diff options
Diffstat (limited to 'src/core/cgroup.c')
| -rw-r--r-- | src/core/cgroup.c | 3074 |
1 files changed, 3074 insertions, 0 deletions
diff --git a/src/core/cgroup.c b/src/core/cgroup.c new file mode 100644 index 0000000..18d470b --- /dev/null +++ b/src/core/cgroup.c @@ -0,0 +1,3074 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <fcntl.h> +#include <fnmatch.h> + +#include "alloc-util.h" +#include "blockdev-util.h" +#include "bpf-firewall.h" +#include "btrfs-util.h" +#include "bpf-devices.h" +#include "bus-error.h" +#include "cgroup-util.h" +#include "cgroup.h" +#include "fd-util.h" +#include "fileio.h" +#include "fs-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "procfs-util.h" +#include "special.h" +#include "stat-util.h" +#include "stdio-util.h" +#include "string-table.h" +#include "string-util.h" +#include "virt.h" + +#define CGROUP_CPU_QUOTA_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) + +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_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(u, LOG_LEVEL_CGROUP_WRITE(r), r, "Failed to set '%s' attribute on '%s' to '%.*s': %m", + strna(attribute), isempty(u->cgroup_path) ? "/" : 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. */ + + *c = (CGroupContext) { + .cpu_weight = CGROUP_WEIGHT_INVALID, + .startup_cpu_weight = CGROUP_WEIGHT_INVALID, + .cpu_quota_per_sec_usec = USEC_INFINITY, + + .cpu_shares = CGROUP_CPU_SHARES_INVALID, + .startup_cpu_shares = CGROUP_CPU_SHARES_INVALID, + + .memory_high = CGROUP_LIMIT_MAX, + .memory_max = CGROUP_LIMIT_MAX, + .memory_swap_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_LIMIT_MAX, + }; +} + +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_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); + + c->ip_address_allow = ip_address_access_free_all(c->ip_address_allow); + c->ip_address_deny = ip_address_access_free_all(c->ip_address_deny); +} + +void cgroup_context_dump(CGroupContext *c, FILE* f, const char *prefix) { + CGroupIODeviceLimit *il; + CGroupIODeviceWeight *iw; + CGroupIODeviceLatency *l; + CGroupBlockIODeviceBandwidth *b; + CGroupBlockIODeviceWeight *w; + CGroupDeviceAllow *a; + IPAddressAccessItem *iaai; + char u[FORMAT_TIMESPAN_MAX]; + + assert(c); + assert(f); + + prefix = strempty(prefix); + + 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" + "%sIOWeight=%" PRIu64 "\n" + "%sStartupIOWeight=%" PRIu64 "\n" + "%sBlockIOWeight=%" PRIu64 "\n" + "%sStartupBlockIOWeight=%" PRIu64 "\n" + "%sMemoryMin=%" PRIu64 "\n" + "%sMemoryLow=%" PRIu64 "\n" + "%sMemoryHigh=%" PRIu64 "\n" + "%sMemoryMax=%" PRIu64 "\n" + "%sMemorySwapMax=%" PRIu64 "\n" + "%sMemoryLimit=%" PRIu64 "\n" + "%sTasksMax=%" PRIu64 "\n" + "%sDevicePolicy=%s\n" + "%sDelegate=%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(u, sizeof(u), c->cpu_quota_per_sec_usec, 1), + prefix, c->io_weight, + prefix, c->startup_io_weight, + prefix, c->blockio_weight, + prefix, c->startup_blockio_weight, + prefix, c->memory_min, + prefix, c->memory_low, + prefix, c->memory_high, + prefix, c->memory_max, + prefix, c->memory_swap_max, + prefix, c->memory_limit, + prefix, c->tasks_max, + prefix, cgroup_device_policy_to_string(c->device_policy), + prefix, yes_no(c->delegate)); + + if (c->delegate) { + _cleanup_free_ char *t = NULL; + + (void) cg_mask_to_string(c->delegate_controllers, &t); + + fprintf(f, "%sDelegateControllers=%s\n", + prefix, + strempty(t)); + } + + LIST_FOREACH(device_allow, a, c->device_allow) + fprintf(f, + "%sDeviceAllow=%s %s%s%s\n", + prefix, + a->path, + a->r ? "r" : "", a->w ? "w" : "", a->m ? "m" : ""); + + 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(u, sizeof(u), l->target_usec, 1)); + + LIST_FOREACH(device_limits, il, c->io_device_limits) { + char buf[FORMAT_BYTES_MAX]; + CGroupIOLimitType type; + + for (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(buf, sizeof(buf), 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) { + char buf[FORMAT_BYTES_MAX]; + + if (b->rbps != CGROUP_LIMIT_MAX) + fprintf(f, + "%sBlockIOReadBandwidth=%s %s\n", + prefix, + b->path, + format_bytes(buf, sizeof(buf), b->rbps)); + if (b->wbps != CGROUP_LIMIT_MAX) + fprintf(f, + "%sBlockIOWriteBandwidth=%s %s\n", + prefix, + b->path, + format_bytes(buf, sizeof(buf), b->wbps)); + } + + LIST_FOREACH(items, iaai, c->ip_address_allow) { + _cleanup_free_ char *k = NULL; + + (void) in_addr_to_string(iaai->family, &iaai->address, &k); + fprintf(f, "%sIPAddressAllow=%s/%u\n", prefix, strnull(k), iaai->prefixlen); + } + + LIST_FOREACH(items, iaai, c->ip_address_deny) { + _cleanup_free_ char *k = NULL; + + (void) in_addr_to_string(iaai->family, &iaai->address, &k); + fprintf(f, "%sIPAddressDeny=%s/%u\n", prefix, strnull(k), iaai->prefixlen); + } +} + +int cgroup_add_device_allow(CGroupContext *c, const char *dev, const char *mode) { + _cleanup_free_ CGroupDeviceAllow *a = NULL; + _cleanup_free_ char *d = NULL; + + assert(c); + assert(dev); + assert(isempty(mode) || in_charset(mode, "rwm")); + + a = new(CGroupDeviceAllow, 1); + if (!a) + return -ENOMEM; + + d = strdup(dev); + if (!d) + return -ENOMEM; + + *a = (CGroupDeviceAllow) { + .path = TAKE_PTR(d), + .r = isempty(mode) || strchr(mode, 'r'), + .w = isempty(mode) || strchr(mode, 'w'), + .m = isempty(mode) || strchr(mode, 'm'), + }; + + LIST_PREPEND(device_allow, c->device_allow, a); + TAKE_PTR(a); + + return 0; +} + +static void cgroup_xattr_apply(Unit *u) { + char ids[SD_ID128_STRING_MAX]; + int r; + + assert(u); + + if (!MANAGER_IS_SYSTEM(u->manager)) + return; + + if (sd_id128_is_null(u->invocation_id)) + return; + + r = cg_set_xattr(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, + "trusted.invocation_id", + sd_id128_to_string(u->invocation_id, ids), 32, + 0); + if (r < 0) + log_unit_debug_errno(u, r, "Failed to set invocation ID on control group %s, ignoring: %m", u->cgroup_path); +} + +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); + rdev = (dev_t)st.st_rdev; + dev = (dev_t)st.st_dev; + mode = st.st_mode; + } else if (r < 0) + return log_warning_errno(r, "Failed to parse major/minor from path '%s': %m", p); + + if (S_ISCHR(mode)) { + log_warning("Device node '%s' is a character device, but block device needed.", p); + return -ENOTBLK; + } else 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 < 0 && r != -ENOTTY) + return log_warning_errno(r, "Failed to determine block device backing btrfs file system '%s': %m", p); + if (r == -ENOTTY) { + log_warning("'%s' is not a block device node, and file system block device cannot be determined or is not local.", p); + return -ENODEV; + } + } + + /* If this is a LUKS device, try to get the originating block device */ + (void) block_get_originating(*ret, ret); + + /* If this is a partition, try to get the originating block device */ + (void) block_get_whole_disk(*ret, ret); + return 0; +} + +static int whitelist_device(BPFProgram *prog, const char *path, const char *node, const char *acc) { + dev_t rdev; + mode_t mode; + int r; + + assert(path); + assert(acc); + + /* Some special handling for /dev/block/%u:%u, /dev/char/%u:%u, /run/systemd/inaccessible/chr and + * /run/systemd/inaccessible/blk paths. Instead of stat()ing these we parse out the major/minor directly. This + * means clients can use these path without the device node actually around */ + r = device_path_parse_major_minor(node, &mode, &rdev); + if (r < 0) { + if (r != -ENODEV) + return log_warning_errno(r, "Couldn't parse major/minor from device path '%s': %m", node); + + struct stat st; + if (stat(node, &st) < 0) + return log_warning_errno(errno, "Couldn't stat device %s: %m", node); + + if (!S_ISCHR(st.st_mode) && !S_ISBLK(st.st_mode)) { + log_warning("%s is not a device.", node); + return -ENODEV; + } + rdev = (dev_t) st.st_rdev; + mode = st.st_mode; + } + + if (cg_all_unified() > 0) { + if (!prog) + return 0; + + return cgroup_bpf_whitelist_device(prog, S_ISCHR(mode) ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, + major(rdev), minor(rdev), acc); + + } else { + char buf[2+DECIMAL_STR_MAX(dev_t)*2+2+4]; + + sprintf(buf, + "%c %u:%u %s", + S_ISCHR(mode) ? 'c' : 'b', + major(rdev), minor(rdev), + acc); + + /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL here. */ + + r = cg_set_attribute("devices", path, "devices.allow", buf); + if (r < 0) + return log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, + r, "Failed to set devices.allow on %s: %m", path); + + return 0; + } +} + +static int whitelist_major(BPFProgram *prog, const char *path, const char *name, char type, const char *acc) { + _cleanup_fclose_ FILE *f = NULL; + char buf[2+DECIMAL_STR_MAX(unsigned)+3+4]; + bool good = false; + unsigned maj; + int r; + + assert(path); + assert(acc); + assert(IN_SET(type, 'b', 'c')); + + if (streq(name, "*")) { + /* If the name is a wildcard, then apply this list to all devices of this type */ + + if (cg_all_unified() > 0) { + if (!prog) + return 0; + + (void) cgroup_bpf_whitelist_class(prog, type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, acc); + } else { + xsprintf(buf, "%c *:* %s", type, acc); + + r = cg_set_attribute("devices", path, "devices.allow", buf); + if (r < 0) + log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to set devices.allow on %s: %m", path); + return 0; + } + } + + if (safe_atou(name, &maj) >= 0 && DEVICE_MAJOR_VALID(maj)) { + /* The name is numeric and suitable as major. In that case, let's take is major, and create the entry + * directly */ + + if (cg_all_unified() > 0) { + if (!prog) + return 0; + + (void) cgroup_bpf_whitelist_major(prog, + type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, + maj, acc); + } else { + xsprintf(buf, "%c %u:* %s", type, maj, acc); + + r = cg_set_attribute("devices", path, "devices.allow", buf); + if (r < 0) + log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to set devices.allow on %s: %m", path); + } + + return 0; + } + + f = fopen("/proc/devices", "re"); + if (!f) + return log_warning_errno(errno, "Cannot open /proc/devices to resolve %s (%c): %m", name, type); + + for (;;) { + _cleanup_free_ char *line = NULL; + char *w, *p; + + r = read_line(f, LONG_LINE_MAX, &line); + if (r < 0) + return log_warning_errno(r, "Failed to read /proc/devices: %m"); + if (r == 0) + break; + + if (type == 'c' && streq(line, "Character devices:")) { + good = true; + continue; + } + + if (type == 'b' && streq(line, "Block devices:")) { + good = true; + continue; + } + + if (isempty(line)) { + good = false; + continue; + } + + if (!good) + continue; + + p = strstrip(line); + + w = strpbrk(p, WHITESPACE); + if (!w) + continue; + *w = 0; + + r = safe_atou(p, &maj); + if (r < 0) + continue; + if (maj <= 0) + continue; + + w++; + w += strspn(w, WHITESPACE); + + if (fnmatch(name, w, 0) != 0) + continue; + + if (cg_all_unified() > 0) { + if (!prog) + continue; + + (void) cgroup_bpf_whitelist_major(prog, + type == 'c' ? BPF_DEVCG_DEV_CHAR : BPF_DEVCG_DEV_BLOCK, + maj, acc); + } else { + sprintf(buf, + "%c %u:* %s", + type, + maj, + acc); + + /* Changing the devices list of a populated cgroup might result in EINVAL, hence ignore EINVAL + * here. */ + + r = cg_set_attribute("devices", path, "devices.allow", buf); + if (r < 0) + log_full_errno(IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, + r, "Failed to set devices.allow on %s: %m", path); + } + } + + 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 uint64_t cgroup_context_cpu_weight(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && + 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) && + 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 void cgroup_apply_unified_cpu_weight(Unit *u, uint64_t weight) { + char buf[DECIMAL_STR_MAX(uint64_t) + 2]; + + xsprintf(buf, "%" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "cpu", "cpu.weight", buf); +} + +static void cgroup_apply_unified_cpu_quota(Unit *u, usec_t quota) { + char buf[(DECIMAL_STR_MAX(usec_t) + 1) * 2 + 1]; + + if (quota != USEC_INFINITY) + xsprintf(buf, USEC_FMT " " USEC_FMT "\n", + quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC, CGROUP_CPU_QUOTA_PERIOD_USEC); + else + xsprintf(buf, "max " USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC); + (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) { + char buf[DECIMAL_STR_MAX(usec_t) + 2]; + + xsprintf(buf, USEC_FMT "\n", CGROUP_CPU_QUOTA_PERIOD_USEC); + (void) set_attribute_and_warn(u, "cpu", "cpu.cfs_period_us", buf); + + if (quota != USEC_INFINITY) { + xsprintf(buf, USEC_FMT "\n", quota * CGROUP_CPU_QUOTA_PERIOD_USEC / USEC_PER_SEC); + (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) { + return CLAMP(weight * CGROUP_CPU_SHARES_DEFAULT / CGROUP_WEIGHT_DEFAULT, + CGROUP_CPU_SHARES_MIN, CGROUP_CPU_SHARES_MAX); +} + +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) && + c->startup_io_weight != CGROUP_WEIGHT_INVALID) + return c->startup_io_weight; + else if (c->io_weight != CGROUP_WEIGHT_INVALID) + return c->io_weight; + else + return CGROUP_WEIGHT_DEFAULT; +} + +static uint64_t cgroup_context_blkio_weight(CGroupContext *c, ManagerState state) { + if (IN_SET(state, MANAGER_STARTING, MANAGER_INITIALIZING) && + c->startup_blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) + return c->startup_blockio_weight; + else if (c->blockio_weight != CGROUP_BLKIO_WEIGHT_INVALID) + return c->blockio_weight; + else + 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 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; + + r = lookup_block_device(dev_path, &dev); + if (r < 0) + return; + + xsprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), io_weight); + (void) set_attribute_and_warn(u, "io", "io.weight", 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, "%u:%u %" PRIu64 "\n", major(dev), minor(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, "%u:%u target=%" PRIu64 "\n", major(dev), minor(dev), target); + else + xsprintf(buf, "%u:%u target=max\n", major(dev), minor(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)]; + char buf[DECIMAL_STR_MAX(dev_t)*2+2+(6+DECIMAL_STR_MAX(uint64_t)+1)*4]; + CGroupIOLimitType type; + dev_t dev; + int r; + + r = lookup_block_device(dev_path, &dev); + if (r < 0) + return; + + for (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, "%u:%u rbps=%s wbps=%s riops=%s wiops=%s\n", major(dev), minor(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; + int r; + + r = lookup_block_device(dev_path, &dev); + if (r < 0) + return; + + sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), rbps); + (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.read_bps_device", buf); + + sprintf(buf, "%u:%u %" PRIu64 "\n", major(dev), minor(dev), wbps); + (void) set_attribute_and_warn(u, "blkio", "blkio.throttle.write_bps_device", buf); +} + +static bool cgroup_context_has_unified_memory_config(CGroupContext *c) { + return c->memory_min > 0 || c->memory_low > 0 || c->memory_high != CGROUP_LIMIT_MAX || c->memory_max != CGROUP_LIMIT_MAX || c->memory_swap_max != CGROUP_LIMIT_MAX; +} + +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_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_weight(u, weight); + cgroup_apply_unified_cpu_quota(u, c->cpu_quota_per_sec_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); + } + } + + /* 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) { + char buf[8+DECIMAL_STR_MAX(uint64_t)+1]; + 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; + + xsprintf(buf, "default %" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "io", "io.weight", buf); + + if (has_io) { + CGroupIODeviceLatency *latency; + CGroupIODeviceLimit *limit; + CGroupIODeviceWeight *w; + + 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) { + CGroupBlockIODeviceWeight *w; + CGroupBlockIODeviceBandwidth *b; + + 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]; + CGroupIOLimitType type; + + for (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) { + char buf[DECIMAL_STR_MAX(uint64_t)+1]; + 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; + + xsprintf(buf, "%" PRIu64 "\n", weight); + (void) set_attribute_and_warn(u, "blkio", "blkio.weight", buf); + + if (has_io) { + CGroupIODeviceWeight *w; + + 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) { + CGroupBlockIODeviceWeight *w; + + LIST_FOREACH(device_weights, w, c->blockio_device_weights) + cgroup_apply_blkio_device_weight(u, w->path, w->weight); + } + } + + /* The bandwith 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) { + CGroupIODeviceLimit *l; + + 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) { + CGroupBlockIODeviceBandwidth *b; + + 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; + + if (cgroup_context_has_unified_memory_config(c)) { + max = c->memory_max; + swap_max = c->memory_swap_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", c->memory_min); + cgroup_apply_unified_memory_limit(u, "memory.low", c->memory_low); + cgroup_apply_unified_memory_limit(u, "memory.high", c->memory_high); + cgroup_apply_unified_memory_limit(u, "memory.max", max); + cgroup_apply_unified_memory_limit(u, "memory.swap.max", swap_max); + + } else { + char buf[DECIMAL_STR_MAX(uint64_t) + 1]; + uint64_t val; + + if (cgroup_context_has_unified_memory_config(c)) { + val = c->memory_max; + log_cgroup_compat(u, "Applying MemoryMax=%" PRIi64 " 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)) { + _cleanup_(bpf_program_unrefp) BPFProgram *prog = NULL; + CGroupDeviceAllow *a; + + if (cg_all_unified() > 0) { + r = cgroup_init_device_bpf(&prog, c->device_policy, c->device_allow); + if (r < 0) + 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 || c->device_policy != CGROUP_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(u, IN_SET(r, -ENOENT, -EROFS, -EINVAL, -EACCES, -EPERM) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to reset devices.allow/devices.deny: %m"); + } + + if (c->device_policy == CGROUP_CLOSED || + (c->device_policy == CGROUP_AUTO && c->device_allow)) { + static const char auto_devices[] = + "/dev/null\0" "rwm\0" + "/dev/zero\0" "rwm\0" + "/dev/full\0" "rwm\0" + "/dev/random\0" "rwm\0" + "/dev/urandom\0" "rwm\0" + "/dev/tty\0" "rwm\0" + "/dev/ptmx\0" "rwm\0" + /* Allow /run/systemd/inaccessible/{chr,blk} devices for mapping InaccessiblePaths */ + "/run/systemd/inaccessible/chr\0" "rwm\0" + "/run/systemd/inaccessible/blk\0" "rwm\0"; + + const char *x, *y; + + NULSTR_FOREACH_PAIR(x, y, auto_devices) + (void) whitelist_device(prog, path, x, y); + + /* PTS (/dev/pts) devices may not be duplicated, but accessed */ + (void) whitelist_major(prog, path, "pts", 'c', "rw"); + } + + LIST_FOREACH(device_allow, a, c->device_allow) { + char acc[4], *val; + unsigned k = 0; + + if (a->r) + acc[k++] = 'r'; + if (a->w) + acc[k++] = 'w'; + if (a->m) + acc[k++] = 'm'; + + if (k == 0) + continue; + + acc[k++] = 0; + + if (path_startswith(a->path, "/dev/")) + (void) whitelist_device(prog, path, a->path, acc); + else if ((val = startswith(a->path, "block-"))) + (void) whitelist_major(prog, path, val, 'b', acc); + else if ((val = startswith(a->path, "char-"))) + (void) whitelist_major(prog, path, val, 'c', acc); + else + log_unit_debug(u, "Ignoring device '%s' while writing cgroup attribute.", a->path); + } + + r = cgroup_apply_device_bpf(u, prog, c->device_policy, c->device_allow); + 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; + } + } + + 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 offical way to release control of the sysctl from + * systemd: set the limit to unbounded and reload. */ + + if (c->tasks_max != CGROUP_LIMIT_MAX) { + u->manager->sysctl_pid_max_changed = true; + r = procfs_tasks_set_limit(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(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 (c->tasks_max != CGROUP_LIMIT_MAX) { + char buf[DECIMAL_STR_MAX(uint64_t) + 2]; + + sprintf(buf, "%" PRIu64 "\n", 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); +} + +static bool unit_get_needs_bpf_firewall(Unit *u) { + CGroupContext *c; + Unit *p; + assert(u); + + c = unit_get_cgroup_context(u); + if (!c) + return false; + + if (c->ip_accounting || + c->ip_address_allow || + c->ip_address_deny) + return true; + + /* If any parent slice has an IP access list defined, it applies too */ + for (p = UNIT_DEREF(u->slice); p; p = UNIT_DEREF(p->slice)) { + c = unit_get_cgroup_context(p); + if (!c) + return false; + + if (c->ip_address_allow || + c->ip_address_deny) + return true; + } + + return false; +} + +static CGroupMask cgroup_context_get_mask(CGroupContext *c) { + CGroupMask mask = 0; + + /* 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_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 || + cgroup_context_has_unified_memory_config(c)) + mask |= CGROUP_MASK_MEMORY; + + if (c->device_allow || + c->device_policy != CGROUP_AUTO) + mask |= CGROUP_MASK_DEVICES | CGROUP_MASK_BPF_DEVICES; + + if (c->tasks_accounting || + c->tasks_max != CGROUP_LIMIT_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; + + 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 (cgroup_context_get_mask(c) | unit_get_bpf_mask(u) | unit_get_delegate_mask(u)) & ~unit_get_ancestor_disable_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); +} + +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) { + void *v; + Unit *member; + Iterator i; + + HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) { + if (UNIT_DEREF(member->slice) == u) + 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) { + 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. */ + + if (UNIT_ISSET(u->slice)) + return unit_get_members_mask(UNIT_DEREF(u->slice)); + + return unit_get_subtree_mask(u); /* we are the top-level slice */ +} + +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; + + 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. */ + + if (UNIT_ISSET(u->slice)) + mask |= unit_get_ancestor_disable_mask(UNIT_DEREF(u->slice)); + + return mask; +} + +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_target_mask(Unit *u) { + CGroupMask 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. */ + + mask = unit_get_own_mask(u) | 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) { + assert(u); + + /* Recurse invalidate the member masks cache all the way up the tree */ + u->cgroup_members_mask_valid = false; + + if (UNIT_ISSET(u->slice)) + unit_invalidate_cgroup_members_masks(UNIT_DEREF(u->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_DEREF(u->slice); + } + + return NULL; +} + +static const char *migrate_callback(CGroupMask mask, void *userdata) { + return unit_get_realized_cgroup_path(userdata, mask); +} + +char *unit_default_cgroup_path(const Unit *u) { + _cleanup_free_ char *escaped = NULL, *slice = NULL; + int r; + + assert(u); + + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + return strdup(u->manager->cgroup_root); + + if (UNIT_ISSET(u->slice) && !unit_has_name(UNIT_DEREF(u->slice), SPECIAL_ROOT_SLICE)) { + r = cg_slice_to_path(UNIT_DEREF(u->slice)->id, &slice); + if (r < 0) + return NULL; + } + + escaped = cg_escape(u->id); + if (!escaped) + return NULL; + + if (slice) + return strjoin(u->manager->cgroup_root, "/", slice, "/", + escaped); + else + return strjoin(u->manager->cgroup_root, "/", escaped); +} + +int unit_set_cgroup_path(Unit *u, const char *path) { + _cleanup_free_ char *p = NULL; + int r; + + assert(u); + + if (path) { + p = strdup(path); + if (!p) + return -ENOMEM; + } else + p = NULL; + + if (streq_ptr(u->cgroup_path, p)) + return 0; + + 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); + + if (!u->cgroup_path) + return 0; + + if (u->cgroup_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; + + /* Don't watch the root slice, it's pointless. */ + if (unit_has_name(u, SPECIAL_ROOT_SLICE)) + return 0; + + r = hashmap_ensure_allocated(&u->manager->cgroup_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_inotify_wd = inotify_add_watch(u->manager->cgroup_inotify_fd, events, IN_MODIFY); + if (u->cgroup_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 inotify watch descriptor for control group %s: %m", u->cgroup_path); + } + + r = hashmap_put(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd), u); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to add inotify watch descriptor to hash map: %m"); + + 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; + + path = unit_default_cgroup_path(u); + if (!path) + return log_oom(); + + r = unit_set_cgroup_path(u, path); + if (r == -EEXIST) + return log_unit_error_errno(u, r, "Control group %s exists already.", path); + if (r < 0) + return log_unit_error_errno(u, r, "Failed to set unit's control group path to %s: %m", path); + + return 0; +} + +static int unit_create_cgroup( + Unit *u, + CGroupMask target_mask, + CGroupMask enable_mask, + ManagerState state) { + + bool created; + 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", u->cgroup_path); + created = r; + + /* Start watching it */ + (void) unit_watch_cgroup(u); + + /* Preserve enabled controllers in delegated units, adjust others. */ + 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", u->cgroup_path); + + /* If we just turned off a controller, this might release the controller for our parent too, let's + * enqueue the parent for re-realization in that case again. */ + if (UNIT_ISSET(u->slice)) { + CGroupMask turned_off; + + turned_off = (u->cgroup_realized ? u->cgroup_enabled_mask & ~result_mask : 0); + if (turned_off != 0) { + Unit *parent; + + /* Force the parent to propagate the enable mask to the kernel again, by invalidating + * the controller we just turned off. */ + + for (parent = UNIT_DEREF(u->slice); parent; parent = UNIT_DEREF(parent->slice)) + unit_invalidate_cgroup(parent, turned_off); + } + } + + /* Remember what's actually enabled now */ + u->cgroup_enabled_mask = result_mask; + } + + /* Keep track that this is now realized */ + u->cgroup_realized = true; + u->cgroup_realized_mask = target_mask; + + if (u->type != UNIT_SLICE && !unit_cgroup_delegate(u)) { + + /* Then, possibly move things over, but not if + * subgroups may contain processes, which is the case + * for slice and delegation units. */ + r = cg_migrate_everywhere(u->manager->cgroup_supported, u->cgroup_path, u->cgroup_path, migrate_callback, u); + if (r < 0) + log_unit_warning_errno(u, r, "Failed to migrate cgroup from to %s, ignoring: %m", u->cgroup_path); + } + + /* Set attributes */ + cgroup_context_apply(u, target_mask, state); + cgroup_xattr_apply(u); + + 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, false); + + r = sd_bus_call_method(u->manager->system_bus, + "org.freedesktop.systemd1", + "/org/freedesktop/systemd1", + "org.freedesktop.systemd1.Manager", + "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) { + CGroupMask delegated_mask; + const char *p; + Iterator i; + void *pidp; + int r, q; + + assert(u); + + if (!UNIT_HAS_CGROUP_CONTEXT(u)) + return -EINVAL; + + if (set_isempty(pids)) + return 0; + + r = unit_realize_cgroup(u); + if (r < 0) + return r; + + if (isempty(suffix_path)) + p = u->cgroup_path; + else + p = strjoina(u->cgroup_path, "/", suffix_path); + + delegated_mask = unit_get_delegate_mask(u); + + r = 0; + SET_FOREACH(pidp, pids, i) { + pid_t pid = PTR_TO_PID(pidp); + CGroupController c; + + /* First, attach the PID to the main cgroup hierarchy */ + q = cg_attach(SYSTEMD_CGROUP_CONTROLLER, p, pid); + if (q < 0) { + log_unit_debug_errno(u, q, "Couldn't move process " PID_FMT " to requested cgroup '%s': %m", pid, p); + + if (MANAGER_IS_USER(u->manager) && IN_SET(q, -EPERM, -EACCES)) { + 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 who's + * top node is not owned by us. */ + + z = unit_attach_pid_to_cgroup_via_bus(u, pid, suffix_path); + if (z < 0) + log_unit_debug_errno(u, z, "Couldn't move process " PID_FMT " to requested cgroup '%s' via the system bus either: %m", pid, p); + else + continue; /* When the bus thing worked via the bus we are fully done for this PID. */ + } + + if (r >= 0) + r = q; /* Remember first error */ + + continue; + } + + q = cg_all_unified(); + if (q < 0) + return q; + if (q > 0) + continue; + + /* In the legacy hierarchy, attach the process to the request cgroup if possible, and if not to the + * innermost realized one */ + + for (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) { + q = cg_attach(cgroup_controller_to_string(c), p, pid); + if (q >= 0) + continue; /* Success! */ + + log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to requested cgroup %s in controller %s, falling back to unit's cgroup: %m", + pid, 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 */ + + q = cg_attach(cgroup_controller_to_string(c), realized, pid); + if (q < 0) + log_unit_debug_errno(u, q, "Failed to attach PID " PID_FMT " to realized cgroup %s in controller %s, ignoring: %m", + pid, realized, cgroup_controller_to_string(c)); + } + } + + return r; +} + +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_PREPEND(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; + 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. */ + if (UNIT_ISSET(u->slice)) { + r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->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_create_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) { + Iterator i; + Unit *m; + void *v; + + assert(u); + + if (u->type != UNIT_SLICE) + return 0; + + HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) { + CGroupMask target_mask, enable_mask, new_target_mask, new_enable_mask; + int r; + + if (UNIT_DEREF(m->slice) != u) + continue; + + /* 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_path) + 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_create_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; + 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 */ + if (UNIT_ISSET(u->slice)) { + r = unit_realize_cgroup_now_enable(UNIT_DEREF(u->slice), state); + if (r < 0) + return r; + } + + /* Now actually deal with the cgroup we were trying to realise and set attributes */ + r = unit_create_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; +} + +static void unit_add_siblings_to_cgroup_realize_queue(Unit *u) { + Unit *slice; + + /* This adds the siblings of the specified unit and the + * siblings of all parent units to the cgroup queue. (But + * neither the specified unit itself nor the parents.) */ + + while ((slice = UNIT_DEREF(u->slice))) { + Iterator i; + Unit *m; + void *v; + + HASHMAP_FOREACH_KEY(v, m, u->dependencies[UNIT_BEFORE], i) { + /* Skip units that have a dependency on the slice + * but aren't actually in it. */ + if (UNIT_DEREF(m->slice) != slice) + continue; + + /* No point in doing cgroup application for units + * without active processes. */ + if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(m))) + 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); + } + + u = slice; + } +} + +int unit_realize_cgroup(Unit *u) { + 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. Otherwise, things + * would become very uneven as each of their processes would + * get as much resources as all our group together. This call + * will synchronously create the parent cgroups, but will + * defer work on the siblings to the next event loop + * iteration. */ + + /* Add all sibling slices to the cgroup queue. */ + unit_add_siblings_to_cgroup_realize_queue(u); + + /* 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_inotify_wd >= 0) { + if (inotify_rm_watch(u->manager->cgroup_inotify_fd, u->cgroup_inotify_wd) < 0) + log_unit_debug_errno(u, errno, "Failed to remove cgroup inotify watch %i for %s, ignoring: %m", u->cgroup_inotify_wd, u->id); + + (void) hashmap_remove(u->manager->cgroup_inotify_wd_unit, INT_TO_PTR(u->cgroup_inotify_wd)); + u->cgroup_inotify_wd = -1; + } +} + +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 */ + + 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) { + log_unit_debug_errno(u, r, "Failed to destroy cgroup %s, ignoring: %m", u->cgroup_path); + return; + } + + if (is_root_slice) + return; + + unit_release_cgroup(u); + + u->cgroup_realized = false; + u->cgroup_realized_mask = 0; + u->cgroup_enabled_mask = 0; + + u->bpf_device_control_installed = bpf_program_unref(u->bpf_device_control_installed); +} + +int unit_search_main_pid(Unit *u, pid_t *ret) { + _cleanup_fclose_ FILE *f = NULL; + pid_t pid = 0, npid, mypid; + 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; + + mypid = getpid_cached(); + while (cg_read_pid(f, &npid) > 0) { + pid_t ppid; + + if (npid == pid) + continue; + + /* Ignore processes that aren't our kids */ + if (get_process_ppid(npid, &ppid) >= 0 && ppid != mypid) + continue; + + if (pid != 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; + + pid = npid; + } + + *ret = pid; + 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 = r; + else { + pid_t pid; + + while ((r = cg_read_pid(f, &pid)) > 0) { + r = unit_watch_pid(u, pid); + if (r < 0 && ret >= 0) + ret = r; + } + + if (r < 0 && ret >= 0) + ret = r; + } + + r = cg_enumerate_subgroups(SYSTEMD_CGROUP_CONTROLLER, path, &d); + if (r < 0) { + if (ret >= 0) + ret = r; + } else { + char *fn; + + while ((r = cg_read_subgroup(d, &fn)) > 0) { + _cleanup_free_ char *p = NULL; + + p = strjoin(path, "/", fn); + free(fn); + + if (!p) + return -ENOMEM; + + r = unit_watch_pids_in_path(u, p); + if (r < 0 && ret >= 0) + ret = r; + } + + if (r < 0 && ret >= 0) + ret = r; + } + + 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 = userdata; + Unit *u; + int r; + + assert(s); + assert(m); + + 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"); + } + + unit_add_to_gc_queue(u); + + 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", 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 int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(fd >= 0); + assert(m); + + for (;;) { + union inotify_event_buffer buffer; + struct inotify_event *e; + ssize_t l; + + l = read(fd, &buffer, sizeof(buffer)); + if (l < 0) { + if (IN_SET(errno, EINTR, EAGAIN)) + return 0; + + return log_error_errno(errno, "Failed to read control group inotify events: %m"); + } + + FOREACH_INOTIFY_EVENT(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; + + u = hashmap_get(m->cgroup_inotify_wd_unit, INT_TO_PTR(e->wd)); + if (!u) /* Not 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. */ + continue; + + unit_add_to_cgroup_empty_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) + mask |= CGROUP_MASK_BPF_FIREWALL; + + /* BPF-based device access control */ + r = bpf_devices_supported(); + if (r > 0) + mask |= CGROUP_MASK_BPF_DEVICES; + + *ret = mask; + return 0; +} + +int manager_setup_cgroup(Manager *m) { + _cleanup_free_ char *path = NULL; + const char *scope_path; + CGroupController c; + 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_flush(); + 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_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"); + + 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_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, but after service notifications and SIGCHLD. 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-4); + 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_CGROUP_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(&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 (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 && 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_unref(m->cgroup_empty_event_source); + + m->cgroup_inotify_wd_unit = hashmap_free(m->cgroup_inotify_wd_unit); + + m->cgroup_inotify_event_source = sd_event_source_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(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_pid_cgroup(Manager *m, pid_t pid) { + _cleanup_free_ char *cgroup = NULL; + + assert(m); + + if (!pid_is_valid(pid)) + return NULL; + + if (cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup) < 0) + return NULL; + + return manager_get_unit_by_cgroup(m, cgroup); +} + +Unit *manager_get_unit_by_pid(Manager *m, pid_t pid) { + Unit *u, **array; + + 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 (!pid_is_valid(pid)) + return NULL; + + if (pid == getpid_cached()) + return hashmap_get(m->units, SPECIAL_INIT_SCOPE); + + u = manager_get_unit_by_pid_cgroup(m, pid); + if (u) + return u; + + u = hashmap_get(m->watch_pids, PID_TO_PTR(pid)); + if (u) + return u; + + array = hashmap_get(m->watch_pids, PID_TO_PTR(-pid)); + if (array) + return array[0]; + + return NULL; +} + +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_current(Unit *u, uint64_t *ret) { + _cleanup_free_ char *v = NULL; + int r; + + 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; + if (r > 0) + r = cg_get_attribute("memory", u->cgroup_path, "memory.current", &v); + else + r = cg_get_attribute("memory", u->cgroup_path, "memory.usage_in_bytes", &v); + if (r == -ENOENT) + return -ENODATA; + if (r < 0) + return r; + + return safe_atou64(v, ret); +} + +int unit_get_tasks_current(Unit *u, uint64_t *ret) { + _cleanup_free_ char *v = NULL; + int r; + + 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; + + r = cg_get_attribute("pids", u->cgroup_path, "pids.current", &v); + if (r == -ENOENT) + return -ENODATA; + if (r < 0) + return r; + + return safe_atou64(v, ret); +} + +static int unit_get_cpu_usage_raw(Unit *u, nsec_t *ret) { + _cleanup_free_ char *v = NULL; + 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 { + r = cg_get_attribute("cpuacct", u->cgroup_path, "cpuacct.usage", &v); + if (r == -ENOENT) + return -ENODATA; + if (r < 0) + return r; + + r = safe_atou64(v, &ns); + if (r < 0) + return r; + } + + *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; +} + +int unit_reset_cpu_accounting(Unit *u) { + nsec_t ns; + int r; + + assert(u); + + u->cpu_usage_last = NSEC_INFINITY; + + r = unit_get_cpu_usage_raw(u, &ns); + if (r < 0) { + u->cpu_usage_base = 0; + return r; + } + + u->cpu_usage_base = ns; + return 0; +} + +int unit_reset_ip_accounting(Unit *u) { + int r = 0, q = 0; + + assert(u); + + if (u->ip_accounting_ingress_map_fd >= 0) + r = bpf_firewall_reset_accounting(u->ip_accounting_ingress_map_fd); + + if (u->ip_accounting_egress_map_fd >= 0) + q = bpf_firewall_reset_accounting(u->ip_accounting_egress_map_fd); + + zero(u->ip_accounting_extra); + + return r < 0 ? r : q; +} + +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; + Iterator i; + void *v; + + HASHMAP_FOREACH_KEY(v, member, u->dependencies[UNIT_BEFORE], i) { + if (UNIT_DEREF(member->slice) == u) + unit_invalidate_cgroup_bpf(member); + } + } +} + +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) { + Iterator i; + Unit *u; + + assert(m); + + SET_FOREACH(u, m->startup_units, i) + unit_invalidate_cgroup(u, CGROUP_MASK_CPU|CGROUP_MASK_IO|CGROUP_MASK_BLKIO); +} + +static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = { + [CGROUP_AUTO] = "auto", + [CGROUP_CLOSED] = "closed", + [CGROUP_STRICT] = "strict", +}; + +DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy); |