Add the library function cgroup_register_unchanged_process().

Hi,

Changelog of v6:
================
 * No change.

Changelog of v5:
================
 * Rebase the patch to the latest code.

Changelog of v4:
================
 * No change.

Changelog of v3:
================
 * No change.

Changelog of v2:
================
 * New patch.

Description:
============
This patch adds the library function cgroup_register_unchanged_process()
for notifying cgrulesengd daemon of the unchanged process.

Thanks
Ken'ichi Ohmichi

Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

3 files changed, 52 insertions, 0 deletions

diff --git a/include/libcgroup.h b/include/libcgroup.h
index 8707412..953703b 100644
--- a/include/libcgroup.h
+++ b/include/libcgroup.h
@@ -324,6 +324,15 @@ int cgroup_get_task_begin(char *cgroup, char *controller, void **handle,
 								pid_t *pid);
 
 /**
+ * Register the unchanged process to a cgrulesengd daemon.
+ * If the daemon does not work, this function returns 0 as success.
+ * @param pid: The process id
+ * @param flags Bit flags to change the behavior, as defined above
+ * @return 0 on success, > 0 on error.
+ */
+int cgroup_register_unchanged_process(pid_t pid, int flags);
+
+/**
  * Read the next task value
  * @handle: The handle used for iterating
  * @pid: The variable where the value will be stored
diff --git a/src/api.c b/src/api.c
index 92bdebd..353b6dc 100644
--- a/src/api.c
+++ b/src/api.c
@@ -40,6 +40,7 @@
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/socket.h>
 #include <fcntl.h>
 #include <sys/syscall.h>
 #include <unistd.h>
@@ -48,6 +49,7 @@
 #include <pwd.h>
 #include <libgen.h>
 #include <assert.h>
+#include <linux/un.h>
 
 #ifndef PACKAGE_VERSION
 #define PACKAGE_VERSION 0.01
@@ -2933,6 +2935,46 @@ int cgroup_get_procname_from_procfs(pid_t pid, char **procname)
 	return ret;
 }
 
+int cgroup_register_unchanged_process(pid_t pid, int flags)
+{
+	int sk;
+	int ret = 1;
+	char buff[sizeof(CGRULE_SUCCESS_STORE_PID)];
+	struct sockaddr_un addr;
+
+	sk = socket(PF_UNIX, SOCK_STREAM, 0);
+	if (sk < 0)
+		return 1;
+
+	bzero((char *)&addr, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, CGRULE_CGRED_TEMP_FILE);
+
+	if (connect(sk, (struct sockaddr *)&addr,
+	    sizeof(addr.sun_family) + strlen(CGRULE_CGRED_TEMP_FILE)) < 0) {
+		/* If the daemon does not work, this function returns 0
+		 * as success. */
+		ret = 0;
+		goto close;
+	}
+	if (write(sk, &pid, sizeof(pid)) < 0)
+		goto close;
+
+	if (write(sk, &flags, sizeof(flags)) < 0)
+		goto close;
+
+	if (read(sk, buff, sizeof(buff)) < 0)
+		goto close;
+
+	if (strncmp(buff, CGRULE_SUCCESS_STORE_PID, sizeof(buff)))
+		goto close;
+
+	ret = 0;
+close:
+	close(sk);
+	return ret;
+}
+
 int cgroup_get_subsys_mount_point(char *controller, char **mount_point)
 {
 	int i;
diff --git a/src/libcgroup.map b/src/libcgroup.map
index 2935d48..aa9d0d2 100644
--- a/src/libcgroup.map
+++ b/src/libcgroup.map
@@ -71,5 +71,6 @@ global:
 	cgroup_get_uid_gid_from_procfs;
 	cgroup_get_subsys_mount_point;
 	cgroup_get_procname_from_procfs;
+	cgroup_register_unchanged_process;
 	cgroup_change_cgroup_flags;
 } CGROUP_0.33;