This patch adds support to mask the nfmark value before the lookup the the fw classifier. Unfortunately it has some drawbacks, so I'd be interested if anyone can think of a better way.
The problem is that in order to avoid walking through all filters contained in one instance, we need to mask the value before the lookup. This means all filters share the same mask, which is taken from the first filter created and stored in the filter head. The user interface however always refers to a single filter, not the head, so it can't be changed afterwards unless we just overwrite it whenever a new filter is installed. Both is not really perfect. The current patch doesn't allow to change the mark and enforces that all filters use the same one, which I think is better than allowing inconsistent configurations. Any better ideas?
[NET_SCHED]: Add mask support to fwmark classifier Support masking the nfmark value before the search. The mask value is global for all filters contained in one instance. It can only be set when a new instance is created, all filters must specify the same mask. Signed-off-by: Patrick McHardy <[EMAIL PROTECTED]> --- commit c7dff54dc2dca206ff54f66bfce290c49f98a3c8 tree 88d48096f13674f29413dc5c9853c7d0a8c5feac parent e5d8ce21a2261f73b078d802bd2ab3508153b177 author Patrick McHardy <[EMAIL PROTECTED]> Fri, 25 Aug 2006 12:03:19 +0200 committer Patrick McHardy <[EMAIL PROTECTED]> Fri, 25 Aug 2006 12:03:19 +0200 include/linux/pkt_cls.h | 1 + net/sched/cls_fw.c | 25 ++++++++++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletions(-) diff --git a/include/linux/pkt_cls.h b/include/linux/pkt_cls.h index bd2c5a2..c3f01b3 100644 --- a/include/linux/pkt_cls.h +++ b/include/linux/pkt_cls.h @@ -305,6 +305,7 @@ enum TCA_FW_POLICE, TCA_FW_INDEV, /* used by CONFIG_NET_CLS_IND */ TCA_FW_ACT, /* used by CONFIG_NET_CLS_ACT */ + TCA_FW_MASK, __TCA_FW_MAX }; diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c index e6973d9..c9385dc 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -50,6 +50,7 @@ #define HTSIZE (PAGE_SIZE/sizeof(struct struct fw_head { struct fw_filter *ht[HTSIZE]; + u32 mask; }; struct fw_filter @@ -101,7 +102,7 @@ static int fw_classify(struct sk_buff *s struct fw_filter *f; int r; #ifdef CONFIG_NETFILTER - u32 id = skb->nfmark; + u32 id = skb->nfmark & head->mask; #else u32 id = 0; #endif @@ -209,7 +210,9 @@ static int fw_change_attrs(struct tcf_proto *tp, struct fw_filter *f, struct rtattr **tb, struct rtattr **tca, unsigned long base) { + struct fw_head *head = (struct fw_head*)tp->root; struct tcf_exts e; + u32 mask; int err; err = tcf_exts_validate(tp, tb, tca[TCA_RATE-1], &e, &fw_ext_map); @@ -232,6 +235,15 @@ #ifdef CONFIG_NET_CLS_IND } #endif /* CONFIG_NET_CLS_IND */ + if (tb[TCA_FW_MASK-1]) { + if (RTA_PAYLOAD(tb[TCA_FW_MASK-1]) != sizeof(u32)) + goto errout; + mask = *(u32*)RTA_DATA(tb[TCA_FW_MASK-1]); + if (mask != head->mask) + goto errout; + } else if (head->mask != 0xFFFFFFFF) + goto errout; + tcf_exts_change(tp, &f->exts, &e); return 0; @@ -267,9 +279,17 @@ static int fw_change(struct tcf_proto *t return -EINVAL; if (head == NULL) { + u32 mask = 0xFFFFFFFF; + if (tb[TCA_FW_MASK-1]) { + if (RTA_PAYLOAD(tb[TCA_FW_MASK-1]) != sizeof(u32)) + return -EINVAL; + mask = *(u32*)RTA_DATA(tb[TCA_FW_MASK-1]); + } + head = kzalloc(sizeof(struct fw_head), GFP_KERNEL); if (head == NULL) return -ENOBUFS; + head->mask = mask; tcf_tree_lock(tp); tp->root = head; @@ -330,6 +350,7 @@ static void fw_walk(struct tcf_proto *tp static int fw_dump(struct tcf_proto *tp, unsigned long fh, struct sk_buff *skb, struct tcmsg *t) { + struct fw_head *head = (struct fw_head *)tp->root; struct fw_filter *f = (struct fw_filter*)fh; unsigned char *b = skb->tail; struct rtattr *rta; @@ -351,6 +372,8 @@ #ifdef CONFIG_NET_CLS_IND if (strlen(f->indev)) RTA_PUT(skb, TCA_FW_INDEV, IFNAMSIZ, f->indev); #endif /* CONFIG_NET_CLS_IND */ + if (head->mask != 0xFFFFFFFF) + RTA_PUT(skb, TCA_FW_MASK, 4, &head->mask); if (tcf_exts_dump(skb, &f->exts, &fw_ext_map) < 0) goto rtattr_failure;