summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
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
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')
-rw-r--r--src/resolve/resolved-conf.c21
-rw-r--r--src/resolve/resolved-link.c6
-rw-r--r--src/resolve/resolved-manager.c116
-rw-r--r--src/resolve/resolved-manager.h4
-rw-r--r--src/shared/util.c24
-rw-r--r--src/shared/util.h2
6 files changed, 153 insertions, 20 deletions
diff --git a/src/resolve/resolved-conf.c b/src/resolve/resolved-conf.c
index 0def80e3a5..ae3773f4f7 100644
--- a/src/resolve/resolved-conf.c
+++ b/src/resolve/resolved-conf.c
@@ -94,20 +94,27 @@ int config_parse_dnsv(
else
l = &m->dns_servers;
- /* Empty assignment means clear the list */
if (isempty(rvalue)) {
+
+ /* Empty assignment means clear the list */
while (*l)
dns_server_free(*l);
- return 0;
- }
+ } else {
- r = manager_parse_dns_server(m, ltype, rvalue);
- if (r < 0) {
- log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue);
- return 0;
+ /* Otherwise add to the list */
+ r = manager_parse_dns_server(m, ltype, rvalue);
+ if (r < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue);
+ return 0;
+ }
}
+ /* If we have a manual setting, then we stop reading
+ * /etc/resolv.conf */
+ if (ltype == DNS_SERVER_SYSTEM)
+ m->read_resolv_conf = false;
+
return 0;
}
diff --git a/src/resolve/resolved-link.c b/src/resolve/resolved-link.c
index 93ccc04491..7418ea1ed9 100644
--- a/src/resolve/resolved-link.c
+++ b/src/resolve/resolved-link.c
@@ -150,13 +150,13 @@ static int link_update_dns_servers(Link *l) {
assert(l);
- LIST_FOREACH(servers, s, l->dns_servers)
- s->marked = true;
-
r = sd_network_get_dns(l->ifindex, &nameservers);
if (r < 0)
goto clear;
+ LIST_FOREACH(servers, s, l->dns_servers)
+ s->marked = true;
+
STRV_FOREACH(nameserver, nameservers) {
union in_addr_union a;
int family;
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);
diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h
index 03386f0a4f..7bb18c0d66 100644
--- a/src/resolve/resolved-manager.h
+++ b/src/resolve/resolved-manager.h
@@ -78,6 +78,9 @@ struct Manager {
LIST_HEAD(DnsServer, fallback_dns_servers);
DnsServer *current_dns_server;
+ bool read_resolv_conf;
+ usec_t resolv_conf_mtime;
+
LIST_HEAD(DnsScope, dns_scopes);
DnsScope *unicast_scope;
@@ -111,6 +114,7 @@ struct Manager {
int manager_new(Manager **ret);
Manager* manager_free(Manager *m);
+int manager_read_resolv_conf(Manager *m);
int manager_write_resolv_conf(Manager *m);
bool manager_known_dns_server(Manager *m, int family, const union in_addr_union *in_addr);
diff --git a/src/shared/util.c b/src/shared/util.c
index 4c30a98318..e2c955bc07 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -140,26 +140,38 @@ char* endswith(const char *s, const char *postfix) {
return (char*) s + sl - pl;
}
-bool first_word(const char *s, const char *word) {
+char* first_word(const char *s, const char *word) {
size_t sl, wl;
+ const char *p;
assert(s);
assert(word);
+ /* Checks if the string starts with the specified word, either
+ * followed by NUL or by whitespace. Returns a pointer to the
+ * NUL or the first character after the whitespace. */
+
sl = strlen(s);
wl = strlen(word);
if (sl < wl)
- return false;
+ return NULL;
if (wl == 0)
- return true;
+ return (char*) s;
if (memcmp(s, word, wl) != 0)
- return false;
+ return NULL;
+
+ p = s + wl;
+ if (*p == 0)
+ return (char*) p;
+
+ if (!strchr(WHITESPACE, *p))
+ return NULL;
- return s[wl] == 0 ||
- strchr(WHITESPACE, s[wl]);
+ p += strspn(p, WHITESPACE);
+ return (char*) p;
}
int close_nointr(int fd) {
diff --git a/src/shared/util.h b/src/shared/util.h
index 45294800e4..fd999bd942 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -169,7 +169,7 @@ static inline const char *startswith_no_case(const char *s, const char *prefix)
char *endswith(const char *s, const char *postfix) _pure_;
-bool first_word(const char *s, const char *word) _pure_;
+char *first_word(const char *s, const char *word) _pure_;
int close_nointr(int fd);
int safe_close(int fd);