-/***
- This file is part of systemd.
-
- Copyright 2015 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
+/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <limits.h>
#include <sys/utsname.h>
#include <unistd.h>
+#include "alloc-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hostname-util.h"
return 0;
}
-static bool hostname_valid_char(char c) {
+bool valid_ldh_char(char c) {
return
(c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
- c == '-' ||
- c == '_' ||
- c == '.';
+ c == '-';
}
/**
bool hostname_is_valid(const char *s, bool allow_trailing_dot) {
unsigned n_dots = 0;
const char *p;
- bool dot;
+ bool dot, hyphen;
if (isempty(s))
return false;
* sequence. Also ensures that the length stays below
* HOST_NAME_MAX. */
- for (p = s, dot = true; *p; p++) {
+ for (p = s, dot = hyphen = true; *p; p++)
if (*p == '.') {
- if (dot)
+ if (dot || hyphen)
return false;
dot = true;
+ hyphen = false;
n_dots++;
+
+ } else if (*p == '-') {
+ if (dot)
+ return false;
+
+ dot = false;
+ hyphen = true;
+
} else {
- if (!hostname_valid_char(*p))
+ if (!valid_ldh_char(*p))
return false;
dot = false;
+ hyphen = false;
}
- }
if (dot && (n_dots < 2 || !allow_trailing_dot))
return false;
+ if (hyphen)
+ return false;
if (p-s > HOST_NAME_MAX) /* Note that HOST_NAME_MAX is 64 on
* Linux, but DNS allows domain names
char* hostname_cleanup(char *s) {
char *p, *d;
- bool dot;
+ bool dot, hyphen;
assert(s);
- strshorten(s, HOST_NAME_MAX);
-
- for (p = s, d = s, dot = true; *p; p++) {
+ for (p = s, d = s, dot = hyphen = true; *p && d - s < HOST_NAME_MAX; p++)
if (*p == '.') {
- if (dot)
+ if (dot || hyphen)
continue;
*(d++) = '.';
dot = true;
- } else if (hostname_valid_char(*p)) {
+ hyphen = false;
+
+ } else if (*p == '-') {
+ if (dot)
+ continue;
+
+ *(d++) = '-';
+ dot = false;
+ hyphen = true;
+
+ } else if (valid_ldh_char(*p)) {
*(d++) = *p;
dot = false;
+ hyphen = false;
}
- }
- if (dot && d > s)
- d[-1] = 0;
- else
- *d = 0;
+ if (d > s && IN_SET(d[-1], '-', '.'))
+ /* The dot can occur at most once, but we might have multiple
+ * hyphens, hence the loop */
+ d--;
+ *d = 0;
return s;
}
* synthetic "gateway" host. */
return
- strcaseeq(hostname, "gateway") ||
- strcaseeq(hostname, "gateway.");
+ strcaseeq(hostname, "_gateway") || strcaseeq(hostname, "_gateway.")
+#if ENABLE_COMPAT_GATEWAY_HOSTNAME
+ || strcaseeq(hostname, "gateway") || strcaseeq(hostname, "gateway.")
+#endif
+ ;
}
int sethostname_idempotent(const char *s) {
return 1;
}
-int read_hostname_config(const char *path, char **hostname) {
- _cleanup_fclose_ FILE *f = NULL;
- char l[LINE_MAX];
- char *name = NULL;
+int shorten_overlong(const char *s, char **ret) {
+ char *h, *p;
- assert(path);
- assert(hostname);
+ /* Shorten an overlong name to HOST_NAME_MAX or to the first dot,
+ * whatever comes earlier. */
- f = fopen(path, "re");
- if (!f)
- return -errno;
+ assert(s);
+
+ h = strdup(s);
+ if (!h)
+ return -ENOMEM;
- /* may have comments, ignore them */
- FOREACH_LINE(l, f, return -errno) {
- truncate_nl(l);
- if (l[0] != '\0' && l[0] != '#') {
- /* found line with value */
- name = hostname_cleanup(l);
- name = strdup(name);
- if (!name)
+ if (hostname_is_valid(h, false)) {
+ *ret = h;
+ return 0;
+ }
+
+ p = strchr(h, '.');
+ if (p)
+ *p = 0;
+
+ strshorten(h, HOST_NAME_MAX);
+
+ if (!hostname_is_valid(h, false)) {
+ 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, true)) /* check that the hostname we return is valid */
+ return -EBADMSG;
+
+ copy = strdup(p);
+ if (!copy)
return -ENOMEM;
- break;
+
+ *ret = copy;
+ return 0;
}
}
+}
- if (!name)
- /* no non-empty line found */
- return -ENOENT;
+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);
- *hostname = name;
- return 0;
}
projects / thirdparty / systemd.git / blobdiff