X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/preload-hacks/blobdiff_plain/c0876c8cd7fe4ee961f4255b07836f29a81075ca..dc3956b3f2f9b13bbf93df2ed7295407cc90ab86:/noip.c

diff --git a/noip.c b/noip.c
index 8a67b64..ee86680 100644
--- a/noip.c
+++ b/noip.c
@@ -34,6 +34,7 @@
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
+#include <stdarg.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -125,7 +126,8 @@ static aclnode *connect_real,  **connect_tail = &connect_real;
   _(recvfrom, ssize_t, (int, void *buf, size_t, int,			\
 			struct sockaddr *from, socklen_t *fromlen))	\
   _(sendmsg, ssize_t, (int, const struct msghdr *, int))		\
-  _(recvmsg, ssize_t, (int, struct msghdr *, int))
+  _(recvmsg, ssize_t, (int, struct msghdr *, int))			\
+  _(ioctl, int, (int, unsigned long, ...))
 
 /* Function pointers to set up. */
 #define DECL(imp, ret, args) static ret (*real_##imp) args;
@@ -159,8 +161,10 @@ static void import(void)
 /* Debugging */
 #ifdef DEBUG
 #  define D(body) { if (debug) { body } }
+#  define Dpid pid_t pid = debug ? getpid() : -1
 #else
 #  define D(body) ;
+#  define Dpid
 #endif
 
 /* Preservation of error status */
@@ -285,6 +289,7 @@ static void port_to_sockaddr(struct sockaddr *sa, int port)
     default: abort();
   }
 }
+
 /* Extract the address part from SA and store it in A. */
 static void ipaddr_from_sockaddr(ipaddr *a, const struct sockaddr *sa)
 {
@@ -404,6 +409,7 @@ static char *present_sockaddr(const struct sockaddr *sa, socklen_t len,
 #define WANT(n_) do { if (sz < (n_)) goto nospace; } while (0)
 #define PUTC(c_) do { *buf++ = (c_); sz--; } while (0)
 
+  if (!sa) return "<null-address>";
   if (!sz) return "<no-space-in-buffer>";
   if (!len) len = family_socklen(sa->sa_family);
 
@@ -502,13 +508,13 @@ static int parse_sockaddr(struct sockaddr *sa, const char *p)
 #ifdef DEBUG
 
 /* Write to standard error a description of the ACL node A. */
-static void dump_aclnode(aclnode *a)
+static void dump_aclnode(const aclnode *a)
 {
   char buf[ADDRBUFSZ];
   const char *p;
   int plen;
 
-  fprintf(stderr, "noip:   %c ", a->act ? '+' : '-');
+  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));
   fprintf(stderr, strchr(p, ':') ? "[%s]" : "%s", p);
@@ -525,7 +531,7 @@ static void dump_aclnode(aclnode *a)
   fputc('\n', stderr);
 }
 
-static void dump_acl(aclnode *a)
+static void dump_acl(const aclnode *a)
 {
   int act = ALLOW;
 
@@ -533,31 +539,34 @@ static void dump_acl(aclnode *a)
     dump_aclnode(a);
     act = a->act;
   }
-  fprintf(stderr, "noip:   [default policy: %s]\n",
+  fprintf(stderr, "noip(%d):   [default policy: %s]\n", getpid(),
 	  act == ALLOW ? "DENY" : "ALLOW");
 }
 
 #endif
 
 /* Returns nonzero if the ACL A allows the socket address SA. */
-static int acl_allows_p(aclnode *a, const struct sockaddr *sa)
+static int acl_allows_p(const aclnode *a, const struct sockaddr *sa)
 {
   unsigned short port = port_from_sockaddr(sa);
   int act = ALLOW;
+  Dpid;
 
   D({ char buf[ADDRBUFSZ];
-      fprintf(stderr, "noip: check %s\n",
+      fprintf(stderr, "noip(%d): check %s\n", pid,
 	      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) &&
 	a->minport <= port && port <= a->maxport) {
-      D( fprintf(stderr, "noip: aha!  %s\n", a->act ? "ALLOW" : "DENY"); )
+      D( fprintf(stderr, "noip(%d): aha!  %s\n", pid,
+		 a->act ? "ALLOW" : "DENY"); )
       return (a->act);
     }
     act = a->act;
   }
-  D( fprintf(stderr, "noip: nothing found: %s\n", act ? "DENY" : "ALLOW"); )
+  D( fprintf(stderr, "noip(%d): nothing found: %s\n", pid,
+	     act ? "DENY" : "ALLOW"); )
   return (!act);
 }
 
@@ -631,7 +640,7 @@ static int encode_inet_addr(struct sockaddr_un *sun,
   char buf[ADDRBUFSZ];
   int rc;
 
-  D( fprintf(stderr, "noip: encode %s (%s)",
+  D( fprintf(stderr, "noip(%d): encode %s (%s)", getpid(),
 	     present_sockaddr(sa, 0, buf, sizeof(buf)),
 	     want == WANT_EXISTING ? "EXISTING" : "FRESH"); )
   sun->sun_family = AF_UNIX;
@@ -695,7 +704,7 @@ static int decode_inet_addr(struct sockaddr *sa, int af_hint,
   if (len > sizeof(*sun)) return (-1);
   ((char *)sun)[len] = 0;
   nn = strlen(sun->sun_path);
-  D( fprintf(stderr, "noip: decode `%s'", sun->sun_path); )
+  D( fprintf(stderr, "noip(%d): decode `%s'", getpid(), sun->sun_path); )
   if (af_hint && !sun->sun_path[0]) {
     wildcard_address(af_hint, sa);
     D( fprintf(stderr, " -- unbound socket\n"); )
@@ -714,9 +723,11 @@ static int decode_inet_addr(struct sockaddr *sa, int af_hint,
 
 /* SK is (or at least might be) a Unix-domain socket we created when an
  * Internet socket was asked for.  We've decided it should be an Internet
- * socket after all, with family AF_HINT, so convert it.
+ * socket after all, with family AF_HINT, so convert it.  If TMP is not null,
+ * then don't replace the existing descriptor: store the new socket in *TMP
+ * and return zero.
  */
-static int fixup_real_ip_socket(int sk, int af_hint)
+static int fixup_real_ip_socket(int sk, int af_hint, int *tmp)
 {
   int nsk;
   int type;
@@ -760,18 +771,22 @@ static int fixup_real_ip_socket(int sk, int af_hint)
 } while (0);
   OPTS(FIX)
 #undef FIX
-  if ((f = fcntl(sk, F_GETFL)) < 0 ||
-      (fd = fcntl(sk, F_GETFD)) < 0 ||
-      fcntl(nsk, F_SETFL, f) < 0 ||
-      dup2(nsk, sk) < 0) {
+  if (tmp)
+    *tmp = nsk;
+  else {
+    if ((f = fcntl(sk, F_GETFL)) < 0 ||
+	(fd = fcntl(sk, F_GETFD)) < 0 ||
+	fcntl(nsk, F_SETFL, f) < 0 ||
+	dup2(nsk, sk) < 0) {
+      close(nsk);
+      return (-1);
+    }
+    unlink(sun.sun_path);
     close(nsk);
-    return (-1);
-  }
-  unlink(sun.sun_path);
-  close(nsk);
-  if (fcntl(sk, F_SETFD, fd) < 0) {
-    perror("noip: fixup_real_ip_socket F_SETFD");
-    abort();
+    if (fcntl(sk, F_SETFD, fd) < 0) {
+      perror("noip: fixup_real_ip_socket F_SETFD");
+      abort();
+    }
   }
   return (0);
 }
@@ -787,7 +802,7 @@ static int do_implicit_bind(int sk, const struct sockaddr **sa,
   socklen_t mylen = sizeof(*sun);
 
   if (acl_allows_p(connect_real, *sa)) {
-    if (fixup_real_ip_socket(sk, (*sa)->sa_family)) return (-1);
+    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) {
@@ -1030,6 +1045,7 @@ static void parse_acl_line(char **pp, aclnode ***tail)
 	maxaddr = minaddr;
 	mask_address(af, &minaddr, n, 0);
 	mask_address(af, &maxaddr, n, 1);
+	RESCAN(del);
       } else
 	maxaddr = minaddr;
       parse_ports(&p, &minport, &maxport);
@@ -1037,12 +1053,14 @@ static void parse_acl_line(char **pp, aclnode ***tail)
     }
     SKIPSPC;
     if (*p != ',') break;
-    p++;
+    if (*p) p++;
   }
+  if (*p) goto bad;
+  *pp = p;
   return;
 
 bad:
-  D( fprintf(stderr, "noip: bad acl spec (ignored)\n"); )
+  D( fprintf(stderr, "noip(%d): bad acl spec (ignored)\n", getpid()); )
   return;
 }
 
@@ -1059,10 +1077,12 @@ static void parse_autoports(char **pp)
   if (*p != '-') goto bad; p++;
   NEXTNUMBER(q, del); y = strtoul(q, 0, 0); RESCAN(del);
   minautoport = x; maxautoport = y;
+  SKIPSPC; if (*p) goto bad;
+  *pp = p;
   return;
 
 bad:
-  D( fprintf(stderr, "bad port range (ignored)\n"); )
+  D( fprintf(stderr, "noip(%d): bad port range (ignored)\n", getpid()); )
   return;
 }
 
@@ -1086,6 +1106,7 @@ static void readconfig(void)
   char buf[1024];
   size_t n;
   char *p, *q, *cmd;
+  Dpid;
 
   parse_acl_env("NOIP_REALBIND_BEFORE", &bind_tail);
   parse_acl_env("NOIP_REALCONNECT_BEFORE", &connect_tail);
@@ -1096,11 +1117,11 @@ static void readconfig(void)
   }
   if ((p = getenv("NOIP_CONFIG")) == 0)
     snprintf(p = buf, sizeof(buf), "%s/.noip", home());
-  D( fprintf(stderr, "noip: config file: %s\n", p); )
+  D( fprintf(stderr, "noip(%d): config file: %s\n", pid, p); )
 
   if ((fp = fopen(p, "r")) == 0) {
-    D( fprintf(stderr, "noip: couldn't read config: %s\n",
-	       strerror(errno)); )
+    D( fprintf(stderr, "noip(%d): couldn't read config: %s\n",
+	       pid, strerror(errno)); )
     goto done;
   }
   while (fgets(buf, sizeof(buf), fp)) {
@@ -1141,52 +1162,104 @@ done:
     snprintf(buf, sizeof(buf), "%s/noip-%s", tmpdir(), user());
     sockdir = xstrdup(buf);
   }
-  D( fprintf(stderr, "noip: socketdir: %s\n", sockdir);
-     fprintf(stderr, "noip: autoports: %u-%u\n",
-	     minautoport, maxautoport);
-     fprintf(stderr, "noip: realbind acl:\n");
+  D( fprintf(stderr, "noip(%d): socketdir: %s\n", pid, sockdir);
+     fprintf(stderr, "noip(%d): autoports: %u-%u\n",
+	     pid, minautoport, maxautoport);
+     fprintf(stderr, "noip(%d): realbind acl:\n", pid);
      dump_acl(bind_real);
-     fprintf(stderr, "noip: realconnect acl:\n");
+     fprintf(stderr, "noip(%d): realconnect acl:\n", pid);
      dump_acl(connect_real); )
 }
 
 /*----- Overridden system calls -------------------------------------------*/
 
+static void dump_syserr(long rc)
+  { fprintf(stderr, " => %ld (E%d)\n", rc, errno); }
+
+static void dump_sysresult(long rc)
+{
+  if (rc < 0) dump_syserr(rc);
+  else fprintf(stderr, " => %ld\n", rc);
+}
+
+static void dump_addrresult(long rc, const struct sockaddr *sa,
+			    socklen_t len)
+{
+  char addrbuf[ADDRBUFSZ];
+
+  if (rc < 0) dump_syserr(rc);
+  else {
+    fprintf(stderr, " => %ld [%s]\n", rc,
+	    present_sockaddr(sa, len, addrbuf, sizeof(addrbuf)));
+  }
+}
+
 int socket(int pf, int ty, int proto)
 {
+  int sk;
+
+  D( fprintf(stderr, "noip(%d): SOCKET pf=%d, type=%d, proto=%d",
+	     getpid(), pf, ty, proto); )
+
   switch (pf) {
     default:
       if (!family_known_p(pf)) {
+	D( fprintf(stderr, " -> unknown; refuse\n"); )
 	errno = EAFNOSUPPORT;
-	return (-1);
+	sk = -1;
       }
+      D( fprintf(stderr, " -> inet; substitute"); )
       pf = PF_UNIX;
       proto = 0;
+      break;
     case PF_UNIX:
 #ifdef PF_NETLINK
     case PF_NETLINK:
 #endif
-      return (real_socket(pf, ty, proto));
+      D( fprintf(stderr, " -> safe; permit"); )
+      break;
   }
+  sk = real_socket(pf, ty, proto);
+  D( dump_sysresult(sk); )
+  return (sk);
 }
 
 int socketpair(int pf, int ty, int proto, int *sk)
 {
-  if (pf == PF_INET) {
+  int rc;
+
+  D( fprintf(stderr, "noip(%d): SOCKETPAIR pf=%d, type=%d, proto=%d",
+	     getpid(), pf, ty, proto); )
+  if (!family_known_p(pf))
+    D( fprintf(stderr, " -> unknown; permit"); )
+  else {
+    D( fprintf(stderr, " -> inet; substitute"); )
     pf = PF_UNIX;
     proto = 0;
   }
-  return (real_socketpair(pf, ty, proto, sk));
+  rc = real_socketpair(pf, ty, proto, sk);
+  D( if (rc < 0) dump_syserr(rc);
+     else fprintf(stderr, " => %d (%d, %d)\n", rc, sk[0], sk[1]); )
+  return (rc);
 }
 
 int bind(int sk, const struct sockaddr *sa, socklen_t len)
 {
   struct sockaddr_un sun;
+  int rc;
+  Dpid;
+
+  D({ char buf[ADDRBUFSZ];
+      fprintf(stderr, "noip(%d): BIND sk=%d, sa[%d]=%s", pid,
+	      sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); })
 
-  if (family_known_p(sa->sa_family)) {
+  if (!family_known_p(sa->sa_family))
+    D( fprintf(stderr, " -> unknown af; pass through"); )
+  else {
+    D( fprintf(stderr, " -> checking...\n"); )
     PRESERVING_ERRNO({
       if (acl_allows_p(bind_real, sa)) {
-	if (fixup_real_ip_socket(sk, sa->sa_family))
+	if (fixup_real_ip_socket(sk, sa->sa_family, 0))
 	  return (-1);
       } else {
 	encode_inet_addr(&sun, sa, WANT_FRESH);
@@ -1194,21 +1267,32 @@ int bind(int sk, const struct sockaddr *sa, socklen_t len)
 	len = SUN_LEN(&sun);
       }
     });
+    D( fprintf(stderr, "noip(%d): BIND ...", pid); )
   }
-  return (real_bind(sk, sa, len));
+  rc = real_bind(sk, sa, len);
+  D( dump_sysresult(rc); )
+  return (rc);
 }
 
 int connect(int sk, const struct sockaddr *sa, socklen_t len)
 {
   struct sockaddr_un sun;
   int rc;
+  Dpid;
 
-  if (!family_known_p(sa->sa_family))
+  D({ char buf[ADDRBUFSZ];
+      fprintf(stderr, "noip(%d): CONNECT sk=%d, sa[%d]=%s", pid,
+	      sk, len, present_sockaddr(sa, len, buf, sizeof(buf))); })
+
+  if (!family_known_p(sa->sa_family)) {
+    D( fprintf(stderr, " -> unknown af; pass through"); )
     rc = real_connect(sk, sa, len);
-  else {
+  } else {
+    D( fprintf(stderr, " -> checking...\n"); )
     PRESERVING_ERRNO({
       do_implicit_bind(sk, &sa, &len, &sun);
     });
+    D( fprintf(stderr, "noip(%d): CONNECT ...", pid); )
     rc = real_connect(sk, sa, len);
     if (rc < 0) {
       switch (errno) {
@@ -1216,6 +1300,7 @@ int connect(int sk, const struct sockaddr *sa, socklen_t len)
       }
     }
   }
+  D( dump_sysresult(rc); )
   return (rc);
 }
 
@@ -1223,13 +1308,28 @@ ssize_t sendto(int sk, const void *buf, size_t len, int flags,
 	       const struct sockaddr *to, socklen_t tolen)
 {
   struct sockaddr_un sun;
+  ssize_t n;
+  Dpid;
 
-  if (to && to->sa_family == AF_INET) {
+  D({ char addrbuf[ADDRBUFSZ];
+      fprintf(stderr, "noip(%d): SENDTO sk=%d, len=%lu, flags=%d, to[%d]=%s",
+	      pid, sk, (unsigned long)len, flags, tolen,
+	      present_sockaddr(to, tolen, addrbuf, sizeof(addrbuf))); })
+
+  if (!to)
+    D( fprintf(stderr, " -> null address; leaving"); )
+  else if (!family_known_p(to->sa_family))
+    D( fprintf(stderr, " -> unknown af; pass through"); )
+  else {
+    D( fprintf(stderr, " -> checking...\n"); )
     PRESERVING_ERRNO({
       do_implicit_bind(sk, &to, &tolen, &sun);
     });
+    D( fprintf(stderr, "noip(%d): SENDTO ...", pid); )
   }
-  return (real_sendto(sk, buf, len, flags, to, tolen));
+  n = real_sendto(sk, buf, len, flags, to, tolen);
+  D( dump_sysresult(n); )
+  return (n);
 }
 
 ssize_t recvfrom(int sk, void *buf, size_t len, int flags,
@@ -1238,57 +1338,91 @@ ssize_t recvfrom(int sk, void *buf, size_t len, int flags,
   char sabuf[1024];
   socklen_t mylen = sizeof(sabuf);
   ssize_t n;
+  Dpid;
 
-  if (!from)
-    return real_recvfrom(sk, buf, len, flags, 0, 0);
-  PRESERVING_ERRNO({
-    n = real_recvfrom(sk, buf, len, flags, SA(sabuf), &mylen);
-    if (n < 0)
-      return (-1);
-    return_fake_name(SA(sabuf), mylen, from, fromlen);
-  });
+  D( fprintf(stderr, "noip(%d): RECVFROM sk=%d, len=%lu, flags=%d",
+	     pid, sk, (unsigned long)len, flags); )
+
+  if (!from) {
+    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); )
+      }
+    });
+  }
+  D( dump_addrresult(n, from, fromlen ? *fromlen : 0); )
   return (n);
 }
 
 ssize_t sendmsg(int sk, const struct msghdr *msg, int flags)
 {
   struct sockaddr_un sun;
-  const struct sockaddr *sa;
+  const struct sockaddr *sa = SA(msg->msg_name);
   struct msghdr mymsg;
-
-  if (msg->msg_name && SA(msg->msg_name)->sa_family == AF_INET) {
+  ssize_t n;
+  Dpid;
+
+  D({ char addrbuf[ADDRBUFSZ];
+      fprintf(stderr, "noip(%d): SENDMSG sk=%d, "
+		      "msg_flags=%d, msg_name[%d]=%s, ...",
+	      pid, sk, msg->msg_flags, msg->msg_namelen,
+	      present_sockaddr(sa, msg->msg_namelen,
+			       addrbuf, sizeof(addrbuf))); })
+
+  if (!sa)
+    D( fprintf(stderr, " -> null address; leaving"); )
+  else if (!family_known_p(sa->sa_family))
+    D( fprintf(stderr, " -> unknown af; pass through"); )
+  else {
+    D( fprintf(stderr, " -> checking...\n"); )
     PRESERVING_ERRNO({
-      sa = SA(msg->msg_name);
       mymsg = *msg;
       do_implicit_bind(sk, &sa, &mymsg.msg_namelen, &sun);
       mymsg.msg_name = SA(sa);
       msg = &mymsg;
     });
+    D( fprintf(stderr, "noip(%d): SENDMSG ...", pid); )
   }
-  return (real_sendmsg(sk, msg, flags));
+  n = real_sendmsg(sk, msg, flags);
+  D( dump_sysresult(n); )
+  return (n);
 }
 
 ssize_t recvmsg(int sk, struct msghdr *msg, int flags)
 {
   char sabuf[1024];
-  struct sockaddr *sa;
-  socklen_t len;
+  struct sockaddr *sa = SA(msg->msg_name);
+  socklen_t len = msg->msg_namelen;
   ssize_t n;
+  Dpid;
+
+  D( fprintf(stderr, "noip(%d): RECVMSG sk=%d msg_flags=%d, ...",
+	     pid, sk, msg->msg_flags); )
 
-  if (!msg->msg_name)
+  if (!msg->msg_name) {
+    D( fprintf(stderr, " -> null addr; pass through"); )
     return (real_recvmsg(sk, msg, flags));
-  PRESERVING_ERRNO({
-    sa = SA(msg->msg_name);
-    len = msg->msg_namelen;
-    msg->msg_name = sabuf;
-    msg->msg_namelen = sizeof(sabuf);
-    n = real_recvmsg(sk, msg, flags);
-    if (n < 0)
-      return (-1);
-    return_fake_name(SA(sabuf), msg->msg_namelen, sa, &len);
-    msg->msg_name = sa;
-    msg->msg_namelen = len;
-  });
+  } 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;
+    });
+  }
+  D( dump_addrresult(n, sa, len); )
   return (n);
 }
 
@@ -1296,35 +1430,60 @@ int accept(int sk, struct sockaddr *sa, socklen_t *len)
 {
   char sabuf[1024];
   socklen_t mylen = sizeof(sabuf);
-  int nsk = real_accept(sk, SA(sabuf), &mylen);
+  int nsk;
+  Dpid;
 
-  if (nsk < 0)
-    return (-1);
-  return_fake_name(SA(sabuf), mylen, sa, len);
+  D( fprintf(stderr, "noip(%d): ACCEPT sk=%d", pid, sk); )
+
+  nsk = real_accept(sk, SA(sabuf), &mylen);
+  if (nsk < 0) /* failed */;
+  else if (!sa) D( fprintf(stderr, " -> address not wanted"); )
+  else {
+    D( fprintf(stderr, " -> converting...\n"); )
+    return_fake_name(SA(sabuf), mylen, sa, len);
+    D( fprintf(stderr, "noip(%d): ... ACCEPT", pid); )
+  }
+  D( dump_addrresult(nsk, sa, len ? *len : 0); )
   return (nsk);
 }
 
 int getsockname(int sk, struct sockaddr *sa, socklen_t *len)
 {
+  int rc;
+  Dpid;
+
+  D( fprintf(stderr, "noip(%d): GETSOCKNAME sk=%d", pid, sk); )
   PRESERVING_ERRNO({
     char sabuf[1024];
     socklen_t mylen = sizeof(sabuf);
-    if (real_getsockname(sk, SA(sabuf), &mylen))
-      return (-1);
-    return_fake_name(SA(sabuf), mylen, sa, len);
+    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); )
+    }
   });
-  return (0);
+  D( dump_addrresult(rc, sa, *len); )
+  return (rc);
 }
 
 int getpeername(int sk, struct sockaddr *sa, socklen_t *len)
 {
+  int rc;
+  Dpid;
+
+  D( fprintf(stderr, "noip(%d): GETPEERNAME sk=%d", pid, sk); )
   PRESERVING_ERRNO({
     char sabuf[1024];
     socklen_t mylen = sizeof(sabuf);
-    if (real_getpeername(sk, SA(sabuf), &mylen))
-      return (-1);
-    return_fake_name(SA(sabuf), mylen, sa, len);
+    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);
 }
 
@@ -1358,6 +1517,36 @@ int setsockopt(int sk, int lev, int opt, const void *p, socklen_t len)
   return (real_setsockopt(sk, lev, opt, p, len));
 }
 
+int ioctl(int fd, unsigned long op, ...)
+{
+  va_list ap;
+  void *arg;
+  int sk;
+  int rc;
+
+  va_start(ap, op);
+  arg = va_arg(ap, void *);
+
+  switch (op) {
+    case SIOCGIFADDR:
+    case SIOCGIFBRDADDR:
+    case SIOCGIFDSTADDR:
+    case SIOCGIFNETMASK:
+      PRESERVING_ERRNO({
+	if (fixup_real_ip_socket(fd, AF_INET, &sk)) goto real;
+      });
+      rc = real_ioctl(sk, op, arg);
+      PRESERVING_ERRNO({ close(sk); });
+      break;
+    default:
+    real:
+      rc = real_ioctl(fd, op, arg);
+      break;
+  }
+  va_end(ap);
+  return (rc);
+}
+
 /*----- Initialization ----------------------------------------------------*/
 
 /* Clean up the socket directory, deleting stale sockets. */
@@ -1368,6 +1557,7 @@ static void cleanup_sockdir(void)
   address addr;
   struct sockaddr_un sun;
   struct stat st;
+  Dpid;
 
   if ((dir = opendir(sockdir)) == 0) return;
   sun.sun_family = AF_UNIX;
@@ -1378,13 +1568,13 @@ static void cleanup_sockdir(void)
     if (decode_inet_addr(&addr.sa, 0, &sun, SUN_LEN(&sun)) ||
 	stat(sun.sun_path, &st) ||
 	!S_ISSOCK(st.st_mode)) {
-      D( fprintf(stderr, "noip: ignoring unknown socketdir entry `%s'\n",
-		 sun.sun_path); )
+      D( fprintf(stderr, "noip(%d): ignoring unknown socketdir entry `%s'\n",
+		 pid, sun.sun_path); )
       continue;
     }
     if (unix_socket_status(&sun, 0) == STALE) {
-      D( fprintf(stderr, "noip: clearing away stale socket %s\n",
-		 d->d_name); )
+      D( fprintf(stderr, "noip(%d): clearing away stale socket %s\n",
+		 pid, d->d_name); )
       unlink(sun.sun_path);
     }
   }
@@ -1399,7 +1589,9 @@ static void get_local_ipaddrs(void)
   struct ifaddrs *ifa_head, *ifa;
   ipaddr a;
   int i;
+  Dpid;
 
+  D( fprintf(stderr, "noip(%d): fetching local addresses...\n", pid); )
   if (getifaddrs(&ifa_head)) { perror("getifaddrs"); return; }
   for (n_local_ipaddrs = 0, ifa = ifa_head;
        n_local_ipaddrs < MAX_LOCAL_IPADDRS && ifa;
@@ -1408,7 +1600,8 @@ static void get_local_ipaddrs(void)
       continue;
     ipaddr_from_sockaddr(&a, ifa->ifa_addr);
     D({ char buf[ADDRBUFSZ];
-	fprintf(stderr, "noip: local addr %s = %s", ifa->ifa_name,
+	fprintf(stderr, "noip(%d):   local addr %s = %s", pid,
+		ifa->ifa_name,
 		inet_ntop(ifa->ifa_addr->sa_family, &a,
 			  buf, sizeof(buf))); })
     for (i = 0; i < n_local_ipaddrs; i++) {