chiark / gitweb /
machined: beef up machined image listing with creation/modification times of subvolumes
[elogind.git] / src / shared / util.c
index 8c1cf52c0a695c653b74b8a9cfd869a84e8d9178..52e5df44a9994e759f1061a1eb715543e85d8350 100644 (file)
@@ -39,7 +39,6 @@
 #include <linux/tiocl.h>
 #include <termios.h>
 #include <stdarg.h>
-#include <sys/inotify.h>
 #include <sys/poll.h>
 #include <ctype.h>
 #include <sys/prctl.h>
@@ -60,6 +59,7 @@
 #include <langinfo.h>
 #include <locale.h>
 #include <sys/personality.h>
+#include <sys/xattr.h>
 #include <libgen.h>
 #undef basename
 
@@ -85,6 +85,7 @@
 #include "gunicode.h"
 #include "virt.h"
 #include "def.h"
+#include "sparse-endian.h"
 
 int saved_argc = 0;
 char **saved_argv = NULL;
@@ -521,7 +522,7 @@ int safe_atod(const char *s, double *ret_d) {
 
 static size_t strcspn_escaped(const char *s, const char *reject) {
         bool escaped = false;
-        size_t n;
+        int n;
 
         for (n=0; s[n]; n++) {
                 if (escaped)
@@ -531,6 +532,7 @@ static size_t strcspn_escaped(const char *s, const char *reject) {
                 else if (strchr(reject, s[n]))
                         break;
         }
+
         /* if s ends in \, return index of previous char */
         return n - escaped;
 }
@@ -558,7 +560,7 @@ const char* split(const char **state, size_t *l, const char *separator, bool quo
                 *l = strcspn_escaped(current + 1, quotechars);
                 if (current[*l + 1] == '\0' ||
                     (current[*l + 2] && !strchr(separator, current[*l + 2]))) {
-                        /* right quote missing or garbage at the end*/
+                        /* right quote missing or garbage at the end */
                         *state = current;
                         return NULL;
                 }
@@ -566,6 +568,11 @@ const char* split(const char **state, size_t *l, const char *separator, bool quo
                 *state = current++ + *l + 2;
         } else if (quoted) {
                 *l = strcspn_escaped(current, separator);
+                if (current[*l] && !strchr(separator, current[*l])) {
+                        /* unfinished escape */
+                        *state = current;
+                        return NULL;
+                }
                 *state = current + *l;
         } else {
                 *l = strcspn(current, separator);
@@ -1436,7 +1443,7 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre
                 }
 
                 case 0:
-                        /* premature end of string.*/
+                        /* premature end of string. */
                         *(t++) = '\\';
                         goto finish;
 
@@ -1504,7 +1511,7 @@ char *ascii_strlower(char *t) {
         return t;
 }
 
-_pure_ static bool ignore_file_allow_backup(const char *filename) {
+_pure_ static bool hidden_file_allow_backup(const char *filename) {
         assert(filename);
 
         return
@@ -1521,13 +1528,13 @@ _pure_ static bool ignore_file_allow_backup(const char *filename) {
                 endswith(filename, ".swp");
 }
 
-bool ignore_file(const char *filename) {
+bool hidden_file(const char *filename) {
         assert(filename);
 
         if (endswith(filename, "~"))
                 return true;
 
-        return ignore_file_allow_backup(filename);
+        return hidden_file_allow_backup(filename);
 }
 
 int fd_nonblock(int fd, bool nonblock) {
@@ -1621,7 +1628,7 @@ int close_all_fds(const int except[], unsigned n_except) {
         while ((de = readdir(d))) {
                 int fd = -1;
 
-                if (ignore_file(de->d_name))
+                if (hidden_file(de->d_name))
                         continue;
 
                 if (safe_atoi(de->d_name, &fd) < 0)
@@ -2100,9 +2107,9 @@ int acquire_terminal(
                 assert(notify >= 0);
 
                 for (;;) {
-                        uint8_t inotify_buffer[sizeof(struct inotify_event) + FILENAME_MAX];
-                        ssize_t l;
+                        union inotify_event_buffer buffer;
                         struct inotify_event *e;
+                        ssize_t l;
 
                         if (timeout != USEC_INFINITY) {
                                 usec_t n;
@@ -2123,9 +2130,8 @@ int acquire_terminal(
                                 }
                         }
 
-                        l = read(notify, inotify_buffer, sizeof(inotify_buffer));
+                        l = read(notify, &buffer, sizeof(buffer));
                         if (l < 0) {
-
                                 if (errno == EINTR || errno == EAGAIN)
                                         continue;
 
@@ -2133,21 +2139,11 @@ int acquire_terminal(
                                 goto fail;
                         }
 
-                        e = (struct inotify_event*) inotify_buffer;
-
-                        while (l > 0) {
-                                size_t step;
-
+                        FOREACH_INOTIFY_EVENT(e, buffer, l) {
                                 if (e->wd != wd || !(e->mask & IN_CLOSE)) {
                                         r = -EIO;
                                         goto fail;
                                 }
-
-                                step = sizeof(struct inotify_event) + e->len;
-                                assert(step <= (size_t) l);
-
-                                e = (struct inotify_event*) ((uint8_t*) e + step);
-                                l -= step;
                         }
 
                         break;
@@ -2279,21 +2275,25 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
                 ssize_t k;
 
                 k = read(fd, p, nbytes);
-                if (k < 0 && errno == EINTR)
-                        continue;
+                if (k < 0) {
+                        if (errno == EINTR)
+                                continue;
 
-                if (k < 0 && errno == EAGAIN && do_poll) {
+                        if (errno == EAGAIN && do_poll) {
 
-                        /* We knowingly ignore any return value here,
-                         * and expect that any error/EOF is reported
-                         * via read() */
+                                /* We knowingly ignore any return value here,
+                                 * and expect that any error/EOF is reported
+                                 * via read() */
 
-                        fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
-                        continue;
+                                fd_wait_for_event(fd, POLLIN, USEC_INFINITY);
+                                continue;
+                        }
+
+                        return n > 0 ? n : -errno;
                 }
 
-                if (k <= 0)
-                        return n > 0 ? n : (k < 0 ? -errno : 0);
+                if (k == 0)
+                        return n;
 
                 p += k;
                 nbytes -= k;
@@ -2303,39 +2303,42 @@ ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll) {
         return n;
 }
 
-ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
         const uint8_t *p = buf;
-        ssize_t n = 0;
 
         assert(fd >= 0);
         assert(buf);
 
+        errno = 0;
+
         while (nbytes > 0) {
                 ssize_t k;
 
                 k = write(fd, p, nbytes);
-                if (k < 0 && errno == EINTR)
-                        continue;
+                if (k < 0) {
+                        if (errno == EINTR)
+                                continue;
 
-                if (k < 0 && errno == EAGAIN && do_poll) {
+                        if (errno == EAGAIN && do_poll) {
+                                /* We knowingly ignore any return value here,
+                                 * and expect that any error/EOF is reported
+                                 * via write() */
 
-                        /* We knowingly ignore any return value here,
-                         * and expect that any error/EOF is reported
-                         * via write() */
+                                fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
+                                continue;
+                        }
 
-                        fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
-                        continue;
+                        return -errno;
                 }
 
-                if (k <= 0)
-                        return n > 0 ? n : (k < 0 ? -errno : 0);
+                if (k == 0) /* Can't really happen */
+                        return -EIO;
 
                 p += k;
                 nbytes -= k;
-                n += k;
         }
 
-        return n;
+        return 0;
 }
 
 int parse_size(const char *t, off_t base, off_t *size) {
@@ -2472,9 +2475,9 @@ int make_stdio(int fd) {
 
         assert(fd >= 0);
 
-        r = dup3(fd, STDIN_FILENO, 0);
-        s = dup3(fd, STDOUT_FILENO, 0);
-        t = dup3(fd, STDERR_FILENO, 0);
+        r = dup2(fd, STDIN_FILENO);
+        s = dup2(fd, STDOUT_FILENO);
+        t = dup2(fd, STDERR_FILENO);
 
         if (fd >= 3)
                 safe_close(fd);
@@ -2482,7 +2485,11 @@ int make_stdio(int fd) {
         if (r < 0 || s < 0 || t < 0)
                 return -errno;
 
-        /* We rely here that the new fd has O_CLOEXEC not set */
+        /* Explicitly unset O_CLOEXEC, since if fd was < 3, then
+         * dup2() was a NOP and the bit hence possibly set. */
+        fd_cloexec(STDIN_FILENO, false);
+        fd_cloexec(STDOUT_FILENO, false);
+        fd_cloexec(STDERR_FILENO, false);
 
         return 0;
 }
@@ -2525,7 +2532,7 @@ int dir_is_empty(const char *path) {
                 if (!de)
                         return 1;
 
-                if (!ignore_file(de->d_name))
+                if (!hidden_file(de->d_name))
                         return 0;
         }
 }
@@ -2779,23 +2786,36 @@ char *getusername_malloc(void) {
         return lookup_uid(getuid());
 }
 
-int getttyname_malloc(int fd, char **r) {
-        char path[PATH_MAX], *c;
-        int k;
+int getttyname_malloc(int fd, char **ret) {
+        size_t l = 100;
+        int r;
 
-        assert(r);
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                char path[l];
 
-        k = ttyname_r(fd, path, sizeof(path));
-        if (k > 0)
-                return -k;
+                r = ttyname_r(fd, path, sizeof(path));
+                if (r == 0) {
+                        const char *p;
+                        char *c;
 
-        char_array_0(path);
+                        p = startswith(path, "/dev/");
+                        c = strdup(p ?: path);
+                        if (!c)
+                                return -ENOMEM;
 
-        c = strdup(startswith(path, "/dev/") ? path + 5 : path);
-        if (!c)
-                return -ENOMEM;
+                        *ret = c;
+                        return 0;
+                }
+
+                if (r != ERANGE)
+                        return -r;
+
+                l *= 2;
+        }
 
-        *r = c;
         return 0;
 }
 
@@ -3063,7 +3083,7 @@ static int rm_rf_internal(const char *path, bool only_dirs, bool delete_root, bo
         fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
         if (fd < 0) {
 
-                if (errno != ENOTDIR)
+                if (errno != ENOTDIR && errno != ELOOP)
                         return -errno;
 
                 if (!dangerous) {
@@ -3670,7 +3690,7 @@ char *unquote(const char *s, const char* quotes) {
         /* This is rather stupid, simply removes the heading and
          * trailing quotes if there is one. Doesn't care about
          * escaping or anything. We should make this smarter one
-         * day...*/
+         * day... */
 
         l = strlen(s);
         if (l < 2)
@@ -3990,7 +4010,7 @@ const char *default_term_for_tty(const char *tty) {
 bool dirent_is_file(const struct dirent *de) {
         assert(de);
 
-        if (ignore_file(de->d_name))
+        if (hidden_file(de->d_name))
                 return false;
 
         if (de->d_type != DT_REG &&
@@ -4009,7 +4029,7 @@ bool dirent_is_file_with_suffix(const struct dirent *de, const char *suffix) {
             de->d_type != DT_UNKNOWN)
                 return false;
 
-        if (ignore_file_allow_backup(de->d_name))
+        if (hidden_file_allow_backup(de->d_name))
                 return false;
 
         return endswith(de->d_name, suffix);
@@ -4251,6 +4271,23 @@ bool machine_name_is_valid(const char *s) {
         return true;
 }
 
+bool image_name_is_valid(const char *s) {
+        if (!filename_is_valid(s))
+                return false;
+
+        if (string_has_cc(s, NULL))
+                return false;
+
+        if (!utf8_is_valid(s))
+                return false;
+
+        /* Temporary files for atomically creating new files */
+        if (startswith(s, ".#"))
+                return false;
+
+        return true;
+}
+
 int pipe_eof(int fd) {
         struct pollfd pollfd = {
                 .fd = fd,
@@ -4292,15 +4329,15 @@ int fd_wait_for_event(int fd, int event, usec_t t) {
 int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
         FILE *f;
         char *t;
-        int fd;
+        int r, fd;
 
         assert(path);
         assert(_f);
         assert(_temp_path);
 
-        t = tempfn_xxxxxx(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_xxxxxx(path, &t);
+        if (r < 0)
+                return r;
 
         fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC);
         if (fd < 0) {
@@ -4411,13 +4448,14 @@ int vt_disallocate(const char *name) {
 
 int symlink_atomic(const char *from, const char *to) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(from);
         assert(to);
 
-        t = tempfn_random(to);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(to, &t);
+        if (r < 0)
+                return r;
 
         if (symlink(from, t) < 0)
                 return -errno;
@@ -4432,12 +4470,13 @@ int symlink_atomic(const char *from, const char *to) {
 
 int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(path);
 
-        t = tempfn_random(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(path, &t);
+        if (r < 0)
+                return r;
 
         if (mknod(t, mode, dev) < 0)
                 return -errno;
@@ -4452,12 +4491,13 @@ int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
 
 int mkfifo_atomic(const char *path, mode_t mode) {
         _cleanup_free_ char *t = NULL;
+        int r;
 
         assert(path);
 
-        t = tempfn_random(path);
-        if (!t)
-                return -ENOMEM;
+        r = tempfn_random(path, &t);
+        if (r < 0)
+                return r;
 
         if (mkfifo(t, mode) < 0)
                 return -errno;
@@ -5569,7 +5609,7 @@ int get_shell(char **_s) {
         return 0;
 }
 
-bool filename_is_safe(const char *p) {
+bool filename_is_valid(const char *p) {
 
         if (isempty(p))
                 return false;
@@ -5900,7 +5940,7 @@ int on_ac_power(void) {
                 if (!de)
                         break;
 
-                if (ignore_file(de->d_name))
+                if (hidden_file(de->d_name))
                         continue;
 
                 device = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY|O_CLOEXEC|O_NOCTTY);
@@ -6971,42 +7011,61 @@ int fflush_and_check(FILE *f) {
         return 0;
 }
 
-char *tempfn_xxxxxx(const char *p) {
+int tempfn_xxxxxx(const char *p, char **ret) {
         const char *fn;
         char *t;
-        size_t k;
 
         assert(p);
+        assert(ret);
 
-        t = new(char, strlen(p) + 1 + 6 + 1);
-        if (!t)
-                return NULL;
+        /*
+         * Turns this:
+         *         /foo/bar/waldo
+         *
+         * Into this:
+         *         /foo/bar/.#waldoXXXXXX
+         */
 
         fn = basename(p);
-        k = fn - p;
+        if (!filename_is_valid(fn))
+                return -EINVAL;
 
-        strcpy(stpcpy(stpcpy(mempcpy(t, p, k), "."), fn), "XXXXXX");
+        t = new(char, strlen(p) + 2 + 6 + 1);
+        if (!t)
+                return -ENOMEM;
 
-        return t;
+        strcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn), "XXXXXX");
+
+        *ret = path_kill_slashes(t);
+        return 0;
 }
 
-char *tempfn_random(const char *p) {
+int tempfn_random(const char *p, char **ret) {
         const char *fn;
         char *t, *x;
         uint64_t u;
-        size_t k;
         unsigned i;
 
         assert(p);
+        assert(ret);
 
-        t = new(char, strlen(p) + 1 + 16 + 1);
-        if (!t)
-                return NULL;
+        /*
+         * Turns this:
+         *         /foo/bar/waldo
+         *
+         * Into this:
+         *         /foo/bar/.#waldobaa2a261115984a9
+         */
 
         fn = basename(p);
-        k = fn - p;
+        if (!filename_is_valid(fn))
+                return -EINVAL;
+
+        t = new(char, strlen(p) + 2 + 16 + 1);
+        if (!t)
+                return -ENOMEM;
 
-        x = stpcpy(stpcpy(mempcpy(t, p, k), "."), fn);
+        x = stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), fn);
 
         u = random_u64();
         for (i = 0; i < 16; i++) {
@@ -7016,7 +7075,40 @@ char *tempfn_random(const char *p) {
 
         *x = 0;
 
-        return t;
+        *ret = path_kill_slashes(t);
+        return 0;
+}
+
+int tempfn_random_child(const char *p, char **ret) {
+        char *t, *x;
+        uint64_t u;
+        unsigned i;
+
+        assert(p);
+        assert(ret);
+
+        /* Turns this:
+         *         /foo/bar/waldo
+         * Into this:
+         *         /foo/bar/waldo/.#3c2b6219aa75d7d0
+         */
+
+        t = new(char, strlen(p) + 3 + 16 + 1);
+        if (!t)
+                return -ENOMEM;
+
+        x = stpcpy(stpcpy(t, p), "/.#");
+
+        u = random_u64();
+        for (i = 0; i < 16; i++) {
+                *(x++) = hexchar(u & 0xF);
+                u >>= 4;
+        }
+
+        *x = 0;
+
+        *ret = path_kill_slashes(t);
+        return 0;
 }
 
 /* make sure the hostname is not "localhost" */
@@ -7355,3 +7447,206 @@ int sethostname_idempotent(const char *s) {
 
         return 1;
 }
+
+int ptsname_malloc(int fd, char **ret) {
+        size_t l = 100;
+
+        assert(fd >= 0);
+        assert(ret);
+
+        for (;;) {
+                char *c;
+
+                c = new(char, l);
+                if (!c)
+                        return -ENOMEM;
+
+                if (ptsname_r(fd, c, l) == 0) {
+                        *ret = c;
+                        return 0;
+                }
+                if (errno != ERANGE) {
+                        free(c);
+                        return -errno;
+                }
+
+                free(c);
+                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), XATTR_CREATE) < 0)
+                return -errno;
+
+        return 0;
+}