From 5f78385c979ad6eea953587c0ecafa0a914ba3c0 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 25 Jan 2011 11:01:48 +1030
Subject: [PATCH] lca2011: dump on SIGHUP.

---
 ccan/oserver/_info                            |  2 +-
 ccan/oserver/oserver.c                        | 31 ++++++++++++++++++-
 ccan/oserver/oserver.h                        |  6 ++--
 ccan/oserver/oserver_types.h                  |  1 +
 ccan/oserver/test/run-one-client-disconnect.c |  3 +-
 ccan/oserver/test/run.c                       |  3 +-
 6 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/ccan/oserver/_info b/ccan/oserver/_info
index 4f54687..9107e66 100644
--- a/ccan/oserver/_info
+++ b/ccan/oserver/_info
@@ -30,7 +30,7 @@
  *		if (argc != 1)
  *			opt_log_stderr_exit("Unknown extra arguments");
  *
- *		if (!oserver_setup(ev, port))
+ *		if (!oserver_setup(ev, port, "/var/run/oserver/dump"))
  *			err(1, "Failed to set up server");
  *
  *		while (tevent_loop_wait(ev) == 0);
diff --git a/ccan/oserver/oserver.c b/ccan/oserver/oserver.c
index 0ec1b68..8a5fdce 100644
--- a/ccan/oserver/oserver.c
+++ b/ccan/oserver/oserver.c
@@ -1,5 +1,6 @@
 #include <ccan/oserver/oserver.h>
 #include <ccan/oserver/oserver_types.h>
+#include <ccan/oserver/oserver_cdump.h>
 #include <ccan/read_write_all/read_write_all.h>
 #include <ccan/opt/opt.h>
 #include <ccan/tevent/tevent.h>
@@ -17,6 +18,9 @@
 #include <errno.h>
 #include <signal.h>
 #include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 static uint16_t state_flag_map[] = {
 	[SENDING_GREETING]		= TEVENT_FD_WRITE,
@@ -284,7 +288,26 @@ static void talloc_dump(struct tevent_context *ev,
 	}
 }
 
-struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
+static void dump(struct tevent_context *ev,
+		 struct tevent_signal *se,
+		 int signum,
+		 int count,
+		 void *siginfo,
+		 void *_oserver)
+{
+	struct oserver *oserver = _oserver;
+	char *str;
+	int fd;
+
+	str = cdump_bundle(ev, cdump_struct_oserver, oserver);
+	fd = open(oserver->dumpfile, O_CREAT|O_TRUNC|O_WRONLY, 0600);
+	write(fd, str, strlen(str));
+	close(fd);
+	talloc_free(str);
+}
+
+struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
+			      const char *dumpfile)
 {
 	struct oserver *oserver;
 	int one = 1;
@@ -327,6 +350,12 @@ struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
 		return NULL;
 	}
 
+	oserver->dumpfile = dumpfile;
+	if (oserver->dumpfile) {
+		tevent_add_signal(ev, oserver, SIGHUP, SA_RESTART,
+				  dump, oserver);
+	}
+
 	/* Don't kill us if client dies. */
 	signal(SIGPIPE, SIG_IGN);
 
diff --git a/ccan/oserver/oserver.h b/ccan/oserver/oserver.h
index a465b2d..3342ba8 100644
--- a/ccan/oserver/oserver.h
+++ b/ccan/oserver/oserver.h
@@ -7,6 +7,7 @@
  * oserver_setup - set up an oserver
  * @ev: tevent context to use.
  * @port: port to use (usually OSERVER_PORT)
+ * @dumpfile: file to save state to on SIGHUP (if non-NULL).
  *
  * Opens a socket and binds it to @port, then sets it up to listen
  * for connections.  talloc_free() the pointer returned to shut it down
@@ -17,14 +18,15 @@
  *	struct tevent_context *ev;
  *
  *	ev = tevent_context_init(NULL);
- *	oserver = oserver_setup(ev, OSERVER_PORT);
+ *	oserver = oserver_setup(ev, OSERVER_PORT, "oserver.dump");
  *	if (!oserver)
  *		err(1, "Failed to set up server");
  *
  *	while (tevent_loop_wait(ev) == 0);
  *	err(1, "Event loop failed");
  */
-struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port);
+struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
+			      const char *dumpfile);
 
 #define OSERVER_PORT 2828
 #endif /* CCAN_OSERVER_H */
diff --git a/ccan/oserver/oserver_types.h b/ccan/oserver/oserver_types.h
index 72717e8..8e99892 100644
--- a/ccan/oserver/oserver_types.h
+++ b/ccan/oserver/oserver_types.h
@@ -41,5 +41,6 @@ CDUMP_SAVED struct oserver {
 	struct client *clients[5];
 	int fd;
 	struct tevent_fd *fde CDUMP_IGNORE;
+	const char *dumpfile;
 };
 #endif /* CCAN_OSERVER_TYPES_H */
diff --git a/ccan/oserver/test/run-one-client-disconnect.c b/ccan/oserver/test/run-one-client-disconnect.c
index 8367aad..6023f78 100644
--- a/ccan/oserver/test/run-one-client-disconnect.c
+++ b/ccan/oserver/test/run-one-client-disconnect.c
@@ -1,4 +1,5 @@
 #include <ccan/oserver/oserver.c>
+#include <ccan/oserver/oserver_cdump.c>
 #include <ccan/oserver/oserver.h>
 #include <ccan/str/str.h>
 #include <ccan/tap/tap.h>
@@ -104,7 +105,7 @@ int main(int argc, char *argv[])
 	/* This is how many tests you plan to run */
 	plan_tests(2);
 
-	oserver = oserver_setup(ev, OSERVER_PORT);
+	oserver = oserver_setup(ev, OSERVER_PORT, NULL);
 	if (!oserver)
 		err(1, "Failed to set up server");
 
diff --git a/ccan/oserver/test/run.c b/ccan/oserver/test/run.c
index 03180c9..a8eb6f2 100644
--- a/ccan/oserver/test/run.c
+++ b/ccan/oserver/test/run.c
@@ -1,4 +1,5 @@
 #include <ccan/oserver/oserver.c>
+#include <ccan/oserver/oserver_cdump.c>
 #include <ccan/oserver/oserver.h>
 #include <ccan/str/str.h>
 #include <ccan/tap/tap.h>
@@ -19,7 +20,7 @@ static void run_server(int readyfd, int exitfd)
 {
 	struct tevent_context *ev = tevent_context_init(NULL);
 
-	if (oserver_setup(ev, OSERVER_PORT) == NULL)
+	if (oserver_setup(ev, OSERVER_PORT, NULL) == NULL)
 		exit(1);
 
 	tevent_add_fd(ev, ev, exitfd, TEVENT_FD_READ, exit_quietly, NULL);
-- 
2.39.2