/* -*-c-*-
*
- * $Id: fw.c,v 1.2 1999/07/03 13:55:17 mdw Exp $
+ * $Id: fw.c,v 1.3 1999/07/26 23:30:42 mdw Exp $
*
* Port forwarding thingy
*
- * (c) 1999 Mark Wooding
+ * (c) 1999 Straylight/Edgeware
*/
/*----- Licensing notice --------------------------------------------------*
/*----- Revision history --------------------------------------------------*
*
* $Log: fw.c,v $
+ * Revision 1.3 1999/07/26 23:30:42 mdw
+ * Major reconstruction work for new design.
+ *
* Revision 1.2 1999/07/03 13:55:17 mdw
* Various changes. Add configuration grammar to help text. Change to
* root directory and open syslog when forking into background.
#include <ctype.h>
#include <errno.h>
+#include <signal.h>
+#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <time.h>
#include <unistd.h>
#include <syslog.h>
+#include <mLib/dstr.h>
#include <mLib/mdwopt.h>
#include <mLib/quis.h>
#include <mLib/report.h>
#include <mLib/sel.h>
+#include <mLib/sig.h>
#include <mLib/sub.h>
-#include "acl.h"
#include "bres.h"
#include "conf.h"
+#include "endpt.h"
+#include "exec.h"
+#include "fattr.h"
#include "fw.h"
-#include "listener.h"
#include "scan.h"
+#include "source.h"
/*----- Global variables --------------------------------------------------*/
sel_state *sel; /* Multiplexor for nonblocking I/O */
-unsigned flags = 0; /* Global state flags */
+
+/*----- Static variables --------------------------------------------------*/
+
+static unsigned flags = 0; /* Global state flags */
+static unsigned active = 0; /* Number of active things */
+
+#define FW_SYSLOG 1u
+#define FW_QUIET 2u
+#define FW_SET 4u
/*----- Main code ---------------------------------------------------------*/
+/* --- @fw_log@ --- *
+ *
+ * Arguments: @time_t t@ = when the connection occurred or (@-1@)
+ * @const char *fmt@ = format string to fill in
+ * @...@ = other arguments
+ *
+ * Returns: ---
+ *
+ * Use: Logs a connection.
+ */
+
+void fw_log(time_t t, const char *fmt, ...)
+{
+ struct tm *tm;
+ dstr d = DSTR_INIT;
+ va_list ap;
+
+ if (flags & FW_QUIET)
+ return;
+
+ if (t == -1)
+ t = time(0);
+ tm = localtime(&t);
+ DENSURE(&d, 64);
+ d.len += strftime(d.buf, d.sz, "%Y-%m-%d %H:%M:%S", tm);
+ DPUTC(&d, ' ');
+ va_start(ap, fmt);
+ dstr_vputf(&d, fmt, ap);
+ va_end(ap);
+ if (flags & FW_SYSLOG)
+ syslog(LOG_NOTICE, "%s", d.buf);
+ else {
+ DPUTC(&d, '\n');
+ dstr_write(&d, stderr);
+ }
+ DDESTROY(&d);
+}
+
+/* --- @fw_inc@, @fw_dec@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Increments or decrements the active thing count. `fw' won't
+ * quit while there are active things.
+ */
+
+void fw_inc(void) { flags |= FW_SET; active++; }
+void fw_dec(void) { if (active) active--; }
+
+/* --- @fw_exit@ --- *
+ *
+ * Arguments: ---
+ *
+ * Returns: ---
+ *
+ * Use: Exits when appropriate.
+ */
+
+static void fw_exit(void)
+{
+ endpt_killall();
+ source_killall();
+}
+
+/* --- @fw_tidy@ --- *
+ *
+ * Arguments: @int n@ = signal number
+ * @void *p@ = an uninteresting argument
+ *
+ * Returns: ---
+ *
+ * Use: Handles various signals and causes a clean tidy-up.
+ */
+
+static void fw_tidy(int n, void *p)
+{
+ const char *sn = "unexpected signal (bug!)";
+ if (n == SIGTERM)
+ sn = "SIGTERM";
+ else if (n == SIGINT)
+ sn = "SIGINT";
+
+ fw_log(-1, "closing down on %s", sn);
+ fw_exit();
+}
+
/* --- Standard GNU help options --- */
static void version(FILE *fp)
fputc('\n', fp);
usage(fp);
fputs("\n\
-A fairly full-featured port-forwarder. Options available are:\n\
+An excessively full-featured port-forwarder, which subsumes large chunks\n\
+of the functionality of inetd, netcat, and normal cat. Options available\n\
+are:\n\
\n\
-h, --help Display this help message.\n\
-v, --version Display the program's version number.\n\
-u, --usage Display a terse usage summary.\n\
\n\
-f, --file=FILE Read configuration from a file.\n\
--d, --dump Dump the configuration to standard output.\n\
--b, --background Fork into background after initializing.\n\
+-d, --daemon Fork into background after initializing.\n\
\n\
Configuration may be supplied in one or more configuration files, or on\n\
the command line (or both). If no `-f' option is present, and no\n\
\n\
Configuration is free-form. Comments begin with a `#' character and\n\
continue to the end of the line. Each command line argument is considered\n\
-to be a separate line. The syntax is as follows:\n\
+to be a separate line.\n\
\n\
-config : stmt...\n\
-stmt : fwd-stmt | acl-stmt\n\
-fwd-stmt : `forward' [`port'] port [`to'] addr [`:'] port [fwd-attr] [`;']\n\
-fwd-attr : `{' acl-stmt... `}'\n\
-acl-stmt : (`allow' | `deny') [`from'] addr [`/' mask] [`;']\n\
+The syntax is too complicated to describe here. Read the manual.\n\
", fp);
}
{
unsigned f = 0;
sel_state sst;
+ sig s_term, s_int;
+ scanner sc;
enum {
f_bogus = 1,
f_file = 2,
- f_dump = 4,
f_fork = 8
};
sel = &sst;
sel_init(sel);
sub_init();
+ sig_init(sel);
bres_init(sel);
+ exec_init();
+ fattr_init(&fattr_global);
+ scan_create(&sc);
+
+ /* --- Set up some signal handlers --- */
+
+ sig_add(&s_term, SIGTERM, fw_tidy, 0);
+ sig_add(&s_int, SIGINT, fw_tidy, 0);
+ atexit(fw_exit);
/* --- Parse command line options --- */
/* --- Other useful arguments --- */
{ "file", OPTF_ARGREQ, 0, 'f' },
- { "dump", 0, 0, 'd' },
- { "fork", 0, 0, 'b' },
- { "background", 0, 0, 'b' },
+ { "fork", 0, 0, 'd' },
+ { "daemon", 0, 0, 'd' },
+ { "quiet", 0, 0, 'q' },
/* --- Magic terminator --- */
{ 0, 0, 0, 0 }
};
- int i = mdwopt(argc, argv, "hvu f:db", opts, 0, 0, 0);
+ int i = mdwopt(argc, argv, "+hvu f:d", opts, 0, 0, 0);
if (i < 0)
break;
usage(stdout);
exit(0);
break;
- case 'f': {
- scan_filectx ctx;
- FILE *fp;
- if ((fp = fopen(optarg, "r")) == 0)
- die(1, "couldn't open file `%s': %s", optarg, strerror(errno));
- scan_fileinit(&ctx, fp, optarg);
- conf_parse(&ctx);
- fclose(fp);
+ case 'f':
+ if (strcmp(optarg, "-") == 0)
+ scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE));
+ else {
+ FILE *fp;
+ if ((fp = fopen(optarg, "r")) == 0)
+ die(1, "couldn't open file `%s': %s", optarg, strerror(errno));
+ scan_add(&sc, scan_file(fp, optarg, 0));
+ }
f |= f_file;
- } break;
- case 'd':
- f |= f_dump;
break;
- case 'b':
+ case 'd':
f |= f_fork;
break;
+ case 'q':
+ flags |= FW_QUIET;
+ break;
default:
f |= f_bogus;
break;
/* --- Deal with the remaining arguments --- */
- if (optind == argc) {
- if (f & f_file)
- /* Cool */;
- else if (isatty(STDIN_FILENO)) {
- moan("no configuration given and stdin is a terminal.");
- moan("type `%s --help' for usage information.", QUIS);
- exit(1);
- } else {
- scan_filectx ctx;
- scan_fileinit(&ctx, stdin, "<stdin>");
- conf_parse(&ctx);
- }
- } else {
- scan_argvctx ctx;
- scan_argvinit(&ctx, argv + optind);
- conf_parse(&ctx);
+ if (optind < argc)
+ scan_add(&sc, scan_argv(argv + optind));
+ else if (f & f_file)
+ /* Cool */;
+ else if (!isatty(STDIN_FILENO))
+ scan_add(&sc, scan_file(stdin, "<stdin>", SCF_NOCLOSE));
+ else {
+ moan("no configuration given and stdin is a terminal.");
+ moan("type `%s --help' for usage information.", QUIS);
+ exit(1);
}
- /* --- Dump out the state --- */
+ /* --- Parse the configuration now gathered --- */
- if (f & f_dump) {
- sel_file *s;
- fputs("global acl:\n", stdout);
- acl_dump(0, stdout);
- for (s = sel->files; s; s = s->next)
- listener_dump((listener *)s, stdout);
- exit(0);
- }
+ conf_parse(&sc);
/* --- Fork into the background --- */
/* --- Let rip --- */
- for (;;)
+ if (!(flags & FW_SET))
+ moan("nothing to do!");
+ signal(SIGPIPE, SIG_IGN);
+ while (active)
sel_select(sel);
return (0);
}