shared/capability: go frugal on space for caps

[elogind.git] / src / shared / cgroup-util.c

diff --git a/src/shared/cgroup-util.c b/src/shared/cgroup-util.c
index e8cb9c73ac6fa4e1c104c842ac9ae4cd57e05282..0d3cc53517de07b7ef779ea5c219f7a052cd566d 100644 (file)
--- a/src/shared/cgroup-util.c
+++ b/src/shared/cgroup-util.c
@@ -161,7 +161,7 @@ int cg_kill(const char *controller, const char *path, int sig, bool sigcont, boo
          * tasks list, to properly handle forking processes */
 
         if (!s) {
-                s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
+                s = allocated_set = set_new(NULL);
                 if (!s)
                         return -ENOMEM;
         }
@@ -195,7 +195,7 @@ int cg_kill(const char *controller, const char *path, int sig, bool sigcont, boo
                                 if (ret >= 0 && errno != ESRCH)
                                         ret = -errno;
                         } else {
-                                if (sigcont)
+                                if (sigcont && sig != SIGKILL)
                                         kill(pid, SIGCONT);
 
                                 if (ret == 0)
@@ -239,7 +239,7 @@ int cg_kill_recursive(const char *controller, const char *path, int sig, bool si
         assert(sig >= 0);
 
         if (!s) {
-                s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
+                s = allocated_set = set_new(NULL);
                 if (!s)
                         return -ENOMEM;
         }
@@ -290,7 +290,7 @@ int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char
         assert(cto);
         assert(pto);
 
-        s = set_new(trivial_hash_func, trivial_compare_func);
+        s = set_new(NULL);
         if (!s)
                 return -ENOMEM;
 
@@ -502,14 +502,16 @@ int cg_get_path(const char *controller, const char *path, const char *suffix, ch
 }
 
 static int check_hierarchy(const char *p) {
-        char *cc;
+        const char *cc;
 
         assert(p);
 
+        if (!filename_is_valid(p))
+                return 0;
+
         /* Check if this controller actually really exists */
-        cc = alloca(strlen("/sys/fs/cgroup/") + strlen(p) + 1);
-        strcpy(stpcpy(cc, "/sys/fs/cgroup/"), p);
-        if (access(cc, F_OK) < 0)
+        cc = strappenda("/sys/fs/cgroup/", p);
+        if (laccess(cc, F_OK) < 0)
                 return -errno;
 
         return 0;
@@ -682,7 +684,7 @@ int cg_set_group_access(
 
         assert(path);
 
-        if (mode != (mode_t) -1)
+        if (mode != MODE_INVALID)
                 mode &= 0777;
 
         r = cg_get_path(controller, path, NULL, &fs);
@@ -704,10 +706,10 @@ int cg_set_task_access(
 
         assert(path);
 
-        if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1)
+        if (mode == MODE_INVALID && uid == UID_INVALID && gid == GID_INVALID)
                 return 0;
 
-        if (mode != (mode_t) -1)
+        if (mode != MODE_INVALID)
                 mode &= 0666;
 
         r = cg_get_path(controller, path, "cgroup.procs", &fs);
@@ -1306,9 +1308,8 @@ int cg_pid_get_machine_name(pid_t pid, char **machine) {
 }
 
 int cg_path_get_session(const char *path, char **session) {
-        const char *e, *n, *x;
+        const char *e, *n, *x, *y;
         char *s;
-        size_t l;
 
         assert(path);
 
@@ -1325,17 +1326,14 @@ int cg_path_get_session(const char *path, char **session) {
         x = startswith(s, "session-");
         if (!x)
                 return -ENOENT;
-        if (!endswith(x, ".scope"))
-                return -ENOENT;
-
-        l = strlen(x);
-        if (l <= 6)
+        y = endswith(x, ".scope");
+        if (!y || x == y)
                 return -ENOENT;
 
         if (session) {
                 char *r;
 
-                r = strndup(x, l - 6);
+                r = strndup(x, y - x);
                 if (!r)
                         return -ENOMEM;
 
@@ -1594,6 +1592,17 @@ int cg_set_attribute(const char *controller, const char *path, const char *attri
         return write_string_file_no_create(p, value);
 }
 
+int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        r = cg_get_path(controller, path, attribute, &p);
+        if (r < 0)
+                return r;
+
+        return read_one_line_file(p, ret);
+}
+
 static const char mask_names[] =
         "cpu\0"
         "cpuacct\0"
@@ -1628,7 +1637,7 @@ int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask ma
         return 0;
 }
 
-int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid) {
+int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid, cg_migrate_callback_t path_callback, void *userdata) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
@@ -1638,8 +1647,18 @@ int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t
                 return r;
 
         NULSTR_FOREACH(n, mask_names) {
-                if (supported & bit)
+
+                if (supported & bit) {
+                        const char *p = NULL;
+
+                        if (path_callback)
+                                p = path_callback(bit, userdata);
+
+                        if (!p)
+                                p = path;
+
                         cg_attach_fallback(n, path, pid);
+                }
 
                 bit <<= 1;
         }
@@ -1647,7 +1666,7 @@ int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t
         return 0;
 }
 
-int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids) {
+int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) {
         Iterator i;
         void *pidp;
         int r = 0;
@@ -1656,7 +1675,7 @@ int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path,
                 pid_t pid = PTR_TO_LONG(pidp);
                 int q;
 
-                q = cg_attach_everywhere(supported, path, pid);
+                q = cg_attach_everywhere(supported, path, pid, path_callback, userdata);
                 if (q < 0)
                         r = q;
         }
@@ -1726,3 +1745,54 @@ CGroupControllerMask cg_mask_supported(void) {
 
         return mask;
 }
+
+int cg_kernel_controllers(Set *controllers) {
+        _cleanup_fclose_ FILE *f = NULL;
+        char buf[LINE_MAX];
+        int r;
+
+        assert(controllers);
+
+        f = fopen("/proc/cgroups", "re");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+                return -errno;
+        }
+
+        /* Ignore the header line */
+        (void) fgets(buf, sizeof(buf), f);
+
+        for (;;) {
+                char *controller;
+                int enabled = 0;
+
+                errno = 0;
+                if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
+
+                        if (feof(f))
+                                break;
+
+                        if (ferror(f) && errno)
+                                return -errno;
+
+                        return -EBADMSG;
+                }
+
+                if (!enabled) {
+                        free(controller);
+                        continue;
+                }
+
+                if (!filename_is_valid(controller)) {
+                        free(controller);
+                        return -EBADMSG;
+                }
+
+                r = set_consume(controllers, controller);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}