xen-project/xen
1
0 Fork 0
mirror of https://github.com/xen-project/xen.git synced 2026-10-28 02:01:24 +01:00
Code Issues Activity
Files
88c10b0d6eeea50302fa276ec78ac0ded393a979
xen/extras/mini-os/netfront.c
T
Matthew Daley c07134ccca tools: remove unnecessary null pointer checks before frees 
Patch generated by the following semantic patch
(http://coccinelle.lip6.fr/):

@@
expression *P;
@@

- if(P) free(P);
+ free(P);

...and then by filtering through the following command:

filterdiff -p1 -x 'stubdom/*' -x 'tools/firmware/*' -x 'tools/qemu-*' -x 'tools/blktap*'

Signed-off-by: Matthew Daley <mattjd@gmail.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2013-10-31 20:04:25 +00:00

678 lines
17 KiB
C
Raw Blame History

/* 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 <mini-os/os.h>
#include <mini-os/xenbus.h>
#include <mini-os/events.h>
#include <errno.h>
#include <xen/io/netif.h>
#include <mini-os/gnttab.h>
#include <mini-os/xmalloc.h>
#include <mini-os/time.h>
#include <mini-os/netfront.h>
#include <mini-os/lib.h>
#include <mini-os/semaphore.h>
DECLARE_WAIT_QUEUE_HEAD(netfront_queue);
#ifdef HAVE_LIBC
#define NETIF_SELECT_RX ((void*)-1)
#endif
#define NET_TX_RING_SIZE __CONST_RING_SIZE(netif_tx, PAGE_SIZE)
#define NET_RX_RING_SIZE __CONST_RING_SIZE(netif_rx, PAGE_SIZE)
#define GRANT_INVALID_REF 0
struct net_buffer {
void* page;
grant_ref_t gref;
};
struct netfront_dev {
domid_t dom;
unsigned short tx_freelist[NET_TX_RING_SIZE + 1];
struct semaphore tx_sem;
struct net_buffer rx_buffers[NET_RX_RING_SIZE];
struct net_buffer tx_buffers[NET_TX_RING_SIZE];
struct netif_tx_front_ring tx;
struct netif_rx_front_ring rx;
grant_ref_t tx_ring_ref;
grant_ref_t rx_ring_ref;
evtchn_port_t evtchn;
char *nodename;
char *backend;
char *mac;
xenbus_event_queue events;
#ifdef HAVE_LIBC
int fd;
unsigned char *data;
size_t len;
size_t rlen;
#endif
void (*netif_rx)(unsigned char* data, int len);
};
void init_rx_buffers(struct netfront_dev *dev);
static inline void add_id_to_freelist(unsigned int id,unsigned short* freelist)
{
freelist[id + 1] = 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 + 1];
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(struct netfront_dev *dev)
{
RING_IDX rp,cons,req_prod;
struct netif_rx_response *rx;
int nr_consumed, some, more, i, notify;
moretodo:
rp = dev->rx.sring->rsp_prod;
rmb(); /* Ensure we see queued responses up to 'rp'. */
cons = dev->rx.rsp_cons;
for (nr_consumed = 0, some = 0;
(cons != rp) && !some;
nr_consumed++, cons++)
{
struct net_buffer* buf;
unsigned char* page;
int id;
rx = RING_GET_RESPONSE(&dev->rx, cons);
if (rx->flags & NETRXF_extra_info)
{
printk("+++++++++++++++++++++ we have extras!\n");
continue;
}
if (rx->status == NETIF_RSP_NULL) continue;
id = rx->id;
BUG_ON(id >= NET_TX_RING_SIZE);
buf = &dev->rx_buffers[id];
page = (unsigned char*)buf->page;
gnttab_end_access(buf->gref);
if(rx->status>0)
{
#ifdef HAVE_LIBC
if (dev->netif_rx == NETIF_SELECT_RX) {
int len = rx->status;
ASSERT(current == main_thread);
if (len > dev->len)
len = dev->len;
memcpy(dev->data, page+rx->offset, len);
dev->rlen = len;
some = 1;
} else
#endif
dev->netif_rx(page+rx->offset,rx->status);
}
}
dev->rx.rsp_cons=cons;
RING_FINAL_CHECK_FOR_RESPONSES(&dev->rx,more);
if(more && !some) goto moretodo;
req_prod = dev->rx.req_prod_pvt;
for(i=0; i<nr_consumed; i++)
{
int id = xennet_rxidx(req_prod + i);
netif_rx_request_t *req = RING_GET_REQUEST(&dev->rx, req_prod + i);
struct net_buffer* buf = &dev->rx_buffers[id];
void* page = buf->page;
/* We are sure to have free gnttab entries since they got released above */
buf->gref = req->gref =
gnttab_grant_access(dev->dom,virt_to_mfn(page),0);
req->id = id;
}
wmb();
dev->rx.req_prod_pvt = req_prod + i;
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&dev->rx, notify);
if (notify)
notify_remote_via_evtchn(dev->evtchn);
}
void network_tx_buf_gc(struct netfront_dev *dev)
{
RING_IDX cons, prod;
unsigned short id;
do {
prod = dev->tx.sring->rsp_prod;
rmb(); /* Ensure we see responses up to 'rp'. */
for (cons = dev->tx.rsp_cons; cons != prod; cons++)
{
struct netif_tx_response *txrsp;
struct net_buffer *buf;
txrsp = RING_GET_RESPONSE(&dev->tx, cons);
if (txrsp->status == NETIF_RSP_NULL)
continue;
if (txrsp->status == NETIF_RSP_ERROR)
printk("packet error\n");
id = txrsp->id;
BUG_ON(id >= NET_TX_RING_SIZE);
buf = &dev->tx_buffers[id];
gnttab_end_access(buf->gref);
buf->gref=GRANT_INVALID_REF;
add_id_to_freelist(id,dev->tx_freelist);
up(&dev->tx_sem);
}
dev->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.
*/
dev->tx.sring->rsp_event =
prod + ((dev->tx.sring->req_prod - prod) >> 1) + 1;
mb();
} while ((cons == prod) && (prod != dev->tx.sring->rsp_prod));
}
void netfront_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
{
int flags;
struct netfront_dev *dev = data;
local_irq_save(flags);
network_tx_buf_gc(dev);
network_rx(dev);
local_irq_restore(flags);
}
#ifdef HAVE_LIBC
void netfront_select_handler(evtchn_port_t port, struct pt_regs *regs, void *data)
{
int flags;
struct netfront_dev *dev = data;
int fd = dev->fd;
local_irq_save(flags);
network_tx_buf_gc(dev);
local_irq_restore(flags);
if (fd != -1)
files[fd].read = 1;
wake_up(&netfront_queue);
}
#endif
static void free_netfront(struct netfront_dev *dev)
{
int i;
for(i=0;i<NET_TX_RING_SIZE;i++)
down(&dev->tx_sem);
mask_evtchn(dev->evtchn);
free(dev->mac);
free(dev->backend);
gnttab_end_access(dev->rx_ring_ref);
gnttab_end_access(dev->tx_ring_ref);
free_page(dev->rx.sring);
free_page(dev->tx.sring);
unbind_evtchn(dev->evtchn);
for(i=0;i<NET_RX_RING_SIZE;i++) {
gnttab_end_access(dev->rx_buffers[i].gref);
free_page(dev->rx_buffers[i].page);
}
for(i=0;i<NET_TX_RING_SIZE;i++)
if (dev->tx_buffers[i].page)
free_page(dev->tx_buffers[i].page);
free(dev->nodename);
free(dev);
}
struct netfront_dev *init_netfront(char *_nodename, void (*thenetif_rx)(unsigned char* data, int len), unsigned char rawmac[6], char **ip)
{
xenbus_transaction_t xbt;
char* err;
char* message=NULL;
struct netif_tx_sring *txs;
struct netif_rx_sring *rxs;
int retry=0;
int i;
char* msg = NULL;
char nodename[256];
char path[256];
struct netfront_dev *dev;
static int netfrontends = 0;
if (!_nodename)
snprintf(nodename, sizeof(nodename), "device/vif/%d", netfrontends);
else {
strncpy(nodename, _nodename, sizeof(nodename) - 1);
nodename[sizeof(nodename) - 1] = 0;
}
netfrontends++;
if (!thenetif_rx)
thenetif_rx = netif_rx;
printk("************************ NETFRONT for %s **********\n\n\n", nodename);
dev = malloc(sizeof(*dev));
memset(dev, 0, sizeof(*dev));
dev->nodename = strdup(nodename);
#ifdef HAVE_LIBC
dev->fd = -1;
#endif
printk("net TX ring size %d\n", NET_TX_RING_SIZE);
printk("net RX ring size %d\n", NET_RX_RING_SIZE);
init_SEMAPHORE(&dev->tx_sem, NET_TX_RING_SIZE);
for(i=0;i<NET_TX_RING_SIZE;i++)
{
add_id_to_freelist(i,dev->tx_freelist);
dev->tx_buffers[i].page = NULL;
}
for(i=0;i<NET_RX_RING_SIZE;i++)
{
/* TODO: that's a lot of memory */
dev->rx_buffers[i].page = (char*)alloc_page();
}
snprintf(path, sizeof(path), "%s/backend-id", nodename);
dev->dom = xenbus_read_integer(path);
#ifdef HAVE_LIBC
if (thenetif_rx == NETIF_SELECT_RX)
evtchn_alloc_unbound(dev->dom, netfront_select_handler, dev, &dev->evtchn);
else
#endif
evtchn_alloc_unbound(dev->dom, netfront_handler, dev, &dev->evtchn);
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(&dev->tx, txs, PAGE_SIZE);
FRONT_RING_INIT(&dev->rx, rxs, PAGE_SIZE);
dev->tx_ring_ref = gnttab_grant_access(dev->dom,virt_to_mfn(txs),0);
dev->rx_ring_ref = gnttab_grant_access(dev->dom,virt_to_mfn(rxs),0);
init_rx_buffers(dev);
dev->netif_rx = thenetif_rx;
dev->events = NULL;
again:
err = xenbus_transaction_start(&xbt);
if (err) {
printk("starting transaction\n");
free(err);
}
err = xenbus_printf(xbt, nodename, "tx-ring-ref","%u",
dev->tx_ring_ref);
if (err) {
message = "writing tx ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename, "rx-ring-ref","%u",
dev->rx_ring_ref);
if (err) {
message = "writing rx ring-ref";
goto abort_transaction;
}
err = xenbus_printf(xbt, nodename,
"event-channel", "%u", dev->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;
}
snprintf(path, sizeof(path), "%s/state", nodename);
err = xenbus_switch_state(xbt, path, XenbusStateConnected);
if (err) {
message = "switching state";
goto abort_transaction;
}
err = xenbus_transaction_end(xbt, 0, &retry);
free(err);
if (retry) {
goto again;
printk("completing transaction\n");
}
goto done;
abort_transaction:
free(err);
err = xenbus_transaction_end(xbt, 1, &retry);
printk("Abort transaction %s\n", message);
goto error;
done:
snprintf(path, sizeof(path), "%s/backend", nodename);
msg = xenbus_read(XBT_NIL, path, &dev->backend);
snprintf(path, sizeof(path), "%s/mac", nodename);
msg = xenbus_read(XBT_NIL, path, &dev->mac);
if ((dev->backend == NULL) || (dev->mac == NULL)) {
printk("%s: backend/mac failed\n", __func__);
goto error;
}
printk("backend at %s\n",dev->backend);
printk("mac is %s\n",dev->mac);
{
XenbusState state;
char path[strlen(dev->backend) + strlen("/state") + 1];
snprintf(path, sizeof(path), "%s/state", dev->backend);
xenbus_watch_path_token(XBT_NIL, path, path, &dev->events);
err = NULL;
state = xenbus_read_integer(path);
while (err == NULL && state < XenbusStateConnected)
err = xenbus_wait_for_state_change(path, &state, &dev->events);
if (state != XenbusStateConnected) {
printk("backend not avalable, state=%d\n", state);
xenbus_unwatch_path_token(XBT_NIL, path, path);
goto error;
}
if (ip) {
snprintf(path, sizeof(path), "%s/ip", dev->backend);
xenbus_read(XBT_NIL, path, ip);
}
}
printk("**************************\n");
unmask_evtchn(dev->evtchn);
/* Special conversion specifier 'hh' needed for __ia64__. Without
this mini-os panics with 'Unaligned reference'. */
if (rawmac)
sscanf(dev->mac,"%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
&rawmac[0],
&rawmac[1],
&rawmac[2],
&rawmac[3],
&rawmac[4],
&rawmac[5]);
return dev;
error:
free(msg);
free(err);
free_netfront(dev);
return NULL;
}
#ifdef HAVE_LIBC
int netfront_tap_open(char *nodename) {
struct netfront_dev *dev;
dev = init_netfront(nodename, NETIF_SELECT_RX, NULL, NULL);
if (!dev) {
printk("TAP open failed\n");
errno = EIO;
return -1;
}
dev->fd = alloc_fd(FTYPE_TAP);
printk("tap_open(%s) -> %d\n", nodename, dev->fd);
files[dev->fd].tap.dev = dev;
return dev->fd;
}
#endif
void shutdown_netfront(struct netfront_dev *dev)
{
char* err = NULL, *err2;
XenbusState state;
char path[strlen(dev->backend) + strlen("/state") + 1];
char nodename[strlen(dev->nodename) + strlen("/request-rx-copy") + 1];
printk("close network: backend at %s\n",dev->backend);
snprintf(path, sizeof(path), "%s/state", dev->backend);
snprintf(nodename, sizeof(nodename), "%s/state", dev->nodename);
if ((err = xenbus_switch_state(XBT_NIL, nodename, XenbusStateClosing)) != NULL) {
printk("shutdown_netfront: error changing state to %d: %s\n",
XenbusStateClosing, err);
goto close;
}
state = xenbus_read_integer(path);
while (err == NULL && state < XenbusStateClosing)
err = xenbus_wait_for_state_change(path, &state, &dev->events);
free(err);
if ((err = xenbus_switch_state(XBT_NIL, nodename, XenbusStateClosed)) != NULL) {
printk("shutdown_netfront: error changing state to %d: %s\n",
XenbusStateClosed, err);
goto close;
}
state = xenbus_read_integer(path);
while (state < XenbusStateClosed) {
err = xenbus_wait_for_state_change(path, &state, &dev->events);
free(err);
}
if ((err = xenbus_switch_state(XBT_NIL, nodename, XenbusStateInitialising)) != NULL) {
printk("shutdown_netfront: error changing state to %d: %s\n",
XenbusStateInitialising, err);
goto close;
}
state = xenbus_read_integer(path);
while (err == NULL && (state < XenbusStateInitWait || state >= XenbusStateClosed))
err = xenbus_wait_for_state_change(path, &state, &dev->events);
close:
free(err);
err2 = xenbus_unwatch_path_token(XBT_NIL, path, path);
free(err2);
snprintf(nodename, sizeof(nodename), "%s/tx-ring-ref", dev->nodename);
err2 = xenbus_rm(XBT_NIL, nodename);
free(err2);
snprintf(nodename, sizeof(nodename), "%s/rx-ring-ref", dev->nodename);
err2 = xenbus_rm(XBT_NIL, nodename);
free(err2);
snprintf(nodename, sizeof(nodename), "%s/event-channel", dev->nodename);
err2 = xenbus_rm(XBT_NIL, nodename);
free(err2);
snprintf(nodename, sizeof(nodename), "%s/request-rx-copy", dev->nodename);
err2 = xenbus_rm(XBT_NIL, nodename);
free(err2);
if (!err)
free_netfront(dev);
}
void init_rx_buffers(struct netfront_dev *dev)
{
int i, requeue_idx;
netif_rx_request_t *req;
int notify;
/* 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 = &dev->rx_buffers[requeue_idx];
req = RING_GET_REQUEST(&dev->rx, requeue_idx);
buf->gref = req->gref =
gnttab_grant_access(dev->dom,virt_to_mfn(buf->page),0);
req->id = requeue_idx;
requeue_idx++;
}
dev->rx.req_prod_pvt = requeue_idx;
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&dev->rx, notify);
if (notify)
notify_remote_via_evtchn(dev->evtchn);
dev->rx.sring->rsp_event = dev->rx.rsp_cons + 1;
}
void netfront_xmit(struct netfront_dev *dev, unsigned char* data,int len)
{
int flags;
struct netif_tx_request *tx;
RING_IDX i;
int notify;
unsigned short id;
struct net_buffer* buf;
void* page;
BUG_ON(len > PAGE_SIZE);
down(&dev->tx_sem);
local_irq_save(flags);
id = get_id_from_freelist(dev->tx_freelist);
local_irq_restore(flags);
buf = &dev->tx_buffers[id];
page = buf->page;
if (!page)
page = buf->page = (char*) alloc_page();
i = dev->tx.req_prod_pvt;
tx = RING_GET_REQUEST(&dev->tx, i);
memcpy(page,data,len);
buf->gref =
tx->gref = gnttab_grant_access(dev->dom,virt_to_mfn(page),1);
tx->offset=0;
tx->size = len;
tx->flags=0;
tx->id = id;
dev->tx.req_prod_pvt = i + 1;
wmb();
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&dev->tx, notify);
if(notify) notify_remote_via_evtchn(dev->evtchn);
local_irq_save(flags);
network_tx_buf_gc(dev);
local_irq_restore(flags);
}
#ifdef HAVE_LIBC
ssize_t netfront_receive(struct netfront_dev *dev, unsigned char *data, size_t len)
{
unsigned long flags;
int fd = dev->fd;
ASSERT(current == main_thread);
dev->rlen = 0;
dev->data = data;
dev->len = len;
local_irq_save(flags);
network_rx(dev);
if (!dev->rlen && fd != -1)
/* No data for us, make select stop returning */
files[fd].read = 0;
/* Before re-enabling the interrupts, in case a packet just arrived in the
* meanwhile. */
local_irq_restore(flags);
dev->data = NULL;
dev->len = 0;
return dev->rlen;
}
#endif
Reference in new issue View Git Blame Copy Permalink