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path: root/drivers/net/pppol2tp.c
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Diffstat (limited to 'drivers/net/pppol2tp.c')
-rw-r--r--drivers/net/pppol2tp.c118
1 files changed, 53 insertions, 65 deletions
diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c
index 266e8b38fe10..abe91cb595f4 100644
--- a/drivers/net/pppol2tp.c
+++ b/drivers/net/pppol2tp.c
@@ -491,44 +491,46 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
u16 hdrflags;
u16 tunnel_id, session_id;
int length;
- struct udphdr *uh;
+ int offset;
tunnel = pppol2tp_sock_to_tunnel(sock);
if (tunnel == NULL)
goto error;
+ /* UDP always verifies the packet length. */
+ __skb_pull(skb, sizeof(struct udphdr));
+
/* Short packet? */
- if (skb->len < sizeof(struct udphdr)) {
+ if (!pskb_may_pull(skb, 12)) {
PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
"%s: recv short packet (len=%d)\n", tunnel->name, skb->len);
goto error;
}
/* Point to L2TP header */
- ptr = skb->data + sizeof(struct udphdr);
+ ptr = skb->data;
/* Get L2TP header flags */
hdrflags = ntohs(*(__be16*)ptr);
/* Trace packet contents, if enabled */
if (tunnel->debug & PPPOL2TP_MSG_DATA) {
+ length = min(16u, skb->len);
+ if (!pskb_may_pull(skb, length))
+ goto error;
+
printk(KERN_DEBUG "%s: recv: ", tunnel->name);
- for (length = 0; length < 16; length++)
- printk(" %02X", ptr[length]);
+ offset = 0;
+ do {
+ printk(" %02X", ptr[offset]);
+ } while (++offset < length);
+
printk("\n");
}
/* Get length of L2TP packet */
- uh = (struct udphdr *) skb_transport_header(skb);
- length = ntohs(uh->len) - sizeof(struct udphdr);
-
- /* Too short? */
- if (length < 12) {
- PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
- "%s: recv short L2TP packet (len=%d)\n", tunnel->name, length);
- goto error;
- }
+ length = skb->len;
/* If type is control packet, it is handled by userspace. */
if (hdrflags & L2TP_HDRFLAG_T) {
@@ -606,7 +608,6 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
"%s: recv data has no seq numbers when required. "
"Discarding\n", session->name);
session->stats.rx_seq_discards++;
- session->stats.rx_errors++;
goto discard;
}
@@ -625,7 +626,6 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
"%s: recv data has no seq numbers when required. "
"Discarding\n", session->name);
session->stats.rx_seq_discards++;
- session->stats.rx_errors++;
goto discard;
}
@@ -634,10 +634,14 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
}
/* If offset bit set, skip it. */
- if (hdrflags & L2TP_HDRFLAG_O)
- ptr += 2 + ntohs(*(__be16 *) ptr);
+ if (hdrflags & L2TP_HDRFLAG_O) {
+ offset = ntohs(*(__be16 *)ptr);
+ skb->transport_header += 2 + offset;
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) + 2))
+ goto discard;
+ }
- skb_pull(skb, ptr - skb->data);
+ __skb_pull(skb, skb_transport_offset(skb));
/* Skip PPP header, if present. In testing, Microsoft L2TP clients
* don't send the PPP header (PPP header compression enabled), but
@@ -673,7 +677,6 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
*/
if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) {
session->stats.rx_seq_discards++;
- session->stats.rx_errors++;
PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG,
"%s: oos pkt %hu len %d discarded, "
"waiting for %hu, reorder_q_len=%d\n",
@@ -698,6 +701,7 @@ static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb)
return 0;
discard:
+ session->stats.rx_errors++;
kfree_skb(skb);
sock_put(session->sock);
@@ -958,7 +962,6 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
int data_len = skb->len;
struct inet_sock *inet;
__wsum csum = 0;
- struct sk_buff *skb2 = NULL;
struct udphdr *uh;
unsigned int len;
@@ -989,41 +992,30 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
*/
headroom = NET_SKB_PAD + sizeof(struct iphdr) +
sizeof(struct udphdr) + hdr_len + sizeof(ppph);
- if (skb_headroom(skb) < headroom) {
- skb2 = skb_realloc_headroom(skb, headroom);
- if (skb2 == NULL)
- goto abort;
- } else
- skb2 = skb;
-
- /* Check that the socket has room */
- if (atomic_read(&sk_tun->sk_wmem_alloc) < sk_tun->sk_sndbuf)
- skb_set_owner_w(skb2, sk_tun);
- else
- goto discard;
+ if (skb_cow_head(skb, headroom))
+ goto abort;
/* Setup PPP header */
- skb_push(skb2, sizeof(ppph));
- skb2->data[0] = ppph[0];
- skb2->data[1] = ppph[1];
+ __skb_push(skb, sizeof(ppph));
+ skb->data[0] = ppph[0];
+ skb->data[1] = ppph[1];
/* Setup L2TP header */
- skb_push(skb2, hdr_len);
- pppol2tp_build_l2tp_header(session, skb2->data);
+ pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len));
/* Setup UDP header */
inet = inet_sk(sk_tun);
- skb_push(skb2, sizeof(struct udphdr));
- skb_reset_transport_header(skb2);
- uh = (struct udphdr *) skb2->data;
+ __skb_push(skb, sizeof(*uh));
+ skb_reset_transport_header(skb);
+ uh = udp_hdr(skb);
uh->source = inet->sport;
uh->dest = inet->dport;
uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
uh->check = 0;
- /* Calculate UDP checksum if configured to do so */
+ /* *BROKEN* Calculate UDP checksum if configured to do so */
if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
- csum = udp_csum_outgoing(sk_tun, skb2);
+ csum = udp_csum_outgoing(sk_tun, skb);
/* Debug */
if (session->send_seq)
@@ -1036,7 +1028,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
if (session->debug & PPPOL2TP_MSG_DATA) {
int i;
- unsigned char *datap = skb2->data;
+ unsigned char *datap = skb->data;
printk(KERN_DEBUG "%s: xmit:", session->name);
for (i = 0; i < data_len; i++) {
@@ -1049,18 +1041,18 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
printk("\n");
}
- memset(&(IPCB(skb2)->opt), 0, sizeof(IPCB(skb2)->opt));
- IPCB(skb2)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
- IPSKB_REROUTED);
- nf_reset(skb2);
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+ IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+ IPSKB_REROUTED);
+ nf_reset(skb);
/* Get routing info from the tunnel socket */
- dst_release(skb2->dst);
- skb2->dst = sk_dst_get(sk_tun);
+ dst_release(skb->dst);
+ skb->dst = sk_dst_get(sk_tun);
/* Queue the packet to IP for output */
- len = skb2->len;
- rc = ip_queue_xmit(skb2, 1);
+ len = skb->len;
+ rc = ip_queue_xmit(skb, 1);
/* Update stats */
if (rc >= 0) {
@@ -1073,17 +1065,12 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
session->stats.tx_errors++;
}
- /* Free the original skb */
- kfree_skb(skb);
-
return 1;
-discard:
- /* Free the new skb. Caller will free original skb. */
- if (skb2 != skb)
- kfree_skb(skb2);
abort:
- return 0;
+ /* Free the original skb */
+ kfree_skb(skb);
+ return 1;
}
/*****************************************************************************
@@ -1326,12 +1313,14 @@ static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
goto err;
}
+ sk = sock->sk;
+
/* Quick sanity checks */
- err = -ESOCKTNOSUPPORT;
- if (sock->type != SOCK_DGRAM) {
+ err = -EPROTONOSUPPORT;
+ if (sk->sk_protocol != IPPROTO_UDP) {
PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
- "tunl %hu: fd %d wrong type, got %d, expected %d\n",
- tunnel_id, fd, sock->type, SOCK_DGRAM);
+ "tunl %hu: fd %d wrong protocol, got %d, expected %d\n",
+ tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP);
goto err;
}
err = -EAFNOSUPPORT;
@@ -1343,7 +1332,6 @@ static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id,
}
err = -ENOTCONN;
- sk = sock->sk;
/* Check if this socket has already been prepped */
tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 16:42:59 +0100