From 39e8956d056b6b3cb886cdc2ff7eae8b07b53fcc Mon Sep 17 00:00:00 2001
From: David Härdeman <david@hardeman.nu>
Date: Mon, 22 Jun 2020 13:40:00 +0200
Subject: Properly hook up igmp with announce

---
 announce.c | 21 +++++++++++++++++----
 announce.h |  2 +-
 igmp.c     | 17 +++++++----------
 main.c     | 13 +++++++------
 main.h     | 18 +++++++++---------
 5 files changed, 41 insertions(+), 30 deletions(-)

diff --git a/announce.c b/announce.c
index 17ab2bb..2510d5d 100644
--- a/announce.c
+++ b/announce.c
@@ -5,6 +5,7 @@
 #include <arpa/inet.h>
 #include <string.h>
 #include <unistd.h>
+#include <time.h>
 
 #include "main.h"
 #include "uring.h"
@@ -15,6 +16,7 @@ struct announce {
 	uint64_t value;
 	struct uring_task task;
 	int mcast_fd;
+	time_t until;
 };
 
 static void
@@ -31,9 +33,15 @@ announce_cb(struct uring_task *task, int res)
 		return;
 	}
 
-	debug(DBG_ANN, "timerfd value %" PRIu64, announce->value);
-	list_for_each_entry(server, &cfg->servers, list)
-		server_announce(server, announce->mcast_fd);
+	if (announce->until != 0 && time(NULL) > announce->until) {
+		debug(DBG_ANN, "stopping announcements");
+		announce_stop();
+	} else {
+		debug(DBG_ANN, "announcing servers");
+		list_for_each_entry(server, &cfg->servers, list)
+			server_announce(server, announce->mcast_fd);
+	}
+
 	uring_read(&announce->task, &announce->value, sizeof(announce->value), announce_cb);
 }
 
@@ -88,7 +96,7 @@ announce_stop()
 }
 
 void
-announce_start()
+announce_start(unsigned duration)
 {
 	struct itimerspec tspec = {
 		.it_interval = {
@@ -103,6 +111,11 @@ announce_start()
 
 	assert_return(cfg->announce);
 
+	if (duration > 0)
+		cfg->announce->until = time(NULL) + duration;
+	else
+		cfg->announce->until = 0;
+
 	if (timerfd_settime(cfg->announce->task.fd, 0, &tspec, NULL) != 0)
 		error("timerfd_settime: %m");
 }
diff --git a/announce.h b/announce.h
index c4bd8e3..77a36f2 100644
--- a/announce.h
+++ b/announce.h
@@ -7,7 +7,7 @@ void announce_delete();
 
 void announce_stop();
 
-void announce_start();
+void announce_start(unsigned duration);
 
 void announce_init();
 
diff --git a/igmp.c b/igmp.c
index 2fb75a2..a9a8980 100644
--- a/igmp.c
+++ b/igmp.c
@@ -12,12 +12,10 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 
-/* FIXME: Remove later */
-#include <time.h>
-
 #include "main.h"
 #include "uring.h"
 #include "igmp.h"
+#include "announce.h"
 
 struct igmp {
 	struct uring_task task;
@@ -173,13 +171,12 @@ csum_valid(const char *buf, size_t len)
 static void
 igmp_match()
 {
-	/* Sent with approx 120-130 sec intervals */
-	time_t t = time(NULL);
-	struct tm *tm = localtime(&t);
-	char s[64];
-	strftime(s, sizeof(s), "%c", tm);
-	debug(DBG_IGMP, "multicast request discovered at: %s", s);
-	//start announce
+	debug(DBG_IGMP, "multicast request discovered");
+	/*
+	 * IGMP messages are sent with approx 120-130 sec intervals,
+	 * so set time to 5 minutes to allow some slack.
+	 */
+	announce_start(5 * 60);
 }
 
 static void
diff --git a/main.c b/main.c
index 86681e8..f0cc399 100644
--- a/main.c
+++ b/main.c
@@ -501,11 +501,11 @@ cfg_apply()
 				    CAPNG_DROP_SUPP_GRP | CAPNG_CLEAR_BOUNDING))
 			die("capng_change_id failed");
 	} else {
-		if (capng_apply(CAPNG_SELECT_BOTH)) {
-			capng_clear(CAPNG_SELECT_BOTH);
-			if (capng_apply(CAPNG_SELECT_BOTH))
-				die("capng_apply failed");
-		}
+		/*
+		 * This can fail if any of the caps are lacking, but it'll
+		 * be re-checked later.
+		 */
+		capng_apply(CAPNG_SELECT_BOTH);
 		setgroups(0, NULL);
 	}
 
@@ -596,7 +596,8 @@ main(int argc, char **argv)
 
 	announce_init();
 
-	announce_start();
+	if (!cfg->igmp)
+		announce_start(0);
 
 	idle_init();
 
diff --git a/main.h b/main.h
index ac3e0a2..05c5c82 100644
--- a/main.h
+++ b/main.h
@@ -20,15 +20,15 @@ enum debug_lvl {
 	DBG_REF		= (0x1 << 5),
 	DBG_MALLOC	= (0x1 << 6),
 	DBG_ANN		= (0x1 << 7),
-	DBG_SIG		= (0x1 << 7),
-	DBG_UR		= (0x1 << 8),
-	DBG_SRV		= (0x1 << 9),
-	DBG_PROXY	= (0x1 << 10),
-	DBG_RCON	= (0x1 << 11),
-	DBG_IDLE	= (0x1 << 12),
-	DBG_IGMP	= (0x1 << 13),
-	DBG_SYSD	= (0x1 << 14),
-	DBG_DNS		= (0x1 << 15),
+	DBG_SIG		= (0x1 << 8),
+	DBG_UR		= (0x1 << 9),
+	DBG_SRV		= (0x1 << 10),
+	DBG_PROXY	= (0x1 << 11),
+	DBG_RCON	= (0x1 << 12),
+	DBG_IDLE	= (0x1 << 13),
+	DBG_IGMP	= (0x1 << 14),
+	DBG_SYSD	= (0x1 << 15),
+	DBG_DNS		= (0x1 << 16),
 };
 
 static inline bool
-- 
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