add NCAT_LOCAL_ADDR, NCAT_LOCAL_PORT, NCAT_REMOTE_ADDR, NCAR_REMOTE_PORT,

NCAT_REMOTE_ADDR environment variables set in all --*-exec child processes.
(this is a merge of ncat-env-conninfo as of r31516)

ncat/Makefile.in

@@ -135,16 +135,16 @@ config.h:
 		        $(SHELL) ./config.status; \
 	fi
 
-test/addrset: test/addrset.o ncat_core.o sys_wrap.o util.o $(LUA_OBJS)
+test/addrset: test/addrset.o ncat_core.o sys_wrap.o util.o ncat_posix.o $(LUA_OBJS)
 	$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $^ $(LIBS) $(NSOCKLIB) $(NBASELIB) $(OPENSSL_LIBS) $(PCAP_LIBS) $(LUA_LIBS)
 
-test/test-uri: test/test-uri.o base64.o http.o ncat_core.o  sys_wrap.o util.o $(LUA_OBJS)
+test/test-uri: test/test-uri.o base64.o http.o ncat_core.o  sys_wrap.o util.o ncat_posix.o $(LUA_OBJS)
 	$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $^ $(LIBS) $(NSOCKLIB) $(NBASELIB) $(OPENSSL_LIBS) $(PCAP_LIBS) $(LUA_LIBS)
 
 test/test-cmdline-split: test/test-cmdline-split.o ncat_posix.o ncat_core.o sys_wrap.o util.o $(LUA_OBJS)
 	$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $^ $(LIBS) $(NSOCKLIB) $(NBASELIB) $(OPENSSL_LIBS) $(PCAP_LIBS) $(LUA_LIBS)
 
-test/test-wildcard: test/test-wildcard.o ncat_core.o ncat_ssl.o sys_wrap.o util.o $(LUA_OBJS)
+test/test-wildcard: test/test-wildcard.o ncat_core.o ncat_ssl.o sys_wrap.o util.o ncat_posix.o $(LUA_OBJS)
 	$(CC) -o $@ $(CFLAGS) $(LDFLAGS) $^ $(LIBS) $(NSOCKLIB) $(NBASELIB) $(OPENSSL_LIBS) $(PCAP_LIBS) $(LUA_LIBS)
 
 .PHONY: uninstall all clean distclean

ncat/docs/ncat.xml

@@ -462,6 +462,30 @@
           accept a maximum, definable, number of simultaneous connections
           controlled by the <option>-m</option> option. By default this is set
           to 100 (60 on Windows).</para>
+
+          <para>--exec adds the following variables to the child's environment:
+            <itemizedlist>
+
+              <listitem>NCAT_REMOTE_ADDR - the remote address - in connect mode,
+              it's the one we're connecting to, in listen mode - it's the one
+              that connected to us,</listitem>
+
+              <listitem>NCAT_REMOTE_PORT - the remote port number, where "remote"
+              means the same as above,</listitem>
+
+              <listitem>NCAT_LOCAL_ADDR - our local address used for
+              establishing/receiving the connection,</listitem>
+
+              <listitem>NCAT_LOCAL_PORT - our local port number,</listitem>
+
+              <listitem>NCAT_PROTO - the protocol name - TCP, UDP or SCTP,</listitem>
+
+            </itemizedlist>
+          </para>
+
+          <para>Currently the address fields are numeric IP addresses. In IPv6
+          mode, the address might be not expanded.</para>
+
         </listitem>
       </varlistentry>
 
@@ -476,7 +500,9 @@
           <para>Same as <option>-e</option>, except it tries to execute
           the command via <filename>/bin/sh</filename>. This means you don't
           have to specify the full path for the command, and shell facilities
-          like environment variables are available.</para>
+          like environment variables are available. Ncat also sets a few
+          special environment variables (see <option>-e</option> for details).
+          </para>
         </listitem>
       </varlistentry>
 

ncat/ncat_core.c

@@ -511,3 +511,45 @@ static int ncat_hexdump(int logfd, const char *data, int len)
 
     return 1;
 }
+
+void setup_environment(struct fdinfo *info)
+{
+    union sockaddr_u su;
+    char ip[INET6_ADDRSTRLEN];
+    char port[16];
+    socklen_t alen = sizeof(su);
+
+    if (getpeername(info->fd, &su.sockaddr, &alen) != 0) {
+        bye("getpeername failed: %s", socket_strerror(socket_errno()));
+    }
+    if (getnameinfo((struct sockaddr *)&su, alen, ip, sizeof(ip),
+            port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
+        setenv_portable("NCAT_REMOTE_ADDR", ip);
+        setenv_portable("NCAT_REMOTE_PORT", port);
+    } else {
+        bye("getnameinfo failed: %s", socket_strerror(socket_errno()));
+    }
+
+    if (getsockname(info->fd, (struct sockaddr *)&su, &alen) < 0) {
+        bye("getsockname failed: %s", socket_strerror(socket_errno()));
+    }
+    if (getnameinfo((struct sockaddr *)&su, alen, ip, sizeof(ip),
+            port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV) == 0) {
+        setenv_portable("NCAT_LOCAL_ADDR", ip);
+        setenv_portable("NCAT_LOCAL_PORT", port);
+    } else {
+        bye("getnameinfo failed: %s", socket_strerror(socket_errno()));
+    }
+
+    switch(o.proto) {
+        case IPPROTO_TCP:
+            setenv_portable("NCAT_PROTO", "TCP");
+            break;
+        case IPPROTO_SCTP:
+            setenv_portable("NCAT_PROTO", "SCTP");
+            break;
+        case IPPROTO_UDP:
+            setenv_portable("NCAT_PROTO", "UDP");
+            break;
+    }
+}

ncat/ncat_core.h

@@ -230,3 +230,6 @@ extern int ncat_hostaccess(char *matchaddr, char *filename, char *remoteip);
 /* Make it so that line endings read from a console are always \n (not \r\n).
    Defined in ncat_posix.c and ncat_win.c. */
 extern void set_lf_mode(void);
+
+extern int setenv_portable(const char *name, const char *value);
+extern void setup_environment(struct fdinfo *fdinfo);

ncat/ncat_exec_win.c

@@ -195,6 +195,28 @@ extern void set_pseudo_sigchld_handler(void (*handler)(void))
     ncat_assert(rc != 0);
 }
 
+int setenv_portable(const char *name, const char *value)
+{
+    BOOL ret = SetEnvironmentVariable(name, value);
+    if (ret == 0) {
+        DWORD last_error = GetLastError();
+        switch (last_error) {
+            case ERROR_INVALID_PARAMETER:
+                errno = EINVAL;
+                break;
+            case ERROR_NOT_ENOUGH_MEMORY:
+                errno = ENOMEM;
+                break;
+            default:
+                if (o.debug)
+                    logdebug("SetEnvironmentVariable: GetLastError returned %d\n", last_error);
+                errno = EINVAL;
+                break;
+        }
+    }
+    return ret != 0;
+}
+
 /* Run a command and redirect its input and output handles to a pair of
    anonymous pipes.  The process handle and pipe handles are returned in the
    info struct. Returns the PID of the new process, or -1 on error. */
@@ -207,6 +229,8 @@ static int run_command_redirected(char *cmdexec, struct subprocess_info *info)
     STARTUPINFO si;
     PROCESS_INFORMATION pi;
 
+    setup_environment(&info->fdn);
+
     /* Make the pipe handles inheritable. */
     sa.nLength = sizeof(sa);
     sa.bInheritHandle = TRUE;

ncat/ncat_posix.c

@@ -192,6 +192,8 @@ void netexec(struct fdinfo *info, char *cmdexec)
         Dup2(child_stdin[0], STDIN_FILENO);
         Dup2(child_stdout[1], STDOUT_FILENO);
 
+        setup_environment(info);
+
         switch (o.execmode) {
         char **cmdargs;
 
@@ -389,3 +391,8 @@ int ssl_load_default_ca_certs(SSL_CTX *ctx)
     return 0;
 }
 #endif
+
+int setenv_portable(const char *name, const char *value)
+{
+    return setenv(name, value, 1);
+}

ncat/scripts/log_ips.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+LOGFILE="log_ips.log"
+
+MSG="[`date`] Incoming connection from $NCAT_REMOTE_ADDR:$NCAT_REMOTE_PORT"
+
+echo $MSG >&2
+echo $MSG >> $LOGFILE
+
+echo "Yeah, hi."

ncat/scripts/p0fme.py

@@ -0,0 +1,97 @@
+#!/usr/bin/python
+
+from __future__ import print_function  # logging, python2-only.
+
+"""
+A script that reads data generated by p0f -f p0f.log, looking for all entries
+about an IP read from NCAT_REMOTE_ADDR environment variable. Then it prints out
+all the information it has found. To try it out, run "p0f -i any -o p0f.log"
+and ncat -l -k --sh-exec "python p0fme.py".
+
+Script tested under Python versions 2.7 and 3.3.
+"""
+
+P0F_LOG_FILE = "p0f.log"
+
+import datetime  # logging
+import sys  # logging
+import os  # environ
+import time  # sleeping to wait for data
+import sys  # to flush STDOUT
+
+
+def expand_ipv6(ip):
+    """
+    Expands short IPv6 address like ::1 into an expanded form without trailing
+    zeros. Copied from:
+
+    http://svn.python.org/projects/python/tags/r31b1/Lib/ipaddr.py
+
+    (Py3 standard library; added some modifications to match p0f's output data)
+    """
+
+    new_ip = []
+    hextet = ip.split('::')
+    sep = len(hextet[0].split(':')) + len(hextet[1].split(':'))
+    new_ip = hextet[0].split(':')
+
+    for _ in range(8 - sep):
+        new_ip.append('0')
+    new_ip += hextet[1].split(':')
+
+    # Now need to make sure every hextet is 4 lower case characters.
+    # If a hextet is < 4 characters, we've got missing leading 0's.
+    ret_ip = []
+    for hextet in new_ip:
+        if hextet == '':
+                hextet = '0'
+        ret_ip.append(hextet.lower())
+    return ':'.join(ret_ip)
+
+
+def split_by_equals(str_):
+    ret = str_.split('=')
+    return ret[0], ''.join(ret[1:])
+
+if __name__ == "__main__":
+    try:
+        ip = os.environ['NCAT_REMOTE_ADDR']
+        if os.environ['NCAT_PROTO'] != 'TCP':
+            sys.exit("ERROR: This script works for TCP servers only!")
+    except KeyError:
+        sys.exit("ERROR: This script has to be run from inside of Ncat.")
+    print("[%s] Got a request from %s" % (
+        datetime.datetime.now().isoformat(' '), ip), file=sys.stderr)
+
+    print("Hold on, I'm collecting data on you...")
+    sys.stdout.flush()
+    time.sleep(3.0)
+
+    if ':' in ip:  # We need to expand IPv6 addresses in a specific way.
+            ip = expand_ipv6(ip)
+    result = {}
+
+    # Reading the log backward will give us more recent results.
+    for line in reversed(open(P0F_LOG_FILE).readlines()):
+
+        without_date = line.split('] ')
+        if without_date == ['\n']:
+            continue
+        without_date = ''.join(without_date[1:])
+
+        # Create a key-value dictionary out of the '|'-separated substrings.
+        properties = dict(map(split_by_equals, without_date.split('|')))
+
+        if not properties['cli'].startswith(ip):
+            continue  # Not the IP we're looking for, check next one.
+
+        for key in properties:
+            if not key in result or result[key] == '???':
+                result[key] = properties[key]
+
+    if not result:
+        print("Got nothing on you. Try again and I will, though.")
+
+    # Now that we've finished, print out the results.
+    for key in sorted(result):
+        print("%s: %s" % (key, result[key].rstrip()))

ncat/scripts/whatismyip.lua

@@ -0,0 +1,4 @@
+--A "what is my IP" service code. Since most web browsers put up with servers
+--not sending proper HTTP headers, you can simply query the service with it.
+
+print(os.getenv("NCAT_REMOTE_ADDR"))

ncat/test/ncat-test.pl

@@ -381,6 +381,16 @@ sub max_conns_test_tcp_ssl {
 	max_conns_test_multi(["tcp", "tcp ssl"], @_);
 }
 
+sub match_ncat_environment {
+	$_ = shift;
+	return /NCAT_REMOTE_ADDR=.+\n
+			NCAT_REMOTE_PORT=.+\n
+			NCAT_LOCAL_ADDR=.+\n
+			NCAT_LOCAL_PORT=.+\n
+			NCAT_PROTO=.+
+	/x;
+}
+
 # Ignore broken pipe signals that result when trying to read from a terminated
 # client.
 $SIG{PIPE} = "IGNORE";
@@ -1084,6 +1094,35 @@ server_client_test_all "--lua-exec",
 	$resp eq "ABC\n" or die "Client received " . d($resp) . ", not " . d("ABC\n");
 };
 
+# Test environment variables being set for --exec, --sh-exec and --lua-exec.
+
+server_client_test_all "--exec, environment variables",
+["--exec", "/bin/sh test-environment.sh"], [], sub {
+	syswrite($c_in, "abc\n");
+	my $resp = timeout_read($c_out) or die "Read timeout";
+	match_ncat_environment($resp) or die "Client received " . d($resp) . ".";
+};
+
+server_client_test_all "--sh-exec, environment variables",
+["--sh-exec", "sh test-environment.sh"], [], sub {
+	syswrite($c_in, "abc\n");
+	my $resp = timeout_read($c_out) or die "Read timeout";
+	match_ncat_environment($resp) or die "Client received " . d($resp) . ".";
+};
+
+proxy_test "--exec through proxy, environment variables",
+[], [], ["--exec", "/bin/sh test-environment.sh"], sub {
+	my $resp = timeout_read($s_out) or die "Read timeout";
+	match_ncat_environment($resp) or die "Client received " . d($resp) . ".";
+};
+
+server_client_test_all "--lua-exec, environment variables",
+["--lua-exec", "test-environment.lua"], [], sub {
+	syswrite($c_in, "abc\n");
+	my $resp = timeout_read($c_out) or die "Read timeout";
+	match_ncat_environment($resp) or die "Client received " . d($resp) . ".";
+};
+
 # Do a syswrite and then a delay to force separate reads in the subprocess.
 sub delaywrite {
 	my ($handle, $data) = @_;

ncat/test/test-environment.lua

@@ -0,0 +1,9 @@
+#!/usr/bin/lua
+
+--Print the following NCAT_* variables and their values:
+envs = {'REMOTE_ADDR', 'REMOTE_PORT', 'LOCAL_ADDR', 'LOCAL_PORT', 'PROTO'}
+
+for _,v in pairs(envs) do
+    v = 'NCAT_' .. v
+    print(("%s=%s"):format(v, os.getenv(v)))
+end

ncat/test/test-environment.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+# Print the contents of all environment variables set by Ncat.
+
+echo "NCAT_REMOTE_ADDR=$NCAT_REMOTE_ADDR"
+echo "NCAT_REMOTE_PORT=$NCAT_REMOTE_PORT"
+
+echo "NCAT_LOCAL_ADDR=$NCAT_LOCAL_ADDR"
+echo "NCAT_LOCAL_PORT=$NCAT_LOCAL_PORT"
+
+echo "NCAT_PROTO=$NCAT_PROTO"