+int manager_read_resolv_conf(Manager *m) {
+ _cleanup_fclose_ FILE *f = NULL;
+ struct stat st, own;
+ char line[LINE_MAX];
+ DnsServer *s, *nx;
+ usec_t t;
+ int r;
+
+ assert(m);
+
+ /* Reads the system /etc/resolv.conf, if it exists and is not
+ * symlinked to our own resolv.conf instance */
+
+ if (!m->read_resolv_conf)
+ return 0;
+
+ r = stat("/etc/resolv.conf", &st);
+ if (r < 0) {
+ if (errno != ENOENT)
+ log_warning("Failed to open /etc/resolv.conf: %m");
+ r = -errno;
+ goto clear;
+ }
+
+ /* Have we already seen the file? */
+ t = timespec_load(&st.st_mtim);
+ if (t == m->resolv_conf_mtime)
+ return 0;
+
+ m->resolv_conf_mtime = t;
+
+ /* Is it symlinked to our own file? */
+ if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 &&
+ st.st_dev == own.st_dev &&
+ st.st_ino == own.st_ino) {
+ r = 0;
+ goto clear;
+ }
+
+ f = fopen("/etc/resolv.conf", "re");
+ if (!f) {
+ if (errno != ENOENT)
+ log_warning("Failed to open /etc/resolv.conf: %m");
+ r = -errno;
+ goto clear;
+ }
+
+ if (fstat(fileno(f), &st) < 0) {
+ log_error("Failed to stat open file: %m");
+ r = -errno;
+ goto clear;
+ }
+
+ LIST_FOREACH(servers, s, m->dns_servers)
+ s->marked = true;
+
+ FOREACH_LINE(line, f, r = -errno; goto clear) {
+ union in_addr_union address;
+ int family;
+ char *l;
+ const char *a;
+
+ truncate_nl(line);
+
+ l = strstrip(line);
+ if (*l == '#' || *l == ';')
+ continue;
+
+ a = first_word(l, "nameserver");
+ if (!a)
+ continue;
+
+ r = in_addr_from_string_auto(a, &family, &address);
+ if (r < 0) {
+ log_warning("Failed to parse name server %s.", a);
+ continue;
+ }
+
+ LIST_FOREACH(servers, s, m->dns_servers)
+ if (s->family == family && in_addr_equal(family, &s->address, &address) > 0)
+ break;
+
+ if (s)
+ s->marked = false;
+ else {
+ r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address);
+ if (r < 0)
+ goto clear;
+ }
+ }
+
+ LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers)
+ if (s->marked)
+ dns_server_free(s);
+
+ return 0;
+
+clear:
+ while (m->dns_servers)
+ dns_server_free(m->dns_servers);
+
+ return r;
+}
+
+static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) {