cgconfigparser: Add 'default' section.

'default' section in cgconfig.conf file describes default owner and
permissions of group's control and task files. Using the 'default' section,
the common permissions can be specified only once per config file instead
of defining it separately for each group.

Signed-off-by: Jan Safranek <jsafrane@redhat.com>
Acked-by: Dhaval Giani <dhaval.giani@gmail.com>

diff --git a/src/config.c b/src/config.c
index 8548174ab547ed0acbf77aa29b335c3d9f05d30e..18c6f553a81da1a24dda0b2e2effd65abf67785d 100644 (file)
--- a/src/config.c
+++ b/src/config.c
@@ -49,6 +49,8 @@ unsigned int MAX_CGROUPS = 64;        /* NOTE: This value changes dynamically */
 extern FILE *yyin;
 extern int yyparse(void);
 
+static struct cgroup default_group;
+
 /*
  * The basic global data structures.
  *
@@ -748,6 +750,34 @@ static void cgroup_free_config(void)
        config_table_index = 0;
 }
 
+/**
+ * Applies default permissions/uid/gid to all groups in config file.
+ */
+static void cgroup_config_apply_default()
+{
+       int i;
+       if (config_cgroup_table) {
+               for (i = 0; i < cgroup_table_index; i++) {
+                       struct cgroup *c = &config_cgroup_table[i];
+
+                       if (c->control_dperm == NO_PERMS)
+                               c->control_dperm = default_group.control_dperm;
+                       if (c->control_fperm == NO_PERMS)
+                               c->control_fperm = default_group.control_fperm;
+                       if (c->control_gid == NO_UID_GID)
+                               c->control_gid = default_group.control_gid;
+                       if (c->control_uid == NO_UID_GID)
+                               c->control_uid = default_group.control_uid;
+                       if (c->task_fperm == NO_PERMS)
+                               c->task_fperm = default_group.task_fperm;
+                       if (c->tasks_gid == NO_UID_GID)
+                               c->tasks_gid = default_group.tasks_gid;
+                       if (c->tasks_uid == NO_UID_GID)
+                               c->tasks_uid = default_group.tasks_uid;
+               }
+       }
+}
+
 static int cgroup_parse_config(const char *pathname)
 {
        int ret;
@@ -773,6 +803,8 @@ static int cgroup_parse_config(const char *pathname)
        config_table_index = 0;
        namespace_table_index = 0;
        cgroup_table_index = 0;
+       /* init the default cgroup */
+       init_cgroup_table(&default_group, 1);
 
        /*
         * Parser calls longjmp() on really fatal error (like out-of-memory).
@@ -866,6 +898,7 @@ int cgroup_config_load_config(const char *pathname)
        if (error)
                goto err_mnt;
 
+       cgroup_config_apply_default();
        error = cgroup_config_create_groups();
        cgroup_dbg("creating all cgroups now, error=%d\n", error);
        if (error)
@@ -1102,3 +1135,37 @@ out_errno:
        cgroup_get_controller_end(&ctrl_handle);
        return ECGOTHER;
 }
+
+/**
+ * Defines the default group. The parser puts content of 'default { }' to
+ * topmost group in config_cgroup_table. This function copies the permissions
+ * from it to our default cgroup.
+ */
+int cgroup_config_define_default(void)
+{
+       struct cgroup *config_cgroup =
+                       &config_cgroup_table[cgroup_table_index];
+
+       init_cgroup_table(&default_group, 1);
+       if (config_cgroup->control_dperm != NO_PERMS)
+               default_group.control_dperm = config_cgroup->control_dperm;
+       if (config_cgroup->control_fperm != NO_PERMS)
+               default_group.control_fperm = config_cgroup->control_fperm;
+       if (config_cgroup->control_gid != NO_UID_GID)
+               default_group.control_gid = config_cgroup->control_gid;
+       if (config_cgroup->control_uid != NO_UID_GID)
+               default_group.control_uid = config_cgroup->control_uid;
+       if (config_cgroup->task_fperm != NO_PERMS)
+               default_group.task_fperm = config_cgroup->task_fperm;
+       if (config_cgroup->tasks_gid != NO_UID_GID)
+               default_group.tasks_gid = config_cgroup->tasks_gid;
+       if (config_cgroup->tasks_uid != NO_UID_GID)
+               default_group.tasks_uid = config_cgroup->tasks_uid;
+
+       /*
+        * Reset all changes made by 'default { }' to the topmost group so it
+        * can be used by following 'group { }'.
+        */
+       init_cgroup_table(config_cgroup, 1);
+       return 0;
+}

diff --git a/src/lex.l b/src/lex.l
index 7a00015971f25df23517e6f4e92f83a8fc6e3834..9ff37ecdf40c09a3b1a5e445df4747a64ef8331b 100644 (file)
--- a/src/lex.l
+++ b/src/lex.l
@@ -39,6 +39,7 @@ jmp_buf parser_error_env;
 "perm"         {return PERM;}
 "group"                {return GROUP;}
 "namespace"    {return NAMESPACE;}
+"default"      {return DEFAULT;}
 [a-zA-Z0-9_\-\/\.\,]+ {yylval.name = strdup(yytext); return ID;}
 \"[^"]*\" {yylval.name = strdup(yytext+1); yylval.name[strlen(yylval.name)-1] = '\0'; return ID; }
 .      {return yytext[0];}

diff --git a/src/libcgroup-internal.h b/src/libcgroup-internal.h
index 7d683f4b29fd6927b4116867136e5fb1c267b435..1b3daf9c9ed593d8241013e20ab1c9cb074cd6e2 100644 (file)
--- a/src/libcgroup-internal.h
+++ b/src/libcgroup-internal.h
@@ -224,6 +224,7 @@ int cgroup_config_insert_into_mount_table(char *name, char *mount_point);
 int cgroup_config_insert_into_namespace_table(char *name, char *mount_point);
 void cgroup_config_cleanup_mount_table(void);
 void cgroup_config_cleanup_namespace_table(void);
+int cgroup_config_define_default(void);
 
 /**
  * Create an empty dictionary.

diff --git a/src/parse.y b/src/parse.y
index e0c70d3c34107fef2a0524b7ff006bd5c269554f..7cc444cfadd655d6629264da1c986447ebb26e29 100644 (file)
--- a/src/parse.y
+++ b/src/parse.y
@@ -37,7 +37,7 @@ int yywrap(void)
 
 %}
 
-%token ID MOUNT GROUP PERM TASK ADMIN NAMESPACE
+%token ID MOUNT GROUP PERM TASK ADMIN NAMESPACE DEFAULT
 
 %union {
        char *name;
@@ -48,7 +48,7 @@ int yywrap(void)
 %type <name> ID
 %type <val> mountvalue_conf mount task_namevalue_conf admin_namevalue_conf
 %type <val> admin_conf task_conf task_or_admin group_conf group start
-%type <val> namespace namespace_conf
+%type <val> namespace namespace_conf default default_conf
 %type <values> namevalue_conf
 %start start
 %%
@@ -61,6 +61,10 @@ start   : start group
        {
                $$ = $1;
        }
+       | start default
+       {
+         $$ = $1;
+       }
         | start namespace
        {
                $$ = $1;
@@ -71,6 +75,22 @@ start   : start group
        }
         ;
 
+default :       DEFAULT '{' default_conf '}'
+       {
+               $$ = $3;
+               if ($$) {
+                       cgroup_config_define_default();
+               }
+       }
+       ;
+
+default_conf
+       :       PERM '{' task_or_admin '}'
+       {
+               $$ = $3;
+       }
+       ;
+
 group   :       GROUP ID '{' group_conf '}'
        {
                $$ = $4;