diff options
Diffstat (limited to 'drivers/net/ppp_generic.c')
| -rw-r--r-- | drivers/net/ppp_generic.c | 88 |
1 files changed, 64 insertions, 24 deletions
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index d3c9958b00d06d..50430f79f8cf81 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -137,13 +137,14 @@ struct ppp { /* * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, - * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP. + * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, + * SC_MUST_COMP * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. * Bits in xstate: SC_COMP_RUN */ #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ - |SC_COMP_TCP|SC_REJ_COMP_TCP) + |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) /* * Private data structure for each channel. @@ -1027,6 +1028,56 @@ ppp_xmit_process(struct ppp *ppp) ppp_xmit_unlock(ppp); } +static inline struct sk_buff * +pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) +{ + struct sk_buff *new_skb; + int len; + int new_skb_size = ppp->dev->mtu + + ppp->xcomp->comp_extra + ppp->dev->hard_header_len; + int compressor_skb_size = ppp->dev->mtu + + ppp->xcomp->comp_extra + PPP_HDRLEN; + new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); + if (!new_skb) { + if (net_ratelimit()) + printk(KERN_ERR "PPP: no memory (comp pkt)\n"); + return NULL; + } + if (ppp->dev->hard_header_len > PPP_HDRLEN) + skb_reserve(new_skb, + ppp->dev->hard_header_len - PPP_HDRLEN); + + /* compressor still expects A/C bytes in hdr */ + len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, + new_skb->data, skb->len + 2, + compressor_skb_size); + if (len > 0 && (ppp->flags & SC_CCP_UP)) { + kfree_skb(skb); + skb = new_skb; + skb_put(skb, len); + skb_pull(skb, 2); /* pull off A/C bytes */ + } else if (len == 0) { + /* didn't compress, or CCP not up yet */ + kfree_skb(new_skb); + new_skb = skb; + } else { + /* + * (len < 0) + * MPPE requires that we do not send unencrypted + * frames. The compressor will return -1 if we + * should drop the frame. We cannot simply test + * the compress_proto because MPPE and MPPC share + * the same number. + */ + if (net_ratelimit()) + printk(KERN_ERR "ppp: compressor dropped pkt\n"); + kfree_skb(skb); + kfree_skb(new_skb); + new_skb = NULL; + } + return new_skb; +} + /* * Compress and send a frame. * The caller should have locked the xmit path, @@ -1113,29 +1164,14 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) /* try to do packet compression */ if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state != 0 && proto != PPP_LCP && proto != PPP_CCP) { - new_skb = alloc_skb(ppp->dev->mtu + ppp->dev->hard_header_len, - GFP_ATOMIC); - if (new_skb == 0) { - printk(KERN_ERR "PPP: no memory (comp pkt)\n"); + if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { + if (net_ratelimit()) + printk(KERN_ERR "ppp: compression required but down - pkt dropped.\n"); goto drop; } - if (ppp->dev->hard_header_len > PPP_HDRLEN) - skb_reserve(new_skb, - ppp->dev->hard_header_len - PPP_HDRLEN); - - /* compressor still expects A/C bytes in hdr */ - len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, - new_skb->data, skb->len + 2, - ppp->dev->mtu + PPP_HDRLEN); - if (len > 0 && (ppp->flags & SC_CCP_UP)) { - kfree_skb(skb); - skb = new_skb; - skb_put(skb, len); - skb_pull(skb, 2); /* pull off A/C bytes */ - } else { - /* didn't compress, or CCP not up yet */ - kfree_skb(new_skb); - } + skb = pad_compress_skb(ppp, skb); + if (!skb) + goto drop; } /* @@ -1155,7 +1191,8 @@ ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) return; drop: - kfree_skb(skb); + if (skb) + kfree_skb(skb); ++ppp->stats.tx_errors; } @@ -1552,6 +1589,9 @@ 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); + if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) + goto err; + proto = PPP_PROTO(skb); switch (proto) { case PPP_VJC_COMP: |