ipcpd, lib: Add flow down events

This adds the flow down event to Ouroboros. In the shim-eth-llc, a
netlink socket is opened which listens to device up/down events. For
each event the flow is then adjusted with fccntl to notify the user
the flow is down or back up again. In the normal IPCP an event is
thrown if a write reports that the flow is down.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/ipcpd/normal/dt.c b/src/ipcpd/normal/dt.c
index 2df17163..56cb5a61 100644
--- a/src/ipcpd/normal/dt.c
+++ b/src/ipcpd/normal/dt.c
@@ -93,6 +93,7 @@ static void sdu_handler(int                  fd,
                         struct shm_du_buff * sdb)
 {
         struct dt_pci dt_pci;
+        int           ret;
 
         memset(&dt_pci, 0, sizeof(dt_pci));
 
@@ -112,8 +113,11 @@ static void sdu_handler(int                  fd,
                         return;
                 }
 
-                if (ipcp_flow_write(fd, sdb)) {
+                ret = ipcp_flow_write(fd, sdb);
+                if (ret < 0) {
                         log_err("Failed to write SDU to fd %d.", fd);
+                        if (ret == -EFLOWDOWN)
+                                notifier_event(NOTIFY_DT_CONN_DOWN, &fd);
                         ipcp_sdb_release(sdb);
                         return;
                 }
@@ -323,6 +327,7 @@ int dt_write_sdu(uint64_t             dst_addr,
 {
         int           fd;
         struct dt_pci dt_pci;
+        int           ret;
 
         assert(sdb);
         assert(dst_addr != ipcpi.dt_addr);
@@ -342,8 +347,11 @@ int dt_write_sdu(uint64_t             dst_addr,
                 return -1;
         }
 
-        if (ipcp_flow_write(fd, sdb)) {
+        ret = ipcp_flow_write(fd, sdb);
+        if (ret < 0) {
                 log_err("Failed to write SDU to fd %d.", fd);
+                if (ret == -EFLOWDOWN)
+                        notifier_event(NOTIFY_DT_CONN_DOWN, &fd);
                 return -1;
         }