From a00eac0c459abecb539fb2a2abd3122dd7ca5d4a Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 5 Oct 2010 01:36:52 -0700 Subject: ppp: Use a real SKB control block in fragmentation engine. 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 --- drivers/net/ppp_generic.c | 46 +++++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 21 deletions(-) (limited to 'drivers/net/ppp_generic.c') diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 736b91703b3e..866e221643ab 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -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; } -- cgit v1.2.3