13823965644

Committed 12 Mar 2025 10:54PM UTC coverage: 71.864% (-0.03%) from 71.892%

Build # 13823965644

Build Type

push

github

Committed by

web-flow

Commit Message

Fix several issues found by Coverity (#36726)

Coverage Stats

263 of 301 new or added lines in 31 files covered. (87.38%)

836 existing lines in 49 files now uncovered.

295777 of 411581 relevant lines covered (71.86%)

718837.67 hits per line

Source File
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74.43

/src/shared/hostname-setup.c

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

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/utsname.h>
#include <unistd.h>

#include "sd-daemon.h"

#include "alloc-util.h"
#include "creds-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "hexdecoct.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "initrd-util.h"
#include "log.h"
#include "macro.h"
#include "proc-cmdline.h"
#include "siphash24.h"
#include "string-table.h"
#include "string-util.h"

static int sethostname_idempotent_full(const char *s, bool really) {
        struct utsname u;

        assert(s);

        if (uname(&u) < 0)
                return -errno;

        if (streq_ptr(s, u.nodename))
                return 0;

        if (really &&
            sethostname(s, strlen(s)) < 0)
                return -errno;

        return 1;
}

int sethostname_idempotent(const char *s) {
        return sethostname_idempotent_full(s, true);
}

int shorten_overlong(const char *s, char **ret) {
        _cleanup_free_ char *h = NULL;

        /* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
         * whatever comes earlier. */

        assert(s);
        assert(ret);

        h = strdup(s);
        if (!h)
                return -ENOMEM;

        if (hostname_is_valid(h, 0)) {
                *ret = TAKE_PTR(h);
                return 0;
        }

        char *p = strchr(h, '.');
        if (p)
                *p = 0;

        strshorten(h, HOST_NAME_MAX);

        if (!hostname_is_valid(h, /* flags= */ 0))
                return -EDOM;

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

static int acquire_hostname_from_credential(char **ret) {
        _cleanup_free_ char *cred = NULL;
        int r;

        assert(ret);

        r = read_credential_with_decryption("system.hostname", (void **) &cred, /* ret_size= */ NULL);
        if (r < 0)
                return log_warning_errno(r, "Failed to read system.hostname credential, ignoring: %m");
        if (r == 0) /* not found */
                return -ENXIO;

        if (!hostname_is_valid(cred, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */
                return log_warning_errno(SYNTHETIC_ERRNO(EBADMSG), "Hostname specified in system.hostname credential is invalid, ignoring: %s", cred);

        log_info("Initializing hostname from credential.");
        *ret = TAKE_PTR(cred);
        return 0;
}

int read_etc_hostname_stream(FILE *f, bool substitute_wildcards, char **ret) {
        int r;

        assert(f);
        assert(ret);

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

                r = read_stripped_line(f, LONG_LINE_MAX, &line);
                if (r < 0)
                        return r;
                if (r == 0) /* EOF without any hostname? the file is empty, let's treat that exactly like no file at all: ENOENT */
                        return -ENOENT;

                /* File may have empty lines or comments, ignore them */
                if (IN_SET(line[0], '\0', '#'))
                        continue;

                if (substitute_wildcards) {
                        r = hostname_substitute_wildcards(line);
                        if (r < 0)
                                return r;
                }

                hostname_cleanup(line); /* normalize the hostname */

                /* check that the hostname we return is valid */
                if (!hostname_is_valid(
                                    line,
                                    VALID_HOSTNAME_TRAILING_DOT|
                                    (substitute_wildcards ? 0 : VALID_HOSTNAME_QUESTION_MARK)))
                        return -EBADMSG;

                *ret = TAKE_PTR(line);
                return 0;
        }
}

int read_etc_hostname(const char *path, bool substitute_wildcards, char **ret) {
        _cleanup_fclose_ FILE *f = NULL;

        assert(ret);

        if (!path)
                path = "/etc/hostname";

        f = fopen(path, "re");
        if (!f)
                return -errno;

        return read_etc_hostname_stream(f, substitute_wildcards, ret);
}

void hostname_update_source_hint(const char *hostname, HostnameSource source) {
        int r;

        assert(hostname);

        /* Why save the value and not just create a flag file? This way we will
         * notice if somebody sets the hostname directly (not going through hostnamed).
         */

        if (source == HOSTNAME_DEFAULT) {
                r = write_string_file("/run/systemd/default-hostname", hostname,
                                      WRITE_STRING_FILE_CREATE | WRITE_STRING_FILE_ATOMIC);
                if (r < 0)
                        log_warning_errno(r, "Failed to create \"/run/systemd/default-hostname\", ignoring: %m");
        } else
                (void) unlink_or_warn("/run/systemd/default-hostname");
}

int hostname_setup(bool really) {
        _cleanup_free_ char *hn = NULL;
        HostnameSource source;
        bool enoent = false;
        int r;

        r = proc_cmdline_get_key("systemd.hostname", 0, &hn);
        if (r < 0)
                log_warning_errno(r, "Failed to retrieve system hostname from kernel command line, ignoring: %m");
        else if (r > 0) {
                if (hostname_is_valid(hn, VALID_HOSTNAME_TRAILING_DOT))
                        source = HOSTNAME_TRANSIENT;
                else  {
                        log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", hn);
                        hn = mfree(hn);
                }
        }

        if (!hn) {
                r = read_etc_hostname(/* path= */ NULL, /* substitute_wildcards= */ true, &hn);
                if (r == -ENOENT)
                        enoent = true;
                else if (r < 0)
                        log_warning_errno(r, "Failed to read configured hostname, ignoring: %m");
                else
                        source = HOSTNAME_STATIC;
        }

        if (!hn) {
                r = acquire_hostname_from_credential(&hn);
                if (r >= 0)
                        source = HOSTNAME_TRANSIENT;
        }

        if (!hn) {
                /* Don't override the hostname if it is already set and not explicitly configured */

                r = gethostname_full(GET_HOSTNAME_ALLOW_LOCALHOST, &hn);
                if (r == -ENOMEM)
                        return log_oom();
                if (r >= 0) {
                        log_debug("No hostname configured, leaving existing hostname <%s> in place.", hn);
                        goto finish;
                }

                if (enoent)
                        log_info("No hostname configured, using default hostname.");

                hn = get_default_hostname();
                if (!hn)
                        return log_oom();

                source = HOSTNAME_DEFAULT;
        }

        r = sethostname_idempotent_full(hn, really);
        if (r < 0)
                return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
        if (r == 0)
                log_debug("Hostname was already set to <%s>.", hn);
        else
                log_info("Hostname %s to <%s>.",
                         really ? "set" : "would have been set",
                         hn);

        if (really)
                hostname_update_source_hint(hn, source);

finish:
        if (!in_initrd())
                (void) sd_notifyf(/* unset_environment= */ false, "X_SYSTEMD_HOSTNAME=%s", hn);

        return 0;
}

static const char* const hostname_source_table[] = {
        [HOSTNAME_STATIC]    = "static",
        [HOSTNAME_TRANSIENT] = "transient",
        [HOSTNAME_DEFAULT]   = "default",
};

DEFINE_STRING_TABLE_LOOKUP(hostname_source, HostnameSource);

int hostname_substitute_wildcards(char *name) {
        static const sd_id128_t key = SD_ID128_MAKE(98,10,ad,df,8d,7d,4f,b5,89,1b,4b,56,ac,c2,26,8f);
        sd_id128_t mid = SD_ID128_NULL;
        size_t left_bits = 0, counter = 0;
        uint64_t h = 0;
        int r;

        assert(name);

        /* Replaces every occurrence of '?' in the specified string with a nibble hashed from
         * /etc/machine-id. This is supposed to be used on /etc/hostname files that want to automatically
         * configure a hostname derived from the machine ID in some form.
         *
         * Note that this does not directly use the machine ID, because that's not necessarily supposed to be
         * public information to be broadcast on the network, while the hostname certainly is. */

        for (char *n = name; ; n++) {
                n = strchr(n, '?');
                if (!n)
                        return 0;

                if (left_bits <= 0) {
                        if (sd_id128_is_null(mid)) {
                                r = sd_id128_get_machine(&mid);
                                if (r < 0)
                                        return r;
                        }

                        struct siphash state;
                        siphash24_init(&state, key.bytes);
                        siphash24_compress(&mid, sizeof(mid), &state);
                        siphash24_compress(&counter, sizeof(counter), &state); /* counter mode */
                        h = siphash24_finalize(&state);
                        left_bits = sizeof(h) * 8;
                        counter++;
                }

                assert(left_bits >= 4);
                *n = hexchar(h & 0xf);
                h >>= 4;
                left_bits -= 4;
        }
}

char* get_default_hostname(void) {
        int r;

        _cleanup_free_ char *h = get_default_hostname_raw();
        if (!h)
                return NULL;

        r = hostname_substitute_wildcards(h);
        if (r < 0) {
                log_debug_errno(r, "Failed to substitute wildcards in hostname, falling back to built-in name: %m");
                return strdup(FALLBACK_HOSTNAME);
        }

        return TAKE_PTR(h);
}

int gethostname_full(GetHostnameFlags flags, char **ret) {
        _cleanup_free_ char *buf = NULL, *fallback = NULL;
        struct utsname u;
        const char *s;

        assert(ret);

        assert_se(uname(&u) >= 0);

        s = u.nodename;
        if (isempty(s) || streq(s, "(none)") ||
            (!FLAGS_SET(flags, GET_HOSTNAME_ALLOW_LOCALHOST) && is_localhost(s)) ||
            (FLAGS_SET(flags, GET_HOSTNAME_SHORT) && s[0] == '.')) {
                if (!FLAGS_SET(flags, GET_HOSTNAME_FALLBACK_DEFAULT))
                        return -ENXIO;

                s = fallback = get_default_hostname();
                if (!s)
                        return -ENOMEM;

                if (FLAGS_SET(flags, GET_HOSTNAME_SHORT) && s[0] == '.')
                        return -ENXIO;
        }

        if (FLAGS_SET(flags, GET_HOSTNAME_SHORT))
                buf = strdupcspn(s, ".");
        else
                buf = strdup(s);
        if (!buf)
                return -ENOMEM;

        *ret = TAKE_PTR(buf);
        return 0;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <errno.h>
4	#include <stdio.h>
5	#include <stdlib.h>
6	#include <sys/utsname.h>
7	#include <unistd.h>
8
9	#include "sd-daemon.h"
10
11	#include "alloc-util.h"
12	#include "creds-util.h"
13	#include "fd-util.h"
14	#include "fileio.h"
15	#include "fs-util.h"
16	#include "hexdecoct.h"
17	#include "hostname-setup.h"
18	#include "hostname-util.h"
19	#include "initrd-util.h"
20	#include "log.h"
21	#include "macro.h"
22	#include "proc-cmdline.h"
23	#include "siphash24.h"
24	#include "string-table.h"
25	#include "string-util.h"
26
27	static int sethostname_idempotent_full(const char *s, bool really) {	332✔
28	struct utsname u;	332✔
29
30	assert(s);	332✔
31
32	if (uname(&u) < 0)	332✔
33	return -errno;	×
34
35	if (streq_ptr(s, u.nodename))	332✔
36	return 0;
37
38	if (really &&	460✔
39	sethostname(s, strlen(s)) < 0)	230✔
40	return -errno;	×
41
42	return 1;
43	}
44
45	int sethostname_idempotent(const char *s) {	246✔
46	return sethostname_idempotent_full(s, true);	246✔
47	}
48
49	int shorten_overlong(const char s, char *ret) {	76✔
50	_cleanup_free_ char *h = NULL;	76✔
51
52	/* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
53	* whatever comes earlier. */
54
55	assert(s);	76✔
56	assert(ret);	76✔
57
58	h = strdup(s);	76✔
59	if (!h)	76✔
60	return -ENOMEM;
61
62	if (hostname_is_valid(h, 0)) {	76✔
63	*ret = TAKE_PTR(h);	73✔
64	return 0;	73✔
65	}
66
67	char *p = strchr(h, '.');	3✔
68	if (p)	3✔
69	*p = 0;	2✔
70
71	strshorten(h, HOST_NAME_MAX);	3✔
72
73	if (!hostname_is_valid(h, /* flags= */ 0))	3✔
74	return -EDOM;
75
76	*ret = TAKE_PTR(h);	2✔
77	return 1;	2✔
78	}
79
80	static int acquire_hostname_from_credential(char **ret) {	×
81	_cleanup_free_ char *cred = NULL;	×
82	int r;	×
83
84	assert(ret);	×
85
86	r = read_credential_with_decryption("system.hostname", (void *) &cred, / ret_size= */ NULL);	×
87	if (r < 0)	×
88	return log_warning_errno(r, "Failed to read system.hostname credential, ignoring: %m");	×
89	if (r == 0) /* not found */	×
90	return -ENXIO;
91
92	if (!hostname_is_valid(cred, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */	×
93	return log_warning_errno(SYNTHETIC_ERRNO(EBADMSG), "Hostname specified in system.hostname credential is invalid, ignoring: %s", cred);	×
94
95	log_info("Initializing hostname from credential.");	×
96	*ret = TAKE_PTR(cred);	×
97	return 0;	×
98	}
99
100	int read_etc_hostname_stream(FILE f, bool substitute_wildcards, char *ret) {	64✔
101	int r;	64✔
102
103	assert(f);	64✔
104	assert(ret);	64✔
105
106	for (;;) {	72✔
107	_cleanup_free_ char *line = NULL;	68✔
108
109	r = read_stripped_line(f, LONG_LINE_MAX, &line);	68✔
110	if (r < 0)	68✔
111	return r;
112	if (r == 0) /* EOF without any hostname? the file is empty, let's treat that exactly like no file at all: ENOENT */	68✔
113	return -ENOENT;
114
115	/* File may have empty lines or comments, ignore them */
116	if (IN_SET(line[0], '\0', '#'))	12✔
117	continue;	4✔
118
119	if (substitute_wildcards) {	8✔
120	r = hostname_substitute_wildcards(line);	1✔
121	if (r < 0)	1✔
122	return r;
123	}
124
125	hostname_cleanup(line); /* normalize the hostname */	8✔
126
127	/* check that the hostname we return is valid */
128	if (!hostname_is_valid(	15✔
129	line,
130	VALID_HOSTNAME_TRAILING_DOT\|
131	(substitute_wildcards ? 0 : VALID_HOSTNAME_QUESTION_MARK)))
132	return -EBADMSG;
133
134	*ret = TAKE_PTR(line);	8✔
135	return 0;	8✔
136	}
137	}
138
139	int read_etc_hostname(const char path, bool substitute_wildcards, char *ret) {	197✔
140	_cleanup_fclose_ FILE *f = NULL;	197✔
141
142	assert(ret);	197✔
143
144	if (!path)	197✔
145	path = "/etc/hostname";	189✔
146
147	f = fopen(path, "re");	197✔
148	if (!f)	197✔
149	return -errno;	188✔
150
151	return read_etc_hostname_stream(f, substitute_wildcards, ret);	9✔
152	}
153
154	void hostname_update_source_hint(const char *hostname, HostnameSource source) {	154✔
155	int r;	154✔
156
157	assert(hostname);	154✔
158
159	/* Why save the value and not just create a flag file? This way we will
160	* notice if somebody sets the hostname directly (not going through hostnamed).
161	*/
162
163	if (source == HOSTNAME_DEFAULT) {	154✔
164	r = write_string_file("/run/systemd/default-hostname", hostname,	32✔
165	WRITE_STRING_FILE_CREATE \| WRITE_STRING_FILE_ATOMIC);
166	if (r < 0)	32✔
167	log_warning_errno(r, "Failed to create \"/run/systemd/default-hostname\", ignoring: %m");	×
168	} else
169	(void) unlink_or_warn("/run/systemd/default-hostname");	122✔
170	}	154✔
171
172	int hostname_setup(bool really) {	86✔
173	_cleanup_free_ char *hn = NULL;	86✔
174	HostnameSource source;	86✔
175	bool enoent = false;	86✔
176	int r;	86✔
177
178	r = proc_cmdline_get_key("systemd.hostname", 0, &hn);	86✔
179	if (r < 0)	86✔
180	log_warning_errno(r, "Failed to retrieve system hostname from kernel command line, ignoring: %m");	×
181	else if (r > 0) {	86✔
182	if (hostname_is_valid(hn, VALID_HOSTNAME_TRAILING_DOT))	86✔
183	source = HOSTNAME_TRANSIENT;
184	else {
185	log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", hn);	×
186	hn = mfree(hn);	×
187	}
188	}
189
190	if (!hn) {	86✔
191	r = read_etc_hostname(/* path= / NULL, / substitute_wildcards= */ true, &hn);	×
192	if (r == -ENOENT)	×
193	enoent = true;
194	else if (r < 0)	×
195	log_warning_errno(r, "Failed to read configured hostname, ignoring: %m");	×
196	else
197	source = HOSTNAME_STATIC;
198	}
199
200	if (!hn) {	86✔
201	r = acquire_hostname_from_credential(&hn);	×
202	if (r >= 0)	×
203	source = HOSTNAME_TRANSIENT;	×
204	}
205
206	if (!hn) {	86✔
207	/* Don't override the hostname if it is already set and not explicitly configured */
208
209	r = gethostname_full(GET_HOSTNAME_ALLOW_LOCALHOST, &hn);	×
210	if (r == -ENOMEM)	×
211	return log_oom();	×
212	if (r >= 0) {	×
213	log_debug("No hostname configured, leaving existing hostname <%s> in place.", hn);	×
214	goto finish;	×
215	}
216
217	if (enoent)	×
218	log_info("No hostname configured, using default hostname.");	×
219
220	hn = get_default_hostname();	×
221	if (!hn)	×
222	return log_oom();	×
223
224	source = HOSTNAME_DEFAULT;
225	}
226
227	r = sethostname_idempotent_full(hn, really);	86✔
228	if (r < 0)	86✔
229	return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);	×
230	if (r == 0)	86✔
231	log_debug("Hostname was already set to <%s>.", hn);	7✔
232	else
233	log_info("Hostname %s to <%s>.",	79✔
234	really ? "set" : "would have been set",
235	hn);
236
237	if (really)	86✔
238	hostname_update_source_hint(hn, source);	85✔
239
240	finish:	1✔
241	if (!in_initrd())	86✔
242	(void) sd_notifyf(/* unset_environment= */ false, "X_SYSTEMD_HOSTNAME=%s", hn);	25✔
243
244	return 0;
245	}
246
247	static const char* const hostname_source_table[] = {
248	[HOSTNAME_STATIC] = "static",
249	[HOSTNAME_TRANSIENT] = "transient",
250	[HOSTNAME_DEFAULT] = "default",
251	};
252
253	DEFINE_STRING_TABLE_LOOKUP(hostname_source, HostnameSource);	148✔
254
255	int hostname_substitute_wildcards(char *name) {	197✔
256	static const sd_id128_t key = SD_ID128_MAKE(98,10,ad,df,8d,7d,4f,b5,89,1b,4b,56,ac,c2,26,8f);	197✔
257	sd_id128_t mid = SD_ID128_NULL;	197✔
258	size_t left_bits = 0, counter = 0;	197✔
259	uint64_t h = 0;	197✔
260	int r;	197✔
261
262	assert(name);	197✔
263
264	/* Replaces every occurrence of '?' in the specified string with a nibble hashed from
265	* /etc/machine-id. This is supposed to be used on /etc/hostname files that want to automatically
266	* configure a hostname derived from the machine ID in some form.
267	*
268	* Note that this does not directly use the machine ID, because that's not necessarily supposed to be
269	* public information to be broadcast on the network, while the hostname certainly is. */
270
271	for (char *n = name; ; n++) {	23✔
272	n = strchr(n, '?');	243✔
273	if (!n)	220✔
274	return 0;	197✔
275
276	if (left_bits <= 0) {	23✔
277	if (sd_id128_is_null(mid)) {	3✔
278	r = sd_id128_get_machine(&mid);	2✔
279	if (r < 0)	2✔
UNCOV 280	return r;	×
281	}
282
283	struct siphash state;	3✔
284	siphash24_init(&state, key.bytes);	3✔
285	siphash24_compress(&mid, sizeof(mid), &state);	3✔
286	siphash24_compress(&counter, sizeof(counter), &state); /* counter mode */	3✔
287	h = siphash24_finalize(&state);	3✔
288	left_bits = sizeof(h) * 8;	3✔
289	counter++;	3✔
290	}
291
292	assert(left_bits >= 4);	23✔
293	*n = hexchar(h & 0xf);	23✔
294	h >>= 4;	23✔
295	left_bits -= 4;	23✔
296	}
297	}
298
299	char* get_default_hostname(void) {	43✔
300	int r;	43✔
301
302	_cleanup_free_ char *h = get_default_hostname_raw();	86✔
303	if (!h)	43✔
304	return NULL;
305
306	r = hostname_substitute_wildcards(h);	43✔
307	if (r < 0) {	43✔
UNCOV 308	log_debug_errno(r, "Failed to substitute wildcards in hostname, falling back to built-in name: %m");	×
309	return strdup(FALLBACK_HOSTNAME);	×
310	}
311
312	return TAKE_PTR(h);
313	}
314
315	int gethostname_full(GetHostnameFlags flags, char **ret) {	2,374✔
316	_cleanup_free_ char buf = NULL, fallback = NULL;	2,374✔
317	struct utsname u;	2,374✔
318	const char *s;	2,374✔
319
320	assert(ret);	2,374✔
321
322	assert_se(uname(&u) >= 0);	2,374✔
323
324	s = u.nodename;	2,374✔
325	if (isempty(s) \|\| streq(s, "(none)") \|\|	2,374✔
326	(!FLAGS_SET(flags, GET_HOSTNAME_ALLOW_LOCALHOST) && is_localhost(s)) \|\|	2,374✔
327	(FLAGS_SET(flags, GET_HOSTNAME_SHORT) && s[0] == '.')) {	2,374✔
UNCOV 328	if (!FLAGS_SET(flags, GET_HOSTNAME_FALLBACK_DEFAULT))	×
329	return -ENXIO;
330
UNCOV 331	s = fallback = get_default_hostname();	×
332	if (!s)	×
333	return -ENOMEM;
334
UNCOV 335	if (FLAGS_SET(flags, GET_HOSTNAME_SHORT) && s[0] == '.')	×
336	return -ENXIO;
337	}
338
339	if (FLAGS_SET(flags, GET_HOSTNAME_SHORT))	8✔
340	buf = strdupcspn(s, ".");	8✔
341	else
342	buf = strdup(s);	2,366✔
343	if (!buf)	2,374✔
344	return -ENOMEM;
345
346	*ret = TAKE_PTR(buf);	2,374✔
347	return 0;	2,374✔
348	}

systemd / systemd / 13823965644

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