diff options
Diffstat (limited to 'src/core/cgroup.c')
| -rw-r--r-- | src/core/cgroup.c | 4665 |
1 files changed, 4665 insertions, 0 deletions
diff --git a/src/core/cgroup.c b/src/core/cgroup.c new file mode 100644 index 0000000..61ac4df --- /dev/null +++ b/src/core/cgroup.c @@ -0,0 +1,4665 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <fcntl.h> + +#include "sd-messages.h" + +#include "af-list.h" +#include "alloc-util.h" +#include "blockdev-util.h" +#include "bpf-devices.h" +#include "bpf-firewall.h" +#include "bpf-foreign.h" +#include "bpf-socket-bind.h" +#include "btrfs-util.h" +#include "bus-error.h" +#include "bus-locator.h" +#include "cgroup-setup.h" +#include "cgroup-util.h" +#include "cgroup.h" +#include "devnum-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "firewall-util.h" +#include "in-addr-prefix-util.h" +#include "inotify-util.h" +#include "io-util.h" +#include "ip-protocol-list.h" +#include "limits-util.h" +#include "nulstr-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "percent-util.h" +#include "process-util.h" +#include "procfs-util.h" +#include "restrict-ifaces.h" +#include "special.h" +#include "stdio-util.h" +#include "string-table.h" +#include "string-util.h" +#include "virt.h" + +#if BPF_FRAMEWORK +#include "bpf-dlopen.h" +#include "bpf-link.h" +#include "bpf/restrict_fs/restrict-fs-skel.h" +#endif + +#define CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC ((usec_t) 100 * USEC_PER_MSEC) + +/* Returns the log level to use when cgroup attribute writes fail. When an attribute is missing or we have access + * problems we downgrade to LOG_DEBUG. This is supposed to be nice to container managers and kernels which want to mask + * out specific attributes from us. */ +#define LOG_LEVEL_CGROUP_WRITE(r) (IN_SET(abs(r), ENOENT, EROFS, EACCES, EPERM) ? LOG_DEBUG : LOG_WARNING) + +uint64_t cgroup_tasks_max_resolve(const CGroupTasksMax *tasks_max) { + if (tasks_max->scale == 0) + return tasks_max->value; + + return system_tasks_max_scale(tasks_max->value, tasks_max->scale); +} + +bool manager_owns_host_root_cgroup(Manager *m) { + assert(m); + + /* Returns true if we are managing the root cgroup. Note that it isn't sufficient to just check whether the + * group root path equals "/" since that will also be the case if CLONE_NEWCGROUP is in the mix. Since there's + * appears to be no nice way to detect whether we are in a CLONE_NEWCGROUP namespace we instead just check if + * we run in any kind of container virtualization. */ + + if (MANAGER_IS_USER(m)) + return false; + + if (detect_container() > 0) + return false; + + return empty_or_root(m->cgroup_root); +} + +bool unit_has_startup_cgroup_constraints(Unit *u) { + assert(u); + + /* Returns true if this unit has any directives which apply during + * startup/shutdown phases. */ + + CGroupContext *c; + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + return c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID || + c->startup_io_weight != CGROUP_WEIGHT_INVALID || + c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID || + c->startup_cpuset_cpus.set || + c->startup_cpuset_mems.set || + c->startup_memory_high_set || + c->startup_memory_max_set || + c->startup_memory_swap_max_set|| + c->startup_memory_zswap_max_set || + c->startup_memory_low_set; +} + +bool unit_has_host_root_cgroup(Unit *u) { + assert(u); + + /* Returns whether this unit manages the root cgroup. This will return true if this unit is the root slice and + * the manager manages the root cgroup. */ + + if (!manager_owns_host_root_cgroup(u->manager)) + return false; + + return unit_has_name(u, SPECIAL_ROOT_SLICE); +} + +static int set_attribute_and_warn(Unit *u, const char *controller, const char *attribute, const char *value) { + int r; + + r = cg_set_attribute(controller, u->cgroup_path, attribute, value); + if (r < 0) + log_unit_full_errno(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to set '%s' attribute on '%s' to '%.*s': %m", + strna(attribute), empty_to_root(u->cgroup_path), (int) strcspn(value, NEWLINE), value); + + return r; +} + +static void cgroup_compat_warn(void) { + static bool cgroup_compat_warned = false; + + if (cgroup_compat_warned) + return; + + log_warning("cgroup compatibility translation between legacy and unified hierarchy settings activated. " + "See cgroup-compat debug messages for details."); + + cgroup_compat_warned = true; +} + +#define log_cgroup_compat(unit, fmt, ...) do { \ + cgroup_compat_warn(); \ + log_unit_debug(unit, "cgroup-compat: " fmt, ##__VA_ARGS__); \ + } while (false) + +void cgroup_context_init(CGroupContext *c) { + assert(c); + + /* Initialize everything to the kernel defaults. When initializing a bool member to 'true', make + * sure to serialize in execute-serialize.c using serialize_bool() instead of + * serialize_bool_elide(), as sd-executor will initialize here to 'true', but serialize_bool_elide() + * skips serialization if the value is 'false' (as that's the common default), so if the value at + * runtime is zero it would be lost after deserialization. Same when initializing uint64_t and other + * values, update/add a conditional serialization check. This is to minimize the amount of + * serialized data that is sent to the sd-executor, so that there is less work to do on the default + * cases. */ + + *c = (CGroupContext) { + .cpu_weight = CGROUP_WEIGHT_INVALID, + .startup_cpu_weight = CGROUP_WEIGHT_INVALID, + .cpu_quota_per_sec_usec = USEC_INFINITY, + .cpu_quota_period_usec = USEC_INFINITY, + + .cpu_shares = CGROUP_CPU_SHARES_INVALID, + .startup_cpu_shares = CGROUP_CPU_SHARES_INVALID, + + .memory_high = CGROUP_LIMIT_MAX, + .startup_memory_high = CGROUP_LIMIT_MAX, + .memory_max = CGROUP_LIMIT_MAX, + .startup_memory_max = CGROUP_LIMIT_MAX, + .memory_swap_max = CGROUP_LIMIT_MAX, + .startup_memory_swap_max = CGROUP_LIMIT_MAX, + .memory_zswap_max = CGROUP_LIMIT_MAX, + .startup_memory_zswap_max = CGROUP_LIMIT_MAX, + + .memory_limit = CGROUP_LIMIT_MAX, + + .io_weight = CGROUP_WEIGHT_INVALID, + .startup_io_weight = CGROUP_WEIGHT_INVALID, + + .blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID, + .startup_blockio_weight = CGROUP_BLKIO_WEIGHT_INVALID, + + .tasks_max = CGROUP_TASKS_MAX_UNSET, + + .moom_swap = MANAGED_OOM_AUTO, + .moom_mem_pressure = MANAGED_OOM_AUTO, + .moom_preference = MANAGED_OOM_PREFERENCE_NONE, + + .memory_pressure_watch = _CGROUP_PRESSURE_WATCH_INVALID, + .memory_pressure_threshold_usec = USEC_INFINITY, + }; +} + +void cgroup_context_free_device_allow(CGroupContext *c, CGroupDeviceAllow *a) { + assert(c); + assert(a); + + LIST_REMOVE(device_allow, c->device_allow, a); + free(a->path); + free(a); +} + +void cgroup_context_free_io_device_weight(CGroupContext *c, CGroupIODeviceWeight *w) { + assert(c); + assert(w); + + LIST_REMOVE(device_weights, c->io_device_weights, w); + free(w->path); + free(w); +} + +void cgroup_context_free_io_device_latency(CGroupContext *c, CGroupIODeviceLatency *l) { + assert(c); + assert(l); + + LIST_REMOVE(device_latencies, c->io_device_latencies, l); + free(l->path); + free(l); +} + +void cgroup_context_free_io_device_limit(CGroupContext *c, CGroupIODeviceLimit *l) { + assert(c); + assert(l); + + LIST_REMOVE(device_limits, c->io_device_limits, l); + free(l->path); + free(l); +} + +void cgroup_context_free_blockio_device_weight(CGroupContext *c, CGroupBlockIODeviceWeight *w) { + assert(c); + assert(w); + + LIST_REMOVE(device_weights, c->blockio_device_weights, w); + free(w->path); + free(w); +} + +void cgroup_context_free_blockio_device_bandwidth(CGroupContext *c, CGroupBlockIODeviceBandwidth *b) { + assert(c); + assert(b); + + LIST_REMOVE(device_bandwidths, c->blockio_device_bandwidths, b); + free(b->path); + free(b); +} + +void cgroup_context_remove_bpf_foreign_program(CGroupContext *c, CGroupBPFForeignProgram *p) { + assert(c); + assert(p); + + LIST_REMOVE(programs, c->bpf_foreign_programs, p); + free(p->bpffs_path); + free(p); +} + +void cgroup_context_remove_socket_bind(CGroupSocketBindItem **head) { + assert(head); + + LIST_CLEAR(socket_bind_items, *head, free); +} + +void cgroup_context_done(CGroupContext *c) { + assert(c); + + while (c->io_device_weights) + cgroup_context_free_io_device_weight(c, c->io_device_weights); + + while (c->io_device_latencies) + cgroup_context_free_io_device_latency(c, c->io_device_latencies); + + while (c->io_device_limits) + cgroup_context_free_io_device_limit(c, c->io_device_limits); + + while (c->blockio_device_weights) + cgroup_context_free_blockio_device_weight(c, c->blockio_device_weights); + + while (c->blockio_device_bandwidths) + cgroup_context_free_blockio_device_bandwidth(c, c->blockio_device_bandwidths); + + while (c->device_allow) + cgroup_context_free_device_allow(c, c->device_allow); + + cgroup_context_remove_socket_bind(&c->socket_bind_allow); + cgroup_context_remove_socket_bind(&c->socket_bind_deny); + + c->ip_address_allow = set_free(c->ip_address_allow); + c->ip_address_deny = set_free(c->ip_address_deny); + + c->ip_filters_ingress = strv_free(c->ip_filters_ingress); + c->ip_filters_egress = strv_free(c->ip_filters_egress); + + while (c->bpf_foreign_programs) + cgroup_context_remove_bpf_foreign_program(c, c->bpf_foreign_programs); + + c->restrict_network_interfaces = set_free_free(c->restrict_network_interfaces); + + cpu_set_reset(&c->cpuset_cpus); + cpu_set_reset(&c->startup_cpuset_cpus); + cpu_set_reset(&c->cpuset_mems); + cpu_set_reset(&c->startup_cpuset_mems); + + c->delegate_subgroup = mfree(c->delegate_subgroup); + + nft_set_context_clear(&c->nft_set_context); +} + +static int unit_get_kernel_memory_limit(Unit *u, const char *file, uint64_t *ret) { + assert(u); + + if (!u->cgroup_realized) + return -EOWNERDEAD; + + return cg_get_attribute_as_uint64("memory", u->cgroup_path, file, ret); +} + +static int unit_compare_memory_limit(Unit *u, const char *property_name, uint64_t *ret_unit_value, uint64_t *ret_kernel_value) { + CGroupContext *c; + CGroupMask m; + const char *file; + uint64_t unit_value; + int r; + + /* Compare kernel memcg configuration against our internal systemd state. Unsupported (and will + * return -ENODATA) on cgroup v1. + * + * Returns: + * + * <0: On error. + * 0: If the kernel memory setting doesn't match our configuration. + * >0: If the kernel memory setting matches our configuration. + * + * The following values are only guaranteed to be populated on return >=0: + * + * - ret_unit_value will contain our internal expected value for the unit, page-aligned. + * - ret_kernel_value will contain the actual value presented by the kernel. */ + + assert(u); + + r = cg_all_unified(); + if (r < 0) + return log_debug_errno(r, "Failed to determine cgroup hierarchy version: %m"); + + /* Unsupported on v1. + * + * We don't return ENOENT, since that could actually mask a genuine problem where somebody else has + * silently masked the controller. */ + if (r == 0) + return -ENODATA; + + /* The root slice doesn't have any controller files, so we can't compare anything. */ + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + return -ENODATA; + + /* It's possible to have MemoryFoo set without systemd wanting to have the memory controller enabled, + * for example, in the case of DisableControllers= or cgroup_disable on the kernel command line. To + * avoid specious errors in these scenarios, check that we even expect the memory controller to be + * enabled at all. */ + m = unit_get_target_mask(u); + if (!FLAGS_SET(m, CGROUP_MASK_MEMORY)) + return -ENODATA; + + assert_se(c = unit_get_cgroup_context(u)); + + bool startup = u->manager && IN_SET(manager_state(u->manager), MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING); + + if (streq(property_name, "MemoryLow")) { + unit_value = unit_get_ancestor_memory_low(u); + file = "memory.low"; + } else if (startup && streq(property_name, "StartupMemoryLow")) { + unit_value = unit_get_ancestor_startup_memory_low(u); + file = "memory.low"; + } else if (streq(property_name, "MemoryMin")) { + unit_value = unit_get_ancestor_memory_min(u); + file = "memory.min"; + } else if (streq(property_name, "MemoryHigh")) { + unit_value = c->memory_high; + file = "memory.high"; + } else if (startup && streq(property_name, "StartupMemoryHigh")) { + unit_value = c->startup_memory_high; + file = "memory.high"; + } else if (streq(property_name, "MemoryMax")) { + unit_value = c->memory_max; + file = "memory.max"; + } else if (startup && streq(property_name, "StartupMemoryMax")) { + unit_value = c->startup_memory_max; + file = "memory.max"; + } else if (streq(property_name, "MemorySwapMax")) { + unit_value = c->memory_swap_max; + file = "memory.swap.max"; + } else if (startup && streq(property_name, "StartupMemorySwapMax")) { + unit_value = c->startup_memory_swap_max; + file = "memory.swap.max"; + } else if (streq(property_name, "MemoryZSwapMax")) { + unit_value = c->memory_zswap_max; + file = "memory.zswap.max"; + } else if (startup && streq(property_name, "StartupMemoryZSwapMax")) { + unit_value = c->startup_memory_zswap_max; + file = "memory.zswap.max"; + } else + return -EINVAL; + + r = unit_get_kernel_memory_limit(u, file, ret_kernel_value); + if (r < 0) + return log_unit_debug_errno(u, r, "Failed to parse %s: %m", file); + + /* It's intended (soon) in a future kernel to not expose cgroup memory limits rounded to page + * boundaries, but instead separate the user-exposed limit, which is whatever userspace told us, from + * our internal page-counting. To support those future kernels, just check the value itself first + * without any page-alignment. */ + if (*ret_kernel_value == unit_value) { + *ret_unit_value = unit_value; + return 1; + } + + /* The current kernel behaviour, by comparison, is that even if you write a particular number of + * bytes into a cgroup memory file, it always returns that number page-aligned down (since the kernel + * internally stores cgroup limits in pages). As such, so long as it aligns properly, everything is + * cricket. */ + if (unit_value != CGROUP_LIMIT_MAX) + unit_value = PAGE_ALIGN_DOWN(unit_value); + + *ret_unit_value = unit_value; + + return *ret_kernel_value == *ret_unit_value; +} + +#define FORMAT_CGROUP_DIFF_MAX 128 + +static char *format_cgroup_memory_limit_comparison(char *buf, size_t l, Unit *u, const char *property_name) { + uint64_t kval, sval; + int r; + + assert(u); + assert(buf); + assert(l > 0); + + r = unit_compare_memory_limit(u, property_name, &sval, &kval); + + /* memory.swap.max is special in that it relies on CONFIG_MEMCG_SWAP (and the default swapaccount=1). + * In the absence of reliably being able to detect whether memcg swap support is available or not, + * only complain if the error is not ENOENT. This is similarly the case for memory.zswap.max relying + * on CONFIG_ZSWAP. */ + if (r > 0 || IN_SET(r, -ENODATA, -EOWNERDEAD) || + (r == -ENOENT && STR_IN_SET(property_name, + "MemorySwapMax", + "StartupMemorySwapMax", + "MemoryZSwapMax", + "StartupMemoryZSwapMax"))) + buf[0] = 0; + else if (r < 0) { + errno = -r; + (void) snprintf(buf, l, " (error getting kernel value: %m)"); + } else + (void) snprintf(buf, l, " (different value in kernel: %" PRIu64 ")", kval); + + return buf; +} + +const char *cgroup_device_permissions_to_string(CGroupDevicePermissions p) { + static const char *table[_CGROUP_DEVICE_PERMISSIONS_MAX] = { + /* Lets simply define a table with every possible combination. As long as those are just 8 we + * can get away with it. If this ever grows to more we need to revisit this logic though. */ + [0] = "", + [CGROUP_DEVICE_READ] = "r", + [CGROUP_DEVICE_WRITE] = "w", + [CGROUP_DEVICE_MKNOD] = "m", + [CGROUP_DEVICE_READ|CGROUP_DEVICE_WRITE] = "rw", + [CGROUP_DEVICE_READ|CGROUP_DEVICE_MKNOD] = "rm", + [CGROUP_DEVICE_WRITE|CGROUP_DEVICE_MKNOD] = "wm", + [CGROUP_DEVICE_READ|CGROUP_DEVICE_WRITE|CGROUP_DEVICE_MKNOD] = "rwm", + }; + + if (p < 0 || p >= _CGROUP_DEVICE_PERMISSIONS_MAX) + return NULL; + + return table[p]; +} + +CGroupDevicePermissions cgroup_device_permissions_from_string(const char *s) { + CGroupDevicePermissions p = 0; + + if (!s) + return _CGROUP_DEVICE_PERMISSIONS_INVALID; + + for (const char *c = s; *c; c++) { + if (*c == 'r') + p |= CGROUP_DEVICE_READ; + else if (*c == 'w') + p |= CGROUP_DEVICE_WRITE; + else if (*c == 'm') + p |= CGROUP_DEVICE_MKNOD; + else + return _CGROUP_DEVICE_PERMISSIONS_INVALID; + } + + return p; +} + +void cgroup_context_dump(Unit *u, FILE* f, const char *prefix) { + _cleanup_free_ char *disable_controllers_str = NULL, *delegate_controllers_str = NULL, *cpuset_cpus = NULL, *cpuset_mems = NULL, *startup_cpuset_cpus = NULL, *startup_cpuset_mems = NULL; + CGroupContext *c; + struct in_addr_prefix *iaai; + + char cda[FORMAT_CGROUP_DIFF_MAX]; + char cdb[FORMAT_CGROUP_DIFF_MAX]; + char cdc[FORMAT_CGROUP_DIFF_MAX]; + char cdd[FORMAT_CGROUP_DIFF_MAX]; + char cde[FORMAT_CGROUP_DIFF_MAX]; + char cdf[FORMAT_CGROUP_DIFF_MAX]; + char cdg[FORMAT_CGROUP_DIFF_MAX]; + char cdh[FORMAT_CGROUP_DIFF_MAX]; + char cdi[FORMAT_CGROUP_DIFF_MAX]; + char cdj[FORMAT_CGROUP_DIFF_MAX]; + char cdk[FORMAT_CGROUP_DIFF_MAX]; + + assert(u); + assert(f); + + assert_se(c = unit_get_cgroup_context(u)); + + prefix = strempty(prefix); + + (void) cg_mask_to_string(c->disable_controllers, &disable_controllers_str); + (void) cg_mask_to_string(c->delegate_controllers, &delegate_controllers_str); + + /* "Delegate=" means "yes, but no controllers". Show this as "(none)". */ + const char *delegate_str = delegate_controllers_str ?: c->delegate ? "(none)" : "no"; + + cpuset_cpus = cpu_set_to_range_string(&c->cpuset_cpus); + startup_cpuset_cpus = cpu_set_to_range_string(&c->startup_cpuset_cpus); + cpuset_mems = cpu_set_to_range_string(&c->cpuset_mems); + startup_cpuset_mems = cpu_set_to_range_string(&c->startup_cpuset_mems); + + fprintf(f, + "%sCPUAccounting: %s\n" + "%sIOAccounting: %s\n" + "%sBlockIOAccounting: %s\n" + "%sMemoryAccounting: %s\n" + "%sTasksAccounting: %s\n" + "%sIPAccounting: %s\n" + "%sCPUWeight: %" PRIu64 "\n" + "%sStartupCPUWeight: %" PRIu64 "\n" + "%sCPUShares: %" PRIu64 "\n" + "%sStartupCPUShares: %" PRIu64 "\n" + "%sCPUQuotaPerSecSec: %s\n" + "%sCPUQuotaPeriodSec: %s\n" + "%sAllowedCPUs: %s\n" + "%sStartupAllowedCPUs: %s\n" + "%sAllowedMemoryNodes: %s\n" + "%sStartupAllowedMemoryNodes: %s\n" + "%sIOWeight: %" PRIu64 "\n" + "%sStartupIOWeight: %" PRIu64 "\n" + "%sBlockIOWeight: %" PRIu64 "\n" + "%sStartupBlockIOWeight: %" PRIu64 "\n" + "%sDefaultMemoryMin: %" PRIu64 "\n" + "%sDefaultMemoryLow: %" PRIu64 "\n" + "%sMemoryMin: %" PRIu64 "%s\n" + "%sMemoryLow: %" PRIu64 "%s\n" + "%sStartupMemoryLow: %" PRIu64 "%s\n" + "%sMemoryHigh: %" PRIu64 "%s\n" + "%sStartupMemoryHigh: %" PRIu64 "%s\n" + "%sMemoryMax: %" PRIu64 "%s\n" + "%sStartupMemoryMax: %" PRIu64 "%s\n" + "%sMemorySwapMax: %" PRIu64 "%s\n" + "%sStartupMemorySwapMax: %" PRIu64 "%s\n" + "%sMemoryZSwapMax: %" PRIu64 "%s\n" + "%sStartupMemoryZSwapMax: %" PRIu64 "%s\n" + "%sMemoryLimit: %" PRIu64 "\n" + "%sTasksMax: %" PRIu64 "\n" + "%sDevicePolicy: %s\n" + "%sDisableControllers: %s\n" + "%sDelegate: %s\n" + "%sManagedOOMSwap: %s\n" + "%sManagedOOMMemoryPressure: %s\n" + "%sManagedOOMMemoryPressureLimit: " PERMYRIAD_AS_PERCENT_FORMAT_STR "\n" + "%sManagedOOMPreference: %s\n" + "%sMemoryPressureWatch: %s\n" + "%sCoredumpReceive: %s\n", + prefix, yes_no(c->cpu_accounting), + prefix, yes_no(c->io_accounting), + prefix, yes_no(c->blockio_accounting), + prefix, yes_no(c->memory_accounting), + prefix, yes_no(c->tasks_accounting), + prefix, yes_no(c->ip_accounting), + prefix, c->cpu_weight, + prefix, c->startup_cpu_weight, + prefix, c->cpu_shares, + prefix, c->startup_cpu_shares, + prefix, FORMAT_TIMESPAN(c->cpu_quota_per_sec_usec, 1), + prefix, FORMAT_TIMESPAN(c->cpu_quota_period_usec, 1), + prefix, strempty(cpuset_cpus), + prefix, strempty(startup_cpuset_cpus), + prefix, strempty(cpuset_mems), + prefix, strempty(startup_cpuset_mems), + prefix, c->io_weight, + prefix, c->startup_io_weight, + prefix, c->blockio_weight, + prefix, c->startup_blockio_weight, + prefix, c->default_memory_min, + prefix, c->default_memory_low, + prefix, c->memory_min, format_cgroup_memory_limit_comparison(cda, sizeof(cda), u, "MemoryMin"), + prefix, c->memory_low, format_cgroup_memory_limit_comparison(cdb, sizeof(cdb), u, "MemoryLow"), + prefix, c->startup_memory_low, format_cgroup_memory_limit_comparison(cdc, sizeof(cdc), u, "StartupMemoryLow"), + prefix, c->memory_high, format_cgroup_memory_limit_comparison(cdd, sizeof(cdd), u, "MemoryHigh"), + prefix, c->startup_memory_high, format_cgroup_memory_limit_comparison(cde, sizeof(cde), u, "StartupMemoryHigh"), + prefix, c->memory_max, format_cgroup_memory_limit_comparison(cdf, sizeof(cdf), u, "MemoryMax"), + prefix, c->startup_memory_max, format_cgroup_memory_limit_comparison(cdg, sizeof(cdg), u, "StartupMemoryMax"), + prefix, c->memory_swap_max, format_cgroup_memory_limit_comparison(cdh, sizeof(cdh), u, "MemorySwapMax"), + prefix, c->startup_memory_swap_max, format_cgroup_memory_limit_comparison(cdi, sizeof(cdi), u, "StartupMemorySwapMax"), + prefix, c->memory_zswap_max, format_cgroup_memory_limit_comparison(cdj, sizeof(cdj), u, "MemoryZSwapMax"), + prefix, c->startup_memory_zswap_max, format_cgroup_memory_limit_comparison(cdk, sizeof(cdk), u, "StartupMemoryZSwapMax"), + prefix, c->memory_limit, + prefix, cgroup_tasks_max_resolve(&c->tasks_max), + prefix, cgroup_device_policy_to_string(c->device_policy), + prefix, strempty(disable_controllers_str), + prefix, delegate_str, + prefix, managed_oom_mode_to_string(c->moom_swap), + prefix, managed_oom_mode_to_string(c->moom_mem_pressure), + prefix, PERMYRIAD_AS_PERCENT_FORMAT_VAL(UINT32_SCALE_TO_PERMYRIAD(c->moom_mem_pressure_limit)), + prefix, managed_oom_preference_to_string(c->moom_preference), + prefix, cgroup_pressure_watch_to_string(c->memory_pressure_watch), + prefix, yes_no(c->coredump_receive)); + + if (c->delegate_subgroup) + fprintf(f, "%sDelegateSubgroup: %s\n", + prefix, c->delegate_subgroup); + + if (c->memory_pressure_threshold_usec != USEC_INFINITY) + fprintf(f, "%sMemoryPressureThresholdSec: %s\n", + prefix, FORMAT_TIMESPAN(c->memory_pressure_threshold_usec, 1)); + + LIST_FOREACH(device_allow, a, c->device_allow) + /* strna() below should be redundant, for avoiding -Werror=format-overflow= error. See #30223. */ + fprintf(f, + "%sDeviceAllow: %s %s\n", + prefix, + a->path, + strna(cgroup_device_permissions_to_string(a->permissions))); + + LIST_FOREACH(device_weights, iw, c->io_device_weights) + fprintf(f, + "%sIODeviceWeight: %s %" PRIu64 "\n", + prefix, + iw->path, + iw->weight); + + LIST_FOREACH(device_latencies, l, c->io_device_latencies) + fprintf(f, + "%sIODeviceLatencyTargetSec: %s %s\n", + prefix, + l->path, + FORMAT_TIMESPAN(l->target_usec, 1)); + + LIST_FOREACH(device_limits, il, c->io_device_limits) + for (CGroupIOLimitType type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) + if (il->limits[type] != cgroup_io_limit_defaults[type]) + fprintf(f, + "%s%s: %s %s\n", + prefix, + cgroup_io_limit_type_to_string(type), + il->path, + FORMAT_BYTES(il->limits[type])); + + LIST_FOREACH(device_weights, w, c->blockio_device_weights) + fprintf(f, + "%sBlockIODeviceWeight: %s %" PRIu64, + prefix, + w->path, + w->weight); + + LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) { + if (b->rbps != CGROUP_LIMIT_MAX) + fprintf(f, + "%sBlockIOReadBandwidth: %s %s\n", + prefix, + b->path, + FORMAT_BYTES(b->rbps)); + if (b->wbps != CGROUP_LIMIT_MAX) + fprintf(f, + "%sBlockIOWriteBandwidth: %s %s\n", + prefix, + b->path, + FORMAT_BYTES(b->wbps)); + } + + SET_FOREACH(iaai, c->ip_address_allow) + fprintf(f, "%sIPAddressAllow: %s\n", prefix, + IN_ADDR_PREFIX_TO_STRING(iaai->family, &iaai->address, iaai->prefixlen)); + SET_FOREACH(iaai, c->ip_address_deny) + fprintf(f, "%sIPAddressDeny: %s\n", prefix, + IN_ADDR_PREFIX_TO_STRING(iaai->family, &iaai->address, iaai->prefixlen)); + + STRV_FOREACH(path, c->ip_filters_ingress) + fprintf(f, "%sIPIngressFilterPath: %s\n", prefix, *path); + STRV_FOREACH(path, c->ip_filters_egress) + fprintf(f, "%sIPEgressFilterPath: %s\n", prefix, *path); + + LIST_FOREACH(programs, p, c->bpf_foreign_programs) + fprintf(f, "%sBPFProgram: %s:%s", + prefix, bpf_cgroup_attach_type_to_string(p->attach_type), p->bpffs_path); + + if (c->socket_bind_allow) { + fprintf(f, "%sSocketBindAllow: ", prefix); + cgroup_context_dump_socket_bind_items(c->socket_bind_allow, f); + fputc('\n', f); + } + + if (c->socket_bind_deny) { + fprintf(f, "%sSocketBindDeny: ", prefix); + cgroup_context_dump_socket_bind_items(c->socket_bind_deny, f); + fputc('\n', f); + } + + if (c->restrict_network_interfaces) { + char *iface; + SET_FOREACH(iface, c->restrict_network_interfaces) + fprintf(f, "%sRestrictNetworkInterfaces: %s\n", prefix, iface); + } + + FOREACH_ARRAY(nft_set, c->nft_set_context.sets, c->nft_set_context.n_sets) + fprintf(f, "%sNFTSet: %s:%s:%s:%s\n", prefix, nft_set_source_to_string(nft_set->source), + nfproto_to_string(nft_set->nfproto), nft_set->table, nft_set->set); +} + +void cgroup_context_dump_socket_bind_item(const CGroupSocketBindItem *item, FILE *f) { + const char *family, *colon1, *protocol = "", *colon2 = ""; + + family = strempty(af_to_ipv4_ipv6(item->address_family)); + colon1 = isempty(family) ? "" : ":"; + + if (item->ip_protocol != 0) { + protocol = ip_protocol_to_tcp_udp(item->ip_protocol); + colon2 = ":"; + } + + if (item->nr_ports == 0) + fprintf(f, "%s%s%s%sany", family, colon1, protocol, colon2); + else if (item->nr_ports == 1) + fprintf(f, "%s%s%s%s%" PRIu16, family, colon1, protocol, colon2, item->port_min); + else { + uint16_t port_max = item->port_min + item->nr_ports - 1; + fprintf(f, "%s%s%s%s%" PRIu16 "-%" PRIu16, family, colon1, protocol, colon2, + item->port_min, port_max); + } +} + +void cgroup_context_dump_socket_bind_items(const CGroupSocketBindItem *items, FILE *f) { + bool first = true; + + LIST_FOREACH(socket_bind_items, bi, items) { + if (first) + first = false; + else + fputc(' ', f); + + cgroup_context_dump_socket_bind_item(bi, f); + } +} + +int cgroup_context_add_device_allow(CGroupContext *c, const char *dev, CGroupDevicePermissions p) { + _cleanup_free_ CGroupDeviceAllow *a = NULL; + _cleanup_free_ char *d = NULL; + + assert(c); + assert(dev); + assert(p >= 0 && p < _CGROUP_DEVICE_PERMISSIONS_MAX); + + if (p == 0) + p = _CGROUP_DEVICE_PERMISSIONS_ALL; + + a = new(CGroupDeviceAllow, 1); + if (!a) + return -ENOMEM; + + d = strdup(dev); + if (!d) + return -ENOMEM; + + *a = (CGroupDeviceAllow) { + .path = TAKE_PTR(d), + .permissions = p, + }; + + LIST_PREPEND(device_allow, c->device_allow, a); + TAKE_PTR(a); + + return 0; +} + +int cgroup_context_add_or_update_device_allow(CGroupContext *c, const char *dev, CGroupDevicePermissions p) { + assert(c); + assert(dev); + assert(p >= 0 && p < _CGROUP_DEVICE_PERMISSIONS_MAX); + + if (p == 0) + p = _CGROUP_DEVICE_PERMISSIONS_ALL; + + LIST_FOREACH(device_allow, b, c->device_allow) + if (path_equal(b->path, dev)) { + b->permissions = p; + return 0; + } + + return cgroup_context_add_device_allow(c, dev, p); +} + +int cgroup_context_add_bpf_foreign_program(CGroupContext *c, uint32_t attach_type, const char *bpffs_path) { + CGroupBPFForeignProgram *p; + _cleanup_free_ char *d = NULL; + + assert(c); + assert(bpffs_path); + + if (!path_is_normalized(bpffs_path) || !path_is_absolute(bpffs_path)) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Path is not normalized: %m"); + + d = strdup(bpffs_path); + if (!d) + return log_oom(); + + p = new(CGroupBPFForeignProgram, 1); + if (!p) + return log_oom(); + + *p = (CGroupBPFForeignProgram) { + .attach_type = attach_type, + .bpffs_path = TAKE_PTR(d), + }; + + LIST_PREPEND(programs, c->bpf_foreign_programs, TAKE_PTR(p)); + + return 0; +} + +#define UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(entry) \ + uint64_t unit_get_ancestor_##entry(Unit *u) { \ + CGroupContext *c; \ + \ + /* 1. Is entry set in this unit? If so, use that. \ + * 2. Is the default for this entry set in any \ + * ancestor? If so, use that. \ + * 3. Otherwise, return CGROUP_LIMIT_MIN. */ \ + \ + assert(u); \ + \ + c = unit_get_cgroup_context(u); \ + if (c && c->entry##_set) \ + return c->entry; \ + \ + while ((u = UNIT_GET_SLICE(u))) { \ + c = unit_get_cgroup_context(u); \ + if (c && c->default_##entry##_set) \ + return c->default_##entry; \ + } \ + \ + /* We've reached the root, but nobody had default for \ + * this entry set, so set it to the kernel default. */ \ + return CGROUP_LIMIT_MIN; \ +} + +UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(memory_low); +UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(startup_memory_low); +UNIT_DEFINE_ANCESTOR_MEMORY_LOOKUP(memory_min); + +static void unit_set_xattr_graceful(Unit *u, const char *name, const void *data, size_t size) { + int r; + + assert(u); + assert(name); + + if (!u->cgroup_path) + return; + + r = cg_set_xattr(u->cgroup_path, name, data, size, 0); + if (r < 0) + log_unit_debug_errno(u, r, "Failed to set '%s' xattr on control group %s, ignoring: %m", name, empty_to_root(u->cgroup_path)); +} + +static void unit_remove_xattr_graceful(Unit *u, const char *name) { + int r; + + assert(u); + assert(name); + + if (!u->cgroup_path) + return; + + r = cg_remove_xattr(u->cgroup_path, name); + if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r)) + log_unit_debug_errno(u, r, "Failed to remove '%s' xattr flag on control group %s, ignoring: %m", name, empty_to_root(u->cgroup_path)); +} + +static void cgroup_oomd_xattr_apply(Unit *u) { + CGroupContext *c; + + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return; + + if (c->moom_preference == MANAGED_OOM_PREFERENCE_OMIT) + unit_set_xattr_graceful(u, "user.oomd_omit", "1", 1); + + if (c->moom_preference == MANAGED_OOM_PREFERENCE_AVOID) + unit_set_xattr_graceful(u, "user.oomd_avoid", "1", 1); + + if (c->moom_preference != MANAGED_OOM_PREFERENCE_AVOID) + unit_remove_xattr_graceful(u, "user.oomd_avoid"); + + if (c->moom_preference != MANAGED_OOM_PREFERENCE_OMIT) + unit_remove_xattr_graceful(u, "user.oomd_omit"); +} + +static int cgroup_log_xattr_apply(Unit *u) { + ExecContext *c; + size_t len, allowed_patterns_len, denied_patterns_len; + _cleanup_free_ char *patterns = NULL, *allowed_patterns = NULL, *denied_patterns = NULL; + char *last; + int r; + + assert(u); + + c = unit_get_exec_context(u); + if (!c) + /* Some unit types have a cgroup context but no exec context, so we do not log + * any error here to avoid confusion. */ + return 0; + + if (set_isempty(c->log_filter_allowed_patterns) && set_isempty(c->log_filter_denied_patterns)) { + unit_remove_xattr_graceful(u, "user.journald_log_filter_patterns"); + return 0; + } + + r = set_make_nulstr(c->log_filter_allowed_patterns, &allowed_patterns, &allowed_patterns_len); + if (r < 0) + return log_debug_errno(r, "Failed to make nulstr from set: %m"); + + r = set_make_nulstr(c->log_filter_denied_patterns, &denied_patterns, &denied_patterns_len); + if (r < 0) + return log_debug_errno(r, "Failed to make nulstr from set: %m"); + + /* Use nul character separated strings without trailing nul */ + allowed_patterns_len = LESS_BY(allowed_patterns_len, 1u); + denied_patterns_len = LESS_BY(denied_patterns_len, 1u); + + len = allowed_patterns_len + 1 + denied_patterns_len; + patterns = new(char, len); + if (!patterns) + return log_oom_debug(); + + last = mempcpy_safe(patterns, allowed_patterns, allowed_patterns_len); + *(last++) = '\xff'; + memcpy_safe(last, denied_patterns, denied_patterns_len); + + unit_set_xattr_graceful(u, "user.journald_log_filter_patterns", patterns, len); + + return 0; +} + +static void cgroup_invocation_id_xattr_apply(Unit *u) { + bool b; + + assert(u); + + b = !sd_id128_is_null(u->invocation_id); + FOREACH_STRING(xn, "trusted.invocation_id", "user.invocation_id") { + if (b) + unit_set_xattr_graceful(u, xn, SD_ID128_TO_STRING(u->invocation_id), 32); + else + unit_remove_xattr_graceful(u, xn); + } +} + +static void cgroup_coredump_xattr_apply(Unit *u) { + CGroupContext *c; + + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return; + + if (unit_cgroup_delegate(u) && c->coredump_receive) + unit_set_xattr_graceful(u, "user.coredump_receive", "1", 1); + else + unit_remove_xattr_graceful(u, "user.coredump_receive"); +} + +static void cgroup_delegate_xattr_apply(Unit *u) { + bool b; + + assert(u); + + /* Indicate on the cgroup whether delegation is on, via an xattr. This is best-effort, as old kernels + * didn't support xattrs on cgroups at all. Later they got support for setting 'trusted.*' xattrs, + * and even later 'user.*' xattrs. We started setting this field when 'trusted.*' was added, and + * given this is now pretty much API, let's continue to support that. But also set 'user.*' as well, + * since it is readable by any user, not just CAP_SYS_ADMIN. This hence comes with slightly weaker + * security (as users who got delegated cgroups could turn it off if they like), but this shouldn't + * be a big problem given this communicates delegation state to clients, but the manager never reads + * it. */ + b = unit_cgroup_delegate(u); + FOREACH_STRING(xn, "trusted.delegate", "user.delegate") { + if (b) + unit_set_xattr_graceful(u, xn, "1", 1); + else + unit_remove_xattr_graceful(u, xn); + } +} + +static void cgroup_survive_xattr_apply(Unit *u) { + int r; + + assert(u); + + if (u->survive_final_kill_signal) { + r = cg_set_xattr( + u->cgroup_path, + "user.survive_final_kill_signal", + "1", + 1, + /* flags= */ 0); + /* user xattr support was added in kernel v5.7 */ + if (ERRNO_IS_NEG_NOT_SUPPORTED(r)) + r = cg_set_xattr( + u->cgroup_path, + "trusted.survive_final_kill_signal", + "1", + 1, + /* flags= */ 0); + if (r < 0) + log_unit_debug_errno(u, + r, + "Failed to set 'survive_final_kill_signal' xattr on control " + "group %s, ignoring: %m", + empty_to_root(u->cgroup_path)); + } else { + unit_remove_xattr_graceful(u, "user.survive_final_kill_signal"); + unit_remove_xattr_graceful(u, "trusted.survive_final_kill_signal"); + } +} + +static void cgroup_xattr_apply(Unit *u) { + assert(u); + + /* The 'user.*' xattrs can be set from a user manager. */ + cgroup_oomd_xattr_apply(u); + cgroup_log_xattr_apply(u); + cgroup_coredump_xattr_apply(u); + + if (!MANAGER_IS_SYSTEM(u->manager)) + return; + + cgroup_invocation_id_xattr_apply(u); + cgroup_delegate_xattr_apply(u); + cgroup_survive_xattr_apply(u); +} + +static int lookup_block_device(const char *p, dev_t *ret) { + dev_t rdev, dev = 0; + mode_t mode; + int r; + + assert(p); + assert(ret); + + r = device_path_parse_major_minor(p, &mode, &rdev); + if (r == -ENODEV) { /* not a parsable device node, need to go to disk */ + struct stat st; + + if (stat(p, &st) < 0) + return log_warning_errno(errno, "Couldn't stat device '%s': %m", p); + + mode = st.st_mode; + rdev = st.st_rdev; + dev = st.st_dev; + } else if (r < 0) + return log_warning_errno(r, "Failed to parse major/minor from path '%s': %m", p); + + if (S_ISCHR(mode)) + return log_warning_errno(SYNTHETIC_ERRNO(ENOTBLK), + "Device node '%s' is a character device, but block device needed.", p); + if (S_ISBLK(mode)) + *ret = rdev; + else if (major(dev) != 0) + *ret = dev; /* If this is not a device node then use the block device this file is stored on */ + else { + /* If this is btrfs, getting the backing block device is a bit harder */ + r = btrfs_get_block_device(p, ret); + if (r == -ENOTTY) + return log_warning_errno(SYNTHETIC_ERRNO(ENODEV), + "'%s' is not a block device node, and file system block device cannot be determined or is not local.", p); + if (r < 0) + return log_warning_errno(r, "Failed to determine block device backing btrfs file system '%s': %m", p); + } + + /* If this is a LUKS/DM device, recursively try to get the originating block device */ + while (block_get_originating(*ret, ret) > 0); + + /* If this is a partition, try to get the originating block device */ + (void) block_get_whole_disk(*ret, ret); + return 0; +} + +static bool cgroup_context_has_cpu_weight(CGroupContext *c) { + return c->cpu_weight != CGROUP_WEIGHT_INVALID || + c->startup_cpu_weight != CGROUP_WEIGHT_INVALID; +} + +static bool cgroup_context_has_cpu_shares(CGroupContext *c) { + return c->cpu_shares != CGROUP_CPU_SHARES_INVALID || + c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID; +} + +static bool cgroup_context_has_allowed_cpus(CGroupContext *c) { + return c->cpuset_cpus.set || c->startup_cpuset_cpus.set; +} + +static bool cgroup_context_has_allowed_mems(CGroupContext *c) { + return c->cpuset_mems.set || c->startup_cpuset_mems.set; +} + +uint64_t cgroup_context_cpu_weight(CGroupContext *c, ManagerState state) { + assert(c); + + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_cpu_weight != CGROUP_WEIGHT_INVALID) + return c->startup_cpu_weight; + else if (c->cpu_weight != CGROUP_WEIGHT_INVALID) + return c->cpu_weight; + else + return CGROUP_WEIGHT_DEFAULT; +} + +static uint64_t cgroup_context_cpu_shares(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_cpu_shares != CGROUP_CPU_SHARES_INVALID) + return c->startup_cpu_shares; + else if (c->cpu_shares != CGROUP_CPU_SHARES_INVALID) + return c->cpu_shares; + else + return CGROUP_CPU_SHARES_DEFAULT; +} + +static CPUSet *cgroup_context_allowed_cpus(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_cpuset_cpus.set) + return &c->startup_cpuset_cpus; + else + return &c->cpuset_cpus; +} + +static CPUSet *cgroup_context_allowed_mems(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_cpuset_mems.set) + return &c->startup_cpuset_mems; + else + return &c->cpuset_mems; +} + +usec_t cgroup_cpu_adjust_period(usec_t period, usec_t quota, usec_t resolution, usec_t max_period) { + /* kernel uses a minimum resolution of 1ms, so both period and (quota * period) + * need to be higher than that boundary. quota is specified in USecPerSec. + * Additionally, period must be at most max_period. */ + assert(quota > 0); + + return MIN(MAX3(period, resolution, resolution * USEC_PER_SEC / quota), max_period); +} + +static usec_t cgroup_cpu_adjust_period_and_log(Unit *u, usec_t period, usec_t quota) { + usec_t new_period; + + if (quota == USEC_INFINITY) + /* Always use default period for infinity quota. */ + return CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC; + + if (period == USEC_INFINITY) + /* Default period was requested. */ + period = CGROUP_CPU_QUOTA_DEFAULT_PERIOD_USEC; + + /* Clamp to interval [1ms, 1s] */ + new_period = cgroup_cpu_adjust_period(period, quota, USEC_PER_MSEC, USEC_PER_SEC); + + if (new_period != period) { + log_unit_full(u, u->warned_clamping_cpu_quota_period ? LOG_DEBUG : LOG_WARNING, + "Clamping CPU interval for cpu.max: period is now %s", + FORMAT_TIMESPAN(new_period, 1)); + u->warned_clamping_cpu_quota_period = true; + } + + return new_period; +} + +static void cgroup_apply_unified_cpu_weight(Unit *u, uint64_t weight) { + char buf[DECIMAL_STR_MAX(uint64_t) + 2]; + + if (weight == CGROUP_WEIGHT_IDLE) + return; + xsprintf(buf, "%" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "cpu", "cpu.weight", buf); +} + +static void cgroup_apply_unified_cpu_idle(Unit *u, uint64_t weight) { + int r; + bool is_idle; + const char *idle_val; + + is_idle = weight == CGROUP_WEIGHT_IDLE; + idle_val = one_zero(is_idle); + r = cg_set_attribute("cpu", u->cgroup_path, "cpu.idle", idle_val); + if (r < 0 && (r != -ENOENT || is_idle)) + log_unit_full_errno(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to set '%s' attribute on '%s' to '%s': %m", + "cpu.idle", empty_to_root(u->cgroup_path), idle_val); +} + +static void cgroup_apply_unified_cpu_quota(Unit *u, usec_t quota, usec_t period) { + char buf[(DECIMAL_STR_MAX(usec_t) + 1) * 2 + 1]; + + period = cgroup_cpu_adjust_period_and_log(u, period, quota); + if (quota != USEC_INFINITY) + xsprintf(buf, USEC_FMT " " USEC_FMT "\n", + MAX(quota * period / USEC_PER_SEC, USEC_PER_MSEC), period); + else + xsprintf(buf, "max " USEC_FMT "\n", period); + (void) set_attribute_and_warn(u, "cpu", "cpu.max", buf); +} + +static void cgroup_apply_legacy_cpu_shares(Unit *u, uint64_t shares) { + char buf[DECIMAL_STR_MAX(uint64_t) + 2]; + + xsprintf(buf, "%" PRIu64 "\n", shares); + (void) set_attribute_and_warn(u, "cpu", "cpu.shares", buf); +} + +static void cgroup_apply_legacy_cpu_quota(Unit *u, usec_t quota, usec_t period) { + char buf[DECIMAL_STR_MAX(usec_t) + 2]; + + period = cgroup_cpu_adjust_period_and_log(u, period, quota); + + xsprintf(buf, USEC_FMT "\n", period); + (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_period_us", buf); + + if (quota != USEC_INFINITY) { + xsprintf(buf, USEC_FMT "\n", MAX(quota * period / USEC_PER_SEC, USEC_PER_MSEC)); + (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", buf); + } else + (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_quota_us", "-1\n"); +} + +static uint64_t cgroup_cpu_shares_to_weight(uint64_t shares) { + return CLAMP(shares * CGROUP_WEIGHT_DEFAULT / CGROUP_CPU_SHARES_DEFAULT, + CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX); +} + +static uint64_t cgroup_cpu_weight_to_shares(uint64_t weight) { + /* we don't support idle in cgroupv1 */ + if (weight == CGROUP_WEIGHT_IDLE) + return CGROUP_CPU_SHARES_MIN; + + return CLAMP(weight * CGROUP_CPU_SHARES_DEFAULT / CGROUP_WEIGHT_DEFAULT, + CGROUP_CPU_SHARES_MIN, CGROUP_CPU_SHARES_MAX); +} + +static void cgroup_apply_unified_cpuset(Unit *u, const CPUSet *cpus, const char *name) { + _cleanup_free_ char *buf = NULL; + + buf = cpu_set_to_range_string(cpus); + if (!buf) { + log_oom(); + return; + } + + (void) set_attribute_and_warn(u, "cpuset", name, buf); +} + +static bool cgroup_context_has_io_config(CGroupContext *c) { + return c->io_accounting || + c->io_weight != CGROUP_WEIGHT_INVALID || + c->startup_io_weight != CGROUP_WEIGHT_INVALID || + c->io_device_weights || + c->io_device_latencies || + c->io_device_limits; +} + +static bool cgroup_context_has_blockio_config(CGroupContext *c) { + return c->blockio_accounting || + c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID || + c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID || + c->blockio_device_weights || + c->blockio_device_bandwidths; +} + +static uint64_t cgroup_context_io_weight(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_io_weight != CGROUP_WEIGHT_INVALID) + return c->startup_io_weight; + if (c->io_weight != CGROUP_WEIGHT_INVALID) + return c->io_weight; + return CGROUP_WEIGHT_DEFAULT; +} + +static uint64_t cgroup_context_blkio_weight(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING) && + c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) + return c->startup_blockio_weight; + if (c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) + return c->blockio_weight; + return CGROUP_BLKIO_WEIGHT_DEFAULT; +} + +static uint64_t cgroup_weight_blkio_to_io(uint64_t blkio_weight) { + return CLAMP(blkio_weight * CGROUP_WEIGHT_DEFAULT / CGROUP_BLKIO_WEIGHT_DEFAULT, + CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX); +} + +static uint64_t cgroup_weight_io_to_blkio(uint64_t io_weight) { + return CLAMP(io_weight * CGROUP_BLKIO_WEIGHT_DEFAULT / CGROUP_WEIGHT_DEFAULT, + CGROUP_BLKIO_WEIGHT_MIN, CGROUP_BLKIO_WEIGHT_MAX); +} + +static int set_bfq_weight(Unit *u, const char *controller, dev_t dev, uint64_t io_weight) { + static const char * const prop_names[] = { + "IOWeight", + "BlockIOWeight", + "IODeviceWeight", + "BlockIODeviceWeight", + }; + static bool warned = false; + char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+STRLEN("\n")]; + const char *p; + uint64_t bfq_weight; + int r; + + /* FIXME: drop this function when distro kernels properly support BFQ through "io.weight" + * See also: https://github.com/systemd/systemd/pull/13335 and + * https://github.com/torvalds/linux/commit/65752aef0a407e1ef17ec78a7fc31ba4e0b360f9. */ + p = strjoina(controller, ".bfq.weight"); + /* Adjust to kernel range is 1..1000, the default is 100. */ + bfq_weight = BFQ_WEIGHT(io_weight); + + if (major(dev) > 0) + xsprintf(buf, DEVNUM_FORMAT_STR " %" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), bfq_weight); + else + xsprintf(buf, "%" PRIu64 "\n", bfq_weight); + + r = cg_set_attribute(controller, u->cgroup_path, p, buf); + + /* FIXME: drop this when kernels prior + * 795fe54c2a82 ("bfq: Add per-device weight") v5.4 + * are not interesting anymore. Old kernels will fail with EINVAL, while new kernels won't return + * EINVAL on properly formatted input by us. Treat EINVAL accordingly. */ + if (r == -EINVAL && major(dev) > 0) { + if (!warned) { + log_unit_warning(u, "Kernel version does not accept per-device setting in %s.", p); + warned = true; + } + r = -EOPNOTSUPP; /* mask as unconfigured device */ + } else if (r >= 0 && io_weight != bfq_weight) + log_unit_debug(u, "%s=%" PRIu64 " scaled to %s=%" PRIu64, + prop_names[2*(major(dev) > 0) + streq(controller, "blkio")], + io_weight, p, bfq_weight); + return r; +} + +static void cgroup_apply_io_device_weight(Unit *u, const char *dev_path, uint64_t io_weight) { + char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; + dev_t dev; + int r, r1, r2; + + if (lookup_block_device(dev_path, &dev) < 0) + return; + + r1 = set_bfq_weight(u, "io", dev, io_weight); + + xsprintf(buf, DEVNUM_FORMAT_STR " %" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), io_weight); + r2 = cg_set_attribute("io", u->cgroup_path, "io.weight", buf); + + /* Look at the configured device, when both fail, prefer io.weight errno. */ + r = r2 == -EOPNOTSUPP ? r1 : r2; + + if (r < 0) + log_unit_full_errno(u, LOG_LEVEL_CGROUP_WRITE(r), + r, "Failed to set 'io[.bfq].weight' attribute on '%s' to '%.*s': %m", + empty_to_root(u->cgroup_path), (int) strcspn(buf, NEWLINE), buf); +} + +static void cgroup_apply_blkio_device_weight(Unit *u, const char *dev_path, uint64_t blkio_weight) { + char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; + dev_t dev; + int r; + + r = lookup_block_device(dev_path, &dev); + if (r < 0) + return; + + xsprintf(buf, DEVNUM_FORMAT_STR " %" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), blkio_weight); + (void) set_attribute_and_warn(u, "blkio", "blkio.weight_device", buf); +} + +static void cgroup_apply_io_device_latency(Unit *u, const char *dev_path, usec_t target) { + char buf[DECIMAL_STR_MAX(dev_t)*2+2+7+DECIMAL_STR_MAX(uint64_t)+1]; + dev_t dev; + int r; + + r = lookup_block_device(dev_path, &dev); + if (r < 0) + return; + + if (target != USEC_INFINITY) + xsprintf(buf, DEVNUM_FORMAT_STR " target=%" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), target); + else + xsprintf(buf, DEVNUM_FORMAT_STR " target=max\n", DEVNUM_FORMAT_VAL(dev)); + + (void) set_attribute_and_warn(u, "io", "io.latency", buf); +} + +static void cgroup_apply_io_device_limit(Unit *u, const char *dev_path, uint64_t *limits) { + char limit_bufs[_CGROUP_IO_LIMIT_TYPE_MAX][DECIMAL_STR_MAX(uint64_t)], + buf[DECIMAL_STR_MAX(dev_t)*2+2+(6+DECIMAL_STR_MAX(uint64_t)+1)*4]; + dev_t dev; + + if (lookup_block_device(dev_path, &dev) < 0) + return; + + for (CGroupIOLimitType type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) + if (limits[type] != cgroup_io_limit_defaults[type]) + xsprintf(limit_bufs[type], "%" PRIu64, limits[type]); + else + xsprintf(limit_bufs[type], "%s", limits[type] == CGROUP_LIMIT_MAX ? "max" : "0"); + + xsprintf(buf, DEVNUM_FORMAT_STR " rbps=%s wbps=%s riops=%s wiops=%s\n", DEVNUM_FORMAT_VAL(dev), + limit_bufs[CGROUP_IO_RBPS_MAX], limit_bufs[CGROUP_IO_WBPS_MAX], + limit_bufs[CGROUP_IO_RIOPS_MAX], limit_bufs[CGROUP_IO_WIOPS_MAX]); + (void) set_attribute_and_warn(u, "io", "io.max", buf); +} + +static void cgroup_apply_blkio_device_limit(Unit *u, const char *dev_path, uint64_t rbps, uint64_t wbps) { + char buf[DECIMAL_STR_MAX(dev_t)*2+2+DECIMAL_STR_MAX(uint64_t)+1]; + dev_t dev; + + if (lookup_block_device(dev_path, &dev) < 0) + return; + + sprintf(buf, DEVNUM_FORMAT_STR " %" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), rbps); + (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.read_bps_device", buf); + + sprintf(buf, DEVNUM_FORMAT_STR " %" PRIu64 "\n", DEVNUM_FORMAT_VAL(dev), wbps); + (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.write_bps_device", buf); +} + +static bool unit_has_unified_memory_config(Unit *u) { + CGroupContext *c; + + assert(u); + + assert_se(c = unit_get_cgroup_context(u)); + + return unit_get_ancestor_memory_min(u) > 0 || + unit_get_ancestor_memory_low(u) > 0 || unit_get_ancestor_startup_memory_low(u) > 0 || + c->memory_high != CGROUP_LIMIT_MAX || c->startup_memory_high_set || + c->memory_max != CGROUP_LIMIT_MAX || c->startup_memory_max_set || + c->memory_swap_max != CGROUP_LIMIT_MAX || c->startup_memory_swap_max_set || + c->memory_zswap_max != CGROUP_LIMIT_MAX || c->startup_memory_zswap_max_set; +} + +static void cgroup_apply_unified_memory_limit(Unit *u, const char *file, uint64_t v) { + char buf[DECIMAL_STR_MAX(uint64_t) + 1] = "max\n"; + + if (v != CGROUP_LIMIT_MAX) + xsprintf(buf, "%" PRIu64 "\n", v); + + (void) set_attribute_and_warn(u, "memory", file, buf); +} + +static void cgroup_apply_firewall(Unit *u) { + assert(u); + + /* Best-effort: let's apply IP firewalling and/or accounting if that's enabled */ + + if (bpf_firewall_compile(u) < 0) + return; + + (void) bpf_firewall_load_custom(u); + (void) bpf_firewall_install(u); +} + +void unit_modify_nft_set(Unit *u, bool add) { + int r; + + assert(u); + + if (!MANAGER_IS_SYSTEM(u->manager)) + return; + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return; + + if (cg_all_unified() <= 0) + return; + + if (u->cgroup_id == 0) + return; + + if (!u->manager->fw_ctx) { + r = fw_ctx_new_full(&u->manager->fw_ctx, /* init_tables= */ false); + if (r < 0) + return; + + assert(u->manager->fw_ctx); + } + + CGroupContext *c = ASSERT_PTR(unit_get_cgroup_context(u)); + + FOREACH_ARRAY(nft_set, c->nft_set_context.sets, c->nft_set_context.n_sets) { + if (nft_set->source != NFT_SET_SOURCE_CGROUP) + continue; + + uint64_t element = u->cgroup_id; + + r = nft_set_element_modify_any(u->manager->fw_ctx, add, nft_set->nfproto, nft_set->table, nft_set->set, &element, sizeof(element)); + if (r < 0) + log_warning_errno(r, "Failed to %s NFT set: family %s, table %s, set %s, cgroup %" PRIu64 ", ignoring: %m", + add? "add" : "delete", nfproto_to_string(nft_set->nfproto), nft_set->table, nft_set->set, u->cgroup_id); + else + log_debug("%s NFT set: family %s, table %s, set %s, cgroup %" PRIu64, + add? "Added" : "Deleted", nfproto_to_string(nft_set->nfproto), nft_set->table, nft_set->set, u->cgroup_id); + } +} + +static void cgroup_apply_socket_bind(Unit *u) { + assert(u); + + (void) bpf_socket_bind_install(u); +} + +static void cgroup_apply_restrict_network_interfaces(Unit *u) { + assert(u); + + (void) restrict_network_interfaces_install(u); +} + +static int cgroup_apply_devices(Unit *u) { + _cleanup_(bpf_program_freep) BPFProgram *prog = NULL; + const char *path; + CGroupContext *c; + CGroupDevicePolicy policy; + int r; + + assert_se(c = unit_get_cgroup_context(u)); + assert_se(path = u->cgroup_path); + + policy = c->device_policy; + + if (cg_all_unified() > 0) { + r = bpf_devices_cgroup_init(&prog, policy, c->device_allow); + if (r < 0) + return log_unit_warning_errno(u, r, "Failed to initialize device control bpf program: %m"); + + } else { + /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore + * EINVAL here. */ + + if (c->device_allow || policy != CGROUP_DEVICE_POLICY_AUTO) + r = cg_set_attribute("devices", path, "devices.deny", "a"); + else + r = cg_set_attribute("devices", path, "devices.allow", "a"); + if (r < 0) + log_unit_full_errno(u, IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to reset devices.allow/devices.deny: %m"); + } + + bool allow_list_static = policy == CGROUP_DEVICE_POLICY_CLOSED || + (policy == CGROUP_DEVICE_POLICY_AUTO && c->device_allow); + if (allow_list_static) + (void) bpf_devices_allow_list_static(prog, path); + + bool any = allow_list_static; + LIST_FOREACH(device_allow, a, c->device_allow) { + const char *val; + + if (a->permissions == 0) + continue; + + if (path_startswith(a->path, "/dev/")) + r = bpf_devices_allow_list_device(prog, path, a->path, a->permissions); + else if ((val = startswith(a->path, "block-"))) + r = bpf_devices_allow_list_major(prog, path, val, 'b', a->permissions); + else if ((val = startswith(a->path, "char-"))) + r = bpf_devices_allow_list_major(prog, path, val, 'c', a->permissions); + else { + log_unit_debug(u, "Ignoring device '%s' while writing cgroup attribute.", a->path); + continue; + } + + if (r >= 0) + any = true; + } + + if (prog && !any) { + log_unit_warning_errno(u, SYNTHETIC_ERRNO(ENODEV), "No devices matched by device filter."); + + /* The kernel verifier would reject a program we would build with the normal intro and outro + but no allow-listing rules (outro would contain an unreachable instruction for successful + return). */ + policy = CGROUP_DEVICE_POLICY_STRICT; + } + + r = bpf_devices_apply_policy(&prog, policy, any, path, &u->bpf_device_control_installed); + if (r < 0) { + static bool warned = false; + + log_full_errno(warned ? LOG_DEBUG : LOG_WARNING, r, + "Unit %s configures device ACL, but the local system doesn't seem to support the BPF-based device controller.\n" + "Proceeding WITHOUT applying ACL (all devices will be accessible)!\n" + "(This warning is only shown for the first loaded unit using device ACL.)", u->id); + + warned = true; + } + return r; +} + +static void set_io_weight(Unit *u, uint64_t weight) { + char buf[STRLEN("default \n")+DECIMAL_STR_MAX(uint64_t)]; + + assert(u); + + (void) set_bfq_weight(u, "io", makedev(0, 0), weight); + + xsprintf(buf, "default %" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "io", "io.weight", buf); +} + +static void set_blkio_weight(Unit *u, uint64_t weight) { + char buf[STRLEN("\n")+DECIMAL_STR_MAX(uint64_t)]; + + assert(u); + + (void) set_bfq_weight(u, "blkio", makedev(0, 0), weight); + + xsprintf(buf, "%" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "blkio", "blkio.weight", buf); +} + +static void cgroup_apply_bpf_foreign_program(Unit *u) { + assert(u); + + (void) bpf_foreign_install(u); +} + +static void cgroup_context_apply( + Unit *u, + CGroupMask apply_mask, + ManagerState state) { + + const char *path; + CGroupContext *c; + bool is_host_root, is_local_root; + int r; + + assert(u); + + /* Nothing to do? Exit early! */ + if (apply_mask == 0) + return; + + /* Some cgroup attributes are not supported on the host root cgroup, hence silently ignore them here. And other + * attributes should only be managed for cgroups further down the tree. */ + is_local_root = unit_has_name(u, SPECIAL_ROOT_SLICE); + is_host_root = unit_has_host_root_cgroup(u); + + assert_se(c = unit_get_cgroup_context(u)); + assert_se(path = u->cgroup_path); + + if (is_local_root) /* Make sure we don't try to display messages with an empty path. */ + path = "/"; + + /* We generally ignore errors caused by read-only mounted cgroup trees (assuming we are running in a container + * then), and missing cgroups, i.e. EROFS and ENOENT. */ + + /* In fully unified mode these attributes don't exist on the host cgroup root. On legacy the weights exist, but + * setting the weight makes very little sense on the host root cgroup, as there are no other cgroups at this + * level. The quota exists there too, but any attempt to write to it is refused with EINVAL. Inside of + * containers we want to leave control of these to the container manager (and if cgroup v2 delegation is used + * we couldn't even write to them if we wanted to). */ + if ((apply_mask & CGROUP_MASK_CPU) && !is_local_root) { + + if (cg_all_unified() > 0) { + uint64_t weight; + + if (cgroup_context_has_cpu_weight(c)) + weight = cgroup_context_cpu_weight(c, state); + else if (cgroup_context_has_cpu_shares(c)) { + uint64_t shares; + + shares = cgroup_context_cpu_shares(c, state); + weight = cgroup_cpu_shares_to_weight(shares); + + log_cgroup_compat(u, "Applying [Startup]CPUShares=%" PRIu64 " as [Startup]CPUWeight=%" PRIu64 " on %s", + shares, weight, path); + } else + weight = CGROUP_WEIGHT_DEFAULT; + + cgroup_apply_unified_cpu_idle(u, weight); + cgroup_apply_unified_cpu_weight(u, weight); + cgroup_apply_unified_cpu_quota(u, c->cpu_quota_per_sec_usec, c->cpu_quota_period_usec); + + } else { + uint64_t shares; + + if (cgroup_context_has_cpu_weight(c)) { + uint64_t weight; + + weight = cgroup_context_cpu_weight(c, state); + shares = cgroup_cpu_weight_to_shares(weight); + + log_cgroup_compat(u, "Applying [Startup]CPUWeight=%" PRIu64 " as [Startup]CPUShares=%" PRIu64 " on %s", + weight, shares, path); + } else if (cgroup_context_has_cpu_shares(c)) + shares = cgroup_context_cpu_shares(c, state); + else + shares = CGROUP_CPU_SHARES_DEFAULT; + + cgroup_apply_legacy_cpu_shares(u, shares); + cgroup_apply_legacy_cpu_quota(u, c->cpu_quota_per_sec_usec, c->cpu_quota_period_usec); + } + } + + if ((apply_mask & CGROUP_MASK_CPUSET) && !is_local_root) { + cgroup_apply_unified_cpuset(u, cgroup_context_allowed_cpus(c, state), "cpuset.cpus"); + cgroup_apply_unified_cpuset(u, cgroup_context_allowed_mems(c, state), "cpuset.mems"); + } + + /* The 'io' controller attributes are not exported on the host's root cgroup (being a pure cgroup v2 + * controller), and in case of containers we want to leave control of these attributes to the container manager + * (and we couldn't access that stuff anyway, even if we tried if proper delegation is used). */ + if ((apply_mask & CGROUP_MASK_IO) && !is_local_root) { + bool has_io, has_blockio; + uint64_t weight; + + has_io = cgroup_context_has_io_config(c); + has_blockio = cgroup_context_has_blockio_config(c); + + if (has_io) + weight = cgroup_context_io_weight(c, state); + else if (has_blockio) { + uint64_t blkio_weight; + + blkio_weight = cgroup_context_blkio_weight(c, state); + weight = cgroup_weight_blkio_to_io(blkio_weight); + + log_cgroup_compat(u, "Applying [Startup]BlockIOWeight=%" PRIu64 " as [Startup]IOWeight=%" PRIu64, + blkio_weight, weight); + } else + weight = CGROUP_WEIGHT_DEFAULT; + + set_io_weight(u, weight); + + if (has_io) { + LIST_FOREACH(device_weights, w, c->io_device_weights) + cgroup_apply_io_device_weight(u, w->path, w->weight); + + LIST_FOREACH(device_limits, limit, c->io_device_limits) + cgroup_apply_io_device_limit(u, limit->path, limit->limits); + + LIST_FOREACH(device_latencies, latency, c->io_device_latencies) + cgroup_apply_io_device_latency(u, latency->path, latency->target_usec); + + } else if (has_blockio) { + LIST_FOREACH(device_weights, w, c->blockio_device_weights) { + weight = cgroup_weight_blkio_to_io(w->weight); + + log_cgroup_compat(u, "Applying BlockIODeviceWeight=%" PRIu64 " as IODeviceWeight=%" PRIu64 " for %s", + w->weight, weight, w->path); + + cgroup_apply_io_device_weight(u, w->path, weight); + } + + LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) { + uint64_t limits[_CGROUP_IO_LIMIT_TYPE_MAX]; + + for (CGroupIOLimitType type = 0; type < _CGROUP_IO_LIMIT_TYPE_MAX; type++) + limits[type] = cgroup_io_limit_defaults[type]; + + limits[CGROUP_IO_RBPS_MAX] = b->rbps; + limits[CGROUP_IO_WBPS_MAX] = b->wbps; + + log_cgroup_compat(u, "Applying BlockIO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as IO{Read|Write}BandwidthMax= for %s", + b->rbps, b->wbps, b->path); + + cgroup_apply_io_device_limit(u, b->path, limits); + } + } + } + + if (apply_mask & CGROUP_MASK_BLKIO) { + bool has_io, has_blockio; + + has_io = cgroup_context_has_io_config(c); + has_blockio = cgroup_context_has_blockio_config(c); + + /* Applying a 'weight' never makes sense for the host root cgroup, and for containers this should be + * left to our container manager, too. */ + if (!is_local_root) { + uint64_t weight; + + if (has_io) { + uint64_t io_weight; + + io_weight = cgroup_context_io_weight(c, state); + weight = cgroup_weight_io_to_blkio(cgroup_context_io_weight(c, state)); + + log_cgroup_compat(u, "Applying [Startup]IOWeight=%" PRIu64 " as [Startup]BlockIOWeight=%" PRIu64, + io_weight, weight); + } else if (has_blockio) + weight = cgroup_context_blkio_weight(c, state); + else + weight = CGROUP_BLKIO_WEIGHT_DEFAULT; + + set_blkio_weight(u, weight); + + if (has_io) + LIST_FOREACH(device_weights, w, c->io_device_weights) { + weight = cgroup_weight_io_to_blkio(w->weight); + + log_cgroup_compat(u, "Applying IODeviceWeight=%" PRIu64 " as BlockIODeviceWeight=%" PRIu64 " for %s", + w->weight, weight, w->path); + + cgroup_apply_blkio_device_weight(u, w->path, weight); + } + else if (has_blockio) + LIST_FOREACH(device_weights, w, c->blockio_device_weights) + cgroup_apply_blkio_device_weight(u, w->path, w->weight); + } + + /* The bandwidth limits are something that make sense to be applied to the host's root but not container + * roots, as there we want the container manager to handle it */ + if (is_host_root || !is_local_root) { + if (has_io) + LIST_FOREACH(device_limits, l, c->io_device_limits) { + log_cgroup_compat(u, "Applying IO{Read|Write}Bandwidth=%" PRIu64 " %" PRIu64 " as BlockIO{Read|Write}BandwidthMax= for %s", + l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX], l->path); + + cgroup_apply_blkio_device_limit(u, l->path, l->limits[CGROUP_IO_RBPS_MAX], l->limits[CGROUP_IO_WBPS_MAX]); + } + else if (has_blockio) + LIST_FOREACH(device_bandwidths, b, c->blockio_device_bandwidths) + cgroup_apply_blkio_device_limit(u, b->path, b->rbps, b->wbps); + } + } + + /* In unified mode 'memory' attributes do not exist on the root cgroup. In legacy mode 'memory.limit_in_bytes' + * exists on the root cgroup, but any writes to it are refused with EINVAL. And if we run in a container we + * want to leave control to the container manager (and if proper cgroup v2 delegation is used we couldn't even + * write to this if we wanted to.) */ + if ((apply_mask & CGROUP_MASK_MEMORY) && !is_local_root) { + + if (cg_all_unified() > 0) { + uint64_t max, swap_max = CGROUP_LIMIT_MAX, zswap_max = CGROUP_LIMIT_MAX, high = CGROUP_LIMIT_MAX; + + if (unit_has_unified_memory_config(u)) { + bool startup = IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING, MANAGER_STOPPING); + + high = startup && c->startup_memory_high_set ? c->startup_memory_high : c->memory_high; + max = startup && c->startup_memory_max_set ? c->startup_memory_max : c->memory_max; + swap_max = startup && c->startup_memory_swap_max_set ? c->startup_memory_swap_max : c->memory_swap_max; + zswap_max = startup && c->startup_memory_zswap_max_set ? c->startup_memory_zswap_max : c->memory_zswap_max; + } else { + max = c->memory_limit; + + if (max != CGROUP_LIMIT_MAX) + log_cgroup_compat(u, "Applying MemoryLimit=%" PRIu64 " as MemoryMax=", max); + } + + cgroup_apply_unified_memory_limit(u, "memory.min", unit_get_ancestor_memory_min(u)); + cgroup_apply_unified_memory_limit(u, "memory.low", unit_get_ancestor_memory_low(u)); + cgroup_apply_unified_memory_limit(u, "memory.high", high); + cgroup_apply_unified_memory_limit(u, "memory.max", max); + cgroup_apply_unified_memory_limit(u, "memory.swap.max", swap_max); + cgroup_apply_unified_memory_limit(u, "memory.zswap.max", zswap_max); + + (void) set_attribute_and_warn(u, "memory", "memory.oom.group", one_zero(c->memory_oom_group)); + + } else { + char buf[DECIMAL_STR_MAX(uint64_t) + 1]; + uint64_t val; + + if (unit_has_unified_memory_config(u)) { + val = c->memory_max; + if (val != CGROUP_LIMIT_MAX) + log_cgroup_compat(u, "Applying MemoryMax=%" PRIu64 " as MemoryLimit=", val); + } else + val = c->memory_limit; + + if (val == CGROUP_LIMIT_MAX) + strncpy(buf, "-1\n", sizeof(buf)); + else + xsprintf(buf, "%" PRIu64 "\n", val); + + (void) set_attribute_and_warn(u, "memory", "memory.limit_in_bytes", buf); + } + } + + /* On cgroup v2 we can apply BPF everywhere. On cgroup v1 we apply it everywhere except for the root of + * containers, where we leave this to the manager */ + if ((apply_mask & (CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES)) && + (is_host_root || cg_all_unified() > 0 || !is_local_root)) + (void) cgroup_apply_devices(u); + + if (apply_mask & CGROUP_MASK_PIDS) { + + if (is_host_root) { + /* So, the "pids" controller does not expose anything on the root cgroup, in order not to + * replicate knobs exposed elsewhere needlessly. We abstract this away here however, and when + * the knobs of the root cgroup are modified propagate this to the relevant sysctls. There's a + * non-obvious asymmetry however: unlike the cgroup properties we don't really want to take + * exclusive ownership of the sysctls, but we still want to honour things if the user sets + * limits. Hence we employ sort of a one-way strategy: when the user sets a bounded limit + * through us it counts. When the user afterwards unsets it again (i.e. sets it to unbounded) + * it also counts. But if the user never set a limit through us (i.e. we are the default of + * "unbounded") we leave things unmodified. For this we manage a global boolean that we turn on + * the first time we set a limit. Note that this boolean is flushed out on manager reload, + * which is desirable so that there's an official way to release control of the sysctl from + * systemd: set the limit to unbounded and reload. */ + + if (cgroup_tasks_max_isset(&c->tasks_max)) { + u->manager->sysctl_pid_max_changed = true; + r = procfs_tasks_set_limit(cgroup_tasks_max_resolve(&c->tasks_max)); + } else if (u->manager->sysctl_pid_max_changed) + r = procfs_tasks_set_limit(TASKS_MAX); + else + r = 0; + if (r < 0) + log_unit_full_errno(u, LOG_LEVEL_CGROUP_WRITE(r), r, + "Failed to write to tasks limit sysctls: %m"); + } + + /* The attribute itself is not available on the host root cgroup, and in the container case we want to + * leave it for the container manager. */ + if (!is_local_root) { + if (cgroup_tasks_max_isset(&c->tasks_max)) { + char buf[DECIMAL_STR_MAX(uint64_t) + 1]; + + xsprintf(buf, "%" PRIu64 "\n", cgroup_tasks_max_resolve(&c->tasks_max)); + (void) set_attribute_and_warn(u, "pids", "pids.max", buf); + } else + (void) set_attribute_and_warn(u, "pids", "pids.max", "max\n"); + } + } + + if (apply_mask & CGROUP_MASK_BPF_FIREWALL) + cgroup_apply_firewall(u); + + if (apply_mask & CGROUP_MASK_BPF_FOREIGN) + cgroup_apply_bpf_foreign_program(u); + + if (apply_mask & CGROUP_MASK_BPF_SOCKET_BIND) + cgroup_apply_socket_bind(u); + + if (apply_mask & CGROUP_MASK_BPF_RESTRICT_NETWORK_INTERFACES) + cgroup_apply_restrict_network_interfaces(u); + + unit_modify_nft_set(u, /* add = */ true); +} + +static bool unit_get_needs_bpf_firewall(Unit *u) { + CGroupContext *c; + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + if (c->ip_accounting || + !set_isempty(c->ip_address_allow) || + !set_isempty(c->ip_address_deny) || + c->ip_filters_ingress || + c->ip_filters_egress) + return true; + + /* If any parent slice has an IP access list defined, it applies too */ + for (Unit *p = UNIT_GET_SLICE(u); p; p = UNIT_GET_SLICE(p)) { + c = unit_get_cgroup_context(p); + if (!c) + return false; + + if (!set_isempty(c->ip_address_allow) || + !set_isempty(c->ip_address_deny)) + return true; + } + + return false; +} + +static bool unit_get_needs_bpf_foreign_program(Unit *u) { + CGroupContext *c; + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + return !!c->bpf_foreign_programs; +} + +static bool unit_get_needs_socket_bind(Unit *u) { + CGroupContext *c; + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + return c->socket_bind_allow || c->socket_bind_deny; +} + +static bool unit_get_needs_restrict_network_interfaces(Unit *u) { + CGroupContext *c; + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + return !set_isempty(c->restrict_network_interfaces); +} + +static CGroupMask unit_get_cgroup_mask(Unit *u) { + CGroupMask mask = 0; + CGroupContext *c; + + assert(u); + + assert_se(c = unit_get_cgroup_context(u)); + + /* Figure out which controllers we need, based on the cgroup context object */ + + if (c->cpu_accounting) + mask |= get_cpu_accounting_mask(); + + if (cgroup_context_has_cpu_weight(c) || + cgroup_context_has_cpu_shares(c) || + c->cpu_quota_per_sec_usec != USEC_INFINITY) + mask |= CGROUP_MASK_CPU; + + if (cgroup_context_has_allowed_cpus(c) || cgroup_context_has_allowed_mems(c)) + mask |= CGROUP_MASK_CPUSET; + + if (cgroup_context_has_io_config(c) || cgroup_context_has_blockio_config(c)) + mask |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO; + + if (c->memory_accounting || + c->memory_limit != CGROUP_LIMIT_MAX || + unit_has_unified_memory_config(u)) + mask |= CGROUP_MASK_MEMORY; + + if (c->device_allow || + c->device_policy != CGROUP_DEVICE_POLICY_AUTO) + mask |= CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES; + + if (c->tasks_accounting || + cgroup_tasks_max_isset(&c->tasks_max)) + mask |= CGROUP_MASK_PIDS; + + return CGROUP_MASK_EXTEND_JOINED(mask); +} + +static CGroupMask unit_get_bpf_mask(Unit *u) { + CGroupMask mask = 0; + + /* Figure out which controllers we need, based on the cgroup context, possibly taking into account children + * too. */ + + if (unit_get_needs_bpf_firewall(u)) + mask |= CGROUP_MASK_BPF_FIREWALL; + + if (unit_get_needs_bpf_foreign_program(u)) + mask |= CGROUP_MASK_BPF_FOREIGN; + + if (unit_get_needs_socket_bind(u)) + mask |= CGROUP_MASK_BPF_SOCKET_BIND; + + if (unit_get_needs_restrict_network_interfaces(u)) + mask |= CGROUP_MASK_BPF_RESTRICT_NETWORK_INTERFACES; + + return mask; +} + +CGroupMask unit_get_own_mask(Unit *u) { + CGroupContext *c; + + /* Returns the mask of controllers the unit needs for itself. If a unit is not properly loaded, return an empty + * mask, as we shouldn't reflect it in the cgroup hierarchy then. */ + + if (u->load_state != UNIT_LOADED) + return 0; + + c = unit_get_cgroup_context(u); + if (!c) + return 0; + + return unit_get_cgroup_mask(u) | unit_get_bpf_mask(u) | unit_get_delegate_mask(u); +} + +CGroupMask unit_get_delegate_mask(Unit *u) { + CGroupContext *c; + + /* If delegation is turned on, then turn on selected controllers, unless we are on the legacy hierarchy and the + * process we fork into is known to drop privileges, and hence shouldn't get access to the controllers. + * + * Note that on the unified hierarchy it is safe to delegate controllers to unprivileged services. */ + + if (!unit_cgroup_delegate(u)) + return 0; + + if (cg_all_unified() <= 0) { + ExecContext *e; + + e = unit_get_exec_context(u); + if (e && !exec_context_maintains_privileges(e)) + return 0; + } + + assert_se(c = unit_get_cgroup_context(u)); + return CGROUP_MASK_EXTEND_JOINED(c->delegate_controllers); +} + +static CGroupMask unit_get_subtree_mask(Unit *u) { + + /* Returns the mask of this subtree, meaning of the group + * itself and its children. */ + + return unit_get_own_mask(u) | unit_get_members_mask(u); +} + +CGroupMask unit_get_members_mask(Unit *u) { + assert(u); + + /* Returns the mask of controllers all of the unit's children require, merged */ + + if (u->cgroup_members_mask_valid) + return u->cgroup_members_mask; /* Use cached value if possible */ + + u->cgroup_members_mask = 0; + + if (u->type == UNIT_SLICE) { + Unit *member; + + UNIT_FOREACH_DEPENDENCY(member, u, UNIT_ATOM_SLICE_OF) + u->cgroup_members_mask |= unit_get_subtree_mask(member); /* note that this calls ourselves again, for the children */ + } + + u->cgroup_members_mask_valid = true; + return u->cgroup_members_mask; +} + +CGroupMask unit_get_siblings_mask(Unit *u) { + Unit *slice; + assert(u); + + /* Returns the mask of controllers all of the unit's siblings + * require, i.e. the members mask of the unit's parent slice + * if there is one. */ + + slice = UNIT_GET_SLICE(u); + if (slice) + return unit_get_members_mask(slice); + + return unit_get_subtree_mask(u); /* we are the top-level slice */ +} + +static CGroupMask unit_get_disable_mask(Unit *u) { + CGroupContext *c; + + c = unit_get_cgroup_context(u); + if (!c) + return 0; + + return c->disable_controllers; +} + +CGroupMask unit_get_ancestor_disable_mask(Unit *u) { + CGroupMask mask; + Unit *slice; + + assert(u); + mask = unit_get_disable_mask(u); + + /* Returns the mask of controllers which are marked as forcibly + * disabled in any ancestor unit or the unit in question. */ + + slice = UNIT_GET_SLICE(u); + if (slice) + mask |= unit_get_ancestor_disable_mask(slice); + + return mask; +} + +CGroupMask unit_get_target_mask(Unit *u) { + CGroupMask own_mask, mask; + + /* This returns the cgroup mask of all controllers to enable for a specific cgroup, i.e. everything + * it needs itself, plus all that its children need, plus all that its siblings need. This is + * primarily useful on the legacy cgroup hierarchy, where we need to duplicate each cgroup in each + * hierarchy that shall be enabled for it. */ + + own_mask = unit_get_own_mask(u); + + if (own_mask & CGROUP_MASK_BPF_FIREWALL & ~u->manager->cgroup_supported) + emit_bpf_firewall_warning(u); + + mask = own_mask | unit_get_members_mask(u) | unit_get_siblings_mask(u); + + mask &= u->manager->cgroup_supported; + mask &= ~unit_get_ancestor_disable_mask(u); + + return mask; +} + +CGroupMask unit_get_enable_mask(Unit *u) { + CGroupMask mask; + + /* This returns the cgroup mask of all controllers to enable + * for the children of a specific cgroup. This is primarily + * useful for the unified cgroup hierarchy, where each cgroup + * controls which controllers are enabled for its children. */ + + mask = unit_get_members_mask(u); + mask &= u->manager->cgroup_supported; + mask &= ~unit_get_ancestor_disable_mask(u); + + return mask; +} + +void unit_invalidate_cgroup_members_masks(Unit *u) { + Unit *slice; + + assert(u); + + /* Recurse invalidate the member masks cache all the way up the tree */ + u->cgroup_members_mask_valid = false; + + slice = UNIT_GET_SLICE(u); + if (slice) + unit_invalidate_cgroup_members_masks(slice); +} + +const char *unit_get_realized_cgroup_path(Unit *u, CGroupMask mask) { + + /* Returns the realized cgroup path of the specified unit where all specified controllers are available. */ + + while (u) { + + if (u->cgroup_path && + u->cgroup_realized && + FLAGS_SET(u->cgroup_realized_mask, mask)) + return u->cgroup_path; + + u = UNIT_GET_SLICE(u); + } + + return NULL; +} + +static const char *migrate_callback(CGroupMask mask, void *userdata) { + /* If not realized at all, migrate to root (""). + * It may happen if we're upgrading from older version that didn't clean up. + */ + return strempty(unit_get_realized_cgroup_path(userdata, mask)); +} + +int unit_default_cgroup_path(const Unit *u, char **ret) { + _cleanup_free_ char *p = NULL; + int r; + + assert(u); + assert(ret); + + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + p = strdup(u->manager->cgroup_root); + else { + _cleanup_free_ char *escaped = NULL, *slice_path = NULL; + Unit *slice; + + slice = UNIT_GET_SLICE(u); + if (slice && !unit_has_name(slice, SPECIAL_ROOT_SLICE)) { + r = cg_slice_to_path(slice->id, &slice_path); + if (r < 0) + return r; + } + + r = cg_escape(u->id, &escaped); + if (r < 0) + return r; + + p = path_join(empty_to_root(u->manager->cgroup_root), slice_path, escaped); + } + if (!p) + return -ENOMEM; + + *ret = TAKE_PTR(p); + return 0; +} + +int unit_set_cgroup_path(Unit *u, const char *path) { + _cleanup_free_ char *p = NULL; + int r; + + assert(u); + + if (streq_ptr(u->cgroup_path, path)) + return 0; + + if (path) { + p = strdup(path); + if (!p) + return -ENOMEM; + } + + if (p) { + r = hashmap_put(u->manager->cgroup_unit, p, u); + if (r < 0) + return r; + } + + unit_release_cgroup(u); + u->cgroup_path = TAKE_PTR(p); + + return 1; +} + +int unit_watch_cgroup(Unit *u) { + _cleanup_free_ char *events = NULL; + int r; + + assert(u); + + /* Watches the "cgroups.events" attribute of this unit's cgroup for "empty" events, but only if + * cgroupv2 is available. */ + + if (!u->cgroup_path) + return 0; + + if (u->cgroup_control_inotify_wd >= 0) + return 0; + + /* Only applies to the unified hierarchy */ + r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); + if (r < 0) + return log_error_errno(r, "Failed to determine whether the name=systemd hierarchy is unified: %m"); + if (r == 0) + return 0; + + /* No point in watch the top-level slice, it's never going to run empty. */ + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + return 0; + + r = hashmap_ensure_allocated(&u->manager->cgroup_control_inotify_wd_unit, &trivial_hash_ops); + if (r < 0) + return log_oom(); + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events", &events); + if (r < 0) + return log_oom(); + + u->cgroup_control_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY); + if (u->cgroup_control_inotify_wd < 0) { + + if (errno == ENOENT) /* If the directory is already gone we don't need to track it, so this + * is not an error */ + return 0; + + return log_unit_error_errno(u, errno, "Failed to add control inotify watch descriptor for control group %s: %m", empty_to_root(u->cgroup_path)); + } + + r = hashmap_put(u->manager->cgroup_control_inotify_wd_unit, INT_TO_PTR(u->cgroup_control_inotify_wd), u); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to add control inotify watch descriptor for control group %s to hash map: %m", empty_to_root(u->cgroup_path)); + + return 0; +} + +int unit_watch_cgroup_memory(Unit *u) { + _cleanup_free_ char *events = NULL; + CGroupContext *c; + int r; + + assert(u); + + /* Watches the "memory.events" attribute of this unit's cgroup for "oom_kill" events, but only if + * cgroupv2 is available. */ + + if (!u->cgroup_path) + return 0; + + c = unit_get_cgroup_context(u); + if (!c) + return 0; + + /* The "memory.events" attribute is only available if the memory controller is on. Let's hence tie + * this to memory accounting, in a way watching for OOM kills is a form of memory accounting after + * all. */ + if (!c->memory_accounting) + return 0; + + /* Don't watch inner nodes, as the kernel doesn't report oom_kill events recursively currently, and + * we also don't want to generate a log message for each parent cgroup of a process. */ + if (u->type == UNIT_SLICE) + return 0; + + if (u->cgroup_memory_inotify_wd >= 0) + return 0; + + /* Only applies to the unified hierarchy */ + r = cg_all_unified(); + if (r < 0) + return log_error_errno(r, "Failed to determine whether the memory controller is unified: %m"); + if (r == 0) + return 0; + + r = hashmap_ensure_allocated(&u->manager->cgroup_memory_inotify_wd_unit, &trivial_hash_ops); + if (r < 0) + return log_oom(); + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "memory.events", &events); + if (r < 0) + return log_oom(); + + u->cgroup_memory_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY); + if (u->cgroup_memory_inotify_wd < 0) { + + if (errno == ENOENT) /* If the directory is already gone we don't need to track it, so this + * is not an error */ + return 0; + + return log_unit_error_errno(u, errno, "Failed to add memory inotify watch descriptor for control group %s: %m", empty_to_root(u->cgroup_path)); + } + + r = hashmap_put(u->manager->cgroup_memory_inotify_wd_unit, INT_TO_PTR(u->cgroup_memory_inotify_wd), u); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to add memory inotify watch descriptor for control group %s to hash map: %m", empty_to_root(u->cgroup_path)); + + return 0; +} + +int unit_pick_cgroup_path(Unit *u) { + _cleanup_free_ char *path = NULL; + int r; + + assert(u); + + if (u->cgroup_path) + return 0; + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return -EINVAL; + + r = unit_default_cgroup_path(u, &path); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to generate default cgroup path: %m"); + + r = unit_set_cgroup_path(u, path); + if (r == -EEXIST) + return log_unit_error_errno(u, r, "Control group %s exists already.", empty_to_root(path)); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to set unit's control group path to %s: %m", empty_to_root(path)); + + return 0; +} + +static int unit_update_cgroup( + Unit *u, + CGroupMask target_mask, + CGroupMask enable_mask, + ManagerState state) { + + bool created, is_root_slice; + CGroupMask migrate_mask = 0; + _cleanup_free_ char *cgroup_full_path = NULL; + int r; + + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return 0; + + /* Figure out our cgroup path */ + r = unit_pick_cgroup_path(u); + if (r < 0) + return r; + + /* First, create our own group */ + r = cg_create_everywhere(u->manager->cgroup_supported, target_mask, u->cgroup_path); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to create cgroup %s: %m", empty_to_root(u->cgroup_path)); + created = r; + + if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) { + uint64_t cgroup_id = 0; + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, NULL, &cgroup_full_path); + if (r == 0) { + r = cg_path_get_cgroupid(cgroup_full_path, &cgroup_id); + if (r < 0) + log_unit_full_errno(u, ERRNO_IS_NOT_SUPPORTED(r) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to get cgroup ID of cgroup %s, ignoring: %m", cgroup_full_path); + } else + log_unit_warning_errno(u, r, "Failed to get full cgroup path on cgroup %s, ignoring: %m", empty_to_root(u->cgroup_path)); + + u->cgroup_id = cgroup_id; + } + + /* Start watching it */ + (void) unit_watch_cgroup(u); + (void) unit_watch_cgroup_memory(u); + + /* For v2 we preserve enabled controllers in delegated units, adjust others, + * for v1 we figure out which controller hierarchies need migration. */ + if (created || !u->cgroup_realized || !unit_cgroup_delegate(u)) { + CGroupMask result_mask = 0; + + /* Enable all controllers we need */ + r = cg_enable_everywhere(u->manager->cgroup_supported, enable_mask, u->cgroup_path, &result_mask); + if (r < 0) + log_unit_warning_errno(u, r, "Failed to enable/disable controllers on cgroup %s, ignoring: %m", empty_to_root(u->cgroup_path)); + + /* Remember what's actually enabled now */ + u->cgroup_enabled_mask = result_mask; + + migrate_mask = u->cgroup_realized_mask ^ target_mask; + } + + /* Keep track that this is now realized */ + u->cgroup_realized = true; + u->cgroup_realized_mask = target_mask; + + /* Migrate processes in controller hierarchies both downwards (enabling) and upwards (disabling). + * + * Unnecessary controller cgroups are trimmed (after emptied by upward migration). + * We perform migration also with whole slices for cases when users don't care about leave + * granularity. Since delegated_mask is subset of target mask, we won't trim slice subtree containing + * delegated units. + */ + if (cg_all_unified() == 0) { + r = cg_migrate_v1_controllers(u->manager->cgroup_supported, migrate_mask, u->cgroup_path, migrate_callback, u); + if (r < 0) + log_unit_warning_errno(u, r, "Failed to migrate controller cgroups from %s, ignoring: %m", empty_to_root(u->cgroup_path)); + + is_root_slice = unit_has_name(u, SPECIAL_ROOT_SLICE); + r = cg_trim_v1_controllers(u->manager->cgroup_supported, ~target_mask, u->cgroup_path, !is_root_slice); + if (r < 0) + log_unit_warning_errno(u, r, "Failed to delete controller cgroups %s, ignoring: %m", empty_to_root(u->cgroup_path)); + } + + /* Set attributes */ + cgroup_context_apply(u, target_mask, state); + cgroup_xattr_apply(u); + + /* For most units we expect that memory monitoring is set up before the unit is started and we won't + * touch it after. For PID 1 this is different though, because we couldn't possibly do that given + * that PID 1 runs before init.scope is even set up. Hence, whenever init.scope is realized, let's + * try to open the memory pressure interface anew. */ + if (unit_has_name(u, SPECIAL_INIT_SCOPE)) + (void) manager_setup_memory_pressure_event_source(u->manager); + + return 0; +} + +static int unit_attach_pid_to_cgroup_via_bus(Unit *u, pid_t pid, const char *suffix_path) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *pp; + int r; + + assert(u); + + if (MANAGER_IS_SYSTEM(u->manager)) + return -EINVAL; + + if (!u->manager->system_bus) + return -EIO; + + if (!u->cgroup_path) + return -EINVAL; + + /* Determine this unit's cgroup path relative to our cgroup root */ + pp = path_startswith(u->cgroup_path, u->manager->cgroup_root); + if (!pp) + return -EINVAL; + + pp = strjoina("/", pp, suffix_path); + path_simplify(pp); + + r = bus_call_method(u->manager->system_bus, + bus_systemd_mgr, + "AttachProcessesToUnit", + &error, NULL, + "ssau", + NULL /* empty unit name means client's unit, i.e. us */, pp, 1, (uint32_t) pid); + if (r < 0) + return log_unit_debug_errno(u, r, "Failed to attach unit process " PID_FMT " via the bus: %s", pid, bus_error_message(&error, r)); + + return 0; +} + +int unit_attach_pids_to_cgroup(Unit *u, Set *pids, const char *suffix_path) { + _cleanup_free_ char *joined = NULL; + CGroupMask delegated_mask; + const char *p; + PidRef *pid; + int ret, r; + + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return -EINVAL; + + if (set_isempty(pids)) + return 0; + + /* Load any custom firewall BPF programs here once to test if they are existing and actually loadable. + * Fail here early since later errors in the call chain unit_realize_cgroup to cgroup_context_apply are ignored. */ + r = bpf_firewall_load_custom(u); + if (r < 0) + return r; + + r = unit_realize_cgroup(u); + if (r < 0) + return r; + + if (isempty(suffix_path)) + p = u->cgroup_path; + else { + joined = path_join(u->cgroup_path, suffix_path); + if (!joined) + return -ENOMEM; + + p = joined; + } + + delegated_mask = unit_get_delegate_mask(u); + + ret = 0; + SET_FOREACH(pid, pids) { + + /* Unfortunately we cannot add pids by pidfd to a cgroup. Hence we have to use PIDs instead, + * which of course is racy. Let's shorten the race a bit though, and re-validate the PID + * before we use it */ + r = pidref_verify(pid); + if (r < 0) { + log_unit_info_errno(u, r, "PID " PID_FMT " vanished before we could move it to target cgroup '%s', skipping: %m", pid->pid, empty_to_root(p)); + continue; + } + + /* First, attach the PID to the main cgroup hierarchy */ + r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, p, pid->pid); + if (r < 0) { + bool again = MANAGER_IS_USER(u->manager) && ERRNO_IS_PRIVILEGE(r); + + log_unit_full_errno(u, again ? LOG_DEBUG : LOG_INFO, r, + "Couldn't move process "PID_FMT" to%s requested cgroup '%s': %m", + pid->pid, again ? " directly" : "", empty_to_root(p)); + + if (again) { + int z; + + /* If we are in a user instance, and we can't move the process ourselves due + * to permission problems, let's ask the system instance about it instead. + * Since it's more privileged it might be able to move the process across the + * leaves of a subtree whose top node is not owned by us. */ + + z = unit_attach_pid_to_cgroup_via_bus(u, pid->pid, suffix_path); + if (z < 0) + log_unit_info_errno(u, z, "Couldn't move process "PID_FMT" to requested cgroup '%s' (directly or via the system bus): %m", pid->pid, empty_to_root(p)); + else { + if (ret >= 0) + ret++; /* Count successful additions */ + continue; /* When the bus thing worked via the bus we are fully done for this PID. */ + } + } + + if (ret >= 0) + ret = r; /* Remember first error */ + + continue; + } else if (ret >= 0) + ret++; /* Count successful additions */ + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) + continue; + + /* In the legacy hierarchy, attach the process to the request cgroup if possible, and if not to the + * innermost realized one */ + + for (CGroupController c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + CGroupMask bit = CGROUP_CONTROLLER_TO_MASK(c); + const char *realized; + + if (!(u->manager->cgroup_supported & bit)) + continue; + + /* If this controller is delegated and realized, honour the caller's request for the cgroup suffix. */ + if (delegated_mask & u->cgroup_realized_mask & bit) { + r = cg_attach(cgroup_controller_to_string(c), p, pid->pid); + if (r >= 0) + continue; /* Success! */ + + log_unit_debug_errno(u, r, "Failed to attach PID " PID_FMT " to requested cgroup %s in controller %s, falling back to unit's cgroup: %m", + pid->pid, empty_to_root(p), cgroup_controller_to_string(c)); + } + + /* So this controller is either not delegate or realized, or something else weird happened. In + * that case let's attach the PID at least to the closest cgroup up the tree that is + * realized. */ + realized = unit_get_realized_cgroup_path(u, bit); + if (!realized) + continue; /* Not even realized in the root slice? Then let's not bother */ + + r = cg_attach(cgroup_controller_to_string(c), realized, pid->pid); + if (r < 0) + log_unit_debug_errno(u, r, "Failed to attach PID " PID_FMT " to realized cgroup %s in controller %s, ignoring: %m", + pid->pid, realized, cgroup_controller_to_string(c)); + } + } + + return ret; +} + +static bool unit_has_mask_realized( + Unit *u, + CGroupMask target_mask, + CGroupMask enable_mask) { + + assert(u); + + /* Returns true if this unit is fully realized. We check four things: + * + * 1. Whether the cgroup was created at all + * 2. Whether the cgroup was created in all the hierarchies we need it to be created in (in case of cgroup v1) + * 3. Whether the cgroup has all the right controllers enabled (in case of cgroup v2) + * 4. Whether the invalidation mask is currently zero + * + * If you wonder why we mask the target realization and enable mask with CGROUP_MASK_V1/CGROUP_MASK_V2: note + * that there are three sets of bitmasks: CGROUP_MASK_V1 (for real cgroup v1 controllers), CGROUP_MASK_V2 (for + * real cgroup v2 controllers) and CGROUP_MASK_BPF (for BPF-based pseudo-controllers). Now, cgroup_realized_mask + * is only matters for cgroup v1 controllers, and cgroup_enabled_mask only used for cgroup v2, and if they + * differ in the others, we don't really care. (After all, the cgroup_enabled_mask tracks with controllers are + * enabled through cgroup.subtree_control, and since the BPF pseudo-controllers don't show up there, they + * simply don't matter. */ + + return u->cgroup_realized && + ((u->cgroup_realized_mask ^ target_mask) & CGROUP_MASK_V1) == 0 && + ((u->cgroup_enabled_mask ^ enable_mask) & CGROUP_MASK_V2) == 0 && + u->cgroup_invalidated_mask == 0; +} + +static bool unit_has_mask_disables_realized( + Unit *u, + CGroupMask target_mask, + CGroupMask enable_mask) { + + assert(u); + + /* Returns true if all controllers which should be disabled are indeed disabled. + * + * Unlike unit_has_mask_realized, we don't care what was enabled, only that anything we want to remove is + * already removed. */ + + return !u->cgroup_realized || + (FLAGS_SET(u->cgroup_realized_mask, target_mask & CGROUP_MASK_V1) && + FLAGS_SET(u->cgroup_enabled_mask, enable_mask & CGROUP_MASK_V2)); +} + +static bool unit_has_mask_enables_realized( + Unit *u, + CGroupMask target_mask, + CGroupMask enable_mask) { + + assert(u); + + /* Returns true if all controllers which should be enabled are indeed enabled. + * + * Unlike unit_has_mask_realized, we don't care about the controllers that are not present, only that anything + * we want to add is already added. */ + + return u->cgroup_realized && + ((u->cgroup_realized_mask | target_mask) & CGROUP_MASK_V1) == (u->cgroup_realized_mask & CGROUP_MASK_V1) && + ((u->cgroup_enabled_mask | enable_mask) & CGROUP_MASK_V2) == (u->cgroup_enabled_mask & CGROUP_MASK_V2); +} + +void unit_add_to_cgroup_realize_queue(Unit *u) { + assert(u); + + if (u->in_cgroup_realize_queue) + return; + + LIST_APPEND(cgroup_realize_queue, u->manager->cgroup_realize_queue, u); + u->in_cgroup_realize_queue = true; +} + +static void unit_remove_from_cgroup_realize_queue(Unit *u) { + assert(u); + + if (!u->in_cgroup_realize_queue) + return; + + LIST_REMOVE(cgroup_realize_queue, u->manager->cgroup_realize_queue, u); + u->in_cgroup_realize_queue = false; +} + +/* Controllers can only be enabled breadth-first, from the root of the + * hierarchy downwards to the unit in question. */ +static int unit_realize_cgroup_now_enable(Unit *u, ManagerState state) { + CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask; + Unit *slice; + int r; + + assert(u); + + /* First go deal with this unit's parent, or we won't be able to enable + * any new controllers at this layer. */ + slice = UNIT_GET_SLICE(u); + if (slice) { + r = unit_realize_cgroup_now_enable(slice, state); + if (r < 0) + return r; + } + + target_mask = unit_get_target_mask(u); + enable_mask = unit_get_enable_mask(u); + + /* We can only enable in this direction, don't try to disable anything. + */ + if (unit_has_mask_enables_realized(u, target_mask, enable_mask)) + return 0; + + new_target_mask = u->cgroup_realized_mask | target_mask; + new_enable_mask = u->cgroup_enabled_mask | enable_mask; + + return unit_update_cgroup(u, new_target_mask, new_enable_mask, state); +} + +/* Controllers can only be disabled depth-first, from the leaves of the + * hierarchy upwards to the unit in question. */ +static int unit_realize_cgroup_now_disable(Unit *u, ManagerState state) { + Unit *m; + + assert(u); + + if (u->type != UNIT_SLICE) + return 0; + + UNIT_FOREACH_DEPENDENCY(m, u, UNIT_ATOM_SLICE_OF) { + CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask; + int r; + + /* The cgroup for this unit might not actually be fully realised yet, in which case it isn't + * holding any controllers open anyway. */ + if (!m->cgroup_realized) + continue; + + /* We must disable those below us first in order to release the controller. */ + if (m->type == UNIT_SLICE) + (void) unit_realize_cgroup_now_disable(m, state); + + target_mask = unit_get_target_mask(m); + enable_mask = unit_get_enable_mask(m); + + /* We can only disable in this direction, don't try to enable anything. */ + if (unit_has_mask_disables_realized(m, target_mask, enable_mask)) + continue; + + new_target_mask = m->cgroup_realized_mask & target_mask; + new_enable_mask = m->cgroup_enabled_mask & enable_mask; + + r = unit_update_cgroup(m, new_target_mask, new_enable_mask, state); + if (r < 0) + return r; + } + + return 0; +} + +/* Check if necessary controllers and attributes for a unit are in place. + * + * - If so, do nothing. + * - If not, create paths, move processes over, and set attributes. + * + * Controllers can only be *enabled* in a breadth-first way, and *disabled* in + * a depth-first way. As such the process looks like this: + * + * Suppose we have a cgroup hierarchy which looks like this: + * + * root + * / \ + * / \ + * / \ + * a b + * / \ / \ + * / \ / \ + * c d e f + * / \ / \ / \ / \ + * h i j k l m n o + * + * 1. We want to realise cgroup "d" now. + * 2. cgroup "a" has DisableControllers=cpu in the associated unit. + * 3. cgroup "k" just started requesting the memory controller. + * + * To make this work we must do the following in order: + * + * 1. Disable CPU controller in k, j + * 2. Disable CPU controller in d + * 3. Enable memory controller in root + * 4. Enable memory controller in a + * 5. Enable memory controller in d + * 6. Enable memory controller in k + * + * Notice that we need to touch j in one direction, but not the other. We also + * don't go beyond d when disabling -- it's up to "a" to get realized if it + * wants to disable further. The basic rules are therefore: + * + * - If you're disabling something, you need to realise all of the cgroups from + * your recursive descendants to the root. This starts from the leaves. + * - If you're enabling something, you need to realise from the root cgroup + * downwards, but you don't need to iterate your recursive descendants. + * + * Returns 0 on success and < 0 on failure. */ +static int unit_realize_cgroup_now(Unit *u, ManagerState state) { + CGroupMask target_mask, enable_mask; + Unit *slice; + int r; + + assert(u); + + unit_remove_from_cgroup_realize_queue(u); + + target_mask = unit_get_target_mask(u); + enable_mask = unit_get_enable_mask(u); + + if (unit_has_mask_realized(u, target_mask, enable_mask)) + return 0; + + /* Disable controllers below us, if there are any */ + r = unit_realize_cgroup_now_disable(u, state); + if (r < 0) + return r; + + /* Enable controllers above us, if there are any */ + slice = UNIT_GET_SLICE(u); + if (slice) { + r = unit_realize_cgroup_now_enable(slice, state); + if (r < 0) + return r; + } + + /* Now actually deal with the cgroup we were trying to realise and set attributes */ + r = unit_update_cgroup(u, target_mask, enable_mask, state); + if (r < 0) + return r; + + /* Now, reset the invalidation mask */ + u->cgroup_invalidated_mask = 0; + return 0; +} + +unsigned manager_dispatch_cgroup_realize_queue(Manager *m) { + ManagerState state; + unsigned n = 0; + Unit *i; + int r; + + assert(m); + + state = manager_state(m); + + while ((i = m->cgroup_realize_queue)) { + assert(i->in_cgroup_realize_queue); + + if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(i))) { + /* Maybe things changed, and the unit is not actually active anymore? */ + unit_remove_from_cgroup_realize_queue(i); + continue; + } + + r = unit_realize_cgroup_now(i, state); + if (r < 0) + log_warning_errno(r, "Failed to realize cgroups for queued unit %s, ignoring: %m", i->id); + + n++; + } + + return n; +} + +void unit_add_family_to_cgroup_realize_queue(Unit *u) { + assert(u); + assert(u->type == UNIT_SLICE); + + /* Family of a unit for is defined as (immediate) children of the unit and immediate children of all + * its ancestors. + * + * Ideally we would enqueue ancestor path only (bottom up). However, on cgroup-v1 scheduling becomes + * very weird if two units that own processes reside in the same slice, but one is realized in the + * "cpu" hierarchy and one is not (for example because one has CPUWeight= set and the other does + * not), because that means individual processes need to be scheduled against whole cgroups. Let's + * avoid this asymmetry by always ensuring that siblings of a unit are always realized in their v1 + * controller hierarchies too (if unit requires the controller to be realized). + * + * The function must invalidate cgroup_members_mask of all ancestors in order to calculate up to date + * masks. */ + + do { + Unit *m; + + /* Children of u likely changed when we're called */ + u->cgroup_members_mask_valid = false; + + UNIT_FOREACH_DEPENDENCY(m, u, UNIT_ATOM_SLICE_OF) { + + /* No point in doing cgroup application for units without active processes. */ + if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m))) + continue; + + /* We only enqueue siblings if they were realized once at least, in the main + * hierarchy. */ + if (!m->cgroup_realized) + continue; + + /* If the unit doesn't need any new controllers and has current ones + * realized, it doesn't need any changes. */ + if (unit_has_mask_realized(m, + unit_get_target_mask(m), + unit_get_enable_mask(m))) + continue; + + unit_add_to_cgroup_realize_queue(m); + } + + /* Parent comes after children */ + unit_add_to_cgroup_realize_queue(u); + + u = UNIT_GET_SLICE(u); + } while (u); +} + +int unit_realize_cgroup(Unit *u) { + Unit *slice; + + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return 0; + + /* So, here's the deal: when realizing the cgroups for this unit, we need to first create all + * parents, but there's more actually: for the weight-based controllers we also need to make sure + * that all our siblings (i.e. units that are in the same slice as we are) have cgroups, too. On the + * other hand, when a controller is removed from realized set, it may become unnecessary in siblings + * and ancestors and they should be (de)realized too. + * + * This call will defer work on the siblings and derealized ancestors to the next event loop + * iteration and synchronously creates the parent cgroups (unit_realize_cgroup_now). */ + + slice = UNIT_GET_SLICE(u); + if (slice) + unit_add_family_to_cgroup_realize_queue(slice); + + /* And realize this one now (and apply the values) */ + return unit_realize_cgroup_now(u, manager_state(u->manager)); +} + +void unit_release_cgroup(Unit *u) { + assert(u); + + /* Forgets all cgroup details for this cgroup — but does *not* destroy the cgroup. This is hence OK to call + * when we close down everything for reexecution, where we really want to leave the cgroup in place. */ + + if (u->cgroup_path) { + (void) hashmap_remove(u->manager->cgroup_unit, u->cgroup_path); + u->cgroup_path = mfree(u->cgroup_path); + } + + if (u->cgroup_control_inotify_wd >= 0) { + if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_control_inotify_wd) < 0) + log_unit_debug_errno(u, errno, "Failed to remove cgroup control inotify watch %i for %s, ignoring: %m", u->cgroup_control_inotify_wd, u->id); + + (void) hashmap_remove(u->manager->cgroup_control_inotify_wd_unit, INT_TO_PTR(u->cgroup_control_inotify_wd)); + u->cgroup_control_inotify_wd = -1; + } + + if (u->cgroup_memory_inotify_wd >= 0) { + if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_memory_inotify_wd) < 0) + log_unit_debug_errno(u, errno, "Failed to remove cgroup memory inotify watch %i for %s, ignoring: %m", u->cgroup_memory_inotify_wd, u->id); + + (void) hashmap_remove(u->manager->cgroup_memory_inotify_wd_unit, INT_TO_PTR(u->cgroup_memory_inotify_wd)); + u->cgroup_memory_inotify_wd = -1; + } +} + +bool unit_maybe_release_cgroup(Unit *u) { + int r; + + assert(u); + + if (!u->cgroup_path) + return true; + + /* Don't release the cgroup if there are still processes under it. If we get notified later when all the + * processes exit (e.g. the processes were in D-state and exited after the unit was marked as failed) + * we need the cgroup paths to continue to be tracked by the manager so they can be looked up and cleaned + * up later. */ + r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path); + if (r < 0) + log_unit_debug_errno(u, r, "Error checking if the cgroup is recursively empty, ignoring: %m"); + else if (r == 1) { + unit_release_cgroup(u); + return true; + } + + return false; +} + +void unit_prune_cgroup(Unit *u) { + int r; + bool is_root_slice; + + assert(u); + + /* Removes the cgroup, if empty and possible, and stops watching it. */ + + if (!u->cgroup_path) + return; + + (void) unit_get_cpu_usage(u, NULL); /* Cache the last CPU usage value before we destroy the cgroup */ + +#if BPF_FRAMEWORK + (void) lsm_bpf_cleanup(u); /* Remove cgroup from the global LSM BPF map */ +#endif + + unit_modify_nft_set(u, /* add = */ false); + + is_root_slice = unit_has_name(u, SPECIAL_ROOT_SLICE); + + r = cg_trim_everywhere(u->manager->cgroup_supported, u->cgroup_path, !is_root_slice); + if (r < 0) + /* One reason we could have failed here is, that the cgroup still contains a process. + * However, if the cgroup becomes removable at a later time, it might be removed when + * the containing slice is stopped. So even if we failed now, this unit shouldn't assume + * that the cgroup is still realized the next time it is started. Do not return early + * on error, continue cleanup. */ + log_unit_full_errno(u, r == -EBUSY ? LOG_DEBUG : LOG_WARNING, r, "Failed to destroy cgroup %s, ignoring: %m", empty_to_root(u->cgroup_path)); + + if (is_root_slice) + return; + + if (!unit_maybe_release_cgroup(u)) /* Returns true if the cgroup was released */ + return; + + u->cgroup_realized = false; + u->cgroup_realized_mask = 0; + u->cgroup_enabled_mask = 0; + + u->bpf_device_control_installed = bpf_program_free(u->bpf_device_control_installed); +} + +int unit_search_main_pid(Unit *u, PidRef *ret) { + _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(u); + assert(ret); + + if (!u->cgroup_path) + return -ENXIO; + + r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, &f); + if (r < 0) + return r; + + for (;;) { + _cleanup_(pidref_done) PidRef npidref = PIDREF_NULL; + + r = cg_read_pidref(f, &npidref); + if (r < 0) + return r; + if (r == 0) + break; + + if (pidref_equal(&pidref, &npidref)) /* seen already, cgroupfs reports duplicates! */ + continue; + + if (pidref_is_my_child(&npidref) <= 0) /* ignore processes further down the tree */ + continue; + + if (pidref_is_set(&pidref) != 0) + /* Dang, there's more than one daemonized PID in this group, so we don't know what + * process is the main process. */ + return -ENODATA; + + pidref = TAKE_PIDREF(npidref); + } + + if (!pidref_is_set(&pidref)) + return -ENODATA; + + *ret = TAKE_PIDREF(pidref); + return 0; +} + +static int unit_watch_pids_in_path(Unit *u, const char *path) { + _cleanup_closedir_ DIR *d = NULL; + _cleanup_fclose_ FILE *f = NULL; + int ret = 0, r; + + assert(u); + assert(path); + + r = cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, path, &f); + if (r < 0) + RET_GATHER(ret, r); + else { + for (;;) { + _cleanup_(pidref_done) PidRef pid = PIDREF_NULL; + + r = cg_read_pidref(f, &pid); + if (r == 0) + break; + if (r < 0) { + RET_GATHER(ret, r); + break; + } + + RET_GATHER(ret, unit_watch_pidref(u, &pid, /* exclusive= */ false)); + } + } + + r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d); + if (r < 0) + RET_GATHER(ret, r); + else { + for (;;) { + _cleanup_free_ char *fn = NULL, *p = NULL; + + r = cg_read_subgroup(d, &fn); + if (r == 0) + break; + if (r < 0) { + RET_GATHER(ret, r); + break; + } + + p = path_join(empty_to_root(path), fn); + if (!p) + return -ENOMEM; + + RET_GATHER(ret, unit_watch_pids_in_path(u, p)); + } + } + + return ret; +} + +int unit_synthesize_cgroup_empty_event(Unit *u) { + int r; + + assert(u); + + /* Enqueue a synthetic cgroup empty event if this unit doesn't watch any PIDs anymore. This is compatibility + * support for non-unified systems where notifications aren't reliable, and hence need to take whatever we can + * get as notification source as soon as we stopped having any useful PIDs to watch for. */ + + if (!u->cgroup_path) + return -ENOENT; + + r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); + if (r < 0) + return r; + if (r > 0) /* On unified we have reliable notifications, and don't need this */ + return 0; + + if (!set_isempty(u->pids)) + return 0; + + unit_add_to_cgroup_empty_queue(u); + return 0; +} + +int unit_watch_all_pids(Unit *u) { + int r; + + assert(u); + + /* Adds all PIDs from our cgroup to the set of PIDs we + * watch. This is a fallback logic for cases where we do not + * get reliable cgroup empty notifications: we try to use + * SIGCHLD as replacement. */ + + if (!u->cgroup_path) + return -ENOENT; + + r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); + if (r < 0) + return r; + if (r > 0) /* On unified we can use proper notifications */ + return 0; + + return unit_watch_pids_in_path(u, u->cgroup_path); +} + +static int on_cgroup_empty_event(sd_event_source *s, void *userdata) { + Manager *m = ASSERT_PTR(userdata); + Unit *u; + int r; + + assert(s); + + u = m->cgroup_empty_queue; + if (!u) + return 0; + + assert(u->in_cgroup_empty_queue); + u->in_cgroup_empty_queue = false; + LIST_REMOVE(cgroup_empty_queue, m->cgroup_empty_queue, u); + + if (m->cgroup_empty_queue) { + /* More stuff queued, let's make sure we remain enabled */ + r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT); + if (r < 0) + log_debug_errno(r, "Failed to reenable cgroup empty event source, ignoring: %m"); + } + + /* Update state based on OOM kills before we notify about cgroup empty event */ + (void) unit_check_oom(u); + (void) unit_check_oomd_kill(u); + + unit_add_to_gc_queue(u); + + if (IN_SET(unit_active_state(u), UNIT_INACTIVE, UNIT_FAILED)) + unit_prune_cgroup(u); + else if (UNIT_VTABLE(u)->notify_cgroup_empty) + UNIT_VTABLE(u)->notify_cgroup_empty(u); + + return 0; +} + +void unit_add_to_cgroup_empty_queue(Unit *u) { + int r; + + assert(u); + + /* Note that there are four different ways how cgroup empty events reach us: + * + * 1. On the unified hierarchy we get an inotify event on the cgroup + * + * 2. On the legacy hierarchy, when running in system mode, we get a datagram on the cgroup agent socket + * + * 3. On the legacy hierarchy, when running in user mode, we get a D-Bus signal on the system bus + * + * 4. On the legacy hierarchy, in service units we start watching all processes of the cgroup for SIGCHLD as + * soon as we get one SIGCHLD, to deal with unreliable cgroup notifications. + * + * Regardless which way we got the notification, we'll verify it here, and then add it to a separate + * queue. This queue will be dispatched at a lower priority than the SIGCHLD handler, so that we always use + * SIGCHLD if we can get it first, and only use the cgroup empty notifications if there's no SIGCHLD pending + * (which might happen if the cgroup doesn't contain processes that are our own child, which is typically the + * case for scope units). */ + + if (u->in_cgroup_empty_queue) + return; + + /* Let's verify that the cgroup is really empty */ + if (!u->cgroup_path) + return; + + r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path); + if (r < 0) { + log_unit_debug_errno(u, r, "Failed to determine whether cgroup %s is empty: %m", empty_to_root(u->cgroup_path)); + return; + } + if (r == 0) + return; + + LIST_PREPEND(cgroup_empty_queue, u->manager->cgroup_empty_queue, u); + u->in_cgroup_empty_queue = true; + + /* Trigger the defer event */ + r = sd_event_source_set_enabled(u->manager->cgroup_empty_event_source, SD_EVENT_ONESHOT); + if (r < 0) + log_debug_errno(r, "Failed to enable cgroup empty event source: %m"); +} + +static void unit_remove_from_cgroup_empty_queue(Unit *u) { + assert(u); + + if (!u->in_cgroup_empty_queue) + return; + + LIST_REMOVE(cgroup_empty_queue, u->manager->cgroup_empty_queue, u); + u->in_cgroup_empty_queue = false; +} + +int unit_check_oomd_kill(Unit *u) { + _cleanup_free_ char *value = NULL; + bool increased; + uint64_t n = 0; + int r; + + if (!u->cgroup_path) + return 0; + + r = cg_all_unified(); + if (r < 0) + return log_unit_debug_errno(u, r, "Couldn't determine whether we are in all unified mode: %m"); + else if (r == 0) + return 0; + + r = cg_get_xattr_malloc(u->cgroup_path, "user.oomd_ooms", &value); + if (r < 0 && !ERRNO_IS_XATTR_ABSENT(r)) + return r; + + if (!isempty(value)) { + r = safe_atou64(value, &n); + if (r < 0) + return r; + } + + increased = n > u->managed_oom_kill_last; + u->managed_oom_kill_last = n; + + if (!increased) + return 0; + + n = 0; + value = mfree(value); + r = cg_get_xattr_malloc(u->cgroup_path, "user.oomd_kill", &value); + if (r >= 0 && !isempty(value)) + (void) safe_atou64(value, &n); + + if (n > 0) + log_unit_struct(u, LOG_NOTICE, + "MESSAGE_ID=" SD_MESSAGE_UNIT_OOMD_KILL_STR, + LOG_UNIT_INVOCATION_ID(u), + LOG_UNIT_MESSAGE(u, "systemd-oomd killed %"PRIu64" process(es) in this unit.", n), + "N_PROCESSES=%" PRIu64, n); + else + log_unit_struct(u, LOG_NOTICE, + "MESSAGE_ID=" SD_MESSAGE_UNIT_OOMD_KILL_STR, + LOG_UNIT_INVOCATION_ID(u), + LOG_UNIT_MESSAGE(u, "systemd-oomd killed some process(es) in this unit.")); + + unit_notify_cgroup_oom(u, /* ManagedOOM= */ true); + + return 1; +} + +int unit_check_oom(Unit *u) { + _cleanup_free_ char *oom_kill = NULL; + bool increased; + uint64_t c; + int r; + + if (!u->cgroup_path) + return 0; + + r = cg_get_keyed_attribute("memory", u->cgroup_path, "memory.events", STRV_MAKE("oom_kill"), &oom_kill); + if (IN_SET(r, -ENOENT, -ENXIO)) /* Handle gracefully if cgroup or oom_kill attribute don't exist */ + c = 0; + else if (r < 0) + return log_unit_debug_errno(u, r, "Failed to read oom_kill field of memory.events cgroup attribute: %m"); + else { + r = safe_atou64(oom_kill, &c); + if (r < 0) + return log_unit_debug_errno(u, r, "Failed to parse oom_kill field: %m"); + } + + increased = c > u->oom_kill_last; + u->oom_kill_last = c; + + if (!increased) + return 0; + + log_unit_struct(u, LOG_NOTICE, + "MESSAGE_ID=" SD_MESSAGE_UNIT_OUT_OF_MEMORY_STR, + LOG_UNIT_INVOCATION_ID(u), + LOG_UNIT_MESSAGE(u, "A process of this unit has been killed by the OOM killer.")); + + unit_notify_cgroup_oom(u, /* ManagedOOM= */ false); + + return 1; +} + +static int on_cgroup_oom_event(sd_event_source *s, void *userdata) { + Manager *m = ASSERT_PTR(userdata); + Unit *u; + int r; + + assert(s); + + u = m->cgroup_oom_queue; + if (!u) + return 0; + + assert(u->in_cgroup_oom_queue); + u->in_cgroup_oom_queue = false; + LIST_REMOVE(cgroup_oom_queue, m->cgroup_oom_queue, u); + + if (m->cgroup_oom_queue) { + /* More stuff queued, let's make sure we remain enabled */ + r = sd_event_source_set_enabled(s, SD_EVENT_ONESHOT); + if (r < 0) + log_debug_errno(r, "Failed to reenable cgroup oom event source, ignoring: %m"); + } + + (void) unit_check_oom(u); + unit_add_to_gc_queue(u); + + return 0; +} + +static void unit_add_to_cgroup_oom_queue(Unit *u) { + int r; + + assert(u); + + if (u->in_cgroup_oom_queue) + return; + if (!u->cgroup_path) + return; + + LIST_PREPEND(cgroup_oom_queue, u->manager->cgroup_oom_queue, u); + u->in_cgroup_oom_queue = true; + + /* Trigger the defer event */ + if (!u->manager->cgroup_oom_event_source) { + _cleanup_(sd_event_source_unrefp) sd_event_source *s = NULL; + + r = sd_event_add_defer(u->manager->event, &s, on_cgroup_oom_event, u->manager); + if (r < 0) { + log_error_errno(r, "Failed to create cgroup oom event source: %m"); + return; + } + + r = sd_event_source_set_priority(s, SD_EVENT_PRIORITY_NORMAL-8); + if (r < 0) { + log_error_errno(r, "Failed to set priority of cgroup oom event source: %m"); + return; + } + + (void) sd_event_source_set_description(s, "cgroup-oom"); + u->manager->cgroup_oom_event_source = TAKE_PTR(s); + } + + r = sd_event_source_set_enabled(u->manager->cgroup_oom_event_source, SD_EVENT_ONESHOT); + if (r < 0) + log_error_errno(r, "Failed to enable cgroup oom event source: %m"); +} + +static int unit_check_cgroup_events(Unit *u) { + char *values[2] = {}; + int r; + + assert(u); + + if (!u->cgroup_path) + return 0; + + r = cg_get_keyed_attribute_graceful(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events", + STRV_MAKE("populated", "frozen"), values); + if (r < 0) + return r; + + /* The cgroup.events notifications can be merged together so act as we saw the given state for the + * first time. The functions we call to handle given state are idempotent, which makes them + * effectively remember the previous state. */ + if (values[0]) { + if (streq(values[0], "1")) + unit_remove_from_cgroup_empty_queue(u); + else + unit_add_to_cgroup_empty_queue(u); + } + + /* Disregard freezer state changes due to operations not initiated by us */ + if (values[1] && IN_SET(u->freezer_state, FREEZER_FREEZING, FREEZER_THAWING)) { + if (streq(values[1], "0")) + unit_thawed(u); + else + unit_frozen(u); + } + + free(values[0]); + free(values[1]); + + return 0; +} + +static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + Manager *m = ASSERT_PTR(userdata); + + assert(s); + assert(fd >= 0); + + for (;;) { + union inotify_event_buffer buffer; + ssize_t l; + + l = read(fd, &buffer, sizeof(buffer)); + if (l < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + return 0; + + return log_error_errno(errno, "Failed to read control group inotify events: %m"); + } + + FOREACH_INOTIFY_EVENT_WARN(e, buffer, l) { + Unit *u; + + if (e->wd < 0) + /* Queue overflow has no watch descriptor */ + continue; + + if (e->mask & IN_IGNORED) + /* The watch was just removed */ + continue; + + /* Note that inotify might deliver events for a watch even after it was removed, + * because it was queued before the removal. Let's ignore this here safely. */ + + u = hashmap_get(m->cgroup_control_inotify_wd_unit, INT_TO_PTR(e->wd)); + if (u) + unit_check_cgroup_events(u); + + u = hashmap_get(m->cgroup_memory_inotify_wd_unit, INT_TO_PTR(e->wd)); + if (u) + unit_add_to_cgroup_oom_queue(u); + } + } +} + +static int cg_bpf_mask_supported(CGroupMask *ret) { + CGroupMask mask = 0; + int r; + + /* BPF-based firewall */ + r = bpf_firewall_supported(); + if (r < 0) + return r; + if (r > 0) + mask |= CGROUP_MASK_BPF_FIREWALL; + + /* BPF-based device access control */ + r = bpf_devices_supported(); + if (r < 0) + return r; + if (r > 0) + mask |= CGROUP_MASK_BPF_DEVICES; + + /* BPF pinned prog */ + r = bpf_foreign_supported(); + if (r < 0) + return r; + if (r > 0) + mask |= CGROUP_MASK_BPF_FOREIGN; + + /* BPF-based bind{4|6} hooks */ + r = bpf_socket_bind_supported(); + if (r < 0) + return r; + if (r > 0) + mask |= CGROUP_MASK_BPF_SOCKET_BIND; + + /* BPF-based cgroup_skb/{egress|ingress} hooks */ + r = restrict_network_interfaces_supported(); + if (r < 0) + return r; + if (r > 0) + mask |= CGROUP_MASK_BPF_RESTRICT_NETWORK_INTERFACES; + + *ret = mask; + return 0; +} + +int manager_setup_cgroup(Manager *m) { + _cleanup_free_ char *path = NULL; + const char *scope_path; + int r, all_unified; + CGroupMask mask; + char *e; + + assert(m); + + /* 1. Determine hierarchy */ + m->cgroup_root = mfree(m->cgroup_root); + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &m->cgroup_root); + if (r < 0) + return log_error_errno(r, "Cannot determine cgroup we are running in: %m"); + + /* Chop off the init scope, if we are already located in it */ + e = endswith(m->cgroup_root, "/" SPECIAL_INIT_SCOPE); + + /* LEGACY: Also chop off the system slice if we are in + * it. This is to support live upgrades from older systemd + * versions where PID 1 was moved there. Also see + * cg_get_root_path(). */ + if (!e && MANAGER_IS_SYSTEM(m)) { + e = endswith(m->cgroup_root, "/" SPECIAL_SYSTEM_SLICE); + if (!e) + e = endswith(m->cgroup_root, "/system"); /* even more legacy */ + } + if (e) + *e = 0; + + /* And make sure to store away the root value without trailing slash, even for the root dir, so that we can + * easily prepend it everywhere. */ + delete_trailing_chars(m->cgroup_root, "/"); + + /* 2. Show data */ + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, NULL, &path); + if (r < 0) + return log_error_errno(r, "Cannot find cgroup mount point: %m"); + + r = cg_unified(); + if (r < 0) + return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m"); + + all_unified = cg_all_unified(); + if (all_unified < 0) + return log_error_errno(all_unified, "Couldn't determine whether we are in all unified mode: %m"); + if (all_unified > 0) + log_debug("Unified cgroup hierarchy is located at %s.", path); + else { + r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER); + if (r < 0) + return log_error_errno(r, "Failed to determine whether systemd's own controller is in unified mode: %m"); + if (r > 0) + log_debug("Unified cgroup hierarchy is located at %s. Controllers are on legacy hierarchies.", path); + else + log_debug("Using cgroup controller " SYSTEMD_CGROUP_CONTROLLER_LEGACY ". File system hierarchy is at %s.", path); + } + + /* 3. Allocate cgroup empty defer event source */ + m->cgroup_empty_event_source = sd_event_source_disable_unref(m->cgroup_empty_event_source); + r = sd_event_add_defer(m->event, &m->cgroup_empty_event_source, on_cgroup_empty_event, m); + if (r < 0) + return log_error_errno(r, "Failed to create cgroup empty event source: %m"); + + /* Schedule cgroup empty checks early, but after having processed service notification messages or + * SIGCHLD signals, so that a cgroup running empty is always just the last safety net of + * notification, and we collected the metadata the notification and SIGCHLD stuff offers first. */ + r = sd_event_source_set_priority(m->cgroup_empty_event_source, SD_EVENT_PRIORITY_NORMAL-5); + if (r < 0) + return log_error_errno(r, "Failed to set priority of cgroup empty event source: %m"); + + r = sd_event_source_set_enabled(m->cgroup_empty_event_source, SD_EVENT_OFF); + if (r < 0) + return log_error_errno(r, "Failed to disable cgroup empty event source: %m"); + + (void) sd_event_source_set_description(m->cgroup_empty_event_source, "cgroup-empty"); + + /* 4. Install notifier inotify object, or agent */ + if (cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) > 0) { + + /* In the unified hierarchy we can get cgroup empty notifications via inotify. */ + + m->cgroup_inotify_event_source = sd_event_source_disable_unref(m->cgroup_inotify_event_source); + safe_close(m->cgroup_inotify_fd); + + m->cgroup_inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC); + if (m->cgroup_inotify_fd < 0) + return log_error_errno(errno, "Failed to create control group inotify object: %m"); + + r = sd_event_add_io(m->event, &m->cgroup_inotify_event_source, m->cgroup_inotify_fd, EPOLLIN, on_cgroup_inotify_event, m); + if (r < 0) + return log_error_errno(r, "Failed to watch control group inotify object: %m"); + + /* Process cgroup empty notifications early. Note that when this event is dispatched it'll + * just add the unit to a cgroup empty queue, hence let's run earlier than that. Also see + * handling of cgroup agent notifications, for the classic cgroup hierarchy support. */ + r = sd_event_source_set_priority(m->cgroup_inotify_event_source, SD_EVENT_PRIORITY_NORMAL-9); + if (r < 0) + return log_error_errno(r, "Failed to set priority of inotify event source: %m"); + + (void) sd_event_source_set_description(m->cgroup_inotify_event_source, "cgroup-inotify"); + + } else if (MANAGER_IS_SYSTEM(m) && manager_owns_host_root_cgroup(m) && !MANAGER_IS_TEST_RUN(m)) { + + /* On the legacy hierarchy we only get notifications via cgroup agents. (Which isn't really reliable, + * since it does not generate events when control groups with children run empty. */ + + r = cg_install_release_agent(SYSTEMD_CGROUP_CONTROLLER, SYSTEMD_CGROUPS_AGENT_PATH); + if (r < 0) + log_warning_errno(r, "Failed to install release agent, ignoring: %m"); + else if (r > 0) + log_debug("Installed release agent."); + else if (r == 0) + log_debug("Release agent already installed."); + } + + /* 5. Make sure we are in the special "init.scope" unit in the root slice. */ + scope_path = strjoina(m->cgroup_root, "/" SPECIAL_INIT_SCOPE); + r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, scope_path, 0); + if (r >= 0) { + /* Also, move all other userspace processes remaining in the root cgroup into that scope. */ + r = cg_migrate(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, SYSTEMD_CGROUP_CONTROLLER, scope_path, 0); + if (r < 0) + log_warning_errno(r, "Couldn't move remaining userspace processes, ignoring: %m"); + + /* 6. And pin it, so that it cannot be unmounted */ + safe_close(m->pin_cgroupfs_fd); + m->pin_cgroupfs_fd = open(path, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK); + if (m->pin_cgroupfs_fd < 0) + return log_error_errno(errno, "Failed to open pin file: %m"); + + } else if (!MANAGER_IS_TEST_RUN(m)) + return log_error_errno(r, "Failed to create %s control group: %m", scope_path); + + /* 7. Always enable hierarchical support if it exists... */ + if (!all_unified && !MANAGER_IS_TEST_RUN(m)) + (void) cg_set_attribute("memory", "/", "memory.use_hierarchy", "1"); + + /* 8. Figure out which controllers are supported */ + r = cg_mask_supported_subtree(m->cgroup_root, &m->cgroup_supported); + if (r < 0) + return log_error_errno(r, "Failed to determine supported controllers: %m"); + + /* 9. Figure out which bpf-based pseudo-controllers are supported */ + r = cg_bpf_mask_supported(&mask); + if (r < 0) + return log_error_errno(r, "Failed to determine supported bpf-based pseudo-controllers: %m"); + m->cgroup_supported |= mask; + + /* 10. Log which controllers are supported */ + for (CGroupController c = 0; c < _CGROUP_CONTROLLER_MAX; c++) + log_debug("Controller '%s' supported: %s", cgroup_controller_to_string(c), + yes_no(m->cgroup_supported & CGROUP_CONTROLLER_TO_MASK(c))); + + return 0; +} + +void manager_shutdown_cgroup(Manager *m, bool delete) { + assert(m); + + /* We can't really delete the group, since we are in it. But + * let's trim it. */ + if (delete && m->cgroup_root && !FLAGS_SET(m->test_run_flags, MANAGER_TEST_RUN_MINIMAL)) + (void) cg_trim(SYSTEMD_CGROUP_CONTROLLER, m->cgroup_root, false); + + m->cgroup_empty_event_source = sd_event_source_disable_unref(m->cgroup_empty_event_source); + + m->cgroup_control_inotify_wd_unit = hashmap_free(m->cgroup_control_inotify_wd_unit); + m->cgroup_memory_inotify_wd_unit = hashmap_free(m->cgroup_memory_inotify_wd_unit); + + m->cgroup_inotify_event_source = sd_event_source_disable_unref(m->cgroup_inotify_event_source); + m->cgroup_inotify_fd = safe_close(m->cgroup_inotify_fd); + + m->pin_cgroupfs_fd = safe_close(m->pin_cgroupfs_fd); + + m->cgroup_root = mfree(m->cgroup_root); +} + +Unit* manager_get_unit_by_cgroup(Manager *m, const char *cgroup) { + char *p; + Unit *u; + + assert(m); + assert(cgroup); + + u = hashmap_get(m->cgroup_unit, cgroup); + if (u) + return u; + + p = strdupa_safe(cgroup); + for (;;) { + char *e; + + e = strrchr(p, '/'); + if (!e || e == p) + return hashmap_get(m->cgroup_unit, SPECIAL_ROOT_SLICE); + + *e = 0; + + u = hashmap_get(m->cgroup_unit, p); + if (u) + return u; + } +} + +Unit *manager_get_unit_by_pidref_cgroup(Manager *m, PidRef *pid) { + _cleanup_free_ char *cgroup = NULL; + + assert(m); + + if (cg_pidref_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup) < 0) + return NULL; + + return manager_get_unit_by_cgroup(m, cgroup); +} + +Unit *manager_get_unit_by_pidref_watching(Manager *m, PidRef *pid) { + Unit *u, **array; + + assert(m); + + if (!pidref_is_set(pid)) + return NULL; + + u = hashmap_get(m->watch_pids, pid); + if (u) + return u; + + array = hashmap_get(m->watch_pids_more, pid); + if (array) + return array[0]; + + return NULL; +} + +Unit *manager_get_unit_by_pidref(Manager *m, PidRef *pid) { + Unit *u; + + assert(m); + + /* Note that a process might be owned by multiple units, we return only one here, which is good + * enough for most cases, though not strictly correct. We prefer the one reported by cgroup + * membership, as that's the most relevant one as children of the process will be assigned to that + * one, too, before all else. */ + + if (!pidref_is_set(pid)) + return NULL; + + if (pidref_is_self(pid)) + return hashmap_get(m->units, SPECIAL_INIT_SCOPE); + if (pid->pid == 1) + return NULL; + + u = manager_get_unit_by_pidref_cgroup(m, pid); + if (u) + return u; + + u = manager_get_unit_by_pidref_watching(m, pid); + if (u) + return u; + + return NULL; +} + +Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) { + assert(m); + + if (!pid_is_valid(pid)) + return NULL; + + return manager_get_unit_by_pidref(m, &PIDREF_MAKE_FROM_PID(pid)); +} + +int manager_notify_cgroup_empty(Manager *m, const char *cgroup) { + Unit *u; + + assert(m); + assert(cgroup); + + /* Called on the legacy hierarchy whenever we get an explicit cgroup notification from the cgroup agent process + * or from the --system instance */ + + log_debug("Got cgroup empty notification for: %s", cgroup); + + u = manager_get_unit_by_cgroup(m, cgroup); + if (!u) + return 0; + + unit_add_to_cgroup_empty_queue(u); + return 1; +} + +int unit_get_memory_available(Unit *u, uint64_t *ret) { + uint64_t available = UINT64_MAX, current = 0; + + assert(u); + assert(ret); + + /* If data from cgroups can be accessed, try to find out how much more memory a unit can + * claim before hitting the configured cgroup limits (if any). Consider both MemoryHigh + * and MemoryMax, and also any slice the unit might be nested below. */ + + do { + uint64_t unit_available, unit_limit = UINT64_MAX; + CGroupContext *unit_context; + + /* No point in continuing if we can't go any lower */ + if (available == 0) + break; + + unit_context = unit_get_cgroup_context(u); + if (!unit_context) + return -ENODATA; + + if (!u->cgroup_path) + continue; + + (void) unit_get_memory_current(u, ¤t); + /* in case of error, previous current propagates as lower bound */ + + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + unit_limit = physical_memory(); + else if (unit_context->memory_max == UINT64_MAX && unit_context->memory_high == UINT64_MAX) + continue; + unit_limit = MIN3(unit_limit, unit_context->memory_max, unit_context->memory_high); + + unit_available = LESS_BY(unit_limit, current); + available = MIN(unit_available, available); + } while ((u = UNIT_GET_SLICE(u))); + + *ret = available; + + return 0; +} + +int unit_get_memory_current(Unit *u, uint64_t *ret) { + int r; + + // FIXME: Merge this into unit_get_memory_accounting after support for cgroup v1 is dropped + + assert(u); + assert(ret); + + if (!UNIT_CGROUP_BOOL(u, memory_accounting)) + return -ENODATA; + + if (!u->cgroup_path) + return -ENODATA; + + /* The root cgroup doesn't expose this information, let's get it from /proc instead */ + if (unit_has_host_root_cgroup(u)) + return procfs_memory_get_used(ret); + + if ((u->cgroup_realized_mask & CGROUP_MASK_MEMORY) == 0) + return -ENODATA; + + r = cg_all_unified(); + if (r < 0) + return r; + + return cg_get_attribute_as_uint64("memory", u->cgroup_path, r > 0 ? "memory.current" : "memory.usage_in_bytes", ret); +} + +int unit_get_memory_accounting(Unit *u, CGroupMemoryAccountingMetric metric, uint64_t *ret) { + + static const char* const attributes_table[_CGROUP_MEMORY_ACCOUNTING_METRIC_MAX] = { + [CGROUP_MEMORY_PEAK] = "memory.peak", + [CGROUP_MEMORY_SWAP_CURRENT] = "memory.swap.current", + [CGROUP_MEMORY_SWAP_PEAK] = "memory.swap.peak", + [CGROUP_MEMORY_ZSWAP_CURRENT] = "memory.zswap.current", + }; + + uint64_t bytes; + bool updated = false; + int r; + + assert(u); + assert(metric >= 0); + assert(metric < _CGROUP_MEMORY_ACCOUNTING_METRIC_MAX); + + if (!UNIT_CGROUP_BOOL(u, memory_accounting)) + return -ENODATA; + + if (!u->cgroup_path) + /* If the cgroup is already gone, we try to find the last cached value. */ + goto finish; + + /* The root cgroup doesn't expose this information. */ + if (unit_has_host_root_cgroup(u)) + return -ENODATA; + + if (!FLAGS_SET(u->cgroup_realized_mask, CGROUP_MASK_MEMORY)) + return -ENODATA; + + r = cg_all_unified(); + if (r < 0) + return r; + if (r == 0) + return -ENODATA; + + r = cg_get_attribute_as_uint64("memory", u->cgroup_path, attributes_table[metric], &bytes); + if (r < 0 && r != -ENODATA) + return r; + updated = r >= 0; + +finish: + if (metric <= _CGROUP_MEMORY_ACCOUNTING_METRIC_CACHED_LAST) { + uint64_t *last = &u->memory_accounting_last[metric]; + + if (updated) + *last = bytes; + else if (*last != UINT64_MAX) + bytes = *last; + else + return -ENODATA; + + } else if (!updated) + return -ENODATA; + + if (ret) + *ret = bytes; + + return 0; +} + +int unit_get_tasks_current(Unit *u, uint64_t *ret) { + assert(u); + assert(ret); + + if (!UNIT_CGROUP_BOOL(u, tasks_accounting)) + return -ENODATA; + + if (!u->cgroup_path) + return -ENODATA; + + /* The root cgroup doesn't expose this information, let's get it from /proc instead */ + if (unit_has_host_root_cgroup(u)) + return procfs_tasks_get_current(ret); + + if ((u->cgroup_realized_mask & CGROUP_MASK_PIDS) == 0) + return -ENODATA; + + return cg_get_attribute_as_uint64("pids", u->cgroup_path, "pids.current", ret); +} + +static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) { + uint64_t ns; + int r; + + assert(u); + assert(ret); + + if (!u->cgroup_path) + return -ENODATA; + + /* The root cgroup doesn't expose this information, let's get it from /proc instead */ + if (unit_has_host_root_cgroup(u)) + return procfs_cpu_get_usage(ret); + + /* Requisite controllers for CPU accounting are not enabled */ + if ((get_cpu_accounting_mask() & ~u->cgroup_realized_mask) != 0) + return -ENODATA; + + r = cg_all_unified(); + if (r < 0) + return r; + if (r > 0) { + _cleanup_free_ char *val = NULL; + uint64_t us; + + r = cg_get_keyed_attribute("cpu", u->cgroup_path, "cpu.stat", STRV_MAKE("usage_usec"), &val); + if (IN_SET(r, -ENOENT, -ENXIO)) + return -ENODATA; + if (r < 0) + return r; + + r = safe_atou64(val, &us); + if (r < 0) + return r; + + ns = us * NSEC_PER_USEC; + } else + return cg_get_attribute_as_uint64("cpuacct", u->cgroup_path, "cpuacct.usage", ret); + + *ret = ns; + return 0; +} + +int unit_get_cpu_usage(Unit *u, nsec_t *ret) { + nsec_t ns; + int r; + + assert(u); + + /* Retrieve the current CPU usage counter. This will subtract the CPU counter taken when the unit was + * started. If the cgroup has been removed already, returns the last cached value. To cache the value, simply + * call this function with a NULL return value. */ + + if (!UNIT_CGROUP_BOOL(u, cpu_accounting)) + return -ENODATA; + + r = unit_get_cpu_usage_raw(u, &ns); + if (r == -ENODATA && u->cpu_usage_last != NSEC_INFINITY) { + /* If we can't get the CPU usage anymore (because the cgroup was already removed, for example), use our + * cached value. */ + + if (ret) + *ret = u->cpu_usage_last; + return 0; + } + if (r < 0) + return r; + + if (ns > u->cpu_usage_base) + ns -= u->cpu_usage_base; + else + ns = 0; + + u->cpu_usage_last = ns; + if (ret) + *ret = ns; + + return 0; +} + +int unit_get_ip_accounting( + Unit *u, + CGroupIPAccountingMetric metric, + uint64_t *ret) { + + uint64_t value; + int fd, r; + + assert(u); + assert(metric >= 0); + assert(metric < _CGROUP_IP_ACCOUNTING_METRIC_MAX); + assert(ret); + + if (!UNIT_CGROUP_BOOL(u, ip_accounting)) + return -ENODATA; + + fd = IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_INGRESS_PACKETS) ? + u->ip_accounting_ingress_map_fd : + u->ip_accounting_egress_map_fd; + if (fd < 0) + return -ENODATA; + + if (IN_SET(metric, CGROUP_IP_INGRESS_BYTES, CGROUP_IP_EGRESS_BYTES)) + r = bpf_firewall_read_accounting(fd, &value, NULL); + else + r = bpf_firewall_read_accounting(fd, NULL, &value); + if (r < 0) + return r; + + /* Add in additional metrics from a previous runtime. Note that when reexecing/reloading the daemon we compile + * all BPF programs and maps anew, but serialize the old counters. When deserializing we store them in the + * ip_accounting_extra[] field, and add them in here transparently. */ + + *ret = value + u->ip_accounting_extra[metric]; + + return r; +} + +static int unit_get_io_accounting_raw(Unit *u, uint64_t ret[static _CGROUP_IO_ACCOUNTING_METRIC_MAX]) { + static const char *const field_names[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = { + [CGROUP_IO_READ_BYTES] = "rbytes=", + [CGROUP_IO_WRITE_BYTES] = "wbytes=", + [CGROUP_IO_READ_OPERATIONS] = "rios=", + [CGROUP_IO_WRITE_OPERATIONS] = "wios=", + }; + uint64_t acc[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = {}; + _cleanup_free_ char *path = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(u); + + if (!u->cgroup_path) + return -ENODATA; + + if (unit_has_host_root_cgroup(u)) + return -ENODATA; /* TODO: return useful data for the top-level cgroup */ + + r = cg_all_unified(); + if (r < 0) + return r; + if (r == 0) /* TODO: support cgroupv1 */ + return -ENODATA; + + if (!FLAGS_SET(u->cgroup_realized_mask, CGROUP_MASK_IO)) + return -ENODATA; + + r = cg_get_path("io", u->cgroup_path, "io.stat", &path); + if (r < 0) + return r; + + f = fopen(path, "re"); + if (!f) + return -errno; + + for (;;) { + _cleanup_free_ char *line = NULL; + const char *p; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return r; + if (r == 0) + break; + + p = line; + p += strcspn(p, WHITESPACE); /* Skip over device major/minor */ + p += strspn(p, WHITESPACE); /* Skip over following whitespace */ + + for (;;) { + _cleanup_free_ char *word = NULL; + + r = extract_first_word(&p, &word, NULL, EXTRACT_RETAIN_ESCAPE); + if (r < 0) + return r; + if (r == 0) + break; + + for (CGroupIOAccountingMetric i = 0; i < _CGROUP_IO_ACCOUNTING_METRIC_MAX; i++) { + const char *x; + + x = startswith(word, field_names[i]); + if (x) { + uint64_t w; + + r = safe_atou64(x, &w); + if (r < 0) + return r; + + /* Sum up the stats of all devices */ + acc[i] += w; + break; + } + } + } + } + + memcpy(ret, acc, sizeof(acc)); + return 0; +} + +int unit_get_io_accounting( + Unit *u, + CGroupIOAccountingMetric metric, + bool allow_cache, + uint64_t *ret) { + + uint64_t raw[_CGROUP_IO_ACCOUNTING_METRIC_MAX]; + int r; + + /* Retrieve an IO account parameter. This will subtract the counter when the unit was started. */ + + if (!UNIT_CGROUP_BOOL(u, io_accounting)) + return -ENODATA; + + if (allow_cache && u->io_accounting_last[metric] != UINT64_MAX) + goto done; + + r = unit_get_io_accounting_raw(u, raw); + if (r == -ENODATA && u->io_accounting_last[metric] != UINT64_MAX) + goto done; + if (r < 0) + return r; + + for (CGroupIOAccountingMetric i = 0; i < _CGROUP_IO_ACCOUNTING_METRIC_MAX; i++) { + /* Saturated subtraction */ + if (raw[i] > u->io_accounting_base[i]) + u->io_accounting_last[i] = raw[i] - u->io_accounting_base[i]; + else + u->io_accounting_last[i] = 0; + } + +done: + if (ret) + *ret = u->io_accounting_last[metric]; + + return 0; +} + +int unit_reset_cpu_accounting(Unit *u) { + int r; + + assert(u); + + u->cpu_usage_last = NSEC_INFINITY; + + r = unit_get_cpu_usage_raw(u, &u->cpu_usage_base); + if (r < 0) { + u->cpu_usage_base = 0; + return r; + } + + return 0; +} + +void unit_reset_memory_accounting_last(Unit *u) { + assert(u); + + FOREACH_ARRAY(i, u->memory_accounting_last, ELEMENTSOF(u->memory_accounting_last)) + *i = UINT64_MAX; +} + +int unit_reset_ip_accounting(Unit *u) { + int r = 0; + + assert(u); + + if (u->ip_accounting_ingress_map_fd >= 0) + RET_GATHER(r, bpf_firewall_reset_accounting(u->ip_accounting_ingress_map_fd)); + + if (u->ip_accounting_egress_map_fd >= 0) + RET_GATHER(r, bpf_firewall_reset_accounting(u->ip_accounting_egress_map_fd)); + + zero(u->ip_accounting_extra); + + return r; +} + +void unit_reset_io_accounting_last(Unit *u) { + assert(u); + + FOREACH_ARRAY(i, u->io_accounting_last, _CGROUP_IO_ACCOUNTING_METRIC_MAX) + *i = UINT64_MAX; +} + +int unit_reset_io_accounting(Unit *u) { + int r; + + assert(u); + + unit_reset_io_accounting_last(u); + + r = unit_get_io_accounting_raw(u, u->io_accounting_base); + if (r < 0) { + zero(u->io_accounting_base); + return r; + } + + return 0; +} + +int unit_reset_accounting(Unit *u) { + int r = 0; + + assert(u); + + RET_GATHER(r, unit_reset_cpu_accounting(u)); + RET_GATHER(r, unit_reset_io_accounting(u)); + RET_GATHER(r, unit_reset_ip_accounting(u)); + unit_reset_memory_accounting_last(u); + + return r; +} + +void unit_invalidate_cgroup(Unit *u, CGroupMask m) { + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return; + + if (m == 0) + return; + + /* always invalidate compat pairs together */ + if (m & (CGROUP_MASK_IO | CGROUP_MASK_BLKIO)) + m |= CGROUP_MASK_IO | CGROUP_MASK_BLKIO; + + if (m & (CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT)) + m |= CGROUP_MASK_CPU | CGROUP_MASK_CPUACCT; + + if (FLAGS_SET(u->cgroup_invalidated_mask, m)) /* NOP? */ + return; + + u->cgroup_invalidated_mask |= m; + unit_add_to_cgroup_realize_queue(u); +} + +void unit_invalidate_cgroup_bpf(Unit *u) { + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return; + + if (u->cgroup_invalidated_mask & CGROUP_MASK_BPF_FIREWALL) /* NOP? */ + return; + + u->cgroup_invalidated_mask |= CGROUP_MASK_BPF_FIREWALL; + unit_add_to_cgroup_realize_queue(u); + + /* If we are a slice unit, we also need to put compile a new BPF program for all our children, as the IP access + * list of our children includes our own. */ + if (u->type == UNIT_SLICE) { + Unit *member; + + UNIT_FOREACH_DEPENDENCY(member, u, UNIT_ATOM_SLICE_OF) + unit_invalidate_cgroup_bpf(member); + } +} + +void unit_cgroup_catchup(Unit *u) { + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return; + + /* We dropped the inotify watch during reexec/reload, so we need to + * check these as they may have changed. + * Note that (currently) the kernel doesn't actually update cgroup + * file modification times, so we can't just serialize and then check + * the mtime for file(s) we are interested in. */ + (void) unit_check_cgroup_events(u); + unit_add_to_cgroup_oom_queue(u); +} + +bool unit_cgroup_delegate(Unit *u) { + CGroupContext *c; + + assert(u); + + if (!UNIT_VTABLE(u)->can_delegate) + return false; + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + return c->delegate; +} + +void manager_invalidate_startup_units(Manager *m) { + Unit *u; + + assert(m); + + SET_FOREACH(u, m->startup_units) + unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_BLKIO|CGROUP_MASK_CPUSET); +} + +int unit_cgroup_freezer_action(Unit *u, FreezerAction action) { + _cleanup_free_ char *path = NULL; + FreezerState target, kernel = _FREEZER_STATE_INVALID; + int r, ret; + + assert(u); + assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW)); + + if (!cg_freezer_supported()) + return 0; + + /* Ignore all requests to thaw init.scope or -.slice and reject all requests to freeze them */ + if (unit_has_name(u, SPECIAL_ROOT_SLICE) || unit_has_name(u, SPECIAL_INIT_SCOPE)) + return action == FREEZER_FREEZE ? -EPERM : 0; + + if (!u->cgroup_realized) + return -EBUSY; + + if (action == FREEZER_THAW) { + Unit *slice = UNIT_GET_SLICE(u); + + if (slice) { + r = unit_cgroup_freezer_action(slice, FREEZER_THAW); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to thaw slice %s of unit: %m", slice->id); + } + } + + target = action == FREEZER_FREEZE ? FREEZER_FROZEN : FREEZER_RUNNING; + + r = unit_freezer_state_kernel(u, &kernel); + if (r < 0) + log_unit_debug_errno(u, r, "Failed to obtain cgroup freezer state: %m"); + + if (target == kernel) { + u->freezer_state = target; + if (action == FREEZER_FREEZE) + return 0; + ret = 0; + } else + ret = 1; + + r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.freeze", &path); + if (r < 0) + return r; + + log_unit_debug(u, "%s unit.", action == FREEZER_FREEZE ? "Freezing" : "Thawing"); + + if (target != kernel) { + if (action == FREEZER_FREEZE) + u->freezer_state = FREEZER_FREEZING; + else + u->freezer_state = FREEZER_THAWING; + } + + r = write_string_file(path, one_zero(action == FREEZER_FREEZE), WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + return r; + + return ret; +} + +int unit_get_cpuset(Unit *u, CPUSet *cpus, const char *name) { + _cleanup_free_ char *v = NULL; + int r; + + assert(u); + assert(cpus); + + if (!u->cgroup_path) + return -ENODATA; + + if ((u->cgroup_realized_mask & CGROUP_MASK_CPUSET) == 0) + return -ENODATA; + + r = cg_all_unified(); + if (r < 0) + return r; + if (r == 0) + return -ENODATA; + + r = cg_get_attribute("cpuset", u->cgroup_path, name, &v); + if (r == -ENOENT) + return -ENODATA; + if (r < 0) + return r; + + return parse_cpu_set_full(v, cpus, false, NULL, NULL, 0, NULL); +} + +static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = { + [CGROUP_DEVICE_POLICY_AUTO] = "auto", + [CGROUP_DEVICE_POLICY_CLOSED] = "closed", + [CGROUP_DEVICE_POLICY_STRICT] = "strict", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy); + +static const char* const freezer_action_table[_FREEZER_ACTION_MAX] = { + [FREEZER_FREEZE] = "freeze", + [FREEZER_THAW] = "thaw", +}; + +DEFINE_STRING_TABLE_LOOKUP(freezer_action, FreezerAction); + +static const char* const cgroup_pressure_watch_table[_CGROUP_PRESSURE_WATCH_MAX] = { + [CGROUP_PRESSURE_WATCH_OFF] = "off", + [CGROUP_PRESSURE_WATCH_AUTO] = "auto", + [CGROUP_PRESSURE_WATCH_ON] = "on", + [CGROUP_PRESSURE_WATCH_SKIP] = "skip", +}; + +DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(cgroup_pressure_watch, CGroupPressureWatch, CGROUP_PRESSURE_WATCH_ON); + +static const char* const cgroup_ip_accounting_metric_table[_CGROUP_IP_ACCOUNTING_METRIC_MAX] = { + [CGROUP_IP_INGRESS_BYTES] = "IPIngressBytes", + [CGROUP_IP_EGRESS_BYTES] = "IPEgressBytes", + [CGROUP_IP_INGRESS_PACKETS] = "IPIngressPackets", + [CGROUP_IP_EGRESS_PACKETS] = "IPEgressPackets", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_ip_accounting_metric, CGroupIPAccountingMetric); + +static const char* const cgroup_io_accounting_metric_table[_CGROUP_IO_ACCOUNTING_METRIC_MAX] = { + [CGROUP_IO_READ_BYTES] = "IOReadBytes", + [CGROUP_IO_WRITE_BYTES] = "IOWriteBytes", + [CGROUP_IO_READ_OPERATIONS] = "IOReadOperations", + [CGROUP_IO_WRITE_OPERATIONS] = "IOWriteOperations", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_io_accounting_metric, CGroupIOAccountingMetric); + +static const char* const cgroup_memory_accounting_metric_table[_CGROUP_MEMORY_ACCOUNTING_METRIC_MAX] = { + [CGROUP_MEMORY_PEAK] = "MemoryPeak", + [CGROUP_MEMORY_SWAP_CURRENT] = "MemorySwapCurrent", + [CGROUP_MEMORY_SWAP_PEAK] = "MemorySwapPeak", + [CGROUP_MEMORY_ZSWAP_CURRENT] = "MemoryZSwapCurrent", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_memory_accounting_metric, CGroupMemoryAccountingMetric); |