| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20080922.191243.177666844.davem@davemloft.net>
Date: Mon, 22 Sep 2008 19:12:43 -0700 (PDT)
From: David Miller <davem@...emloft.net>
To: netdev@...r.kernel.org
Subject: [PATCH 6/7]: isdn: isdn_ppp: Use SKB list facilities instead of
home-grown implementation.
isdn: isdn_ppp: Use SKB list facilities instead of home-grown implementation.
Signed-off-by: David S. Miller <davem@...emloft.net>
---
drivers/isdn/i4l/isdn_ppp.c | 352 +++++++++++++++++++++++--------------------
include/linux/isdn_ppp.h | 2 +-
2 files changed, 190 insertions(+), 164 deletions(-)
diff --git a/drivers/isdn/i4l/isdn_ppp.c b/drivers/isdn/i4l/isdn_ppp.c
index 127cfda..77c280e 100644
--- a/drivers/isdn/i4l/isdn_ppp.c
+++ b/drivers/isdn/i4l/isdn_ppp.c
@@ -1533,8 +1533,10 @@ static int isdn_ppp_mp_bundle_array_init(void)
int sz = ISDN_MAX_CHANNELS*sizeof(ippp_bundle);
if( (isdn_ppp_bundle_arr = kzalloc(sz, GFP_KERNEL)) == NULL )
return -ENOMEM;
- for( i = 0; i < ISDN_MAX_CHANNELS; i++ )
+ for (i = 0; i < ISDN_MAX_CHANNELS; i++) {
spin_lock_init(&isdn_ppp_bundle_arr[i].lock);
+ skb_queue_head_init(&isdn_ppp_bundle_arr[i].frags);
+ }
return 0;
}
@@ -1567,7 +1569,7 @@ static int isdn_ppp_mp_init( isdn_net_local * lp, ippp_bundle * add_to )
if ((lp->netdev->pb = isdn_ppp_mp_bundle_alloc()) == NULL)
return -ENOMEM;
lp->next = lp->last = lp; /* nobody else in a queue */
- lp->netdev->pb->frags = NULL;
+ skb_queue_head_init(&lp->netdev->pb->frags);
lp->netdev->pb->frames = 0;
lp->netdev->pb->seq = UINT_MAX;
}
@@ -1579,28 +1581,29 @@ static int isdn_ppp_mp_init( isdn_net_local * lp, ippp_bundle * add_to )
static u32 isdn_ppp_mp_get_seq( int short_seq,
struct sk_buff * skb, u32 last_seq );
-static struct sk_buff * isdn_ppp_mp_discard( ippp_bundle * mp,
- struct sk_buff * from, struct sk_buff * to );
-static void isdn_ppp_mp_reassembly( isdn_net_dev * net_dev, isdn_net_local * lp,
- struct sk_buff * from, struct sk_buff * to );
-static void isdn_ppp_mp_free_skb( ippp_bundle * mp, struct sk_buff * skb );
+static void isdn_ppp_mp_discard(ippp_bundle *mp, struct sk_buff *from,
+ struct sk_buff *to);
+static void isdn_ppp_mp_reassembly(isdn_net_dev *net_dev, isdn_net_local *lp,
+ struct sk_buff *from, struct sk_buff *to,
+ u32 lastseq);
+static void isdn_ppp_mp_free_skb(ippp_bundle *mp, struct sk_buff *skb);
static void isdn_ppp_mp_print_recv_pkt( int slot, struct sk_buff * skb );
static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
- struct sk_buff *skb)
+ struct sk_buff *skb)
{
- struct ippp_struct *is;
- isdn_net_local * lpq;
- ippp_bundle * mp;
- isdn_mppp_stats * stats;
- struct sk_buff * newfrag, * frag, * start, *nextf;
+ struct sk_buff *newfrag, *frag, *start, *nextf;
u32 newseq, minseq, thisseq;
+ isdn_mppp_stats *stats;
+ struct ippp_struct *is;
unsigned long flags;
+ isdn_net_local *lpq;
+ ippp_bundle *mp;
int slot;
spin_lock_irqsave(&net_dev->pb->lock, flags);
- mp = net_dev->pb;
- stats = &mp->stats;
+ mp = net_dev->pb;
+ stats = &mp->stats;
slot = lp->ppp_slot;
if (slot < 0 || slot >= ISDN_MAX_CHANNELS) {
printk(KERN_ERR "%s: lp->ppp_slot(%d)\n",
@@ -1611,20 +1614,19 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
return;
}
is = ippp_table[slot];
- if( ++mp->frames > stats->max_queue_len )
+ if (++mp->frames > stats->max_queue_len)
stats->max_queue_len = mp->frames;
-
+
if (is->debug & 0x8)
isdn_ppp_mp_print_recv_pkt(lp->ppp_slot, skb);
- newseq = isdn_ppp_mp_get_seq(is->mpppcfg & SC_IN_SHORT_SEQ,
- skb, is->last_link_seqno);
-
+ newseq = isdn_ppp_mp_get_seq(is->mpppcfg & SC_IN_SHORT_SEQ,
+ skb, is->last_link_seqno);
/* if this packet seq # is less than last already processed one,
* toss it right away, but check for sequence start case first
*/
- if( mp->seq > MP_LONGSEQ_MAX && (newseq & MP_LONGSEQ_MAXBIT) ) {
+ if (mp->seq > MP_LONGSEQ_MAX && (newseq & MP_LONGSEQ_MAXBIT)) {
mp->seq = newseq; /* the first packet: required for
* rfc1990 non-compliant clients --
* prevents constant packet toss */
@@ -1634,7 +1636,7 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
spin_unlock_irqrestore(&mp->lock, flags);
return;
}
-
+
/* find the minimum received sequence number over all links */
is->last_link_seqno = minseq = newseq;
for (lpq = net_dev->queue;;) {
@@ -1655,22 +1657,31 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
* packets */
newfrag = skb;
- /* if this new fragment is before the first one, then enqueue it now. */
- if ((frag = mp->frags) == NULL || MP_LT(newseq, MP_SEQ(frag))) {
- newfrag->next = frag;
- mp->frags = frag = newfrag;
- newfrag = NULL;
- }
+ /* Insert new fragment into the proper sequence slot. */
+ skb_queue_walk(&mp->frags, frag) {
+ if (MP_SEQ(frag) == newseq) {
+ isdn_ppp_mp_free_skb(mp, newfrag);
+ newfrag = NULL;
+ break;
+ }
+ if (MP_LT(newseq, MP_SEQ(frag))) {
+ __skb_queue_before(&mp->frags, frag, newfrag);
+ newfrag = NULL;
+ break;
+ }
+ }
+ if (newfrag)
+ __skb_queue_tail(&mp->frags, newfrag);
- start = MP_FLAGS(frag) & MP_BEGIN_FRAG &&
- MP_SEQ(frag) == mp->seq ? frag : NULL;
+ frag = skb_peek(&mp->frags);
+ start = ((MP_FLAGS(frag) & MP_BEGIN_FRAG) &&
+ (MP_SEQ(frag) == mp->seq)) ? frag : NULL;
+ if (!start)
+ goto check_overflow;
- /*
- * main fragment traversing loop
+ /* main fragment traversing loop
*
* try to accomplish several tasks:
- * - insert new fragment into the proper sequence slot (once that's done
- * newfrag will be set to NULL)
* - reassemble any complete fragment sequence (non-null 'start'
* indicates there is a continguous sequence present)
* - discard any incomplete sequences that are below minseq -- due
@@ -1679,71 +1690,46 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
* come to complete such sequence and it should be discarded
*
* loop completes when we accomplished the following tasks:
- * - new fragment is inserted in the proper sequence ('newfrag' is
- * set to NULL)
* - we hit a gap in the sequence, so no reassembly/processing is
* possible ('start' would be set to NULL)
*
* algorithm for this code is derived from code in the book
* 'PPP Design And Debugging' by James Carlson (Addison-Wesley)
*/
- while (start != NULL || newfrag != NULL) {
-
- thisseq = MP_SEQ(frag);
- nextf = frag->next;
-
- /* drop any duplicate fragments */
- if (newfrag != NULL && thisseq == newseq) {
- isdn_ppp_mp_free_skb(mp, newfrag);
- newfrag = NULL;
- }
-
- /* insert new fragment before next element if possible. */
- if (newfrag != NULL && (nextf == NULL ||
- MP_LT(newseq, MP_SEQ(nextf)))) {
- newfrag->next = nextf;
- frag->next = nextf = newfrag;
- newfrag = NULL;
- }
-
- if (start != NULL) {
- /* check for misplaced start */
- if (start != frag && (MP_FLAGS(frag) & MP_BEGIN_FRAG)) {
- printk(KERN_WARNING"isdn_mppp(seq %d): new "
- "BEGIN flag with no prior END", thisseq);
- stats->seqerrs++;
- stats->frame_drops++;
- start = isdn_ppp_mp_discard(mp, start,frag);
- nextf = frag->next;
- }
- } else if (MP_LE(thisseq, minseq)) {
- if (MP_FLAGS(frag) & MP_BEGIN_FRAG)
+ skb_queue_walk_safe(&mp->frags, frag, nextf) {
+ thisseq = MP_SEQ(frag);
+
+ /* check for misplaced start */
+ if (start != frag && (MP_FLAGS(frag) & MP_BEGIN_FRAG)) {
+ printk(KERN_WARNING"isdn_mppp(seq %d): new "
+ "BEGIN flag with no prior END", thisseq);
+ stats->seqerrs++;
+ stats->frame_drops++;
+ isdn_ppp_mp_discard(mp, start, frag);
+ start = frag;
+ } else if (MP_LE(thisseq, minseq)) {
+ if (MP_FLAGS(frag) & MP_BEGIN_FRAG)
start = frag;
- else {
+ else {
if (MP_FLAGS(frag) & MP_END_FRAG)
- stats->frame_drops++;
- if( mp->frags == frag )
- mp->frags = nextf;
+ stats->frame_drops++;
+ __skb_unlink(skb, &mp->frags);
isdn_ppp_mp_free_skb(mp, frag);
- frag = nextf;
continue;
- }
+ }
}
-
- /* if start is non-null and we have end fragment, then
- * we have full reassembly sequence -- reassemble
- * and process packet now
+
+ /* if we have end fragment, then we have full reassembly
+ * sequence -- reassemble and process packet now
*/
- if (start != NULL && (MP_FLAGS(frag) & MP_END_FRAG)) {
- minseq = mp->seq = (thisseq+1) & MP_LONGSEQ_MASK;
- /* Reassemble the packet then dispatch it */
- isdn_ppp_mp_reassembly(net_dev, lp, start, nextf);
-
- start = NULL;
- frag = NULL;
+ if (MP_FLAGS(frag) & MP_END_FRAG) {
+ minseq = mp->seq = (thisseq+1) & MP_LONGSEQ_MASK;
+ /* Reassemble the packet then dispatch it */
+ isdn_ppp_mp_reassembly(net_dev, lp, start, frag, thisseq);
- mp->frags = nextf;
- }
+ start = NULL;
+ frag = NULL;
+ }
/* check if need to update start pointer: if we just
* reassembled the packet and sequence is contiguous
@@ -1754,26 +1740,25 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
* below low watermark and set start to the next frag or
* clear start ptr.
*/
- if (nextf != NULL &&
+ if (nextf != (struct sk_buff *)&mp->frags &&
((thisseq+1) & MP_LONGSEQ_MASK) == MP_SEQ(nextf)) {
- /* if we just reassembled and the next one is here,
- * then start another reassembly. */
-
- if (frag == NULL) {
+ /* if we just reassembled and the next one is here,
+ * then start another reassembly.
+ */
+ if (frag == NULL) {
if (MP_FLAGS(nextf) & MP_BEGIN_FRAG)
- start = nextf;
- else
- {
- printk(KERN_WARNING"isdn_mppp(seq %d):"
- " END flag with no following "
- "BEGIN", thisseq);
+ start = nextf;
+ else {
+ printk(KERN_WARNING"isdn_mppp(seq %d):"
+ " END flag with no following "
+ "BEGIN", thisseq);
stats->seqerrs++;
}
}
-
- } else {
- if ( nextf != NULL && frag != NULL &&
- MP_LT(thisseq, minseq)) {
+ } else {
+ if (nextf != (struct sk_buff *)&mp->frags &&
+ frag != NULL &&
+ MP_LT(thisseq, minseq)) {
/* we've got a break in the sequence
* and we not at the end yet
* and we did not just reassembled
@@ -1782,41 +1767,39 @@ static void isdn_ppp_mp_receive(isdn_net_dev * net_dev, isdn_net_local * lp,
* discard all the frames below low watermark
* and start over */
stats->frame_drops++;
- mp->frags = isdn_ppp_mp_discard(mp,start,nextf);
+ isdn_ppp_mp_discard(mp, start, nextf);
}
/* break in the sequence, no reassembly */
- start = NULL;
- }
-
- frag = nextf;
- } /* while -- main loop */
-
- if (mp->frags == NULL)
- mp->frags = frag;
-
+ start = NULL;
+ }
+ if (!start)
+ break;
+ }
+
+check_overflow:
/* rather straighforward way to deal with (not very) possible
- * queue overflow */
+ * queue overflow
+ */
if (mp->frames > MP_MAX_QUEUE_LEN) {
stats->overflows++;
- while (mp->frames > MP_MAX_QUEUE_LEN) {
- frag = mp->frags->next;
- isdn_ppp_mp_free_skb(mp, mp->frags);
- mp->frags = frag;
+ skb_queue_walk_safe(&mp->frags, frag, nextf) {
+ if (mp->frames <= MP_MAX_QUEUE_LEN)
+ break;
+ __skb_unlink(frag, &mp->frags);
+ isdn_ppp_mp_free_skb(mp, frag);
}
}
spin_unlock_irqrestore(&mp->lock, flags);
}
-static void isdn_ppp_mp_cleanup( isdn_net_local * lp )
+static void isdn_ppp_mp_cleanup(isdn_net_local *lp)
{
- struct sk_buff * frag = lp->netdev->pb->frags;
- struct sk_buff * nextfrag;
- while( frag ) {
- nextfrag = frag->next;
- isdn_ppp_mp_free_skb(lp->netdev->pb, frag);
- frag = nextfrag;
- }
- lp->netdev->pb->frags = NULL;
+ struct sk_buff *skb, *tmp;
+
+ skb_queue_walk_safe(&lp->netdev->pb->frags, skb, tmp) {
+ __skb_unlink(skb, &lp->netdev->pb->frags);
+ isdn_ppp_mp_free_skb(lp->netdev->pb, skb);
+ }
}
static u32 isdn_ppp_mp_get_seq( int short_seq,
@@ -1853,72 +1836,115 @@ static u32 isdn_ppp_mp_get_seq( int short_seq,
return seq;
}
-struct sk_buff * isdn_ppp_mp_discard( ippp_bundle * mp,
- struct sk_buff * from, struct sk_buff * to )
+static void isdn_ppp_mp_discard(ippp_bundle *mp, struct sk_buff *from,
+ struct sk_buff *to)
{
- if( from )
- while (from != to) {
- struct sk_buff * next = from->next;
- isdn_ppp_mp_free_skb(mp, from);
- from = next;
+ if (from) {
+ struct sk_buff *skb, *tmp;
+ int freeing = 0;
+
+ skb_queue_walk_safe(&mp->frags, skb, tmp) {
+ if (skb == to)
+ break;
+ if (skb == from)
+ freeing = 1;
+ if (!freeing)
+ continue;
+ __skb_unlink(skb, &mp->frags);
+ isdn_ppp_mp_free_skb(mp, skb);
}
- return from;
+ }
}
-void isdn_ppp_mp_reassembly( isdn_net_dev * net_dev, isdn_net_local * lp,
- struct sk_buff * from, struct sk_buff * to )
+static unsigned int calc_tot_len(struct sk_buff_head *queue,
+ struct sk_buff *from, struct sk_buff *to)
{
- ippp_bundle * mp = net_dev->pb;
- int proto;
- struct sk_buff * skb;
+ unsigned int tot_len = 0;
+ struct sk_buff *skb;
+ int found_start = 0;
+
+ skb_queue_walk(queue, skb) {
+ if (skb == from)
+ found_start = 1;
+ if (!found_start)
+ continue;
+ tot_len += skb->len - MP_HEADER_LEN;
+ if (skb == to)
+ break;
+ }
+ return tot_len;
+}
+
+/* Reassemble packet using fragments in the reassembly queue from
+ * 'from' until 'to', inclusive.
+ */
+static void isdn_ppp_mp_reassembly(isdn_net_dev *net_dev, isdn_net_local *lp,
+ struct sk_buff *from, struct sk_buff *to,
+ u32 lastseq)
+{
+ ippp_bundle *mp = net_dev->pb;
unsigned int tot_len;
+ struct sk_buff *skb;
+ int proto;
if (lp->ppp_slot < 0 || lp->ppp_slot >= ISDN_MAX_CHANNELS) {
printk(KERN_ERR "%s: lp->ppp_slot(%d) out of range\n",
__func__, lp->ppp_slot);
return;
}
- if( MP_FLAGS(from) == (MP_BEGIN_FRAG | MP_END_FRAG) ) {
- if( ippp_table[lp->ppp_slot]->debug & 0x40 )
+
+ tot_len = calc_tot_len(&mp->frags, from, to);
+
+ if (MP_FLAGS(from) == (MP_BEGIN_FRAG | MP_END_FRAG)) {
+ if (ippp_table[lp->ppp_slot]->debug & 0x40)
printk(KERN_DEBUG "isdn_mppp: reassembly: frame %d, "
- "len %d\n", MP_SEQ(from), from->len );
+ "len %d\n", MP_SEQ(from), from->len);
skb = from;
skb_pull(skb, MP_HEADER_LEN);
+ __skb_unlink(skb, &mp->frags);
mp->frames--;
} else {
- struct sk_buff * frag;
- int n;
+ struct sk_buff *walk, *tmp;
+ int found_start = 0;
- for(tot_len=n=0, frag=from; frag != to; frag=frag->next, n++)
- tot_len += frag->len - MP_HEADER_LEN;
-
- if( ippp_table[lp->ppp_slot]->debug & 0x40 )
+ if (ippp_table[lp->ppp_slot]->debug & 0x40)
printk(KERN_DEBUG"isdn_mppp: reassembling frames %d "
- "to %d, len %d\n", MP_SEQ(from),
- (MP_SEQ(from)+n-1) & MP_LONGSEQ_MASK, tot_len );
- if( (skb = dev_alloc_skb(tot_len)) == NULL ) {
+ "to %d, len %d\n", MP_SEQ(from), lastseq,
+ tot_len);
+
+ skb = dev_alloc_skb(tot_len);
+ if (!skb)
printk(KERN_ERR "isdn_mppp: cannot allocate sk buff "
- "of size %d\n", tot_len);
- isdn_ppp_mp_discard(mp, from, to);
- return;
- }
+ "of size %d\n", tot_len);
+
+ found_start = 0;
+ skb_queue_walk_safe(&mp->frags, walk, tmp) {
+ if (walk == from)
+ found_start = 1;
+ if (!found_start)
+ continue;
- while( from != to ) {
- unsigned int len = from->len - MP_HEADER_LEN;
+ if (skb) {
+ unsigned int len = walk->len - MP_HEADER_LEN;
+ skb_copy_from_linear_data_offset(walk, MP_HEADER_LEN,
+ skb_put(skb, len),
+ len);
+ }
+ __skb_unlink(walk, &mp->frags);
+ isdn_ppp_mp_free_skb(mp, walk);
- skb_copy_from_linear_data_offset(from, MP_HEADER_LEN,
- skb_put(skb,len),
- len);
- frag = from->next;
- isdn_ppp_mp_free_skb(mp, from);
- from = frag;
+ if (walk == to)
+ break;
}
}
+ if (!skb)
+ return;
+
proto = isdn_ppp_strip_proto(skb);
isdn_ppp_push_higher(net_dev, lp, skb, proto);
}
-static void isdn_ppp_mp_free_skb(ippp_bundle * mp, struct sk_buff * skb)
+static void isdn_ppp_mp_free_skb(ippp_bundle *mp, struct sk_buff *skb)
{
dev_kfree_skb(skb);
mp->frames--;
diff --git a/include/linux/isdn_ppp.h b/include/linux/isdn_ppp.h
index 8687a7d..4c218ee 100644
--- a/include/linux/isdn_ppp.h
+++ b/include/linux/isdn_ppp.h
@@ -157,7 +157,7 @@ typedef struct {
typedef struct {
int mp_mrru; /* unused */
- struct sk_buff * frags; /* fragments sl list -- use skb->next */
+ struct sk_buff_head frags; /* fragments sl list */
long frames; /* number of frames in the frame list */
unsigned int seq; /* last processed packet seq #: any packets
* with smaller seq # will be dropped
--
1.5.6.5
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists