diff options
Diffstat (limited to 'shared/systemd/src/basic/util.c')
| -rw-r--r-- | shared/systemd/src/basic/util.c | 643 |
1 files changed, 643 insertions, 0 deletions
diff --git a/shared/systemd/src/basic/util.c b/shared/systemd/src/basic/util.c new file mode 100644 index 00000000..7686ecd2 --- /dev/null +++ b/shared/systemd/src/basic/util.c @@ -0,0 +1,643 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include "nm-sd-adapt-shared.h" + +#include <alloca.h> +#include <errno.h> +#include <fcntl.h> +#include <sched.h> +#include <signal.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <sys/prctl.h> +#include <sys/statfs.h> +#include <sys/sysmacros.h> +#include <sys/types.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "btrfs-util.h" +#include "build.h" +#include "cgroup-util.h" +#include "def.h" +#include "device-nodes.h" +#include "dirent-util.h" +#include "env-file.h" +#include "env-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "hashmap.h" +#include "hostname-util.h" +#include "log.h" +#include "macro.h" +#include "missing.h" +#include "parse-util.h" +#include "path-util.h" +#include "process-util.h" +#include "procfs-util.h" +#include "set.h" +#include "signal-util.h" +#include "stat-util.h" +#include "string-util.h" +#include "strv.h" +#include "time-util.h" +#include "umask-util.h" +#include "user-util.h" +#include "util.h" +#include "virt.h" + +#if 0 /* NM_IGNORED */ +int saved_argc = 0; +char **saved_argv = NULL; +static int saved_in_initrd = -1; +#endif /* NM_IGNORED */ + +size_t page_size(void) { + static thread_local size_t pgsz = 0; + long r; + + if (_likely_(pgsz > 0)) + return pgsz; + + r = sysconf(_SC_PAGESIZE); + assert(r > 0); + + pgsz = (size_t) r; + return pgsz; +} + +#if 0 /* NM_IGNORED */ +bool plymouth_running(void) { + return access("/run/plymouth/pid", F_OK) >= 0; +} + +bool display_is_local(const char *display) { + assert(display); + + return + display[0] == ':' && + display[1] >= '0' && + display[1] <= '9'; +} + +bool kexec_loaded(void) { + _cleanup_free_ char *s = NULL; + + if (read_one_line_file("/sys/kernel/kexec_loaded", &s) < 0) + return false; + + return s[0] == '1'; +} + +int prot_from_flags(int flags) { + + switch (flags & O_ACCMODE) { + + case O_RDONLY: + return PROT_READ; + + case O_WRONLY: + return PROT_WRITE; + + case O_RDWR: + return PROT_READ|PROT_WRITE; + + default: + return -EINVAL; + } +} + +bool in_initrd(void) { + struct statfs s; + int r; + + if (saved_in_initrd >= 0) + return saved_in_initrd; + + /* We make two checks here: + * + * 1. the flag file /etc/initrd-release must exist + * 2. the root file system must be a memory file system + * + * The second check is extra paranoia, since misdetecting an + * initrd can have bad consequences due the initrd + * emptying when transititioning to the main systemd. + */ + + r = getenv_bool_secure("SYSTEMD_IN_INITRD"); + if (r < 0 && r != -ENXIO) + log_debug_errno(r, "Failed to parse $SYSTEMD_IN_INITRD, ignoring: %m"); + + if (r >= 0) + saved_in_initrd = r > 0; + else + saved_in_initrd = access("/etc/initrd-release", F_OK) >= 0 && + statfs("/", &s) >= 0 && + is_temporary_fs(&s); + + return saved_in_initrd; +} + +void in_initrd_force(bool value) { + saved_in_initrd = value; +} + +/* hey glibc, APIs with callbacks without a user pointer are so useless */ +void *xbsearch_r(const void *key, const void *base, size_t nmemb, size_t size, + __compar_d_fn_t compar, void *arg) { + size_t l, u, idx; + const void *p; + int comparison; + + assert(!size_multiply_overflow(nmemb, size)); + + l = 0; + u = nmemb; + while (l < u) { + idx = (l + u) / 2; + p = (const uint8_t*) base + idx * size; + comparison = compar(key, p, arg); + if (comparison < 0) + u = idx; + else if (comparison > 0) + l = idx + 1; + else + return (void *)p; + } + return NULL; +} + +bool memeqzero(const void *data, size_t length) { + /* Does the buffer consist entirely of NULs? + * Copied from https://github.com/systemd/casync/, copied in turn from + * https://github.com/rustyrussell/ccan/blob/master/ccan/mem/mem.c#L92, + * which is licensed CC-0. + */ + + const uint8_t *p = data; + size_t i; + + /* Check first 16 bytes manually */ + for (i = 0; i < 16; i++, length--) { + if (length == 0) + return true; + if (p[i]) + return false; + } + + /* Now we know first 16 bytes are NUL, memcmp with self. */ + return memcmp(data, p + i, length) == 0; +} + +int on_ac_power(void) { + bool found_offline = false, found_online = false; + _cleanup_closedir_ DIR *d = NULL; + struct dirent *de; + + d = opendir("/sys/class/power_supply"); + if (!d) + return errno == ENOENT ? true : -errno; + + FOREACH_DIRENT(de, d, return -errno) { + _cleanup_close_ int fd = -1, device = -1; + char contents[6]; + ssize_t n; + + device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (device < 0) { + if (IN_SET(errno, ENOENT, ENOTDIR)) + continue; + + return -errno; + } + + fd = openat(device, "type", O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) { + if (errno == ENOENT) + continue; + + return -errno; + } + + n = read(fd, contents, sizeof(contents)); + if (n < 0) + return -errno; + + if (n != 6 || memcmp(contents, "Mains\n", 6)) + continue; + + safe_close(fd); + fd = openat(device, "online", O_RDONLY|O_CLOEXEC|O_NOCTTY); + if (fd < 0) { + if (errno == ENOENT) + continue; + + return -errno; + } + + n = read(fd, contents, sizeof(contents)); + if (n < 0) + return -errno; + + if (n != 2 || contents[1] != '\n') + return -EIO; + + if (contents[0] == '1') { + found_online = true; + break; + } else if (contents[0] == '0') + found_offline = true; + else + return -EIO; + } + + return found_online || !found_offline; +} + +int container_get_leader(const char *machine, pid_t *pid) { + _cleanup_free_ char *s = NULL, *class = NULL; + const char *p; + pid_t leader; + int r; + + assert(machine); + assert(pid); + + if (streq(machine, ".host")) { + *pid = 1; + return 0; + } + + if (!machine_name_is_valid(machine)) + return -EINVAL; + + p = strjoina("/run/systemd/machines/", machine); + r = parse_env_file(NULL, p, + "LEADER", &s, + "CLASS", &class); + if (r == -ENOENT) + return -EHOSTDOWN; + if (r < 0) + return r; + if (!s) + return -EIO; + + if (!streq_ptr(class, "container")) + return -EIO; + + r = parse_pid(s, &leader); + if (r < 0) + return r; + if (leader <= 1) + return -EIO; + + *pid = leader; + return 0; +} + +int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *userns_fd, int *root_fd) { + _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1, usernsfd = -1; + int rfd = -1; + + assert(pid >= 0); + + if (mntns_fd) { + const char *mntns; + + mntns = procfs_file_alloca(pid, "ns/mnt"); + mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (mntnsfd < 0) + return -errno; + } + + if (pidns_fd) { + const char *pidns; + + pidns = procfs_file_alloca(pid, "ns/pid"); + pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (pidnsfd < 0) + return -errno; + } + + if (netns_fd) { + const char *netns; + + netns = procfs_file_alloca(pid, "ns/net"); + netnsfd = open(netns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (netnsfd < 0) + return -errno; + } + + if (userns_fd) { + const char *userns; + + userns = procfs_file_alloca(pid, "ns/user"); + usernsfd = open(userns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (usernsfd < 0 && errno != ENOENT) + return -errno; + } + + if (root_fd) { + const char *root; + + root = procfs_file_alloca(pid, "root"); + rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (rfd < 0) + return -errno; + } + + if (pidns_fd) + *pidns_fd = pidnsfd; + + if (mntns_fd) + *mntns_fd = mntnsfd; + + if (netns_fd) + *netns_fd = netnsfd; + + if (userns_fd) + *userns_fd = usernsfd; + + if (root_fd) + *root_fd = rfd; + + pidnsfd = mntnsfd = netnsfd = usernsfd = -1; + + return 0; +} + +int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd) { + if (userns_fd >= 0) { + /* Can't setns to your own userns, since then you could + * escalate from non-root to root in your own namespace, so + * check if namespaces equal before attempting to enter. */ + _cleanup_free_ char *userns_fd_path = NULL; + int r; + if (asprintf(&userns_fd_path, "/proc/self/fd/%d", userns_fd) < 0) + return -ENOMEM; + + r = files_same(userns_fd_path, "/proc/self/ns/user", 0); + if (r < 0) + return r; + if (r) + userns_fd = -1; + } + + if (pidns_fd >= 0) + if (setns(pidns_fd, CLONE_NEWPID) < 0) + return -errno; + + if (mntns_fd >= 0) + if (setns(mntns_fd, CLONE_NEWNS) < 0) + return -errno; + + if (netns_fd >= 0) + if (setns(netns_fd, CLONE_NEWNET) < 0) + return -errno; + + if (userns_fd >= 0) + if (setns(userns_fd, CLONE_NEWUSER) < 0) + return -errno; + + if (root_fd >= 0) { + if (fchdir(root_fd) < 0) + return -errno; + + if (chroot(".") < 0) + return -errno; + } + + return reset_uid_gid(); +} + +uint64_t physical_memory(void) { + _cleanup_free_ char *root = NULL, *value = NULL; + uint64_t mem, lim; + size_t ps; + long sc; + int r; + + /* We return this as uint64_t in case we are running as 32bit process on a 64bit kernel with huge amounts of + * memory. + * + * In order to support containers nicely that have a configured memory limit we'll take the minimum of the + * physically reported amount of memory and the limit configured for the root cgroup, if there is any. */ + + sc = sysconf(_SC_PHYS_PAGES); + assert(sc > 0); + + ps = page_size(); + mem = (uint64_t) sc * (uint64_t) ps; + + r = cg_get_root_path(&root); + if (r < 0) { + log_debug_errno(r, "Failed to determine root cgroup, ignoring cgroup memory limit: %m"); + return mem; + } + + r = cg_all_unified(); + if (r < 0) { + log_debug_errno(r, "Failed to determine root unified mode, ignoring cgroup memory limit: %m"); + return mem; + } + if (r > 0) { + r = cg_get_attribute("memory", root, "memory.max", &value); + if (r < 0) { + log_debug_errno(r, "Failed to read memory.max cgroup attribute, ignoring cgroup memory limit: %m"); + return mem; + } + + if (streq(value, "max")) + return mem; + } else { + r = cg_get_attribute("memory", root, "memory.limit_in_bytes", &value); + if (r < 0) { + log_debug_errno(r, "Failed to read memory.limit_in_bytes cgroup attribute, ignoring cgroup memory limit: %m"); + return mem; + } + } + + r = safe_atou64(value, &lim); + if (r < 0) { + log_debug_errno(r, "Failed to parse cgroup memory limit '%s', ignoring: %m", value); + return mem; + } + if (lim == UINT64_MAX) + return mem; + + /* Make sure the limit is a multiple of our own page size */ + lim /= ps; + lim *= ps; + + return MIN(mem, lim); +} + +uint64_t physical_memory_scale(uint64_t v, uint64_t max) { + uint64_t p, m, ps, r; + + assert(max > 0); + + /* Returns the physical memory size, multiplied by v divided by max. Returns UINT64_MAX on overflow. On success + * the result is a multiple of the page size (rounds down). */ + + ps = page_size(); + assert(ps > 0); + + p = physical_memory() / ps; + assert(p > 0); + + m = p * v; + if (m / p != v) + return UINT64_MAX; + + m /= max; + + r = m * ps; + if (r / ps != m) + return UINT64_MAX; + + return r; +} + +uint64_t system_tasks_max(void) { + + uint64_t a = TASKS_MAX, b = TASKS_MAX; + _cleanup_free_ char *root = NULL; + int r; + + /* Determine the maximum number of tasks that may run on this system. We check three sources to determine this + * limit: + * + * a) the maximum tasks value the kernel allows on this architecture + * b) the cgroups pids_max attribute for the system + * c) the kernel's configured maximum PID value + * + * And then pick the smallest of the three */ + + r = procfs_tasks_get_limit(&a); + if (r < 0) + log_debug_errno(r, "Failed to read maximum number of tasks from /proc, ignoring: %m"); + + r = cg_get_root_path(&root); + if (r < 0) + log_debug_errno(r, "Failed to determine cgroup root path, ignoring: %m"); + else { + _cleanup_free_ char *value = NULL; + + r = cg_get_attribute("pids", root, "pids.max", &value); + if (r < 0) + log_debug_errno(r, "Failed to read pids.max attribute of cgroup root, ignoring: %m"); + else if (!streq(value, "max")) { + r = safe_atou64(value, &b); + if (r < 0) + log_debug_errno(r, "Failed to parse pids.max attribute of cgroup root, ignoring: %m"); + } + } + + return MIN3(TASKS_MAX, + a <= 0 ? TASKS_MAX : a, + b <= 0 ? TASKS_MAX : b); +} + +uint64_t system_tasks_max_scale(uint64_t v, uint64_t max) { + uint64_t t, m; + + assert(max > 0); + + /* Multiply the system's task value by the fraction v/max. Hence, if max==100 this calculates percentages + * relative to the system's maximum number of tasks. Returns UINT64_MAX on overflow. */ + + t = system_tasks_max(); + assert(t > 0); + + m = t * v; + if (m / t != v) /* overflow? */ + return UINT64_MAX; + + return m / max; +} + +int version(void) { + puts("systemd " STRINGIFY(PROJECT_VERSION) " (" GIT_VERSION ")\n" + SYSTEMD_FEATURES); + return 0; +} + +/* This is a direct translation of str_verscmp from boot.c */ +static bool is_digit(int c) { + return c >= '0' && c <= '9'; +} + +static int c_order(int c) { + if (c == 0 || is_digit(c)) + return 0; + + if ((c >= 'a') && (c <= 'z')) + return c; + + return c + 0x10000; +} + +int str_verscmp(const char *s1, const char *s2) { + const char *os1, *os2; + + assert(s1); + assert(s2); + + os1 = s1; + os2 = s2; + + while (*s1 || *s2) { + int first; + + while ((*s1 && !is_digit(*s1)) || (*s2 && !is_digit(*s2))) { + int order; + + order = c_order(*s1) - c_order(*s2); + if (order != 0) + return order; + s1++; + s2++; + } + + while (*s1 == '0') + s1++; + while (*s2 == '0') + s2++; + + first = 0; + while (is_digit(*s1) && is_digit(*s2)) { + if (first == 0) + first = *s1 - *s2; + s1++; + s2++; + } + + if (is_digit(*s1)) + return 1; + if (is_digit(*s2)) + return -1; + + if (first != 0) + return first; + } + + return strcmp(os1, os2); +} + +/* Turn off core dumps but only if we're running outside of a container. */ +void disable_coredumps(void) { + int r; + + if (detect_container() > 0) + return; + + r = write_string_file("/proc/sys/kernel/core_pattern", "|/bin/false", WRITE_STRING_FILE_DISABLE_BUFFER); + if (r < 0) + log_debug_errno(r, "Failed to turn off coredumps, ignoring: %m"); +} +#endif /* NM_IGNORED */ |