pf: Add configuration via rc.conf.

rtemsbsd/include/machine/rtems-bsd-config.h

@@ -123,8 +123,11 @@ extern "C" {
  */
 #if defined(RTEMS_BSD_CONFIG_FIREWALL_PF)
   #define RTEMS_BSD_CFGDECL_FIREWALL_PF SYSINIT_NEED_FIREWALL_PF
+  #define RTEMS_BSD_CFGDECL_FIREWALL_PF_SERVICE \
+      RTEMS_BSD_RC_CONF_SYSINT(rc_conf_firewall_pf)
 #else
   #define RTEMS_BSD_CFGDECL_FIREWALL_PF
+  #define RTEMS_BSD_CFGDECL_FIREWALL_PF_SERVICE
 #endif /* RTEMS_BSD_CONFIG_FIREWALL_PF */
 
 #if defined(RTEMS_BSD_CONFIG_FIREWALL_PFLOG)
@@ -192,6 +195,7 @@ extern "C" {
    * Create the firewall
    */
   RTEMS_BSD_CFGDECL_FIREWALL_PF;
+  RTEMS_BSD_CFGDECL_FIREWALL_PF_SERVICE;
   RTEMS_BSD_CFGDECL_FIREWALL_PFLOG;
   RTEMS_BSD_CFGDECL_FIREWALL_PFSYNC;
 

rtemsbsd/include/machine/rtems-bsd-rc-conf-services.h

@@ -155,6 +155,7 @@ extern void rtems_bsd_rc_conf_print_cmd(rtems_bsd_rc_conf* rc_conf,
  * Decls for the handlers.
  */
 void rc_conf_net_init(void* arg);           /* Installed by default. */
+void rc_conf_firewall_pf_init(void* arg);   /* pf_enabled="YES" */
 void rc_conf_telnetd_init(void* arg);       /* telnetd_enabled="YES" */
 void rc_conf_ftpd_init(void* arg);          /* ftpd_enabled="YES" */
 

rtemsbsd/rtems/rtems-bsd-rc-conf-pf.c

@@ -0,0 +1,261 @@
+/*
+ * Copyright (c) 2016 embedded brains GmbH.  All rights reserved.
+ *
+ *  embedded brains GmbH
+ *  Dornierstr. 4
+ *  82178 Puchheim
+ *  Germany
+ *  <rtems@embedded-brains.de>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Handle the PF firewall directives found in rc.conf.
+ * - pf_enable
+ * - pf_rules
+ * - pf_flags
+ *
+ * Note: RTEMS ignores the
+ * - pf_program
+ * directive.
+ */
+
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+#include <machine/rtems-bsd-commands.h>
+#include <machine/rtems-bsd-rc-conf-services.h>
+
+static char firewall_pf_rules_default[] = "/etc/pf.conf";
+
+static int
+firewall_pf_enable(rtems_bsd_rc_conf* rc_conf)
+{
+  char *args[] = {
+    "pfctl",
+    "-q",
+    "-e",
+    NULL
+  };
+
+  rtems_bsd_rc_conf_print_cmd(rc_conf, "pfctl", RTEMS_BSD_ARGC(args),
+      (const char **) args);
+  return rtems_bsd_command_pfctl(RTEMS_BSD_ARGC(args), args);
+}
+
+static int
+firewall_pf_flush(
+    rtems_bsd_rc_conf* rc_conf,
+    char what[])
+{
+  char *flush[] = {
+    "pfctl",
+    "-q",
+    "-F",
+    what,
+    NULL
+  };
+
+  rtems_bsd_rc_conf_print_cmd(rc_conf, "pfctl", RTEMS_BSD_ARGC(flush),
+      (const char **) flush);
+  return rtems_bsd_command_pfctl(RTEMS_BSD_ARGC(flush), flush);
+}
+
+/*
+ * Executes something like the following command line:
+ *   pfctl -f <rules> [<argv[1]> [<argv[2]> [..]]]
+ */
+static int
+firewall_pf_load_rules_with_extra_args(
+    rtems_bsd_rc_conf* rc_conf,
+    char *rules,
+    int argc,
+    const char **argv)
+{
+  char** args;
+  const int fixed_args = 2; /* "-f" and filename */
+  int arg;
+  int r = -1;
+  bool prepare_failed = false;
+
+  /*
+   * argc/argv contains something like the following:
+   *   argc = 3
+   *   argv = {"pf_flags", "-i", "lo0"}
+   *
+   * Alternatively it might be
+   *   argc = 0
+   *   argv = NULL
+   */
+
+  /* The code below assumes an argc >= 1. Fake it if there are no additional
+   * arguments. */
+  if(argc == 0) {
+    argc = 1;
+  }
+
+  args = calloc(argc + fixed_args + 1, sizeof(char*));
+  if (args == NULL) {
+    return -1;
+  }
+
+  args[0] = "pfctl";
+  args[1] = "-f";
+  args[2] = rules;
+  args[argc + fixed_args] = NULL;
+
+  for (arg = 1; arg < argc; ++arg) {
+    args[arg + fixed_args] = strdup(argv[arg]);
+    if (args[arg + fixed_args] == NULL) {
+      prepare_failed = true;
+      break;
+    }
+  }
+
+  if (prepare_failed == false) {
+    rtems_bsd_rc_conf_print_cmd(rc_conf, "pfctl", argc + fixed_args,
+        (const char **) args);
+    r = rtems_bsd_command_pfctl(argc + fixed_args, args);
+  } else {
+    r = EXIT_FAILURE;
+  }
+
+  for (arg = 1; arg < argc; ++arg) {
+    free(args[arg + fixed_args]);
+  }
+  free(args);
+
+  return r;
+}
+
+static int
+firewall_pf_service(rtems_bsd_rc_conf* rc_conf)
+{
+  rtems_bsd_rc_conf_argc_argv* aa;
+  int r;
+  int erroroccured = 0;
+
+  aa = rtems_bsd_rc_conf_argc_argv_create();
+  if (aa == NULL)
+    return -1;
+
+  r = rtems_bsd_rc_conf_find(rc_conf, "pf_enable", aa);
+  if (r == 0) {
+    if (aa->argc == 2 && strcasecmp("YES", aa->argv[1]) == 0) {
+      char* rules = firewall_pf_rules_default;
+      int argc = 0;
+      const char** argv = NULL;
+
+      if (erroroccured == 0) {
+        r = rtems_bsd_rc_conf_find(rc_conf, "pf_rules", aa);
+        if (r == 0) {
+          if (aa->argc == 2) {
+            rules = strdup(aa->argv[1]);
+            if (rules == NULL) {
+              fprintf(stderr,
+                  "error: pf: Could not create rule file string: %s\n",
+                  strerror(errno));
+              erroroccured = -1;
+            }
+          } else {
+            fprintf(stderr,
+                "error: pf: Syntax error in pf_rules directive.\n");
+              erroroccured = -1;
+          }
+        }
+      }
+
+      if (erroroccured == 0) {
+        r = rtems_bsd_rc_conf_find(rc_conf, "pf_flags", aa);
+        if (r == 0) {
+          argc = aa->argc;
+          argv = aa->argv;
+        }
+      }
+
+      /*
+       * FreeBSD does the following on pf_start() in /etc/rc.d/pf:
+       * ----
+       *    check_startmsgs && echo -n 'Enabling pf'
+       *    $pf_program -F all > /dev/null 2>&1
+       *    $pf_program -f "$pf_rules" $pf_flags
+       *    if ! $pf_program -s info | grep -q "Enabled" ; then
+       *        $pf_program -eq
+       *    fi
+       *    check_startmsgs && echo '.'
+       * ----
+       * We should do roughly the same
+       */
+      if (erroroccured == 0) {
+        r = firewall_pf_flush(rc_conf, "all");
+        if(r != EXIT_SUCCESS) {
+          fprintf(stderr,
+              "error: pf: Could not flush.\n");
+          erroroccured = -1;
+        }
+      }
+
+      if (erroroccured == 0) {
+        r = firewall_pf_load_rules_with_extra_args(rc_conf, rules, argc, argv);
+        if (r != EXIT_SUCCESS) {
+          fprintf(stderr,
+              "error: pf: Could not load rules.\n");
+          erroroccured = -1;
+        }
+      }
+
+      if (erroroccured == 0) {
+        r = firewall_pf_enable(rc_conf);
+        if (r != EXIT_SUCCESS) {
+          fprintf(stderr,
+              "error: pf: Could not enable firewall.\n");
+          erroroccured = -1;
+        }
+      }
+
+      if (rules != firewall_pf_rules_default && rules != NULL) {
+        free(rules);
+      }
+    }
+  }
+
+  rtems_bsd_rc_conf_argc_argv_destroy(aa);
+
+  return erroroccured;
+}
+
+void
+rc_conf_firewall_pf_init(void* arg)
+{
+  int r;
+  r = rtems_bsd_rc_conf_service_add("pf",
+                                    "after:network;before:telnetd;",
+                                    firewall_pf_service);
+  if (r < 0)
+    fprintf(stderr,
+            "error: pf service add failed: %s\n", strerror(errno));
+}