {
     sa = SA(&sin);
     len = sizeof(sin);
   }
@@ -877,17 +882,22 @@ int connect(int sk, const struct sockaddr *sa, socklen_t len)
   int fixup_p = 0;
   int rc;
 
-  if (sa->sa_family == AF_INET) {
-    PRESERVING_ERRNO({
-      do_implicit_bind(sk, &sa, &len, &sun);
-      fixup_p = 1;
-    });
-  }
-  rc = real_connect(sk, sa, len);
-  if (rc < 0) {
-    switch (errno) {
-      case ENOENT:	errno = ECONNREFUSED;	break;
-    }
+  switch (sa->sa_family) {
+    case AF_INET:
+      PRESERVING_ERRNO({
+	do_implicit_bind(sk, &sa, &len, &sun);
+	fixup_p = 1;
+      });
+      rc = real_connect(sk, sa, len);
+      if (rc < 0) {
+	switch (errno) {
+	  case ENOENT:	errno = ECONNREFUSED;	break;
+	}
+      }
+      break;
+    default:
+      rc = real_connect(sk, sa, len);
+      break;
   }
   return rc;
 }
@@ -1049,7 +1059,7 @@ static void cleanup_sockdir(void)
     if (d->d_name[0] == '.') continue;
     snprintf(sun.sun_path, sizeof(sun.sun_path),
 	     "%s/%s", sockdir, d->d_name);
-    if (decode_inet_addr(&sin, &sun, SUN_LEN(&sun)) ||
+    if (decode_inet_addr(&sin, &sun, SUN_LEN(&sun), 0) ||
 	stat(sun.sun_path, &st) ||
 	!S_ISSOCK(st.st_mode)) {
       D( fprintf(stderr, "noip: ignoring unknown socketdir entry `%s'\n",
@@ -1080,7 +1090,7 @@ static void get_local_ipaddrs(void)
     return;
   for (i = n_local_ipaddrs = 0;
        n_local_ipaddrs < MAX_LOCAL_IPADDRS &&
-         ifn[i].if_name && *ifn[i].if_name;
+	 ifn[i].if_name && *ifn[i].if_name;
        i++) {
     strcpy(ifr.ifr_name, ifn[i].if_name);
     if (ioctl(sk, SIOCGIFADDR, &ifr) || ifr.ifr_addr.sa_family != AF_INET)
@@ -1094,7 +1104,8 @@ static void get_local_ipaddrs(void)
 }
 
 /* Print the given message to standard error.  Avoids stdio. */
-static void printerr(const char *p) { write(STDERR_FILENO, p, strlen(p)); }
+static void printerr(const char *p)
+  { int hunoz; hunoz = write(STDERR_FILENO, p, strlen(p)); }
 
 /* Create the socket directory, being careful about permissions. */
 static void create_sockdir(void)