diff options
| -rw-r--r-- | include/linux/dccp.h | 19 | ||||
| -rw-r--r-- | net/dccp/feat.c | 66 | ||||
| -rw-r--r-- | net/dccp/feat.h | 2 |
3 files changed, 57 insertions, 30 deletions
diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 61734e27abb..990e97fa1f0 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -369,28 +369,9 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) * Will be used to pass the state from dccp_request_sock to dccp_sock. * * @dccpms_sequence_window - Sequence Window Feature (section 7.5.2) - * @dccpms_pending - List of features being negotiated - * @dccpms_conf - */ struct dccp_minisock { __u64 dccpms_sequence_window; - struct list_head dccpms_pending; - struct list_head dccpms_conf; -}; - -struct dccp_opt_conf { - __u8 *dccpoc_val; - __u8 dccpoc_len; -}; - -struct dccp_opt_pend { - struct list_head dccpop_node; - __u8 dccpop_type; - __u8 dccpop_feat; - __u8 *dccpop_val; - __u8 dccpop_len; - int dccpop_conf; - struct dccp_opt_conf *dccpop_sc; }; extern void dccp_minisock_init(struct dccp_minisock *dmsk); diff --git a/net/dccp/feat.c b/net/dccp/feat.c index 35a57ab3bb1..a687740e442 100644 --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -1110,24 +1110,70 @@ int dccp_feat_parse_options(struct sock *sk, struct dccp_request_sock *dreq, return 0; /* ignore FN options in all other states */ } +/** + * dccp_feat_init - Seed feature negotiation with host-specific defaults + * This initialises global defaults, depending on the value of the sysctls. + * These can later be overridden by registering changes via setsockopt calls. + * The last link in the chain is finalise_settings, to make sure that between + * here and the start of actual feature negotiation no inconsistencies enter. + * + * All features not appearing below use either defaults or are otherwise + * later adjusted through dccp_feat_finalise_settings(). + */ int dccp_feat_init(struct sock *sk) { - struct dccp_sock *dp = dccp_sk(sk); - struct dccp_minisock *dmsk = dccp_msk(sk); + struct list_head *fn = &dccp_sk(sk)->dccps_featneg; + u8 on = 1, off = 0; int rc; + struct { + u8 *val; + u8 len; + } tx, rx; + + /* Non-negotiable (NN) features */ + rc = __feat_register_nn(fn, DCCPF_SEQUENCE_WINDOW, 0, + sysctl_dccp_feat_sequence_window); + if (rc) + return rc; + + /* Server-priority (SP) features */ + + /* Advertise that short seqnos are not supported (7.6.1) */ + rc = __feat_register_sp(fn, DCCPF_SHORT_SEQNOS, true, true, &off, 1); + if (rc) + return rc; - INIT_LIST_HEAD(&dmsk->dccpms_pending); /* XXX no longer used */ - INIT_LIST_HEAD(&dmsk->dccpms_conf); /* XXX no longer used */ + /* RFC 4340 12.1: "If a DCCP is not ECN capable, ..." */ + rc = __feat_register_sp(fn, DCCPF_ECN_INCAPABLE, true, true, &on, 1); + if (rc) + return rc; + + /* + * We advertise the available list of CCIDs and reorder according to + * preferences, to avoid failure resulting from negotiating different + * singleton values (which always leads to failure). + * These settings can still (later) be overridden via sockopts. + */ + if (ccid_get_builtin_ccids(&tx.val, &tx.len) || + ccid_get_builtin_ccids(&rx.val, &rx.len)) + return -ENOBUFS; - /* Ack ratio */ - rc = __feat_register_nn(&dp->dccps_featneg, DCCPF_ACK_RATIO, 0, - dp->dccps_l_ack_ratio); -out: + if (!dccp_feat_prefer(sysctl_dccp_feat_tx_ccid, tx.val, tx.len) || + !dccp_feat_prefer(sysctl_dccp_feat_rx_ccid, rx.val, rx.len)) + goto free_ccid_lists; + + rc = __feat_register_sp(fn, DCCPF_CCID, true, false, tx.val, tx.len); + if (rc) + goto free_ccid_lists; + + rc = __feat_register_sp(fn, DCCPF_CCID, false, false, rx.val, rx.len); + +free_ccid_lists: + kfree(tx.val); + kfree(rx.val); return rc; } -EXPORT_SYMBOL_GPL(dccp_feat_init); - int dccp_feat_activate_values(struct sock *sk, struct list_head *fn_list) { struct dccp_sock *dp = dccp_sk(sk); diff --git a/net/dccp/feat.h b/net/dccp/feat.h index 177e9c39ea9..f73b47abca9 100644 --- a/net/dccp/feat.h +++ b/net/dccp/feat.h @@ -112,13 +112,13 @@ static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val) #define dccp_feat_debug(type, feat, val) #endif /* CONFIG_IP_DCCP_DEBUG */ +extern int dccp_feat_init(struct sock *sk); extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local, u8 const *list, u8 len); extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val); extern int dccp_feat_parse_options(struct sock *, struct dccp_request_sock *, u8 mand, u8 opt, u8 feat, u8 *val, u8 len); extern int dccp_feat_clone_list(struct list_head const *, struct list_head *); -extern int dccp_feat_init(struct sock *sk); /* * Encoding variable-length options and their maximum length. |