Imported Upstream version 7.20.0

1 files changed, 1056 insertions, 0 deletions

diff --git a/tests/server/sockfilt.c b/tests/server/sockfilt.c
new file mode 100644
index 00000000..48df891e
--- /dev/null
+++ b/tests/server/sockfilt.c
@@ -0,0 +1,1056 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id: sockfilt.c,v 1.68 2010-02-04 17:17:19 yangtse Exp $
+ ***************************************************************************/
+
+/* Purpose
+ *
+ * 1. Accept a TCP connection on a custom port (ipv4 or ipv6), or connect
+ *    to a given (localhost) port.
+ *
+ * 2. Get commands on STDIN. Pass data on to the TCP stream.
+ *    Get data from TCP stream and pass on to STDOUT.
+ *
+ * This program is made to perform all the socket/stream/connection stuff for
+ * the test suite's (perl) FTP server. Previously the perl code did all of
+ * this by its own, but I decided to let this program do the socket layer
+ * because of several things:
+ *
+ * o We want the perl code to work with rather old perl installations, thus
+ *   we cannot use recent perl modules or features.
+ *
+ * o We want IPv6 support for systems that provide it, and doing optional IPv6
+ *   support in perl seems if not impossible so at least awkward.
+ *
+ * o We want FTP-SSL support, which means that a connection that starts with
+ *   plain sockets needs to be able to "go SSL" in the midst. This would also
+ *   require some nasty perl stuff I'd rather avoid.
+ *
+ * (Source originally based on sws.c)
+ */
+
+/*
+ * Signal handling notes for sockfilt
+ * ----------------------------------
+ *
+ * This program is a single-threaded process.
+ *
+ * This program is intended to be highly portable and as such it must be kept as
+ * simple as possible, due to this the only signal handling mechanisms used will
+ * be those of ANSI C, and used only in the most basic form which is good enough
+ * for the purpose of this program.
+ *
+ * For the above reason and the specific needs of this program signals SIGHUP,
+ * SIGPIPE and SIGALRM will be simply ignored on systems where this can be done.
+ * If possible, signals SIGINT and SIGTERM will be handled by this program as an
+ * indication to cleanup and finish execution as soon as possible.  This will be
+ * achieved with a single signal handler 'exit_signal_handler' for both signals.
+ *
+ * The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal
+ * will just set to one the global var 'got_exit_signal' storing in global var
+ * 'exit_signal' the signal that triggered this change.
+ *
+ * Nothing fancy that could introduce problems is used, the program at certain
+ * points in its normal flow checks if var 'got_exit_signal' is set and in case
+ * this is true it just makes its way out of loops and functions in structured
+ * and well behaved manner to achieve proper program cleanup and termination.
+ *
+ * Even with the above mechanism implemented it is worthwile to note that other
+ * signals might still be received, or that there might be systems on which it
+ * is not possible to trap and ignore some of the above signals.  This implies
+ * that for increased portability and reliability the program must be coded as
+ * if no signal was being ignored or handled at all.  Enjoy it!
+ */
+
+#define CURL_NO_OLDIES
+
+#include "setup.h" /* portability help from the lib directory */
+
+#ifdef HAVE_SIGNAL_H
+#include <signal.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+
+#define ENABLE_CURLX_PRINTF
+/* make the curlx header define all printf() functions to use the curlx_*
+   versions instead */
+#include "curlx.h" /* from the private lib dir */
+#include "getpart.h"
+#include "inet_pton.h"
+#include "util.h"
+
+/* include memdebug.h last */
+#include "memdebug.h"
+
+#define DEFAULT_PORT 8999
+
+#ifndef DEFAULT_LOGFILE
+#define DEFAULT_LOGFILE "log/sockfilt.log"
+#endif
+
+const char *serverlogfile = DEFAULT_LOGFILE;
+
+static bool verbose = FALSE;
+#ifdef ENABLE_IPV6
+static bool use_ipv6 = FALSE;
+#endif
+static const char *ipv_inuse = "IPv4";
+static unsigned short port = DEFAULT_PORT;
+static unsigned short connectport = 0; /* if non-zero, we activate this mode */
+
+enum sockmode {
+  PASSIVE_LISTEN,    /* as a server waiting for connections */
+  PASSIVE_CONNECT,   /* as a server, connected to a client */
+  ACTIVE,            /* as a client, connected to a server */
+  ACTIVE_DISCONNECT  /* as a client, disconnected from server */
+};
+
+/* do-nothing macro replacement for systems which lack siginterrupt() */
+
+#ifndef HAVE_SIGINTERRUPT
+#define siginterrupt(x,y) do {} while(0)
+#endif
+
+/* vars used to keep around previous signal handlers */
+
+typedef RETSIGTYPE (*SIGHANDLER_T)(int);
+
+#ifdef SIGHUP
+static SIGHANDLER_T old_sighup_handler  = SIG_ERR;
+#endif
+
+#ifdef SIGPIPE
+static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
+#endif
+
+#ifdef SIGALRM
+static SIGHANDLER_T old_sigalrm_handler = SIG_ERR;
+#endif
+
+#ifdef SIGINT
+static SIGHANDLER_T old_sigint_handler  = SIG_ERR;
+#endif
+
+#ifdef SIGTERM
+static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
+#endif
+
+/* var which if set indicates that the program should finish execution */
+
+SIG_ATOMIC_T got_exit_signal = 0;
+
+/* if next is set indicates the first signal handled in exit_signal_handler */
+
+static volatile int exit_signal = 0;
+
+/* signal handler that will be triggered to indicate that the program
+  should finish its execution in a controlled manner as soon as possible.
+  The first time this is called it will set got_exit_signal to one and
+  store in exit_signal the signal that triggered its execution. */
+
+static RETSIGTYPE exit_signal_handler(int signum)
+{
+  int old_errno = ERRNO;
+  if(got_exit_signal == 0) {
+    got_exit_signal = 1;
+    exit_signal = signum;
+  }
+  (void)signal(signum, exit_signal_handler);
+  SET_ERRNO(old_errno);
+}
+
+static void install_signal_handlers(void)
+{
+#ifdef SIGHUP
+  /* ignore SIGHUP signal */
+  if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR)
+    logmsg("cannot install SIGHUP handler: %s", strerror(ERRNO));
+#endif
+#ifdef SIGPIPE
+  /* ignore SIGPIPE signal */
+  if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR)
+    logmsg("cannot install SIGPIPE handler: %s", strerror(ERRNO));
+#endif
+#ifdef SIGALRM
+  /* ignore SIGALRM signal */
+  if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR)
+    logmsg("cannot install SIGALRM handler: %s", strerror(ERRNO));
+#endif
+#ifdef SIGINT
+  /* handle SIGINT signal with our exit_signal_handler */
+  if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR)
+    logmsg("cannot install SIGINT handler: %s", strerror(ERRNO));
+  else
+    siginterrupt(SIGINT, 1);
+#endif
+#ifdef SIGTERM
+  /* handle SIGTERM signal with our exit_signal_handler */
+  if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR)
+    logmsg("cannot install SIGTERM handler: %s", strerror(ERRNO));
+  else
+    siginterrupt(SIGTERM, 1);
+#endif
+}
+
+static void restore_signal_handlers(void)
+{
+#ifdef SIGHUP
+  if(SIG_ERR != old_sighup_handler)
+    (void)signal(SIGHUP, old_sighup_handler);
+#endif
+#ifdef SIGPIPE
+  if(SIG_ERR != old_sigpipe_handler)
+    (void)signal(SIGPIPE, old_sigpipe_handler);
+#endif
+#ifdef SIGALRM
+  if(SIG_ERR != old_sigalrm_handler)
+    (void)signal(SIGALRM, old_sigalrm_handler);
+#endif
+#ifdef SIGINT
+  if(SIG_ERR != old_sigint_handler)
+    (void)signal(SIGINT, old_sigint_handler);
+#endif
+#ifdef SIGTERM
+  if(SIG_ERR != old_sigterm_handler)
+    (void)signal(SIGTERM, old_sigterm_handler);
+#endif
+}
+
+/*
+ * fullread is a wrapper around the read() function. This will repeat the call
+ * to read() until it actually has read the complete number of bytes indicated
+ * in nbytes or it fails with a condition that cannot be handled with a simple
+ * retry of the read call.
+ */
+
+static ssize_t fullread(int filedes, void *buffer, size_t nbytes)
+{
+  int error;
+  ssize_t rc;
+  ssize_t nread = 0;
+
+  do {
+    rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread);
+
+    if(got_exit_signal) {
+      logmsg("signalled to die");
+      return -1;
+    }
+
+    if(rc < 0) {
+      error = ERRNO;
+      if((error == EINTR) || (error == EAGAIN))
+        continue;
+      logmsg("unrecoverable read() failure: %s", strerror(error));
+      return -1;
+    }
+
+    if(rc == 0) {
+      logmsg("got 0 reading from stdin");
+      return 0;
+    }
+
+    nread += rc;
+
+  } while((size_t)nread < nbytes);
+
+  if(verbose)
+    logmsg("read %zd bytes", nread);
+
+  return nread;
+}
+
+/*
+ * fullwrite is a wrapper around the write() function. This will repeat the
+ * call to write() until it actually has written the complete number of bytes
+ * indicated in nbytes or it fails with a condition that cannot be handled
+ * with a simple retry of the write call.
+ */
+
+static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes)
+{
+  int error;
+  ssize_t wc;
+  ssize_t nwrite = 0;
+
+  do {
+    wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite);
+
+    if(got_exit_signal) {
+      logmsg("signalled to die");
+      return -1;
+    }
+
+    if(wc < 0) {
+      error = ERRNO;
+      if((error == EINTR) || (error == EAGAIN))
+        continue;
+      logmsg("unrecoverable write() failure: %s", strerror(error));
+      return -1;
+    }
+
+    if(wc == 0) {
+      logmsg("put 0 writing to stdout");
+      return 0;
+    }
+
+    nwrite += wc;
+
+  } while((size_t)nwrite < nbytes);
+
+  if(verbose)
+    logmsg("wrote %zd bytes", nwrite);
+
+  return nwrite;
+}
+
+/*
+ * read_stdin tries to read from stdin nbytes into the given buffer. This is a
+ * blocking function that will only return TRUE when nbytes have actually been
+ * read or FALSE when an unrecoverable error has been detected. Failure of this
+ * function is an indication that the sockfilt process should terminate.
+ */
+
+static bool read_stdin(void *buffer, size_t nbytes)
+{
+  ssize_t nread = fullread(fileno(stdin), buffer, nbytes);
+  if(nread != (ssize_t)nbytes) {
+    logmsg("exiting...");
+    return FALSE;
+  }
+  return TRUE;
+}
+
+/*
+ * write_stdout tries to write to stdio nbytes from the given buffer. This is a
+ * blocking function that will only return TRUE when nbytes have actually been
+ * written or FALSE when an unrecoverable error has been detected. Failure of
+ * this function is an indication that the sockfilt process should terminate.
+ */
+
+static bool write_stdout(const void *buffer, size_t nbytes)
+{
+  ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes);
+  if(nwrite != (ssize_t)nbytes) {
+    logmsg("exiting...");
+    return FALSE;
+  }
+  return TRUE;
+}
+
+static void lograw(unsigned char *buffer, ssize_t len)
+{
+  char data[120];
+  ssize_t i;
+  unsigned char *ptr = buffer;
+  char *optr = data;
+  ssize_t width=0;
+
+  for(i=0; i<len; i++) {
+    switch(ptr[i]) {
+    case '\n':
+      sprintf(optr, "\\n");
+      width += 2;
+      optr += 2;
+      break;
+    case '\r':
+      sprintf(optr, "\\r");
+      width += 2;
+      optr += 2;
+      break;
+    default:
+      sprintf(optr, "%c", (ISGRAPH(ptr[i]) || ptr[i]==0x20) ?ptr[i]:'.');
+      width++;
+      optr++;
+      break;
+    }
+
+    if(width>60) {
+      logmsg("'%s'", data);
+      width = 0;
+      optr = data;
+    }
+  }
+  if(width)
+    logmsg("'%s'", data);
+}
+
+/*
+  sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
+
+  if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
+  accept()
+*/
+static bool juggle(curl_socket_t *sockfdp,
+                   curl_socket_t listenfd,
+                   enum sockmode *mode)
+{
+  struct timeval timeout;
+  fd_set fds_read;
+  fd_set fds_write;
+  fd_set fds_err;
+  curl_socket_t sockfd = CURL_SOCKET_BAD;
+  curl_socket_t maxfd = CURL_SOCKET_BAD;
+  ssize_t rc;
+  ssize_t nread_socket;
+  ssize_t bytes_written;
+  ssize_t buffer_len;
+  int error = 0;
+
+ /* 'buffer' is this excessively large only to be able to support things like
+    test 1003 which tests exceedingly large server response lines */
+  unsigned char buffer[17010];
+  char data[16];
+
+  if(got_exit_signal) {
+    logmsg("signalled to die, exiting...");
+    return FALSE;
+  }
+
+#ifdef HAVE_GETPPID
+  /* As a last resort, quit if sockfilt process becomes orphan. Just in case
+     parent ftpserver process has died without killing its sockfilt children */
+  if(getppid() <= 1) {
+    logmsg("process becomes orphan, exiting");
+    return FALSE;
+  }
+#endif
+
+  timeout.tv_sec = 120;
+  timeout.tv_usec = 0;
+
+  FD_ZERO(&fds_read);
+  FD_ZERO(&fds_write);
+  FD_ZERO(&fds_err);
+
+#ifdef USE_WINSOCK
+  /*
+  ** WinSock select() does not support standard file descriptors,
+  ** it can only check SOCKETs. Since this program in its current
+  ** state will not work on WinSock based systems, next line is
+  ** commented out to allow warning-free compilation awaiting the
+  ** day it will be fixed to also run on WinSock systems.
+  */
+#else
+  FD_SET(fileno(stdin), &fds_read);
+#endif
+
+  switch(*mode) {
+
+  case PASSIVE_LISTEN:
+
+    /* server mode */
+    sockfd = listenfd;
+    /* there's always a socket to wait for */
+    FD_SET(sockfd, &fds_read);
+    maxfd = sockfd;
+    break;
+
+  case PASSIVE_CONNECT:
+
+    sockfd = *sockfdp;
+    if(CURL_SOCKET_BAD == sockfd) {
+      /* eeek, we are supposedly connected and then this cannot be -1 ! */
+      logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
+      maxfd = 0; /* stdin */
+    }
+    else {
+      /* there's always a socket to wait for */
+      FD_SET(sockfd, &fds_read);
+      maxfd = sockfd;
+    }
+    break;
+
+  case ACTIVE:
+
+    sockfd = *sockfdp;
+    /* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
+    if(CURL_SOCKET_BAD != sockfd) {
+      FD_SET(sockfd, &fds_read);
+      maxfd = sockfd;
+    }
+    else {
+      logmsg("No socket to read on");
+      maxfd = 0;
+    }
+    break;
+
+  case ACTIVE_DISCONNECT:
+
+    logmsg("disconnected, no socket to read on");
+    maxfd = 0;
+    sockfd = CURL_SOCKET_BAD;
+    break;
+
+  } /* switch(*mode) */
+
+
+  do {
+
+    rc = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
+
+    if(got_exit_signal) {
+      logmsg("signalled to die, exiting...");
+      return FALSE;
+    }
+
+  } while((rc == -1) && ((error = SOCKERRNO) == EINTR));
+
+  if(rc < 0) {
+    logmsg("select() failed with error: (%d) %s",
+           error, strerror(error));
+    return FALSE;
+  }
+
+  if(rc == 0)
+    /* timeout */
+    return TRUE;
+
+
+  if(FD_ISSET(fileno(stdin), &fds_read)) {
+    /* read from stdin, commands/data to be dealt with and possibly passed on
+       to the socket
+
+       protocol:
+
+       4 letter command + LF [mandatory]
+
+       4-digit hexadecimal data length + LF [if the command takes data]
+       data                       [the data being as long as set above]
+
+       Commands:
+
+       DATA - plain pass-thru data
+    */
+
+    if(!read_stdin(buffer, 5))
+      return FALSE;
+
+    logmsg("Received %c%c%c%c (on stdin)",
+           buffer[0], buffer[1], buffer[2], buffer[3] );
+
+    if(!memcmp("PING", buffer, 4)) {
+      /* send reply on stdout, just proving we are alive */
+      if(!write_stdout("PONG\n", 5))
+        return FALSE;
+    }
+
+    else if(!memcmp("PORT", buffer, 4)) {
+      /* Question asking us what PORT number we are listening to.
+         Replies to PORT with "IPv[num]/[port]" */
+      sprintf((char *)buffer, "%s/%hu\n", ipv_inuse, port);
+      buffer_len = (ssize_t)strlen((char *)buffer);
+      snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len);
+      if(!write_stdout(data, 10))
+        return FALSE;
+      if(!write_stdout(buffer, buffer_len))
+        return FALSE;
+    }
+    else if(!memcmp("QUIT", buffer, 4)) {
+      /* just die */
+      logmsg("quits");
+      return FALSE;
+    }
+    else if(!memcmp("DATA", buffer, 4)) {
+      /* data IN => data OUT */
+
+      if(!read_stdin(buffer, 5))
+        return FALSE;
+
+      buffer[5] = '\0';
+
+      buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
+      if (buffer_len > (ssize_t)sizeof(buffer)) {
+        logmsg("ERROR: Buffer size (%zu bytes) too small for data size "
+               "(%zd bytes)", sizeof(buffer), buffer_len);
+        return FALSE;
+      }
+      logmsg("> %zd bytes data, server => client", buffer_len);
+
+      if(!read_stdin(buffer, buffer_len))
+        return FALSE;
+
+      lograw(buffer, buffer_len);
+
+      if(*mode == PASSIVE_LISTEN) {
+        logmsg("*** We are disconnected!");
+        if(!write_stdout("DISC\n", 5))
+          return FALSE;
+      }
+      else {
+        /* send away on the socket */
+        bytes_written = swrite(sockfd, buffer, buffer_len);
+        if(bytes_written != buffer_len) {
+          logmsg("Not all data was sent. Bytes to send: %zd sent: %zd",
+                 buffer_len, bytes_written);
+        }
+      }
+    }
+    else if(!memcmp("DISC", buffer, 4)) {
+      /* disconnect! */
+      if(!write_stdout("DISC\n", 5))
+        return FALSE;
+      if(sockfd != CURL_SOCKET_BAD) {
+        logmsg("====> Client forcibly disconnected");
+        sclose(sockfd);
+        *sockfdp = CURL_SOCKET_BAD;
+        if(*mode == PASSIVE_CONNECT)
+          *mode = PASSIVE_LISTEN;
+        else
+          *mode = ACTIVE_DISCONNECT;
+      }
+      else
+        logmsg("attempt to close already dead connection");
+      return TRUE;
+    }
+  }
+
+
+  if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
+
+    if(*mode == PASSIVE_LISTEN) {
+      /* there's no stream set up yet, this is an indication that there's a
+         client connecting. */
+      sockfd = accept(sockfd, NULL, NULL);
+      if(CURL_SOCKET_BAD == sockfd)
+        logmsg("accept() failed");
+      else {
+        logmsg("====> Client connect");
+        if(!write_stdout("CNCT\n", 5))
+          return FALSE;
+        *sockfdp = sockfd; /* store the new socket */
+        *mode = PASSIVE_CONNECT; /* we have connected */
+      }
+      return TRUE;
+    }
+
+    /* read from socket, pass on data to stdout */
+    nread_socket = sread(sockfd, buffer, sizeof(buffer));
+
+    if(nread_socket <= 0) {
+      logmsg("====> Client disconnect");
+      if(!write_stdout("DISC\n", 5))
+        return FALSE;
+      sclose(sockfd);
+      *sockfdp = CURL_SOCKET_BAD;
+      if(*mode == PASSIVE_CONNECT)
+        *mode = PASSIVE_LISTEN;
+      else
+        *mode = ACTIVE_DISCONNECT;
+      return TRUE;
+    }
+
+    snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
+    if(!write_stdout(data, 10))
+      return FALSE;
+    if(!write_stdout(buffer, nread_socket))
+      return FALSE;
+
+    logmsg("< %zd bytes data, client => server", nread_socket);
+    lograw(buffer, nread_socket);
+  }
+
+  return TRUE;
+}
+
+static curl_socket_t sockdaemon(curl_socket_t sock,
+                                unsigned short *listenport)
+{
+  /* passive daemon style */
+  struct sockaddr_in me;
+#ifdef ENABLE_IPV6
+  struct sockaddr_in6 me6;
+#endif /* ENABLE_IPV6 */
+  int flag;
+  int rc;
+  int totdelay = 0;
+  int maxretr = 10;
+  int delay= 20;
+  int attempt = 0;
+  int error = 0;
+
+  do {
+    attempt++;
+    flag = 1;
+    rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+         (void *)&flag, sizeof(flag));
+    if(rc) {
+      error = SOCKERRNO;
+      logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
+             error, strerror(error));
+      if(maxretr) {
+        rc = wait_ms(delay);
+        if(rc) {
+          /* should not happen */
+          error = SOCKERRNO;
+          logmsg("wait_ms() failed with error: (%d) %s",
+                 error, strerror(error));
+          sclose(sock);
+          return CURL_SOCKET_BAD;
+        }
+        if(got_exit_signal) {
+          logmsg("signalled to die, exiting...");
+          sclose(sock);
+          return CURL_SOCKET_BAD;
+        }
+        totdelay += delay;
+        delay *= 2; /* double the sleep for next attempt */
+      }
+    }
+  } while(rc && maxretr--);
+
+  if(rc) {
+    logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
+           attempt, totdelay, error, strerror(error));
+    logmsg("Continuing anyway...");
+  }
+
+  /* When the specified listener port is zero, it is actually a
+     request to let the system choose a non-zero available port. */
+
+#ifdef ENABLE_IPV6
+  if(!use_ipv6) {
+#endif
+    memset(&me, 0, sizeof(me));
+    me.sin_family = AF_INET;
+    me.sin_addr.s_addr = INADDR_ANY;
+    me.sin_port = htons(*listenport);
+    rc = bind(sock, (struct sockaddr *) &me, sizeof(me));
+#ifdef ENABLE_IPV6
+  }
+  else {
+    memset(&me6, 0, sizeof(me6));
+    me6.sin6_family = AF_INET6;
+    me6.sin6_addr = in6addr_any;
+    me6.sin6_port = htons(*listenport);
+    rc = bind(sock, (struct sockaddr *) &me6, sizeof(me6));
+  }
+#endif /* ENABLE_IPV6 */
+  if(rc) {
+    error = SOCKERRNO;
+    logmsg("Error binding socket on port %hu: (%d) %s",
+           *listenport, error, strerror(error));
+    sclose(sock);
+    return CURL_SOCKET_BAD;
+  }
+
+  if(!*listenport) {
+    /* The system was supposed to choose a port number, figure out which
+       port we actually got and update the listener port value with it. */
+    curl_socklen_t la_size;
+    struct sockaddr *localaddr;
+    struct sockaddr_in localaddr4;
+#ifdef ENABLE_IPV6
+    struct sockaddr_in6 localaddr6;
+    if(!use_ipv6) {
+#endif
+      la_size = sizeof(localaddr4);
+      localaddr = (struct sockaddr *)&localaddr4;
+#ifdef ENABLE_IPV6
+    }
+    else {
+      la_size = sizeof(localaddr6);
+      localaddr = (struct sockaddr *)&localaddr6;
+    }
+#endif
+    memset(localaddr, 0, (size_t)la_size);
+    if(getsockname(sock, localaddr, &la_size) < 0) {
+      error = SOCKERRNO;
+      logmsg("getsockname() failed with error: (%d) %s",
+             error, strerror(error));
+      sclose(sock);
+      return CURL_SOCKET_BAD;
+    }
+    switch (localaddr->sa_family) {
+    case AF_INET:
+      *listenport = ntohs(localaddr4.sin_port);
+      break;
+#ifdef ENABLE_IPV6
+    case AF_INET6:
+      *listenport = ntohs(localaddr6.sin6_port);
+      break;
+#endif
+    default:
+      break;
+    }
+    if(!*listenport) {
+      /* Real failure, listener port shall not be zero beyond this point. */
+      logmsg("Apparently getsockname() succeeded, with listener port zero.");
+      logmsg("A valid reason for this failure is a binary built without");
+      logmsg("proper network library linkage. This might not be the only");
+      logmsg("reason, but double check it before anything else.");
+      sclose(sock);
+      return CURL_SOCKET_BAD;
+    }
+  }
+
+  /* start accepting connections */
+  rc = listen(sock, 5);
+  if(0 != rc) {
+    error = SOCKERRNO;
+    logmsg("listen() failed with error: (%d) %s",
+           error, strerror(error));
+    sclose(sock);
+    return CURL_SOCKET_BAD;
+  }
+
+  return sock;
+}
+
+
+int main(int argc, char *argv[])
+{
+  struct sockaddr_in me;
+#ifdef ENABLE_IPV6
+  struct sockaddr_in6 me6;
+#endif /* ENABLE_IPV6 */
+  curl_socket_t sock = CURL_SOCKET_BAD;
+  curl_socket_t msgsock = CURL_SOCKET_BAD;
+  int wrotepidfile = 0;
+  char *pidname= (char *)".sockfilt.pid";
+  bool juggle_again;
+  int rc;
+  int error;
+  int arg=1;
+  enum sockmode mode = PASSIVE_LISTEN; /* default */
+  const char *addr = NULL;
+
+  while(argc>arg) {
+    if(!strcmp("--version", argv[arg])) {
+      printf("sockfilt IPv4%s\n",
+#ifdef ENABLE_IPV6
+             "/IPv6"
+#else
+             ""
+#endif
+             );
+      return 0;
+    }
+    else if(!strcmp("--verbose", argv[arg])) {
+      verbose = TRUE;
+      arg++;
+    }
+    else if(!strcmp("--pidfile", argv[arg])) {
+      arg++;
+      if(argc>arg)
+        pidname = argv[arg++];
+    }
+    else if(!strcmp("--logfile", argv[arg])) {
+      arg++;
+      if(argc>arg)
+        serverlogfile = argv[arg++];
+    }
+    else if(!strcmp("--ipv6", argv[arg])) {
+#ifdef ENABLE_IPV6
+      ipv_inuse = "IPv6";
+      use_ipv6 = TRUE;
+#endif
+      arg++;
+    }
+    else if(!strcmp("--ipv4", argv[arg])) {
+      /* for completeness, we support this option as well */
+#ifdef ENABLE_IPV6
+      ipv_inuse = "IPv4";
+      use_ipv6 = FALSE;
+#endif
+      arg++;
+    }
+    else if(!strcmp("--port", argv[arg])) {
+      arg++;
+      if(argc>arg) {
+        char *endptr;
+        long lnum = -1;
+        lnum = strtol(argv[arg], &endptr, 10);
+        if((endptr != argv[arg] + strlen(argv[arg])) ||
+           ((lnum != 0L) && ((lnum < 1025L) || (lnum > 65535L)))) {
+          fprintf(stderr, "sockfilt: invalid --port argument (%s)\n",
+                  argv[arg]);
+          return 0;
+        }
+        port = (unsigned short)(lnum & 0xFFFFL);
+        arg++;
+      }
+    }
+    else if(!strcmp("--connect", argv[arg])) {
+      /* Asked to actively connect to the specified local port instead of
+         doing a passive server-style listening. */
+      arg++;
+      if(argc>arg) {
+        char *endptr;
+        long lnum = -1;
+        lnum = strtol(argv[arg], &endptr, 10);
+        if((endptr != argv[arg] + strlen(argv[arg])) ||
+           (lnum < 1025L) || (lnum > 65535L)) {
+          fprintf(stderr, "sockfilt: invalid --connect argument (%s)\n",
+                  argv[arg]);
+          return 0;
+        }
+        connectport = (unsigned short)(lnum & 0xFFFFL);
+        arg++;
+      }
+    }
+    else if(!strcmp("--addr", argv[arg])) {
+      /* Set an IP address to use with --connect; otherwise use localhost */
+      arg++;
+      if(argc>arg) {
+        addr = argv[arg];
+        arg++;
+      }
+    }
+    else {
+      puts("Usage: sockfilt [option]\n"
+           " --version\n"
+           " --verbose\n"
+           " --logfile [file]\n"
+           " --pidfile [file]\n"
+           " --ipv4\n"
+           " --ipv6\n"
+           " --port [port]\n"
+           " --connect [port]\n"
+           " --addr [address]");
+      return 0;
+    }
+  }
+
+#ifdef WIN32
+  win32_init();
+  atexit(win32_cleanup);
+#endif
+
+  install_signal_handlers();
+
+#ifdef ENABLE_IPV6
+  if(!use_ipv6)
+#endif
+    sock = socket(AF_INET, SOCK_STREAM, 0);
+#ifdef ENABLE_IPV6
+  else
+    sock = socket(AF_INET6, SOCK_STREAM, 0);
+#endif
+
+  if(CURL_SOCKET_BAD == sock) {
+    error = SOCKERRNO;
+    logmsg("Error creating socket: (%d) %s",
+           error, strerror(error));
+    goto sockfilt_cleanup;
+  }
+
+  if(connectport) {
+    /* Active mode, we should connect to the given port number */
+    mode = ACTIVE;
+#ifdef ENABLE_IPV6
+    if(!use_ipv6) {
+#endif
+      memset(&me, 0, sizeof(me));
+      me.sin_family = AF_INET;
+      me.sin_port = htons(connectport);
+      me.sin_addr.s_addr = INADDR_ANY;
+      if (!addr)
+        addr = "127.0.0.1";
+      Curl_inet_pton(AF_INET, addr, &me.sin_addr);
+
+      rc = connect(sock, (struct sockaddr *) &me, sizeof(me));
+#ifdef ENABLE_IPV6
+    }
+    else {
+      memset(&me6, 0, sizeof(me6));
+      me6.sin6_family = AF_INET6;
+      me6.sin6_port = htons(connectport);
+      if (!addr)
+        addr = "::1";
+      Curl_inet_pton(AF_INET6, addr, &me6.sin6_addr);
+
+      rc = connect(sock, (struct sockaddr *) &me6, sizeof(me6));
+    }
+#endif /* ENABLE_IPV6 */
+    if(rc) {
+      error = SOCKERRNO;
+      logmsg("Error connecting to port %hu: (%d) %s",
+             connectport, error, strerror(error));
+      goto sockfilt_cleanup;
+    }
+    logmsg("====> Client connect");
+    msgsock = sock; /* use this as stream */
+  }
+  else {
+    /* passive daemon style */
+    sock = sockdaemon(sock, &port);
+    if(CURL_SOCKET_BAD == sock)
+      goto sockfilt_cleanup;
+    msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
+  }
+
+  logmsg("Running %s version", ipv_inuse);
+
+  if(connectport)
+    logmsg("Connected to port %hu", connectport);
+  else
+    logmsg("Listening on port %hu", port);
+
+  wrotepidfile = write_pidfile(pidname);
+  if(!wrotepidfile)
+    goto sockfilt_cleanup;
+
+  do {
+    juggle_again = juggle(&msgsock, sock, &mode);
+  } while(juggle_again);
+
+sockfilt_cleanup:
+
+  if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
+    sclose(msgsock);
+
+  if(sock != CURL_SOCKET_BAD)
+    sclose(sock);
+
+  if(wrotepidfile)
+    unlink(pidname);
+
+  restore_signal_handlers();
+
+  if(got_exit_signal) {
+    logmsg("============> sockfilt exits with signal (%d)", exit_signal);
+    /*
+     * To properly set the return status of the process we
+     * must raise the same signal SIGINT or SIGTERM that we
+     * caught and let the old handler take care of it.
+     */
+    raise(exit_signal);
+  }
+
+  logmsg("============> sockfilt quits");
+  return 0;
+}
+