dccp: Upgrade NDP count from 3 to 6 bytes

RFC 4340, 7.7 specifies up to 6 bytes for the NDP Count option, whereas the code
is currently limited to up to 3 bytes. This seems to be a relict of an earlier 
draft version and is brought up to date by the patch.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>

4 files changed, 15 insertions, 13 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index a1929f33d703..523db262c18f 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -794,7 +794,7 @@ static void ccid3_hc_rx_packet_recv(struct sock *sk, struct sk_buff *skb)
 {
         struct ccid3_hc_rx_sock *hcrx = ccid3_hc_rx_sk(sk);
         enum ccid3_fback_type do_feedback = CCID3_FBACK_NONE;
-        const u32 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp;
+        const u64 ndp = dccp_sk(sk)->dccps_options_received.dccpor_ndp;
         const bool is_data_packet = dccp_data_packet(skb);
 
         if (unlikely(hcrx->ccid3hcrx_state == TFRC_RSTATE_NO_DATA)) {
diff --git a/net/dccp/ccids/lib/packet_history.c b/net/dccp/ccids/lib/packet_history.c
index 8b5c41ec7ee1..712930564c38 100644
--- a/net/dccp/ccids/lib/packet_history.c
+++ b/net/dccp/ccids/lib/packet_history.c
@@ -153,7 +153,7 @@ void tfrc_rx_packet_history_exit(void)
 
 static inline void tfrc_rx_hist_entry_from_skb(struct tfrc_rx_hist_entry *entry,
                                                const struct sk_buff *skb,
-                                               const u32 ndp)
+                                               const u64 ndp)
 {
         const struct dccp_hdr *dh = dccp_hdr(skb);
 
@@ -166,7 +166,7 @@ static inline void tfrc_rx_hist_entry_from_skb(struct tfrc_rx_hist_entry *entry,
 
 void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h,
                              const struct sk_buff *skb,
-                             const u32 ndp)
+                             const u64 ndp)
 {
         struct tfrc_rx_hist_entry *entry = tfrc_rx_hist_last_rcv(h);
 
@@ -356,7 +356,7 @@ static void __three_after_loss(struct tfrc_rx_hist *h)
  */
 int tfrc_rx_handle_loss(struct tfrc_rx_hist *h,
                         struct tfrc_loss_hist *lh,
-                        struct sk_buff *skb, u32 ndp,
+                        struct sk_buff *skb, const u64 ndp,
                         u32 (*calc_first_li)(struct sock *), struct sock *sk)
 {
         int is_new_loss = 0;
diff --git a/net/dccp/ccids/lib/packet_history.h b/net/dccp/ccids/lib/packet_history.h
index c7eeda49cb20..6976156cda3c 100644
--- a/net/dccp/ccids/lib/packet_history.h
+++ b/net/dccp/ccids/lib/packet_history.h
@@ -64,7 +64,7 @@ struct tfrc_rx_hist_entry {
         u64              tfrchrx_seqno:48,
                          tfrchrx_ccval:4,
                          tfrchrx_type:4;
-        u32              tfrchrx_ndp; /* In fact it is from 8 to 24 bits */
+        u64              tfrchrx_ndp:48;
         ktime_t          tfrchrx_tstamp;
 };
 
@@ -145,14 +145,14 @@ static inline int tfrc_rx_hist_new_loss_indicated(struct tfrc_rx_hist *h,
 }
 
 extern void tfrc_rx_hist_add_packet(struct tfrc_rx_hist *h,
-                                    const struct sk_buff *skb, const u32 ndp);
+                                    const struct sk_buff *skb, const u64 ndp);
 
 extern int tfrc_rx_hist_duplicate(struct tfrc_rx_hist *h, struct sk_buff *skb);
 
 struct tfrc_loss_hist;
 extern int  tfrc_rx_handle_loss(struct tfrc_rx_hist *h,
                                 struct tfrc_loss_hist *lh,
-                                struct sk_buff *skb, u32 ndp,
+                                struct sk_buff *skb, const u64 ndp,
                                 u32 (*first_li)(struct sock *sk),
                                 struct sock *sk);
 extern u32 tfrc_rx_hist_sample_rtt(struct tfrc_rx_hist *h,
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 43bc24e761d0..dc7c158a2f4b 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -124,12 +124,12 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
                                 mandatory = 1;
                         break;
                 case DCCPO_NDP_COUNT:
-                        if (len > 3)
+                        if (len > 6)
                                 goto out_invalid_option;
 
                         opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
-                        dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
-                                      opt_recv->dccpor_ndp);
+                        dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
+                                      (unsigned long long)opt_recv->dccpor_ndp);
                         break;
                 case DCCPO_CHANGE_L:
                         /* fall through */
@@ -307,9 +307,11 @@ static void dccp_encode_value_var(const u32 value, unsigned char *to,
                 *to++ = (value & 0xFF);
 }
 
-static inline int dccp_ndp_len(const int ndp)
+static inline u8 dccp_ndp_len(const u64 ndp)
 {
-        return likely(ndp <= 0xFF) ? 1 : ndp <= 0xFFFF ? 2 : 3;
+        if (likely(ndp <= 0xFF))
+                return 1;
+        return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
 }
 
 int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
@@ -336,7 +338,7 @@ EXPORT_SYMBOL_GPL(dccp_insert_option);
 static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
 {
         struct dccp_sock *dp = dccp_sk(sk);
-        int ndp = dp->dccps_ndp_count;
+        u64 ndp = dp->dccps_ndp_count;
 
         if (dccp_non_data_packet(skb))
                 ++dp->dccps_ndp_count;