From 4c7e8084fd467ddb2b0e6c6011f9c1064afb7e56 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Mon, 3 Jun 2019 20:19:51 -0700 Subject: ipv4: Plumb support for nexthop object in a fib_info Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the fib_info side of the nexthop <-> fib_info relationship. Add fi_list list_head to 'struct nexthop' to track fib_info entries using a nexthop instance. Add __remove_nexthop_fib and add it to __remove_nexthop to walk the new list_head and mark those fib entries as dead when the nexthop is deleted. Add a few nexthop helpers for use when a nexthop is added to fib_info: - nexthop_cmp to determine if 2 nexthops are the same - nexthop_path_fib_result to select a path for a multipath 'struct nexthop' - nexthop_fib_nhc to select a specific fib_nh_common within a multipath 'struct nexthop' Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop case. Update the fib_info functions to check for fi->nh and take a different path as needed: - free_fib_info_rcu - put the nexthop object reference - fib_release_info - remove the fib_info from the nexthop's fi_list - nh_comp - use nexthop_cmp when either fib_info references a nexthop object - fib_info_hashfn - use the nexthop id for the hashing vs the oif of each fib_nh in a fib_info - fib_nlmsg_size - add space for the RTA_NH_ID attribute - fib_create_info - verify nexthop reference can be taken, verify nexthop spec is valid for fib entry, and add fib_info to fi_list for a nexthop - fib_select_multipath - use the new nexthop_path_fib_result to select a path when nexthop objects are used - fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat it the same as a fib entry using 'blackhole' The bulk of the changes are in fib_semantics.c and most of that is moving the existing change_nexthops into an else branch. Update the nexthop code to walk fi_list on a nexthop deleted to remove fib entries referencing it. Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/nexthop.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) (limited to 'net/ipv4/nexthop.c') diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c index aec4ecb145a0..63cbb04f697f 100644 --- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -105,6 +105,7 @@ static struct nexthop *nexthop_alloc(void) nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL); if (nh) { + INIT_LIST_HEAD(&nh->fi_list); INIT_LIST_HEAD(&nh->grp_list); } return nh; @@ -515,6 +516,54 @@ struct nexthop *nexthop_select_path(struct nexthop *nh, int hash) } EXPORT_SYMBOL_GPL(nexthop_select_path); +static int nexthop_check_scope(struct nexthop *nh, u8 scope, + struct netlink_ext_ack *extack) +{ + struct nh_info *nhi; + + nhi = rtnl_dereference(nh->nh_info); + if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) { + NL_SET_ERR_MSG(extack, + "Route with host scope can not have a gateway"); + return -EINVAL; + } + + if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) { + NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop"); + return -EINVAL; + } + + return 0; +} + +/* Invoked by fib add code to verify nexthop by id is ok with + * config for prefix; parts of fib_check_nh not done when nexthop + * object is used. + */ +int fib_check_nexthop(struct nexthop *nh, u8 scope, + struct netlink_ext_ack *extack) +{ + int err = 0; + + if (nh->is_group) { + struct nh_group *nhg; + + if (scope == RT_SCOPE_HOST) { + NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops"); + err = -EINVAL; + goto out; + } + + nhg = rtnl_dereference(nh->nh_grp); + /* all nexthops in a group have the same scope */ + err = nexthop_check_scope(nhg->nh_entries[0].nh, scope, extack); + } else { + err = nexthop_check_scope(nh, scope, extack); + } +out: + return err; +} + static void nh_group_rebalance(struct nh_group *nhg) { int total = 0; @@ -607,9 +656,24 @@ static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo) } } +static void __remove_nexthop_fib(struct net *net, struct nexthop *nh) +{ + bool do_flush = false; + struct fib_info *fi; + + list_for_each_entry(fi, &nh->fi_list, nh_list) { + fi->fib_flags |= RTNH_F_DEAD; + do_flush = true; + } + if (do_flush) + fib_flush(net); +} + static void __remove_nexthop(struct net *net, struct nexthop *nh, struct nl_info *nlinfo) { + __remove_nexthop_fib(net, nh); + if (nh->is_group) { remove_nexthop_group(nh, nlinfo); } else { -- cgit v1.2.3