chiark / gitweb /
shared/capability: go frugal on space for caps
[elogind.git] / src / shared / cgroup-util.c
index 74889b636324dea71c0426e05740198a5f21286b..0d3cc53517de07b7ef779ea5c219f7a052cd566d 100644 (file)
@@ -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;
         }
@@ -194,12 +194,12 @@ int cg_kill(const char *controller, const char *path, int sig, bool sigcont, boo
                         if (kill(pid, sig) < 0) {
                                 if (ret >= 0 && errno != ESRCH)
                                         ret = -errno;
-                        } else if (ret == 0) {
-
-                                if (sigcont)
+                        } else {
+                                if (sigcont && sig != SIGKILL)
                                         kill(pid, SIGCONT);
 
-                                ret = 1;
+                                if (ret == 0)
+                                        ret = 1;
                         }
 
                         done = false;
@@ -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;
 
@@ -472,9 +472,7 @@ static int join_path(const char *controller, const char *path, const char *suffi
         if (!t)
                 return -ENOMEM;
 
-        path_kill_slashes(t);
-
-        *fs = t;
+        *fs = path_kill_slashes(t);
         return 0;
 }
 
@@ -504,14 +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(sizeof("/sys/fs/cgroup/") + strlen(p));
-        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;
@@ -643,9 +643,9 @@ int cg_attach(const char *controller, const char *path, pid_t pid) {
         if (pid == 0)
                 pid = getpid();
 
-        snprintf(c, sizeof(c), "%lu\n", (unsigned long) pid);
+        snprintf(c, sizeof(c), PID_FMT"\n", pid);
 
-        return write_string_file(fs, c);
+        return write_string_file_no_create(fs, c);
 }
 
 int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {
@@ -684,7 +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);
@@ -706,10 +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);
@@ -746,10 +746,7 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
         } else
                 controller = SYSTEMD_CGROUP_CONTROLLER;
 
-        if (pid == 0)
-                fs = "/proc/self/cgroup";
-        else
-                fs = procfs_file_alloca(pid, "cgroup");
+        fs = procfs_file_alloca(pid, "cgroup");
 
         f = fopen(fs, "re");
         if (!f)
@@ -758,9 +755,9 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
         cs = strlen(controller);
 
         FOREACH_LINE(line, f, return -errno) {
-                char *l, *p, *w, *e;
+                char *l, *p, *e;
                 size_t k;
-                char *state;
+                const char *word, *state;
                 bool found = false;
 
                 truncate_nl(line);
@@ -776,16 +773,16 @@ int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
 
                 *e = 0;
 
-                FOREACH_WORD_SEPARATOR(w, k, l, ",", state) {
+                FOREACH_WORD_SEPARATOR(word, k, l, ",", state) {
 
-                        if (k == cs && memcmp(w, controller, cs) == 0) {
+                        if (k == cs && memcmp(word, controller, cs) == 0) {
                                 found = true;
                                 break;
                         }
 
                         if (k == 5 + cs &&
-                            memcmp(w, "name=", 5) == 0 &&
-                            memcmp(w+5, controller, cs) == 0) {
+                            memcmp(word, "name=", 5) == 0 &&
+                            memcmp(word+5, controller, cs) == 0) {
                                 found = true;
                                 break;
                         }
@@ -822,7 +819,7 @@ int cg_install_release_agent(const char *controller, const char *agent) {
 
         sc = strstrip(contents);
         if (sc[0] == 0) {
-                r = write_string_file(fs, agent);
+                r = write_string_file_no_create(fs, agent);
                 if (r < 0)
                         return r;
         } else if (!streq(sc, agent))
@@ -842,7 +839,7 @@ int cg_install_release_agent(const char *controller, const char *agent) {
 
         sc = strstrip(contents);
         if (streq(sc, "0")) {
-                r = write_string_file(fs, "1");
+                r = write_string_file_no_create(fs, "1");
                 if (r < 0)
                         return r;
 
@@ -863,7 +860,7 @@ int cg_uninstall_release_agent(const char *controller) {
         if (r < 0)
                 return r;
 
-        r = write_string_file(fs, "0");
+        r = write_string_file_no_create(fs, "0");
         if (r < 0)
                 return r;
 
@@ -874,7 +871,7 @@ int cg_uninstall_release_agent(const char *controller) {
         if (r < 0)
                 return r;
 
-        r = write_string_file(fs, "");
+        r = write_string_file_no_create(fs, "");
         if (r < 0)
                 return r;
 
@@ -960,8 +957,7 @@ int cg_split_spec(const char *spec, char **controller, char **path) {
                         if (!t)
                                 return -ENOMEM;
 
-                        path_kill_slashes(t);
-                        *path = t;
+                        *path = path_kill_slashes(t);
                 }
 
                 if (controller)
@@ -1044,19 +1040,18 @@ int cg_mangle_path(const char *path, char **result) {
         assert(path);
         assert(result);
 
-        /* First check if it already is a filesystem path */
+        /* First, check if it already is a filesystem path */
         if (path_startswith(path, "/sys/fs/cgroup")) {
 
                 t = strdup(path);
                 if (!t)
                         return -ENOMEM;
 
-                path_kill_slashes(t);
-                *result = t;
+                *result = path_kill_slashes(t);
                 return 0;
         }
 
-        /* Otherwise treat it as cg spec */
+        /* Otherwise, treat it as cg spec */
         r = cg_split_spec(path, &c, &p);
         if (r < 0)
                 return r;
@@ -1082,42 +1077,62 @@ int cg_get_root_path(char **path) {
         return 0;
 }
 
-int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
-        _cleanup_free_ char *cg_root = NULL;
-        char *cg_process, *p;
+int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
+        _cleanup_free_ char *rt = NULL;
+        char *p;
         int r;
 
-        assert(pid >= 0);
         assert(cgroup);
+        assert(shifted);
 
         if (!root) {
                 /* If the root was specified let's use that, otherwise
                  * let's determine it from PID 1 */
 
-                r = cg_get_root_path(&cg_root);
+                r = cg_get_root_path(&rt);
                 if (r < 0)
                         return r;
 
-                root = cg_root;
+                root = rt;
         }
 
-        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cg_process);
+        p = path_startswith(cgroup, root);
+        if (p)
+                *shifted = p - 1;
+        else
+                *shifted = cgroup;
+
+        return 0;
+}
+
+int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
+        _cleanup_free_ char *raw = NULL;
+        const char *c;
+        int r;
+
+        assert(pid >= 0);
+        assert(cgroup);
+
+        r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
         if (r < 0)
                 return r;
 
-        p = path_startswith(cg_process, root);
-        if (p) {
-                char *c;
+        r = cg_shift_path(raw, root, &c);
+        if (r < 0)
+                return r;
 
-                c = strdup(p - 1);
-                free(cg_process);
+        if (c == raw) {
+                *cgroup = raw;
+                raw = NULL;
+        } else {
+                char *n;
 
-                if (!c)
+                n = strdup(c);
+                if (!n)
                         return -ENOMEM;
 
-                *cgroup = c;
-        } else
-                *cgroup = cg_process;
+                *cgroup = n;
+        }
 
         return 0;
 }
@@ -1132,7 +1147,7 @@ int cg_path_decode_unit(const char *cgroup, char **unit){
         c = strndupa(cgroup, e - cgroup);
         c = cg_unescape(c);
 
-        if (!unit_name_is_valid(c, false))
+        if (!unit_name_is_valid(c, TEMPLATE_INVALID))
                 return -EINVAL;
 
         s = strdup(c);
@@ -1265,39 +1280,18 @@ int cg_pid_get_user_unit(pid_t pid, char **unit) {
 }
 
 int cg_path_get_machine_name(const char *path, char **machine) {
-        const char *e, *n, *x;
-        char *s, *r;
-        size_t l;
-
-        assert(path);
-        assert(machine);
-
-        /* Skip slices, if there are any */
-        e = skip_slices(path);
-
-        n = strchrnul(e, '/');
-        if (e == n)
-                return -ENOENT;
-
-        s = strndupa(e, n - e);
-        s = cg_unescape(s);
-
-        x = startswith(s, "machine-");
-        if (!x)
-                return -ENOENT;
-        if (!endswith(x, ".scope"))
-                return -ENOENT;
+        _cleanup_free_ char *u = NULL, *sl = NULL;
+        int r;
 
-        l = strlen(x);
-        if (l <= 6)
-                return -ENOENT;
+        r = cg_path_get_unit(path, &u);
+        if (r < 0)
+                return r;
 
-        r = strndup(x, l - 6);
-        if (!r)
+        sl = strjoin("/run/systemd/machines/unit:", u, NULL);
+        if (!sl)
                 return -ENOMEM;
 
-        *machine = r;
-        return 0;
+        return readlink_malloc(sl, machine);
 }
 
 int cg_pid_get_machine_name(pid_t pid, char **machine) {
@@ -1314,12 +1308,10 @@ 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;
-        char *s, *r;
-        size_t l;
+        const char *e, *n, *x, *y;
+        char *s;
 
         assert(path);
-        assert(session);
 
         /* Skip slices, if there are any */
         e = skip_slices(path);
@@ -1334,18 +1326,20 @@ int cg_path_get_session(const char *path, char **session) {
         x = startswith(s, "session-");
         if (!x)
                 return -ENOENT;
-        if (!endswith(x, ".scope"))
+        y = endswith(x, ".scope");
+        if (!y || x == y)
                 return -ENOENT;
 
-        l = strlen(x);
-        if (l <= 6)
-                return -ENOENT;
+        if (session) {
+                char *r;
 
-        r = strndup(x, l - 6);
-        if (!r)
-                return -ENOMEM;
+                r = strndup(x, y - x);
+                if (!r)
+                        return -ENOMEM;
+
+                *session = r;
+        }
 
-        *session = r;
         return 0;
 }
 
@@ -1353,8 +1347,6 @@ int cg_pid_get_session(pid_t pid, char **session) {
         _cleanup_free_ char *cgroup = NULL;
         int r;
 
-        assert(session);
-
         r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
         if (r < 0)
                 return r;
@@ -1546,7 +1538,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
         assert(unit);
         assert(ret);
 
-        if (!unit_name_is_valid(unit, false))
+        if (!unit_name_is_valid(unit, TEMPLATE_INVALID))
                 return -EINVAL;
 
         if (!endswith(unit, ".slice"))
@@ -1563,7 +1555,7 @@ int cg_slice_to_path(const char *unit, char **ret) {
 
                 strcpy(stpncpy(n, p, dash - p), ".slice");
 
-                if (!unit_name_is_valid(n, false))
+                if (!unit_name_is_valid(n, TEMPLATE_INVALID))
                         return -EINVAL;
 
                 escaped = cg_escape(n);
@@ -1597,7 +1589,18 @@ int cg_set_attribute(const char *controller, const char *path, const char *attri
         if (r < 0)
                 return r;
 
-        return write_string_file(p, value);
+        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[] =
@@ -1634,7 +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;
@@ -1644,8 +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;
         }
@@ -1653,7 +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;
@@ -1662,7 +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;
         }
@@ -1670,7 +1683,7 @@ int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path,
         return r;
 }
 
-int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to) {
+int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
         CGroupControllerMask bit = 1;
         const char *n;
         int r;
@@ -1682,8 +1695,17 @@ int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, cons
         }
 
         NULSTR_FOREACH(n, mask_names) {
-                if (supported & bit)
-                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, to, false, false);
+                if (supported & bit) {
+                        const char *p = NULL;
+
+                        if (to_callback)
+                                p = to_callback(bit, userdata);
+
+                        if (!p)
+                                p = to;
+
+                        cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, p, false, false);
+                }
 
                 bit <<= 1;
         }
@@ -1723,3 +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;
+}