diff options
| author | Xie He | 2020-10-07 11:32:03 -0700 |
|---|---|---|
| committer | Jakub Kicinski | 2020-10-10 12:05:05 -0700 |
| commit | df41c19abbeaae6e24c8e31cff5fdb48632be380 (patch) | |
| tree | db693470e851226ab41fb2131e0257d01c0ecabc /drivers | |
| parent | e0b2e0d8e6692ee488387aba871d0b70e1ed400a (diff) | |
drivers/net/wan/hdlc_fr: Move the skb_headroom check out of fr_hard_header
Move the skb_headroom check out of fr_hard_header and into pvc_xmit.
This has two benefits:
1. Originally we only do this check for skbs sent by users on Ethernet-
emulating PVC devices. After the change we do this check for skbs sent on
normal PVC devices, too.
(Also add a comment to make it clear that this is only a protection
against upper layers that don't take dev->needed_headroom into account.
Such upper layers should be rare and I believe they should be fixed.)
2. After the change we can simplify the parameter list of fr_hard_header.
We no longer need to use a pointer to pointers (skb_p) because we no
longer need to replace the skb inside fr_hard_header.
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/wan/hdlc_fr.c | 30 |
1 files changed, 17 insertions, 13 deletions
diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c index 4dfdbca54296..409e5a7ad8e2 100644 --- a/drivers/net/wan/hdlc_fr.c +++ b/drivers/net/wan/hdlc_fr.c @@ -271,10 +271,8 @@ static inline struct net_device **get_dev_p(struct pvc_device *pvc, } -static int fr_hard_header(struct sk_buff **skb_p, u16 dlci) +static int fr_hard_header(struct sk_buff *skb, u16 dlci) { - struct sk_buff *skb = *skb_p; - if (!skb->dev) { /* Control packets */ switch (dlci) { case LMI_CCITT_ANSI_DLCI: @@ -316,13 +314,6 @@ static int fr_hard_header(struct sk_buff **skb_p, u16 dlci) } } else if (skb->dev->type == ARPHRD_ETHER) { - if (skb_headroom(skb) < 10) { - struct sk_buff *skb2 = skb_realloc_headroom(skb, 10); - if (!skb2) - return -ENOBUFS; - dev_kfree_skb(skb); - skb = *skb_p = skb2; - } skb_push(skb, 10); skb->data[3] = FR_PAD; skb->data[4] = NLPID_SNAP; @@ -429,8 +420,21 @@ static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev) } } + /* We already requested the header space with dev->needed_headroom. + * So this is just a protection in case the upper layer didn't take + * dev->needed_headroom into consideration. + */ + if (skb_headroom(skb) < 10) { + struct sk_buff *skb2 = skb_realloc_headroom(skb, 10); + + if (!skb2) + goto drop; + dev_kfree_skb(skb); + skb = skb2; + } + skb->dev = dev; - if (fr_hard_header(&skb, pvc->dlci)) + if (fr_hard_header(skb, pvc->dlci)) goto drop; dev->stats.tx_bytes += skb->len; @@ -498,9 +502,9 @@ static void fr_lmi_send(struct net_device *dev, int fullrep) memset(skb->data, 0, len); skb_reserve(skb, 4); if (lmi == LMI_CISCO) { - fr_hard_header(&skb, LMI_CISCO_DLCI); + fr_hard_header(skb, LMI_CISCO_DLCI); } else { - fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI); + fr_hard_header(skb, LMI_CCITT_ANSI_DLCI); } data = skb_tail_pointer(skb); data[i++] = LMI_CALLREF; |