On 02/22/2016 02:21 PM, Jamal Hadi Salim wrote: [...]
diff --git a/net/sched/act_meta_skbhash.c b/net/sched/act_meta_skbhash.c new file mode 100644 index 0000000..c3140ea --- /dev/null +++ b/net/sched/act_meta_skbhash.c @@ -0,0 +1,87 @@ +/* + * net/sched/act_meta_skbhash.c IFE skb->hash metadata module + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * copyright Jamal Hadi Salim (2015) + * +*/ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/module.h> +#include <linux/init.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <uapi/linux/tc_act/tc_ife.h> +#include <net/tc_act/tc_ife.h> + +static int skbhash_check(struct sk_buff *skb, struct tcf_meta_info *e) +{ + u32 skbhash = skb->hash; + + if (e->metaval) { + skbhash = *(u32 *)e->metaval; + } + if (!skbhash) + return 0; + + return 8;
What's magic number 8?
+} + +static int skbhash_encode(struct sk_buff *skb, void *skbdata, + struct tcf_meta_info *e) +{ + u32 skbhash = skb->hash; + + return encode_meta_u32(skbhash, skbdata, e); +} + +static int skbhash_decode(struct sk_buff *skb, void *data, u16 len) +{ + u32 skbhash = *(u32 *) data; + + skb->hash = ntohl(skbhash);
Depending on your scenario/use case, the next skb_get_hash() call could overwrite what you've transferred and set here.
+ return 0; +} + +static struct tcf_meta_ops ife_skbhash_ops = { + .metaid = IFE_META_HASHID, + .metatype = NLA_U32, + .name = "skbhash", + .synopsis = "skb hash metadata",
MODULE_DESCRIPTION()?
+ .check_presence = skbhash_check, + .encode = skbhash_encode, + .decode = skbhash_decode, + .get = get_meta_u32, + .alloc = alloc_meta_u32, + .owner = THIS_MODULE, +}; + +static int __init ifeskbhash_init_module(void) +{ + pr_info("Loaded IFE skbhash\n");
Leftover pr_info()?
+ return register_ife_op(&ife_skbhash_ops); +} + +static void __exit ifeskbhash_cleanup_module(void) +{ + pr_info("Unloaded IFE skb hash\n");
Ditto?
+ unregister_ife_op(&ife_skbhash_ops); +} + +module_init(ifeskbhash_init_module); +module_exit(ifeskbhash_cleanup_module); + +MODULE_AUTHOR("Jamal Hadi Salim(2015)"); +MODULE_DESCRIPTION("Inter-FE skb hash meta action"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_IFE_META(IFE_META_HASHID);