[systemd-devel] [PATCH] core/cryptsetup: Add WantsMountFor option to enable fallback to password request for crypt mounts. Signed-off-by: Przemek Rudy <prudy1 at o2.pl>

Tom Gundersen teg at jklm.no
Mon Apr 28 02:15:37 PDT 2014


On Mon, Apr 28, 2014 at 12:46 AM, Przemek Rudy <prudy1 at o2.pl> wrote:
> This patch is a proposal for a problem with not falling back to password request
> if the device with unlocking key for crypt volumes is not mounted for defined time.

Looks good to me (but I didn't test it). Only one minor nit below.

Also, you probably want to rewrite the subject of the patch (you can
drop the signed-off-by as we don't use that here).

Cheers,

Tom

> ---
>  src/core/dbus-unit.c                  |   1 +
>  src/core/load-fragment-gperf.gperf.m4 |   1 +
>  src/core/load-fragment.c              |  47 +++++++++++
>  src/core/load-fragment.h              |   1 +
>  src/core/manager.c                    |  15 ++++
>  src/core/manager.h                    |   6 ++
>  src/core/mount.c                      |  25 +++++-
>  src/core/unit.c                       | 144 ++++++++++++++++++++++++++++++++++
>  src/core/unit.h                       |   5 ++
>  src/cryptsetup/cryptsetup-generator.c |   3 +-
>  10 files changed, 246 insertions(+), 2 deletions(-)
>
> diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
> index 07e7f20..31a35e9 100644
> --- a/src/core/dbus-unit.c
> +++ b/src/core/dbus-unit.c
> @@ -516,6 +516,7 @@ const sd_bus_vtable bus_unit_vtable[] = {
>          SD_BUS_PROPERTY("ReloadPropagatedFrom", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_RELOAD_PROPAGATED_FROM]), SD_BUS_VTABLE_PROPERTY_CONST),
>          SD_BUS_PROPERTY("JoinsNamespaceOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_JOINS_NAMESPACE_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
>          SD_BUS_PROPERTY("RequiresMountsFor", "as", NULL, offsetof(Unit, requires_mounts_for), SD_BUS_VTABLE_PROPERTY_CONST),
> +        SD_BUS_PROPERTY("WantsMountsFor", "as", NULL, offsetof(Unit, wants_mounts_for), SD_BUS_VTABLE_PROPERTY_CONST),
>          SD_BUS_PROPERTY("Documentation", "as", NULL, offsetof(Unit, documentation), SD_BUS_VTABLE_PROPERTY_CONST),
>          SD_BUS_PROPERTY("Description", "s", property_get_description, 0, SD_BUS_VTABLE_PROPERTY_CONST),
>          SD_BUS_PROPERTY("LoadState", "s", property_get_load_state, offsetof(Unit, load_state), SD_BUS_VTABLE_PROPERTY_CONST),
> diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
> index 21bccbb..4e51866 100644
> --- a/src/core/load-fragment-gperf.gperf.m4
> +++ b/src/core/load-fragment-gperf.gperf.m4
> @@ -139,6 +139,7 @@ Unit.PropagateReloadFrom,        config_parse_unit_deps,             UNIT_RELOAD
>  Unit.PartOf,                     config_parse_unit_deps,             UNIT_PART_OF,                  0
>  Unit.JoinsNamespaceOf,           config_parse_unit_deps,             UNIT_JOINS_NAMESPACE_OF,       0
>  Unit.RequiresMountsFor,          config_parse_unit_requires_mounts_for, 0,                          0
> +Unit.WantsMountsFor,             config_parse_unit_wants_mounts_for, 0,                             0
>  Unit.StopWhenUnneeded,           config_parse_bool,                  0,                             offsetof(Unit, stop_when_unneeded)
>  Unit.RefuseManualStart,          config_parse_bool,                  0,                             offsetof(Unit, refuse_manual_start)
>  Unit.RefuseManualStop,           config_parse_bool,                  0,                             offsetof(Unit, refuse_manual_stop)
> diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
> index 3b36d15..24c1849 100644
> --- a/src/core/load-fragment.c
> +++ b/src/core/load-fragment.c
> @@ -2048,6 +2048,52 @@ int config_parse_unit_requires_mounts_for(
>          return 0;
>  }
>
> +int config_parse_unit_wants_mounts_for(
> +                const char *unit,
> +                const char *filename,
> +                unsigned line,
> +                const char *section,
> +                unsigned section_line,
> +                const char *lvalue,
> +                int ltype,
> +                const char *rvalue,
> +                void *data,
> +                void *userdata) {
> +
> +        Unit *u = userdata;
> +        char *state;
> +        size_t l;
> +        char *w;
> +
> +        assert(filename);
> +        assert(lvalue);
> +        assert(rvalue);
> +        assert(data);
> +
> +        FOREACH_WORD_QUOTED(w, l, rvalue, state) {
> +                int r;
> +                _cleanup_free_ char *n;
> +
> +                n = strndup(w, l);
> +                if (!n)
> +                        return log_oom();
> +
> +                if (!utf8_is_valid(n)) {
> +                        log_invalid_utf8(unit, LOG_ERR, filename, line, EINVAL, rvalue);
> +                        continue;
> +                }
> +
> +                r = unit_want_mounts_for(u, n);
> +                if (r < 0) {
> +                        log_syntax(unit, LOG_ERR, filename, line, r,
> +                                   "Failed to add wanted mount for, ignoring: %s", rvalue);
> +                        continue;
> +                }
> +        }
> +
> +        return 0;
> +}
> +
>  int config_parse_documentation(const char *unit,
>                                 const char *filename,
>                                 unsigned line,
> @@ -3422,6 +3468,7 @@ void unit_dump_config_items(FILE *f) {
>                  { config_parse_nsec,                  "NANOSECONDS" },
>                  { config_parse_namespace_path_strv,   "PATH [...]" },
>                  { config_parse_unit_requires_mounts_for, "PATH [...]" },
> +                { config_parse_unit_wants_mounts_for, "PATH [...]" },
>                  { config_parse_exec_mount_flags,      "MOUNTFLAG [...]" },
>                  { config_parse_unit_string_printf,    "STRING" },
>                  { config_parse_trigger_unit,          "UNIT" },
> diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
> index 242fd27..761d936 100644
> --- a/src/core/load-fragment.h
> +++ b/src/core/load-fragment.h
> @@ -74,6 +74,7 @@ int config_parse_kill_mode(const char *unit, const char *filename, unsigned line
>  int config_parse_notify_access(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>  int config_parse_failure_action(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>  int config_parse_unit_requires_mounts_for(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
> +int config_parse_unit_wants_mounts_for(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>  int config_parse_syscall_filter(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>  int config_parse_syscall_archs(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
>  int config_parse_syscall_errno(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
> diff --git a/src/core/manager.c b/src/core/manager.c
> index 5772f40..84ce11d 100644
> --- a/src/core/manager.c
> +++ b/src/core/manager.c
> @@ -830,6 +830,9 @@ void manager_free(Manager *m) {
>          assert(hashmap_isempty(m->units_requiring_mounts_for));
>          hashmap_free(m->units_requiring_mounts_for);
>
> +        assert(hashmap_isempty(m->units_want_mounts_for));
> +        hashmap_free(m->units_want_mounts_for);
> +
>          free(m);
>  }
>
> @@ -2849,6 +2852,18 @@ Set *manager_get_units_requiring_mounts_for(Manager *m, const char *path) {
>          return hashmap_get(m->units_requiring_mounts_for, streq(p, "/") ? "" : p);
>  }
>
> +Set *manager_get_units_want_mounts_for(Manager *m, const char *path) {
> +        char p[strlen(path)+1];
> +
> +        assert(m);
> +        assert(path);
> +
> +        strcpy(p, path);
> +        path_kill_slashes(p);
> +
> +        return hashmap_get(m->units_want_mounts_for, streq(p, "/") ? "" : p);
> +}
> +
>  const char *manager_get_runtime_prefix(Manager *m) {
>          assert(m);
>
> diff --git a/src/core/manager.h b/src/core/manager.h
> index a3de351..ba5e688 100644
> --- a/src/core/manager.h
> +++ b/src/core/manager.h
> @@ -269,6 +269,11 @@ struct Manager {
>           * value where Unit objects are contained. */
>          Hashmap *units_requiring_mounts_for;
>
> +        /* This maps all possible path prefixes to the units want
> +         * them. It's a hashmap with a path string as key and a Set as
> +         * value where Unit objects are contained. */
> +        Hashmap *units_want_mounts_for;

Shouldn't this be "units_wanting_mounts_for" to mimic
"units_requiring_mounts_for"?

>          /* Reference to the kdbus bus control fd */
>          int kdbus_fd;
>  };
> @@ -335,6 +340,7 @@ void manager_status_printf(Manager *m, bool ephemeral, const char *status, const
>  void manager_flip_auto_status(Manager *m, bool enable);
>
>  Set *manager_get_units_requiring_mounts_for(Manager *m, const char *path);
> +Set *manager_get_units_want_mounts_for(Manager *m, const char *path);
>
>  const char *manager_get_runtime_prefix(Manager *m);
>
> diff --git a/src/core/mount.c b/src/core/mount.c
> index a979837..64d6914 100644
> --- a/src/core/mount.c
> +++ b/src/core/mount.c
> @@ -264,7 +264,7 @@ static int mount_add_mount_links(Mount *m) {
>                          return r;
>          }
>
> -        /* Adds in links to other units that use this path or paths
> +        /* Adds in links to other units that use (require) this path or paths
>           * further down in the hierarchy */
>          s = manager_get_units_requiring_mounts_for(UNIT(m)->manager, m->where);
>          SET_FOREACH(other, s, i) {
> @@ -287,6 +287,29 @@ static int mount_add_mount_links(Mount *m) {
>                  }
>          }
>
> +        /* Adds in links to other units that use (want) this path or paths
> +         * further down in the hierarchy */
> +        s = manager_get_units_want_mounts_for(UNIT(m)->manager, m->where);
> +        SET_FOREACH(other, s, i) {
> +
> +                if (other->load_state != UNIT_LOADED)
> +                        continue;
> +
> +                if (other == UNIT(m))
> +                        continue;
> +
> +                r = unit_add_dependency(other, UNIT_AFTER, UNIT(m), true);
> +                if (r < 0)
> +                        return r;
> +
> +                if (UNIT(m)->fragment_path) {
> +                        /* If we have fragment configuration, then make this dependency required */
> +                        r = unit_add_dependency(other, UNIT_WANTS, UNIT(m), true);
> +                        if (r < 0)
> +                                return r;
> +                }
> +        }
> +
>          return 0;
>  }
>
> diff --git a/src/core/unit.c b/src/core/unit.c
> index 6ac359e..f7c03f7 100644
> --- a/src/core/unit.c
> +++ b/src/core/unit.c
> @@ -428,6 +428,34 @@ static void unit_free_requires_mounts_for(Unit *u) {
>          u->requires_mounts_for = NULL;
>  }
>
> +static void unit_free_wants_mounts_for(Unit *u) {
> +        char **j;
> +
> +        STRV_FOREACH(j, u->wants_mounts_for) {
> +                char s[strlen(*j) + 1];
> +
> +                PATH_FOREACH_PREFIX_MORE(s, *j) {
> +                        char *y;
> +                        Set *x;
> +
> +                        x = hashmap_get2(u->manager->units_want_mounts_for, s, (void**) &y);
> +                        if (!x)
> +                                continue;
> +
> +                        set_remove(x, u);
> +
> +                        if (set_isempty(x)) {
> +                                hashmap_remove(u->manager->units_want_mounts_for, y);
> +                                free(y);
> +                                set_free(x);
> +                        }
> +                }
> +        }
> +
> +        strv_free(u->wants_mounts_for);
> +        u->wants_mounts_for = NULL;
> +}
> +
>  static void unit_done(Unit *u) {
>          ExecContext *ec;
>          CGroupContext *cc;
> @@ -464,6 +492,7 @@ void unit_free(Unit *u) {
>          unit_done(u);
>
>          unit_free_requires_mounts_for(u);
> +        unit_free_wants_mounts_for(u);
>
>          SET_FOREACH(t, u->names, i)
>                  hashmap_remove_value(u->manager->units, t, u);
> @@ -885,6 +914,16 @@ void unit_dump(Unit *u, FILE *f, const char *prefix) {
>                  fputs("\n", f);
>          }
>
> +        if (!strv_isempty(u->wants_mounts_for)) {
> +                fprintf(f,
> +                        "%s\tWantsMountsFor:", prefix);
> +
> +                STRV_FOREACH(j, u->wants_mounts_for)
> +                        fprintf(f, " %s", *j);
> +
> +                fputs("\n", f);
> +        }
> +
>          if (u->load_state == UNIT_LOADED) {
>
>                  fprintf(f,
> @@ -1068,6 +1107,35 @@ static int unit_add_mount_dependencies(Unit *u) {
>                  }
>          }
>
> +        STRV_FOREACH(i, u->wants_mounts_for) {
> +                char prefix[strlen(*i) + 1];
> +
> +                PATH_FOREACH_PREFIX_MORE(prefix, *i) {
> +                        Unit *m;
> +
> +                        r = manager_get_unit_by_path(u->manager, prefix, ".mount", &m);
> +                        if (r < 0)
> +                                return r;
> +                        if (r == 0)
> +                                continue;
> +                        if (m == u)
> +                                continue;
> +
> +                        if (m->load_state != UNIT_LOADED)
> +                                continue;
> +
> +                        r = unit_add_dependency(u, UNIT_AFTER, m, true);
> +                        if (r < 0)
> +                                return r;
> +
> +                        if (m->fragment_path) {
> +                                r = unit_add_dependency(u, UNIT_WANTS, m, true);
> +                                if (r < 0)
> +                                        return r;
> +                        }
> +                }
> +        }
> +
>          return 0;
>  }
>
> @@ -3289,6 +3357,82 @@ int unit_require_mounts_for(Unit *u, const char *path) {
>          return 0;
>  }
>
> +int unit_want_mounts_for(Unit *u, const char *path) {
> +        char prefix[strlen(path) + 1], *p;
> +        int r;
> +
> +        assert(u);
> +        assert(path);
> +
> +        /* Registers a unit for want a certain path and all its
> +         * prefixes. We keep a simple array of these paths in the
> +         * unit, since its usually short. However, we build a prefix
> +         * table for all possible prefixes so that new appearing mount
> +         * units can easily determine which units to make themselves a
> +         * dependency of. */
> +
> +        if (!path_is_absolute(path))
> +                return -EINVAL;
> +
> +        p = strdup(path);
> +        if (!p)
> +                return -ENOMEM;
> +
> +        path_kill_slashes(p);
> +
> +        if (!path_is_safe(p)) {
> +                free(p);
> +                return -EPERM;
> +        }
> +
> +        if (strv_contains(u->wants_mounts_for, p)) {
> +                free(p);
> +                return 0;
> +        }
> +
> +        r = strv_consume(&u->wants_mounts_for, p);
> +        if (r < 0)
> +                return r;
> +
> +        PATH_FOREACH_PREFIX_MORE(prefix, p) {
> +                Set *x;
> +
> +                x = hashmap_get(u->manager->units_want_mounts_for, prefix);
> +                if (!x) {
> +                        char *q;
> +
> +                        if (!u->manager->units_want_mounts_for) {
> +                                u->manager->units_want_mounts_for = hashmap_new(string_hash_func, string_compare_func);
> +                                if (!u->manager->units_want_mounts_for)
> +                                        return -ENOMEM;
> +                        }
> +
> +                        q = strdup(prefix);
> +                        if (!q)
> +                                return -ENOMEM;
> +
> +                        x = set_new(NULL, NULL);
> +                        if (!x) {
> +                                free(q);
> +                                return -ENOMEM;
> +                        }
> +
> +                        r = hashmap_put(u->manager->units_want_mounts_for, q, x);
> +                        if (r < 0) {
> +                                free(q);
> +                                set_free(x);
> +                                return r;
> +                        }
> +                }
> +
> +                r = set_put(x, u);
> +                if (r < 0)
> +                        return r;
> +        }
> +
> +        return 0;
> +}
> +
>  int unit_setup_exec_runtime(Unit *u) {
>          ExecRuntime **rt;
>          size_t offset;
> diff --git a/src/core/unit.h b/src/core/unit.h
> index 3e61067..0db0b91 100644
> --- a/src/core/unit.h
> +++ b/src/core/unit.h
> @@ -143,6 +143,7 @@ struct Unit {
>          Set *dependencies[_UNIT_DEPENDENCY_MAX];
>
>          char **requires_mounts_for;
> +        char **wants_mounts_for;
>
>          char *description;
>          char **documentation;
> @@ -189,6 +190,9 @@ struct Unit {
>          /* All units which have requires_mounts_for set */
>          LIST_FIELDS(Unit, has_requires_mounts_for);
>
> +        /* All units which have wantss_mounts_for set */
> +        LIST_FIELDS(Unit, has_wants_mounts_for);
> +
>          /* Load queue */
>          LIST_FIELDS(Unit, load_queue);
>
> @@ -625,6 +629,7 @@ int unit_kill_context(Unit *u, KillContext *c, bool sigkill, pid_t main_pid, pid
>  int unit_make_transient(Unit *u);
>
>  int unit_require_mounts_for(Unit *u, const char *path);
> +int unit_want_mounts_for(Unit *u, const char *path);
>
>  const char *unit_active_state_to_string(UnitActiveState i) _const_;
>  UnitActiveState unit_active_state_from_string(const char *s) _pure_;
> diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c
> index f4eeb2a..ce7ae92 100644
> --- a/src/cryptsetup/cryptsetup-generator.c
> +++ b/src/cryptsetup/cryptsetup-generator.c
> @@ -153,7 +153,8 @@ static int create_disk(
>
>                                  fprintf(f, "After=%1$s\nRequires=%1$s\n", dd);
>                          } else
> -                                fprintf(f, "RequiresMountsFor=%s\n", password);
> +                                /* Do not use 'RequiresMountsFor=' here to allow fallback to password in case the key device is not available */
> +                                fprintf(f, "WantsMountsFor=%s\n", password);
>                  }
>          }
>
> --
> 1.9.0
>
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