* Al Longyear <longyear@netcom.com>
* Extensively rewritten by Paul Mackerras <paulus@cs.anu.edu.au>
*
- * ==FILEVERSION 990114==
+ * ==FILEVERSION 990325==
*
* NOTE TO MAINTAINERS:
* If you modify this file at all, please set the number above to the
#define PPP_MAX_RCV_QLEN 32 /* max # frames we queue up for pppd */
-/* $Id: ppp.c,v 1.21 1999/02/26 06:48:21 paulus Exp $ */
+/* $Id: ppp.c,v 1.22 1999/03/30 06:33:07 paulus Exp $ */
#include <linux/version.h>
#include <linux/config.h>
static void ppp_async_init(struct ppp *ppp);
static void ppp_async_release(struct ppp *ppp);
+static int ppp_tty_sync_push(struct ppp *ppp);
static int ppp_tty_push(struct ppp *ppp);
static int ppp_async_encode(struct ppp *ppp);
static int ppp_async_send(struct ppp *, struct sk_buff *);
+static int ppp_sync_send(struct ppp *, struct sk_buff *);
static int ppp_ioctl(struct ppp *, unsigned int, unsigned long);
static int ppp_set_compression (struct ppp *ppp, struct ppp_option_data *odp);
ppp_output_wakeup(ppp);
}
+/*
+ * Send a packet to the peer over a synchronous tty line.
+ * All encoding and FCS are handled by hardware.
+ * Addr/Ctrl and Protocol field compression implemented.
+ * Returns -1 iff the packet could not be accepted at present,
+ * 0 if the packet was accepted but we can't accept another yet, or
+ * 1 if we can accept another packet immediately.
+ * If this procedure returns 0, ppp_output_wakeup will be called
+ * exactly once.
+ */
+static int
+ppp_sync_send(struct ppp *ppp, struct sk_buff *skb)
+{
+ unsigned char *data;
+ int islcp;
+
+ CHECK_PPP(0);
+
+ if (ppp->tpkt != NULL)
+ return -1;
+ ppp->tpkt = skb;
+
+ data = ppp->tpkt->data;
+
+ /*
+ * LCP packets with code values between 1 (configure-reqest)
+ * and 7 (code-reject) must be sent as though no options
+ * had been negotiated.
+ */
+ islcp = PPP_PROTOCOL(data) == PPP_LCP
+ && 1 <= data[PPP_HDRLEN] && data[PPP_HDRLEN] <= 7;
+
+ /* only reset idle time for data packets */
+ if (PPP_PROTOCOL(data) < 0x8000)
+ ppp->last_xmit = jiffies;
+ ++ppp->stats.ppp_opackets;
+ ppp->stats.ppp_ooctects += ppp->tpkt->len;
+
+ if ( !(data[2]) && (ppp->flags & SC_COMP_PROT) ) {
+ /* compress protocol field */
+ data[2] = data[1];
+ data[1] = data[0];
+ skb_pull(ppp->tpkt,1);
+ data = ppp->tpkt->data;
+ }
+
+ /*
+ * Do address/control compression
+ */
+ if ((ppp->flags & SC_COMP_AC) && !islcp
+ && PPP_ADDRESS(data) == PPP_ALLSTATIONS
+ && PPP_CONTROL(data) == PPP_UI) {
+ /* strip addr and control field */
+ skb_pull(ppp->tpkt,2);
+ }
+
+ return ppp_tty_sync_push(ppp);
+}
+
+/*
+ * Push a synchronous frame out to the tty.
+ * Returns 1 if frame accepted (or discarded), 0 otherwise.
+ */
+static int
+ppp_tty_sync_push(struct ppp *ppp)
+{
+ int sent;
+ struct tty_struct *tty = ppp2tty(ppp);
+ unsigned long flags;
+
+ CHECK_PPP(0);
+
+ if (ppp->tpkt == NULL)
+ return 0;
+
+ /* prevent reentrancy with tty_pushing flag */
+ save_flags(flags);
+ cli();
+ if (ppp->tty_pushing) {
+ /* record wakeup attempt so we don't loose */
+ /* a wakeup call while doing push processing */
+ ppp->woke_up=1;
+ restore_flags(flags);
+ return 0;
+ }
+ ppp->tty_pushing = 1;
+ restore_flags(flags);
+
+ if (tty == NULL || tty->disc_data != (void *) ppp)
+ goto flush;
+
+ for(;;){
+ ppp->woke_up=0;
+
+ /* Note: Sync driver accepts complete frame or nothing */
+ tty->flags |= (1 << TTY_DO_WRITE_WAKEUP);
+ sent = tty->driver.write(tty, 0, ppp->tpkt->data, ppp->tpkt->len);
+ if (sent < 0) {
+ /* write error (possible loss of CD) */
+ /* record error and discard current packet */
+ ppp->stats.ppp_oerrors++;
+ break;
+ }
+ ppp->stats.ppp_obytes += sent;
+ if (sent < ppp->tpkt->len) {
+ /* driver unable to accept frame just yet */
+ save_flags(flags);
+ cli();
+ if (ppp->woke_up) {
+ /* wake up called while processing */
+ /* try to send the frame again */
+ restore_flags(flags);
+ continue;
+ }
+ /* wait for wakeup callback to try send again */
+ ppp->tty_pushing = 0;
+ restore_flags(flags);
+ return 0;
+ }
+ break;
+ }
+flush:
+ /* done with current packet (sent or discarded) */
+ KFREE_SKB(ppp->tpkt);
+ ppp->tpkt = 0;
+ ppp->tty_pushing = 0;
+ return 1;
+}
+
/*
* Send a packet to the peer over an async tty line.
* Returns -1 iff the packet could not be accepted at present,
{
int avail, sent, done = 0;
struct tty_struct *tty = ppp2tty(ppp);
+
+ if ( ppp->flags & SC_SYNC )
+ return ppp_tty_sync_push(ppp);
CHECK_PPP(0);
if (ppp->tty_pushing)
ppp->stats.ppp_ibytes += count;
skb = ppp->rpkt;
+
+ if ( ppp->flags & SC_SYNC ) {
+ /* synchronous mode */
+
+ if (ppp->toss==0xE0) {
+ /* this is the 1st frame, reset vj comp */
+ ppp_receive_error(ppp);
+ ppp->toss = 0;
+ }
+
+ /*
+ * Allocate an skbuff for frame.
+ * The 128 is room for VJ header expansion.
+ */
+
+ if (skb == NULL)
+ skb = dev_alloc_skb(ppp->mru + 128 + PPP_HDRLEN);
+
+ if (skb == NULL) {
+ if (ppp->flags & SC_DEBUG)
+ printk(KERN_DEBUG "couldn't "
+ "alloc skb for recv\n");
+ } else {
+ LIBERATE_SKB(skb);
+ /*
+ * Decompress A/C and protocol compression here.
+ */
+ p = skb_put(skb, 2);
+ p[0] = PPP_ALLSTATIONS;
+ p[1] = PPP_UI;
+ if (*data == PPP_ALLSTATIONS) {
+ data += 2;
+ count -= 2;
+ }
+ if ((*data & 1) != 0) {
+ p = skb_put(skb, 1);
+ p[0] = 0;
+ }
+
+ /* copy frame to socket buffer */
+ p = skb_put(skb, count);
+ memcpy(p,data,count);
+
+ /*
+ * Check if we've overflowed the MRU
+ */
+ if (skb->len >= ppp->mru + PPP_HDRLEN + 2
+ || skb_tailroom(skb) <= 0) {
+ ++ppp->estats.rx_length_errors;
+ if (ppp->flags & SC_DEBUG)
+ printk(KERN_DEBUG "rcv frame too long: "
+ "len=%d mru=%d hroom=%d troom=%d\n",
+ skb->len, ppp->mru, skb_headroom(skb),
+ skb_tailroom(skb));
+ } else {
+ if (!ppp_receive_frame(ppp, skb)) {
+ KFREE_SKB(skb);
+ ppp_receive_error(ppp);
+ }
+ }
+
+ /* Reset for the next frame */
+ skb = NULL;
+ }
+ ppp->rpkt = skb;
+ return;
+ }
+
while (count-- > 0) {
/*
* Collect the character and error condition for the character.
return 0;
}
- /*
- * Verify the FCS of the frame and discard the FCS characters
- * from the end of the buffer.
- */
- if (ppp->rfcs != PPP_GOODFCS) {
- if (ppp->flags & SC_DEBUG) {
- printk(KERN_DEBUG
- "ppp: frame with bad fcs, length = %d\n",
- count);
- ppp_print_buffer("bad frame", data, count);
+ if ( !(ppp->flags & SC_SYNC) ) {
+ /*
+ * Verify the FCS of the frame and discard the FCS characters
+ * from the end of the buffer.
+ */
+ if (ppp->rfcs != PPP_GOODFCS) {
+ if (ppp->flags & SC_DEBUG) {
+ printk(KERN_DEBUG
+ "ppp: frame with bad fcs, length = %d\n",
+ count);
+ ppp_print_buffer("bad frame", data, count);
+ }
+ ++ppp->estats.rx_crc_errors;
+ return 0;
}
- ++ppp->estats.rx_crc_errors;
- return 0;
+ count -= 2; /* ignore the fcs characters */
+ skb_trim(skb, count);
}
- count -= 2; /* ignore the fcs characters */
- skb_trim(skb, count);
-
+
/*
* Process the active decompressor.
*/
/*
* Send the frame
*/
- ret = ppp_async_send(ppp, skb);
+ if ( ppp->flags & SC_SYNC )
+ ret = ppp_sync_send(ppp, skb);
+ else
+ ret = ppp_async_send(ppp, skb);
if (ret > 0) {
/* we can release the lock */
ppp->xmit_busy = 0;
projects / ppp.git / commitdiff