sd-network: expose both admin and operational state directly

Also add a call to check if a link is loopback, as this should commonly be ignored.

5 files changed, 117 insertions, 37 deletions

diff --git a/src/libsystemd-network/network-internal.c b/src/libsystemd-network/network-internal.c
index e7ba628fc7..52e614c4ea 100644
--- a/src/libsystemd-network/network-internal.c
+++ b/src/libsystemd-network/network-internal.c
@@ -326,17 +326,3 @@ int net_parse_inaddr(const char *address, unsigned char *family, void *dst) {
 
         return 0;
 }
-
-bool link_has_carrier(unsigned flags, uint8_t operstate) {
-        /* see Documentation/networking/operstates.txt in the kernel sources */
-
-        if (operstate == IF_OPER_UP)
-                return true;
-
-        if (operstate == IF_OPER_UNKNOWN)
-                /* operstate may not be implemented, so fall back to flags */
-                if ((flags & IFF_LOWER_UP) && !(flags & IFF_DORMANT))
-                        return true;
-
-        return false;
-}
diff --git a/src/libsystemd-network/network-internal.h b/src/libsystemd-network/network-internal.h
index ef3cb8b91d..836472a776 100644
--- a/src/libsystemd-network/network-internal.h
+++ b/src/libsystemd-network/network-internal.h
@@ -65,5 +65,3 @@ int config_parse_ifalias(const char *unit, const char *filename, unsigned line,
 int net_parse_inaddr(const char *address, unsigned char *family, void *dst);
 
 int net_get_unique_predictable_data(struct udev_device *device, uint8_t result[8]);
-
-bool link_has_carrier(unsigned flags, uint8_t operstate);
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index 058fbc24f1..2f99b5374a 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1117,6 +1117,20 @@ static int link_acquire_conf(Link *link) {
         return 0;
 }
 
+static bool link_has_carrier(unsigned flags, uint8_t operstate) {
+        /* see Documentation/networking/operstates.txt in the kernel sources */
+
+        if (operstate == IF_OPER_UP)
+                return true;
+
+        if (operstate == IF_OPER_UNKNOWN)
+                /* operstate may not be implemented, so fall back to flags */
+                if ((flags & IFF_LOWER_UP) && !(flags & IFF_DORMANT))
+                        return true;
+
+        return false;
+}
+
 static int link_update_flags(Link *link, sd_rtnl_message *m) {
         unsigned flags, flags_added, flags_removed, generic_flags;
         uint8_t operstate;
@@ -1216,6 +1230,8 @@ static int link_update_flags(Link *link, sd_rtnl_message *m) {
         link->flags = flags;
         link->operstate = operstate;
 
+        link_save(link);
+
         if (carrier_gained) {
                 log_info_link(link, "gained carrier");
 
@@ -1514,8 +1530,7 @@ static int link_configure(Link *link) {
                 }
         }
 
-        if (link_has_carrier(link->flags, link->operstate))
-        {
+        if (link_has_carrier(link->flags, link->operstate)) {
                 r = link_acquire_conf(link);
                 if (r < 0)
                         return r;
@@ -1669,16 +1684,26 @@ int link_update(Link *link, sd_rtnl_message *m) {
 }
 
 int link_save(Link *link) {
-        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_free_ char *temp_path = NULL, *lease_file = NULL;
         _cleanup_fclose_ FILE *f = NULL;
-        const char *state;
+        const char *admin_state, *oper_state = "unknown";
         int r;
 
         assert(link);
         assert(link->state_file);
 
-        state = link_state_to_string(link->state);
-        assert(state);
+        admin_state = link_state_to_string(link->state);
+        assert(admin_state);
+
+        if (link->operstate & IF_OPER_DORMANT)
+                oper_state = "dormant";
+        else if (link_has_carrier(link->flags, link->operstate))
+                oper_state = "carrier";
+
+        r = asprintf(&lease_file, "/run/systemd/network/leases/%"PRIu64,
+                             link->ifindex);
+        if (r < 0)
+                return -ENOMEM;
 
         r = fopen_temporary(link->state_file, &f, &temp_path);
         if (r < 0)
@@ -1688,22 +1713,19 @@ int link_save(Link *link) {
 
         fprintf(f,
                 "# This is private data. Do not parse.\n"
-                "STATE=%s\n", state);
+                "ADMIN_STATE=%s\n"
+                "OPER_STATE=%s\n"
+                "FLAGS=%u\n",
+                admin_state, oper_state, link->flags);
 
         if (link->dhcp_lease) {
-                _cleanup_free_ char *lease_file = NULL;
-
-                r = asprintf(&lease_file, "/run/systemd/network/leases/%"PRIu64,
-                             link->ifindex);
-                if (r < 0)
-                        return -ENOMEM;
-
                 r = dhcp_lease_save(link->dhcp_lease, lease_file);
                 if (r < 0)
                         goto finish;
 
                 fprintf(f, "DHCP_LEASE=%s\n", lease_file);
-        }
+        } else
+                unlink(lease_file);
 
         fflush(f);
 
@@ -1721,7 +1743,7 @@ finish:
 }
 
 static const char* const link_state_table[_LINK_STATE_MAX] = {
-        [LINK_STATE_INITIALIZING] = "configuring",
+        [LINK_STATE_INITIALIZING] = "initializing",
         [LINK_STATE_ENSLAVING] = "configuring",
         [LINK_STATE_SETTING_ADDRESSES] = "configuring",
         [LINK_STATE_SETTING_ROUTES] = "configuring",
diff --git a/src/network/sd-network.c b/src/network/sd-network.c
index 1dfb282a0a..c867812209 100644
--- a/src/network/sd-network.c
+++ b/src/network/sd-network.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <sys/inotify.h>
 #include <sys/poll.h>
+#include <net/if.h>
 
 #include "util.h"
 #include "macro.h"
@@ -33,6 +34,38 @@
 #include "sd-network.h"
 #include "dhcp-lease-internal.h"
 
+static int link_get_flags(unsigned index, unsigned *flags) {
+        _cleanup_free_ char *s = NULL, *p = NULL;
+        int r;
+
+        assert(index);
+        assert(flags);
+
+        if (asprintf(&p, "/run/systemd/network/links/%u", index) < 0)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "FLAGS", &s, NULL);
+        if (r == -ENOENT)
+                return -ENODATA;
+        else if (r < 0)
+                return r;
+        else if (!s)
+                return -EIO;
+
+        return safe_atou(s, flags);
+}
+
+_public_ int sd_network_link_is_loopback(unsigned index) {
+        unsigned flags;
+        int r;
+
+        r = link_get_flags(index, &flags);
+        if (r < 0)
+                return 0;
+
+        return flags & IFF_LOOPBACK;
+}
+
 _public_ int sd_network_get_link_state(unsigned index, char **state) {
         _cleanup_free_ char *s = NULL, *p = NULL;
         int r;
@@ -43,8 +76,7 @@ _public_ int sd_network_get_link_state(unsigned index, char **state) {
         if (asprintf(&p, "/run/systemd/network/links/%u", index) < 0)
                 return -ENOMEM;
 
-        r = parse_env_file(p, NEWLINE, "STATE", &s, NULL);
-
+        r = parse_env_file(p, NEWLINE, "ADMIN_STATE", &s, NULL);
         if (r == -ENOENT)
                 return -ENODATA;
         else if (r < 0)
@@ -54,6 +86,32 @@ _public_ int sd_network_get_link_state(unsigned index, char **state) {
 
         if (streq(s, "unmanaged"))
                 return -EUNATCH;
+        else if (streq(s, "initializing"))
+                return -EBUSY;
+
+        *state = s;
+        s = NULL;
+
+        return 0;
+}
+
+_public_ int sd_network_get_link_operational_state(unsigned index, char **state) {
+        _cleanup_free_ char *s = NULL, *p = NULL;
+        int r;
+
+        assert_return(index, -EINVAL);
+        assert_return(state, -EINVAL);
+
+        if (asprintf(&p, "/run/systemd/network/links/%u", index) < 0)
+                return -ENOMEM;
+
+        r = parse_env_file(p, NEWLINE, "OPER_STATE", &s, NULL);
+        if (r == -ENOENT)
+                return -ENODATA;
+        else if (r < 0)
+                return r;
+        else if (!s)
+                return -EIO;
 
         *state = s;
         s = NULL;
diff --git a/src/systemd/sd-network.h b/src/systemd/sd-network.h
index 9562b78feb..40bd75a23a 100644
--- a/src/systemd/sd-network.h
+++ b/src/systemd/sd-network.h
@@ -51,8 +51,24 @@
 
 _SD_BEGIN_DECLARATIONS;
 
-/* Get state from ifindex. Possible states: unknown, unmanaged, failed, configuring, configured */
-int sd_network_get_link_state(unsigned index, char**state);
+/* Get state from ifindex.
+ * Possible states: failed, configuring, configured
+ * Possible return codes:
+ *   -ENODATA: networkd is not aware of the link
+ *   -EUNATCH: networkd is not managing this link
+ *   -EBUSY: udev is still processing the link, networkd does not yet know if it will manage it
+ */
+int sd_network_get_link_state(unsigned index, char **state);
+
+/* Get operatinal state from ifindex.
+ * Possible states: unknown, dormant, carrier
+ * Possible return codes:
+ *   -ENODATA: networkd is not aware of the link
+ */
+int sd_network_get_link_operational_state(unsigned index, char **state);
+
+/* Returns true if link exists and is loopback, and false otherwise */
+int sd_network_link_is_loopback(unsigned index);
 
 /* Get DHCPv4 lease from ifindex. */
 int sd_network_get_dhcp_lease(unsigned index, sd_dhcp_lease **ret);
@@ -65,7 +81,7 @@ int sd_network_get_ifindices(unsigned **indices);
 typedef struct sd_network_monitor sd_network_monitor;
 
 /* Create a new monitor. Category must be NULL, "links" or "leases". */
-int sd_network_monitor_new(const char *category, sd_network_monitor** ret);
+int sd_network_monitor_new(const char *category, sd_network_monitor **ret);
 
 /* Destroys the passed monitor. Returns NULL. */
 sd_network_monitor* sd_network_monitor_unref(sd_network_monitor *m);