X-Git-Url: https://git.distorted.org.uk/~mdw/fwd/blobdiff_plain/372a98e2893234a482e59ca32313db1bb86146d7..00e3c0f1bbe99682debd4e34d3d3bd950f8c30cb:/fw.c

diff --git a/fw.c b/fw.c
index fdaf9a5..b0eed70 100644
--- a/fw.c
+++ b/fw.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: fw.c,v 1.10 2001/02/03 20:30:03 mdw Exp $
+ * $Id: fw.c,v 1.14 2003/01/24 20:12:40 mdw Exp $
  *
  * Port forwarding thingy
  *
@@ -29,6 +29,19 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: fw.c,v $
+ * Revision 1.14  2003/01/24 20:12:40  mdw
+ * Correctly cast uid and gid sentinel values.
+ *
+ * Revision 1.13  2002/02/22 23:45:20  mdw
+ * Add option to change the listen(2) parameter.  Receive `fw'-specific
+ * code from `conf.c'.
+ *
+ * Revision 1.12  2002/01/13 14:49:17  mdw
+ * Track @dstr_vputf@ change.
+ *
+ * Revision 1.11  2001/02/03 20:33:26  mdw
+ * Fix flags to be unsigned.
+ *
  * Revision 1.10  2001/02/03 20:30:03  mdw
  * Support re-reading config files on SIGHUP.
  *
@@ -97,8 +110,10 @@
 #include "endpt.h"
 #include "exec.h"
 #include "fattr.h"
+#include "file.h"
 #include "fw.h"
 #include "scan.h"
+#include "socket.h"
 #include "source.h"
 
 /*----- Global variables --------------------------------------------------*/
@@ -120,7 +135,179 @@ static conffile *conffiles = 0;		/* List of configuration files */
 #define FW_QUIET 2u
 #define FW_SET 4u
 
-/*----- Main code ---------------------------------------------------------*/
+/*----- Configuration parsing ---------------------------------------------*/
+
+/* --- @parse@ --- *
+ *
+ * Arguments:	@scanner *sc@ = pointer to scanner definition
+ *
+ * Returns:	---
+ *
+ * Use:		Parses a configuration file from the scanner.
+ */
+
+static source_ops *sources[] =
+  { &xsource_ops, &fsource_ops, &ssource_ops, 0 };
+static target_ops *targets[] =
+  { &xtarget_ops, &ftarget_ops, &starget_ops, 0 };
+
+void parse(scanner *sc)
+{
+  token(sc);
+
+  for (;;) {
+    if (sc->t == CTOK_EOF)
+      break;
+    if (sc->t != CTOK_WORD)
+      error(sc, "parse error, keyword expected");
+
+    /* --- Handle a forwarding request --- */
+
+    if (strcmp(sc->d.buf, "forward") == 0 ||
+	strcmp(sc->d.buf, "fw") == 0 ||
+        strcmp(sc->d.buf, "from") == 0) {
+      source *s;
+      target *t;
+
+      token(sc);
+
+      /* --- Read a source description --- */
+
+      {
+	source_ops **sops;
+
+	/* --- Try to find a source type which understands --- */
+
+	s = 0;
+	for (sops = sources; *sops; sops++) {
+	  if ((s = (*sops)->read(sc)) != 0)
+	    goto found_source;
+	}
+	error(sc, "unknown source name `%s'", sc->d.buf);
+
+	/* --- Read any source-specific options --- */
+
+      found_source:
+	if (sc->t == '{') {
+	  token(sc);
+	  while (sc->t == CTOK_WORD) {
+	    if (!s->ops->option || !s->ops->option(s, sc)) {
+	      error(sc, "unknown %s source option `%s'",
+		    s->ops->name, sc->d.buf);
+	    }
+	    if (sc->t == ';')
+	      token(sc);
+	  }
+	  if (sc->t != '}')
+	    error(sc, "parse error, missing `}'");
+	  token(sc);
+	}
+      }
+
+      /* --- Read a destination description --- */
+
+      if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 ||
+				 strcmp(sc->d.buf, "->") == 0))
+	token(sc);
+
+      {
+	target_ops **tops;
+
+	/* --- Try to find a target which understands --- */
+
+	t = 0;
+	for (tops = targets; *tops; tops++) {
+	  if ((t = (*tops)->read(sc)) != 0)
+	    goto found_target;
+	}
+	error(sc, "unknown target name `%s'", sc->d.buf);
+
+	/* --- Read any target-specific options --- */
+
+      found_target:
+	if (sc->t == '{') {
+	  token(sc);
+	  while (sc->t == CTOK_WORD) {
+	    if (!t->ops->option || !t->ops->option(t, sc)) {
+	      error(sc, "unknown %s target option `%s'",
+		    t->ops->name, sc->d.buf);
+	    }
+	    if (sc->t == ';')
+	      token(sc);
+	  }
+	  if (sc->t != '}')
+	    error(sc, "parse error, `}' expected");
+	  token(sc);
+	}
+      }
+
+      /* --- Combine the source and target --- */
+
+      s->ops->attach(s, sc, t);
+    }
+
+    /* --- Include configuration from a file --- *
+     *
+     * Slightly tricky.  Scan the optional semicolon from the including
+     * stream, not the included one.
+     */
+
+    else if (strcmp(sc->d.buf, "include") == 0) {
+      FILE *fp;
+      dstr d = DSTR_INIT;
+
+      token(sc);
+      conf_name(sc, '/', &d);
+      if ((fp = fopen(d.buf, "r")) == 0)
+	error(sc, "can't include `%s': %s", d.buf, strerror(errno));
+      if (sc->t == ';')
+	token(sc);
+      pushback(sc);
+      scan_push(sc, scan_file(fp, d.buf, 0));
+      token(sc);
+      dstr_destroy(&d);
+      continue;				/* Don't parse a trailing `;' */
+    }
+
+    /* --- Other configuration is handled elsewhere --- */
+
+    else {
+
+      /* --- First try among the sources --- */
+
+      {
+	source_ops **sops;
+
+	for (sops = sources; *sops; sops++) {
+	  if ((*sops)->option && (*sops)->option(0, sc))
+	    goto found_option;
+	}
+      }
+
+      /* --- Then try among the targets --- */
+
+      {
+	target_ops **tops;
+
+	for (tops = targets; *tops; tops++) {
+	  if ((*tops)->option && (*tops)->option(0, sc))
+	    goto found_option;
+	}
+      }
+
+      /* --- Nobody wants the option --- */
+
+      error(sc, "unknown global option or prefix `%s'", sc->d.buf);
+
+    found_option:;
+    }
+
+    if (sc->t == ';')
+      token(sc);
+  }
+}
+
+/*----- General utility functions -----------------------------------------*/
 
 /* --- @fw_log@ --- *
  *
@@ -148,7 +335,7 @@ void fw_log(time_t t, const char *fmt, ...)
   DENSURE(&d, 64);
   d.len += strftime(d.buf, d.sz, "%Y-%m-%d %H:%M:%S ", tm);
   va_start(ap, fmt);
-  dstr_vputf(&d, fmt, ap);
+  dstr_vputf(&d, fmt, &ap);
   va_end(ap);
   if (flags & FW_SYSLOG)
     syslog(LOG_NOTICE, "%s", d.buf);
@@ -263,10 +450,12 @@ static void fw_reload(int n, void *p)
     else
       scan_add(&sc, scan_file(fp, cf->name, 0));
   }
-  conf_parse(&sc);
+  parse(&sc);
   fw_log(-1, "... reload completed OK");
 }
 
+/*----- Startup and options parsing ---------------------------------------*/
+
 /* --- Standard GNU help options --- */
 
 static void version(FILE *fp)
@@ -405,8 +594,11 @@ Exec options\n\
 \n\
 Socket options\n\
 	socket.conn [=] number|unlimited|one-shot\n\
+	socket.listen [=] number\n\
 	socket.logging [=] yes|no\n\
+\n\
 	socket.inet.[allow|deny] [from] address [/ address]\n\
+\n\
 	socket.unix.fattr.*\n\
 ");
 }
@@ -432,9 +624,9 @@ int main(int argc, char *argv[])
   conffile *cf, **cff = &conffiles;
 
 #define f_bogus 1u
-#define	f_file 2u
-#define	f_syslog 4u
-#define	f_fork 8u
+#define f_file 2u
+#define f_syslog 4u
+#define f_fork 8u
 
   /* --- Initialize things --- */
 
@@ -587,7 +779,7 @@ int main(int argc, char *argv[])
 
   /* --- Parse the configuration now gathered --- */
 
-  conf_parse(&sc);
+  parse(&sc);
 
   /* --- Set up some signal handlers --- *
    *
@@ -608,12 +800,12 @@ int main(int argc, char *argv[])
   /* --- Drop privileges --- */
 
 #ifdef HAVE_SETGROUPS
-  if ((dropg != -1 && (setgid(dropg) || setgroups(1, &dropg))) ||
-      (drop != -1 && setuid(drop)))
+  if ((dropg != (gid_t)-1 && (setgid(dropg) || setgroups(1, &dropg))) ||
+      (drop != (uid_t)-1 && setuid(drop)))
     die(1, "couldn't drop privileges: %s", strerror(errno));
 #else
-  if ((dropg != -1 && setgid(dropg)) ||
-      (drop != -1 && setuid(drop)))
+  if ((dropg != (gid_t)-1 && setgid(dropg)) ||
+      (drop != (uid_t)-1 && setuid(drop)))
     die(1, "couldn't drop privileges: %s", strerror(errno));
 #endif