dhcpcd: Add hooks

dhcpcd/dhcpcd.c

@@ -1599,3 +1599,17 @@ main(int argc, char **argv)
 	eloop_start(&dhcpcd_sigset);
 	exit(EXIT_SUCCESS);
 }
+#ifdef __rtems__
+int
+dhcpcd_script_runreason_do_nothing(const struct interface *ifp,
+    const char *reason)
+{
+	return 0;
+}
+
+/*
+ * Do not pull in the script support if it is not used, e.g. no call to
+ * rtems_dhcpcd_add_hook() is present.
+ */
+__weak_reference(dhcpcd_script_runreason_do_nothing, dhcpcd_script_runreason);
+#endif /* __rtems__ */

dhcpcd/namespace.h

@@ -156,6 +156,7 @@ extern rtems_recursive_mutex dhcpcd_mutex;
 #define print_string dhcpcd_print_string
 #define read_config dhcpcd_read_config
 #define read_lease dhcpcd_read_lease
+#define script_runreason dhcpcd_script_runreason
 #define select_profile dhcpcd_select_profile
 #define set_cloexec dhcpcd_set_cloexec
 #define set_nonblock dhcpcd_set_nonblock

dhcpcd/script.c

@@ -51,7 +51,30 @@
 #include "ipv6nd.h"
 #include "net.h"
 #include "script.h"
+#ifdef __rtems__
+#include <rtems/dhcpcd.h>
 
+static SLIST_HEAD(, rtems_dhcpcd_hook) dhcpcd_hooks =
+  SLIST_HEAD_INITIALIZER(dhcpcd_hooks);
+
+void
+rtems_dhcpcd_add_hook(rtems_dhcpcd_hook *hook)
+{
+	rtems_recursive_mutex_lock(&dhcpcd_mutex);
+	SLIST_INSERT_HEAD(&dhcpcd_hooks, hook, node);
+	rtems_recursive_mutex_unlock(&dhcpcd_mutex);
+}
+
+void
+rtems_dhcpcd_remove_hook(rtems_dhcpcd_hook *hook)
+{
+	rtems_recursive_mutex_lock(&dhcpcd_mutex);
+	SLIST_REMOVE(&dhcpcd_hooks, hook, rtems_dhcpcd_hook, node);
+	rtems_recursive_mutex_unlock(&dhcpcd_mutex);
+}
+#endif /* __rtems__ */
+
+#ifndef __rtems__
 #define DEFAULT_PATH	"PATH=/usr/bin:/usr/sbin:/bin:/sbin"
 
 static const char * const if_params[] = {
@@ -104,6 +127,7 @@ exec_script(char *const *argv, char *const *env)
 	}
 	return pid;
 }
+#endif /* __rtems__ */
 
 #ifdef INET
 static char *
@@ -168,6 +192,7 @@ append_config(char ***env, ssize_t *len,
 }
 #endif
 
+#ifndef __rtems__
 static size_t
 arraytostr(const char *const *argv, char **s)
 {
@@ -191,6 +216,7 @@ arraytostr(const char *const *argv, char **s)
 	}
 	return len;
 }
+#endif /* __rtems__ */
 
 static ssize_t
 make_env(const struct interface *ifp, const char *reason, char ***argv)
@@ -435,6 +461,7 @@ eexit:
 	return -1;
 }
 
+#ifndef __rtems__
 static int
 send_interface1(int fd, const struct interface *iface, const char *reason)
 {
@@ -507,29 +534,43 @@ send_interface(int fd, const struct interface *iface)
 	}
 	return retval;
 }
+#endif /* __rtems__ */
 
 int
 script_runreason(const struct interface *ifp, const char *reason)
 {
+#ifndef __rtems__
 	char *const argv[2] = { UNCONST(ifp->options->script), NULL };
+#endif /* __rtems__ */
 	char **env = NULL, **ep;
+#ifndef __rtems__
 	char *path, *bigenv;
 	ssize_t e, elen = 0;
 	pid_t pid;
+#else /* __rtems__ */
+	ssize_t elen;
+	rtems_dhcpcd_hook *hook;
+	rtems_dhcpcd_hook *hook2;
+#endif /* __rtems__ */
 	int status = 0;
+#ifndef __rtems__
 	const struct fd_list *fd;
 	struct iovec iov[2];
+#endif /* __rtems__ */
 
 	if (ifp->options->script == NULL ||
 	    ifp->options->script[0] == '\0' ||
 	    strcmp(ifp->options->script, "/dev/null") == 0)
 		return 0;
 
+#ifndef __rtems__
 	syslog(LOG_DEBUG, "%s: executing `%s' %s",
 	    ifp->name, argv[0], reason);
+#endif /* __rtems__ */
 
 	/* Make our env */
 	elen = make_env(ifp, reason, &env);
+#ifndef __rtems__
 	ep = realloc(env, sizeof(char *) * (elen + 2));
 	if (ep == NULL) {
 		elen = -1;
@@ -596,6 +637,17 @@ script_runreason(const struct interface *ifp, const char *reason)
 	free(bigenv);
 
 out:
+#else /* __rtems__ */
+	rtems_recursive_mutex_lock(&dhcpcd_mutex);
+
+	SLIST_FOREACH_SAFE(hook, &dhcpcd_hooks, node, hook2) {
+		syslog(LOG_DEBUG, "%s: executing `%s' %s", ifp->name,
+		    hook->name, reason);
+		(*hook->handler)(hook, env);
+	}
+
+	rtems_recursive_mutex_unlock(&dhcpcd_mutex);
+#endif /* __rtems__ */
 	/* Cleanup */
 	ep = env;
 	while (*ep)

dhcpcd/script.h

@@ -33,16 +33,12 @@
 void if_printoptions(void);
 #ifndef __rtems__
 int send_interface(int, const struct interface *);
-int script_runreason(const struct interface *, const char *);
 #else /* __rtems__ */
 static inline int send_interface(int fd, const struct interface *iface)
 {
 	return 0;
 }
-static inline int script_runreason(const struct interface *ifp, const char *reason)
-{
-	return 0;
-}
 #endif /* __rtems__ */
+int script_runreason(const struct interface *, const char *);
 
 #endif

libbsd.py

@@ -4553,6 +4553,7 @@ class dhcpcd(builder.Module):
                 'dhcpcd/ipv6nd.c',
                 'dhcpcd/net.c',
                 'dhcpcd/platform-bsd.c',
+                'dhcpcd/script.c',
                 'dhcpcd/compat/pselect.c',
                 'dhcpcd/crypt/hmac_md5.c',
             ],

rtemsbsd/include/rtems/dhcpcd.h

@@ -40,6 +40,9 @@
 #ifndef _RTEMS_DHCPCD_H_
 #define _RTEMS_DHCPCD_H_
 
+#include <sys/cdefs.h>
+#include <sys/queue.h>
+
 #include <rtems.h>
 
 #ifdef __cplusplus
@@ -75,6 +78,29 @@ typedef struct rtems_dhcpcd_config {
  */
 rtems_status_code rtems_dhcpcd_start(const rtems_dhcpcd_config *config);
 
+typedef struct rtems_dhcpcd_hook {
+	SLIST_ENTRY(rtems_dhcpcd_hook) node;
+	const char *name;
+	void (*handler)(struct rtems_dhcpcd_hook *hook, char *const *env);
+} rtems_dhcpcd_hook;
+
+/**
+ * @brief Adds a DHCP client hook.
+ *
+ * The hook handler is invoked with an environment list (NULL terminated) of
+ * strings ('\0' terminated).  Each string of the environment list has usually
+ * the format "key=value", e.g. "interface=eth0", "reason=BOUND".
+ *
+ * The hook handler are called by the DHCP client task.  It is safe to
+ * add/remove hooks in the hook handler.
+ */
+void rtems_dhcpcd_add_hook(rtems_dhcpcd_hook *hook);
+
+/**
+ * @brief Removes a DHCP client hook.
+ */
+void rtems_dhcpcd_remove_hook(rtems_dhcpcd_hook *hook);
+
 /** @} */
 
 #ifdef __cplusplus

testsuite/dhcpcd01/test_main.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014 embedded brains GmbH.  All rights reserved.
+ * Copyright (c) 2013, 2018 embedded brains GmbH.  All rights reserved.
  *
  *  embedded brains GmbH
  *  Dornierstr. 4
@@ -30,14 +30,36 @@
  */
 
 #include <assert.h>
+#include <stdio.h>
 
 #include <rtems.h>
+#include <rtems/dhcpcd.h>
 
 #define TEST_NAME "LIBBSD DHCPCD 1"
 
+static void
+dhcpcd_hook_handler(rtems_dhcpcd_hook *hook, char *const *env)
+{
+
+	(void)hook;
+
+	while (*env != NULL) {
+		printf("%s\n", *env);
+		++env;
+	}
+}
+
+static rtems_dhcpcd_hook dhcpcd_hook = {
+	.name = "test",
+	.handler = dhcpcd_hook_handler
+};
+
 static void
 test_main(void)
 {
+
+	rtems_dhcpcd_add_hook(&dhcpcd_hook);
+
 	rtems_task_delete(RTEMS_SELF);
 	assert(0);
 }