X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=88fd78ec8d61f5b0de698d085e9e68c2ec83b346;hp=6bd278e7901a888fedd6c946c3f97130711a76c7;hb=11689d2a021d95a8447d938180e0962cd9439763;hpb=9d8c4979c0c9b09bd3d0d57ee585f6792c6add26 diff --git a/src/shared/util.c b/src/shared/util.c index 6bd278e79..88fd78ec8 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -39,7 +39,6 @@ #include #include #include -#include #include #include #include @@ -60,7 +59,10 @@ #include #include #include +#include #include +#include +#include #undef basename #ifdef HAVE_SYS_AUXV_H @@ -85,6 +87,7 @@ #include "gunicode.h" #include "virt.h" #include "def.h" +#include "sparse-endian.h" int saved_argc = 0; char **saved_argv = NULL; @@ -1151,7 +1154,7 @@ char *delete_chars(char *s, const char *bad) { } char *file_in_same_dir(const char *path, const char *filename) { - char *e, *r; + char *e, *ret; size_t k; assert(path); @@ -1164,17 +1167,17 @@ char *file_in_same_dir(const char *path, const char *filename) { if (path_is_absolute(filename)) return strdup(filename); - if (!(e = strrchr(path, '/'))) + e = strrchr(path, '/'); + if (!e) return strdup(filename); k = strlen(filename); - if (!(r = new(char, e-path+1+k+1))) + ret = new(char, (e + 1 - path) + k + 1); + if (!ret) return NULL; - memcpy(r, path, e-path+1); - memcpy(r+(e-path)+1, filename, k+1); - - return r; + memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1); + return ret; } int rmdir_parents(const char *path, const char *stop) { @@ -2106,7 +2109,7 @@ int acquire_terminal( assert(notify >= 0); for (;;) { - uint8_t buffer[INOTIFY_EVENT_MAX] _alignas_(struct inotify_event); + union inotify_event_buffer buffer; struct inotify_event *e; ssize_t l; @@ -2129,7 +2132,7 @@ int acquire_terminal( } } - l = read(notify, buffer, sizeof(buffer)); + l = read(notify, &buffer, sizeof(buffer)); if (l < 0) { if (errno == EINTR || errno == EAGAIN) continue; @@ -3455,7 +3458,7 @@ unsigned columns(void) { c = 80; cached_columns = c; - return c; + return cached_columns; } int fd_lines(int fd) { @@ -3472,7 +3475,7 @@ int fd_lines(int fd) { unsigned lines(void) { const char *e; - unsigned l; + int l; if (_likely_(cached_lines > 0)) return cached_lines; @@ -3480,7 +3483,7 @@ unsigned lines(void) { l = 0; e = getenv("LINES"); if (e) - (void) safe_atou(e, &l); + (void) safe_atoi(e, &l); if (l <= 0) l = fd_lines(STDOUT_FILENO); @@ -4003,7 +4006,7 @@ bool tty_is_vc_resolve(const char *tty) { const char *default_term_for_tty(const char *tty) { assert(tty); - return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt102"; + return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt220"; } bool dirent_is_file(const struct dirent *de) { @@ -5183,6 +5186,9 @@ char *format_bytes(char *buf, size_t l, off_t t) { { "K", 1024ULL }, }; + if (t == (off_t) -1) + return NULL; + for (i = 0; i < ELEMENTSOF(table); i++) { if (t >= table[i].factor) { @@ -6854,6 +6860,15 @@ int umount_recursive(const char *prefix, int flags) { return r ? r : n; } +static int get_mount_flags(const char *path, unsigned long *flags) { + struct statvfs buf; + + if (statvfs(path, &buf) < 0) + return -errno; + *flags = buf.f_flag; + return 0; +} + int bind_remount_recursive(const char *prefix, bool ro) { _cleanup_set_free_free_ Set *done = NULL; _cleanup_free_ char *cleaned = NULL; @@ -6888,6 +6903,7 @@ int bind_remount_recursive(const char *prefix, bool ro) { _cleanup_set_free_free_ Set *todo = NULL; bool top_autofs = false; char *x; + unsigned long orig_flags; todo = set_new(&string_hash_ops); if (!todo) @@ -6965,7 +6981,11 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0) return -errno; - if (mount(NULL, prefix, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) + orig_flags = 0; + (void) get_mount_flags(cleaned, &orig_flags); + orig_flags &= ~MS_RDONLY; + + if (mount(NULL, prefix, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) return -errno; x = strdup(cleaned); @@ -6985,7 +7005,14 @@ int bind_remount_recursive(const char *prefix, bool ro) { if (r < 0) return r; - if (mount(NULL, x, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) { + /* Try to reuse the original flag set, but + * don't care for errors, in case of + * obstructed mounts */ + orig_flags = 0; + (void) get_mount_flags(x, &orig_flags); + orig_flags &= ~MS_RDONLY; + + if (mount(NULL, x, NULL, orig_flags|MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) { /* Deal with mount points that are * obstructed by a later mount */ @@ -7473,3 +7500,276 @@ int ptsname_malloc(int fd, char **ret) { l *= 2; } } + +int openpt_in_namespace(pid_t pid, int flags) { + _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, rootfd = -1; + _cleanup_close_pair_ int pair[2] = { -1, -1 }; + union { + struct cmsghdr cmsghdr; + uint8_t buf[CMSG_SPACE(sizeof(int))]; + } control = {}; + struct msghdr mh = { + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + struct cmsghdr *cmsg; + siginfo_t si; + pid_t child; + int r; + + assert(pid > 0); + + r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &rootfd); + if (r < 0) + return r; + + if (socketpair(AF_UNIX, SOCK_DGRAM, 0, pair) < 0) + return -errno; + + child = fork(); + if (child < 0) + return -errno; + + if (child == 0) { + int master; + + pair[0] = safe_close(pair[0]); + + r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd); + if (r < 0) + _exit(EXIT_FAILURE); + + master = posix_openpt(flags); + if (master < 0) + _exit(EXIT_FAILURE); + + cmsg = CMSG_FIRSTHDR(&mh); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &master, sizeof(int)); + + mh.msg_controllen = cmsg->cmsg_len; + + if (sendmsg(pair[1], &mh, MSG_NOSIGNAL) < 0) + _exit(EXIT_FAILURE); + + _exit(EXIT_SUCCESS); + } + + pair[1] = safe_close(pair[1]); + + r = wait_for_terminate(child, &si); + if (r < 0) + return r; + if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS) + return -EIO; + + if (recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) < 0) + return -errno; + + for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) + if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { + int *fds; + unsigned n_fds; + + fds = (int*) CMSG_DATA(cmsg); + n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int); + + if (n_fds != 1) { + close_many(fds, n_fds); + return -EIO; + } + + return fds[0]; + } + + return -EIO; +} + +ssize_t fgetxattrat_fake(int dirfd, const char *filename, const char *attribute, void *value, size_t size, int flags) { + _cleanup_close_ int fd = -1; + ssize_t l; + + /* The kernel doesn't have a fgetxattrat() command, hence let's emulate one */ + + fd = openat(dirfd, filename, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOATIME|(flags & AT_SYMLINK_NOFOLLOW ? O_NOFOLLOW : 0)); + if (fd < 0) + return -errno; + + l = fgetxattr(fd, attribute, value, size); + if (l < 0) + return -errno; + + return l; +} + +static int parse_crtime(le64_t le, usec_t *usec) { + uint64_t u; + + assert(usec); + + u = le64toh(le); + if (u == 0 || u == (uint64_t) -1) + return -EIO; + + *usec = (usec_t) u; + return 0; +} + +int fd_getcrtime(int fd, usec_t *usec) { + le64_t le; + ssize_t n; + + assert(fd >= 0); + assert(usec); + + /* Until Linux gets a real concept of birthtime/creation time, + * let's fake one with xattrs */ + + n = fgetxattr(fd, "user.crtime_usec", &le, sizeof(le)); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int fd_getcrtime_at(int dirfd, const char *name, usec_t *usec, int flags) { + le64_t le; + ssize_t n; + + n = fgetxattrat_fake(dirfd, name, "user.crtime_usec", &le, sizeof(le), flags); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int path_getcrtime(const char *p, usec_t *usec) { + le64_t le; + ssize_t n; + + assert(p); + assert(usec); + + n = getxattr(p, "user.crtime_usec", &le, sizeof(le)); + if (n < 0) + return -errno; + if (n != sizeof(le)) + return -EIO; + + return parse_crtime(le, usec); +} + +int fd_setcrtime(int fd, usec_t usec) { + le64_t le; + + assert(fd >= 0); + + le = htole64((uint64_t) usec); + if (fsetxattr(fd, "user.crtime_usec", &le, sizeof(le), 0) < 0) + return -errno; + + return 0; +} + +int same_fd(int a, int b) { + struct stat sta, stb; + pid_t pid; + int r, fa, fb; + + assert(a >= 0); + assert(b >= 0); + + /* Compares two file descriptors. Note that semantics are + * quite different depending on whether we have kcmp() or we + * don't. If we have kcmp() this will only return true for + * dup()ed file descriptors, but not otherwise. If we don't + * have kcmp() this will also return true for two fds of the same + * file, created by separate open() calls. Since we use this + * call mostly for filtering out duplicates in the fd store + * this difference hopefully doesn't matter too much. */ + + if (a == b) + return true; + + /* Try to use kcmp() if we have it. */ + pid = getpid(); + r = kcmp(pid, pid, KCMP_FILE, a, b); + if (r == 0) + return true; + if (r > 0) + return false; + if (errno != ENOSYS) + return -errno; + + /* We don't have kcmp(), use fstat() instead. */ + if (fstat(a, &sta) < 0) + return -errno; + + if (fstat(b, &stb) < 0) + return -errno; + + if ((sta.st_mode & S_IFMT) != (stb.st_mode & S_IFMT)) + return false; + + /* We consider all device fds different, since two device fds + * might refer to quite different device contexts even though + * they share the same inode and backing dev_t. */ + + if (S_ISCHR(sta.st_mode) || S_ISBLK(sta.st_mode)) + return false; + + if (sta.st_dev != stb.st_dev || sta.st_ino != stb.st_ino) + return false; + + /* The fds refer to the same inode on disk, let's also check + * if they have the same fd flags. This is useful to + * distuingish the read and write side of a pipe created with + * pipe(). */ + fa = fcntl(a, F_GETFL); + if (fa < 0) + return -errno; + + fb = fcntl(b, F_GETFL); + if (fb < 0) + return -errno; + + return fa == fb; +} + +int chattr_fd(int fd, bool b, int mask) { + int old_attr, new_attr; + + assert(fd >= 0); + + if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0) + return -errno; + + if (b) + new_attr = old_attr | mask; + else + new_attr = old_attr & ~mask; + + if (new_attr == old_attr) + return 0; + + if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0) + return -errno; + + return 0; +} + +int chattr_path(const char *p, bool b, int mask) { + _cleanup_close_ int fd = -1; + + fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); + if (fd < 0) + return -errno; + + return chattr_fd(fd, b, mask); +}