From 63d10e12b00dfc8d8387bea9eaab376881335731 Mon Sep 17 00:00:00 2001 From: Ander Juaristi Date: Sat, 17 Aug 2019 13:17:53 +0200 Subject: [PATCH] netfilter: nft_meta: support for time matching This patch introduces meta matches in the kernel for time (a UNIX timestamp), day (a day of week, represented as an integer between 0-6), and hour (an hour in the current day, or: number of seconds since midnight). All values are taken as unsigned 64-bit integers. The 'time' keyword is internally converted to nanoseconds by nft in userspace, and hence the timestamp is taken in nanoseconds as well. Signed-off-by: Ander Juaristi Signed-off-by: Pablo Neira Ayuso --- include/uapi/linux/netfilter/nf_tables.h | 6 ++++ net/netfilter/nft_meta.c | 46 ++++++++++++++++++++++++ 2 files changed, 52 insertions(+) diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 82abaa183fc3..b83b62eb4b01 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -799,6 +799,9 @@ enum nft_exthdr_attributes { * @NFT_META_OIFKIND: packet output interface kind name (dev->rtnl_link_ops->kind) * @NFT_META_BRI_IIFPVID: packet input bridge port pvid * @NFT_META_BRI_IIFVPROTO: packet input bridge vlan proto + * @NFT_META_TIME_NS: time since epoch (in nanoseconds) + * @NFT_META_TIME_DAY: day of week (from 0 = Sunday to 6 = Saturday) + * @NFT_META_TIME_HOUR: hour of day (in seconds) */ enum nft_meta_keys { NFT_META_LEN, @@ -831,6 +834,9 @@ enum nft_meta_keys { NFT_META_OIFKIND, NFT_META_BRI_IIFPVID, NFT_META_BRI_IIFVPROTO, + NFT_META_TIME_NS, + NFT_META_TIME_DAY, + NFT_META_TIME_HOUR, }; /** diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c index f69afb9ff3cb..317e3a9e8c5b 100644 --- a/net/netfilter/nft_meta.c +++ b/net/netfilter/nft_meta.c @@ -26,8 +26,36 @@ #include /* NF_BR_PRE_ROUTING */ +#define NFT_META_SECS_PER_MINUTE 60 +#define NFT_META_SECS_PER_HOUR 3600 +#define NFT_META_SECS_PER_DAY 86400 +#define NFT_META_DAYS_PER_WEEK 7 + static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state); +static u8 nft_meta_weekday(unsigned long secs) +{ + unsigned int dse; + u8 wday; + + secs -= NFT_META_SECS_PER_MINUTE * sys_tz.tz_minuteswest; + dse = secs / NFT_META_SECS_PER_DAY; + wday = (4 + dse) % NFT_META_DAYS_PER_WEEK; + + return wday; +} + +static u32 nft_meta_hour(unsigned long secs) +{ + struct tm tm; + + time64_to_tm(secs, 0, &tm); + + return tm.tm_hour * NFT_META_SECS_PER_HOUR + + tm.tm_min * NFT_META_SECS_PER_MINUTE + + tm.tm_sec; +} + void nft_meta_get_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) @@ -218,6 +246,15 @@ void nft_meta_get_eval(const struct nft_expr *expr, goto err; strncpy((char *)dest, out->rtnl_link_ops->kind, IFNAMSIZ); break; + case NFT_META_TIME_NS: + nft_reg_store64(dest, ktime_get_real_ns()); + break; + case NFT_META_TIME_DAY: + nft_reg_store8(dest, nft_meta_weekday(get_seconds())); + break; + case NFT_META_TIME_HOUR: + *dest = nft_meta_hour(get_seconds()); + break; default: WARN_ON(1); goto err; @@ -330,6 +367,15 @@ int nft_meta_get_init(const struct nft_ctx *ctx, len = sizeof(u8); break; #endif + case NFT_META_TIME_NS: + len = sizeof(u64); + break; + case NFT_META_TIME_DAY: + len = sizeof(u8); + break; + case NFT_META_TIME_HOUR: + len = sizeof(u32); + break; default: return -EOPNOTSUPP; }