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Move hostname setup logic to new shared/hostname-setup.[ch] 

No functional change, just moving a bunch of things around. Before
we needed a rather complicated setup to test hostname_setup(), because
the code was in src/core/. When things are moved to src/shared/
we can just test it as any function.

The test is still "unsafe" because hostname_setup() may modify the
hostname.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2020-12-04 18:39:23 +01:00
parent 7d9ec60990
commit e2054217d5
20 changed files with 289 additions and 280 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

120
src/basic/hostname-util.c
View File

@ -7,28 +7,10 @@
#include <unistd.h>
#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hostname-util.h"
#include "macro.h"
#include "string-util.h"
#include "strv.h"
bool hostname_is_set(void) {
struct utsname u;
assert_se(uname(&u) >= 0);
if (isempty(u.nodename))
return false;
/* This is the built-in kernel default hostname */
if (streq(u.nodename, "(none)"))
return false;
return true;
}
char* gethostname_malloc(void) {
struct utsname u;
const char *s;
@ -208,105 +190,3 @@ bool is_localhost(const char *hostname) {
endswith_no_case(hostname, ".localhost.localdomain") ||
endswith_no_case(hostname, ".localhost.localdomain.");
}
int sethostname_idempotent(const char *s) {
char buf[HOST_NAME_MAX + 1] = {};
assert(s);
if (gethostname(buf, sizeof(buf)) < 0)
return -errno;
if (streq(buf, s))
return 0;
if (sethostname(s, strlen(s)) < 0)
return -errno;
return 1;
}
int shorten_overlong(const char *s, char **ret) {
char *h, *p;
/* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
* whatever comes earlier. */
assert(s);
h = strdup(s);
if (!h)
return -ENOMEM;
if (hostname_is_valid(h, 0)) {
*ret = h;
return 0;
}
p = strchr(h, '.');
if (p)
*p = 0;
strshorten(h, HOST_NAME_MAX);
if (!hostname_is_valid(h, 0)) {
free(h);
return -EDOM;
}
*ret = h;
return 1;
}
int read_etc_hostname_stream(FILE *f, char **ret) {
int r;
assert(f);
assert(ret);
for (;;) {
_cleanup_free_ char *line = NULL;
char *p;
r = read_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;
p = strstrip(line);
/* File may have empty lines or comments, ignore them */
if (!IN_SET(*p, '\0', '#')) {
char *copy;
hostname_cleanup(p); /* normalize the hostname */
if (!hostname_is_valid(p, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */
return -EBADMSG;
copy = strdup(p);
if (!copy)
return -ENOMEM;
*ret = copy;
return 0;
}
}
}
int read_etc_hostname(const char *path, 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, ret);
}

9
src/basic/hostname-util.h
View File

@ -7,8 +7,6 @@
#include "macro.h"
#include "strv.h"
bool hostname_is_set(void);
char* gethostname_malloc(void);
char* gethostname_short_malloc(void);
int gethostname_strict(char **ret);
@ -29,10 +27,3 @@ static inline bool is_gateway_hostname(const char *hostname) {
/* This tries to identify the valid syntaxes for the our synthetic "gateway" host. */
return STRCASE_IN_SET(hostname, "_gateway", "_gateway.");
}
int sethostname_idempotent(const char *s);
int shorten_overlong(const char *s, char **ret);
int read_etc_hostname_stream(FILE *f, char **ret);
int read_etc_hostname(const char *path, char **ret);

62
src/core/hostname-setup.c
View File

@ -1,62 +0,0 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "fileio.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "log.h"
#include "macro.h"
#include "proc-cmdline.h"
#include "string-util.h"
#include "util.h"
int hostname_setup(void) {
_cleanup_free_ char *b = NULL;
const char *hn = NULL;
bool enoent = false;
int r;
r = proc_cmdline_get_key("systemd.hostname", 0, &b);
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(b, VALID_HOSTNAME_TRAILING_DOT))
hn = b;
else {
log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", b);
b = mfree(b);
}
}
if (!hn) {
r = read_etc_hostname(NULL, &b);
if (r == -ENOENT)
enoent = true;
else if (r < 0)
log_warning_errno(r, "Failed to read configured hostname, ignoring: %m");
else
hn = b;
}
if (isempty(hn)) {
/* Don't override the hostname if it is already set and not explicitly configured */
if (hostname_is_set())
return 0;
if (enoent)
log_info("No hostname configured.");
hn = FALLBACK_HOSTNAME;
}
r = sethostname_idempotent(hn);
if (r < 0)
return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
log_info("Set hostname to <%s>.", hn);
return 0;
}

4
src/core/hostname-setup.h
View File

@ -1,4 +0,0 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
int hostname_setup(void);

2
src/core/meson.build
View File

@ -76,8 +76,6 @@ libcore_sources = '''
execute.h
generator-setup.c
generator-setup.h
hostname-setup.c
hostname-setup.h
ima-setup.c
ima-setup.h
ip-address-access.c

2
src/fuzz/fuzz-hostname-util.c → src/fuzz/fuzz-hostname-setup.c
View File

@ -4,7 +4,7 @@
#include "fd-util.h"
#include "fileio.h"
#include "fuzz.h"
#include "hostname-util.h"
#include "hostname-setup.h"
int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
_cleanup_fclose_ FILE *f = NULL;

2
src/fuzz/meson.build
View File

@ -123,7 +123,7 @@ fuzzers += [
[libshared],
[]],
[['src/fuzz/fuzz-hostname-util.c'],
[['src/fuzz/fuzz-hostname-setup.c'],
[libshared],
[]],

1
src/hostname/hostnamed.c
View File

@ -17,6 +17,7 @@
#include "env-util.h"
#include "fileio-label.h"
#include "fileio.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "id128-util.h"
#include "main-func.h"

1
src/network/networkd-dhcp4.c
View File

@ -8,6 +8,7 @@
#include "escape.h"
#include "alloc-util.h"
#include "dhcp-client-internal.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "parse-util.h"
#include "network-internal.h"

2
src/network/test-network.c
View File

@ -8,7 +8,7 @@
#include "alloc-util.h"
#include "dhcp-lease-internal.h"
#include "ether-addr-util.h"
#include "hostname-util.h"
#include "hostname-setup.h"
#include "network-internal.h"
#include "networkd-manager.h"
#include "string-util.h"

1
src/nspawn/nspawn.c
View File

@ -46,6 +46,7 @@
#include "fs-util.h"
#include "gpt.h"
#include "hexdecoct.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "id128-util.h"
#include "io-util.h"

2
src/shared/dissect-image.c
View File

@ -32,7 +32,7 @@
#include "fsck-util.h"
#include "gpt.h"
#include "hexdecoct.h"
#include "hostname-util.h"
#include "hostname-setup.h"
#include "id128-util.h"
#include "mkdir.h"
#include "mount-util.h"

183
src/shared/hostname-setup.c Normal file
View File

@ -0,0 +1,183 @@
/* 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 "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hostname-setup.h"
#include "hostname-util.h"
#include "log.h"
#include "macro.h"
#include "proc-cmdline.h"
#include "string-util.h"
#include "util.h"
int sethostname_idempotent(const char *s) {
char buf[HOST_NAME_MAX + 1] = {};
assert(s);
if (gethostname(buf, sizeof(buf)) < 0)
return -errno;
if (streq(buf, s))
return 0;
if (sethostname(s, strlen(s)) < 0)
return -errno;
return 1;
}
int shorten_overlong(const char *s, char **ret) {
char *h, *p;
/* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
* whatever comes earlier. */
assert(s);
h = strdup(s);
if (!h)
return -ENOMEM;
if (hostname_is_valid(h, 0)) {
*ret = h;
return 0;
}
p = strchr(h, '.');
if (p)
*p = 0;
strshorten(h, HOST_NAME_MAX);
if (!hostname_is_valid(h, 0)) {
free(h);
return -EDOM;
}
*ret = h;
return 1;
}
int read_etc_hostname_stream(FILE *f, char **ret) {
int r;
assert(f);
assert(ret);
for (;;) {
_cleanup_free_ char *line = NULL;
char *p;
r = read_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;
p = strstrip(line);
/* File may have empty lines or comments, ignore them */
if (!IN_SET(*p, '\0', '#')) {
char *copy;
hostname_cleanup(p); /* normalize the hostname */
if (!hostname_is_valid(p, VALID_HOSTNAME_TRAILING_DOT)) /* check that the hostname we return is valid */
return -EBADMSG;
copy = strdup(p);
if (!copy)
return -ENOMEM;
*ret = copy;
return 0;
}
}
}
int read_etc_hostname(const char *path, 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, ret);
}
static bool hostname_is_set(void) {
struct utsname u;
assert_se(uname(&u) >= 0);
if (isempty(u.nodename))
return false;
/* This is the built-in kernel default hostname */
if (streq(u.nodename, "(none)"))
return false;
return true;
}
int hostname_setup(void) {
_cleanup_free_ char *b = NULL;
const char *hn = NULL;
bool enoent = false;
int r;
r = proc_cmdline_get_key("systemd.hostname", 0, &b);
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(b, true))
hn = b;
else {
log_warning("Hostname specified on kernel command line is invalid, ignoring: %s", b);
b = mfree(b);
}
}
if (!hn) {
r = read_etc_hostname(NULL, &b);
if (r < 0) {
if (r == -ENOENT)
enoent = true;
else
log_warning_errno(r, "Failed to read configured hostname: %m");
} else
hn = b;
}
if (isempty(hn)) {
/* Don't override the hostname if it is already set and not explicitly configured */
if (hostname_is_set())
return 0;
if (enoent)
log_info("No hostname configured.");
hn = FALLBACK_HOSTNAME;
}
r = sethostname_idempotent(hn);
if (r < 0)
return log_warning_errno(r, "Failed to set hostname to <%s>: %m", hn);
log_info("Set hostname to <%s>.", hn);
return 0;
}

13
src/shared/hostname-setup.h Normal file
View File

@ -0,0 +1,13 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include <stdio.h>
int sethostname_idempotent(const char *s);
int shorten_overlong(const char *s, char **ret);
int read_etc_hostname_stream(FILE *f, char **ret);
int read_etc_hostname(const char *path, char **ret);
int hostname_setup(void);

2
src/shared/machine-image.c
View File

@ -22,7 +22,7 @@
#include "fd-util.h"
#include "fs-util.h"
#include "hashmap.h"
#include "hostname-util.h"
#include "hostname-setup.h"
#include "id128-util.h"
#include "lockfile-util.h"
#include "log.h"

2
src/shared/meson.build
View File

@ -115,6 +115,8 @@ shared_sources = files('''
gpt.h
group-record.c
group-record.h
hostname-setup.c
hostname-setup.h
id128-print.c
id128-print.h
idn-util.c

16
src/test/meson.build
View File

@ -105,17 +105,6 @@ tests += [
libmount,
libblkid]],
[['src/test/test-hostname.c'],
[libcore,
libshared],
[threads,
librt,
libseccomp,
libselinux,
libmount,
libblkid],
'', 'unsafe'],
[['src/test/test-dns-domain.c'],
[libcore,
libshared],
@ -339,6 +328,11 @@ tests += [
[],
[]],
[['src/test/test-hostname-setup.c'],
[],
[],
'', 'unsafe'],
[['src/test/test-hostname-util.c'],
[],
[]],

76
src/test/test-hostname-setup.c Normal file
View File

@ -0,0 +1,76 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <unistd.h>
#include "alloc-util.h"
#include "fileio.h"
#include "hostname-setup.h"
#include "string-util.h"
#include "tests.h"
#include "tmpfile-util.h"
static void test_read_etc_hostname(void) {
char path[] = "/tmp/hostname.XXXXXX";
char *hostname;
int fd;
fd = mkostemp_safe(path);
assert(fd > 0);
close(fd);
/* simple hostname */
assert_se(write_string_file(path, "foo", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* with comment */
assert_se(write_string_file(path, "# comment\nfoo", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* with comment and extra whitespace */
assert_se(write_string_file(path, "# comment\n\n foo ", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* cleans up name */
assert_se(write_string_file(path, "!foo/bar.com", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foobar.com"));
hostname = mfree(hostname);
/* no value set */
hostname = (char*) 0x1234;
assert_se(write_string_file(path, "# nothing here\n", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == -ENOENT);
assert_se(hostname == (char*) 0x1234); /* does not touch argument on error */
/* nonexisting file */
assert_se(read_etc_hostname("/non/existing", &hostname) == -ENOENT);
assert_se(hostname == (char*) 0x1234); /* does not touch argument on error */
unlink(path);
}
static void test_hostname_setup(void) {
int r;
r = hostname_setup();
if (r < 0)
log_error_errno(r, "hostname: %m");
}
int main(int argc, char *argv[]) {
test_setup_logging(LOG_INFO);
test_read_etc_hostname();
test_hostname_setup();
return 0;
}

55
src/test/test-hostname-util.c
View File

@ -6,8 +6,8 @@
#include "fileio.h"
#include "hostname-util.h"
#include "string-util.h"
#include "tests.h"
#include "tmpfile-util.h"
#include "util.h"
static void test_hostname_is_valid(void) {
assert_se(hostname_is_valid("foobar", 0));
@ -91,55 +91,6 @@ static void test_hostname_cleanup(void) {
assert_se(streq(hostname_cleanup(s), "xxxx.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"));
}
static void test_read_etc_hostname(void) {
char path[] = "/tmp/hostname.XXXXXX";
char *hostname;
int fd;
fd = mkostemp_safe(path);
assert(fd > 0);
close(fd);
/* simple hostname */
assert_se(write_string_file(path, "foo", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* with comment */
assert_se(write_string_file(path, "# comment\nfoo", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* with comment and extra whitespace */
assert_se(write_string_file(path, "# comment\n\n foo ", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foo"));
hostname = mfree(hostname);
/* cleans up name */
assert_se(write_string_file(path, "!foo/bar.com", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == 0);
assert_se(hostname);
assert_se(streq(hostname, "foobar.com"));
hostname = mfree(hostname);
/* no value set */
hostname = (char*) 0x1234;
assert_se(write_string_file(path, "# nothing here\n", WRITE_STRING_FILE_CREATE) == 0);
assert_se(read_etc_hostname(path, &hostname) == -ENOENT);
assert_se(hostname == (char*) 0x1234); /* does not touch argument on error */
/* nonexisting file */
assert_se(read_etc_hostname("/non/existing", &hostname) == -ENOENT);
assert_se(hostname == (char*) 0x1234); /* does not touch argument on error */
unlink(path);
}
static void test_hostname_malloc(void) {
_cleanup_free_ char *h = NULL, *l = NULL;
@ -158,12 +109,10 @@ static void test_fallback_hostname(void) {
}
int main(int argc, char *argv[]) {
log_parse_environment();
log_open();
test_setup_logging(LOG_INFO);
test_hostname_is_valid();
test_hostname_cleanup();
test_read_etc_hostname();
test_hostname_malloc();
test_fallback_hostname();

14
src/test/test-hostname.c
View File

@ -1,14 +0,0 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include "hostname-setup.h"
#include "util.h"
int main(int argc, char* argv[]) {
int r;
r = hostname_setup();
if (r < 0)
log_error_errno(r, "hostname: %m");
return 0;
}