29132483780

Committed 10 Jul 2026 08:43PM UTC coverage: 72.912% (+0.2%) from 72.702%

Build # 29132483780

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push

github

Committed by

bluca

Commit Message

man: run forgotten 'update-man-rules'

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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 "dlopen-note.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 "ssh-util.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 bool arg_auto = true;
static char **arg_listen_extra = NULL;

STATIC_DESTRUCTOR_REGISTER(arg_listen_extra, strv_freep);

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 under the name we want to use */
        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;

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

                /* sshd reads AuthorizedKeysFile after dropping to the authenticating user's UID, so the
                 * 0400 credential file under $CREDENTIALS_DIRECTORY is unreadable for non-root users.
                 * Materialize a 0444 copy in a RuntimeDirectory so the ephemeral key works for any user. */
                fprintf(f,
                        "[Unit]\n"
                        "Description=OpenSSH Per-Connection Server Daemon\n"
                        "Documentation=man:systemd-ssh-generator(8) man:sshd(8)\n"
                        "\n"
                        "[Service]\n"
                        "ExecStartPre=systemd-tmpfiles --create --inline 'f^ /run/sshd-generated-%%i/authorized_keys 0444 root root - ssh.ephemeral-authorized_keys-all'\n"
                        "ExecStart=-%s -i -o \"AuthorizedKeysFile /run/sshd-generated-%%i/authorized_keys .ssh/authorized_keys\"\n"
                        "StandardInput=socket\n"
                        "ImportCredential=ssh.ephemeral-authorized_keys-all\n"
                        "RuntimeDirectory=sshd-generated-%%i\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;
        }

        r = vsock_open_or_warn(/* ret= */ NULL);
        if (r <= 0)
                return r;

        /* 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_or_warn(&local_cid);
        if (r <= 0)
                return r;

        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_IS_FS_WRITE_REFUSED(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);

        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(dest);

        LIBCRYPTO_NOTE(suggested);
        TPM2_NOTE(suggested);

        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,
                                  SEARCH_FOLLOW_CONFIG_SYMLINKS,
                                  "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 "dlopen-note.h"
8	#include "errno-util.h"
9	#include "fd-util.h"
10	#include "fileio.h"
11	#include "generator.h"
12	#include "install.h"
13	#include "log.h"
14	#include "parse-util.h"
15	#include "path-lookup.h"
16	#include "path-util.h"
17	#include "proc-cmdline.h"
18	#include "socket-netlink.h"
19	#include "socket-util.h"
20	#include "special.h"
21	#include "ssh-util.h"
22	#include "string-util.h"
23	#include "strv.h"
24	#include "virt.h"
25
26	/* A small generator binding potentially five or more SSH sockets:
27	*
28	* 1. Listen on AF_VSOCK port 22 if we run in a VM with AF_VSOCK enabled
29	* 2. Listen on AF_UNIX socket /run/host/unix-export/ssh if we run in a container with /run/host/ support
30	* 3. Listen on AF_UNIX socket /run/ssh-unix-local/socket (always)
31	* 4. Listen on any socket specified via kernel command line option systemd.ssh_listen=
32	* 5. Similar, but from system credential ssh.listen
33	*
34	* The first two provide a nice way for hosts to connect to containers and VMs they invoke via the usual SSH
35	* logic, but without waiting for networking or suchlike. The third allows the same for local clients. */
36
37	static bool arg_auto = true;
38	static char **arg_listen_extra = NULL;
39
40	STATIC_DESTRUCTOR_REGISTER(arg_listen_extra, strv_freep);	×
41
42	static int parse_proc_cmdline_item(const char key, const char value, void *data) {	×
43	int r;	×
44
45	assert(key);	×
46
47	if (proc_cmdline_key_streq(key, "systemd.ssh_auto")) {	×
48	r = value ? parse_boolean(value) : 1;	×
49	if (r < 0)	×
50	log_warning_errno(r, "Failed to parse systemd.ssh_auto switch \"%s\", ignoring: %m", value);	×
51	else
52	arg_auto = r;	×
53
54	} else if (proc_cmdline_key_streq(key, "systemd.ssh_listen")) {	×
55
56	if (proc_cmdline_value_missing(key, value))	×
57	return 0;	×
58
59	SocketAddress sa;	×
60	r = socket_address_parse(&sa, value);	×
61	if (r < 0)	×
62	log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", value);	×
63	else {
64	_cleanup_free_ char *s = NULL;	×
65	r = socket_address_print(&sa, &s);	×
66	if (r < 0)	×
67	return log_error_errno(r, "Failed to format socket address: %m");	×
68
69	if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)	×
70	return log_oom();	×
71	}
72	}
73
74	return 0;
75	}
76
77	static int make_sshd_template_unit(	×
78	const char *dest,
79	const char *template,
80	const char *sshd_binary,
81	const char *found_sshd_template_service,
82	char **generated_sshd_template_unit) {
83
84	int r;	×
85
86	assert(dest);	×
87	assert(template);	×
88	assert(sshd_binary);	×
89	assert(generated_sshd_template_unit);	×
90
91	/* If the system has a suitable template already, symlink it under the name we want to use */
92	if (found_sshd_template_service)	×
93	return generator_add_symlink(	×
94	dest,
95	template,
96	/* dep_type= */ NULL,
97	found_sshd_template_service);
98
99	if (!*generated_sshd_template_unit) {	×
100	_cleanup_fclose_ FILE *f = NULL;	×
101
102	/* We use a generic name for the unit, since we'll use it for both AF_UNIX and AF_VSOCK */
103	r = generator_open_unit_file_full(	×
104	dest,
105	/* source= */ NULL,
106	"sshd-generated@.service",
107	&f,
108	generated_sshd_template_unit,
109	/* ret_temp_path= */ NULL);
110	if (r < 0)	×
111	return r;
112
113	/* sshd reads AuthorizedKeysFile after dropping to the authenticating user's UID, so the
114	* 0400 credential file under $CREDENTIALS_DIRECTORY is unreadable for non-root users.
115	* Materialize a 0444 copy in a RuntimeDirectory so the ephemeral key works for any user. */
116	fprintf(f,	×
117	"[Unit]\n"
118	"Description=OpenSSH Per-Connection Server Daemon\n"
119	"Documentation=man:systemd-ssh-generator(8) man:sshd(8)\n"
120	"\n"
121	"[Service]\n"
122	"ExecStartPre=systemd-tmpfiles --create --inline 'f^ /run/sshd-generated-%%i/authorized_keys 0444 root root - ssh.ephemeral-authorized_keys-all'\n"
123	"ExecStart=-%s -i -o \"AuthorizedKeysFile /run/sshd-generated-%%i/authorized_keys .ssh/authorized_keys\"\n"
124	"StandardInput=socket\n"
125	"ImportCredential=ssh.ephemeral-authorized_keys-all\n"
126	"RuntimeDirectory=sshd-generated-%%i\n",
127	sshd_binary);
128
129	r = fflush_and_check(f);	×
130	if (r < 0)	×
131	return log_error_errno(r, "Failed to write sshd template: %m");	×
132	}
133
134	return generator_add_symlink(	×
135	dest,
136	template,
137	/* dep_type= */ NULL,
138	*generated_sshd_template_unit);
139	}
140
141	static int write_socket_unit(	×
142	const char *dest,
143	const char *unit,
144	const char *listen_stream,
145	const char *comment,
146	const char *extra,
147	bool with_ssh_access_target_dependency) {
148
149	int r;	×
150
151	assert(dest);	×
152	assert(unit);	×
153	assert(listen_stream);	×
154	assert(comment);	×
155
156	_cleanup_fclose_ FILE *f = NULL;	×
157	r = generator_open_unit_file(	×
158	dest,
159	/* source= */ NULL,
160	unit,
161	&f);
162	if (r < 0)	×
163	return r;
164
165	fprintf(f,	×
166	"[Unit]\n"
167	"Description=OpenSSH Server Socket (systemd-ssh-generator, %s)\n"
168	"Documentation=man:systemd-ssh-generator(8)\n",
169	comment);
170
171	/* When this is a remotely accessible socket let's mark this with a milestone: ssh-access.target */
172	if (with_ssh_access_target_dependency)	×
173	fputs("Wants=ssh-access.target\n"	×
174	"Before=ssh-access.target\n",
175	f);
176
177	fprintf(f,	×
178	"\n[Socket]\n"
179	"ListenStream=%s\n"
180	"Accept=yes\n"
181	"PollLimitIntervalSec=30s\n"
182	"PollLimitBurst=50\n",
183	listen_stream);
184
185	if (extra)	×
186	fputs(extra, f);	×
187
188	r = fflush_and_check(f);	×
189	if (r < 0)	×
190	return log_error_errno(r, "Failed to write %s SSH socket unit: %m", comment);	×
191
192	r = generator_add_symlink(	×
193	dest,
194	SPECIAL_SOCKETS_TARGET,
195	"wants",
196	unit);
197	if (r < 0)	×
198	return r;	×
199
200	return 0;
201	}
202
203	static int add_vsock_socket(	×
204	const char *dest,
205	const char *sshd_binary,
206	const char *found_sshd_template_unit,
207	char **generated_sshd_template_unit) {
208
209	int r;	×
210
211	assert(dest);	×
212	assert(generated_sshd_template_unit);	×
213
214	Virtualization v = detect_virtualization();	×
215	if (v < 0)	×
216	return log_error_errno(v, "Failed to detect if we run in a VM: %m");	×
217	if (!VIRTUALIZATION_IS_VM(v)) {	×
218	/* NB: if we are running in a container inside a VM, then we'll not do AF_VSOCK stuff */
219	log_debug("Not running in a VM, not listening on AF_VSOCK.");	×
220	return 0;
221	}
222
223	r = vsock_open_or_warn(/* ret= */ NULL);	×
224	if (r <= 0)	×
225	return r;
226
227	/* Determine the local CID so that we can log it to help users to connect to this VM */
228	unsigned local_cid;	×
229	r = vsock_get_local_cid_or_warn(&local_cid);	×
230	if (r <= 0)	×
231	return r;
232
233	r = make_sshd_template_unit(	×
234	dest,
235	"sshd-vsock@.service",
236	sshd_binary,
237	found_sshd_template_unit,
238	generated_sshd_template_unit);
239	if (r < 0)	×
240	return r;
241
242	r = write_socket_unit(	×
243	dest,
244	"sshd-vsock.socket",
245	"vsock::22",
246	"AF_VSOCK",
247	"ExecStartPost=-/usr/lib/systemd/systemd-ssh-issue make-vsock\n"
248	"ExecStopPre=-/usr/lib/systemd/systemd-ssh-issue rm-vsock\n",
249	/* with_ssh_access_target_dependency= */ true);
250	if (r < 0)	×
251	return r;
252
253	log_debug("Binding SSH to AF_VSOCK vsock::22.\n"	×
254	"→ connect via 'ssh vsock/%u' from host", local_cid);
255	return 0;
256	}
257
258	static int add_local_unix_socket(	×
259	const char *dest,
260	const char *sshd_binary,
261	const char *found_sshd_template_unit,
262	char **generated_sshd_template_unit) {
263
264	int r;	×
265
266	assert(dest);	×
267	assert(sshd_binary);	×
268	assert(generated_sshd_template_unit);	×
269
270	r = make_sshd_template_unit(	×
271	dest,
272	"sshd-unix-local@.service",
273	sshd_binary,
274	found_sshd_template_unit,
275	generated_sshd_template_unit);
276	if (r < 0)	×
277	return r;
278
279	r = write_socket_unit(	×
280	dest,
281	"sshd-unix-local.socket",
282	"/run/ssh-unix-local/socket",
283	"AF_UNIX Local",
284	/* extra= */ NULL,
285	/* with_ssh_access_target_dependency= */ false);
286	if (r < 0)	×
287	return r;
288
289	log_debug("Binding SSH to AF_UNIX socket /run/ssh-unix-local/socket.\n"	×
290	"→ connect via 'ssh .host' locally");
291	return 0;
292	}
293
294	static int add_export_unix_socket(	×
295	const char *dest,
296	const char *sshd_binary,
297	const char *found_sshd_template_unit,
298	char **generated_sshd_template_unit) {
299
300	int r;	×
301
302	assert(dest);	×
303	assert(sshd_binary);	×
304	assert(generated_sshd_template_unit);	×
305
306	Virtualization v = detect_container();	×
307	if (v < 0)	×
308	return log_error_errno(v, "Failed to detect if we run in a container: %m");	×
309	if (v == VIRTUALIZATION_NONE) {	×
310	log_debug("Not running in container, not listening on /run/host/unix-export/ssh");	×
311	return 0;
312	}
313
314	if (access("/run/host/unix-export/", W_OK) < 0) {	×
315	if (errno == ENOENT) {	×
316	log_debug("Container manager does not provide /run/host/unix-export/ mount, not binding AF_UNIX socket there.");	×
317	return 0;
318	}
319	if (ERRNO_IS_FS_WRITE_REFUSED(errno)) {	×
320	log_debug("Container manager does not provide write access to /run/host/unix-export/, not binding AF_UNIX socket there.");	×
321	return 0;
322	}
323
324	return log_error_errno(errno, "Unable to check if /run/host/unix-export exists: %m");	×
325	}
326
327	r = make_sshd_template_unit(	×
328	dest,
329	"sshd-unix-export@.service",
330	sshd_binary,
331	found_sshd_template_unit,
332	generated_sshd_template_unit);
333	if (r < 0)	×
334	return r;
335
336	r = write_socket_unit(	×
337	dest,
338	"sshd-unix-export.socket",
339	"/run/host/unix-export/ssh",
340	"AF_UNIX Export",
341	/* extra= */ NULL,
342	/* with_ssh_access_target_dependency= */ true);
343	if (r < 0)	×
344	return r;
345
346	log_debug("Binding SSH to AF_UNIX socket /run/host/unix-export/ssh\n"	×
347	"→ connect via 'ssh unix/run/systemd/nspawn/\?\?\?/unix-export/ssh' from host");
348
349	return 0;
350	}
351
352	static int add_extra_sockets(	×
353	const char *dest,
354	const char *sshd_binary,
355	const char *found_sshd_template_unit,
356	char **generated_sshd_template_unit) {
357
358	unsigned n = 1;	×
359	int r;	×
360
361	assert(dest);	×
362	assert(sshd_binary);	×
363	assert(generated_sshd_template_unit);	×
364
365	STRV_FOREACH(i, arg_listen_extra) {	×
366	_cleanup_free_ char service = NULL, socket = NULL;	×
367
368	if (n > 1) {	×
369	if (asprintf(&service, "sshd-extra-%u@.service", n) < 0)	×
370	return log_oom();	×
371
372	if (asprintf(&socket, "sshd-extra-%u.socket", n) < 0)	×
373	return log_oom();	×
374	}
375
376	r = make_sshd_template_unit(	×
377	dest,
378	service ?: "sshd-extra@.service",	×
379	sshd_binary,
380	found_sshd_template_unit,
381	generated_sshd_template_unit);
382	if (r < 0)	×
383	return r;
384
385	r = write_socket_unit(	×
386	dest,
387	socket ?: "sshd-extra.socket",	×
388	*i,
389	*i,
390	/* extra= */ NULL,
391	/* with_ssh_access_target_dependency= */ true);
392	if (r < 0)	×
393	return r;
394
395	log_debug("Binding SSH to socket %s.", *i);	×
396	n++;	×
397	}
398
399	return 0;
400	}
401
402	static int parse_credentials(void) {	×
403	_cleanup_free_ char *b = NULL;	×
404	size_t sz = 0;	×
405	int r;	×
406
407	r = read_credential_with_decryption("ssh.listen", (void**) &b, &sz);	×
408	if (r <= 0)	×
409	return r;
410
411	_cleanup_fclose_ FILE *f = NULL;	×
412	f = fmemopen_unlocked(b, sz, "r");	×
413	if (!f)	×
414	return log_oom();	×
415
416	for (;;) {	×
417	_cleanup_free_ char *item = NULL;	×
418
419	r = read_stripped_line(f, LINE_MAX, &item);	×
420	if (r == 0)	×
421	break;
422	if (r < 0) {	×
423	log_error_errno(r, "Failed to parse credential 'ssh.listen': %m");	×
424	break;
425	}
426
427	if (startswith(item, "#"))	×
428	continue;	×
429
430	SocketAddress sa;	×
431	r = socket_address_parse(&sa, item);	×
432	if (r < 0) {	×
433	log_warning_errno(r, "Failed to parse systemd.ssh_listen= expression, ignoring: %s", item);	×
434	continue;	×
435	}
436
437	_cleanup_free_ char *s = NULL;	×
438	r = socket_address_print(&sa, &s);	×
439	if (r < 0)	×
440	return log_error_errno(r, "Failed to format socket address: %m");	×
441
442	if (strv_consume(&arg_listen_extra, TAKE_PTR(s)) < 0)	×
443	return log_oom();	×
444	}
445
446	return 0;	×
447	}
448
449	static int run(const char dest, const char dest_early, const char *dest_late) {	×
450	int r;	×
451
452	assert(dest);	×
453
454	LIBCRYPTO_NOTE(suggested);	×
455	TPM2_NOTE(suggested);	×
456
457	r = proc_cmdline_parse(parse_proc_cmdline_item, /* userdata= / NULL, / flags= */ 0);	×
458	if (r < 0)	×
459	log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");	×
460
461	(void) parse_credentials();	×
462
463	strv_sort_uniq(arg_listen_extra);	×
464
465	if (!arg_auto && strv_isempty(arg_listen_extra)) {	×
466	log_debug("Disabling SSH generator logic, because it has been turned off explicitly.");	×
467	return 0;	×
468	}
469
470	_cleanup_free_ char *sshd_binary = NULL;	×
471	r = find_executable("sshd", &sshd_binary);	×
472	if (r == -ENOENT) {	×
473	log_debug("Disabling SSH generator logic, since sshd is not installed.");	×
474	return 0;
475	}
476	if (r < 0)	×
477	return log_error_errno(r, "Failed to determine if sshd is installed: %m");	×
478
479	_cleanup_(lookup_paths_done) LookupPaths lp = {};	×
480	r = lookup_paths_init_or_warn(&lp, RUNTIME_SCOPE_SYSTEM, LOOKUP_PATHS_EXCLUDE_GENERATED, /* root_dir= */ NULL);	×
481	if (r < 0)	×
482	return r;
483
484	_cleanup_free_ char *found_sshd_template_unit = NULL;	×
485	r = unit_file_exists_full(RUNTIME_SCOPE_SYSTEM, &lp,	×
486	SEARCH_FOLLOW_CONFIG_SYMLINKS,
487	"sshd@.service",
488	&found_sshd_template_unit);
489	if (r < 0)	×
490	return log_error_errno(r, "Unable to detect if sshd@.service exists: %m");	×
491
492	_cleanup_free_ char *generated_sshd_template_unit = NULL;	×
493	RET_GATHER(r, add_extra_sockets(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
494
495	if (arg_auto) {	×
496	RET_GATHER(r, add_vsock_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
497	RET_GATHER(r, add_local_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
498	RET_GATHER(r, add_export_unix_socket(dest, sshd_binary, found_sshd_template_unit, &generated_sshd_template_unit));	×
499	}
500
501	return r;	×
502	}
503
504	DEFINE_MAIN_GENERATOR_FUNCTION(run);	×

systemd / systemd / 29132483780

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