net: fib: move metrics parsing to a helper

fib_create_info() is already quite large, so before adding more
code to the metrics section move that to a helper, similar to
ip6_convert_metrics.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 41 insertions, 30 deletions

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 1b2d01170a4d..88afbae893f0 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -876,6 +876,44 @@ static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
         return true;
 }
 
+static int
+fib_convert_metrics(struct fib_info *fi, const struct fib_config *cfg)
+{
+        struct nlattr *nla;
+        int remaining;
+
+        if (!cfg->fc_mx)
+                return 0;
+
+        nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
+                int type = nla_type(nla);
+                u32 val;
+
+                if (!type)
+                        continue;
+                if (type > RTAX_MAX)
+                        return -EINVAL;
+
+                if (type == RTAX_CC_ALGO) {
+                        char tmp[TCP_CA_NAME_MAX];
+
+                        nla_strlcpy(tmp, nla, sizeof(tmp));
+                        val = tcp_ca_get_key_by_name(tmp);
+                        if (val == TCP_CA_UNSPEC)
+                                return -EINVAL;
+                } else {
+                        val = nla_get_u32(nla);
+                }
+                if (type == RTAX_ADVMSS && val > 65535 - 40)
+                        val = 65535 - 40;
+                if (type == RTAX_MTU && val > 65535 - 15)
+                        val = 65535 - 15;
+                fi->fib_metrics[type - 1] = val;
+        }
+
+        return 0;
+}
+
 struct fib_info *fib_create_info(struct fib_config *cfg)
 {
         int err;
@@ -948,36 +986,9 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
                         goto failure;
         } endfor_nexthops(fi)
 
-        if (cfg->fc_mx) {
-                struct nlattr *nla;
-                int remaining;
-
-                nla_for_each_attr(nla, cfg->fc_mx, cfg->fc_mx_len, remaining) {
-                        int type = nla_type(nla);
-
-                        if (type) {
-                                u32 val;
-
-                                if (type > RTAX_MAX)
-                                        goto err_inval;
-                                if (type == RTAX_CC_ALGO) {
-                                        char tmp[TCP_CA_NAME_MAX];
-
-                                        nla_strlcpy(tmp, nla, sizeof(tmp));
-                                        val = tcp_ca_get_key_by_name(tmp);
-                                        if (val == TCP_CA_UNSPEC)
-                                                goto err_inval;
-                                } else {
-                                        val = nla_get_u32(nla);
-                                }
-                                if (type == RTAX_ADVMSS && val > 65535 - 40)
-                                        val = 65535 - 40;
-                                if (type == RTAX_MTU && val > 65535 - 15)
-                                        val = 65535 - 15;
-                                fi->fib_metrics[type - 1] = val;
-                        }
-                }
-        }
+        err = fib_convert_metrics(fi, cfg);
+        if (err)
+                goto failure;
 
         if (cfg->fc_mp) {
 #ifdef CONFIG_IP_ROUTE_MULTIPATH