mount: replace PID1 internal fstab parser with generator

Bit by bit we should remove non-unit parsing from PID 1 and move into
generators, to clean up our code base a bit and clearly separate
parsers.

2 files changed, 518 insertions, 0 deletions

diff --git a/src/fstab-generator/Makefile b/src/fstab-generator/Makefile
new file mode 120000
index 0000000000..d0b0e8e008
--- /dev/null
+++ b/src/fstab-generator/Makefile
@@ -0,0 +1 @@
+../Makefile
\ No newline at end of file
diff --git a/src/fstab-generator/fstab-generator.c b/src/fstab-generator/fstab-generator.c
new file mode 100644
index 0000000000..39af18a9c8
--- /dev/null
+++ b/src/fstab-generator/fstab-generator.c
@@ -0,0 +1,517 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 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 <stdio.h>
+#include <mntent.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "log.h"
+#include "util.h"
+#include "unit-name.h"
+#include "path-util.h"
+#include "mount-setup.h"
+#include "special.h"
+#include "mkdir.h"
+
+static const char *arg_dest = "/tmp";
+
+static int device_name(const char *path, char **unit) {
+        char *p;
+
+        assert(path);
+
+        if (!is_device_path(path))
+                return 0;
+
+        p = unit_name_from_path(path, ".device");
+        if (!p)
+                return -ENOMEM;
+
+        *unit = p;
+        return 1;
+}
+
+static int mount_find_pri(struct mntent *me, int *ret) {
+        char *end, *pri;
+        unsigned long r;
+
+        assert(me);
+        assert(ret);
+
+        pri = hasmntopt(me, "pri");
+        if (!pri)
+                return 0;
+
+        pri += 4;
+
+        errno = 0;
+        r = strtoul(pri, &end, 10);
+        if (errno != 0)
+                return -errno;
+
+        if (end == pri || (*end != ',' && *end != 0))
+                return -EINVAL;
+
+        *ret = (int) r;
+        return 1;
+}
+
+static int add_swap(const char *what, struct mntent *me) {
+        char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL;
+        FILE *f = NULL;
+        bool noauto, nofail;
+        int r, pri = -1;
+
+        assert(what);
+        assert(me);
+
+        r = mount_find_pri(me, &pri);
+        if (r < 0) {
+                log_error("Failed to parse priority");
+                return pri;
+        }
+
+        noauto = !!hasmntopt(me, "noauto");
+        nofail = !!hasmntopt(me, "nofail");
+
+        name = unit_name_from_path(what, ".swap");
+        if (!name) {
+                log_error("Out of memory");
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        unit = join(arg_dest, "/", name, NULL);
+        if (!unit) {
+                log_error("Out of memory");
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        f = fopen(unit, "wxe");
+        if (!f) {
+                r = -errno;
+                log_error("Failed to create unit file: %m");
+                goto finish;
+        }
+
+        fputs("# Automatically generated by systemd-fstab-generator\n\n"
+              "[Unit]\n"
+              "DefaultDependencies=no\n"
+              "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
+              "Before=" SPECIAL_UMOUNT_TARGET "\n", f);
+
+        if (!noauto && !nofail)
+                fputs("Before=" SPECIAL_SWAP_TARGET "\n", f);
+
+        fprintf(f,
+                "\n"
+                "[Swap]\n"
+                "What=%s\n",
+                what);
+
+        if (pri >= 0)
+                fprintf(f,
+                        "Priority=%i\n",
+                        pri);
+
+        fflush(f);
+        if (ferror(f)) {
+                log_error("Failed to write unit file: %m");
+                r = -errno;
+                goto finish;
+        }
+
+        if (!noauto) {
+                lnk = join(arg_dest, "/" SPECIAL_SWAP_TARGET ".wants/", name, NULL);
+                if (!lnk) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                mkdir_parents(lnk, 0755);
+                if (symlink(unit, lnk) < 0) {
+                        log_error("Failed to create symlink: %m");
+                        r = -errno;
+                        goto finish;
+                }
+
+                r = device_name(what, &device);
+                if (r < 0) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (r > 0) {
+                        free(lnk);
+                        lnk = join(arg_dest, "/", device, ".wants/", name, NULL);
+                        if (!lnk) {
+                                log_error("Out of memory");
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        mkdir_parents(lnk, 0755);
+                        if (symlink(unit, lnk) < 0) {
+                                log_error("Failed to create symlink: %m");
+                                r = -errno;
+                                goto finish;
+                        }
+                }
+        }
+
+        r = 0;
+finish:
+        if (f)
+                fclose(f);
+
+        free(unit);
+        free(lnk);
+        free(name);
+        free(device);
+
+        return r;
+}
+
+static bool mount_is_bind(struct mntent *me) {
+        assert(me);
+
+        return
+                hasmntopt(me, "bind") ||
+                streq(me->mnt_opts, "bind");
+}
+
+static bool mount_is_network(struct mntent *me) {
+        assert(me);
+
+        return
+                hasmntopt(me, "_netdev") ||
+                fstype_is_network(me->mnt_type);
+}
+
+static int add_mount(const char *what, const char *where, struct mntent *me) {
+        char *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL, *automount_name = NULL, *automount_unit = NULL;
+        FILE *f = NULL;
+        bool noauto, nofail, automount, isbind, isnetwork;
+        int r;
+        const char *post, *pre;
+
+        assert(what);
+        assert(where);
+        assert(me);
+
+        if (streq(me->mnt_type, "autofs"))
+                return 0;
+
+        if (!is_path(where)) {
+                log_warning("Mount point %s is not a valid path, ignoring.", where);
+                return 0;
+        }
+
+        if (mount_point_is_api(where) ||
+            mount_point_ignore(where))
+                return 0;
+
+        isnetwork = mount_is_network(me);
+        isbind = mount_is_bind(me);
+
+        noauto = !!hasmntopt(me, "noauto");
+        nofail = !!hasmntopt(me, "nofail");
+        automount =
+                hasmntopt(me, "comment=systemd.automount") ||
+                hasmntopt(me, "x-systemd.automount");
+
+        if (isnetwork) {
+                post = SPECIAL_REMOTE_FS_TARGET;
+                pre = SPECIAL_REMOTE_FS_PRE_TARGET;
+        } else {
+                post = SPECIAL_LOCAL_FS_TARGET;
+                pre = SPECIAL_LOCAL_FS_PRE_TARGET;
+        }
+
+        name = unit_name_from_path(where, ".mount");
+        if (!name)  {
+                log_error("Out of memory");
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        unit = join(arg_dest, "/", name, NULL);
+        if (!unit) {
+                log_error("Out of memory");
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        f = fopen(unit, "wxe");
+        if (!f) {
+                r = -errno;
+                log_error("Failed to create unit file: %m");
+                goto finish;
+        }
+
+        fputs("# Automatically generated by systemd-fstab-generator\n\n"
+              "[Unit]\n"
+              "DefaultDependencies=no\n", f);
+
+        if (!path_equal(where, "/"))
+                fprintf(f,
+                        "After=%s\n"
+                        "Wants=%s\n"
+                        "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
+                        "Before=" SPECIAL_UMOUNT_TARGET "\n",
+                        pre,
+                        pre);
+
+
+        if (!noauto && !nofail && !automount)
+                fprintf(f,
+                        "Before=%s\n",
+                        post);
+
+        fprintf(f,
+                "\n"
+                "[Mount]\n"
+                "What=%s\n"
+                "Where=%s\n"
+                "Type=%s\n"
+                "FsckPassNo=%i\n",
+                what,
+                where,
+                me->mnt_type,
+                me->mnt_passno);
+
+        if (!isempty(me->mnt_opts) &&
+            !streq(me->mnt_opts, "defaults"))
+                fprintf(f,
+                        "Options=%s\n",
+                        me->mnt_opts);
+
+        fflush(f);
+        if (ferror(f)) {
+                log_error("Failed to write unit file: %m");
+                r = -errno;
+                goto finish;
+        }
+
+        if (!noauto) {
+                lnk = join(arg_dest, "/", post, nofail || automount ? ".wants/" : ".requires/", name, NULL);
+                if (!lnk) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                mkdir_parents(lnk, 0755);
+                if (symlink(unit, lnk) < 0) {
+                        log_error("Failed to create symlink: %m");
+                        r = -errno;
+                        goto finish;
+                }
+
+                if (!isbind &&
+                    !path_equal(where, "/")) {
+
+                        r = device_name(what, &device);
+                        if (r < 0) {
+                                log_error("Out of memory");
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        if (r > 0) {
+                                free(lnk);
+                                lnk = join(arg_dest, "/", device, ".wants/", name, NULL);
+                                if (!lnk) {
+                                        log_error("Out of memory");
+                                        r = -ENOMEM;
+                                        goto finish;
+                                }
+
+                                mkdir_parents(lnk, 0755);
+                                if (symlink(unit, lnk) < 0) {
+                                        log_error("Failed to creat symlink: %m");
+                                        r = -errno;
+                                        goto finish;
+                                }
+                        }
+                }
+        }
+
+        if (automount && !path_equal(where, "/")) {
+                automount_name = unit_name_from_path(where, ".automount");
+                if (!name) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                automount_unit = join(arg_dest, "/", automount_name, NULL);
+                if (!automount_unit) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                fclose(f);
+                f = fopen(automount_unit, "wxe");
+                if (!f) {
+                        r = -errno;
+                        log_error("Failed to create unit file: %m");
+                        goto finish;
+                }
+
+                fprintf(f,
+                        "# Automatically generated by systemd-fstab-generator\n\n"
+                        "[Unit]\n"
+                        "DefaultDependencies=no\n"
+                        "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
+                        "Before=" SPECIAL_UMOUNT_TARGET " %s\n"
+                        "\n"
+                        "[Automount]\n"
+                        "Where=%s\n",
+                        post,
+                        where);
+
+                fflush(f);
+                if (ferror(f)) {
+                        log_error("Failed to write unit file: %m");
+                        r = -errno;
+                        goto finish;
+                }
+
+                free(lnk);
+                lnk = join(arg_dest, "/", post, nofail ? ".wants/" : ".requires/", automount_name, NULL);
+                if (!lnk) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                mkdir_parents(lnk, 0755);
+                if (symlink(automount_unit, lnk) < 0) {
+                        log_error("Failed to create symlink: %m");
+                        r = -errno;
+                        goto finish;
+                }
+        }
+
+        r = 0;
+finish:
+        if (f)
+                fclose(f);
+
+        free(unit);
+        free(lnk);
+        free(name);
+        free(device);
+        free(automount_name);
+        free(automount_unit);
+
+        return r;
+}
+
+static int parse_fstab(void) {
+        FILE *f;
+        int r = 0;
+        struct mntent *me;
+
+        errno = 0;
+        f = setmntent("/etc/fstab", "r");
+        if (!f) {
+                if (errno == ENOENT)
+                        return 0;
+
+                log_error("Failed to open /etc/fstab: %m");
+                return -errno;
+        }
+
+        while ((me = getmntent(f))) {
+                char *where, *what;
+                int k;
+
+                what = fstab_node_to_udev_node(me->mnt_fsname);
+                if (!what) {
+                        log_error("Out of memory");
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                where = strdup(me->mnt_dir);
+                if (!where) {
+                        log_error("Out of memory");
+                        free(what);
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                if (is_path(what))
+                        path_kill_slashes(what);
+
+                if (is_path(where))
+                        path_kill_slashes(where);
+
+                log_debug("Found entry what=%s where=%s type=%s", what, where, me->mnt_type);
+
+                if (streq(me->mnt_type, "swap"))
+                        k = add_swap(what, me);
+                else
+                        k = add_mount(what, where, me);
+
+                free(what);
+                free(where);
+
+                if (k < 0)
+                        r = k;
+        }
+
+finish:
+        endmntent(f);
+        return r;
+}
+
+int main(int argc, char *argv[]) {
+        int r;
+
+        if (argc > 2) {
+                log_error("This program takes one or no arguments.");
+                return EXIT_FAILURE;
+        }
+
+        if (argc > 1)
+                arg_dest = argv[1];
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        log_set_max_level(LOG_DEBUG);
+
+        umask(0022);
+
+        r = parse_fstab();
+
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}