[MINIOS] Implement a network frontend driver.

Signed-off-by: Jacob Gorm Hansen <jacobg@diku.dk>

1 files changed, 455 insertions, 0 deletions

diff --git a/extras/mini-os/netfront.c b/extras/mini-os/netfront.c
new file mode 100644
index 0000000000..a013cdbe80
--- /dev/null
+++ b/extras/mini-os/netfront.c
@@ -0,0 +1,455 @@
+/* Minimal network driver for Mini-OS. 
+ * Copyright (c) 2006-2007 Jacob Gorm Hansen, University of Copenhagen.
+ * Based on netfront.c from Xen Linux.
+ *
+ * Does not handle fragments or extras.
+ */
+
+#include <os.h>
+#include <xenbus.h>
+#include <events.h>
+#include <errno.h>
+#include <xen/io/netif.h>
+#include <gnttab.h>
+#include <xmalloc.h>
+#include <time.h>
+
+void init_rx_buffers(void);
+
+struct net_info {
+    struct netif_tx_front_ring tx;
+    struct netif_rx_front_ring rx;
+    int tx_ring_ref;
+    int rx_ring_ref;
+    unsigned int evtchn, local_port;
+
+} net_info;
+
+
+char* xenbus_printf(xenbus_transaction_t xbt,
+        char* node,char* path,
+        char* fmt,unsigned int arg)
+{
+    char fullpath[256];
+    char val[256];
+
+    sprintf(fullpath,"%s/%s",node,path);
+    sprintf(val,fmt,arg);
+    xenbus_write(xbt,fullpath,val);
+
+    return NULL;
+}
+
+
+#define NET_TX_RING_SIZE __RING_SIZE((struct netif_tx_sring *)0, PAGE_SIZE)
+#define NET_RX_RING_SIZE __RING_SIZE((struct netif_rx_sring *)0, PAGE_SIZE)
+#define GRANT_INVALID_REF 0
+
+
+unsigned short rx_freelist[NET_RX_RING_SIZE];
+unsigned short tx_freelist[NET_TX_RING_SIZE];
+
+struct net_buffer {
+    void* page;
+    int gref;
+};
+struct net_buffer rx_buffers[NET_RX_RING_SIZE];
+struct net_buffer tx_buffers[NET_TX_RING_SIZE];
+
+static inline void add_id_to_freelist(unsigned int id,unsigned short* freelist)
+{
+    freelist[id] = freelist[0];
+    freelist[0]  = id;
+}
+
+static inline unsigned short get_id_from_freelist(unsigned short* freelist)
+{
+    unsigned int id = freelist[0];
+    freelist[0] = freelist[id];
+    return id;
+}
+
+__attribute__((weak)) void netif_rx(unsigned char* data,int len)
+{
+    printk("%d bytes incoming at %p\n",len,data);
+}
+
+__attribute__((weak)) void net_app_main(void*si,unsigned char*mac) {}
+
+static inline int xennet_rxidx(RING_IDX idx)
+{
+    return idx & (NET_RX_RING_SIZE - 1);
+}
+
+void network_rx(void)
+{
+    struct net_info *np = &net_info;
+    RING_IDX rp,cons;
+    struct netif_rx_response *rx;
+
+
+moretodo:
+    rp = np->rx.sring->rsp_prod;
+    rmb(); /* Ensure we see queued responses up to 'rp'. */
+    cons = np->rx.rsp_cons;
+
+    int nr_consumed=0;
+    while ((cons != rp))
+    {
+        struct net_buffer* buf;
+        unsigned char* page;
+
+        rx = RING_GET_RESPONSE(&np->rx, cons);
+
+        if (rx->flags & NETRXF_extra_info)
+        {
+            printk("+++++++++++++++++++++ we have extras!\n");
+            continue;
+        }
+
+
+        if (rx->status == NETIF_RSP_NULL) continue;
+
+        int id = rx->id;
+
+        buf = &rx_buffers[id];
+        page = (unsigned char*)buf->page;
+        gnttab_end_access(buf->gref);
+
+        if(rx->status>0)
+        {
+            netif_rx(page+rx->offset,rx->status);
+        }
+
+        add_id_to_freelist(id,rx_freelist);
+
+        nr_consumed++;
+
+        ++cons;
+    }
+    np->rx.rsp_cons=rp;
+
+    int more;
+    RING_FINAL_CHECK_FOR_RESPONSES(&np->rx,more);
+    if(more) goto moretodo;
+
+    RING_IDX req_prod = np->rx.req_prod_pvt;
+
+    int i;
+    netif_rx_request_t *req;
+
+    for(i=0; i<nr_consumed; i++)
+    {
+        int id = xennet_rxidx(req_prod + i);
+        req = RING_GET_REQUEST(&np->rx, req_prod + i);
+        struct net_buffer* buf = &rx_buffers[id];
+        void* page = buf->page;
+
+        buf->gref = req->gref = 
+            gnttab_grant_access(0,virt_to_mfn(page),0);
+
+        req->id = id;
+    }
+
+    wmb();
+
+    np->rx.req_prod_pvt = req_prod + i;
+    
+    int notify;
+    RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
+    if (notify)
+        notify_remote_via_evtchn(np->evtchn);
+
+}
+
+void network_tx_buf_gc(void)
+{
+
+
+    RING_IDX cons, prod;
+    unsigned short id;
+    struct net_info *np = &net_info;
+
+    do {
+        prod = np->tx.sring->rsp_prod;
+        rmb(); /* Ensure we see responses up to 'rp'. */
+
+        for (cons = np->tx.rsp_cons; cons != prod; cons++) 
+        {
+            struct netif_tx_response *txrsp;
+
+            txrsp = RING_GET_RESPONSE(&np->tx, cons);
+            if (txrsp->status == NETIF_RSP_NULL)
+                continue;
+
+            id  = txrsp->id;
+            struct net_buffer* buf = &tx_buffers[id];
+            gnttab_end_access(buf->gref);
+            buf->gref=GRANT_INVALID_REF;
+
+            add_id_to_freelist(id,tx_freelist);
+        }
+
+        np->tx.rsp_cons = prod;
+
+        /*
+         * Set a new event, then check for race with update of tx_cons.
+         * Note that it is essential to schedule a callback, no matter
+         * how few tx_buffers are pending. Even if there is space in the
+         * transmit ring, higher layers may be blocked because too much
+         * data is outstanding: in such cases notification from Xen is
+         * likely to be the only kick that we'll get.
+         */
+        np->tx.sring->rsp_event =
+            prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
+        mb();
+    } while ((cons == prod) && (prod != np->tx.sring->rsp_prod));
+
+
+}
+
+void netfront_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
+{
+    int flags;
+
+    local_irq_save(flags);
+
+    network_tx_buf_gc();
+    network_rx();
+
+    local_irq_restore(flags);
+}
+
+char* backend;
+
+void init_netfront(void* si)
+{
+    xenbus_transaction_t xbt;
+    struct net_info* info = &net_info;
+    char* err;
+    char* message=NULL;
+    char nodename[] = "device/vif/0";
+    struct netif_tx_sring *txs;
+    struct netif_rx_sring *rxs;
+    int retry=0;
+    int i;
+    char* mac;
+    char* msg;
+
+    printk("************************ NETFRONT **********\n\n\n");
+
+    for(i=0;i<NET_TX_RING_SIZE;i++)
+    {
+        add_id_to_freelist(i,tx_freelist);
+        tx_buffers[i].page = (char*)alloc_page();
+    }
+
+    for(i=0;i<NET_RX_RING_SIZE;i++)
+    {
+        add_id_to_freelist(i,rx_freelist);
+        rx_buffers[i].page = (char*)alloc_page();
+    }
+
+    txs = (struct netif_tx_sring*) alloc_page();
+    rxs = (struct netif_rx_sring *) alloc_page();
+    memset(txs,0,PAGE_SIZE);
+    memset(rxs,0,PAGE_SIZE);
+
+
+    SHARED_RING_INIT(txs);
+    SHARED_RING_INIT(rxs);
+    FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
+    FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
+
+    info->tx_ring_ref = gnttab_grant_access(0,virt_to_mfn(txs),0);
+    info->rx_ring_ref = gnttab_grant_access(0,virt_to_mfn(rxs),0);
+
+    evtchn_alloc_unbound_t op;
+    op.dom = DOMID_SELF;
+    op.remote_dom = 0;
+    HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, &op);
+    clear_evtchn(op.port);        /* Without, handler gets invoked now! */
+    info->local_port = bind_evtchn(op.port, netfront_handler, NULL);
+    info->evtchn=op.port;
+
+again:
+    err = xenbus_transaction_start(&xbt);
+    if (err) {
+        printk("starting transaction\n");
+    }
+
+    err = xenbus_printf(xbt, nodename, "tx-ring-ref","%u",
+                info->tx_ring_ref);
+    if (err) {
+        message = "writing tx ring-ref";
+        goto abort_transaction;
+    }
+    err = xenbus_printf(xbt, nodename, "rx-ring-ref","%u",
+                info->rx_ring_ref);
+    if (err) {
+        message = "writing rx ring-ref";
+        goto abort_transaction;
+    }
+    err = xenbus_printf(xbt, nodename,
+                "event-channel", "%u", info->evtchn);
+    if (err) {
+        message = "writing event-channel";
+        goto abort_transaction;
+    }
+
+    err = xenbus_printf(xbt, nodename, "request-rx-copy", "%u", 1);
+
+    if (err) {
+        message = "writing request-rx-copy";
+        goto abort_transaction;
+    }
+
+    err = xenbus_printf(xbt, nodename, "state", "%u",
+            4); /* connected */
+
+
+    err = xenbus_transaction_end(xbt, 0, &retry);
+    if (retry) {
+            goto again;
+        printk("completing transaction\n");
+    }
+
+    goto done;
+
+abort_transaction:
+    xenbus_transaction_end(xbt, 1, &retry);
+
+done:
+
+    msg = xenbus_read(XBT_NIL, "device/vif/0/backend", &backend);
+    msg = xenbus_read(XBT_NIL, "device/vif/0/mac", &mac);
+
+    printk("backend at %s\n",backend);
+    printk("mac is %s\n",mac);
+
+    char *res;
+    char path[256];
+    sprintf(path,"%s/state",backend);
+
+    xenbus_watch_path(XBT_NIL, path);
+
+    xenbus_wait_for_value(path,"4");
+
+    //free(backend);
+    free(res);
+
+    printk("**************************\n");
+
+    init_rx_buffers();
+
+    unsigned char rawmac[6];
+    sscanf(mac,"%x:%x:%x:%x:%x:%x",
+            &rawmac[0],
+            &rawmac[1],
+            &rawmac[2],
+            &rawmac[3],
+            &rawmac[4],
+            &rawmac[5]);
+
+    net_app_main(si,rawmac);
+}
+
+void shutdown_netfront(void)
+{
+    //xenbus_transaction_t xbt;
+    char* err;
+    char nodename[] = "device/vif/0";
+
+    char path[256];
+
+    printk("close network: backend at %s\n",backend);
+
+    err = xenbus_printf(XBT_NIL, nodename, "state", "%u", 6); /* closing */
+    sprintf(path,"%s/state",backend);
+
+    xenbus_wait_for_value(path,"6");
+
+    err = xenbus_printf(XBT_NIL, nodename, "state", "%u", 1);
+
+    xenbus_wait_for_value(path,"2");
+
+    unbind_all_ports();
+
+}
+
+
+void init_rx_buffers(void)
+{
+    struct net_info* np = &net_info;
+    int i, requeue_idx;
+    netif_rx_request_t *req;
+    int notify;
+
+    np->rx.req_prod_pvt = requeue_idx;
+
+
+    /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
+    for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) 
+    {
+        struct net_buffer* buf = &rx_buffers[requeue_idx];
+        req = RING_GET_REQUEST(&np->rx, requeue_idx);
+
+        buf->gref = req->gref = 
+            gnttab_grant_access(0,virt_to_mfn(buf->page),0);
+
+        req->id = requeue_idx;
+
+        requeue_idx++;
+    }
+
+    np->rx.req_prod_pvt = requeue_idx;
+
+
+
+    RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify);
+
+    if(notify) 
+        notify_remote_via_evtchn(np->evtchn);
+
+    np->rx.sring->rsp_event = np->rx.rsp_cons + 1;
+
+
+}
+
+
+void netfront_xmit(unsigned char* data,int len)
+{
+    int flags;
+    local_irq_save(flags);
+
+    struct net_info* info = &net_info;
+    struct netif_tx_request *tx;
+    RING_IDX i = info->tx.req_prod_pvt;
+    int notify;
+    int id = get_id_from_freelist(tx_freelist);
+    struct net_buffer* buf = &tx_buffers[id];
+    void* page = buf->page;
+
+    tx = RING_GET_REQUEST(&info->tx, i);
+
+    memcpy(page,data,len);
+
+    buf->gref = 
+        tx->gref = gnttab_grant_access(0,virt_to_mfn(page),0);
+
+    tx->offset=0;
+    tx->size = len;
+    tx->flags=0;
+    tx->id = id;
+    info->tx.req_prod_pvt = i + 1;
+
+    wmb();
+
+    RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->tx, notify);
+
+    if(notify) notify_remote_via_evtchn(info->evtchn);
+
+    network_tx_buf_gc();
+
+    local_irq_restore(flags);
+}