Added LWIP_SINGLE_NETIF for small targets with only one netif (see task #13515, there might be more optimizations to come with this option)

CHANGELOG

@@ -6,6 +6,9 @@ HISTORY
 
   ++ New features:
 
+  2017-02-28: Simon Goldschmidt
+  * Added LWIP_SINGLE_NETIF for small targets with only one netif
+
   2017-02-17: Simon Goldschmidt
   * Improved DNS_LOCAL_HOSTLIST interface
 

src/apps/snmp/snmp_mib2_interfaces.c

@@ -65,10 +65,9 @@ interfaces_get_value(struct snmp_node_instance* instance, void* value)
     s32_t *sint_ptr = (s32_t*)value;
     s32_t num_netifs = 0;
 
-    struct netif *netif = netif_list;
+    struct netif *netif;
-    while (netif != NULL) {
+    NETIF_FOREACH(netif) {
       num_netifs++;
-      netif = netif->next;
     }
 
     *sint_ptr = num_netifs;
@@ -109,14 +108,12 @@ interfaces_Table_get_cell_instance(const u32_t* column, const u32_t* row_oid, u8
   ifIndex = row_oid[0];
 
   /* find netif with index */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     if (netif_to_num(netif) == ifIndex) {
       /* store netif pointer for subsequent operations (get/test/set) */
       cell_instance->reference.ptr = netif;
       return SNMP_ERR_NOERROR;
     }
-    netif = netif->next;
   }
 
   /* not found */
@@ -136,15 +133,12 @@ interfaces_Table_get_next_cell_instance(const u32_t* column, struct snmp_obj_id*
   snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(interfaces_Table_oid_ranges));
 
   /* iterate over all possible OIDs to find the next one */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     u32_t test_oid[LWIP_ARRAYSIZE(interfaces_Table_oid_ranges)];
     test_oid[0] = netif_to_num(netif);
 
     /* check generated OID: is it a candidate for the next one? */
     snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(interfaces_Table_oid_ranges), netif);
-
-    netif = netif->next;
   }
 
   /* did we find a next one? */

src/apps/snmp/snmp_mib2_ip.c

@@ -262,14 +262,11 @@ ip_AddrTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_
   snmp_oid_to_ip4(&row_oid[0], &ip); /* we know it succeeds because of oid_in_range check above */
 
   /* find netif with requested ip */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     if (ip4_addr_cmp(&ip, netif_ip4_addr(netif))) {
       /* fill in object properties */
       return ip_AddrTable_get_cell_value_core(netif, column, value, value_len);
     }
-
-    netif = netif->next;
   }
 
   /* not found */
@@ -287,15 +284,12 @@ ip_AddrTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_o
   snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges));
 
   /* iterate over all possible OIDs to find the next one */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     u32_t test_oid[LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges)];
     snmp_ip4_to_oid(netif_ip4_addr(netif), &test_oid[0]);
 
     /* check generated OID: is it a candidate for the next one? */
     snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges), netif);
-
-    netif = netif->next;
   }
 
   /* did we find a next one? */
@@ -419,8 +413,7 @@ ip_RouteTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row
   }
 
   /* find netif with requested route */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     ip4_addr_t dst;
     ip4_addr_get_network(&dst, netif_ip4_addr(netif), netif_ip4_netmask(netif));
 
@@ -428,8 +421,6 @@ ip_RouteTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row
       /* fill in object properties */
       return ip_RouteTable_get_cell_value_core(netif, 0, column, value, value_len);
     }
-
-    netif = netif->next;
   }
 
   /* not found */
@@ -454,8 +445,7 @@ ip_RouteTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_
   }
 
   /* iterate over all possible OIDs to find the next one */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     ip4_addr_t dst;
     ip4_addr_get_network(&dst, netif_ip4_addr(netif), netif_ip4_netmask(netif));
 
@@ -464,8 +454,6 @@ ip_RouteTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_
       snmp_ip4_to_oid(&dst, &test_oid[0]);
       snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges), netif);
     }
-
-    netif = netif->next;
   }
 
   /* did we find a next one? */

src/core/ipv4/autoip.c

@@ -364,9 +364,9 @@ autoip_stop(struct netif *netif)
 void
 autoip_tmr(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
   /* loop through netif's */
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     struct autoip* autoip = netif_autoip_data(netif);
     /* only act on AutoIP configured interfaces */
     if (autoip != NULL) {
@@ -438,8 +438,6 @@ autoip_tmr(void)
           break;
       }
     }
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 }
 

src/core/ipv4/dhcp.c

@@ -408,10 +408,10 @@ dhcp_select(struct netif *netif)
 void
 dhcp_coarse_tmr(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
   LWIP_DEBUGF(DHCP_DEBUG | LWIP_DBG_TRACE, ("dhcp_coarse_tmr()\n"));
   /* iterate through all network interfaces */
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     /* only act on DHCP configured interfaces */
     struct dhcp *dhcp = netif_dhcp_data(netif);
     if ((dhcp != NULL) && (dhcp->state != DHCP_STATE_OFF)) {
@@ -433,8 +433,6 @@ dhcp_coarse_tmr(void)
         dhcp_t1_timeout(netif);
       }
     }
-    /* proceed to next netif */
-    netif = netif->next;
   }
 }
 
@@ -448,9 +446,9 @@ dhcp_coarse_tmr(void)
 void
 dhcp_fine_tmr(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
   /* loop through netif's */
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     struct dhcp *dhcp = netif_dhcp_data(netif);
     /* only act on DHCP configured interfaces */
     if (dhcp != NULL) {
@@ -466,8 +464,6 @@ dhcp_fine_tmr(void)
         dhcp_timeout(netif);
       }
     }
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 }
 

src/core/ipv4/igmp.c

@@ -456,8 +456,7 @@ igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
   LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
 
   /* loop through netif's */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     /* Should we join this interface ? */
     if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) {
       err = igmp_joingroup_netif(netif, groupaddr);
@@ -467,8 +466,6 @@ igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
         return err;
       }
     }
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 
   return err;
@@ -552,8 +549,7 @@ igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
   LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
 
   /* loop through netif's */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     /* Should we leave this interface ? */
     if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) {
       err_t res = igmp_leavegroup_netif(netif, groupaddr);
@@ -562,8 +558,6 @@ igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
         err = res;
       }
     }
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 
   return err;
@@ -638,9 +632,9 @@ igmp_leavegroup_netif(struct netif *netif, const ip4_addr_t *groupaddr)
 void
 igmp_tmr(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
 
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     struct igmp_group *group = netif_igmp_data(netif);
 
     while (group != NULL) {
@@ -652,7 +646,6 @@ igmp_tmr(void)
       }
       group = group->next;
     }
-    netif = netif->next;
   }
 }
 

src/core/ipv4/ip4.c

@@ -151,6 +151,7 @@ ip4_route_src(const ip4_addr_t *dest, const ip4_addr_t *src)
 struct netif *
 ip4_route(const ip4_addr_t *dest)
 {
+#if !LWIP_SINGLE_NETIF
   struct netif *netif;
 
 #if LWIP_MULTICAST_TX_OPTIONS
@@ -205,6 +206,7 @@ ip4_route(const ip4_addr_t *dest)
     return netif;
   }
 #endif
+#endif /* !LWIP_SINGLE_NETIF */
 
   if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default) ||
       ip4_addr_isany_val(*netif_ip4_addr(netif_default))) {
@@ -534,7 +536,8 @@ ip4_input(struct pbuf *p, struct netif *inp)
       if (!ip4_addr_isloopback(ip4_current_dest_addr()))
 #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
       {
-        for (netif = netif_list; netif != NULL; netif = netif->next) {
+#if ! LWIP_SINGLE_NETIF
+        NETIF_FOREACH(netif) {
           if (netif == inp) {
             /* we checked that before already */
             continue;
@@ -543,6 +546,7 @@ ip4_input(struct pbuf *p, struct netif *inp)
             break;
           }
         }
+#endif /* !LWIP_SINGLE_NETIF */
       }
     }
   }

src/core/ipv6/ip6.c

@@ -85,6 +85,10 @@
 struct netif *
 ip6_route(const ip6_addr_t *src, const ip6_addr_t *dest)
 {
+#if LWIP_SINGLE_NETIF
+  LWIP_UNUSED_ARG(src);
+  LWIP_UNUSED_ARG(dest);
+#else /* LWIP_SINGLE_NETIF */
   struct netif *netif;
   s8_t i;
 
@@ -239,6 +243,7 @@ ip6_route(const ip6_addr_t *src, const ip6_addr_t *dest)
     return NULL;
   }
 #endif /* LWIP_NETIF_LOOPBACK && !LWIP_HAVE_LOOPIF */
+#endif /* !LWIP_SINGLE_NETIF */
 
   /* no matching netif found, use default netif, if up */
   if ((netif_default == NULL) || !netif_is_up(netif_default) || !netif_is_link_up(netif_default)) {
@@ -636,7 +641,8 @@ ip6_input(struct pbuf *p, struct netif *inp)
         goto netif_found;
       }
 #endif /* !LWIP_NETIF_LOOPBACK || LWIP_HAVE_LOOPIF */
-      for (netif = netif_list; netif != NULL; netif = netif->next) {
+#if ! LWIP_SINGLE_NETIF
+      NETIF_FOREACH(netif) {
         if (netif == inp) {
           /* we checked that before already */
           continue;
@@ -645,6 +651,7 @@ ip6_input(struct pbuf *p, struct netif *inp)
           break;
         }
       }
+#endif /* !LWIP_SINGLE_NETIF */
     }
 netif_found:
     LWIP_DEBUGF(IP6_DEBUG, ("ip6_input: packet accepted on interface %c%c\n",

src/core/ipv6/mld6.c

@@ -313,8 +313,7 @@ mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
   struct netif *netif;
 
   /* loop through netif's */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     /* Should we join this interface ? */
     if (ip6_addr_isany(srcaddr) ||
         netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
@@ -323,9 +322,6 @@ mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
         return err;
       }
     }
-
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 
   return err;
@@ -402,8 +398,7 @@ mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
   struct netif *netif;
 
   /* loop through netif's */
-  netif = netif_list;
+  NETIF_FOREACH(netif) {
-  while (netif != NULL) {
     /* Should we leave this interface ? */
     if (ip6_addr_isany(srcaddr) ||
         netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
@@ -413,8 +408,6 @@ mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
         err = res;
       }
     }
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 
   return err;
@@ -489,9 +482,9 @@ mld6_leavegroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
 void
 mld6_tmr(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
 
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     struct mld_group *group = netif_mld6_data(netif);
 
     while (group != NULL) {
@@ -508,7 +501,6 @@ mld6_tmr(void)
       }
       group = group->next;
     }
-    netif = netif->next;
   }
 }
 

src/core/ipv6/nd6.c

@@ -1042,7 +1042,7 @@ nd6_tmr(void)
   }
 
   /* Process our own addresses, updating address lifetimes and/or DAD state. */
-  for (netif = netif_list; netif != NULL; netif = netif->next) {
+  NETIF_FOREACH(netif) {
     for (i = 0; i < LWIP_IPV6_NUM_ADDRESSES; ++i) {
       u8_t addr_state;
 #if LWIP_IPV6_ADDRESS_LIFETIMES
@@ -1121,7 +1121,7 @@ nd6_tmr(void)
 
 #if LWIP_IPV6_SEND_ROUTER_SOLICIT
   /* Send router solicitation messages, if necessary. */
-  for (netif = netif_list; netif != NULL; netif = netif->next) {
+  NETIF_FOREACH(netif) {
     if ((netif->rs_count > 0) && netif_is_up(netif) &&
         netif_is_link_up(netif) &&
         !ip6_addr_isinvalid(netif_ip6_addr_state(netif, 0)) &&

src/core/netif.c

@@ -106,7 +106,9 @@
 static netif_ext_callback_t* ext_callback;
 #endif
 
+#if !LWIP_SINGLE_NETIF
 struct netif *netif_list;
+#endif /* !LWIP_SINGLE_NETIF */
 struct netif *netif_default;
 
 #define netif_index_to_num(index)   ((index) - 1)
@@ -250,12 +252,17 @@ netif_add(struct netif *netif,
 #endif /* LWIP_IPV4 */
           void *state, netif_init_fn init, netif_input_fn input)
 {
-  struct netif *netif2;
-  int num_netifs;
 #if LWIP_IPV6
   s8_t i;
 #endif
 
+#if LWIP_SINGLE_NETIF
+  if (netif_default != NULL) {
+    LWIP_ASSERT("single netif already set", 0);
+    return NULL;
+  }
+#endif
+
   LWIP_ASSERT("No init function given", init != NULL);
 
   /* reset new interface configuration state */
@@ -323,30 +330,36 @@ netif_add(struct netif *netif,
     return NULL;
   }
 
+#if !LWIP_SINGLE_NETIF
   /* Assign a unique netif number in the range [0..254], so that (num+1) can
      serve as an interface index that fits in a u8_t.
      We assume that the new netif has not yet been added to the list here.
      This algorithm is O(n^2), but that should be OK for lwIP.
      */
-  do {
+  {
-    if (netif->num == 255) {
+    struct netif *netif2;
-      netif->num = 0;
+    int num_netifs;
-    }
+    do {
-    num_netifs = 0;
+      if (netif->num == 255) {
-    for (netif2 = netif_list; netif2 != NULL; netif2 = netif2->next) {
+        netif->num = 0;
-      num_netifs++;
-      LWIP_ASSERT("too many netifs, max. supported number is 255", num_netifs <= 255);
-      if (netif2->num == netif->num) {
-        netif->num++;
-        break;
       }
-    }
+      num_netifs = 0;
-  } while (netif2 != NULL);
+      for (netif2 = netif_list; netif2 != NULL; netif2 = netif2->next) {
+        num_netifs++;
+        LWIP_ASSERT("too many netifs, max. supported number is 255", num_netifs <= 255);
+        if (netif2->num == netif->num) {
+          netif->num++;
+          break;
+        }
+      }
+    } while (netif2 != NULL);
+  }
   netif_num = netif->num + 1;
 
   /* add this netif to the list */
   netif->next = netif_list;
   netif_list = netif;
+#endif /* "LWIP_SINGLE_NETIF */
   mib2_netif_added(netif);
 
 #if LWIP_IGMP
@@ -476,6 +489,7 @@ netif_remove(struct netif *netif)
     /* reset default netif */
     netif_set_default(NULL);
   }
+#if !LWIP_SINGLE_NETIF
   /*  is it the first netif? */
   if (netif_list == netif) {
     netif_list = netif->next;
@@ -492,6 +506,7 @@ netif_remove(struct netif *netif)
       return; /* netif is not on the list */
     }
   }
+#endif /* !LWIP_SINGLE_NETIF */
   mib2_netif_removed(netif);
 #if LWIP_NETIF_REMOVE_CALLBACK
   if (netif->remove_callback) {
@@ -1037,12 +1052,10 @@ netif_poll(struct netif *netif)
 void
 netif_poll_all(void)
 {
-  struct netif *netif = netif_list;
+  struct netif *netif;
   /* loop through netifs */
-  while (netif != NULL) {
+  NETIF_FOREACH(netif) {
     netif_poll(netif);
-    /* proceed to next network interface */
-    netif = netif->next;
   }
 }
 #endif /* !LWIP_NETIF_LOOPBACK_MULTITHREADING */
@@ -1427,7 +1440,7 @@ netif_get_by_index(u8_t idx)
   struct netif* netif;
 
   if (idx != NETIF_NO_INDEX) {
-    for (netif = netif_list; netif != NULL; netif = netif->next) {
+    NETIF_FOREACH(netif) {
       if (idx == netif_get_index(netif)) {
         return netif; /* found! */
       }
@@ -1456,7 +1469,7 @@ netif_find(const char *name)
 
   num = (u8_t)atoi(&name[2]);
 
-  for (netif = netif_list; netif != NULL; netif = netif->next) {
+  NETIF_FOREACH(netif) {
     if (num == netif->num &&
        name[0] == netif->name[0] &&
        name[1] == netif->name[1]) {

src/include/lwip/netif.h

@@ -229,8 +229,10 @@ u8_t netif_alloc_client_data_id(void);
  *  The following fields should be filled in by the initialization
  *  function for the device driver: hwaddr_len, hwaddr[], mtu, flags */
 struct netif {
+#if !LWIP_SINGLE_NETIF
   /** pointer to next in linked list */
   struct netif *next;
+#endif
 
 #if LWIP_IPV4
   /** IP address configuration in network byte order */
@@ -365,8 +367,13 @@ struct netif {
 #define IF__NETIF_CHECKSUM_ENABLED(netif, chksumflag)
 #endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
 
+#if LWIP_SINGLE_NETIF
+#define NETIF_FOREACH(netif) if (((netif) = netif_default) != NULL)
+#else /* LWIP_SINGLE_NETIF */
 /** The list of network interfaces. */
 extern struct netif *netif_list;
+#define NETIF_FOREACH(netif) for (netif = netif_list; netif != NULL; netif = netif->next)
+#endif /* LWIP_SINGLE_NETIF */
 /** The default network interface. */
 extern struct netif *netif_default;
 

src/include/lwip/opt.h

@@ -626,7 +626,7 @@
  * (but this should only occur for AutoIP).
  */
 #if !defined ETHARP_TABLE_MATCH_NETIF || defined __DOXYGEN__
-#define ETHARP_TABLE_MATCH_NETIF        0
+#define ETHARP_TABLE_MATCH_NETIF        !LWIP_SINGLE_NETIF
 #endif
 /**
  * @}
@@ -1417,6 +1417,14 @@
  * @ingroup lwip_opts
  * @{
  */
+/**
+ * LWIP_SINGLE_NETIF==1: use a single netif only. This is the common case for
+ * small real-life targets. Some code like routing etc. can be left out.
+ */
+#if !defined LWIP_SINGLE_NETIF || defined __DOXYGEN__
+#define LWIP_SINGLE_NETIF               0
+#endif
+
 /**
  * LWIP_NETIF_HOSTNAME==1: use DHCP_OPTION_HOSTNAME with netif's hostname
  * field.
@@ -1516,7 +1524,7 @@
  * netif is available, loopback traffic uses this netif.
  */
 #if !defined LWIP_HAVE_LOOPIF || defined __DOXYGEN__
-#define LWIP_HAVE_LOOPIF                LWIP_NETIF_LOOPBACK
+#define LWIP_HAVE_LOOPIF                (LWIP_NETIF_LOOPBACK && !LWIP_SINGLE_NETIF)
 #endif
 
 /**
@@ -2199,7 +2207,7 @@
  * setting only for single-interface configurations.
  */
 #if !defined LWIP_IPV6_SCOPES || defined __DOXYGEN__
-#define LWIP_IPV6_SCOPES                (LWIP_IPV6)
+#define LWIP_IPV6_SCOPES                (LWIP_IPV6 && !LWIP_SINGLE_NETIF)
 #endif
 
 /**