X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=43ec62eac653d67a10190187c82eb0c76a551934;hp=53185403d62d8e762682d1f7b499e04904fd15c1;hb=d05c5031ad4c528fe6bbfed289519edb9f13180a;hpb=f67cc036ba92a3c71acb664ed2d548de5827cf1f

diff --git a/src/shared/util.c b/src/shared/util.c
index 53185403d..43ec62eac 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -50,11 +50,12 @@
 #include <linux/kd.h>
 #include <dlfcn.h>
 #include <sys/wait.h>
-#include <sys/capability.h>
 #include <sys/time.h>
 #include <glob.h>
 #include <grp.h>
 #include <sys/mman.h>
+#include <sys/vfs.h>
+#include <linux/magic.h>
 
 #include "macro.h"
 #include "util.h"
@@ -1082,7 +1083,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char *
                 if (h < 0)
                         return h;
 
-                r = join("[", t, "]", NULL);
+                r = strjoin("[", t, "]", NULL);
                 free(t);
 
                 if (!r)
@@ -2306,12 +2307,14 @@ int open_terminal(const char *name, int mode) {
          */
 
         for (;;) {
-                if ((fd = open(name, mode)) >= 0)
+                fd = open(name, mode);
+                if (fd >= 0)
                         break;
 
                 if (errno != EIO)
                         return -errno;
 
+                /* Max 1s in total */
                 if (c >= 20)
                         return -errno;
 
@@ -2322,7 +2325,8 @@ int open_terminal(const char *name, int mode) {
         if (fd < 0)
                 return -errno;
 
-        if ((r = isatty(fd)) < 0) {
+        r = isatty(fd);
+        if (r < 0) {
                 close_nointr_nofail(fd);
                 return -errno;
         }
@@ -2374,8 +2378,16 @@ int flush_fd(int fd) {
         }
 }
 
-int acquire_terminal(const char *name, bool fail, bool force, bool ignore_tiocstty_eperm) {
-        int fd = -1, notify = -1, r, wd = -1;
+int acquire_terminal(
+                const char *name,
+                bool fail,
+                bool force,
+                bool ignore_tiocstty_eperm,
+                usec_t timeout) {
+
+        int fd = -1, notify = -1, r = 0, wd = -1;
+        usec_t ts = 0;
+        struct sigaction sa_old, sa_new;
 
         assert(name);
 
@@ -2392,40 +2404,57 @@ int acquire_terminal(const char *name, bool fail, bool force, bool ignore_tiocst
          * on the same tty as an untrusted user this should not be a
          * problem. (Which he probably should not do anyway.) */
 
+        if (timeout != (usec_t) -1)
+                ts = now(CLOCK_MONOTONIC);
+
         if (!fail && !force) {
-                if ((notify = inotify_init1(IN_CLOEXEC)) < 0) {
+                notify = inotify_init1(IN_CLOEXEC | (timeout != (usec_t) -1 ? IN_NONBLOCK : 0));
+                if (notify < 0) {
                         r = -errno;
                         goto fail;
                 }
 
-                if ((wd = inotify_add_watch(notify, name, IN_CLOSE)) < 0) {
+                wd = inotify_add_watch(notify, name, IN_CLOSE);
+                if (wd < 0) {
                         r = -errno;
                         goto fail;
                 }
         }
 
         for (;;) {
-                if (notify >= 0)
-                        if ((r = flush_fd(notify)) < 0)
+                if (notify >= 0) {
+                        r = flush_fd(notify);
+                        if (r < 0)
                                 goto fail;
+                }
 
                 /* We pass here O_NOCTTY only so that we can check the return
                  * value TIOCSCTTY and have a reliable way to figure out if we
                  * successfully became the controlling process of the tty */
-                if ((fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0)
+                fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+                if (fd < 0)
                         return fd;
 
+                /* Temporarily ignore SIGHUP, so that we don't get SIGHUP'ed
+                 * if we already own the tty. */
+                zero(sa_new);
+                sa_new.sa_handler = SIG_IGN;
+                sa_new.sa_flags = SA_RESTART;
+                assert_se(sigaction(SIGHUP, &sa_new, &sa_old) == 0);
+
                 /* First, try to get the tty */
-                r = ioctl(fd, TIOCSCTTY, force);
+                if (ioctl(fd, TIOCSCTTY, force) < 0)
+                        r = -errno;
+
+                assert_se(sigaction(SIGHUP, &sa_old, NULL) == 0);
 
                 /* Sometimes it makes sense to ignore TIOCSCTTY
                  * returning EPERM, i.e. when very likely we already
                  * are have this controlling terminal. */
-                if (r < 0 && errno == EPERM && ignore_tiocstty_eperm)
+                if (r < 0 && r == -EPERM && ignore_tiocstty_eperm)
                         r = 0;
 
-                if (r < 0 && (force || fail || errno != EPERM)) {
-                        r = -errno;
+                if (r < 0 && (force || fail || r != -EPERM)) {
                         goto fail;
                 }
 
@@ -2441,9 +2470,29 @@ int acquire_terminal(const char *name, bool fail, bool force, bool ignore_tiocst
                         ssize_t l;
                         struct inotify_event *e;
 
-                        if ((l = read(notify, inotify_buffer, sizeof(inotify_buffer))) < 0) {
+                        if (timeout != (usec_t) -1) {
+                                usec_t n;
 
-                                if (errno == EINTR)
+                                n = now(CLOCK_MONOTONIC);
+                                if (ts + timeout < n) {
+                                        r = -ETIMEDOUT;
+                                        goto fail;
+                                }
+
+                                r = fd_wait_for_event(fd, POLLIN, ts + timeout - n);
+                                if (r < 0)
+                                        goto fail;
+
+                                if (r == 0) {
+                                        r = -ETIMEDOUT;
+                                        goto fail;
+                                }
+                        }
+
+                        l = read(notify, inotify_buffer, sizeof(inotify_buffer));
+                        if (l < 0) {
+
+                                if (errno == EINTR || errno == EAGAIN)
                                         continue;
 
                                 r = -errno;
@@ -2707,7 +2756,7 @@ int parse_usec(const char *t, usec_t *usec) {
                 { "m", USEC_PER_MINUTE },
                 { "usec", 1ULL },
                 { "us", 1ULL },
-                { "", USEC_PER_SEC },
+                { "", USEC_PER_SEC }, /* default is sec */
         };
 
         const char *p;
@@ -2753,6 +2802,71 @@ int parse_usec(const char *t, usec_t *usec) {
         return 0;
 }
 
+int parse_nsec(const char *t, nsec_t *nsec) {
+        static const struct {
+                const char *suffix;
+                nsec_t nsec;
+        } table[] = {
+                { "sec", NSEC_PER_SEC },
+                { "s", NSEC_PER_SEC },
+                { "min", NSEC_PER_MINUTE },
+                { "hr", NSEC_PER_HOUR },
+                { "h", NSEC_PER_HOUR },
+                { "d", NSEC_PER_DAY },
+                { "w", NSEC_PER_WEEK },
+                { "msec", NSEC_PER_MSEC },
+                { "ms", NSEC_PER_MSEC },
+                { "m", NSEC_PER_MINUTE },
+                { "usec", NSEC_PER_USEC },
+                { "us", NSEC_PER_USEC },
+                { "nsec", 1ULL },
+                { "ns", 1ULL },
+                { "", 1ULL }, /* default is nsec */
+        };
+
+        const char *p;
+        nsec_t r = 0;
+
+        assert(t);
+        assert(nsec);
+
+        p = t;
+        do {
+                long long l;
+                char *e;
+                unsigned i;
+
+                errno = 0;
+                l = strtoll(p, &e, 10);
+
+                if (errno != 0)
+                        return -errno;
+
+                if (l < 0)
+                        return -ERANGE;
+
+                if (e == p)
+                        return -EINVAL;
+
+                e += strspn(e, WHITESPACE);
+
+                for (i = 0; i < ELEMENTSOF(table); i++)
+                        if (startswith(e, table[i].suffix)) {
+                                r += (nsec_t) l * table[i].nsec;
+                                p = e + strlen(table[i].suffix);
+                                break;
+                        }
+
+                if (i >= ELEMENTSOF(table))
+                        return -EINVAL;
+
+        } while (*p != 0);
+
+        *nsec = r;
+
+        return 0;
+}
+
 int parse_bytes(const char *t, off_t *bytes) {
         static const struct {
                 const char *suffix;
@@ -2836,7 +2950,8 @@ int make_stdio(int fd) {
 int make_null_stdio(void) {
         int null_fd;
 
-        if ((null_fd = open("/dev/null", O_RDWR|O_NOCTTY)) < 0)
+        null_fd = open("/dev/null", O_RDWR|O_NOCTTY);
+        if (null_fd < 0)
                 return -errno;
 
         return make_stdio(null_fd);
@@ -2963,26 +3078,22 @@ bool hostname_is_set(void) {
         return !isempty(u.nodename) && !streq(u.nodename, "(none)");
 }
 
-char* getlogname_malloc(void) {
-        uid_t uid;
+
+static char *lookup_uid(uid_t uid) {
         long bufsize;
         char *buf, *name;
         struct passwd pwbuf, *pw = NULL;
-        struct stat st;
-
-        if (isatty(STDIN_FILENO) && fstat(STDIN_FILENO, &st) >= 0)
-                uid = st.st_uid;
-        else
-                uid = getuid();
 
         /* Shortcut things to avoid NSS lookups */
         if (uid == 0)
                 return strdup("root");
 
-        if ((bufsize = sysconf(_SC_GETPW_R_SIZE_MAX)) <= 0)
+        bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+        if (bufsize <= 0)
                 bufsize = 4096;
 
-        if (!(buf = malloc(bufsize)))
+        buf = malloc(bufsize);
+        if (!buf)
                 return NULL;
 
         if (getpwuid_r(uid, &pwbuf, buf, bufsize, &pw) == 0 && pw) {
@@ -2999,6 +3110,28 @@ char* getlogname_malloc(void) {
         return name;
 }
 
+char* getlogname_malloc(void) {
+        uid_t uid;
+        struct stat st;
+
+        if (isatty(STDIN_FILENO) && fstat(STDIN_FILENO, &st) >= 0)
+                uid = st.st_uid;
+        else
+                uid = getuid();
+
+        return lookup_uid(uid);
+}
+
+char *getusername_malloc(void) {
+        const char *e;
+
+        e = getenv("USER");
+        if (e)
+                return strdup(e);
+
+        return lookup_uid(getuid());
+}
+
 int getttyname_malloc(int fd, char **r) {
         char path[PATH_MAX], *c;
         int k;
@@ -3139,14 +3272,14 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) {
         return 0;
 }
 
-int rm_rf_children(int fd, bool only_dirs, bool honour_sticky) {
+int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
         DIR *d;
         int ret = 0;
 
         assert(fd >= 0);
 
         /* This returns the first error we run into, but nevertheless
-         * tries to go on */
+         * tries to go on. This closes the passed fd. */
 
         d = fdopendir(fd);
         if (!d) {
@@ -3157,7 +3290,8 @@ int rm_rf_children(int fd, bool only_dirs, bool honour_sticky) {
 
         for (;;) {
                 struct dirent buf, *de;
-                bool is_dir, keep_around = false;
+                bool is_dir, keep_around;
+                struct stat st;
                 int r;
 
                 r = readdir_r(d, &buf, &de);
@@ -3172,51 +3306,41 @@ int rm_rf_children(int fd, bool only_dirs, bool honour_sticky) {
                 if (streq(de->d_name, ".") || streq(de->d_name, ".."))
                         continue;
 
-                if (de->d_type == DT_UNKNOWN) {
-                        struct stat st;
-
+                if (de->d_type == DT_UNKNOWN ||
+                    honour_sticky ||
+                    (de->d_type == DT_DIR && root_dev)) {
                         if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
                                 if (ret == 0 && errno != ENOENT)
                                         ret = -errno;
                                 continue;
                         }
 
-                        if (honour_sticky)
-                                keep_around =
-                                        (st.st_uid == 0 || st.st_uid == getuid()) &&
-                                        (st.st_mode & S_ISVTX);
-
                         is_dir = S_ISDIR(st.st_mode);
-
+                        keep_around =
+                                honour_sticky &&
+                                (st.st_uid == 0 || st.st_uid == getuid()) &&
+                                (st.st_mode & S_ISVTX);
                 } else {
-                        if (honour_sticky) {
-                                struct stat st;
-
-                                if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
-                                        if (ret == 0 && errno != ENOENT)
-                                                ret = -errno;
-                                        continue;
-                                }
-
-                                keep_around =
-                                        (st.st_uid == 0 || st.st_uid == getuid()) &&
-                                        (st.st_mode & S_ISVTX);
-                        }
-
                         is_dir = de->d_type == DT_DIR;
+                        keep_around = false;
                 }
 
                 if (is_dir) {
                         int subdir_fd;
 
-                        subdir_fd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
+                        /* if root_dev is set, remove subdirectories only, if device is same as dir */
+                        if (root_dev && st.st_dev != root_dev->st_dev)
+                                continue;
+
+                        subdir_fd = openat(fd, de->d_name,
+                                           O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
                         if (subdir_fd < 0) {
                                 if (ret == 0 && errno != ENOENT)
                                         ret = -errno;
                                 continue;
                         }
 
-                        r = rm_rf_children(subdir_fd, only_dirs, honour_sticky);
+                        r = rm_rf_children(subdir_fd, only_dirs, honour_sticky, root_dev);
                         if (r < 0 && ret == 0)
                                 ret = r;
 
@@ -3240,18 +3364,61 @@ int rm_rf_children(int fd, bool only_dirs, bool honour_sticky) {
         return ret;
 }
 
-int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
-        int fd;
-        int r;
+int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) {
+        struct statfs s;
+
+        assert(fd >= 0);
+
+        if (fstatfs(fd, &s) < 0) {
+                close_nointr_nofail(fd);
+                return -errno;
+        }
+
+        /* We refuse to clean disk file systems with this call. This
+         * is extra paranoia just to be sure we never ever remove
+         * non-state data */
+
+        if (s.f_type != TMPFS_MAGIC &&
+            s.f_type != RAMFS_MAGIC) {
+                log_error("Attempted to remove disk file system, and we can't allow that.");
+                close_nointr_nofail(fd);
+                return -EPERM;
+        }
+
+        return rm_rf_children_dangerous(fd, only_dirs, honour_sticky, root_dev);
+}
+
+static int rm_rf_internal(const char *path, bool only_dirs, bool delete_root, bool honour_sticky, bool dangerous) {
+        int fd, r;
+        struct statfs s;
 
         assert(path);
 
+        /* We refuse to clean the root file system with this
+         * call. This is extra paranoia to never cause a really
+         * seriously broken system. */
+        if (path_equal(path, "/")) {
+                log_error("Attempted to remove entire root file system, and we can't allow that.");
+                return -EPERM;
+        }
+
         fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME);
         if (fd < 0) {
 
                 if (errno != ENOTDIR)
                         return -errno;
 
+                if (!dangerous) {
+                        if (statfs(path, &s) < 0)
+                                return -errno;
+
+                        if (s.f_type != TMPFS_MAGIC &&
+                            s.f_type != RAMFS_MAGIC) {
+                                log_error("Attempted to remove disk file system, and we can't allow that.");
+                                return -EPERM;
+                        }
+                }
+
                 if (delete_root && !only_dirs)
                         if (unlink(path) < 0 && errno != ENOENT)
                                 return -errno;
@@ -3259,8 +3426,21 @@ int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky
                 return 0;
         }
 
-        r = rm_rf_children(fd, only_dirs, honour_sticky);
+        if (!dangerous) {
+                if (fstatfs(fd, &s) < 0) {
+                        close_nointr_nofail(fd);
+                        return -errno;
+                }
+
+                if (s.f_type != TMPFS_MAGIC &&
+                    s.f_type != RAMFS_MAGIC) {
+                        log_error("Attempted to remove disk file system, and we can't allow that.");
+                        close_nointr_nofail(fd);
+                        return -EPERM;
+                }
+        }
 
+        r = rm_rf_children_dangerous(fd, only_dirs, honour_sticky, NULL);
         if (delete_root) {
 
                 if (honour_sticky && file_is_priv_sticky(path) > 0)
@@ -3275,6 +3455,14 @@ int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky
         return r;
 }
 
+int rm_rf(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
+        return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, false);
+}
+
+int rm_rf_dangerous(const char *path, bool only_dirs, bool delete_root, bool honour_sticky) {
+        return rm_rf_internal(path, only_dirs, delete_root, honour_sticky, true);
+}
+
 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
         assert(path);
 
@@ -4717,7 +4905,12 @@ int socket_from_display(const char *display, char **path) {
         return 0;
 }
 
-int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) {
+int get_user_creds(
+                const char **username,
+                uid_t *uid, gid_t *gid,
+                const char **home,
+                const char **shell) {
+
         struct passwd *p;
         uid_t u;
 
@@ -4738,6 +4931,10 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
 
                 if (home)
                         *home = "/root";
+
+                if (shell)
+                        *shell = "/bin/sh";
+
                 return 0;
         }
 
@@ -4769,6 +4966,9 @@ int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **h
         if (home)
                 *home = p->pw_dir;
 
+        if (shell)
+                *shell = p->pw_shell;
+
         return 0;
 }
 
@@ -4985,7 +5185,7 @@ finish:
         return r;
 }
 
-char *join(const char *x, ...) {
+char *strjoin(const char *x, ...) {
         va_list ap;
         size_t l;
         char *r, *p;
@@ -5639,3 +5839,163 @@ bool is_valid_documentation_url(const char *url) {
 
         return false;
 }
+
+bool in_initrd(void) {
+        static int saved = -1;
+        struct statfs s;
+
+        if (saved >= 0)
+                return saved;
+
+        /* 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 bad consequences due the initrd
+         * emptying when transititioning to the main systemd.
+         */
+
+        saved = access("/etc/initrd-release", F_OK) >= 0 &&
+                statfs("/", &s) >= 0 &&
+                (s.f_type == TMPFS_MAGIC || s.f_type == RAMFS_MAGIC);
+
+        return saved;
+}
+
+void warn_melody(void) {
+        int fd;
+
+        fd = open("/dev/console", O_WRONLY|O_CLOEXEC|O_NOCTTY);
+        if (fd < 0)
+                return;
+
+        /* Yeah, this is synchronous. Kinda sucks. Bute well... */
+
+        ioctl(fd, KIOCSOUND, (int)(1193180/440));
+        usleep(125*USEC_PER_MSEC);
+
+        ioctl(fd, KIOCSOUND, (int)(1193180/220));
+        usleep(125*USEC_PER_MSEC);
+
+        ioctl(fd, KIOCSOUND, (int)(1193180/220));
+        usleep(125*USEC_PER_MSEC);
+
+        ioctl(fd, KIOCSOUND, 0);
+        close_nointr_nofail(fd);
+}
+
+int make_console_stdio(void) {
+        int fd, r;
+
+        /* Make /dev/console the controlling terminal and stdin/stdout/stderr */
+
+        fd = acquire_terminal("/dev/console", false, true, true, (usec_t) -1);
+        if (fd < 0) {
+                log_error("Failed to acquire terminal: %s", strerror(-fd));
+                return fd;
+        }
+
+        r = make_stdio(fd);
+        if (r < 0) {
+                log_error("Failed to duplicate terminal fd: %s", strerror(-r));
+                return r;
+        }
+
+        return 0;
+}
+
+int get_home_dir(char **_h) {
+        char *h;
+        const char *e;
+        uid_t u;
+        struct passwd *p;
+
+        assert(_h);
+
+        /* Take the user specified one */
+        e = getenv("HOME");
+        if (e) {
+                h = strdup(e);
+                if (!h)
+                        return -ENOMEM;
+
+                *_h = h;
+                return 0;
+        }
+
+        /* Hardcode home directory for root to avoid NSS */
+        u = getuid();
+        if (u == 0) {
+                h = strdup("/root");
+                if (!h)
+                        return -ENOMEM;
+
+                *_h = h;
+                return 0;
+        }
+
+        /* Check the database... */
+        errno = 0;
+        p = getpwuid(u);
+        if (!p)
+                return errno ? -errno : -ENOENT;
+
+        if (!path_is_absolute(p->pw_dir))
+                return -EINVAL;
+
+        h = strdup(p->pw_dir);
+        if (!h)
+                return -ENOMEM;
+
+        *_h = h;
+        return 0;
+}
+
+int get_shell(char **_sh) {
+        char *sh;
+        const char *e;
+        uid_t u;
+        struct passwd *p;
+
+        assert(_sh);
+
+        /* Take the user specified one */
+        e = getenv("SHELL");
+        if (e) {
+                sh = strdup(e);
+                if (!sh)
+                        return -ENOMEM;
+
+                *_sh = sh;
+                return 0;
+        }
+
+        /* Hardcode home directory for root to avoid NSS */
+        u = getuid();
+        if (u == 0) {
+                sh = strdup("/bin/sh");
+                if (!sh)
+                        return -ENOMEM;
+
+                *_sh = sh;
+                return 0;
+        }
+
+        /* Check the database... */
+        errno = 0;
+        p = getpwuid(u);
+        if (!p)
+                return errno ? -errno : -ESRCH;
+
+        if (!path_is_absolute(p->pw_shell))
+                return -EINVAL;
+
+        sh = strdup(p->pw_shell);
+        if (!sh)
+                return -ENOMEM;
+
+        *_sh = sh;
+        return 0;
+}