The start of a lwIP netif for xv6

dba994ab · Silas Boyd-Wickizer · 3d835a09 · dba994ab · dba994ab
--- a/net.mk
+++ b/net.mk
@@ -53,6 +53,7 @@ LWIP_SRCFILES += \
 	lwip/src/core/udp.c \
 	lwip/src/netif/etharp.c \
 	net/sys_arch.c \
+	net/if.c \

 LWIP_OBJFILES := $(patsubst %.c, $(O)/%.o, $(LWIP_SRCFILES))
 LWIP_OBJFILES := $(patsubst %.S, $(O)/%.o, $(LWIP_OBJFILES))

--- a/net/if.c
+++ b/net/if.c
+#include "lwip/stats.h"
+#include "netif/etharp.h"
+#include "kernel.h"
+
+/**
+ * In this function, the hardware should be initialized.
+ * Called from if_init().
+ *
+ * @param netif the already initialized lwip network interface structure
+ *        for this ethernetif
+ */
+static void
+low_level_init(struct netif *netif)
+{
+  /* set MAC hardware address length */
+  netif->hwaddr_len = ETHARP_HWADDR_LEN;
+
+  /* set MAC hardware address */
+  e1000hwaddr(netif->hwaddr);
+
+  /* maximum transfer unit */
+  netif->mtu = 1500;
+  
+  /* device capabilities */
+  /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
+  netif->flags = NETIF_FLAG_BROADCAST; //| NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
+ 
+  /* Do whatever else is needed to initialize interface. */  
+}
+
+/**
+ * This function should do the actual transmission of the packet. The packet is
+ * contained in the pbuf that is passed to the function. This pbuf
+ * might be chained.
+ *
+ * @param netif the lwip network interface structure for this ethernetif
+ * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
+ * @return ERR_OK if the packet could be sent
+ *         an err_t value if the packet couldn't be sent
+ *
+ * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
+ *       strange results. You might consider waiting for space in the DMA queue
+ *       to become availale since the stack doesn't retry to send a packet
+ *       dropped because of memory failure (except for the TCP timers).
+ */
+
+static err_t
+low_level_output(struct netif *netif, struct pbuf *p)
+{
+  struct pbuf *q;
+
+  panic("low_level_output");
+
+//  initiate transfer();
+  
+#if ETH_PAD_SIZE
+  pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
+#endif
+
+  for(q = p; q != NULL; q = q->next) {
+    /* Send the data from the pbuf to the interface, one pbuf at a
+       time. The size of the data in each pbuf is kept in the ->len
+       variable. */
+//    send data from(q->payload, q->len);
+  }
+
+//  signal that packet should be sent();
+
+#if ETH_PAD_SIZE
+  pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
+#endif
+  
+  LINK_STATS_INC(link.xmit);
+
+  return ERR_OK;
+}
+
+
+/**
+ * Should be called at the beginning of the program to set up the
+ * network interface. It calls the function low_level_init() to do the
+ * actual setup of the hardware.
+ *
+ * This function should be passed as a parameter to netif_add().
+ *
+ * @param netif the lwip network interface structure for this ethernetif
+ * @return ERR_OK if the loopif is initialized
+ *         ERR_MEM if private data couldn't be allocated
+ *         any other err_t on error
+ */
+err_t
+if_init(struct netif *netif)
+{
+  netif->state = NULL;
+  netif->output = etharp_output;
+  netif->linkoutput = low_level_output;
+  memmove(&netif->name[0], "en", 2);
+
+  /* initialize the hardware */
+  low_level_init(netif);
+  
+  return ERR_OK;
+}