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authorLennart Poettering <lennart@poettering.net>2014-08-01 17:03:28 +0200
committerLennart Poettering <lennart@poettering.net>2014-08-01 18:10:01 +0200
commit5cb36f41f01cf4b1f4395abfffd1b33116591e58 (patch)
tree1b8b7e319ce4d7d3ea94a3e84aa9e41723270faa /src/resolve/resolved-manager.c
parentafe7fd56f5b5b81294dcb794214f97fc5e39dfea (diff)
resolved: read the system /etc/resolv.conf unless we wrote it ourselves
This way we integrate nicely with foreign network management stacks, such as NM.
Diffstat (limited to 'src/resolve/resolved-manager.c')
-rw-r--r--src/resolve/resolved-manager.c116
1 files changed, 113 insertions, 3 deletions
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c
index 1e86c1003b..ba2380d682 100644
--- a/src/resolve/resolved-manager.c
+++ b/src/resolve/resolved-manager.c
@@ -184,7 +184,6 @@ fail:
return 0;
}
-
static int manager_rtnl_listen(Manager *m) {
_cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
sd_rtnl_message *i;
@@ -410,6 +409,7 @@ int manager_new(Manager **ret) {
m->hostname_fd = -1;
m->llmnr_support = SUPPORT_YES;
+ m->read_resolv_conf = true;
r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS);
if (r < 0)
@@ -520,6 +520,110 @@ Manager *manager_free(Manager *m) {
return NULL;
}
+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_resolve_conf_server(DnsServer *s, FILE *f, unsigned *count) {
_cleanup_free_ char *t = NULL;
int r;
@@ -553,6 +657,9 @@ int manager_write_resolv_conf(Manager *m) {
assert(m);
+ /* Read the system /etc/resolv.conf first */
+ manager_read_resolv_conf(m);
+
r = fopen_temporary(path, &f, &temp_path);
if (r < 0)
return r;
@@ -953,11 +1060,11 @@ bool manager_known_dns_server(Manager *m, int family, const union in_addr_union
assert(in_addr);
LIST_FOREACH(servers, s, m->dns_servers)
- if (s->family == family && in_addr_equal(family, &s->address, in_addr))
+ if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
return true;
LIST_FOREACH(servers, s, m->fallback_dns_servers)
- if (s->family == family && in_addr_equal(family, &s->address, in_addr))
+ if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)
return true;
return false;
@@ -985,6 +1092,9 @@ DnsServer *manager_get_dns_server(Manager *m) {
Link *l;
assert(m);
+ /* Try to read updates resolv.conf */
+ manager_read_resolv_conf(m);
+
if (!m->current_dns_server)
manager_set_dns_server(m, m->dns_servers);