./move.sh

1 files changed, 481 insertions, 0 deletions

diff --git a/src/libbasic/user-util.c b/src/libbasic/user-util.c
new file mode 100644
index 0000000000..f65ca3edaa
--- /dev/null
+++ b/src/libbasic/user-util.c
@@ -0,0 +1,481 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "missing.h"
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "formats-util.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "string-util.h"
+#include "user-util.h"
+
+bool uid_is_valid(uid_t uid) {
+
+        /* Some libc APIs use UID_INVALID as special placeholder */
+        if (uid == (uid_t) UINT32_C(0xFFFFFFFF))
+                return false;
+
+        /* A long time ago UIDs where 16bit, hence explicitly avoid the 16bit -1 too */
+        if (uid == (uid_t) UINT32_C(0xFFFF))
+                return false;
+
+        return true;
+}
+
+int parse_uid(const char *s, uid_t *ret) {
+        uint32_t uid = 0;
+        int r;
+
+        assert(s);
+
+        assert_cc(sizeof(uid_t) == sizeof(uint32_t));
+        r = safe_atou32(s, &uid);
+        if (r < 0)
+                return r;
+
+        if (!uid_is_valid(uid))
+                return -ENXIO; /* we return ENXIO instead of EINVAL
+                                * here, to make it easy to distuingish
+                                * invalid numeric uids from invalid
+                                * strings. */
+
+        if (ret)
+                *ret = uid;
+
+        return 0;
+}
+
+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 uid_to_name(uid);
+}
+
+char *getusername_malloc(void) {
+        const char *e;
+
+        e = getenv("USER");
+        if (e)
+                return strdup(e);
+
+        return uid_to_name(getuid());
+}
+
+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;
+
+        assert(username);
+        assert(*username);
+
+        /* We enforce some special rules for uid=0: in order to avoid
+         * NSS lookups for root we hardcode its data. */
+
+        if (streq(*username, "root") || streq(*username, "0")) {
+                *username = "root";
+
+                if (uid)
+                        *uid = 0;
+
+                if (gid)
+                        *gid = 0;
+
+                if (home)
+                        *home = "/root";
+
+                if (shell)
+                        *shell = "/bin/sh";
+
+                return 0;
+        }
+
+        if (parse_uid(*username, &u) >= 0) {
+                errno = 0;
+                p = getpwuid(u);
+
+                /* If there are multiple users with the same id, make
+                 * sure to leave $USER to the configured value instead
+                 * of the first occurrence in the database. However if
+                 * the uid was configured by a numeric uid, then let's
+                 * pick the real username from /etc/passwd. */
+                if (p)
+                        *username = p->pw_name;
+        } else {
+                errno = 0;
+                p = getpwnam(*username);
+        }
+
+        if (!p)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (uid) {
+                if (!uid_is_valid(p->pw_uid))
+                        return -EBADMSG;
+
+                *uid = p->pw_uid;
+        }
+
+        if (gid) {
+                if (!gid_is_valid(p->pw_gid))
+                        return -EBADMSG;
+
+                *gid = p->pw_gid;
+        }
+
+        if (home)
+                *home = p->pw_dir;
+
+        if (shell)
+                *shell = p->pw_shell;
+
+        return 0;
+}
+
+int get_group_creds(const char **groupname, gid_t *gid) {
+        struct group *g;
+        gid_t id;
+
+        assert(groupname);
+
+        /* We enforce some special rules for gid=0: in order to avoid
+         * NSS lookups for root we hardcode its data. */
+
+        if (streq(*groupname, "root") || streq(*groupname, "0")) {
+                *groupname = "root";
+
+                if (gid)
+                        *gid = 0;
+
+                return 0;
+        }
+
+        if (parse_gid(*groupname, &id) >= 0) {
+                errno = 0;
+                g = getgrgid(id);
+
+                if (g)
+                        *groupname = g->gr_name;
+        } else {
+                errno = 0;
+                g = getgrnam(*groupname);
+        }
+
+        if (!g)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (gid) {
+                if (!gid_is_valid(g->gr_gid))
+                        return -EBADMSG;
+
+                *gid = g->gr_gid;
+        }
+
+        return 0;
+}
+
+char* uid_to_name(uid_t uid) {
+        char *ret;
+        int r;
+
+        /* Shortcut things to avoid NSS lookups */
+        if (uid == 0)
+                return strdup("root");
+
+        if (uid_is_valid(uid)) {
+                long bufsize;
+
+                bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+                if (bufsize <= 0)
+                        bufsize = 4096;
+
+                for (;;) {
+                        struct passwd pwbuf, *pw = NULL;
+                        _cleanup_free_ char *buf = NULL;
+
+                        buf = malloc(bufsize);
+                        if (!buf)
+                                return NULL;
+
+                        r = getpwuid_r(uid, &pwbuf, buf, (size_t) bufsize, &pw);
+                        if (r == 0 && pw)
+                                return strdup(pw->pw_name);
+                        if (r != ERANGE)
+                                break;
+
+                        bufsize *= 2;
+                }
+        }
+
+        if (asprintf(&ret, UID_FMT, uid) < 0)
+                return NULL;
+
+        return ret;
+}
+
+char* gid_to_name(gid_t gid) {
+        char *ret;
+        int r;
+
+        if (gid == 0)
+                return strdup("root");
+
+        if (gid_is_valid(gid)) {
+                long bufsize;
+
+                bufsize = sysconf(_SC_GETGR_R_SIZE_MAX);
+                if (bufsize <= 0)
+                        bufsize = 4096;
+
+                for (;;) {
+                        struct group grbuf, *gr = NULL;
+                        _cleanup_free_ char *buf = NULL;
+
+                        buf = malloc(bufsize);
+                        if (!buf)
+                                return NULL;
+
+                        r = getgrgid_r(gid, &grbuf, buf, (size_t) bufsize, &gr);
+                        if (r == 0 && gr)
+                                return strdup(gr->gr_name);
+                        if (r != ERANGE)
+                                break;
+
+                        bufsize *= 2;
+                }
+        }
+
+        if (asprintf(&ret, GID_FMT, gid) < 0)
+                return NULL;
+
+        return ret;
+}
+
+int in_gid(gid_t gid) {
+        gid_t *gids;
+        int ngroups_max, r, i;
+
+        if (getgid() == gid)
+                return 1;
+
+        if (getegid() == gid)
+                return 1;
+
+        if (!gid_is_valid(gid))
+                return -EINVAL;
+
+        ngroups_max = sysconf(_SC_NGROUPS_MAX);
+        assert(ngroups_max > 0);
+
+        gids = alloca(sizeof(gid_t) * ngroups_max);
+
+        r = getgroups(ngroups_max, gids);
+        if (r < 0)
+                return -errno;
+
+        for (i = 0; i < r; i++)
+                if (gids[i] == gid)
+                        return 1;
+
+        return 0;
+}
+
+int in_group(const char *name) {
+        int r;
+        gid_t gid;
+
+        r = get_group_creds(&name, &gid);
+        if (r < 0)
+                return r;
+
+        return in_gid(gid);
+}
+
+int get_home_dir(char **_h) {
+        struct passwd *p;
+        const char *e;
+        char *h;
+        uid_t u;
+
+        assert(_h);
+
+        /* Take the user specified one */
+        e = secure_getenv("HOME");
+        if (e && path_is_absolute(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 > 0 ? -errno : -ESRCH;
+
+        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 **_s) {
+        struct passwd *p;
+        const char *e;
+        char *s;
+        uid_t u;
+
+        assert(_s);
+
+        /* Take the user specified one */
+        e = getenv("SHELL");
+        if (e) {
+                s = strdup(e);
+                if (!s)
+                        return -ENOMEM;
+
+                *_s = s;
+                return 0;
+        }
+
+        /* Hardcode home directory for root to avoid NSS */
+        u = getuid();
+        if (u == 0) {
+                s = strdup("/bin/sh");
+                if (!s)
+                        return -ENOMEM;
+
+                *_s = s;
+                return 0;
+        }
+
+        /* Check the database... */
+        errno = 0;
+        p = getpwuid(u);
+        if (!p)
+                return errno > 0 ? -errno : -ESRCH;
+
+        if (!path_is_absolute(p->pw_shell))
+                return -EINVAL;
+
+        s = strdup(p->pw_shell);
+        if (!s)
+                return -ENOMEM;
+
+        *_s = s;
+        return 0;
+}
+
+int reset_uid_gid(void) {
+
+        if (setgroups(0, NULL) < 0)
+                return -errno;
+
+        if (setresgid(0, 0, 0) < 0)
+                return -errno;
+
+        if (setresuid(0, 0, 0) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int take_etc_passwd_lock(const char *root) {
+
+        struct flock flock = {
+                .l_type = F_WRLCK,
+                .l_whence = SEEK_SET,
+                .l_start = 0,
+                .l_len = 0,
+        };
+
+        const char *path;
+        int fd, r;
+
+        /* This is roughly the same as lckpwdf(), but not as awful. We
+         * don't want to use alarm() and signals, hence we implement
+         * our own trivial version of this.
+         *
+         * Note that shadow-utils also takes per-database locks in
+         * addition to lckpwdf(). However, we don't given that they
+         * are redundant as they they invoke lckpwdf() first and keep
+         * it during everything they do. The per-database locks are
+         * awfully racy, and thus we just won't do them. */
+
+        if (root)
+                path = prefix_roota(root, "/etc/.pwd.lock");
+        else
+                path = "/etc/.pwd.lock";
+
+        fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
+        if (fd < 0)
+                return -errno;
+
+        r = fcntl(fd, F_SETLKW, &flock);
+        if (r < 0) {
+                safe_close(fd);
+                return -errno;
+        }
+
+        return fd;
+}