7 files changed, 54 insertions, 8 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 135b70c9a734..95bb237152e0 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -846,7 +846,14 @@ extern struct tcp_congestion_ops tcp_reno;
 
 struct tcp_congestion_ops *tcp_ca_find_key(u32 key);
 u32 tcp_ca_get_key_by_name(const char *name);
+#ifdef CONFIG_INET
 char *tcp_ca_get_name_by_key(u32 key, char *buffer);
+#else
+static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer)
+{
+        return NULL;
+}
+#endif
 
 static inline bool tcp_ca_needs_ecn(const struct sock *sk)
 {
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 9c9b8b4480cd..d81f22d5b390 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -389,6 +389,8 @@ enum {
 #define RTAX_INITRWND RTAX_INITRWND
         RTAX_QUICKACK,
 #define RTAX_QUICKACK RTAX_QUICKACK
+        RTAX_CC_ALGO,
+#define RTAX_CC_ALGO RTAX_CC_ALGO
         __RTAX_MAX
 };
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index da983d4bac02..6a6cdade1676 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -50,6 +50,7 @@
 #include <net/arp.h>
 #include <net/route.h>
 #include <net/udp.h>
+#include <net/tcp.h>
 #include <net/sock.h>
 #include <net/pkt_sched.h>
 #include <net/fib_rules.h>
@@ -669,9 +670,19 @@ int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics)
 
         for (i = 0; i < RTAX_MAX; i++) {
                 if (metrics[i]) {
+                        if (i == RTAX_CC_ALGO - 1) {
+                                char tmp[TCP_CA_NAME_MAX], *name;
+
+                                name = tcp_ca_get_name_by_key(metrics[i], tmp);
+                                if (!name)
+                                        continue;
+                                if (nla_put_string(skb, i + 1, name))
+                                        goto nla_put_failure;
+                        } else {
+                                if (nla_put_u32(skb, i + 1, metrics[i]))
+                                        goto nla_put_failure;
+                        }
                         valid++;
-                        if (nla_put_u32(skb, i+1, metrics[i]))
-                                goto nla_put_failure;
                 }
         }
 
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index d332aefb0846..df4803437888 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -298,7 +298,8 @@ struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct nlattr *att
                         int type = nla_type(attr);
 
                         if (type) {
-                                if (type > RTAX_MAX || nla_len(attr) < 4)
+                                if (type > RTAX_MAX || type == RTAX_CC_ALGO ||
+                                    nla_len(attr) < 4)
                                         goto err_inval;
 
                                 fi->fib_metrics[type-1] = nla_get_u32(attr);
diff --git a/net/decnet/dn_table.c b/net/decnet/dn_table.c
index 86e3807052e9..3f19fcbf126d 100644
--- a/net/decnet/dn_table.c
+++ b/net/decnet/dn_table.c
@@ -29,6 +29,7 @@
 #include <linux/route.h> /* RTF_xxx */
 #include <net/neighbour.h>
 #include <net/netlink.h>
+#include <net/tcp.h>
 #include <net/dst.h>
 #include <net/flow.h>
 #include <net/fib_rules.h>
@@ -273,7 +274,8 @@ static inline size_t dn_fib_nlmsg_size(struct dn_fib_info *fi)
         size_t payload = NLMSG_ALIGN(sizeof(struct rtmsg))
                          + nla_total_size(4) /* RTA_TABLE */
                          + nla_total_size(2) /* RTA_DST */
-                         + nla_total_size(4); /* RTA_PRIORITY */
+                         + nla_total_size(4) /* RTA_PRIORITY */
+                         + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 
         /* space for nested metrics */
         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f99f41bd15b8..d2b7b5521b1b 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -360,7 +360,8 @@ static inline size_t fib_nlmsg_size(struct fib_info *fi)
                          + nla_total_size(4) /* RTA_TABLE */
                          + nla_total_size(4) /* RTA_DST */
                          + nla_total_size(4) /* RTA_PRIORITY */
-                         + nla_total_size(4); /* RTA_PREFSRC */
+                         + nla_total_size(4) /* RTA_PREFSRC */
+                         + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 
         /* space for nested metrics */
         payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
@@ -859,7 +860,16 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
 
                                 if (type > RTAX_MAX)
                                         goto err_inval;
-                                val = nla_get_u32(nla);
+                                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)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 454771d20b21..34dcbb59df75 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1488,10 +1488,22 @@ static int ip6_convert_metrics(struct mx6_config *mxc,
                 int type = nla_type(nla);
 
                 if (type) {
+                        u32 val;
+
                         if (unlikely(type > RTAX_MAX))
                                 goto err;
+                        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;
+                        } else {
+                                val = nla_get_u32(nla);
+                        }
 
-                        mp[type - 1] = nla_get_u32(nla);
+                        mp[type - 1] = val;
                         __set_bit(type - 1, mxc->mx_valid);
                 }
         }
@@ -2571,7 +2583,8 @@ static inline size_t rt6_nlmsg_size(void)
                + nla_total_size(4) /* RTA_OIF */
                + nla_total_size(4) /* RTA_PRIORITY */
                + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
-               + nla_total_size(sizeof(struct rta_cacheinfo));
+               + nla_total_size(sizeof(struct rta_cacheinfo))
+               + nla_total_size(TCP_CA_NAME_MAX); /* RTAX_CC_ALGO */
 }
 
 static int rt6_fill_node(struct net *net,