16082515961

Committed 04 Jul 2025 08:23PM UTC coverage: 72.095% (-0.1%) from 72.193%

Build # 16082515961

Build Type

push

github

Committed by

poettering

Commit Message

seccomp-util: allowlist open_tree() as part of @file-system

Now that we make use of open_tree() in places we previously used
openat() with O_PATH, it makes sense to move it from @mount to
@file-system. Without the OPEN_TREE_CLONE flag open_tree() is after all
unprivileged.

Note that open_tree_attr() I left in @mount, since it's purpose is
really to set mount options when cloning, and that's clearly a mount
related thing, not so much something you could use unpriv.

Follow-up for: c5de7b14a

This addresses an issue tracked down by Antonio Feijoo: since the commit
that started to use open_tree() various apps started to crash because
they used seccomp filters and sd-device started to use open_tree()
internally.

Run Details

300842 of 417287 relevant lines covered (72.09%)

715300.57 hits per line

Source File
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0.0

/src/ssh-generator/ssh-generator.c

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

#include <unistd.h>

#include "alloc-util.h"
#include "creds-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "generator.h"
#include "install.h"
#include "log.h"
#include "parse-util.h"
#include "path-lookup.h"
#include "path-util.h"
#include "proc-cmdline.h"
#include "socket-netlink.h"
#include "socket-util.h"
#include "special.h"
#include "string-util.h"
#include "strv.h"
#include "virt.h"

/* A small generator binding potentially five or more SSH sockets:
 *
 *     1. Listen on AF_VSOCK port 22 if we run in a VM with AF_VSOCK enabled
 *     2. Listen on AF_UNIX socket /run/host/unix-export/ssh if we run in a container with /run/host/ support
 *     3. Listen on AF_UNIX socket /run/ssh-unix-local/socket (always)
 *     4. Listen on any socket specified via kernel command line option systemd.ssh_listen=
 *     5. Similar, but from system credential ssh.listen
 *
 * The first two provide a nice way for hosts to connect to containers and VMs they invoke via the usual SSH
 * logic, but without waiting for networking or suchlike. The third allows the same for local clients. */

static const char *arg_dest = NULL;
static bool arg_auto = true;
static char **arg_listen_extra = NULL;

static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
        int r;

        assert(key);

        if (proc_cmdline_key_streq(key, "systemd.ssh_auto")) {
                r = value ? parse_boolean(value) : 1;
                if (r < 0)
                        log_warning_errno(r, "Failed to parse systemd.ssh_auto switch \"%s\", ignoring: %m", value);
                else
                        arg_auto = r;

        } else if (proc_cmdline_key_streq(key, "systemd.ssh_listen")) {

                if (proc_cmdline_value_missing(key, value))
                        return 0;

                SocketAddress sa;
                r = socket_address_parse(&sa, value);
                if (r < 0)
                        log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", value);
                else {
                        _cleanup_free_ char *s = NULL;
                        r = socket_address_print(&sa, &s);
                        if (r < 0)
                                return log_error_errno(r, "Failed to format socket address: %m");

                        if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)
                                return log_oom();
                }
        }

        return 0;
}

static int make_sshd_template_unit(
                const char *dest,
                const char *template,
                const char *sshd_binary,
                const char *found_sshd_template_service,
                char **generated_sshd_template_unit) {

        int r;

        assert(dest);
        assert(template);
        assert(sshd_binary);
        assert(generated_sshd_template_unit);

        /* If the system has a suitable template already, symlink it to the name we want to reuse it */
        if (found_sshd_template_service)
                return generator_add_symlink(
                                dest,
                                template,
                                /* dep_type= */ NULL,
                                found_sshd_template_service);

        if (!*generated_sshd_template_unit) {
                _cleanup_fclose_ FILE *f = NULL;

                r = generator_open_unit_file_full(
                                dest,
                                /* source= */ NULL,
                                "sshd-generated@.service", /* Give this generated unit a generic name, since we want to use it for both AF_UNIX and AF_VSOCK */
                                &f,
                                generated_sshd_template_unit,
                                /* ret_temp_path= */ NULL);
                if (r < 0)
                        return r;

                fprintf(f,
                        "[Unit]\n"
                        "Description=OpenSSH Per-Connection Server Daemon\n"
                        "Documentation=man:systemd-ssh-generator(8) man:sshd(8)\n"
                        "\n"
                        "[Service]\n"
                        "ExecStart=-%s -i -o \"AuthorizedKeysFile ${CREDENTIALS_DIRECTORY}/ssh.ephemeral-authorized_keys-all .ssh/authorized_keys\"\n"
                        "StandardInput=socket\n"
                        "ImportCredential=ssh.ephemeral-authorized_keys-all\n",
                        sshd_binary);

                r = fflush_and_check(f);
                if (r < 0)
                        return log_error_errno(r, "Failed to write sshd template: %m");
        }

        return generator_add_symlink(
                        dest,
                        template,
                        /* dep_type= */ NULL,
                        *generated_sshd_template_unit);
}

static int write_socket_unit(
                const char *dest,
                const char *unit,
                const char *listen_stream,
                const char *comment,
                const char *extra,
                bool with_ssh_access_target_dependency) {

        int r;

        assert(dest);
        assert(unit);
        assert(listen_stream);
        assert(comment);

        _cleanup_fclose_ FILE *f = NULL;
        r = generator_open_unit_file(
                        dest,
                        /* source= */ NULL,
                        unit,
                        &f);
        if (r < 0)
                return r;

        fprintf(f,
                "[Unit]\n"
                "Description=OpenSSH Server Socket (systemd-ssh-generator, %s)\n"
                "Documentation=man:systemd-ssh-generator(8)\n",
                comment);

        /* When this is a remotely accessible socket let's mark this with a milestone: ssh-access.target */
        if (with_ssh_access_target_dependency)
                fputs("Wants=ssh-access.target\n"
                      "Before=ssh-access.target\n",
                      f);

        fprintf(f,
                "\n[Socket]\n"
                "ListenStream=%s\n"
                "Accept=yes\n"
                "PollLimitIntervalSec=30s\n"
                "PollLimitBurst=50\n",
                listen_stream);

        if (extra)
                fputs(extra, f);

        r = fflush_and_check(f);
        if (r < 0)
                return log_error_errno(r, "Failed to write %s SSH socket unit: %m", comment);

        r = generator_add_symlink(
                        dest,
                        SPECIAL_SOCKETS_TARGET,
                        "wants",
                        unit);
        if (r < 0)
                return r;

        return 0;
}

static int add_vsock_socket(
                const char *dest,
                const char *sshd_binary,
                const char *found_sshd_template_unit,
                char **generated_sshd_template_unit) {

        int r;

        assert(dest);
        assert(generated_sshd_template_unit);

        Virtualization v = detect_virtualization();
        if (v < 0)
                return log_error_errno(v, "Failed to detect if we run in a VM: %m");
        if (!VIRTUALIZATION_IS_VM(v)) {
                /* NB: if we are running in a container inside a VM, then we'll *not* do AF_VSOCK stuff */
                log_debug("Not running in a VM, not listening on AF_VSOCK.");
                return 0;
        }

        _cleanup_close_ int vsock_fd = socket(AF_VSOCK, SOCK_STREAM|SOCK_CLOEXEC, 0);
        if (vsock_fd < 0) {
                if (ERRNO_IS_NOT_SUPPORTED(errno)) {
                        log_debug("Not creating AF_VSOCK ssh listener, since AF_VSOCK is not available.");
                        return 0;
                }

                return log_error_errno(errno, "Unable to test if AF_VSOCK is available: %m");
        }

        vsock_fd = safe_close(vsock_fd);

        /* Determine the local CID so that we can log it to help users to connect to this VM */
        unsigned local_cid;
        r = vsock_get_local_cid(&local_cid);
        if (r < 0) {
                if (ERRNO_IS_DEVICE_ABSENT(r)) {
                        log_debug("Not creating AF_VSOCK ssh listener, since /dev/vsock is not available (even though AF_VSOCK is).");
                        return 0;
                }

                return log_error_errno(r, "Failed to query local AF_VSOCK CID: %m");
        }

        r = make_sshd_template_unit(
                        dest,
                        "sshd-vsock@.service",
                        sshd_binary,
                        found_sshd_template_unit,
                        generated_sshd_template_unit);
        if (r < 0)
                return r;

        r = write_socket_unit(
                        dest,
                        "sshd-vsock.socket",
                        "vsock::22",
                        "AF_VSOCK",
                        "ExecStartPost=-/usr/lib/systemd/systemd-ssh-issue --make-vsock\n"
                        "ExecStopPre=-/usr/lib/systemd/systemd-ssh-issue --rm-vsock\n",
                        /* with_ssh_access_target_dependency= */ true);
        if (r < 0)
                return r;

        log_debug("Binding SSH to AF_VSOCK vsock::22.\n"
                  "→ connect via 'ssh vsock/%u' from host", local_cid);
        return 0;
}

static int add_local_unix_socket(
                const char *dest,
                const char *sshd_binary,
                const char *found_sshd_template_unit,
                char **generated_sshd_template_unit) {

        int r;

        assert(dest);
        assert(sshd_binary);
        assert(generated_sshd_template_unit);

        r = make_sshd_template_unit(
                        dest,
                        "sshd-unix-local@.service",
                        sshd_binary,
                        found_sshd_template_unit,
                        generated_sshd_template_unit);
        if (r < 0)
                return r;

        r = write_socket_unit(
                        dest,
                        "sshd-unix-local.socket",
                        "/run/ssh-unix-local/socket",
                        "AF_UNIX Local",
                        /* extra= */ NULL,
                        /* with_ssh_access_target_dependency= */ false);
        if (r < 0)
                return r;

        log_debug("Binding SSH to AF_UNIX socket /run/ssh-unix-local/socket.\n"
                  "→ connect via 'ssh .host' locally");
        return 0;
}

static int add_export_unix_socket(
                const char *dest,
                const char *sshd_binary,
                const char *found_sshd_template_unit,
                char **generated_sshd_template_unit) {

        int r;

        assert(dest);
        assert(sshd_binary);
        assert(generated_sshd_template_unit);

        Virtualization v = detect_container();
        if (v < 0)
                return log_error_errno(v, "Failed to detect if we run in a container: %m");
        if (v == VIRTUALIZATION_NONE) {
                log_debug("Not running in container, not listening on /run/host/unix-export/ssh");
                return 0;
        }

        if (access("/run/host/unix-export/", W_OK) < 0) {
                if (errno == ENOENT) {
                        log_debug("Container manager does not provide /run/host/unix-export/ mount, not binding AF_UNIX socket there.");
                        return 0;
                }
                if (errno == EROFS || ERRNO_IS_PRIVILEGE(errno)) {
                        log_debug("Container manager does not provide write access to /run/host/unix-export/, not binding AF_UNIX socket there.");
                        return 0;
                }

                return log_error_errno(errno, "Unable to check if /run/host/unix-export exists: %m");
        }

        r = make_sshd_template_unit(
                        dest,
                        "sshd-unix-export@.service",
                        sshd_binary,
                        found_sshd_template_unit,
                        generated_sshd_template_unit);
        if (r < 0)
                return r;

        r = write_socket_unit(
                        dest,
                        "sshd-unix-export.socket",
                        "/run/host/unix-export/ssh",
                        "AF_UNIX Export",
                        /* extra= */ NULL,
                        /* with_ssh_access_target_dependency= */ true);
        if (r < 0)
                return r;

        log_debug("Binding SSH to AF_UNIX socket /run/host/unix-export/ssh\n"
                  "→ connect via 'ssh unix/run/systemd/nspawn/unix-export/\?\?\?/ssh' from host");

        return 0;
}

static int add_extra_sockets(
                const char *dest,
                const char *sshd_binary,
                const char *found_sshd_template_unit,
                char **generated_sshd_template_unit) {

        unsigned n = 1;
        int r;

        assert(dest);
        assert(sshd_binary);
        assert(generated_sshd_template_unit);

        if (strv_isempty(arg_listen_extra))
                return 0;

        STRV_FOREACH(i, arg_listen_extra) {
                _cleanup_free_ char *service = NULL, *socket = NULL;

                if (n > 1) {
                        if (asprintf(&service, "sshd-extra-%u@.service", n) < 0)
                                return log_oom();

                        if (asprintf(&socket, "sshd-extra-%u.socket", n) < 0)
                                return log_oom();
                }

                r = make_sshd_template_unit(
                                dest,
                                service ?: "sshd-extra@.service",
                                sshd_binary,
                                found_sshd_template_unit,
                                generated_sshd_template_unit);
                if (r < 0)
                        return r;

                r = write_socket_unit(
                                dest,
                                socket ?: "sshd-extra.socket",
                                *i,
                                *i,
                                /* extra= */ NULL,
                                /* with_ssh_access_target_dependency= */ true);
                if (r < 0)
                        return r;

                log_debug("Binding SSH to socket %s.", *i);
                n++;
        }

        return 0;
}

static int parse_credentials(void) {
        _cleanup_free_ char *b = NULL;
        size_t sz = 0;
        int r;

        r = read_credential_with_decryption("ssh.listen", (void**) &b, &sz);
        if (r <= 0)
                return r;

        _cleanup_fclose_ FILE *f = NULL;
        f = fmemopen_unlocked(b, sz, "r");
        if (!f)
                return log_oom();

        for (;;) {
                _cleanup_free_ char *item = NULL;

                r = read_stripped_line(f, LINE_MAX, &item);
                if (r == 0)
                        break;
                if (r < 0) {
                        log_error_errno(r, "Failed to parse credential 'ssh.listen': %m");
                        break;
                }

                if (startswith(item, "#"))
                        continue;

                SocketAddress sa;
                r = socket_address_parse(&sa, item);
                if (r < 0) {
                        log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", item);
                        continue;
                }

                _cleanup_free_ char *s = NULL;
                r = socket_address_print(&sa, &s);
                if (r < 0)
                        return log_error_errno(r, "Failed to format socket address: %m");

                if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)
                        return log_oom();
        }

        return 0;
}

static int run(const char *dest, const char *dest_early, const char *dest_late) {
        int r;

        assert_se(arg_dest = dest);

        r = proc_cmdline_parse(parse_proc_cmdline_item, /* userdata= */ NULL, /* flags= */ 0);
        if (r < 0)
                log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");

        (void) parse_credentials();

        strv_sort_uniq(arg_listen_extra);

        if (!arg_auto && strv_isempty(arg_listen_extra)) {
                log_debug("Disabling SSH generator logic, because it has been turned off explicitly.");
                return 0;
        }

        _cleanup_free_ char *sshd_binary = NULL;
        r = find_executable("sshd", &sshd_binary);
        if (r == -ENOENT) {
                log_debug("Disabling SSH generator logic, since sshd is not installed.");
                return 0;
        }
        if (r < 0)
                return log_error_errno(r, "Failed to determine if sshd is installed: %m");

        _cleanup_(lookup_paths_done) LookupPaths lp = {};
        r = lookup_paths_init_or_warn(&lp, RUNTIME_SCOPE_SYSTEM, LOOKUP_PATHS_EXCLUDE_GENERATED, /* root_dir= */ NULL);
        if (r < 0)
                return r;

        _cleanup_free_ char *found_sshd_template_unit = NULL;
        r = unit_file_exists_full(RUNTIME_SCOPE_SYSTEM, &lp, "sshd@.service", &found_sshd_template_unit);
        if (r < 0)
                return log_error_errno(r, "Unable to detect if sshd@.service exists: %m");

        _cleanup_free_ char *generated_sshd_template_unit = NULL;
        RET_GATHER(r, add_extra_sockets(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));

        if (arg_auto) {
                RET_GATHER(r, add_vsock_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));
                RET_GATHER(r, add_local_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));
                RET_GATHER(r, add_export_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));
        }

        return r;
}

DEFINE_MAIN_GENERATOR_FUNCTION(run);

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <unistd.h>
4
5	#include "alloc-util.h"
6	#include "creds-util.h"
7	#include "errno-util.h"
8	#include "fd-util.h"
9	#include "fileio.h"
10	#include "generator.h"
11	#include "install.h"
12	#include "log.h"
13	#include "parse-util.h"
14	#include "path-lookup.h"
15	#include "path-util.h"
16	#include "proc-cmdline.h"
17	#include "socket-netlink.h"
18	#include "socket-util.h"
19	#include "special.h"
20	#include "string-util.h"
21	#include "strv.h"
22	#include "virt.h"
23
24	/* A small generator binding potentially five or more SSH sockets:
25	*
26	* 1. Listen on AF_VSOCK port 22 if we run in a VM with AF_VSOCK enabled
27	* 2. Listen on AF_UNIX socket /run/host/unix-export/ssh if we run in a container with /run/host/ support
28	* 3. Listen on AF_UNIX socket /run/ssh-unix-local/socket (always)
29	* 4. Listen on any socket specified via kernel command line option systemd.ssh_listen=
30	* 5. Similar, but from system credential ssh.listen
31	*
32	* The first two provide a nice way for hosts to connect to containers and VMs they invoke via the usual SSH
33	* logic, but without waiting for networking or suchlike. The third allows the same for local clients. */
34
35	static const char *arg_dest = NULL;
36	static bool arg_auto = true;
37	static char **arg_listen_extra = NULL;
38
39	static int parse_proc_cmdline_item(const char key, const char value, void *data) {	×
40	int r;	×
41
42	assert(key);	×
43
44	if (proc_cmdline_key_streq(key, "systemd.ssh_auto")) {	×
45	r = value ? parse_boolean(value) : 1;	×
46	if (r < 0)	×
47	log_warning_errno(r, "Failed to parse systemd.ssh_auto switch \"%s\", ignoring: %m", value);	×
48	else
49	arg_auto = r;	×
50
51	} else if (proc_cmdline_key_streq(key, "systemd.ssh_listen")) {	×
52
53	if (proc_cmdline_value_missing(key, value))	×
54	return 0;	×
55
56	SocketAddress sa;	×
57	r = socket_address_parse(&sa, value);	×
58	if (r < 0)	×
59	log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", value);	×
60	else {
61	_cleanup_free_ char *s = NULL;	×
62	r = socket_address_print(&sa, &s);	×
63	if (r < 0)	×
64	return log_error_errno(r, "Failed to format socket address: %m");	×
65
66	if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)	×
67	return log_oom();	×
68	}
69	}
70
71	return 0;
72	}
73
74	static int make_sshd_template_unit(	×
75	const char *dest,
76	const char *template,
77	const char *sshd_binary,
78	const char *found_sshd_template_service,
79	char **generated_sshd_template_unit) {
80
81	int r;	×
82
83	assert(dest);	×
84	assert(template);	×
85	assert(sshd_binary);	×
86	assert(generated_sshd_template_unit);	×
87
88	/* If the system has a suitable template already, symlink it to the name we want to reuse it */
89	if (found_sshd_template_service)	×
90	return generator_add_symlink(	×
91	dest,
92	template,
93	/* dep_type= */ NULL,
94	found_sshd_template_service);
95
96	if (!*generated_sshd_template_unit) {	×
97	_cleanup_fclose_ FILE *f = NULL;	×
98
99	r = generator_open_unit_file_full(	×
100	dest,
101	/* source= */ NULL,
102	"sshd-generated@.service", /* Give this generated unit a generic name, since we want to use it for both AF_UNIX and AF_VSOCK */
103	&f,
104	generated_sshd_template_unit,
105	/* ret_temp_path= */ NULL);
106	if (r < 0)	×
107	return r;
108
109	fprintf(f,	×
110	"[Unit]\n"
111	"Description=OpenSSH Per-Connection Server Daemon\n"
112	"Documentation=man:systemd-ssh-generator(8) man:sshd(8)\n"
113	"\n"
114	"[Service]\n"
115	"ExecStart=-%s -i -o \"AuthorizedKeysFile ${CREDENTIALS_DIRECTORY}/ssh.ephemeral-authorized_keys-all .ssh/authorized_keys\"\n"
116	"StandardInput=socket\n"
117	"ImportCredential=ssh.ephemeral-authorized_keys-all\n",
118	sshd_binary);
119
120	r = fflush_and_check(f);	×
121	if (r < 0)	×
122	return log_error_errno(r, "Failed to write sshd template: %m");	×
123	}
124
125	return generator_add_symlink(	×
126	dest,
127	template,
128	/* dep_type= */ NULL,
129	*generated_sshd_template_unit);
130	}
131
132	static int write_socket_unit(	×
133	const char *dest,
134	const char *unit,
135	const char *listen_stream,
136	const char *comment,
137	const char *extra,
138	bool with_ssh_access_target_dependency) {
139
140	int r;	×
141
142	assert(dest);	×
143	assert(unit);	×
144	assert(listen_stream);	×
145	assert(comment);	×
146
147	_cleanup_fclose_ FILE *f = NULL;	×
148	r = generator_open_unit_file(	×
149	dest,
150	/* source= */ NULL,
151	unit,
152	&f);
153	if (r < 0)	×
154	return r;
155
156	fprintf(f,	×
157	"[Unit]\n"
158	"Description=OpenSSH Server Socket (systemd-ssh-generator, %s)\n"
159	"Documentation=man:systemd-ssh-generator(8)\n",
160	comment);
161
162	/* When this is a remotely accessible socket let's mark this with a milestone: ssh-access.target */
163	if (with_ssh_access_target_dependency)	×
164	fputs("Wants=ssh-access.target\n"	×
165	"Before=ssh-access.target\n",
166	f);
167
168	fprintf(f,	×
169	"\n[Socket]\n"
170	"ListenStream=%s\n"
171	"Accept=yes\n"
172	"PollLimitIntervalSec=30s\n"
173	"PollLimitBurst=50\n",
174	listen_stream);
175
176	if (extra)	×
177	fputs(extra, f);	×
178
179	r = fflush_and_check(f);	×
180	if (r < 0)	×
181	return log_error_errno(r, "Failed to write %s SSH socket unit: %m", comment);	×
182
183	r = generator_add_symlink(	×
184	dest,
185	SPECIAL_SOCKETS_TARGET,
186	"wants",
187	unit);
188	if (r < 0)	×
189	return r;	×
190
191	return 0;
192	}
193
194	static int add_vsock_socket(	×
195	const char *dest,
196	const char *sshd_binary,
197	const char *found_sshd_template_unit,
198	char **generated_sshd_template_unit) {
199
200	int r;	×
201
202	assert(dest);	×
203	assert(generated_sshd_template_unit);	×
204
205	Virtualization v = detect_virtualization();	×
206	if (v < 0)	×
207	return log_error_errno(v, "Failed to detect if we run in a VM: %m");	×
208	if (!VIRTUALIZATION_IS_VM(v)) {	×
209	/* NB: if we are running in a container inside a VM, then we'll not do AF_VSOCK stuff */
210	log_debug("Not running in a VM, not listening on AF_VSOCK.");	×
211	return 0;	×
212	}
213
214	_cleanup_close_ int vsock_fd = socket(AF_VSOCK, SOCK_STREAM\|SOCK_CLOEXEC, 0);	×
215	if (vsock_fd < 0) {	×
216	if (ERRNO_IS_NOT_SUPPORTED(errno)) {	×
217	log_debug("Not creating AF_VSOCK ssh listener, since AF_VSOCK is not available.");	×
218	return 0;	×
219	}
220
221	return log_error_errno(errno, "Unable to test if AF_VSOCK is available: %m");	×
222	}
223
224	vsock_fd = safe_close(vsock_fd);	×
225
226	/* Determine the local CID so that we can log it to help users to connect to this VM */
227	unsigned local_cid;	×
228	r = vsock_get_local_cid(&local_cid);	×
229	if (r < 0) {	×
230	if (ERRNO_IS_DEVICE_ABSENT(r)) {	×
231	log_debug("Not creating AF_VSOCK ssh listener, since /dev/vsock is not available (even though AF_VSOCK is).");	×
232	return 0;	×
233	}
234
235	return log_error_errno(r, "Failed to query local AF_VSOCK CID: %m");	×
236	}
237
238	r = make_sshd_template_unit(	×
239	dest,
240	"sshd-vsock@.service",
241	sshd_binary,
242	found_sshd_template_unit,
243	generated_sshd_template_unit);
244	if (r < 0)	×
245	return r;
246
247	r = write_socket_unit(	×
248	dest,
249	"sshd-vsock.socket",
250	"vsock::22",
251	"AF_VSOCK",
252	"ExecStartPost=-/usr/lib/systemd/systemd-ssh-issue --make-vsock\n"
253	"ExecStopPre=-/usr/lib/systemd/systemd-ssh-issue --rm-vsock\n",
254	/* with_ssh_access_target_dependency= */ true);
255	if (r < 0)	×
256	return r;
257
258	log_debug("Binding SSH to AF_VSOCK vsock::22.\n"	×
259	"→ connect via 'ssh vsock/%u' from host", local_cid);
260	return 0;
261	}
262
263	static int add_local_unix_socket(	×
264	const char *dest,
265	const char *sshd_binary,
266	const char *found_sshd_template_unit,
267	char **generated_sshd_template_unit) {
268
269	int r;	×
270
271	assert(dest);	×
272	assert(sshd_binary);	×
273	assert(generated_sshd_template_unit);	×
274
275	r = make_sshd_template_unit(	×
276	dest,
277	"sshd-unix-local@.service",
278	sshd_binary,
279	found_sshd_template_unit,
280	generated_sshd_template_unit);
281	if (r < 0)	×
282	return r;
283
284	r = write_socket_unit(	×
285	dest,
286	"sshd-unix-local.socket",
287	"/run/ssh-unix-local/socket",
288	"AF_UNIX Local",
289	/* extra= */ NULL,
290	/* with_ssh_access_target_dependency= */ false);
291	if (r < 0)	×
292	return r;
293
294	log_debug("Binding SSH to AF_UNIX socket /run/ssh-unix-local/socket.\n"	×
295	"→ connect via 'ssh .host' locally");
296	return 0;
297	}
298
299	static int add_export_unix_socket(	×
300	const char *dest,
301	const char *sshd_binary,
302	const char *found_sshd_template_unit,
303	char **generated_sshd_template_unit) {
304
305	int r;	×
306
307	assert(dest);	×
308	assert(sshd_binary);	×
309	assert(generated_sshd_template_unit);	×
310
311	Virtualization v = detect_container();	×
312	if (v < 0)	×
313	return log_error_errno(v, "Failed to detect if we run in a container: %m");	×
314	if (v == VIRTUALIZATION_NONE) {	×
315	log_debug("Not running in container, not listening on /run/host/unix-export/ssh");	×
316	return 0;	×
317	}
318
319	if (access("/run/host/unix-export/", W_OK) < 0) {	×
320	if (errno == ENOENT) {	×
321	log_debug("Container manager does not provide /run/host/unix-export/ mount, not binding AF_UNIX socket there.");	×
322	return 0;	×
323	}
324	if (errno == EROFS \|\| ERRNO_IS_PRIVILEGE(errno)) {	×
325	log_debug("Container manager does not provide write access to /run/host/unix-export/, not binding AF_UNIX socket there.");	×
326	return 0;	×
327	}
328
329	return log_error_errno(errno, "Unable to check if /run/host/unix-export exists: %m");	×
330	}
331
332	r = make_sshd_template_unit(	×
333	dest,
334	"sshd-unix-export@.service",
335	sshd_binary,
336	found_sshd_template_unit,
337	generated_sshd_template_unit);
338	if (r < 0)	×
339	return r;
340
341	r = write_socket_unit(	×
342	dest,
343	"sshd-unix-export.socket",
344	"/run/host/unix-export/ssh",
345	"AF_UNIX Export",
346	/* extra= */ NULL,
347	/* with_ssh_access_target_dependency= */ true);
348	if (r < 0)	×
349	return r;
350
351	log_debug("Binding SSH to AF_UNIX socket /run/host/unix-export/ssh\n"	×
352	"→ connect via 'ssh unix/run/systemd/nspawn/unix-export/\?\?\?/ssh' from host");
353
354	return 0;
355	}
356
357	static int add_extra_sockets(	×
358	const char *dest,
359	const char *sshd_binary,
360	const char *found_sshd_template_unit,
361	char **generated_sshd_template_unit) {
362
363	unsigned n = 1;	×
364	int r;	×
365
366	assert(dest);	×
367	assert(sshd_binary);	×
368	assert(generated_sshd_template_unit);	×
369
370	if (strv_isempty(arg_listen_extra))	×
371	return 0;
372
373	STRV_FOREACH(i, arg_listen_extra) {	×
374	_cleanup_free_ char service = NULL, socket = NULL;	×
375
376	if (n > 1) {	×
377	if (asprintf(&service, "sshd-extra-%u@.service", n) < 0)	×
378	return log_oom();	×
379
380	if (asprintf(&socket, "sshd-extra-%u.socket", n) < 0)	×
381	return log_oom();	×
382	}
383
384	r = make_sshd_template_unit(	×
385	dest,
386	service ?: "sshd-extra@.service",	×
387	sshd_binary,
388	found_sshd_template_unit,
389	generated_sshd_template_unit);
390	if (r < 0)	×
391	return r;
392
393	r = write_socket_unit(	×
394	dest,
395	socket ?: "sshd-extra.socket",	×
396	*i,
397	*i,
398	/* extra= */ NULL,
399	/* with_ssh_access_target_dependency= */ true);
400	if (r < 0)	×
401	return r;
402
403	log_debug("Binding SSH to socket %s.", *i);	×
404	n++;	×
405	}
406
407	return 0;
408	}
409
410	static int parse_credentials(void) {	×
411	_cleanup_free_ char *b = NULL;	×
412	size_t sz = 0;	×
413	int r;	×
414
415	r = read_credential_with_decryption("ssh.listen", (void**) &b, &sz);	×
416	if (r <= 0)	×
417	return r;
418
419	_cleanup_fclose_ FILE *f = NULL;	×
420	f = fmemopen_unlocked(b, sz, "r");	×
421	if (!f)	×
422	return log_oom();	×
423
424	for (;;) {	×
425	_cleanup_free_ char *item = NULL;	×
426
427	r = read_stripped_line(f, LINE_MAX, &item);	×
428	if (r == 0)	×
429	break;
430	if (r < 0) {	×
431	log_error_errno(r, "Failed to parse credential 'ssh.listen': %m");	×
432	break;
433	}
434
435	if (startswith(item, "#"))	×
436	continue;	×
437
438	SocketAddress sa;	×
439	r = socket_address_parse(&sa, item);	×
440	if (r < 0) {	×
441	log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", item);	×
442	continue;	×
443	}
444
445	_cleanup_free_ char *s = NULL;	×
446	r = socket_address_print(&sa, &s);	×
447	if (r < 0)	×
448	return log_error_errno(r, "Failed to format socket address: %m");	×
449
450	if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)	×
451	return log_oom();	×
452	}
453
454	return 0;	×
455	}
456
457	static int run(const char dest, const char dest_early, const char *dest_late) {	×
458	int r;	×
459
460	assert_se(arg_dest = dest);	×
461
462	r = proc_cmdline_parse(parse_proc_cmdline_item, /* userdata= / NULL, / flags= */ 0);	×
463	if (r < 0)	×
464	log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");	×
465
466	(void) parse_credentials();	×
467
468	strv_sort_uniq(arg_listen_extra);	×
469
470	if (!arg_auto && strv_isempty(arg_listen_extra)) {	×
471	log_debug("Disabling SSH generator logic, because it has been turned off explicitly.");	×
472	return 0;	×
473	}
474
475	_cleanup_free_ char *sshd_binary = NULL;	×
476	r = find_executable("sshd", &sshd_binary);	×
477	if (r == -ENOENT) {	×
478	log_debug("Disabling SSH generator logic, since sshd is not installed.");	×
479	return 0;	×
480	}
481	if (r < 0)	×
482	return log_error_errno(r, "Failed to determine if sshd is installed: %m");	×
483
484	_cleanup_(lookup_paths_done) LookupPaths lp = {};	×
485	r = lookup_paths_init_or_warn(&lp, RUNTIME_SCOPE_SYSTEM, LOOKUP_PATHS_EXCLUDE_GENERATED, /* root_dir= */ NULL);	×
486	if (r < 0)	×
487	return r;
488
489	_cleanup_free_ char *found_sshd_template_unit = NULL;	×
490	r = unit_file_exists_full(RUNTIME_SCOPE_SYSTEM, &lp, "sshd@.service", &found_sshd_template_unit);	×
491	if (r < 0)	×
492	return log_error_errno(r, "Unable to detect if sshd@.service exists: %m");	×
493
494	_cleanup_free_ char *generated_sshd_template_unit = NULL;	×
495	RET_GATHER(r, add_extra_sockets(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
496
497	if (arg_auto) {	×
498	RET_GATHER(r, add_vsock_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
499	RET_GATHER(r, add_local_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
500	RET_GATHER(r, add_export_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
501	}
502
503	return r;	×
504	}
505
506	DEFINE_MAIN_GENERATOR_FUNCTION(run);	×

systemd / systemd / 16082515961

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