From patchwork Sat Oct 4 09:13:23 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerrit Renker X-Patchwork-Id: 2684 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by ozlabs.org (Postfix) with ESMTP id DCBB3DDDE3 for ; Sat, 4 Oct 2008 19:13:55 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752335AbYJDJNw (ORCPT ); Sat, 4 Oct 2008 05:13:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752311AbYJDJNt (ORCPT ); Sat, 4 Oct 2008 05:13:49 -0400 Received: from dee.erg.abdn.ac.uk ([139.133.204.82]:52934 "EHLO erg.abdn.ac.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752240AbYJDJNp (ORCPT ); Sat, 4 Oct 2008 05:13:45 -0400 Received: from laptev.erg.abdn.ac.uk (Debian-exim@ra-gerrit.erg.abdn.ac.uk [139.133.204.38]) by erg.abdn.ac.uk (8.13.4/8.13.4) with ESMTP id m949DQKt016043 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Sat, 4 Oct 2008 10:13:27 +0100 (BST) Received: from root by laptev.erg.abdn.ac.uk with local (Exim 4.69) (envelope-from ) id 1Km3CZ-0001OK-0M; Sat, 04 Oct 2008 11:13:27 +0200 From: Gerrit Renker To: davem@davemloft.net Cc: dccp@vger.kernel.org, netdev@vger.kernel.org, Gerrit Renker Subject: [PATCH 2/5] dccp: Implement lookup table for feature-negotiation information Date: Sat, 4 Oct 2008 11:13:23 +0200 Message-Id: <1223111606-5308-3-git-send-email-gerrit@erg.abdn.ac.uk> X-Mailer: git-send-email 1.6.0.rc2 In-Reply-To: <1223111606-5308-2-git-send-email-gerrit@erg.abdn.ac.uk> References: <20081002.125252.202124982.davem@davemloft.net> <1223111606-5308-1-git-send-email-gerrit@erg.abdn.ac.uk> <1223111606-5308-2-git-send-email-gerrit@erg.abdn.ac.uk> X-ERG-MailScanner: Found to be clean X-ERG-MailScanner-From: root@erg.abdn.ac.uk X-Spam-Status: No Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org A lookup table for feature-negotiation information, extracted from RFC 4340/42, is provided by this patch. All currently known features can be found in this table, along with their feature location, their default value, and type. Signed-off-by: Gerrit Renker Acked-by: Ian McDonald Acked-by: Arnaldo Carvalho de Melo --- include/linux/dccp.h | 9 ++-- net/dccp/feat.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 113 insertions(+), 4 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -176,19 +176,20 @@ enum { }; /* DCCP features (RFC 4340 section 6.4) */ -enum { +enum dccp_feature_numbers { DCCPF_RESERVED = 0, DCCPF_CCID = 1, - DCCPF_SHORT_SEQNOS = 2, /* XXX: not yet implemented */ + DCCPF_SHORT_SEQNOS = 2, DCCPF_SEQUENCE_WINDOW = 3, - DCCPF_ECN_INCAPABLE = 4, /* XXX: not yet implemented */ + DCCPF_ECN_INCAPABLE = 4, DCCPF_ACK_RATIO = 5, DCCPF_SEND_ACK_VECTOR = 6, DCCPF_SEND_NDP_COUNT = 7, DCCPF_MIN_CSUM_COVER = 8, - DCCPF_DATA_CHECKSUM = 9, /* XXX: not yet implemented */ + DCCPF_DATA_CHECKSUM = 9, /* 10-127 reserved */ DCCPF_MIN_CCID_SPECIFIC = 128, + DCCPF_SEND_LEV_RATE = 192, /* RFC 4342, sec. 8.4 */ DCCPF_MAX_CCID_SPECIFIC = 255, }; --- a/net/dccp/feat.c +++ b/net/dccp/feat.c @@ -23,6 +23,73 @@ #define DCCP_FEAT_SP_NOAGREE (-123) +static const struct { + u8 feat_num; /* DCCPF_xxx */ + enum dccp_feat_type rxtx; /* RX or TX */ + enum dccp_feat_type reconciliation; /* SP or NN */ + u8 default_value; /* as in 6.4 */ +/* + * Lookup table for location and type of features (from RFC 4340/4342) + * +--------------------------+----+-----+----+----+---------+-----------+ + * | Feature | Location | Reconc. | Initial | Section | + * | | RX | TX | SP | NN | Value | Reference | + * +--------------------------+----+-----+----+----+---------+-----------+ + * | DCCPF_CCID | | X | X | | 2 | 10 | + * | DCCPF_SHORT_SEQNOS | | X | X | | 0 | 7.6.1 | + * | DCCPF_SEQUENCE_WINDOW | | X | | X | 100 | 7.5.2 | + * | DCCPF_ECN_INCAPABLE | X | | X | | 0 | 12.1 | + * | DCCPF_ACK_RATIO | | X | | X | 2 | 11.3 | + * | DCCPF_SEND_ACK_VECTOR | X | | X | | 0 | 11.5 | + * | DCCPF_SEND_NDP_COUNT | | X | X | | 0 | 7.7.2 | + * | DCCPF_MIN_CSUM_COVER | X | | X | | 0 | 9.2.1 | + * | DCCPF_DATA_CHECKSUM | X | | X | | 0 | 9.3.1 | + * | DCCPF_SEND_LEV_RATE | X | | X | | 0 | 4342/8.4 | + * +--------------------------+----+-----+----+----+---------+-----------+ + */ +} dccp_feat_table[] = { + { DCCPF_CCID, FEAT_AT_TX, FEAT_SP, 2 }, + { DCCPF_SHORT_SEQNOS, FEAT_AT_TX, FEAT_SP, 0 }, + { DCCPF_SEQUENCE_WINDOW, FEAT_AT_TX, FEAT_NN, 100 }, + { DCCPF_ECN_INCAPABLE, FEAT_AT_RX, FEAT_SP, 0 }, + { DCCPF_ACK_RATIO, FEAT_AT_TX, FEAT_NN, 2 }, + { DCCPF_SEND_ACK_VECTOR, FEAT_AT_RX, FEAT_SP, 0 }, + { DCCPF_SEND_NDP_COUNT, FEAT_AT_TX, FEAT_SP, 0 }, + { DCCPF_MIN_CSUM_COVER, FEAT_AT_RX, FEAT_SP, 0 }, + { DCCPF_DATA_CHECKSUM, FEAT_AT_RX, FEAT_SP, 0 }, + { DCCPF_SEND_LEV_RATE, FEAT_AT_RX, FEAT_SP, 0 }, +}; +#define DCCP_FEAT_SUPPORTED_MAX ARRAY_SIZE(dccp_feat_table) + +/** + * dccp_feat_index - Hash function to map feature number into array position + * Returns consecutive array index or -1 if the feature is not understood. + */ +static int dccp_feat_index(u8 feat_num) +{ + /* The first 9 entries are occupied by the types from RFC 4340, 6.4 */ + if (feat_num > DCCPF_RESERVED && feat_num <= DCCPF_DATA_CHECKSUM) + return feat_num - 1; + + /* + * Other features: add cases for new feature types here after adding + * them to the above table. + */ + switch (feat_num) { + case DCCPF_SEND_LEV_RATE: + return DCCP_FEAT_SUPPORTED_MAX - 1; + } + return -1; +} + +static u8 dccp_feat_type(u8 feat_num) +{ + int idx = dccp_feat_index(feat_num); + + if (idx < 0) + return FEAT_UNKNOWN; + return dccp_feat_table[idx].reconciliation; +} + /* copy constructor, fval must not already contain allocated memory */ static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len) { @@ -37,6 +104,45 @@ static int dccp_feat_clone_sp_val(dccp_feat_val *fval, u8 const *val, u8 len) return 0; } +static void dccp_feat_val_destructor(u8 feat_num, dccp_feat_val *val) +{ + if (unlikely(val == NULL)) + return; + if (dccp_feat_type(feat_num) == FEAT_SP) + kfree(val->sp.vec); + memset(val, 0, sizeof(*val)); +} + +static struct dccp_feat_entry * + dccp_feat_clone_entry(struct dccp_feat_entry const *original) +{ + struct dccp_feat_entry *new; + u8 type = dccp_feat_type(original->feat_num); + + if (type == FEAT_UNKNOWN) + return NULL; + + new = kmemdup(original, sizeof(struct dccp_feat_entry), gfp_any()); + if (new == NULL) + return NULL; + + if (type == FEAT_SP && dccp_feat_clone_sp_val(&new->val, + original->val.sp.vec, + original->val.sp.len)) { + kfree(new); + return NULL; + } + return new; +} + +static void dccp_feat_entry_destructor(struct dccp_feat_entry *entry) +{ + if (entry != NULL) { + dccp_feat_val_destructor(entry->feat_num, &entry->val); + kfree(entry); + } +} + int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature, u8 *val, u8 len, gfp_t gfp) { @@ -653,6 +759,8 @@ const char *dccp_feat_name(const u8 feat) if (feat > DCCPF_DATA_CHECKSUM && feat < DCCPF_MIN_CCID_SPECIFIC) return feature_names[DCCPF_RESERVED]; + if (feat == DCCPF_SEND_LEV_RATE) + return "Send Loss Event Rate"; if (feat >= DCCPF_MIN_CCID_SPECIFIC) return "CCID-specific";