inet: fix state transitions in driver receipt code

This resolves a problem with ioctl(NIOCGETHSTAT) hanging forever
as identified by Erik van der Kouwe, and possibly many other corner
cases.

Change-Id: I2350c882dc6a0862e16454ec6b6c320d78780bcd

diff --git a/minix/net/inet/mnx_eth.c b/minix/net/inet/mnx_eth.c
index bc4fc25445fcbc97049c1cd9b14e6f43a5c72e69..0fe58409928077a09021eee5ad71184eabd56f65 100644 (file)
--- a/minix/net/inet/mnx_eth.c
+++ b/minix/net/inet/mnx_eth.c
@@ -177,14 +177,9 @@ acc_t *pack;
 
 void eth_rec(message *m)
 {
-       int i, r, m_type, flags;
+       int i, r, flags;
        eth_port_t *loc_port, *vlan_port;
 
-       m_type= m->m_type;
-
-       assert(m_type == DL_CONF_REPLY || m_type == DL_TASK_REPLY ||
-               m_type == DL_STAT_REPLY);
-
        for (i=0, loc_port= eth_port_table; i<eth_conf_nr; i++, loc_port++)
        {
                if (loc_port->etp_osdep.etp_task == m->m_source)
@@ -193,28 +188,16 @@ void eth_rec(message *m)
        if (i >= eth_conf_nr)
        {
                printf("eth_rec: message 0x%x from unknown driver %d\n",
-                       m_type, m->m_source);
+                       m->m_type, m->m_source);
                return;
        }
 
-       if (loc_port->etp_osdep.etp_state == OEPS_CONF_SENT)
-       {
-               if (m_type == DL_TASK_REPLY)
-               {
-                       flags= m->m_netdrv_net_dl_task.flags;
-
-                       if (flags & DL_PACK_SEND)
-                               write_int(loc_port);
-                       if (flags & DL_PACK_RECV)
-                               read_int(loc_port, m->m_netdrv_net_dl_task.count);
-                       return;
-               }
-
-               if (m_type != DL_CONF_REPLY)
-               {
-                       printf(
-       "eth_rec: got bad message type 0x%x from %d in CONF state\n",
-                               m_type, m->m_source);
+       switch (m->m_type) {
+       case DL_CONF_REPLY:
+               if (loc_port->etp_osdep.etp_state != OEPS_CONF_SENT) {
+                       printf("eth_rec: got DL_CONF_REPLY from %d while in "
+                           "state %d (ignoring)\n", m->m_source,
+                           loc_port->etp_osdep.etp_state);
                        return;
                }
 
@@ -257,44 +240,17 @@ void eth_rec(message *m)
                                eth_restart_ioctl(vlan_port);
                        }
                }
-               if (!(loc_port->etp_flags & EPF_READ_IP))
-                       setup_read (loc_port);
 
-#if 0
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_SEND)
-               {
-                       printf("eth_rec(conf): OEPF_NEED_SEND is set\n");
-               }
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_RECV)
-               {
-                       printf("eth_rec(conf): OEPF_NEED_RECV is set\n");
-               }
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_STAT)
-               {
-                       printf("eth_rec(conf): OEPF_NEED_STAT is set\n");
-               }
-#endif
-
-               return;
-       }
-       if (loc_port->etp_osdep.etp_state == OEPS_GETSTAT_SENT)
-       {
-               if (m_type == DL_TASK_REPLY)
-               {
-                       flags= m->m_netdrv_net_dl_task.flags;
+               if (!(loc_port->etp_flags & EPF_READ_IP))
+                       loc_port->etp_osdep.etp_flags |= OEPF_NEED_RECV;
 
-                       if (flags & DL_PACK_SEND)
-                               write_int(loc_port);
-                       if (flags & DL_PACK_RECV)
-                               read_int(loc_port, m->m_netdrv_net_dl_task.count);
-                       return;
-               }
+               break;
 
-               if (m_type != DL_STAT_REPLY)
-               {
-                       printf(
-       "eth_rec: got bad message type 0x%x from %d in GETSTAT state\n",
-                               m_type, m->m_source);
+       case DL_STAT_REPLY:
+               if (loc_port->etp_osdep.etp_state != OEPS_GETSTAT_SENT) {
+                       printf("eth_rec: got DL_STAT_REPLY from %d while in "
+                           "state %d (ignoring)\n", m->m_source,
+                           loc_port->etp_osdep.etp_state);
                        return;
                }
 
@@ -310,43 +266,25 @@ void eth_rec(message *m)
                assert(loc_port->etp_flags & EPF_GOT_ADDR);
                eth_restart_ioctl(loc_port);
 
-#if 0
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_SEND)
-               {
-                       printf("eth_rec(stat): OEPF_NEED_SEND is set\n");
-               }
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_RECV)
-               {
-                       printf("eth_rec(stat): OEPF_NEED_RECV is set\n");
-               }
-               if (loc_port->etp_osdep.etp_flags & OEPF_NEED_CONF)
-               {
-                       printf("eth_rec(stat): OEPF_NEED_CONF is set\n");
-               }
-#endif
+               break;
 
-#if 0
-               if (loc_port->etp_osdep.etp_state == OEPS_IDLE &&
-                       (loc_port->etp_osdep.etp_flags & OEPF_NEED_CONF))
-               {
-                       eth_set_rec_conf(loc_port,
-                               loc_port->etp_osdep.etp_recvconf);
-               }
-#endif
-               return;
-       }
-       assert(loc_port->etp_osdep.etp_state == OEPS_IDLE  ||
-               loc_port->etp_osdep.etp_state == OEPS_RECV_SENT ||
-               loc_port->etp_osdep.etp_state == OEPS_SEND_SENT ||
-               (printf("etp_state = %d\n", loc_port->etp_osdep.etp_state), 0));
-       loc_port->etp_osdep.etp_state= OEPS_IDLE;
+       case DL_TASK_REPLY:
+               if (loc_port->etp_osdep.etp_state == OEPS_RECV_SENT ||
+                   loc_port->etp_osdep.etp_state == OEPS_SEND_SENT)
+                       loc_port->etp_osdep.etp_state= OEPS_IDLE;
 
-       flags= m->m_netdrv_net_dl_task.flags;
+               flags= m->m_netdrv_net_dl_task.flags;
 
-       if (flags & DL_PACK_SEND)
-               write_int(loc_port);
-       if (flags & DL_PACK_RECV)
-               read_int(loc_port, m->m_netdrv_net_dl_task.count);
+               if (flags & DL_PACK_SEND)
+                       write_int(loc_port);
+               if (flags & DL_PACK_RECV)
+                       read_int(loc_port, m->m_netdrv_net_dl_task.count);
+
+               break;
+
+       default:
+               panic("invalid ethernet reply %d", m->m_type);
+       }
 
        if (loc_port->etp_osdep.etp_state == OEPS_IDLE &&
                loc_port->etp_osdep.etp_flags & OEPF_NEED_SEND)
@@ -362,11 +300,11 @@ void eth_rec(message *m)
                if (!(loc_port->etp_flags & EPF_READ_IP))
                        setup_read (loc_port);
        }
-       if (loc_port->etp_osdep.etp_flags & OEPF_NEED_CONF)
+       if (loc_port->etp_osdep.etp_state == OEPS_IDLE &&
+               (loc_port->etp_osdep.etp_flags & OEPF_NEED_CONF))
        {
-#if 0
-               printf("eth_rec: OEPF_NEED_CONF is set\n");
-#endif
+               eth_set_rec_conf(loc_port,
+                       loc_port->etp_osdep.etp_recvconf);
        }
        if (loc_port->etp_osdep.etp_state == OEPS_IDLE &&
                (loc_port->etp_osdep.etp_flags & OEPF_NEED_STAT))