From patchwork Tue Oct 5 08:37:28 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Miller X-Patchwork-Id: 66770 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 487A1B70AA for ; Tue, 5 Oct 2010 19:37:16 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757919Ab0JEIhJ (ORCPT ); Tue, 5 Oct 2010 04:37:09 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:43227 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752673Ab0JEIhH (ORCPT ); Tue, 5 Oct 2010 04:37:07 -0400 Received: from localhost (localhost [127.0.0.1]) by sunset.davemloft.net (Postfix) with ESMTP id E99D124C087 for ; Tue, 5 Oct 2010 01:37:28 -0700 (PDT) Date: Tue, 05 Oct 2010 01:37:28 -0700 (PDT) Message-Id: <20101005.013728.108772953.davem@davemloft.net> To: netdev@vger.kernel.org Subject: [PATCH] ppp: Use a real SKB control block in fragmentation engine. From: David Miller X-Mailer: Mew version 6.3 on Emacs 23.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 --- Committed to net-next-2.6 drivers/net/ppp_generic.c | 46 ++++++++++++++++++++++++-------------------- 1 files changed, 25 insertions(+), 21 deletions(-) diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 736b917..866e221 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; }