14895667988

Committed 07 May 2025 08:57PM UTC coverage: 72.225% (-0.007%) from 72.232%

Build # 14895667988

Build Type

push

github

Committed by

yuwata

Commit Message

network: log_link_message_debug_errno() automatically append %m if necessary

Follow-up for d28746ef5.
Fixes CID#1609753.

Coverage Stats

0 of 1 new or added line in 1 file covered. (0.0%)

20297 existing lines in 338 files now uncovered.

297407 of 411780 relevant lines covered (72.22%)

695716.85 hits per line

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82.25

/src/nspawn/nspawn-bind-user.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include "alloc-util.h"
#include "chase.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "json-util.h"
#include "log.h"
#include "nspawn.h"
#include "nspawn-bind-user.h"
#include "path-util.h"
#include "user-util.h"
#include "userdb.h"

static int check_etc_passwd_collisions(
                const char *directory,
                const char *name,
                uid_t uid) {

        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(directory);
        assert(name || uid_is_valid(uid));

        r = chase_and_fopen_unlocked("/etc/passwd", directory, CHASE_PREFIX_ROOT, "re", NULL, &f);
        if (r == -ENOENT)
                return 0; /* no user database? then no user, hence no collision */
        if (r < 0)
                return log_error_errno(r, "Failed to open /etc/passwd of container: %m");

        for (;;) {
                struct passwd *pw;

                r = fgetpwent_sane(f, &pw);
                if (r < 0)
                        return log_error_errno(r, "Failed to iterate through /etc/passwd of container: %m");
                if (r == 0) /* EOF */
                        return 0; /* no collision */

                if (name && streq_ptr(pw->pw_name, name))
                        return 1; /* name collision */
                if (uid_is_valid(uid) && pw->pw_uid == uid)
                        return 1; /* UID collision */
        }
}

static int check_etc_group_collisions(
                const char *directory,
                const char *name,
                gid_t gid) {

        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(directory);
        assert(name || gid_is_valid(gid));

        r = chase_and_fopen_unlocked("/etc/group", directory, CHASE_PREFIX_ROOT, "re", NULL, &f);
        if (r == -ENOENT)
                return 0; /* no group database? then no group, hence no collision */
        if (r < 0)
                return log_error_errno(r, "Failed to open /etc/group of container: %m");

        for (;;) {
                struct group *gr;

                r = fgetgrent_sane(f, &gr);
                if (r < 0)
                        return log_error_errno(r, "Failed to iterate through /etc/group of container: %m");
                if (r == 0)
                        return 0; /* no collision */

                if (name && streq_ptr(gr->gr_name, name))
                        return 1; /* name collision */
                if (gid_is_valid(gid) && gr->gr_gid == gid)
                        return 1; /* gid collision */
        }
}

static int convert_user(
                const char *directory,
                UserRecord *u,
                GroupRecord *g,
                uid_t allocate_uid,
                UserRecord **ret_converted_user,
                GroupRecord **ret_converted_group) {

        _cleanup_(group_record_unrefp) GroupRecord *converted_group = NULL;
        _cleanup_(user_record_unrefp) UserRecord *converted_user = NULL;
        _cleanup_free_ char *h = NULL;
        sd_json_variant *p, *hp = NULL, *ssh = NULL;
        int r;

        assert(u);
        assert(g);
        assert(user_record_gid(u) == g->gid);

        r = check_etc_passwd_collisions(directory, u->user_name, UID_INVALID);
        if (r < 0)
                return r;
        if (r > 0)
                return log_error_errno(SYNTHETIC_ERRNO(EBUSY),
                                       "Sorry, the user '%s' already exists in the container.", u->user_name);

        r = check_etc_group_collisions(directory, g->group_name, GID_INVALID);
        if (r < 0)
                return r;
        if (r > 0)
                return log_error_errno(SYNTHETIC_ERRNO(EBUSY),
                                       "Sorry, the group '%s' already exists in the container.", g->group_name);

        h = path_join("/run/host/home/", u->user_name);
        if (!h)
                return log_oom();

        /* Acquire the source hashed password array as-is, so that it retains the JSON_VARIANT_SENSITIVE flag */
        p = sd_json_variant_by_key(u->json, "privileged");
        if (p) {
                hp = sd_json_variant_by_key(p, "hashedPassword");
                ssh = sd_json_variant_by_key(p, "sshAuthorizedKeys");
        }

        r = user_record_build(
                        &converted_user,
                        SD_JSON_BUILD_OBJECT(
                                        SD_JSON_BUILD_PAIR("userName", SD_JSON_BUILD_STRING(u->user_name)),
                                        SD_JSON_BUILD_PAIR("uid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
                                        SD_JSON_BUILD_PAIR("gid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
                                        SD_JSON_BUILD_PAIR_CONDITION(u->disposition >= 0, "disposition", SD_JSON_BUILD_STRING(user_disposition_to_string(u->disposition))),
                                        SD_JSON_BUILD_PAIR("homeDirectory", SD_JSON_BUILD_STRING(h)),
                                        SD_JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn")),
                                        SD_JSON_BUILD_PAIR("privileged", SD_JSON_BUILD_OBJECT(
                                                                           SD_JSON_BUILD_PAIR_CONDITION(!strv_isempty(u->hashed_password), "hashedPassword", SD_JSON_BUILD_VARIANT(hp)),
                                                                           SD_JSON_BUILD_PAIR_CONDITION(!!ssh, "sshAuthorizedKeys", SD_JSON_BUILD_VARIANT(ssh))))));
        if (r < 0)
                return log_error_errno(r, "Failed to build container user record: %m");

        r = group_record_build(
                        &converted_group,
                        SD_JSON_BUILD_OBJECT(
                                        SD_JSON_BUILD_PAIR("groupName", SD_JSON_BUILD_STRING(g->group_name)),
                                        SD_JSON_BUILD_PAIR("gid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
                                        SD_JSON_BUILD_PAIR_CONDITION(g->disposition >= 0, "disposition", SD_JSON_BUILD_STRING(user_disposition_to_string(g->disposition))),
                                        SD_JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn"))));
        if (r < 0)
                return log_error_errno(r, "Failed to build container group record: %m");

        *ret_converted_user = TAKE_PTR(converted_user);
        *ret_converted_group = TAKE_PTR(converted_group);

        return 0;
}

static int find_free_uid(const char *directory, uid_t max_uid, uid_t *current_uid) {
        int r;

        assert(directory);
        assert(current_uid);

        for (;; (*current_uid)++) {
                if (*current_uid > MAP_UID_MAX || *current_uid > max_uid)
                        return log_error_errno(
                                        SYNTHETIC_ERRNO(EBUSY),
                                        "No suitable available UID in range " UID_FMT "…" UID_FMT " in container detected, can't map user.",
                                        MAP_UID_MIN, MAP_UID_MAX);

                r = check_etc_passwd_collisions(directory, NULL, *current_uid);
                if (r < 0)
                        return r;
                if (r > 0) /* already used */
                        continue;

                /* We want to use the UID also as GID, hence check for it in /etc/group too */
                r = check_etc_group_collisions(directory, NULL, (gid_t) *current_uid);
                if (r <= 0)
                        return r;
        }
}

BindUserContext* bind_user_context_free(BindUserContext *c) {
        if (!c)
                return NULL;

        FOREACH_ARRAY(d, c->data, c->n_data) {
                user_record_unref(d->host_user);
                group_record_unref(d->host_group);
                user_record_unref(d->payload_user);
                group_record_unref(d->payload_group);
        }

        return mfree(c);
}

int bind_user_prepare(
                const char *directory,
                char **bind_user,
                uid_t uid_shift,
                uid_t uid_range,
                CustomMount **custom_mounts,
                size_t *n_custom_mounts,
                BindUserContext **ret) {

        _cleanup_(bind_user_context_freep) BindUserContext *c = NULL;
        uid_t current_uid = MAP_UID_MIN;
        int r;

        assert(custom_mounts);
        assert(n_custom_mounts);
        assert(ret);

        /* This resolves the users specified in 'bind_user', generates a minimalized JSON user + group record
         * for it to stick in the container, allocates a UID/GID for it, and updates the custom mount table,
         * to include an appropriate bind mount mapping.
         *
         * This extends the passed custom_mounts/n_custom_mounts with the home directories, and allocates a
         * new BindUserContext for the user records */

        if (strv_isempty(bind_user)) {
                *ret = NULL;
                return 0;
        }

        c = new0(BindUserContext, 1);
        if (!c)
                return log_oom();

        STRV_FOREACH(n, bind_user) {
                _cleanup_(user_record_unrefp) UserRecord *u = NULL, *cu = NULL;
                _cleanup_(group_record_unrefp) GroupRecord *g = NULL, *cg = NULL;
                _cleanup_free_ char *sm = NULL, *sd = NULL;

                r = userdb_by_name(*n, /* match= */ NULL, USERDB_DONT_SYNTHESIZE_INTRINSIC|USERDB_DONT_SYNTHESIZE_FOREIGN, &u);
                if (r < 0)
                        return log_error_errno(r, "Failed to resolve user '%s': %m", *n);

                /* For now, let's refuse mapping the root/nobody users explicitly. The records we generate
                 * are strictly additive, nss-systemd is typically placed last in /etc/nsswitch.conf. Thus
                 * even if we wanted, we couldn't override the root or nobody user records. Note we also
                 * check for name conflicts in /etc/passwd + /etc/group later on, which would usually filter
                 * out root/nobody too, hence these checks might appear redundant — but they actually are
                 * not, as we want to support environments where /etc/passwd and /etc/group are non-existent,
                 * and the user/group databases fully synthesized at runtime. Moreover, the name of the
                 * user/group name of the "nobody" account differs between distros, hence a check by numeric
                 * UID is safer. */
                if (user_record_is_root(u))
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'root' user not supported, sorry.");

                if (user_record_is_nobody(u))
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'nobody' user not supported, sorry.");

                if (!uid_is_valid(u->uid))
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot bind user with no UID, refusing.");

                if (u->uid >= uid_shift && u->uid < uid_shift + uid_range)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "UID of user '%s' to map is already in container UID range, refusing.", u->user_name);

                r = groupdb_by_gid(user_record_gid(u), /* match= */ NULL, USERDB_DONT_SYNTHESIZE_INTRINSIC|USERDB_DONT_SYNTHESIZE_FOREIGN, &g);
                if (r < 0)
                        return log_error_errno(r, "Failed to resolve group of user '%s': %m", u->user_name);

                if (g->gid >= uid_shift && g->gid < uid_shift + uid_range)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "GID of group '%s' to map is already in container GID range, refusing.", g->group_name);

                /* We want to synthesize exactly one user + group from the host into the container. This only
                 * makes sense if the user on the host has its own private group. We can't reasonably check
                 * this, so we just check of the name of user and group match.
                 *
                 * One of these days we might want to support users in a shared/common group too, but it's
                 * not clear to me how this would have to be mapped, precisely given that the common group
                 * probably already exists in the container. */
                if (!streq(u->user_name, g->group_name))
                        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                               "Sorry, mapping users without private groups is currently not supported.");

                r = find_free_uid(directory, uid_range, &current_uid);
                if (r < 0)
                        return r;

                r = convert_user(directory, u, g, current_uid, &cu, &cg);
                if (r < 0)
                        return r;

                if (!GREEDY_REALLOC(c->data, c->n_data + 1))
                        return log_oom();

                sm = strdup(user_record_home_directory(u));
                if (!sm)
                        return log_oom();

                sd = strdup(user_record_home_directory(cu));
                if (!sd)
                        return log_oom();

                if (!GREEDY_REALLOC(*custom_mounts, *n_custom_mounts + 1))
                        return log_oom();

                (*custom_mounts)[(*n_custom_mounts)++] = (CustomMount) {
                        .type = CUSTOM_MOUNT_BIND,
                        .source = TAKE_PTR(sm),
                        .destination = TAKE_PTR(sd),
                };

                c->data[c->n_data++] = (BindUserData) {
                        .host_user = TAKE_PTR(u),
                        .host_group = TAKE_PTR(g),
                        .payload_user = TAKE_PTR(cu),
                        .payload_group = TAKE_PTR(cg),
                };

                current_uid++;
        }

        *ret = TAKE_PTR(c);
        return 1;
}

static int write_and_symlink(
                const char *root,
                sd_json_variant *v,
                const char *name,
                uid_t uid,
                const char *suffix,
                WriteStringFileFlags extra_flags) {

        _cleanup_free_ char *j = NULL, *f = NULL, *p = NULL, *q = NULL;
        int r;

        assert(root);
        assert(v);
        assert(name);
        assert(uid_is_valid(uid));
        assert(suffix);

        r = sd_json_variant_format(v, SD_JSON_FORMAT_NEWLINE, &j);
        if (r < 0)
                return log_error_errno(r, "Failed to format user record JSON: %m");

        f = strjoin(name, suffix);
        if (!f)
                return log_oom();

        p = path_join(root, "/run/host/userdb/", f);
        if (!p)
                return log_oom();

        if (asprintf(&q, "%s/run/host/userdb/" UID_FMT "%s", root, uid, suffix) < 0)
                return log_oom();

        if (symlink(f, q) < 0)
                return log_error_errno(errno, "Failed to create symlink '%s': %m", q);

        r = userns_lchown(q, 0, 0);
        if (r < 0)
                return log_error_errno(r, "Failed to adjust access mode of '%s': %m", q);

        r = write_string_file(p, j, WRITE_STRING_FILE_CREATE|extra_flags);
        if (r < 0)
                return log_error_errno(r, "Failed to write %s: %m", p);

        r = userns_lchown(p, 0, 0);
        if (r < 0)
                return log_error_errno(r, "Failed to adjust access mode of '%s': %m", p);

        return 0;
}

int bind_user_setup(
                const BindUserContext *c,
                const char *root) {

        static const UserRecordLoadFlags strip_flags = /* Removes privileged info */
                USER_RECORD_LOAD_MASK_PRIVILEGED|
                USER_RECORD_PERMISSIVE;
        static const UserRecordLoadFlags shadow_flags = /* Extracts privileged info */
                USER_RECORD_EXTRACT_PRIVILEGED|
                USER_RECORD_EMPTY_OK|
                USER_RECORD_PERMISSIVE;
        int r;

        assert(root);

        if (!c || c->n_data == 0)
                return 0;

        r = make_run_host(root);
        if (r < 0)
                return r;

        r = userns_mkdir(root, "/run/host/home", 0755, 0, 0);
        if (r < 0)
                return log_error_errno(r, "Failed to create /run/host/home: %m");

        r = userns_mkdir(root, "/run/host/userdb", 0755, 0, 0);
        if (r < 0)
                return log_error_errno(r, "Failed to create /run/host/userdb: %m");

        FOREACH_ARRAY(d, c->data, c->n_data) {
                _cleanup_(group_record_unrefp) GroupRecord *stripped_group = NULL, *shadow_group = NULL;
                _cleanup_(user_record_unrefp) UserRecord *stripped_user = NULL, *shadow_user = NULL;

                /* First, write shadow (i.e. privileged) data for group record */
                r = group_record_clone(d->payload_group, shadow_flags, &shadow_group);
                if (r < 0)
                        return log_error_errno(r, "Failed to extract privileged information from group record: %m");

                if (!sd_json_variant_is_blank_object(shadow_group->json)) {
                        r = write_and_symlink(
                                        root,
                                        shadow_group->json,
                                        d->payload_group->group_name,
                                        d->payload_group->gid,
                                        ".group-privileged",
                                        WRITE_STRING_FILE_MODE_0600);
                        if (r < 0)
                                return r;
                }

                /* Second, write main part of group record. */
                r = group_record_clone(d->payload_group, strip_flags, &stripped_group);
                if (r < 0)
                        return log_error_errno(r, "Failed to strip privileged information from group record: %m");

                r = write_and_symlink(
                                root,
                                stripped_group->json,
                                d->payload_group->group_name,
                                d->payload_group->gid,
                                ".group",
                                0);
                if (r < 0)
                        return r;

                /* Third, write out user shadow data. i.e. extract privileged info from user record */
                r = user_record_clone(d->payload_user, shadow_flags, &shadow_user);
                if (r < 0)
                        return log_error_errno(r, "Failed to extract privileged information from user record: %m");

                if (!sd_json_variant_is_blank_object(shadow_user->json)) {
                        r = write_and_symlink(
                                        root,
                                        shadow_user->json,
                                        d->payload_user->user_name,
                                        d->payload_user->uid,
                                        ".user-privileged",
                                        WRITE_STRING_FILE_MODE_0600);
                        if (r < 0)
                                return r;
                }

                /* Finally write out the main part of the user record */
                r = user_record_clone(d->payload_user, strip_flags, &stripped_user);
                if (r < 0)
                        return log_error_errno(r, "Failed to strip privileged information from user record: %m");

                r = write_and_symlink(
                                root,
                                stripped_user->json,
                                d->payload_user->user_name,
                                d->payload_user->uid,
                                ".user",
                                0);
                if (r < 0)
                        return r;
        }

        return 1;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include "alloc-util.h"
4	#include "chase.h"
5	#include "fd-util.h"
6	#include "fileio.h"
7	#include "format-util.h"
8	#include "json-util.h"
9	#include "log.h"
10	#include "nspawn.h"
11	#include "nspawn-bind-user.h"
12	#include "path-util.h"
13	#include "user-util.h"
14	#include "userdb.h"
15
16	static int check_etc_passwd_collisions(	28✔
17	const char *directory,
18	const char *name,
19	uid_t uid) {
20
21	_cleanup_fclose_ FILE *f = NULL;	28✔
22	int r;	28✔
23
24	assert(directory);	28✔
25	assert(name \|\| uid_is_valid(uid));	28✔
26
27	r = chase_and_fopen_unlocked("/etc/passwd", directory, CHASE_PREFIX_ROOT, "re", NULL, &f);	28✔
28	if (r == -ENOENT)	28✔
29	return 0; /* no user database? then no user, hence no collision */
30	if (r < 0)	24✔
UNCOV 31	return log_error_errno(r, "Failed to open /etc/passwd of container: %m");	×
32
33	for (;;) {	183✔
34	struct passwd *pw;	207✔
35
36	r = fgetpwent_sane(f, &pw);	207✔
37	if (r < 0)	207✔
38	return log_error_errno(r, "Failed to iterate through /etc/passwd of container: %m");	24✔
39	if (r == 0) /* EOF */	207✔
40	return 0; /* no collision */
41
42	if (name && streq_ptr(pw->pw_name, name))	184✔
43	return 1; /* name collision */
44	if (uid_is_valid(uid) && pw->pw_uid == uid)	183✔
45	return 1; /* UID collision */
46	}
47	}
48
49	static int check_etc_group_collisions(	27✔
50	const char *directory,
51	const char *name,
52	gid_t gid) {
53
54	_cleanup_fclose_ FILE *f = NULL;	27✔
55	int r;	27✔
56
57	assert(directory);	27✔
58	assert(name \|\| gid_is_valid(gid));	41✔
59
60	r = chase_and_fopen_unlocked("/etc/group", directory, CHASE_PREFIX_ROOT, "re", NULL, &f);	27✔
61	if (r == -ENOENT)	27✔
62	return 0; /* no group database? then no group, hence no collision */
63	if (r < 0)	27✔
UNCOV 64	return log_error_errno(r, "Failed to open /etc/group of container: %m");	×
65
66	for (;;) {	532✔
67	struct group *gr;	559✔
68
69	r = fgetgrent_sane(f, &gr);	559✔
70	if (r < 0)	559✔
71	return log_error_errno(r, "Failed to iterate through /etc/group of container: %m");	27✔
72	if (r == 0)	559✔
73	return 0; /* no collision */
74
75	if (name && streq_ptr(gr->gr_name, name))	533✔
76	return 1; /* name collision */
77	if (gid_is_valid(gid) && gr->gr_gid == gid)	532✔
78	return 1; /* gid collision */
79	}
80	}
81
82	static int convert_user(	14✔
83	const char *directory,
84	UserRecord *u,
85	GroupRecord *g,
86	uid_t allocate_uid,
87	UserRecord **ret_converted_user,
88	GroupRecord **ret_converted_group) {
89
90	_cleanup_(group_record_unrefp) GroupRecord *converted_group = NULL;	14✔
UNCOV 91	_cleanup_(user_record_unrefp) UserRecord *converted_user = NULL;	×
92	_cleanup_free_ char *h = NULL;	14✔
93	sd_json_variant p, hp = NULL, *ssh = NULL;	14✔
94	int r;	14✔
95
96	assert(u);	14✔
97	assert(g);	14✔
98	assert(user_record_gid(u) == g->gid);	14✔
99
100	r = check_etc_passwd_collisions(directory, u->user_name, UID_INVALID);	14✔
101	if (r < 0)	14✔
102	return r;
103	if (r > 0)	14✔
104	return log_error_errno(SYNTHETIC_ERRNO(EBUSY),	1✔
105	"Sorry, the user '%s' already exists in the container.", u->user_name);
106
107	r = check_etc_group_collisions(directory, g->group_name, GID_INVALID);	13✔
108	if (r < 0)	13✔
109	return r;
110	if (r > 0)	13✔
111	return log_error_errno(SYNTHETIC_ERRNO(EBUSY),	1✔
112	"Sorry, the group '%s' already exists in the container.", g->group_name);
113
114	h = path_join("/run/host/home/", u->user_name);	12✔
115	if (!h)	12✔
UNCOV 116	return log_oom();	×
117
118	/* Acquire the source hashed password array as-is, so that it retains the JSON_VARIANT_SENSITIVE flag */
119	p = sd_json_variant_by_key(u->json, "privileged");	12✔
120	if (p) {	12✔
121	hp = sd_json_variant_by_key(p, "hashedPassword");	12✔
122	ssh = sd_json_variant_by_key(p, "sshAuthorizedKeys");	12✔
123	}
124
125	r = user_record_build(	36✔
126	&converted_user,
127	SD_JSON_BUILD_OBJECT(	24✔
128	SD_JSON_BUILD_PAIR("userName", SD_JSON_BUILD_STRING(u->user_name)),
129	SD_JSON_BUILD_PAIR("uid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
130	SD_JSON_BUILD_PAIR("gid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
131	SD_JSON_BUILD_PAIR_CONDITION(u->disposition >= 0, "disposition", SD_JSON_BUILD_STRING(user_disposition_to_string(u->disposition))),
132	SD_JSON_BUILD_PAIR("homeDirectory", SD_JSON_BUILD_STRING(h)),
133	SD_JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn")),
134	SD_JSON_BUILD_PAIR("privileged", SD_JSON_BUILD_OBJECT(
135	SD_JSON_BUILD_PAIR_CONDITION(!strv_isempty(u->hashed_password), "hashedPassword", SD_JSON_BUILD_VARIANT(hp)),
136	SD_JSON_BUILD_PAIR_CONDITION(!!ssh, "sshAuthorizedKeys", SD_JSON_BUILD_VARIANT(ssh))))));
137	if (r < 0)	12✔
UNCOV 138	return log_error_errno(r, "Failed to build container user record: %m");	×
139
140	r = group_record_build(	36✔
141	&converted_group,
142	SD_JSON_BUILD_OBJECT(	12✔
143	SD_JSON_BUILD_PAIR("groupName", SD_JSON_BUILD_STRING(g->group_name)),
144	SD_JSON_BUILD_PAIR("gid", SD_JSON_BUILD_UNSIGNED(allocate_uid)),
145	SD_JSON_BUILD_PAIR_CONDITION(g->disposition >= 0, "disposition", SD_JSON_BUILD_STRING(user_disposition_to_string(g->disposition))),
146	SD_JSON_BUILD_PAIR("service", JSON_BUILD_CONST_STRING("io.systemd.NSpawn"))));
147	if (r < 0)	12✔
UNCOV 148	return log_error_errno(r, "Failed to build container group record: %m");	×
149
150	*ret_converted_user = TAKE_PTR(converted_user);	12✔
151	*ret_converted_group = TAKE_PTR(converted_group);	12✔
152
153	return 0;	12✔
154	}
155
156	static int find_free_uid(const char directory, uid_t max_uid, uid_t current_uid) {	14✔
157	int r;	14✔
158
159	assert(directory);	14✔
160	assert(current_uid);	14✔
161
UNCOV 162	for (;; (*current_uid)++) {	×
163	if (current_uid > MAP_UID_MAX \|\| current_uid > max_uid)	14✔
UNCOV 164	return log_error_errno(	×
165	SYNTHETIC_ERRNO(EBUSY),
166	"No suitable available UID in range " UID_FMT "…" UID_FMT " in container detected, can't map user.",
167	MAP_UID_MIN, MAP_UID_MAX);
168
169	r = check_etc_passwd_collisions(directory, NULL, *current_uid);	14✔
170	if (r < 0)	14✔
171	return r;
172	if (r > 0) /* already used */	14✔
UNCOV 173	continue;	×
174
175	/* We want to use the UID also as GID, hence check for it in /etc/group too */
176	r = check_etc_group_collisions(directory, NULL, (gid_t) *current_uid);	14✔
177	if (r <= 0)	14✔
178	return r;
179	}
180	}
181
182	BindUserContext* bind_user_context_free(BindUserContext *c) {	6✔
183	if (!c)	6✔
184	return NULL;
185
186	FOREACH_ARRAY(d, c->data, c->n_data) {	13✔
187	user_record_unref(d->host_user);	7✔
188	group_record_unref(d->host_group);	7✔
189	user_record_unref(d->payload_user);	7✔
190	group_record_unref(d->payload_group);	7✔
191	}
192
193	return mfree(c);	6✔
194	}
195
196	int bind_user_prepare(	220✔
197	const char *directory,
198	char **bind_user,
199	uid_t uid_shift,
200	uid_t uid_range,
201	CustomMount **custom_mounts,
202	size_t *n_custom_mounts,
203	BindUserContext **ret) {
204
205	_cleanup_(bind_user_context_freep) BindUserContext *c = NULL;	220✔
206	uid_t current_uid = MAP_UID_MIN;	220✔
207	int r;	220✔
208
209	assert(custom_mounts);	220✔
210	assert(n_custom_mounts);	220✔
211	assert(ret);	220✔
212
213	/* This resolves the users specified in 'bind_user', generates a minimalized JSON user + group record
214	* for it to stick in the container, allocates a UID/GID for it, and updates the custom mount table,
215	* to include an appropriate bind mount mapping.
216	*
217	* This extends the passed custom_mounts/n_custom_mounts with the home directories, and allocates a
218	* new BindUserContext for the user records */
219
220	if (strv_isempty(bind_user)) {	220✔
221	*ret = NULL;	210✔
222	return 0;	210✔
223	}
224
225	c = new0(BindUserContext, 1);	10✔
226	if (!c)	10✔
UNCOV 227	return log_oom();	×
228
229	STRV_FOREACH(n, bind_user) {	22✔
230	_cleanup_(user_record_unrefp) UserRecord u = NULL, cu = NULL;	14✔
231	_cleanup_(group_record_unrefp) GroupRecord g = NULL, cg = NULL;	14✔
232	_cleanup_free_ char sm = NULL, sd = NULL;	14✔
233
234	r = userdb_by_name(n, / match= */ NULL, USERDB_DONT_SYNTHESIZE_INTRINSIC\|USERDB_DONT_SYNTHESIZE_FOREIGN, &u);	14✔
235	if (r < 0)	14✔
UNCOV 236	return log_error_errno(r, "Failed to resolve user '%s': %m", *n);	×
237
238	/* For now, let's refuse mapping the root/nobody users explicitly. The records we generate
239	* are strictly additive, nss-systemd is typically placed last in /etc/nsswitch.conf. Thus
240	* even if we wanted, we couldn't override the root or nobody user records. Note we also
241	* check for name conflicts in /etc/passwd + /etc/group later on, which would usually filter
242	* out root/nobody too, hence these checks might appear redundant — but they actually are
243	* not, as we want to support environments where /etc/passwd and /etc/group are non-existent,
244	* and the user/group databases fully synthesized at runtime. Moreover, the name of the
245	* user/group name of the "nobody" account differs between distros, hence a check by numeric
246	* UID is safer. */
247	if (user_record_is_root(u))	14✔
UNCOV 248	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'root' user not supported, sorry.");	×
249
250	if (user_record_is_nobody(u))	14✔
UNCOV 251	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Mapping 'nobody' user not supported, sorry.");	×
252
253	if (!uid_is_valid(u->uid))	14✔
UNCOV 254	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Cannot bind user with no UID, refusing.");	×
255
256	if (u->uid >= uid_shift && u->uid < uid_shift + uid_range)	14✔
UNCOV 257	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "UID of user '%s' to map is already in container UID range, refusing.", u->user_name);	×
258
259	r = groupdb_by_gid(user_record_gid(u), /* match= */ NULL, USERDB_DONT_SYNTHESIZE_INTRINSIC\|USERDB_DONT_SYNTHESIZE_FOREIGN, &g);	14✔
260	if (r < 0)	14✔
UNCOV 261	return log_error_errno(r, "Failed to resolve group of user '%s': %m", u->user_name);	×
262
263	if (g->gid >= uid_shift && g->gid < uid_shift + uid_range)	14✔
UNCOV 264	return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "GID of group '%s' to map is already in container GID range, refusing.", g->group_name);	×
265
266	/* We want to synthesize exactly one user + group from the host into the container. This only
267	* makes sense if the user on the host has its own private group. We can't reasonably check
268	* this, so we just check of the name of user and group match.
269	*
270	* One of these days we might want to support users in a shared/common group too, but it's
271	* not clear to me how this would have to be mapped, precisely given that the common group
272	* probably already exists in the container. */
273	if (!streq(u->user_name, g->group_name))	14✔
UNCOV 274	return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),	×
275	"Sorry, mapping users without private groups is currently not supported.");
276
277	r = find_free_uid(directory, uid_range, &current_uid);	14✔
278	if (r < 0)	14✔
279	return r;
280
281	r = convert_user(directory, u, g, current_uid, &cu, &cg);	14✔
282	if (r < 0)	14✔
283	return r;
284
285	if (!GREEDY_REALLOC(c->data, c->n_data + 1))	12✔
UNCOV 286	return log_oom();	×
287
288	sm = strdup(user_record_home_directory(u));	12✔
289	if (!sm)	12✔
UNCOV 290	return log_oom();	×
291
292	sd = strdup(user_record_home_directory(cu));	12✔
293	if (!sd)	12✔
UNCOV 294	return log_oom();	×
295
296	if (!GREEDY_REALLOC(custom_mounts, n_custom_mounts + 1))	12✔
UNCOV 297	return log_oom();	×
298
299	(custom_mounts)[(n_custom_mounts)++] = (CustomMount) {	12✔
300	.type = CUSTOM_MOUNT_BIND,
301	.source = TAKE_PTR(sm),	12✔
302	.destination = TAKE_PTR(sd),	12✔
303	};
304
305	c->data[c->n_data++] = (BindUserData) {	12✔
306	.host_user = TAKE_PTR(u),	12✔
307	.host_group = TAKE_PTR(g),	12✔
308	.payload_user = TAKE_PTR(cu),	12✔
309	.payload_group = TAKE_PTR(cg),	12✔
310	};
311
312	current_uid++;	12✔
313	}
314
315	*ret = TAKE_PTR(c);	8✔
316	return 1;	8✔
317	}
318
319	static int write_and_symlink(	30✔
320	const char *root,
321	sd_json_variant *v,
322	const char *name,
323	uid_t uid,
324	const char *suffix,
325	WriteStringFileFlags extra_flags) {
326
327	_cleanup_free_ char j = NULL, f = NULL, p = NULL, q = NULL;	30✔
328	int r;	30✔
329
330	assert(root);	30✔
331	assert(v);	30✔
332	assert(name);	30✔
333	assert(uid_is_valid(uid));	30✔
334	assert(suffix);	30✔
335
336	r = sd_json_variant_format(v, SD_JSON_FORMAT_NEWLINE, &j);	30✔
337	if (r < 0)	30✔
UNCOV 338	return log_error_errno(r, "Failed to format user record JSON: %m");	×
339
340	f = strjoin(name, suffix);	30✔
341	if (!f)	30✔
UNCOV 342	return log_oom();	×
343
344	p = path_join(root, "/run/host/userdb/", f);	30✔
345	if (!p)	30✔
UNCOV 346	return log_oom();	×
347
348	if (asprintf(&q, "%s/run/host/userdb/" UID_FMT "%s", root, uid, suffix) < 0)	30✔
UNCOV 349	return log_oom();	×
350
351	if (symlink(f, q) < 0)	30✔
UNCOV 352	return log_error_errno(errno, "Failed to create symlink '%s': %m", q);	×
353
354	r = userns_lchown(q, 0, 0);	30✔
355	if (r < 0)	30✔
UNCOV 356	return log_error_errno(r, "Failed to adjust access mode of '%s': %m", q);	×
357
358	r = write_string_file(p, j, WRITE_STRING_FILE_CREATE\|extra_flags);	30✔
359	if (r < 0)	30✔
UNCOV 360	return log_error_errno(r, "Failed to write %s: %m", p);	×
361
362	r = userns_lchown(p, 0, 0);	30✔
363	if (r < 0)	30✔
UNCOV 364	return log_error_errno(r, "Failed to adjust access mode of '%s': %m", p);	×
365
366	return 0;
367	}
368
369	int bind_user_setup(	218✔
370	const BindUserContext *c,
371	const char *root) {
372
373	static const UserRecordLoadFlags strip_flags = /* Removes privileged info */	218✔
374	USER_RECORD_LOAD_MASK_PRIVILEGED\|
375	USER_RECORD_PERMISSIVE;
376	static const UserRecordLoadFlags shadow_flags = /* Extracts privileged info */	218✔
377	USER_RECORD_EXTRACT_PRIVILEGED\|
378	USER_RECORD_EMPTY_OK\|
379	USER_RECORD_PERMISSIVE;
380	int r;	218✔
381
382	assert(root);	218✔
383
384	if (!c \|\| c->n_data == 0)	218✔
385	return 0;
386
387	r = make_run_host(root);	8✔
388	if (r < 0)	8✔
389	return r;
390
391	r = userns_mkdir(root, "/run/host/home", 0755, 0, 0);	8✔
392	if (r < 0)	8✔
UNCOV 393	return log_error_errno(r, "Failed to create /run/host/home: %m");	×
394
395	r = userns_mkdir(root, "/run/host/userdb", 0755, 0, 0);	8✔
396	if (r < 0)	8✔
UNCOV 397	return log_error_errno(r, "Failed to create /run/host/userdb: %m");	×
398
399	FOREACH_ARRAY(d, c->data, c->n_data) {	18✔
400	_cleanup_(group_record_unrefp) GroupRecord stripped_group = NULL, shadow_group = NULL;	10✔
401	_cleanup_(user_record_unrefp) UserRecord stripped_user = NULL, shadow_user = NULL;	10✔
402
403	/* First, write shadow (i.e. privileged) data for group record */
404	r = group_record_clone(d->payload_group, shadow_flags, &shadow_group);	10✔
405	if (r < 0)	10✔
UNCOV 406	return log_error_errno(r, "Failed to extract privileged information from group record: %m");	×
407
408	if (!sd_json_variant_is_blank_object(shadow_group->json)) {	10✔
UNCOV 409	r = write_and_symlink(	×
410	root,
411	shadow_group->json,	×
412	d->payload_group->group_name,	×
UNCOV 413	d->payload_group->gid,	×
414	".group-privileged",
415	WRITE_STRING_FILE_MODE_0600);
UNCOV 416	if (r < 0)	×
417	return r;
418	}
419
420	/* Second, write main part of group record. */
421	r = group_record_clone(d->payload_group, strip_flags, &stripped_group);	10✔
422	if (r < 0)	10✔
UNCOV 423	return log_error_errno(r, "Failed to strip privileged information from group record: %m");	×
424
425	r = write_and_symlink(	20✔
426	root,
427	stripped_group->json,	10✔
428	d->payload_group->group_name,	10✔
429	d->payload_group->gid,	10✔
430	".group",
431	0);
432	if (r < 0)	10✔
433	return r;
434
435	/* Third, write out user shadow data. i.e. extract privileged info from user record */
436	r = user_record_clone(d->payload_user, shadow_flags, &shadow_user);	10✔
437	if (r < 0)	10✔
UNCOV 438	return log_error_errno(r, "Failed to extract privileged information from user record: %m");	×
439
440	if (!sd_json_variant_is_blank_object(shadow_user->json)) {	10✔
441	r = write_and_symlink(	20✔
442	root,
443	shadow_user->json,	10✔
444	d->payload_user->user_name,	10✔
445	d->payload_user->uid,	10✔
446	".user-privileged",
447	WRITE_STRING_FILE_MODE_0600);
448	if (r < 0)	10✔
449	return r;
450	}
451
452	/* Finally write out the main part of the user record */
453	r = user_record_clone(d->payload_user, strip_flags, &stripped_user);	10✔
454	if (r < 0)	10✔
UNCOV 455	return log_error_errno(r, "Failed to strip privileged information from user record: %m");	×
456
457	r = write_and_symlink(	20✔
458	root,
459	stripped_user->json,	10✔
460	d->payload_user->user_name,	10✔
461	d->payload_user->uid,	10✔
462	".user",
463	0);
464	if (r < 0)	10✔
465	return r;
466	}
467
468	return 1;
469	}

systemd / systemd / 14895667988

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