From: "Jorge Boncompte [DTI2]" <jorge@xxxxxxxx>
Currently decompressors can't signal the generic PPP layer to silently
drop a packet without notifying the PPP daemon or the other party.
Signed-off-by: Jorge Boncompte [DTI2] <jorge@xxxxxxxx>
---
drivers/net/ppp/ppp_generic.c | 12 ++++++++++++
include/linux/ppp-comp.h | 6 ++++--
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 72ff14b..7d26825 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -1729,6 +1729,10 @@ ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb)
(ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0)
skb = ppp_decompress_frame(ppp, skb);
+ /* Packet dropped */
+ if (skb == NULL)
+ goto err;
+
if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR)
goto err;
@@ -1888,6 +1892,13 @@ ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2,
skb->len + 2, ns->data, obuff_size);
if (len < 0) {
+ /* Drop the packet and continue */
+ if (len == DECOMP_DROPERROR) {
+ kfree_skb(ns);
+ kfree_skb(skb);
+ skb = NULL;
+ goto out;
+ }
/* Pass the compressed frame to pppd as an
error indication. */
if (len == DECOMP_FATALERROR)
@@ -1909,6 +1920,7 @@ ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb)
skb->len + 2);
}
+out:
return skb;
err:
diff --git a/include/linux/ppp-comp.h b/include/linux/ppp-comp.h
index 4ea1d37..12a8ce8 100644
--- a/include/linux/ppp-comp.h
+++ b/include/linux/ppp-comp.h
@@ -89,8 +89,9 @@ struct compressor {
/*
* The return value from decompress routine is the length of the
* decompressed packet if successful, otherwise DECOMP_ERROR
- * or DECOMP_FATALERROR if an error occurred.
- *
+ * or DECOMP_FATALERROR if an error occurred but don't want the
+ * PPP generic layer to drop the packet.
+ *
* We need to make this distinction so that we can disable certain
* useful functionality, namely sending a CCP reset-request as a result
* of an error detected after decompression. This is to avoid infringing
@@ -100,6 +101,7 @@ struct compressor {
#define DECOMP_ERROR -1 /* error detected before decomp. */
#define DECOMP_FATALERROR -2 /* error detected after decomp. */
+#define DECOMP_DROPERROR -3 /* error detected, drop packet. */
extern int ppp_register_compressor(struct compressor *);
extern void ppp_unregister_compressor(struct compressor *);
--
1.7.10.4
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