From 2cf630034e4ebcc52e0b69b776cafd90dc4f3919 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 11 Sep 2024 12:37:45 +0300 Subject: [PATCH] ipv6: fib_rules: Add DSCP selector support Implement support for the new DSCP selector that allows IPv6 FIB rules to match on the entire DSCP field. This is done despite the fact that the above can be achieved using the existing TOS selector, so that user space program will be able to work with IPv4 and IPv6 rules in the same way. Differentiate between both selectors by adding a new bit in the IPv6 FIB rule structure that is only set when the 'FRA_DSCP' attribute is specified by user space. Reject rules that use both selectors. Signed-off-by: Ido Schimmel Reviewed-by: Guillaume Nault Reviewed-by: David Ahern Link: https://patch.msgid.link/20240911093748.3662015-4-idosch@nvidia.com Signed-off-by: Jakub Kicinski --- net/ipv6/fib6_rules.c | 43 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 40 insertions(+), 3 deletions(-) diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c index 9e254de7462f..04a9ed5e8310 100644 --- a/net/ipv6/fib6_rules.c +++ b/net/ipv6/fib6_rules.c @@ -27,6 +27,7 @@ struct fib6_rule { struct rt6key src; struct rt6key dst; dscp_t dscp; + u8 dscp_full:1; /* DSCP or TOS selector */ }; static bool fib6_rule_matchall(const struct fib_rule *rule) @@ -345,6 +346,20 @@ INDIRECT_CALLABLE_SCOPE int fib6_rule_match(struct fib_rule *rule, return 1; } +static int fib6_nl2rule_dscp(const struct nlattr *nla, struct fib6_rule *rule6, + struct netlink_ext_ack *extack) +{ + if (rule6->dscp) { + NL_SET_ERR_MSG(extack, "Cannot specify both TOS and DSCP"); + return -EINVAL; + } + + rule6->dscp = inet_dsfield_to_dscp(nla_get_u8(nla) << 2); + rule6->dscp_full = true; + + return 0; +} + static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb, struct fib_rule_hdr *frh, struct nlattr **tb, @@ -361,6 +376,9 @@ static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb, } rule6->dscp = inet_dsfield_to_dscp(frh->tos); + if (tb[FRA_DSCP] && fib6_nl2rule_dscp(tb[FRA_DSCP], rule6, extack) < 0) + goto errout; + if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) { if (rule->table == RT6_TABLE_UNSPEC) { NL_SET_ERR_MSG(extack, "Invalid table"); @@ -413,9 +431,19 @@ static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, if (frh->dst_len && (rule6->dst.plen != frh->dst_len)) return 0; - if (frh->tos && inet_dscp_to_dsfield(rule6->dscp) != frh->tos) + if (frh->tos && + (rule6->dscp_full || + inet_dscp_to_dsfield(rule6->dscp) != frh->tos)) return 0; + if (tb[FRA_DSCP]) { + dscp_t dscp; + + dscp = inet_dsfield_to_dscp(nla_get_u8(tb[FRA_DSCP]) << 2); + if (!rule6->dscp_full || rule6->dscp != dscp) + return 0; + } + if (frh->src_len && nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr))) return 0; @@ -434,7 +462,15 @@ static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb, frh->dst_len = rule6->dst.plen; frh->src_len = rule6->src.plen; - frh->tos = inet_dscp_to_dsfield(rule6->dscp); + + if (rule6->dscp_full) { + frh->tos = 0; + if (nla_put_u8(skb, FRA_DSCP, + inet_dscp_to_dsfield(rule6->dscp) >> 2)) + goto nla_put_failure; + } else { + frh->tos = inet_dscp_to_dsfield(rule6->dscp); + } if ((rule6->dst.plen && nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) || @@ -450,7 +486,8 @@ nla_put_failure: static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule) { return nla_total_size(16) /* dst */ - + nla_total_size(16); /* src */ + + nla_total_size(16) /* src */ + + nla_total_size(1); /* dscp */ } static void fib6_rule_flush_cache(struct fib_rules_ops *ops)