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ppp: Use a real SKB control block in fragmentation engine.

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Do this instead of subverting fields in skb proper.

The macros that could very easily match variable or function
names were also just asking for trouble.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2010-10-05 01:36:52 -07:00
parent c61393ea83
commit a00eac0c45
1 changed files with 25 additions and 21 deletions
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46
drivers/net/ppp_generic.c
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@ -1547,9 +1547,11 @@ ppp_channel_push(struct channel *pch)
* Receive-side routines.
*/
/* misuse a few fields of the skb for MP reconstruction */
#define sequence priority
#define BEbits cb[0]
struct ppp_mp_skb_parm {
u32 sequence;
u8 BEbits;
};
#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb))
static inline void
ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
@ -1878,13 +1880,13 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5];
mask = 0xffffff;
}
skb->BEbits = skb->data[2];
PPP_MP_CB(skb)->BEbits = skb->data[2];
skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */
/*
* Do protocol ID decompression on the first fragment of each packet.
*/
if ((skb->BEbits & B) && (skb->data[0] & 1))
if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1))
*skb_push(skb, 1) = 0;
/*
@ -1896,7 +1898,7 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
seq += mask + 1;
else if ((int)(seq - ppp->minseq) > (int)(mask >> 1))
seq -= mask + 1; /* should never happen */
skb->sequence = seq;
PPP_MP_CB(skb)->sequence = seq;
pch->lastseq = seq;
/*
@ -1932,8 +1934,8 @@ ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
before the start of the queue. */
if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) {
struct sk_buff *mskb = skb_peek(&ppp->mrq);
if (seq_before(ppp->minseq, mskb->sequence))
ppp->minseq = mskb->sequence;
if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence))
ppp->minseq = PPP_MP_CB(mskb)->sequence;
}
/* Pull completed packets off the queue and receive them. */
@ -1963,12 +1965,12 @@ ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb)
{
struct sk_buff *p;
struct sk_buff_head *list = &ppp->mrq;
u32 seq = skb->sequence;
u32 seq = PPP_MP_CB(skb)->sequence;
/* N.B. we don't need to lock the list lock because we have the
ppp unit receive-side lock. */
skb_queue_walk(list, p) {
if (seq_before(seq, p->sequence))
if (seq_before(seq, PPP_MP_CB(p)->sequence))
break;
}
__skb_queue_before(list, p, skb);
@ -1997,22 +1999,22 @@ ppp_mp_reconstruct(struct ppp *ppp)
tail = NULL;
for (p = head; p != (struct sk_buff *) list; p = next) {
next = p->next;
if (seq_before(p->sequence, seq)) {
if (seq_before(PPP_MP_CB(p)->sequence, seq)) {
/* this can't happen, anyway ignore the skb */
printk(KERN_ERR "ppp_mp_reconstruct bad seq %u < %u\n",
p->sequence, seq);
PPP_MP_CB(p)->sequence, seq);
head = next;
continue;
}
if (p->sequence != seq) {
if (PPP_MP_CB(p)->sequence != seq) {
/* Fragment `seq' is missing. If it is after
minseq, it might arrive later, so stop here. */
if (seq_after(seq, minseq))
break;
/* Fragment `seq' is lost, keep going. */
lost = 1;
seq = seq_before(minseq, p->sequence)?
minseq + 1: p->sequence;
seq = seq_before(minseq, PPP_MP_CB(p)->sequence)?
minseq + 1: PPP_MP_CB(p)->sequence;
next = p;
continue;
}
@ -2026,7 +2028,7 @@ ppp_mp_reconstruct(struct ppp *ppp)
*/
/* B bit set indicates this fragment starts a packet */
if (p->BEbits & B) {
if (PPP_MP_CB(p)->BEbits & B) {
head = p;
lost = 0;
len = 0;
@ -2035,7 +2037,8 @@ ppp_mp_reconstruct(struct ppp *ppp)
len += p->len;
/* Got a complete packet yet? */
if (lost == 0 && (p->BEbits & E) && (head->BEbits & B)) {
if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) &&
(PPP_MP_CB(head)->BEbits & B)) {
if (len > ppp->mrru + 2) {
++ppp->dev->stats.rx_length_errors;
printk(KERN_DEBUG "PPP: reconstructed packet"
@ -2061,7 +2064,7 @@ ppp_mp_reconstruct(struct ppp *ppp)
* and we haven't found a complete valid packet yet,
* we can discard up to and including this fragment.
*/
if (p->BEbits & E)
if (PPP_MP_CB(p)->BEbits & E)
head = next;
++seq;
@ -2071,10 +2074,11 @@ ppp_mp_reconstruct(struct ppp *ppp)
if (tail != NULL) {
/* If we have discarded any fragments,
signal a receive error. */
if (head->sequence != ppp->nextseq) {
if (PPP_MP_CB(head)->sequence != ppp->nextseq) {
if (ppp->debug & 1)
printk(KERN_DEBUG " missed pkts %u..%u\n",
ppp->nextseq, head->sequence-1);
ppp->nextseq,
PPP_MP_CB(head)->sequence-1);
++ppp->dev->stats.rx_dropped;
ppp_receive_error(ppp);
}
@ -2083,7 +2087,7 @@ ppp_mp_reconstruct(struct ppp *ppp)
/* copy to a single skb */
for (p = head; p != tail->next; p = p->next)
skb_copy_bits(p, 0, skb_put(skb, p->len), p->len);
ppp->nextseq = tail->sequence + 1;
ppp->nextseq = PPP_MP_CB(tail)->sequence + 1;
head = tail->next;
}