along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include <errno.h>
#include <sys/socket.h>
#include <net/if.h>
#include <asm/types.h>
#include <netinet/in.h>
-#include <linux/rtnetlink.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "sd-rtnl.h"
#include "rtnl-util.h"
-static int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
- int *counter = userdata;
- int r;
-
- (*counter) --;
+/* this is hardcoded in the kernel, so don't look it up */
+#define LOOPBACK_IFINDEX 1
- r = sd_rtnl_message_get_errno(m);
-
- return r == -EEXIST ? 0 : r;
-}
-
-static int add_addresses(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
- _cleanup_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL;
+static int start_loopback(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL;
int r;
- r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET, &ipv4);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_prefixlen(ipv4, 8);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_flags(ipv4, IFA_F_PERMANENT);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_scope(ipv4, RT_SCOPE_HOST);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address);
- if (r < 0)
- return r;
-
- r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL);
+ r = sd_rtnl_message_new_link(rtnl, &req, RTM_SETLINK, LOOPBACK_IFINDEX);
if (r < 0)
return r;
- (*counter) ++;
-
- if (!socket_ipv6_is_supported())
- return 0;
-
- r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET6, &ipv6);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_prefixlen(ipv6, 128);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_flags(ipv6, IFA_F_PERMANENT);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_addr_set_scope(ipv6, RT_SCOPE_HOST);
- if (r < 0)
- return r;
-
- r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback);
+ r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP);
if (r < 0)
return r;
- r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL);
+ r = sd_rtnl_call(rtnl, req, 0, NULL);
if (r < 0)
return r;
- (*counter) ++;
-
return 0;
}
-static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) {
- _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL;
+static bool check_loopback(sd_rtnl *rtnl) {
+ _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
+ unsigned flags;
int r;
- r = sd_rtnl_message_link_new(RTM_SETLINK, if_loopback, &req);
+ r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, LOOPBACK_IFINDEX);
if (r < 0)
- return r;
+ return false;
- r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP);
+ r = sd_rtnl_call(rtnl, req, 0, &reply);
if (r < 0)
- return r;
+ return false;
- r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
+ r = sd_rtnl_message_link_get_flags(reply, &flags);
if (r < 0)
- return r;
+ return false;
- (*counter) ++;
-
- return 0;
-}
-
-static int check_loopback(void) {
- int r;
- _cleanup_close_ int fd = -1;
- union {
- struct sockaddr sa;
- struct sockaddr_in in;
- } sa = {
- .in.sin_family = AF_INET,
- .in.sin_addr.s_addr = INADDR_LOOPBACK,
- };
-
- /* If we failed to set up the loop back device, check whether
- * it might already be set up */
-
- fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
- if (fd < 0)
- return -errno;
-
- if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
- r = 1;
- else
- r = errno == EADDRNOTAVAIL ? 0 : -errno;
-
- return r;
+ return flags & IFF_UP;
}
int loopback_setup(void) {
_cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
- int r, if_loopback, counter = 0;
- bool eperm = false;
- struct in_addr ipv4_address;
-
- errno = 0;
- if_loopback = (int) if_nametoindex("lo");
- if (if_loopback <= 0)
- return errno ? -errno : -ENODEV;
-
- ipv4_address.s_addr = htonl(INADDR_LOOPBACK);
-
- r = sd_rtnl_open(0, &rtnl);
- if (r < 0)
- return r;
+ int r;
- r = add_addresses(rtnl, if_loopback, &ipv4_address, &counter);
+ r = sd_rtnl_open(&rtnl, 0);
if (r < 0)
return r;
- r = start_interface(rtnl, if_loopback, &ipv4_address, &counter);
- if (r < 0)
- return r;
+ r = start_loopback(rtnl);
+ if (r == -EPERM) {
+ if (!check_loopback(rtnl))
+ return log_warning_errno(EPERM, "Failed to configure loopback device: %m");
+ } else if (r < 0)
+ return log_warning_errno(r, "Failed to configure loopback device: %m");
- while (counter > 0) {
- r = sd_rtnl_wait(rtnl, 0);
- if (r < 0)
- return r;
-
- r = sd_rtnl_process(rtnl, 0);
- if (r < 0) {
- if (r == -EPERM)
- eperm = true;
- else {
- log_warning("Failed to configure loopback device: %s", strerror(-r));
- return r;
- }
- }
- }
-
- if (eperm && check_loopback() < 0) {
- log_warning("Failed to configure loopback device: %s", strerror(EPERM));
- return -EPERM;
- }
return 0;
}