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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2010-11-10 21:21:02 +0100
committerGerrit Renker <gerrit@erg.abdn.ac.uk>2010-11-10 21:21:02 +0100
commit7d870936602533836bba821bd5c679c62c52a95f (patch)
tree35ffc317699b1700b27dfd8c5da4512d87848e65 /net/dccp/options.c
parentf17a37c9b8c4b32c01e501a84fa6f30e344c6110 (diff)
downloadlinux-7d870936602533836bba821bd5c679c62c52a95f.tar.bz2
dccp ccid-2: Separate internals of Ack Vectors from option-parsing code
This patch * separates Ack Vector housekeeping code from option-insertion code; * shifts option-specific code from ackvec.c into options.c; * introduces a dedicated routine to take care of the Ack Vector records; * simplifies the dccp_ackvec_insert_avr() routine: the BUG_ON was redundant, since the list is automatically arranged in descending order of ack_seqno. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Diffstat (limited to 'net/dccp/options.c')
-rw-r--r--net/dccp/options.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 799c6f4547cd..f4ff0a308269 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -425,6 +425,66 @@ static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
return 0;
}
+static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
+{
+ struct dccp_sock *dp = dccp_sk(sk);
+ struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
+ /* Figure out how many options do we need to represent the ackvec */
+ const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
+ u16 len = av->av_vec_len + 2 * nr_opts;
+ u8 i, nonce = 0;
+ const unsigned char *tail, *from;
+ unsigned char *to;
+
+ if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
+ return -1;
+
+ DCCP_SKB_CB(skb)->dccpd_opt_len += len;
+
+ to = skb_push(skb, len);
+ len = av->av_vec_len;
+ from = av->av_buf + av->av_buf_head;
+ tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
+
+ for (i = 0; i < nr_opts; ++i) {
+ int copylen = len;
+
+ if (len > DCCP_SINGLE_OPT_MAXLEN)
+ copylen = DCCP_SINGLE_OPT_MAXLEN;
+
+ /*
+ * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
+ * its type; ack_nonce is the sum of all individual buf_nonce's.
+ */
+ nonce ^= av->av_buf_nonce[i];
+
+ *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
+ *to++ = copylen + 2;
+
+ /* Check if buf_head wraps */
+ if (from + copylen > tail) {
+ const u16 tailsize = tail - from;
+
+ memcpy(to, from, tailsize);
+ to += tailsize;
+ len -= tailsize;
+ copylen -= tailsize;
+ from = av->av_buf;
+ }
+
+ memcpy(to, from, copylen);
+ from += copylen;
+ to += copylen;
+ len -= copylen;
+ }
+ /*
+ * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
+ */
+ if (dccp_ackvec_update_records(av, DCCP_SKB_CB(skb)->dccpd_seq, nonce))
+ return -ENOBUFS;
+ return 0;
+}
+
/**
* dccp_insert_option_mandatory - Mandatory option (5.8.2)
* Note that since we are using skb_push, this function needs to be called