Fix #130: add support for IPv6 (*,G) cache flushing

The code base has now been sufficiently refactored to share the same
code paths for (*,G) cache handling between IPv4 and IPv6.

Test available in test/expire.sh

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/mroute.c

@@ -41,7 +41,7 @@
 #include "util.h"
 
 /*
- * Cache flush timeout, used only for IPv4 (*,G) atm.
+ * Cache flush timeout, used for learned S in (*,G) that stop xmit
  */
 static int cache_timeout = 0;
 
@@ -62,7 +62,6 @@ LIST_HEAD(, mroute) mroute_asm_kern_list = LIST_HEAD_INITIALIZER();
  */
 LIST_HEAD(, mroute) mroute_ssm_list = LIST_HEAD_INITIALIZER();
 
-static void mroute4_dyn_expire (int max_idle);
 static int mroute4_add_vif (struct iface *iface);
 static int mroute_dyn_add (struct mroute *route);
 static int is_match (struct mroute *rule, struct mroute *cand);
@@ -155,12 +154,12 @@ static void handle_nocache4(int sd, void *arg)
  }
 }
 
-static void cache4_flush(void *arg)
+static void cache_flush(void *arg)
 {
  (void)arg;
 
  smclog(LOG_INFO, "Cache timeout, flushing unused IPv4 (*,G) routes!");
- mroute4_dyn_expire(cache_timeout);
+ mroute_expire(cache_timeout);
 }
 
 /**
@@ -172,10 +171,9 @@ static void cache4_flush(void *arg)
  * Returns:
  * POSIX OK(0) on success, non-zero on error with @errno set.
  */
-int mroute4_enable(int do_vifs, int table_id, int timeout)
+static int mroute4_enable(int do_vifs, int table_id)
 {
  struct iface *iface;
- static int running = 0;
 
  if (kern_mroute_init(table_id, handle_nocache4, NULL)) {
  switch (errno) {
@@ -212,12 +210,6 @@ int mroute4_enable(int do_vifs, int table_id, int timeout)
  mroute4_add_vif(iface);
  }
 
- if (timeout && !running) {
- running++;
- cache_timeout = timeout;
- timer_add(timeout, cache4_flush, NULL);
- }
-
  return 0;
 }
 
@@ -385,7 +377,7 @@ static int is_active(struct mroute *route)
  * Get valid packet usage statistics (i.e. number of actually forwarded
  * packets) from the kernel for an installed MFC entry
  */
-static unsigned long get_valid_pkt4(struct mroute *route)
+static unsigned long get_valid_pkt(struct mroute *route)
 {
  struct mroute_stats ms = { 0 };
 
@@ -396,7 +388,7 @@ static unsigned long get_valid_pkt4(struct mroute *route)
 }
 
 /**
- * mroute4_dyn_expire - Expire dynamically added (*,G) routes
+ * mroute_expire - Expire dynamically added (*,G) routes
  * @max_idle: Timeout for routes in seconds, 0 to expire all dynamic routes
  *
  * This function flushes all (*,G) routes which haven't been used (i.e. no
@@ -405,7 +397,7 @@ static unsigned long get_valid_pkt4(struct mroute *route)
  * The latter is useful in case of topology changes (e.g. VRRP fail-over)
  * or similar.
  */
-static void mroute4_dyn_expire(int max_idle)
+void mroute_expire(int max_idle)
 {
  struct mroute *entry, *tmp;
  struct timespec now;
@@ -416,13 +408,13 @@ static void mroute4_dyn_expire(int max_idle)
  if (!entry->last_use) {
  /* New entry */
  entry->last_use = now.tv_sec;
- entry->valid_pkt = get_valid_pkt4(entry);
+ entry->valid_pkt = get_valid_pkt(entry);
  }
 
  if (entry->last_use + max_idle <= now.tv_sec) {
  unsigned long valid_pkt;
 
- valid_pkt = get_valid_pkt4(entry);
+ valid_pkt = get_valid_pkt(entry);
  if (valid_pkt != entry->valid_pkt) {
  /* Used since last check, update */
  entry->last_use = now.tv_sec;
@@ -779,7 +771,7 @@ static void handle_nocache6(int sd, void *arg)
  * Returns:
  * POSIX OK(0) on success, non-zero on error with @errno set.
  */
-int mroute6_enable(int do_vifs, int table_id)
+static int mroute6_enable(int do_vifs, int table_id)
 {
 #ifndef HAVE_IPV6_MULTICAST_ROUTING
  (void)do_vifs;
@@ -1009,11 +1001,19 @@ static int mroute_dyn_add(struct mroute *route)
 
 int mroute_init(int do_vifs, int table_id, int cache_tmo)
 {
+ static int running = 0;
+
  LIST_INIT(&mroute_asm_conf_list);
  LIST_INIT(&mroute_asm_kern_list);
  LIST_INIT(&mroute_ssm_list);
 
- return mroute4_enable(do_vifs, table_id, cache_tmo) ||
+ if (cache_tmo > 0 && !running) {
+ running++;
+ cache_timeout = cache_tmo;
+ timer_add(cache_tmo, cache_flush, NULL);
+ }
+
+ return mroute4_enable(do_vifs, table_id) ||
  mroute6_enable(do_vifs, table_id);
 }
 
@@ -1069,11 +1069,6 @@ int mroute_del_vif(char *ifname)
  return ret;
 }
 
-void mroute_expire(int max_idle)
-{
- mroute4_dyn_expire(max_idle);
-}
-
 /*
  * Called on SIGHUP/reload. Mark all known configured routes as
  * 'unused', let mroute*_add() unmark and mroute_reload_end() take