diff options
| author | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2008-09-04 07:30:19 +0200 |
|---|---|---|
| committer | Gerrit Renker <gerrit@erg.abdn.ac.uk> | 2008-09-04 07:45:27 +0200 |
| commit | 20f41eee82864e308a5499308a1722dc3181cc3a (patch) | |
| tree | 145a2d1d72f956286dfde7fe3e821049b6aa797f | |
| parent | 668144f7b41716a9efe1b398e15ead32a26cd101 (diff) | |
dccp: Feature negotiation for minimum-checksum-coverage
This provides feature negotiation for server minimum checksum coverage
which so far has been missing.
Since sender/receiver coverage values range only from 0...15, their
type has also been reduced in size from u16 to u4.
Feature-negotiation options are now generated for both sender and receiver
coverage, i.e. when the peer has `forgotten' to enable partial coverage
then feature negotiation will automatically enable (negotiate) the partial
coverage value for this connection.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
| -rw-r--r-- | include/linux/dccp.h | 4 | ||||
| -rw-r--r-- | net/dccp/proto.c | 53 |
2 files changed, 42 insertions, 15 deletions
diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 6eaaca9b037..5a5a89935db 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -527,8 +527,8 @@ struct dccp_sock { __u32 dccps_timestamp_time; __u16 dccps_l_ack_ratio; __u16 dccps_r_ack_ratio; - __u16 dccps_pcslen; - __u16 dccps_pcrlen; + __u8 dccps_pcslen:4; + __u8 dccps_pcrlen:4; __u64 dccps_ndp_count:48; unsigned long dccps_rate_last; struct dccp_minisock dccps_minisock; diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 108d56bd25c..47b137a3fea 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -470,6 +470,42 @@ static int dccp_setsockopt_service(struct sock *sk, const __be32 service, return 0; } +static int dccp_setsockopt_cscov(struct sock *sk, int cscov, bool rx) +{ + u8 *list, len; + int i, rc; + + if (cscov < 0 || cscov > 15) + return -EINVAL; + /* + * Populate a list of permissible values, in the range cscov...15. This + * is necessary since feature negotiation of single values only works if + * both sides incidentally choose the same value. Since the list starts + * lowest-value first, negotiation will pick the smallest shared value. + */ + if (cscov == 0) + return 0; + len = 16 - cscov; + + list = kmalloc(len, GFP_KERNEL); + if (list == NULL) + return -ENOBUFS; + + for (i = 0; i < len; i++) + list[i] = cscov++; + + rc = dccp_feat_register_sp(sk, DCCPF_MIN_CSUM_COVER, rx, list, len); + + if (rc == 0) { + if (rx) + dccp_sk(sk)->dccps_pcrlen = cscov; + else + dccp_sk(sk)->dccps_pcslen = cscov; + } + kfree(list); + return rc; +} + static int do_dccp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, int optlen) { @@ -502,20 +538,11 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname, else dp->dccps_server_timewait = (val != 0); break; - case DCCP_SOCKOPT_SEND_CSCOV: /* sender side, RFC 4340, sec. 9.2 */ - if (val < 0 || val > 15) - err = -EINVAL; - else - dp->dccps_pcslen = val; + case DCCP_SOCKOPT_SEND_CSCOV: + err = dccp_setsockopt_cscov(sk, val, false); break; - case DCCP_SOCKOPT_RECV_CSCOV: /* receiver side, RFC 4340 sec. 9.2.1 */ - if (val < 0 || val > 15) - err = -EINVAL; - else { - dp->dccps_pcrlen = val; - /* FIXME: add feature negotiation, - * ChangeL(MinimumChecksumCoverage, val) */ - } + case DCCP_SOCKOPT_RECV_CSCOV: + err = dccp_setsockopt_cscov(sk, val, true); break; default: err = -ENOPROTOOPT; |