Add optional "hotplug mode" to init scripts

The hotplug mode is only used in XPP_HOTPLUG_DAHDI=yes is set in
/etc/dahdi/init.conf . If it is set and the system actually has
Astribanks, most of the init script will actually be run from the
context of a udev event.

Merged revisions 6987,7014,7334-7335,7409,7476 via svnmerge from 
https://origsvn.digium.com/svn/dahdi/tools/trunk

........
  r6987 | tzafrir | 2009-08-13 18:15:49 +0300 (Thu, 13 Aug 2009) | 9 lines
  
  xpp: Add astribank_is_starting:
  
  astribank_is_running is used to tell when we may have an Astribank that
  is initializing (and may be re-enumerating and thus not listed as a
  device).
  
  It uses a semaphore as we can always write to one and we can't always
  write to a file.
........
  r7014 | tzafrir | 2009-08-16 19:05:11 +0300 (Sun, 16 Aug 2009) | 4 lines
  
  xpp: A man page for astribank_is_starting
  
  xpp rev: 7321
........
  r7334 | tzafrir | 2009-10-04 15:35:51 +0200 (Sun, 04 Oct 2009) | 7 lines
  
  dahdi.init: move module loading to a separate function
  
  Move the module loading parts of the dahdi init script to a seperate
  function - load_modules. To be used by a later commit.
  
  There is not functional change here (but the diff is confusing).
........
  r7335 | tzafrir | 2009-10-04 15:53:01 +0200 (Sun, 04 Oct 2009) | 16 lines
  
  Add XPP_HOTPLUG_DAHDI mode: cfg initiated mostly from hotplug
  
  If XPP_HOTPLUG_DAHDI=yes is set in /etc/dahdi/init.conf (which is not
  the default), the normal run of the 'start' operation of the dahdi init
  script will only be responsible for loading modules. The rest will be
  done (if there are indeed Astribanks on the system) by a second call to
  the init script once all of them have connected.
  
  The astribank_hook has also been mostly rewritten. Most of the
  functionality of twinstar_hook moved to it. The current twinstar_hook is
  a simple example script.
  
  XPP_HOTPLUG_DAHDI mode assumes that all Astribanks on the system are
  listed in /etc/dahdi/xpp_order (which can be generated using, e.g.
  'dahdi_genconf xpporder')
........
  r7409 | tzafrir | 2009-10-21 16:30:32 +0200 (Wed, 21 Oct 2009) | 21 lines
  
  Fix XPP_HOTPLUG_DAHDI: logic; end of init.d script
  
  'Hotplug mode' was introduced in r7335.
  
  * The logic in the script was broken.
    - Negative logic is not such a grand idea to start with.
  * Interactive invocation of init.d ends when expected and not sooner.
  
  This change makes waitfor_xpds wait longer. Rather than waiting for all
  the Astribanks to load, it will now wait until the initialization of
  dahdi from the Astribanks hook script is run.
  
  This allows running e.g.: /etc/init.d/dahdi start; /etc/init.d/asterisk start
  
  It also means that 'astribank_is_starting' is actually used as a
  semaphore and not only as stamp file.
   
  As before, those changes have no effect if hotplug mode is not
  explicitly enabled (setting 'XPP_HOTPLUG_DAHDI=yes' in init.conf).
........
  r7476 | tzafrir | 2009-11-04 22:12:35 +0200 (Wed, 04 Nov 2009) | 6 lines
  
  xpp: make astribank_is_starting build without warnings.
  
  autoconfig.h is needed as semtimedop() requires _GNU_SOURCE.
  
  xpp rev: 7471
........


git-svn-id: http://svn.asterisk.org/svn/dahdi/tools/branches/2.2@7477 a0bf4364-ded3-4de4-8d8a-66a801d63aff

1 files changed, 190 insertions, 0 deletions

diff --git a/xpp/astribank_is_starting.c b/xpp/astribank_is_starting.c
new file mode 100644
index 0000000..578ea9b
--- /dev/null
+++ b/xpp/astribank_is_starting.c
@@ -0,0 +1,190 @@
+#define _GNU_SOURCE /* 2.3 and later will define this from autoconfig.h */
+#include <sys/types.h>
+#include <sys/ipc.h>
+#include <sys/sem.h>
+#include <errno.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+static char		*progname;
+static const key_t	key_astribanks = 0xAB11A0;
+static int		debug;
+static int		verbose;
+static int		timeout_seconds = 60;
+
+
+static void usage(void)
+{
+	fprintf(stderr, "Usage: %s [-d] [-t <seconds>] [-a|-r|-w]\n", progname);
+	exit(1);
+}
+
+static int absem_get(int createit)
+{
+	int	flags = (createit) ? IPC_CREAT | 0644 : 0;
+	int	absem;
+
+	if((absem = semget(key_astribanks, 1, flags)) < 0)
+		absem = -errno;
+	return absem;
+}
+
+static int absem_touch(void)
+{
+	int		absem;
+
+	if((absem = absem_get(1)) < 0) {
+		perror(__FUNCTION__);
+		return absem;
+	}
+	if(semctl(absem, 0, SETVAL, 0) < 0) {
+		perror("SETVAL");
+		return -errno;
+	}
+	if(debug)
+		fprintf(stderr, "%s: touched absem\n", progname);
+	if(verbose)
+		printf("Astribanks initialization is starting\n");
+	return 0;
+}
+
+static int absem_remove(void)
+{
+	int	absem;
+
+	if((absem = absem_get(0)) < 0) {
+		if(absem == -ENOENT) {
+			if(debug)
+				fprintf(stderr, "%s: absem already removed\n", progname);
+			return 0;
+		}
+		perror(__FUNCTION__);
+		return absem;
+	}
+	if(semctl(absem, 0, IPC_RMID, 0) < 0) {
+		perror("RMID");
+		return -errno;
+	}
+	if(debug)
+		fprintf(stderr, "%s: removed absem\n", progname);
+	if(verbose)
+		printf("Astribanks initialization is done\n");
+	return 0;
+}
+
+static int absem_wait(void)
+{
+	int		absem;
+	struct sembuf	sops;
+	long		now;
+	long		start_wait;
+	struct timespec	timeout;
+
+	if((absem = absem_get(0)) < 0) {
+		perror(__FUNCTION__);
+		return absem;
+	}
+	sops.sem_num = 0;
+	sops.sem_op = -1;
+	sops.sem_flg = 0;
+	start_wait = time(NULL);
+	timeout.tv_sec = timeout_seconds;
+	timeout.tv_nsec = 0;
+	if(semtimedop(absem, &sops, 1, &timeout) < 0) {
+		switch(errno) {
+		case EIDRM:	/* Removed -- OK */
+			break;
+		case EAGAIN:	/* Timeout -- Report */
+			fprintf(stderr, "Astribanks waiting timed out\n");
+			return -errno;
+		default:	/* Unexpected errors */
+			perror("semop");
+			return -errno;
+		}
+		/* fall-thgough */
+	}
+	now = time(NULL);
+	if(debug)
+		fprintf(stderr, "%s: waited on absem %ld seconds\n", progname, now - start_wait);
+	if(verbose)
+		printf("Finished after %ld seconds\n", now - start_wait);
+	return 0;
+}
+
+static int absem_detected(void)
+{
+	int	absem;
+
+	if((absem = absem_get(0)) < 0) {
+		if(debug)
+			fprintf(stderr, "%s: absem does not exist\n", progname);
+		return absem;
+	}
+	if(debug)
+		fprintf(stderr, "%s: absem exists\n", progname);
+	if(verbose)
+		printf("Astribanks are initializing...\n");
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	const char	options[] = "dvarwt:h";
+	int		val;
+
+	progname = argv[0];
+	while (1) {
+		int	c;
+		int	t;
+
+		c = getopt (argc, argv, options);
+		if (c == -1)
+			break;
+
+		switch (c) {
+			case 'd':
+				debug++;
+				break;
+			case 'v':
+				verbose++;
+				break;
+			case 't':
+				t = atoi(optarg);
+				if(t <= 0) {
+					fprintf(stderr,
+						"%s: -t expect a positive number of seconds: '%s'\n",
+						progname, optarg);
+					usage();
+				}
+				timeout_seconds = t;
+				break;
+			case 'a':
+				if((val = absem_touch()) < 0) {
+					fprintf(stderr, "%s: Add failed: %d\n", progname, val);
+					return 1;
+				}
+				return 0;
+			case 'r':
+				if((val = absem_remove()) < 0) {
+					fprintf(stderr, "%s: Remove failed: %d\n", progname, val);
+					return 1;
+				}
+				return 0;
+			case 'w':
+				if((val = absem_wait()) < 0) {
+					fprintf(stderr, "%s: Wait failed: %d\n", progname, val);
+					return 1;
+				}
+				return 0;
+			case 'h':
+			default:
+				fprintf(stderr, "Unknown option '%c'\n", c);
+				usage();
+		}
+	}
+	val = absem_detected();
+	return (val == 0) ? 0 : 1;
+}