isdn/gigaset: honor CAPI application's buffer size request

Fix the Gigaset CAPI driver to limit the length of a connection's
payload data receive buffers to the corresponding CAPI application's
data buffer size, as some real-life CAPI applications tend to be
rather unhappy if they receive bigger data blocks than requested.

Impact: bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 33 deletions

diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/isdn/gigaset/asyncdata.c
index c5016bd2d94f..c3b1dc3a13a0 100644
--- a/drivers/isdn/gigaset/asyncdata.c
+++ b/drivers/isdn/gigaset/asyncdata.c
@@ -126,26 +126,6 @@ static unsigned lock_loop(unsigned numbytes, struct inbuf_t *inbuf)
         return numbytes;
 }
 
-/* set up next receive skb for data mode
- */
-static void new_rcv_skb(struct bc_state *bcs)
-{
-        struct cardstate *cs = bcs->cs;
-        unsigned short hw_hdr_len = cs->hw_hdr_len;
-
-        if (bcs->ignore) {
-                bcs->skb = NULL;
-                return;
-        }
-
-        bcs->skb = dev_alloc_skb(SBUFSIZE + hw_hdr_len);
-        if (bcs->skb == NULL) {
-                dev_warn(cs->dev, "could not allocate new skb\n");
-                return;
-        }
-        skb_reserve(bcs->skb, hw_hdr_len);
-}
-
 /* process a block of received bytes in HDLC data mode
  * (mstate != MS_LOCKED && !(inputstate & INS_command) && proto2 == L2_HDLC)
  * Collect HDLC frames, undoing byte stuffing and watching for DLE escapes.
@@ -159,8 +139,8 @@ static unsigned hdlc_loop(unsigned numbytes, struct inbuf_t *inbuf)
         struct cardstate *cs = inbuf->cs;
         struct bc_state *bcs = cs->bcs;
         int inputstate = bcs->inputstate;
-        __u16 fcs = bcs->fcs;
-        struct sk_buff *skb = bcs->skb;
+        __u16 fcs = bcs->rx_fcs;
+        struct sk_buff *skb = bcs->rx_skb;
         unsigned char *src = inbuf->data + inbuf->head;
         unsigned procbytes = 0;
         unsigned char c;
@@ -245,8 +225,7 @@ byte_stuff:
 
                                 /* prepare reception of next frame */
                                 inputstate &= ~INS_have_data;
-                                new_rcv_skb(bcs);
-                                skb = bcs->skb;
+                                skb = gigaset_new_rx_skb(bcs);
                         } else {
                                 /* empty frame (7E 7E) */
 #ifdef CONFIG_GIGASET_DEBUG
@@ -255,8 +234,7 @@ byte_stuff:
                                 if (!skb) {
                                         /* skipped (?) */
                                         gigaset_isdn_rcv_err(bcs);
-                                        new_rcv_skb(bcs);
-                                        skb = bcs->skb;
+                                        skb = gigaset_new_rx_skb(bcs);
                                 }
                         }
 
@@ -279,11 +257,11 @@ byte_stuff:
 #endif
                 inputstate |= INS_have_data;
                 if (skb) {
-                        if (skb->len == SBUFSIZE) {
+                        if (skb->len >= bcs->rx_bufsize) {
                                 dev_warn(cs->dev, "received packet too long\n");
                                 dev_kfree_skb_any(skb);
                                 /* skip remainder of packet */
-                                bcs->skb = skb = NULL;
+                                bcs->rx_skb = skb = NULL;
                         } else {
                                 *__skb_put(skb, 1) = c;
                                 fcs = crc_ccitt_byte(fcs, c);
@@ -292,7 +270,7 @@ byte_stuff:
         }
 
         bcs->inputstate = inputstate;
-        bcs->fcs = fcs;
+        bcs->rx_fcs = fcs;
         return procbytes;
 }
 
@@ -308,18 +286,18 @@ static unsigned iraw_loop(unsigned numbytes, struct inbuf_t *inbuf)
         struct cardstate *cs = inbuf->cs;
         struct bc_state *bcs = cs->bcs;
         int inputstate = bcs->inputstate;
-        struct sk_buff *skb = bcs->skb;
+        struct sk_buff *skb = bcs->rx_skb;
         unsigned char *src = inbuf->data + inbuf->head;
         unsigned procbytes = 0;
         unsigned char c;
 
         if (!skb) {
                 /* skip this block */
-                new_rcv_skb(bcs);
+                gigaset_new_rx_skb(bcs);
                 return numbytes;
         }
 
-        while (procbytes < numbytes && skb->len < SBUFSIZE) {
+        while (procbytes < numbytes && skb->len < bcs->rx_bufsize) {
                 c = *src++;
                 procbytes++;
 
@@ -343,7 +321,7 @@ static unsigned iraw_loop(unsigned numbytes, struct inbuf_t *inbuf)
         if (inputstate & INS_have_data) {
                 gigaset_skb_rcvd(bcs, skb);
                 inputstate &= ~INS_have_data;
-                new_rcv_skb(bcs);
+                gigaset_new_rx_skb(bcs);
         }
 
         bcs->inputstate = inputstate;