Skip to content

Commit

Permalink
ipv4: Refactor nexthop attributes in fib_dump_info
Browse files Browse the repository at this point in the history 
Similar to ipv6, move addition of nexthop attributes to dump
message into helpers that are called for both single path and
multipath routes. Align the new helpers to the IPv6 variant
which most notably means computing the flags argument based on
settings in nh_flags.

The RTA_FLOW argument is unique to IPv4, so it is appended after
the new fib_nexthop_info helper. The intent of a later patch is to
make both fib_nexthop_info and fib_add_nexthop usable for both IPv4
and IPv6. This patch is stepping stone in that direction.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
David Ahern authored and David S. Miller committed Apr 4, 2019
1 parent eba618a commit b0f6019
Showing 1 changed file with 107 additions and 59 deletions.
166 changes: 107 additions & 59 deletions net/ipv4/fib_semantics.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1317,6 +1317,103 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
return ERR_PTR(err);
}

static int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh *nh,
unsigned int *flags, bool skip_oif)
{
if (nh->fib_nh_flags & RTNH_F_DEAD)
*flags |= RTNH_F_DEAD;

if (nh->fib_nh_flags & RTNH_F_LINKDOWN) {
*flags |= RTNH_F_LINKDOWN;

rcu_read_lock();
if (ip_ignore_linkdown(nh->fib_nh_dev))
*flags |= RTNH_F_DEAD;
rcu_read_unlock();
}

if (nh->fib_nh_gw4 &&
nla_put_in_addr(skb, RTA_GATEWAY, nh->fib_nh_gw4))
goto nla_put_failure;

*flags |= (nh->fib_nh_flags & RTNH_F_ONLINK);
if (nh->fib_nh_flags & RTNH_F_OFFLOAD)
*flags |= RTNH_F_OFFLOAD;

if (!skip_oif && nh->fib_nh_dev &&
nla_put_u32(skb, RTA_OIF, nh->fib_nh_dev->ifindex))
goto nla_put_failure;

if (nh->fib_nh_lws &&
lwtunnel_fill_encap(skb, nh->fib_nh_lws) < 0)
goto nla_put_failure;

return 0;

nla_put_failure:
return -EMSGSIZE;
}

#ifdef CONFIG_IP_ROUTE_MULTIPATH
static int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh *nh)
{
const struct net_device *dev = nh->fib_nh_dev;
struct rtnexthop *rtnh;
unsigned int flags = 0;

rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
if (!rtnh)
goto nla_put_failure;

rtnh->rtnh_hops = nh->fib_nh_weight - 1;
rtnh->rtnh_ifindex = dev ? dev->ifindex : 0;

if (fib_nexthop_info(skb, nh, &flags, true) < 0)
goto nla_put_failure;

rtnh->rtnh_flags = flags;

/* length of rtnetlink header + attributes */
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;

return 0;

nla_put_failure:
return -EMSGSIZE;
}

static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
{
struct nlattr *mp;

mp = nla_nest_start(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;

for_nexthops(fi) {
if (fib_add_nexthop(skb, nh) < 0)
goto nla_put_failure;
#ifdef CONFIG_IP_ROUTE_CLASSID
if (nh->nh_tclassid &&
nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
goto nla_put_failure;
#endif
} endfor_nexthops(fi);

nla_nest_end(skb, mp);

return 0;

nla_put_failure:
return -EMSGSIZE;
}
#else
static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
{
return 0;
}
#endif

int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
u32 tb_id, u8 type, __be32 dst, int dst_len, u8 tos,
struct fib_info *fi, unsigned int flags)
Expand Down Expand Up @@ -1357,72 +1454,23 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
goto nla_put_failure;
if (fi->fib_nhs == 1) {
if (fi->fib_nh->fib_nh_gw4 &&
nla_put_in_addr(skb, RTA_GATEWAY, fi->fib_nh->fib_nh_gw4))
goto nla_put_failure;
if (fi->fib_nh->fib_nh_oif &&
nla_put_u32(skb, RTA_OIF, fi->fib_nh->fib_nh_oif))
struct fib_nh *nh = &fi->fib_nh[0];
unsigned int flags = 0;

if (fib_nexthop_info(skb, nh, &flags, false) < 0)
goto nla_put_failure;
if (fi->fib_nh->fib_nh_flags & RTNH_F_LINKDOWN) {
rcu_read_lock();
if (ip_ignore_linkdown(fi->fib_nh->fib_nh_dev))
rtm->rtm_flags |= RTNH_F_DEAD;
rcu_read_unlock();
}
if (fi->fib_nh->fib_nh_flags & RTNH_F_OFFLOAD)
rtm->rtm_flags |= RTNH_F_OFFLOAD;

rtm->rtm_flags = flags;
#ifdef CONFIG_IP_ROUTE_CLASSID
if (fi->fib_nh[0].nh_tclassid &&
nla_put_u32(skb, RTA_FLOW, fi->fib_nh[0].nh_tclassid))
if (nh->nh_tclassid &&
nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
goto nla_put_failure;
#endif
if (fi->fib_nh->fib_nh_lws &&
lwtunnel_fill_encap(skb, fi->fib_nh->fib_nh_lws) < 0)
} else {
if (fib_add_multipath(skb, fi) < 0)
goto nla_put_failure;
}
#ifdef CONFIG_IP_ROUTE_MULTIPATH
if (fi->fib_nhs > 1) {
struct rtnexthop *rtnh;
struct nlattr *mp;

mp = nla_nest_start(skb, RTA_MULTIPATH);
if (!mp)
goto nla_put_failure;

for_nexthops(fi) {
rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
if (!rtnh)
goto nla_put_failure;

rtnh->rtnh_flags = nh->fib_nh_flags & 0xFF;
if (nh->fib_nh_flags & RTNH_F_LINKDOWN) {
rcu_read_lock();
if (ip_ignore_linkdown(nh->fib_nh_dev))
rtnh->rtnh_flags |= RTNH_F_DEAD;
rcu_read_unlock();
}
rtnh->rtnh_hops = nh->fib_nh_weight - 1;
rtnh->rtnh_ifindex = nh->fib_nh_oif;

if (nh->fib_nh_gw4 &&
nla_put_in_addr(skb, RTA_GATEWAY, nh->fib_nh_gw4))
goto nla_put_failure;
#ifdef CONFIG_IP_ROUTE_CLASSID
if (nh->nh_tclassid &&
nla_put_u32(skb, RTA_FLOW, nh->nh_tclassid))
goto nla_put_failure;
#endif
if (nh->fib_nh_lws &&
lwtunnel_fill_encap(skb, nh->fib_nh_lws) < 0)
goto nla_put_failure;

/* length of rtnetlink header + attributes */
rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *) rtnh;
} endfor_nexthops(fi);

nla_nest_end(skb, mp);
}
#endif
nlmsg_end(skb, nlh);
return 0;

Expand Down

0 comments on commit b0f6019

Please sign in to comment.