core: general cgroup rework

Replace the very generic cgroup hookup with a much simpler one. With
this change only the high-level cgroup settings remain, the ability to
set arbitrary cgroup attributes is removed, so is support for adding
units to arbitrary cgroup controllers or setting arbitrary paths for
them (especially paths that are different for the various controllers).

This also introduces a new -.slice root slice, that is the parent of
system.slice and friends. This enables easy admin configuration of
root-level cgrouo properties.

This replaces DeviceDeny= by DevicePolicy=, and implicitly adds in
/dev/null, /dev/zero and friends if DeviceAllow= is used (unless this is
turned off by DevicePolicy=).

1 files changed, 280 insertions, 155 deletions

diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 15fabe860e..57c8156fdd 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -51,6 +51,7 @@
 #include "path-util.h"
 #include "syscall-list.h"
 #include "env-util.h"
+#include "cgroup.h"
 
 #ifndef HAVE_SYSV_COMPAT
 int config_parse_warn_compat(const char *unit,
@@ -996,58 +997,6 @@ int config_parse_limit(const char *unit,
         return 0;
 }
 
-int config_parse_unit_cgroup(const char *unit,
-                             const char *filename,
-                             unsigned line,
-                             const char *section,
-                             const char *lvalue,
-                             int ltype,
-                             const char *rvalue,
-                             void *data,
-                             void *userdata) {
-
-        Unit *u = userdata;
-        char *w;
-        size_t l;
-        char *state;
-
-        if (isempty(rvalue)) {
-                /* An empty assignment resets the list */
-                cgroup_bonding_free_list(u->cgroup_bondings, false);
-                u->cgroup_bondings = NULL;
-                return 0;
-        }
-
-        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
-                _cleanup_free_ char *t = NULL, *k = NULL, *ku = NULL;
-                int r;
-
-                t = strndup(w, l);
-                if (!t)
-                        return log_oom();
-
-                k = unit_full_printf(u, t);
-                if (!k)
-                        log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                                   "Failed to resolve unit specifiers on %s. Ignoring.",
-                                   t);
-
-                ku = cunescape(k ? k : t);
-                if (!ku)
-                        return log_oom();
-
-                r = unit_add_cgroup_from_text(u, ku, true, NULL);
-                if (r < 0) {
-                        log_syntax(unit, LOG_ERR, filename, line, -r,
-                                   "Failed to parse cgroup value %s, ignoring: %s",
-                                   k, rvalue);
-                        return 0;
-                }
-        }
-
-        return 0;
-}
-
 #ifdef HAVE_SYSV_COMPAT
 int config_parse_sysv_priority(const char *unit,
                                const char *filename,
@@ -1793,108 +1742,6 @@ int config_parse_unit_condition_null(const char *unit,
 DEFINE_CONFIG_PARSE_ENUM(config_parse_notify_access, notify_access, NotifyAccess, "Failed to parse notify access specifier");
 DEFINE_CONFIG_PARSE_ENUM(config_parse_start_limit_action, start_limit_action, StartLimitAction, "Failed to parse start limit action specifier");
 
-int config_parse_unit_cgroup_attr(const char *unit,
-                                  const char *filename,
-                                  unsigned line,
-                                  const char *section,
-                                  const char *lvalue,
-                                  int ltype,
-                                  const char *rvalue,
-                                  void *data,
-                                  void *userdata) {
-
-        Unit *u = data;
-        size_t a, b;
-        _cleanup_free_ char *n = NULL, *v = NULL;
-        const CGroupSemantics *s;
-        int r;
-
-        assert(filename);
-        assert(lvalue);
-        assert(rvalue);
-        assert(data);
-
-        if (isempty(rvalue)) {
-                /* Empty assignment clears the list */
-                cgroup_attribute_free_list(u->cgroup_attributes);
-                u->cgroup_attributes = NULL;
-                return 0;
-        }
-
-        a = strcspn(rvalue, WHITESPACE);
-        b = strspn(rvalue + a, WHITESPACE);
-        if (a <= 0 || b <= 0) {
-                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
-                           "Failed to parse cgroup attribute value, ignoring: %s",
-                           rvalue);
-                return 0;
-        }
-
-        n = strndup(rvalue, a);
-        if (!n)
-                return log_oom();
-
-        r = cgroup_semantics_find(NULL, n, rvalue + a + b, &v, &s);
-        if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to parse cgroup attribute value, ignoring: %s",
-                           rvalue);
-                return 0;
-        }
-
-        r = unit_add_cgroup_attribute(u, s, NULL, n, v ? v : rvalue + a + b, NULL);
-        if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to add cgroup attribute value, ignoring: %s", rvalue);
-                return 0;
-        }
-
-        return 0;
-}
-
-int config_parse_unit_cgroup_attr_pretty(const char *unit,
-                                         const char *filename,
-                                         unsigned line,
-                                         const char *section,
-                                         const char *lvalue,
-                                         int ltype,
-                                         const char *rvalue,
-                                         void *data,
-                                         void *userdata) {
-
-        Unit *u = data;
-        _cleanup_free_ char *v = NULL;
-        const CGroupSemantics *s;
-        int r;
-
-        assert(filename);
-        assert(lvalue);
-        assert(rvalue);
-        assert(data);
-
-        r = cgroup_semantics_find(NULL, lvalue, rvalue, &v, &s);
-        if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to parse cgroup attribute value, ignoring: %s",
-                           rvalue);
-                return 0;
-        } else if (r == 0) {
-                log_syntax(unit, LOG_ERR, filename, line, ENOTSUP,
-                           "Unknown or unsupported cgroup attribute %s, ignoring: %s",
-                           lvalue, rvalue);
-                return 0;
-        }
-
-        r = unit_add_cgroup_attribute(u, s, NULL, NULL, v, NULL);
-        if (r < 0) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to add cgroup attribute value, ignoring: %s", rvalue);
-                return 0;
-        }
-
-        return 0;
-}
-
 int config_parse_unit_requires_mounts_for(const char *unit,
                                           const char *filename,
                                           unsigned line,
@@ -2104,6 +1951,285 @@ int config_parse_unit_slice(
         return 0;
 }
 
+DEFINE_CONFIG_PARSE_ENUM(config_parse_device_policy, cgroup_device_policy, CGroupDevicePolicy, "Failed to parse device policy");
+
+int config_parse_cpu_shares(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        CGroupContext *c = data;
+        unsigned long lu;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        if (isempty(rvalue)) {
+                c->cpu_shares = 1024;
+                return 0;
+        }
+
+        r = safe_atolu(rvalue, &lu);
+        if (r < 0 || lu <= 0) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "CPU shares '%s' invalid. Ignoring.", rvalue);
+                return 0;
+        }
+
+        c->cpu_shares = lu;
+        return 0;
+}
+
+int config_parse_memory_limit(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        CGroupContext *c = data;
+        uint64_t *limit;
+        off_t bytes;
+        int r;
+
+        limit = streq(lvalue, "MemoryLimit") ? &c->memory_limit : &c->memory_soft_limit;
+
+        if (isempty(rvalue)) {
+                *limit = (uint64_t) -1;
+                return 0;
+        }
+
+        assert_cc(sizeof(uint64_t) == sizeof(off_t));
+
+        r = parse_bytes(rvalue, &bytes);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Memory limit '%s' invalid. Ignoring.", rvalue);
+                return 0;
+        }
+
+        *limit = (uint64_t) bytes;
+        return 0;
+}
+
+int config_parse_device_allow(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_free_ char *path = NULL;
+        CGroupContext *c = data;
+        CGroupDeviceAllow *a;
+        const char *m;
+        size_t n;
+
+        if (isempty(rvalue)) {
+                while (c->device_allow)
+                        cgroup_context_free_device_allow(c, c->device_allow);
+
+                return 0;
+        }
+
+        n = strcspn(rvalue, WHITESPACE);
+        path = strndup(rvalue, n);
+        if (!path)
+                return log_oom();
+
+        if (!path_startswith(path, "/dev")) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Invalid device node path '%s'. Ignoring.", path);
+                return 0;
+        }
+
+        m = rvalue + n + strspn(rvalue + n, WHITESPACE);
+        if (isempty(m))
+                m = "rwm";
+
+        if (!in_charset(m, "rwm")) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Invalid device rights '%s'. Ignoring.", m);
+                return 0;
+        }
+
+        a = new0(CGroupDeviceAllow, 1);
+        if (!a)
+                return log_oom();
+
+        a->path = path;
+        path = NULL;
+        a->r = !!strchr(m, 'r');
+        a->w = !!strchr(m, 'w');
+        a->m = !!strchr(m, 'm');
+
+        LIST_PREPEND(CGroupDeviceAllow, device_allow, c->device_allow, a);
+        return 0;
+}
+
+int config_parse_blockio_weight(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_free_ char *path = NULL;
+        CGroupContext *c = data;
+        unsigned long lu;
+        const char *weight;
+        size_t n;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        if (isempty(rvalue)) {
+                c->blockio_weight = 1000;
+
+                while (c->blockio_device_weights)
+                        cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights);
+
+                return 0;
+        }
+
+        n = strcspn(rvalue, WHITESPACE);
+        weight = rvalue + n;
+        if (*weight) {
+                /* Two params, first device name, then weight */
+                path = strndup(rvalue, n);
+                if (!path)
+                        return log_oom();
+
+                if (!path_startswith(path, "/dev")) {
+                        log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                                   "Invalid device node path '%s'. Ignoring.", path);
+                        return 0;
+                }
+
+                weight += strspn(weight, WHITESPACE);
+        } else
+                /* One param, only weight */
+                weight = rvalue;
+
+        r = safe_atolu(weight, &lu);
+        if (r < 0 || lu < 10 || lu > 1000) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Block IO weight '%s' invalid. Ignoring.", rvalue);
+                return 0;
+        }
+
+        if (!path)
+                c->blockio_weight = lu;
+        else {
+                CGroupBlockIODeviceWeight *w;
+
+                w = new0(CGroupBlockIODeviceWeight, 1);
+                if (!w)
+                        return log_oom();
+
+                w->path = path;
+                path = NULL;
+
+                w->weight = lu;
+
+                LIST_PREPEND(CGroupBlockIODeviceWeight, device_weights, c->blockio_device_weights, w);
+        }
+
+        return 0;
+}
+
+int config_parse_blockio_bandwidth(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        _cleanup_free_ char *path = NULL;
+        CGroupBlockIODeviceBandwidth *b;
+        CGroupContext *c = data;
+        const char *bandwidth;
+        off_t bytes;
+        size_t n;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+
+        if (isempty(rvalue)) {
+                while (c->blockio_device_bandwidths)
+                        cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths);
+
+                return 0;
+        }
+
+        n = strcspn(rvalue, WHITESPACE);
+        bandwidth = rvalue + n;
+        bandwidth += strspn(bandwidth, WHITESPACE);
+
+        if (!*bandwidth) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Expected space separated pair of device node and bandwidth. Ignoring.");
+                return 0;
+        }
+
+        path = strndup(rvalue, n);
+        if (!path)
+                return log_oom();
+
+        if (!path_startswith(path, "/dev")) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Invalid device node path '%s'. Ignoring.", path);
+                return 0;
+        }
+
+        r = parse_bytes(bandwidth, &bytes);
+        if (r < 0 || bytes <= 0) {
+                log_syntax(unit, LOG_ERR, filename, line, EINVAL,
+                           "Block IO Bandwidth '%s' invalid. Ignoring.", rvalue);
+                return 0;
+        }
+
+        b = new0(CGroupBlockIODeviceBandwidth, 1);
+        if (!b)
+                return log_oom();
+
+        b->path = path;
+        path = NULL;
+        b->bandwidth = (uint64_t) bytes;
+
+        LIST_PREPEND(CGroupBlockIODeviceBandwidth, device_bandwidths, c->blockio_device_bandwidths, b);
+
+        return 0;
+}
+
 #define FOLLOW_MAX 8
 
 static int open_follow(char **filename, FILE **_f, Set *names, char **_final) {
@@ -2463,7 +2589,6 @@ void unit_dump_config_items(FILE *f) {
                 { config_parse_exec_secure_bits,      "SECUREBITS" },
                 { config_parse_bounding_set,          "BOUNDINGSET" },
                 { config_parse_limit,                 "LIMIT" },
-                { config_parse_unit_cgroup,           "CGROUP [...]" },
                 { config_parse_unit_deps,             "UNIT [...]" },
                 { config_parse_exec,                  "PATH [ARGUMENT [...]]" },
                 { config_parse_service_type,          "SERVICETYPE" },